In patients with
chronic kidney disease (CKD), there is an unmet need for novel
biomarkers that reliably track kidney injury, demonstrate treatment-response, and predict outcomes. Here, we investigate the potential of
retinal optical coherence tomography (OCT) to achieve these ends in a series of prospective studies of patients with pre-dialysis CKD (including those with a kidney transplant), patients with
kidney failure undergoing
kidney transplantation, living kidney donors, and healthy volunteers. Compared to health, we observe similar
retinal thinning and reduced macular volume in patients with CKD and in those with a kidney transplant. However, the choroidal thinning observed in CKD is not seen in patients with a kidney transplant whose choroids resemble those of healthy volunteers. In CKD, the degree of choroidal thinning relates to falling eGFR and extent of
kidney scarring. Following
kidney transplantation, choroidal thickness increases rapidly (~10%) and is maintained over 1-year, whereas gradual choroidal thinning is seen during the 12 months following kidney donation. In patients with CKD,
retinal and choroidal thickness independently associate with eGFR decline over 2 years. These observations highlight the potential for
retinal OCT to act as a non-invasive monitoring and prognostic
biomarker of kidney injury.