En-face spectral-domain optical coherence tomography versus multifocal electroretinogram in hydroxychloroquine retinopathy screening.

Introduction: The performance of en-face optical coherence tomography (OCT) in screening for chloroquine (CQ) or hydroxychloroquine (HCQ) retinopathy has not been largely explored. The aim of this study was to determine the concordance of en-face OCT with multifocal electroretinography (mfERG) in screening for CQ/HCQ retinopathy. Methods: This is a prospective cohort study conducted at the Rothschild Foundation Hospital - Paris between August 2016 and February 2021. Patients taking hydroxychloroquine were followed up over 2 consecutive years and received an en-face OCT and a mfERG on each visit. Results: A total of 91 patients (182 eyes) were analyzed. mfERG and en-face OCT were concordant in 147 eyes (86.3%). Cohen's Kappa coefficient for concordance between mfERG and en-face OCT was considered weak with a value 0.61 (95% CI: 0.50-0.72). The sensitivity and specificity of en-face OCT are 70% (95% CI: 59-79%) and 91% (95% CI: 83-96%) respectively, relatively to mfERG. Proportion of abnormal R2/R5 and R3/R5 ratios did not differ between patients with normal and abnormal en-face OCT (p=0.2). Discussion/Conclusion: En-face OCT and mfERG have low concordance and cannot be used interchangeably as each investigation evaluates a different facet of CQ/HCQ retinopathy. En-face OCT could be used as a complement in screening for CQ/HCQ retinal toxicity if the anomalies detected on en-face OCT are confirmed by B-scan OCT sections.

Automated summary

This study aimed to determine the concordance of en-face OCT with mfERG in screening for CQ/HCQ retinopathy. The results showed that en-face OCT and mfERG have low concordance and cannot be used interchangeably, as they evaluate different facets of CQ/HCQ retinopathy. If anomalies are detected on en-face OCT, they can be confirmed by B-scan OCT sections.