Eye bank

Eye banks retrieve and store eyes for cornea transplants and research. US eye banks provide tissue for about 46,000 cornea transplants a year to treat conditions such as keratoconus and cornea scarring. The cornea 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 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.

References

• Eye Bank Association of America
• Iowa Lions Eye Bank
• SightLife
• Chu W. "The Past Twenty-Five Years in Eye Banking". Cornea 2000:19(5); 754-765. PMID 11009327.
• What is eye banking?
• Perspectives in eye banking