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EW FEATURE 50 in the anterior chamber, just like I'm staining the anterior capsule," Dr. Brown said. "Then when I'm doing the implantation of the iStent or the trabeculotomy, the trypan blue lights up the canal." He is reluctant to use the blood reflux here. "I hate bleeding. Blood reflux can work well, but I don't like to tempt fate," he warned. For procedures such as using the Trabectome (NeoMedix, Tustin, California) in the angle, Dr. Fellman recommended tilting the tip of the device up initially to make it easier to get it into the canal. "If you don't do that, the tip of the Trabectome tends to skim along the surface of the canal," Dr. Fellman said. For MIGS cases, Dr. Fellman rec- ommended using what he terms the episcleral venous fluid wave (EVFW) as a "poor man's angiography" to help determine the functional ca- pacity of the downstream trabecular outflow system. A diffuse whitening or blanching of the episcleral vas- culature next to the MIGS site may occur when balanced salt solution surges into the anterior chamber and out of the episcleral veins indi- cating a patent outflow system. 1,2 He pointed out that some patients have an incredible response to MIGS with pressure in the low teens on one drop, while others don't get as much of a reduction. "When I'm in the OR and I've done my canal-based procedure and I see a lot of adjacent distal flow, I feel good that the pa- tient is going to do well unless he or she has healing that causes scarring in the canal," Dr. Fellman said. Very little distal flow as seen by the EVFW indicates reduced outflow capacity with a higher likelihood of outcome failure. Postoperative perspective Postoperatively, Dr. Fellman finds patients may be prone to a pressure spike with steroids. One would think that if you bypassed or cleaved open the trabecular meshwork, you could avoid a steroid IOP spike. However, that is not the case, and a steroid spike is very common. "The whole postoperative regimen is geared toward using the least amount of steroids to calm the eye and getting the patient off the steroids as quick- ly as possible," he said. Dr. Fellman also recommends being careful with blood thinners. "Don't forget that Schlemm's canal is a blood vessel and it can have blood in it," he said, adding that he tries to hold off on stronger anti-coagulation medica- tion until he knows that the patient is safe as far as wound healing. Usu- ally, by the end of the first week, he finds that the eye is stable. Dr. Brown recommended keeping patients on their glauco- ma medications initially following MIGS. "I am going for a good pres- sure on the first day, and I do that psychologically to get the patient off on the right foot," Dr. Brown said. On the other hand, preoperatively it might behoove patients not to take their medications, he noted. "I've done a couple of studies in my own practice and I have found that the higher the pressure is preoperatively, the better it improves postoperative- ly," Dr. Brown said, adding that the patients who do the best are ones with the highest pressures. "It begs the question, if someone is on 2 eye drops and the pressure is 15, should we stop the drops before surgery? I don't, but the data says that this may be a better way to do it," he said. Although finding Schlemm's canal is a new skill for many oph- thalmologists, most experienced MIGS surgeons can find the canal essentially every time with current techniques. According to Dr. Brown, the goal in improving these tech- niques is to make finding the canal as simple and straightforward as possible. Both Dr. Brown and Dr. Fellman think that MIGS is easily within the skill set of comprehensive cataract surgeons. EW References 1. Fellman RL, et al. Episcleral venous fluid wave correlates with Trabectome outcomes: Intraoperative evaluation of the trabecular outflow pathway. Ophthalmology. 2015;122:2385–2391. 2. Fellman RL, et al. Episcleral venous fluid wave: Intraoperative evidence for patency of the conventional outflow system. J Glaucoma. 2014;23:347–350. Editors' note: Dr. Brown has financial interests with Glaukos. Dr. Fellman has no financial interests related to his comments. Contact information Brown: reaymary@comcast.net Fellman: rfellman@glaucomaassociates.com Tips continued from page 49

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