Retinal and choroidal microvascular changes in hemodialysis and peritoneal dialysis: a comparative OCT and OCTA study

This study aimed to evaluate retinal and choroidal structural and microvascular parameters using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) in patients undergoing hemodialysis (HD) and peritoneal dialysis (PD). Furthermore, it aimed to compare short-term dialysis-associated ocular changes between the two dialysis modalities.

This prospective observational study encompassed 84 eyes from 46 patients undergoing either HD or PD. Ocular measurements were conducted at two time points according to the dialysis modality. Measurements for HD patients were taken before and after dialysis, whereas for PD patients, measurements were performed after dialysate drainage and following refilling. Comprehensive ophthalmologic assessments and OCT/OCTA imaging were performed. Statistical analyses were used to compare pre- and post-dialysis measurements and changes between the HD and PD groups.

CMT significantly increased after dialysis, whereas subfoveal choroidal thickness significantly decreased. Systolic and diastolic blood pressures also decreased significantly. No significant changes were observed in OCTA-derived retinal microvascular parameters, including vessel density and FAZ parameters. A significant difference in ΔCMT was observed between the HD and PD groups (p = 0.002). Correlation analysis showed a moderate negative correlation between ΔCMT and the change in systolic blood pressure and a moderate positive correlation between ΔCMT and dialysis session duration.

Most OCTA-derived retinal microvascular parameters remained stable following dialysis, whereas small but statistically significant structural changes were observed in CMT and subfoveal choroidal thickness. The magnitude of short-term CMT change differed between HD and PD; however, the mechanism underlying this difference remains uncertain. OCT and OCTA may serve as useful non-invasive tools for evaluating ocular structural and microvascular changes in patients with ESRD undergoing dialysis.