| Abstract: | Objective: To investigate visual acuity in preschoolers and the application value of refractive screening with the Spot Vision Screener. Methods: In this cross-sectional study, 5 866 preschool children in the Haidian District of Beijing were selected for noncycloplegic visual and refractive examinations. The visual acuity distribution was analyzed by the likelihood-ratio Chi-square test. The refractive results of children with normal vision were tested by a rank sum test. The Kruskal-Wallis H test was used to analyze the differences in refractive values and anisometropia for different age groups. A two-way comparison between any two groups was performed using a Wilcoxon rank test. Medians (Q1, Q3) were used to describe the distribution characteristics of each refraction and anisometropia. The cut-off points for refractive screenings were calculated by percentiles. Results: The respective incidences of visual abnormalities were 4.25% and 17.29% based on the two methods. The differences between different age groups were statistically significant (P<0.05). The differences in spherical values, cylindrical values and spherical anisometropia values in children with normal vision were statistically significant among different age groups (P<0.05).Hyperopia and astigmatism values decreased as age increased. The values of spherical equivalent (SE), cylindrical anisometropia and SE variability were not statistically significant among different age groups (P>0.05). P2.5 and P97.5 of the spherical value and SE were 0 D, +1.50 D, -0.25 D, and +1.00 D, respectively. P5 for the cylinder value was -1.25 D. P95 for spherical and cylindrical anisometropia was 0.75 D. Conclusions: The Spot Vision Screener is considered a useful device in large-scale refractive screening work with children. The cut-off points of refractive screening and visual acuity can be used for referral. |
