Abstract:【Abstract】 Objective To characterize the changes in macular retinal microvascular circulation in patients taking hydroxychloroquine (HCQ) using optical coherence tomography angiography (OCTA), and to explore the value of OCTA in the early screening of HCQ-related retinal toxicity. Methods A retrospective case-control study was conducted. Forty-one patients with rheumatic immune diseases (case group) treated at The First People’s Hospital of Lianyungang from January 2025 to March 2026 were enrolled. All patients regularly took HCQ, with no obvious organic abnormalities found on fundus examination. Nineteen healthy subjects matched for age, gender and other demographic characteristics were selected as the control group.A total of 60 subjects were included, and data from the right eye were used for statistical analysis.The subjects were divided into three groups according to the duration of HCQ intake: healthy control group (Group A), HCQ intake < 5 years (Group B), and HCQ intake ≥ 5 years (Group C).All subjects underwent best-corrected visual acuity (BCVA), spectral-domain optical coherence tomography (SD-OCT), visual field examination and fundus examination.OCTA was used to measure vessel density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the 6 mm×6 mm macular region (fovea, parafovea and perifovea), as well as the area, perimeter, and vessel density of the foveal avascular zone (FAZ) and outer retinal Flow Area.One-way analysis of variance (ANOVA) was used for comparison of quantitative data among multiple groups, and t-test was used for pairwise comparison. Spearman’s rank correlation was used to analyze the correlation between regional retinal vessel density and duration of HCQ intake in the case group (Groups B and C). Results Macular retinal DCP vessel density in Group C was significantly lower than that in Group A (P<0.05). There was no significant difference in SCP vessel density among the three groups (P>0.05).Regional DCP vessel density (whole image, superior hemi-field, inferior hemi-field, fovea, parafovea, perifovea) was negatively correlated with the duration of HCQ intake in patients taking HCQ (r=-0.176, -0.219, -0.184, -0.317, -0.436, -0.259, all P<0.05). Conclusions OCTA reveals reduced vascular density in macular deep capillary plexus (DCP) among patients with rheumatic disorders receiving long-term hydroxychloroquine (HCQ). This parameter correlates negatively with treatment duration, suggesting OCTA may serve as an adjunctive tool for early screening of HCQ-related retinal toxicity.
