Unusual Presentation of Acute Hydroxychloroquine Retinopathy

To report a rare case of cystoid macular edema (CME) as a presentation of acute hydroxychloroquine-related retinal toxicity.A 37-year-old female patient visited our ophthalmology department in October 2019 complaining of bilateral blurred vision and metamorphopsia for 3 days. Best-corrected visual acuity (BCVA) was 6/6 in the right eye and 6/7.5 in the left eye under the Snellen E chart. Before presentation, she had taken hydroxychloroquine as a "reproduction-facilitating medication" prior to the in vitro fertilization (IVF) procedures with the daily dose of 200 mg for 1 week in March 2019 and 400 mg for 1 month in September 2019. She also took a combination of several herbal medicine including "Angelica sinensis" for 6 months in this period. On examination, typical signs of hydroxychloroquine maculopathy such as bilateral paracentral retinal pigment epithelium (RPE) change in blue autofluorescence and loss of the paracentral ellipsoid zone in optical coherence tomography ("flying saucer sign") were noted. CME was also found in fluorescein angiography. Her symptoms improved gradually after cessation of hydroxychloroquine and herb medicine without any further treatment. Resolution of bilateral CME was revealed at 16 weeks with final bilateral BCVA 6/6.Although rare, acute hydroxychloroquine maculopathy could occur in patients with concomitant usage of medications that could interfere with P450 enzymes system. Careful acquisition of drug history and serial ophthalmological examinations are advised in using hydroxychloroquine for disease management even for a short period of time.