The FDA announced today that it had approved the Raindrop corneal inlay as a treatment for presbyopia — the age related loss of the ability to see up close without reading glasses (cheaters). Presbyopia is caused by the gradual stiffening of the human lens, which sits inside the eye behind the pupil. Generally it starts to become noticeable after age 40 and continues to get progressively worse until just after age 60, after which time near vision is very poor. Unfortunately, currently there is no good way to restore flexibility to the human lens, so the Raindrop inlay uses a different strategy. It works by reshaping the cornea, the clear domed cap of the eye which serves as the front of the eye. The Raindrop inlay is place into the cornea. Although it is very thin, it creates just enough bulging of the front shape of the cornea overlying it to refocus some light rays for better near vision. It is placed only in the non-dominant eye. In a recent clinical trial, 336 of 364 patients (92%) had 20/40 near vision 2 years after implantation. The inlay is approved only for patients between 41 and 65 years old who do not need any distance glasses or contacts, but only need reading glasses of the strength between +1.50 and +2.50 diopters.

The Raindrop is actually the second corneal inlay to be approved by the FDA for treatment of presbyopia. The first one approved was the KAMRA inlay, which works by yet another strategy. The KAMRA uses “small aperture optics” — essentially a pinhole effect. The KAMRA inlay also is placed in the cornea of the non-dominant eye and has a small hole in its center, which selects for light rays that are focused up close as well as in the distance.

Other treatments for presbyopia include monovision and blended vision with either LASIK or PRK.