Medical Device Daily

Optonol's (Kansas City, Missouri/Nevellan, Israel) Ex-Press Mini Glaucoma Shunt has been approved by the FDA and on the market since early 2002, but the company believes it will have more market share to gain with the results of a recent study being published in the Journal of Glaucoma.

When the Ex-Press shunt was implanted in 24 eyes of 23 patients with severe open angle glaucoma, it was found to be "safe and effective" in the study, led by Elie Dahan, MD, of the department of ophthalmology at the University of Witwatersrand (Johannesburg, South Africa).

"The product is widely used in the U.S. by either glaucoma specialists or general ophthalmologists," Haral Orbach, Optonol's director of marketing, told Medical Device Daily.

In the journal article, Dahan said that the Ex-Press Mini Glaucoma Shunt is "simpler and more predictable than the 'gold standard' procedure, trabeculectomy" and that it "may reduce complications of hypotony, particularly when operating on patients who might be regarded as being at high risk for failure of filtering surgery."

Severe open angle glaucoma is the most common form of glaucoma, which affects about 3 million Americans, many of whom don't even realize they have it, the company said. Glaucoma is a disease usually characterized by an increase in pressure within the eye. That may, in time, result in damage to the optic nerve, loss of peripheral or side vision, and ultimately blindness. The higher the pressure within the eye, the greater the chance of damage to the optic nerve.

The intraocular pressure (IOP) is determined by a balance of the eye's production and drainage of aqueous humor, or the clear fluid inside the eye, from the anterior chamber into the trabecular meshwork.

Optonol expects that with added credibility afforded the device by publications such as the Journal of Glaucoma, it will be used by even more surgeons, or those beyond the group considered to be glaucoma specialists.

The company said that now there are about 500 surgeons who are skilled at performing trabeculectomy. However, there are about 6,000 general ophthalmologists who ultimately could use the Ex-Press Shunt, because the trabeculectomy procedure comes with challenges and potential complications.

With trabeculectomy, Orbach said, the procedure involves removing tissue from the eye. The problem, he explained, is that once the tissue is removed, a physician cannot undo the procedure. Also, the procedure has "unpredictable results" and can result in cataracts later.

The Ex-Press shunt is a very small device – "smaller than a grain of rice," Orbach said.

"The procedure is something that you can learn [easily] – three to five cases and you are very familiar with this procedure," he said. "The valve has a regulator, modulating flow unit on it, [and] the device will control the flow of [fluid] out of the eye."

The device is not detectable in the eye by others after the procedure. Also, he said, "it is entirely reversible."

"In other words, if you put it in the eye, and if for some reason, you are not happy with it, you can take it out, and nobody will be able to tell that there was something in the eye before," he said.

Orbach said the potential to develop cataracts is "much less than" with trabeculectomy, "mainly because of the different way of flow in the aqueous humor," compared to the current gold standard.

"Glaucoma is a chronic disease that silently steals eyesight," Orbach said in a statement. "Fortunately, Ex-Press now offers hope for thousands of victims a year who may not have had access to physicians who could perform the complicated alternative procedure, or who could not afford it."

The Ex-Press shunt is reimbursed by insurers, and because it is a simpler procedure, Optonol expects those individuals to take advantage of the Ex-Press.

Optonol is a privately held company founded by a group of clinicians, engineers and entrepreneurs. With its initial focus on devices for ophthalmologic applications, the Ex-Press shunt is its first product.