A study published in Alzheimer’s & Dementia has revealed that non-invasive retinal imaging could offer critical insights into a person’s risk for Alzheimer’s disease and related dementias (ADRD). Conducted by Barrett-Young et al., the research explores how several retinal health measures, derived from routine eye scans, correlate with ADRD risk markers and cognitive performance.
The study leveraged data from the Dunedin Study’s age 45 assessment, New Zealand’s longest-running longitudinal study, which has examined the lives of 1037 babies born between April 1, 1972 and March 31, 1973 since birth. Examining optical coherence tomography (OCT) scans, the researchers focused on retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC), and macular thickness. They found that thinner RNFL and GCC layers were associated with poorer cognitive performance and increased genetic risk for Alzheimer’s, based on polygenic risk scores (PRS). These associations remained significant even after controlling for confounding factors like age and cardiovascular health.
The authors conclude that OCT, a widely available and inexpensive imaging technology, could become a valuable tool for early ADRD risk screening. Unlike brain MRIs or spinal taps, OCT is non-invasive, rapid, and patient-friendly, and this could democratize access to early detection methods, enabling large-scale population screening and more targeted intervention strategies.
However, it is emphasized that retinal biomarkers are not yet a replacement for existing diagnostic tools, and their predictive power should be viewed as a complementary approach. Future longitudinal studies are now needed to confirm whether retinal thinning precedes cognitive decline and can thus serve as a true early warning signal for ADRD.
