Association Between Laser Interferometric Measurement of Fundus Pulsation and Pneumotonometric Measurement of Pulsatile Ocular Blood Flow in Patients With Age-related Macular Degeneration

Overview

Several methods have been proposed for the measurement of pulsatile ocular blood flow (POBF). The pneumatic tonometer, which is commercially available, assesses POBF by measurement of intraocular pressure (IOP) changes during the cardiac cycle. The investigators have recently developed a method for the measurement of ocular fundus pulsation, which is based on laser interferometry. In contrast to the Langham system the method is non-contractile and yields a high topographic resolution. Moreover, the pneumatic tonometer assesses the ocular pressure pulse, whereas ocular fundus pulsation is a point measure of the ocular volume pulse. These two parameters are related by the ocular rigidity, which refers to the mechanical properties of the eye coats. Age-related macular degeneration (AMD) is the most common cause of blindness in the industrialized nations. The mechanisms behind this severe eye disease are, however, still obscure. It has been hypothesized that alterations in choroidal blood flow and ocular rigidity may contribute to the development and progression of AMD. However, there is currently little data to confirm this hypothesis. The present study is an attempt to investigate choroidal blood flow and ocular rigidity by employing laser interferometric measurement of fundus pulsation and pneumotonometric measurement of fundus pulsation.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Non-Randomized
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Basic Science
    • Masking: None (Open Label)
  • Study Primary Completion Date: February 2011

Interventions

  • Procedure: blood flow measurement
    • Fundus pulsation amplitude measurement Pulsatile ocular blood flow measurement

Arms, Groups and Cohorts

  • Experimental: 1
    • AMD Patients
  • Active Comparator: 2
    • healthy controls

Clinical Trial Outcome Measures

Primary Measures

  • Fundus pulsation amplitude
    • Time Frame: 10 minutes measurement of FPA
  • Pulsatile ocular blood flow
    • Time Frame: 10 minutes measurement of pulsatile ocular blood flow
  • Ocular rigidity
    • Time Frame: 10 minutes measurement of ocular rigidity

Participating in This Clinical Trial

Inclusion Criteria

  • Patients with AMD (defined as soft drusen > 63 µm, hyperpigmentation and/or hypopigmentation of the retinal pigment epithelium (RPE), RPE and associated neurosensory detachment, (peri)retinal hemorrhages, geographic atrophy of the RPE, or (peri)retinal fibrous scarring) – Age between 50 and 90 years Exclusion Criteria:

  • Evidence of any other retinal or choroidal vascular disease – Regular use of pentoxifylline in the last month before the trial period – Evidence of a choroidal neovascular membrane – Diabetes mellitus

Gender Eligibility: All

Minimum Age: 50 Years

Maximum Age: 90 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Medical University of Vienna
  • Provider of Information About this Clinical Study
    • Principal Investigator: Gerhard Garhofer, Assoc. Prof. Priv. – Doz. Dr – Medical University of Vienna
  • Overall Official(s)
    • Leopold Schmetterer, Prof. Dr., Principal Investigator, Department of Clinical Pharmacology, Medical University of Vienna

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