Journal of Neuro-Ophthalmology, June 2001, Volume 21, Issue 2

Abstracts of the 27th Annual NANOS Meeting

Journal ofNeuro- Ophthalmology 21( 2): 138- 159, 2001. © 2001 Lippincott Williams & Wilkins, Inc., Philadelphia Abstracts of the 27th Annual North American Neuro- Ophthalmology Society Meeting Rancho Mirage, California February 18- 22, 2001 PLATFORM PRESENTATIONS BILATERAL ORBITAL CONGESTION IS A RISK FAC­TOR FOR CORTICAL VENOUS DRAINAGE IN CAV­ERNOUS SINUS AREA DURAL AVMS H. Stiebel- Kalish, A. Setton, A. Berenstein, M. J. Kupersmith; Petah Tikva, Israel Background: Dural arteriovenous malformations ( dAVM) that drain into cortical veins have increased risk of developing cen­tral nervous system dysfunction due to local venous hyperten­sion, intracerebral hemorrhages or cerebral venous infarct. Objective: We attempted to find whether a specific clinical sign might predict which patients have cortical venous drainage of dAVM in the region of the cavernous sinus ( CSdAVM). We hypothesized that because of associated extensive thrombosis in the cavernous sinus, bilateral orbital signs should be a sig­nificant risk factor. Methods: The records of 118 patients with CSdAVM were evaluated for the clinical features of the disorder and the results were correlated with presence of cortical venous drainage ( CVD) identified by cerebral angiography or contrast- enhanced high- resolution magnetic resonance imaging ( MRI) using Chi square test. Results: 28 patients had some degree of bilateral orbital signs, 12 ( 43%) of whom had CVD and 16 without CVD. Bilateral orbital congestion was significantly associated with presence of CVD ( p = 0.0005, RR 3.9). 40 patients had cranial nerve dys­function, 12 ( 30%) of whom had CVD ( p = 0.04, RR 2.3). No other clinical sign, including white- eyed shunt ( p = 0.42), ex­traocular muscle dysfunction ( p = 0.29), normal intraocular pressure ( IOP) ( p = 0.6), IOP greater than 25 mmHg on maxi­mally tolerated medication ( p = 0.84), venous stasis retinopathy ( p = 0.49), choroidal effusion ( p = 0.23), optic neuropathy ( p = 0.69), subjective bruit ( p = 0.12), objective orbital bruit ( p = 0.75) or objective retro- auricular bruit ( p = 0.33) correlated with presence of CVD. Conclusions: Patients who present with or develop bilateral orbital congestion or cranial nerve dysfunction should be rec­ognized as being at increased risk for CVD. At the very least, a contrast enhanced high resolution MRI should be performed to look for CVD. If CVD is found, cerebral angiography and endovascular closure of their AV shunt should be considered. SELF- REPORTED VISUAL DYSFUNCTION IN MUL­TIPLE SCLEROSIS: NEW DATA FROM THE VFQ- 25 L. J. Balcer, S. Ma, D. A. Jacobs, C. E. Markowitz, S. L. Galetta, M. G. Maguire; Philadelphia, PA Background: Despite the high prevalence of visual impair­ment in multiple sclerosis ( MS), the usefulness of standard vision- specific quality of life measures, such as the 25- Item National Eye Institute Visual Function Questionnaire ( VFQ- 25), has not been determined for clinically heterogeneous MS cohorts. Objective: The primary aim of this study was to examine VFQ- 25 scores in a large cohort of MS patients, and to deter­mine construct validity for the VFQ- 25 in patients with MS. The relation of VFQ- 25 composite scores to ambulation status in MS was also examined. Methods: As part of an ongoing study to develop an MS-specific vision questionnaire, the VFQ- 25 was administered to 80 patients with MS using an interview format. Binocular visual acuities were obtained using ETDRS charts ( 3.2 meters). Results: Compared with those of a published eye disease- free reference group ( n = 118), VFQ- 25 scores were significantly lower ( worse) in our MS cohort ( composite score and 10/ 12 sub- scales, p = 0.0001- 0.009, two- tailed t- test). These differ­ences were observed despite the younger age of the MS cohort ( mean 43 years for MS vs. 64 for reference group). Median disease duration was 2.5 years ( 0- 30), and the median binocu­lar visual acuity was 20/ 16 ( 20/ 12.5- 20/ 250). Rank correlations of VFQ- 25 composite scores with visual acuity were modest but significant ( rs = 0.33, p = 0.003), supporting construct validity for the VFQ- 25 in MS . Ambulation status did not pre­dict VFQ- 25 composite scores to a significant degree, even when accounting for patient age and disease duration ( Wald test, p = 0.29- 0.63) ( 0.92- 0.63). Conclusion: Patients with MS have a high degree of self-reported visual dysfunction that is not entirely captured by visual acuity or ambulation status. The VFQ- 25 is an effec­tive measure for capturing visual loss in MS, and should be used to complement visual function outcome measures in MS populations. Supported by NIH grant EY 00351. THREE- DIMENSIONAL KINEMATICS OF BLINKS IN HUMANS O. Bergamin, S. Bizzarri, D. Straumann; Zurich, Switzerland Background: So far, most studies on eye movements during blinks were restricted to rotations about the horizontal and vertical axes. Two phases have been identified: an initial downward and inward rotation and, with prolonged lid clo­sure, an optional secondary upward and outward rotation (= Bell phenomenon). Objective: We hypothesized that the initial eye movement dur­ing blinks is related to a pulse innervation of the inferior rectus muscle triggered by the omnipause neurons. 138 NANOS ABSTRACTS 139 Methods: Lid movements and binocular three- dimensional ocular rotations were recorded with search coils in five healthy human subjects. Durations of eye- lid closure were " as short as possible," 0.83s, or 1.67s. The inter- blink interval was held constant at 1.67s. In all three paradigms, data of 60 blinks were collected. Between blinks, subjects fixed upon a dot that was located straight- ahead at a distance of 1.24m. During blinks, search coils are frequently rotated about the line- of- sight due to the upper eyelid touching the nasally exiting wire- leads. We therefore modified the searchcoils such that the wires left the silicon annulus from its inner border at 6 o'clock. Results: The initial eye movement during blinks consisted of a pulse in a direction that was always extorsional, downward, and inward, irrespective of the duration of lid closure. Typically, the beginning of all three movement- components preceded the eyelid movement, thus a coil artifact is unlikely. During eyelid opening after 0.83s or 1.67s eyelid closure, a pulse of three-dimensional eye movements occurred in the opposite direction. Conclusions: During the initial phase of eyelid closure, the eyes move in a direction that is consistent with a pulse- like activation of the inferior rectus muscle. We hypothesize that this pulse reflects downward premotor burst activity that, be­sides increasing the firing rate of the inferior rectus muscle, drives the firing rate of the levator palpebrae into inhibitory cut- off. VERTICAL MISALIGNMENT AND STATIC OCULAR COUNTERROLL IN UNILATERAL SIXTH NERVE PALSY A. M. F. Wong, D. Tweed, J. A. Sharpe; Toronto, Ontario Background: Our preliminary clinical observations suggested that patients with isolated sixth nerve palsy could present with a small hypertropia. Purpose: To determine the magnitude of vertical deviation and static ocular counter- roll ( OCR) gain in patients with unilateral sixth nerve palsy. Methods: Twenty patients with peripheral palsy, 7 patients with central palsy caused by brainstem lesions, and 10 normal subjects were studied. Eye alignments were recorded using the prism- cover test, the Maddox rod and prism test, and magnetic search coil recordings. Static OCR gain, defined as change in torsional eye position divided by the change in head position in static roll, was also measured. Results: All patients had an abduction deficit and incomitant esodeviation that increased in the field of action of the paretic muscle, indicating sixth nerve palsy. Mean vertical deviations in peripheral palsy were: 0.33 prism diopter ( PD) by prism-cover test, 1.29 PD by Maddoxtest, and 1.98 PD by coil re­cordings. Mean vertical deviations in normal subjects were: 0.00 PD by prism- cover test, 0.99 PD by Maddox test, and 1.94 PD by coil recordings. Peripheral palsy did not cause abnormal vertical deviation. Mean vertical deviations in central palsy were: 0.89 PD by prism- cover test, 1.41 PD by Maddox test, and 2.51 PD by coil recordings. Although mean vertical devia­tions in central palsy were significantly greater than normal ( p < 0.05), individual patients did not have abnormal vertical deviations when compared with normal subjects ( Z- test). Dur­ing static head roll, patients with peripheral palsy had a right hyperdeviation on right head tilt, and a left hyperdeviation on left head tilt, regardless of the side of the palsy. In contrast, the vertical strabismus in central palsy remained on the same side during static head tilt to either side. Static OCR gains were subnormal. In peripheral palsy, OCR gain was 0.13 in light and 0.12 in dark, compared with 0.21 in light and 0.20 in dark in normal subjects ( p < 0.01). In central palsy, OCR gain was also subnormal, with a gain of 0.12 in both light and dark ( p < 0.02). Conclusions: The small vertical deviation in peripheral and central palsy was consistent with hyperphoria that become manifest in the presence of esotropia. OCR gain was subnormal in both groups of patients. Disruption of the otolith- ocular re­flex pathway may explain the vertical strabismus and subnor­mal OCR gain in central palsy. CONTRAST LETTER ACUITY IN HEREDITARY AND NON- HEREDITARY ATAXIAS D. R. Lynch, J. Farmer, L. J. Balcer; Philadelphia, Pennsylvania Background: Although visual complaints are common in pa­tients with hereditary ataxias, systematic measures for readily evaluating visual function have not been ascertained. Objective: To characterize the visual function of patients with hereditary and non- hereditary ataxias using the Low- Contrast Sloan Letter Charts ( LCSLC). Methods: Subjects included patients with hereditary autosomal dominant ataxias ( ADA) ( SCA 1, 23, 7, 8, other), autosomal recessive ataxia ( Friedreich ataxia), sporadic ataxia ( most com­monly multiple system atrophy), hereditary spastic paraparesis ( HSP), and visually- and neurologically asymptomatic volun-teers. Binocular LCSLC scores were based upon the numbers of letters read correctly ( letter scores) at high contrast ( visual acu­ity) and at 5%, 1.25%, and 0.6% contrast levels ( low contrast). Results: Patients with Friedreich ataxia and ADA demon­strated lower ( worse) mean letter scores on the LCSLC com­pared with asymptomatic controls ( Wilcoxon rank- sum test): Disease type Friedreich ADA Sporadic HSP Control High contrast 56 ± 1 44 ± 5 44 ± 4 56 ± 2 60 ± 1 5% 45 ± 3 35 ± 6 34 ± 3 48 ± 5 57 ± 1 1.25% 24 ± 3 20 ± 5 13 ± 5 30 ± 6 42 ± 2 0.6% 13 ± 3 6± 3 4± 3 16 ± 6 33 ± 1 The most affected group was SCA7, consistent with the pig­mentary retinal degeneration of this disorder. However, the dif­ference in letter scores was still significant between ADA and controls, even with exclusion of the SCA7 patients. For each disease, greater differences between asymptomatic volunteers and patients were noted at lower contrast levels. Conclusions: The present data suggest that LCSLC may be used to capture visual dysfunction in patients with degenerative ataxia. Further studies will investigate the anatomic components and disease features that correlate with decreased low contrast letter acuities. MAGNETIC RESONANCE DIAGNOSIS OF CONGENI­TAL HYPOPITUITARISM IN CHILDREN WITH OPTIC NERVE HYPOPLASIA P. H. Phillips, M. C. Brodsky; Little Rock, Arkansas Purpose: To determine whether structural neurohypophyseal abnormalities can be used to diagnose hypopituitarism in chil­dren with optic nerve hypoplasia. Methods: Retrospective analysis of 67 children with optic nerve hypoplasia who had high resolution cranial magnetic resonance imaging and endocrinologic evaluation at Arkansas Children's Hospital from 1989 to 1999. Results: In the 26 children with pituitary hormone deficiency, Tl- weighted sagittal magnetic resonance imaging showed pos­terior pituitary ectopia in 16 cases, absence of the pituitary J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 140 NANOS ABSTRACTS infundibulum and posterior pituitary bright spot in seven cases, and a normal neurohypophysis in three cases. In all 41 children with normal endocrinologic function, magnetic resonance im­aging disclosed a normal neurohypophysis. Conclusion: Neurohypophyseal abnormalities, as disclosed by magnetic resonance imaging, can be used to direct endocrino­logic referral in children with optic nerve hypoplasia. DYSLEXIA: A VISUAL PROBLEM? S. Trauzettel- Klosinski, M. Mackeben, J. Reinhard, A. Feucht, U. Duerrwaechter, G. Klosinski; Tuebingen, Germany Background: The cause of dyslexia is controversial: hypoth­eses are based on a deficit in central auditory processing, an impairment of the magnocellular system of the visual path­ways and oculomotor control deficits. The analysis of eye movements provides information not only about the oculo­motor system, but also about deficits in perception and infor­mation processing. Objective: To differentiate potential deficits in pure oculomo­tor tasks ( fixation stability, 5 saccades), in a logographic task ( pictogram naming) and a phonologic task ( reading), by as­sessing the scanning strategies under direct fundus control in a pilot study. Methods: 14 dyslexic and 12 normally reading children were examined by a Scanning Laser Ophthalmoscope ( SLO), which allows a direct monitoring of the fovea position during fixation of different stimuli and during reading aloud text and picto-grams. Naming time for single pictograms was determined by the time between the fovea landing on the pictogram and the beginning of the speech. Results: No differences between the groups were found regard­ing fixation stability of a single fixation cross and after 5 sac-cades. During reading texts, reading speed was highly de­creased in dyslexics. However, during naming pictograms, we found two subgroups: children with prolonged pictogram nam­ing times and others, who were as fast as the controls. Conclusions: The dyslexic children showed significant differ­ences comparedto the controls, when written language was pre­sented, whereas they were equal to the normals in isolated fixation tasks and some of them also in pictogram naming. This shows that the children examined in this study had no primary oculomotor disability, but a deficit in language processing. The two subgroups regarding pictogram naming time indicate a parallel processing of pictorial and linguistic stimuli. The SLO allows a subtle and precise analysis of the reading process and the pictogram naming, which provides valuable information about linguistic and visual information processing. RU- 486 ( MIFEPRISTONE) AND MENINGIOMAS S. C. Benes, H. Newton, S. Scott, M. A. Slivka; Columbus, Ohio Eleven patients with visual complaints had subtotal resec­tions of meningiomas. They chose oral Mifepristone ( RU486) therapy rather than radiation, repeated surgeries, hydroxyurea or watching and were followed prospectively. Five were in a randomized SWOG protocol, 6 treated compassionately ( not randomized). Serial MRI scanning every 6 months showed 1 with tumor shrinkage ( 24 