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Show ! ollrllal of Clinical NflIro- 0I'i1tltall1loIt1gl/ J2( 3): 173- 177. J992. ',' 1'! 92 Rdven Press. Ltd .. New York Prolonged Course of Bilateral Acute Idiopathic Blind Spot Enlargement Michael Lee Cooper, M. D., ph. D. and Robert L. Lesser, M. D. We report a patient with bilateral " acute idiopathic blind spot enlargement" ( AIBSE) in whom visual symptoms and enlarged blind spots persisted for over 6 years and preceded the development of peripapillary hyperfluorescence on fluorescein angiography. These findings confirm the prolonged course that AIBSE can sometimes take and the suggestion that this rare disorder is due to peripapillary retinal dysfunction. Key Words: Acute idiopathic blind spot enlargementPeripapillary retinal dysfunction. Address reprint requests to Dr. Robert L. Lesser, Department of Ophthalmology, Yale University School of Medicine, Boardman Building, 330 Cedar St .. New Haven. CT 06510, U. S. A. From the Department of Ophthalmology and Visual Science. Yale University School of Medicine, New Haven, Connecticut. U. s. A. Dr. Michael Lee Cooper is currently at the Department of Ophthalmology, Boston University School of Medicine, Boston. Massachusetts, U. S. A. This paper was presented at the American Academy of Ophthalmology Annual Meeting, October- November 1990. Atlanta, Georgia. 173 Blind spot enlargement in the absence of optic nerve dysfunction is most often associated with papilledema due to increased intracranial pressure. However, enlargement of the blind spot without disk swelling has been found in " acute idiopathic blind spot enlargement" ( AIBSE) ( 1), which, in some cases, is associated with multiple evanescent white dot syndrome ( MEWOS) ( 2- 5). These big blind spot disorders are usually transient and unilateral; their etiologies are unknown. We describe a case of AIBSE in which blind spot enlargement occurred simultaneously in both eyes and persisted for over 6 years; this enlargement preceded peripapillary angiographic changes. Our patient also had laboratory findings suggestive of syphilis. CASE REPORT A 39- year- old white woman was well until January 1984, when she developed continuous scintillations described as " pinwheels" and " silver flashing circular images" located in the area of the blind spot in each eye. The patient had no other associated symptoms. She had had genital herpes in 1976. The patient had traveled to Zaire, BraziL and Afghanistan in the preceding 7 to 10 years. Examination by the patient's private ophthalmologist within 3 weeks of symptom onset revealed vision of 20/ 20 au with bilateral tilted disks and enlarged blind spots on Goldmann field testing. Neurological evaluation 6 weeks later was unremarkable except for the visual field changes. We examined the patient in April 1984. Her best corrected visual acuity was 20/ 20 in each eye ( - 3.25 - 1.25 x 1050 00; - 4.50 - 1.25 x 1050 OS). HRR color vision, extraocular motility, cranial nerve testing, slit lamp examination, and intraocular tensions were all within normal limits. The pupils were 2 mm on the right and 2.5 mm on the 174 M. L. COOPER AND R. L. LESSER left, but there was no ptosis and the cocaine test was negative. Goldmann visual fields showed marked enlargement of the blind spots, right greater than left, with full peripheral fields ( Fig. 1). Examination of the fundi revealed no abnormalities except slight tilting of the right disk and marked tilting of the left disk. No disk edema or macular pathology could be seen. Fluorescein angiography showed hyperfluorescence around the right disk with areas of blocked fluorescence; there was no staining or leakage. The left posterior pole .