Clinical spectrum of atypical ocular toxoplasma chorioretinitis

Abstract

Purpose To describe the clinical spectrum of patients with atypical ocular toxoplasmosis, requiring confirmatory diagnosis with PCR (due to uncommon clinical presentation or non‐response to conventional treatment). Methods All cases with confirmed positive PCR for Toxoplasma gondii seen in the Bristol Eye Hospital over the last 5 years were retrospectively reviewed for patient demographic, known systemic immunosuppression, clinical presentation, response to treatment and recurrences/complications. Results A total number of 16 patients were included. Five of which were immunocompromised. Bilateral disease was seen in three cases (18.7%). The mean age at diagnosis was 64.9, with 37.5% female and 62.5% male patients. 10 out of the 19 affected eyes (52.6%) had multifocal lesions with 9 eyes (47.4%) having an isolated lesion. Eleven patients (one bilateral) had fluorescein angiography during their follow‐up, which confirmed the presence of vasculitis in nine of those eyes (75%) with five of these having occlusive vasculitis (41.7%). Of the twelve patients treated with azithromycin as first line, only 4 (25%) showed a response to treatment. Conclusions PCR is warranted to identify cases of atypical ocular toxoplasmosis. These atypical forms were also seen in immunocompetent patients. Although azithromycin has been proved to be an alternative therapy in the treatment of ocular toxoplasmosis, we identified a lack of response to azithromycin in 75% of patients in our series of patients with atypical ocular toxoplasmosis.