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Show Journal of Clinical Neuro- ophthalmology 10( 1): 1- 8. 1990. Clinical Studies on the Occurrence and the Pathogenesis of Optociliary Veins Yoshimasa Masuyama, M. D., Yoshihisa Kodama, M. D., Yoshifumi Matsuura, M. D., Atsushi Sawada, M. D., Kazumichi Harada, M. D., and Toshinori Tsuchiya, M. D. © 1990 Raven Press, Ltd., New York We reviewed retrospectively 20 cases of optociliary vein over the past 5 years. Fifteen of the 20 cases ( 75%) were over 40 years of age. There was no sex differences ( 9 males and 11 females). Causative ocular diseases were: central retinal vein occlusion ( 14 cases, 70%); optic disc drusen ( 2 cases, 10%); and optic nerve sheath meningioma, high myopia, glaucoma, congenital anomaly ( 1 case each, total 20%). The number of patients with an optociliary vein was high in central retinal vein occlusion ( 14/ 190 cases, 7.4%). We concluded that occurrence of optociliary vein is not restricted to cases with optic nerve sheath meningioma and this shunt vessel may occur under other conditions in which central retinal venous return is seriously disturbed. The most common cause of optociliary vein is central retinal vein occlusion. Key Words: Central retinal occlusion- Fluorescein fundus angiography- Optic nerve sheath meningiomaOptociliary vein. From the Department of Ophthalmology, Miyazaki Medical College, ( Y. M., Y. K., Y. M., A. S.); and the Miyazaki Central Eye Hospital ( K. H., T. T.), Miyazaki, Japan . Address correspondence and reprint requests to Yoshlmasa Masuyama, M. D., at Department of Ophthalmology, Miyazaki Medical College, Kiyotake, MIyazakI 889- 16, Japan. Presented at the Annual Meeting of the Amencan Academy of Ophthalmology, San Francisco, September 29 to October 3, 1985. 1 An optociliary vein rarely occurs between the central retinal vein and the peripapillary choroidal vein in the prelaminar region of the optic nerve head. This anomalous shunt vessel is thought to represent enlargement of a pre- existing capillary vessel between the central retinal vein and the choroid when the retinal venous return is obstructed ( 1,2). Salzmann ( 3) reported an evidence of optociliary vein for the first time in a case of myxosarcoma of the optic nerve in 1893. An optociliary vein is a well- known characteristic finding of the optic nerve sheath meningioma, and therefore, it has been mentioned as one of the triad symptoms in spheno- orbital meningiomas, including optic nerve sheath meningioma ( the HoytSpencer's sign) ( 4- 9). However, these shunt vessels are encountered in other ocular disorders such as optic disc drusen ( 10), arachnoid cyst of optic nerve ( 11), chronic papilledema ( 12- 15), optic nerve glioma ( 16), central retinal vein occlusion ( 1,17- 19), phakomatosis ( 20), and chronic glaucoma ( 21). In addition to the above acquired optociliary veins, a congenital optociliary vein has been reported even in the normal eye ( 17,21,22). We have experienced 20 cases with optociliary vein during the past 5 years. The purpose of this study is to clarify the occurrence and the pathogenesis of the optociliary vein. PATIENTS AND METHODS A retrospective review was made of those cases diagnosed as optociliary vein at the general clinics of the Department of Ophthalmology, Miyazaki Medical College Hospital and Miyazaki Central Eye Hospital for 5 years from 1978 to 1982. The appearance of an optociliary vein was examined with fundus photography and fluorescein fundus 2 Y. MASUYAMA ET AL. angiography in patients with various ocular diseases. RESULTS In our study, we found 20 total cases of optociliary vein. The occurrence was 11 of 6,851 patients at Miyazaki Medical College Hospital and 9 of 296,948 patients at the Miyazaki Central Eye Hospital, respectively. As to the age distribution, 15 patients ( 75%) were above 40 years of age, and of these eight ( 40%) were in their 60s, indicating a high incidence after middle age. No sex difference was noted in this study, which consisted of 9 men and 11 women. The right eye and the left eye were involved in 10 cases, each without any preference for the affected side. As to the causative diseases, central retinal vein occlusion was found to be the most frequent cause, in 14 of 20 cases ( 70%), followed by optic disc drusen in two cases ( 10%), and optic nerve sheath meningioma, high myopia, glaucoma, and congenital anomaly in one case each ( 5%) ( Fig. 1). We examined