EyeWorld India December 2017 Issue

16 EWAP FEATURE December 2017 Managing cataract – from page 15 the more aggressive traditional glaucoma filtration surgeries later if you need to. In my experience, that will only very rarely be the case.” Dr. Kim will typically com- bine glaucoma procedures in patients with more advanced disease, especially when seek- ing to avoid traditional filtration surgery in patients at a high risk for complications, such as high myopes and those who are post- vitrectomy or post-scleral buckle. He prefers to avoid traditional fil- tration surgery in monocular and young patients as well because they would have to live many decades with the lifelong risks of bleb-related infections and tube- related complications. “I have used the Trabectome [NeoMedix, Tustin, California] and endo- scopic cyclophotocoagulation (ECP) combination in post-vitrec- tomy and scleral buckle patients because of the high risk for trab failure and the increased risk for complications such as tube erosion after tube shunts. I have used that combination for pa- tients with very thin sclera such as osteogenesis imperfecta and scleritis where their sclera likely would not have allowed for a trab or tube. For patients with ad- vanced disease who have already failed consecutively both trab and tube I have often performed the gonioscopy-assisted trans- luminal trabeculotomy (GATT) and 360-degree ECP combina- tion. In monocular patients with advanced disease where I want to minimize the risk for hyphema but I want greater IOP lower- ing than what a typical MIGS procedure might provide, I have combined limited ab interno trabeculectomy, performed with the Trabectome or Kahook Dual Blade [New World Medical, Rancho Cucamonga, California], with ab interno canaloplasty and ECP. More recently I have been utilizing the CyPass Micro- Stent [Alcon, Fort Worth, Texas] combined with multiple targeted iStent [Glaukos, San Clemente, California] placement. All of these combinations can work very well and not uncommonly will produce IOP in the low teens with a reduction in medication bur- den,” Dr. Kim said. Yes to iStent for moderate glaucoma Yuri McKee, MD , Mesa, Ari- zona, agrees that the more help you have in lowering IOP, the bet- ter. However, to avoid reimburse- ment issues, Dr. McKee sticks to the iStent, which is indicated for implantation at the time of cataract surgery. “I use the iStent in patients with mild, moderate, or advanced glaucoma because the higher the pressure, the better the effect of the iStent. In these cases, every little bit helps. I do not think the iStent is the last thing that will be required in cases of advanced glaucoma, as its indication is for mild to moder- ate disease, but it still is useful in advanced glaucoma because it is going to give you some pressure reduction, and every little bit counts,” Dr. McKee said. The iStent is most effective in patients with still viable drain- age systems. Advanced glaucoma, however, is often associated with pathology of the trabecular mesh- work, blocking egress of aqueous humor through the conventional pathway. The uveoscleral pathway and suprachoroidal space there- fore represent important outflow alternatives. Despite the large absorptive capacity of the supra- ciliary space, Dr. McKee thinks that it may be best to avoid stenting to the suprachoroidal/su- praciliary spaces. “My issue with suprachoroidal MIGS is that there is a concerning rate of CME as- sociated with these devices. If you think about it, you are connect- ing the anterior chamber directly to the suprachoroidal space, so any inflammation in the anterior chamber is going to have a direct passageway to the subfoveal space and can cause CME. Currently, I am not doing any suprachoroidal MIGS procedures. I prefer to stick to the iStent and the XEN Gel Stent [Allergan, Dublin, Ireland]. I prefer to do the XEN as a stan- dalone procedure,” he said. The XEN is approved for patients with refractory glaucoma who failed previous surgical treatments or in patients with open-angle glauco- ma, pseudoexfoliative or pigmen- tary glaucoma with open angles that are unresponsive to maxi- mum tolerated medical therapy. Yes to XEN for advanced glaucoma “XEN diverts fluids to the sub- conjunctival space, and I have found that to be extremely effective in cases of advanced glaucoma,” Dr. McKee said. “The iStent gives somewhat less pres- sure reduction. My experience with the iStent, of which I have done approximately 455 in the last 24 months, is a two-point reduction when combined with cataract surgery. For mild to mod- erate glaucoma, where you want a pressure of 14 mmHg or less, with the patient’s IOP between 15 and 17 mmHg, you can combine the iStent with cataract surgery. But if you need a pressure reduction of 8–10 mmHg in advanced or refractory glaucoma, the XEN is going to get you there 80% of the time straight out of the gate, and stays there. But in the other 20% of the time, you will need a little extra maneuvering, like drops or bleb needling.” Dr. Kim has a similar mindset that trab and tubes have been largely replaced by the XEN. “Tube and trab in the setting of cataract and glaucoma, for me, are only applicable in those cases with severe field loss and IOP out of control on maximum medi- cal therapy. With the advent of the XEN, if patients have healthy conjunctiva, I will almost always choose this over trab or tube. This is because the XEN offers a more controlled and predictable postop course, with less chance for hypotony. There will be no risk for diplopia, tube erosion, or wound leaks. It doesn’t violate anatomy as much, will be more astigmatically neutral, and allows for more rapid visual recovery, making it a better partner for cataract surgery. In this setting, I would only choose a trab if the conjunctiva is healthy and I needed very low single digit IOP, perhaps in the setting of an NTG patient showing progression with relatively low IOP. I would only choose a tube in this setting if the conjunctiva was compro- mised,” Dr. Kim said. Dr. McKee implements the following measures in his ad- vanced glaucoma patients need- ing cataract surgery. “First I’d do the cataract surgery with an iStent. I’d continue the topical drops and let them heal. Occa- sionally it is enough, but most of the times it is not—but it does get you to a better place. From here, I will do a XEN implantation. I