months), 8 with stable non- growth ( 3, 4, 14, 20, 50, 64, 68, and 77 months), and 2 with growth ( 4, 6 months). Serial exophthalmometry, visual acuities and fields revealed clinical responses: 2 patients with radiologic growth ceased RU486 after 4 and 6 months and later died; 2 had initial continued decline in vision and symptoms for 2 and 7 months then stabilized over the next 4 and 14 months; 7 had stable or slightly improved vision ( 1- 2 lines) but improvement in their proptosis, redness, pain, headache, overall comfort or well- being. Due to temporary unavailability of the drug, three patients had 2, 6, and 6 month interruptions in RU- 486 treat­ment and experienced: rebound pain, redness, proptosis, eyelid matting, headache and visual darkening ( 1), decreased vision but increased pain ( 1), and decreased vision ( 1). Their symp­toms reversed when the drug was restarted. Adverse reactions included hot flashes ( 2), breast tenderness and slight gyneco­mastia ( 1), decreased appetite and weight loss ( 1), new unilat­eral headache and eye aches ( 1), hair loss ( 1), nightmares dur­ing naps ( 1), chronic blepharitis ( 1) and the rebound of pain and swelling symptoms upon discontinuance of the drug ( 3). Three of the 9 living patients chose radiation therapy ( 2) and further surgery ( 1) after 14, 20 and 42 months of RU- 486. The other 6 continue RU- 486 at this time. Nine of 11 patients believe the RU- 486 provided them clinical stability, fewer surgeries, fewer doctor's visits and time to think and research the field. Four patients publicly fought to retain access to RU- 486 in the USA anti- abortion controversy. PORTABLE PUPILLOGRAPHY OF THE SWINGING FLASHLIGHT TEST TO DETECT AFFERENT PUPIL­LARY DEFECTS N. J. Volpe, S. K. Kim, M. Maguire, G. Ying, M. L. Moster, S. L Galetta; Philadelphia, Pennsylvania Background: Previously we found, using six light swings and monocular recording, that pupiUography was not efficient enough to screen for mild afferent pupil defects ( APDs). Objective: To investigate the ability of a portable ( Windows based) pupiilometer, using binocular recording of the swinging flashlight test ( SFT) for 20 seconds, to detect APDs. Methods: Pupillary response curves ( both eyes) of healthy vol­unteers ( n = 22) with and without simulated APDs ( created with neutral density filters ( NDF)), and of abnormal patients ( n = 21) with clinically graded APDs, were recorded. The light stimulus ( 0.2 sec or 2 sec duration) alternated ( 1 sec or 0.4 sec interval) between both eyes, simulating the SFT. Constriction amplitude, velocity and pupillary release were calculated by computer algorithm. In patients with APDs, NDFs were used to neutralize inter- eye differences. Results: Significant correlation ( Pearson coefficient 0.74, 0.77) between NDF strength and inter- eye differences was seen for diameter and velocity in simulated APDs. All abnormal pa­tients ( 15/ 15) with APDs greater than 0.5 log units could be distinguished from normal ( 95% specificity). PupiUography was able to quantify APDs in all 21 abnormal patients when NDFs were used to neutralize inter- eye differences. Inter- eye variability in some normals prevented confident distinction of abnormal patients with .3 log unit APDs, from normal patients with large inter- eye differences. Using a .3 log unit NDF to accentuate or reduce inter- eye differences, subtle APDs were predicted in 5/ 6 patients with possible APDs on clinical exami­nation. Amplitude and velocity measurements were more ac­curate than pupillary release for all comparisons. Conclusions: Using a 20 second, binocular recording of the SFT, this pupiilometer identifies all patients with > .6 log unit APDs. With the addition of NDFs to reduce inter- eye differ­ences, all patients with APDs can be accurately identified and quantified. Variability in some normals makes them indistin­guishable from patients with subtle APDs. / Neuro- Ophthalmol, Vol. 21, No. 2, 2001 NANOS ABSTRACTS 141 ANALYSIS OF THE RETINAL NERVE FIBER LAYER IN PATIENTS WITH OPTIC NEUROPATHIES K. P. Cockerham, R. Sudesh; Pittsburgh, Pennsylvania Background: The Heidelberg Retinal Tomograph II ( HRT) measures the birefringence of the retinal nerve fiber layer ( RNFL). The computer model provides indirect measurements of optic disc area, rim area, rim volume, height variation con­tour, mean RNFL thickness, RNFL cross sectional area, refer­ence height contour, rim and total nerve fiber layer thickness that are applicable to analysis of optic nerve swelling and at­rophy seen in neuro- ophthalmology patients. Other parameters that target glaucoma cup- to- disc analysis are also provided. Objective: To evaluate the efficacy of HRT in patients with afferent dysfunction. Methods: Thirty- five patients with afferent dysfunction had complete neuro- ophthalmic examination performed to include visual field testing. Diagnoses included ischemic optic neurop­athy, optic neuritis, traumatic optic neuropathy and compres­sive optic neuropathy. Patients with visual acuity less than 20/ 400, difficulty with fixation or significant media opacifica­tion were excluded due to machine limitations. Results: The HRT was successfully performed in twenty- five patients. The objective information obtained from the HRT augmented the subjective visual field data. In three patients, all with bilateral afferent dysfunction, the HRT demonstrated an asymmetry in the retinal nerve fiber layer not identified with visual field testing. Conclusions: HRT may provide useful objective information that augments a complete neuroophthalmic examination and visual field testing. HRT is not possible if central vision is poor, fixation instability is present or significant media abnormalities occlude imaging. We plan to compare serial HRT to visual field testing in patients with known optic neuropathies to assess whether the HRT is more sensitive to change. NORMAL ERYTHROCYTE SEDIMENTATION RATE IN BIOPSY PROVEN GIANT CELL ARTERITIS W. T. Cornblath; Ann Arbor, Michigan The diagnosis of giant cell arteritis ( GCA) can be very dif­ficult to make and decisions to treat or not to treat can have far- reaching consequences. One standard test used in the diag­nostic process is the Westergren erythrocyte sedimentation rate ( WESR). However, the reliability of this test is unclear, with widely varying results being reported. In addition, the range of normal in elderly patients is also disputed, with 20, 40, or age divided by 2 all being used as the upper limit of normal. Our objective was to determine the range of WESRs in a large group of patients with biopsy proven GCA. We reviewed the charts of all patients with a biopsy proven diagnosis of GCA seen at the University of Michigan in a 10 year period. Ninety-six patients were seen with complete data available on 79. There were 12 men and 67 women. Age ranged from 61 to 86 for men ( average 74), and from 55 to 93 for women ( average 73). Five percent of patients ( 4/ 79) had an ESR below 20 ( normal range 0- 20). Twenty percent of patients ( 16/ 79) had an ESR below 40. Twenty- three percent of patients ( 18/ 79) had an ESR less than the age divided by 2 ( for males), or age divided by 2 plus 5 ( for females). ESRs less than 40 occurred between ages 63 and 85. In conclusion, relying on an elevated WESR to decide the presence or absence of GCA will exclude anywhere between 5% and 23% of patients, depending on what upper limit of normal is defined. As usual in neuroophthalmology an astute clinician must evaluate laboratory results in the context of the whole patient. DIFFUSION- WEIGHTED MR IMAGING IN THE SHAKEN- IMPACT BABY SYNDROME V. Biousse, D. Suh, P. C. Davis, K. L Hopkins, T. Mapstone, N. J. Newman, S. R. Lambert; Atlanta, Georgia Introduction: Shaken impact baby syndrome ( SIBS) is char­acterized by subdural hematoma ( SDH), occult bone fractures and retinal hemorrhages. Diffusion- weighted MR imaging ( DWI- MRI) has recently proven useful in the diagnosis of acute cerebral ischemia and is more sensitive than conventional MRI to detect diffuse axonal injury from head trauma. In this study we evaluated the role of DWI- MRI in the diagnosis and management of children with suspected SIBS. Methods: Retrospective review of medical records and neu-roimaging findings of all children less than 2 with confirmed or suspected SIBS admitted to a Children's hospital. Only chil­dren who had an ocular examination by an ophthalmologist, and a brain MRI with DWI were included. Results: Twenty- six children ( 14M/ 12F, mean age 7.1 mo [ 6 wk- 24 mo]) were included. SIBS was confirmed in 18 chil­dren. All had SDHs. Ten had associated long bone fractures. Eighteen patients had diffuse retinal hemorrhages ( unilateral in 3, bilateral in 15) associated with vitreous hemorrhage in 1. None of the patients died, but the short- term prognosis was poor in 19 children. Seven of the 8 cases without retinal hem­orrhages had isolated SDH without parenchymal lesions on both conventional and DWI- MRI. The short term prognosis was excellent in 6 of them. In only 1 case with normal fundus was SIBS confirmed. Among the 18 patients with retinal hem­orrhages, SIBS was confirmed in all but 1 case. All 17 patients with retinal hemorrhages and confirmed SIBS had an abnormal DWI- MRI. In 13 of them, DWI showed lesions that were larger than on conventional MRI. Discussion/ Conclusions: In all but 1 case with confirmed SIBS, the DWI- MRI was abnormal, suggesting diffuse cerebral injury associated with SDHs. In all other cases, DWI- MRI was normal. When DWI showed additional lesions not seen on conventional MRI, the short- term prognosis was poorer. DWI helps differentiate infarction from diffuse axonal injury, which may have implications regarding the acute management of chil­dren with SIBS. DWI- MRI may also provide better information about the timing of injury, which may help to determine the sequence of events and identify potential perpetrators. FREQUENCY DOUBLING PERIMETRY IN NEURO-OPHTHALMOLOGIC DISORDERS: A COMPARISON WITH CONVENTIONAL AUTOMATED PERIMETRY M. Wall, R. Neahring, K. Woodward; Iowa City, Iowa Purpose: Frequency doubling technology perimetry ( FDT) was developed as a screening test for glaucoma. It is now used as a general visual screener. Patients with damage to the sen­sory visual pathways have different patterns of visual loss than glaucoma patients. Our aim, therefore, was to determine the sensitivity and specificity of FDT as a screening test compared with conventional automated perimetry ( CAP) in neuro-ophthalmologic disorders and also to evaluate the extent to which FDT may isolate the My cells. Methods: We tested 42 subjects from the general population recruited by randomly calling phone numbers from a phone book and 96 subjects with neuro- ophthalmologic disorders. Twenty- four patients had hemianopias. All subjects were tested with both FDT and CAP. The tests were compared based on total deviation probability plot abnormalities for test loci com- J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 142 NANOS ABSTRACTS mon to the two perimetric tests. Our gold standard was an unequivocal clinical diagnosis. Results: The sensitivity of FDT was 81.3% with a specificity of 76.2%. The sensitivity of CAP was 87.5%. Its specificity was 81.0%. These differences were not statistically significant ( Chi square). In patients with optic neuropathies, the similarity of the defect shown on FDT and CAP was judged good or fair in 62/ 72 cases. The extent of the defect on FDT and CAP was equal in 41/ 72 cases, more extensive on FDT in 12/ 72 and more extensive on CAP in 19/ 72 cases. These differences were not significant. Although FDT perimetry revealed defects in 18/ 24 patients ( 75%), hemianopic patterns were missed in 15/ 24 ( 62%). In contrast, 2/ 24 hemianopic patterns defects were missed with CAP using the total deviation probability plots. In one hemianopic patient, FDT perimetry was superior but noise ( scat­tered abnormal test locations) made interpretation difficult. Noise impaired interpretation in 4 other hemianopic patients with FDT. Conclusion: FDT perimetry is a sensitive test to detect optic neuropathies. It fails as a screening test for hemianopias. This is likely due to scatter of light across the vertical midline from the large ( 10) stimuli. Since FDT perimetry is no more sensitive than conventional automated perimetry and fails to show de­fects more extensively, it probably works by a contrast sensi­tivity mechanism rather than by isolating the My cells. THROMBOPHILIA AS RISK FACTOR FOR CENTRAL AND BRANCH ARTERY OCCLUSION WITHOUT EVI­DENCE OF EMBOLIC ORIGIN R. Huna- Baron, O. Salomon, J. Moisseiev, U. Seligsohn; Tel Hashomer, Israel Objective: To assess the prevalence of acquired and inherited thrombophilias in patients with central and branch retinal artery occlusion without embolic origin. Methods: The study group comprised 21 consecutive patients with retinal artery occlusion ( RAO) and 243 healthy subjects. All patients underwent Doppler ultrasonography of the carotid arteries and transthoracic or transesophageal echocardiography. Laboratory methods included polymerase chain reaction and restriction analysis for detection of factor V G1691A, factor II G20210A and methylenetetrahydrofolate reductase ( MTHFR) C677T mutations; determination of plasma levels of protein C, free protein S, antithrombin, fibrinogen and homocysteine; and tests for the presence of lupus anticoagulant and titer of anti-cardiolipin antibodies. Results: Nine of the 21 ( 43%) patients had at least one throm-bophilic marker: four were homozygous for MTHFR C677T, one was heterozygous for factor V G1691A, one had a high titer of IgM anticardiolipin, two were heterozygous for factor V G1691A and homozygous for MTHFR C677T, and one had lupus anticoagulant, a high titer of IgM anticardiolipin, ho­mozygosity for MTHFR C677T and hyperhomocystinemia. An interaction between vascular risk factors and thrombophilias seems important since out of 14 patients with hypertension, diabetes and/ or hypercholesterolemia seven ( 50%) had a thrombophilia. Analysis of the data disclosed that homozygous MTHFR 677T was a significant risk factor with odds ratio of 3.18 ( 95% C. I 1.20- 8.47). The prevalence of factor V G1691A was also higher in the RAO patients with odds ratio of 2.36 ( 95% C. I 0.63- 8.88), but it did not reach statistical significance probably due to the small sample size. Conclusions: The results suggest that acquired and inherited thrombophilias are contributory risk factors in non- embolic RAO. CHARACTER COUNTING USING SNELLEN EYE CHART TO ESTIMATE VISUAL ACUITY A. H. Levy, T. J. McCulley, B. L. Lam; Miami, Florida Purpose: To evaluate the usefulness of estimating visual acuity based on the ability to count the number of letters on the Snellen visual acuity chart so that this method may be used in patients with non- organic visual loss or cognitive dysfunction. Method: The right eyes of 35 healthy adults with visual acuity of 20/ 30 or better were fogged with phoropter plus lenses at random 0.25 diopter intervals ( from + 0.25 to + 4.25 spheres) and tested with the popular standard projected Snellen visual acuity chart ( Reichert 11180). Visual acuity and counting acu­ity were assessed repeatedly under various degree of fogging. Counting