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Show J. Clin Neuro-ophthalmol. 4: 79-84, 1984. Ischemic Optic Neuropathy Associated with Optic Disc Drusen JOHN W. GITTINGER, JR., M.D. SIMMONS LESSELL, M.D. ROBERTA L. BONDAR, M.D., Ph.D. Abstract Ischemic optic neuropathy developed in five eyes of four patients with optic nerve drusen. Two of the patients were in their 20s, a decade when idiopathic ischemic optic neuropathy is rare. This argues against a chance concurrence of drusen and idiopathic ischemic optic neuropathy. Infarction of the distal portion of the optic nerve in patients with drusen may result from mechanical distortion of blood vessels in the laminar and prelaminar regions. Optic nerve drusen are discrete, but usually multiple deposits of amorphous extracellular material in the prelaminar portion of the optic nerve.l,~ While generally an isolated finding, optic nerve drusen may be associated with retinal pigmentary degeneration or angioid streaks. 3,4 Buried drusen elevate the optic nerve head causing confusion with papilledema, especially in the young.5 In older adults, the axons and glial tissue overlying the drusen atrophy. This exposes the drusen, which resemble the crystals inside a geode. The term drusen derives from this appearance." Some patients with drusen suffer progressive loss of visual field; characteristically inferonasal and in a nerve fiber bundle distribution. 7,8 Central vision has been severely impaired in rare instances. q-I~ Drusen also cause superficial and deep retinal hemorrhages,13-~o the latter secondary to subretinal neovascularization.~l Several eyes with optic nerve drusen have developed retinal vascular occlusions.~1-~4 In 1972, Karel et al. reported transient disc swelling and sudden loss of vision in three patients with optic nerve drusen. ~5 They suggested that such ischemic optic neuropathy may occur From the Division of Ophthalmology and the Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts OWG); the Departments of Ophthalmology, Neurology, and Neurosurgery, Boston University Medical School, Boston, Massachusetts (SL); and the Division of Neurology, McMaster University, Hamilton, Ontario (RLB). June 1984 more commonly with drusen than is generally appreciated since the acute episode may go unrecognized. The field loss is then falsely attributed to the more characteristic gradual axonal drop out. We report five examples of ischemic optic neuropathy in four patients with intrapapillary drusen and discuss the possible pathogenesis. Case Reports Case 1 In 1956, a 43-year-old woman with Sheehan's syndrome was found to have bilaterally elevated discs. Seven years later, two small drusen became visible on the right disc. At that time visual fields were full. In July 1977, she suddenly saw a veil over her right eye that progressively darkened over several days. On examination vision was count fingers at 5 ft. in the right eye and 20/20 in the left eye. The visual field in the right eye was constricted with a superior altitudinal defect; the field in the left eye was full. The right optic disc was pale and swollen with a small superotemporal splinter hemorrhage (Fig. 1). The left disc had no physiological cup and was slightly elevated. Sedimentation rate was 6 mm/hour. She was treated with high-dose prednisone tapered over 2 weeks. One month later, her vision was 20/400 in the right eye and 20/20 in the left eye. The edema had resolved, leaving exposed drusen. In May 1978, vision decreased suddenly in the left eye. Acuity was 20/200 in both eyes. The field was unchanged in the right eye, but there was now nasal constriction and a central scotoma in the right eye. The left disc showed pale swelling without hemorrhage. Vision in the left eye deteriorated over the next 3 