Abstract
Purpose :
We investigated the consistency of the subjective ocular refraction between Binocular Simultaneous Looking-in Type (Chronos, Topcon) and real space.
Methods :
Twenty-eight healthy volunteers (21.2 ± 1.4 years old) participated in this study. The objective ocular refraction in all subjects was achieved by a conventional autorefractometer that measures eyes one by one (KR-800, Topcon Corp.) and Chronos. The subjects were undergone four times of visual acuity tests in four conditions randomly: performing the subjective refraction test with the Chronos value using the Chronos (Condition i); performing the test with the Chronos value using the real space (TCU-600, Fuji Kogaku Co., Ltd.) (Condition ii); performing the test with the KR-800 value using the Chronos (Condition iii); and performing the test with the KR-800 value using the real space (Condition iv). In both the real space and Chronos, the subjective refraction test distance was set at 5.0 m. The best-corrected subjective ocular refraction was defined as 0.18 logMAR. The subjective ocular refraction was converted to spherical equivalent (SE). Furthermore, astigmatism was transformed into a power vector. Then, the SE and astigmatism were compared between Chronos (merged Conditions i and ii) and real space (merged Conditions iii and iv).
Results :
The SE was significantly and negatively greater in Chronos (−3.68 ± 2.83 D) than in the real space (−3.37 ± 2.85 D) (P < 0.001). No significant difference in J0 and J45 was observed between Chronos (J0, 0.28 ± 0.42 D; J45, −0.01 ± 0.18 D) and real space (J0, 0.29 ± 0.42 D; J45, −0.04 ± 0.16 D).
Conclusions :
Chronos measured with an error of less than 0.50 D compared with the real space. We considered that Chronos is valuable for screening refractive errors and visual acuity in eye checkups.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.