In corneal transplant, also known as keratoplasty, a patient's damaged cornea is replaced by the cornea from the eye of a human cadaver. This is the most common type of human transplant surgery and has the highest success rate. Eye banks acquire and store eyes from donors to supply the need for transplant corneas.
Corneal transplant is used when vision is lost because the cornea has been damaged by disease or traumatic injury, and there are no other viable options. Some of the conditions that might require corneal transplant include the bulging outward of the cornea (keratoconus), a malfunction of the cornea's inner layer (Fuchs' dystrophy), and painful corneal swelling (pseudophakic bullous keratopathy). Other conditions that might make a corneal transplant necessary are tissue growth on the cornea (pterygium) and Stevens-Johnson syndrome, a skin disorder that can affect the eyes. Some of these conditions cause cloudiness of the cornea; others alter its natural curvature, which also can reduce vision quality.
Injury to the cornea can occur because of chemical burns, mechanical trauma, or infection by viruses, bacteria, fungi, or protozoa. The herpes virus produces one of the more common infections leading to corneal transplant.
Corneal transplants are used only when damage to the cornea is too severe to be treated with corrective lenses. Occasionally, corneal transplant is combined with other eye surgery such as cataract surgery to solve multiple eye problems with one procedure.
The Eye Bank Association of America reported that corneal transplant recipients range in age from nine days to 103 years. More than 40,000 corneal transplants are performed in the United States each year. The cost is usually covered in part by Medicare and health insurers, although the patient might be required to incur part of the cost for the procedure. All eye tissue is donated. It is illegal to buy or sell human tissue.
The cornea is the transparent layer of tissue at the front of the eye. It is composed almost entirely of a special
In a corneal transplant, a disc of tissue is removed from the center of the eye and replaced by a corresponding disc from a donor eye. The circular incision is made using an instrument called a trephine, which resembles a cookie cutter. In one form of corneal transplant, penetrating keratoplasty (PK), the disc removed is the entire thickness of the cornea and so is the replacement disc.
The donor cornea is attached with extremely fine sutures. Surgery can be performed under anesthesia that is confined to one area of the body while the patient is awake (local anesthesia) or under anesthesia that places the entire body of the patient in a state of unconsciousness (general anesthesia). Surgery requires 30–90 minutes.
Over 90% of all corneal transplants in the United States are PK. In lamellar keratoplasty (LK), only the outer layer of the cornea is removed and replaced. LK has many advantages, including early suture removal and decreased infection risk. It is not as widely used as PK, however, because it is more time consuming and requires much greater technical ability by the surgeon.
A less common but related procedure called epikeratophakia involves suturing the donor cornea directly onto the surface of the existing host cornea. The only tissue removed from the host is the extremely thin epithelial cell layer on the outside of the host cornea. There is no permanent damage to the host cornea, and this procedure can be reversed. This procedure is mostly performed on children. In adults, the use of contact lenses can usually achieve the same goals.
Surgeons may discuss the need for corneal transplants after other viable options to remedy corneal trauma or disease have been discussed. No special preparation for corneal transplant is needed. Some ophthalmologists may request that the patient have a complete physical examination before surgery. Any active eye infection or eye inflammation usually needs to be brought under control before surgery. The patient may also be asked to skip breakfast on the day of surgery.
Corneal transplant is often performed on an outpatient basis, although some patients need brief hospitalization after surgery. The patient will wear an eye patch at least overnight. An eye shield or glasses must be worn to protect the eye until the surgical wound has healed. Eye drops will be prescribed for the patient to use for several weeks after surgery. Some patients require medication for at least a year. These drops include antibiotics to prevent infection as well as corticosteroids to reduce inflammation and prevent graft rejection.
For the first few days after surgery, the eye may feel scratchy and irritated. Vision will be somewhat blurry for as long as several months.
Sutures are often left in place for six months, and occasionally for as long as two years. Some surgeons may prescribe rigid contact lenses to reduce corneal astigmatism that follows corneal transplant.
Corneal transplants are highly successful, with over 90% of the operations in United States achieving restoration of sight. However, there is always some risk associated with any surgery. Complications that can occur include infection, glaucoma, retinal detachment, cataract formation, and rejection.
Graft rejection occurs in 5–30% of patients, a complication possible with any procedure involving tissue transplantation from another person (allograft). Allograft rejection results from a reaction of the patient's immune system to the donor tissue. Cell surface proteins called histocompatibility antigens trigger this reaction. These antigens are often associated with vascular tissue (blood vessels) within the graft tissue. Because the cornea normally contains no blood vessels, it experiences a very low rate of rejection. Generally, blood typing and tissue typing are not needed in corneal transplants, and no close match between donor and recipient is required. However, the Collaborative Corneal Transplantation Study found that patients at high risk for rejection could benefit from receiving corneas from a donor with a matching blood type.
