New proposal for a multimodal imaging approach for the subclinical detection of hydroxychloroquine-induced retinal toxicity in patients with systemic lupus erythematosus

Abstract

ObjectiveTo compare multimodal structural and functional diagnostic methods in patients with systemic lupus erythematosus (SLE) treated with hydroxychloroquine, to identify the best complementary approach for detecting subclinical retinal toxicity.MethodsA cross-sectional, unicentric study was conducted on patients with SLE treated with hydroxychloroquine. Each patient underwent a comprehensive ophthalmic evaluation, comprising structural tests (spectral-domain optical coherence tomography (SD-OCT),en faceOCT,en faceOCT angiography (OCTA), fundus autofluorescence (FAF)) and functional tests (automated perimetry for visual field (VF) testing, multifocal electroretinography (mfERG)). A diagnosis of macular toxicity required the presence of abnormalities in at least one structural and functional test. The Kappa Concordance Index was used to assess the concordance among the different tests in detecting potential macular toxicity-associated alterations.ResultsSixty-six patients with SLE (132 eyes) were consecutively enrolled. Four (6.1%) patients developed subclinical hydroxychloroquine-induced retinal toxicity without visual acuity impairment. The proportion of abnormal results was 24% for bothen faceOCT anden faceOCTA. Regarding functional analysis, VF was less specific than mfERG in detecting subclinical retinal toxicity (VF specificity 47.5%).En faceOCT anden faceOCTA structural findings showed better concordance, with akappaindex >0.8, and both identified the same cases of toxicity as FAF.ConclusionAlthough structural OCT and VF are frequently used to screen for hydroxychloroquine-induced retinal toxicity, our findings suggest that a combination of mfERG,en faceOCT anden faceOCTA could improve the diagnostic accuracy for subclinical retinal damage. This study emphasises the importance of a multimodal imaging strategy to promptly detect signs of hydroxychloroquine-induced retinal toxicity.