Early Detection of Neurovascular Alterations and the Impact of Medication Treatment on the Retina in Systemic Lupus Erythematosus Patients: A Retrospective Cohort Study and Mendelian Randomization Analysis

This study aimed to evaluate early retinal structural and microvascular changes in patients with systemic lupus erythematosus (SLE) and to assess the impact of treatment on these alterations. This study used optical coherence tomography angiography (OCTA) to compare the retinal microstructure between patients with SLE and healthy controls. SLE patients were stratified into subgroups based on the treatment regimen they received: the hydroxychloroquine (HCQ)-glucocorticoid (GC) subgroup, the HCQ subgroup, and the GC subgroup. Mendelian randomization (MR) analysis was employed to explore the causal relationship between HCQ/GC use and retinal vascular disorders. A retrospective analysis was conducted on data from 100 participants (59 SLE patients and 41 controls). SLE patients showed reduced vascular density (VD) in superficial/deep capillary plexuses (SCP/DCP), radial peripapillary capillaries (RPC), choriocapillaris flow areas (CCFAs), and foveal 300-µm wide vascular density (FD-300) (P < 0.05). Inner limiting membrane-retinal pigment epithelium (ILM-RPE) thickness in foveal/perifoveal regions was thinner in SLE patients (P < 0.05). HCQ or GC subgroups exhibited lower SCP-VD, DCP-VD, FD-300, and CCFAs versus controls and HCQ-GC subgroup (P < 0.05). The ILM-RPE thickness was thinnest in the HCQ monotherapy subgroup (P < 0.05). The MR analysis indicated that GC had an inhibitory effect on retinal vascular disorders (OR=0.733, P = 0.037), whereas HCQ was not significantly correlated with these disorders. OCTA can detect early retinal changes in asymptomatic patients with SLE. Compared with monotherapy, combination therapy with HCQ and GCs is associated with less retinal damage.