Purpose To generate continuous growth curves for axial length (AL) in German children. We hypothesise that percentile curves of AL can be used as a predictive measure of myopia. Methods In this longitudinal and cross‐sectional LIFE Child Study, children’s non‐cycloplegic refraction data was collected using the Zeiss i.Profiler plus while AL was measured using the Haag‐Streit Lenstar. Reference growth curves were estimated as a continuous non‐parametric function of age. Results Data from 4511 visits of 1965 participants (1021 boys and 944 girls) between 3 and 18 years of age were analysed. For all ages and percentiles, the estimated AL was higher in boys than girls. AL differences between boys and girls were most pronounced in the 98th percentile at 3 years of age, being 0.93 mm longer eyes in boys. This difference decreased to 0.21 mm at 18 years of age. While the lower percentiles of AL reach their final value around age 13, the 50th percentile was still increasing by 0.05 mm per year until the end of the observation period. While, in general, children with longer eyes are more likely to develop myopia, this relationship is weaker between the ages of 5 and 8. Conclusion The LIFE Child Study data provides European AL data. In both Germany and China, AL has comparable growth rates when the baseline ALs are compared as percentiles. Thus, percentile curves of AL can be used as a predictive measure for the likelihood of developing as well as the progression of myopia.

Percentile curves of refractive development for German children were generated. We hypothesize that refraction in children in central Europe might differ from data in central Asia. Methods Non-cycloplegic refraction was measured using the ZEISS i.Profiler plus (Carl Zeiss Vision GmbH, Germany) in 1999 children, of which were 1046 male and 953 female, aged 3 to 18 years. Reference curves were calculated with the R-package GAMLSS as continuous function of age.

Background To investigate environmental and social risk factors for myopia in children and adolescents in Germany. Methods 1437 children aged between 3 and 18 inclusive were examined as part of the LIFE Child study based in Leipzig, Germany. Information about leisure time activities and social status was ascertained by parents and children in a questionnaire. Refractive status was attained by measuring noncycloplegic autorefraction. Myopia was defined as spherical equivalent (SE) ≤ − 0.75 D. Risk factors were identified using multiple logistic regression analysis. Results In multiple logistic regression analysis, myopia was significantly associated with less frequent outdoor activity (“once a week” vs. “twice a week or more”: odds ratio (OR) 4.35, 95% confidence interval (CI) 1.89–9.98, p<0.01) and longer near work sessions (1–2 h vs. < 1 h: OR 1.83, CI 1.10–3.04, p=0.02; > 3 h vs. < 1 h: OR 3.71, CI 1.43–9.61, p<0.01) after adjustment for age, sex and socioeconomic status (SES). Duration of outdoor activity, near work frequency and SES showed no significant association with myopia (p > 0.05). Children with a lower SES were involved in longer periods of outdoor and near work activities but on fewer occasions over the course of the week, although this connection was not significant. Conclusion Myopia is associated with environmental factors. The present findings suggest that daily exposure to sunlight and a restriction of long-duration near work activities might protect against pathological eye growth. Prevention strategies should be implemented for children at all ages.

Purpose This study describes the prevalence of visual impairment caused by uncorrected distance refractive error and the spectacle coverage in a large cohort of German children and adolescents. Furthermore, we determined the prevalence of amblyopia and amblyopia treatment. Methods Optometrists carried out visual acuity (VA) testing, non‐cycloplegic autorefraction, VA retesting with the refractive correction obtained by autorefraction, and if necessary subjective refraction and cover‐test in 1,874 subjects (901 girls/973 boys), aged 3 to 16 years. Additionally, a questionnaire on the history of previous eye care was completed. Results Distance visual impairment (VI) with VA worse than 6/18 Snellen in the better eye was present in 0.5% (95% confidence interval [95% CI]: 0.2% to 0.9%) of children. Logistic regression showed a significant positive association between VI and older age (OR = 1.21, P = 0.03). Gender differences were not found (P = 0.77). The spectacle coverage of all participants was 74.8% (95% CI: 65.2% to 82.8%). Amblyopia was found in 29 participants (1.5%; 95% CI: 1.0% to 2.2%) with no age or sex differences. The causes of unilateral amblyopia (27 cases, 93.1%) were anisometropia in 55.6% of children, strabismus in 25.9% and the combination of these factors in 18.5%. All children with bilateral amblyopia (2 cases, 6.9%) showed bilateral high ametropia. We observed 15 children with current amblyopia, who had been treated with occlusion therapy in the past (62.2%; 95% CI: 42.7% to 83.6%). Conclusions The prevalence of impaired VA caused by uncorrected refractive error and amblyopia is comparable with previous studies conducted in urban areas worldwide. Adding the measurement of refractive error to existing medical check‐ups, possibly using autorefraction, would be desirable.

Purpose. Current prevalence rates of myopia in children and adolescents vary all over the world, with especially high prevalence rates in East Asian countries. The objective of this study was to describe the refractive status in children and adolescents growing up in Germany. Material and Methods. Non-cycloplegic refractive status of children of the LIFE Child study in Leipzig, Germany, was measured by wavefront-based autorefraction in 1934 sub- jects (925 girls / 1009 boys), aged 3 to 16 years (mean = 9.05 ± 3.91). Myopia was defined as spherical equivalent refractive error (SE) ≤ -0.75 diopters (D), emmetropia as -0.75 D > SE < +0.75 D, hyperopia as SE ≥ +0.75 D and astigmatism as cylinder ≤ -0.75 D. Anisometropia was defined as a difference of ≥ 1.0 D in the SE between the two eyes. Results. Analysis revealed that refractive error became more myopic with older age (b = -0.08, p < 0.001), with an observed prevalence of myopia of 27 % in 16-year-old children (4 % in 3-year-olds). The true prevalence of myopia might be lower as non-cycloplegic measurements might overestimate ref- ractive error in myopes and underestimate refractive error in hyperopes which in turn may overestimate the prevalence of myopia. The prevalence of anisometropia also increased with growing age (OR = 1.14, observed prevalence in 3- versus 16-year-olds = 2.3 % and 8.1 %, respectively). The prevalence of astigmatism was 11.8 %. Conclusion. Myopia prevalence in German children aged 3 to 16 years is around or even less than 10 %, taking into consideration that measurements were carried out without cycloplegia. Our results are comparable to other European paediatric studies. In comparison to East-Asian countries myopia prevalence, and thus the risk for eye diseases related to high myopia, is much lower in Germany. Keywords Myopia, prevalence, refraction, anisometropia, astigmatism, hyperopia