Randomized Prospective Study of Selective Laser Trabeculoplasty (SLT) Versus Argon Trabeculoplasty (ALT) in Patients With Pseudoexfoliation Glaucoma and Ocular Hypertension

Sponsor

University of Calgary (Other)

Overall Status

Completed

CT.gov ID

NCT01126203

Collaborator

Canadian Glaucoma Clinical Research Council (Other)

Enrollment

Locations

Arms

Duration (Months)

Patients Per Site

0.1

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Multi-center, prospective, randomized, controlled clinical trial to compare selective laser trabeculoplasty (SLT) and Argon laser trabeculoplasty (ALT) in pseudoexfoliation glaucoma and ocular hypertension patients. IOP will be recorded, at baseline, 6 weeks, 6 months and 1 year after the laser procedure.

Condition or Disease	Intervention/Treatment	Phase
Exfoliation Syndrome Ocular Hypertension	Procedure: SLT Procedure: ALT	Phase 3

Detailed Description

This study derives from a clinical observation that laser treated eyed with PXF glaucoma may have a similar long-term response rates when either ALT or SLT is performed. Some authors have considered that there is a risk of IOP elevation in the immediate post laser period with ALT or SLT as a complication to be related to denser angle pigmentation (20,48). (46) No long-term analysis comparing response rates of both laser treatments in these types of patients has been done.

Primary objective is to determine which laser therapy has more IOP lowering effect as primary or adjunctive treatment in eyes diagnosed with ocular hypertension and glaucoma associated to PXF. Response rates will be compared between groups at long-term.

Secondary objective is to determine the relationship between the type of laser therapy performed and angle pigmentation, number of applications, and amount of energy used with age, number and type of medication used post laser and phakic status.

Study Design

Study Type:

Interventional

Actual Enrollment :

25 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Randomized Multicentre Prospective Study of Selective Laser Trabeculoplasty (SLT) vs. Argon Trabeculoplasty (ALT) in Patients With Pseudoexfoliation Glaucoma and Ocular Hypertension

Study Start Date :

Sep 1, 2006

Actual Primary Completion Date :

Sep 1, 2009

Actual Study Completion Date :

Oct 1, 2009

Arms and Interventions

Arm	Intervention/Treatment
Experimental: selective laser trabeculoplasty (SLT)	Procedure: SLT All eyes will be treated using a commercially available Q-switched Nd:YAG laser (Coherent Selecta 7000, Coherent Inc., Palo Alto , CA, USA) calibrated by the manufacturer. On the day of treatment, IOP will be measured, then one drop of Apraclonidine 1% or Brimonidine 0.2% and pilocarpine 1% or 2% will be instilled. Before the patient is seated at the laser slit-lamp system a proparacaine hydrochloride drop will be instilled in the eye to be treated. A Goldmann goniolens or a Latina SLT or any other goniolens will be placed on the eye to be treated with methyl cellulose 1%. The helium-neon aiming beam is focused onto the pigmented trabecular meshwork. SLT will be performed with approximately 50 applications, a 400um spot size with energies varying from 0.8-1.2 mjoules.
Experimental: Argon laser trabeculoplasty (ALT)	Procedure: ALT All eyes will be treated using Ophthalas 532 Eyelite Laser Photocoagulator (Alcon Surgical, Dallas-Fort Worth, Texas, USA. On the day of treatment, IOP will be measured, then on the day of treatment, IOP will be measured, then one drop of Apraclonidine 1% or Brimonidine 0.2% and pilocarpine 1% will be instilled. Before the patient is seated at the laser slit-lamp system a proparacaine hydrochloride drop will be instilled in the eye to be treated. A Goldmann goniolens will be placed on the eye to be treated with methyl cellulose 1%. The aiming beam is focused onto the anterior portion of the pigmented trabecular meshwork. ALT will be performed to the superior or inferior 180 degrees with ~ 50 applications, a 50um spot size with energies varying from 400-700 mW with 0.1 second duration.

Arm

Intervention/Treatment

Experimental: selective laser trabeculoplasty (SLT)

Procedure: SLT

All eyes will be treated using a commercially available Q-switched Nd:YAG laser (Coherent Selecta 7000, Coherent Inc., Palo Alto , CA, USA) calibrated by the manufacturer. On the day of treatment, IOP will be measured, then one drop of Apraclonidine 1% or Brimonidine 0.2% and pilocarpine 1% or 2% will be instilled. Before the patient is seated at the laser slit-lamp system a proparacaine hydrochloride drop will be instilled in the eye to be treated. A Goldmann goniolens or a Latina SLT or any other goniolens will be placed on the eye to be treated with methyl cellulose 1%. The helium-neon aiming beam is focused onto the pigmented trabecular meshwork. SLT will be performed with approximately 50 applications, a 400um spot size with energies varying from 0.8-1.2 mjoules.

Experimental: Argon laser trabeculoplasty (ALT)

Procedure: ALT

All eyes will be treated using Ophthalas 532 Eyelite Laser Photocoagulator (Alcon Surgical, Dallas-Fort Worth, Texas, USA. On the day of treatment, IOP will be measured, then on the day of treatment, IOP will be measured, then one drop of Apraclonidine 1% or Brimonidine 0.2% and pilocarpine 1% will be instilled. Before the patient is seated at the laser slit-lamp system a proparacaine hydrochloride drop will be instilled in the eye to be treated. A Goldmann goniolens will be placed on the eye to be treated with methyl cellulose 1%. The aiming beam is focused onto the anterior portion of the pigmented trabecular meshwork. ALT will be performed to the superior or inferior 180 degrees with ~ 50 applications, a 50um spot size with energies varying from 400-700 mW with 0.1 second duration.

Outcome Measures

Primary Outcome Measures

IOP (Intraocular Pressure) [1 hour, 6 weeks, 3, 6 &12 months]
The main primary outcome variable will be the intraocular pressures (IOP) at 1 hour, 6 weeks, 3, 6 & 12 months post-operatively

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Only patients with clinical evidence of unilateral or bilateral open angle pseudoexfoliation ocular hypertension (IOP > 22mmHg) or glaucoma (Evidence on Humphrey 30-2 or Goldmann of nerve fiber layer damage) with uncontrolled IOP, over 18 years of age, and are willing to participate in the study will be included. If increased IOP is bilateral then the worst eye will be treated.

Exclusion Criteria:

Patients will be excluded if they have evidence of any glaucoma other than pseudoexfoliative open angle, if the trabecular meshwork cannot be seen in 360 degrees, if they had previous laser therapy ALT or SLT, if they have advanced visual field defect (split fixation or a scotoma within 10 degrees fixation), taking any systemic or topical steroids, have had any previous ocular surgery (glaucoma or cataract extraction included) or laser within the previous six months, if they are monocular patients, if they have any corneal disease precluding the angle evaluation and treatment, or if they had ocular trauma.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Rockyview General Hospital Eye Clinic	Calgary	Alberta	Canada	T2V1P9
2	St. Joseph's Health Care London Eye Clinic	London	Ontario	Canada	N6A 4V2
3	University of Ottawa Eye Institute	Ottawa	Ontario	Canada	K1H 8L6
4	Dr. C Birt	Toronto	Ontario	Canada	M4N 3M5
5	Montreal Glaucoma Institute	Montreal	Quebec	Canada	H1V 1G5