Corneal Transplant or Keratoplasty or Penetrating Keratoplasty
Definition:
A cornea transplant or keratoplasty is a surgical procedure that replaces the diseased or scarred corneal tissue with healthy corneal tissue from an organ donor.
Cornea is a transparent, dome-shaped surface of the eye that is responsible for clear vision. Any abnormality in the healthy cornea can lead to scattering or distorting of light and causes glare and blurred vision. In such cases, corneal transplant is required to restore or improve vision.
Conditions that require Corneal Transplant:
Corneal transplant is generally required in those patients whose cornea is either damaged or diseased. The damaged cornea causes complete or partial loss of vision and patient finds it difficult to see anything even in day light. There are so many conditions that may require transplantation of cornea to restore vision and ease patient’s discomfort.
- Trauma or injury to the cornea
- An outward bulging cornea (keratoconus)
- Fuchs’ dystrophy
- Thinning of the cornea
- Cornea scarring (caused by infection or injury)
- Herpes keratitis
- Clouding of the cornea
- Swelling of the cornea
- Chemical burns of the cornea
- Corneal ulcers
- Eyeglasses or contact lenses can’t restore functional vision
- Graft rejection following a previous corneal transplant
- Complications caused by previous eye surgery
Corneal Transplant Surgery Options
There are following main types of corneal transplants:
- Traditional, full thickness cornea transplant also known as penetrating keratoplasty, or PK, involves replacement of a circular central portion of the diseased cornea with matching circular central portion of healthy, clear donor cornea using sutures.
- Back layer cornea transplant also known as endothelial keratoplasty, or EK, involves the replacement of the abnormal inner lining of the cornea with a thin disc of donor tissue containing the healthy endothelial cell layer.
- Lamellar corneal transplant procedure, involves replacement of the superficial layers of the cornea with donor tissue.
The procedure is performed either under local or general anaesthesia, depending on the health, age, eye injury or disease of the patient.
After the procedure, patient is required to follow all the instructions given by the eye surgeon to minimize corneal transplant complications and expedite healing.
Advantages of corneal transplant
- Restored vision
- Improved visibility
- Reduced pain and other symptoms of the disease
- Improved appearance of a damaged or diseased cornea
Risks associated with corneal transplant
Although it is a very safe procedure nowadays due to growing advances of technology used in this surgery, but there are certain risks associated with this that includes:
- Infection in the eye
- Cataracts
- Glaucoma
- Suture complications
- Corneal swelling
- Bleeding
- Loss of vision
- Most important is the risk of rejection of the donor cornea
Cornea rejection
Although most of the cornea transplant procedures are successful, but cornea transplant carries a small risk of complications, such as rejection of the donor cornea by patient’s immune system. The major signs and symptoms of corneal rejection are:
- Loss of vision
- Pain
- Redness
- Sensitivity to light
Corneal rejection may occur in about 20% of the cases of corneal transplant. It may occur immediately after the surgery or can take years to show its signs and symptoms. Although it can be managed with medication but some cases may also need another transplant. A routine follow up and examination with your eye surgeon can save your vision and keep the cornea healthy.
Vision after a Cornea Transplant
After corneal transplant, there can be initial worsening of vision that is because of the eye adjusting to the new cornea. It may take several months for the cornea to heal and vision to improve. After corneal healing, following may be required to further improve patient’s vision:
- LASIK eye surgery
- Eye glasses or contact lens to settle myopia (near-sightedness) and astigmatism
Results of Corneal transplant
- Improved vision
- Reduced eye pain
- Improved appearance of a damaged or diseased cornea
- Improved functioning of the cornea
Prognosis of corneal transplant
Prognosis of corneal transplant is very good and patient experiences good vision recovery. Vision may recover immediately after the surgery or full recovery of eyesight may take up to a year. A successful corneal transplant will give good vision to the patient for many years.
Patient may need to wear glasses or contact lens to achieve best vision.
Patient with any other eye problem may still have vision loss after corneal transplant due to these conditions.