the number of the patients with optociliary vein in this patient population. The number of the patients with central retinal vein occlusion was 190 cases; 65 cases at Miyazaki Medical College Hospital and 125 cases at Miyazaki Central Eye Hospital. Of these cases with central retinal vein occlusion, 14 cases ( 7.4%), including two cases of hemi- central retinal vein occlusion, had optociliary vein; seven cases ( 10.8%) and seven cases ( 5.6%) in respective hospitals. When evaluated by the l test the frequencies for these two hospitals were not statistically significant ( p < 0.05). Patients with branch retinal vein occlusion examined in both hospitals totaled 575 cases, but we could not find any cases involving an optociliary vein. Of 1,465 glaucoma patients and 1,920 high myopia patients, optociliary vein was seen in one case each ( 0.07% and 0.05%). The incidence of the optociliary vein in the population with the same disease was significantly higher in central retinal vein occlusion patients than in glaucoma and high myopia patients ( p < 0.01). Of seven patients with optic disc drusen, optociliary vein was seen in two cases. Only one optic nerve sheath meningioma patient was found, and they had an optociliary vein. These conditions showed no statistical significance when compared with that of central retinal vein occlusion. Congenital optociliary vein was found in one case in this study making its incidence extremely low. In these 20 cases, 25 optociliary veins were found in all. Out of the four quadrants of the disc, nine ( 36%) were found on the temporal quadrant, seven ( 28%) on the nasal, five ( 20%) on the lower, and 4 ( 16%) on the upper quadrant ( Fig. 2). Representative cases of optociliary vein are discussed as follows. Case 1: Central Retinal Vein Occlusion A 31- year- old woman had a I- month history of blurred vision in her left eye. She had suffered from renal hypertension in the past. On examination, visual acuity was 20/ 20 in the right eye and 20/ 40 in the left eye. Intraocular pressure was 16 mmHg in the right eye and 14 mmHg in the left eye. The right fundus showed no abnormalities. The left fundus revealed venous dilation and loop upper lower FIG. 2. The site of the optociliary vein on four quadrants of the optic disc. Optic Nerve Sheath Meningioma Congenital Anomaly FIG. 1. The incidence of the causative ocular diseases on the optociliary vein J Clm Ncuru- uphthalmuJ. Vol. 11), /'\ iu. I, ! eJ') 1I temporal nasal CLINICAL STUDIES ON OPTOCILIARY VEIN 3 formation near the disc margin at the 12 o'clock position and a tortuous optociliary vein was present at the temporal margin. Fluorescein angiography indicated that this vein filled in the arteriovenous phase from the central retinal vein to the choroid and fluoresced along with the retinal vein until the late stage. The optociliary vein did not leak fluorescein dye ( Fig. 3). Case 2: Hemi- Central Retinal Vein Occlusion A 39- year- old man presented with a 3- month history of blurred vision in his right eye. He had no other ocular or neurological symptoms, and his past medical history and family history were unremarkable. Visual acuity was 20/ 60 in the right eye and 20/ 20 in the left eye. Ophthalmoscopy of the left eye revealed no abnormalities. In the right eye, retinal hemorrhages spread in the inferior half of the fundus due to occlusion of the inferior retinal venous trunk. There was a venous loop connection between the superior and inferior major venous trunk at the nasal disc margin. An optociliary vein was seen between the venous loop and the choroid at the 9 o'clock position of the disc margin. Fluorescein angiography demonstrated the optociliary vein filled in the arteriovenous phase from the central retinal vein to the choroid FIG. 3. Fluorescein angiogram of case 1 with central retinal vein occlusion. Loop formation of the dilated veins is seen at the upper disc margin. The tortuous optociliary shunt vessel was present a~ 3 o'clock ( arrowhead) and filled from the central retinal vein to the choroid during the arteriovenous phase. FIG. 4. Fluorescein angiogram of case 2 with hemlcentral retinal vein occlusion. The optociliary vein is present near the margin of the disc at the 9 o'clock position ( arrowhead). This vessel was filled in the arteriovenous phase from the central retinal vein and remained fluorescent until the late stage. and remained fluorescent until the late stage ( Fig. 4). Case 15: Optic