days to count fingers at 10ft, prompting another course of steroids. By April 1980, visual acuity was 20/80-1 slowly in the right eye and 20/200 in the left eye. Both discs were pale with exposed drusen (Fig. 1). Case 2 A 26-year-old airline stewardess developed blurred vision in the right eye in September 1980, soon after she had been placed on flight duty. 79 Optic Disc Drusen Figure 1. Case 1: Above left, right disc 1 month after onset of symptoms, showing disc swelling and splinter hemorrhage. Above right, left disc at the same time. Below left, right disc after resolution of swelling, showing exposed drusen. Below right, left disc after intervening episode of ischemic optic neuropathy. An ophthalmologist found disc swelling and made the diagnosis of optic neuritis. She was placed on steroids. Computed tomography of the head and orbit was reportedly normal. She sought further consultation. On examination in October 1980, visual acuity was 20/20 in both eyes, but the right eye had a relative afferent pupillary defect. All but the superotemporal quadrant of the visual field had been lost in the right eye; there was only nasal constriction in the left eye. Prominent drusen were observed bilaterally, and the right disc was pale (Figs. 2a and 2b). Fluorescein angiography showed poor filling of the disc except in a temporal wedge from 8 to 10:00. Her findings remained unchanged on subsequent examinations up to October 1982. Case 3 A 24-year-old woman was referred in November 1970, with the diagnosis of optic neuritis in the right eye. In 1959 on a routine eye examination, blurred disc margins in the right eye were noted. Visual fields were normal, and she was sent to a neurosurgeon who interpreted the disc changes as pseudopapilledema. In the summer of 1970 immediately after vomiting, she lost all vision in the right eye for an hour, but recovered without apparent residua. One week prior to her examination she noted blurred vision in the right eye with a scotoma below fixation. This worsened for several days and then stabilized. She was taking an oral contraceptive, but did not smoke. Visual acuity was 20/25 in the right eye and 20/15 in the left eye with normal color vision. Visual fields showed a dense inferior nerve fiber bundle defect in the right eye. There were drusen on the right disc. The veins appeared full, and there were finely reticulated vessels and hemorrhages over the disc margin with wrinking of the internal limiting membrane (Fig. 3). The left eye was normal. Plain skull radiographs, serum protein electrophoresis, routine tests of blood and urine, and an electroencephalogram were normal. On fluorescein angiography the superior half of the disc did not fill with dye as late as 25 minutes after injection. The acuity improved to 20/20 in the right eye, and the disc swelling resolved leaving the drusen. The field defect was present on examination in March 1972. Journal of Clinical Neuro-ophthalmology Gittinger, Lessell, Bondar Figure 2a. Case 2: Above left, right disc. Above center, fluorescein angiogram of right disc in early venous phase showing hypoperfusion except for a temporal wedge. Above right, left disc. (b) Below, visual fields showing loss of three quadrants in right eye, nasal constriction, left eye. ~ . il\ \ 240 255 270"'-----';'285;;--""----';'300'" 210 \ Figure 2b. ,,--~ 240 > j 255 270 .45 135. ___ 1~__ 1~~_: -¥-~~'?