Overestimation of hyperopia with autorefraction compared with retinoscopy under cycloplegia in school-age children

Abstract

Aim: To compare sphere and cylinder refraction values using retinoscopy and autorefraction under cycloplegic conditions in children.

Methods: This cross-sectional study was carried out using multistage cluster sampling. The target population was children aged 6-12 years in Shahroud, a northern city in Iran. Examinations included measurements of visual acuity, subjective refraction and objective refraction. Objective refraction was measured with and without cycloplegia with a retinoscope and an autorefractometer.

Results: After applying the exclusion criteria, data from 5053 children were analysed. Spherical refraction results with autorefraction were significantly higher than results with retinoscopy (P<0.001). Refraction overestimation was significant in all age groups (P<0.0001). Comparison of differences in different spherical ametropia subgroups also showed a significant intermethod difference in all refractive states (P<0. 01). Overall, autorefraction tended to over plus hyperopics and under minus myopic cases compared with retinoscopy. The 95% limits of agreement for spherical values measured with the two techniques were -0.35 Diopter (D) to 0.50 D. The values of J₀ and J₄₅ vectors with autorefraction were significantly higher than those with retinoscopy (P<0.001). The 95% limits of agreement between the two methods for vectors J₀ and J₄₅ were -0.12 D to 0.15 D and -0.10 D to 0.11 D, respectively.

Conclusion: Since the observed differences in spherical refraction and the cylindrical components obtained through retinoscopy and autorefraction are statistically significant, but clinically insignificant, and the two methods have a strong correlation and agreement, it can be concluded that autorefraction can be a suitable substitute for retinoscopy in children under cycloplegic conditions.

Keywords: autorefraction; cycloplegic; retinoscopy; sphere.