The importance of Toxoplasma as the cause of a substantial percentage of cases of posterior uveitis has been indicated by histopathological, serological, and clinical studies (see Frenkel and Jacobs, 1958, for review). The value of this advance has been mainly the possibility for successful treatment of some uveitides which were previously managed, without much success, by nonspecific therapy. A presumptive diagnosis of ocular toxoplasmosis has allowed the use of anti-Toxoplasma drugs, with encouraging results in a number of cases.
The effectiveness of pyrimethamine in murine toxoplasmosis was first reported by Eyles and Coleman (1952) and by Summers (1953) working independently. Eyles and Coleman (1953) demonstrated synergism between pyrimethamine and sulfadiazine in experimental infections in mice. These drugs have been used either singly or in combination in various clinical studies of ocular toxoplasmosis (Ryan et al, 1954; Perkins et al, 1956; Jacobs et al, 1956; Burnham and Beuerman, 1956; Kaufman,