The fellow eye in naion: report from the ichemic optic neuropathy decompreion trial follow-up tudy

PURPOE: To examine the prevalence and incidence of econd eye nonarteritic anterior ichemic optic neuropathy (NAION) and aociated patient characteritic in patient enrolled in the Ichemic Optic Neuropathy Decompreion Trial (IONDT) Follow-up tudy. DEIGN: Randomized clinical trial with obervational cohort. METHOD: Patient randomized to optic nerve heath decompreion urgery or careful follow-up had a diagnoi of acute unilateral NAION, viual acuity between 20/64 and light perception, and were aged 50 year or older. Eligible patient who declined randomization or whoe viual acuity wa better than 20/64 were not randomized but followed a part of an obervational cohort. Follow-up examination took place at 3, 6, 12, 18, and 24 month and annually thereafter. REULT: Four hundred eighteen patient were enrolled; 258 randomized and 160 oberved. Previou NAION or other optic neuropathy wa preent in the fellow eye of 21.1% (88/418) of patient at baeline. Four patient developed optic neuropathy in the fellow eye at follow up that could not be concluively diagnoed a NAION. New NAION in the fellow eye occurred in 14.7% (48/326) of patient at rik during a median follow up of 5.1 year. Randomized patient experienced a higher incidence (35/201; 17.4%) than nonrandomized patient (13/125; 10.4%). A hitory of diabete and baeline viual acuity of 20/200 or wore in the tudy eye, but not age, ex, apirin ue, or moking were ignificantly aociated with new NAION in the fellow eye. Final fellow eye viual acuity wa ignificantly wore in thoe patient with new fellow eye NAION whoe baeline tudy eye viual acuity wa 20/200 or wore. CONCLUION: Follow-up data from the IONDT cohort provide evidence that the incidence of fellow eye NAION i lower than expected: new NAION wa diagnoed in 14.7% of IONDT patient over approximately 5 year. Increaed incidence i aociated with poor baeline viual acuity in the tudy eye and diabete, but not age, ex, moking hitory, or apirin ue.