Optical Quality, Threshold Target Identification, and Military Target Task Performance After Advanced Keratorefractive Surgery

March 12, 2015 updated by: LTC Bruce Rivers, Fort Belvoir Community Hospital
To determine the effect of two types of wavefront modalities (WFG vs. WFO) and two types of refractive surgery (PRK vs. LASIK) on visual and military task performance after laser refractive surgery.

Study Overview

Study Type

Interventional

Enrollment (Actual)

224

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Maryland
      • Bethesda, Maryland, United States, 20889
        • Walter Reed National Military Medical Center
    • Virginia
      • Fort Belvoir, Virginia, United States, 22060
        • Fort Belvoir Community Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

19 years to 53 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Normal, healthy active adults with access to medical care at Walter Reed Health Care System.
  2. Male or female at least 21 years old at the time of the pre-operative examination, and have signed an informed consent. The lower age limit of 21 years is intended to ensure documentation of refractive stability.
  3. Myopic spherical manifest refractive error from -1.00D up to -10.00D inclusive, with no more than 4.00D of manifest cylinder refractive error.
  4. Inclusion based on pre-op Central Corneal Thickness (CCT) will be assessed according to Residual Stromal Bed Thickness
  5. BSCVA of at least 20/20 in the study eye.
  6. Soft contact lens users must have removed their lenses at least two weeks prior to baseline and follow-up measurements.
  7. Hard contact lens users (PMMA or rigid gas permeable lenses) must have removed their lenses at least four weeks prior to baseline and follow-up measurements.
  8. Refractive stability must be documented by previous refractions. Spherical and cylindrical portion of the manifest refraction must not have varied by more than 0.50 diopters over the previous 12 months.
  9. Exhibits strong motivation for keeping the follow-up visits.
  10. Available for evaluation at Walter Reed during the 1 year follow-up period
  11. If selected, willing and available to undergo testing at Ft. Belvoir during the study period.
  12. All service members must have a signed command authorization to receive government sponsored refractive surgery. The signed command authorization will be included in the original application.
  13. Access to transportation to meet follow-up requirements.

Exclusion Criteria:

  1. Residual, recurrent or active ocular diseases or congenital corneal abnormalities in either eye such as iritis, uveitis, keratoconjunctivitis sicca, herpetic keratitis, vernal conjunctivitis, lagophthalmos, corneal scarring, anterior basement membrane disease, recurrent erosions, glaucoma, previous steroid responder, occludable chamber angles, visually significant cataracts.
  2. History of any previous eye surgery or trauma, including previous refractive surgery.
  3. Dry eye as reflected by Schirmer's test, subjective complaints or symptoms of dry eye, findings during slit lamp exam that would be consistent with dry eye (e.g. superficial punctuate keratitis).
  4. Corneal thickness insufficient to allow the residual remaining stromal bed to be no less than 300 microns in each eye. The residual stromal bed thickness will be determined by subtracting both the LASIK flap thickness and depth of the ablation from the total central corneal thickness measured by pachymetry.
  5. Female subjects who are pregnant, breast-feeding or intend to become pregnant during the study. This is standard of care exclusion for refractive surgery at the Walter Reed Refractive Surgery Center because of the medications that are routinely given as part of the procedures. Standard of care analgesia consists of medications (e.g. narcotics) labeled as Pregnancy Category "C" by the FDA. Teratogenic effects are not known, however, physical dependence in the neonate may occur if the mother is given narcotics. Female subjects will be given a urine pregnancy test prior to participating in the study to rule out pregnancy.
  6. Concurrent topical or systemic medications that may impair healing, including corticosteroids, antimetabolites, isotretinoin (Accutane), amiodarone hydrochloride (Cordarone) and/or sumatripin (Imitrex).
  7. Significant corneal neovascularization.
  8. Progressive myopia or keratoconus.
  9. Medical condition(s), which, in the judgment of the investigator, may impair healing, including but not limited to: collagen vascular disease, autoimmune disease, immunodeficiency diseases, and ocular herpes zoster or simplex.
  10. Patients with known sensitivity or inappropriate responsiveness to any of the medications used in the post-operative course.
  11. Any physical or mental impairment which would preclude participation in any of the examinations.
  12. Inability to meet the mandated follow-up visit schedule for any reason such as duty hours, impending deployments, or PCS.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Wavefront guided (WFG) PRK
Active Comparator: WFG LASIK
Active Comparator: Wavefront optimized (WFO) PRK
Active Comparator: WFO LASIK

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
visual outcomes
Time Frame: 12 months postoperatively

Visual outcomes will be measured in terms of:

  • number of eyes achieving uncorrected visual acuity (UDVA) 20/20 or better.
  • number of eyes maintaining one Snellen line of corrected distance visual acuity (CDVA).
  • number of eyes within 0.50 diopter of manifest spherical equivalent.
12 months postoperatively
objective image quality
Time Frame: 12 months postoperatively
as measured by wavefront aberrometry
12 months postoperatively
military task performance
Time Frame: 6 months postoperatively
as measured by threshold target identification and night firing range
6 months postoperatively
visual performance
Time Frame: 12 months postoperatively
as measured by contrast sensitivity
12 months postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Kraig S Bower, MD, The Wilmer Eye Institute, Johns Hopkins University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 2010

Primary Completion (Actual)

October 1, 2014

Study Completion (Actual)

October 1, 2014

Study Registration Dates

First Submitted

March 31, 2010

First Submitted That Met QC Criteria

March 31, 2010

First Posted (Estimate)

April 1, 2010

Study Record Updates

Last Update Posted (Estimate)

March 13, 2015

Last Update Submitted That Met QC Criteria

March 12, 2015

Last Verified

March 1, 2015

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 20481

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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