Glaucoma experts seek consensus on open-angle glaucoma surgery

Donald S. Minckler, MD, said that long-term evidence of the efficacy of the newer procedures does not yet exist.

VIENNA, Austria — Newer surgical and laser therapies for open-angle glaucoma may have merit, but some glaucoma experts say these procedures still lack long-term evidence of efficacy. This was one of the conclusions of a panel discussion here seeking consensus on the surgical management of open-angle glaucoma.

An international panel of glaucoma experts here at the World Glaucoma Congress debated the merits of a range of issues in the surgical management of glaucoma, including indications for glaucoma surgery, laser trabeculoplasty, wound healing and the future of wound modulation, nonpenetrating glaucoma surgery and glaucoma drainage devices.

The panel discussed these topics in the context of a previously approved document, a consensus on open-angle glaucoma from the Association of International Glaucoma Societies, which was reached during a special meeting in April 2005. The panel then opened the floor to take live votes from the audience on each subject, the results of which were immediately tallied and projected for discussion by the whole panel.

Topics discussed included a comparison of trabeculectomy vs. glaucoma drainage devices, and a comparison of glaucoma drainage devices vs. cyclodestruction.

Two topics in the consensus that generated considerable controversy were the merits of argon laser trabeculoplasty (ALT) vs. selective laser trabeculoplasty (SLT) and the efficacy of nonpenetrating glaucoma surgery techniques.

In a refrain that was common to both controversies, Donald S. Minckler, MD, said that long-term evidence of the efficacy of the newer procedures does not yet exist.

“There’s really very little convincing evidence SLT works any better than ALT, and it just hasn’t been around long enough or studied well enough to be sure it’s a better option in terms of pressure-lowering, which is the goal of the procedure,” said Dr. Minckler, of Los Angeles.

Added Robert N. Weinreb, MD, “So don’t throw out your argon laser. It’s still the preferred method of many experienced glaucoma surgeons.”

And while the AIGS glaucoma consensus guidelines stated that lower IOP can be achieved with trabeculectomy than with nonpenetrating glaucoma surgery techniques, which include deep sclerectomy and viscocanalostomy, some surgeons said they a nonpenetrating technique as their primary treatment.

Some panel members noted that the nonpenetrating procedures are more skill-dependent than trabeculectomy, which may account for some surgeons’ reluctance to adopt them.

“Glaucoma surgery worldwide is decreasing in frequency, and it becomes a difficult point for us to decide how often you need to perform a procedure in order to remain at a high enough competency level to offer patients the best chance of success,” said Ivan Goldberg, MD, of Sydney, Australia.

If surgeons are performing fewer trabeculectomies, Dr. Goldberg said, they are going to be more reluctant to switch to a nonpenetrating technique that is more skill-dependent.

The panel was chaired by Dr. Weinreb; in addition to those mentioned above, participants included Robert D. Fechtner, MD, of New York; John Crowston, of La Jolla, Calif.; Peng T. Khaw, MD, PhD, of London; Jeffrey M. Liebmann, MD, of New York; Tarek Shaarawy, of Geneva, Switzerland; Roberto G. Carassa, MD, of Milan, Italy; George A. Cioffi, MD, of Portland, Ore.; Ann L. Coleman, MD, of Los Angeles; Franz Grehn, MD, of Wurzberg, Germany; Dennis S.C. Lam, MBBS, of Hong Kong; and Kuldev Singh, MD, of Stanford, Calif.