The cornea is the eye's outermost layer. It is the clear, dome-shaped surface that covers the front of the eye. The main function of the cornea is to allow light to pass through the eye to the retina. For this reason the cornea must be transparent. A second chief function is to help focus light, like a camera lens.
Health of the cornea depends on a number of factors, including the health of the conjunctiva and of the eyelids. The conjunctiva is the tissue which covers the front part of the eyeball (but not the cornea) and lines the back of the eyelids. Both the conjunctiva and the eyelids contain glands which make tear fluid. Tear fluid is an essential part of the systems which maintain the health of the cornea.
Diseases of the cornea can cause distorted vision or even loss of vision. Keeping the cornea healthy is a vital part in protecting your vision and the health of your eyes.
Cornea transplants are typically performed in cases where non-surgical options have been exhausted, and when non-transplant surgical alternatives are inadequate. Corneal transplants can be performed under local or general anesthesia, depending on each patient. After the anesthetic is given, Dr. Shah will remove the diseased portion of the cornea and will replace it with new corneal tissue. Corneal donor tissue is obtained through a national eye-banking system that processes donor tissue, including assessment of quality and suitability, and comprehensive testing for infectious disease. For conventional transplants, corneal sutures are used, and generally remain in place for many months. Routine exams are required to monitor the healing process. During this phase, use of eye drops is essential to regulate healing, and success generally depends on their regular use as prescribed. It is important to understand that healing can be a lengthy process.
Many people wonder about the risk of a cornea transplant failure. The good news is that corneal transplants are generally successful, and more so than any other organ transplant. Individual prognosis however depends on the reason for the transplant, and the individual patient’s condition.
A new kind of corneal transplant, known as Descemet's Stripping Endothelial Keratoplasty (DSEK), has been introduced for treatment of corneal disease that is confined to the inner layers of the cornea, including Fuchs’ Dystrophy and some cases of cataract surgery complications. This technique employs only a very thin portion of the donor’s cornea for transplant. When appropriate, this procedure has substantial advantages over a full cornea transplant.
In DSEK, Decemets Membrane and the endothelial lining of the cornea are removed through a small incision in the eye and replaced with a small disc of donor cornea bearing this important cell layer. The replacement of the diseased endothelial cells allows the cornea to once again become clear by restoring more normal function. In comparison to conventional full-thickness transplants, recovery after DSEK is more rapid - the cornea may be greatly cleared within 4 to 6 weeks after the procedure. Please contact Dr Shah to learn more about this procedure.
We see through the cornea, which is the clear, central part of the front surface of the eye. Normally, the cornea has a dome shape, like a ball. Sometimes, however, the structure of the cornea is just not strong enough to hold this round shape and the cornea bulges outward like a cone.
What Causes Keratoconus?
Tiny fibers of protein in the eye called collagen help hold the cornea in place and keep it from bulging. When these fibers become weak, they cannot hold the shape and the cornea becomes progressively more cone shaped.
The changes in the shape of the cornea can happen quickly or may occur over several years. The changes can result in blurred vision, glare and halos at night, and the streaking of lights.
New Scleral Contact lenes have been introduced to help treat Keratoconus.
The lens is shaped to remain completely above the cornea, without touching it at all; the outer edges of the lens rest on the sclera (the white part of the eye). The space between the lens and the cornea is filled by tears. This provides comfort as well as a smooth optical surface that corrects vision problems. Please make an appointment with Dr. Shah to learn more.
People with pterygium have a growth of pink, fleshy tissue on the white of the eye. The growth usually forms on the side closest to the nose and grows toward the center of the eye. It affects people who are outdoors a lot, exposed to wind and sun without UV protection, and/or people with Dry Eye symptoms left untreated.
Pterygium is a noncancerous lesion that usually grows slowly throughout life. It may even stop growing after a certain point. In advanced cases, a pterygium can continue growing until it covers the pupil of the eye and interferes with vision. A pterygium may affect one or both eyes. When it affects both eyes, it is called a bilateral pterygium. Pterygium is usually not a serious condition. It can, though, cause annoying symptoms such as the feeling of having a foreign body in the eye. Sometimes the growth becomes red and irritated and requires medical treatment.
If the Pterygium causes persistant discomfort, or interferes with vision, it can be surgically removed with an outpatient procedure.