EYE MANIFESTATIONS OF CONGENITAL TOXOPLASMOSIS

PURPOSE: To determine the natural history of treated and untreated con genital toxoplasmosis and impact of this infection on vision. METHODS: In this prospective, longitudinal study, 76 newborns were treated wit h pyrimethamine and sulfadiazine for approximately one year, and 18 in dividual not treated during their first year of life entered the study after age 1 year (historical patients). RESULTS: Chorioretinal scars were the most common eye finding in all patients and were most common in the periphery (58% of treated and 82% of historical patients). Macu lar scars were present in 54% of the treated patients; 41% were bilate ral. Macular scars were present in 76% of the historical patients; 23% were bilateral. Visual acuity in the presence of macular lesions rang ed from 20/20 to 20/400. Of the patients followed up from the newborn period and treated, 29% had bilateral visual impairment, with visual a cuity for the best eye of less than 20/40. Causes for this visual impa irment in eyes with quiescent lesions included macular scars, dragging of the macula secondary to a peripheral lesion, retinal detachment, o ptic atrophy, cataract, amblyopia, and phthisis. There were recurrence s in both treated (13%, 7/54) and previously untreated historical pati ents (44%, 8/18). The total, median, and range of years of follow-up d uring which recurrences were observed were, for treated patients, 189 years (total), five years (median), and three to ten years (range) and , for historical, untreated patients, 160 years (total), 11 years (med ian), and three to 24 years (range). New lesions occurred in previousl y normal retinas and also contiguous to older scars. Active lesions ap peared to become quiescent within ten to 14 days after beginning pyrim ethamine and sulfadiazine therapy. CONCLUSION: Many children with cong enital toxoplasmosis have substantial retinal damage at birth and cons equent loss of vision. Nonetheless, vision may be remarkably good in t he presence of large macular scars. Active lesions become quiescent wi th treatment.