Question

Laser iridotomy is done in which type of glaucoma?

• A. Angle closure glaucoma
• B. Open angle glaucoma
• C. Pigmentary glaucoma
• D. None

Hint:

Iridotomy relieves pupillary block - which glaucoma has a blocked angle?

Answer 1

The Correct Option is A

Step 1: In primary angle closure glaucoma (PACG) the peripheral iris is pushed forward and blocks the trabecular meshwork. The key underlying problem is a relative pupillary block, where aqueous cannot pass freely from the posterior to the anterior chamber.

Step 2: Peripheral laser iridotomy creates a small full thickness hole in the peripheral iris. This provides an alternative route for aqueous to flow forward, equalises pressure between the two chambers, relieves the pupillary block, and reopens the angle. It is therefore the treatment of choice for PACG.

Step 3: This makes angle closure glaucoma the correct answer.

Step 4: Open angle glaucoma has an anatomically open angle and is managed with pressure lowering drops, laser trabeculoplasty, or trabeculectomy, not iridotomy. Pigmentary glaucoma is also an open angle condition, so iridotomy is not the standard primary treatment in these.