Adaptability of Myopic Children to Progressive Addition Lenses with a Modified Fitting Protocol in the Correction of Myopia Evaluation Trial (COMET)

Abstract

The purpose of this study was to evaluate the adaptability of myopic children participating in the Correction of Myopia Evaluation Trial (COMET) to the use of progressive addition lenses (PALs) with a modified fitting protocol of setting the distance fitting cross 4 mm above the pupil center. COMET was a multicenter, randomized clinical trial to evaluate whether PALs vs. single-vision lenses (SVLs) slowed the rate of progression in children with juvenile-onset myopia over 3 years. Of the 469 children enrolled, 234 were assigned to SVLs and 235 were assigned to PALs (+2.00 D near addition), which were fit according to a standard study protocol with the fitting cross positioned 4 mm above the pupil center. The children's adaptability to the use of PALs was evaluated by comparing the frequency and reasons for problem visits, visual symptoms, cover test results, and adherence to wearing glasses between treatment groups. During the first 3 years of follow-up, no differences were observed between children wearing PALs and those wearing SVLs with respect to the number or reasons for problem visits. One week after receipt of the study glasses, children wearing PALs showed a higher frequency of three visual symptoms related to adaptability: looking down from the blackboard and getting items on their desk in focus (p = 0.001), blur when reading (p = 0.003), and difficulty going down steps (p = 0.02). Children wearing PALs were more likely to report at least one adaptation symptom at 1 week: odds ratio of 2.76 (95% confidence interval = 1.28-5.95). By 1 month, these differences disappeared and the frequency of all visual symptoms remained low and similar for both treatment groups over 3 years. Strabismus was observed on cover test in five children (three SVLs, two PALs). None of the children had to be changed from PALs to SVLs, whereas two of the children were changed from SVLs to PALs as a result of binocular vision problems. The children and parents reported adherence to wearing the eyeglasses approached 100% compliance throughout the follow-up period for both groups. Most (98%) of the 235 children assigned to PALs maintained the modified fitting protocol without any problems over 3 years. These data show that children can safely and comfortably wear PALs for at least 3 years.