Corneal inlays and onlays are corneal implants that are used to correct presbyopia, a common condition in which the eyes have difficulty focusing on near objects. Presbyopia usually affects individuals above the age of 40 as the lens of the eye begins to age, requiring them to use reading glasses when viewing objects at a close distance.
Corneal implants are one of the treatment options for those with presbyopia that want to experience clear near vision without the need for reading glasses or multifocals. Corneal inlays and onlays are actually small lenses, similar to tiny contact lenses, that are inserted into the cornea to improve near vision by increasing the depth of focus or refractive power of the cornea.
Corneal inlays and onlays work by altering the shape of the cornea to improve its’ refractive power. Unlike LASIK surgery for presbyopia the actual cornea isn’t altered, but the transplanted lens is placed on the cornea to reshape it.
Corneal inlays are placed near the middle layer of the cornea in a layer called the stroma, while onlays are placed near the surface of the eye, directly under the thin outer layer of corneal cells called the epithelium. Both procedures are relatively quick and recovery is minimal.
Corneal Inlay and Onlay procedures are still in the early stages of development and many types are currently undergoing clinical trials.