Background  

To describe the clinical characteristics of active ocular toxoplasmosis in a large population of Turkish patients.

Methods  

A retrospective study of 109 consecutive patients with active ocular toxoplasmosis seen at the Department of Ophthalmology, Istanbul Faculty of Medicine, from 1995 to 2005.

Results  

Fifty-seven patients were female and 52 were male. The mean age at presentation was 25.7 ± 6.8 years. All patients had positive serum anti-toxoplasma IgG antibodies, but negative IgM antibodies. Preexisting retinochoroidal scars were found in 90 (83%) patients. Central active lesions were significantly more common in eyes without previous involvement than in eyes with preexisting scars (97% vs. 59%). Active lesions were adjacent to a scar in 60 (78.9%) of 76 eyes with preexisting scars. The most common accompanying signs were vitritis (100%), anterior uveitis (49.5%), and periphlebitis (33%). All patients received antiparasitic treatment. Systemic corticosteroids were used in 86% of the patients. Kaplan–Meier survival analysis estimated the cumulative risk of recurrence as 74% at 42 months of follow-up. In 29 (80.5%) of 36 recurrent attacks, active lesions were associated with the scars of the most recent attack. After the resolution of the presenting attack, visual acuity was better than 0.5 in 90%, between 0.1 and 0.5 in 5%, and less than 0.1 in 5% of eyes. Further decrease in visual acuity occurred in only two eyes during our follow-up.

Conclusions  

Most of the patients with active ocular toxoplasmosis have asymptomatic retinochoroidal scars. Proximity of active lesions to the scars, and especially to those of the most recent episode, may have implications for treatment. Although the recurrence risk is high, the visual prognosis is good in most patients with typical ocular toxoplasmosis.