ASCRS 2023: Comparing outcomes of 2 different trabecular MIGS devices with or without ab interno canaloplasty for patients with glaucoma

Ophthalmology Times® spoke with Mitch Shultz, MD at ASCRS 2023 in San Diego where he shared insights from his presentation comparing patient results of the Hydrus stent and the iStent inject W with or without ABiC (or ab-interno canaloplasty).

Video transcript

Editor’s note: Transcript lightly edited for clarity.

Mitchell C. Shultz, MD:

Hi, I'm Dr. Mitch Shultz from Shultz Chang Vision in Los Angeles, California. I'm here today to share with you some interesting information from one of the papers that I'm presenting looking at a comparison between the Hydrus stent and the iStent inject W with or without ABiC (or ab-interno canaloplasty). The data was stratified into two different groups. We looked at patients who we did stent alone versus stent with ABiC. It was interesting to see what the data showed us.

So first of all, if we talk about the pivotal data from the FDA, it's very interesting that both devices perform relatively similarly, when we compare the data comparing the stent versus cataract surgery alone. But clearly there was a difference in implanting stents. So now the question was whether or not adding ABiC might help to improve results and outcomes.

When we compare the data, I actually did a study looking at 40 patients. I implanted contralateral eyes, so one eye with iStent inject W and one eye with Hydrus. We round these patients out. We're now at about two and a half years. But we looked at the 1-year data, which is a very complete set, to determine the efficacy of the procedures. What we found was with the iStent inject W group that we had a significant improvement in IOPs, both with and without ABiC. Interestingly enough, patients were looked at whether they had a pre-existing IOP of greater than 18 on medications; unmedicated patients greater than 21 mm Hg, and then the third group was looking at patients that were controlled on medications and whether or not they were on zero, 1, or 2 medications.

So in the group that we did no ABiC, those patients were on zero or 1 medication as a rule. The patients that were on 2 medications or more had an IOP uncontrolled on 2 medications or 1 medication uncontrolled; the patients that started with preoperative IOPs greater than 22, we performed a stent including ab-interno canaloplasty.

The results showed us that the IOPs were relatively equal between the two groups, and we compared the patients with ABiC versus stent alone. It's really kind of important to understand that these were two different groups, however.

So even though the IOPs were the same, it was really that we were able to reduce the number of medications greater by having ABiC than compared to stent alone. So when we look at the two groups evenly, if you just look at the data itself, they look pretty equivocal. The postop IOPs really started about the same place, and they ended up in the same place. ABiC really just helped to improve the number of patients we were able to get off medications.
When we look at the number of patients that were medication-free, in both groups, it was about 80% that we were able to achieve medication-free results.

However, when we look at patients that we were able to achieve IOPs of 15 or less, interestingly enough, iStent inject W outperformed Hydrus in this manner. This may or may not be related to the number of patients that may have been on more than two medications in either group, but it was still very interesting information to achieve.

In addition, we looked at the number of intraoperative adverse events as well as secondary surgical interventions. Here again, iStent inject W outperformed Hydrus when we compare the two groups. In the iStent inject group, we had no intraoperative adverse events, and we had no secondary surgical interventions.

Unfortunately, with the Hydrus group, we did see several intraoperative adverse events with malpositions of stents, as well as postoperatively where there were problems that required secondary surgical interventions. These are things that happen, unfortunately, with late posterior synechiae that can attach to the stent snorkel as well as to the trabecular meshwork postoperatively.
So in summary, both devices achieve excellent results for our patients. I think that iStent inject W does offer us a little bit more safety postoperatively even though the results are equivocal. Thank you very much.