Relationship of Age, Sex, and Ethnicity With Myopia Progression and Axial Elongation in the Correction of Myopia Evaluation Trial

Abstract

To identify the baseline factors independently related to 3-year myopia progression and axial elongation in COMET.Methods: A total of 469 children were enrolled, randomly assigned to progressive addition lenses with aϩ2.00 diopter (D) addition or to single vision lenses and observed for 3 years. Eligible children were 6 to 11 years old, with spherical equivalent myopia of − 1.25 to−4.50 D, bilaterally. The primary and secondary outcomes, myopia progression by cycloplegic autorefraction and axial elongation by A-scan ultrasonography, were measured annually. Multiple linear regression was used to adjust for covariates, including treatment.Results: Younger baseline age (6-7 vs 11 years, 8 vs 11 years, and 9 vs 11 years, PϽ.001; 10 vs 11 years, P=.04), female sex (P=.01), and each ethnic group compared with African Americans (Asian, P = .02; Hispanic, P = .002; mixed, P=.002; white, P = .001) were independently as-sociated with faster 3-year progression. Children aged 6 to 7 years had the fastest progression of all age groups, progressing by a mean (±SD) of 1.31 D±0.13 more than children aged 11 years. Females progressed 0.16 D more than the males. Children of mixed, Hispanic, Asian, and white ethnicity progressed more than African American children by 0.49 D±0.16, 0.33 D±0.11, 0.32 D±0.13, 0.27 D±0.08, respectively. Age and ethnicity, but not sex, were independently associated with axial elongation. Among these myopic children, a 0.5 mm increase in axial length was associated with 1 D of myopia progression.Conclusions: Younger baseline age was the strongest factor independently associated with faster myopic progression and greater axial elongation at 3 years. African American children had less myopic progression and axial elongation than the other ethnic groups.

Axial Length in Orthokeratology Patients: Large Case Series

“…But, children who start Ortho-K younger have the largest reduction in axial length change vs. children wearing glasses. In this study, children who started Ortho-K at age 6-7 showed a mean increase of 0.57mm in axial length over a 3 year period compared to spectacle-wearing children in a study by Hyman et al [33], who showed 1.10 mm of axial length increase in three years. In contrast, the 10-11 yearold Ortho-K wearers in our study showed0.15 mm axial length increase versus 0.50 mm of axial length increase in the 11 yearold spectacle wearers.…”

“…While these data provide a reference point, they do not provide normative data on axial length increase during childhood. This is due to numerous variables that may contribute to refractive and axial length changes including age of myopia onset [27,31], ethnicity [31][32][33][34][35][36], hours of near work [37], hours of time spent outdoors [38], mode of refractive correction [20,24,39] and parental history of myopia [40]. …”

“…Asian children have been shown to develop myopia at younger age and progress at a higher rate than other ethnic/racial groups [31,33,34]. This may relate to differences in posterior scleral/retinal contour and the resulting difference in peripheral refraction [41][42][43].…”

“…As a point of reference in evaluating axial length changes relative to refractive changes, Hyman et al [33] reported that a 1 mm increase in axial length was associated with 2.04 D of myopia progression and alternatively, 1 D of myopia progression was associated with 0.50 mm of axial elongation. Those numbers, applied to our study, would suggest that our mean increase of 0.28 mm over the three-year study period would result in a 0.57D increase in myopic refraction.…”

Binocular Visual Function in Orthokeratology Contact Lens Wear for Myopia

“…An earlier age of onset is linked to faster progression, which in turn contributes to increased myopia severity and a higher risk of associated ocular pathologies. (Lin et al 1999, Mitchell et al 1999, Hyman et al 2005, Saw et al 2005, Flitcroft 2012 …”