EyeWorld Asia-Pacific June 2018 issue

June 2018 EWAP SECONDARY FEATURE 37 Views from Asia-Pacific Prin ROJANAPONGPUN, MD Associate Professor Chulalongkorn University & King Chulalongkorn Memorial Hospital 1873 Rama4 Road, Pathumwan, Bangkok 10330, Thailand Tel. no. +6622564142 Fax no. +6622528290 prinoph@gmail.com, tvisanee@gmail.com T he article discusses different aspects of MIGS procedure, including the learning curves, the skill of intraoperative gonioscopy, postoperative surveillance for complications, and MIGS reimbursement for adopters in different areas of USA. We agree that starting MIGS procedures requires a learning curve and very good skill in surgical gonioscopy, especially for canal-based MIGS devices because one hand of the surgeon will be holding the surgical goniolens while the other hand is needed for the precise placement of MIGS device such as the iStent and Hydrus. Overall, canal- based devices are very limited in our region. Its cost could be a major barrier for such a moderate IOP reduction with no reimbursement scheme. The subconjunctival and supraciliary MIGS devices such as the XEN and CyPass are usually easier to perform and offer greater IOP reduction with or without cataract surgery. Such devices are widely available in our region. The merits are reduction of filtering complications, shorter operative time, and surgical skill is less critical. We also agree that direct gonioscopy offers excellent surgical view and not always necessary for the XEN. In our institute, we also find that the double-mirror “Mori” goniolens is an excellent alternative that requires no head tilt or microscope adjustment to achieve adequate angle visualization. We also employ the intraoperative OCT (iOCT, Zeiss) frequently in our MIGS surgery, which allows us to visualize the precise angle anatomy to facilitate accurate device placement. We strongly agree that postoperative care of MIGS is as important as learning how to implant the device, especially for the XEN. This means that the treating physician must be good in performing needling and bleb procedures. But with any MIGS, the surgeon will need to monitor glaucoma long-term and keep monitoring glaucoma as well as adjustinging as appropriate the postoperative medication. When necessary, another, more definitive procedure must be performed in a timely manner. For canal- based MIGS, nothing much can be offered except putting more stents or switching to other treatments. Device reimbursement will be varied among countries and healthcare systems in Asia. Adopting MIGS into our practice will not only depend on indications or proper case selection but also affordability and accessibility. We could not agree more on the importance of providing patients with options and get them into the decision- making process whenever possible. MIGS will have an important role in glaucoma surgery. Filtering surgery will need to adopt new technology to become safer for the patient while achieving a more reproducible outcome by any level of surgeon. Adopting MIGS will be widespread and structured training is needed specifically for each device category, just as refractive and vitreoretinal surgeons need to learn new procedures and how to manage their complications. Editors’ note: Drs. RojanaPongpun and Tantisevi declared no relevant financial interests. Shamira PERERA, MD Associate Professor Singapore National Eye Centre 11 Third Hospital Avenue, Singapore 168751 Tel. no. +96312157 shamira.perera@singhealth.com.sg S urgeons in the region are realizing that gonioscopic guided surgery has several intricacies which differentiate it from traditional microsurgery. The main areas being in visualization and patient preparation and for postop management. Placing corneal incisions slightly more anterior than usual to avoid blood in the interface between the cornea and the goniolens helps, as does turning the patient’s head in preference to the microscope to achieve a relative angle of 30 degrees to allow a closer working distance between the surgeon and the patient. “ Surgeons in the region are realizing that gonioscopic guided surgery has several intricacies which differentiate it from traditional microsurgery. ” –Shamira Perera, MD Keeping the IOP (estimated digitally) around 15–20 mmHg for the insertion of these devices offers the best compromise between a striae-free view and having adequate reflux of blood into Schlemm’s Canal (SC) to guide placement. Generally speaking, reflux of blood through the device is considered a promising sign for a successful implantation. Removal and re-implantation of the devices to ensure a perfect implantation must be balanced against the risk of a compromised view: “Your best shot is your first shot.” For the KDB, prominent iris strands may complicate the smooth passage of the blade. If bleeding occurs during the initial cut into the TM before ABiC insertion, one may blow the blood away using the viscoelastic in the catheter. There is anecdotal evidence that the Trabecular Meshwork (TM) MIGS confer greater IOP lowering if placed close to a collector channel. While it is impossible to be sure of the position of these highways of aqueous drainage from gonioscopy, it may be prudent to place the TM MIGS close to areas of pigment clumping in the TM, away from areas where there are constrictions or discontinuities of the band of blood reflux in the SC and away from iris bulges which may potentially block the device’s inlets. The MIGS that produce blebs are more challenging to manage. Sometimes the needlings with antifibrotics need to be even more aggressive than the ones for trabeculectomy rescue. One needs to remove scar tissue or tight Tenons from in front of and behind the subconjunctival implants leaving a straight and mobile implant. Often, multiple needlings are required to resurrect good flow. There may be postop bleeding with the TM MIGS. Fortunately, this is self-limiting and rarely needs intervention; however, it is worth stressing this preoperatively to patients. Similarly, IOP spikes from viscoelastic, blood, and even a steroid response in some cases can usually be waited out. Editors’ note: Dr. Perera is a consultant for Alcon, Allergan, and Glaukos. Visanee TANTISEVI, MD Assistant Professor continued on page 38