|Majority Of Laser Eye Surgery Patients Show Unchanged Night Vision |
TORONTO, ON -- October 20, 2000 -- A laser eye surgery study conducted by TLC Laser Eye Centres (TLC) for the U.S. Food and Drug Administration (FDA) has shown that 98.7 per cent of patients said their night vision was unchanged and had not been reduced as a result of the surgery.
|LASIK Has Significant Advantages Over Photorefractive Keratectomy For Farsightedness |
DALLAS, TX -- JULY 21, 2000 -- LASIK surgery is far better at correcting farsightedness than photorefractive keratectomy (PRK), ophthalmologists at UT Southwestern Medical Center at Dallas have discovered.
The researchers found that the LASIK procedure to correct hyperopia, or farsightedness, caused less discomfort, allowed a speedier recovery and required no pain medication afterward. The eye also stabilized more quickly after LASIK when compared with PRK. The researchers reported their findings in the 2000 issue of Transactions of the American Ophthalmological Society.
"We demonstrated for the first time in a scientific study the superiority of hyperoptic LASIK over PRK and that the relative advantages of LASIK to correct nearsightedness were all present in hyperoptic LASIK," said Dr. James McCulley, chairman of ophthalmology at UT Southwestern.
The study was not randomized. Data from consecutive PRK patients came from a Food and Drug Administration trial. Data for LASIK and PRK came from patients at the Laser Center for Vision at Zale Lipshy University Hospital. All procedures were done using the VISX Star 2 excimer laser.
In PRK, the laser is used directly on the surface of the eye; in LASIK, the laser is used under a protective flap of tissue.
The review of PRK data included 22 eyes of 15 consecutive patients; LASIK data came from 26 eyes of 22 consecutive patients.
The long-term efficacy and safety of both PRK and LASIK were comparable.
The most notable, immediate difference between PRK and LASIK was the degree of postoperative pain. PRK was consistently associated with significant postoperative pain that required systemic medication in every case. The onset of pain after PRK was typically 36 hours after surgery, lasting up to 72 hours.
In contrast, LASIK was associated with minor and transient discomfort that did not require systemic medication. Post-LASIK discomfort occurred in the first few hours after surgery and did not interfere with patients' activities. In LASIK, vision was recovered within hours and stabilized between one week and a month. In contrast, there was significant delay in vision recovery and stabilization after the PRK procedure.
The study, which evaluated patients between June 1997 and May 1999, was funded by an unrestricted grant from Research to Prevent Blindness in New York.