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Completed

NCT Number: NCT00708929

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

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.

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Key information

Conditions

Genetic Polymorphism Eye Diseases Macular Degeneration Ocular Physiology Regional Blood Flow Retinal Degeneration Retinal Diseases

Age range

18 year–45 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Department of Clinical Pharmacology, Medical University of Vienna

Vienna, Austria

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Squatting

Procedure

Squatting for 6 minutes

Primary outcomes

  1. Choroidal blood flow during isometric exercise

    Time frame: 10 minutes

  2. Tyr402His genotyping

    Time frame: screening

Secondary outcomes

  1. Mean arterial pressure

    Time frame: 20 minutes

  2. Intraocular pressure

    Time frame: before and after blood flow measurements

  3. Systolic/diastolic blood pressure

    Time frame: 20 minutes

  4. Pulse rate

    Time frame: 20 minutes

Sponsors and collaborators

Lead sponsor

Medical University of Vienna

Other

Registry information

Important dates

Study start
2009
Primary completion
2011
Study completion
2011
First posted
Jul 3, 2008
Registry last updated
Mar 19, 2013

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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