Macular nerve‐fiber‐layer measurement in early stage Alzheimer’s disease using optical coherence tomography

Purpose Alzheimer’s disease (AD) is characterized by brain neuronal loss resulting in brain atrophy. Post‐mortem studies show a loss of retinal ganglion cells in this neurodegenerative disease. The purpose of this study was to compare thicknesses of the macular nerve‐fiber layer (MNFL) by Optical Coherence Tomography (OCT) between early AD patients and control. Methods Twenty GDS 4 AD patients and 25 controls were examined at Hospital Clínico San Carlos in Madrid (Spain). Patients underwent a complete ophthalmologic exam (visual acuity, refraction, color test, biomicroscopy, IOP, dilated fundoscopy, and OCT). OCT macular measurements were made by dividing the macula into 9 areas: i) a central area of 1mm radius (fovea); ii) two concentric areas of 3 mm and 6 mm each were subdivided in 4 regions: nasal, temporal, upper and lower. Results In comparison with the control group, patients with early‐stage AD presented a significant MNFL decrease (p