Chorioretinal and choriovitreal neovascularization after photocoagulation for proliferative diabetic retinopathy. A clinicopathologic correlation.

A patient with proliferative diabetic retinopathy was treated by panretinal and focal photocoagulation. Later, he developed one area of clinically diagnosed chorioretinal and choriovitreal neovascularization (CNV), neovascular glaucoma, and a blind painful eye necessitating enucleation. Clinicopathologic correlations of this eye including fundus photography, fluorescein angiography, light and electron microscopy are reported. Histopathologic examination revealed three areas of CNV, suggesting that some CNV may go undetected clinically also in other cases and thus may occur more frequently than evident from the literature. Our CNV occurred at sites of focal treatment. Retreatment of one area was unsuccessful. Choriovitreal neovascularization passed through discontinuities of Bruch's membrane into the retina and showed fenestrae of the endothelial cells. Endothelial fenestrae may account for the profuse fluorescein leakage seen clinically in CNV.