Corneal Transplant Surgery
Frequently Asked Questions
Corneal Transplant Surgery FAQs
Corneal transplantation surgery is the most successful kind of organ transplant surgery in all of medicine. For many patients, their vision after transplant surgery represents a life-changing improvement. As the eye is considered an immunoprivileged zone, patients are not taking lifelong systemic immunosuppressants or steroids. Many patients will require prolonged usage of steroid eyedrops; however these have minimal absorption into the body, and unlike other organ transplant patients, patients after corneal transplant surgery are not considered to be immunocompromised.
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Corneas for corneal transplant procedures come from organ donors; people who have donated their eyes to be used after their death for the benefit of others. A nationwide eye bank network (the Eye Bank Association of America) facilitates the processing and distribution of donor tissue, usually within 24 hours. The eye bank carefully screens all donor tissue to ensure that it is healthy and in excellent condition. This includes screening for diseases such as hepatitis, HIV/AIDS, and recently, COVID-19.
As the eye is considered an immunoprivileged zone, donors and recipients do not need to be genetically type-matched. Factors such as sex, race, color of the iris, or the previous vision of the donor have no influence on the surgical result. With few exceptions, donor tissue from people ranging in age from one to 75 is usable. Donor corneal tissue can be used for up to seven days after death of the donor. Since we have a nationwide network of eye banks to obtain corneal tissue, patients do not have to be placed on a waiting list for their corneal transplant.
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With any organ transplant, there is a lifetime risk of graft rejection. For a penetrating keratoplasty, the lifetime risk of graft rejection is approximately 22%. For a DSEK, the graft rejection rate is 2-5%, with ultrathin DSEK, the rejection rate is approximately 2%, and with DMEK, the graft rejection rate is approximately 1-2%.
During episodes of graft rejection, a patient will feel their vision suddenly becoming blurry, cloudy, and/or hazy. Episodes of graft rejection are treated with high-dose topical steroid eyedrops, and sometimes steroid tablets over the course of 2-6 weeks.
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Very rarely, a corneal transplant may fail, either due to trauma, infection, subsequent eye surgery, untreated or prolonged transplant rejection, or the transplant wearing out over time. Should this occur, the patient will require a repeat corneal transplant to restore vision again.
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In general, many factors such as age of the patient at the time of surgery, lifestyle and general health factors (smoking, history of autoimmune disease, eye rubbing, trauma, prior and subsequent surgery) all affect the general health and longevity of a corneal transplant. On average, the lifetime of a penetrating keratoplasty, a full-thickness graft, is approximately 20 years (though we have many patients with penetrating keratoplasty grafts lasting 35+ years). For an endothelial keratoplasty (DSEK & DMEK) graft, the lifetime is approximately 40 years. After this point, the risk of corneal graft failure increases.
What are corneal sutures made out of?
Corneal sutures are amongst the smallest types of stitches that exist in medicine. Typically, surgeons will use a material called 10-0 nylon, comprised of a nylon monofilament thread that has been sterilized. This material is approximately 15-20 microns thick, about approximately one-tenth the diameter of a human hair. The sutures are not meant to dissolve, though they often will lose their structural integrity after a year. Typically, the sutures are removed from the patient’s eye one year after their corneal transplant surgery. However, this timing may vary with each patient, and they may sometimes be left in the eye permanently. Your surgeon will discuss with you when it is appropriate to remove corneal sutures.
Can corneal sutures break?
The 10-0 nylon sutures used in corneal transplant surgery are not meant to dissolve. Your doctor may choose to selectively remove some or all of the sutures after one week to over one year after surgery. However, like all sutures, after a time, the sutures may snap and break. When this happens, a patient will often feel a sudden foreign body sensation in their eye, like there is an eyelash stuck in their eye. A broken corneal suture warrants an urgent visit to your ophthalmologist, as a loose suture thread can represent a risk for infection. The loose suture thread creates a channel for bacteria to creep along from the outside of the eye, to the inside of the eye and potentially cause a devastating eye infection. If you feel that you may have a broken corneal suture, please contact your ophthalmologist.
An eye exam is the best way to screen for, and evaluate any eye conditions affecting your health, comfort, and quality of vision.