This was my patient, and her primary desire was to achieve improved functional vision. Accordingly, cataract surgery was planned along with a procedure to help to maintain IOP control and potentially reduce the requirement for glaucoma medications. I also specifically addressed her coagulation status; although I do not discontinue warfarin for routine cataract surgery or canal stenting surgery, I will hold it for glaucoma surgery involving transscleral or supraciliary surgery, always in consultation with the patient’s primary physician. In the event that anticoagulants cannot be discontinued safely, my strategy is to request that the INR be in the lower therapeutic range perioperatively rather than the high therapeutic or supratherapeutic range.
Given that there was reluctance to discontinue warfarin by this patient, even transiently, I felt she should continue it without interruption. I always factor the coagulation status into the equation when selecting which glaucoma procedure to be combined with phacoemulsification. For example, I strongly lean toward canal-based procedures in such cases and I am less inclined to perform supraciliary or transscleral surgery in anticoagulated patients. Moreover, because trabecular microbypass devices augment physiological outflow, the extent of IOP reduction is limited by episcleral venous pressure and hypotony is not possible, essentially eliminating the risk for suprachoroidal hemorrhage, which can be more extreme in anticoagulated patients. Although comparative data are lacking, within the canal portfolio of procedures, I believe that trabecular microbypass stenting has the lowest risk for significant bleeding and devices such as the iStent might prove safer than canal ablative or incisional procedures. Admittedly, this statement is anecdotal and simply an opinion. Hopefully, data can guide us after comparative studies become available.
Four of the 6 respondents reported that their choice of glaucoma procedure for this patient was influenced by the coagulation status. Three of these surgeons selected trabecular microbypass stenting as their preferred option; the other would perform phacoemulsification combined with ECP. Two of the 6 respondents were not significantly influenced by the coagulation status, 1 recommended goniotomy with a dual blade combined with ab interno canaloplasty, whereas the other preferred combined phacoemulsification combined with trabecular microbypass stenting in the right eye and phacoemulsification combined with transscleral filtration surgery with the gel stent in the left eye. Each respondent provided sound reasoning for his or her preferred approach. Of note, none of the responding surgeons recommended traditional trabeculectomy or aqueous drainage device surgery as their recommended approach, perhaps a sign of the times and yet another indicator that the glaucoma surgical landscape has changed considerably in recent years. It is also noteworthy that none of the suggested approaches would limit the option for traditional filtration or tube surgery in the future should the MIGS approach fail to control this patient’s glaucoma.