~--T~~t .45 ·315 '~330 15 Case 4 A 58-year-old woman presented to an ophthalmologist in September 1982, complaining of darkening of the vision in the right eye for 5 days. The right disc was swollen, and she was referred to a neurologist. A neurological examination, sedimentation rate, computed tomography of the head and orbit, and carotid Doppler study were normal. Her vision continued to deteriorate, and she sought further evaluation. On examination she could not perceive light with the right eye, but saw 20/20 in the left eye. The visual field in the left eye was slightly constricted nasally. The right disc was swollen without hemorrhages, and the left disc was slightly elevated (Fig. 4). She was placed on 60 mg of prednisone daily, and a temporal artery biopsy was performed. The steroid dosage was rapidly tapered when the biopsy showed normal artery. As the disc swelling resolved, multiple small drusen appeared, best seen with monochromatic light. Vision in the right eye improved only to hand motions. A June 1984 fluorescein angiogram performed months after the onset of her visual loss showed hypofluorescence of the entire disc. Discussion Neither drusen nor ischemic optic neuropathy is rare. The prevalence of drusen clinically is estimated at 0.3%, and they are found in up to 2% of patients at autopsy.2b Its incidence is unknown, but ischemic optic neuropathy is one of the more common reasons for referral in a neuroophthalmic practice. The two entities could be expected to occur together solely by chance. There are, however, several lines of evidence that suggest that this may be a significant association. Ours are not the only cases of ischemic optic neuropathy associated with drusen. In addition to the cases of Karel et al.,25 Cohen's two cases, 2~ and one described by Hoyt and Beeston27 and figured in Walsh and Hoyt,11 also appear to be instances of ischemic optic neuropathy. Two of Rosenberg et al's.2H 98 patients with visible drusen had ischemic optic neuropathy. 81 Optic Disc Drusen Figure 3. Case 3: Above left, right disc at presentation. Above right, right disc 2 years later. Below left, venous phase of angiogram showing hypoperfusion of superior disc. Below right, persistence of hypofluorescence in late phase. Figure 4. Case 4: Above left, right disc at time of presentation, showing swelling without hemorrhage. Above right, left disc same day. Below left, right disc after resolution of swelling. Below center, preinjection photograph with filters in place, showing drusen autofluorescence. Below right, angiogram in early venous phase showing hypofluorescence of entire disc. Journal of Clinical Neuro-ophthalmology Two of our patients were in their 20s, well below the typical age for idiopathic ischemic optic neuropathy. Dutton and Burde's recent report of recurrent anterior ischemic optic neuropathy in three otherwise healthy people under the age of 30 attests to how rarely this has been recognized. 29 As with Dutton and Burde's cases, the clinical picture in both of the younger patients was that of ischemic optic neuropathy: disc swelling followed by-optic atrophy and accompanied by persistent visual field loss in a nerve fiber bundle or altitudinal pattern. The possibility that optic neuritis in an eye with drusen mimics ischemic optic neuropathy cannot be absolutely excluded, but the filling defects on fluorescein angiography point to a vascular rather than inflammatory event. Both young women were followed for at least 2 years without the appearance of other signs of a systemic disease. Neither had a history of migraine, which has been associated with ischemic optic neuropathy in the young.30 The young woman in case 2 had just recently begun frequent flying, exposing her to alterations in ambient oxygen pressure. Retinal hemorrhages have been observed at high altitudes in mountain climbers,3! and relative hypoxia could be a contributing factor in this case. In this regard, it is interesting to note the report of a 41-year-old pilot with drusen and extensive field loss in one eye.32 In case 3, the patient was on oral contraceptives. A recent review of the ocular complications of oral