Eyeworld

EW REFRACTIVE SURGERY 96 March 2015 by Ellen Stodola EyeWorld Staff Writer PROWL 1 and 2 studies look at patient experiences after LASIK surgery T he recent PROWL 1 and PROWL 2 LASIK studies evaluated the measurement characteristics of a ques- tionnaire assessing patients' experience after LASIK. Edward Manche, MD, Stanford, Calif.; Elizabeth Hofmeister, MD, San Diego; Doyle Stulting, MD, PhD, Atlanta; and Malvina B. Eydelman, MD, director of the Division of Oph- thalmic and Ear, Nose and Throat Devices, Office of Device Evaluation, Center for Devices and Radiological Health, Food and Drug Administra- tion (FDA), spoke about the topic. Key results Unlike a clinical trial for the evalu- ation of LASIK devices, the PROWL studies evaluated the measurement characteristics of a newly developed questionnaire assessing the patient's experience following LASIK surgery, Dr. Eydelman said. "This questionnaire was de- veloped by incorporating feedback from patients and providers about their postoperative experience," she said. PROWL 2 assessed the presence of visual symptoms and their sever- ity in the civilian U.S. population, and also measured the impact those symptoms had on a patient's ability to function. "Overall, the prevalence of visu- al symptoms did not increase post- operatively as compared to preoper- atively. A noteworthy percentage of the patients with visual symptoms preoperatively in both PROWL 1 and PROWL 2 had resolution of those symptoms postoperatively," Dr. Eydelman said. Dr. Hofmeister was an investiga- tor with the PROWL 1 study, which focused on the U.S. military popu- lation. The most important study result was the validation of the questionnaire, she said. "At 6 months, 99.5% of patients had 20/20 or better uncorrected bin- ocular visual acuity, and 76% were 20/12.5 or better (n=217 patients, 434 eyes)," she said. Patients reported a relatively high level of preoperative visual complaints, but 6 months after surgery, complaints had decreased in every category, she said. The biggest drop was for glare symptoms, with 41% complaining of glare symptoms preop and only 17% of the cohort with the symptom at 6 months postop. "The only increase in symptoms was an increase in reported halos at 1 month postop, but these decreased to levels lower than preop by 3 months postop," she said. Dry eye symptoms in the postoperative peri- od were also examined. While some patients did experience worse dry eye symptoms, overall more patients saw an improvement. "Our satisfaction results were outstanding," Dr. Hofmeister said. "Six months after treatment, 98% of subjects were satisfied with the result of their LASIK surgery, and 97% of patients were satisfied with their present vision." Dr. Manche was an investigator at one of the PROWL 2 study sites, which included a civilian popula- tion, and he thinks that the study showed great results. "If you look at visual outcomes, greater than 91% of eyes had an uncorrected visual acuity of 20/20 or better at 3 months," he said. "If you look at binocular, uncorrected visual acuity was greater than 95% of eyes 20/20 or better." "The other noteworthy thing is the safety of the surgery," Dr. Manche said. If you look at symptoms, com- paring preop to postop and looking at things like ghosting, glare, halos, and starbursts, the preop values were significantly higher compared to postop, Dr. Manche said. It is in- credible to note that this data is one treatment with no enhancement surgery, he said. Further study "We need to remember that the purpose of the PROWL studies was to develop a questionnaire to assess visual symptoms, not to evaluate the safety and efficacy of LASIK," Dr. Stulting, who is chair of the ASCRS Refractive Surgery Clinical Commit- tee, said. "Outcomes were measured 3 months (PROWL 2) or 6 months (PROWL 2) after surgery—well before temporary side effects like dry eye resolve and the long-term visual effects are achieved. So it would be inappropriate and scientifical- ly inaccurate to draw conclusions about LASIK outcomes on the basis of the PROWL studies. Nevertheless, the results of the PROWL studies are consistent with published studies showing the outstanding safety and efficacy of LASIK," he said. "In our short-term natural his- tory study (3 to 6 months) of LASIK, the percentage of subjects expe- riencing disabling symptoms was low," Dr. Eydelman said. "Less than 1% of patients had symptoms that prevented them from doing their usual activities following LASIK. All patients contemplating LASIK should be informed of this small but significant risk. A very large clinical study would be necessary to more accurately estimate the prevalence and find useful predictors for these patients because there are so few. FDA shines light on LASIK O ne of the most eagerly await- ed refractive trials was recently presented at the 2014 American Academy of Ophthalmology annual meeting. PROWL 1, in a military setting, and PROWL 2, in a civilian population, evaluated LASIK in a total of 574 enrolled patients. The results were a defining referendum on the efficacy of LASIK. The remarkable aspect of the studies was not only the high patient satisfaction and visual acuity results, but also the documentation that the previous concerns of glare, halo, ghosting, and star- bursting dramatically improved following LASIK without glasses or contact lenses as compared to patients' experience with their best refractive correction preoperatively. In addition, patients' ability to perform visual tasks was overwhelmingly better following surgery as compared to before LASIK, al- though not every patient's visual difficulties resolved. In this article, 2 participants in the trial, Edward Manche, MD, and Elizabeth Hofmeister, MD, the organizer of the trial, Malvina B. Eydelman, MD, and Doyle Stulting, MD, PhD, chair of the ASCRS Refractive Surgery Clinical Committee, discuss the PROWL trials. Eric Donnenfeld, MD, refractive editor Patients were asked, "How satisfied are you with the result of your LASIK surgery?" Source: Elizabeth Hofmeister, MD Refractive editor's corner of the world

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