The effect of long-term hemodialysis on diabetic retinopathy observed by swept-source optical coherence tomography...

Diabetes can cause chronic microvascular complications such as diabetic retinopathy (DR) and diabetic nephropathy (DN). DR and DN can lead to or exacerbate diabetic macular edema (DME). Hemodialysis (HD) is the main treatment method for patients with end-stage kidney disease (ESKD) secondary to DN.

The aim of this prospective cohort study was to determine the immediate effect of single HD session on retinal and choroidal thickness in DR patients with ESKD and the features of DR and the prevalence of DME in these patients who have received long-term HD.

Eighty-five eyes of 44 DR patients with ESKD who underwent long-term HD were examined by swept-source optical coherence tomography angiography (SS-OCTA). Based on OCTA images, the characteristics of DR and the prevalence of DME in these patients were analyzed. Changes in central retinal thickness (CRT), central retinal volume (CRV), subfoveal choroidal thickness (SFCT) and subfoveal choroidal volume (SFCV) within 30 min before and after single HD session were compared. CRT, CRV, SFCT and SFCV were compared before single HD session and before the next single HD session.

There was no significant difference in the average CRT (251.69 ± 39.21 μm vs. 251.46 ± 39.38 μm, P = 0.286) or CRV (0.15 ± 0.62 μm vs. 0.15 ± 0.63 μm, P = 0.324) between before and after single HD session. After single HD session, SFCT (243.11 ± 77.15 μm vs. 219.20 ± 72.84 μm, P < 0.001) and SFCV (0.15 ± 0.10 μm vs. 0.13 ± 0.90 μm, P < 0.001) significantly decreased. There was no statistically significant difference in CRT (251.69 ± 39.21 μm vs. 251.11 ± 38.47 μm, P = 0.206), CRV (0.15 ± 0.62 μm vs. 0.15 ± 0.61 μm, P = 0.154), SFCT (243.11 ± 77.15 μm vs. 245.41 ± 76.23 μm, P = 0.108), or SFCV (0.15 ± 0.10 μm vs. 0.16 ± 0.10 μm, P = 0.174) before HD and before the next single HD session. On en face OCTA images, eighty-five eyes (100%) had retinal nonperfusion areas, foveal avascular zone (FAZ) enlargement, and abnormal retinal microvasculature. Based on cross-sectional OCTA images, retinal neovascularization (RNV) was confirmed in 42 eyes (49.41%), and intraretinal microvascular abnormalities (IRMAs) were detected in 85 eyes (100%). Seventeen eyes (20%) still had DME, all of which were cystoid macular edema (CME). Among eyes with DME, the epiretinal membrane (ERM) was present in 7 eyes (8.24%).

For DR patients with ESKD who have undergone long-term HD, the choroidal thickness still changes significantly before and after single HD session, which may be related to short-term effects such as reduced blood volume and plasma osmotic pressure caused by single HD session. Although macular features seem to have stabilized in DR patients undergoing long-term dialysis, the DR of patients with ESKD should still be given attention.