Histopathologic verification of position of laser burns in argon laser trabeculoplasty

Surgical trabeculectomy was performed on 10 eyes of 10 patients following failure of argon laser trabeculoplasty. All specimens were examined by scanning electron microscopy to determine anatomic location of laser damage. Correlation with clinical data revealed accurate placement of laser burns in 11 out of 13 treatment sessions. The degree of laser injury varied with energy delivered and pigmentation of the posterior trabecular meshwork. Complications such as corneal endothelial, oblique, and confluent burns were present in 50% of cases studied.