What is the Cornea?
The cornea is a dime-sized clear tissue that is the front of the eyeball. It is the eye’s outermost layer, normally invisible when viewed straight on. The cornea is a clear, dome-shaped surface that covers the front of the eye, much like a watch crystal or “window” of the eye. It helps direct light rays towards the lens for focusing, and allows light to pass through it to reach the back of the eye.
In order for vision to be clear, the cornea must be clean and clear. Corneal disease can cause the cornea to become opaque or cloudy, preventing light from passing through clearly. Corneal scars, scratches, surface roughness, and irregular curvature will distort vision, and are frequently associated with sensitivity to light (photophobia).
Corneal health 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 eye (but not the cornea) and lines the back of the eyelids. Both the conjunctiva and the eyelid contain glands that create the tear film, which is essential to the maintenance and overall health of the cornea.
Diseases and conditions affecting the cornea can cause distorted vision or vision loss. Keeping the cornea healthy is a vital aspect of protecting your sight and the health of your eyes. Dr. David O’Day is an experienced, board certified ophthalmologist who has been specially trained in treatment of cornea diseases and injuries.
As a cornea specialist, Dr. O’Day utilizes the latest techniques and advances in the field to treat simple and advanced problems caused by disease, genetic predisposition, injury or aging to the structures in the outer most layer of the eye, the cornea. Dr. O’Day offers the widest possible range of treatment options for each patient’s unique conditions.
Corneal Crosslinking (CXL)
Corneal Cross Linking is a procedure performed to treat ocular conditions where the cornea becomes weakened or starts to degenerate. One of the most common issues that Corneal Cross Linking is used to treat is keratoconus, a degenerative disorder that causes structural changes to the shape of the cornea. In a healthy cornea, the epithelial tissue has a natural gradual curve. In an eye affected by keratoconus, however, the cornea becomes thinner and takes on a more pronounced conical shape.
A corneal transplant is recommended for a patient whose cornea is damaged due to disease, infection, or injury. Common indications for corneal transplantation include but are not limited to the following:
- Corneal edema (swelling)
- Corneal ulcers
- Corneal dystrophies – Fuchs’ Dystrophy
- Traumatic injury
A full thickness corneal transplant (Penetrating Keratoplasty) involves the replacement of the damaged cornea with a healthy donor cornea (obtained through an eye bank). There is a 90% success rate for full-thickness corneal transplants in patients with non-infectious causes.
During the procedure, a circular incision is made into the cornea. A segment of the diseased corneal tissue is removed and replaced with healthy tissue that is sutured into place. Depending on the patient, local or general anesthesia may be used. The procedure time can range between 30-90 minutes.
A partial corneal transplant replaces only the damaged portion of the cornea, leaving the remainder of the cornea intact. Descemet’s Stripping and Automated Endothelial Keratoplasty (DSAEK) replaces only the innermost layers of the cornea. This allows the procedure to be performed through a much smaller incision with shorter recovery times and fewer risks than a traditional corneal transplant.