Comparison of response AC/A ratio with two refractive correction methods for myopia teenagers

Abstract:

Objective：To observe and compare the response accommodative convergence/accommodation（AC/A） ratio of myopic teenagers with orthokeratology and frame glasses. Methods：This was a prospective case-control study. One hundred and twentyjuve－nile myopia aged 10-16 years were divided into orthokeratology group and frame glasses group according to the test results and wish－es of patients，with 60 cases in each group.The AC/A ratios before and after correction of all the cases in the two groups will be fol－lowed up and compared after one，three，six and twelve months. AC/A ratios were also analyzed in stratification with different diopters in each correction. Data were analyzed using ANOVA for repeated measuring，SNK-q test，two independent t-test. Results：A total of 113 cases completed the study. The AC/A ratios before and after correction in orthokeratology group and frame glasses group were respectively（4.52±0.58），（3.40±0.46），（3.48±0.42），（3.54±0.42），（3.63±0.44）D，（4.54±0.64），（4.46±0.65），（3.88±0.64），（4.11±0.61），（4.48±0.64）D. There was signifi－cant difference in AC/A rate between two refractive correc－tion methods（F=43.737，all P=0.000）. The degree of myopia had no significant effect on AC/A rate in orthokeratology group，but significant effect in frame glasses group. The effects of measurement time on AC/A ratio of each group were significant（F=94.037，F=168.559，F=26.661，P=0.000）. The interaction between the group and the measurement time also had significant effects（F=36.226，P=0.000）. But the interaction between degree of myopia and measurement time had no significant effects（F=0.814，P=0.502，F=0.288，P=0.814）. The AC/A ratio in orthokeratology group after correction were less than frame glasses group respectively（t=-9.898，t=-3.859，t=-5.748，t=-8.093，all P=0.000），but no significant difference was observed between two groups before correction（t=-0.140，P=0.889）. Conclusion：Frame glasses and orthokeratology can both reduce the AC/A ratio，but the effect of wearing orthokeratology is superior to wearing frame glasses.