The Effect of Genetic Factors on the Occurrence of Myopia.

PURPOSE: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. MATERIAL AND 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.