Intravitreal triamcinolone acetonide inhibits choroidal neovascularizationin a laser-treated rat model

Objective: To determine if intravitreal triamcinolone acetonide (TAAC) inhi bits experimental choroidal neovascular membranes induced by laser trauma i n a rat model. Methods: Nineteen anesthetized male Brown Norway rats received a series of 8 krypton red laser lesions per eye (647 nm, 0.05 seconds, 50 mum, and 150 mW in 17 rats, and 200 mW in 2 rats). One eye received an intravitreal inje ction of triamcinolone acetonide (20 muL, 0.8 mg) and the other eye receive d an injection of isotonic sodium chloride solution. Fundus and fluorescein angiography examinations occurred just before euthanasia and tissue proces sing for histopathology on day(s) 0, 1, 3, 7, 14, 21, 28, and 35. Results: From the control eyes that underwent photocoagulation at 150 mW, 5 7 discrete lesions with definitive fibrovascular proliferations were observ ed at 21, 28, and 35 days, arising from a total of 72 spots placed (79% yie ld). From the control eyes that underwent photocoagulation at 200 mW, 11 di screte lesions with definitive fibrovascular proliferations were observed a t 28 days, arising from a total of 16 spots placed (69% yield). In the TAAC -treated group, no fibrovascular proliferations were observed in the 72 les ions and in the 16 lesions created with 150 mW and 200 mW, respectively. Conclusion: Intravitreal TAAC is a potent inhibitor of fibrovascular prolif erations in a rat model of choroidal neovascular membranes induced by laser trauma. Clinical Relevance: This study corroborates previous investigations that pr opose TAAC as a potential treatment for choroidal neovascular membranes in humans.