Retinal ganglion cell–inner plexiform layer thickness is nonlinearly associated with cognitive impairment in the community‐dwelling elderly

Abstract

Abstract Introduction Thinning of optical coherence tomography–measured retinal nerve fiber layer thickness and ganglion cell–inner plexiform layer (GC‐IPL) thickness has been found in patients with Alzheimer's disease. However, the association of these retinal markers and cognition in nondemented elders may not be linear. Methods This cross‐sectional study included 227 community‐dwelling elders (age 65+ years). Multivariable regression analyses were performed to investigate the association between retinal nerve fiber layer/GC‐IPL and global/domain‐specific cognition. Results The performance of global cognition decreased as mean GC‐IPL of bilateral eyes deviated from the sample mean (77.5 μm) (quadratic GC‐IPL: β = –0.49 × 10−2; 95% confidence interval: −0.74 × 10−2 to −0.23 × 10−2). Similar associations were also found for logical memory. No significant association was observed between retinal nerve fiber layer and cognition. Discussion Either thinning or thickening of GC‐IPL was associated with poor cognition in nondemented elderly (a U‐shaped association). GC‐IPL may serve as a noninvasive preclinical predictor of Alzheimer's disease.

Keywords

• Retina
• Alzheimer's disease
• Biomarkers
• Preclinical AD
• Cognitive impairment
• Optical coherence tomography