Disc Drusen A 46- year- old woman was seen with a chief complaint of blurred vision in the right eye. Visual acuity was 20/ 25 in the right eye and 20/ 20 in the left eye. In the right fundus, the disc margins were poorly demarcated and slightly elevated with drusen. The retinal veins were mildly dilated but no retinal hemorrhage was present. An optociliary vein was found on the temporal aspect of the disc, partially hidden by the overlying nerve fibers ( Fig. 5). On fluorescein angiography, this optociliary vein filled in the arteriovenous phase from the central retinal vein to the choroid. The drusen remained hyperfluorescent after the late stage even after the veins had emptied ( Fig. 6). The optic nerve head showed high acoustic reflectivity on echography. The optociliary vein remains unchanged on follow- up 5 years later. Case 17: Optic Nerve Sheath Meningioma A 58- year- old woman had a recurrent optic nerve sheath meningioma in the left eye. Her initial surgery was 6 years previous to this examination. Visual acuity was 20/ 20 in the right eye and JClill Neuro- ophthalmol, Vol. 10. No. 1. 1990 4 Y. MASUYAMA ET AL. FIG. 5. Fundus photograph of case 15 with optic disc drusen. The optic disc was ill margined and slightly elevated with granular conglomerates. The retinal veins were mildly dilated. An optociliary vein was noted at 9 o'clock position of the disc margin ( arrowhead). no light perception in the left eye. Exophthalomometry was 12 mm in the right eye and 21 mm in the left eye. Ophthalmoscopy before her second operation revealed two optociliary veins in the upper quadrant and one in the nasal quadrant. On fluorescein angiography, these three shunt veins filled in the early arteriovenous phase from the central retinal vein and followed the venous pattern, remaining eufluorescent into the late stage. These veins did not leak fluorescein dye ( Fig. 7). FIG. 6. Fluorescein angiogram of case 15 with optic disc drusen. The disc margins are poorly demarcated with fluorescent conglomerates. The retinal veins show laminar flow of the fluorescein. The optociliary vein is noted on the temporal aspect of the disc ( arrowhead). This shunt vessel filled in the arteriovenous Oh'J" c fr".' T' th. c, ' 8n"~! retinal vein to the choroid . FIG. 7. Fluorescein angiogram of case 17 with optic nerve sheath meningioma. Two optociliary veins on the upper quadrant and one on the nasal quadrant are noted ( arrowheads). These veins filled from the central retinal vein during the arteriovenous phase. The optociliary veins disappeared after a second extirpative operation ( Fig. 8). Case 18: High Myopia A 57- year- old woman had a history of high myopia. Visual acuity was 20/ 100 ( better with - 7. 00) in the right eye and 20/ 200 ( better with - 7. 00) in the left eye. There was a mild cortical opacity to the lens in each eye. Ophthalmoscopy of the left eye revealed a temporally distorted disc with conus and posterior staphyloma. There was neither retinal hemorrhage or vascular sheathing. Only mild dilation of the retinal veins was present. An optociliary vein was seen at the temporal conus margin ( Fig. 9). Fluorescein angiography indicated that the optociliary vein communicating with the FIG. 8. Fluorescein angiogram of case 17 after removal of the tumor. The optic disc is atrophic and the optociliary veins have disappeared. I Clm Neuro- uphllwlflll! l, ~ oi. ill, " I! • 0"/' CLINICAL STUDIES ON OPTOCILIARY VEIN 5 FIG. 9. Fundus photograph of case 18 with high myopia. The fundus revealed temporally distorted disc and posterior staphyloma. There are coiling of retinal vein on the disc and venous dilation. An optociliary vein is seen at the temporal aspect of the disc ( arrowhead). choroid filled from the central retinal vein during the early venous phase and fluoresced along with the retinal vein until the late stage ( Fig. 10). Case 19: Congenital Glaucoma A 16- year- old girl had a history of congenital glaucoma in both eyes. Her highest intraocular pressure readings were 35 mm Hg in the right eye and 33 mm Hg in the left eye, with a corneal radius of 13 mm in both eyes. The right eye was more seriously affected due to the prolonged high pressure. She had had a trabeculectomy in both eyes 4 years before and her intraocular pressure has been well controlled. On examination after surgery, vi- FIG. 10. Fluorescein angiogram of case 18 with high myopia. A white surrounding scleral crescent is present. The