Optical Defocus to Stimulate Eye Elongation in Hyperopia

Refractive Error Clinical Trial

— ODSEEH  

Official title:

Use of Multifocal Contact Lenses to Stimulate Axial Elongation in Axial Hyperopia

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT00950924
• Other study ID #: NCT00950924
• Status: Active, not recruiting
• Phase: N/A
• Start date: January 2015
• Est. completion date: January 1, 2022

Study information

• Verified date: January 2021
• Source: Aller, Thomas A., OD
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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, O.D., Ph.D. 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.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 30
• Est. completion date: January 1, 2022
• Est. primary completion date: October 2021
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 5 Years to 12 Years

Eligibility

Inclusion Criteria:

• Aged 5-12

• 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

Related Conditions & MeSH terms

• Hyperopia
• Refractive Error
• Refractive Errors

Intervention

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.
• 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.

Locations

Country	Name	City	State
United States	711 Kains Ave	San Bruno	California

Sponsors (1)

Lead Sponsor	Collaborator
Aller, Thomas A., OD

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Axial length		One year
Secondary	Refractive Error		One year