Cornea FAQ’s
What is a cornea?
The cornea is a thin, clear layer of the eye that covers the iris (the coloured part of the eye) and the pupil. It looks just like a contact lens and it is the size of a 1 cent piece. It is a vital part of the eye. Light first penetrates the corneas, becomes focused by the lens, and is then projected onto the retina where the stimulation becomes interpreted as a visual picture by the brain. In addition to its optical functions, the cornea forms part of the outer protective layer of the eye and maintains the shape and integrity of the eyeball. In order to perform at its optimum, the cornea must remain crystal clear and have the correct shape.
What are the consequences of corneal disease or injury?
Should the cornea become cloudy from disease, injury or any other cause, one’s vision will become dramatically reduced and sight can be lost. Severe damage of the cornea also impairs the protection of the eye from the drying environment and from infection. Corneal disease and corneal injuries lead to blindness in millions of people worldwide and is a common cause of poor vision in South Africa.
Who needs a cornea transplant?
Adults, children and even babies may need a transplant because of cornea failure due to:
- Hereditary problems such as Fuchs’ dystrophy or keratoconus (thinning and steepening of the cornea);
- Scarring after injury, ulceration or infection;
- Ageing processes may affect the clarity and health of the cornea,
- Corneal disease.
How great is the need for cornea and eye tissue?
Despite hundreds of corneal graft surgeries taking place each year in South Africa, the need is ever increasing and unfortunately never satisfied. To date, the use of artificial materials for corneal transplants has been unsuccessful. As a result, patients awaiting corneal transplants depend solely on the gift of tissue donation. If you choose to donate the whole eye instead of the cornea alone, the white of the eye (sclera) can also be used for other types of eye disease.
What is a cornea transplant?
A corneal transplant is a delicate, micro-surgical procedure that replaces a disc segment of an injured or diseased cornea with a similarly shaped piece of healthy donor cornea. The operation has an extremely high success rate.
Who can be a cornea donor?
Anyone can be a donor. Individuals often believe that they have to have good vision in order to donate; however, the truth is that corneas can be used even if a donor wears glasses. Persons under the age of 18 require parental permission. The exclusions are as follows: positive virology results for infectious diseases such as HIV/AIDS, Hepatitis B or C and Septicemia.
When and how are the corneas removed?
Ideally, corneas need to be removed within 6 to 12 hours after death. The procedure is performed by trained Eye Bank Technicians and can be carried out at the mortuary, at the undertaker, at the hospital, or even at the home. Because the procurement is performed mere hours after death, there is no delay in funeral procedures.
How soon will the donated corneas be used for transplantation?
A corneal transplant is usually performed within 1 to 10 days after donation, depending on the completion of testing, the location of the receiving hospital and the preparation of the selected recipient.
What happens to the corneas if they are found to be unsuitable after procurement?
All donors and corneas are carefully evaluated. Less than 1% of corneas previously donated to the bank have been deemed unsuitable for transplant. In the unlikely event of this occurring, the Eye Bank has a policy regarding the medical discarding of tissue through an established hospital procedure.
If I donate my loved ones eyes or corneas, can we still have an open casket funeral?
Yes. Great care is taken to preserve the appearance of the donor. Following donation, it is very difficult to notice that anything looks any different. Any funeral option is available to the family, including a viewing. Donor families are encouraged to discuss their funeral arrangements, times and circumstances with the Eye Bank staff in order for their wishes to be respected and adhered to.
Do corneal transplant and scleral graft recipients pay for their tissue?
Donated tissue is procured by trained personnel. Thereafter, it is carefully stored in preservation media and is transported to the Eye Bank where it is placed in a temperature regulated refrigerator. The tissue is then evaluated for infections and imperfections before being made available for recipient selection and allocation, with the assistance of an evidence based computer allocation process. The tissue is then transported to the requesting hospital in a controlled environment with tracking procedures to ensure its safe arrival. Naturally, this process involves utilising sterile, disposable consumables, employing professional staff and possessing the necessary refrigeration and support resources for the efficient operation of the service. As a result, a fee is levied for the tissue in order to cover costs and ensure the development of the Eye Bank, which is an essential and community driven health care resource within the province. Patients receiving grafts and transplants within state hospitals receive tissue that is paid for by that state hospital. Private hospital patients belonging to medical aid schemes receive tissue that is usually reimbursed by the scheme.