During the 2020 ASCRS Virtual Annual Meeting, glaucoma specialists reviewed a variety of treatment algorithms for minimally invasive glaucoma surgery (MIGS). Davinder Grover, MD, described several scenarios in which MIGS might not be indicated, such as in younger patients or patients who have had 360-degree trabeculotomy. He cited a complex surgical case that was successfully treated with MMC and the biodegradable collagen matrix implant Ologen (Aeon Astron Europe), and he noted that a stepwise approach and learning about this patient’s inherent drainage system helped guide him to the decision not to use MIGS in the second eye.
In his presentation on stenting the trabecular meshwork, Manjool Shah, MD, said that all of the many available stents have nuances in their use, but that a key point to remember for all of them is proper angling of the cannula for correct placement. Inder Paul Singh, MD, noted that in viscodilation, the shorter the procedure the better, and to do this surgeons would benefit from externally advancing catheters parallel to the otomy to avoid kinking.
In a section addressing subconjunctival filtration, Arsham Sheybani, MD, presented tips on ab-interno implantation of Xen (Allergan). Key points he noted were that surgeons should make sure the back end of the bevel is fully through the sclera, that the needle be slowly and carefully released after deployment to avoid a “flick” that can displace the stent, and that special attention should be paid to the bleb to avoid intra-Tenon adhesions. Jacob Brubaker, MD, presented on off-label ab-externo Xen implantation and said that this method can be helpful in that reduces risk of complications, allows for varied hand position of the surgeon, and also can be employed in an office setting. Joseph Panarelli, MD, noted that he prefers to perform Xen implantation with open conjunctiva rather than closed, because the procedure is more predictable and teachable, there is more room to work, the implant is less prone to early failure, and there is a shorter learning curve.
A final session addressed MIGS for patients with uncontrolled POAG. Michelle Butler, MD, argued that the target pressure is a logical benchmark to use when choosing MIGS vs surgery, and she reminded attendees to keep cost and insurance coverage in mind. She added that a recent retrospective study of gonioscopy-assisted transluminal trabeculotomy (GATT) after failed glaucoma surgery showed GATT to be effective in 60% to 70% of patients, which could be encouraging news for glaucoma specialists treating this difficult patient population.
Helen Kornmann, MD, PhD discussed the “MIGS-plus” devices, Preserflo (Santen) and Xen, noting that these devices can bridge the gap between trabecular bypass or ablative procedures and traditional surgery. She said that these devices can work well for patients who need very low IOP, and that although more study is needed, they are showing promise in a wide variety of subtypes and severities of glaucoma.
- Grover DS, Godfrey DG, Smith O, Shi W, Feuer WJ, Fellman RL. Outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) in eyes with prior glaucoma surgery. J Glaucoma. 2017;26(1):41-45.