Laser Peripheral Iridotomy

Laser iridotomy functions to relieve pupillary block by allowing an equalization of pressure between the anterior and posterior chambers. Patients should have had nonindentation gonioscopy that demonstrated contact between the iris and the trabecular meshwork typically for greater than 180° of the angle, although clinician discretion may be employed on a case-by-case basis. Other indications include aphakic or pseudophakic pupillary block, plateau iris, or phacomorphic angle closure with a component of pupillary block and some cases of pigment dispersion syndrome. The procedure may be performed with an argon laser, Nd:YAG laser, or a combination of the two. This author prefers Nd:YAG for hazel or blue irides and combination argon/YAG for darker irides. Simply put, all patients should be informed of at least a 2 % risk of a linear dysphotopsia from the laser. Recent literature shows that a temporal iridotomy is less likely to result in linear dysphotopsia as compared to a superior iridotomy, although a temporal iridotomy may be more painful, and again clinician discretion may be indicated.