Growing up the son of a radiologist, I was always impressed by the constant need for a physician to self-educate throughout his or her career. Magnetic resonance imaging, computed tomography, and the entire field of interventional radiology did not exist when my father (who is still in practice) finished his radiology residency.
In ophthalmology, including my subspecialty of glaucoma, our field is constantly being peppered with technological evolutions and revolutions that should keep physicians on their toes. Furthermore, we strive not merely to keep up with (adopt) new technology but rather to master it (become adept) and incorporate it into our own treatment algorithms (adapt). In some cases, this process involves combining several new techniques or even creating our own novel procedures. To learn more about how busy glaucoma and cataract docs adapt to new technology, I asked a few of my colleagues from the Vanguard Ophthalmology Society how they approach new surgical options.
I began by asking Hylton Mayer, MD, a glaucoma specialist at the Eye Doctors of Washington, Washington, DC, why our field needs to move forward. Dr. Mayer explained, “The inherent limitations to traditional glaucoma therapies: topical IOP-lowering medications, laser trabeculoplasty, and traditional incisional surgeries, have driven the development and application of microinvasive glaucoma surgeries (MIGS). Topical medications depend on patients’ compliance with often-complex dosing regimens, and these agents also require the successful instillation of drops, a significant challenge for many patients (often older patients in particular, who have vision loss or other comorbidities such as arthritis). Numerous reports have identified significant deficiencies in medication persistence and appropriate instillation technique, limiting the ‘real-world’ efficacy of topical IOP-lowering medications.”
Dr. Mayer went on to explain that traditional incisional surgeries, trabeculectomy, and glaucoma drainage devices, can definitively control glaucoma, but they have well-known risks, including the potential for vision loss from hemorrhage, hypotony, and infection. “The newer MIGS procedures’ favorable risk-benefit profile should shift practice patterns to promote earlier surgical intervention when IOP control, medication side effects, or medication persistence and utilization are problematic.”
Although some argue that MIGS procedures should avoid tissue destruction and that coagulative (endocyclophotocoagulation) or ablative (Trabectome, NeoMedix Corporation) procedures may not be MIGS, many would consider the iStent Trabecular Micro Bypass (Glaukos Corporation), endocyclophotocoagulation, and Trabectome to fall safely within the MIGS category. The iStent procedure is performed in conjunction with cataract surgery and uses a microstent (the smallest FDA- approved device in medicine) to bypass aqueous outflow resistance at the trabecular meshwork. The iStent is placed into Schlemm canal through the view afforded by a gonioprism.
John Berdahl, MD, at Vance Thompson Vision in Sioux Falls, South Dakota, has a busy refractive cataract surgical practice, but he also serves the needs of many patients with glaucoma. To meet the needs and expectations of his patients, he developed a combination of refractive laser-assisted cataract surgery (they call it ReLacs) and iStent implantation.
According to Dr. Berdahl, “The advent of laser-assisted cataract surgery and the iStent have provided us a unique opportunity to use an innovative surgical approach that allows cataract patients to be less dependent on their glasses while targeting mild to moderate glaucoma, all in one surgery.” Although cataract surgery itself may reduce IOP in many patients, Dr. Berdahl noted that the iStent’s implantation improves IOP control better than just cataract surgery while avoiding the large refractive changes associated with traditional incisional glaucoma surgeries. “One advantage of the iStent in combination with ReLacs is that the refractive predictability is similar to cataract surgery alone.”
In the accompanying video, I have provided a few tales from my adventure of adapting the iStent into my practice at Cornell. In order to adopt interoperative gonioscopy and the iStent, I relied on online videos, industry-sponsored didactic courses and wet labs, and of course, some help from my friends.
Adventures in adapting the iStent into practice.
Stay tuned for the next issue, where you will hear from Drs. Parag Parekh and Hylton Mayer about combining MIGS procedures and from Dr. Malik Kahook, who recently developed his own MIGS device.
