Ocular neovascularization following central retinal artery occlusion: prevalence and timing of onset

PURPOSE. Debate exists in the literature on the prevalence and etiology of neovascularization following central retinal artery occlusion (CRAO). The reported prevalence varies from 2.5% to 31.6%. We conducted a retrospective study to determine the prevalence of ocular neovascularization following acute CRAO in our institution. METHODS. A retrospective audit of consecutive patients with nonarteritic/thromboembolic CRAO presenting between 1997 and 2009 in a single tertiary teaching hospital. RESULTS. Thirty-three patients were identified as having nonarteritic CRAO, and of this cohort 6 patients (18.2%) developed ocular neovascularization. Neovascular glaucoma was present in 5 cases (15.2%); 2 of these presented through an emergency department with painful eyes, both at 16 weeks post CRAO. The other cases of neovascularization were detected on scheduled follow-ups. Mean time from retinal occlusive event to observed neovascularization was 8.5 weeks (range 2-16 weeks). One case of neovascularization was associated with hemodynamically significant ipsilateral carotid stenosis; no patient had proliferative diabetic retinopathy or other causes of neovascularization. CONCLUSIONS. The prevalence of neovascularization following acute CRAO in our population was 18.2% at an average of 8.5 weeks post CRAO. There was a temporal relationship between the 2 events and no other causes of neovascularization demonstrable in our cohort of patients. There is no consensus on the follow-up regimen post CRAO to detect ocular neovascularization complications. Our study suggests that neovascularization can occur early and regular follow-up especially in the first 4 months is important post CRAO.