Argon laser pretreatment 4 to 6 weeks before Nd:YAG laser iridotomy

Argon laser pretreatment followed by Nd:YAG laser iridotomy 4 to 6 weeks later was performed in the right eye of 10 patients. Primary Nd:YAG laser iridotomy was performed in the left eye. Significantly more Nd:YAG laser energy was needed to produce an iridotomy in pretreated eyes (P less than .001). Pretreated eyes developed a significantly larger pigment epithelium defect around the iridotomy site and a greater degree of pigmentation of the inferior part of the trabecular meshwork 6 months following treatment. Argon laser pretreatment followed by Nd:YAG laser iridotomy 4 to 6 weeks later appears to offer no advantages over primary Nd:YAG laser iridotomy.