This is a supplement to EyeWorld Magazine.
Issue link: https://supplements.eyeworld.org/i/824592
Innovative Technologies Designed to Meet the Needs of Surgeons and their Patients Nathan Radcliffe, MD, is in practice at NYU Langone Medical Center in New York City. He is a consultant for Alcon and received compensation for his contribution to this supplement. He can be reached at drradcliffe@gmail.com. Unlocking the potential of the supraciliary space By Nathan Radcliffe, MD O ver the past 4 years or so, many cata- ract surgeons have become familiar with the ab interno approach to minimally invasive glauco- ma surgery (MIGS). For many of us, this has been achieved by implanting trabecular mi- crobypass stents. In the more recent years, we have had alternative approaches to ad- dressing glaucoma through the angle, such as ab interno goniotomy and ab interno viscocanalostomy. As a result, we are becoming familiar and comfortable with the algo- rithm of treating glaucoma in the angle at the time of cataract surgery. The ciliary body represents a large, easily visualized, and easily treatable target that can be comfortably approached using intra- operative gonioscopy at the time of cataract sur- gery. Unlike the trabecular meshwork, which varies in pigmentation, appearance, and microanatomy, the ciliary body can be reli- ably found at the iris root. The CyPass Micro-Stent is placed into the supraciliary space under gonioscopic visualization after cataract extraction and intraocular lens implantation. My experience has been that the ciliary body is the easiest landmark to identi- fy gonioscopically, and the tissue has also been the most intuitive target to hit with the supraciliary stent. When we target the trabec- ular meshwork, we know there is a floor in terms of how low we can get the in- traocular pressure because we will have additional resistance to the remain- der of Schlemm's canal, the collector channels, and the episcleral venous system. Episcleral venous pressures can typically be around 12 mm Hg, so with the add- ed resistance, trabecular bypass can often result in pressures higher than that. The ciliary space presents a unique opportunity to achieve significant pressure reduction in a safe and minimally invasive manner. The design of the CyPass Micro-Stent provides a level of resistance to aqueous outflow, and the supracili- ary space provides access to the uveoscleral outflow pathway, whereby the intraocular pressure will not be limited by episcleral venous pressure. Signifi- cant pressure reduction can occur, and, because the tip of the CyPass Micro-Stent remains in the angle and free of obstruction, iris adhesions and other forms of scar formation are less likely to influence pressure reduction. Because we are accessing a space with so much pressure-lowering potential and using a mi- crostent that is designed to protect against clinically significant hypotony, we are maximizing the potential of the supraciliary space with- out compromising on safety as compared to cataract surgery alone. Therefore, it makes so much sense to approach the supracil- iary space using a MIGS implant—so that we can control the flow. Glaucoma is a progressive and blinding disease, and medications themselves carry risk of ocular surface disease and are often diffi- cult for patients to comply with. We cannot call topical therapy risk-free. Cataract surgery provides us the op- portunity to lower the pres- sure. Often, the pressure reduction from cataract sur- gery alone is insufficient to meet our patients' needs. The 2-year COMPASS trial showed significant addi- tive intraocular pressure lowering as well as sig- nificant reduction in the requirements for topical medications with a safety signature that was similar to cataract extraction by itself. 1 These data, which carry out to 2 years with- out a degradation in the procedure's value, show us that the risk-to-benefit ratio of performing supraciliary micro-stenting in combina- tion with cataract surgery in patients with mild to mod- erate open-angle glaucoma is indeed favorable. It is always important for patients to understand the procedure they are having and the risks and benefits. My patients have been excited at the prospect of getting better glaucoma control and reducing their eyedrop burden along with the burden of the side ef- fects from drops. In my dis- cussion with patients, I have found that they are open to the idea of internally drain- ing the fluid and using a mi- cro-stent to do so. Typically, patients will have concerns with drains that are exter- nal to the eye because they know that they can be seen and felt. I have been im- pressed with patient accep- tance and excitement about this approach. n 1. Vold S, Ahmed II, Craven ER, et al; CyPass Study Group. Two-year COMPASS trial results: supracili- ary microstenting with phacoemulsification in pa- tients with open-angle glaucoma and cataracts. Ophthalmology. 2016;123(10):2103-2112. Please see page 8 for Important Product Information.