Yag iridotomy is the preferred procedure for treating angle-closure glaucoma caused
by relative or absolute pupillary block. It eliminates pupillary block by allowing
the aqueous to pass directly from the posterior chamber into the anterior chamber,
bypassing the pupil. It can be performed with an argon laser, with a neodymium:
yttrium-aluminum-garnet (Nd:YAG) laser, or, in certain circumstances, with both.