A Prospective Evaluation of Contrast Sensitivity and Disability Glare in Refractive Surgery, a Sub-Study of: Initial Evaluation of Excimer Laser Keratorefractive Surgery in U.S. Army Personnel (WU # 2335-99)

This study has been completed.
Sponsor:
Information provided by:
Walter Reed Army Medical Center
ClinicalTrials.gov Identifier:
NCT00413868
First received: December 19, 2006
Last updated: March 31, 2008
Last verified: March 2008
  Purpose

The purpose of this study is to conduct a prospective assessment of small target contrast sensitivity and disability glare in refractive surgery. Study subjects will undergo the treatment of their choice (PRK or LASIK) and will be evaluated before and after treatment. Evaluations will include best corrected visual acuity, uncorrected visual acuity, psychometric questionnaire, pupil size, biomicroscopic examination, manifest refraction, wavefront measurements, low contrast acuity, and contrast sensitivity at normal and at low luminance with and without disability glare.


Condition Intervention
Myopia
Procedure: LASIK
Procedure: PRK
Behavioral: Small target contrast sensitivity and disability glare

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Open Label

Further study details as provided by Walter Reed Army Medical Center:

Estimated Enrollment: 50
  Eligibility

Ages Eligible for Study:   21 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Informed consent.
  • Normal, healthy active adults with access to medical care at Walter Reed Health Care System.
  • Age 21 years or older.
  • Spherical equivalent of the manifest refractive error between -1.0 to -6.0 diopters (D), inclusive, with no more than 3.0D of cylinder. The absolute value of the cylinder (expressed in minus cylinder) will be limited such that the short axis of the elliptical ablation will be no smaller than 4.9mm. The following specifies the maximum cylinder for a given spherical component of the manifest refraction:

Spherical component / Maximum cylinder

  • 1.0D / -0.5D
  • 2.0D / -1.0D
  • 3.0D / -1.5D
  • 4.0D / -2.0D
  • 5.0D / -2.5D
  • 6.0D / -3.0D
  • Corrected vision of at least 20/20
  • Soft contact lens users must havE removed their lenses at least two weeks prior to baseline measurements.
  • Hard contact lens users (PMMA or rigid gas permeable lenses) must have removed their lenses at least four weeks prior to baseline measurements. At least two weekly manifest refractions and keratometry measurements will be required in this interval. The last two measurements must not vary by more than 0.50D in any meridian.
  • Patients undergoing orthokeratology must have their lenses removed at least 6 months prior to the baseline examination. At least two monthly manifest refractions and keratometry measurements taken after the third month out of lenses must not vary by more than 0.50D in any meridian.
  • Refractive stability must be documented by previous refractions. Spherical and cylindrical portion of the manifest refraction must not have varied by more than 0.50D over the previous 12 months.
  • Exhibits strong motivation for keeping the follow-up visits.
  • Available for evaluation at Walter Reed during the two-year follow-up period.
  • Service members must have their command approval to participate in the study.
  • Access to transportation to meet follow-up requirements.

Exclusion Criteria:

  • Residual, recurrent or active ocular diseases or corneal abnormalities in either eye such as iritis, uveitis, keratoconjunctivitis sicca, herpetic keratitis, vernal conjunctivitis, lagophthalmos, corneal scarring, glaucoma, previous steroid responder, occludable chamber angles, visually significant cataracts.
  • Either one or both eyes suffering from chronic dryness.
  • Taking any systemic medications that may affect wound healing such as corticosteroids or antimetabolites.
  • Patient corneal neovascularization within one mm of the ablation zone.
  • History of any previous eye surgery, including previous refractive surgery.
  • Best corrected visual acuity of less than 20/20.
  • Progressive myopia or keratoconus.
  • Any systemic disease that may affect wound healing, such as connective tissue disorders (rheumatoid arthritis, systemic lupus erythematosus, etc.), diabetes, or severe atopic disease.
  • Any physical or mental impairment that would preclude participation in any of the examinations.
  • For contact lens users there must be no evidence of contact lens corneal warpage on computerized topography.
  • Currently on flight status or projected to be on flight status within ten years.
  • Pregnant or breast-feeding an infant. Women of childbearing age must take a urine blood pregnancy test before starting this study
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00413868

Locations
United States, District of Columbia
Walter Reed Army Medical Center, Center For Refractive Surgery
Washington, District of Columbia, United States, 20307
Sponsors and Collaborators
Walter Reed Army Medical Center
Investigators
Principal Investigator: KRAIG S. BOWER, MD Walter Reed Army Medical Center
  More Information

No publications provided

ClinicalTrials.gov Identifier: NCT00413868     History of Changes
Other Study ID Numbers: WRAMC WU 3 04-2335-99f
Study First Received: December 19, 2006
Last Updated: March 31, 2008
Health Authority: United States: Federal Government

Keywords provided by Walter Reed Army Medical Center:
Myopia with our without astigmatism

Additional relevant MeSH terms:
Myopia
Refractive Errors
Eye Diseases

ClinicalTrials.gov processed this record on April 17, 2014