title: The effect of genetic factors on the occurrence of myopia.
abstract: OBJECTIVE
  The aim of this study was to investigate on a large population if and how genetic factors have an influence on the occurrence of myopia.
  
  
  METHODS
  A total of 5533 students were examined (2659 boys and 2874 girls, in age 6 18 years, mean age 11.9, S.D. 3.2). The examination included retinoscopy under cycloplegia induced with 1% tropicamide. Myopia was defined as a spherical equivalent of at least -0.5 dioptres. The students and their parents completed a questionnaire on the child's family history of myopia. Data analysis was performed using chi-squared test; p-values of < 0.05 were considered statistically significant.
  
  
  RESULTS
  It was found that myopia occurs more often in students whose father (p < 0.001), mother (p < 0.001) or siblings (p < 0.0001) have myopia. A relation between the occurrence of myopia in grandparents and grandchildren was not observed (p > 0.05).
  
  
  CONCLUSIONS
  The obtained results indicate that genetic factors have a significant effect on the occurrence of myopia.
authors.affiliation: Department of Ophthalmology, Pomeranian Medical Academy, Szczecin, Poland. czepita@pro.onet.pl
authors.forename: Damian
authors.initials: D
authors.lastname: Czepita
authors.forename: Artur
authors.initials: A
authors.lastname: Mojsa
authors.forename: Maria
authors.initials: M
authors.lastname: Ustianowska
authors.forename: Maciej
authors.initials: M
authors.lastname: Czepita
authors.forename: Ewelina
authors.initials: E
authors.lastname: Lachowicz
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D008297:Male; D009216:Myopia / Q000453:epidemiology / Q000235:genetics*; D016017:Odds Ratio; D010290:Parents; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D012029:Refraction, Ocular; D012307:Risk Factors; D014792:Visual Acuity; D044465:White People / Q000235:genetics* / Q000706:statistics & numerical data