Autorefraction Compared to Subjectve Refraction: A Literature Review

Background: Autorefraction is ubiquitous throughout the optometric profession, as it aids
in the managing and prescribing of refractive error correction for patients. Subjective
refraction is currently the gold standard for measurement of refractive errors, but
autorefraction continues to evolve with advancements in technology. The goal of this
review was to assess studies done on the general accuracy and precision of autorefraction
technology and how it compares with the conventional subjective refraction. Included in
this review were studies involving the different types of features that can be incorporated
into autorefractors, such as wavefront analysis, portability, and open-view construction.
Also discussed are studies that assess newer automated refractive technologies, which
includes portable videorefractors and smartphone-based autorefractors. Methods: A
literature search was performed using PubMed and the Ferris State University Flite
Library databases regarding the validity of autorefraction. Studies that were published
within the past twenty years and that compared autorefraction to subjective refraction
were selected and reviewed. Results: Content analysis showed that there is no consistent
data to support the replacement of subjective refraction with autorefraction. However, the
studies assessed indicate that variability in autorefraction accuracy and precision is based
on many factors, including: refractive error type, age of the subject, use of mydriatics,
and type of autorefractor used. Conclusions: Autorefraction is not ready to take the place
of subjective refraction due to the inadequate evidence available to support their accuracy
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and precision as acceptable alternatives. This is largely based upon the studies’
significant differences in accuracy when autorefraction is compared to subjective
refraction and their lack of evaluating the refractive methods in clinically relevant
settings. However, autorefractors may be useful in certain situations and settings when
subjective refraction is unavailable.