- was within normal limits angiographically ( Fig. 2A, B). The electroretinogram was normal. Routine urine and blood chemistries and hematologic studies were normal, as were thyroid and liver function tests, serum folate and vitamin B12, angiotensin- converting enzyme, serum lysozyme, urine heavy metal screen, and erythrocyte sedimentation rate. Serum protein electrophoresis ( SPEP), purified protein derivative, anti- nuclear antibody, rheumatoid factor, and serum VORL were negative. Serum immunoelectrophoresis • A HAAG !! RfIf ..... ,•• ~------.:.., ..'_' ,~~-- -:~~~- ;,. ". -: I." • ..-~. .' '-' {.. t 1:' = , B 8:.:::: ,',: FIG. 1. Goldmann visual fields showing marked enlargement of both blind - t ( A) Left eye; ( B) nght eye. These fields were unchanged over the course of 6 ySePaOrss.. "/'' 1 "': 11,- 0-( 11111111111", 01, Vol. 12. No. 3. 1992 PROLONGED BILATERAL AIBSE FIG. 2. ( Top): Fluorescein angiogram made about 4 months after the onset of symptoms. There was peripapillary hyperfluorescence in the right eye ( A), with an angiographically normal peripapillary region in the left ( B). These patterns remained constant through the angiographic study. ( Bottom): In an angiogram obtained 6 years later, the right fundus was unchanged ( C), but the left fundus had now also developed peripapillary hyperfluorescence ( D). 175 showed no monoclonal spike, although the IgM was moderately elevated and albumin moderately decreased. The chest x- ray was normal. EEG and triple evoked responses were normal except for an abnormal pattern visual evoked response in the right eye, felt to be consistent with right optic nerve or retinal dysfunction. During the 5 months following her onset of symptoms, the patient had normal contrast computed tomography scans of the brain and sellar region. Five lumbar punctures were performed during this time, showing normal protein, glucose, albumin, and opening pressure. The VORL was negative on each tap. Three to four oligoclonal bands of moderate intensity were seen on one examination. The cerebrospinal fluid ( CSF) IgG was elevated ( 5.2 to 7.1 mg%; upper limit of normal 3.5), as was the IgG/ albumin ratio ( 0.3 to 0.4; upper limit of normal 0.18). Although the cell count was normal on the first two taps, slight pleocytosis was noted on the last three in June 1984, with 16 to 20 white cells on each tap ( 4 to 26% monocytes and the rest nonmonoclonal lymphocytes). CSF cytology was negative for malignancy. CSF cultures were negative. The serum VORL was nonreactive; however, the serum fluorescent treponemal antibody absorption ( FTA- ABS) was positive. The testing laboratory considered the FTA- ABS to be definitely positive and not an atypical test result; a borderline Lyme IgG titer ( 1: 200) was felt to represent a crossreaction. Extensive serological studies for other infectious agents were within normal limits. The T- 4: T- 8 lymphocyte ratio was normal. , Clill Neuro- ophthalmol, Vol. 12, No. 3, 1992 176 M. L. COOPER AND R. L. LESSER Because of the positive FTA- ABS, the patient received penicillin G ( 5 million units i. v. q6h) for 10 days, followed by 3 weekly injections of 2.4 million units of i. m. benzithine penicillin. Repeat blood VORL and FTA- ABS were both negative at the time antibiotics were started in late June 1984, and repeat lumbar puncture at that time showed a negative VORL, with the white blood cell count having decreased to two. Shortly after completing her treatment, the patient was lost to follow- up. She was examined again in March 1990, when she reported persistence of her visual symptoms. Her best corrected acuity was 20/ 20 - 2 00 and 20/ 25 + 2 OS. Her pupillary responses and color vision were normal, and Goldmann fields showed enlarged blind spots unchanged from 1984. However, fundus examination showed some increased peripapillary atrophy OU. The fluorescein angiogram of the right eye was unchanged from 1984, but that of the left now also showed extensive peripapillary hyperfluorescence ( Fig. 2C, D). The electroretinogram was again unremarkable. The patient