New data confirm the success of glaucoma drainage device

The glaucoma device has an ab interno approach that is less invasive than an ab externo approach, a clinician says.

PARIS — A glaucoma drainage device helps to reduce both IOP and medication use, according to a surgeon.

The ab interno CyPass (Transcend Medical) is being studied in a multicenter trial in combination with phacoemulsification, Helmut Höh, MD, FEBO, said at the European Society of Cataract and Refractive Surgeons meeting.

“Preliminary results of a multicenter study show safety and efficacy of the device in combined glaucoma and cataract procedures. In my own series of patients, I have used the CyPass as a standalone procedure, with equally good results,” he said.

Medical management of glaucoma has limitations, Dr. Höh said. Medications are effective in either reducing the rate of aqueous production or increasing the rate of aqueous outflow. However, compliance problems are reported in 30% of the cases, and long-term administration can cause issues that prevent continuation of the treatment.

Surgery is directed almost exclusively at increasing the outflow. Current options, including trabeculectomy and tube implants, may lead to significant IOP lowering, but also to complications such as hypotony, bleb leak and fibrosis.

“When the ab externo surgical approach is used, surgery is far from being minimally invasive. We dissect the conjunctiva and penetrate the sclera,” Dr. Höh said.

The device

The CyPass is a micro-implantable device, 6 mm in length, with a small lumen of 300 ìm. It allows for an ab interno surgical approach, which spares the conjunctiva, does not penetrate the sclera and leaves the trabecular meshwork intact.

“It is simply implanted in the suprachoroidal space through a clear corneal incision, which coincides with the phaco incision in combined procedures,” he said. “A special inserter is used to make the distal end of the device penetrate into the suprachoroidal space, while the proximal collar remains in the anterior chamber. Three rings on the collar keep the device in place, preventing movement. Implantation may be tricky but not difficult for experienced surgeons.”

The device has a high absorptive capacity and provides access and drainage of the aqueous from the anterior chamber to the suprachoroidal space.

The study

A multicenter clinical study was carried out in Canada, Manila and Malaysia. A total of 27 patients with primary open-angle glaucoma were enrolled and underwent clear corneal surgical implantation of the CyPass device combined with phaco. Postoperative follow-up visits took place at 1 and 7 days and at 3 and 6 months.

“All 27 cases were successfully implanted, and gonioscopy confirmed the correct positioning of the CyPass in all eyes. No device-related intraoperative complications were reported. Postoperatively, there were no cases of hypotony or device migration,” Dr. Höh said.

Results were promising, he said. At 6 months, IOP was lowered from an average of 25 mm Hg at baseline to 15 mm Hg. At the same time, the number of medications dropped from 1.8 to 0.65.

“Quite a remarkable, more than 60% reduction,” Dr. Höh said. “Next year we will be able to disclose long-term outcomes and assess stability.”

In this study, CyPass implantation was combined with cataract surgery. However, Dr. Höh has implanted more than 100 eyes in his practice, and many of those cases were standalone procedures. Outcomes, he said, were equally good. – by Michela Cimberle

• Helmut Höh, MD, FEBO, can be reached at Postfach 40 01 35, 17022, Neubrandenburg, Germany; +49 395 775 3470; fax +49 395 775 3468; e-mail: Aug@dbknb.de.
• Disclosure: Dr. Hoh has no financial interest in the product discussed in the article.

The CyPass implant, like other modalities of gonioscopic surgery, is likely to become first choice in the near future because complications are less and minor compared to filtering procedures. In addition, it is a repeatable procedure, which leaves an intact superior conjunctiva, allowing filtering procedures to be performed at a later stage in case of failure. Obviously, preliminary findings need to be confirmed in prospective trials with larger series, evaluating long-term results. If our first impressions are confirmed, CyPass and similar procedures will represent in glaucoma surgery the advancement we were waiting for.

— Marco Nardi, MD
Ocular Surgery News Europe Board Member
Disclosure: Dr. Nardi is a consultant for Transcend, makers of the CyPass device.