Comparison between two autorefractor performances in large scale vision screening in Chinese school age children

AIM:To evaluate the effectiveness of Grand Seiko Ref/Keratometer WAM-5500 compared to Topcon KR800 autorefractor in detecting refractive error in large scale vision screening for Chinese school age children with the WHO criteria.METHODS:A total of 886 participants were enrolled with mean age of 9.49±1.88 y from Tianjin,China.Spherical equivalent(SE)was obtained from un-cycloplegic autorefraction and cycloplegic autorefraction.Topcon KR 800(Topcon)and Grand Seiko WAM-5500(WAM)autorefractors were used.Bland-Altman Plot and regression were generated to compare their performance.The overall effectiveness of detecting early stage refractive error was analyzed with receiver operating characteristic(ROC)curves.RESULTS:The mean SE was-0.98±1.81 diopter(D)and the prevalence of myopia was 48.9%defined by WHO criteria according to the result of cycloplegic autorefraction.The mean SE of un-cycloplegic autorefraction with Topcon and WAM were-1.21±1.65 and-1.20±1.68 D respectively.There was a strong linear agreement between result obtained from WAM and cycloplegic autorefraction with an R2 of 0.8318.Bland-Altman plot indicated a moderate agreement of cylinder values between the two methods.The sensitivity and specificity for detecting hyperopia were 90.52%and 83.51%;for detecting myopia were 95.60%and 90.24%;for detecting astigmatism were 79.40%and 90.21%;for detecting high myopia were 98.16%and 98.91%respectively.CONCLUSION:These findings suggest that both Grand Seiko and Topcon autorefractor can be used in large-scale vision screening for detecting refractive error in Chinese population.Grand Seiko gives relatively better performance in detecting myopia,hyperopia,and high myopia for school age children.