Retinal Nerve Fiber Layer Thickness and Cerebrospinal Fluid Aβ/Tau

Study Overview
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Brief Summary
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To test the hypothesis that retinal nerve fiber layer (RNFL) thickness is correlated with Aβ and Tau concentration of cerebrospinal fluid (CSF) in an older population.

Detailed Description
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retinal nerve fiber layer (RNFL) thickness changing has been reported in Alzheimer's Disease (AD) patients at an early stage, and has been demonstrated as a potential biomarker able to predict cognitive deterioration (Hinton DR et al., N Engl J Med 1986; London A et al. Nat Rev Neurol 2013; Chang LY et al., Alzheimers Dement 2014). However, whether RNFL thickness is correlated with cerebrospinal fluid (CSF) features of AD pathogenesis (e.g., Aβ and Tau) remains unclear. The investigators thus conducted this observational cohort study to test the correlation between RNFL thickness changing and CSF, to further validate RNFL as a potential AD biomarker.

Official Title
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Association of Retinal Nerve Fiber Layer (RNFL) Thickness With Cerebrospinal Fluid Aβ and Tau Concentration

Conditions
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Alzheimer Disease

Intervention / Treatment
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* Procedure: surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 50 years old or older; five years or more of education and scores of MMSE ≥ 24 points; Chinese as their first language; Having spinal anesthesia. Exclusion Criteria: prior diagnoses of neurologic diseases, e.g., dementia, Parkinson's diseases, multiple sclerosis or stroke according to DSM-IV; history of mental disorders (e.g., major depressive disorder and schizophrenia) diagnosed according to DSM-IV; known diseases contributing to the retina pathologies, e.g., diabetes, glaucoma or increased intraocular pressure (more than 22 mmHg), cataract, and macular degeneration and hypermyopia; unwillingness to comply with the cognitive assessments; ungradable images of OCT.

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| elderly participants with surgery<br>The studied cohort were participants 50 years old or older, without a diagnosis of dementia, and scheduled to have orthopedic or urological surgery under spinal anesthesia at Shanghai 10th People's Hospital. | Procedure: surgery<br>* All participants were scheduled to have elective total hip or knee replacement surgery, ureteroscopic lithotripsy and transurethral resection of the prostate under spinal anesthesia at the Shanghai 10th People's Hospital. After 5 years, the investigaors will follow up the participants including cognitive functions, PET-CT, thickness of Retinal Nerve Fiber Layer.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Specific cognitive function | Neuropsychological test battery to assess specific cognitive function, including immediate memory, visuospatial memory and executive function. | Within one week before surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| retinal nerve fiber layer (RNFL) thickness | Optical coherence tomography (Carl Zeiss Meditec, Inc., Dublin, CA, USA) to measure RNFL thickness | Within one week before surgery | 
| Cerebrospinal fluid (CSF) Aβ concentration | ELISA kits (Aβ40: Cat. # 292-62301; Aβ42: Cat. # 296-64401, Wako, Richmond, VA) to measure Aβ concentration | During the spinal anesthesia before the administration of the local anesthetic. | 
| Cerebrospinal fluid (CSF) Tau concentration | ELISA kits (Tau: Cat. # KHB0041, Invitrogen, San Francisco, CA) to measure Aβ concentration | During the spinal anesthesia before the administration of the local anesthetic. | 
| Global cognitive state | Mini-Mental State Examination (MMSE) to assess global cognitive function | Within one week before surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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retinal nerve fiber layer, cerebrospinal fluid Aβ and Tau