Retinal and optic nerve microvasculature assessment in nephritic and nonnephritic systemic lupus erythematosus: a comparative analysis

Background Lupus nephritis is considered one of the most common complications of systemic lupus erythematosus (SLE) that greatly affects the overall prognosis. Retinopathy, as one of the disease complications, is an indicator of disease severity, frequent renal impairment, and poor prognosis. Therefore, screening of subclinical retinopathy is of great importance as retinopathy and nephropathy are somehow associated in SLE patients. Aim The aim of this study was to assess the changes in retinal and optic nerve microcirculation in nephritic and nonnephritic SLE patients without clinical evidence of retinopathy or optic neuropathy. Patients and methods This is a prospective observational study that included 66 SLE patients. They were divided into two groups: group A that included 34 patients with nephritis and group B that included 32 patients without nephritis. In addition, 33 healthy participants (group C) were included as a control group. The participants were assessed with optical coherence tomography angiography of the macula and optic nerve. Assessment of vessel densities (VD), foveal avascular zone, retinal nerve fiber layer thickness, and optic nerve head and peripapillary VD were done. Results Group B patients were found to have significantly lower VDs in whole superficial VD ( P =0.014) and all sectors of perifovea ( P =0.005, 0.006, and 0.013 for whole, superior hemiretina, and inferior hemiretina, respectively). In addition, there was a significantly lower VD of the deep capillary plexus (DCP) in the parafovea ( P =0.003, 0.004, and 0.01 for whole, superior, and inferior hemiretina, respectively) and in the perifovea ( P =0.007, 0.002, and 0.014 for whole, superior hemiretina, and inferior hemiretina, respectively). Group A showed specific reduction of VD of the DCP of whole and perifoveal superior hemiretina ( P =0.04) and choriocapillaris flow parameters ( P =0.003). They also showed increase of inferior retinal nerve fiber layer thickness and whole image capillary density ( P =0.036 and 0.001, respectively). Concerning the peripapillary capillary density, the whole image peripapillary capillary density and inferior peripapillary VD of group A was increased in comparison to group B ( P =0.023 and 0.009, respectively) with no statistically significant difference with group C. Conclusion Nephritic SLE patients showed reduction in VD of the DCP of the perifoveal superior hemiretina and choriocapillaris, while nonnephritic SLE patients showed reduction of VD of the SCP of the perifovea and DCP of parafovea and perifovea.