Laboured reading and musculoskeletal pain in school children - the role of lifestyle behaviour and eye wear: a cross-sectional study.

BACKGROUND: Lifestyle behaviour in children and adolescents has become increasingly sedentary and occupied with digital work. Concurrently, there has been an increase in the prevalence of headache, neck- and low back pain, which are leading causes of disability globally. Extensive near work and use of digital devices are demanding for both the visual system and the upper body head-stabilizing musculature. Uncorrected vision problems are present in up to 40% of Nordic school children, and a lack of corrective eye wear may cause eyestrain, musculoskeletal pain and headache. The aim of this study was to investigate associations between laboured reading, musculoskeletal pain, uncorrected vision, and lifestyle behaviours in children and adolescents. METHODS: This was a cross-sectional study with a total of 192 Norwegian school children aged 10-11 and 15-16 years. As a part of a school vision testing program, the children completed an online questionnaire about general and ocular health, socioeconomic status, academic ambition, near work and related symptoms, upper body musculoskeletal pain, and physical and outdoor activities. RESULTS: The 15-16-year-olds had a more indoor, sedentary, digital-based lifestyle with higher academic demands, compared with the 10-11-year-olds. Concurrently, reading became more laboured and upper body musculoskeletal pain increased with age. Girls reported more symptoms, higher academic ambitions, and more time spent on schoolwork and reading, compared with boys. Non-compliance in wearing prescribed eye wear (glasses or contact lenses), increased use of near digital devices, and experiencing visual stress (glare) were positively associated with laboured reading and upper body musculoskeletal pain. CONCLUSIONS: A screen-based lifestyle with high academic demands challenges the ability to sustain long hours of static, intensive near work. Extensive near work tires the visual system and upper body musculature and provokes laboured reading and musculoskeletal pain symptoms. This study emphasizes the importance of regular eye examinations in school children, and the need to raise awareness among children, parents, and school- and health personnel about the importance of optimal vision and visual environment for academic performance and health.

Vision status of children aged 7-15 years referred from school vision screening in Norway during 2003-2013: a retrospective study.

BACKGROUND: Undetected vision problems is an important cause of reduced academic achievement, performance in everyday life and self-esteem. This receives little attention in national health care services in Norway even though most of these vision problems are easily correctable. There are no published data on how many Norwegian schoolchildren are affected by correctable vision problems. This study aims to determine the vision status in primary and secondary schoolchildren referred from vision screening during the 10 year period of 2003-2013. METHODS: Of the 1126 children (15%) aged 7-15 years referred to the university eye clinic by the school screening program, all 782 who attended the eye clinic were included in the study. Patient records were retrospectively reviewed with regard to symptoms, refractive error, best corrected visual acuity (BCVA) of logMAR, binocular vision, ocular health and management outcomes. RESULTS: Previously undetected vision problems were confirmed in 650 (83%) of the children. The most frequent outcomes were glasses (346) or follow-up (209), but types of treatment modalities varied with age. Mean refractive errors were hyperopic for all age groups but reduced with age (ANOVA, p < 0.001). Overall, 51% were hyperopic, 32% emmetropic and 17% myopic. Refractive errors did not change across the decade (linear regression, all p > 0.05). Mean logMAR BCVAs were better than 0.0 and improved with age (ANOVA, p < 0.001). The most prevalent symptoms were headaches (171), near vision problems (149) and reduced distance vision (107). CONCLUSIONS: The vision screening identified children with previously undetected visual problems. This study shows that the types of visual problems varied with age and that most problems could be solved with glasses. Our results stress the importance of regular eye examinations and that vision examinations should be included in primary health care services. Furthermore, there is a need for raised awareness among parents and teaching staff regarding vision problems in children.

Accommodative instability: relationship to progression of early onset myopia.

BACKGROUND: In a previous study, we demonstrated that children with early onset myopia had greater instability of accommodation than a group of emmetropic children. Since that study was correlational, we were unable to determine the causal relationship between this and myopic progression. To address this, we examined the children two years later. We predicted that if accommodative instability was causing the myopic progression, instability at Visit 1 should predict the refractive error at Visit 2. Additionally, instability at Visit 1 should predict myopic progression. METHODS: Thirteen myopic and 16 emmetropic children were included in the analysis. Dynamic measures of accommodation were made using eccentric photorefraction (PowerRefractor) while children viewed targets set at three distances (accommodative demands), namely, 0.25 metres (4.00 D demand), 0.5 metres (2.00 D demand) and 4.00 metres (0.25 D demand). RESULTS: Both refractive error and accommodative instability at Visit 1 were highly correlated with the same measures at Visit 2. Children with myopia showed greater instability of accommodation (0.38 D) than children with emmetropia (0.26 D) at the 4.00 D target on Visit 1 and this instability of accommodation weakly predicted myopic progression. CONCLUSIONS: The results presented in the present study suggest that instability of accommodation accompanies myopic progression, although a casual relationship cannot be established.

Variability of the accommodation response in early onset myopia.

PURPOSE: Hyperopic retinal defocus (blur) is thought to be a cause of myopia. If the retinal image of an object is not clearly focused, the resulting blur is thought to cause the continuing lengthening of the eyeball during development causing a permanent refractive error. Both lag of accommodation, especially for near targets, and greater variability in the accommodative response, have been suggested as causes of increased hyperopic retinal blur. Previous studies of lag of accommodation show variable findings. In comparison, greater variability in the accommodative response has been demonstrated in adults with late onset myopia but has not been tested in children. This study looked at the lag and variability of accommodation in children with early onset myopia. METHODS: Twenty-one myopic and 18 emmetropic children were tested. Dynamic measures of accommodation and pupil size were made using eccentric photorefraction (PowerRefractor) while children viewed targets set at three different accommodative demands (0.25, 2, and 4 D). RESULTS: We found no difference in accommodative lag between groups. However, the accommodative response was more variable in the myopes than emmetropes when viewing both the near (4 D) and far (0.25 D) targets. Since pupil size and variability also varied, we analyzed the data to determine whether this could account for the inter-group differences in accommodation variability. Variation in these factors was not found to be sufficient to explain these differences. Changes in the accommodative response variability with target distance were similar to patterns reported previously in adult emmetropes and late onset myopes. CONCLUSIONS: Children with early onset myopia demonstrate greater accommodative variability than emmetropic children, and have similar patterns of response to adult late onset myopes. This increased variability could result in an increase in retinal blur for both near and far targets. The role of accommodative variability in the etiology of myopia is discussed.