ABSTRACT: Purpose. To compare the agreement between subjective refraction and autorefraction using two commercially available autorefractors. Methods. Prospective data were collected for 190 subjects using either the Nidek ARK‐700A (Fremont, CA) or the Topcon KR‐8000 (Paramus, NJ) and subjective refraction (masked to autorefraction). Refractions were compared in terms of spherical equivalent using Bland‐Altman limits of agreement and astigmatic vector difference using median and 95th percentile. Results. The two groups were similar for age, gender, spherical equivalent, and astigmatic power. The differences in spherical equivalent between subjective and autorefraction were significantly different (mean ± SD; Nidek, −0.03 ± 0.36 D; Topcon, +0.11 ± 0.34 D; analysis of variance, F = 7.84; p 1.00 D) differences in spherical equivalent, 1.1% with each autorefractor. There were five cases with astigmatic vector difference >1 D, all with the Topcon KR‐8000 (5.3%). Conclusions. Both autorefractors show excellent agreement with subjective refraction. Despite a statistically significant difference in mean spherical equivalent (0.14 D), near identical limits of agreement (0.10 D difference) suggest clinical equivalence. Conversely, for astigmatism, despite similar median scores, major outliers were more likely with the Topcon, reflected in a 0.42 D larger 95th percentile, which suggests a small advantage for the Nidek for avoiding large astigmatic errors.
Pesudovs et al. (Thu,) studied this question.