Conjunctival and retinal microvascular loss in systemic lupus erythematosus: a swept-source OCTA study.

Purpose: This study aimed to characterize conjunctival and retinal microvascular alterations in Systemic lupus erythematosus (SLE) using swept-source optical coherence tomography angiography (SS-OCTA), and to evaluate their correlation with systemic clinical manifestations.

Methods: This cross-sectional study enrolled 32 SLE patients and 32 age, sex, and spherical equivalent matched controls. Participants underwent swept-source OCTA imaging of nasal and temporal conjunctiva (16 × 12 mm scans) and macula (6 × 6 mm scans). Vessel density of conjunctival vessel, superficial vascular plexus (SVP), and deep vascular plexus (DVP) were quantified using automated segmentation. Correlation analyses were conducted to evaluate the association between conjunctival and retinal vascular densities, as well as their relationships with clinical parameters of systemic involvement and disease activity.

Results: SLE patients showed significant reductions in nasal (45.0% vs. 60.1%, p < 0.001) and temporal (51.8% vs. 60.5%, p = 0.009) conjunctival vascular density, alongside pan-retinal DVP attenuation (p < 0.05). Combined nasal conjunctival and retinal nasal DVP analysis yielded high diagnostic accuracy (AUC 0.897). Microvascular loss was independent of organ involvement or disease activity (p > 0.05).

Conclusions: SLE is associated with significant reductions in conjunctival and retinal DVP vascular density. Combined multimodal SS-OCTA analysis achieved superior diagnostic accuracy, with microvascular loss independent of disease activity or organ-specific involvement, suggesting systemic microvascular injury as a unifying SLE feature. Conjunctival-retinal vascular metrics may serve as potential new biomarkers for SLE.