A recent posting on the Glaucoma Net suggested performing IZHV. If you don't know what that is, don't feel bad. I had no idea, either. Not only is the abbreviation unfamiliar, but the procedure, iridozonulohylovitrectomy, is not something taught in most glaucoma training programs. Ike Ahmed, MD, recently coined the term to refer to a comprehensive surgical approach for a recalcitrant problem in glaucoma, aqueous misdirection.
Not so long ago, the terms glaucoma surgery and filtration procedure were essentially interchangeable. In the early 1980s, the treatment paradigm was simple. If topical medications (including perhaps Diamox [Duramed Pharmaceuticals Inc.]) and argon laser trabeculoplasty did not control the IOP, we recommended filtering surgery. We reserved tubes for failed trabeculectomies. Rocket science it was not. Cyclocyrotherapy, then cyclophotocoagulation, was only used in blind end-stage eyes. The fact that filtering surgery had a poor long-term success rate and was plagued by acute and chronic bleb-related complications did not alter our approach.
Thankfully, the treatment of glaucoma has come a long way. We now have options, including Trabectome surgery (NeoMedix Corporation, Tustin, CA), canaloplasty (iScience Interventional, Menlo Park, CA), and endocyclophotocoagulation (Endo Optiks, Little Silver, NJ). On July 30, the FDA's Ophthalmic Devices Panel of the Medical Devices Advisory Committee voted in favor of a premarket approval application for the iStent (Glaukos Corp., Laguna Hills, CA). Clinical trials are to begin later this year for the ab interno procedures from Aquesys (Irvine, CA), Transcend Medical (Menlo Park, CA), and Ivantis Inc. (Irvine, CA). Other procedures are still under the radar yet discussed at scientific meetings. Can gene transfer and stem cell implantation be far off?
The implication is that we glaucoma surgeons, as a group, are willing to move past conventional surgical approaches. Thanks in part to innovative surgeons here and abroad, new technology, and an improved understanding of the outflow system, glaucoma surgery is coming of age. Sophisticated technology is now being more specifically directed to the site of pathology, which should help reduce complications involving collateral tissue and improve patients' visual recovery. Perhaps the most important measure of change is the willingness of the international glaucoma community to push the field forward, past classical filtering surgery.
Stay tuned! Rumor has it that GCLGNP (ganglioncelllateralgeniculatenucleusoplasty) is about to be a hot, new topic on the Net. It is an exciting time for glaucoma surgeons!
