Diurnal Fluctuations of Intraocular Pressure in EX-Press Valve Blebs in Glaucoma Patients

January 24, 2016 updated by: Hillel Yaffe Medical Center

Diurnal fluctuations of intraocular pressure in EX-Press Valve Blebs in Glaucoma Patients

Intraocular pressure (IOP) reduction is the mainstay of glaucoma management. (1) Open-angle glaucoma (OAG) is generally managed by decreasing the intraocular pressure (IOP) to a level that the physician believes will prevent further glaucomatous damage. However, in a significant proportion of patients, the visual fields continue to deteriorate in spite of office pressures within the range of normal values (8). It has been suggested that the progressive damage in some cases could be caused by peaks of IOP or diurnal IOP variability not detected by tonometry during office hours. It is possible that certain drugs or surgical interventions are more effective than others in dampening these fluctuations. The purpose of our study is to compare the diurnal IOP fluctuations in glaucoma patients treated with medications or Ex-press filtration surgery.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Diurnal fluctuations of intraocular pressure in EX-Press Valve Blebs in Glaucoma Patients

Department of Ophthalmology, Hillel-Yaffe Medical Center, affiliated with the Bruce Rappaport School of Medicine, The Technion, Haifa, Israel

Introduction:

Intraocular pressure (IOP) reduction is the mainstay of glaucoma management. (1) Medication alone is sometimes not sufficient to reduce excessively high IOP, and pharmaceutical intolerance may develop or damage can occur to the optic nerve, warranting surgical intervention. (2) The filtering bleb is considered to be the cornerstone of IOP control after glaucoma filtration surgery drainage device implantation. (3) It enables the flow of the aqueous humor from the anterior chamber to the subconjunctiva, episclera, sclera and choroid, thereby lowering the IOP. (4-6) Filtration and drainage devices, such as the EX-Press device (Alcon Laboratories, Fort Worth, Texas, USA), offer a surgical alternative to glaucoma medical therapy. (7) Open-angle glaucoma (OAG) is generally managed by decreasing the intraocular pressure (IOP) to a level that the physician believes will prevent further glaucomatous damage. However, in a significant proportion of patients, the visual fields continue to deteriorate in spite of office pressures within the range of normal values (8). It has been suggested that the progressive damage in some cases could be caused by peaks of IOP or diurnal IOP variability not detected by tonometry during office hours. (9, 10) In another study, Asrani et al. (11) showed that IOP fluctuations are an independent risk factor in patients with glaucoma and as such may need to be treated specifically. It is possible that certain drugs or surgical interventions are more effective than others in dampening these fluctuations. The purpose of our study is to compare the diurnal IOP fluctuations in glaucoma patients treated with medications or Ex-press filtration surgery.

Materials and Methods The study will include 20 open-angle glaucoma (OAG) patients underwent Ex-Press filtration surgery, and 20 OAG patients treated with medications alone. All patients will have 12 IOP measurements with 2 hours interval, starting at 10 AM until 10 AM of the following morning.

ICARE® PRO tonometer (Icare Finland Oy, Espoo, Finland) will be used for the measurement of IOP. The rebound motion of its light weighted probe will be recorded during contact of the probe with the cornea. (12, 13) The rate of deceleration of the probe is a function of IOP. The ICARE® PRO has a built-in inclination sensor that allows downward measurement of the eye in the supine position as well as in the normal upright sitting position. ICARE® PRO allows for measurement of IOP in the seated and supine positions. During IOP recording, patients will be supine or upright, and the tip of the probe will be applied perpendicular to the cornea. Two markers engraved on the piston of the probe indicated its ideal positioning. The reliability of the measurement is displayed on the ICARE® PRO tonometer screen and guided our measurements.

Fluctuations in IOP will be compared between the Ex-press filtration surgery eye and the fellow (intra-group comparison). Inter-group comparison of IOP fluctuation will be performed between the Ex-press filtration surgery eye and medically treated eye of different patients.

Study Type

Observational

Enrollment (Anticipated)

40

Contacts and Locations

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

Study Locations

  • Israel
      • Hadera, Israel, 38100
        • Hillel Yaffe Medical Center

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

30 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

The study will include 20 open-angle glaucoma (OAG) patients underwent Ex-Press filtration surgery, and 20 OAG patients treated with medications alone.

Description

Inclusion Criteria: .

  • Glaucoma patients that underwent EX-PRESS surgery

Exclusion Criteria:

  • Angle closure glaucoma
  • Neovascular glaucoma
  • High refractive error

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

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Glaucoma EX-PRESS
Glaucoma patients who underwent glaucoma surgery between the years 2014-2015 and had diurnal intraocular pressure measurements over 24 hours.
Other: Intraocular Pressure Measurement
Diurnal fluctuations of intraocular pressure will be measured and compared
Control Group
Glaucoma patients who had been treated with anti-glaucoma drops and had diurnal intraocular pressure measurements over 24 hours.
Other: Intraocular Pressure Measurement
Diurnal fluctuations of intraocular pressure will be measured and compared

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Comparison of diurnal fluctuations of intraocular pressure
Time Frame: One year
Comparison of diurnal fluctuations of intraocular pressure in glaucoma patients with and without EX-Press valve surgery
One year

Collaborators and Investigators

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

Sponsor

Hillel Yaffe Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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

February 1, 2016

Primary Completion (Anticipated)

February 1, 2017

Study Completion (Anticipated)

February 1, 2017

Study Registration Dates

First Submitted

November 29, 2015

First Submitted That Met QC Criteria

January 24, 2016

First Posted (Estimate)

January 28, 2016

Study Record Updates

Last Update Posted (Estimate)

January 28, 2016

Last Update Submitted That Met QC Criteria

January 24, 2016

Last Verified

November 1, 2015

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 0085-15-HYMC

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

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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