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Purpose: To study the prevalence and risk factors of myopia with data from a questionnaire study conducted in 1983 among Finnish school children. Methods: School children (n = 4 961) from the 1st, 5th and 8th grades of school (7‐, 11‐ and 15‐year‐olds) in Central Finland were screened for vision followed by a questionnaire, which was returned by 4 352 (87.7%) participants. Myopia was categorized based on the questionnaire. Items concerned daily time spent on near work and outdoor activities, excluding time spent at school, watching TV and parental myopia and the associations of myopia with these factors were studied. Results: The prevalence of myopia was 3%, 15% and 27% among the 7‐, 11‐ and 15‐year‐olds, and if daily near work at home was ≤1 hr, myopia prevalence was 0.5%, 3.3% and 17.6%, respectively. The adjusted risk of myopia for each daily near work hour was OR 1.476 (95% confidence interval 1.099–1.984, p = 0.010), OR 1.346 (1.170–1.584, p < 0.001) and OR 1.206 (1.076–1.352, p = 0.001), in the 3 age groups, respectively. The adjusted risk of myopia for each daily hour spent outdoors was OR 0.764 (0.648–0.900, p = 0.001) in the 11‐year‐olds and OR (0.840, 0.743–0.950, p = 0.005) in the 15‐year‐olds. Outdoors time prevented myopia at different levels of near work, although less at the highest levels, and near work increased risk of myopia with the level of outdoors time. If the ratio between near work and outdoors time was ≤0. 5 or >1.5, the prevalence of myopia was 1.4% versus 5.6%, 6.3% versus 24.7% and 15.9% versus 36.9%, among the 7‐, 11‐ and 15‐year‐olds, respectively. The higher prevalence of myopia among the 11‐ and 15‐year‐old girls than boys was explained by more near work and less outdoor time among the girls. Having two myopic parents roughly doubled the risk of myopia compared to if one myopic parent in the 11‐ and 15‐year‐olds. Conclusions: Myopic parents, greater near work time, less outdoors time, a higher near work/outdoors ratio, and being a girl increased the risk of myopia. Myopia was rare in the 7‐ and 11‐year‐olds if daily near work at home did not exceed one hour or if the near work/outdoors ratio was not higher than 0.5. Outdoors time was associated with the prevalence of myopia at all levels of near work, although the association was weaker at the highest level. [ABSTRACT FROM AUTHOR]

Purpose: To compare 3‐year myopic progression between Finnish and Singaporean children. Methods: Myopic progression was compared between 9‐year‐old (mean age 9.7 ± 0.4 years, n = 92) and 11‐year‐old (mean age 11.7 ± 0.4 years, n = 144) Finnish (Finnish RCT) children and Singaporean children matched by age and refraction (SCORMMatched, n = 403) and 7‐ to 8‐year‐old Singaporean children matched only by refraction (SCORM Young, n = 186). Spherical equivalent (SE) was between −0.50 and −3.00 D. Refraction with cycloplegia was controlled annually for 3 years. Information on parental myopia, mother's education, time spent on near‐work and outdoor time was gathered by parental questionnaire. Results: Three‐year myopic progression was −2.08 ± 0.96 D and −1.30 ± 0.69 D in the Finnish RCT and Singaporean SCORM Matched 9‐year‐olds, respectively, and −1.34 ± 0.78 D, and −0.52 ± 0.44 D in the 11‐year‐olds, respectively (p < 0.001 between all groups). Myopic progression was fastest (−2.69 ± 0.89 D) in the SCORM 7‐year‐olds and similar between the SCORM Matched 9‐year‐olds and Finnish RCT 11‐year‐olds (p = 0.55). The Finnish RCT and SCORM Matched children showed significant differences in both daily near‐work time (1.8 ± 1.0 versus 3.4 ± 1.9 hours per day, p < 0.001) and outdoor time (2.6 ± 0.9 versus 0.5 ± 0.4 hours per day, p < 0.001). These differences did not, however, explain the differences in myopic progression between the groups. More time spent outdoors was associated with less myopic progression in the Finnish RCT (r = 0.17, p = 0.009) group only. In the whole materials, greater myopic progression was associated with younger age at baseline (p < 0.001), younger age was associated with mother's higher education (p < 0.001), and mothers higher education was associated with myopia in both parents (p < 0.001). Conclusion: Age at baseline was the most significant factor associated with myopic progression. However, at the same age and with the same initial refraction, the Finnish and Singaporean children showed different myopic progression. This result remains unexplained. Thus, age of myopia onset should be considered when comparing myopic progression between different samples and conducting treatment trials. Parental myopia may be a weak indicator of heredity of myopia. [ABSTRACT FROM AUTHOR]

