Relationship Between Alzheimer Disease and Diminution of the Three Macular Nervous Retinal Layers

Inclusion Criteria: * Patients having a consultation in the Research and Resources Memory Center of Amiens (RRMC) , * patients registered in the Alzheimer National Bank and having an Alzheimer Disease based on NIA-AA (McKahnn2011)and IWG2 (Dubois et al, 2014) criteria or, having a Lewy body disease based on revised criteria of McKeith et al 2020 * patients having a complete neuropsychological evaluation including a visual inspection time. * patients having a MMSE ≥ 18/30 so as to ensure a good homogeneity of the group and to have an adequate ocular exam's quality. * patients having an available MRI in the CHU's database including a 3DT1 sequence * patients having a visual acuity better than 5/10, spherical refraction of +/- 5D, an astigmatism \< 3D and an applanation IOP \<22mmHg Exclusion Criteria: * Any other neurocognitive disorder * Any other optical neuropathy including glaucoma * All kind of retinal disease (diabetic retinopathy, age-related macular degeneration…) * Diabetes mellitus * Uncontrolled hypertension blood pressure * Any ophthalmological conditions interfering with a good ocular examination or OCT quality (cataract, corneal opacity..) * Severe dementia preventing a good ophthalmological examination * Not consenting patient * Patient with guardianship or curatorship having symptoms preventing a good ophthalmological examination (agitation, unstable ocular fixation)