Purchase this article with an account.
Christina Newman, Christopher Lievens, Alan Kabat, Jacob Weber; REPEATABILITY OF THE VMAX VOICE ACTIV™ SUBJECTIVE REFRACTOR (VASR) AND TRADITIONAL REFRACTIVE METHODS IN A HEALTHY POPULATION. Invest. Ophthalmol. Vis. Sci. 2018;59(9):1284.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The Vmax VASR (Voice Activ™ Subjective Refractor) is a new digital refracting platform that utilizes wavefront aberrometry and point spread function (PSF) technology combined with computer-generated artificial intelligence to conduct a complete objective and subjective refraction. In a clinical study, we compared the results obtained with the VASR to traditional refraction performed by an experienced optometrist.
Fifty healthy subjects were examined by a masked investigator using a standard autorefractor (Nidek TonoRef™ II) as an objective measurement, followed by subjective refinement through the phoropter (monocular subjective refraction with binocular balance). Subjects were then evaluated by a different investigator using the VASR to obtain an objective and subjective refraction result. This process of evaluation by autorefractor, subjective phoropter refraction and VASR refraction was repeated twice: once later on same day as the initial evaluation, and again on a subsequent date to validate the repeatability of the measurements.
A total of three refractive assessments were obtained for each subject using each of the three methods previously mentioned, and the data was assessed by analysis of variance (ANOVA). The average differences noted upon repeat testing of spherical power were 0.02 D for the autorefractor (p=0.62), 0.02 D for the subjective/phoropter refraction (p=0.55) and 0.07 D for the VASR (p=0.58). The average differences noted upon repeat testing of cylinder power were 0.01 D for the autorefractor (p=0.49), 0.02 D for the phoropter refraction (p=0.11) and 0.03 D for the VASR (p=0.39). The average differences noted upon repeat testing of spherical equivalent power were 0.03 D for the autorefractor (p=0.43), 0.01 D for the phoropter refraction (p=0.98) and 0.10 D for the VASR (p=0.23). For all refractive methods, the differences between measurements amounted to ≤ 0.10 diopters, which is neither clinically nor statistically significant in terms of repeatability.
Over this cohort, the Vmax VASR demonstrated clinically and statistically significant repeatability of measurement with regard to sphere power, cylinder power and spherocylindrical power. The repeatability of VASR was consistent with the other refractive modalities tested, including autorefraction and subjective or “manual” refraction using the phoropter.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
This PDF is available to Subscribers Only