The Reliability and Acceptability of RDx-Based Tele-Controlled Subjective Refraction Compared with Traditional Subjective Refraction

Purpose: The purpose of this study was to compare the reliability and acceptability of tele-controlled subjective refraction supported by RDx, a new technique that involves optical software designed for controlling phoropters remotely, to traditional subjective refraction. Methods: Sixty-five participants underwent tele-controlled subjective refraction and traditional subjective refraction randomly and nine of them underwent the second tele-controlled subjective refraction measurement on the same day. After their examinations, we distributed a validated satisfaction questionnaire to each participant. The elapsed time taken for refraction, sphere (S), cylinder (C), spherical equivalent (SE), vertical and oblique cylindrical vectors (J0 and J45), and best corrected visual acuity (BCVA) were compared. Age and refractive error type were included as covariates. Bland-Altman analysis was used to assess the agreement between both methods of refraction. Results: The mean age was 20.5 ± 5.9 years for all participants (aged 9 to 40 years); 57% were female participants. The repeatability analysis of tele-controlled method showed no significant differences for all parameters (P > 0.05). We found no statistical differences (P > 0.05) between tele-controlled subjective refraction and traditional subjective refraction for all parameters in either group. The mean difference and 95% limits of agreement for SE, J0, and J45 were -0.03 ± 0.36 diopters (D), -0.00 ± 0.57 D, and -0.01 ± 0.79 D, respectively. The tele-controlled method took more time to perform than the traditional one (P < 0.05). Completed questionnaires were returned by 55 participants (85%), and they showed high satisfaction and acceptance of the tele-controlled method (98%). Conclusions: Tele-controlled subjective refraction results agreed with traditional subjective refraction for all refraction components except for cylinder vectors. In addition, the broad acceptability of tele-controlled subjective refraction means practicability in clinical practice. Translation Relevance: The RDx-based tele-controlled method can provide an alternative to subjective refraction, especially in areas that lack experienced optometrists.