Photodynamic therapy for corneal neovascularization.

BACKGROUND AND OBJECTIVE

Photodynamic therapy with tin ethyl etiopurpurin (SnET2) was evaluated as a treatment modality for rat corneal neovascularization.

MATERIALS AND METHODS

Escalating light doses at 664 nm were applied focally to corneal neovascularization in rats 10 minutes following an intravenous injection of SnET2 using a low-power diode laser. Controls consisted of light-only and drug-only treatments. Clinical, 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/cm2), all eyes showed occlusion at every follow-up evaluation up to 28 days. 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 neovascularization in the rat model with minimal side effects and good clinical outcomes.