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Study of Theories About Myopia Progression (STAMP)
This study is ongoing, but not recruiting participants.
Sponsors and Collaborators: Ohio State University
National Eye Institute (NEI)
Information provided by: Ohio State University
ClinicalTrials.gov Identifier: NCT00335049
  Purpose

At this time, we do not know what causes a child to become more nearsighted (myopic). STAMP will help us better understand nearsightedness in children. Children will be randomly chosen to wear regular glasses (single vision lenses) or no-line bifocal glasses (progressive addition lenses) for the first year of the study. All children will wear regular glasses for the second year of the study. STAMP will compare how the eye changes shape in the two groups to help us understand why children become nearsighted. The two theories of myopia progression that are being evaluated are based on different factors. One theory is based on environmental factors such as extended near work while the other theory is based on genetically coded factors.


Condition Intervention
Myopia
Device: progressive addition spectacle lens (bifocal)
Device: Single Vision Lenses (SVLs)

MedlinePlus related topics: Eye Wear
U.S. FDA Resources
Study Type: Interventional
Study Design: Treatment, Randomized, Double Blind (Subject, Outcomes Assessor), Active Control, Crossover Assignment, Efficacy Study
Official Title: Study of Theories About Myopia Progression (STAMP)

Further study details as provided by Ohio State University:

Primary Outcome Measures:
  • Cycloplegic autorefraction measured at 6 month intervals over two years [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • All secondary outcome measures will be measured at 6 month intervals over two years. [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Phoria [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Accommodative lag [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • AC/A ratio [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Corneal shape and thickness [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Intraocular pressure [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Peripheral ocular shape [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Central and peripheral aberrations [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Crystalline lens thickness and curvature [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Anterior chamber depth [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]
  • Axial length [ Time Frame: Every 6 months ] [ Designated as safety issue: No ]

Estimated Enrollment: 84
Study Start Date: December 2006
Estimated Study Completion Date: June 2010
Estimated Primary Completion Date: June 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
PAL: Experimental
Progressive Addition Spectacle Lenses (PALs) with a +2.00 D add worn for first year off study. Single Vision Lenses worn for second year of study.
Device: progressive addition spectacle lens (bifocal)
Progressive addition lenses (PAL) with a +2.00 D add.
SVL: Placebo Comparator
Single Vision Lenses (SVLs) worn both years of the study.
Device: Single Vision Lenses (SVLs)
Single vision spectacle lenses.

Detailed Description:

Eligible children will be enrolled, randomized, and followed at six-month intervals for two years with all children wearing single vision lenses for the second year. At each visit, complete measurements of the components of the eye will be made to explain the mechanism responsible for the Progressive Addition Lens (PAL) treatment effect and why it occurs mainly during the first year of bifocal wear (Gwiazda et al. 2003). While hyperopic retinal blur (blur at the back of the eye) due to accommodative lag (poor focusing when doing close work) has been proposed as a possible mechanism driving myopia progression (Gwiazda et al. 1993), others have shown that accommodative lag accompanies rather than precedes the onset of myopia (Mutti et al., 2006). This suggests that accommodative lag is a result of another possible mechanism resulting in myopia progression such as crystalline lens-induced ciliary-choroidal tension (a model in which the lens in the eye is stretched and is not as good at focusing up close) (Mutti et al., 2000). According to this proposed mechanism, high accommodative lag in myopia results from increased crystalline lens tension that is transmitted through the choroid (an outside layer of the eye). This tension results in restricted equatorial (the vertical dimension of the eye) eye growth with no axial (front to back) restriction to eye growth and yields a prolate ocular shape (an eye that is longer than it is wide) in myopes (Mutti et al., 2000).

Comparisons: Refractive error (glasses prescription), axial length (length of the eye), peripheral eye shape, accommodation (focusing ability), corneal shape (shape of the front of the eye), anterior chamber depth, crystalline lens thickness and curvatures (shape of the lens in the eye), central and peripheral higher-order aberrations (how well light focuses in the eye), and phoria (eye alignment) will be measured at six-month intervals. The primary study outcome is refractive error measured by cycloplegic autorefraction. Comparison of the biometric data collected both during the first year when the PAL intervention is present and during the second year when the PAL intervention is removed will allow us to differentiate between the two theories under consideration. We will also evaluate whether the modest PAL treatment effect that has been reported during the first year of PAL wear is permanent.

  Eligibility

Ages Eligible for Study:   6 Years to 11 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • 6 to 11 years of age
  • Best corrected vision of at least 20/30 in each eye
  • Birth weight > 1250g

(The criteria below will be evaluated at a screening visit to find out if the child can participate)

  • Accommodative lag >= 1.30 D (for a 4D stimulus)
  • At least -0.75 D myopia in each meridian measured with cycloplegic autorefraction but not more than -4.50 D in each meridian in each eye
  • Esophoria at near if more than -2.25 D spherical equivalent (high myopia)
  • Astigmatism < 2.00 DC in each eye
  • Anisometropia < 2.00 D

Exclusion Criteria:

  • Strabismus (eye turn)
  • History of contact lens wear
  • History of previous bifocal wear
  • Diabetes mellitus
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00335049

Locations
United States, Ohio
The Ohio State University College of Optometry
Columbus, Ohio, United States, 43210
Sponsors and Collaborators
Ohio State University
Investigators
Principal Investigator: David A Berntsen, OD, MS Ohio State University
Principal Investigator: Karla Zadnik, OD, PhD Ohio State University
Principal Investigator: Donald O Mutti, OD, PhD Ohio State University
  More Information

Publications:
Responsible Party: The Ohio State University ( Karla Zadnik, OD PhD / Principal Investigator )
Study ID Numbers: 2005H0157, K12-EY015447
Study First Received: June 7, 2006
Last Updated: July 1, 2008
ClinicalTrials.gov Identifier: NCT00335049  
Health Authority: United States: Institutional Review Board

Keywords provided by Ohio State University:
myopia progression
bifocal

Study placed in the following topic categories:
Eye Diseases
Disease Progression
Myopia
Refractive Errors

Additional relevant MeSH terms:
Disease Attributes
Pathologic Processes

ClinicalTrials.gov processed this record on January 16, 2009