Retinal nerve fibre layer thickness changes in Alzheimer’s disease: Results from a 12-month prospective case series

• Progressive thinning of the retinal nerve fibre layer by SD-OCT in AD has been described in this prospective comparative case series on AD patients.
• The progression of the retinal abnormalities found AD participants correlated with their cognitive decline over time.
• Repeated measurements of the retinal nerve fibre layer could serve as a new potential dynamic AD biomarker in the eye.

PurposeTo compare the 12-month peripapillary retinal nerve fibre layer (pRNFL) thickness change between AD patients and normal subjects.MethodsIn this prospective case series, thirty-six patients with a diagnosis of mild to moderate AD and 36 age-matched control subjects were included. All the subjects underwent neuropsychological (MMSE, ADAS-Cog and CDR) and ophthalmological evaluation, including spectral domain optical coherence tomography (SD-OCT), at baseline and after 12 months.ResultsCompared with controls, AD patients had a significant reduction of the total pRNFL thickness, as well as the pRNFL thickness of the inferior and superior quadrants (p = 0.04, p = 0.001, and p = 0.01, respectively, adjusted for baseline pRNFL measurement, age, gender, and axial length). Correlation analysis showed a significant relationship between inferior pRNFL thickness change and ADAS-Cog scores change (r = −0.35, p = 0.02) as well as CDR scores at 12 months (r = −0.39, p = 0.008).ConclusionsCompared with controls, AD patients had a significant reduction in pRNFL thickness over a period of 12 months. The pRNFL reduction was more prominent in the inferior quadrant and paralleled patient’s cognitive decline.