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

Study Overview
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Brief Summary
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Alzheimer disease is hard, long and expensive to diagnose. In order to help the clinician, a new biomarker in Alzheimer disease seems to be very useful. The retina, as a window of the brain, could offer a new way to diagnose this common disease. Indeed, a retinal atrophy could especially appear in Alzheimer disease. Besides, many aspects about retinal alteration, visual function and their link with the disease deserve to be more explored. So as to fill these gaps, a new study about retinal specificity in Alzheimer disease appears to be relevant.

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

Conditions
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Optical Coherence Tomography, Optical Coherence Tomography Angiography, Retinal Thickening, Alzheimer Disease, Lewy Body Disease, Retina, Cortical Atrophy, Retinal Nerve Fibres Layer

Intervention / Treatment
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* Diagnostic Test: Optical coherence tomography (OCT)
* Diagnostic Test: Optical coherence tomograpohy angiography (OCTA)


Participation Criteria
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Eligibility Criteria
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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)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Alzheimer Disease<br> | Diagnostic Test: Optical coherence tomography (OCT)<br>* to make a complete ophthalmological and neurological examination, an OCT to AD and to compare their results with LD and controls subjects<br>Diagnostic Test: Optical coherence tomograpohy angiography (OCTA)<br>* to make a complete ophthalmological and neurological examination, an OCT and OCTA, to AD and to compare their results with LD and controls subjects<br>|
| Experimental: Lewy body disease<br> | Diagnostic Test: Optical coherence tomography (OCT)<br>* to make a complete ophthalmological and neurological examination, an OCT to AD and to compare their results with LD and controls subjects<br>Diagnostic Test: Optical coherence tomograpohy angiography (OCTA)<br>* to make a complete ophthalmological and neurological examination, an OCT and OCTA, to AD and to compare their results with LD and controls subjects<br>|
| Active Comparator: healthy patient<br> | Diagnostic Test: Optical coherence tomography (OCT)<br>* to make a complete ophthalmological and neurological examination, an OCT to AD and to compare their results with LD and controls subjects<br>Diagnostic Test: Optical coherence tomograpohy angiography (OCTA)<br>* to make a complete ophthalmological and neurological examination, an OCT and OCTA, to AD and to compare their results with LD and controls subjects<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Variation of retinal nerve fibres layer (RNFL) thickness in AD patient compared to healthy and LMD patients | Thickness of retinal nerve fibres layer (RNFL), ganglion cell layer (CGL), intern plexiform layer (IPL) within the macular zone of patients suffering from AD. | one day | 
| Variation of ganglion cell layer (CGL) thickness in AD patient compared to healthy and LMD patients | Thickness of retinal nerve fibres layer (RNFL), ganglion cell layer (CGL), intern plexiform layer (IPL) within the macular zone of patients suffering from AD. | one day | 
| Variation of intern plexiform layer (IPL) thickness in AD patient compared to healthy and LMD patients | Thickness of retinal nerve fibres layer (RNFL), ganglion cell layer (CGL), intern plexiform layer (IPL) within the macular zone of patients suffering from AD. | one day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Retina, Optical coherence tomography, Optical coherence tomography angiography, Retinal Thickening, Alzheimer Disease, Lewy Body Disease, Cortical Atrophy, Retinal Nerve Fibres Layer, Cell Ganglion Layer, Intern Plexiform Layer