Optic nerve involvement in ocular toxoplasmosis: 12 year data from a tertiary referral center in Turkey

ABSTRACT Purpose: To evaluate the prevalence, clinical characteristics, and types of optic nerve involvement in patients with ocular toxoplasmosis. Methods: For this retrospective cross-sectional study, we examined all patients with active ocular toxoplasmosis referred to our Uveitis Section during the last 12 years, and we included patients with optic nerve involvement in the study. The primary outcome was the prevalence of optic nerve involvement, and secondary outcomes included the types of optic nerve involvement and the final best-corrected visual acuity after treatment. Results: The prevalence of optic nerve involvement was 14.4%, with the leading cause being the activation of a juxtapapillary lesion (70.5%). We found papillitis in two eyes and neuroretinitis in two eyes (11.7% for each). We only detected one optic nerve involvement secondary to a distant active lesion (5.8%). Sixteen patients (94.1%) had unilateral ocular toxoplasmosis. The overall final best-corrected visual acuity after treatment was 10/10 (LogMAR = 0.0) excluding the three patients with a juxtapapillary scar involving the macula. Conclusions: Optic nerve involvement was common in patients with ocular toxoplasmosis. The main type of optic nerve involvement was caused by activation of an old juxtapapillary lesion. Treatment was quickly effective, but the best-corrected visual acuity was dependent on the presence of a scar in the papillomacular bundle.