European study with microstent demonstrates lowered IOP, use of fewer drugs

Take-home message: Patients with cataract surgery and microstent implantation had a lowered IOP and a reduced number of medications used at 3 years postoperatively.

By Vanessa Caceres; Reviewed by Steven R. Sarkisian Jr., MD

Three-year results with the microinvasive glaucoma surgery (MIGS) device (CyPass Micro-Stent, Alcon Laboratories) combined with cataract surgery showed sustained IOP control and a lower need for glaucoma medications, said Steven R. Sarkisian Jr., MD.

The device is placed in the supraciliary space and is implanted in an ab interno fashion via a clear cornea incision. This approach spares the conjunctiva, sclera, and trabecular meshwork.

Two cohorts

European data presented by Dr. Sarkisian from the multicenter prospective CyCLE study focused on two patient cohorts (245 eyes) that both had combined small-incision cataract surgery and device implantation. In one cohort (93 eyes), the patients had uncontrolled IOP (21 mm Hg or greater) at baseline.

“The goal with this group was to lower the IOP,” said Dr. Sarkisian, clinical professor and Glaucoma Fellowship Director, Dean McGee Eye Institute, University of Oklahoma, Oklahoma City, OK.

In a second cohort of 152 eyes, the IOP was controlled (21 mm Hg or lower), and the goal was to lower the number of medications used.

The mean baseline IOP in cohort 1 was 25.3 mm Hg versus 16.4 mm Hg in cohort 2. At baseline, both groups used about 2.1 medications on average.

Thirty-two patients in the study had previous glaucoma surgery, Dr. Sarkisian said

After implantation of the device, the mean IOP in cohort 1 lowered from 25.3 mm Hg to 17.2 mm Hg at 3 years. At 12 and 24 months, the mean IOP in cohort 1 had lowered by 34% and 30%, respectively, he said.

In cohort 2, the mean IOP stayed the same postoperatively. However, by month 36, the mean number of medications used had dropped to one.

“Of note, we see that the percentage of patients on 0 to 1 medications at baseline was only 31.6% and then increased to 64.1% by 36 months,” Dr. Sarkisian said. “Moreover, at 36 months the number of patients on zero medications was 45%.”

The most commonly seen adverse event was device obstruction (9.4%).

“There were 2 reports of transient device obstruction by blood within the first postoperative week,” Dr. Sarkisian said. “However, in the vast majority of cases (n = 19), obstruction appeared to have been related to intraoperative device positioning that was more posterior than optimal and, over time, iris tissue overgrew some portion of the device lumen, which was resolved by use of a YAG laser.

“Also, retinal complications occurred in 4.1% of patients, but only one case was related to the CyPass, and was due to hypotony that resolved after device explantation,” he said.

Although visual loss occurred in some patients, none of it was related to the implant.

“The three-year safety profile gives long-term evidence of compatibility with cataract surgery and the potential to employ this therapy earlier in the glaucoma treatment paradigm,” Dr. Sarkisian said.

Steven R. Sarkisian Jr., MD

E: steven-sarkisian@dmei.org

This article was adapted from Dr. Sarkisian’s presentation at the 2016 meeting of the American Academy of Ophthalmology. Dr. Sarkisian is a consultant for Alcon Laboratories.