acuity was defined as the smallest line that the subject could count the number of letters correctly. Visual acuity was fogged to a maximum of 20/ 200. Results: The number of subjects for each counting acuity level varied as each subject was not fogged to all levels of visual acuity. For each counting acuity level, the corresponding me­dian visual acuity and the rounded upper 95% confidence in­terval are given below. The upper 95% confidence interval of the visual acuity represents the minimal visual acuity needed to attain the specific level of counting acuity. A close correlation was found between visual acuity and counting acuity, and in general, counting acuity was approximately 3 lines better than the median visual acuity. Count acuity 20/ 10 20/ 15 20/ 20 20/ 25 20/ 30 20/ 40 20/ 50 20/ 60 N 17 24 31 14 9 24 16 17 Visual acuity ( median) 20/ 25 20/ 30 20/ 40 20/ 50 20/ 80 20/ 80 20/ 100 20/ 200 Visual Rounded 95% 20/ 30 20/ 50 20/ 80 20/ 80 20/ 200 20/ 200 20/ 200 20/ 200 C. I. acuity ( Actual % C. I.) ( 94%) ( 96%) ( 94%) ( 100%) ( 100%) ( 100%) ( 100%) ( 100%) Conclusion: Our data suggests that the ability to count the number of letters on the Snellen visual acuity chart is a valid method in estimating visual acuity, which may be used in pa­tients with non- organic visual loss or cognitive dysfunction. C. R. None. NON- ARTERITIC ISCHEMIC OPTIC NEUROPATHY IN PATIENTS WITH FACTOR V LEIDEN MUTATION A. R. Harrison, J. D. Wirtschafter; Minneapolis, Minnesota Background: The factor V Leiden deficiency is a recently described mutation leading to thrombosis. Previous studies have not determined whether factor V Leiden mutation is a risk factor for, modulator of, or unrelated to nonarteritic ischemic optic neuropathy ( NAION). Objective: Review the findings in patients with NAION with factor V Leiden mutation. Methods: Retrospective case review. Results: Three patients were identified who had NAION and factor V Leiden mutation. Two patients were under 40 years of age. Two patients had bilateral disease. Visual acuity was better than 20/ 40 on last visit in all affected eyes. Magnetic resonance / Neuro- Ophthalmol, Vol. 21, No. 2, 2001 NANOS ABSTRACTS 143 imaging of the brain and orbits was normal in 2 patients and in 1 patient showed multiple T2 hyperintensities. Conclusions: Prospective studies are needed to determine if Factor V Leiden deficiency is ( 1) a causative or risk factor for NAION and ( 2) if Factor V Leiden mutation modulates the clinical presentation of NAION. CAN SITA FAST BE USED AS A RELIABLE ALTER­NATIVE TO GOLDMANN PERIMETRY IN NEURO-OPHTHALMIC PRACTICE? G. Szatmary, V. Biousse, N. J. Newman; Atlanta, Georgia Objective: To assess the potential role of SITA Fast ( SF) com­puterized static perimetry compared with Goldmann manual kinetic perimetry ( GVF) to reliably detect visual field defects in neuro- ophthalmic practice. Background: Automated visual field tests may be a challenge in patients with severe neurological disease or poor visual acu­ity. In these patients, GVF is often preferred but is not often available and requires a skilled technician. The recent devel­opment of the SITA family of perimeters has allowed for shorter testing time without increasing test- retest variability in normal subjects and in glaucoma patients. However, its use­fulness for detecting visual field defects in patients with neurological disease or severely decreased vision has not been evaluated. Design/ Methods: Prospective evaluation of 24 consecutive, neuro- ophthalmologically impaired patients with neurologic disability ( Modified Rankin Scale [ MRS] 3 or worse), or visual acuity 20/ 200 or worse in at least one eye. Goldmann and SF visual field tests were obtained on the same day. The two visual fields were compared with special attention to reliability, test duration, detection and quantification of neuro- ophthalmic visual field defects. Patients M test preference was subjec­tively assessed. Results: Patients were separated into two groups, depending on their entry criteria. Group I: patients with moderate neurologi­cal disability but poor visual acuity ( n = 14, 8 M, 6 W, mean age 51 [ range 20- 81]). Group II: neurological disability of MRS 3 or worse ( n = 10, 6 M, 4 W, mean age 54.8 [ range 30- 83]). GVF was reliable in 13/ 14 ( 93 %) patients of group I and in 9/ 10 ( 90%) of group II, while SF was reliable in 13/ 14 ( 93%) patients of group I and in 7/ 10 ( 70%) of group II ( NS). GVF and SF showed similar VF defects in 12/ 14 ( 86%) of group I and in 7/ 10 ( 70%) of group II ( NS). Two patients from group II who had a full GVF, had diffuse non- specific changes and poor reliability parameters on SF. In one patient from group II with cognitive disorders, SF was not reliable and failed to demonstrate visual field defects related to bilateral parietal- occipital lobe lesions. The mean duration time for GVF in both eyes was 18.1 ± 4.6 minutes [ range 11- 25] in group I, and 15.4 ± 5.0 minutes [ rangel0- 18] in group II, while for SF it was 10.7 ± 1.43 minutes [ range 8.12- 12.37] in group I, and 11.5 ± 3.02 [ range 7.45- 16.55] in group II ( p < .05). All pa­tients preferred GVF testing. Conclusion: SF strategy seems to be reliable and useful in most patients with neuro- ophthalmologic deficits associated with either severe neurological impairment or severely de­creased vision. As opposed to full threshold perimetry, the shorter testing time and flexibility of SF likely reduce visual fatigue, one of the major limiting factors in the assessment of patients with neurogenic visual field defects. However, all our patients preferred GVF to SF testing. SCANNING LASER POLARIMETRY FOR THE DE­TECTION OF NERVE FIBER LAYER DEFECTS IN PA­TIENTS WITH OPTIC NERVE DRUSEN V. A. Klair, B. J. Katz, K. B. Digre, J. E. A. Warner, R. P. Harrie; Salt Lake City, Utah Patients with optic nerve drusen may have other diseases of the optic nerve, including glaucoma, complicating the evalua­tion of visual field defects. In diseases of the optic nerve, visual field defects result from loss of ganglion cells and thinning of the retinal nerve fiber layer. We performed scanning laser po-larimetry using the GDx Nerve Fiber Layer Analyzer on pa­tients with optic nerve drusen in an attempt to determine if there were characteristic patterns of nerve fiber layer thinning unique to optic nerve drusen. All patients had complete eye exams, automated perimetry, and ultrasound confirmation of drusen. We found that eyes with buried drusen showed neither visual field defects nor nerve fiber layer abnormalities. Eyes with visible drusen, but no vi­sual field defect, had normal retinal nerve fiber layer param­eters. Eyes with visible drusen and visual field defects always had nerve fiber layer abnormalities. We noted that the unaf­fected fellow eyes in patients with unilateral drusen had normal visual fields and normal nerve fiber layer thickness. The pattern of retinal nerve fiber layer abnormalities was not unique to optic nerve drusen and had many characteristics similar to the pattern seen in glaucoma. Scanning laser polarimetry provides an additional means of documenting and following retinal nerve fiber layer loss in patients with optic nerve drusen. How­ever, this method may not provide a means of separating the nerve fiber layer loss of optic nerve drusen from that associated with other optic nerve diseases, including glaucoma. Further analysis of the data acquired by the laser polarimeter may, in the future, provide a means of specifically identifying nerve fiber layer loss caused by drusen. Because scanning laser po­larimetry measurements reflect optic nerve damage, it provides an additional means of following optic nerve damage in optic nerve drusen patients who are unable to reliably perform. TEMPORAL FIELD LOSS IN ' UNAFFECTED' EYE WITH ACUTE OPTIC NEURITIS: A LESION AT WIL-BRAND'S KNEE M. J. Kupersmith, J. Straga, B. Zeiffer, R. Krager; New York, New York Background: Recent work suggests that Wilbrand's ' knee' is an artifact of longstanding unilateral optic nerve damage and the associated junctional scotoma is due to compression of the chiasm at multiple sites rather than a focal lesion where the posterior optic nerve enters the chiasm. Objective: We investigated patients with optic neuritis in­volvement of the intracranial optic nerve to determine whether a junctional type scotoma can occur in an acute disorder with­out mass effect. Methods: Retrospective analysis of patients with acute optic neuritis and no optic atrophy in either eye who had gadolinium MRI demonstrating abnormal enhancement of the intracranial optic nerve but not the chiasm. We also analyzed the pre­sentation visual field data from the ONTT to determine the prevalence of temporal field loss in the second eye ( previ­ously unaffected). Results: The signature case, a woman with painless loss of vision in one eye and a definite mild superior temporal field defect in the 2nd eye, was referred for MRI with a diagnosis of J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 144 NANOS ABSTRACTS pituitary adenoma but had posterior optic nerve enhancement. In our database of 92 patients with acute optic neuritis and gadolinium MRI, 14 had intracranial optic nerve enhancement, 8 cases met our MRI criteria and had visual fields done at the time of the MRI. We had 2 other patients who had concomitant involvement of the chiasm. Only 1 patient had the typical junc­tional scotoma. In the ONTT data, 110/ 416 eyes without atro­phy had 2nd eye abnormal visual fields. Two of these eyes had temporal field defects. Conclusion: Junctional scotoma in optic neuritis is uncommon. Due to the lack of exact localization, the ONTT data can not explain the anatomy. However, our case suggests that a junc­tional scotoma can occur from a focal lesion in the posterior optic nerve and the ' knee' of Wilbrand may not be an artifact. PARANEOPLASTIC OPTIC NEUROPATHY WITH EVIDENCE FOR VITREAL AND INTRATHECAL IN­FLAMMATION IN 8 PATIENTS WITH CRMP- 5 NEU­RONAL AUTOANTIBODY AND LUNG CANCER S. A. Cross, J. A. Mines, V. A. Lennon; Rochester, Minnesota Background: Paraneoplastic optic neuropathy has been re­ported with lung carcinoma and incompletely defined autoan­tibodies. CRMP- 5 autoantibody is specific for a newly recog­nized collapsin response- mediator protein in retina, small- cell carcinomas and neurons. CRMP- 5- IgG is a marker of neuro­logical autoimmunity with lung carcinoma or thymoma ( Yu et al., Ann Neurol, v. 49, Feb. 2001). Objective: To report ophthalmologic, neurologic and labora­tory profiles of 8 patients with optic neuropathy, CRMP- 5- IgG in serum or cerebrospinal fluid ( CSF), and lung carcinoma. Methods: The 8 patients were amongst 116 in whom paraneo­plastic autoantibody testing revealed CRMP- 5- IgG. Clinical in­formation was obtained from records and physician interviews. All 116 had a neurological presentation; 90% had cancer. Results: The 8 patients ( 5 males) were smokers. Small- cell carcinoma was confirmed in 7, confined to the chest in 6; 1 had an unbiopsied chest mass. All had subacute visual loss, ceco-central scotomata and/ or arcuate defects in visual fields, and swollen discs. Some fundi had nerve fiber layer hemorrhages. Fluorescein angiography showed nerve head hyperfluores-cence. The vitreous contained numerous small non- clumped cells ( 5/ 7). Diagnostic vitrectomy ( 2 patients) disclosed inflam­matory reaction without evidence of lymphoma. MRI scans revealed no structural lesions in the visual pathway. Neurologi­cal accompaniments included cerebellar ataxia ( 4), dementia ( 3), myoclonus ( 1), chorea/ dystonia ( 2), neuropathies ( 3 so­matic, 4 autonomic), Lambert- Eaton syndrome ( 1) and altered taste and smell ( 4). Lumbar puncture ( n = 5) revealed normal opening pressure, pleocytosis ( 7- 32 cells, monocytes and im­mature forms), elevated protein and CRMP- 5- IgG ( 5/ 5 posi­tive, titers 1: 500 to 1: 1,000). Serum titers ( 7/ 8 positive) were < 1: 60 to 1: 500,000. CSF was positive at 1: 500 in the patient whose serum was negative, indicative of CRMP- 5- specific T-and B- lymphocyte activity within the nervous system. Conclusions: Optic neuropathy with the CRMP- 5 autoanti­body marker is associated with inflammatory vitreous and CSF, intrathecal CRMP- 5- IgG synthesis, multifocal neurological ab­normalities, and limited small- cell lung carcinoma. OPTIC DISC CUPPING ALL OVER K. Landau, B. Gloor; Zurich, Switzerland Background: Various pathogenic mechanisms are known to produce optic atrophy. In many instances, diagnosis can be readily established by combining information from history, functional evaluation, clinical examination including assess­ment of optic disc morphology, and ancillary testing. Occa­sionally, a patient may present with a cupped optic disc re­minding of glaucomatous optic neuropathy in whom a different mechanism than glaucoma is responsible for the resulting op­tic neuropathy. Objective: To present examples of cupped optic discs caused by a variety of insults other than glaucoma. Methods: Over a period of 10 years the authors collected ex­amples of non- glaucomatous cupping of the optic disc in their neuro- ophthalmology and glaucoma services. Results: We found patients with glaucomatous looking discs in almost every category of optic neuropathies. In some cases low tension glaucoma was the initial diagnosis that later had to be revised, but in most instances the authors were impressed by the development of optic disc cupping following entities such as demyelinative optic neuropathy, compression from suprasel­lar lesions, arteritic AION, central retinal artery occlusion, op­tic nerve or chiasmal trauma, periventricular leukomalacia, dominant optic atrophy and toxic optic neuropathy. Conclusion: Optic disc cupping is a non- specific sign of glau­comatous optic neuropathy. If additional clinical evidence is not characteristic of glaucoma and diurnal curve does not re­veal increased intraocular pressure, a search for other causes is indicated. Most helpful parameters in distinguishing non-glaucomatous from glaucomatous cupping are the color of the remaining rim and the pattern of visual field damage. References 1. Trobe JD, Glaser JS, Cassady JC, Herschler J, Anderson DR: Nonglaucomatous excavation of the optic disc. Arch Ophthalmol 1980; 98: 1046- 1050. 2. Sebag J, Thomas JV, Epstein DL, Grant WM: Optic disc cupping in arteritic anterior ischemic optic neuropathy resembles glauco­matous cupping. Ophthalmology 1986; 93: 357- 361. 