Retinal biomarkers may help detect early Alzheimer disease

Functional and structural changes of retina measured by multifocal electroretinogram and swept-source optical coherence tomography suggest retinal biomarkers may be a useful tool in the early detection of in vivo Alzheimer disease (AD) pathologic abnormalities in cognitively normal older adults, according to a study.

In this cross-sectional study, 49 cognitively normal (CN) participants underwent an ophthalmic examination, including swept-source optical coherence tomography (SS-OCT) and multifocal electroretinogram, in addition to amyloid-β (Aβ) positron emission tomography and magnetic resonance imaging.

Reduced inner nasal macular thickness and retinal nerve fiber layer thickness, particularly in the inferior quadrant was found in the 16 participants with Aβ compared with the 33 participants without Aβ deposition. This group also had prolonged implicit time, particularly in ring 5.

Neurodegeneration related to AD was correlated with ganglion cell-inner plexiform layer thickness only. The model to differentiate the groups derived from the results showed 90% accuracy.

The authors concluded that retinal biomarkers can reflect in vivo Alzheimer disease–related brain abnormalities in CN older adults and have the potential to be used as surrogate biomarkers of early Alzheimer disease.

Reference
Byun MS, Park SW, Lee JH, et al. Association of retinal changes with Alzheimer disease neuroimaging biomarkers in cognitively normal individuals. JAMA Ophthalmol. Published online March 25, 2021. doi:10.1001/jamaophthalmol.2021.0320