optociliary vein at the 3 o'clock position ( arrowhead) filled from the central retinal vein during the early venous phase. sual acuity with best correction was 20/ 400 in the right eye and 20/ 40 in the left eye. Intraocular pressure was 16 mm Hg in the right eye and 14 mm Hg in the left eye. Ophthalmoscopy of the right eye revealed the disc to be pale with a large cup. At the 7 o'clock position of the disc margin an optociliary vein was seen communicating with the choroid ( Fig. 11). Fluorescein angiography indicated this shunt vein to be filling during the arteriovenous phase from the inferotemporal retinal vein ( Fig. 12). The optociliary vein was present before the operation and remains afterwards. The left fundus showed marked optic atrophy with a large cup but had no optociliary vein. Case 20: Congenital Anomaly A 32- year- old woman was seen who complained of itching in the left eye. Her past medical history was unremarkable and her present health was excellent. Visual acuity in each eye was 20/ 20 with full visual fields. The eye examination was normal with the exception of the right fundus, which showed a prominent optociliary vein at the inferior disc margin. This vessel displayed a light red color and straight course ( Fig. 13). On fluorescein angiography this vein filled during the early arteriovenous phase and remained as equally fluorescent as the retinal veins during the late venous phase, and was identified as a veno- venous anastomosis. The direction of flow was from the choroid to the retinal vein. There were no other abnormalities in the right fundus ( Fig. 14). She had no neurological abnormalities and computerized tomographic scans showed a normal optic nerve and no retro- FIG. 11. Fundus photograph of case 19 with congenital glaucoma. The disc is atropic with a large glaucomatous cup. There is coiling of the retinal veins at the upper part of the disc. An optociliary vein is seen at the 7 o'clock position ( arrowhead) of the disc margin. JGin Neuro-{) phthalmol. Vol. 10. No. 1. 1990 6 Y. MASUYAMA ET AL. Flu. 12. I- Iuoresceln angiogram ot case HI with congenital glaucoma. The disc has a large glaucomatous cup. The optociliary shunt vessel ( arrowhead) is seen communicating between the inferotemporal retinal vein and the choroid. This vein filled from the retinal vein during the arteriovenous phase. bulbar lesions. The optociliary vein has remained unchanged over a 5- year follow- up. DISCUSSION We reviewed retrospectively 20 cases with optociliary vein during the past 5 years. The important fact to emphasize from this study is that central retinal vein occlusion is the most common cause of optociliary vein among the various causative diseases, accounting for 14 cases ( 70%). Central retinal vein occlusion has a high prevalence in middle and advanced age. For this reason optociliary vein is seen more frequently in this same age group. FIG. 13. Fundus photograph of case 20 with congenital optociliary vein. A prominent optociliary vein is present at the 6 o'clock position ( arrowhead). This vessel shows liQht red color and no tortuosity com- " ,< ,- q,-,,,,-: rj ootociliary vein I elm NetlfuophtlUlllllli/, ~" I JII, j~! i J FIG. 14. Fluorescein angiogram of case 20 with congenital optociliary vein ( arrowhead). The optociliary vein filled during the early arteriovenous phase and remained as fluorescent as the retinal veins during the late venous phase. The direction of flow was from the choroid to the retinal vein. The incidence of the optociliary vein was high in central retinal vein occlusion patients among various causative diseases ( 7.4%). This explanation is supported by the evidence that the central retinal vein is seriously blocked in the prelaminar region of the optic disc. Branch retinal vein occlusion, however, was not a causative factor of optociliary vein because the venous return is blocked at the arteriovenous crossing, which is away from the disc. Collateral vessels occur among the adjoining retinal veins. We could not find the optociliary vein in branch retinal vein occlusion patients in this study. Anderson et al. ( 21) reported four cases of branch retinal vein occlusion with optociliary vein. From the fundus and fluorescein photographs of case 8 published in their article, the patient was thought to have a hemi- central retinal vein occlusion because narrowing of the inferior trunk of central retinal vein was apparently found in the prelaminar