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Show Journal of Neiim- Ophlliiilmohgy I8( J): 169- 170, 1998. © 1998 Uppincolt Williams & Wilkins, Philadelphia Anterior Ischemic Optic Neuropathy in a Disc With a Cup An Exception to the Rule Cameron F. Parsa, M. D., Rafael Muci- Mendoza, M. D., and William F. Hoyt, M. D. Manuscript received August 1997; accepted December 1997. From the Neuro- Ophtrialmology Unit, Department of Ophthalmology, School of Medicine, University of California, San Francisco, U. S. A. ( C. F. P., W. F. H.) and the Unidad de Neuro- Oftalmologia, Hospital Vargas dc Caracas, Universidad Central dc Venezuela, Caracas, Venezuela ( R. M.- M.). Address reprint requests and correspondence to Dr. William F. Hoyt, 533 Parnassus Avenue, Room U- 521, U. C. S. F., San Francisco, CA 94143- 0350. Since Beck and his coworkers ( 1,2) in 1984 and 1987, and later others ( 3), confirmed that anterior ischemic optic neuropathy ( AION) occurs most frequently in discs without an optic cup ( the so- called " disc at risk") ( 4), we have asked whether the presence of a definite optic cup would protect an eye from the disease. In February 1991, one of us ( R. M.) examined a 61- year- old man several weeks after he lost vision in his FIG 1. Top Left: Photograph of right optic disc in a patient who presented several weeks after an episode of anterior ischemic optic neuropathy. Pallid disc edema with capillary telangiectasia was present interiorly. Top Right: Photograph of the normal left optic disc showing the optic cup. Bottom Left: Right optic disc 6 years later showed an absence of the nerve fiber layer superiorly; pallor, typical post- anterior ischemic optic neuropathy arteriolar narrowings; and shallow temporal cupping. Bottom Right: The left disc showed pallid swelling with ischemic hemorrhages. 769 170 C. F. PARSA ETAL. right eye. Visual acuity was 20/ 800 with an inferior altitudinal field defect and pallid edema of the disc ( Fig. I, upper left). The diagnosis was nonarteritic AION. The left eye had a normal disc with a moderate- sized physiologic cup ( cup- to- disc ratio was 0.5) ( Fig. 1, upper right). Six years later, in December 1996, he had a similar attack in his left eye. He had an inferior altitudinal field defect with a relative central scotoma and an acuity of 20/ 30. The left disc showed typical pallid swelling with ischemic hemorrhages and obliteration of most of the optic cup ( Fig. 1, bottom right). The right eye now saw 20/ 40. It had an inferior altitudinal field defect, a pale disc with typical post- AION arteriolar narrowings, shallow temporal cupping, and complete loss of the superior peripapillary nerve fiber layer ( Fig. 1, bottom left). Although rare, AION can occur in an optic disc with a " generous" cup. REFERENCES 1. Beck RW, Savino PJ, Repka MX, Schatz NJ, Scrgott RC. Optic disc structure in anterior ischemic optic neuropathy. Ophthalmology 1984; 91: 1334- 7. 2. Beck RW, Servais GE, Hayreh SS. Anterior ischemic optic neuropathy. Cup- to- disc ratio and its role in pathogenesis. Ophthalmology 1987; 94: 1503- 8. 3. Doro S, Lessell S. Cup- disc ratio and ischemic optic neuropathy. Arch Ophthalmol 1985; 103: 1143- 4. 4. Burde RM. Optic disc risk factors for nonarteritic anterior ischemic optic neuropathy. Am J Ophthalmol 1993;! 16: 759- 64. EDITOR'S NOTE The key to this paper is that AION does occur in discs with characteristics that do not fit the " disc at risk." ./ Neiim- Oplulmlnml. Vol. IX, No. J. 1998 |
