A new laser-assisted cornea transplant surgical technique has been described by a group of ophthalmologists from UC Irvine:
While most transplants are successful in providing the patient with a clear cornea, the majority of cornea transplants take more than six months to provide good vision, and even then strong glasses or contact lenses are needed. In addition, stitches usually need to stay in place for years, because the cornea is slow to heal and, as a result, the transplant remains a weak spot, vulnerable to injury for the rest of the patient’s life. After the laser-based transplant, suture removal may be as soon as three months, and the strength of the repaired area may be nearly 10 times that of conventional transplants.
“By using the laser, a highly precise incision is created, resulting in a perfect match of the donor and the patient,” said Steinert, a professor of ophthalmology in the School of Medicine. “In addition to precision that exceeds anything that can be duplicated by even a highly skilled surgeon, the laser can create complex shapes that are impossible to achieve with conventional surgery.”
The study compared the results of conventional transplant surgical techniques to the results of the laser surgery. Utilizing 14 donated human corneas that were not medically suitable for transplantation, Steinert and his team performed simulated transplant surgery and then tested for the mechanical strength of the incisions and for induced distortion.
They found that the initial strength of the laser incision, even before any healing, measured almost seven times higher than that of the incision from the usual transplant technique performed by hand.
The laser used to cut the cornea is known as a femtosecond-pulsed laser, manufactured by Irvine-based IntraLase Corp. The laser fires 15,000 pulses per second, each pulse lasting only 400 quadrillionths of a second. (To understand how brief each laser pulse lasts, in one second a pulse of light would travel around the equator of the Earth seven times, but in one femtosecond a pulse of laser travels only the width of three human hairs.)
The location of the pulses in the cornea to create the incision is controlled by sophisticated optics and a computer, so that each pulse interconnects with the next, similar to the perforations in paper sheets that allow the paper to be torn cleanly.
The technique was developed by Roger F. Steinert, M.D., director of cornea, refractive and cataract surgery at UCI Health Sciences.
The press release…