Clinical evaluation of autorefraction and subjective refraction with and without cycloplegia in Chinese school-aged children: a cross-sectional study

BACKGROUND: The accuracy of open-field autorefractors is important for vision screening, clinical care, and vision research, especially in patients with childhood myopia. TOPCON KR3000 autorefractor was conventional autorefractor and subjective refraction after cycloplegia was gold criteria for assessing the refraction. Results of refractive error in Chinese school-aged children obtained by three methods were evaluated and compared. METHODS: A cross-sectional study was conducted. A total of 89 patients (with a total of 177 eyes) diagnosed as refractive error in the Affiliated Hospital of Nanjing University of Chinese Medicine from July 2020 to September 2020 were sequentially enrolled in this study. All subjects underwent routine ophthalmic examination to exclude other ocular diseases and had a best corrected visual acuity no less than 0.1 The spherical diopter (SD), spherical equivalence (SE), and astigmatism (J0 and J45) were determined in patients before cycloplegia using two autorefractors, and again after cycloplegia. Subjective refraction results were obtained simultaneously after cycloplegia as gold criteria for comparison. A comparison of data between three methods was performed using paired t-tests and presented graphically using Bland-Altman plots. RESULTS: Before cycloplegia, the SD and SE results from WAM were 0.14 D and 0.12 D more positive than the reading from TOPCON (P=0.011 and P=0.021, respectively). The SD measured by WAM and TOPCON was 0.31 D and 0.45 D more negative than the values obtained by subjective refraction after cycloplegia, respectively (P<0.001 and P<0.001, respectively). The SE readings also showed a similar trend (P<0.001, P<0.001). After cycloplegia, the SD and SE measurement obtained with WAM were 0.13 D and 0.12 D more positive than those measured by TOPCON (P<0.001 and P<0.001, respectively), and this was not significantly different to the results obtained using subjective refraction. However, the results of SD, SE, and J0 measured by the TOPCON were significantly different from the results obtained using subjective refraction (P<0.001, P<0.001, and P=0.002, respectively). CONCLUSIONS: In clinical application, the measurements obtained with the WAM-5500 autorefractor were more reliable than those of the TOPCON KR3000 autorefractor in patients with or without cycloplegia. The WAM-5500 Autorefractor represents a reliable and valid objective refraction tool for optometric practice.