Ocular findings in Japanese patients with hydroxychloroquine retinopathy developing within 3 years of treatment

Purpose: To describe the characteristics of Japanese patients with hydroxychloroquine (HCQ) retinopathy developing within 3 years of treatment outset. Study design: Retrospective case series Methods: Three patients with HCQ retinopathy developing within 3 years of treatment outset have been identified in Japan since HCQ became available in 2015. Their medical charts, containing optical coherence tomography (OCT), fundus autofluorescence imaging, and visual field tests, were reviewed. Results: The treatment durations and cumulative doses until onset were 29–36 months and 182–326 g, respectively. The first patient had possible pre-existing maculopathy, although the abnormalities were ambiguous. The second and third patients had impaired renal function. The patients did not complain of severe visual disturbance at diagnosis, but visual field loss and disruption of the outer retinal segments consisting of a parafoveal pattern in the first case and a pericentral pattern (localized, 8 or more degrees from the center of the fovea) in the second and third cases were clearly observed on OCT. Even after HCQ discontinuation, their retinopathy showed slight progression on the visual field tests and OCT images. A blood sample was obtained from 1 patient on the day after HCQ discontinuation, and the whole blood level of HCQ was measured using validated liquid chromatography-tandem mass spectrometry. The HCQ level 27 h after the last dose was high, at 2240 ng/mL (suggested threshold > 1733 ng/mL). Conclusion: Ophthalmologic screening from the initiation of HCQ treatment detected 3 cases of HCQ retinopathy developing within 3 years of treatment outset, including a patient with a high blood level of HCQ.