Decreased Retinal Thickness in Patients With Alzheimer's Disease

ABSTRACT

BACKGROUND: The loss of ganglion cells observed in Alzheimer's disease (AD) patients might be attributable to a neurodegenerative process involving the neuroretinal structure. The objective of this study was to determine the retinal thickness in patients with AD using optical coherence tomography (OCT). METHODS: Neuro-ophthalmologic examinations were performed in eight AD patients and eight age-matched control subjects. The average thicknesses of the retinal nerve fiber layer (RNFL) and the ganglion cell-inner plexiform layer (GCIPL) were measured using spectral-domain OCT in both subject groups, and the results were compared. RESULTS: The RNFL was thinner in AD patients than in the age-matched controls (p<0.05), especially at the nasal and inferior retina, and the GCIPL was also significantly thinner (p<0.05). CONCLUSIONS: The decreased retinal thickness observed in AD patients suggests that OCT can be used as a biological marker of AD. The findings of this preliminary study suggest that the extent of the reduction in GCIPL and RNFL thicknesses should be investigated further.