contraception notes 82 reported local ocular vascular disorders in women on birth control pills.33 None of these was an ischemic optic neu~ ropathy. Birth control pills are thus unlikely to be the cause of ischemic optic neuropathy in our patient. The majority of cases of ischemic optic neuropathy in older persons are idiopathic, but giant cell arteritis must always be excluded. Neither of the older patients had other signs or symptoms of arteritis, and both had normal sedimentation rates. The woman in case 1 has remained otherwise asymptomatic for 5 years; the woman in case 4 had a negative temporal artery biopsy. Hayreh has adduced considerable evidence that ischemic optic neuropathy is the consequence of occlusion of the posterior ciliary arteries34; however, no satisfactory explanation has been offered as to why, when the distribution of the ciliary vascular supply is usually segmented vertically, partial disc infarctions are almost always oriented horizontally. Smaller vessels in or near the optic nerve itself are probably involved in some cases, as in Green et aI's. patient with ischemic optic neuropathy complicating papilledema. 35 June 1984 Gittinger, Lessell, Bondar Optic nerve drusen can interfere with local circulation. Hemorrhages, neovascularization, and cilioretinal shunts2 are signs of disrupted regional hemodynamics. Some cases of ischemic optic neuropathy may be another effect of drusen on the vascular supply of the prelaminar optic nerve. Discs with drusen are anomalous in other ways; they are small with abnormal vascular branching. 28 Alterations ofaxoplasmic transport as the result of a crowded nerve head are sug§ested as a substrate for the formation of drusen3 and for the gradual loss ofaxons in optic nerves with drusen. 3 ? Optic nerve drusen develop in anomalous eyes and distort already abnormal anatomy further. Pollack and Becker38 found posterior bowing of the lamina cribosa in an autopsy eye, and Boyce et al. demonstrated large drusen narrowing the central retinal vein and apparently accounting for its occlusion.2 Such mechanical effects may predispose to the development of ischemic optic neuropathy in eyes with drusen. References 1. Friedman, A.H., Henkind, P., and Gartner, S.: Drusen of the optic disc: Ahistopathological study. Trans. Ophtha/mo/. Soc. U.K. 95: 4-9, 1975. 2. Boyce, S.W., Platia, E.V., and Green, W.R.: Drusen of the optic nerve head. Ann. Ophtha/mo/. 10: 695704,1978. 3. Goldstein, I., and Givner, l.: Calcified hyaline deposits (drusen) in the optic disc associated with pigmentary changes in the retina. Arch. Ophtha/mol. 10: 76-82, 1933. 4. Meislik, J., NeIder, K., Reeve, E.B., et al.: Atypical drusen in pseudoxanthoma elasticum. Ann. Ophtha/mo/. 11: 653-656,1979. 5. Hoyt, W.F., and Pont, M.E.: Pseudopapilledema: Anomalous elevation of optic disk; pitfalls in diagnosis and management. J. Am. Med. Assoc. 181: 191-196,1962. 6. Lorentzen, S.E.: Drusen of the optic disk. Dan. Med. Bull. 14: 293-298, 1967. 7. Rucker, CW.: Defects in visual fields produced by hyaline bodies in the optic disks. Arch. Ophtha/mo/. 32: 56-59, 1944. 8. Lanche, R.K., and Rucker, CW.: Progression of defects in visual fields produced by hyaline bodies in optic disks. Arch. Ophtha/mo/. 58: 115-121, 1956. 9. Knight, CL., and Hoyt, W.F.: Monocular blindness from drusen of the optic disk. Am. f. Ophtha/mol. 73: 890-892, 1972. 10. Kamin, D.F., Hepler, R.S., and Foos, RY.: Optic nerve drusen. Arch. Ophtha/mo/. 89: 359-362, 1973. 11. Walsh, F.B., and Hoyt, W.F.: Cli/lira/ Neuro-ophtha/ mology (3rd ed.). Williams & Wilkins, Baltimore, 1969, p. 673. 12. Frisen, L., Scholdstrom, G., and Svendsen, P.: Drusen in the optic nerve head. Verification by computerized tomography. Arch. Ophtha/mo/. 96: 16111614,1978. 