Purpose: To investigate the ability of the second generation photosensitizer, Tin Ethyl Etiopurpurin (SnET2) to produce occlusion of experimental choroidal neovascularization (CNV) in a primate model. Methods: CNV was produced in cynomolgus monkeys with high intensity photocoagulation burns (647 nm krypton red at 400 mW, 100 um, 0.1 second). Therapy with either SnET2 (1 mg/kg) or a control lipid emulsion (1 mg/kg) was administered by slow intravenous push. 15 to 30 minutes after injection, irradiation was performed with a 665 nm diode laser with the following parameters: 1200um spot size, exposure interval 60 to 120 seconds, irradiance 600 mW/cm2 and fluence 35 to 70 J/cm2. Eyes were evaluated with fundus photography, fluorescein angiography and optical coherence tomography (OCT) before and after treatment Results: Treatment with SnET2 and 665 nm light resulted in complete angiographic occlusion of the CNV. Late stages in the angiogram demonstrated fluorescein dye leakage at the margins of the irradiated field. Control eyes treated with lipid emulsion and 665 nm light did not show any effect on CNV leakage. CNV was demonstrated on OCT as thickening and disruption of the layer corresponding to the RPE/choriocapillaris: changes in reflectivity were observed after PDT therapy. Conclusions: Photodynamic therapy with SnET2 combined with 665 nm irradiation is effective in producing selective closure of experimental CNV.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience