EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/407647
EW FEATURE 42 Combined procedures for glaucoma November 2014 • Many glaucoma surgeons use phacoemulsification as a way to reduce IOP, especially in patients with angle closure glaucoma. • These same surgeons will do cataract surgery alone or a combined cataract/glaucoma procedure to further lower IOP and then evaluate. • Glaucoma patients require more frequent monitoring after phaco to check for IOP spikes. • Clear lens extraction is an option for certain glaucoma patients, although physicians want to see more evidence to support its use. by Vanessa Caceres EyeWorld Contributing Writer When managing an acute ACG attack or even chronic ACG, Dr. Parekh also prefers to do a laser peripheral iridotomy (LPI) first and then proceed with phaco afterward. For narrow angles in the setting of poor vision, he would go straight to cataract surgery instead of doing an LPI first. Clear lens extraction Clear lens extraction in a glaucoma patient as a means to lower IOP is still controversial, Dr. Friedman said. He believes that the EAGLE trial— short for "The effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle-closure glauco- ma"—will soon shed light on this treatment approach. The enrolled patients are located in the U.K. and East Asia. "If there are good arguments and data to support clear lens ex- traction, I think it will become more common," Dr. Friedman said. Dr. Parekh has not yet done clear lens extraction but is not op- posed to the idea. "If the patient is young and does not have a visually significant cataract and they go into angle closure, I will do an LPI and if that still doesn't work, lens extraction is the next step for me," he said. Dr. Lam considers a few factors when deciding whether to perform clear lens extraction. "The higher the peak IOP, the more difficulty in getting the IOP back to normal, and the more hypermetropia, the lower the threshold," he said. "The threshold to do phaco will be much higher if there is advanced glaucomatous damage, as there is a risk of significant visual field and visual function loss." EW Editors' note: Dr. Mansberger has financial interests with Alcon (Fort Worth, Texas), Allergan (Irvine, Calif.), Envisia Therapeutics (Research Triangle Park, N.C.), Santen (Osaka, Japan), and Welch Allyn (New York). The other physicians have no financial interests related to their comments. Contact information Friedman: David.Friedman@jhu.edu Lam: dlam.sklo.sysu.cn@gmail.com Mansberger: smansberger@deverseye.org Parekh: parag2020@gmail.com bigger proponent of performing phaco along with endoscopic cyclo- photocoagulation or the iStent, with the goal of having patients on as few medications as possible. He has seen too many medication compliance problems despite his attempts to explain how and when to take drops, which leads him to favor a surgical approach for patients. "I think adherence to drops is a bigger issue than most doctors estimate that it is," he said. "In addition, insurance doesn't cover iStent alone, so there's a 'now-or-never' aspect to this as well." Any glaucoma patient having phaco requires closer monitoring, Dr. Mansberger recommended. "These patients need to be followed a little differently than your typical cataract patient. You need to see them more often postoperatively to make sure they aren't having pressure spikes," he said. That could even mean checking the patient the evening of surgery to detect any IOP spikes. Phaco and angle closure Patients with angle closure glauco- ma (ACG) or narrow angles often benefit from phaco. "The best timing of phaco to prevent chronic ACG development is 1 to 3 months after the acute attack," Dr. Lam said. "This is a time window where the eyes have devel- oped a pressure rise but are quiet enough to do a safe phaco surgery." Dr. Friedman favors a similar timing of 1 month post-attack. "After an acute attack, a lot of eyes are predisposed to permanent scarring of the angle. If you take out the lens, you're much less likely to develop synechial closure," he said. Dr. Friedman said that 2 recently completed randomized clinical trials in Asia demonstrated much better IOP control for patients with acute attacks who had early cataract surgery. Dr. Mansberger will use phaco for chronic ACG but makes the point to manage patient expecta- tions. "Cataract extraction can work. Again, the patient and doctor need to realize that the outflow mech- anism may be permanently dam- aged, and they may need glaucoma surgery to lower their IOP to a stable level," Dr. Mansberger said. Glaucoma patients generally see better, experience an IOP drop M any glaucoma patients continue to see an IOP-lowering benefit from phaco alone or phaco combined with a glaucoma procedure. "In ocular hypertension, about 80% will have a reduction in IOP, 10% will have no change, and 10% will have a small increase in pres- sure," said Steven L. Mansberger, MD, vice chair and director of the glaucoma service, Devers Eye Insti- tute, Portland, Ore. Dr. Mansberger has published studies on the topic. Although surgeons have realized for quite some time that phaco can lower IOP, only recent studies have documented the amount of IOP lowering with cataract surgery. "In comparison to a decade ago, we understood that cataract surgery lowered IOP, but we didn't know by how much," Dr. Mansberger said. "Recent papers suggest a 10% to 20% reduction in pressure on average with cataract extraction. That gives us more evidence of its effect. Modern cataract surgery may provide more IOP lowering than previous studies using large incision, extracapsular cataract extraction." Here is how some surgeons use phaco as a treatment tool to lower IOP. Choosing phaco to lower IOP Who benefits from phaco There is no one definitive factor to indicate which glaucoma patients will have a better IOP response from cataract surgery, Dr. Mansberger said. He will choose patients with mild to moderate glaucoma whose target IOP is well controlled on medications, and he'll offer cataract surgery alone. "I'll also tell them there's a chance their pressure will go high and that we may need to do subse- quent glaucoma [surgery]," he said. Anecdotally, most patients receiving cataract surgery alone experience better vision postop, have lower pressure, and can remove one or more medications from the treatment mix, he said. "I will try phaco first as a gener- al principle," said Dennis Lam, MD, director and professor, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, China. "I will consider combined surgery when the IOP is higher than 35 mmHg." Dr. Lam added that he is doing fewer combined procedures nowadays compared with a few years ago. David S. Friedman, MD, Alfred Sommer Professor, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, tries to stick with cataract surgery alone, with the idea that he can always go back and perform a glaucoma- specific procedure if necessary. Dr. Friedman will choose combined cataract and glaucoma surgery if the patient needs a very low IOP or has more severe disease and a postop IOP spike could lead to vision loss. "I definitely feel more comfort- able just taking out the lens and see- ing where I am. I can always go back and do a trabeculectomy a month or 2 later," said Dr. Friedman, who also feels that using the iStent (Glaukos, Laguna Hills, Calif.) or Trabectome (NeoMedix, Tustin, Calif.) as needed is a reasonable option. Parag Parekh, MD, a glaucoma specialist in private practice, Laurel Eye Clinic, Brookville, Pa., also sees patients experience a reduction in IOP after phaco. However—"I don't make much of it because it's sometimes been a short-lived and inconsistent effect in my experience. Therefore, I don't plan on the IOP benefiting long term from phaco alone," Dr. Parekh said. He is a AT A GLANCE