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

Purpose

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.

Condition	Intervention
Genetic Polymorphism Macular Degeneration Regional Blood Flow Ocular Physiology	Procedure: Squatting

Genetics Home Reference related topics:

X-linked juvenile retinoschisis

MedlinePlus related topics:

Macular Degeneration

U.S. FDA Resources

Study Type:	Interventional
Study Design:	Basic Science, Double Blind (Subject, Investigator), Parallel Assignment, Safety/Efficacy Study

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

Further study details as provided by Medical University of Vienna:

Primary Outcome Measures:

Choroidal blood flow during isometric exercise [ Time Frame: 10 minutes ] [ Designated as safety issue: No ]
Tyr402His genotyping [ Time Frame: screening ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

Mean arterial pressure [ Time Frame: 20 minutes ] [ Designated as safety issue: No ]
Intraocular pressure [ Time Frame: before and after blood flow measurements ] [ Designated as safety issue: No ]
Systolic/diastolic blood pressure [ Time Frame: 20 minutes ] [ Designated as safety issue: Yes ]
Pulse rate [ Time Frame: 20 minutes ] [ Designated as safety issue: Yes ]

Estimated Enrollment:	100
Study Start Date:	October 2008
Estimated Study Completion Date:	October 2009
Estimated Primary Completion Date:	October 2009 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
1 14 subjects homozygous HH for the Tyr402His single nucleotide polymorphism	Procedure: Squatting Squatting for 6 minutes
2 14 subjects homozygous TT for the Tyr402His single nucleotide polymorphism	Procedure: Squatting Squatting for 6 minutes

Eligibility

Ages Eligible for Study:	18 Years to 35 Years
Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	Yes

Criteria

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, paricipation 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

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00708929

Contacts


Contact: Gerhard Garhöfer, MD	43-14-0400	gerhard.garhoefer@meduniwien.ac.at

Locations


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

Sponsors and Collaborators

Medical University of Vienna

Investigators


Principal Investigator:	Gerhard Garhöfer, MD	Department of Clinical Pharmacology, Medical University of Vienna

More Information

Responsible Party:	Department of Clinical Pharmacology, Medical University of Vienna ( Gerhard Garhöfer, MD )
Study ID Numbers:	OPHT-040607
First Received:	July 1, 2008
Last Updated:	July 2, 2008
ClinicalTrials.gov Identifier:	NCT00708929
Health Authority:	Austria: Agency for Health and Food Safety

Keywords provided by Medical University of Vienna:

Age-related macular degeneration

Complement factor H

Choroidal blood flow

Study placed in the following topic categories:

Eye Diseases

Retinal Degeneration

Macular Degeneration

Complement Factor H

Retinal Diseases

Retinal degeneration

Additional relevant MeSH terms:

Immunologic Factors

Physiological Effects of Drugs

Immunosuppressive Agents

Complement Inactivating Agents

Pharmacologic Actions

ClinicalTrials.gov processed this record on November 04, 2008

Sponsored by:	Medical University of Vienna
Information provided by:	Medical University of Vienna
ClinicalTrials.gov Identifier:	NCT00708929