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Analyses of data collected in U.S. FDA trials of wavefront-guided LASIK for myopia and mixed astigmatism using a new high-definition aberrometer (STAR S4 IR Laser System/iDESIGN AWS System, Johnson & Johnson Vision) show that treated patients benefit with significant improvements in visual functioning and well-being and are doing better than a population that has not undergone refractive surgery, said Daniel S. Durrie, MD.
“In the field of excimer laser refractive surgery, the traditional endpoints have been based on assessments of uncorrected visual acuity, refractive predictability and stability, and higher-order aberrations,” said Dr. Durrie, clinical professor and director of refractive surgery services, University of Kansas Medical Center, Kansas City.
However, there is a big focus on patient-reported outcomes for determining the value of a new modality. When it comes to LASIK, patients care about how they see and not about the parameters we typically measure, he noted.
“Ophthalmologists who have been in this field for a while are used to having patients complaining about some things being worse after surgery than before,” Dr. Durrie said. “With advances in our technologies, we seem to be moving in the right direction.”
The study for myopia was performed at 12 sites; 8 sites participated in the study for mixed astigmatism. The myopia study enrolled eyes with up to -11.0 D spherical equivalent and up to -5.0 D cylinder as measured with the high-definition aberrometer. It included 334 eyes of 170 subjects. The mixed astigmatism study included 149 eyes of 84 patients with up to 6.0 D of cylinder.
All patients self-administered the National Eye Institute Refractive Error Quality of Life Instrument-42 (NEI-RQL-42, 2001 version) preoperatively and at all postoperative visits.
The NEI-RQL-42 is a validated self-administered tool for assessing visual functioning and quality of life in patients who have correction of refractive error. It contains 42 items that comprise 13 subscale domains: clarity of vision, expectations, near vision, far vision, diurnal fluctuation, activity limitations, glare, symptoms, dependence on correction, worry, suboptimal correction, appearance, satisfaction with correction.
Each of the 42 items on the questionnaire is scored using a scale of 0% to 100%, where 100% is the best possible score. The scores for items within each domain are averaged together to generate the domain score.
The analyses of change after LASIK compared scores from questionnaires completed at baseline and at the time of refractive stability, which was at 6 months in the myopia study and 3 months in the mixed astigmatism study, Dr. Durrie said.
In both the myopia and the mixed astigmatism studies, statistically significant improvements from baseline (p <0.01) were achieved in all 13 domains of the NEI-RQL-42.
Dr. Durrie presented the preoperative and postoperative data from activity limitation, expectations, dependence on correction, and appearance domains that showed the highest levels of improvement.
For expectations, mean score was 7 preoperatively in both the myopia and mixed astigmatism groups and increased to 76 in the myopia group and 65 in the mixed astigmatism group postoperatively. Mean scores for worry preoperatively in the myopia and mixed astigmatism studies were 42 and 43, respectively, and 81 and 75, respectively, postoperatively.
For the dependence on correction and appearance domains, mean scores ranged from 32 to 38 preoperatively across the two studies and increased to between 88 and 94 postoperatively.
The data for the comparison with the unoperated population were taken from the NEI-RQL-42 validation study that included more than 1,150 subjects representing emmetropes, myopes, and hyperopes.
Concluding his talked, Dr. Durrie remarked that he was very impressed when he first saw the data he presented and he spoke to his larger significance.
“I think this kind of information shows the value of the FDA clinical trials that the companies spend a lot of time and money conducting,” he said.
Dr. Durrie is a consultant for Johnson & Johnson Vision.