From a trash compactor to SMILE: 30 years of laser vision correction
CHICAGO — Innovation, teamwork and serendipity have led to the worldwide use of laser vision correction over the course of its three-decade existence, according to a speaker here.
“After 30 and a half years of laser vision correction in humans, how do we feel about it now? I think we’re just getting started,” Marguerite B. McDonald, MD, FACS, said during the keynote address of the Refractive Surgery Subspecialty Day preceding the American Academy of Ophthalmology annual meeting.
McDonald detailed the history of laser vision correction since Stephen Trokel, MD, published his 1983 study in the American Journal of Ophthalmology documenting the use of an excimer laser to make precise cuts in animal cadaver eyes without thermal damage.
“In his discussion he said, ‘perhaps this could be used for refractive surgery,’” McDonald said.
McDonald asked Trokel, who was then working with Charles Munnerlyn, PhD, a physicist, to take advantage of Louisiana State University’s large vivarium and work together to research the procedure’s refractive surgery potential.
McDonald, Trokel and Munnerlyn started with PRK and ablated thousands of plastic test plates, cadaver pig and cow eyes, and human eyes.
Series of animal tests were performed, with data being sent to the FDA, before the trio received an opportunity to experiment on a human subject. A 61-year-old woman, Alberta Cassady, with a normal, healthy eye, was facing an exenteration due to an orbital cancer surrounding her eye. The FDA granted the group special permission to perform the procedure. McDonald performed the first-ever laser vision correction on a living human subject on March 25, 1988, and Cassady was evaluated for 11 days leading up to the eye’s removal, she said.
“The specimen was amazing. There was no subepithelial scarring in those 11 days and we nailed the refractive correction,” she said.
The FDA allowed the group to move on from animal work and begin its blind eye human clinical trial. The laser was brought to LSU and placed in a trailer next to the LSU trash compactor, which would shake the trailer gently when in action. In an effort to stop the university from running the trash compactor during procedure, McDonald compared the outcomes of patients who underwent their procedures when the compactor was in use to those when it was not in use to show it was detrimentally affecting their work.
“The stunning truth was the trash compactor patients were doing significantly better,” she said.
The researchers realized that the swaying of the trailer from the trash compactor gave the patients a blend zone and improved outcomes, she said.
“Eventually, the approvals began to come in. First for lower myopia, then higher myopia, then myopia with astigmatism, then low hyperopia, higher hyperopia, hyperoptic astigmatism, mixed astigmatism, and the university felt confident enough to let the technology come indoors,” McDonald said.
Ten years after PRK was developed, LASIK was introduced by Ioannis Pallikaris, MD, and became popular worldwide. Both procedures are still used worldwide, she said.
“Yogi Berra, the famous American baseball legend, said it well, ‘The future lies ahead.’ We’re really just getting started,” she said. – by Robert Linnehan
Reference: McDonald M. 30 years of laser vision correction. Presented at: AAO Subspecialty Day; Oct. 26-27, 2018; Chicago.Disclosure: McDonald reports relevant financial interest in Johnson & Johnson Vision.