Chorioretinal and choriovitreal neovascularization. Their presence after photocoagulation of proliferative sickle cell retinopathy.

Delayed development of choroidally fed neovascularization represents a potentially serious complication of feeder vessel photocoagulation of proliferative sickle cell retinopathy (PSR). Of the 53 photocoagulated eyes, choroidally fed neovascularization developed in 21 within one month to seven years (mean, 32.8 months). This complication appeared in eyes treated with argon laser and xenon arc. In 11, neovascular tissue remained flat in the chorioretinal scar (chorioretinal neovascularization), but in ten, the vessels grew into the vitreous (choriovitreal neovascularization). In many cases of chorioretinal neovascularization, the only subsequent complication was local vitreous hemorrhage. Visual acuities remained near normal. The development of choriovitreal neovascularization was associated with vitreous hemorrhages or retinal detachment in six of ten cases. Final visual acuities, however, were 20/50 or better in nine. Photocoagulation in some cases converted chorioretinal neovascularization to choriovitreal neovascularization or seemed to stimulate further growth of choriovitreal neovascularization. We now recommend no treatment for most cases of choroidally fed neovascularization. Photocoagulation techniques for PSR should attempt to minimize the development of choroidally fed neovascularization.