Clinical manifestations and visual outcomes associated with ocular toxoplasmosis in a Brazilian population

Ocular toxoplasmosis is the leading cause of posterior uveitis worldwide. We conducted an observational study of 262 consecutive individuals (n=344 eyes) with ocular toxoplasmosis who were followed over a 34-month period. Most subjects were T. gondii IgG+/IgM- (n=242; 92.4%; 317 eyes), and 140 eyes (40.7%) had active lesions. For eyes in which retinal lesions were active at recruitment and best-corrected visual acuity (BCVA) could be measured (n=133), 21.0% (n=28) remained blind (BCVA below 20/400) after inflammation resolved. In these eyes, atypical ocular toxoplasmosis (OR 4.99; 95% CI 1.14-22.85; p=0.0330), macular lesion (OR 9.95; 95% CI 2.45-47.15; p=0.0019) and any complication (OR 10.26; 95% CI 3.82-30.67; p<0.0001) were associated with BCVA below 20/200. For eyes with only inactive lesions at recruitment and BCVA measured (n=178), 28.1% (n=50) were blind. In these eyes, having at least one lesion larger than one disc-diameter (OR 6.30; 95% CI 2.28-22.46; p=0.0013) and macular lesion (OR 5.69; 95% CI 2.53-13.54; p<0.0001) were associated with BCVA below 20/200. Older age (OR 1.02; 95% CI 1.00-1.05; p=0.0493) and active disease at presentation (OR 4.74; 95% CI 1.95-12.91; p=0.0011) were associated with recurrences. Additional clinical attention should be directed towards patients with risk factors for poor visual outcome.