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Sequential Laser Iridotomy Using Argon and Q-Switched 532 nm Frequency Doubled Neodymium Yag Laser: A Pilot Study

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: NCT00452998
Recruitment Status : Completed
First Posted : March 28, 2007
Last Update Posted : May 14, 2008
Information provided by:
National University Hospital, Singapore

Brief Summary:
Sequential Laser Iridotomy uses argon and Nd:yag laser in the first and second steps, respectively. Using q-switched 532 nm laser in the second step is hypothesized to be as good and effective as the conventional Nd:yag laser, because it selectively targets pigmented cells and delivers a short pulse duration of 3 nanoseconds, causing less thermal and collateral damage.

Condition or disease Intervention/treatment Phase
Chronic Angle Closure Glaucoma Primary Angle Closure Primary Angle Closure Suspect Fellow Eyes of Acute Angle Closure Glaucoma Procedure: Q-switched fd Nd:yag in Laser Iridotomy Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 10 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Sequential Laser Iridotomy Using Argon and Q-Switched 532 nm Frequency Doubled Neodymium Yag Laser: A Pilot Study
Study Start Date : November 2006
Actual Primary Completion Date : December 2007
Actual Study Completion Date : December 2007

Resource links provided by the National Library of Medicine

Drug Information available for: Neodymium

Primary Outcome Measures :
  1. Visual Acuity
  2. Intraocular pressure
  3. Total power delivered by each laser modality
  4. Iridotomy patency and size
  5. Pain rating during the procedure
  6. Anterior segment inflammation
  7. Endothelial cell count
  8. Cataract progression
  9. Rate of complications

Information from the National Library of Medicine

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Ages Eligible for Study:   22 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • More than 21 years old
  • Able to give informed consent
  • Diagnosis of either: chronic angle closure glaucoma (CACG), primary angle closure (PAC), primary angle closure suspect (PACS) or fellow eyes of acute angle closure glaucoma (AACG), and in need of a laser iridotomy

Exclusion Criteria:

  • History of any prior laser treatment or intraocular surgery to the eye
  • History of any corneal disease
  • Any ocular infection/ inflammation within the last two months
  • Inability to give informed consent

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): NCT00452998

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National University Hospital
Singapore, Singapore, 119074
Sponsors and Collaborators
National University Hospital, Singapore
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Principal Investigator: Paul Chew, FRCSEd,MMed National University Hospital, Singapore
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Responsible Party: Cecilia Aquino, MD, National University Hospital, Singapore Identifier: NCT00452998    
Other Study ID Numbers: DSRB A/06/293
First Posted: March 28, 2007    Key Record Dates
Last Update Posted: May 14, 2008
Last Verified: May 2008
Keywords provided by National University Hospital, Singapore:
Sequential Laser Iridotomy
Q-Switched 532 nm Laser
Frequency Doubled Neodymium Yag Laser
Additional relevant MeSH terms:
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Glaucoma, Angle-Closure
Ocular Hypertension
Eye Diseases