The cornea is the clear front surface of the eye. It lies directly in front of the iris and pupil, and it allows light to enter the eye. It also serves to protect the eye from the environment and helps filter out some of the sun’s most damaging ultraviolet (UV) rays.
In order to function properly and provide the best vision, the cornea must remain healthy and clear. When the cornea is damaged either by injury, disease or due to hereditary conditions, it may become swollen or scarred. These scars may cause the cornea to scatter or distort light, resulting in reduced vision, sometimes to the point of blindness. If the cornea becomes cloudy or distorted, the only way to restore sight may be a corneal transplant.
Common Corneal Issues
A scratched cornea can be very painful and can lead to an eye infection.
A chalazion is a fibrous growth that starts on the outer sclera of the eye but can encroach upon the cornea, causing irritation, vision problems and disfigurement of the front of the eye.
Though the cause of dry eyes typically begins in the tears gland and eyelids, it can lead to damage of the corneal epithelium, which causes eye discomfort and vision disturbances.
A corneal ulcer is a serious abscess-like infection of the cornea that can lead to significant pain, scarring and vision loss.
A dystrophy is a weakening or degeneration of a tissue. The most common corneal dystrophy — called Fuch’s dystrophy — affects the corneal endothelium, causing corneal swelling, foggy vision, light sensitivity and other problems.
This is a very serious and painful corneal infection that can cause significant pain and vision loss.
This is another dangerous corneal infection that (like Acanthamoeba keratitis) tends to affect contact lens wearers more often than people who wear glasses.
This is a thinning and deformation of the cornea that causes vision problems that can’t be corrected with regular eyeglasses or contact lenses. In some cases, vision problems from keratoconus can be corrected with scleral contact lenses or hybrid contacts. But in severe cases, a cornea transplant may be required.
This is thinning and deformation of the cornea that resembles keratoconus but occurs as a rare complication of LASIK or other corneal refractive surgery.
Advances in Corneal Transplantation
There are two types of corneal transplantation: full thickness and partial thickness. With a full thickness transplant, the diseased cornea is removed and a full thickness donor cornea is sutured into place.
When the corneal disease is limited to the “endothelium” layer of the cornea, as in Fuchs dystrophy, a hereditary condition, Dr. Pierson may recommend a DSAEK (Descemet’s Stripping Automated Endothelial Keratoplasty) transplant. DSAEK is a partial thickness corneal transplant that replaces only the diseased posterior layer of the cornea (the endothelium). This procedure is performed through a smaller incision and involves stripping away the damaged endothelium tissue and replacing it with a thin disc of healthy donor endothelium tissue. Because of the smaller incision, many people experience improvement in their vision within weeks and sutures may not be required.