what is peripheral iridotomy
Background. Laser peripheral iridotomy (LPI) is the preferred procedure for treating angle-closure glaucoma caused by relative or absolute pupillary block. LPI eliminates pupillary block by allowing the aqueous to pass directly from the posterior chamber into the anterior chamber, bypassing the pupil.he iridotomy site should be in the peripheral third of the iris just anterior to the arcus. A crypt or a thinned area of the iris is recommended. Most ophthalmologists place the iridotomy between 11 oâclock and 1 oâclock, where it is superiorly covered by the lids.