Environmental and Behavioral Factors with Refractive Error in Israeli Boys

Abstract

Significance: Evidence supporting the contributions of near work in myopia is equivocal. Findings from this pilot study suggest that a high prevalence of myopia in ultra-Orthodox boys may be attributed to intense near work at school and learning to read in preschool at an early age.

Purpose: This study aimed to assess factors that may influence myopia in three groups of Jewish boys with different educational demands.

Methods: Healthy ultra-Orthodox, religious, and secular Jewish boys (n = 36) aged 8 to 12 years participated. Refractive status, education, time spent reading and writing, and electronic device use were assessed using a questionnaire, and time outdoors and physical activity were assessed objectively using an Actiwatch. Data were analyzed with χ2 and Kruskal-Wallis tests with Bonferroni post hoc comparisons.

Results: Ultra-Orthodox (n = 14) and religious (n = 13) children had greater myopia prevalence compared with secular children (n = 9; P = .01), despite no differences in parental myopia. Actigraph data showed that there were no differences in activity (P = .52) or time spent outdoors (P = .48) between groups. Ultra-Orthodox children learned to read at a younger age and spent more hours at school (P < .001 for both). All groups engaged in a similar amount of near work while not in school (P = .52). However, ultra-Orthodox boys had less electronic device use than did religious (P = .007) and secular children (P < .001).

Conclusions: This pilot study demonstrates that ultra-Orthodox, religious, and secular children have distinct educational demands but similar time outdoors, physical activity, and near work while not in school. The findings suggest that near work at school and/or learning to read in preschool at an early age may contribute to previously reported differences in refractive error between groups. However, conclusions should be confirmed in a larger sample size.

FIGURE 1

Environmental and behavioral measures. Mean ± standard deviation daily (in hours) physical activity (A), time outdoors (B), near work (approximately <40 cm; C), and intermediate work (approximately 40 to 100 cm; D), television (far work; E), and all electronic device use (F) are shown for weekdays, Shabbat, and the whole week for ultra-Orthodox (filled bars), religious (gray bars), and secular (open bars) children; *P < .05, **P < .01, ***P < .001 for Bonferroni-corrected post hoc pairwise comparisons.

FIGURE 2

Objectively measured activity and light exposure across 24 hours. Mean ± standard error activity (in counts per minute) across 24 hours for weekdays (A), Shabbat (B), and total for the week (C), and mean light exposure (in lux) across 24 hours for weekdays (D), Shabbat (E), and total for the week (F) for ultra-Orthodox (filled circles), religious (filled triangles), and secular (open squares) children; *Significant difference between ultra-Orthodox and religious children. †Significant difference between ultra-Orthodox and secular children. ‡Significant difference between religious and secular children.

FIGURE 3

Parent-reported daily behaviors across 24 hours. Wake period is shown in gold and sleep period in black. Wake is further divided into the percentage of the day spent in school (seafoam) and outside of school performing near work (blue), intermediate work (red), and far viewing (gray) for ultra-Orthodox (A), religious (B), and secular children (C).