The outermost layer of the eye is the cornea. It protects the eye from harmful matter like dust or germs, and helps to focus the eye by allowing light in. There are a number of diseases and disorders that may affect the cornea.
There are five layers that make up the cornea:
If you are nearsighted or farsighted, it is due to an irregularly shaped cornea. This can be corrected with glasses, contact lenses, or refractive surgery. Refractive surgery works by shaving the cornea’s curve to reshape it. Refractive surgery is referred to as refractive keratoplasty; keratoplasty meaning “to mold the cornea.”
When a person suffers from a serious disorder or disease of the cornea, the obvious fear is that they will go blind. Sometimes the best course of action is a corneal transplant. This completely replaces the damaged or diseased cornea with a new one from a donor. They’ve become a common transplant in the U.S. with 40,000 of them performed every year.
Rather than replacing the entire cornea, lamellar keratoplasty replaces only the diseased Bowman’s layer and the anterior, or upper part of the corneal stroma with donor material. The epithelium needs to be removed to get to these layers, but will grow back. Or a flap can be created as in LASIK, which will heal on its own. Lamellar keratoplasty preserves Descemet’s membrane and the endothelium, as well as the deep stroma.
One of the concerns with a corneal transplant is rejection of the donor material. Because lamellar keratoplasty does not touch the endothelium, the threat of rejection is much smaller than that of a corneal transplant and more of your own eye is preserved. Ophthalmologists have greatly improved the techniques used in lamellar keratoplasty, which has improved the results.
If you are suffering from a corneal disease or corneal dystrophy, please contact an experienced ophthalmologist in your area to discuss lamellar keratoplasty as an alternative to a corneal transplant.