Investigation of the association between retinal microcirculation and renal function in children with lupus nephritis

To investigate the association between retinal microcirculation and renal function in childhood-onset systemic lupus erythematosus (cSLE) patients with lupus nephritis (LN).

This cross-sectional study involved 22 cSLE patients with LN (group 1), 24 cSLE patients without LN (group 2), and 23 normal controls (group 3). All participants underwent slit-lamp examination, best-corrected visual acuity testing, intraocular pressure measurement, fundus photography, and optical coherence tomography. Vessel density (VD) of the superficial capillary plexus (SCP), intermediate capillary plexus (ICP), deep capillary plexus (DCP), and choriocapillaris (CC), as well as the foveal avascular zone (FAZ) area, were measured from 4.5 × 4.5 mm optical coherence tomography angiography images. Laboratory parameters of renal function were collected from the patients.

There were no statistical differences in the thickness of the whole, inner, and outer layers of the fovea among the three groups. The VD of the SCP decreased progressively from group 3 to group 2 to group 1. The VD of the ICP differed significantly only between group 1 and group 3 (P = 0.004). Compared with group 3, the VD of the CC in groups 1 and 2 decreased (P = 0.030 and P = 0.005, respectively), while the FAZ area increased (P = 0.013 and P = 0.005, respectively). The VD of the DCP did not differ significantly among the three groups. A positive correlation was found between creatinine and the VD of the SCP (r = 0.338, P = 0.021). The VD of the SCP showed diagnostic accuracy in discriminating between cSLE patients with and without LN (AUC = 0.706, P = 0.017).

In cSLE patients with nephritis, the VD of the SCP decreases further. Although this decline does not parallel the severity of nephritis, it may help identify cSLE patients with nephritis. Key Points • Retinal blood flow of cSLE patients is affected even before visual acuity is impaired or lupus retinopathy develops. • When cSLE patients are complicated with LN, the VD of the SCP is further reduced.