Optical Coherence Tomography Angiography (OCTA) Study of Microvascular Changes in Systemic Lupus Erythematosus (SLE) Patients with no Clinical Ocular Manifestations

Abstract Purpose The aim of this study is to evaluate retinal microvasculature using OCTA in patients with SLE without signs of retinopathy according to standard lupus retinopathy classification and correlate abnormal vascular density with disease activity and severity. Methods in this Prospective observational non-interventional study, 36 eyes of 18 SLE patients were compared with 36 eyes of normal subjects. The retinal capillary plexuses were examined by OCTA at time of enrollment and every 4 months for a year using Angio-OCT Optovue RTVue XR Avanti system (Optovue Inc., Fairmont, CA) with documentation of Foveal avascular zone (FAZ) area in mm, acircularity index(AI), Retinal vessel density in a 300-μm-wide region around the FAZ (FD-300), Retinal vessel density in superficial and deep retinal layers (foveal, parafoveal and perifoveal areas). The scanning area was captured in 6 × 6-mm sections, automatically centered on the fovea (HD angio retina 6 × 6-mm), also radial peripapillary vessel density (HD angio disc 4.5 × 4.5-mm) (superior, inferior, nasal and temporal) were studied. The disease activity and damage risk were evaluated by the SLEDAI-2 K and SLICC/ACR system and a correlation was done between changes found and disease activity. Results No difference was found between SLE patients and the normal in foveal avascular zone (FAZ) area, FAZ perimeter, Acircularity Index (AI)(P > 0.05). No difference was found between SLE patients’ macular thickness in foveal region and parafoveal region and the normal (P > 0.05),while mean perifoveal average macular thickness was significantly lower in SLE patients group (p = 0.025). There was a significant decrease in foveal thickness measurements in SLE patients group during follow up period (p = 0.007). SLE patients had significantly lower superficial vessel densities (SVD) than normal in the parafoveal and perifoveal regions (p = 0.001),(p < 0.001) respectively, and during follow up period significant decrease was observed in SVD values (p = 0.001). Regarding the deep capillary plexus (DCP), There was no significant difference between SLE patients group and the normal (p > 0.05), while during follow up period Significant decrease was observed in deep foveal vessel density in SLE patients group (p = 0.013). There was a significant negative correlation between disease activity (measured by SLEDAI-2K and SLICC/ACR scores) and SVD & foveal deep vessel density. Conclusions OCTA permits noninvasive quantitative assessment of retinal vessel density in SLE, allowing early detection of altered retinal circulation. superificial Vessel density and foveal deep vessel density could be included in future assessment of SLE activity and damage scores to early detect any changes for early management and treatment.