[Iris neovascularization as a complication of central artery occlusion]

Iris neovascularization (IN) with a secondary angle closure glaucoma is a complication of central retinal artery occlusion (CRAO). Its incidence is greatly underestimated.

In a retrospective study we analyzed all patients with CRAO seen within 2 years who were treated in our department. We looked especially for the frequency of the occurrence of IN.

In 27 patients with CRAO, 5 developed an IN with a secondary neovascular glaucoma with high intraocular pressure. Thus, the frequency of IN was 18 % in our patients. The IN occurred 2 months to 2 years after the occlusion. Visual acuity in three eyes was between 1/20 and light perception and two eyes had no light perception. In all cases a panretinal laser treatment was performed. Three eyes were additionally treated with a peripheral retinal cryocoagulation and cyclophotocoagulation. In the histories of these patients, diabetes mellitus and arterial hypertension were found.

In previous studies it has been shown, that ischemia/reperfusion injuries of the retina after CRAO predispose to IN (incidence 3 - 18 %). Although it has been shown that the majority of IN occurs within three months, our data show that IN may occur as a severe complication of CRAO even later. Patients should be followed-up closely (including gonioscopy), to diagnose the occurrence of IN early. Recommended treatment is panretinal laser coagulation or -- in the case of a secondary angle closure glaucoma -- cyclophotocoagulation, respectively.