The US Food and Drug Administration (FDA) approved the Kamra inlay, a device implanted in the cornea of one eye (the clear, front surface) to improve near vision in certain patients with presbyopia.
It is the first implantable device for correction of near vision in patients who have not had cataract surgery. The Kamra inlay is manufactured by AcuFocus Inc., based in Irvine, California.
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. 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.
“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.”
The device works by blocking unfocused light rays entering the eye in order to improve near vision. It 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 insert the device, an eye surgeon uses a laser to create a pocket in the cornea of one eye of the patient and implants the device in that pocket. This is intended to allow the patient to have improved near vision in the eye containing the implant, while not affecting the distance vision of the two eyes working together.
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.
The device is not intended for patients who have had cataract surgery or patients with severe dry eye; an active eye infection or inflammation; corneal abnormalities related to thinning and irregular shape of the surface of their eyes; insufficient corneal thickness to withstand the procedure; a recent or recurring herpes eye infection or problems resulting from past infection; uncontrolled glaucoma; uncontrolled diabetes; or active autoimmune or connective tissue disease.
The labeling warns that the device’s safety and effectiveness in patients who have had LASIK or other refractive procedures is unknown.
The Kamra inlay may cause or worsen dry eye and various vision-related problems, such as glare, halos, night vision problems, and blurry vision. It also can cause corneal complications such as swelling, clouding, thinning and potential perforation, and challenges evaluating and managing eye problems. For patients experiencing vision problems after the surgery, removal of the device may improve vision in some cases. In other cases, decreased vision could become permanent. There is also a potential risk for the focusing power of the eye to change, causing blurry vision and requiring glasses.