Internal sclerectomy for glaucoma filtering surgery with an automated trephine.

A technique is described for performing full-thickness glaucoma filtering operation from within the anterior chamber. The procedure utilizes an automated trephine, designated the "trabecuphine," that is capable of simultaneous cutting and irrigation. The trabecuphine is brought into the anterior chamber through a limbal incision 180 degrees away from the planned filter site. The trephine is passed across the anterior chamber, above the iris, and into the angle to perform the sclerotomy. This procedure was performed successfully in 13 eyes of seven cynomolgus monkeys. Complications included two small hyphemas that cleared completely. Other complications such as flat anterior chamber, corneal damage, iridodialysis, conjunctival buttonhole, and cataract formation did not occur. Internal scleral trephination may offer another alternative in the surgical management of patients with intractable glaucoma.