Glaucoma surgical options provide varied, confusing choices for physicians

With more surgical options now available for treating earlier stages of primary open-angle glaucoma, choosing the best treatment can be difficult. But for surgeons who do not frequently perform glaucoma surgery, selecting the most appropriate procedure can be downright confounding, according to glaucoma specialists.

“I think currently, it can be confusing for the occasional glaucoma surgeon. There are simply too many options. Occasional glaucoma surgeons can’t master all of them,” Thomas W. Samuelson, MD, OSN Glaucoma Section Editor, said. “I wouldn’t recommend trying to be unless you’re heavily involved in glaucoma surgery and you do a lot of cases, because you can’t possibly master all the techniques. I would recommend selecting one or two of the newer procedures, and have a few options available to offer your patients.”

Medical therapy is still considered first-line treatment, but newer surgical options have added more choices to the glaucoma treatment paradigm. In the U.S., Trabectome (NeoMedix), canaloplasty (iScience Interventional) and endoscopic cyclophotocoagulation (ECP) appear effective in treating early- to moderate-stage disease. The Ex-PRESS mini glaucoma shunt (Alcon) is an option for patients with more advanced disease.

Other surgical options that could be adopted in the United States, after approval by the U.S. Food and Drug Administration, include the iStent (Glaukos) and the Gold Micro-Shunt (Solx). Both devices are currently used in Canada and Europe.

Malik Y. Kahook, MD, stresses quality over quantity when choosing surgical procedures to suit his specific patient population. Image: Cass CA/University of Colorado

Trabeculectomy, still the gold standard in glaucoma surgery, is typically reserved for advanced cases because of its potential complications. Patients who undergo filtration surgery or tube shunt surgery are often on maximally tolerated medical therapy and have uncontrolled IOP or progressive optic nerve damage.

“Having all these other options now allows us to provide surgery at an earlier stage, thereby ideally stabilizing glaucoma in a better fashion, relying less on medications, saving cost, and improving compliance and side effects of medications. And, in the end, hopefully overall reducing the disease burden,” Ike K. Ahmed, MD, FRCSC, OSN Glaucoma Board Member, said.

New surgical options

New glaucoma surgical options could alter not only the treatment paradigm, but also how therapeutic decisions are made. Patients in early- to moderate-stage disease could undergo surgery earlier, resulting in reduced or no medical treatment. This may also reduce follow-up time, with fewer office visits needed because these surgical options have fewer complications than filtration surgery.

“In the past, incisional glaucoma surgery has been used predominantly as an option of last resort,” Steven D. Vold, MD, said. “With the recent development of more minimally invasive surgical techniques, I foresee a paradigm shift toward earlier surgical intervention. If early glaucoma can be addressed surgically with a safe and effective procedure, patient long-term outcomes may be enhanced significantly, and more cost-effective care can be achieved.”

Recent Medicare data show that use of trabeculectomy is on the decline, while procedures such as laser trabeculoplasty and ECP are used more frequently. Because trabeculectomy is traditionally viewed as the gold standard in the glaucoma surgical treatment paradigm, the perception of surgical intervention will have to change before it is considered earlier in treatment, Malik Y. Kahook, MD, said.

Dr. Kahook said a factor that could contribute to adoption of new surgical options is the number of surgeries performed a year by most surgeons. For glaucoma specialists without high-volume practices, general ophthalmologists and other specialists who rarely or never perform glaucoma surgery, gaining expertise in all surgical options could be impossible, he said.

“I think in the real world, for the number of glaucoma surgeries that the average glaucoma specialist is doing in the United States, it’s going to be hard for any one surgeon to take on three or four of these new procedures at the same time and implement them in their clinic in a way that would allow them to master the procedures,” he said.

According to Dr. Vold, adoption of the new surgical options by leading glaucoma experts could assist in determining the best procedure for all cases. Offering patients the most appropriate procedure or device could benefit both physicians and patients by halting progression and reducing compliance issues associated with medication use.

In his practice, Dr. Vold performs canaloplasty, Trabectome, ECP and trabeculectomy and implants the Ex-PRESS mini shunt. He has also taken part in a clinical study of the iStent and other surgical devices not yet approved for use by the FDA.

“The goal is not to provide the most surgical options possible, but rather to offer enough procedures to meet the needs of our patients,” he said.

Coexisting cataract options

For general ophthalmologists or other subspecialists treating the growing population of patients with glaucoma and coexisting cataract, a device such as the iStent could be a good surgical option, Kerry D. Solomon, MD, said. Dr. Solomon, a cataract/refractive specialist and OSN Refractive Surgery Board Member, said the device could offer a new treatment modality to comprehensive ophthalmologists and cataract surgeons. It can be implanted after cataract surgery through the cataract incision, he said.

Kerry D. Solomon

“Let’s face it: It’s a challenge to remember to take one drop every day or multiple times a day. It’s even more of a challenge to remember to take multiple drops multiple times during the day. So anything I think that we can do to simplify that for our patients is going to be a real benefit,” Dr. Solomon said.

