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

This study has been completed.
Walter Reed National Military Medical Center
US Army Night Vision and Electronic Sensors Directorate
Information provided by (Responsible Party):
LTC Bruce Rivers, Fort Belvoir Community Hospital Identifier:
First received: March 31, 2010
Last updated: March 12, 2015
Last verified: March 2015
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.

Condition Intervention
Myopic Astigmatism
Procedure: WFG PRK
Procedure: WFG LASIK
Procedure: WFO PRK
Procedure: WFO LASIK

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Optical Quality, Threshold Target Identification, and Military Target Task Performance After Advanced Keratorefractive Surgery

Further study details as provided by LTC Bruce Rivers, Fort Belvoir Community Hospital:

Primary Outcome Measures:
  • 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.

  • objective image quality [ Time Frame: 12 months postoperatively ]
    as measured by wavefront aberrometry

  • military task performance [ Time Frame: 6 months postoperatively ]
    as measured by threshold target identification and night firing range

  • visual performance [ Time Frame: 12 months postoperatively ]
    as measured by contrast sensitivity

Enrollment: 224
Study Start Date: April 2010
Study Completion Date: October 2014
Primary Completion Date: October 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Wavefront guided (WFG) PRK Procedure: WFG PRK
Active Comparator: WFG LASIK Procedure: WFG LASIK
Active Comparator: Wavefront optimized (WFO) PRK Procedure: WFO PRK
Active Comparator: WFO LASIK Procedure: WFO LASIK


Ages Eligible for Study:   21 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01097525

United States, Maryland
Walter Reed National Military Medical Center
Bethesda, Maryland, United States, 20889
United States, Virginia
Fort Belvoir Community Hospital
Fort Belvoir, Virginia, United States, 22060
Sponsors and Collaborators
Fort Belvoir Community Hospital
Walter Reed National Military Medical Center
US Army Night Vision and Electronic Sensors Directorate
Principal Investigator: Kraig S Bower, MD The Wilmer Eye Institute, Johns Hopkins University
  More Information

Responsible Party: LTC Bruce Rivers, Director, Warfighter Refractive Eye Surgery Program and Research Center at FT Belvoir, Fort Belvoir Community Hospital Identifier: NCT01097525     History of Changes
Other Study ID Numbers: 20481
Study First Received: March 31, 2010
Last Updated: March 12, 2015

Additional relevant MeSH terms:
Refractive Errors
Eye Diseases processed this record on May 25, 2017