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About Prowl

LASIK Quality of Life Collaboration Project

In October 2009, the FDA, the National Eye Institute (NEI), and the Department of Defense (DoD) launched the LASIK Quality of Life Collaboration Project (LQOLCP) to help better understand the potential risk of severe problems that can result from LASIK. The project aimed to develop a tool to determine the percent of patients who develop difficulties performing their usual activities following LASIK, and to identify predictors for those patients.

At the time we developed our project, there was a limited amount of valid scientific data on certain patient-reported outcomes (PROs) related to LASIK. A PRO is a report of a condition experienced and reported by the patient, not the health care provider.

Most LASIK studies used tools, such as questionnaires, to assess visual symptoms, but only after the surgery. The Patient-Reported Outcomes with LASIK (PROWL) studies in the LQOLCP assessed visual symptoms both before and after their LASIK surgery to identify changes over time. The studies also measured the impact symptoms directly had on performing usual activities, which had not previously been done.

For more information, see LASIK Quality of Life Collaboration Project

Pilot

During the pilot phase, patients with various eye conditions took previously-developed paper-based and web-based questionnaires. This study showed that participants found web-based instruments for assessing PROs are easy to use and understand. This phase of the project was completed in 2011 with 118 participants.

 

Phase I

After expert interviews and an extensive literature search, this phase involved interviews with patients contemplating LASIK, as well as patients who had LASIK done and had experienced either poor or positive outcomes. As a result of these patient interviews, a new web-based questionnaire was developed that was easy to use, comprehensive, and understandable. This phase of the project was completed in 2011 with 22 participants.

 

Patient-Reported Outcomes with LASIK (PROWL)

Initial Study/PROWL-1

The PROWL-1 study was designed to evaluate newly created scales to measure visual symptoms, patient satisfaction, and expectations for and following LASIK surgery.  The study also provides an initial estimate of the prevalence of PROs in a select patient population - to estimate the percentage of patients developing difficulties performing their usual activities following LASIK. The study was conducted at the US Naval Medical Center San Diego refractive surgery clinic. This phase of the project was completed in 2014 with 262 participants.

Initial Study/PROWL-2

This study was conducted in a civilian population across the U.S. to further evaluate the newly created scales to measure visual symptoms, satisfaction and expectations for and following LASIK surgery. This phase of the project was completed in 2014 with 312 participants.

 

Measurement Tool

The project produced a questionnaire (see links below) with new scales that can be used to more thoroughly assess candidates’ symptoms before LASIK surgery, monitor them for visual symptoms as well as satisfaction after LASIK surgery, and measure the impact any post-LASIK symptoms have on a patient’s ability to function. The questionnaire also includes images and clear definitions for the visual symptoms (ghosting/double vision, halos, glare, and starbursts). In addition to a literature search and expert interviews, we conducted focus groups with patients and cognitive interviews to develop the new scales.

The questionnaire also included previously-developed scales for evaluating dry eye symptoms and night driving difficulties. Each of these scales can be used in further research to identify patients more likely to experience serious difficulties.

Investigators may select the most relevant scales for their research questions.  Since some of the questions measure similar things, the questionnaire is not meant to be used in its entirety in future clinical studies.  Patients and health care providers now have a well-defined tool to guide medical decision making and future research. 

The PROWL Pre-Op Questionnaire can be used to more thoroughly assess candidates’ symptoms before LASIK surgery. The PROWL Post-op Questionnaire can be used to monitor patients for visual symptoms as well as satisfaction after LASIK surgery, and measure the impact any post-LASIK symptoms have on a patient’s ability to function.

More information on the scales and questions used in the PROWL Questionnaire to aid health care providers in selecting the most appropriate scales.

PROWL Pre-op Questionnaire

PROWL Post-op Questionnaire

 

Study Results

The problems some study participants developed after having LASIK surgery, such as difficulty driving at night, severely impacted a patient’s daily living, and included debilitating vision symptoms (seeing starbursts, glare, ghosting, or halos) and severe dry eye. In each of the PROWL studies, less than 1 percent of patients experienced difficulty performing their usual activities following LASIK surgery due to any one symptom.

When LQOLP was designed, we intended to conduct a larger study to identify predictors for those patients who develop difficulties performing their usual activities following LASIK. Given our findings of so few patients experiencing debilitating symptoms, a very large clinical study would be necessary to more accurately estimate the prevalence and find useful predictors for these patients. Although we are pleased to have our questionnaire available to researchers interested in this area, resource limitations prevent the FDA from conducting a study of this size.

Based on further analyses of our studies:

  • Up to 46 percent of participants, who had no visual symptoms before surgery, reported at least one visual symptom at three months after surgery.
  • Participants who developed new visual symptoms after surgery, most often developed halos. Up to 40 percent of participants with no halos before LASIK had halos three months following surgery.
  • Up to 28 percent of participants with no symptoms of dry eyes before LASIK, reported dry eye symptoms at three months after their surgery. This is consistent with previous studies.
  • Less than 1 percent of study participants experienced "a lot of difficulty" with or inability to do usual activities without corrective lenses because of any one visual symptom (starbursts, ghosting, halos, glare) after LASIK surgery.
  • More than 95% of participants were satisfied with their vision following LASIK surgery.
  • Participants were more than twice as likely to report their visual symptoms on a questionnaire than to tell them to their health care provider

The findings from this study will help to refine our current thoughts on the labeling for LASIK devices which will be incorporated into our patient labeling guidance. In addition, we will ensure our website reflects these findings to better inform consumers of the potential outcomes following LASIK.

 

Publications

 

Presentations

LASIK Quality of Life Collaboration Project: Study Results Presentations at a Symposium of the American Academy of Ophthalmology (AAO)