NATURAL-HISTORY OF NONARTERITIC ANTERIOR ISCHEMIC OPTIC NEUROPATHY

Visual acuity and quantitative perimetry (Octopus Program 32) testing was performed in the acute (<30 days after onset) and convalescent (>3 months after onset) phases of disease in 27 patients with untreated N AION. Initial group mean acuity and sensitivity loss were compared to final values using the t test. Proportions of patients demonstrating a change of >2 lines acuity or >2 dB mean sensitivity were calculated. Patients were classified as either ''progressive'' (n = 6) or ''stable '' (n = 21) for purposes of additional subgroup analysis. There was no significant change in group mean visual acuity or field over time. Ov erall, significant worsening occurred in 11.1% for visual acuity and 2 2.2% for visual field; improvement occurred in 23.8% for acuity and 24 .0% for field. Of 21 ''stable'' patients, none worsened for acuity and 4.7% showed late worsening of field; 31.3% showed significant improve ment for acuity and 31.6% for field. No ''progressive'' patients demon strated worsening or improvement after the initial progressive phase.