Accuracy, speed and repeatability of the voice assisted subjective refractor (VASR)

Abstract

Purpose

To compare the accuracy, speed and repeatability of the voice assisted subjective refractor (VASR) to traditional refractive methods.

Methods

Fifty healthy adult subjects were examined by autorefractor, followed by subjective phoropter refinement. Subjects were then evaluated using the VASR (Vmax Vision) to obtain an objective and subjective result. Three total assessments were performed for each subject using each of the methods described. Corrected visual acuity was recorded for each eye after each procedure. The total time was measured for both the traditional and VASR refraction.

Results

A comparison of the results obtained by traditional refraction and VASR revealed no statistically significant difference from the mean in equivalent sphere measurements (P=0.1383), and the datasets were highly correlated (r=0.993). The data comparisons for cylinder power and axis were similar (cylinder: P=0.6377, r=0.864) (axis: P=0.6991, r=0.738). VASR, on average, required 71 additional seconds to complete when compared to traditional phoropter refraction. In terms of repeatability, the average difference noted upon repeat of equivalent sphere power was 0.01 D for the phoropter (P=0.98) and 0.10 D for the VASR (P=0.23). For sphere power, the average difference was 0.02 D for the phoropter (P=0.55) and 0.07 D for the VASR (P=0.58). For cylinder power, the average difference was 0.02 D for the phoropter (P=0.11) and 0.03 D for the VASR (P=0.39). For all refractive methods, the differences between measurements amounted to ≤0.10 diopters, which is neither clinically nor statistically significant.

Conclusion

Refractive error results obtained with the VASR were not statistically different from those achieved using traditional phoropter methods. Time elapsed for the VASR was slightly longer than a more traditional refractive sequence. The VASR demonstrated clinically and statistically significant repeatability of measurement, consistent with traditional refraction.

Keywords:

• autorefractor
• subjective refraction
• wavefront aberrometry
• point-spread function
• VASR

Acknowledgments

Financial support for this study was provided in the form of an educational grant by Vmax Vision, Inc. The company did not play any role in manuscript preparation, study design, or the decision to publish. This data set and its conclusions were originally presented as two posters at the Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting 2018. The posters’ abstracts were published in Investigative Ophthalmology and Visual Science, July 2018, Vol.59, 1283–1284; https://iovs.arvojournals.org/article.aspx?articleid=2689763; https://iovs.arvojournals.org/article.aspx?articleid=2689764.

Disclosure

Dr Kabat reports grants, personal fees, non-financial support from Vmax Vision, Inc., during the conduct of the study, personal fees, non-financial support from Bruder Healthcare Company, Inc., personal fees, non-financial support from Jobson Healthcare Information, personal fees from Kala Pharmaceuticals, Lacrivera, Ocusoft, Inc., National Vision Administrators, LLC, Quidel, Sight Sciences, Sun Pharmaceuticals, Takeda Pharmaceutical Company (formerly Shire), personal fees, non-financial support from Avellino Labs, grants, personal fees from Bio-Tissue, Inc., personal fees, non-financial support from EyeGate Pharma, personal fees from TearScience, grants from Thermi, personal fees from BlephEx, outside the submitted work. Dr Kabat is a consultant for Vmax Vision. Dr Lievens reports grants from Southern College of Optometry, during the conduct of the study. The authors report no other conflicts of interest in this work.