Sleep Duration, Bedtime, and Myopia Progression in a 4-Year Follow-up of Chinese Children: The Anyang Childhood Eye Study

Abstract

To investigate the relationship between sleep duration and bedtime with myopia progression and axial elongation during a 4-year follow-up in primary school children. METHODS. This study included 1887 children (aged 7.09 ± 0.41 years) who had cycloplegic refractions data at baseline and a fourth visit and 2209 children (aged 7.10 ± 0.41 years) for axial length. All children underwent comprehensive ophthalmologic examinations, including cycloplegic refraction and ocular biometry, and standardized questionnaires, including average night-time sleep duration (h/d) and bedtime (time to bed). Myopia was defined as spherical equivalent <-0.5 diopters. RESULTS. At the last follow-up, the mean myopia progression and axial elongation for all children were-1.89 ± 1.28 diopters and 1.22 ± 0.57 mm. After stratifying the sleep duration into tertile groups, myopia progression and axial elongation were slower in children with highest sleep duration tertile (P = 0.04 and P =0.014) in girls but not in boys, compared with the middle sleep duration tertile. However, after adjusting for potential confounders, no significant association was found for sleep duration with myopia progression and axial elongation for the children (P = 0.255 and P = 0.068), and the association with axial elongation was only of borderline significance in girls (P = 0.045). The bedtime was not associated with myopia progression and axial elongation in the regression analyses (P = 0.538; P = 0.801). CONCLUSIONS. These results show that there was no significant association between sleep duration and bedtime with myopia progression and axial elongation among children. The findings in girls might be related to the earlier onset of puberty.

Sleeping late is a risk factor for myopia development amongst school-aged children in China

“…A recent Chinese study also reported negative results for sleep duration and myopia progression, although the association became significant in girls after stratifying the sample by gender 23 . Moreover, unlike the Korean adolescent sample studied by Jee et al or the Chinese children sample studied by Xu et al 11,20 , children of the current sample had sufficient sleep for their age group (an average of 9.49 ± 0.54 h per night at baseline) according to consensus recommendations developed by the American Academy of Sleep Medicine, who recommends at least 9 h sleep every night for 6 to 9 years old 24 .…”

“…As previously iterated, our study demonstrated no evidence supporting a relationship between sleep duration and myopia, which is similar to the conclusion drawn by a Singaporean study on 376 infants, where they found no association between sleep duration at 12 months and myopia at 3 years 22 . A recent Chinese study also reported negative results for sleep duration and myopia progression, although the association became significant in girls after stratifying the sample by gender 23 . Moreover, unlike the Korean adolescent sample studied by Jee et al or the Chinese children sample studied by Xu et al 11 , 20 , children of the current sample had sufficient sleep for their age group (an average of 9.49 ± 0.54 h per night at baseline) according to consensus recommendations developed by the American Academy of Sleep Medicine, who recommends at least 9 h sleep every night for 6 to 9 years old 24 .…”

IMI Risk Factors for Myopia

“…Associations between sleep and myopia have also been reported, but the evidence is quite inconsistent. [208][209][210][211][212][213] A large longitudinal study from Shanghai reported consistent significant associations of going to sleep late with greater myopia prevalence at baseline, incident myopia, and myopic shift in refraction, after adjustment for several variables including age, but did not find that sleep duration was an important factor. 214 The authors noted that going to sleep late was more prevalent in children who lived in urban areas, were older, had more parents with myopia, had better educated parents, tended to wake up late, spent more time reading and on screens, and spent less time outdoors -all characteristics that were also identified as risk factors for myopia.…”

Sleep in Myopic and Non-Myopic Children

“…However, other studies have found no association between sleep duration and myopia in Chinese children. 30,31 These studies utilized subjective measures to assess various sleep parameters, which may contribute to the inconsistent findings between studies. Questionnaires and sleep diaries have been found to be less accurate than objective measures, such as polysomnography and actigraphy.…”