What is the purpose of laser peripheral iridotomy in angle-closure risk?

• A. Increase aqueous production
• B. Create a small opening in the peripheral iris to relieve pupillary block and prevent angle closure
• C. Photocoagulate the retina
• D. Tighten iris to widen the angle

Answer: (B)

Laser peripheral iridotomy prevents angle-closure by relieving pupillary block. In eyes at risk for angle closure, fluid backs up from the posterior chamber to the anterior chamber because the pupil blocks flow, causing the iris to bow forward (iris bombe) and narrow or close the drainage angle. Creating a tiny hole in the peripheral iris with a laser gives aqueous humor an alternate route to move from back to front, equalizing pressures, flattening the iris configuration, and widening the angle to lower the risk of an acute attack. It’s a prophylactic or recurrence-prevention procedure and doesn’t increase aqueous production, photocoagulate the retina, or tighten the iris to widen the angle; instead, it establishes a new outflow path for fluid.