Lawrence Eye Care is now offering cornea transplantation surgery and cornea care exclusively in Lawrence!
Cornea transplantation replaces the diseased layers of the cornea to create an optically clear window for your eye for better vision. Different types of cornea surgery are indicated based on the cornea problem. Please see below for more detail.
What is the cornea?
Your cornea is the outermost part of your eye and covers your iris, pupil, and anterior chamber. It is often called the windshield of your eye since it covers the front of your eye and needs to be clear for good vision. The cornea helps to refract light and focus it onto the back of the eye to help you see, and it makes up for two-thirds of your eye’s total optical power. If the cornea loses its clarity due to various processes like Fuchs’s dystrophy, keratoconus, infections, swelling, or scarring, then it is like seeing through a cloudy windshield and worsens the vision.
What is cornea transplantation?
Cornea transplantation is replacing the diseased, cloudy layers of the cornea with a new clear cornea. Depending on the cause, a full thickness or partial thickness cornea transplantation is performed to replace the damaged layers with healthy ones. The new corneas are supplied by the local eye bank.
Corneal transplants are very common in the United States; over 50,000 are performed each year. While success rates may vary due to pre-existing conditions in your eye, technological advancements have increased your chance of success. Approximately 90% of corneal transplants are successful, and the new cornea will stay healthy for an average of 10 years. In the unlikely event that your surgery is not successful, or if your cornea does become cloudy again, you can always receive another transplant.
Full thickness cornea transplantation (PK)
If all layers of the cornea are cloudy or damaged, then a full thickness transplant called a penetrating keratoplasty (PK) is needed. During the corneal transplant surgery, Dr. Farhat will remove about an eight-millimeter central portion of the cloudy or damaged cornea and replace it with a new, clear one. Your new cornea will often come from an eye bank after being screened for suitability and infectious diseases. Your surgeon will place the brand new cornea in the opening left from removing the old cornea and secure it in place with a very fine suture. These tiny sutures will remain in your eye for a few months while the eye heals, and then will be removed easily and gradually during visits to our office.
Your surgeon will prescribe you eye drops to use after surgery to help your eye heal and to prevent infection. Your vision will be blurry at first due to stitches and post-operative swelling, but most people are able to return to work and daily life about a week after surgery. Full visual recovery can take up to a year, and it is vital that patients take their medication as directed, keep follow-up appointments and pay close attention for any increased redness, discharge, sensitivity to light, pain or blurring. This can be an indication of transplant rejection and should be reported to our office immediately so that we may be able to reverse the condition.
Partial thickness cornea transplantation
If only specific layers of the cornea are damaged, then we often only need to replace specific layers of your cornea, which longterm decreases the risk of rejection and potentially better vision. Three types of partial thickness cornea transplantation exist including DSAEK, DMEK, and DALK.
Endothelial Keratoplasty (EK/DSAEK)
Endothelial Keratoplasty (EK), also known as Descemet Stripping Automated Endothelial Keratoplasty (DSAEK), is a newer method of corneal transplantation and only involves replacing some of the posterior or inner layers of the cornea, instead of its full thickness as in standard corneal transplantation. For this reason, if your disease affects the full thickness of the cornea, you are not a candidate for EK.
While EK is a relatively new surgery, and therefore hasn’t been studied as thoroughly as the standard procedure, there are many advantages. Compared to the standard transplant procedure, your surgeon can make a smaller incision in the eye so fewer stitches are needed. Your recovery is drastically shortened with the eye healing in 3-6 months, as opposed to a year. Your eye will have less chance of injury during surgery, and with fewer stitches there is less chance of infection.
Descemet Membrane Endothelial Keratoplasty (DMEK)
A Descemet membrane endothelial keratoplasty (DMEK) is very similar to DSAEK, except that the implanted donor tissue does not include any stromal tissue. A DMEK is an exciting option to treat decreased vision and swollen cloud corneas, such as in Fuch’s dystrophy, and it is a pure replacement of endothelium. There are three generations in the evolution of corneal transplantation and DMEK is the third and newest. DMEK is the most anatomical repair of the three generations of corneal transplantation with just one cell layer and a thin membrane, all of which is only 15 to 20 microns thick.
During DMEK surgery, the diseased innermost layer of the cornea is removed and the thin layer from a healthy donor cornea is put in its place. The transplant is then held in place by only an air bubble. Patients will be required to lay flat on their backs with their faces directed upwards immediately after surgery to float the bubble into place. DMEK has been shown to offer patients the best chance to see 20/25 and resume their daily activities quickly.
Deep Anterior Lamellar Keratoplasty (DALK)
Deep Anterior Lamellar Keratoplasty (DALK) is an additional newer method of corneal transplantation. It only replaces the superficial layers of the cornea, so there is less risk of damage to the eye. You are a good candidate if you have a disease that only affects the outermost layers of the cornea, like keratoconus. Because this procedure is extremely technical, the success rate is approximately 75%. Fortunately, if the cornea does not divide optimally at the time of the procedure, a full-thickness keratoplasty remains an option to rehabilitate vision. The advantages to DALK include greater structural integrity of the eye and decreased chance of rejection.
Eyeglasses have been a traditional solution for correcting vision problems for many centuries. When contact lenses arrived on the scene, they offered a new practical solution for restoring vision. Now an increasing number of eye surgery options have displaced glasses or contacts as the only solutions for healthy vision.