Eye bank
Encyclopedia
Eye banks retrieve and store eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...

s for cornea transplant
Cornea transplant
Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced by donated corneal tissue in its entirety or in part...

s and research. US eye banks provide tissue for about 46,000 cornea transplants a year to treat conditions such as keratoconus
Keratoconus
Keratoconus , is a degenerative disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal gradual curve....

 and cornea scarring. The cornea
Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...

 is not the only part of the eye that can currently undergo transplantation. The sclera can also be used to repair recipient eyes in surgery. In contrast to other organs, there is an adequate supply of corneas for transplants.

When an organ/tissue donor dies, consent for donation is obtained either from a donor registry or from the donor's next of kin. A certified eye bank technician is then dispatched to the hospital, funeral home, or medical examiner's office to recover the donor's eyes. The whole eye, called a globe, is enucleated from the donor and taken back to the eye bank for processing. Or the cornea is excised in-situ and placed in storage media. A sample of the donor's blood is also collected to test for infectious diseases such as HIV, Hep B and C, CMV, RPR, and sometimes others. The blood type is also tested, even though corneas are not a vascular tissue and match typing is not necessary to transplantation. Back at the eye bank, if the cornea was not excised in-situ, the cornea and part of the white sclera are cut away from the rest of the eye and placed in a container with preservation medium, and the sclera is then cleaned and preserved in alcohol. The corneas undergo visual examination and evaluation underneath a slit-lamp and endothelial cell counts
Corneal endothelium
The corneal endothelium is a single layer of cells on the inner surface of the cornea. It faces the chamber formed between the cornea and the iris....

 underneath a specular microscope. The corneas are rated, usually on a scale of 0-4 for donor suitability based on the specular and slit-lamp evaluations.

There is a wide variety of storage media used in eye banking. The most popular is Optisol GS, which can preserve cornea tissue for up to 14 days if kept refrigerated. Eusol-C is another commonly used media. Organ culture media can also preserve corneas and does not require refrigeration.

To avoid violating the Health Insurance Portability and Accountability Act, Eye banks must through their legal anatomical authorizations obtain consent which allows EBAA representatives access to donor information for accreditation reviews.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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