Retinal toxicity due to antimalarials: frequency and risk factors

To study the frequency of retinal toxicity and associated risk factors in a cohort of patients treated with antimalarials and seen at a tertiary level hospital.

Retrospective study of 40 patients treated with antimalarials, who were referred to ophthalmology for the study of retinal toxicity during 2011. Data collection included type of antimalarial prescribed, daily and cumulative doses, presence of rheumatic disease, corticosteroid use, associated diseases and ophthalmologic examination. Retinal toxicity was confirmed if two of the following tests were altered: fundus examination, visual field with a macular pattern, changes in spectral domain optical coherence tomography and full-field electroretinography.

Toxic retinopathy was detected in 13.1% of patients (95% confidence interval 5-21%) and a trend for a higher risk was observed in case of chloroquine (CQ) treatment. Among the patients with retinopathy, the mean cumulative dose was 229 g for CQ and 111 g for Hydroxychloroquine (HCQ), and the mean daily dose of CQ was 250 mg and 333 mg for HCQ. Arterial hypertension had a statistically significant effect on retinopathy development.

Toxic retinopathy defined by ophthalmological evaluation was detected in 13.1% of patients. A trend for a higher risk was observed in case of chloroquine treatment.