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 <0.05) in the central area and in the 3 mm paracentral area. In the 6mm paracentral area statistically significant differences were restricted to the temporal region.Conclusion
In early-stage AD (GDS4), the MNFL was decreased. The measurement of macular thickness by OCT could be a complementary tool for early diagnosis and control progression of AD.