Application of SS- OCTA to evaluate the effects of long- term hydroxychloroquine treatment on retinal structure and microcirculation in patients with systemic lupus erythematosus

Abstract

Propose The application of swept-source optical coherence tomography angiography (SS-OCTA)technique is used to detect the effects of long-term use of hydroxychloroquine (HCQ) on retinal structure and microcirculation in patients with systemic lupus erythematosus (SLE) before visual dysfunction occurs. Methods Retrospective case-control study. A total of 73 SLE patients (73 eyes) who had taken HCQ regularly for a long period of time were included as the SLE patient group, while 21 healthy individuals (21 eyes) were included as the control group. Based on the duration of HCQ use (HCQ course), the SLE patient group was divided into baseline group(6 months ≤ medication time< 1 year), low-risk group ( 1 year ≤ medication time < 5 years), and high-risk group (medication time ≥ 5 years). All participants underwent bilateral SS-OCTA macular imaging(6mm*6mm), slit-lamp examination, non-contact tonometry, computerized visual field (30-2) test, and fundus autofluorescence imaging (FAF). Results Compared with the control group, the thickness of the inner retina of the central fovea, the inner retina of the parafoveal area, and the outer retina in three areas, as well as the superficial vessel density in the central fovea, inner ring below, and outer ring were decreased in the SLE patient group,while the FAZ area and circumference increased (P<0.05). In comparison to the SLE patients, the high-risk group showed a decrease in the inner retinal thickness, full retinal thickness of the macular area (6mm*6mm), and shallow retinal blood flow density in the central foveal area, temporal periphery, and superior periphery. Additionally, the FAZ (foveal avascular zone) area and perimeter increased (P<0.05). Correlation analysis showed that the duration of SLE, cumulative dose of HCQ and the thickness of the total retina in three regions including inner retinal layer, central foveal area, and inner superior and temporal quadrant SCP-VD were negatively correlated (r<0, P<0.05), while the FAZ area and perimeter were positively correlated (r>0, P<0.05). Conclusion Analysis by SS-OCTA examination showed that long-term HCQ treatment had adverse effects on the inner retina, SCP-VD and FAZ parameters in subclinical SLE patients without visual impairment.