The KAMRA inlay reverses the effects of presbyopia
Intended to aid those affected by presbyopia, the KAMRA intracorneal inlay is surgically implanted into one of the patient’s eyes to increase the depth of focus.
Nick Tarantino, OD, chief clinical and regulatory officer of the KAMRA inlay’s parent company AcuFocus, Inc., explained, “Until now, presbyopia has not really had a good correcting option. Eyeglasses, monovision contact lenses and the monovision surgical option all have compromises. We believe our surgical option provides a very good outcome.
“The reason we chose a surgically implanted [intracorneal inlay]is because of the small aperture it provides,” Tarantino continued. “It’s an elegant way of increasing depth of focus without the compromises associated with other solutions, such as the out-of-focus images that can result from bifocals or the loss of binocularity that monovision can cause by changing the refraction of only one eye.”
Tarantino explained that the KAMRA inlay increases depth of focus and maintains binocularity, particularly for distance viewing, without the compromises that come with other means of correcting presbyopia. It works much like the aperture of a camera. “When a photographer wants to have the foreground and the background in focus, he makes the camera’s aperture small,” he said. “That’s the principle we’re using. It also doesn’t reduce the patient’s field of view.”
Although the inlay is implanted into only one eye, Tarantino noted that it doesn’t create the focusing and binocularity issues that monovision does, especially with higher disparate adds. “That’s because the inlay doesn’t use additional plus power to provide the focusing help needed. It provides an increased depth of focus instead. It’s a different paradigm than the additional plus power model used by multifocals and monovision solutions,” explained Tarantino. “Most patients have good binocular distance vision, stereopsis and near vision with the implant.”
The fact that there is no need for additional adjustments once the inlay is implanted is another major benefit offered by this depth-of-field technology, according to Tarantino. In other words, unlike patients who will eventually need stronger additional plus power as their presbyopia increases, the inlay’s depth-of-field enhancement is appropriate for presbyopes of all ages.
Tarantino explained that during the investigational device exemption (sometimes referred to as IDE) trial, the age range of patients was 45 to 60. Over the five-year study, the near vision in the implanted eye stayed the same while presbyopia progressed in the non-surgical eye. He attributed this to the depth-of-field enhancement of the inlay remaining the same even as the patient’s presbyopia changes.
Who is a suitable candidate for this product? Tarantino suggested that it is any patient who has good binocular vision and a normal, healthy cornea (as opposed to one that’s too thin or that has corneal complications). While the application of this product is worldwide, some sophisticated technology and suitable medical expertise must be available for implanting the inlay, which will be found mostly in the developed world. For example, a femtosecond laser is needed to create a pocket in the cornea for the inlay.
With over 1,000 eyes implanted in the U.S., and more than 20,000 worldwide, the results have exceeded expectations, according to Tarantino. Will the KAMRA inlay be the mainstream method for correcting presbyopia in the future? “We believe the surgical correction of presbyopia is a good way to go because it frees the patient from depending on multiple pairs of eyewear,” he said. “It may not completely eliminate the need for an optical solution, but it clearly reduces it.”
What’s the downside of the inlay? Tarantino’s guess is that it may be cost. While this is clearly an ophthalmological procedure, he sees a large role for optometrists, especially in referring patients to ophthalmologists and co-managing them.
The procedure is also reversible, so patients who decide it’s not for them can have it removed. With the future clearly in focus, AcuFocus’s KAMRA inlay promises to relieve the symptoms of presbyopia, potentially for the two billion people affected by presbyopia worldwide.
Ed De Gennaro, MEd, ABOM, is director, professional content, of First Vision Media Group.