Asymptomatic Narrow Angles, Primary Angle Closure Suspects
Conditions
Keywords
Asymptomatic Narrow Angles, Primary Angle Closure Suspects, Laser Peripheral Iridotomy, Randomised Controlled Trial
Brief summary
This is a multicentric, randomised, controlled study comparing Laser Iridotomy (LI) to no treatment in subjects with asymptomatic narrow angles (ANA).One eye of each subject with ANA will be randomised to undergo LI and the other eye will be left alone and will serve as an internal control. Subjects are proposed to be followed up once a year for 5 years.
Detailed description
Objective: This study will compare LI versus no treatment in subjects with asymptomatic narrow angles, the anatomical trait that predisposes to primary angle closure glaucoma (PACG), in order to assess the effectiveness of prophylactic treatment in the prevention of blindness due to PACG. Eligibility: 1. Bilateral Narrow angles; 2. Age 50 years and above; 3. Informed consent obtained prior to or at baseline visit. Trial Design: Subjects with asymptomatic ANA undergoes randomisation after comprehensive ocular exam followed by randomisation to LI in one eye and no treatment in the other eye. Follow up is done for 5 years with yearly examination.
Interventions
PROCEDURELaser Peripheral Iridotomy
Sponsors
National Medical Research Council (NMRC), Singapore
Singapore National Eye Centre
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Bilateral Narrow angles 2. Age 50 years and above 3. Informed consent obtained prior to or at baseline visit
Exclusion criteria
1. Presence of PAS 2. IOP \> 21 mm Hg 3. Glaucomatous optic neuropathy and/or CDR \> 0.7 4. Secondary angle closure such as uveitis, neovascularisation etc. 5. Prior intraocular surgery or penetrating eye injury 6. Corneal disorders such as corneal endothelial dystrophy except mild corneal guttae 7. Evidence of prior acute angle closure event 8. High risk of acute angle closure. 9. Significant cataract and visual acuity less than 20/40 10. Constant use of contact lens for refractive correction 11. Chronic use of topical or systemic steroids 12. Established retinopathies on ocular treatments (e.g. Diabetic) 13. Any other disease which is likely to cause field loss in next 3 years 14. Severe health problems decreasing life expectancy to less than one year.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Peripheral anterior synechiae formation | — |
| IOP elevation >21 mm Hg | — |
| Development of acute angle closure event | — |
Secondary
| Measure | Time frame |
|---|---|
| Change in HRT optic disc parameters | — |
| Changes in the grading of Modified Schaffer Grading | — |
| Formation of disc pallor | — |
| Change in UBM angle parameters | — |
| Development of glaucomatous optic neuropathy | — |
| Development of corresponding visual field loss by automated perimetry | — |
Countries
Singapore
Contacts
Primary ContactTin - Aung, FRCSEd PhD
Outcome results
None listed