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Asymptomatic Narrow Angles - Laser Iridotomy Study; Multicentric RCT

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00347178
Recruitment Status : Unknown
Verified June 2006 by Singapore National Eye Centre.
Recruitment status was:  Recruiting
First Posted : July 4, 2006
Last Update Posted : July 4, 2006
National Medical Research Council (NMRC), Singapore
Information provided by:
Singapore National Eye Centre

Brief Summary:
This is a multicentric, randomised, controlled study comparing Laser Iridotomy (LI) to no treatment in subjects with asymptomatic narrow angles (ANA).One eye of each subject with ANA will be randomised to undergo LI and the other eye will be left alone and will serve as an internal control. Subjects are proposed to be followed up once a year for 5 years.

Condition or disease Intervention/treatment Phase
Asymptomatic Narrow Angles Primary Angle Closure Suspects Procedure: Laser Peripheral Iridotomy Not Applicable

Detailed Description:

Objective: This study will compare LI versus no treatment in subjects with asymptomatic narrow angles, the anatomical trait that predisposes to primary angle closure glaucoma (PACG), in order to assess the effectiveness of prophylactic treatment in the prevention of blindness due to PACG.

Eligibility: 1. Bilateral Narrow angles; 2. Age 50 years and above; 3. Informed consent obtained prior to or at baseline visit.

Trial Design: Subjects with asymptomatic ANA undergoes randomisation after comprehensive ocular exam followed by randomisation to LI in one eye and no treatment in the other eye. Follow up is done for 5 years with yearly examination.

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Study Type : Interventional  (Clinical Trial)
Enrollment : 544 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Prophylactic Laser Iridotomy for Eyes With Narrow Drainage Angles; A Randomised Controlled Trial
Study Start Date : January 2005
Study Completion Date : January 2013

Primary Outcome Measures :
  1. Peripheral anterior synechiae formation
  2. IOP elevation >21 mm Hg
  3. Development of acute angle closure event

Secondary Outcome Measures :
  1. Changes in the grading of Modified Schaffer Grading
  2. Development of glaucomatous optic neuropathy
  3. Development of corresponding visual field loss by automated perimetry
  4. Change in HRT optic disc parameters
  5. Change in UBM angle parameters
  6. Formation of disc pallor

Information from the National Library of Medicine

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Ages Eligible for Study:   50 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Bilateral Narrow angles
  2. Age 50 years and above
  3. Informed consent obtained prior to or at baseline visit

Exclusion Criteria:

  1. Presence of PAS
  2. IOP > 21 mm Hg
  3. Glaucomatous optic neuropathy and/or CDR > 0.7
  4. Secondary angle closure such as uveitis, neovascularisation etc.
  5. Prior intraocular surgery or penetrating eye injury
  6. Corneal disorders such as corneal endothelial dystrophy except mild corneal guttae
  7. Evidence of prior acute angle closure event
  8. High risk of acute angle closure.
  9. Significant cataract and visual acuity less than 20/40
  10. Constant use of contact lens for refractive correction
  11. Chronic use of topical or systemic steroids
  12. Established retinopathies on ocular treatments (e.g. Diabetic)
  13. Any other disease which is likely to cause field loss in next 3 years
  14. Severe health problems decreasing life expectancy to less than one year.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00347178

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Contact: Tin - Aung, FRCSEd PhD +65 63224581

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Singapore Eye Research Institute Recruiting
Singapore, Singapore, 168751
Principal Investigator: Tin Aung, FRCSEd, PhD         
Sub-Investigator: Steve KL Seah, FRCS (Ed)         
Sub-Investigator: Paul TK Chew, FRCS (Ed)         
Sub-Investigator: Hon T Wong, FRCS (Ed)         
Sub-Investigator: Aliza - Jap, FRCOph (Lon)         
Sub-Investigator: Kah G AuEong, FRCS (Ed)         
Sponsors and Collaborators
Singapore National Eye Centre
National Medical Research Council (NMRC), Singapore
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Principal Investigator: Tin - Aung, FRCSEd PhD Singapoe National Eye Centre
Publications automatically indexed to this study by Identifier (NCT Number):
Layout table for additonal information Identifier: NCT00347178    
Other Study ID Numbers: R358/16/2004
First Posted: July 4, 2006    Key Record Dates
Last Update Posted: July 4, 2006
Last Verified: June 2006
Keywords provided by Singapore National Eye Centre:
Asymptomatic Narrow Angles
Primary Angle Closure Suspects
Laser Peripheral Iridotomy
Randomised Controlled Trial