bifocal lenses in nearsighted kids

Conditions: Refractive Errors

Summary: this study will evaluate the use of two different bifocal contact lens add powers to prevent further nearsighted progression in children ages 7 to 11 years old. it is theorized that the profile of the bifocal lenses will decrease the amount of change in nearsightedness that the children experience.

the primary goal of this project is to determine whether a commercially available soft bifocal contact lens with a distance-center design can slow myopia progression in children. using soft bifocal contact lenses to manipulate the peripheral optics of the eye is a novel use for a standard contact lens that may keep children from becoming as nearsighted as they would otherwise. secondary goals are to determine whether the amount of myopic defocus imposed on the peripheral retina by soft bifocal contact lenses is associated in a dose-dependent manner with slowed myopic progression and to determine whether peripheral myopic blur acts to slow eye growth locally or globally. these important pieces of information will enable investigators to learn about the role of peripheral optics for regulating eye growth, which could ultimately lead to optimization of optical signals to slow myopia progression. ultimately, the information could be used to design optical devices to prevent the onset of myopia in young children. slowing myopia progression or eventually preventing myopia onset could potentially affect approximately 60 million children in the united states alone. while the consequences of myopia are rarely sight-threatening, the quality of life for myopic patients is negatively affected and the health care costs to treat myopia are astronomical (approximately $4.6 billion in 1990). the national eye institute recognizes the need to "evaluate the efficacy of potential treatments for delaying the onset or for slowing the progression of myopia, such as lenses that alter peripheral defocus." using a common treatment of myopia (contact lenses) to potentially slow myopia progression and to learn about optical signals that regulate eye growth is a very novel approach to solving a problem that affects a large proportion of people in the united states.

Eligibility criteria:
inclusion criteria: * 7 to 11 years, inclusive, at baseline examination * -0.75 to -5.00 d, inclusive, spherical component, cycloplegic autorefraction * ≤1.00 dc, cycloplegic autorefraction * ≥ 2.00 d difference between the sphere components of the two eyes (anisometropia), cycloplegic autorefraction * 0.1 logmar or better best-corrected visual acuity in each eye * 0.1 logmar or better visual acuity ou distance and near with a +2.50 d add contact lens * +2.50 d add lens provides adequate fit with respect to movement and centration exclusion criteria: * eye disease or binocular vision problems (e.g., strabismus, amblyopia, oculomotor nerve palsies, corneal disease, etc.) * systemic disease that may affect vision, vision development, or contact lens wear (eg, diabetes, down syndrome, etc.) * previous gas permeable, soft bifocal, or orthokeratology contact lens wear or bifocal/pal spectacle wear (longer than 1 month of wear) * previous or current participation in myopia control studies * chronic use of medications that may affect immunity, such as oral or ophthalmic corticosteroids for ocular or systemic diseases * issues that may interfere with the ability to participate over the next 3 years

Keywords: pediatrics refractive error - myopia contact lenses intervention