Eyeworld

EW FEATURE 68 because that is what happens when you take out a cataract in any pa- tient. We don't know if the addition- al deepening that you get from lens extraction—and getting additional deepening is an assumption from data from sources other than EAGLE, which you do not get from iridoto- my—changes the outcome and pre- vents progression of the actual angle closure and ultimately, the glaucoma long term." EW References 1. Azuara-Blanco A, et al. Effectiveness of early lens extraction for the treatment of primary angle-closure glaucoma (EAGLE): A randomised controlled trial. Lancet. 2016;388:1389–1397. 2. Brown RH, et al. Lens-based glaucoma surgery: Using cataract surgery to reduce intraocular pressure. J Cataract Refract Surg. 2014;40:1255–1262. 3. Panarelli JF, et al. Clinical impact of 8 pro- spective, randomized, multicenter glaucoma trials. J Glaucoma. 2015;24:64–68. Editors' note: Dr. Panarelli has finan- cial interests with Aerie Pharmaceuti- cals (Irvine, California) and Allergan. Drs. Brown and Feldman have no financial interests related to their comments. Contact information Brown: reaymary@comcast.net Feldman: rfeldman@cizikeye.org Panarelli: ilana.nikravesh@mountsinai.org through Schlemm's canal and the trabecular meshwork is compro- mised offers surgeons a new treat- ment option. The XEN stent shunts fluid from the anterior chamber to the subconjunctival space. Although traditionally glaucoma surgeons have avoided shunt placement in the already shallow anterior cham- ber out of concern about endothelial cell loss, the 6 mm XEN Gel Stent just barely protrudes into the eye and should be a safe, viable alterna- tive in patients with PACG. Tell all: PAS For Dr. Feldman, who does some- times perform clear lens extraction for angle closure, the EAGLE study does not always translate. "Not everyone has pressures of 30 mm Hg like the participants of the EAGLE study. Most patients that I manage don't. We are catching them before that happens and treating them before their pressures go up that high. I do not perform lens removal in PACG because of high pressure, but rather to fix the anatomy to prevent additional angle closure. The determining factor is how much peripheral anterior synechiae (PAS) they have and if I think I can get the closed angle working again," he said. Lens removal can be effective in lowering IOP in PACG patients who have less than 270 degrees of PAS. Dr. Feldman couples lens removal with additional measures, as needed, to reduce the IOP or open the angle, depending on the anatomy captured on imaging. He considers cataract surgery alone in patients with even up to 270 degrees of PAS, without the need for additional glaucoma surgery. With more than 270 degrees of PAS, lens removal may not suffice to lower IOP because of the pauci- ty of viable trabecular meshwork draining the eye, and he will opt for glaucoma surgery alone if there is no visually significant cataract and combined if there is. Dr. Feldman thinks it is import- ant to address the potential causes of angle closure when possible. While cataract surgery may deepen the anterior chamber, it may not be the lone cause of the problem. If the angle remains closed or narrow after cataract surgery or LPI, it can often be traced back to an anteriorly rotat- ed ciliary body. Patients may benefit from endocycloplasty in these cases and if diagnosed preoperatively with an ultrasound biomicroscope may be combined with clear lens extraction. The procedure is performed after cat- aract surgery and IOL implantation and involves the use of the endo- scope's laser attachment to shrink the posterior ciliary process, which allows the ciliary muscle to rotate back and open the angle. "We still don't know what the long-term outcomes are of lens removal in PACG," Dr. Feldman said. "We have 3-year data that says it costs less to take out the lens, that vision and quality of life are better, and that IOP is lower for a few years, but this comes as no big surprise that eye doctors want to provide the highest standards of care, he ex- plained, "We want to be on the cut- ting edge, but we know that for our patients it isn't always the newest thing out there that is gaining a lot of press that is best. We have to look at these studies, critically review them, and see if this is best for our patients, especially if we are talking about doing something invasive, when we otherwise might not have. I am not 100% ready to change my ways and perform cataract surgery routinely in this more challenging patient population." That said, Dr. Panarelli noted that he is open to changing his approach, especially if the patient has had a less than ideal outcome with a previous method of treatment in the contralateral eye. Dr. Panarelli encourages the use of certain MIGS devices in patients with PACG, assuming synechiae do not hamper visualization of the outflow pathway, which a number of MIGS devices rely on for strategic stent placement. Goniosynechial- ysis can help restore aqueous flow, reduce IOP, and possibly even allow later stent implantation in the pri- mary outflow pathway. It is thought to be most effective when performed early on in the process, i.e., within 6 months of synechiae formation. When present for greater periods of time, however, breaking synechiae may cause more damage to the canal network. Using the XEN Gel Stent (Allergan, Dublin, Ireland) in cases where the physiologic outflow Glaucoma and the cataract patient • February 2017 Debating continued from page 67

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