Glaucoma - Surgery

Nonpenetrating Surgical Techniques: Deep Sclerectomy and Viscocanalostomy

Deep sclerectomy and viscocanalostomy are less invasive techniques than filtering surgery that leave the anterior chamber (front of the eye) intact and avoid creation of blebs.

text continues below

In deep sclerectomy, the surgeon removes a deep piece of the sclera (the white part of the eye), part of the trabecular meshwork, and the front of Schlemm's canal (the vessels that return fluid into the blood stream).

In both deep sclerectomy and viscocanalostomy, the surgeon first creates a flap in the outer part of the sclera (the white part of the eye) and then removes a deep piece of the sclera underneath. This opens up Schlemm's canal (the vessels that return fluid into the blood stream) and exposes a layer above the anterior chamber called Descemet's membrane. A space has also been created between the inner and outer layers of the sclera.
In deep sclerectomy, this space now serves as a tiny reservoir for aqueous fluid that flows now through the membrane and pools here. The fluid then flows out without the surgeon having to open the anterior chamber (as in standard filtering surgery).
In viscocanalostomy, the surgeon typically injects gel-like materials into the ends of Schlemm's canal in order to enlarge the canal for fluid outflow and lower IOP. The tiny reservoir is sewn tightly up.

Many variations are under investigation. In general, the procedures have fewer complications afterward than standard filtering surgery, although they require excellent surgical skill. Nonpenetrating techniques do not lower IOPs as much as conventional surgery does, however. In time, however, these nonpenetrating techniques are expected to be as effective as filtration surgery.

Treatment for Patients with both Glaucoma and Cataracts

Cataracts and Glaucoma. For patients with both glaucoma and cataracts, experts recommend the following:

In patients with cataracts and poorly controlled glaucoma, a two-step procedure for both eye conditions is needed. These are typically first trabeculectomy for glaucoma followed by cataract surgery. Fluid leakage and the presence of blood in the back chamber of the eye are potential complications of this combined procedure. Phacoemulsification has improved success rates and reduced high complication rates of the double procedure compared with extracapsular cataract extraction. New advances that replace trabeculectomy with nonpenetrating glaucoma surgery may prove to be beneficial.
In patients who have cataracts plus either closed-angle glaucoma or open angle glaucoma that is stabilized with medication, the cataract may be able to be extracted and medication continued for the glaucoma.