Symptoms of rejection include persistent discomfort, sensitivity to light, redness, or a change in vision. If a rejection reaction does occur, it can usually be blocked by steroid treatment. Rejection reactions may become noticeable within weeks after surgery, but may not occur until 10 or even 20 years after the transplant. When full rejection does occur, the surgery will usually need to be repeated.
Although the cornea is not normally vascular, some corneal diseases cause vascularization (the growth of blood vessels) into the cornea. In patients with these conditions, careful testing of both donor and recipient is performed just as in transplantation of other organs and tissues such as hearts, kidneys, and bone marrow. In such patients, repeated surgery is sometimes necessary in order to achieve a successful transplant.
Patients can expect restored vision after the healing process is complete. In some patients, this might take as long as a year. Patients with keratoconus, corneal scars, early bullous keratopathy, or corneal stromal dystrophies have the highest rate of transplant success. Corneal transplants for keratoconus patients have a success rate of more than 90%.
While there is risk involved with any surgery, corneal transplants are relatively safe. In 2001, there was some concern about cornea donors transmitting Creutzfeldt-Jakob disease, a fatal bone-deteriorating disease, after questions of infection arose in Europe. A study showed the risk of transmission in the United States was small, as was any infection risk from cornea donors. Currently, cornea donors are screened using medical standards of the Eye Bank Association of America. These guidelines restrict donors who died from unknown causes, or suffered from immune deficiency diseases, hepatitis, and other infectious diseases.
Transplant recipients may have to receive another transplant if the first is unsuccessful or if, after a number of years, the disease returns.
An increasingly popular alternative to corneal transplants is phototherapeutic keratectomy (PTK). This technique is now used to treat corneal scars and dystrophies, and some infections. Surgeons use an excimer laser and a computer to vaporize diseased tissue, leaving a smooth surface. New tissue begins growing immediately and recovery takes only a few days. Patients must be carefully selected, however, and success is greatest if damage is restricted to the cornea's top layer.
Intrastromal corneal rings are implantable devices that could be used for some keratoconus patients. The rings are implanted and the procedure is reversible. However, not much is known about long-term stability. Some companies also are developing synthetic corneas that are implanted using synthetic penetrating keratoplasty. This procedure may become more widely used for high-risk patients and those with severe chemical burns.
Boruchoff, S. Arthur, and Richard A. Thoft. "Keratoplasty: Lamellar and Penetrating." In The Cornea, edited by Gilbert Smolin and Richard A. Thoft. Boston: Little, Brown and Co., 1994.
Brightbill, Frederick S., ed. Corneal Surgery. St. Louis: Mosby, 1993.
Bruner, William E., Walter J. Stark, and A. Edward Maumenee. Manual of Corneal Surgery. New York: Churchill Livingstone, 1987.
Miller, Stephen J. H. Parsons' Diseases of the Eye, 18th ed. New York: Churchill Livingstone, 1990.
Vaughan, Daniel, ed. General Ophthalmology, 14th ed. Stamford: Appleton & Lange, 1995.
Kennedy, R. H., et al. "Eye Banking and Screening for Creutzfeldt-Jakob Disease." Archives of Ophthalmology 119 (May 2001): 721–6.
Watson, B. C., and G. L. White Jr. "Corneal Transplantation." American Family Physician 54 (Nov. 1996): 1945–48.
American Academy of Ophthalmology. 655 Beach Street, P.O. Box 7424, San Francisco, CA 94120-7424. http://www.aao.org .
Eye Bank Association of America. 1015 Eighteenth Street NW, Suite 1010, Washington, D.C. 20036. (202) 775-4999. http://www.restoresight.org .
Asbell, Penny A., and Syed M. Ahmad. "New Techniques in Corneal Transplant." Review of Ophthalmology, May 15, 2002 [cited February 20, 2003]. http://www.revophth.com/index.asp?page=1_94.htm .
Cimberle, Michela. "New Type of Artificial Cornea Performs Better than Donor Grafts in High-Risk Cases." Ocular Surgery News, June 1, 2002 [cited February 23, 2003]. http://www.osnsupersite.com/view.asp?ID=2346 .
"Collaborative Corneal Transplantation Studies." National Eye Institute, October 21, 1999 [cited February 25, 2003]. http://www.nei.nih.gov/neitrials/statics/study36.htm .
"Corneal Transplantation." Merck Manual of Diagnosis and Therapy, [cited February 25, 2003]. http://www.merck.com/pubs/mmanual/section8/chapter96/96l.htm .
"Facts About the Cornea and Corneal Disease." National Eye Institute, June 2001 [cited March 4, 2003]. http://www.nei.nih.gov/health/cornealdisease/index.htm .
