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

• Sponsor: Medical University of Vienna (Other)
• Overall Status: Completed
• CT.gov ID: NCT00708929
• Collaborator: (none)
• Enrollment: 100
• Location: 1
• Arms: 2
• Duration (Months): 30
• Patients Per Site Per Month: 3.3

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Genetic Polymorphism; Macular Degeneration; Regional Blood Flow; Ocular Physiology	Procedure: Squatting	N/A

Study Design

• Study Type: Interventional
• Actual Enrollment: 100 participants
• Allocation: Non-Randomized
• Intervention Model: Parallel Assignment
• Masking: None (Open Label)
• Primary Purpose: Basic Science
• Official Title: Does Complement Factor H Gene Polymorphism Play a Role in the Regulation of Vascular Tone in the Choroid?
• Study Start Date: Jun 1, 2009
• Actual Primary Completion Date: Dec 1, 2011
• Actual Study Completion Date: Dec 1, 2011

Arms and Interventions

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

Outcome Measures

Primary Outcome Measures

1. Choroidal blood flow during isometric exercise [10 minutes]

2. Tyr402His genotyping [screening]

Secondary Outcome Measures

1. Mean arterial pressure [20 minutes]

2. Intraocular pressure [before and after blood flow measurements]

3. Systolic/diastolic blood pressure [20 minutes]

4. Pulse rate [20 minutes]

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 45 Years
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	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

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: Gerhard Garhofer, Ass.Prof.Priv.Doz.Dr., Medical University of Vienna
• ClinicalTrials.gov Identifier: NCT00708929
• Other Study ID Numbers: OPHT-040607
• First Posted: Jul 3, 2008
• Last Update Posted: Mar 19, 2013
• Last Verified: Mar 1, 2013

• Keywords provided by Gerhard Garhofer, Ass.Prof.Priv.Doz.Dr., Medical University of Vienna: Age-related macular degeneration; Complement factor H; Choroidal blood flow
• Additional relevant MeSH terms: Macular Degeneration

Study Results

No Results Posted as of Mar 19, 2013