83 Optic Disc Drusen 13. Gaynes, P.M., and Towle, P.A: Hemorrhage in hyaline bodies (drusen) of the optic disc during an attack of migraine. Am. f. Ophthalmol. 63: 16931696,1963. 14. Sanders, T.E., Gay, A.]., and Newman, M.: Drusen of the optic disk-hemorrhagic complications. Trans. Am. Ophthalmol. Soc. 68: 186-217, 1970. 15. Otradovec, J., and Vladykova, J.: 2ur Frage der Blutungen und der Venosen Stauung bei der Drusenpapille. Ophthalmologica 161: 21-30,1970. 16. Brodrick, ].D.: Drusen of the disc and retinal haemorrhages. Br. f. Ophthalmol. 57: 299-306, 1973. 17. Mooney, D.: Bilateral haemorrhages associated with disc drusen. Trans. Ophthalmol. Soc. U.K. 93: 739-743,1973. 18. Hitchings, RA, Corbett, J.J., Winkelman, J., et al.: Hemorrhages with optic nerve drusen. A differentiation from early papilledema. Arch. Neural. 33: 675-677, 1976. 19. Wise, G.N., Henkind, P., and Alterman, M.: Optic disc drusen and subretinal hemorrhage. Trans. Am. Acad. Ophthalmol. Otolaryngol. 78: OP 212-0P 219, 1974. 20. Harris, M.]., Fine, S.L., and Owens, S.L.: Hemorrhagic complications of optic nerve drusen. Am. f. Ophthalmol. 92: 70-76, 1981. 21. Purcell,].]., Jr., and Goldberg, RE.: Hyaline bodies of the optic papilla and bilateral acute vascular occlusions. Ann. Ophthalmol. 6: 1069-1076, 1974. 22. Savino, P.]., Glasser, J.5., and Rosenberg, M.A: A clinical analysis of pseudopapilledema II. Visual field defects. Arch. Ophthalmol. 97: 71-75, 1979. 23. Uehara, M., Inomata, H., Yamana, Y., et al.: Optic disk drusen with central retinal artery occlusion. Jpn. f. Ophthalmol. 26: 10-17, 1982. 24. Cohen, D.N.: Drusen of the optic disc and the development of field defects. Arch. Ophthalmol. 85: 224-226, 1971. 25. Karel, J. Otradovec, J., and Peleska, M.: Fluorescence angiography in circulatory disturbances in drusen of the optic disk. Ophthalmologica 164: 449462,1972. 26. Friedman, AH., Beckerman, B., Gold, D.H., et al.: Drusen of the optic disc. Surv. Ophthalmol. 21: 375390, 1977. 84 27. Hoyt, W.F., and Beeston, D.: The Ocular Fundus in Neurologic Disease. C.V. Mosby Co., St. Louis, 1966. 28. Rosenberg, M.A, Savino, P.J., and Glaser, J.5.: A clinical analysis of pseudopapilledema 1. Population, laterality, acuity, refractive error, ophthalmoscopic characteristics, and coincident disease. Arch. Ophthalmol. 97: 65-70, 1979. 29. Dutton, J.]" and Burde, R.M.: Anterior ischemic optic neuropathy of the young. f. Clin. Neuroophthalmol. 3: 137-146, 1983. 30. Weinstein, J.M., and Feman, S.5.: Ischemic optic neuropathy in migraine. Arch. Ophthalmol. 100: 1097-1100,1982. 31. Frayser, R, Houston, C.S., Bryan, AC., et al.: Retinal hemorrhage at high altitude. N. Engl. f. Med. 282: 1183-1184, 1970. 32. Barry, W.E., and Tredici, T.J.: Drusen of the optic disc with visual field defect and Marcus Gunn pupillary phenomenon (Aeromedical consultation service case report). Aerospace Med. 43: 203-206, 1972. 33. Petursson, G.J., Fraunfelder, FT, and Meyer, S.M.: 6. Oral Contraceptives. Ophthalmology 88: 368371,1981. 34. Hayreh, S.5.: Anterior Ischemic Optic Neuropathy. Springer-Verlag, New York, 1975. 35. Green, G.J., Lessell, S., and Loewenstein, J.I.: Ischemic optic neuropathy in chronic papilledema. Arch. Ophthalmol. 98: 502-504, 1980. 36. Spencer, W.H.: Drusen of the optic disk and aberrant axoplasmic transport. Am. f. Ophthalmol. 85: 1-12,1978. 37. Stevens, R.A, and Newman, N.M.: Abnormal visual- evoked potentials from eyes with optic nerve head drusen. Am. f. Ophthalmol. 92: 857-862, 1981. 38. Pollack, J.P., and Becker, B.: Hyaline bodies (drusen) of the optic nerve. Am. f. Ophthalmol. 54: 651654, 1962. Write for reprints to: John W. Gittinger, Jr., M.D., Division of Ophthalmology, 55 Lake Avenue North, Worcester, Massachusetts 01605. Journal of Clinical Neuro-ophthalmology |
