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

March 15, 2013 updated by: Gerhard Garhofer, Medical University of Vienna

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

100

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Austria
      • Vienna, Austria
        • Department of Clinical Pharmacology, Medical University of Vienna

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 45 years (ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

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 Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: BASIC_SCIENCE
  • Allocation: NON_RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
OTHER: 1
14 subjects homozygous HH for the Tyr402His single nucleotide polymorphism
Procedure: Squatting
Squatting for 6 minutes
OTHER: 2
14 subjects homozygous TT for the Tyr402His single nucleotide polymorphism
Procedure: Squatting
Squatting for 6 minutes

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Choroidal blood flow during isometric exercise
Time Frame: 10 minutes
10 minutes
Tyr402His genotyping
Time Frame: screening
screening

Secondary Outcome Measures

Outcome Measure
Time Frame
Pulse rate
Time Frame: 20 minutes
20 minutes
Mean arterial pressure
Time Frame: 20 minutes
20 minutes
Intraocular pressure
Time Frame: before and after blood flow measurements
before and after blood flow measurements
Systolic/diastolic blood pressure
Time Frame: 20 minutes
20 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Medical University of Vienna

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2009

Primary Completion (ACTUAL)

December 1, 2011

Study Completion (ACTUAL)

December 1, 2011

Study Registration Dates

First Submitted

July 1, 2008

First Submitted That Met QC Criteria

July 2, 2008

First Posted (ESTIMATE)

July 3, 2008

Study Record Updates

Last Update Posted (ESTIMATE)

March 19, 2013

Last Update Submitted That Met QC Criteria

March 15, 2013

Last Verified

March 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OPHT-040607

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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