A study of optical coherence tomography angiography of changes in retina and choroid immediately after hemodialysis

Abstract

Purpose : To evaluate the changes in macular perfusion density (MPD), choroidal thickness (CT), retinal thickness (RT) and foveal avascular zone (FAZ) in patients with end-stage renal disease (ESRD) being treated with hemodialysis (HD).

Methods : 32 eyes of 32 patients with ESRD undergoing HD were recruited prospectively. All patients underwent swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography just beside the dialysis center immediately before and after HD. The retinal and choroidal thickness maps were generated automatically by SS-OCT. En face OCTA image and density map of microvasculature were obtained with automated segmentation using SS-OCT angiography. MPD and FAZ area were measured at the level of the superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina, and choriocapillaris.

Results : After HD, MPD significantly decreased at the level of the choriocapillaris (p = 0.01), while MPD in the SCP, DCP and outer retina were not statistically changed (p = 0.39, p= 0.40 and p = 0.19, respectively). The changes in FAZ were not statistically significant (in the SCP, p = 0.35; in the DCP, p = 0.38). Total CT was significantly decreased (p<0.001) and total RT was significantly increased (p<0.001). There was no significant correlation among the changes in CT, RT and MPD after HD.

Conclusions : This is the first study to measure changes in blood flow before and after HD using OCTA. Our study suggests blood volume changes due to HD may affect the choroidal layer than the retinal layer without significant correlation with CT and RT changes.