Evaluation of toxic retinopathy caused by antimalarial medications with spectral domain optical coherence tomography.

Renata Tavares De Souza Cabral,Maria Isabel Noronha Neta Couto,Sueli Carneiro,Evandro Mendes Klumb

doi:10.5935/0004-2749.20190002

Renata Tavares De Souza Cabral, Maria Isabel Noronha Neta Couto + Show 2 more

Open Access

https://doi.org/10.5935/0004-2749.20190002

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Abstract

To investigate the frequency of toxic retinopathy in patients with lupus erythematosus and rheumatoid arthritis with long-term use of chloroquine diphosphate or hydroxychloroquine through spectral domain optical coherence tomography and the outcomes of ophthalmological exams (visual acuity - Snellen's table, color vision test - Ishihara's table, fundoscopy, and retinography - red-free). A cross-sectional study was carried out involving the ophthalmologic evaluation of patients using regular chloroquine diphosphate or hydroxychloroquine for a period of 1 year or longer. The patients completed a questionnaire on their opinions and treatment regularity. The same patients underwent ophthalmologic examination and spectral domain optical coherence tomography. The prevalence of toxic retinopathy caused by antimalarials was 4.15% (9 of 217 patients), 7.4% (4 of 54 patients) following chloroquine diphosphate usage, and 0.82% (1 of 121 patients) following hydroxychloroquine usage. Only patients with advanced stage maculopathy presented abnormalities during the ophthalmologic exam: the color vision test was altered in 11.1%, and visual acuity and fundoscopy were altered in 33.3%. Identification of early toxic retinopathy, detected in six patients, was possible using spectral domain optical coherence tomography. The mean duration of antimalarial drug usage among patients with toxic retinopathy was 10.4 years. Only 31% of the patients reported some symptoms during treatment, and although 24% were afraid to use the medication, they did so as prescribed. Use of spectral domain optical coherence tomography was essential for the diagnosis of early-stage antimalarial toxic retinopathy in patients with the following characteristics: asymptomatic, antimalarial use 7 days a week for a period of more than 5 years, and normal clinical ophthalmologic examination.

Highlights

Toxic retinopathy (TR) caused by antimalarials, first described in 1951, is a rare adverse effect that causes irreversible vision loss[1,2,3,4]
The prevalence of TR caused by antimalarials was 4.15%, occurring in 9 of 217 patients
The prevalence of toxic maculopathy was 7.4% from chloroquine diphosphate (CQ) usage (4 of 54 patients; 95% CI: 0.0042 to 0.143) and 0.82% from HCQ usage (1 in 121 patients; 95% CI: 0.00786 to 0.02438)

Summary

Introduction

Toxic retinopathy (TR) caused by antimalarials, first described in 1951, is a rare adverse effect that causes irreversible vision loss[1,2,3,4]. The prevalence of TR differs among antimalarials. The risk factors for antimalarial TR described by the American Academy of Ophthalmology in 2016 were categorized as major and minor. The minor risk factors are age over 60 years, presence of liver disease, and generic factors (anomaly in ABCA423-2016 or P45024-2016 gene 4). The major risk factors are period of exposure greater than 5 years, nephropathy, concomitant use of tamoxifen, previous presence of ma culopathy, and dose/kg of antimalarials (for hydroxychloroquine - HCQ, greater than 5.0 mg/kg of actual weight and for CQ, greater than 2.3 mg/kg of actual weight)(4)

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