Correction of Myopia Evaluation Trial 2 (COMET2)

• Distribution of Change in Spherical Equivalent Refractive Error From Baseline to 3 Years [ Time Frame: Baseline to 3 years ]
  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.
  
  
• Mean Change in Spherical Equivalent Refractive Error From Baseline to 3 Years [ Time Frame: 3 years ]
  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.
  
  

• Distribution of Spherical Equivalent Refractive Error at 3 Years [ Time Frame: 3 years ]
  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.
  
  
• Mean Spherical Equivalent Refractive Error at 3 Years [ Time Frame: 3 years ]
  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 [ Time Frame: Baseline to 3 years ]
  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 [ Time Frame: Baseline to 3 years ]
  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 1 Year [ Time Frame: Baseline to 1 year ]
  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.
  
  
• Mean Change in Spherical Equivalent Refractive Error From Baseline to 2 Years [ Time Frame: Baseline to 2 years ]
  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.
  
  
• Excellent Spectacle Compliance [ Time Frame: Baseline to 3 years ]
  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.
  
  

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.