The Role of Complement Factor H Polymorphism in the Regulation of Choroidal Vascular Tone in Young Healthy Subjects

Study Overview
=================
Brief Summary
-----------------
Age related macular degeneration (AMD) is a multifactorial disease with a strong genetic component. Given that it is known that impaired regulation of choroidal vascular tone is present in patients with AMD, the current study seeks to investigate whether genetic polymorphisms in risk alleles for AMD are associated with altered choroidal blood flow regulation in healthy subjects. For this purpose a total of 220 healthy volunteers will be included. Choroidal blood flow regulation will be evaluated by measuring choroidal blood flow during isometric exercise. In addition, flicker induced vasodilatation will be studied and retinal vessel calibers will assessed, as well as retinal thickness and macular pigment optical density.

Official Title
-----------------
The Role of Complement Factor H Polymorphism in the Regulation of Choroidal Vascular Tone in Young Healthy Subjects

Conditions
-----------------
Age-Related Macular Degeneration

Intervention / Treatment
-----------------
* Genetic: the polymerase chain reaction (PCR)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Men and women aged between 18 and 45 years, nonsmokers Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant Systolic blood pressure < 160 mmHg, diastolic blood pressure < 90 mmHg Normal ophthalmic findings, ametropia less than 3 diopters Exclusion Criteria: Regular use of medication Abuse of alcoholic beverages Participation in a clinical trial in the 3 weeks preceding the study Treatment in the previous 3 weeks with any drug (except hormonal contraceptives) Symptoms of a clinically relevant illness in the 3 weeks before the first study day Blood donation during the previous 3 weeks History or family history of epilepsy Pregnancy, planned pregnancy or lactating

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Healthy Subjects<br> | Genetic: the polymerase chain reaction (PCR)<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Choroidal blood flow during isometric exercise (LDF) |  | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Flicker induced vasodilatation, expressed as percent change to baseline (DVA) |  | 1 day | 
| Genotyping (PCR) |  | 1 day | 
| Retinal vessel calibers and AV- ratio (DVA) |  | 1 day | 
| Laser Speckle Flowmetry (LSFG) |  | 1 day | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Genetic Association Studies