Disordered Sleep and Myopia Risk among Chinese Children

Purpose

Disordered sleep and myopia are increasingly prevalent among Chinese children. Similar pathways may be involved in regulation of both sleep cycles and eye growth. We therefore sought to examine the association between disordered sleep and myopia in this group.

Methods

Urban primary school children participating in a clinical trial on myopia and outdoor activity underwent automated cycloplegic refraction with subjective refinement. Parents answered questions about children''s sleep duration, sleep disorders (Children''s Sleep Habits Questionnaire CSHQ]), near work and time spent outdoors.

Results

Among 1970 children, 1902 (96.5%, mean standard deviation SD] age 9.80 0.44] years, 53.1% boys) completed refraction and questionnaires. Myopia < = -0.50 Diopters was present in both eyes of 588 (30.9%) children (1329/3804 = 34.9% of eyes) and 1129 children (59.4%) had abnormal CSHQ scores (> 41). In logistic regression models by eye, odds of myopia < = -0.50D increased with worse CSHQ score (Odds Ratio OR] 1.01 per point, 95% Confidence Interval CI] 1.001, 1.02], P = 0.014) and more night-time sleep (OR 1.02, 95% CI 1.01, 1.04, P = 0.002], while male sex (OR 0.82, 95% CI 0.70, 0.95], P = 0.008) and time outdoors (OR = 0.97, 95% CI 0.95, 0.99], P = 0.011) were associated with less myopia. The association between sleep duration and myopia was not significant (p = 0.199) for total (night + midday) sleep.

Conclusions

Myopia and disordered sleep were both common in this cohort, but we did not find consistent evidence for an association between the two.

Trial Registration

clinicaltrials.gov NCT00848900