Purpose: To evaluate repeatability of the ETDRS log MAR visual acuity measurement in children and the relative influence factors.
Methods: The children (n = 348) with visual acuity less than 0.5 (equal to 0.3 log unit) in either eye, or one tenth in children with normal visual acuity were chosen to do repeatable uncorrected VA measurement with Bland-Altman analysis and Kappa analysis using ETDRS acuity chart.
Results: The mean difference of visual acuity was 0.004 log +/- 0.07. There was a significant repeatability (k = 0.71) between two visual acuity examination. There were significant consistent results both on male and female patients (P = 0.845). A significant relationship was found between age and VA repeatability (P = 0.019). The VA repeatability could also be influenced by refractive error (P = 0.000). The acuity measurement in children with emmetropia (k = 0.82) had a higher repeatability than in the children with myopia (k = 0.66).
Conclusions: The ETDRS visual acuity chart can provide a repeatable measure of visual acuity in children. It is recommended for clinic examination of children.