Keratoplasty, or corneal transplantation, is performed when the curvature of the cornea (the transparent covering on the eye’s anterior wall) is too steep or too flat to be treated with other methods, when extensive damage has occurred due to injury or disease, or when a tumor is present. Traditional keratoplasty is a procedure that removes and replaces the cornea with donor tissue. In recent years, less invasive procedures, which remove only selected portions of corneal tissue, have also been perfected.
Reasons For Keratoplasty
The most common reason for performing a keratoplasty is to improve diminished vision. More rarely, the surgery is performed to treat a chronic corneal infection. In extremely rare cases, the operation is performed for cosmetic reasons, when corneal scars have affected the appearance of the eye.
Other conditions that may require a corneal transplantation include:
- Corneal scarring
- Inherited corneal disorders, like Fuchs’ dystrophy
- Infections of the eye
- External tumor or pterygia
- Irreversible cornea edema
- Corneal ulceration or erosion
- Corneal thinning or perforation
Types Of Keratoplasty Procedures
Keratoplasty is a relatively low-risk surgical procedure. It is the most common type of transplant surgery currently performed and has the highest rate of success. There are several different corneal transplant methods available to help restore vision in patients with corneal problems.
Penetrating keratoplasty is the traditional method used for corneal transplantation where the central two-thirds of the damaged cornea is surgically removed and replaced with a healthy cornea from a human donor.
Deep Anterior Lamellar Keratoplasty
Deep anterior lamellar keratoplasty, also known as DALK, removes only the outermost layers of the cornea, while preserving the healthy, well-functioning inner layers, known as Descemet’s membrane and the endothelium. New laser technology used in a DALK procedure reduces the likelihood of scarring or irregularities in shape that might impair vision.
Endothelial keratoplasty, of which there are several types (DSAEK, DSEK and DMEK), is a surgical procedure that removes the abnormal inner lining of the cornea, known as the endothelium. Endothelial keratoplasty requires much smaller incisions than a penetrating keratoplasty, resulting in fewer risks and a shorter recovery time.
The Keratoplasty Procedure
Corneal transplants are usually performed with patients under local anesthesia. While there is some chance of graft rejection or the failure of donor tissue to attach properly to the patient’s own tissue, in the less invasive procedures, this risk is greatly reduced. In these less invasive, shorter surgeries, there is also less scarring and a shorter recovery period.