Objective: To evaluate the prevalence of cupping in arteritic anterior ischemic optic neuropathy (AAION) and nonarteritic anterior ischemic optic neuropathy (NAION).
Design: Retrospective, observational case series.
Participants: Three hundred one patients.
Methods: Review of clinical records and color fundus photographs.
Main outcome measures: Photographic and clinical interpretation of optic nerve appearance.
Results: Ninety-two patients with AAION and 102 with NAION were included in the study. Disc photographs of 42 patients (48%) with AAION and 32 patients (31%) with NAION were available for reassessment. These were presented in a masked fashion along with a random sample of 27 disc pairs considered to be 'normal' and 27 disc pairs with 'established glaucoma' according to two examiners. Cupping was present in 92% of eyes with AAION secondary to giant cell arteritis and in 2% of eyes with NAION (kappa = 0.96; P < 0.001).
Conclusions: The end-stage optic disc appearance in AAION secondary to giant cell arteritis is cupping, whereas segmental or diffuse pallor without cupping is the typical disc appearance after NAION.