The epidemiologic association of Fuchs' heterochromic iridocyclitis and ocular toxoplasmosis.

Between January 1983 and July 1987, I examined 25 patients at the Department of Ophthalmology, West Virginia University, who had the anterior segment characteristics of Fuchs' heterochromic iridocyclitis. Of these patients, 16 had fundus lesions suggestive of ocular toxoplasmosis. Of these 16 patients, 13 had a positive serologic test for toxoplasmosis, two patients were not tested, and one patient had a negative test at 1:16. The remaining nine patients with Fuchs' heterochromic iridocyclitis had no fundus lesions suggestive of toxoplasmosis. A chart review of 792 consecutive patients at the Retinal Unit, West Virginia University, during a six-month period disclosed that 24 of 590 patients (4%) had chorioretinal scars suggestive of toxoplasmosis. I concluded from these data that in at least one subgroup of patients with Fuchs' heterochromic iridocyclitis there is a significant association with the chorioretinal scars of toxoplasmosis (P less than .01), and this is suggestive of a causal relationship.