PKP (Keratoconus, Corneal Scarring)
Corneal transplants are one of the most common transplant surgeries performed in the United States. One of the reasons is that the donor tissue does not have to be typed / screened because there are no blood vessels in the cornea.
Corneal transplants PKP for Keratoconus or corneal scarring is a viable surgical option for certain patients. Our cornea is so integral to our vision that even a tiny scratch can damage our ability to see clearly. Regardless of how simple a scratch may be, an ophthalmologist should examine your eyes as soon as possible. Tiny scratches, infections, to severe damage can affect our ability to see and lead to the possibility of a cornea transplant.
Our Amazing Cornea
Before we discuss corneal transplants and why certain patients might need one, it would be wise to understand the importance of the cornea.
The cornea is the clear front surface of our eye and it is the window to the retina. Along with our natural crystalline lens it helps to focus light precisely onto the retina for clear vision. How well we see is dependent on the shape of the cornea and exactly where the light touches the retina. If it focuses light directly on the retina, we see clearly.
If the light focuses in front of or behind the retina, we are nearsighted or farsighted respectively. If a patient has astigmatism, or an irregularly shaped cornea, light focuses in multiple places and vision is always blurred. Patients can choose refractive surgeries like LASIK which alter the shape of our cornea enabling light to focus precisely on the retina. Glasses and contact lenses also serve to improve vision. Unfortunately, when our cornea is severely damaged or misshapen, then a cornea transplant may be recommended.
Symptoms of a Problem Cornea
The cornea like any other part of our bodies can be susceptible to disease. If it is not healthy, is severely misshapen, damaged, scarred, or swollen, your vision becomes distorted.
If vision can’t be improved with normal corrective lenses like glasses or contacts, then a corneal transplant may be the only way to restore your vision. This is especially true if normal everyday activities and one’s employment are negatively affected. A corneal transplant might be the only solution.
Other reasons for a corneal transplant:
- Scarring from infections
- Keratoconus where the cornea progressively thins and weakens creating a conical shape cornea
- Damage due to an eye injury or trauma
- Workplace injury or chemical burn
- Excessive swelling of the cornea
- Complications from previous surgeries
It is essential to find an experienced and trained corneal specialist like Dr. Lisa Marten. If you or someone you know is having an issue with their cornea, contact the eye specialists at South Texas Eye Institute.
Traditional Corneal Transplants PKP
Dr. Marten describes the Corneal Transplant Process
PKP, Penetrating Keratoplasty, is a surgical procedure to remove the diseased portion of the cornea and replace it with healthy donor tissue.
When tissue in the cornea is diseased, weak or scarred, a corneal transplant becomes an option. The diseased tissue is replaced with healthy tissue from a donor. Dr. Marten and South Texas Eye Institute requests tissue from the local eye banks in San Antonio or Austin with the exact specifications to match the recipient. The tissue must be cleared for any transmissible diseases like HIV or Hepatitis B or C and to prevent any possible donor rejection.
PKP stands for a full thickness cornea transplant or Penetrating Keratoplasty (PK). With this type of surgery a round button-shaped full thickness section of tissue is removed using a femtosecond laser or a round blade. This type of transplant is used to treat diseases which affect the full thickness of the cornea.
A matching button from the donor is placed in the exact position and soft sutures are used to keep it in place during healing. The entire procedure can take approximately 1 to 2 hours performed mostly on an out-patient basis. Eye shields protect the eye during the healing process. Patients can expect gradual improvement in their vision and it will continue over the next few months but it is a long process.
Healing after a Penetrating Keratoplasty corneal transplant can take a year or more. Although PKP for keratoconus is highly successful, patients should confer with their ophthalmologist about the benefits and risks of the surgery and decide if the benefits of improved vision balance out or outweigh any risks.
Do you Need a Corneal Transplant?
Patients will be slightly nearsighted and experience some astigmatism after corneal transplant surgery. Many times glasses or contact lenses will be needed for clear vision. Gas-permeable or rigid contacts seem to work best.
The doctors at South Texas Eye Institute regularly see patients with problem corneas and are trained to handle all types of corneal issues including treatment with PKP Penetrating Keratoplasty.
We are here to help if you or someone you know has questions about corneal transplant surgery.
DSEK (Fuchs Dystrophy)
Fuchs’ Dystrophy: Overview
Corneal Transplants DSEK for Fuchs’ Dystrophy
One of the newer transplant surgeries available to patients is a corneal transplant DSEK. It affords patients with Fuchs’ Dystrophy a faster healing time plus many other advantages over traditional corneal transplant surgery.
Of all organ transplant surgeries corneal transplants are the most common and they are very successful. This type of transplant surgery is different from the traditional PKP or Penetrating Keratoplasty.
Differences between Corneal Transplant Surgery PKP and DSEK
Whereas PKP is a full thickness corneal transplant, DSEK is a partial thickness corneal transplant. It replaces only the posterior or innermost layers of tissue with healthy tissue from a donor. It stands for Descemet Stripping Endothelial Keratoplasty.
These single layer of cells known as endothelial cells are important because they pump fluid out of the cornea to provide clear vision. If a critical amount of these cells is damaged, the cornea swells, thickens and becomes cloudy. Endothelial cells can become lost or damaged from aging, trauma or from a genetic disease like Fuchs’ Dystrophy.
Fuchs’ Dystrophy becomes progressively worse over time and it results in blurred vision. Only patients with endothelial cell loss are candidates for DSEK Endothelial Keratoplasty. Other specific issues like scarring and Keratoconus require the full thickness PKP Penetrating Keratoplasty.
With any corneal transplant surgery it is important to find a specially trained and skilled corneal specialist, like Dr. Lisa Marten.
Both are complex surgeries and require special care and management like those found at South Texas Eye Institute.
Advantages of DSEK
Endothelial Keratoplasty DSEK is a relatively new transplant surgery, but it has quickly become the standard of care for patients with Fuchs’ Dystrophy.
Among its advantages over standard corneal transplant surgery:
- DSEK takes less time to perform
- There is a smaller incision required
- Minimal or no stitches needed
- Less chance of infection or irritation
- Healing takes 2-6 months compared to a year with PKP
- Faster visual recovery time
Patients should expect their vision to be blurry for a few weeks as the cornea heals, and they will return for multiple follow up visits. As with all eye surgeries it is important to discuss with your doctor the risks and benefits of the procedure. If after treatment with medications and glasses or contact lenses vision has not improved, then surgical intervention may be the only other alternative. It is still unknown how the long term success rates with DSEK will compare with the traditional corneal transplant surgery. Each patient must decide whether the benefits of surgery outweigh all the risks.
You can be confident in the knowledge that South Texas Eye Institute has the most advanced diagnostic tools and treatment options for all corneal problems. Trust all your eye issues to the professionals at South Texas Eye Institute.