Modulation of experimental retinal vasculitis using dexamethasone, cyclosporin A, and prazosin.

The effects of dexamethasone, cyclosporin A and prazosin were investigated in an animal model of retinal vasculitis. Both dexamethasone and cyclosporin A reduced the clinical and pathological signs of disease when given from the day of disease onset. Prazosin, an alpha 1 adrenergic antagonist, was given during the period of disease induction and blocked fluorescein leakage from actively inflamed retinal vessels, but had little effect on the clinical and pathological signs of disease. This study demonstrates the feasibility of using this animal model for therapeutic trials of anti-inflammatory agents in retinal vasculitis. The effect of prazosin on reducing vascular leakage from retinal vessels has implications for the treatment of inflammatory macula oedema in human disease.