Medical treatment as the initial therapy for open-angle glaucoma

Nonpenetrating filtering procedures: viscocanalostomy and collagen wick

Unroofing of Schlemm's canal without entering the anterior chamber has been performed previously to lower intraocular pressure. Initial results were good, but long-term results were discouraging, and the techniques were abandoned. Recently, two variations have surfaced. Visco canalostomy is a technique devised by Robert Stegmann of South Africa. The glaucoma drainage device (Collagen Wick) was initially introduced by Koslov in Russia. These techniques are described in this article.

Nonpenetrating trabeculectomy with placement of a collagen drainage device

Since the advent of trabeculectomy with antimetabolite therapy, there have been few changes in the surgical management of glaucoma. This is the first report of a new technique, nonpenetrating trabeculectomy with placement of a collagen drainage device. The procedure facilitates aqueous drainage without entering the human eye. Meticulous surgical dissection of the trabecular meshwork is required with creation of an external filtration tract and subscleral positioning of a collagen device to facilitate aqueous drainage. With this procedure, the surgeon can avoid common complications of glaucoma surgery such as synechias, overfiltration, hypotony, intraocular infection, uveal prolapse, and failed surgical blebs. The procedure and device have been used extensively in Russia.