3. Bianchi- Marzoli S, Rizzo JF, Brancato R, Lessell S: Quantitative analysis of optic disc cupping in compressive optic neuropathy. Ophthalmology 1995; 102: 436^ 140 EQUIVALENT DOSE ORAL STEROID USE IN OPTIC NEURITIS: READY FOR PRIMETIME? R. D. Bailey, J. E. Carter; San Antonio, Texas Background: Modifications of the Optic Neuritis Treatment Trial ( ONTT) steroid protocol are commonly used in daily practice. During the 2000 North American Neuro- Ophthal-mology Society ( NANOS) meeting, a survey was conducted to determine whether the representative neuro- ophthalmologists would use doses of oral steroids equivalent to those employed in the ONTT. Discussions on NANOS- NET have explored us­ing an oral dose equivalent to the intravenous dose employed intravenously in the ONTT. Objective: To investigate the use of oral equivalent high- dose steroid regimens for treatment of optic neuritis. Methods: A questionnaire was distributed during the poster session of the 2000 NANOS meeting. Results: Eighty- eight surveys were returned during the meet­ing. Twenty- seven neuro- ophthalmologists routinely treat their ON patients with steroids, and an additional use steroids if the MRI shows white matter lesions. Forty- eight attendees did not answer the question regarding the proposed use of a high- dose oral regimen. Of the 40 who did respond, 30 would use an oral equivalent, nine would never use an oral equivalent, three re­sponded don't know or need more information. Conclusion: Among the neuro- ophthalmologists attending the 2000 NANOS meeting and responding to the questionnaire, there is no consensus on substituting a high- dose oral steroid / Neuro- Ophthalmol, Vol. 21, No. 2, 2001 NANOS ABSTRACTS 145 regimen for the ONTT intravenous regimen. The most obvious explanation may be that data supporting the use of high- dose oral steroids are not available, a common theme in the discus­sion that ensued during the survey distribution. An equivalent oral regimen may more closely parallel the ONTT protocol than the once daily IV methylprednisolone dose used by many, since an oral regimen can be given in divided doses as in the ONTT. Pending more systematic data, we propose that oral steroids at a regimen equivalent to the ONTT IV regimen should be used as an acceptable alternative to the common protocols in use today. A COMPARISON OF MULTIFOCAL VEPS FROM PA­TIENTS WITH ACUTE ONSET OF EITHER ION OR OPTIC NEURITIS J. E. Hong, J. G. Odel, X. Zhang, M. M. Behrens, D. C. Hood; New York, New York Background: Ischemic optic neuropathy ( ION) and optic neu­ritis ( ON) can sometimes be difficult to distinguish. Objective: To record multifocal visual evoked poten­tials ( mVEP) from patients with ION or ON during their acute phases. Methods: Patients experiencing unilateral attacks of ION ( n = 7) or ON ( n = 8) were studied. Monocular mVEPs were obtained using a scaled, 60 sector, dartboard array [ 1]. Two 7- min. runs were obtained for each eye. A pseudo S/ N ratio was obtained for each response based upon the two runs. Signals with S/ N ratio < 2 were omitted from the analysis. For each of the 60 pairs of monocular responses, the ratio of the RMS amplitudes was determined [ 1]. Implicit times were obtained using a cross- correlation method. Estimates of visual field changes in the 60 sectors of the mVEP array were interpolated from the visual fields [ 1,2]. Results: The relative loss in amplitude of the mVEP from the affected eye is correlated with field loss for both groups [ r2 of 0.59 ( ON) and 0.58 ( ION)]. For field losses of 10 dB or less, the log of the ratio of the relative amplitude was linearly related to log field loss ( i. e. dB values) for both ON ( r2 = 0.70; slope = 0.67) and ION ( r2 = 0.38; slope = 0.48). The implicit times for ON, but not ION, were significantly delayed and these delays correlated with field loss. However, only 4 of the patients with ON had reliable signals; 3 of these had one or more responses with a significant delay. Conclusion: During the acute phase, in some cases ON can be distinguished from ION, but in others the mVEP responses are too small to allow measurement of implicit time. After recov­ery, ON can be distinguished from ION in many cases based upon prolonged implicit times [ 1,3]. References 1. Hood, Odel, Zhang, ( 2000) 2. Hood, Zhang, ( 2000) 3. Kardon, Givre, et al., ( in press) PATIENTS WITH IDIOPATHIC INTRACRANIAL HY­PERTENSION FREQUENTLY HAVE OTHER DEFINED HEADACHE DISORDERS D. I. Friedman, E. Rausch; Syracuse, New York Objective: To determine the following in patients with idio­pathic intracranial hypertension ( IIH): ( 1) the initial symp­toms and ( 2) whether patients subsequently developed head­aches that were classifiable by International Headache Society ( IHS) criteria. Methods: Medical records were reviewed from 1991- 2000. Inclusion criteria were papilledema at presentation, normal brain neuroimaging study ( except empty sella), and a lumbar puncture confirming an opening pressure > 250 mm water with normal CSF contents. Results: Eighty- four patients ( 82 females, 2 males) between ages 10- 59 ( mean = 29) years met the criteria. At the onset of symptoms, patients described their headaches as pounding/ throbbing ( 20), pressure ( 18), aching ( 17) and explo­sive ( 1). Ten patients did not have headache on presentation and no description of the pain was available in 16. Severity, location and frequency of head pain were variable. The most frequent accompanying symptoms were transient visual obscu­rations ( 38), intracranial noises ( 36), blurred vision ( 25), dip­lopia ( 16), scotoma ( 14), nausea/ anorexia ( 13) and vomiting ( 11). Eleven adults related a history of headaches since child­hood: 3 migraine with aura ( MWA), 3 migraine without aura ( MWOA), 1 menstrually- associated headache, 2 chronic ten­sion- type headache ( CTTH), 1 episodic tension- type headache ( ETTH), 1 " sinus" headache. Following the diagnosis of IIH, 15 patients ( 18%) had resolution of their headaches after the initial lumbar puncture. Fifty- six patients ( 67%) developed IHS classifiable headache disorders: ETTH ( 30), MWOA ( 20, plus 2 patients whose headaches were < 4 hours long), CTTH ( 10), analgesic overuse headache ( 8), idiopathic stabbing headache ( 3), cluster headache ( 1), benign exertional headache ( 1). Only 1 patient developed MWA who did not have it pre- morbidly; however, she had a history of MWOA. Nineteen patients ( 23%) had more than one type of headache. Conclusion: Patients with IIH usually have headaches during the course of their illness that may bear no resemblance to their presenting headache pattern. The most common headache types are ETTH and migraine without aura. Due to the retrospective nature of this study all headache types, especially analgesic rebound headache, are probably underestimated. Recognition and treatment of specific headache disorders is an important aspect of the care of patients with IIH. MAR SYNDROME 64 PATIENTS, UPDATE 2001 J. L. Keltner, C. Thirkhill, P. Yip; Sacramento, California Purpose: The purpose of this study is to evaluate the signs, symptoms, and immune response of patients with Melanoma- Associated Retinopathy ( MAR) syndrome. Methods: The clinical information and immunologic findings from UC Davis patients and the clinical information available on patients from the world's literature were analyzed in a com­bined fashion. Results: A total of 64 MAR syndrome patients ( 11 UC Davis patients and 53 from the world's literature) have been studied. 36 patients had available age and gender information, showing 30 males and 6 females. The average age at onset of vision disturbance was 56.8 years ( ranging from 30- 78 years). 26: 30 patients had good initial visual acuity at the time of presenta­tion, ranging from 20/ 20 to 20/ 60. However, in 7: 33 patients moderate to severe visual loss occurred in one or both eyes. Visual field findings included central scotomas, arcuate de­fects, and generalized constriction. Fundus examination was normal in 19: 41 patients, 10: 41 showed optic nerves pallor, and 11: 41 had vessel attenuation. 9: 41 patients were described as having moderate numbers of vitreous cells. Electroretinograms ( ERG) tested on 55 patients revealed congenital stationary night blindness ( CSNB) patterns and ERG findings typical of MAR syndrome. The time from the diagnosis of melanoma to the onset of metastatic disease was an average of 3.6 years ( ranging from 2 months to 19 years) in 28 patients. In 35 J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 146 NANOS ABSTRACTS patients the time from the diagnosis of melanoma to the ap­pearance of MAR syndrome averaged 3.8 years ( ranging from 3 months to 17 years). The average survival time was 6.28 years. Surgery, chemotherapy, and immunologic and radiation therapy were used to treat the primary tumor and metastasis. Five patients had visual improvement with various treatment regimes. All patients studied produced auto- antibodies reactive with components of the bipolar layer. Those studies in this laboratory were also found to exhibit a variety of additional antigen- antibody reactions with different ocular components and in their Western blot reactions on extracts of retina. Conclusion: The MAR syndrome demonstrates a greater di­versity in the clinical and immunologic presentations than those previously considered. THE EFFECT OF STIMULUS BRIGHTNESS ON THE SEPARATION OF PATIENTS FROM NORMAL SUBJECTS USING COMPUTER RECORDING OF THE PUPIL LIGHT REFLEX R. H. Kardon, A. L. Bassman; Iowa City, Iowa Background: Recent evidence from our studies of unilateral optic neuropathy has shown a greater relative afferent pupillary defect ( RAPD) with brighter light stimuli, which may indicate how damage may affect the neuronal firing properties of gan­glion cells. Objective: To determine if the brightness of the stimulus light used to determine the relative afferent pupil defect ( RAPD) can influence the ability to differentiate normal subjects from pa­tients with asymmetric visual loss. Methods: Computerized infrared pupillography was performed on 53 normal subjects with normal visual field testing and 52 patients with asymmetric visual field loss. A 0.2 second light stimulus subtending a 30 degree radius visual field was alter­nately presented to the right and left eye every 3 seconds. At each of 10 different stimulus light intensities, the distribution of the asymmetry in pupil contraction ( right eye stimulation- left eye stimulation) was compared between the normal and patient groups using an unpaired t- test assuming unequal variance. Results: There was a highly significant effect of stimulus brightness on the separation of the normal and patient groups ( linear correlation of log p value vs. intensity; p < 0.001). Brighter stimuli produced a greater separation between the nor­mal and patient group and this was also statistically significant when the patients were subdivided into those with mild, mod­erate, or severe damage. Conclusions: A brighter stimulus light ( short duration, under computer- control) causes a greater separation between normal subjects and patients with unilateral or asymmetric visual dys­function. Our results indicate that disease of the afferent visual system impairs the pupil light reflex to a greater extent in patients compared to normal subjects when using a brighter light stimulus. This may have implications on how optic nerve disease affects the ability of ganglion cells to respond to light intensities near threshold ( low neuronal firing rate) vs. supra-threshold ( high neuronal firing rate). LOCAL USE OF TRIAMCINOLONE IN DYSTHYROID ASSOCIATED OPHTHALMOPATHY R. Ebner, M. Devoto, D. Weil, M. Bordaberry, C. Mir, H. Martinez, L. Bonelli, H. Niepomminszcze; Buenos Aires, Argentina Objective: To study the local effects of intra- orbital triamci­nolone in patients with DAO. Study design: Prospective randomized unmasked- pilot study. Methods: Fifty patients were included in this study from April 98 to April 99 with the following inclusion criteria: DAO of 6 months maximum, diplopia as the main complaint and com­pletely free of treatment for ophthalmopathy regardless of the stage of dysthyroidism. Patients were randomized in 2 groups; Gl, who received para- bulbar injections of 20 mgrs of triam­cinolone on each orbit every week, totaling 4 applications ( per-orbit) and G2, a control group. Diplopia was measured with a Goldmann perimeter. With both eyes open patients determined the area of non- diplopia which was calculated at week 0, 10 and 24. The thickness of extraocular muscles was measured with a caliper on CT scan-coronal views at week 0 and 24. Results: Thirty- seven patients completed this study ( Gl n = 20, G2 n = 17). After 6 months Gl patients demonstrated improve­ments in the field of non- diplopia at week 10 ( change: 91.56%, p = 0.054) and maintained the improvement at week 24 ( change: 105.9%, p = 0.041), while in G2 we observed a ten­dency to deteriorate the non- diplopic area ( 2%, p = 0.6 and 1.3%, p = 0.84 at weeks 10 and 24 respectively). The thickness of extraocular recti improved dramatically in the injected group ( change; inferior rectus: - 13.21%, p = 0.001, medial rectus: - 8.24%, superior rectus: - 9.5%, p = 0.032, lateral rectus: - 11.49%, p = 0.0005) compared to the changes observed in controls ( inferior rectus: - 4.02%, p = 0.33, medial rectus: 0.56%, p = 0.89, superior rectus: 12.54%, p = 0.081, lateral rec­tus: - 0.53%, p = 0.92). Non- undesirable local effects, due to the procedure, were observed out of few hematomas in the site of the injections. Conclusions: Local injections of triamcinolone demonstrated an increase in the non- diplopic area and a decrease in the recti thickness, compared with the results obtained in the con­trol group. Minimum local side effects, due to the injections, were observed. We favor the use of this treatment in patients with DAO. LOCAL USE OF TRIAMCINOLONE IN DYSTHYROID ASSOCIATED OPHTHALMOPATHY DAO. Part II Study design: Prospective randomized unmasked- pilot study. Methods: 50 patients were included in this study from April 98 to April 99 with the following inclusion criteria: DAO of 6 months maximum, diplopia as the main complaint and com­pletely free of treatment for ophthalmopathy regardless of the stage of dysthyroidism. Patients were randomized in 2 groups; Gl, who received para- bulbar injections of 20 mgrs of triam­cinolone on each orbit every week, totaling 4 applications ( per-orbit) and G2, a control group. Visual acuity ( VA), ocular tension ( OT), exophthalmos ( EX), body weight ( BW) and blood pressure ( BP) were checked on week 0, 10 and 24. Labo­ratory data: Glycemia, calcemia, plasmatic and urinary Cortisol ( PC and UC) were obtained at week 0 and 10 for each group. In Gl, urinary Cortisol was also measured on week 3. BW and BP were measured on weeks 1, 2, 3 and 4. Results: Thirty- seven patients completed this study ( Gl n = 20, G2 n = 17). After 6 months, VA and OT did not vary in either group. EX improved in Gl, being (- 2.91 mm +/- 7.36 SD) at week 10 and (- 1.76mm +/- 10.06 SD) at week 24, while no significant changes were observed in G2 ( 1.52 mm +/- 5.94 SD at week 10 and 0.63mm +/- 7.7 SD at week 24). Glycemia and calcemia as well as BW and BP remained within normal pa­rameters in both groups during the study- period. Both PC and UC checked slightly bellow normal limits in Gl, while remain­ing normal in G2. Conclusions: Local injections of triamcinolone demonstrated no change in VA and OT, while amelioration in the EX level / Neuro- Ophthalmol, Vol. 21, No. 2, 2001 NANOS ABSTRACTS 147 was observed compared with G2. Glycemia and calcemia were not altered as well as BP and BW. PC and UC were below normal range in Gl. Due to the benefit in EX level, the absence of ocular or major systemic ( unwanted) effects, we favor the use of this treatment in patients with DAO. POSTER PRESENTATIONS INFRARED PUPILLOGRAPHY AND VISUAL EVOKED RESPONSE IN UNILATERAL HYPEROPIC AMBLYO­PIA P- I. Chou, J- T. Chen; Taipei, Taiwan Background: Unilateral hyperopic amblyopia has distinct clinical manifestations