Intraocular Pressure (IOP) Lowering Effect of Selective Laser Trabeculoplasty Versus Prostaglandin Analogues in Angle Closure Glaucoma

The recruitment status of this study is unknown because the information has not been verified recently.
Verified May 2010 by Singapore Eye Research Institute.
Recruitment status was  Recruiting
Sponsor:
Information provided by:
Singapore Eye Research Institute
ClinicalTrials.gov Identifier:
NCT01004900
First received: October 29, 2009
Last updated: May 10, 2010
Last verified: May 2010
  Purpose

Glaucoma affects 66 million people worldwide and is the leading cause of irreversible blindness, and Primary angle-closure glaucoma (PACG) is a major form of glaucoma in Asia.

Laser peripheral iridotomy (LPI) has been advocated as the first line treatment in all cases of PACG. In addition to relieving the relative pupil block element of the condition, it can open up the drainage angle, alleviating appositional and synechial angle-closure and in the long-term this may control intraocular pressure (IOP) and prevent progression of glaucomatous optic neuropathy. However recent data indicate that iridotomy is not successful in controlling IOP in the long term, and the majority of cases develop a clinically significant rise in IOP requiring medical therapy or surgery.

Laser trabeculoplasty has been a recognized treatment option for Primary open angle glaucoma (POAG) since the 1980s. Recently a more selective and less destructive method of performing laser trabeculoplasty has evolved. Selective Laser Trabeculoplasty (SLT) specifically targets the pigmented trabecular meshwork cells without producing collateral damage and destruction to adjacent structures. Morphologic study performed on human autopsy eyes treated with SLT noted no structural or collateral thermal damage to the trabecular beams in the uveal and corneoscleral meshwork. As SLT specifically has its effect on the targeted pigmented trabecular meshwork it is unlikely to generate PAS. It may be a useful treatment option for PACG patients in whom the angle has widened following laser peripheral iridotomy.

The proposed study is a randomized controlled trial to assess the effectiveness of SLT in reducing IOP in cases of PACG in which the angle has opened up following LPI, but IOP remains high(>21 mmHg). 100 subjects will be randomized to receive either SLT or medical treatment to achieve IOP control. They will be followed up for 6 months.


Condition Intervention Phase
Glaucoma
Procedure: Selective Laser Trabeculoplasty
Drug: Travoprost/ Timolol/ Azopt/ Brimonidine
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Comparison of Selective Laser Trabeculoplasty With Prostaglandin Analogues for Lowering Intraocular Pressure in Eyes With Primary Angle Closure Glaucoma

Resource links provided by NLM:


Further study details as provided by Singapore Eye Research Institute:

Primary Outcome Measures:
  • Intraocular Pressure [ Time Frame: 6 months ] [ Designated as safety issue: Yes ]
    Fluid pressure inside the eye


Estimated Enrollment: 90
Study Start Date: June 2009
Estimated Study Completion Date: March 2011
Estimated Primary Completion Date: March 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Trabeculoplasty Procedure: Selective Laser Trabeculoplasty
This is a laser procedure used to treat glaucoma by reducing the pressure in the eye. SLT works by using laser light to stimulate the body's own healing response to lower your eye pressure. Using a special wavelength and energy, the laser affects only pigmented (melanin containing) cells of your eye. SLT improves the flow of fluid in the eye, which in turn lowers your eye pressure.
Active Comparator: Control (Medication) Drug: Travoprost/ Timolol/ Azopt/ Brimonidine
Travoprost (Topical eye drops) administered once daily before sleep

  Show Detailed Description

  Eligibility

Ages Eligible for Study:   21 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Diagnosis of primary angle closure or primary angle closure glaucoma with documented pre-LPI angle closure of ≥180 degrees of the angle (Trabecular meshwork not visible in primary position using gonioscopy)
  • One month post LPI, angle has opened up (visibility of trabecular meshwork) for at least 180 degrees of the angle
  • Intraocular pressure between 21-≤30 mmHg without treatment following LPI OR Intraocular pressure between 21-≤30 mmHg after wash out regimen as described below for patients who are already medications following LPI.
  • Informed Consent
  • Age more than 21 years

Exclusion Criteria:

  • Secondary causes of angle closure like subluxed lens, uveitis, trauma and neovascular glaucoma
  • Presence of advanced sight-threatening glaucoma defined as vertical cup-disc ratio > 0.9 or visual field constriction involving <100 of the central visual field performed with the Humphrey Visual Field Analyzer II using the SITA STD algorithm with a 24-2 test pattern.
  • Cataract that is deemed significant enough to require surgery during the course of the trial or that makes field testing or optic disc imaging not technically possible- visual acuity less than 20/40 due to any type of cataract.
  • Previous intraocular surgery, SLT, ALT, refractive surgery or iridoplasty.
  • Documented previous history of angle closure.
  • Use of contact lens
  • Chronic use of topical or systemic steroids
  • Participation in another therapeutic drug study within the last 30 days
  • Severe health problems precluding follow-up such as end-stage heart disease, kidney disease, respiratory disease, or cancer and life expectancy less than one year.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01004900

Contacts
Contact: Tin Aung, FRCOphth 62277255 aung.tin@snec.com.sg

Locations
Singapore
Singapore National Eye Centre Recruiting
Singapore, Singapore, 168751
Contact: Tin Aung, FRCOphth    62277255    aung.tin@snec.com.sg   
Principal Investigator: Tin Aung, FRCOphth         
Sponsors and Collaborators
Singapore Eye Research Institute
Investigators
Principal Investigator: Tin Aung, FRCOphth Singapore National Eye Centre
  More Information

No publications provided

Responsible Party: A/ Prof Aung Tin, A/ PROF & CONSULTANT, Singapore National Eye Centre
ClinicalTrials.gov Identifier: NCT01004900     History of Changes
Other Study ID Numbers: R657/07/2009
Study First Received: October 29, 2009
Last Updated: May 10, 2010
Health Authority: Singapore: Domain Specific Review Boards

Keywords provided by Singapore Eye Research Institute:
Glaucoma, Angle Closure
Selective laser trabeculoplasty
Primary Angle Closure Disease

Additional relevant MeSH terms:
Glaucoma
Glaucoma, Angle-Closure
Eye Diseases
Ocular Hypertension
Travoprost
Antihypertensive Agents
Cardiovascular Agents
Pharmacologic Actions
Therapeutic Uses

ClinicalTrials.gov processed this record on October 22, 2014