Purpose: To determine the effect of the definition of high myopia on its prevalence and risk factors for high myopia. Methods: A total of 240 myopic schoolchildren (119 boys and 121 girls) at the mean age of 10.9 years (range 8.8–12.8 years) were recruited to a randomized clinical trial of myopia treatment among children from 3rd‐ and 5th grades of school referred for an eye examination due to poor distant vision and having no previous spectacles. Clinical follow‐ups, including refraction with cycloplegia, were conducted annually at 3 years [third follow‐up here = clinical follow‐up 1, (n = 237)], and thereafter twice at approximately 10‐year intervals [clinical follow‐ups 2 (n = 179) and 3, (n = 134)]. Additional refraction values between follow‐ups 2 and 3 were received from ophthalmologists and opticians' prescriptions and records. The most recent adulthood refraction measure available was taken as the final refraction value for 204 (85%) of the original cohort [mean follow‐up time (±standard deviation) 22.1 (±3.9) years]. Parental myopia, time spent on reading and close work, watching TV and outdoor activities were assessed with a questionnaire at the clinical follow‐ups. The influence of different definitions of high myopia on its prevalence was analysed. The associations of different factors with high myopia were investigated. Results: Mean spherical equivalent (SE) at baseline was −1.43 (±0.60) D, ranging from ‐0.38 D to −3.00 D. At follow‐up end, mean SE of the more myopic eye was −5.29 (±1.95) D, ranging from −1.00 D to −11.25 D. High myopia prevalence with the definitions SE < −6.00 D in the right eye and SE ≤ −6.00 D or ≤−5.00 D in either eye was 24%, 32% and 52%, respectively. In this study, high myopia was defined as spherical equivalent (SE) ≤ −6.00 D in either eye. If both parents were myopic, the odds ratio (OR) of having high myopia was 3.9 (95% CI: 1.5–10.4). Younger age at baseline predicted higher prevalence of high myopia; baseline ages between 8.8 and 9.7 and between 11.9 and 12.8 years gave prevalences 65% and 7%. Higher myopia at baseline, higher myopic progression between the first follow‐ups and more time spent on reading and close work as compared with time spent outdoors were associated with high myopia. Conclusion: About 32% of the children receiving first spectacles for myopia between ages of 8.8–12.8 years had high myopia (SE ≤ −6.00 D in either eye) in adulthood. Different definitions of high myopia ranging between −5 D and −6 D lead to large differences in prevalence. A generally accepted definition of high myopia is thus needed. Parental myopia, age at baseline, myopic progression during the first post onset year, and more time spent on reading and close work and less on outdoor activities in childhood were associated with adulthood high myopia. [ABSTRACT FROM AUTHOR]

Purpose: To examine myopic progression and factors connected with myopic progression. Methods: Myopic schoolchildren, with no previous spectacles, 119 boys and 121 girls, were recruited during 1983-1984 to a randomized 3-year clinical trial of bifocal treatment of myopia with a subsequent 20-year follow-up. Participants' mean age at Baseline was 10.9, ranging from 8.7 to 12.8 years. An ophthalmological examination was carried out annually for 3 years and twice thereafter at ca. 10-year intervals. Additional refraction values were received from prescriptions issued by different ophthalmologists and opticians. Altogether, 1915 refraction values were available. Reading distance and accommodation were measured at each control visit. Data on parents' myopia, daily time spent on reading and close work, outdoor activities and watching television were gathered with a structured questionnaire. Results: Using bifocals (+1.75 add) or reading without glasses or accommodation stimulus during the 3-year period in childhood did not correlate with adulthood refraction. Short reading distance in childhood predicted higher adulthood myopia among females. The factors predicting faster myopic progression were parents' myopia and less time spent on sports and outdoor activities at childhood. Time spent on reading and close work in childhood was related to myopic progression during the first 3 years but did not predict adulthood myopia. Myopia throughout follow-up was higher among those who watched television <3 hr daily than those who spent more time watching television. Mean myopic progression 8 years after age 20-24 was -0.45 D ± 0.71 (SD), and in 45% of cases, progression was =0.5 D. Conclusions: In nearly half of the cases, myopia beginning at school continued to progress into adulthood. Higher adulthood myopia was mainly related to parents' myopia and less time spent on sports and outdoor activities in childhood. [ABSTRACT FROM AUTHOR]