Why transplanted cornea may be rejected

Although these complications occur rarely about 3 times in operations they have serious consequences and could make the vision worse after the operation than before.

Rejection of the graft can occur, especially in patients who have had injuries, or infections, or previous operations on the eye. The risk of rejection is to be assessed for each particular case. Should rejection occur, vision is usually poor and replacing the graft may need to be considered. Astigmatism is very common after corneal transplantation, and only when severe does it threaten the visual outcome.

Astigmatism occurs when the curvature of the grafted cornea is distorted. A minor degree is almost inevitable and can be overcome by the patient wearing spectacles or in some cases contact lenses. Occasionally, when astigmatism is more marked, a small corrective operation is required to correct the distorted corneal shape. Patients are advised to stop playing contact sports after corneal transplantation because the weakest part of the eye becomes the corneal graft scar.

Consequently any minor trauma such as a poke in the eye can result in rupture of the weak scar and damage to the graft. The operation is usually done at a time convenient to the patient and surgeon. Few corneal grafts are urgent. Corneal transplantation is most commonly done as an elective procedure.

This means that the operation is scheduled and the donor cornea is made available at a pre-arranged time. The Eye Bank of South Australia is within Flinders Medical Centre and is almost always able to supply a suitable eye for transplantation as arranged. Very occasionally, the operation may be delayed due to non-availability of a donor. Only the healthiest corneas from donors are used for transplantation.

This ensures that only the safest and best quality tissue is distributed to surgeons for transplantation. In spite of this, for reasons that are not entirely clear, a corneal graft may fail to function in less than one in cases.

Corneal transplantation can be done under general or local anaesthesia. Not all patients need to be put to sleep for surgery general anaesthetic. For the majority of patients a local anaesthetic is preferred. With a local anaesthetic, an anaesthetic solution is delivered by a blunt cannula around the eye to completely remove all movement and sensation. Whenever possible a local anaesthetic is preferable, however, young adults tend to be more apprehensive and are best done with a general anaesthetic, as are children.

No, surgery is usually done as a day procedure. In some cases the patient may be admitted overnight. All patients need to come back to see the surgeon on the day after surgery.

Not usually. There is always some discomfort after any operation but after a corneal transplant the discomfort is minimal. Be informed! If the transplanted cornea fails, the graft may be replaced with a new donor, usually with good results, but the overall rejection rates for repeated transplants are higher than for the first transplant.

After uncomplicated Corneal Transplantation, vision may continue to improve up to a year or more after surgery. All contributors:. Assigned editor:. Victoria Chang, MD. Graft rejection and graft failure after penetrating keratoplasty or posterior lamellar keratoplasty for fuchs endothelial dystrophy. Twenty-five-year panorama of corneal immunology: emerging concepts in the immunopathogenesis of microbial keratitis, peripheral ulcerative keratitis, and corneal transplant rejection.

Elsevier Mosby, , Primary corneal graft failure. A national reporting system. Arch Ophthalmol ; Long-term rejection incidence and reversibility after penetrating and lamellar keratoplasty. Am J Ophthalmol. Graft rejection episodes after Descemet stripping with endothelial keratoplasty: part two: the statistical analysis of probability and risk factors. Br J Ophthalmol ; Deep anterior lamellar keratoplasty as an alternative to penetrating keratoplasty a report by the american academy of ophthalmology.

O hthalmology ; Descemet's stripping endothelial keratoplasty: safety and outcomes: a report by the American Academy of Ophthalmology. Ophthalmology ; Factors Predictive of Corneal Graft Survival. Corneal Allograft Rejection: Immunopathogenesis to Therapeutics. J Clin Cell Immunol. Risk of corneal transplant rejection varies from low to high and depends on various factors. A recent study found that corneal transplant rejection occurs largely due to patients not using medications properly and consistently after surgery.

Corneal transplantation, or keratoplasty, is a surgery that replaces your poorly functioning cornea with a new donated one. It also helps focus light into your eye. Different medical problems can damage your cornea. They can make it cloudy and opaque or distort its shape. If this happens, your vision can be impaired. In some cases, corneal damage can even lead to blindness. If you have scarring or damage to your cornea, your vision can be impaired.

Your eye doctor may need to treat the underlying cause of the damage to your cornea. If the damage is severe enough, you might need corneal transplantation to restore your sight. Conditions that might require corneal transplantation include:.