Paterson EN, Ravindran ML, Griffiths K, et al. - Among participants (n = 241) with a high burden of comorbidity selected from nuclear cardiology or renal medicine clinics, researchers examined the links between retinal thickness, retinal microvascular and choroidal measures, and renal function. The study sample had a mean age of 65 years and mean estimated glomerular filtration rate (eGFR) was 66.9 ml/min/1.73m², 39% were having diabetes and 27% were using diuretics. Via spectral-domain optical coherence tomograms, retinal and choroidal thickness was measured. The main outcome measure included chronic kidney disease (CKD) classified as: CKD stages 1–2, eGFR ≥ 60 ml/min/1.73m²; CKD stage 3, eGFR 30–59 ml/min/1.73m², and CKD stages 4–5, eGFR ≤ 29 ml/min/1.73m². Findings revealed the link of inner retinal thinning and retinal microvascular variation with advanced CKD (stages 4 & 5), independent of significant confounding factors, but not with earlier stage CKD (stage 3), and thus, findings did not lend support to its utility as a biomarker for early CKD.