Iatrogenic choroidal neovascularization in sickle cell retinopathy

Fifteen patients (16 eyes) with proliferative sickle retinopathy treated with argon or xenon arc feeder vessel photocoagulation had chorioretinal (CRN) or choriovitreal (CVN) neovascularization develop. These patients were followed from 2 1/2 to 11 1/2 years with a mean follow-up of 6 years and 8 months. Clinically important late complications of the choroidal neovascularization included vitreous hemorrhage (in three of eight patients with CVN). However, in only two of these three eyes was there any drop in vision related to residual vitreous hemorrhage, and this was limited to loss of only one line of Snellen visual acuity. Therefore, treatment is not usually recommended if CRN or CVN develops after intense photocoagulation. Vitreous fluorophotometry was performed on these patients to examine the breakdown of the blood-retinal barrier. This gave a quantitative measure of fluorescein leakage not obtained with fluorescein angiography. Midvitreous measurements, which are more representative of these peripherally located proliferative lesions than are pre-retinal measurements, suggest that vitreous fluorophotometry may be helpful in differentiating the higher leakage of CVN from the CRN.