Cataract surgery combined with glaucoma procedures is an option for some patients. Ocular hypertensive or mild glaucoma cases with coexisting cataract could benefit from the lowered IOP and reduced medications that can accompany cataract extraction, especially when combined with newer surgical options.

“I put the glaucoma patients who have cataracts into different categories depending on the stage of their disease,” Dr. Kahook said. “Visually significant cataracts can range from mild to advanced, and glaucoma may also range from mild to advanced disease. My approach to each individual patient depends on which component, cataract or glaucoma, might be of most importance at any given time.”

Dr. Kahook said in cases in which removing a cataract alone could assist with lowering pressure and reducing medications, phacoemulsification alone should be considered.

“These are usually the cases where the glaucoma is mild to moderate, and a very low IOP is not necessarily the goal,” he said. “On the other hand, there are patients with coexistent cataract and glaucoma where a very low target IOP is needed, and in these cases, I often do standalone trabeculectomy without addressing the cataracts, which in my hands allows for greater IOP lowering success.”

“There’s still this gray area that exists between the mild and advanced categories for both cataract and glaucoma,” he said. “There are particular patients who have cataract and glaucoma who might benefit from a combined cataract-glaucoma procedure.”

Dr. Kahook said that pseudoexfoliation cases, in his hands, tend to have adequately lowered pressure after cataract surgery combined with Trabectome surgery. For monocular patients with both cataract and glaucoma, he finds phaco and implantation of the Ex-PRESS allow for adequate IOP lowering while also allowing for quicker visual recovery compared with combined cataract-trabeculectomy surgery.

“I also combine cataract surgery with ECP in some cases. The cases that I choose for cataract-ECP are those that have previous trabeculectomy or glaucoma drainage device surgery and they just don’t have enough healthy conjunctiva for repeat filtration procedures,” he said.

Choosing a surgical option

Physicians should select surgical options based on the needs of the individual patient. Their selections should be made after assessing many factors, including stage of disease and physician expertise with the surgical device or procedure.

Ike K. Ahmed

Dr. Ahmed said that he bases surgical treatment decisions on the efficacy, risk and learning curve of each procedure or device. He performs canaloplasty, Trabectome, ECP and Ex-PRESS mini shunt and, because he practices in Canada, regularly uses the iStent.

He divides surgical options into low-risk, moderate-risk and high-risk categories. As surgical procedures and devices increase in risk, they also increase in efficacy, especially in treating advanced disease, he said. Through careful consideration, physicians can determine what outcome is needed at what risk for individual patients.

Dr. Ahmed suggested that clinicians think outside the box of traditional therapy and reframe minimally invasive glaucoma surgery as a practice within a practice. “Minimally invasive glaucoma surgery, or what we call MIGS, is not your traditional glaucoma surgery. This is ultra-safe, low-risk, minimally invasive glaucoma intervention that we can offer patients over a wider range of disease,” he said.

Dr. Samuelson said that the grade of glaucoma severity helps him choose the best surgical option for a given patient. He performs canaloplasty, ECP and Ex-PRESS mini shunt and has taken part in clinical trials for devices, including the iStent. He also performs cataract surgery for some glaucoma cases.

Thomas W. Samuelson

He said a patient with mild to moderate visual field loss and high IOP that is not reduced by medicine could be a good candidate for a minimally invasive glaucoma surgical procedure. That patient would not be at risk for complications associated with a filtration bleb or tube shunts, such as hypotony or diplopia.

Dr. Kahook adopts one new procedure or device at a time. He first evaluates how his patients will benefit from additional procedures or devices, choosing an option based on that assessment.

“We have to ask ourselves, ‘How does this new device or procedure add to what we are already doing in the operating room?’” he said. “If my patients will benefit from a new procedure, I take the time to learn how to do it so that the full benefit can be achieved in my hands.”

He performs trabeculectomy and glaucoma drainage device implantation, as well as Ex-PRESS mini shunt and Trabectome surgery. He adopted Trabectome surgery after he and his partners determined that it would work well for a specific patient population, in this case patients with pseudoexfoliation. He said selecting surgical procedures that meet the needs of a practice’s patient population is important because practices in some regions of the U.S. might encounter more advanced cases, while others might treat less advanced or varied stages of the disease.

“I’d rather have two or three minimally invasive surgeries that I do very well that I can match up to the particular patients that I’m seeing rather than have five to 10 new procedures that I’m doing, and trying to figure out in addition to which patient will get a new procedure, which new procedure will that patient get. It’s really quality over quantity in adopting new technologies,” Dr. Kahook said.

Cost-effectiveness, cost risks

Earlier and better surgical options in glaucoma treatment could be cost-effective in many ways. As patients progress into later stages of the disease, ophthalmology costs rise, according to a study by Giesera and colleagues.

Performing surgery sooner could reduce the medical burden on patients, especially for those who have difficulty taking their medication on a regular basis, Dr. Kahook said. Glaucoma is now the second leading cause of blindness in the world, behind cataracts, with rates expected to rise in the next 10 years. With compliance rates low and medical therapy difficult for many glaucoma patients to adhere to, effective treatment options other than medicine will be necessary.

