Ocular Toxoplasmosis: Clinical Features and Prognosis of 154 Patients

Purpose: To ascertain the clinical features, visual outcome, and recurrence rates of ocular toxoplasmosis (OT) in a large series of patients. To determine the efficacy of various treatment strategies and identify the patients at risk of visual loss.

Design: Retrospective noncomparative observational case series.

Participants: One hundred fifty-four consecutive patients with active lesions of OT (first attack and/or recurrence) were identified in a cohort of 1300 consecutive patients with uveitis. Mean follow-up was 5.8 years.

Intervention: A review of the medical records of 154 patients with active OT.

Main Outcome Measures: Patients were subdivided according to clinical and laboratory criteria. Numerous variables were compared per patient and group, including age and gender distribution, onset and course of infection, clinical ocular features, laboratory data, therapeutic strategies and their outcomes, number of recurrences, complications, final visual acuity, and features associated with poor visual outcome.

Results: Primary retinal lesions were observed in 28% and a combination of active lesions and old retinochoroidal scars in 72% of the patients at first presentation to the ophthalmologist. Mean age at first presentation with an active OT lesion was 29.5 years. Patients with primary OT were older than those with a combination of active lesions and old scars (P < 0.001). Serologic characteristics of the acute phase of systemic infection were found in 11% of the patients. Ocular involvement in these patients was associated with advanced age at onset (P < 0.001) and was characterized by severe intraocular inflammation. Most (82%) of the patients with serologic characteristics of the acute phase of systemic infection had primary lesions (compared with 23% of OT in the chronic phase of systemic infection; P < 0.001). Extensive retinal lesions were more frequently observed during the acute phase of systemic infection (P = 0.02) and in patients with primary OT (P < 0.04). Recurrences, which developed in 79% of all patients followed for more than 5 years, were located predominantly in previously affected eyes (with old scars) in contrast to the sporadic cases of recurrence in the healthy contralateral eye (P < 0.0001). Standard short-term therapeutic modalities had no effect on visual outcome or future recurrence rates. Legal blindness in one or both eyes was confirmed for 24% of the patients. Blindness of both eyes was more frequent in patients with congenital OT (P < 0.001). Risk factors for visual loss included congenital infection, OT manifesting during the acute phase of systemic infection, central location and/or extensive retinal lesions, and the administration of corticosteroids without a shield of antiparasitic drugs.

Conclusions: Legal blindness in at least one eye developed in 24% of the patients with OT. Recurrences, which developed in 79% of the patients with long-term follow-up, were located predominantly in eyes with toxoplasmic scars. Various short-term therapeutic modalities had no effect on visual outcomes or future recurrence rates, with the exception of a poor visual outcome for patients who received corticosteroids without a shield of antiparasitic drugs.