Optical Defocus to Stimulate Eye Elongation in Hyperopia (ODSEEH)

This study is not yet open for participant recruitment.
Verified July 2013 by Aller, Thomas A., OD
Sponsor:
Information provided by (Responsible Party):
Aller, Thomas A., OD
ClinicalTrials.gov Identifier:
NCT00950924
First received: July 30, 2009
Last updated: July 9, 2013
Last verified: July 2013
  Purpose

Axial hyperopia results when the length of the eye is too short for the eye to properly focus distance objects on the retina while the focusing system is relaxed. Emmetropization is the process by which the eye actively adjusts various components of the eye to gradually improve the focus of the eye. Emmetropization frequently involves either an increase or a decrease in the growth of the eye, particularly during infancy and childhood. Numerous animal studies suggest that if an animal is exposed to retinal images located behind the retina either centrally or peripherally, the eye will grow in the direction of the focused image. If an abnormally short eye has resulted in hyperopia, exposing such an eye to retinal images partially located behind the retina might encourage axial elongation, thus reducing the hyperopia.


Condition Intervention
Hyperopia
Refractive Error
Device: Simultaneous Vision Bifocal Soft Contact Lenses
Device: Single Vision Soft Contact Lenses

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Treatment
Official Title: Use of Multifocal Contact Lenses to Stimulate Axial Elongation in Axial Hyperopia

Resource links provided by NLM:


Further study details as provided by Aller, Thomas A., OD:

Primary Outcome Measures:
  • Axial length [ Time Frame: One year ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Refractive Error [ Time Frame: One year ] [ Designated as safety issue: No ]

Estimated Enrollment: 30
Study Start Date: June 2014
Estimated Study Completion Date: June 2016
Estimated Primary Completion Date: December 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Bifocal Contact Lenses
Simultaneous Vision Bifocal Soft Contact Lenses will be prescribed such that the distance vision as measured by manifest subjective refraction will be properly corrected by the near vision add power and undercorrected by the distance power.
Device: Simultaneous Vision Bifocal Soft Contact Lenses
Simultaneous Vision Bifocal Soft Contact Lenses will be prescribed such that the distance vision as measured by manifest subjective refraction will be properly corrected by the near vision add power and undercorrected by the distance power.
Placebo Comparator: Single Vision Soft Contact Lenses
Subjects will be fitted with single vision soft contact lenses with goal of corrected emmetropia at a distance of 6M.
Device: Single Vision Soft Contact Lenses
Single vision soft contact lenses will be prescribed to properly correct the distance vision as measured by manifest subjective refraction.

Detailed Description:

Hyperopia or farsightedness may cause distance vision and near vision to be blurred. Depending on the severity of the condition and the age of the patient and the status of the binocular vision system, hyperopia can also cause fatigue, asthenopia, headaches, double vision, and amblyopia. Low to moderate amounts of hyperopia rarely cause much difficulty in the young person, but will eventually cause significant near vision problems as the patient ages. Hyperopia can be caused by the eye being too short (axial hyperopia) or by the cornea being too flat or the crystalline lens being to weak (refractive hyperopia). It has been established by the PI that axial growth can be dramatically lessened in children and adolescents with myopia through the use of bifocal contact lenses prescribed in a particular way (The CONTROL Study). Studies by Earl Smith, OD, PhD have suggested that multi-zonal contact lenses that provide proper axial focus while manipulating peripheral defocus can either discourage or encourage axial growth to treat myopia or hyperopia respectively. In the present study, simultaneous vision bifocal soft contact lenses will be used to encourage axial growth in hyperopic children and adolescents with axial hyperopia in an effort to reduce hyperopia. Subjects will be randomly assigned to wear either bifocal soft contact lenses or single vision soft lenses. The bifocal contact lenses will be prescribed to provide for clear central vision at both distance and near with the near zone of the contact, thus exposing the retina to hyperopic defocus from the distance zone.

  Eligibility

Ages Eligible for Study:   7 Years to 25 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Aged 7-25
  • Hyperopia > +1.25 each eye (cycloplegic refraction)
  • Ability to wear soft contact lenses

Exclusion Criteria:

  • Amblyopia
  • Strabismus
  • Astigmatism > 1.00 diopters
  • Axial Length > 24.00 mm
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00950924

Contacts
Contact: Thomas A Aller, O.D. 6508711816 cptreyes@earthlink.net

Locations
United States, California
711 Kains Ave Not yet recruiting
San Bruno, California, United States, 94066
Contact: Thomas A Aller, O.D.    650-871-1816    cptreyes@earthlink.net   
Principal Investigator: Thomas A Aller, O.D.         
Sponsors and Collaborators
Aller, Thomas A., OD
Investigators
Principal Investigator: Thomas A Aller, O.D. Unafilliated
  More Information

No publications provided

Responsible Party: Aller, Thomas A., OD
ClinicalTrials.gov Identifier: NCT00950924     History of Changes
Other Study ID Numbers: NCT07312009
Study First Received: July 30, 2009
Last Updated: July 9, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Aller, Thomas A., OD:
Hyperopia
Refractive Error
Ocular Biometrics
Axial Length
Contact Lenses
Bifocal Contact Lenses

Additional relevant MeSH terms:
Hyperopia
Refractive Errors
Eye Diseases

ClinicalTrials.gov processed this record on April 16, 2014