EyeWorld Asia-Pacific June 2018 issue

be certain that steroids are dis- continued in a timely fashion and those patients developing a steroid response are adequately monitored and treated.” Dr. Samuelson added that it’s important to move on to more aggressive procedures if the MIGS procedure fails to adequately con- trol the disease process. Intraoperative gonioscopy Dr. Brubaker said that there is a learning curve with gonioscopy. “This can be practiced on non- MIGS patients initially,” he said. “It is crucial to tilt the head and microscope enough to obtain an enface view of the angle.” A chal- lenge that he often sees with begin- ning MIGS surgeons is they don’t get the right angle and the TM or ciliary body is viewed at an oblique angle. “This makes visualization and treatment much more difficult than it needs to be,” he said. “In addition to this the dominant hand that is holding the intraoperative devices and instruments needs to have adequate support to prevent posterior or anterior wound stretch, which can also cause corneal dis- tortions.” Dr. Brubaker said that he will use a standard Swan-Jacob lens for most of his cases. It is nice if it has a cutout at the apex of the prism to allow for a free insertion of the intraocular instruments, he said. “The single use iPrism in conjunc- tion with the iClip from Glaukos has an enhanced viewing angle,” Dr. Brubaker said. “The clip helps to move and stabilize the eye if necessary.” He finds this prism es- pecially useful for procedures that treat a wider portion of the angle such as KDB, GATT, or if placing multiple stents. Dr. Huang noted that intraop- erative gonioscopy can be a barrier, as good visualization is needed for implantation of devices. “However, once intraoperative gonioscopy is learned and mastered, it can be a skill that is useful in many differ- ent types of MIGS procedures,” she said. “I recommend a direct gonio lens to visualize the angle, such as a Swan-Jacob lens.” She added that certain direct lenses have a ring that contacts the limbus, which allows for stabilization and control of the globe. The ring also allows the gonio lens to float over the cornea, Dr. Huang said, minimiz- ing pressure and distortion of the cornea and thus allowing a clear view. “Intraoperative gonioscopy, however, is easy to practice at the end of cataract surgery,” she said. “For surgeons who wish to master the skill, I recommend that at the end of a cataract case, they rotate the patient’s head and microscope and use the gonio lens to view the angle.” Then, she said to use a cannula to gently touch the TM and perhaps mimic the motion of device implantation. How refractive cataract surgery patients resemble MIGS candidates Dr. Samuelson said that one aspect of MIGS surgery that will appeal to refractive cataract surgeons is that MIGS surgery by definition is microinvasive. “For example, canal- based surgery does not influence the postoperative refractive result,” he said. “Moreover, for the canal device surgery, such as iStent or Hydrus [Ivantis, Irvine, California], the intraoperative and periopera- tive adverse event and complica- tion rate in the pivotal trials was not statistically different from cataract surgery alone.” Therefore, Dr. Samuelson said that adding MIGS surgery to refractive cataract surgery follows a similar, premium visual outcomes mindset and strat- egy. “That said, I am cautious about the use of multifocal implants in patients with manifest glaucoma and visual field loss, primarily due to loss of contrast sensitivity as well as the possibility that the glaucoma could progress in years to come, which could further compromise the visual function,” Dr. Samuelson said. Many MIGS procedures are for patients with mild to moderate glaucoma and are often coupled with cataract surgery, Dr. Huang said. “Often MIGS procedures do not require an additional inci- sion and are easily performed after the cataract is removed,” she said. “MIGS procedures have been shown to decrease intraocular pressures and may also decrease medication burden.” Dr. Huang added that the patient should be aware of the op- tions for MIGS procedures when they are being evaluated for cata- ract surgery because some MIGS procedures are only performed at the time of cataract surgery. Standalone MIGS surgeries with refractive patients “Some MIGS procedures are performed in conjunction with cataract surgery,” Dr. Huang said. If done as a standalone, the patient’s insurance may not cover the procedure, she noted. In those instances, Dr. Huang usually offers a self-pay option or may offer a MIGS procedure that is approved as a standalone procedure. MIGS procedures may be useful in patients who are pseudophakic or post-refractive surgery as they often involve small corneal inci- sions and are sutureless, she said. “Compared to traditional filter- ing surgery, MIGS procedures will likely cause less astigmatism and also affect the tear film less.” Dr. Samuelson thinks that stan- dalone MIGS surgeries will play a more important role in the future. “Currently, both iStent and CyPass are approved only in conjunction with cataract surgery,” he said. “Other procedures such as Kahook Dual Blade, Trabectome [NeoMe- dix, Tustin, California], ab interno canaloplasty, and GATT can be per- formed as standalone procedures.” Hopefully, as more evidence-based information becomes available, MIGS devices will be available for standalone surgery as well, he said, adding that patients may sometimes be willing to pay out of pocket for some of the procedures that are currently not covered by insurance or Medicare. Reimbursement for MIGS Dr. Patterson thinks that some of the biggest barriers are insur- ance and reimbursement patterns. Surgeons will have to reassess if it’s worth their time to continue put- ting in these devices, he said. He noted that in his area, the prices of the stents and devices re- main the same, but reimbursement has decreased to just a few hundred dollars. This change happened just this year, Dr. Patterson said, and he noted it will have a particular impact on his practice, where he does 300–400 MIGS procedures in a year. Adopting MIGS – from page 37 June 2018 38 EWAP SECONDARY FEATURE