Evaluation of retinal microcirculation by optical coherence tomography angiography in patients with primary membranous nephropathy

•Optical coherence tomography angiography (OCTA) is a non-invasive fundus imaging technique that enables to display retinal microvasculature.•The damage of primary membranous nephropathy (PMN) on microvasculature is well-known.•There is currently no literature discussing the impact of PMN on retinal microcirculation.•We found that the vascular density (VD) and perfusion density (PD) in the macular area of the PMN group are significantly reduced. Primary membranous nephropathy (PMN) patients may experience retinal microvascular changes. However, current diagnostic methods for PMN are not accurate in analyzing these modifications. In the present study, optical coherence tomography angiography (OCTA) was used for quantitative measurement of microvascular changes in the eyes of PMN patients. A total of 26 patients with PMN and 26 healthy control (HC) were evaluated in this cross-sectional study. Optical coherence tomography (OCT) and OCTA were used to collect retinal thickness (RT) and microvascular parameters in the macula and optic disk in the superficial capillary plexus (SCP) of all subjects. Clinical data were collected from the PMN group. The OCT and OCTA data for PMN and HC group were compared, and the correlation between the OCTA and clinical data in the PMN group was determined. Vascular density (VD) and perfusion density (PD) in the macular area of the PMN group were significantly lower than those of the HC group, especially in the temporal quadrant. No significant difference in the foveal avascular zone (FAZ), optic disc microvascular parameters, RT, and retinal nerve fiber layer (RNFL) thickness was observed between the two groups. Correlation was noted between VD and PD in the macular area and clinical indicators, such as serum creatinine, serum urea nitrogen, 24 h urine volume and urinary protein concentration. Microvascular alterations in PMN patients occurred before ocular symptoms. The present quantitative study proposed a measurement method for detecting early retinal vascular injury in PMN patients.