Guidelines for glaucoma

Group sets out to clear the muddy waters when it comes to rules, standards

When it comes to glaucoma research, many subspecialists agree that the rules have been anything but clear as to how glaucoma research all over the world is undertaken and reported.
To that end, the World Glaucoma Association (WGA) recently published "Guidelines on Design and Reporting of Glaucoma Surgical Trials" and presented it at the WGA meeting in Paris in June 2011.
The document, surgeons said, was an answer to the huge interest in research on how to improve glaucoma surgery, trabeculectomy, and drainage devices, as well as to determine how new surgical methods might fit into a practitioner's list of options. "Clinical glaucoma surgical research is currently hindered by, among other things, the lack of uniform guidelines for clinical glaucoma surgical trials reporting," the document states. "This has been clearly highlighted in the last 10 years by the controversy that arose from the introduction of non-penetrating glaucoma surgery. Despite a plethora of reports currently in the literature, it is quite difficult to make certain and accurate evaluation of the exact location of NPGS among our options. This is mainly because of the absence of a common platform (guidelines) on which studies can be reported and thus compared."
Kuldev Singh, M.D., professor of ophthalmology, and director, glaucoma service, Stanford University School of Medicine, Calif., said the goal of the document is to be a reference for glaucoma specialists around the world who plan to publish a study.
"The catalyst was that there were no standards for how people present data in clinical trials," Dr. Singh said. "There's so much variability that it's hard to compare studies with each other because the data is presented very differently. The idea with the guidelines was to have people present data for studies that are published more or less the same to establish the standard and to allow us a better comparison between different studies in different parts of the world with regard to efficacy, safety, and other parameters."
One of the major highlights of the document is how intraocular pressure should be reported in studies, including IOP parameters, what times of day the measurements should be taken, what constitutes success in IOP lowering, and what constitutes failure in IOP lowering.
"There was so much time and effort that was put into this, and I think it's a wonderful document," said Carla J. Siegfried, M.D., associate professor, ophthalmology and visual sciences, Washington University School of Medicine, St. Louis. "There weren't many established guidelines to begin with, which is why this started. Everyone was looking at different criteria for success, and some studies that were done in foreign countries, for example, may not have addressed the Institutional Review Board approval of the trials and proper consent, etc."
Dr. Siegfried said the information is particularly relevant as glaucoma surgeons grapple with which procedures may best suit patients while avoiding risk.
Newer devices, she said, are looking at improving natural aqueous outflow, rather than using an external device or channel to bring the aqueous from the anterior chamber where it's building pressure into the subconjunctival space.
"Intuitively, that makes more sense; it seems safer and it's been proven to be safer," she said. "The question, at least in preliminary studies, is will it be as effective or nearly as effective as some of our other glaucoma filtering procedures, thereby avoiding risk and increasing benefit? That will be the big answer. We may never have the perfect glaucoma procedure, but the more options we have for different scenarios, the better."
Establishing guidelines for studies of these procedures may help clinicians decide what path they will take with their patients.
"I think the question is what is an adequate clinical trial," Dr. Siegfried continued. "I think it is one that shows in a peer-reviewed process that there is safety and efficacy. We have to be cautious but not so overly cautious. Once safety has been determined, and efficacy for a reasonable period of time, then I think people will be out there implementing these new devices and using them in appropriate patients as described in the studies."
Of course, the only way a device is going to get to market in the United States is by going through the FDA, the surgeons said. "This document was not designed to have anything to do with the FDA," Dr. Singh cautioned. He is also a member of the American National Standards Institute (ANSI) Device Panel, a group where the FDA does interact with researchers.
"WGA is for publishing new studies while ANSI is for studying new products and sometimes guidelines for regulatory approval," Dr. Singh explained.
He added that the WGA document, although it has no bearing on FDA decisions, has been well received.
"It has become well accepted and used widely as a reference point for publishing studies," he said, adding that researchers want to publish in U.S. journals, which have become more international over the years.
"It's a global world now. No one [is restricted] to sending papers to just their own country's journals. People publish all over the world," he said. "If you set standards in the U.S., it's not that hard to get the global community to agree on what to do. The standards don't vary that much in different parts of the world because everyone is submitting to the same types of journals."

Editors' note: Dr. Singh has financial interests with Alcon (Fort Worth, Texas), Allergan (Irvine, Calif.), Bausch + Lomb (Rochester, N.Y.), iScience Interventional (Menlo Park, Calif.), Ivantis (Irvine, Calif.), and Transcend Medical (Menlo Park, Calif.). Dr. Siegfried has no financial interests related to this article.

Contact information

Siegfried: 314-362-3937, siegfried@vision.wustl.edu
Singh: 650-575-8849, kuldev@yahoo.com