correction of myopia evaluation trial 2

Conditions: Myopia

Summary: the purpose of the study is to determine if progressive addition lenses (pals) versus single vision lenses (svls) slow the progression of low myopia in children with poor accommodative responses (i.e., large accommodative lags) and near esophoria.

myopia is a significant public health problem that affects at least 34% of children in the united states and a much higher percentage in asia. it is a predisposing factor for retinal detachment, myopic retinopathy, and glaucoma, thus contributing to loss of vision and blindness. as might be expected for such a prevalent condition, treatment costs are high. if interventions to retard myopia progression are successful, sight-threatening complications might be avoided and costs should be reduced. the study has been designed as a simple trial that, other than the type of lenses being determined through the randomization process and the addition of accommodation testing using an autorefractor, largely approximates standard clinical practice. screening consists of non-cycloplegic procedures of subjective refraction, testing of oculomotor alignment, and testing of accommodative response using the grand seiko autorefractor. patients who appear to be eligible for the randomized trial will be tested with their eyes dilated to determine whether refractive error in each eye is within the eligibility range for the randomized trial. patients will be randomized to either progressive addition lenses (pals) with a +2.00 d addition or to single vision lenses (svls). children will have three years of follow up, with visits every 6 months. the primary outcome visit is timed 3 years from randomization, with the primary analysis being a comparison of the average change from baseline to 3 years in amount of myopia between children in the single-vision lens group and the children in the progressive-addition lens group. the primary outcome is change in spherical equivalent refractive error (ser) in diopters (d) as measured by cycloplegic autorefraction. a separate ancillary study nested within the screening process will collect data on two additional methods of measuring accommodation, monocular estimate method (mem) retinoscopy and nott retinoscopy. the aim of the ancillary study to help determine whether a simple, effective measure exists that can be easily used by clinicians to identify children with reduced accommodative response who, if they have low myopia and esophoria, might benefit from the treatment with pals.

Eligibility criteria:
inclusion criteria: * refractive error determined by cycloplegic autorefraction which meets all of the following: 1. spherical equivalent: -0.50 to -3.00 d in both eyes 2. astigmatism \<= 1.5 d in both eyes 3. anisometropia \<= 1.00 d difference between eyes in spherical equivalent * visual acuity is at least 20/20 with best subjective refraction in both eyes * accommodative response at near (33 cm) is less than 2.0d by non-cycloplegic autorefraction * near esophoria (\>= 2.0 pd) present by alternate prism and cover test (apct) at near using best refractive correction determined from non-cycloplegic subjective refraction exclusion criteria: * strabismus present by cover-uncover test at far, near, and/or near with +2.00d over best subjective refraction * current or prior use of pals, bifocals, or contact lenses in either eye (prior or current use of svls is allowed)

Keywords: myopia progressive addition lenses (pals) single vision lenses (svls) accommodative lags near esophoria refractive error