Photodynamic therapy with verteporfin for choroidal neovascularization in patients with diabetic retinopathy

PURPOSE: To report the use of photodynamic therapy (PDT) with verteporfin in three patients with choroidal neovascularization (CNV) from age-related macular degeneration and underlying diabetic retinopathy. The level of diabetic retinopathy would have excluded these patients from participation in previously reported randomized clinical trials evaluating PDT with verteporfin due to a theoretic concern of damage to the overlying retinal vasculature. DESIGN: Retrospective interventional case series. METHODS: Three patients from a referral practice with at least severe nonproliferative diabetic retinopathy and a history of clinically significant macular edema developed loss of vision from concurrent choroidal neovascularization evaluated with fundus photography and fluorescein angiography before and after PDT with verteporfin to identify adverse retinal vascular events. RESULTS: Four eyes in three patients had PDT using verteporfin. Three eyes received two treatments. With short follow-up, visual acuity remained stable in two eyes, improved from 20/400 to 20/320 in one eye, and decreased from 20/200 to 20/400 in one eye. Fluorescein angiograms at intervals from 2 weeks to 3 months after PDT showed no damage to the retinal vasculature or progression of the diabetic retinopathy, but did show a decreased area of fluorescein leakage from CNV. One eye that had new subretinal hemorrhage following treatment appeared to show new vasculopathy on initial evaluation of the post-treatment angiogram. Retrospective review suggested that the subretinal hemorrhage provided increased contrast to more easily visualize vasculopathy that was present before the PDT. CONCLUSIONS: Three patients with diabetic retinopathy undergoing a total of seven PDT treatments with verteporfin in four eyes had no new retinal vascular abnormalities develop. No other atypical responses of CNV to PDT were noted except new subretinal hemorrhage, providing increased contrast of the overlying vasculature, which gave the false impression of the development of new vasculopathy in one eye. Patients with diabetic retinopathy who have concurrent CNV for which PDT with verteporfin is recommended should be cautioned regarding the theoretical concerns of harming the retinal vasculature. Periodic surveillance for such concerns seems warranted until more experience is obtained.