Argon Laser Peripheral Iridoplasty for Primary Angle Closure Glaucoma (ALPI)
Recruitment status was: Recruiting
Glaucoma is the leading cause of irreversible blindness worldwide. With ageing of the population, glaucoma morbidity will rise, causing increased health care costs and economic burden for a condition in which visual loss, once established, cannot be reversed. In contrast to western countries, primary angle closure glaucoma (PACG) is a major form of glaucoma in Asia. In a recent population based survey in Singapore, the prevalence of glaucoma was 3.2% in the Chinese population over 40. Glaucoma was the leading cause of blindness, with PACG the most visually destructive form of the disease.
Laser iridotomy is the current first line treatment for PACG. It acts by relieving pupil block, which in turn may reduce intraocular pressure (IOP) and prevent progression of glaucoma. However recent data indicate that iridotomy is not successful in controlling IOP in the long term, and the majority of cases develop a clinically significant rise in IOP requiring medical therapy or surgery.
Argon laser peripheral iridoplasty (ALPI) offers a new therapeutic option for PACG. The procedure consists of placing contraction burns in the iris periphery which results in contraction of the iris stroma and opening of the angle.
The proposed study is a 2-centre randomized controlled trial to determine whether ALPI is an effective and safe treatment in the management of PACG. 210 patients with PACG and high IOP (>21 mmHg) following laser iridotomy will be randomized to receive ALPI or medical treatment to achieve IOP control. Subjects will be followed up for 12 months and the outcome criteria will be the rate of medical treatment and surgery in each group, and the angle width and configuration.
This will be the first RCT worldwide to address the role of ALPI in PACG. The study findings will have great relevance for the prevention of glaucoma blindness in the elderly.
Procedure: Argon Laser Iridoplasty
Drug: Travatan/ Timolol/Azopt
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Primary Purpose: Treatment
|Official Title:||Argon Laser Peripheral Iridoplasty for Primary Angle Closure Glaucoma: A Randomised Controlled Trial|
- The primary outcome will be the number of patients in each group on medical treatment or having had surgical treatment at 12 months. The mean number of medications required to control IOP in each group will also be analyzed. [ Time Frame: one year ] [ Designated as safety issue: Yes ]
- The secondary outcome will be the change in angle width and configuration as measured by gonioscopic examination, ultrasound biomicroscopy (UBM) and anterior segment OCT assessment at 1 month, 6 months and 12 months following entry into the study. [ Time Frame: one year ] [ Designated as safety issue: Yes ]
|Study Start Date:||September 2007|
|Estimated Primary Completion Date:||September 2011 (Final data collection date for primary outcome measure)|
|Active Comparator: Iridoplasty||Procedure: Argon Laser Iridoplasty|
|Active Comparator: Control (Medication)||Drug: Travatan/ Timolol/Azopt|
Show Detailed Description
Please refer to this study by its ClinicalTrials.gov identifier: NCT00980473
|Singapore National Eye Centre|
|Singapore, Singapore, 168751|