Comorbidity of glaucoma poses some increased risks for cataract surgery, but even when there are intraoperative complications during the lens removal procedure, it is almost always possible to still add micro-invasive glaucoma surgery (MIGS), said Reay H. Brown, MD.
“We have never been better at complex cataracts, and it is rare not to do the MIGS,” said Dr. Brown, private practice, Atlanta. “Once the cataract portion is completed, it really doesn’t matter how complicated it was, as long as you were able to deal with the problem. Then, it is just you and the angle. MIGS adds very little time or risk to the case.”
Dr. Brown said that cataract surgery itself is good for glaucoma, but it also presents an opportunity to use a glaucoma implant or to perform goniotomy. In fact, it is his general practice to plan MIGS for any patient who is having cataract surgery and under treatment for glaucoma with even one medication.
“My primary goal, however, is to have safe and successful cataract surgery, and I will modify the plan and abandon the glaucoma step if the MIGS procedure is a threat,” he said.
Listing reasons not to do MIGS, Dr. Brown mentioned presence of poor visibility, which may be due to bleeding or corneal edema; if there is a narrow angle; or when the surgeon is fatigued.
“Sometimes you are just worn out, and that is not a good time to push it,” he said.
Tips for success
Dr. Brown provided several pearls for performing MIGS. First, he said he warns patients that the glaucoma procedure may not be possible, especially if he is worried about the case.
“I usually say there may not be enough room. This is part of the informed consent and it gives the surgeon an out,” he explained.
“It is better to have this conversation before the surgery than after. It is part of the under-promise and over-deliver approach.”
Intraoperatively, Dr. Brown uses trypan blue 0.06% dye (VisionBlue, DORC) in every MIGS case. He explained that it stains the trabecular meshwork. Therefore, it provides a “landing strip” if he is implanting a stent (Stent, Glaukos). Or, if he is implanting another device (CyPass Micro-Stent, Alcon Laboratories), it helps him to position the device so that the tip is at the desired location at the top of the meshwork.
Other tools are used whenever needed, including a pupil expansion ring, capsular tension hooks, or pars plana vitrectomy. Dr. Brown presented some intraoperative videos demonstrating challenging cases where he used these adjuncts to achieve a good outcome.
Dr. Brown receives patents/royalty from Glaukos Corp.