Retinal toxicity by antimalarial agents in a Brazilian reference service: Prevalence and risk factors

Hydroxychloroquine sulfate (HCQ) and chloroquine diphosphate (CQ) are antimalarial drugs, used as anti-inflammatories and immunomodulators in the treatment of various autoimmune diseases, notably Systemic Lupus Erythematosus. From a systemic point of view, these drugs are considered safe and well tolerated. However, a serious adverse effect is the retinotoxicity that can result from prolonged use, in a dose-dependent manner. Recent studies estimate a higher prevalence of retinotoxicity than previously assumed, up to 7.5%. Considering that toxic damage is irreversible, the need for ophthalmological screening is considered a consensus, whose intention is to detect early signs of injury before functional impairment occurs. On the other hand, inappropriate cessation of HCQ can impair the patient’s systemic control, so a clear definition of the diagnosis of toxicity is essential. The classic clinical manifestation in these cases is a bilateral “bull’s eye maculopathy”, in which there is damage to the outer layers of the photoreceptors in the parafoveal region, progressing to secondary atrophy of the retinal pigment epithelium. Recently, the finding that Asians may have an atypical pattern of pericentral lesions has raised scientific interest in terms of the clinical picture of retinotoxicity in different ethnic groups. When these changes become apparent on funduscopic examination, they indicate advanced disease. Therefore, for the investigation of lesions caused by HCQ and CQ, complementary tests are necessary, such as Computerized Visual Perimetry, Spectral Domain Optical Coherence Tomography and Background Autofluorescence. Despite this, divergences persist regarding sensitivity and the ideal combination of these methods. Based on this sample, the intention is to assess the adequacy of international guidelines to the ethnic and social particularities of the Brazilian reality.

Project details

Basic Science

Mar 2022

Brazil