Minimally Invasive Glaucoma Surgery (MIGS):
The acronym MIGS refers to a group of glaucoma surgeries that lower IOP through small incisions and improve the natural outflow pathways, as opposed to bypassing the drainage system which occurs with traditional glaucoma surgery. Traditional glaucoma surgery has a higher reward in more likely achieving the lowest IOP possible with surgery; however, there also is higher risk with traditional bypass surgery. The main, although infrequent, feared risk with traditional surgery is achieving TOO low of IOP thus exposing the patient to vision-threatening complications. Although MIGS procedures typically do not produce as dramatic of IOP reduction, the risk of achieving TOO low of IOP is virtually impossible with MIGS procedures.
I like to use the analogy comparing abnormal eye fluid outflow to abnormal blood flow in coronary artery disease. Angioplasty is traditionally attempted first to alleviate a blocked coronary artery through a small incision with less potential complications than a coronary artery bypass. If angioplasty works, then great for the patient. However, if it does not, then a bypass is necessary and the additional risks of the procedure are more justifiable. Similarly, if a MIGS procedure is unsuccessful, then traditional surgery is still possible if necessary.
At SEE, we were the first in this area and one of the first in the country, to offer MIGS procedures to our patients. Since we first began with the first Trabectome procedure in 2007, many more MIGS procedures have been developed, and MIGS is one of the most exciting and explosive developments in the treatment of glaucoma in decades. Only within the last two to four years have these procedures become more mainstream within ophthalmic communities. During that time, we have been involved with passing on our experience to other local physicians who observe us in surgery or listen to our lectures on the topic. We also have presented our experience to other physicians at national ophthalmology meetings over several years. Our patients can rest assured that they will not find MIGS surgeons more experienced than the surgeons at SEE.
Type of MIGS include:
In 2007, SEE was among the first advanced eye care providers in the nation, and the first in Kansas and Missouri, to offer a new minimally invasive surgical procedure called Trabectome® for treatment of open-angle glaucoma. Since then, hundreds of SEE patients, diagnosed with glaucoma, have benefited from this safe and effective treatment.
When medication does not bring eye pressure down, Trabectome is often an excellent treatment option.
Trabectome is a breakthrough procedure that successfully lowers intraocular pressure in diseased eyes 80 percent of the time. During the minimally invasive surgery, the surgeon makes just one small incision. Using the Trabectome, a specially designed device, the surgeon removes tissue debris that blocks the flow of fluid in the eye. The procedure is performed on an outpatient basis using local anesthesia. It just takes one suture, if any, to close the incision and best of all – the procedure takes less than 10 minutes on average!
The risk of infection and post-operative complications is significantly lower than traditional glaucoma procedures. Additional benefits include:
• No pain. Patients do not report significant discomfort during or after the procedure.
• Minimally invasive. A small incision means less pain and quicker recovery.
• High success. Improved eye health and function occurs in 80% of patients.
• Precision. Specially designed surgical instruments enhance accuracy.
• Safety. It’s approved by the FDA and Dr. Stiles has completed thorough clinical training prior to making the procedure available. He currently trains other surgeons from around the country on this procedure.
• Flexible. The procedure can be combined with cataract extraction.
Cost-effective. Patients’ need for glaucoma management medication usually drops dramatically. Our goal is always to maximize health care resources.
Ab-Interno Canaloplasty (ABiC):
This procedure involves making a microscopic incision into the drainage tissue and inserting a catheter within the drainage canal. The catheter is advanced for 360 degrees into the entire drainage canal. The catheter is then withdrawn while injecting an expansive and clear substance (viscoelastic) throughout the entire drainage system. By breaking down adhesions and blockages within the drainage system, fluid drainage is improved, and the IOP is improved. This can be performed with cataract surgery or as a stand-alone procedure.
GATT is most successful in glaucoma which developed at an unusually young age (Juvenile Glaucoma), however recently has been shown successful in open angle glaucoma in other ages as well. Similar to ABiC, a catheter is used to intubate the entire drainage canal. However, with GATT, the catheter is removed in a way to cut through the maldeveloped drainage tissue to produce more direct outflow of eye fluid downstream.
CyPASS was FDA approved for use with cataract surgery in mild to moderate open angle glaucoma in November 2016. (illustration) CyPASS is a surgical device which is implanted in the suprachoroidal space. This space is normally responsible for about 20% of the eye’s natural outflow system. CyPASS enhances this outflow pathway thus lowering IOP. Similar to iStent, it only has insurance coverage when combined with cataract surgery and not as a stand-alone procedure.
Although FDA approved in June of 2012, SEE was involved years prior in the multi-center research study which led to its approval. The iStent is currently the smallest implant known to be placed in the human body. Under high magnification the device is delicately placed in the drainage angle to bypass ocular fluid around the diseased trabecular meshwork outflow tissue directly into the less diseased tissue downstream. Unlike traditional glaucoma surgery, the surgeon is NOT bypassing the entire outflow system thus not exposing the patient to the higher risks of traditional surgery.
In 2012, Glaukos, the company which developed the iStent, declared SEE as one of 12 MIGS Centers of Excellence (see oversized map and abnoxious logo below) within the US. These locations were chosen as centers trusted to train other eye surgeons in performing the iStent procedure to the company’s standards.
Unfortunately, the Medicare carrier in this area as well as commercial insurance companies, will not cover the use of the iStent “off-label”. Therefore, the procedure is limited to only certain patients, only when performed with cataract surgery, and only one iStent can be used. This policy is despite multiple studies displaying safety and efficacy of the procedure as a stand-alone procedure in nearly all types of glaucoma patients, and despite studies showing additional IOP lowering achieved with two or three iStents. If you or your loved one is interested in one of the off-label uses, please discuss this with your surgeon. Such uses can be employed; however, insurance assistance is unlikely to be available for such uses without a persistent appeal process.
Recently, SEE participated in the iStent Inject multicenter study. In this study, two second generation iStents were used. The study has been closed, is being evaluated, and we are hoping for a favorable outcome. If approved, the use and benefit of multiple iStents will be readily available for more patients.
As one can see, there are now many MIGS options available to increase the safety of glaucoma surgery when indicated for lower IOP or for reduction of medications which may be causing intolerable side effects. If indicated, your doctor will discuss these options with you and determine which MIGS procedure is the best option for your case. There has never been a more exciting time in the field of surgical glaucoma with many industrious and creative minds
There has never been a more exciting time in the field of surgical glaucoma with many industrious and creative minds exploring additional avenues to safely treat glaucoma. Rest assured that SEE’s research department will continue to be on the forefront of new developments as they occur.