stated that she had never had a follow- up lumbar tap; a repeat FTA- ABS was negative. DISCUSSION Fletcher et al. ( 1) recently described seven patients who had " acute idiopathic blind spot enlargement" ( AIBSE). These young, typically female patients had monocular blind spot enlargement and positive visual phenomena ( e. g., photopsias) without disk edema; visual acuities and color vision were normal. All the patients had resolution of symptoms within 2 to 3 months, and visual fields in three patients showed normal blind spot size within 1 year. Our patient had simultaneously bilateral AIBSE, with a pattern similar in many respects to the patient of Wakakura and Furuno ( 6) and to case 3 of Singh et al. ( 7). These latter two patients also showed bilateral blind spot enlargement and peripapillary hyperfluorescence 4 to 5 years after the onset of symptoms. However, while the patient of Wakakura and Furuno did have simultaneous bilateral involvement, 4 years elapsed before the development of symptoms in the second eye of the case in Singh et al. ( 7). Two of Fletcher et al.' s ( 1) AIBSE patients had prolonged photostress recovery tests, and, although fluorescein angiography was reported as normal, multifocal electroretinography done in two patients was abnormal around the disk. Four of the original AIBSE patients had positive visual symptoms in the area of the enlarged blind spot, and all had an absolute scotoma with steep borders. Fletcher et al. ( 1) concluded that these findings were consistent with peripapillary retinal dysfunction rather than optic nerve disease. While peripapillary myopic degeneration and primary choroidal atrophy can produce enlarged blind spots, we feel it unlikely that such etiologies account for the findings in our patient. These processes are felt to begin in the retinal pigment epithelium ( RPE) or, more likely, the choroid, with retinal changes occurring secondarily ( 8-- 10). However, in our patient the left blind spot enlargement preceded any angiographic abnormalities; furthermore, the left eye was the more myopiC ( 11), but the angiogram was initially abnormal only in the right. The fact that visual symptoms and blind spot enlargement preceded angiographic abnormalities in our patient's left eye supports the contention that AIBSE is due to peripapillary retinal dysfunction. The finding that blind spot enlargement preceded the development of peripapillary atrophy in our patient's left eye is also significant because it suggests either a marked delay in the depigmentation of the affected pigment epithelium or that the patient had further episodes of AIBSE affecting the RPE of this eye. It does not seem likely that the patient had a recurrence of AIBSE since, although she reported persistence of symptoms for 6 years, she had no period of increased symptoms. Moreover, the left blind spot was no larger after 6 years than at the time of initial presentation, although one would expect additional enlargement of the blind spot in the case of recurring disease. Thus, in the absence of evidence suggesting exacerbation of the disease, we believe our case demonstrates that RPE damage in AIBSE may take many months, or possibly even years, to become apparent. It has been suggested ( 2- 5,12) that the patients of Fletcher et al. ( 1) and of Wakakura and Furuno ( 6) actually represent late cases of multiple evanescent white dot syndrome ( MEWDS). MEWDS ( 1315) also typically occurs in young healthy individuals, and presents with visual loss, scotomata, and multiple white lesions in the RPE or deep retina of the posterior pole. The fundus lesions resolve in a few weeks, although photopsias and blind spot enlargement can occasionally persist. However, it seems unlikely that all cases of AIBSE are secondary to MEWDS, since a number of AIBSE patients seen shortly after symptom onset have shown no evidence of this second