Thanks to recent advances, surgical management of glaucoma may be entering a new age in which it will be possible to tailor the procedure to individual patients and preserve vision with fewer complications than with trabeculectomy, said Robert L. Stamper, MD.
San Francisco-Thanks to recent advances, surgical management of glaucoma may be entering a new age in which it will be possible to tailor the procedure to individual patients and preserve vision with fewer complications than with trabeculectomy, said Robert L. Stamper, MD.
“Mechanical surgery has generally been reserved for treatment of glaucoma when other approaches fail because of the actual and perceived problems associated with the most common operations,” said Dr. Stamper, professor of ophthalmology and director of the glaucoma service, University of California, San Francisco. “However, developments are occurring rapidly in the field of glaucoma surgery.
“Still, we need to see if the new procedures stand the test of time, and then we can evaluate if surgery may become an option earlier in the disease process so that adherence to medications will be less of a problem,” he said.
Discussing the new FDA-approved procedures, Dr. Stamper said that canaloplasty using a flexible microcatheter (iTrack, iScience Interventional) is useful for open-angle glaucoma and also in congenital glaucoma. Surgery using a microcautery device (Trabectome, NeoMedix) is a minimally invasive procedure that can be done easily with cataract surgery and is safer than trabeculectomy.
Regarding techniques that are still investigational in the United States, preliminary results from studies of a micro-stent (Cypass, Transcend Medical) indicate that it is an effective procedure with fewer complications than trabeculectomy that can be performed alone or in combination with phacoemulsification. The surgery for placing the device is relatively straightforward, and thanks to a recent development, it can be done without a gonioprism, which would make the surgery accessible to the general ophthalmologist, Dr. Stamper said.
Implantation of a trabecular microbypass implant (iStent, Glaukos) is also a relatively rapid, minimally invasive procedure, but it does require careful gonioscopic control. Results from the FDA clinical trial and other independent studies show it produces significant IOP-lowering accompanied by reduction in medication use, and the benefits may be titratable as surgeons are now starting to put in more than one device.
For use in trabeculectomy, a biodegradable porcine-derived collagen matrix (Ologen, Optous) is FDA-approved as an adjunctive wound-healing agent. It provides a biodegradable scaffold outside the trabeculectomy where it theoretically suppresses growth of fibroblasts.
Dr. Stamper noted he was disappointed in his early experience using the product alone, but speaking anecdotally, he said the results are more positive when the matrix is soaked in 5-fluorouracil.
“We are seeing nice diffuse blebs and no leaks so far, but more data from longer-term studies are needed,” he said.