In addition, more complicated and risky surgical procedures cost office time for physicians. Dr. Kahook and colleagues conducted a study comparing the number of follow-up visits in the first 3 months after Ex-PRESS device implantation compared with trabeculectomy. They found that Ex-PRESS patients had on average two fewer visits than trabeculectomy patients after surgery. The study is currently submitted for peer review.

There is also a cost risk to physicians regarding new equipment and required training time. Dr. Ahmed said that when compared with the cost to society of visual loss, blindness and medical therapy, the outlay cost of an implant or equipment is affordable.

“I think as far as the cost-effectiveness of a procedure, one argument has been made, oh, it’s too expensive,” Dr. Ahmed said. “It costs $800 to put implants in — is it worth it? Obviously, there is a cost, but let’s look at — what is the alternative if we didn’t do that? What’s the cost, for example, of, say, three bottles of medication that we pay for the whole year, multiply that by many years. There has to be balance.”

Learning curve

Glaucoma surgical options have learning curves and refinement curves, Dr. Ahmed said, with some procedures and devices requiring more time to learn. Physicians agree that while canaloplasty takes multiple procedures to master, for physicians who have performed trabeculectomy, the Ex-PRESS shunt is usually quicker to learn.

Dr. Solomon said that for general ophthalmologists and others using the iStent, there is a learning curve, but not an insurmountable one. Physicians will need to know how to use a goniolens, he said.

“Like anything else, once you get used to it, it’s not a big deal. And the visualization is necessary to be able to really place this device where we want it to be. For the actual insertion of the device, they have injectors that have been developed to make the insertion of the device fairly routine,” Dr. Solomon said.

The typical turnaround for using new glaucoma devices and procedures has been fairly rapid for many glaucoma specialists, Dr. Vold said. Performing the procedures more often will assist in the learning and refinement curve for many.

“I sincerely believe that we are practicing in one of the most exciting times of glaucoma care advancement during my lifetime,” he said. “Although caution, requests for well-controlled studies and critical analysis are important and welcome, we must not let unbridled negativity stifle creativity and slow current advances in glaucoma care.” – by Erin L. Boyle

Do physicians have an obligation to provide all the newest glaucoma surgical procedures and devices to patients in their practices?

References:

• Giesera DK, Williams RT, O’Connell W, et al. Costs and utilization of end-stage glaucoma patients receiving visual rehabilitation care: A U.S. multi-site retrospective study. Int Congr Ser. 2005;1282:387-392.
• Hendrick AM, Kahook MY. Ex-PRESS mini glaucoma shunt: surgical technique and review of clinical experience. Expert Rev Med Devices. 2008;5(6):673-677.

• Ike K. Ahmed, MD, FRCSC, can be reached at Credit Valley EyeCare, 3200 Erin Mills Parkway, Unit 1, Mississauga, Ontario L5L 1W8; Canada; 905-820-6789; fax: 905-820-0111; e-mail: ike.ahmed@utoronto.ca. Dr. Ahmed is a consultant for Glaukos, iScience and Solx, and has received speaking honorarium from Optonol.
• Malik Y. Kahook, MD, can be reached at Department of Ophthalmology, University of Colorado School of Medicine, Rocky Mountain Lions Eye Institute, 1675 Aurora Court, P.O. Box 6510, Mailstop F-731, Aurora, CO 80045; 720-848-2500; fax: 720-848-5014; e-mail: malik.kahook@ucdenver.edu. Dr. Kahook consults for Alcon, Allergan, Merck and the U.S. Food and Drug Administration. He has received research support from Alcon, Allergan, Actelion, Merck, Pfizer and the state of Colorado. He is an owner and co-founder of Shape Ophthalmics LLC.
• Thomas W. Samuelson, MD, can be reached at Minnesota Eye Consultants, 701 E. 24th St., Suite 100, Minneapolis, MN 55404; 612-813-3628; fax: 612-813-3656; e-mail: twsamuelson@mneye.com. Dr. Samuelson is a consultant for Alcon, Allergan, Abbott Medical Optics, AqueSys, Endo Optiks, Glaukos, iScience, Ivantis, Pfizer, QLT and Santen.
• Kerry D. Solomon, MD, can be reached at Carolina Eyecare Physicians, 1280 Johnnie Dodds Blvd., Suite 100, Mt. Pleasant, SC 29464; 843-881-3937, 888-849-3937; fax: 843-884-8587; e-mail: kerry.solomon@carolinaeyecare.com. Dr. Solomon has a financial interest with Glaukos.
• Steven D. Vold, MD, can be reached at Boozman-Hof Regional Eye Clinic, 3737 West Walnut, Rogers, AR 72756; 479-246-1700; e-mail: svold@cox.net. Dr. Vold serves as a consultant and receives research support from Alcon, NeoMedix, iScience Interventional, Glaukos, Transcend Medical and AqueSys.