New surgical tool for complicated eye surgery

May 28 2009

Eye surgeons will soon have a new surgical tool to help make a complicated eye surgery less labor intensive while providing significant advantages for corneal transplant patients, as a result of an invention by a Wake Forest University Baptist Medical Center physician.

The new surgical tool, called the EndoSaver Corneal Endothelium Delivery Instrument, is the brainchild of ophthalmologist Keith A. Walter, M.D. Having done hundreds of Descemet's Stripping Endothelial Keratoplasty (DSEK) surgeries, Walter knew he needed a better way of inserting donor endothelial tissue. DSEK is a corneal transplant procedure where surgeons remove only the diseased innermost layer of a host cornea and replace it with healthy cornea tissue from a donor.

"The purpose of the EndoSaver is to make it easier for eye surgeons to insert the living donor tissue without damaging the tissue or crushing the cells," said Walter, an associate professor of ophthalmology at Wake Forest University Eye Center, part of Wake Forest Baptist. "Sparing injury to the fragile button of tissue during this procedure is a key part of patients' quicker visual recovery and provides better long-term results."

Traditionally, eye surgeons use forceps to grasp and fold the donor tissue, insert the tissue into the patient's eye through a 5- to 6-millimeter incision and then unfold the tissue, while attempting to limit damage to the tissue and cells.

With the new device, the donor's tissue layer is rolled up inside itself, similar to a cinnamon roll, and placed inside a spoon-shaped protective sheath. It is then inserted into the patient's eye through a smaller, 4-millimeter incision. "While turning the knob to remove the protective casing, the tissue layer unrolls itself into position as fluid maintains space to accomplish this," said Walter.

Many patients will benefit from use of this device, explained Walter, because the damage to the tissue is limited. It also results in a smaller wound, fewer sutures, fewer problems with post-operative astigmatism, less pain and a quicker visual recovery overall.

To facilitate the design and testing of the surgical device prototype, which is a little larger than a ballpoint pen, Walter worked with staff from the Office of Technology Asset Management at Wake Forest Baptist, which collaborated with Ocular Systems Inc. and Cathtek LLC, companies in the Piedmont Triad Research Park in downtown Winston-Salem, to co-invent the new surgical tool.

"This device demonstrates how quickly an idea can come to market when the inventor, industry partner and university work as a team. It's also very exciting that all the expertise to develop this device is present right here in the Research Park," said Dean Stell, associate director of the Office of Technology Asset Management, which is also located in the Research Park.

The surgical device is currently in clinical trials and has been submitted to the U.S. Food and Drug Administration for approval, which is expected soon. Since the initial idea, it has been a three-year process to develop the EndoSaver. Walter said that similar devices are emerging in the market, but the EndoSaver should be the first one with FDA approval.