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

Abstract

Background 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. Purpose The aim of this prospective cohort study was to determine the changes in retinal and choroidal thickness in patients with ESKD before and after HD and the impact of long-term HD on DR. Methods Eighty-five eyes of 44 DR patients with ESKD who underwent 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 minutes before and after HD were compared. CRT, CRV, SFCT and SFCV were compared before HD and before the next HD. Results 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 HD. After HD, 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 HD. On en face OCTA images, eighty-five eyes (100%) had retinal nonperfusion areas, focal 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, and all had cystoid macular edema (CME). Among eyes with DME, the epiretinal membrane (ERM) was present in 7 eyes (8.24%). Conclusions For DR patients with ESKD who have undergone long-term HD, the choroidal thickness still changes significantly before and after HD, which may be related to short-term effects such as reduced blood volume and plasma osmotic pressure caused by HD. Although HD can improve DME, the DR of patients with ESKD should still be given attention.