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

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StatusCompleted

Keywords

hemorrhage

Abstract

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.

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.

Dates

Last Verified:	07/31/2018
First Submitted:	06/10/2015
Estimated Enrollment Submitted:	06/11/2015
First Posted:	06/16/2015
Last Update Submitted:	08/23/2018
Last Update Posted:	08/26/2018
Actual Study Start Date:	04/30/2015
Estimated Primary Completion Date:	07/31/2018
Estimated Study Completion Date:	07/31/2018

Condition or disease

Angle Closure Glaucoma

Intervention/treatment

Device: The sequential technique

Device: The pure Nd:YAG laser technique

Phase

Arm Groups

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.

Eligibility Criteria

Ages Eligible for Study	18 Years To 18 Years
Sexes Eligible for Study	All
Accepts Healthy Volunteers	Yes
Criteria	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

Outcome

Primary Outcome Measures

1. Laser energy [1-hour]

Total energy used to create patency on the iris

Secondary Outcome Measures

1. Bleeding [1-hour]

iris bleeding immediate after laser reported as Yes or No

2. Corneal endothelial cell count [12-month]

Corneal endothelial cell count directly over the area of laser

3. Central corneal thickness [12-month]

Central corneal thickness

4. Patency of iridotomy [12-month]

Iridotomy patency is confirmed objectively reported as yes or no

5. Intraocular pressure spike [1-hour]

Intraocular pressure spike if present mean that IOP evelation of at least 8mmHg from baseline intraocular pressure