region. Hemi- central retinal vein occlusion should be sharply distinguished from branch retinal vein occlusion. We emphasize that optociliary vein occurs only in a condition where venous return is blocked or impaired in the prelaminar region of the optic disc. An optociliary vein has appeared in monographs as one of the characteristic clinical features of optic nerve sheath meningioma. In the single optic nerve sheath meningioma patient in this series, optociliary veins developed and grew slowly for 6 years. These veins disappeared after tumor excision that has been previously reported ( 7,14,15). Boschetti et al. ( 23) reported differences CLINICAL STUDIES ON OPTOCILIARY VEIN 7 in fluorescein angiograms between optociliary veins developing secondary to retinal vein occlusion and those developing with optic nerve sheath meningioma. In the optic nerve sheath meningioma patients, the shunt vessels filled in the arteriovenous phase and demonstrated hyperfluorescence in the late venous phase when compared with the retinal veins. During fluorescein angiography of our patient ( case 17), the optociliary veins initially filled in the arteriovenous phase as seen in cases of Boschetti et al. However, we could not find any hyperfluorescence in these veins during all of the studies phases. Hyperfluorescence seen in Boschetti et al.' s cases may suggest the presence of an arteriovenous shunt or drainage from the tumor behind the optic nerve head to the retinal vein. Further clinical studies will be needed to clarify the fluorescein angiographic differences between these two conditions. Two cases with optic disc drusen in this series showed large and well- developed optociliary veins. The deep- seated drusen or their conglomerates are the most probable obstacle for blood flow in the prelaminar section of the central retinal vein, which the dilated optociliary communications try to bypass. Reports ( 10,24) that optic disc drusen disturb the retinal venous return are supported by our observations. In the case of high myopia, the extension of the axis of the globe seems to have affected the optic disc somehow, probably interfering with venous return in the central retinal vein. Retinal venous dilation seen in this case may indicate the presence of impaired blood return. In glaucoma the optociliary vein is most likely the result of sustained high intraocular pressure. The sustained high intraocular pressure is probably the cause for the distortion of the lamina cribrosa, as well as causing the corneal enlargement. As a result the optociliary vein remains even after the pressure returns to normal. Usually the optociliary vein is an acquired condition as described above. The occurrence of optociliary veins as a congenital vascular malformation is extremely rare. A few authors ( 21,22) indicated that the direction of blood flow is from the choroid into the central retinal vein. The optociliary vein in our case ( case 20) revealed the same direction of flow. Acquired optociliary veins were tortuous and dark red, and the blood flow was from the retinal to the choroidal circulation. Our congenital optociliary vein patient showed a light red color, indicating a higher oxygen content, and the vein's blood flow was from the choroidal to the retinal circulation. This vein is straight in course and stable without other intraocular lesions. These find-ings indicate that a congenital optociliary vein is not concerned with disturbance of retinal venous return. Fluorescein angiography helps in identification of the optociliary vein and may ascertain the direction of blood flow. Optociliary veins are veins of larger caliber as compared with the new vessels on the disc, and do not leak fluorescein. They fill during the arteriovenous phase or the venous phase of the angiogram and are seen connecting the central retinal vein with the choroidal vessel. New vessels, on the contrary, are much finer structures that originate from a vein and end in the same vessels, and are a network of fine vessels that leak fluorescein profusely. This differentiation is important because of the frequent interpretation of COllaterals on the disc as new vessels. Other congenital vascular abnormalities on the optic disc, for example, arteriovenous anastomosis associated with Wyburn- Mason syndrome ( 25) and prepapillary vascular loops ( 26) are easily differentiated with fluorescein angiography. 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