A comparison of autorefraction and subjective refraction with and without cycloplegia in primary school children.

PURPOSE To evaluate the accuracy of autorefraction using three autorefractors comparing to subjective refraction in diagnosing refractive error in children. DESIGN A cross-sectional study. METHODS setting: Community based study. study population: 117 children sampled from primary schools. procedures: All subjects underwent autorefraction using three auto refractors and subjective refraction with and without cycloplegia. main outcome measures: Spherical power, cylindrical power, and spherical equivalence (SE). RESULTS Without cycloplegia, the mean SE were significantly different for Retinomax K plus 2 (-1.55 diopters, SD 2.37 diopters; 95% CI -1.98 to -1.12; P < .0001) and Canon RF10 (-1.11 diopters; SD 2.61 diopters; 95% CI -1.59 to -0.64; P = .0023) compared with monocular subjective refraction (-0.80 diopters; SD 2.25 diopters; 95% CI -1.21 to -0.35). Mean SE was significantly different for Grand Seiko WR5100K (-0.79 diopters; SD 2.40 diopters; 95% CI -1.23 to -0.35; P = .0002) compared with binocular subjective refraction (-0.62 diopters; SD 2.51 diopters; 95% CI -1.07 to -0.16). With cycloplegia, there was no significant difference in mean SE between refraction methods. Sensitivity and specificity results for the diagnosis of myopia: Without cycloplegia: Retinomax K plus 2 (sensitivity 1.0, specificity 0.51); Canon RF10 (sensitivity 0.92, specificity 0.81); and Grand Seiko WR5100K (sensitivity 0.91, specificity 0.98). With cycloplegia: Retinomax K plus 2 (sensitivity 0.97, specificity 0.99); Canon RF10 (sensitivity 0.97, specificity 0.96); and Grand Seiko WR5100K (sensitivity 1.0, specificity 0.97). CONCLUSIONS Under noncycloplegic conditions, all three autorefractors have a tendency towards minus over correction in children resulting in over diagnosis of myopia. However autorefractors were accurate under cycloplegic conditions.