Randomized Prospective Study of Selective Laser Trabeculoplasty (SLT) Versus Argon Trabeculoplasty (ALT) in Patients With Pseudoexfoliation Glaucoma and Ocular Hypertension
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.
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: 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|
- IOP (Intraocular Pressure) [ Time Frame: 1 hour, 6 weeks, 3, 6 &12 months ] [ Designated as safety issue: No ]The main primary outcome variable will be the intraocular pressures (IOP) at 1 hour, 6 weeks, 3, 6 & 12 months post-operatively
|Study Start Date:||September 2006|
|Study Completion Date:||October 2009|
|Primary Completion Date:||September 2009 (Final data collection date for primary outcome measure)|
|Experimental: selective laser trabeculoplasty (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)||
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.
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.
|Rockyview General Hospital Eye Clinic|
|Calgary, Alberta, Canada, T2V1P9|
|St. Joseph's Health Care London Eye Clinic|
|London, Ontario, Canada, N6A 4V2|
|University of Ottawa Eye Institute|
|Ottawa, Ontario, Canada, K1H 8L6|
|Dr. C Birt|
|Toronto, Ontario, Canada, M4N 3M5|
|Montreal Glaucoma Institute|
|Montreal, Quebec, Canada, H1V 1G5|
|Principal Investigator:||Andrew C Crichton||University of Calgary|