Blood Flow of Ophthalmic Artery and Glaucoma

August 1, 2019 updated by: Umeå University

Blood Flow of Ophthalmic Artery and Its Relationship to Structural Properties of the Optic Nerve and Intraocular Pressure in Glaucoma

The main purpose of this project is to investigate the blood flow of the ophthalmic artery (OA) in patients with ocular hypertension, high tension glaucoma and normal tension glaucoma. It is also to study the influence of the intraocular pressure difference on OA blood flow in the two first groups. Furthermore, the investigators want to understand the relationship between ocular dynamics, blood flow and structural alternations of the optic nerve head (ONH). The rationale behind the study is to improve knowledge of the pathogenesis of glaucoma.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

The investigators will investigate the OA blood flow, intraocular pressure (IOP) and structural properties of the optic nerve. The investigators will include glaucoma patients as they believe that glaucoma may be caused by or influenced by OA blood flow. The investigators will include also patients with intraocular hypertension with and without pseudoexfoliation in order to study how changes in IOP interact with OA blood flow and the structural properties of the optic nerve in a group that does not develop glaucoma. In addition, the investigators will investigate patients that develop glaucoma in spite of a normal IOP. Therefore, the investigators will study three fundamentally different groups (G1, G2 and G3) of patients as well as a control group of healthy subjects (G4):

G1: Newly diagnosed and untreated Glaucoma (optic and visual field damage exists).

G2: Ocular hypertension with IOP ≥ 23 mmHg (i.e. only elevated eye pressure).

G3: Normal Tension Glaucoma.

G4: Healthy subjects.

Each group will include 25 patients apart from G2 where 50 patients will be included, half of which have pseudoexfoliation syndrome. The study will be performed in accordance with the tenets of the Helsinki Declaration and is approved by the regional ethical board.

Study protocol overview:

Study protocol consists of two parts of examinations repeated with approximately one week between: Each part is divided into two examinations; one at the Department of radiology followed by one at the Department of ophthalmology. The measurements are repeated approximately one week later for G1 and G2.

Day 1: First, MRI scans on the brain to measure the blood flow of OA as well as the structural and morphological properties of the ON (see method below). Second, just after MRI examination, the patient will be examined at the Department of ophthalmology. Measurement of intraocular pressure, ocular pulse amplitude, central corneal thickness, bulb length, investigation with optical coherence tomography (OCT) and blood pressure will be performed. The patients from G3 (Normal Pressure Glaucoma) will participate only in Day 1, since most cases already has pressure-lowering treatment. Also subjects in G4 vill only participate in Day 1. All other participants will receive pressure lowering drug (Latanoprost) in one eye once daily, until the protocol is repeated at Day 2.

Day 2: The measurements at Day 1 are repeated approximately one week later. The measurements will be made in both eyes, which is why an eye can serve as a control. That way the investigators will have a good opportunity to assess how much of the change the investigators see in the treated eye that may be due to normal variations in OA blood flow and how much depends on the given treatment.

The findings will be compared between the groups and to the normal material in G4. The investigators will be able to see whether, and if so, to what extent, eyes with glaucoma differ from normal eyes in terms of blood flow through OA as compared to the IOP measurements, and different biomechanical parameters of the eye. Thus, determine the pressure dynamics and calculate ocular compliance with the three different groups of research subjects; newly diagnosed glaucoma, ocular hypertension, normal tension glaucoma.

Study Type

Interventional

Enrollment (Anticipated)

125

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Västerbotten
      • Umeå, Västerbotten, Sweden, 90187
        • Recruiting
        • Department of Clinical Science, Ophthalmology, Umeå University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

55 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Newly diagnosed and untreated glaucoma patients
  • Treated normal tension glaucoma patients
  • Untreated patients with ocular hypertension
  • Subjects with healthy eyes

Exclusion Criteria:

  • Heart disease except treated hypertension
  • Intracranial pathology such as stroke, tumor, previous intracranial surgery
  • Insulin treated diabetes mellitus

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: Blood flow pre&post IOP lowering
After measurement of blood flow with MRI and measurements of ocular parameters the patient receives the IOP lowering eye drop latanoprost once daily in one eye for approximately one week and then the measurements are are repeated in the same manner.
Between measurements on day 1 and day 2, the subjects will receive a drop of latanoprost which is an IOP lowering drug once daily in one eye.
No Intervention: Blood flow
The subjects will do blood flow measurements with MRI and measurements of ocular parameters only once. No intervention with IOP lowering drops.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
The blood flow (ml/min) of the ophthalmic artery in patients with different types of glaucoma/ocular hypertension and healthy individuals will be measured with MRI
Time Frame: Up to four years
Up to four years

Secondary Outcome Measures

Outcome Measure
Time Frame
The change of ophthalmic artery blood flow (ml/min) after a reduction in IOP in glaucoma and intraocular hypertension will be measured with MRI
Time Frame: Up to four years
Up to four years
The change of structural properties (μm) of the optic nerve after a reduction in IOP in glaucoma and intraocular hypertension will be measured with MRI
Time Frame: Up to four years
Up to four years
Difference in the ophthalmic artery blood flow (ml/min) measured with MRI in patients with ocular hypertension with and without pseudoexfoliation.
Time Frame: Up to four years
Up to four years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Gauti Jóhannesson, M.D., Ph.D., Department of Clinical Science, Ophthalmology, Umeå University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

December 1, 2013

Primary Completion (Anticipated)

September 1, 2019

Study Completion (Anticipated)

September 1, 2019

Study Registration Dates

First Submitted

December 15, 2015

First Submitted That Met QC Criteria

January 13, 2016

First Posted (Estimate)

January 15, 2016

Study Record Updates

Last Update Posted (Actual)

August 2, 2019

Last Update Submitted That Met QC Criteria

August 1, 2019

Last Verified

February 1, 2019

More Information

Terms related to this study

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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