Changes in retinal nerve fiber layer (RNFL) thickness have been reported in patients with mild cognitive impairment
(MCI), the pre-dementia stage of Alzheimer’s disease (AD). However, whether RNFL thickness is associated
with specific cognitive impairment of MCI patients remains unknown. Therefore, we set out to investigate the potential
association between RNFL thickness and episodic memory in MCI patients. Seventy five older adults (mean age 74 ± 3
years, 55% men) were included in the study. Fifty-two participants had normal cognition (NC), and 23 participants were
diagnosed with MCI. RNFL thickness was obtained by optical coherence tomography measurement. Cognitive function
was evaluated by the Repeatable Battery for the Assessment of Neuropsychological Status on the same day of the optical
examination. We found that nasal quadrant RNFL thickness was positively associated with episodic memory scores in the
participants with normal cognition: word list learning (r=0.392, p=0.004) and story recall (r=0.307, p=0.027). In the participants
with MCI, however, the inferior quadrant RNFL thickness was inversely associated with the episodic memory
score: word list learning (r=-0.652, p=0.001), story memory (r=-0.429, p=0.041), and story recall (r=-0.502, p=0.015,).
The findings from this pilot study suggest that the inferior quadrant RNFL thickness was associated with specific episodic
memory in MCI patients and could serve as a biomarker of MCI and AD. These findings would promote more studies to
determine the potential application of RNFL as an AD biomarker.