Ophthalmic Scans Provide Insight into Kidney Health

Earlier this week, researchers at the University of Edinburgh published an article in Nature Communications revealing that choroidal and retinal thinning may be biomarkers for chronic kidney disease (CKD). These conclusions imply that ophthalmic scans can provide insight into overall kidney health.

“We hope that this research, which shows that the eye is a useful window into the kidney, will help identify more people with early kidney disease — providing an opportunity to start treatments before it progresses,” said Neeraj Dhaun, MD, Professor of Nephrology at the University of Edinburgh’s Center for Cardiovascular Sciences, in the university announcement. It also offers potential for new clinical trials and the development of drug treatments for a chronic disease that, so far, has proved extremely difficult to treat.

The researchers theorized that retinal optical coherence tomography (OCT), a type of 3D ophthalmic imaging, could be a novel biomarker for CKD. According to the publication, the study was based on the theory that OCT can track kidney imaging, monitor treatment response, and predict patient outcomes.

To analyze this hypothesis, researchers evaluated OCT scans from prospective studies, including scans of pre-dialysis CKD patients — with and without kidney transplants, patients with kidney failure undergoing transplantation, live kidney donors, and healthy patients.

Approximately 204 patients with varying stages of kidney disease and 86 healthy patients were included in the analysis.

Based on the insights from the scans, researchers concluded that retinal thinning is a biomarker for kidney disease. Patients with CKD had thinner retinas and a reduced macular volume than healthy patients, with more significant differences detected in patients with advanced stages of the disease. The retinal thickness and macular volume changes were maintained in patients with or without a kidney transplant.

Conversely, choroidal thinning was only detected in CKD patients before a transplant. The researchers theorize that restoring kidney function can re-establish choroidal thickness, with a 10% restoration for one year after transplantation.

Beyond identifying these biomarkers, the scientists also note that these factors can indicate CKD regardless of the estimated glomerular filtration rate (eGFR).

Although more studies are required to validate this biomarker, researchers are optimistic about its potential. The investigators predict that this discovery could have implications in clinical trials, providing an easier way to monitor improvement for CKD treatments.

“Kidney patients often face invasive procedures to monitor their kidney health, often on top of receiving grueling treatments like dialysis,” added Aisling McMahon, PhD, Executive Director of Research and Policy at Kidney Research UK. “This fantastic research shows the potential for a far kinder way of monitoring kidney health. We are continuing to support the team as they investigate whether their approach could also be used to diagnose and intervene in kidney disease earlier.”