What is the Cornea?
The cornea is the front surface of the eye, functioning like a window for the eye. This five-layer transparent tissue has a large role in how the eye focuses. If the cornea is misshapen or opaque due to disease or injury, vision will become impaired. Common refractive issues arising from a misshapen cornea include: myopia (nearsightedness); hyperopia (farsightedness); and astigmatism. These common corneal issues can be corrected with contact lenses, glasses, or IntraLasik.
The cornea plays a major role in how you focus on images. In conjunction with your natural crystalline lens the cornea helps to provide required focusing power. If the cornea becomes weak or damaged serious visual problems may arise. Because the cornea is such an important part of your visual system, please make sure to contact the ophthalmologists of the Omaha Eye & Laser Institute if you think you might have damaged your cornea. Treating damaged or irregular corneas is something that is routinely done at our eye care office. Each damaged cornea requires special attention by our eye doctors. Typically we can start treating the cornea with medication. If your vision cannot be accurately corrected with medications, a corneal transplant may be required.
Your cornea is the clear tissue in front of your iris and pupil. Although it is completely clear, it actually has three layers. The cornea does not have blood vessels, relying on tears and the fluid behind your eye for nourishment. This is because the cornea needs to be completely clear for the best vision. When the cornea is damaged, obstructed or misshapen, this can affect vision. A misshapen cornea is a very common condition, and can affect vision in many ways. Common conditions such as myopia or astigmatism, in which the cornea is misshapen, can be corrected with glasses and contacts, and even laser surgery.
How does damage to the cornea occur?
Damage to the cornea may arise from various reasons such hereditary issues, chemical burns, blunt object trauma, viruses or bacteria. Conditions that may require a patient seek a cornea transplant involve, clouding of the cornea, keratoconus, fuchs dystrophy, irregular corneal surface tissue growths, or corneal swelling.
Can cornea problems be prevented?
Corneal infections caused by bacteria and viruses can be prevented by good hygiene and limiting contact with those who have contagious forms of conjunctivitis. Do not share eye makeup, contact lens cases, contact lens solution, and eye drops with people who are infected. Follow strict guidelines for contact lens hygiene to decrease the risk of corneal infections. Corneal disease resulting from hereditary factors, like dystrophies, cannot be prevented, but vision can be preserved with early detection.
One corneal disorder not easily corrected with glasses or contact lenses is keratoconus. Keratoconus is a disease causing gradual steepening of the cornea. As the disease progresses the cornea becomes more irregular and vision becomes compromised. The cause of keratoconus is unknown; however, genetics and excessive eye rubbing are thought to contribute. Keratoconus typically arises during puberty. While some patients are able to manage their keratoconus with specialty contact lenses, others with poorer resulting vision may require a corneal transplant. A corneal specialist will determine whether a patient is a good candidate for a corneal transplant (otherwise known as penetrating keratoplasty, or PKP).
Fuchs Endothelial Dystrophy
Another corneal disease that may require surgical treatment is Fuchs endothelial dystrophy. In Fuchs the back layer of the cornea (endothelium) is compromised, leading to an accumulation of fluid or edema in the cornea. This results in hazy, cloudy vision. Fuchs is a genetic condition that typically presents later in life. Early and mild cases of Fuchs can be treated with topical drops. These drops work by dehydrating the cornea and reducing corneal edema. If topical drops do not offer sufficient vision, a partial thickness corneal transplant (DSEK) may be considered.
PKP (Full thickness corneal transplant)
Corneal transplants are performed using a donor cornea. The entire central portion of the cornea is replaced and held in place with sutures. Because the cornea possesses no blood vessels, rejection rates are low in comparison to other types of transplants. Recovery, though, can be lengthy nonetheless, and requires frequent follow-up visits.
DSEK (Partial thickness Corneal Transplant)
DESK (Descemet’s Stripping Endothelial Keratoplasy) is a partial thickness corneal transplant. During this procedure only the back layer of the cornea (endothelium) is transplanted from a donor cornea. This tissue will replace the compromised endothelium and help restore vision. DSEK is a relatively new procedure and is done in place of a full thickness corneal transplant. Benefits of DESK include: fewer sutures; smaller incision; decreased risk or corneal rejection; improved healing time and visual prognosis.