Correction of Myopia Evaluation Trial 2 (COMET2)

Correction of Myopia Evaluation Trial 2 (COMET2): A Randomized Trial of the Effect of Progressive Addition Lenses Versus Single Vision Lenses on Low Myopia Associated With Large Accommodative Lags and Near Esophoria in Children

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.

Myopia, Progressive Addition Lenses (PALs), Single Vision Lenses (SVLs), Accommodative lags, Near esophoria, Refractive error

Measured in diopters (D) using cycloplegic refraction sphere (amount of myopia) and cylinder (amount of astigmatism at an angle (axis)). Spherical equivalent (SE) is the sphere plus 1/2 the cylinder. For baseline and each time point, a SE was calculated for each eye for each of the five trials of cycloplegic autorefraction; the median for each eye was averaged to obtain the SE used for analysis. Change was calculated as SE at baseline minus SE at 3 years. A negative value indicates that the myopia worsened; a positive value indicates that it improved.

Measured in diopters (D) using cycloplegic refraction sphere (amount of myopia) and cylinder (amount of astigmatism at an angle (axis)). Spherical equivalent (SE) is defined as the sphere plus 1/2 the cylinder. For baseline and each time point, a SE was calculated for each eye for each of the five trials of cycloplegic autorefraction; the median for each eye was averaged to obtain the SE used for analysis. Change was calculated as SE at baseline minus SE at 3 years. A negative value indicates that the myopia worsened; a positive value indicates that it improved.

Measured in diopters (D) using cycloplegic refraction sphere (amount of myopia) and cylinder (amount of astigmatism at an angle (axis)). Spherical equivalent (SE) is defined as the sphere plus 1/2 the cylinder. A SE was calculated for each eye for each of the five trials of cycloplegic autorefraction, and the median for each eye was averaged to obtain the SE used for analysis.

Measured in diopters (D) using cycloplegic refraction sphere (amount of myopia) and cylinder (amount of astigmatism at an angle (axis)). Spherical equivalent (SE) is defined as the sphere plus 1/2 the cylinder. A SE was calculated for each eye for each of the five trials of cycloplegic autorefraction, and the median for each eye was averaged to obtain the SE used for analysis.

Distribution of Change in Spherical Equivalent Refractive Error From Baseline to 3 Years According to Baseline Characteristics

Measured in diopters (D) using cycloplegic refraction sphere (amount of myopia) and cylinder (amount of astigmatism at an angle (axis)). Spherical equivalent (SE) is defined as the sphere plus 1/2 the cylinder. For baseline and 3 years, a SE was calculated for each eye for each of the five trials of cycloplegic autorefraction; the median for each eye was averaged to obtain the SE used for analysis. Change was calculated as SE at baseline minus SE at 3 years. A negative value indicates that the myopia worsened; a positive value indicates that it improved.

Mean Change in Spherical Equivalent Refractive Error From Baseline to 3 Years According to Baseline Characteristics

Measured in diopters (D) using cycloplegic refraction sphere (amount of myopia) and cylinder (amount of astigmatism at an angle (axis)). Spherical equivalent (SE) is defined as the sphere plus 1/2 the cylinder. For baseline and 3 years, a SE was calculated for each eye for each of the five trials of cycloplegic autorefraction; the median for each eye was averaged to obtain the SE used for analysis. Change was calculated as SE at baseline minus SE at 3 years. A negative value indicates that the myopia worsened; a positive value indicates that it improved.

Measured in diopters (D) using cycloplegic refraction sphere (amount of myopia) and cylinder (amount of astigmatism at an angle (axis)). Spherical equivalent (SE) is defined as the sphere plus 1/2 the cylinder. For baseline and 1 year, a SE was calculated for each eye for each of the five trials of cycloplegic autorefraction; the median for each eye was averaged to obtain the SE used for analysis. Change was calculated as SE at baseline minus SE at 1 year. A negative value indicates that the myopia worsened; a positive value indicates that it improved.

Measured in diopters (D) using cycloplegic refraction sphere (amount of myopia) and cylinder (amount of astigmatism at an angle (axis)). Spherical equivalent (SE) is defined as the sphere plus 1/2 the cylinder. For baseline and 2 years, a SE was calculated for each eye for each of the five trials of cycloplegic autorefraction; the median for each eye was averaged to obtain the SE used for analysis. Change was calculated as SE at baseline minus SE at 2 years. A negative value indicates that the myopia worsened; a positive value indicates that it improved.

Spectacle compliance was assessed on a five-point Likert scale: always, 5; often, 4; sometimes, 3; rarely, 2; and never, 1. Excellent compliance indicates that for the specified period (during school, after school, on weekends), spectacles were estimated at all visits to have been worn either always or often.

Inclusion Criteria: Refractive error determined by cycloplegic autorefraction which meets all of the following: Spherical equivalent: -0.50 to -3.00 D in both eyes Astigmatism <= 1.5 D in both eyes 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)

Correction of Myopia Evaluation Trial 2 Study Group for the Pediatric Eye Disease Investigator Group; Manny RE, Chandler DL, Scheiman MM, Gwiazda JE, Cotter SA, Everett DF, Holmes JM, Hyman LG, Kulp MT, Lyon DW, Marsh-Tootle W, Matta N, Melia BM, Norton TT, Repka MX, Silbert DI, Weissberg EM. Accommodative lag by autorefraction and two dynamic retinoscopy methods. Optom Vis Sci. 2009 Mar;86(3):233-43. doi: 10.1097/OPX.0b013e318197180c.

Correction of Myopia Evaluation Trial 2 Study Group for the Pediatric Eye Disease Investigator Group. Progressive-addition lenses versus single-vision lenses for slowing progression of myopia in children with high accommodative lag and near esophoria. Invest Ophthalmol Vis Sci. 2011 Apr 25;52(5):2749-57. doi: 10.1167/iovs.10-6631.