Short-term Intraocular Pressure Control After YAG Iridotomy - Comparison Between Brimonidine 0.1% vs. 0.2%

Postoperative IOP elevation is one of the most common complications after LPI.Previous studies showed that brimonidine 0.2% is effective in blunting IOP spikes after LPI.This prospective randomized double-masked interventional study will include patients with bilateral narrow angles, defined by irido-trabecular contact in >180o on gonioscopy.Pilocarpine 1% will be used in both eyes, and 30 minutes later, brimonidine 0.1% randomly used in one eye and brimonidine 0.2% in the contra-lateral eye. LPI with Nd:YAG laser is performed 30 minutes later in both eyes by a single glaucoma specialist. IOP measurements are assessed before the use of any eyedrop (basal IOP), 30 minutes after pilocarpine (pre-brimonidine), and 30, 60, 120, 180 minutes after LPI. Pachymetry, ultrasonic biometry, gonioscopy, and total YAG laser energy are recorded. Non-parametric test will be used for analysis.