including unilateral hyperopia with early onset amblyopia. Determination of whether this type of amblyopia subserves different neuronal defects requires fur­ther investigation. Objective: To evaluate the pupillary light reflex and vi­sual evoked response ( VER) in unilateral hyperopic amblyo­pia patients. Methods: Infrared pupillography ( IRP) and pattern VER were obtained for normal and fellow hyperopic amblyopic eyes in 21 young adults. Results: The IRP initial diameter was significantly larger in the amblyopic eyes than in the normal eyes ( p = 0.0479). Time to minimum diameter was delayed in the amblyopic eyes with statistical significance ( p = 0.0453). The plOO latency of pat­tern VER was significantly delayed in the amblyopic eyes ( p = 0.0011). Conclusion: Both IRP and pattern VER were sensitive in de­tecting unilateral hyperopic amblyopia. Physiologic distur­bance in the retinal level! , mainly in the fovea region, together with a deficit in the parvocellular layer of the lateral genicu­late body is responsible for the visual acuity deficit in hyper­opic amblyopia. BRUCKNER'S REFLEX AND THE FOVEAL PIT: A RE­LATIONSHIP BROUGHT TO LIGHT C. F. Parsa; Baltimore, Maryland Popularized by Bruckner in 1962, the reason for the asym­metry of red reflexes in the test that today bears his name has eluded explanation. In practice, an ophthalmoscope or other paraxial light source is used to make a qualitative comparison between simultaneous light reflexes from both fundi as the patient fixates on a light source at arm's length. The presence of even a slight deviation of an eye, or of an asymmetry in refractive power, manifests as a brighter reflex in the non-fixing or unfocused eye and alerts the clinician to the presence of a strabismic or an anisometropic condition. Various hypoth­eses have been put forth in the past to explain this effect, invoking phenomena such as decreasing macular pigment density away from the fovea, off- axis optical aberrations, im­perfect conjugacy of the retinal image of the light source with the observer eye, specular reflections from the retina, retinal backscattering of light, or a combination of the above. No conclusive evidence has been available to determine which, if any, of these hypotheses are correct. The use of a new optical model, however, demonstrates that it is in fact specular reflec­tion from the parafoveal area which is the predominant factor, with other previously proposed factors producing perhaps only minor contributions. Such knowledge is important in the design and utilization of mass screening devices now being contem­plated for the detection of predisposing factors for amblyopia in the pediatric population. TRANSIENT HORIZONTAL NYSTAGMUS IN IN­FANTS FROM DRUG- ADDICTED WOMEN: A WITH­DRAWAL SYNDROME? F- X. Borruat, M. Gaillard; Lausanne, Switzerland Background: Horizontal pendular nystagmus is usually a be­nign isolated congenital disorder manifesting during infancy. Both its frequency and amplitude tend to decrease with age, but pendular nystagmus will remain present. Objective: To report an unusual evolution of horizontal pen­dular nystagmus. Methods: Three case histories. Results: Three infants presented with the sudden onset of horizontal pendular nystagmus a few weeks after birth. All three infants were delivered from drug- addicted mothers who were actively abusing illegal substances during pregnancy. Apart from nystagmus, the three infants were healthy at the time of examination. Within a few months after the onset of oculomotility disturbance, the nystagmus disappeared in all three cases. Conclusion: We postulate that the appearance of transient hori­zontal pendular nystagmus in infants born from drug- addicted women might represent a withdrawal syndrome. BOTULINUM TOXIN THERAPY FOR APRAXIA OF LID OPENING D. Boghen, V. Tozlovanu, A. Iancu, R. Forget; Montreal, Quebec Background: Apraxia of lid opening ( ALO) designates an in­termittent inability to open the eyes voluntarily in the absence of apparent orbicularis oculi ( OOc) contraction. Previous stud­ies have suggested that clinically undetectable, but recordable activity of OOc plays an important role in ALO. Objective: To verify the hypothesis that Botulinum toxin ( BTX) injection in OOc will improve eye opening delays and clinical disability in ALO patients. Methods: Lid movement and EMG activity of OOc were si­multaneously recorded in twelve ALO patients ( 60 ± 11 years) before and after BTX treatment. Patients' disability was mea­sured before and after treatment by means of a " clinical dis­ability index." The BTX injections were given at four sites in the pretarsal portion of the OOc. The subjects were asked to open the eyes " as fast as possible" in response to a sound signal and to keep them open ( 20 trials). The time latencies to the onset of eye opening and to complete the eye opening and the time during which eye opening was sustained were determined and correlated with OOc activity. The results of pre- and post-treatment evaluations were then compared. Results: Following treatment: the time delay to complete eye opening ( 754 ± 207 ms) was significantly shorter than before treatment ( 1038 ± 385 ms); the latency to the onset of lid opening decreased from 441 ± 196 ms to 322 ± 85 ms; the time of sustained lid opening increased from 7543 ± 3194 ms to 10641 ± 3430 ms; the time delay to inhibit the OOc activity showed a strong tendency to decrease; the quantity of EMG during lid opening was significantly decreased; the clinical dis­ability index showed a marked improvement in 10 out of the 12 patients. Conclusion: In ALO patients, BTX treatment leads to an im­provement of lid movement metrics and clinical outcome. This is best explained by a diminished activity of the hyperac­tive OOc. Grant provided by: Fonds Derecherche Besner Valois, Univer­sity of Montreal. J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 148 NANOS ABSTRACTS THALIDOMIDE AS A STEROID- SPARING AGENT IN REFRACTORY NEUROSARCOIDOSIS J. C. Calkwood, S. Maguluri; New Orleans, Louisiana Background: Sarcoid is a multi- system granulomatous disease of unknown etiology that is mediated by macrophages, acti­vated T- cells and cytokines IL- 2, IL- 12, and TNF alpha. Neu-rosarcoid occurs in approximately 5- 10% of patients. Cortico­steroids are the primary treatment for neurosarcoidosis; how­ever, one- third of patients are refractory to corticosteroids alone and may require a steroid- sparing agent. Thalidomide inhibits macrophages, T- cells and suppresses IL- 2 and IL- 12 and TNF- alpha. Objective: We report our experience with the off- label use of thalidomide as a steroid- sparing agent in five cases of biopsy-proven refractory neurosarcoidosis. Methods: Refractory neurosarcoid patients were selected from a clinical neuro- ophthalmology practice over the course of two years. Treatment with thalidomide was begun at a dose of 50 mg q. h. s. and increased by 50 mg as- tolerated with an initial target dose of 200 mg and a secondary target dose of 400 mg per day. After baseline nerve conduction velocities ( NCV), patients were monitored for compliance with birth control, side effects, clinical examinations, blood counts, and hepatic func­tion. Neuroimaging and NCV were repeated at six months or with a change in clinical status. Results: Thalidomide was well- tolerated by three of the five patients treated. One patient ( Case # 1) developed fever and thalidomide treatment was discontinued. No therapeutic effect was observed. Case # 2 was titrated up to 400 mg per day of thalidomide with no visual improvement, but with complete resolution of pachymeningitis. Case # 3 developed a rash fol­lowing two weeks of thalidomide therapy and treatment was discontinued without therapeutic effect. In case # 4 thalidomide was discontinued secondary to paresthesias, but repeat neu­roimaging revealed a marked improvement of orbital mass and cervical cord lesion. Case # 5 tolerated the thalidomide well with minimal drowsiness. No therapeutic effect has been observed. Conclusion: Thalidomide has a potential use as a steroid-sparing agent in refractory neurosarcoidosis, but warrants fur­ther study. ISOLATED UNILATERAL POST- TRAUMATIC INTER-NUCLEAR OPHTHALMOLPLEGIA J. W. Chan; Las Vegas, Nevada Internuclear ophthalmoplegia ( INO) is an uncommon com­plication of closed head trauma. A review of the literature showed 13 documented cases. Of these only 4 were unilateral and 2 of them were associated with other neurological findings. I present an unusual case of isolated, unilateral INO after blunt head trauma. This 32- year- old man was assaulted by gangsters who hit and kicked the right side of his head. He had loss of conscious­ness for several hours. On examination he had a right mandibular fracture and right periorbital edema. His corrected visual acuity was 20/ 20 in both eyes. Pupillary responses and Humphrey automated visual field testing were normal. Ocular motility examination demonstrated orthophoria in primary position. His right eye was unable to adduct and his left eye had abduction nystagmus during leftward gaze. This nys­tagmus had a vertical and rotary component. He had no other associated neurological abnormalities. His MRI of the brain with contrast revealed a right medial longitudinal fasciculus ( MLF) lesion. CSF studies confirmed no infectious or inflam­matory processes, such as multiple sclerosis. After 4 months he had a mild adduction deficit in his right eye and mild diplopia on left gaze. Isolated unilateral INO is a rare complication of blunt head trauma. Possible mechanisms include an ischemic etiology in which the shearing forces within the brainstem compress the perforating arteries of the basilar artery to cause decreased blood flow to the MLF. Mechanical injury from stretching forces can also damage fibers of the MLF. Therefore, isolated INO should be considered in the differential diagnosis when an acute head trauma patient presents with an adduction deficit. QUANTIFYING MOTILITY DEFICITS BY ALTER­NATE COVER, RED MADDOX ROD, AND GOLD-MANN PERIMETER A. Coleman, E. Eggenberger; East Lansing, Michigan Background: Alternate Cover ( AC) and Red Maddox Rod ( RMR) tests have been used to measure deficits from cranial nerve palsies in prism diopters. The Goldmann perimeter has been used to measure duction limitations in degrees of motility. The correlation between duction limitations by perimeter and deficits measured in prism diopters has yet to be elucidated. Objective: To determine the correlation between prism mea­surement obtained by AC or RMR testing and degrees of duc­tion measured by the Goldmann perimeter. Methods: Retrospective chart review on patients with sixth nerve palsies seen at Michigan State University Neuro- Visual Unit between July 1998 and August 2000. Inclusion criteria included patients with isolated unilateral sixth nerve palsy with measurements performed by the Goldmann perimeter and by either the AC or RMR on the same visit. The data was recorded as degrees of abduction by Goldmann and prism diopters in both primary gaze and abduction. Results: A total of 25 patients yielded 35 measurement com­parisons. The Pearson correlation coefficient between esotropia in primary gaze and abduction were 0.94508. The correlation coefficient between degree of abduction and diopters of esotro­pia on abduction was - 0.59173. The correlation coefficient between degree of abduction and esotropia in primary gaze was - 0.55401. Conclusion: The consistent correlation between measurements of unilateral motility deficits by Goldmann perimeter compared to the AC or RMR examinations supports the use of all three methods in quantifying motility defects. INFRAORBITAL NERVE PALSY SECONDARY TO LASIK Charles Eifrig, T. McCulley, B. Lam, N. Schatz, S. Rosenfeld; Miami, Florida Objective: To describe a case of infraorbital nerve palsy asso­ciated with laser in situ keratomileusis ( LASIK). Method: Case report. Results: A healthy 46- year- old woman underwent bilateral LASIK on 11/ 18/ 99 for mild myopia (- 2.00 OD, - 2.25 OS). LASIK was performed on the right eye first without compli­cation. During the procedure of the left eye, mild difficulty with seeding of the suction cup was encountered due to a small palpebral fissure. During this maneuver, the patient experi­enced extreme knife- like left facial pain which was followed post- operatively by persistent numbness and tingling over a similar area. On postoperative day 5, she noticed twitching in the left corner of the mouth and the left upper eyelid, which subsequently resolved. Examination showed decreased sensa­tion over the left cheek in the distribution of the infraorbital / Neuro- Ophthalmol, Vol. 21, No. 2, 2001 NANOS ABSTRACTS 149 nerve. The ophthalmic and neurologic exam was otherwise unremarkable. Brain MRI revealed rare small white matter le­sions consistent with arteriosclerosis. CT of the orbits was un­remarkable with an intact orbital floor. The patient was treated with gabapentin and nortriptyline followed by self- prescribed acupuncture therapy. One year postoperatively, symptoms have improved but numbness, tingling, and pain involving her left cheek has continued. Conclusions: LASIK may rarely produce infraorbital nerve dysfunction, which to our knowledge has not been reported. Our case suggests that compression by the suction cup is the contributing factor. OPTIC TRACT COMPRESSION FROM DOLICHOEC-TATIC BASILAR ARTERY M. F. Guirgis, B. L. Lam, S. F. Falcone; Miami, Florida Purpose: To report a case of optic tract compression due to a dolichoectatic basilar artery. Method: Case report. Results: A 74- year- old man with progressive loss of vision over 13 years and no other neurologic signs or symptoms was found to have bilateral optic nerve head pallor and a left hom­onymous hemianopia. Magnetic resonance imaging and angi­ography revealed a severe dolichoectatic basilar artery com­pressing the right optic tract. Conclusion: Basilar artery dolichoectasia may rarely cause compression of the optic tract and progressive visual loss. ACQUIRED ARNOLD- CHIARI- LIKE MALFORMA­TIONS AFTER LP SHUNTING IN PSEUDOTUMOR CEREBRI S. C. Benes; Columbus, Ohio Retrospective chart review of 300 patients with pseudotumor cerebri followed over 1 to 20 years found 245 female, 55 ( 18%) male. For those in whom baseline preoperative head scans were MRIs, only 3 had Arnold- Chiari Type I malformations ( pro­lapse of the cerebellar tonsils below the level of the Foramen Magnum on sagittal section) at the time of diagnosis. These 3 have not undergone lumboperitoneal ( LP) shunting in their care and have been medically managed ( 2) or undergone optic nerve sheath decompression surgery for medical failure to prevent progressive visual loss ( 1). However, 4 patients ( all female) who had normal Foramen Magnum anatomy preoperatively developed Arnold- Chiari- like malformations after LP shunting. These occurred between 4 months and 10 years into their dis­ease. A true incidence at 10 years cannot be ascertained be­cause patients with no ongoing or changing symptoms do not have serial MRIs and many patients have been followed for fewer than 10 years after LP shunting. Symptoms in these 4 patients prompted MRI re- evaluation and discovery of their new cerebellar tonsillar prolapse ( all 4) and cervical