FDA Approval Recommended for Implantable Macular Degeneration Device

FDA Approval Recommended for Implantable Macular Degeneration Device
By Emily P. Walker, Washington Correspondent, MedPage Today
Published: March 30, 2009

GAITHERSBURG, Md., March 30 -- An FDA advisory panel agreed that the agency should approve a miniature implantable telescope to improve central vision in elderly people with end-stage age-related macular degeneration.

The Ophthalmic Devices Panel voted unanimously Friday to recommend approval for the Implantable Miniature Telescope, made by Vision Care Ophthalmic Technologies, for use in patients who are 65 or older.

The thumbs-up came despite the device's association with loss of corneal cells over time.

Many elderly people would likely choose the telescope -- which could help maintain their ability to carry out daily tasks such as recognizing faces and reading books -- even if it meant developing corneal edema four or five years down the road, the panel decided.

Four years after the implant, about 15% of patients will have a significant depletion in endothelial cells, which can lead to corneal edema, according to an estimate by the panel's biostatistician, Karen Bandeen-Roche, Ph.D., of Johns Hopkins University in Baltimore.

The telescope works by directing light from the lens onto still-functioning portions of the macula to maintain central sight. It increases vision up to about three meters, helping patients perform close-up tasks, though doing nothing for their ability to drive.

The device would be implanted in one eye, after patients wear an external version for a few days to get a feel for it. Because it only improves central vision, implant recipients would rely on the opposite eye for peripheral sight.

The outcome of the Friday meeting was a major victory for the Vision Care, especially because the FDA turned down its original application in 2006 because of safety concerns.

New, longer-term data convinced the panel that the telescope can deliver improved vision for certain patients and that the associated cell loss is an acceptable risk.

Vision Care applied for a much narrower indication this time around. So narrow, in fact, that only about one-quarter of the participants included in the company's original trial would meet the new criteria, according to Henry Hudson, M.D., an vitreoretinal specialist in Tucson, Ariz., and lead investigator of the main clinical study submitted to the FDA.

The device was originally intended for patients 55 and older, but the sponsors bumped the age requirement up to 65. The new application also excludes patients with corneal guttata, and those who have an anterior chamber depth of less than 3 mm. Patients must also have retinal cell counts that are normal for their age group before receiving the implant.

The application calls for the device to be implanted by cornea specialists who are trained by Vision Care.

The panel's approval was based largely on a trial involving 206 patients with incurable central vision disorders and who were over 55 and had a need for cataract surgery.

The primary endpoint for efficacy was improvement of two lines or greater in either near or distance vision, which was achieved in 86% of patients at follow-up.

In a four-year follow-up that the company completed at the request of the FDA, 68% of the patients achieved a two-line or greater gain in either long distance or near vision four years after the surgery.

The panel heard from three octogenarians who said that if it weren't for their implantable telescopes, they would not be able to read books, make crafts, recognize their grandchildren, or carry out daily chores.

The committee suggested that the original trial cohort -- of which 130 are alive and still have the implant -- be followed for additional five years to monitor for complications such as rates of corneal transplant, retinal detachments and corneal edema.

The committee, chaired by Jayne Weiss, M.D., an ophthalmologist from the Kresge Eye Institute in Detroit, also said patients should be informed of the risk of cell loss and the possible benefits of improved central vision associated with the device.

The lead researcher agreed.

"The key consideration is proper patient expectation to get the maximum effect of this technology," Dr. Hudson said.