Spectral domain optical coherence tomography–based prevalence of hydroxychloroquine maculopathy in Indian patients on hydroxychloroquine therapy: A utopia of underdiagnosis

BACKGROUND: Spectral domain optical coherence tomography (SD-OCT) detects early structural damage to macula in patients on Hydroxychloroquine (HCQ) therapy. The current screening protocols emphasize concurrent use of both SD-OCT and Visual field analysis (VFA) which detects functional damage to detect Hydroxychloroquine maculopathy. However, VFA is a time-consuming and subjective test which is often neglected. This study gives the prevalence of Hydroxychloroquine maculopathy using SD-OCT alone which often fails to detect macular damage in peri-foveal and extra-foveal area of the retina. METHODS: Three hundred thirty four eyes of 167 patients taking systemic Hydroxychloroquine were studied with SD-OCT macular cube 512 x 128 to diagnose structural macular damage to detect prevalence of Hydroxychloroquine maculopathy. RESULTS: Out of 167 patients, only four patients showed features suggestive of Hydroxychloroquine maculopathy. One patient had ELM loss, two had para-foveal and one had peri-foveal IS-OS disruption. The SD-OCT gave prevalence as 2.4%. CONCLUSION: SD-OCT alone can underdiagnose burden of Hydroxychloroquine maculopathy (prevalence = 2.4%) when compared to studies which use both SD-OCT and Visual field analysis (prevalence = 7.5%).