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.

Lag of accommodation predicts clinically significant change of spherical equivalents after cycloplegia

AIM: To evaluate related factors with the change of spherical equivalents(ΔSE) and determine the suitable predictor of clinically significant ΔSE(≥0.50 D) with cyclopentolate hydrochloride on Chinese children. METHODS: A total of 145 right eyes of 145 children aged 4 to 15 y were enrolled. Intraocular pressure, axial length and lag of accommodation(LOA) were assessed before cycloplegia induced by 3 drops of 1% cyclopentolate at 5-minute intervals. SE was measured before and 1 h after the first drop of cyclopentolate. ΔSE was compared between different gender groups and among refractive groups. Multivariate linear regression analysis was performed to find related factors with ΔSE. ROC analysis was used to figure out the suitable predictor of clinically significant ΔSE.RESULTS: For the total 145 eyes, the mean SE reached up to-0.70±1.86 D from-1.30±1.62 D, with the mean ΔSE of 0.60±0.55 D. The mean ΔSE were 0.63±0.55 D and 0.57±0.56 D respectively in the male and female group(P=0.40). The mean ΔSE was significantly different among different refractive groups(P<0.0001), with the ΔSE of hyperopia group(1.12±0.64 D) larger than that of the emmetropia(0.56±0.43 D, P=0.001) and myopia group(0.32±0.28 D, P<0.0001). The ΔSE was correlated with LOA(B=-0.54, P<0.0001), cycloplegic SE(B=0.10, P<0.0001) and age(B=-0.04, P=0.015). ROC curve indicated that LOA predicted clinically significant ΔSE by 82% [area under the curve(AUC)=0.82] alone, while the value was slightly improved to 85%(AUC=0.85) in combination with axial length and 86%(AUC=0.86) in association with axial length as well as age.CONCLUSION: After cycloplegia with cyclopentolate, the ΔSE decreases with larger LOA, longer axial length and older age. Specifically, LOA plays a more vital role in predicting clinically significant ΔSE.