Victor Leipzig, PhD Mary Bekker
Corneal transplants are performed by an ophthalmologist, who is a corneal specialist and is expert at transplants and corneal diseases. Patients might be referred to a corneal specialist by their ophthalmologist or optometrist.
Surgery is performed in a hospital setting, usually on an outpatient basis. Some surgeons may also perform the procedure at an ambulatory surgery center designed for outpatient procedures.
Thank you
THANKS IN ADVANCE FOR YOUR HELP!
I need new information regarding the eye which is not at all formed by birth is it possible to transplant the cornea or there any other chances of transplanting the eye which as vision
My brother is having eye problem since birth .As per doctors the eye ball is not on proper place, so he's using lenses with power -7 and still he is not able to see properly. please suggest me d treatment needed and the name of top surgeon in India. Thanx you
Sincerely,
Cathi Rodgers
How limited are activities after surgery? Do sneezing, blowing nose, etc cause a problem? how long before one can resume normal activities such as driving, if all goes well.
Difficult to decide when to have this done because my present vision is ok and there is no pain involved.
my mother has no eye sight and she is a dibatic patient.she lose his eyesight last year in right eye and his left eye was good.during this year she got surgery in his left eye .but know she has no sight both left and right eyes.so plz plz tell me that my mother's eye sight can be back can you transplant his eyes as you know she is a dibatic patient.pls send me your hospital address..
thanks
I'm a 27-years-old person. I lost the left eye due of high pressure, and the current right eye is a glaukomatic one. Is there a chance for the eyes to be transplanted? Thanks to the glaukoma, as I heard there's no other remedy than to put on medical water drops in a everyday basis. And mostly, I heard about the Japanese scientists, who found a very solid way to help those with glaukoma, and those with blind eyes, and it's currently in the testing procedure.
Please, contact me, because it's most important for me, because it's a martyr for me to put on the water drops every day, without even relaxing myself... I want to be at ease from this martyr. I have been putting water drops since kindergarden.
Thanks
I am a mother of 6 year old girl. When She was born her both eyes were white where no cornea was visible. But when days passed her left eye was getting cleared but the right eye still had the white thing on the cornea. Doct recommend for a transplant which we did on her but then her eye starting bulging out and the white thing was again displayed on the cornea. We seeked second opinion where the doctors recommened to take out the eye. I want my daughter to see from both her eyes. Is it possible as I have taken opinions from several doctors and they are saying it is not possible for a grating again as her eye ball has been taken out. Science have done a lot of changes and progress. Can anything been done. Please reply back to me.
I understand this eye disease is rare with no studies being done about the success or failure rate of cornea replacement for ICE syndrome patients. What do you know about the effectiveness of this surgical intervention? Can you direct me to an ICE syndrome study or group where I can learn more about the successes and failures of surgical interventions? Thank you.
Thanks, MARY
Thanks, Katrina
John Biegun
Thanks in advance of a reply.
Nancy
I have corneal ulcer due to contacts.
Barbara
I am a 33 year old american, curently in Bangkok 6 weeks after a chemical burn to the entire surface of my left eye. The entire cornea epithelium was removed from the chemical. Good vasculature in the conjunctiva remained. The new epithelium is healing very slowly and not ataching well to the eye. Vision has gotten worse as the epithelium closes over the pupil. There are also 3 small blood vesels begining to grow over the iris at 6 oclock. Does anyone have insight into this injury? Is the need for cornea stem cell transplant, PTK, or full cornea transplant operations likely based on your experience?
Thanks,
Graham,
sebika213@yahoo.com
very recently his left eye has also lost vision by viral Keratitis.
Ophthalmologist has suggested for corneal transplant for left eye.
Should the Corneal transplant be successfull for him?
The operation went very well and I have already much better vision but still blurry.
It continues to be somewhat irritated but not very painful.
Please contact me privately if you need information on how the procedure can be financially covered.
My email address is mrjgascon@gmail.com
Good Luck and my God Bless you all with many years of Good Eye Sight
I just returned from a visit to India at LV Prasad Eye Institute in Hyderabad Andra Pradesh India.
My daugthter was diagnosed of congeital bilaterla peter's anomaly. The consultant advised surgery be performed for right eye alone after examination of both eyes.
Please kindly clarify if the graft takes and rejection does not occur. Will the seven year old child need to go through he operation again in life?
What other treatment can be given to the child aside the transplsnt.
Thank You.
and was told that I'd probably need a corneal transplant. My ulcer is not getting better, I'm afraid to lose my eye, if it is Fungal, which I have not been treated for. I wanted a corneal biopsy and was turned down. Is there any cornea Specialist that just specializes in Cornea ulcers. I think 2 months is too long to have this ulcer!
How many chances to success second cornea transplant. Please tell me any madicine or drops for eye pressure control
How many chances to success second cornea transplant. Please tell me any madicine or drops for eye pressure control