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Treatment of Experimental Anterior and Intermediate Uveitis by a Dexamethasone Intravitreal Implant

2011; Cadmus Press; Volume: 52; Issue: 6 Linguagem: Inglês

10.1167/iovs.10-5939

1552-5783

Corine Ghosn, Yong Li, Werhner Orilla, Ton Lin, Larry Wheeler, James A. Burke, Michael R. Robinson, Scott M. Whitcup,

Ocular Infections and Treatments

Purpose.: To assess the efficacy of a dexamethasone (DEX) intravitreal implant in a rabbit model of anterior and intermediate uveitis. Methods.: Experimental anterior and intermediate uveitis was induced by a unilateral intracameral injection of Mycobacterium tuberculosis H37Ra antigen in preimmunized rabbits. Four days after uveitis induction, rabbits received DEX implant or underwent a sham procedure (no implant). Clinical and histopathologic signs of uveitis were assessed for 13 days, and levels of inflammatory markers in the iris/ciliary body were measured after 21 days. Results.: All signs of anterior and intermediate uveitis were reduced by the DEX implant compared with sham procedure. At day 13, mean anterior chamber cell scores ± SD for the DEX implant versus the sham procedure were, respectively, 1.9 ± 1.3 versus 4.0 ± 0.0 (P = 0.04), and mean total histologic inflammatory scores were 3.9 ± 2.5 versus 15.4 ± 6.0 (P = 0.026). Similarly, at day 13, mean vitreous haze severity scores (SD) for the DEX implant versus the sham procedure were, respectively, 0.1 ± 0.2 versus 2.7 ± 1.5 (P = 0.026), and mean vitreous inflammatory cell infiltration scores were 0.0 ± 0.0 versus 1.5 ± 1.3. Treatment with the DEX intravitreal implant also significantly reduced the proinflammatory immune response, as measured by cytokine levels in iris/ciliary body. Conclusions.: A single administration of DEX implant significantly reduced inflammation in an animal model of anterior and intermediate uveitis.