WHAT IS A CORNEAL TRANSPLANT? THE CORNEA, THE CLEAR TRANSPARENT TISSUE COVERING OVER THE IRIS CAN BE affected by many different disorders, significantly diminishing vision. When the clarity of the cornea becomes opaque to the degree of causing vision loss or is severely impacted by disease, a corneal transplant (known as a keratoplasty) may be necessary to restore vision. A corneal transplant is the replacement of a damaged or diseased cornea (host cornea) by a donor cornea. Like organ transplants, the donor corneal tissue comes from a special bank, which receives donor tissue to save lives, and in this case, preserve vision. Unlike other transplants, the corneal graft does not need to go through extensive typing procedure in order to match donor and host. Donor corneal tissue is selected by factors such as the donor's age, cause of death, duration between the death and transplant, and the presence of donor eye disease, such as AIDS, syphilis or hepatitis, or previous eye surgery. In this procedure, a surgeon carefully removes the central cornea tissue that is damaged or diseased with an instrument called a trephine and replaces it with a precisely matched donor corneal graft. The donor graft is anchored to the surrounding host tissue by tiny hair-thin sutures. The surgery is performed with general or local anesthetic on an outpatient basis for most cases. > Return to top REASONS FOR RECEIVING A CORNEAL TRANSPLANT Corneal transplants are performed for the following reasons: Optical treatment To improve optical quality and enhance vision. Examples of conditions requiring optical treatment are replacing an opaque, scarred cornea or a cornea distorted by severe astigmatism due to keratoconus. Reconstructive treatment To reconstruct the anatomy of the cornea and preserve the eye, as in such cases where the cornea is perforated. Therapeutic treatment To preserve the eye by treating diseases that are unresponsive to medications or other forms of medical therapy. As example, therapeutic management may involve treating recurrent ruptured bullae in bullous keratopathy or a severe, uncontrolled fungal corneal ulcer. Common conditions for corneal transplantation are bullous keratopathy (as in diseases such as Fuch's dystrophy that cause endothelium cell loss), keratoconus, keratitis (viral, bacterial or fungal inflammation of the cornea causing perforation), corneal stromal dystrophies (degradation of the middle layer or stroma of the cornea) and regrafts. > Return to top RECOVERY The recovery period after a corneal transplant is long in that it takes adjustment time for vision to gradually return. After surgery, to prevent the eye from possible trauma (bumping, hitting or rubbing the cornea), shields are worn. Topical antibiotics are used for several weeks and topical corticosteroids for several months to reduce the possibility of infection or graft rejection. Strenuous activity such as lifting, bending or straining should be avoided for several weeks. Early in the postoperative stage, the surgeon can monitor the cornea shape through corneal topography, a computer mapping of the cornea, to control astigmatism (caused by sutures changing the cornea shape). By adjusting sutures or selectively removing sutures, the cornea shape can be controlled to avoid or reduce astigmatism. In some cases, patients may wear a rigid, hard contact lens over the corneal transplant to reduce astigmatism. Achieving full vision function can occur after surgery from six months to a year depending upon wound healing time, changing refraction and corneal astigmatism. > Return to top COMPLICATIONS Corneal transplant complications include possible infection (intraocular and corneal), graft rejection or failure, intraocular bleeding, glaucoma, high refractive error (astigmatism or myopia) and recurrence of disease, such as corneal stroma dystrophy. Medications such as antibiotics and corticosteroids, or careful monitoring with treatment adjustment can reduce or prevent complications such as these. Graft rejection is not uncommon. Symptoms such as photosensitivity, ocular ache or redness, and decreased vision can be an indication of rejection. Treatment with corticosteroids, ocular injections or occaisionally IV, may be used to reverse graft rejection. The graft may fail if the graft rejection is severe, endures for a long period of time or has multiple occurrences of rejection. Regraft is a possible solution. However, long-term prognosis for a regraft is lower than it was for the original graft. > Return to top PROGNOSIS The success rate of corneal transplant surgery varies according to your diagnosis and factors such as glaucoma, retinal degeneration or optic nerve disease, which may affect final vision. On average the long-term transplant success rate is about 85%-90% for conditions such as keratoconus, corneal scars, early bullous keratopathy, corneal stromal dystrophies or inactive viral keratitis. Active corneal infections and chemical or radiation injuries are much more difficult to treat for full vision restoration due to progressive inflammation or damage to other portions of the eye. Your ophthalmologist will consult with you about your specific condition and can assess more accurately your long-term prognosis based on the specific factors affecting your individual case. > Return to top Our Practice l Services l Publications l Map & Directions l Contact Us l Privacy Policy Cataracts l Cornea and External Diseases l Corneal Transplants l Refractive Errors Refractive Surgery l Optics All contents © copyright 2002-2004 Corneal Consultants of Colorado, P.C. All rights reserved. Development by Mindshare HDV. The basic reason for a transplant is loss of vision due to corneal opacification-- the inability to see through a diseased or damaged cornea. One of the risks of any transplant is the possibility of rejection. The body's defense system tries to destroy things that are not natural parts of itself, as such, it will attack the foreign corneal graft and may cause inflammation. Signs of rejection are loss of clarity and swelling. Often, corneal transplant rejection can be stopped with medication.