NCT01758237

Brief Summary

To establish the correlation of the location of the Nd:YAG laser peripheral iridotomy to the post operative visual symptoms experienced by some patients. The investigators hypothesize that fully uncovered laser peripheral iridotomy will produce less significant dysphotopsia, due to avoidance of the prismatic effect produced by the tear film than those covered.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
214

participants targeted

Target at P75+ for not_applicable

Timeline
Completed

Started Jan 2008

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

January 1, 2008

Completed
1 year until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 1, 2009

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

January 1, 2009

Completed
4 years until next milestone

First Submitted

Initial submission to the registry

December 20, 2012

Completed
12 days until next milestone

First Posted

Study publicly available on registry

January 1, 2013

Completed
Last Updated

February 13, 2013

Status Verified

February 1, 2013

Enrollment Period

1 year

First QC Date

December 20, 2012

Last Update Submit

February 11, 2013

Conditions

Narrow Angle Patients at Risk for Angle Closure Glaucoma

Keywords

Laser Peripheral IridotomyVisual DysphotopsiaVisual DisturbancesAngle Closure Glaucoma

Outcome Measures

Primary Outcomes (1)

  • Presence of Linear Dysphotopsia

    The change in presence of linear dysphotopsia from baseline (prior to intervention) to 1 month after the Nd:YAG laser intervention is performed.

    Baseline (Time =0),1 month

Secondary Outcomes (3)

  • Presence of Visual Dysphotopsia

    Baseline (Time = 0), 1 month

  • Pain Experienced

    Procedure (Time = 0)

  • Nd:YAG Laser Power Used

    Procedure (Time = 0)

Study Arms (2)

Superior Laser Peripheral Iridotomy

EXPERIMENTAL

Neodymium-doped: Yttrium Aluminum Garnet (Nd:YAG) laser peripheral iridotomy was performed on the superior aspect of the iris in the eye being treated. This will be in the 11 to 1 o'clock position.

Device: Neodymium-doped: Yttrium Aluminum Garnet (Nd:YAG) laserProcedure: Nd:YAG Laser Peripheral Iridotomy

Temporal Laser Peripheral Iridotomy

EXPERIMENTAL

Neodymium-doped: Yttrium Aluminum Garnet (Nd:YAG) laser peripheral iridotomy was performed on the temporal aspect of the iris in the eye being treated. The position will be in the 2 to 4 o'clock in the left eye and 8 to 10 o'clock in the right eye.

Device: Neodymium-doped: Yttrium Aluminum Garnet (Nd:YAG) laserProcedure: Nd:YAG Laser Peripheral Iridotomy

Interventions

Neodymium-doped: Yttrium Aluminum Garnet (Nd:YAG) laserDEVICE

This device is used to perform the peripheral iridotomy on all patients. It is a standard of care approved device.

Also known as: Nd:YAG Laser
Superior Laser Peripheral IridotomyTemporal Laser Peripheral Iridotomy
Nd:YAG Laser Peripheral IridotomyPROCEDURE

After application of topical anesthetic to the eye undergoing the LPI, the patient is seated at the laser machine. Abraham iridotomy lens filled with a viscous material will be used to facilitate the procedure. The thinnest area of the iris quadrant treated will be chosen. Nd:YAG Laser will be applied until iridotomy is opened satisfactory.

Also known as: Nd:YAG LPI
Superior Laser Peripheral IridotomyTemporal Laser Peripheral Iridotomy

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Able and willing to make the required study visit
  • Able and willing to give consent and follow study instructions
  • An indication to undergo laser peripheral iridotomy (narrow angles, occludeable angle at risk of acute angle closure, pupil block condition, chronic angle closure, pigment dispersion syndrome)

You may not qualify if:

  • Previous intraocular surgery
  • Best corrected visual acuity worse than 20/40
  • Asymmetrical ptosis of more than 2mm
  • Any active intraocular inflammation
  • Acute attack of angle closure glaucoma

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Credit Valley EyeCare

Mississauga, Ontario, L5L 1W8, Canada

Location

Related Publications (7)

  • Khodadoust AA, Arkfeld DF, Caprioli J, Sears ML. Ocular effect of neodymium-YAG laser. Am J Ophthalmol. 1984 Aug 15;98(2):144-52. doi: 10.1016/0002-9394(87)90348-5.

    PMID: 6548087BACKGROUND

  • Murphy PH, Trope GE. Monocular blurring. A complication of YAG laser iridotomy. Ophthalmology. 1991 Oct;98(10):1539-42. doi: 10.1016/s0161-6420(91)32091-8.

    PMID: 1961641BACKGROUND

  • Spaeth GL, Idowu O, Seligsohn A, Henderer J, Fonatanarosa J, Modi A, Nallamshetty HS, Chieh J, Haim L, Steinmann WC, Moster M. The effects of iridotomy size and position on symptoms following laser peripheral iridotomy. J Glaucoma. 2005 Oct;14(5):364-7. doi: 10.1097/01.ijg.0000177213.31620.02.

    PMID: 16148584BACKGROUND

  • Weintraub J, Berke SJ. Blurring after iridotomy. Ophthalmology. 1992 Apr;99(4):479-80. doi: 10.1016/s0161-6420(92)38516-1. No abstract available.

    PMID: 1584561BACKGROUND

  • Congdon N, Yan X, Friedman DS, Foster PJ, van den Berg TJ, Peng M, Gangwani R, He M. Visual symptoms and retinal straylight after laser peripheral iridotomy: the Zhongshan Angle-Closure Prevention Trial. Ophthalmology. 2012 Jul;119(7):1375-82. doi: 10.1016/j.ophtha.2012.01.015. Epub 2012 Mar 14.

    PMID: 22424576BACKGROUND

  • Chung RS, Guan AE. Unusual visual disturbance following laser peripheral iridotomy for intermittent angle closure glaucoma. Graefes Arch Clin Exp Ophthalmol. 2006 Apr;244(4):532-3. doi: 10.1007/s00417-005-0129-x. Epub 2005 Oct 14. No abstract available.

    PMID: 16228219BACKGROUND

  • Vera V, Naqi A, Belovay GW, Varma DK, Ahmed II. Dysphotopsia after temporal versus superior laser peripheral iridotomy: a prospective randomized paired eye trial. Am J Ophthalmol. 2014 May;157(5):929-35. doi: 10.1016/j.ajo.2014.02.010. Epub 2014 Feb 14.

    PMID: 24531024DERIVED

MeSH Terms

Conditions

Glaucoma, Angle-Closure

Interventions

Lasers

Condition Hierarchy (Ancestors)

GlaucomaOcular HypertensionEye Diseases

Intervention Hierarchy (Ancestors)

Optical DevicesEquipment and SuppliesRadiation Equipment and Supplies

Study Officials

  • Iqbal Ike K Ahmed, MD

    University of Toronto, Toronto, Canada. University of Utah, Salt Lake City, USA

    PRINCIPAL INVESTIGATOR

  • Vanessa Vera, MD

    University of Toronto, Canada

    STUDY DIRECTOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
INDUSTRY
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Principle Investigator

Study Record Dates

First Submitted

December 20, 2012

First Posted

January 1, 2013

Study Start

January 1, 2008

Primary Completion

January 1, 2009

Study Completion

January 1, 2009

Last Updated

February 13, 2013

Record last verified: 2013-02

Locations

CA(1)