Open versus closed view autorefraction in young adults

Purpose: While there are numerous studies comparing open-view autorefractors to subjective refraction or other open-view autorefractors, most studies between closed and open-view autorefraction tend to focus on children rather than young adults. The aim of this study was to determine the concordance in non-cycloplegic refractive error between two modern objective autorefractors: the closed-view monocular Topcon TRK-2P and the binocular open-view Grand Seiko WR-5500. Methods: Fifty young adults aged 20-29 years (mean age 22 1.6 years) underwent noncycloplegic autorefraction using the Grand Seiko WAM-5500 (open view) and Topcon TRK-2P (closed-view) autorefractors on both eyes. Findings were expressed as the isolated spherical component and were also converted from clinical to vector notation: Mean Spherical Error (MSE) and the astigmatic components JO and J45. Results: Mean MSE +/- SD was 1.00 +/- 2.40D for the Grand Seiko WAM-5500 compared to 1.23 +/- 2.29D for the Topcon TRK-2R Up to seventy-six percent of the cohort had mean spherical errors from the Topcon TRK-2P which fell within 0.50D of the Grand Seiko reading and 58% fell within 0.25D. Mean differences between the two instruments were statistically significant for all components (JO, spherical, and MSE) (p < 0.01), except J45 (p > 0.05). Conclusions: The differences in non-cycloplegic MSE between these two instruments are small, but statistically significant. From a clinical perspective the Topcon TRK-2P may serve as a useful starting point for subjective refraction, but additional work is needed to help further minimise differences between the instruments. (C) 2020 Spanish General Council of Optometry. Published by Elsevier Espana, S.L.U.

Automated summary

This study compared the concordance in non-cycloplegic refractive error between two modern autorefractors in young adults. The differences between the two instruments were small but statistically significant. While the Topcon TRK-2P may serve as a useful starting point for subjective refraction, further work is needed to minimize differences between the instruments.