Corneal transplantation
In order to
fully comprehend the cornea, it is integral to briefly outline the functioning
of the eye. The cornea is the translucent layer of the eye, which refracts
incoming light. The cornea separates and protects the eyeball from all outside
sources (i.e. dust, air, water).
Complications
resulting from various diseases may cause opacity, deformation or scars of the
cornea. Often, the
corneal transplantation remains the only option to improve the visual acuity
and preservation of the eyeball.
Cornea transplantations (or keratoplasties) are the most common organ transplantation, with more than 40.000 transplantations occurring in Europe and the USA per year. Thus, the number of individuals awaiting donated cornea exceeds the current availability. Each year thousands of patients world wide are waiting for a new cornea. The shortage of donated cornea can be attributed to the lack of common knowledge regarding the possibility of donating the cornea. The possibility of cornea donation is not often mentioned at informational sessions and events focused upon organ donation. However, after direct contact with the relatives of the deceased, a significant response rate to cornea donation is notable.
What patients benifit from
a corneal
transplantation?
Severe
injuries of the cornea often lead to irreversible scarring, which highly affects
optical visibility. Patients with irreversible scarring may benefit from a
corneal
transplantation. Other potential benefices include those who have experienced
scarring of the cornea, damages occured following eye surgery, or those who have
experienced decreased visual capacity due to congenital diseases.
Risks involved in a corneal transplantation
The probability of successful corneal transplantation (when severe inflammation or vascularisation of the cornea do not exist) remains exceedingly high under normal circumstances. Currently, the rate for successfully transplantated corneas is over 96%.
High risk patients (i.e. with vascularisation of cornea after chemical burns or corneal scarring after herpes infection), undergoing a corneal transplant may result in varying outcomes. In high-risk cases it is essential to carefully match as many corneal attributes as possible in order to ensure graft survival. Although this process minimizes the danger of rejection in high-risk patients, a rejection rate can remain 40 to 60 percent.
corneal transplantation: the
continuous V- shaped suture
fixing the transplant is clearly visible in the
picture
above
Who can donate?
Potential cornea donors include all deceased individuals who do not have a corneal disease. Potential donors are identified through official donor cards or by contacting and receiving permission from the deceased ’s relatives. It is integral to know that individuals between the ages of ten and eighty-five are potential cornea donors.
An added advantage to the acquiring of donated corneas remains that corneas may be extracted up to 48 hours post-mortem. Often, the decisive factor for agreeing to a cornea donation is the very knowledge that someone will be helped by a donated organ. Donor cards and consent of the relatives for the donation of the cornea of the deceased will be documented and kept respectively. Thus, the origin of every cornea remains traceable.