As we age, the eye starts to harden and grows very slowly in all dimensions. These changes result in the waning of accommodation, the ability to zoom in and out as one looks at near and distant objects. This difficulty of seamless focusing usually shows up around the age of 40, and is called presbyopia. Presbyopia is different than astigmatism, nearsightedness and farsightedness as the condition is age-related.
People suffering from presbyopia are often prescribed reading glasses and bifocals in increasing magnifications as they age. Often, they have several pairs of glasses that never seem to be where they are needed.
However recent advancements in corneal implant surgery may eliminate the need for reading glasses.
There are three focusing devices pending US FDA approval that aim to restore near vision for presbyopic people by implanting a device within the corneal tissue. They use different principles of adding plus power to the cornea (like a bifocal contact lens, which has the reading portion in the center), or by using the principle of increased depth of focus that results from looking through a small aperture.
Here is a link to a nice summary about these devices: http://www.reviewofophthalmology.com/content/i/2746/c/46512/
It’s important to note that each of these devices has drawbacks and advantages, but most importantly they all seem to have the safety necessary in an elective device. Since the devices are implanted in the cornea, not further inside the eye, they are removable in the office setting.
The first real breakthrough in the corneal inlays came about when materials were developed that were well-tolerated by the surrounding tissue. Secondly, the increasing sophistication of the femtosecond lasers used for LASIK and cataract surgery allowed creation of the corneal pocket into which the inlays are inserted.
In the investigational studies, these devices are being compared to reading vision with glasses, and to patients’ satisfaction with mono vision, in which one eye is corrected for distance and one for near.
The Kamra inlay is furthest along in the FDA process, followed by the Raindrop, then the Flexivue. Although the Kamra was thought to be approved in late 2014, the FDA has asked for more safety data.
The pricing on these inlays is also uncertain at this time.
The corneal inlays represent another intriguing approach to the treatment of presbyopia, which affects everyone as they age, but which also affects people who have had cataract and refractive (Lasik, PRK) surgery. With such a large number of people who could benefit from a safe and effective treatment, the resources devoted to the problem are huge, and the ideas out there are numerous and ingenious.
We’ll be watching with great interest.
Triangle Eye Physicians have been at the forefront in adopting new technology that appears to confer advantages in safety and results. Our experience in cataract and refractive surgery, and with using the state of the art Ziemer femtosecond laser, positions us to offer the inlay solution to presbyopia as soon as it becomes available.