Does Complement Factor H Gene Polymorphism Play a Role in the Regulation of Vascular Tone in the Choroid?

Not Applicable

Completed

• Conditions: Genetic Polymorphism; Macular Degeneration; Regional Blood Flow; Ocular Physiology
• Interventions: Procedure: Squatting

• Registration Number: NCT00708929
• Lead Sponsor: Medical University of Vienna

Brief Summary

Age related macular degeneration (AMD) is a multifactorial disease with a strong genetic component. Most importantly a genetic polymorphism in the gene encoding for the complement factor H (CFH) has been recently identified which is highly associated with an increased risk of developing AMD. This Tyr402His polymorphism located on chromosome 1q31 has been implicated to play a role in the development of the disease.

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 the Tyr402His polymorphism is associated with altered choroidal autoregulation in healthy subjects. For this purpose a total of 100 healthy volunteers will be included in order to test the hypothesis that an impaired regulation of choroidal blood flow is present in subjects with homozygous Tyr402His variant.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2008-07-01
• Study First Submitted QC: 2008-07-02
• Study First Posted: 2008-07-03
• Study Start: 2009-06
• Primary Completion: 2011-12
• Study Completion: 2011-12
• Status Verified: 2013-03
• Last Update Submitted: 2013-03-15
• Last Update Posted: 2013-03-19

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 100

Inclusion Criteria

• Men and women aged between 18 and 35 years
• Nonsmokers
• Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
• Normal ophthalmic findings, ametropy 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
• Symptoms of a clinically relevant illness in the 3 weeks before the first study day
• Blood donation during the previous 3 weeks

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
1	Squatting	14 subjects homozygous HH for the Tyr402His single nucleotide polymorphism
2	Squatting	14 subjects homozygous TT for the Tyr402His single nucleotide polymorphism

Primary Outcome Measures

Name	Time	Method
Choroidal blood flow during isometric exercise	10 minutes
Tyr402His genotyping	screening

Secondary Outcome Measures

Name	Time	Method
Pulse rate	20 minutes
Mean arterial pressure	20 minutes
Intraocular pressure	before and after blood flow measurements
Systolic/diastolic blood pressure	20 minutes

Trial Locations

Locations (1)

Department of Clinical Pharmacology, Medical University of Vienna; 🇦🇹 Vienna, Austria