Scanning electron microscopy of trabeculectomy specimens in open-angle glaucoma.

We examined trabeculectomy specimens obtained at the time of surgery for inadequately controlled open-angle glaucoma by scanning electron microscopy. Of the 50 specimens ten included a broad area of the trabecular meshwork. In these ten specimens the meshwork was obscured by material. We believe the degree of occlusion was significant in these specimens, which would lead to obstruction of aqueous outflow. No similar material was found in control specimens from persons of similar age.