Table 2

Cohort of children pre-COVID-19 : changes of myopia prevalence, spherical equivalent and axial length (AL) over 3 years

BaselineAt 3 year follow-upDifferences between baseline and 3-year year follow-up
Myopia prevalenceSER (D)
Mean (SD)
AL (mm)
Mean (SD)
Myopia prevalenceSER (D)
Mean (SD)
AL (mm)
Mean (SD)
Changes in myopia prevalenceP valueChanges in SER (D)
Mean (SD)
P valueChanges in AL (mm)
Mean (SD)
P value
Age group (years)
 6 (n=286)9.09%0.60 (1.64)22.82 (0.93)51.94%−0.77 (2.36)23.85 (1.17)42.85%<0.001*−1.38 (1.46)<0.001* 1.02 (0.51)<0.001*
 7 (n=363)19.28%0.41 (1.46)22.95 (0.89)51.82%−0.98 (2.18)23.82 (1.14)-32.54%<0.001*−1.39 (1.26)<0.001* 0.89 (0.47)<0.001*
 8 (n=435)23.45%0.10 (1.38)23.20 (0.88)54.66%−1.00 (1.95)23.96 (1.04)31.21%<0.001*−1.10 (1.31)<0.001* 0.77 (0.47)<0.001*
 Total (n=1084)19.02%0.34 (1.49)23.02 (0.91)52.99%−0.93 (2.14)23.89 (1.11)33.97%<0.001*−1.27 (1.34)<0.001* 0.88 (0.49)<0.001*
  • Χ2 was used to compare categorical variables between groups; a paired t-test was used to compare continuous variable between groups

  • *Significance was set at 0.05

  • AL, axial length; D, diopter; SER, spherical equivalent refraction.