Corneal Transplant - DSAEK
The cornea is the clear covering of the front of the eye which bends, or refracts, light rays as they enter the eye. For clear vision to occur, the cornea must have the correct shape and clarity to focus incoming light rays precisely on the retina at the back of the eye. When the cornea becomes cloudy or misshapen from injury, infection or disease, transplantation may be recommended to replace it.
There are several different corneal transplant procedures available to help restore vision in patients with corneal problems. The traditional corneal transplant procedure involves replacing the entire damaged cornea with a healthy one from a human donor, which is usually obtained from an eye bank. However, technological advances have allowed for the development of specialized procedures that replace only the damaged part of the cornea, while leaving the healthy parts intact.
Short for Descemet's stripping and automated endothelial keratoplasty, DSAEK replaces only the innermost layers of cells within the cornea, known as the endothelium. This allows the procedure to be performed through a much smaller incision with shorter recovery times and fewer risks than a traditional corneal transplant.
Candidates for DSAEK
DSAEK is commonly performed on patients with Fuchs' Dystrophy, an inherited eye disease that causes the cells of the endothelium to deteriorate, resulting in distorted vision and corneal swelling. As this condition progresses, vision will continue to worsen as damaged cells cannot grow back.
During the DSEAK procedure, your surgeon will make an incision in the sclera, the white part of the eye. This incision allows the surgeon to access the cornea and removed the damaged endothelial tissue using a microkeratome blade, the same instrument used during LASIK surgery. The donor tissue is then folded and implanted on the eye and the incision is closed with a single stitch.
After the donor tissue has been placed, it will either unfold on its own or be unfolded by the surgeon. Another stitch will then be used to secure the new cornea in place, while an air bubble is injected to properly position it. This procedure is performed with a topical anesthetic to minimize any potential discomfort. The actual DSAEK procedure only takes about 20 to 30 minutes to perform, although patients should plan on being at the surgical facility for about two hours.
Recovery from DSAEK
After the DSAEK procedure, patients will be moved to a recovery room, where they will be monitored for about an hour before being able to go home. Your doctor will prescribe antibiotic and steroid eye drops to be used for the next few days as the eye heals. You will need to return to your doctor the next day for a follow-up appointment as well.
Most patients notice improvements to their vision within the first two weeks after surgery, with results continuing to develop during the next four to six weeks. This is significantly faster than the traditional corneal transplant procedure, which may take six to 12 months before effective results are achieved. Other existing eye conditions may slow or hinder the improvement of vision after the DSAEK procedure.
Risks of DSAEK
While the DSAEK procedure is considered safe for most patients with cornea damage, there are certain risks involved with any type of surgical procedure, including infection, bleeding and more. Although rare, there is a risk of transplant rejection, which may result in redness, sensitivity to light and blurred vision. If you are experiencing these or any other symptoms after DSAEK, you should contact your doctor to prevent any damage from occurring.
To learn more about the DSAEK corneal transplant procedure, and to find out whether or not this procedure is right for you, please call us today to schedule a consultation with one of our experienced doctors.
Keratoconus is a progressive eye disease in which the normally round cornea thins and begins to bulge into a cone-like shape. The cornea is the clear, central part of the surface of the eye. In patients with keratoconus, the cone-shaped cornea deflects light and causes distorted vision.
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Causes of Keratoconus
Although many theories have been proposed, there is no definite known cause of keratoconus. Possible causes include genetics, a collagen deficiency, overexposure to ultraviolet (UV) rays from the sun, or excessive eye-rubbing.
Sign and Symptoms of Keratoconus
Keratoconus often begins to develop in the teen years to the early 20s, although it can develop at any age. Changes in the shape of the cornea occur gradually, usually over several years. In most patients with keratoconus, both eyes eventually become affected.
Keratoconus can be difficult to detect because it usually develops very slowly. Signs of keratoconus may include:
- Distorted and blurred vision
- Myopia (nearsightedness)
- Double vision
- Headaches due to eye strain
- Light sensitivity
Your doctor will measure the curvature of your cornea to determine whether these symptoms are a result of keratoconus.
In the early stages of keratoconus, glasses or soft contact lenses may help to correct the nearsightedness and astigmatism associated with the disease. As the condition progresses and the cornea becomes increasingly thin, more advanced treatment is required.
- Rigid Gas-Permeable Contact Lenses – If eyeglasses or regular soft contact lenses cannot control keratoconus, rigid gas-permeable (RGP) contact lenses are usually the preferred treatment. The rigid lens covers the cornea, replacing the cornea's irregular shape with a smooth, uniform refracting surface, improving vision.
Rigid contact lenses can be less comfortable to wear than soft lenses. Further, fitting contact lenses on a cornea with keratoconus can be challenging and time-consuming. If you are using RGP contact lenses, you will need to visit your doctor frequently to fine-tune the fit and prescription of the lenses, especially if your keratoconus continues to progress.
- INTACS – INTACS are plastic rings inserted into the mid-layer of the cornea to flatten it, changing the shape and location of the cone. INTACS may be needed when the distorted vision from keratoconus can no longer be corrected with contact lenses or eyeglasses. The implants are removable and exchangeable. If the keratoconus continues to progress, however, INTACS can only delay the need for a corneal transplant, not prevent it.
- Collagen Cross-Linking – Collagen cross-linking is a relatively new method for treating keratoconus. It works by strengthening the corneal tissue to stop it from bulging. In this procedure, eye drops containing riboflavin (vitamin B2) are applied to the cornea and then activated by ultraviolet light. This strengthens the collagen fibers within the cornea.
Penetrating Keratoplasty (PKP)
An improperly curved cornea may be corrected surgically for patients whose curvature is too steep or flat to be treated with other methods, or when extensive damage has occurred due to disease, infection or surgery. Corneal transplantation, also known as keratoplasty, may be performed in patients with:
- Dry eyes
- Corneal ulceration
- Corneal dystrophies
- Traumatic injury
Penetrating keratoplasty (PKP) involves replacing the entire thickness of the cornea with a donor graft. The new cornea is stitched into place, and stitches are usually removed after a year. It may take this long for vision to be restored to satisfactory levels as well, requiring many patients to wear glasses or contact lenses after this procedure.
As with any type of surgical procedure, there are certain risks associated with PKP, including bleeding, infection, graft rejection and astigmatism. With the development of technological advances, PKP is performed less and less often. Your doctor will determine whether or not this procedure is right for you after a thorough evaluation of your eyes and any pre-existing conditions.