Ischemic index and neovascularization in central retinal vein occlusion.

PURPOSE: To explore the association of angiographic nonperfusion with anterior segment and posterior segment neovascularization in central retinal vein occlusion (CRVO). METHODS: An imaging database at one institution was searched for the diagnosis of central retinal vein occlusion. Ultra wide field fluorescein angiograms were graded for image quality, the presence of retinal neovascularization, and the quantity of nonperfusion; an ischemic index (ISI) was calculated. Charts were reviewed to exclude eyes with previous treatment and to determine which eyes had anterior segment or posterior segment neovascularization on the day of the angiogram. Time from onset to presentation could not accurately be ascertained. RESULTS: In a 39-month period, there were 69 eyes that met inclusion criteria. The mean ISI was 25% (SD, 26%; range, 0-100%), and 15 eyes (21%) with neovascularization had a mean ISI of 75% (range, 47-100%) compared with eyes without neovascularization that had an ISI of 6% (range, 0-43%). Ischemic index significantly correlated to neovascularization, and eyes that had evidence of neovascularization had an ISI >45% (P < 0.0001). CONCLUSION: Ultra wide field fluorescein angiography provides visualization of nonperfusion in eyes with central retinal vein occlusion. Eyes with neovascularization on the day of the angiogram were found to have significantly larger areas of retinal nonperfusion compared with eyes without neovascularization. A prospective study is indicated to know if early treatment of peripheral retinal nonperfusion in CRVO improves outcomes.