What is the Cornea?
The cornea is the natural, transparent lens located at the front of the eye – a dome shaped surface that covers the iris, pupil, and anterior chamber where a second internal lens exists. The cornea has fixed focusing capabilities just like a contact lens. It is commonly referred to as the window into the eye. Light is focused while passing through the cornea, delivering an image to the retina, so you can see. The cornea also helps shield the eye from harmful matter such as dust, germs and debris. If the cornea is damaged, it may become swollen or scarred. Scars, swelling or an irregular shape cause the cornea to scatter or distort light, resulting in glare or blurred vision.
The cornea is the only part of a human body that has no blood supply; it gets oxygen directly through the air. If the cornea is scratched or irritated it can be a very painful experience. Amazingly, the cornea is the fastest healing tissue in the human body, thus, most corneal abrasions will heal within 24-36 hours. However, there are conditions and diseases that may impact the cornea. These conditions may require medical or surgical treatment if ignored.
Please contact The Eye Institute for more information on corneal conditions and treatment options, or to schedule an appointment.
Diseases Related to the Cornea
A pterygium is a fleshy tissue that can grow over the cornea of the eye. What causes a pterygium to develop is not certain, although it’s thought to be linked to long term exposure to sunlight or dry, dusty conditions. If the pterygium grows toward the central cornea, it may need to be surgically removed. It is a good idea to protect your eyes with sunglasses if you will be in the sun, or goggles if you’re in a dusty, dry environment.
Dry Eye is a condition where the eyes are incapable of producing enough tears to properly lubricate the eyes. Tears are important in maintaining clear vision by keeping the eyes lubricated, reducing the risk of infection, washing away foreign objects, and by keeping the eyes smooth and clear. Dry Eye is a common and often chronic condition, particularly common in older adults.
Symptoms of dry eye include redness, burning, grittiness, pain, excess watering or blurred vision. Dry eye can be treated with artifical tears, RESTASIS®, punctal plugs, LipiFlow® or IPL therapies among other treatments.
When one or more parts of the cornea lose their normal clarity due to cloudy buildup, a condition called corneal dystrophy can occur as a result. More than 20 corneal dystrophies exist that affect all parts of the cornea. These diseases are often inherited, affecting both eyes, and are not caused by external factors such as injury or diet. Most progress gradually over time and some can cause serious visual impairment, while others cause no visual problems. Some of the most common corneal dystrophies include: Fuchs’ dystrophy, keratoconus, lattice dystrophy and map-dot-fingerprint dystrophy. Treatment options for dystrophies include corneal transplant surgery such as DSEK or PKP, or Intacs® surgery for patients with keratoconus.
Keratoconus is a progressive eye disease that causes the cornea to become thinner, resulting in deteriorated vision. The eye’s cornea is typically spherical; however, keratoconus results in the cornea taking on a cone-like shape. While eyeglasses can help individuals see clearly during the early stages of keratoconus, vision will likely become more distorted as the disorder advances, often requiring surgical treatment. Intacs® (described below), and other procedures available at our practice have proven very effective at treating keratoconus. Our cornea specialists, Dr. Darcy Wolsey and Dr. Zachary Zavodni, also participate in corneal cross-linking clinical studies to treat keratoconus patients.
Treating Corneal Disease
Corneal disease is a serious condition that can cause clouding of the cornea, visual distortions, and eventually blindness. At The Eye Institute of Utah, our eye doctors routinely check for corneal disease by examining your eyes with powerful microscopes. Dr. Darcy Wolsey specializes in the diagnosis of advanced corneal disease, routinely performing surgical treatments such as DSEK, PKP and Intacs® to fight corneal diseases.
Corneal Transplant Surgery
If the cornea becomes cloudy as a result of corneal disease, the only way to restore sight may be surgery. Corneal tissue for transplants comes from a donor. With a full thickness transplant, the diseased cornea is removed and a full thickness donor cornea is sutured into place. This procedure is called Penetrating Keratoplasty, or PKP. Return of best vision may be recognized in three or four months, while for some patients it may take up to a year. Descemet’s Stripping Endothelial Keratoplasty, or DSEK, is a relatively new surgical technique that can help some patients who previously required a full thickness corneal transplant. Both surgical procedures require the use of a donor cornea, but DSEK replaces only the diseased posterior section of the cornea called the endothelium. First, the damaged endothelium is removed from the diseased cornea and the healthy endothelium is removed from the donor’s cornea. The healthy endothelium is then placed inside the eye where it is held in place by an air bubble. With DSEK, many people experience improvement in their vision within weeks and there is no need for sutures.
In the past, patients with keratoconus (described above) had to receive a corneal transplant; however, the advanced Intacs® procedure can offer some patients an alternative to corneal transplantation. Intacs® corneal implants are designed for keratoconus patients to help correct nearsightedness and astigmatism. During this procedure, two tiny plastic corneal implants are placed into the cornea that subtly change the curvature of the eye, resulting in normal vision. Intacs® can be replaced with a different size if an adjustment is needed in the future.
For more information on our corneal disease treatments, or to schedule an appointment here at our practice, please contact The Eye Institute today.