PHOTODYNAMIC THERAPY FOR CORNEAL NEOVASCULARIZATION

BACKGROUND AND OBJECTIVE: Photodynamic therapy with tin ethyl etiopurp urin (SnET2) was evaluated as a treatment modality for rat corneal neo vascularization.MATERIALS AND METHODS: Escalating light doses at 664 n m were applied focally to corneal neovascularization in rats 10 minute s following an intravenous injection of SnET2 using a low-power diode laser. Controls consisted of light-only and drug-only treatments. Clin ical, angiographic, and histopathologic evaluations were performed on the animals up to 28 days after drug and/or light treatment. RESULTS: A drug and light dose-response was seen in producing neovessel closure . In animals treated with SnET2 and the highest light dose (25 J/cm(2) ), all eyes showed occlusion at every follow-up evaluation up to 28 da ys. Control eyes demonstrated progressive disease at all time points. CONCLUSIONS: Photodynamic therapy appears to be safe and effective for eliciting prolonged (> 28 days) occlusion of corneal neovascularizati on in the rat model with minimal side effects and good clinical outcom es.