Comparing Nd:YAG Laser and Sequential Double Frequency YAG-Nd:YAG Laser Iridotomy

Randomized Clinical Trial Comparing Neodynium:Ytrium-aluminium-garnet (Nd:YAG) Laser and Sequential Double Frequency YAG-Nd:YAG Laser Iridotomy in Patients With Dark Iris

No single type of laser or set of laser parameters is appropriate for all type of irides. Pure Nd:YAG laser iridotomy is very effective in the light color irides. It was considered as the gold standard for iridotomy. It, however, is less effective and causes some complication such as iris hemorrhage especially in patients with dark iris.

Study Overview

• Status: Completed
• Conditions: Angle Closure Glaucoma
• Intervention / Treatment: Device: The sequential technique; Device: The pure Nd:YAG laser technique

Detailed Description

By using the double frequency YAG to make the initial bore and the Nd:YAG laser to complete the perforation, the technique should be able to effectively combine most of the advantages of both lasers whilst avoiding their disadvantages. It is possibly the ideal iridotomy technique to use in the Asian irides. The investigators aim to study the energy use for laser iridotomy comparing between the two techniques as well as objectively measure the variables associated with complications.

• Study Type: Interventional
• Enrollment (Actual): 82
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Thailand
  • Songkhla
    • Hat Yai, Songkhla, Thailand, 90110
      • Weerawat Kiddee

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Patient in need to have a laser iridotomy

  • primary angle closure glaucoma or
  • primary angle closure or
  • primary angle closure suspect (needed repeated pupil dilation) or
  • fellow eyes of acute angle closure crisis, and
• Age of at least 18 years, and
• Dark iris patients (only black and dark brown color)

Exclusion Criteria:

• Eye with acute angle closure crisis
• Active conjunctiva or corneal infection or inflammation
• Active anterior uveitis
• History of any prior laser treatment
• History intraocular surgery
• Eye with corneal scar
• Corneal haziness obscure iridotomy site
• Endothelial cell count less than 1000 cells/mm2 (pre-laser)
• Iris color other than black or dark brown
• Inability to sit at the slit lamp to have laser done

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: The sequential technique; By using the double frequency YAG laser to make the initial bore and the Nd:YAG laser to complete the perforation on iris.	Device: The sequential technique; By using 'the double frequency YAG laser' to make the initial bore and 'the Nd:YAG laser' to complete the perforation on iris.
Active Comparator: The pure Nd:YAG laser technique; By using the pure Nd:YAG to make a complete perforation on iris.	Device: The pure Nd:YAG laser technique; By using 'the pure Nd:YAG laser' to make a complete perforation on iris.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Laser energy	Total energy used to create patency on the iris	1-hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Bleeding	iris bleeding immediate after laser reported as Yes or No	1-hour
Corneal endothelial cell count	Corneal endothelial cell count directly over the area of laser	12-month
Central corneal thickness	Central corneal thickness	12-month
Patency of iridotomy	Iridotomy patency is confirmed objectively reported as yes or no	12-month
Intraocular pressure spike	Intraocular pressure spike if present mean that IOP evelation of at least 8mmHg from baseline intraocular pressure	1-hour

Collaborators and Investigators

• Sponsor: Prince of Songkla University
• Investigators: Principal Investigator: Asst.Prof.Weerawat Kiddee, MD, Prince of Songkla University

Study record dates

Study Major Dates

• Study Start: May 1, 2015
• Primary Completion (Actual): August 1, 2018
• Study Completion (Actual): August 1, 2018

Study Registration Dates

• First Submitted: June 11, 2015
• First Submitted That Met QC Criteria: June 12, 2015
• First Posted (Estimate): June 17, 2015

Study Record Updates

• Last Update Posted (Actual): August 27, 2018
• Last Update Submitted That Met QC Criteria: August 24, 2018
• Last Verified: August 1, 2018

More Information

Terms related to this study

• Keywords: Iridotomy
• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Glaucoma; Glaucoma, Angle-Closure
• Other Study ID Numbers: EC-58-093-02-1