syrinx to C7 ( 1). All four had ongoing and escalating headache and transient visual obscurations but no new visual loss. Two had neck and backaches, one with cervical radiculopathy ( syrinx). One developed sixth nerve paresis and diplopia. All 4 com­plained of dizziness, concern about safe footing and depth per­ception, inability to exercise or tolerate steps and pounding, and slower thinking and impaired concentration. One suffered syn­cope, a fall down a flight of steps, and subdural hematoma necessitating urgent management. Management in these 4 pa­tients was removal of the LP shunt followed by ventriculoperi-toneal ( VP) shunting and optic nerve sheath decompression in the syrinx patient, additional VP shunt in 1, and suboccipital decompression in 2. All 4 improved after these procedures. ORBITAL FRACTURES COMPLICATED BY LATE ORBITAL HEMORRHAGE AND VISION LOSS C. S. Otto, R. B. Carroll, R. A. Mazzoli, M. B. Grazko, D. J. Ainbinder, W. R. Raymond, E. A. Hansen; Tacoma, Washington Background: Although the nature of orbital fractures usually provides an avenue for ready orbital decompression, seques­tered and clotted blood within the adjacent sinus or subperi­osteal space can limit this decompression, leading to late orbital and visual compromise. Purpose: To present two cases of delayed retrobulbar hemor­rhage and vision loss in the setting of facial trauma. Patients/ Methods: Two patients, both of whom suffered or­bital floor fractures, presented with normal visual acuity that deteriorated within hours of initial exam due to retrobulbar hemorrhage. Although the orbital fractures should have permit­ted free drainage of orbital blood, CT showed sequestered blood within the maxillary sinus of one patient and in the inferior subperiosteal space of the other, thus compromising orbital drainage. Both patients underwent canthotomy and can-tholysis, with return of baseline vision. Results/ Conclusion: Orbital hemorrhage with visual compro­mise is a well known sequela of both orbital trauma and the subsequent reconstructive surgery. Visual loss in this situation is usually occurs in the acute setting. Late visual loss is un­usual. Although the nature of orbital fractures usually provides an avenue for ready orbital decompression, sequestered and clotted blood within the adjacent sinus or subperiosteal space can limit this decompression. Visually threatening hemorrhage can then occur, especially in the face of recurrent or persistent hemorrhage. This may occur even hours after an initial normal exam. Clinicians must be vigilant of late visual deterioration, as prompt intervention can be sight sparing. LATE COMPLICATIONS OF RETAINED INTRA­ORBITAL FOREIGN BODIES AND INDICATIONS FOR SURGICAL MANAGEMENT C. S. Otto, R. A. Mazzoli, M. A. Grazko, G. Gilliland, J. B. Holds, J. V. Linberg, D. M. Reifler, W. R. Raymond III, D. J. Ainbinder, E. A. Hansen, MD; Tacoma, Washington Background: The devastating effect of ocular trauma from intra- ocular and intra- orbital projectiles has been well docu­mented in the medical literature. While common knowledge suggests that retained intra- orbital metallic foreign bodies that are not causing any sequelae should be left in place, there are currently no clear guidelines of when removal of a symptom­atic retained intra- orbital should be undertaken. We present five cases with late complications of retained intra- orbital foreign bodies, where surgical management was employed to preserve vision and provide symptomatic relief. Objective: To present five cases with late complications from retained intra- orbital foreign bodies and discuss their surgi­cal management. Methods: Case series and discussion of findings. Results: Of the five cases in this series, four presented with a retained BB at the orbital apex; one with progressive visual loss and gaze- evoked amaurosis, one with vision that progressed to CF within 24 hours of presentation, one with a late complica­tion of severe pain with abduction, and the fourth with vision of NLP at presentation that failed to improve on steroids. All showed resolution of symptoms following surgical removal of the offending foreign body, except for the fourth case, which did not show any improvement in vision after removal. The fifth case involved incursion of an anteriorly retained BB into the lacrimal sac, with resulting dacryocystitis that also resolved with surgical removal. J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 150 NANOS ABSTRACTS Conclusion: While non- symptomatic retained intra- orbital for­eign bodies can often be left in place in order to avoid the risks of surgical removal, foreign bodies that begin to cause visual deterioration or create significant pain and disruption of sur­rounding structures should be considered for surgical manage­ment. The best surgical result seems to be obtained when func­tional vision existed prior to late complications. Surgical re­moval did not provide any improvement in the patient with visual acuity of NLP at presentation. OPTIC NEUROPATHY IN CHILDREN WITH LYME DISEASE T. R. Hedges III, A. Steere; Boston, Massachusetts Four children with Lyme disease developed different types of optic neuropathy after contracting Lyme disease. One had bilateral papillitis with visual loss due to subretinal fluid accu­mulation ( demonstrated by optical coherence tomography). A second child had unilateral optic neuritis six months after the initial illness. A third had papilledema associated with Lyme meningitis and a fourth child went blind from atrophic papil­ledema possibly combined with optic neuritis. Children with optic neuritis or papilledema may have Lyme disease and those with Lyme disease should be evaluated for optic neuropathy if they have visual complaints. Visual loss from " papillitis" may be due to submacular edema as well as inflammation within the optic nerve. VISUAL FIELD TECHNICIAN PERFORMANCE IN THE OCULAR HYPERTENSIVE TREATMENT STUDY ( OHTS) J. L. Keltner, C. A. Johnson, K. E. Cello, M. A. Kass, M. O. Gordon, S. E. Bandermann, M. A. Edwards, The OHTS Group; Sacramento, California Purpose: The goal of the OHTS is to determine if topical ocular hypotensive medications prevent or delay the onset of glaucoma in ocular hypertensive patients. We examined the trends of visual field technician performance in quality control and reliability of visual fields. Methods: Follow- up visual fields are performed every six months and are monitored for quality control and reliability. As of September 2000, 38,517 eligibility and follow- up visual fields have been performed on 1,636 patients in the OHTS. The Visual Field Reading Center examined quality control scores and reliability parameters of all the visual fields. The OHTS quality control system addresses three areas of technician qual­ity control performance: ( 1) test parameter errors, ( 2) patient data errors, and ( 3) shipment errors. An average number of fields and error points were generated for both technician and year. We identified trends and performance in correla­tion between reliability and quality of performance with such factors as: ( 1) technician testing volume, ( 2) experience with protocol, ( 3) progression of abnormal fields, and ( 4) changes in equipment. Results: We observed an increase in total error rate during transition of new technicians and equipment; however, the vast majority of quality control scores for each technician improved over time ( experience). Of 38,486 visual fields ( 31 visual fields had unknown reliability due to a non 30- 2 test parameter being used), a total of only 2% ( 753) of the visual fields were un­reliable. There was an increase in the percentage of unreli­able fields vs total number of fields performed ( 1.1% to 2.6%) per year. Conclusions: We believe technicians who are trained and cer­tified in a standard fashion produce the most reliable data and show an improvement in quality control scores over time. The increase in percentage of unreliable visual fields per year could possibly be due to a high volume of testing, changes in equip­ment, or progression of abnormal fields. CORRELATION BETWEEN OPTICAL COHERENCE TOMOGRAPHY ( OCT) AND AUTOMATED VISUAL FIELD ( HVF) IN PATIENTS WITH NON-GLAUCOMATOUS OPTIC NEUROPATHY R. H. Kardon, S. C. Anderson, M. M. Pereira; Iowa City, Iowa Background: New approaches are needed for correlating structure and function of the optic nerve in order to help de­termine the etiology, extent, and potential for recovery of op­tic neuropathy. Objective: To understand the relationship between retinal nerve fiber layer thickness and visual sensitivity in different forms of non- glaucomatous optic neuropathy. Methods: Automated visual fields ( Humphrey 24- 2) and OCT were performed on both eyes of 16 patients with different types of optic nerve damage ( raised intracranial pressure = 3, isch­emic = 4, compressive = 5, optic neuritis = 1, drusen= l, toxic = 2). Seven of these patients were also re- tested over time. The asymmetry in visual threshold and nerve fiber layer thick­ness between the two eyes at six regions of the visual field and the corresponding nerve fiber layer asymmetry in the same sectors were displayed on a scatter- plot. Results: Patients that had reversible optic neuropathy clustered into a group of points on the scatter- plot that showed significant asymmetry of visual field sensitivity but little asymmetry of nerve fiber layer thickness. Patients with recovered visual func­tion but optic atrophy clustered into a group of points which showed asymmetry of nerve fiber layer thickness but little asymmetry in visual field sensitivity. Patients with chronic op­tic neuropathy with visual loss and optic atrophy showed a proportional asymmetry in visual threshold and nerve fiber layer thickness. Conclusions: Comparisons between the structure and function of the nerve fiber layer in non- glaucomatous optic neuropathy may provide a new means of classifying damage to the visual pathway as to etiology, extent, and reversibility. Asymmetry analysis may help to overcome inter- individual variability ob­served in the visual field and nerve fiber layer measurement. Veterans Administration Merit Review Grant. THE TRANSFORMATION OF PSEUDOTUMOR CERE­BRI TO PSEUDOTUMOR SYNDROME: SAGITTAL SI­NUS MENINGIOMA NINE YEARS LATER R. N. Santos, J. D. Wirtschafter, A. R. Harrison; Minneapolis, Minnesota Background: Most pseudotumor cerebri ( PTC) patients have a protracted course during which other disease entities may develop and their symptoms may actually masquerade as merely a continuation of the patients' already existent PTC. Objective: To report a case of PTC which later developed into a PTC secondary to a sagittal sinus meningioma. Methods: Case report. Results: In 1991, a mildly obese 25- year- old woman presented with a three- month history of headaches and bilateral decreased vision. Her CT scan was normal while a lumbar puncture re­vealed an increased opening pressure of 240 mm CSF. The patient was managed medically without satisfactory relief of symptoms. Within three weeks of initial neuro- ophthalmology consultation, the patient's visual acuities rapidly declined along with significant deterioration of Goldmann visual fields. Bilat- / Neuro- Ophthalmol, Vol. 21, No. 2, 2001 NANOS ABSTRACTS 151 eral optic nerve sheath fenestration was performed. The patient responded well to the procedure. During the next eight years, the patient had intermittent headaches as well as fluctuating vision especially in the right eye. The patient had normal head MRIs in 1995 and 1997 as well as a normal MRV in 1997. The patient would eventually undergo two more repeat optic nerve fenestrations in the right eye ( 1992 and 1995), placement of a ventriculoperitoneal shunt ( 1997), and a revision of the VP shunt which malfunctioned ( July 2000). Prior to the VP shunt revision, a repeat head MRI showed a tumor thought to be a meningioma adjacent to and infiltrating the sagittal sinus from the left posterior parietal region. The tumor could not be iden­tified on the prior studies. The meningioma was partially ob­structing venous flow and may well have contributed to the patient's " PTC." Conclusion: This case illustrates the need to closely follow PTC patients not only clinically but also with repeated timely appropriate neuro- imaging techniques ( MRI and/ or MRV) at the point where there is even the slightest suspicion of other causes of increased intracranial pressures. THE INTRACRANIAL TUBERCULOMA THAT WAS THOUGHT TO BE NEUROSARCOIDOSIS R. N. Santos, E. Eggenberger, D. Kaufman; Minneapolis, Minnesota Background: Intracranial tuberculomas and neurosarcoidosis, although both granulomatous disorders, are distinct clinical en­tities that are managed quite differently. As much as they are different from each other, it may be difficult to differentiate their neurologic manifestations from one another or even from other intrinsic masses of the brain. Intracranial tuberculomas are rare in developed countries thus making their underdiagno-sis likely. Objective: To describe some of the dilemmas in the diag­nosis and management of a case of an intracranial tuber­culoma that was initially thought to be a biopsy- proven case of neurosarcoidosis. Methods: Case report. Results: A 27- year- old Somalian woman with an unremarkable past medical history had a generalized tonic- clonic seizure one day after giving birth to a healthy baby girl. Neuro- ophthal-mologic exam was essentially unremarkable with the exception of Goldmann visual fields which demonstrated a right superior greater than inferior homonymous defect. CT scan of the brain showed a 3 cm left parieto- occipital mass with edema. MRI of the brain showed a solid- appearing, irregular enhancing left mesio parieto- occipital mass with some corpus callosal mass effect. Stereotactic brain biopsy revealed non- necrotizing granulomas consistent with neurosarcoidosis. AFB culture of the tissue sample was negative. The patient was treated with Prednisone and was eventually lost to follow- up. Two months later, the patient had another seizure and she was re- hospitalized with Frisin grade 5 disc edema OU ( OD> OS). Repeat MRI of the brain revealed a new 1 cm left occipital extension of the previously noted mass within the calvarium. A brain biopsy via a craniotomy done showed caseating granu­lomatous inflammation, consistent with a tuberculoma. There were few suspected non- viable mycobacteria organisms iden­tified by special stain. There was no evidence of malignancy. The patient was then treated accordingly with isoniazid, py-razinamide, rifampicin, ethambutol, pyridoxine, prednisone, and phenytoin. Conclusion: As much as a brain biopsy would most of the time, validate the diagnosis of an intracranial tuberculoma, it would not be unwise to try a 6- 8 week therapeutic trial with anti- TB drugs with regular monitoring of the patients with CT or MRI scans where facilities are limited and when a brain biopsy may be contraindicated. Surgical excision is usually reserved for cases that result in increased intracranial pressure secondary to the lesion that is not responsive to medical therapy. Occasionally, new intracranial tuberculomas or expan­sion of the existing lesions may occur despite anti- TB therapy. In such cases an adjuvant therapy of steroids ( e. g. dexameth-asone, prednisone) for 4- 8 weeks may be effective. BILATERAL OPTIC NEUROPATHY SECONDARY TO MANGANESE TOXICITY J. R. Lewis; Edmonton, Alberta Background: Manganese is a common heavy metal, occupa­tional exposure to which may occur via skin absorption or inhalation of fumes in the pottery and electroplating industries. A syndrome of chronic manganism has been described in the occupational medicine literature, with neurological symptoms including Parkinson- like tremor, fatigue, tinnitus, memory loss and vague visual disturbances. No documentation of visual loss could be found in the ophthalmological literature. Objective: To describe a case of severe central visual loss in a man with manganese toxicity. Methods: Observational case report and literature search. Results: A 50- year- old male machinist working in an electro­plating laboratory developed blurred vision and polyopia first in his right eye, and a few weeks later in his left eye. The blurred vision persisted, and he subsequently developed head­aches, memory loss, leg pain, fatigue, weight loss and a con­stant resting tremor of his right hand. These features were felt to be clinically consistent with manganese toxicity, and serum manganese was elevated. Visual acuity was 20/ 300 in each eye, despite a structurally normal neuro- ophthalmological ex­amination. Goldmann visual fields demonstrated bilateral ce-cocentral scotomata. CT scan and MRI of brain and orbits were normal. ESR was normal, and temporal artery biopsy was negative. Electroretinogram was normal. Visual evoked re­sponse on two occasions demonstrated significantly prolonged latency bilaterally. Conclusion: Manganese has not previously been reported to be significantly toxic to the visual pathways. A case is pre­sented that demonstrates severe bilateral central visual loss in a machinist with neurological manifestations consistent with manganese poisoning and no other apparent cause for the visual loss. PHOTOSENSITIVITY AS THE PRESENTING SYMP­TOM OF CHIASMAL COMPRESSION A. Kawasaki, V. Purvin; Indianapolis, Indiana Background: Compressive optic neuropathies typically pro­duce dimming and loss of vision. We describe five patients with a chief visual complaint of photosensitivity and/ or glare and who were subsequently found to have a compressive lesion of the optic chiasm. Objective: To describe an unusual symptom of chiasmal com­pression. Methods: Five case histories. Results: Five patients between ages 19 and 43 years were identified. The primary symptom in each patient was an in­creased sensitivity to light, described as things " looking too bright" or " glarey". The duration of the photosensitivity from J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 152 NANOS ABSTRACTS onset to diagnosis ranged from 1 week to 1 year. The only other visual symptom was mild blur of one eye in one patient. An additional patient developed blur in one eye 9 months after onset of photosensitivity. Four patients had associated head­ache. Examination showed no loss of visual acuity in 7 of 10 eyes, one line drop in one eye, two lines in one eye and three lines in one eye. Visual field testing was normal in one patient. In two patients, there was a bitemporal visual field defect ( mild in one and marked in the other but not respecting the vertical meridian) and in one patient, there was mild central defects. The fifth patient had extensive pre- existing field losses from chorioretinal scarring. MRI scanning revealed a suprasellar mass in all patients ( pituitary adenoma in three patients, chordoma in one patient and craniopharyngioma in one patient). Conclusion: Although photosensitivity is usually considered to have an ocular origin, we have encountered five patients in whom this symptom was the presenting manifestation of an intracranial lesion, specifically a suprasellar mass. THREE DIMENSIONAL ANALYSIS OF SACCADE AB­NORMALITIES IN UNILATERAL SIXTH NERVE PALSY A. M. F. Wong, D. Tweed, J. A. Sharpe; Toronto, Ontario Background: The effects of unilateral sixth nerve palsy on dynamic properties of saccades have not been systemati­cally investigated. Objective: To analyze saccade performance in patients with unilateral sixth nerve palsy. Methods: Twenty- seven patients with unilateral sixth nerve palsy ( 7 severe, 11 moderate, 9 mild) and 10 normal subjects were studied. Eye movement recordings were performed using magnetic scleral search coils in each eye during monocular viewing. Saccades amplitude and peak velocity were calculated for horizontal, vertical and torsional ( quick phases) saccades. Results: In patients with severe palsy, during paretic eye view­ing, the paretic eye made a series of hypometric horizontal saccades in the direction of the paretic gaze until the final eye position reached was close to the target. At the same time, the normal occluded eye made a series of saccades of decreasing amplitude, and reached a final eye position that overshot the target ( secondary deviation). During normal eye viewing, the paretic eye made a hypometric saccade in the direction of the paretic gaze with the final eye position undershooting the tar­get, while the normal eye made a normometric saccade and reached a final eye position that matched the target position ( primary deviation). The peak velocity of horizontal saccades were subnormal in both eyes in both directions under both viewing conditions ( p < 0.001). In contrast, in moderate and mild palsy, horizontal saccade amplitude was normal, but peak velocity was subnormal in both eyes in both directions under both viewing conditions ( p < 0.001). Vertical saccades and torsional quick phases were normal in all three groups of patients. Conclusions: In severe palsy, during paretic eye viewing, the normal eye made a series of saccades in the direction of the paretic gaze, the amplitude of which correlated with the differ­ence in target position and actual position of the paretic eye. This suggests that Hering's law is obeyed, with retinal error signal from the paretic eye driving both eyes. Saccade velocity was decreased in both abduction and adduction in the paretic eye, suggesting that elasticity and/ or viscosity of the plant were altered. Adaptation to changes in the paretic eye may explain the decreased saccade velocity in the normal eye. Grant: E. A. Baker Foundation ( Canadian National Institute). EPIDEMIOLOGY OF INTRACRANIAL HYPERTEN­SION IN ISRAEL A. Kesler, N. Gadoth; Kfar Saba, Israel Objectives: To determine the incidence, demographic, and clinical features of Pseudo Tumor Cerebri ( PTC) / Idiopathic Intracranial Hypertension ( IIH), in Israel. Methods: The chairmen of all neurology and ophthalmology departments in Israel were asked to complete questionnaires regarding patients with PTC/ IIH diagnosed during the years 1998- 1999. Each questionnaire contained details regarding pa­tient's age, sex, country of birth, age at diagnosis, weight, height, presence of obesity, and the results of lumbar puncture, brain CT, MRI, and / or MRV. Results: Ninety- one patients with PTC/ IIH were diagnosed during the years 1998- 1999. Eighty- five ( 93.4%) were females and 6 ( 6.6%) were males. The calculated incidence of PTC/ IIH in the Israeli general population was 0.57- 0.94 per 100000, with incidence of 1.82 per 100000 for women and 0.034 per 100000 for men . The incidence for women during the childbirth years was 4.02 per 100000. The female to male ratio was higher than previously reported for Western countries. Conclusions: Although the population of Israel is a mixture of people originating from Eastern and Western countries, the incidence of PTC/ IIH was found to be similar to that of West­ern countries. This is an additional support to the notion that PTC/ IIH is more common in obese populations. MITOCHONDRIAL ATP- SENSITIVE K CHANNELS, NOVEL SITES OF NEUROPROTECTION AGAINST GLUTAMATE NEUROTOXICITY IN RETINAL NEURONS S. Kashii; Kyoto, Japan Background: The background of this study originates from our findings about dual actions of nitric oxide ( NO) on NMDA-induced neurotoxicity in the retina. Immediately after NO is formed by stimulation of NMDA receptors of amacrine cells, it diffuses freely from its site of origin, passing through mem­branes and affects all adjacent neurons. NO alone has no toxic effects on retinal neurons, but it becomes toxic in the presence of superoxide anion. It is, thus, oxygen radicals generated in response to overstimulation of NMDA receptors that determine which neuron to die ( Brain Res 1996; 711: 93- 101). Our recent study on bradykinin- induced protection against retinal glutamate neurotoxicity suggested that inhibition of mitochon­drial membrane depolarization following the overstimulation of NMDA receptors results in reduced oxygen radical formation and protects retinal neurons against NMDA receptor- mediated neurotoxicity ( IOVS 2000; 41: 2273- 8). Objective: To clarify the effect of opening the ATP- sensitive potassium channel of mitochondria ( mtK/ ATP channel) on glutamate neurotoxicity, we examined the effect of diazoxide, a specific opener of the mtK/ ATP channel, and 5- HD, an mtK/ ATP channel blocker, on delayed retinal neuronal death after glutamate exposure and mitochondrial membrane poten­tials of the retinal neurons following glutamate applications. Methods: Primary cultures were obtained from fetal rat retinas ( 17- 19 day gestation). Ten ( xM cytosine arabinoside was added to the culture on the 6th day to eliminate non- neuronal cells. We used only cultures maintained for 9- 10 days in vitro. The neurotoxic effects of glutamate and the protective effects of drugs on the retinal cultures were quantitatively assessed by the trypan blue exclusion method. Mitochondrial membrane poten­tials were measured by using the ratio of the 590 nm/ 527 nm fluorescence of JC- 1, a radiometric dye. / Neuro- Ophthalmol, Vol. 21, No. 2, 2001 NANOS ABSTRACTS 153 Results: Cell viability was markedly reduced by 10 min expo­sure to 1 mM glutamate followed by 1 hr incubation in glutamate- free medium. Simultaneous application of diazoxide at concentrations of 0.1- 10 ( xM with glutamate exhibited dose-dependent protection against glutamate neurotoxicity. The pro­tective action of diazoxide ( 10 ( xM) was inhibited by simulta­neous application of 5- HD ( 10 ( xM). One min after exposure to ImM glutamate, most of the retinal neurons showed mitochon­drial membrane depolarization, which was inhibited by simul­taneous application of diazoxide ( 10 ( xM). Conclusions: These results suggest that opening of mtK/ ATP channel protects retinal neurons against glutamate neurotoxic­ity by inhibiting the glutamate- induced mitochondrial mem­brane depolarization that leads to neuronal death. Grant in aid for Scientific Research from the Ministry of Edu­cation, Science and Culture, Japan. HYDROCEPHALUS SECONDARY TO ISOLATED SPI­NAL CYSTICERCOSIS M. B. Strominger, D. L. Carter- Meehan, R. N. Hargrove; Brooklyn, New York Background: Hydrocephalus is a common complication of Neurocysticercosis and is usually due to obstruction by cister­nal or ventricular cysts, or subarachnoid spaces by diffuse bas­ilar meningitis. Spinal cysticercosis is an uncommon manifes­tation seen in 0.7 to 6% of cases. It is thought to be due to downward migration of larvae from the cerebral to the spinal subarachnoid spaces with possible ventriculoependymal infil­tration or hematogenous dissemination. We report the unusual case of isolated spinal involvement leading to hydrocephalus. Case Report: A 35- year- old Mexican gentleman presented with chronic headaches for six months. Visual acuity was 20/ 20 OU with normal color vision. Dilated fundus examination showed both optic nerves to be swollen without significant hemorrhage or exudates. MRI revealed enlargement of the lat­eral and third ventricles consistent with hydrocephalus. No in­traventricular or intraparenchymal lesions were seen. CSF re­vealed 87 WBC ' s ( 86% lymphocytes, 6% monocytes, and 6% eosinophils). Protein was 100 mg/ dl and glucose 37 mg/ dl. MRI of the spine revealed an intraspinal increased intensity focus at thoracic level T10/ T11. Neurosurgical biopsy of the intraspinal mass revealed multiple intradural and epidural cys­tic masses consistent with cysticercosis. The patient was started on Albendazole 400mg bid and Decadron lOmg q6h with reso­lution of his headaches and papilledema. Conclusion: Neurocysticercosis usually presents with hydro­cephalus associated with cysts within the ventricular system or brain parenchyma. Our case is unusual in that the Cysticercus cysts were isolated to the spinal column. Grant: SUNY Downstate Medical Center. EXTREMELY HIGH RESOLUTION MRI OF THE HU­MAN OPTIC NERVE REVEALS LHON ASSOCIATED PATHOLOGY A. A. Sadun, V. Carelli, S. Bose, E. T. Ahrens; Los Angeles, California Magnetic Resonance Imaging ( MRI) is a potent tool in both the clinical and research realms as it is non- invasive and allows views into optically opaque specimens. Extremely high-resolution MRI ( MR microscopy- MRN) is an emergent tech­nique which provides three- dimensional views in intact living animals or excised tissue. The high- resolution in combination with the availability to view the tissue in any plane allows this method to complement established morphological approaches. We examined the optic nerves from two normal controls ( 69- year- old man and 70- year- old woman) and one 73 year old woman with Leber's Hereditary Optic Neuropathy ( LHON- 3460). In each case an 8 mm diameter ring of peripapillary retina choroid and sclera together with about 6- 8 mm of optic nerve were dissected free and drop fixed in mixed aldehydes. The specimens were then rinsed and emersed in perfluoropoly-ether and sealed into a 10 mm diameter quartz tube. Imaging was performed on a 15 Tesla Bruker MRI with an Acustar shielded grading coil. Data was acquired from a conventional three- dimensional Fourier transform spin- echo imaging proto­col that yielded a final isotrophic resolution of 30 ( x. Sagittal axial and coronal sections through all three optic nerves pro­vided far more detail and histoarchitecture than ever before demonstrated on MRI. The ophthalmic artery and vein could be seen as well as the individual plates of the lamina cribosa. The Circle of Zinn- Haller could be seen in various planes. Even the retinal layers were discernible. The MRN of the LHON case demonstrated marked atrophy, wide fibrous septa and deep folds of the arachnoid and dura. These dramatic results demonstrate the feasibility of obtain­ing extremely high resolution ( 30 ( x) 3- D images of the human optic nerve by this novel technology. Several specific features, such as the collapse of the lamina cribosa in the LHON case would be very difficult to demonstrate with standard histologi­cal preparations but most easily appreciated by rotation of the MRN imaged plane. We expect this new methodology to be useful by providing three- dimensional and microscopic char­acterization of optic neuropathies. OPHTHALMOPLEGIA AND FAMILIAL FACIAL PALSY A. G. Lee, P. W. Brazis, E. Eggenberger; Iowa City, Iowa Objective: To alert clinicians to unusual neuro- ophthalmic pre­sentations of patients with recurrent or familial facial palsy. Design: Retrospective case series. Setting: Tertiary care referral ophthalmology centers. Participants: