To report a patient with ocular ischemic syndrome who suffered from sudden decrease in visual acuity after bevacizumab injection.

A 70-year-old patient visited the Department of Ophthalmology due to progressively decreasing visual acuity in the right eye. Corrected visual acuity in his right eye was 0.1 on the first visit; ocular ischemic syndrome was suspected. Despite panretinal photocoagulation, severe iris neovascularization was still present in the right eye. Intravitreal bevacizumab injection was performed to regress the iris neovascularization. One day after injection, iris neovascularization regressed significantly, however, visual acuity was decreased to finger counting.

In ocular ischemic syndrome, bevacizumab injection for reduction of iris neovascularization should be carefully considered due to possibility of acute visual loss.