OPTIC DISC MORPHOLOGY IN EYES AFTER NONARTERITIC ANTERIOR ISCHEMIC OPTIC NEUROPATHY

Purpose. Parapapillary chorioretinal atrophy, neuroretinal rim loss, a nd a decrease of retinal vessel diameter have been described to occur in glaucomatous eyes. This study was conducted to evaluate the frequen cy and degree of these signs in nonarteritic anterior ischemic optic n europathy (AION). Methods. We evaluated morphometrically and compared stereo color optic disc photographs of 17 patients after AION, 184 pat ients with primary open-angle glaucoma, and 98 normal subjects. Result s. The optic disc area and retinal vessel diameter were significantly smaller and the visibility of the retinal nerve fiber bundles was sign ificantly reduced in patients after nonarteritic AION compared with th at of the normal subjects. The optic disc shape, area, and form of zon es alpha and beta of the parapapillary chorioretinal atrophy and the s ize and form of the neuroretinal rim did not differ significantly betw een these two groups. In the group of eyes with glaucoma, the neuroret inal rim was significantly smaller and the parapapillary chorioretinal atrophy was significantly larger than in the group of eyes with AION. Visibility of the retinal nerve fiber bundles and retinal vessel cali ber did not differ statistically between the eyes with AION and those with glaucoma. Conclusions. These results indicate that the parapapill ary chorioretinal atrophy is not larger in eyes after nonarteritic AIO N compared with normal eyes. They show that the area and shape of the neuroretinal rim, as determined planimetrically, may not markedly chan ge after nonarteritic AION. They confirm previous reports on a small o ptic disc size as a risk factor for nonarteritic AION. They agree with findings of a reduced retinal vessel caliber in eyes with optic nerve damage, independently of the cause.