Three patients with familial facial palsy and ophthalmoplegia. Results: Presentation of cases and review of literature. Conclusion: Clinicians should be aware that ophthalmoplegia and familial cases can occur in facial palsy. ORBITAL APEX COMPLICATIONS OF NEUROSUR­GERY A. G. Lee, R. Tang, J. Schiffman; Iowa City, Iowa Purpose: To report orbital complications of Neurosurgery. Method: Retrospective case series. Setting: Tertiary care neuro- ophthalmology referral center. Results: Case one: right orbital apex syndrome with loss of vision and a third nerve palsy in the right eye after attempted transsphenoidal surgery. Case two: Orbital apex syndrome due to presumed orbital compression during face down lumbar spine surgery. Conclusions: Although rare, clinicians should be aware of the potential for orbital apex syndrome during neurosurgi­cal procedures. J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 154 NANOS ABSTRACTS ORBITAL PRESENTATIONS OF GIANT CELL AR­TERITIS A. G. Lee, R. A. Tang, S. E. Feldon, M. Pless, J. S. Schiffman, R. M. Rubin, N. Rao; Iowa City, Iowa Background: To alert clinicians to the orbital presentations of giant cell arteritis. Design: Retrospective case series. Setting: Tertiary care referral ophthalmology centers. Participants: Four patients with orbital manifestations of giant cell arteritis. Results: Presentation of cases and review of literature. Conclusion: Clinicians should be aware that giant cell arteritis may have orbital manifestations. IMPROVEMENT IN PAPILLEDEMA AND VISUAL LOSS AFTER ENDOVASCULAR STENT PLACEMENT IN DURAL SINUS THROMBOSIS M. G. Hunt, A. Lee, R. Kardon, J. Chaloupka; Iowa City, Iowa Objective: To report two cases of cerebral venous sinus throm­bosis with papilledema and visual loss that improved after en-dovascular stent placement. Materials and Methods: Retrospective case series from a ter­tiary ophthalmic center. Results: Two cases of venous sinus occlusion treated with angioplasty and stenting are described. Both cases experienced improvement in optic disc edema and visual function following the procedures. Conclusion: Endovascular stent placement may relieve in­creased intracranial pressure and papilledema caused by cere­bral sinus thrombosis and may prevent further visual loss. ANTERIOR ISCHEMIC OPTIC NEUROPATHY ASSO­CIATION WITH CATARACT EXTRACTION: TIME OF OCCURRENCE AND RISK FACTORS T. J. McCulley, B. L. Lam, W. J. Feuer; Kettering, Ohio Background: The existence and nature of a causal relationship between cataract extraction ( CE) and non- arteritic anterior ischemic optic neuropathy ( NAION) have been debated. Objective: To evaluate the association between CE and NAION by 1) analysis of time of NAION occurrence after CE and 2) comparison of prevalence of risk factors between pa­tients with CE- associated NAION and patients with spontane­ous NAION. Methods: First, the records of all patients diagnosed with NAION and cataract at Bascom Palmer Eye Institute from 1993 to 2000 were reviewed for occurrence of NAION within one year after CE by phacoemulsification or phacofracture. Next, using the Fisher's exact test, the prevalence of NAION risk factors were compared between patients with NAION after CE and patients with spontaneous NAION during the same study period. Results: All 17 cases of NAION occurring within 1 year after CE occurred within 6 months after CE with none occurring during the second 6- month period ( p < 0.001, binomial distri­bution). When these 17 CE- associated NAION cases were compared with the 37 spontaneous NAION cases found during the study period, the prevalence of diabetes mellitus, hypercho­lesterolemia, and tobacco use were similar, but the following risk factors were notably lower in the CE- associated NAION group: HTN ( 29% vs. 68%, p = 0.017), the proportion of pa­tients with a C: D < 0.2 in the involved eye, ( 60% vs. 94%, p = 0.007) and, the proportion of patients with a C: D < 0.2 in the contralateral eye, ( 63% vs. 89%, p = 0.052). Conclusion: The time distribution of NAION after CE strongly suggests a causal relationship between CE and occurrence of NAION. Patients with NAION following CE have a lower prevalence of hypertension and tend to have larger cup- to- disc ratio than those with spontaneous NAION. VISUAL FIELD SCREENING: PROSPECTIVE, MASKED TRIAL WITH A COMMERCIAL LASER POINTER M. S. Lee, N. J. Volpe, S. L. Galetta, G. T. Liu, M. G. Maguire, L. J. Balcer; Philadelphia, Pennsylvania Background: Visual field screening identifies patients requir­ing further diagnostic testing and formal visual fields. Conven­tional confrontation techniques are quick and simple to per­form, but may miss subtle defects. Objective: To compare the sensitivity of another technique, laser pointer visual fields ( LVF), with confrontation visual fields ( CVF) for identifying eyes with abnormal Humphrey visual fields ( HVF). Methods: Patients presenting for HVF prospectively under­went CVF and LVF testing in an outpatient exam room setting. The examiner was masked to diagnoses or known field defects. LVF was performed using a commercial laser pointer projected onto a tangent screen. Points were tested along the horizontal and vertical meridians, around the blindspot, and in each quad­rant. CVF subjectively assessed central field and then single and double simultaneous finger counting in all quadrants. LVF and CVF were considered abnormal for any defect. HVF was regarded as abnormal if the mean deviation ( MD) <- 3.00. Sensitivity and specificity were calculated to account for inter-eye correlation. Results: 90 patients underwent testing ( 175 eyes). 25 eyes were excluded for unreliable HVF parameters. There were 80 normal and 70 abnormal HVF. The LVF and CVF had an overall sensitivity of 71% and 26% and a specificity of 89% and 99% respectively ( p < 0.0001). The average testing time per eye was 0.5 min for CVF, 1.5 min for LVF and 8.0 min for HVF. A subset analysis of more severe HVF defects ( MD < - 6.00) increased sensitivity to 90% and 40% for LVF and CVF respectively. Conclusions: LVF testing is significantly more sensitive than confrontation techniques to screen visual fields. While HVF should be performed when possible in patients with suspected defects, LVF testing represents an effective and time efficient tool for bedside and office visual field screening in patients with suspected afferent visual pathway disease. WILD CAT SCRATCH DISEASE M. A. Lana- Peixoto, L. Osvaldo, M. Cabral, I. R. Souza; Belo Horizonte, Brazil Background: Cat scratch disease is a common cause of fever, malaise and lymphadenitis. Neuro- retinitis occurs in less than 1.5 % of these patients and is usually characterized by loss of vision, optic disc edema and exudates in the retina forming a macular star. Objective: To report a case of cat scratch disease transmitted by a wild cat. To demonstrate that wild cats and not only domestic cats and fleas can transmit the disease. Case Report: A 34- year- old man, Captain of the Brazilian Army in service in the Amazonian forest noticed severe pain in his right eye followed by sudden loss of vision. He had pre­sented with low- grade fever, malaise and cervical lymphadeni­tis two weeks earlier. He reported he had been scratched by a wild cat few weeks before the onset of the symptoms. The / Neuro- Ophthalmol, Vol. 21, No. 2, 2001 NANOS ABSTRACTS 155 examination showed visual acuity RE 20/ 400; LE 20/ 20; he could read no Ishihara plate with the RE and 6 of 8 with the LE. Fundus examination disclosed bilateral optic disk edema ( more severe in the RE) and the presence of retinal exudates forming a macular star bilaterally. There was also an afferent pupillary defect in the RE. A brain MRI was normal and a CSF exami­nation revealed opening pressure of 12 cm H20, 6 cells/ mm3 ( neutrophils 15%), glucose 73%, protein 55 mg% and a gamma- globulin concentration of 9.5%. ELISA for Bartonella henselae was positive in the serum and CSF. The patient was given IV methylprednisolone and ciprofloxacin. Two months later his visual acuity was RE 20/ 40, LE 20/ 20, there was complete recovery of the optic disc edema but only slight ab­sorption of the macular star in both eyes. Conclusion: To the best of our knowledge this is the first report of cat scratch disease transmitted through scratches by a wild cat. OPTIC NEUROMYELITIS IN SCHISTOSOMIASIS MANSONI M. A. Lana- Peixoto, L. O. Cabral, A. Muniz; Belo Horizonte, Brazil Background: The cause of optic neuromyelitis ( Devic's Syn­drome) is unknown. A few reports have described Devic's syndrome in association with systemic lupus erythematosus, tuberculosis and AIDS. Objective: To describe a case of optic neuromyelitis secondary to schistosomiasis mansoni. Case Report: A 34- year- old man developed sudden loss of the temporal field of vision of both eyes three days following the onset of severe headache. In the next few days he could only see hand movements with both eyes. A brain MRI showed a T2- hyperintense and gadolinium- enhanced lesion in the sellar and suprasellar areas, extending to the intracranial portion of both optic nerves and thickening of the optic chiasm and optic tract. A biopsy of the lesion showed the presence of inflam­matory cells and reactive glial tissue. The patient was treated with corticosteroids with good recovery. Fourteen months later he developed severe pain at T10 level, dysesthesia caudal to this level and marked paraparesis with urinary sphincter dis­turbance. A spinal cord MRI revealed a T2- hyperintense lesion in dorsal and lumbar levels. Cerebrospinal fluid examination disclosed 35 cells/ mm3 ( 38% eosinophils); proteins 60 mg%; glucose 55 mg% and a positive indirect immunofluorescence reaction to schistosoma mansoni. The patient was treated with IV methylprednisolone followed by oral prednisone. At follow-up he presents VA RE 20/ 25, LE 20/ 30, a slight pallor of the temporal aspect of the optic discs and normal visual fields. Motor examination is normal but there are decreased light touch sensation below to T10 and decreased vibration sense in the knees and malleoli. Conclusion: Neuromyelitis optica is usually considered a form of acute disseminated encephalomyelitis. To the best of our knowledge this is the first case of optic neuromyelitis in association with schistosomiasis mansoni reported in the world literature. THE SHAPE DISTORTION EFFECT IN CEREBRAL DYSCHROMATOPSIA AND PROSOPAGNOSIA J. S. Kim, J. Rivest, J. Intrilligator, J. A. Sharpe; Cheju, Cheju, Korea Background: Form perception, face recognition, and color perception are processed by the parvocellular visual pathway in the ventral stream of the occipital and temporal lobes. When two shapes are presented successively and briefly to normal subjects, the perceived form of the second ( test) shape is changed dissimilar to the form of the first ( priming) shape. This shape distortion effect has been postulated to originate from adaptation of non- retinotopic and non feature- specific neurons in the ventral stream. Objective: To determine differential effects of cerebral lesions on the perception of face and color, and on higher cortical processing of shape interaction. Methods: We measured the shape distortion effect in two pa­tients, one with cerebral dyschromatopsia and the other with cerebral dyschromatopsia and prosopagnosia from bilateral oc­cipitotemporal infarcts. For each trial, flashed in succession were a priming rectangle ( 45 ms; vertically or horizontally), a gap of 180 ms, a test circle ( 60 ms), and a random- dot mask ( 300 ms). The priming rectangle and the test circle were flashed in each quadrant with an eccentricity of 8.6 degrees from the fixation point that located in the center of the monitor. After each trial, using the method of adjustment, the % elongation ([ longer diameter] - [ shorter diameter])/( shorter diameter) X 100) of the reproduced circle or ellipse was computed. Results: The two patients demonstrated normal perception of shape distortion, and normal evaluation of shapes in general. Conclusions: Impaired recognition of faces or perception of colors can be dissociated from shape perception. Normal per­ception of the shape distortion in the presence of cerebral ach­romatopsia and prosopagnosia provides evidence for corti­cal segregation of specialized visual areas in the ventral stream for recognition of faces and colors and for processing of shape interactions. ASYMETRIC PAPILLEDEMA IN IDIOPATHIC INTRA­CRANIAL HYPERTENSION: AN INSIGHT E. R. Eggenberger, A. Pathak, N. P. Desai; East Lansing, Michigan Background: Papilledema may be asymmetric or unilateral. Proposed mechanisms have included asymmetric intraocular pressure and anatomical variations in the optic nerve sheaths, such as adhesions or leaks that prevent transmission of intra­cranial pressure along one nerve. Objective: To gain insight into the mechanism of unilate­ral papilledema. Method: We report a case of a 33- year- old, healthy female presenting with a three week history of transient visual obscu­rations OD. Examination was notable for weight of 180 pounds on a 5' 1" frame. Visual acuity was 20/ 15 OU, while color perception was 10/ 10 HRR plates OU, and there was no evi­dence of RAPD. Goldmann perimetry revealed an enlarged blind spot OD. Fundus examination revealed disc edema OD with fine splinter hemorrhages ( Frisin Grade 4), and an unre­markable appearing disc OS. Results: Orbital T- 2 coronal MR imaging demonstrated in­creased CSF fluid symmetrically along both optic nerve sheaths. Specifically, no adhesions or restrictions to CSF flow were noted along the left optic nerve sheath. A lumber puncture revealed an opening pressure of 240 mm H20 with normal composition and cytology. A diagnosis of idiopathic intracra­nial hypertension ( IIH) was made and the therapy was initiated with acetazolamide 1000 mg qd. Follow- up examinations two and six months later demonstrated resolution of disc edema OD. Conclusions: The factors contributing to the occurrence of unilateral papilledema in IIH probably act at the level of the lamina cribrosa, and have yet to be fully elucidated. Possibili­ties include differences in the scleral canal, nerve head vascular supply or glial supporting structures. J Neuro- Ophthalmol, Vol. 21, No. 2, 2001 156 NANOS ABSTRACTS TWO UNUSUAL CASES OF PROLACTINOMA D. Lin, A. Benton, R. L. Sogg; Stanford, California Two males, one age 17, the other 36, presented with unusual manifestations of prolactin- secreting pituitary tumor. The first has a history of hyperparathyroidism with renal calculi. This past summer he had noticed an inability to follow a passed football when directly overhead but not before or after it ar­rived and left. No change in libido or impotency noted, nor galactorrhea. Prolactin was 470 ng/ ml. Almost complete bitem­poral hemianopia with large bilobed pituitary adenoma. After a single pill of cabergoline (. 5 mg BIW) VF almost returned to normal and prolactin to 40. 2 mos after therapy VF normal, but tumor showed NO REGRESSION on MRI Second case concerns a 36 year old man with long history of depression, left hemiplegia, left homonymous hemianopia, ga­lactorrhea, and prolactin greater than 10,000 ng/ ml. Huge pi­tuitary adenoma invading both cerebral hemispheres, initially treated by cabergoline with only TRANSIENT LOWERING of prolactin, then