Prevalence of Myopia, Hyperopia, and Astigmatism in Non-Hispanic White and Asian Children

Abstract

Purpose To determine the age-, gender- and ethnicity-specific prevalence of myopia, hyperopia and astigmatism in Non-Hispanic White (NHW) and Asian preschool children. Design Population-based cross-sectional study. Participants A population based sample of 1501 NHW children and 1507 Asian children aged 6-72 months from Los Angeles County and Riverside County, California. Methods Eligible children underwent an in-home and in-clinic interview and a comprehensive eye examination including cycloplegic auto-refraction from 100 census tracts. Main outcome measures The proportion of children with myopia (spherical equivalent (SE) <=−1.00 diopter (D)), hyperopia (SE >=+2.00) D and cylindrical refractive error >=1.50 D in the worse eye. The astigmatism type was defined as with-the-rule (WTR) (+cylinder axis 90° ± 15°) and against-the-rule (ATR) (+ cylinder axis 180° ± 15°); all other orientations were considered oblique (OBL). Results The prevalence of myopia, hyperopia and astigmatism in NHW children was 1.20% (95% Confidence Interval (CI) = 0.76-1.89%), 25.65% (95% CI= 23.5-27.9%), and 6.33% (95% CI = 5.21-7.68%), respectively. The prevalence of WTR, ATR and OBL astigmatism in NHW children was 4.33%, 1.00% and 1.00% respectively. Prevalence was lower with older age groups for astigmatism (p=0.0002), but not for myopia or hyperopia (p=0.82 and p=0.31, respectively). In Asian children, the prevalence of myopia, hyperopia and astigmatism was 3.98% (95% CI = 3.11-5.09%), 13.47% (95% CI= 11.8-15.3%) and 8.29% (95% CI=7.01-9.80%), respectively. The prevalence of WTR, ATR and OBL astigmatism was 6.50%, 0.80% and 1.00% respectively. The prevalence of hyperopia was higher in girls than boys (p=0.0002), but no significant differences were found for myopia and astigmatism. Conclusion Hyperopia was the most common refractive error in both Asian and NHW children. However, compared to NHW children, myopia was relatively more prevalent, and hyperopia less prevalent, in Asian children. The prevalence of astigmatism was highest in infants, and WTR astigmatism predominated at all ages. Myopia showed relatively stable prevalence across age groups, while hyperopia prevalence decreased after infancy and then increased again in older age groups; however, longitudinal studies are needed to evaluate refractive changes over time in individual children.

Prevalence and associated factors of myopia among primary and middle school-aged students: a school-based study in Guangzhou

“…29 These data can reflect that there might be an increase in the prevalence of myopia in school-aged children in Guangzhou. In addition, a prior study in 2012 showed that the prevalence of child myopia in Korea was 22.6%, 8 and a recent study in the United States demonstrated that the prevalence of myopia in non-Hispanic white children was only 1.20% and in Asian children was 3.98%; 30 the prevalence of myopia in these studies were lower than that described in our study. A possible explanation for the variance in the prevalence of myopia in children could be differences in the nature of the samples, in the ethnic backgrounds, in the age, or in the definition of myopia.…”

Epidemiology of myopia

“…Myopia is generally defined as a spherical refractive error caused by excessive refractive power and/or axial lengthening of the eye, which result in anterior displacement of focus from the retina. 20 In recent epidemiological studies reporting prevalence rates of myopia, although a majority of studies defined myopia as spherical equivalence (SE)r À 0.5 dioptres (D), a wide variety of definitions was adopted for the identification of individuals with myopia: from an SEr À 0.12 D to SEr À 1.0 D. 7,8,[10][11][12] Great variation in methodology, including sampling procedure, cut-off points for definition of age groups, and methods used for measuring refractive error, still exists in recent epidemiological studies on myopia.…”

“…These studies have confirmed the previous data indicating that prevalence of refractive error varies according to ethnicity and geographic regions. [7][8][9][10][11][12][13][14][15][16][17] Recent epidemiological studies also point to an increase in myopia prevalence over the past half-century. Various environmental factors related to socioeconomic status and lifestyle have been reported, and are widely considered to be possibly responsible for these changes.…”

Axial Length in Orthokeratology Patients: Large Case Series

“…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]. …”