The U.S. FDA has approved the first implantable device for correction of near vision in patients who have not had cataract surgery.The KAMRA inlay is a device implanted in the cornea of one eye to improve near vision in certain patients with presbyopia.
Presbyopia is the loss of the ability to change the focusing power of the eye. It occurs with normal aging and results in difficulty with near vision, generally in adults 40 to 50 years of age.
Manufactured by AcuFocus Inc., the KAMRA inlay is an opaque, ring-shaped device intended for use in patients 45 to 60 years old who, in addition to not having had cataract surgery, are unable to focus clearly on near objects or small print and need reading glasses with +1.00 to +2.50 diopters of power—but do not need glasses or contacts for clear distance vision.
Anyone who understand cameras will understand the concept here. By shuttering down the aperture in a camera, so the depth of field gets bigger, thereby bringing more things into focus. Normally the focusing job in the eye is performed by the accommodatory changes to the lens, but as this gets older and stiffer that ability is often lost. By effectively narrowing the aperture, the KAMRA inlay does a couple of things. Primarily it blocks unfocused light rays entering the eye in order to improve near vision. It also blocks peripheral light rays while allowing central light rays to pass through a small opening in the center of the device, making near objects and small print less blurry.
To evaluate the safety and efficacy of the KAMRA inlay, the FDA reviewed the results of three clinical studies. The results of the main study showed that 83.5 percent of the evaluable 478 participants achieved uncorrected near visual acuity of 20/40 or better at 12 months. This is the level of vision needed to read most text in magazines and newspapers.
“Presbyopia is a natural part of aging and can make reading and performing close-up work difficult,” said William Maisel, M.D., deputy center director for science in the FDA’s Center for Devices and Radiological Health. “The KAMRA inlay provides a new option for correcting near vision in certain patients.”