disorder ( 1,6,7). Indeed, Singhet al. ~ 7) consider AIBSE to be a disease spectrum 10 whIch MEWDS is one type. While we cannot state with certainty that our PROLONGED BILATERAL AIBSE 177 patient did not initially have fundus findings of MEWOS, no such lesions were seen by an ophthalmologist within several weeks of symptom onset. In addition, MEWOS is not known to be associated with CSF pleocytosis ( Dr. L. JampoL personal communication). The patient's positive FTA- ABS, elevated CSF IgG, and CSF pleocytosis suggest that she had neurosyphilis ( 16), and it is known that syphilis can cause neuroretinitis. Although Lyme disease can also have neurologic and ophthalmic findings, this disease does not seem a likely etiology in the present case. Our patient's Lyme titer was only borderline, and she had no other typical findings of Lyme disease, such as erythema chronicum migrans, constitutional symptoms, or arthritis. While the FTA- ABS false- positive rate is less than 1% ( 17), we cannot state with certainty that our patient did indeed have syphilis, because two repeat FTA- ABS tests were negative. Further, even if the patient definitely had syphilis, her AIBSE could have been unrelated to this. In any event, the present case suggests that obtaining spirochetal serologies may be of benefit in future attempts to characterize AIBSE. Further, our patient is unusual even for this uncommon disorder, given her simultaneous bilateral involvement, prolonged course, and delayed onset of peripapillary angiographic changes. REFERENCES 1. Fletcher WA, Imes RK, Goodman 0, Hoyt WF. Acute idiopathic blind spot enlargement: a big blind spot syn-drome without optic disc edema. Arch Ophtha/ moI1988; 106: 44-- 9 2. Aaberg TM. Multiple evanescent white dot syndrome. Arch Ophtha/ mo/ 1988; 106: 1162- 3. 3. Gass JOM, Hamed LM. Acute macular neuroretinopathy and multiple evanescent white dot syndrome occurring in the same patients Arch Ophtha/ mol 1989; 107: 189- 93. 4. Hamed LM, Glaser JS, Gass JOM, Schatz Nj. Protracted enlargement of the blind spot in multiple evanescent white dot syndrome. Arch Ophtha/ mo/ 1989; 107: 194- 8. 5. Kimmel AS, Folk jC, Thompson HS, Strand LS. The multiple evanescent white- dot syndrome with acute blind spot enlargement. Am' Ophtha/ mo/ 1989; 107: 425- 6. 6. Wakakura M, Furuno K. Bilateral slowly progressive big blind spot syndrome. I Clin Neuro- ophtha/ moI1989; 9: 141- 3. 7. Singh K. de Frank MP, Shults WT, Watzke RC. Acute idiopathic blind spot enlargement: a spectrum of disease. Ophthalmology 1991; 98: 497- 502. 8. Carr RE, Mitt! RN, Noble KG. Choroidal abiotrophies. Trails Am Acad Ophtha/ mol Otolaryllgo/ 1977; 79: 796- 816. 9. Weiter J, Fine BS. A histological study of regional choroidal dystrophy. Am I OphthalmoI1977; 83: 741- 50. 10. Spencer WH, Font RL. Green WR, Howes EL, jakobiec FA. Zimmerman LE. Ophthalmic pathology. an atlas and textbook. Philadelphia: W. B. Saunders, 1985: 915- 21. 11. Curtin BJ, Karlin DB. Axial length measurements and fundus changes of the myopic eye. Am I Ophthalmol 1971; 71: 42- 53. 12. Gass JOM. Retinal causes of the big blind spot syndrome. I Chn Neuro- ophthalmol 1989; 9: 144-- 5. 13. jampol LM, Sieving PA, Pugh 0, et al. Multiple evanescent white dot syndrome. I. Clinical findings. Arch Ophthalmol 1984; 102: 671- 4. 14. Takeda M, Kimura S, Tamiya M. Acute disseminated retinal pigment epitheliopathy. Folia Ophtha/ mol ' pn 1984; 35: 2613- 20. 15. Oodwell OG, Jampol LM, Rosenberg M, et al. Optic nerve involvement associated with the multiple evanescent white- dot syndrome. Ophthalmology 1990; 97: 862- 8. 16. Spoor TC, Wynn P, Hartel WC, Bryan CS. Ocular syphiliS: acute and chronic. , Clill Neuro- ophtha/ mo/ 1983; 3: 197- 203. 17. Goldman IN, Lantz MA. FTA- ABS and VORL slide test reactivity in a population of nuns. lAMA 1971; 217: 53- 5. I Cli" Nel/ ro- ophtha/ mol, Vol. 12, No. 3, 1992 |
