Clindamycin Effects on Experimental Ocular Toxoplasmosis in the Rabbit

The effect of treating experimental toxoplasmic retinochoroiditis with clindamycin (7-chlorolincomycin) phosphate was evaluated in 14 rabbits. Clinical improvement was evident in 71.4% of the treated eyes but in only 28.6% of the untreated eyes. Toxoplasma organisms could not be isolated from treated eyes but could be isolated from 78.6% of the untreated eyes. Histopathologic examination showed normal retinal architecture was preserved in three fourths of the treated eyes and inflammatory changes were only mild to moderate. In contrast, more than two thirds of the untreated eyes showed marked to severe retinochoroiditis with complete disruption of the normal retinal architecture and severe tissue destruction. These data indicate that clindamycin is effective in the treatment of experimental toxoplasmic retinochoroiditis in rabbits. Investigation of the potential value of this antibiotic for the treatment of ocular toxoplasmosis in humans should be pursued.