A cornea transplant, also known as keratoplasty, is a surgical procedure that replaces damaged or diseased corneal tissue with healthy tissue from a donor. This procedure aims to restore vision by replacing the cloudy or distorted cornea, the transparent front part of the eye that helps focus light. Cornea transplants are performed to address various conditions, including scarring, disease, or injury that impair vision.
What is a Cornea Transplant?
The cornea, a clear, dome-shaped layer at the front of the eye, is crucial for focusing light onto the retina and protecting the eye. A cornea transplant replaces damaged tissue with healthy tissue from a deceased donor. This procedure is performed when other treatments, such as glasses or contact lenses, are no longer sufficient to improve vision or alleviate pain. Donated tissue is carefully screened and evaluated for suitability.
Typical Lifespan by Transplant Type
The longevity of a cornea transplant varies depending on the type of procedure performed. Penetrating Keratoplasty (PKP), a full-thickness transplant where the entire cornea is replaced, has shown graft survival rates of approximately 90% at 5 years and 82% at 10 years. For specific conditions like keratoconus or Fuchs’ dystrophy, PKP grafts can have even higher 5-year and 10-year survival rates, reaching 97% and 90-92% respectively.
Descemet’s Stripping Endothelial Keratoplasty (DSEK or DSAEK) and Descemet’s Membrane Endothelial Keratoplasty (DMEK) are partial-thickness transplants that replace only the inner layers of the cornea. DSEK/DSAEK grafts have a reported 5-year survival rate of 93%. DMEK, which involves transplanting an even thinner layer of tissue, shows promising long-term results, with graft survival probabilities of 83% at 5 years and 79% at 10 years. These newer partial-thickness procedures generally offer faster visual recovery and lower complication rates compared to full-thickness transplants.
Factors Influencing Transplant Longevity
Several factors influence how long a cornea transplant remains clear and functional. The underlying eye condition plays a significant role; for example, keratoconus and Fuchs’ dystrophy often have better graft survival rates than extensive corneal scarring or inflammation. Patient age and overall health also impact longevity, as younger patients may have a more robust immune response, potentially increasing rejection risk.
Adherence to post-operative immunosuppressants is important for preventing donor tissue rejection. Regular follow-up appointments allow ophthalmologists to monitor graft health, detect early complications, and adjust treatment. Donor tissue quality, including its endothelial cell density, also contributes to long-term success.
Recognizing and Addressing Complications
Complications can arise after a cornea transplant, potentially affecting its longevity. Graft rejection is a primary concern, occurring when the recipient’s immune system identifies the donor cornea as foreign. Symptoms include redness, blurred vision, and light sensitivity. Early diagnosis and treatment, often with steroid eye drops, can reverse rejection and prevent permanent graft failure.
Other complications include infection, increased intraocular pressure (glaucoma), and recurrence of the original disease. Infections, though rare, can be severe and require immediate antibiotic treatment. Glaucoma, characterized by increased eye pressure, can damage the optic nerve. If a transplant fails due to these, re-transplantation is often a viable option to restore vision.