Effects of Intravitreal Injection of Tacrolimus (FK506) in Experimental Uveitis

Abstract

Purpose: To examine the immunosuppressive and neuroprotective effects of intravitreal injection of tacrolimus in experimental uveitis. Methods: Tacrolimus (40 μ g) was injected intravitreally in rabbits to examine safety. Experimental uveitis was induced in rabbits by systemic immunization with bovine serum albumin (BSA) followed by intravitreal challenge with BSA. On day 1 after BSA challenge, tacrolimus (20 or 40 μ g) or betamethasone (400 μ g) was injected intravitreally in one eye and balanced salt solution in the contralateral eye. The eyes were evaluated by slit-lamp biomicroscopy, electroretinography, and histopathology.Results: No local or systemic adverse reaction was observed in normal rabbits. In experimental uveitis, intravitreal injection of tacrolimus significantly reduced intraocular inflammation in histopathological analysis (p < 0.03). Amplitudes on the electroretinogram were restored (p < 0.01), and retinal thickness was preserved in tacrolimus-treated eyes (p < 0.03). Conclusions: In experimental uveitis, intravitreal injection of tacrolimus effectively suppresses ocular inflammation and preserves retinal architecture.

KEYWORDS:

• experimental uveitis;
• immunosuppression;
• intravitreal injection;
• neuroprotection;
• tacrolimus