Implanted eye devices could one day allow patients to see up close again
As anyone between the age 40 of and 50 knows, there comes a time in life when reading books, menus or smartphones gets more difficult.
The medical term for this is presbyopia — a stiffening of the eye's lens that makes it harder for eye muscles to focus on objects at near range. In fact, 1 in 5 Americans wears reading glasses to improve near vision, according to a 2014 American Academy of Ophthalmology national survey. But now, scientists are working on a device to allow aging eyes see up close again without glasses.
While they are still being evaluated for safety and efficacy, the implantable devices called corneal inlays could one day become an option in the United States.
"Inlays have been in development for decades," said John Vukich, M.D., a clinical adjunct professor in ophthalmology and vision sciences at the University of Wisconsin, Madison, who has conducted research on corneal inlays. "We're finally at the point with the technology where in the near future, this could potentially be an alternative to reading glasses."
The surgery is fairly quick, about 10 to 15 minutes, and involves making a small incision into the cornea on the front of the eye. The inlay is inserted into the slit. Three types of corneal inlays are under review by the Federal Drug Administration. One is the Presbylens Flexivue Microlens, a clear disk with rings of different levels of magnifying power so that the eye can focus up close and far away. When implanted into the cornea, the effect is similar to multifocal glasses.
The Raindrop Near Vision inlay works differently by reshaping the cornea. Unlike the other implants, this one is made of hydrogel (a soft material that used in many contact lenses), which is similar in water content to the cornea itself.
The third type is known as a small aperture inlay. The Kamra inlay is a doughnut shaped ring that constricts the field of vision to help create better sight at near range, similar to how a pinhole camera works. In clinical trial results, Kamra demonstrated improved near vision in more than 75 percent of cases over a three-year period.
While promising, inlays have displayed side effects and complications that include dry eye, haziness and reduced night vision. Because of these risks, ophthalmologists caution that corneal implants — like any eye surgery — should be weighed for benefit versus risk by both patients and physicians.
"We know everyone wants to get rid of their reading glasses, but every time you go in for eye surgery, you do face the risk of complications or side effects," said Anne Sumers, M.D., clinical spokesperson for the American Academy of Ophthalmology. "This is new technology. While it is exciting to see advances in this area, sometimes we find that procedures involving implants may have unforeseen complications."
Cost could also become a factor in how many people adopt corneal inlays: many of them require laser surgery to create a hole into which the device is inserted. Because the surgery would be elective, it is doubtful that insurance would cover the cost, which could be on par with LASIK and similar procedures.
"Is everybody going to run out and get this surgery if it costs thousands of dollars? I imagine not," said Dr. Sumers. "But if inlays prove to be safe, and they work like they say it should, then corneal inlays could become common in the future."