TY - JOUR
T1 - Refractive error, axial length, environmental and hereditary factors associated with myopia in Swedish children
AU - Demir, Pelsin
AU - Baskaran, Karthikeyan
AU - Theagarayan, Baskar
AU - Gierow, Peter
AU - Sankaridurg, Padmaja
AU - Macedo, Antonio Filipe
N1 - Funding Information:
This study was supported by Specsavers Sweden AB and by the faculty of Health and Life Sciences, Linnaeus University Kalmar; Brien Holden Vision Institute; Carl Zeiss Meditec Sweden. The authors would also like to acknowledge the Brien Holden Vision Institute for providing the Shin-Nippon Nvision-K 5001 autorefractor and Carl Zeiss Meditec Sweden for providing the IOLMaster 500.
Publisher Copyright:
© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Clinical relevance: Investigation of refractive errors amongst Swedish schoolchildren will help identify risk factors associated with myopia development. Background: Genetic and hereditary aspects have been linked with the development of myopia. Nevertheless, in the case of ‘school myopia’ some authors suggest that environmental factors may affect gene expression, causing school myopia to soar. Additional understanding about which environmental factors play a relevant role can be gained by studying refractive errors in countries like Sweden, where prevalence of myopia is expected to be low. Methods: Swedish schoolchildren aged 8-16 years were invited to participate. Participants underwent an eye examination, including cycloplegic refraction and axial length (AL) measurements. Predictors such as time spent in near work, outdoor activities and parental myopia were obtained using a questionnaire. Myopia was defined as spherical equivalent refraction (SER) ≤ −0.50D and hyperopia as SER ≥ +0.75D.Results: A total of 128 children (70 females and 58 males) participated in this study with mean age of 12.0 years (SD = 2.4). Based on cycloplegic SER of the right eye, the distribution of refractive errors was: hyperopia 48.0% (CI95 = 38.8-56.7), emmetropia 42.0% (CI95 = 33.5-51.2) and myopia 10.0%. (CI95 = 4.4-14.9). The mean AL was 23.1 mm (SD = 0.86), there was a correlation between SER and AL, r = −0.65 (p < 0.001). Participants with two myopic parents had higher myopia and increased axial length than those with one or no myopic parents. The mean time spent in near work, outside of school, was 5.3 hours-per-day (SD = 3.1), and mean outdoor time reported was 2.6 hours-per-day (SD = 2.2) for all the participants. The time spent in near work and outdoor time were different for different refractive error categories. Conclusion: The prevalence of myopia amongst Swedish schoolchildren is low. Hereditary and environmental factors are associated with refractive error categories. Further studies with this sample are warranted to investigate how refractive errors and environmental factors interact over time.
AB - Clinical relevance: Investigation of refractive errors amongst Swedish schoolchildren will help identify risk factors associated with myopia development. Background: Genetic and hereditary aspects have been linked with the development of myopia. Nevertheless, in the case of ‘school myopia’ some authors suggest that environmental factors may affect gene expression, causing school myopia to soar. Additional understanding about which environmental factors play a relevant role can be gained by studying refractive errors in countries like Sweden, where prevalence of myopia is expected to be low. Methods: Swedish schoolchildren aged 8-16 years were invited to participate. Participants underwent an eye examination, including cycloplegic refraction and axial length (AL) measurements. Predictors such as time spent in near work, outdoor activities and parental myopia were obtained using a questionnaire. Myopia was defined as spherical equivalent refraction (SER) ≤ −0.50D and hyperopia as SER ≥ +0.75D.Results: A total of 128 children (70 females and 58 males) participated in this study with mean age of 12.0 years (SD = 2.4). Based on cycloplegic SER of the right eye, the distribution of refractive errors was: hyperopia 48.0% (CI95 = 38.8-56.7), emmetropia 42.0% (CI95 = 33.5-51.2) and myopia 10.0%. (CI95 = 4.4-14.9). The mean AL was 23.1 mm (SD = 0.86), there was a correlation between SER and AL, r = −0.65 (p < 0.001). Participants with two myopic parents had higher myopia and increased axial length than those with one or no myopic parents. The mean time spent in near work, outside of school, was 5.3 hours-per-day (SD = 3.1), and mean outdoor time reported was 2.6 hours-per-day (SD = 2.2) for all the participants. The time spent in near work and outdoor time were different for different refractive error categories. Conclusion: The prevalence of myopia amongst Swedish schoolchildren is low. Hereditary and environmental factors are associated with refractive error categories. Further studies with this sample are warranted to investigate how refractive errors and environmental factors interact over time.
KW - Axial length
KW - environmental factors
KW - hereditary factors
KW - myopia
KW - refractive error
UR - http://www.scopus.com/inward/record.url?scp=85102313065&partnerID=8YFLogxK
U2 - 10.1080/08164622.2021.1878833
DO - 10.1080/08164622.2021.1878833
M3 - Article
AN - SCOPUS:85102313065
VL - 104
SP - 595
EP - 601
JO - Clinical and Experimental Optometry
JF - Clinical and Experimental Optometry
SN - 0816-4622
IS - 5
ER -
