Prevalence, clinical features, and causes of vision loss among patients with ocular toxocariasis

To describe the prevalence, clinical features, and causes of vision loss among patients with ocular toxocariasis seen at a uveitis referral center.

A review was completed of the charts of patients with ocular toxocariasis who were examined between 1977 and 1996 at the Francis I. Proctor Foundation of the University of California at San Francisco. The prevalence of ocular toxocariasis among all uveitis patients seen at the center was determined. Demographic features, symptoms, and signs in all patients were evaluated.

Ocular toxocariasis occurred in 22 (1.0%) of 2,185 uveitis patients. The mean patient age was 16.5 years. Inflammation was usually unilateral (90.9%). Toxocara uveitis presented as a granuloma in the peripheral retina in 50% of cases, as a granuloma in the macula in 25% of cases, and as a moderate to severe vitreous inflammation mimicking endophthalmitis in 25% cases. The primary causes of vision loss were vitritis (52.6%), cystoid macular edema (47.4%), and traction retinal detachment (36.8%).

Ocular toxocariasis is an uncommon cause of uveitis that mainly affects younger patients. Inflammation is typically unilateral and presents as either a granuloma in the peripheral or posterior retina or a moderate to severe vitreous inflammation mimicking endophthalmitis.