Formation of peripheral anterior synechiae following argon laser trabeculoplasty. A prospective study to determine relationship to position of laser burns.

One hundred eighteen eyes with primary open-angle glaucoma underwent argon laser trabeculoplasty . Laser burns were placed in the anterior trabecular meshwork (ATM) in 58 eyes and directly over Schlemm's canal in the posterior trabecular meshwork (PTM) in 60 eyes. Twenty-nine eyes received 100 burns and 89 eyes received 50 burns distributed equally over 360 degrees. Peripheral anterior synechiae (PAS) developed in seven (12%) of the eyes having anterior trabeculoplasty and in 26 (43%) of those having posterior trabeculoplasty . There was no correlation between the development of PAS and sex, width of the anterior chamber angle, or the number of laser burns. Eyes having anterior trabeculoplasty had a final decrease in intraocular pressure equal to those having posterior trabeculoplasties . Our results strongly suggest that trabeculoplasty is a safer but no less effective procedure when the laser burns are placed on the ATM rather than the PTM.