Laser iridotomy uses a very focused beam of light to create a hole on the outer edge, or rim, of the iris, the colored part of the eye. This opening allows fluid (aqueous humor) to flow between the anterior chamber, the front part of the eye, and the area behind the iris, the posterior chamber. This opening may decrease pressure in the eye and usually prevents sudden buildup of pressure within the eye, which occurs during an episode of acute closed-angle glaucoma.
Some people feel a sensation of heat in the eye during laser surgeries. But there usually is no pain after laser iridotomy.