Incisional therapies: What's on the horizon?

Abstract

For decades, the primary resistance to aqueous outflow has been thought to reside in the outer one-third of the trabecular meshwork including the juxtacanalicular connective tissue in continuity with the inner wall of Schlemm's canal. Dysfunction of this portion of the trabecular outflow system has been considered to be the main cause of open-angle glaucoma (COAG). Surgical therapies have either targeted this tissue directly or bypassed it via scleral fistulas such as trabeculectomy. Goniotomy and ab externo trabeculotomy, still considered the mainstay of surgeries for congenital glaucoma worldwide, have not been considered useful by North American surgeons in adult open-angle glaucoma, but have remained popular in Europe and especially Japan. Other types of microincisional surgery utilizing lasers, such as Q-switched neodymium: YAG, have also been attempted but not been found successful because of a posttreatment healing process described as tissue filling-in whether utilizing micropuncture or strip-ablations. The amount of tissue removed during laser ablation has been increased and thermal damage minimized through the application of erbium: YAG lasers still being clinically utilized in Europe. © 2010 Springer-Verlag New York.