AEB Touching the World with Sight
The Alabama Eye Bank (AEB) is literally touching the world with sight.
Fifty countries and counting, AEB and an organization it established, Global Sight Network (GSN), are working together to not only bring sight to the sightless but partner with doctors performing new kinds of surgeries using donated corneas.
Traditional corneal transplant surgery, called Penetrating Keratoplasty, required removal of the patient’s entire cornea, which may have only been partially diseased or damaged, and was replaced with a healthy donor cornea. Innovative new surgeries, such as the ones described below, can now take place with only the damaged cells of the endothelial layer of the cornea being removed and replaced. These surgeries are safer and heal more quickly. The cornea has five layers, which perform various functions. The endothelium is a single layer of cells on the inner surface of the cornea that acts to keep it dehydrated and pump in nutrients.
“For many years the Alabama Eye Bank (AEB) has worked to help change lives dramatically for the better. Supplying the best corneal transplant tissue to those in need regardless of finances is just part of what they do. Even so, February 7, 2012, was a special day for many, thanks to AEB. That day marks the transfer of some of the world’s most refined and life-changing eye surgery to the residents of Nicaragua,” Dr. John Parker, UAB ophthalmologist, said.
Dr. Parker was referring to a corneal transplant using DMEK (Descemet’s Membrane Endothelial Keratoplasty), a type of corneal transplant that is done without stitches, which heals at least 10 times faster than a standard transplant. The surgery was performed by missionary surgeon Dr. Miguel Naveiras of Oviedo, Spain on a young woman named Nubia Ortiz who had experienced corneal swelling that had limited her activities to a minimum.
In addition, Dr. Parker himself performed a similar procedure on the same day in Nicaragua called DSAEK (Descemet’s Stripping Automated Endothelial Keratoplasty). In DSAEK the unhealthy or damaged corneal tissue (endothelial layer) is replaced with healthy donor corneal tissue from the eye bank. The entire eye operation can be completed in about 30 minutes.
Back in Birmingham UAB researchers were confirming a new use for AEB-GSN corneas: glaucoma shunt coverage. The breakthrough provides a choice for patients undergoing glaucoma surgery to relieve pressure build up in the eye, between pericardium (which is most commonly used to cover these drainage devices), and glycerol-preserved corneas provided by GSN. Pericardium is the membrane which surrounds the heart, while glycerol corneas are specially preserved corneas that are not suitable for sight-restoring transplant but can be used for shunt coverage and patch grafts for other ocular surgeries.
The study by the UAB researchers that was recently published in the Journal of Glaucoma showed that in patients undergoing tube implantations for the first time, corneal grafts were less likely to thin or erode over time than the pericardium grafts, and therefore are less likely to encounter risk for infection or subsequent reparative surgery. Corneas preserved in glycerol have a longer shelf life (up to five years) and can be stored at room temperature.
Eric Wigton, MD, lead researcher in the glaucoma shunt study, said, “This is the first study to directly compare glycerol preserved corneal tissue to another patch graft material in glaucoma shunt surgery. It demonstrates that corneal tissue is at least as effective as pericardium in preventing tube erosion and may also delay the time to erosion. Additionally, it is less cosmetically obvious than other available materials.”
Years ago we never could have imagined a world so small that a gift given by a family in Alabama would be flown half-way around the world to restore sight, or that donated corneas could be used in any way other than a traditional penetrating keratoplasty surgery.
It all starts with the kindness and willingness of donor families to say yes to AEB counselors when asked about donating their loved one’s corneas. The need is always great, but so is the potential for meeting that need thanks to the generosity of donors and their next-of-kin.
Hospitals and their staff also play an important role in meeting the need. “We are so grateful to all the nurses across Alabama who believe in what we do. Their positive influence acts as a bridge to consent. Whether we’re providing tissue for transplant, research or education, we want to thank everyone for using their influence in a positive way for the gift of sight,” Ellen Kerns, Vice President of Technical Services, said.