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

NCT00708929 | Completed DMC

• 1 other identifier: OPHT-040607
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

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.

Conditions

Genetic Polymorphism; Macular Degeneration; Regional Blood Flow; Ocular Physiology

Keywords

Age-related macular degeneration; Complement factor H; Choroidal blood flow

Outcome Measures

Primary Outcomes (2)

• Choroidal blood flow during isometric exercise

  10 minutes

• Tyr402His genotyping

  screening

Secondary Outcomes (4)

• Mean arterial pressure

  20 minutes

• Intraocular pressure

  before and after blood flow measurements

• Systolic/diastolic blood pressure

  20 minutes

• Pulse rate

  20 minutes

Study Arms (2)

1

OTHER

14 subjects homozygous HH for the Tyr402His single nucleotide polymorphism

Procedure: Squatting

2

OTHER

14 subjects homozygous TT for the Tyr402His single nucleotide polymorphism

Procedure: Squatting

Interventions

Squatting PROCEDURE

Squatting for 6 minutes

1; 2

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Medical University of Vienna: lead

Study Sites (1)

Department of Clinical Pharmacology, Medical University of Vienna

Vienna, Austria

Location

MeSH Terms

Conditions

Macular Degeneration

Condition Hierarchy (Ancestors)

Retinal Degeneration; Retinal Diseases; Eye Diseases

Study Officials

• Gerhard Garhöfer, MD

  Department of Clinical Pharmacology, Medical University of Vienna

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Ass.Prof.Priv.Doz.Dr.

Study Record Dates

• First Submitted: July 1, 2008
• First Posted: July 3, 2008
• Study Start: June 1, 2009
• Primary Completion: December 1, 2011
• Study Completion: December 1, 2011
• Last Updated: March 19, 2013

Record last verified: 2013-03

Locations

AU (1)