What is the influence of parents' myopia on their children's myopic progression? A 22-year follow-up study

PurposeTo study the connection between parental myopia and their children's myopia from school age to adulthood. MethodsTwo hundred and forty myopic schoolchildren (119 boys, 121 girls, mean age 10.9years) with no previous spectacles for myopia were recruited to a 3-year treatment trial with different use of spectacles. Follow-ups were performed at mean ages of 13.9, 23.7 and 33.2years for 238, 176 and 170 subjects respectively. Subjective refraction was calibrated to the spherical equivalent at corneal level (SEcor). Corneal refractive power (CR) and axial length (AL) were measured. Parental myopia was assessed with a questionnaire and the children assigned accordingly to one of three hereditary groups: both parents myopic H++, one myopic parent=H+- and no myopic parents=H-. ResultsAt baseline, no significant gender differences in age or SEcor were found in the different hereditary groups. Among girls, CR was significantly higher in hereditary group H++ (45.201.08 D) than in group H+- (44.19 +/- 1.28 D; p=0.006) or H- (43.84 +/- 1.18 D; p<0.001). Among boys, the differences in CR between the hereditary groups were smaller and significant at follow-up 2 only. At follow-up end, among males, no significant differences between the hereditary groups were found in SEcor, CR, AL or myopic progression. Among females, myopic progression was 4.21 +/- 1.81 D if one or both parents were myopic and -3.19 +/- 1.36 D if neither parent was myopic (p=0.035), but no significant difference was observed in AL. ConclusionsThe main difference between the hereditary groups was higher CR and myopic progression among females with myopic parents than non-myopic parents, but with no significant difference in AL with respect to parental myopia at study end.