Comparing pegaptanib and triamcinolone efficacy in the rat choroidal neovascularization model.

Abstract

OBJECTIVE: To evaluate the prophylactic effect of intravitreal pegaptanib sodium on choroidal neovascularization membrane (CNVM) development and compare its performance with that of triamcinolone acetonide. METHODS: In drug-treated and control groups, CNVMs were induced by laser trauma. Immediately after undergoing the laser procedure, animals received intravitreal injections of pegaptanib sodium, 8 or 17 mug; triamcinolone acetonide, 200 mug; or a vehicle solution. After 21 days, fluorescein angiography was performed. The CNVM mean diameters and radial thicknesses were measured histologically. RESULTS: Mean CNVM diameters were 10% to 13% smaller in pegaptanib-treated eyes and 43% smaller in triamcinolone-treated eyes compared with laser-only control eyes. Late-stage fluorescein angiography leakage scores, on a scale of 0 to 3, suggested a statistical difference between triamcinolone- (0.6) and pegaptanib(8 microg)-treated (1.5) groups compared with the laser-only control group (2.0). The CNVM mean thicknesses were greater in the pegaptanib(8 microg)- (79 microm) and pegaptanib(17 microg)-treated (71 microm) groups and significantly smaller in the triamcinolone-treated group (26 microm) compared with the laser-only control group (67 microm). CONCLUSION: In this animal model of choroidal neovascularization, intravitreal pegaptanib exhibited marginal or no effect on CNVM development; whereas intravitreal triamcinolone evoked robust inhibition of CNVMs. Clinical Relevance Pegaptanib treatment may be insufficient to prevent CNVM formation.