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

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.

Retinal ganglion cell degeneration correlates with hippocampal spine loss in experimental Alzheimer’s disease

“…RGC degeneration in the IPL can be imaged in vivo at high resolution using optical coherence tomography (OCT). With the development of broad-spectrum light sources, OCT can detect changes in the optical scattering characteristic of neurons undergoing degeneration and even changes in neuronal membrane refractive index that correlate with neuronal activity [ 21 , 27 , 34 ]. The demonstration that retinal changes occur in both the 3xTg-AD and APP NL-G-F AD models early in the disease process and correlate with synaptic dysfunction, an early pathological event preceding neuronal cell loss and amyloid deposition in AD [ 9 ], indicates that retinal imaging has the potential to provide insights into the CNS health in mild cognitive impairment and the early stages of AD.…”

Retinal imaging in Alzheimer's and neurodegenerative diseases

“…Photoreceptors capture visual information and transmit it via interneurons to retinal ganglion cells (RGCs). Extending from the inner retina, these cells make direct synaptic connections with the CNS through the optic nerve and optic pathways 13 …”

“…A PubMed search using the terms "retina" and "Alzheimer" Extending from the inner retina, these cells make direct synaptic connections with the CNS through the optic nerve and optic pathways. 13 Retinal changes have been observed across the continuum of AD and in other proteinopathies and neurodegenerative disorders, clearly establishing the importance of eye pathology in these diseases. 14 For example, the hallmark biomarkers of AD-amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) composed of the protein tau-have been identified in the retina of individuals with AD 15 and may either trigger, or be otherwise associated with, a pathological cascade.…”

Ganglion Cell-Inner Plexiform Layer Thickness is Associated with Persistently Cognitive Decline -The Rugao Longevity and Aging Study

“…Firstly, we assessed the cognitive function for three times in each subjects among 5-years follow-up. Previous studies concentrated on the relationship between retinal thickness and cognitive function assessed by single one-point and found close relationship between them [7,[41][42][43]. However, not all individuals with CD progressed to dementia or consistently stabilized CD, while 18%-24% of mild cognitive impairments individuals reverted to normal cognition [26,[44][45][46], which potentially leading to partial association of neurodegeneration with retinal thickness.…”