Macular ganglion cell-inner plexiform layer thickness for detection of early retinal toxicity of hydroxychloroquine

Abstract

This study evaluated the macular ganglion cell-inner plexiform layer (GC-IPL) thickness using spectral-domain (SD) optical coherence tomography (OCT) in patients with chronic exposure to hydroxychloroquine (HCQ). A total of 90 patients (90 eyes) treated with HCQ for at least 5 years and normal controls were included in the study. A fundus examination, automated threshold perimetry, and GC-IPL thickness measurements using the Cirrus high-definition OCT ganglion cell analysis algorithm were performed in all patients treated with HCQ. Average, minimum, and sectorial macular GC-IPL thicknesses were compared between the patients and controls. There was no statistically significant difference in age or sex between the groups. The anterior segment and fundoscopy were normal in all patients and controls. Visual field (VF) testing was normal in all patients. The average, minimum, and sectorial macular GC-IPL thicknesses were significantly lower in patients than those in control subjects. There was significant thinning of the macular GC-IPL in the absence of clinically evident HCQ-related retinopathy and VF abnormalities. Measurements of the macular GC-IPL thickness using SD-OCT may therefore be useful in the early diagnosis and in monitoring the progression of retinal changes in patients receiving long-term HCQ therapy.