Visual outcome in eyes with asymptomatic optic disc edema

Background: Asymptomatic optic disc edema may last for months before conversion to anterior ischemic optic neuropathy (AION). Alternatively, the optic disc edema may resolve with preservation of normal vision. The conversion rate of asymptomatic optic disc edema to AION has not been prospectively studied. We prospectively followed patients with asymptomatic disc edema to determine this conversion rate. Methods: The cohort was followed from 1991 to 2000 at a single ophthalmology clinic in Israel. There were 23 patients aged 47-74 years with asymptomatic disc edema and no signs of optic nerve dysfunction in whom the disc edema had been incidentally discovered on routine fundus examination performed for diabetes, hypertension, or follow-up after AION in the fellow eye. Results: In 9 (36%) eyes, optic disc edema progressed to overt AION with a mean latency of 16.8 weeks (range 2-80 weeks). In 16 (64%) eyes, optic disc edema resolved without loss of vision with a mean latency of 15.5 weeks (range 4-44 weeks). The conversion rate to AION was 40% in patients who had had AION in the fellow eye, 31% in patients with diabetes, 43% in patients with diabetic retinopathy, and 0% in four amiodarone-treated patients. Conclusion: Asymptomatic disc edema generally resolves with no visual loss, but one third of patients progress to full-blown AION. Diabetes mellitus is common in patients with asymptomatic optic disc edema. Perhaps patients diagnosed as having diabetic papillopathy actually have an impending AION that does not progress to overt disease.