Better one or two? A systematic review of portable automated refractors

Abstract Introduction More than 400 million people suffer from visual impairment globally, with more than half due to uncorrected refractive error. Autorefraction (AR) is the most common examination performed prior to prescribing glasses. As technology advances, so has the accuracy and number of portable autorefractors available. Portable technology has become acutely important with the coronavirus disease 2019 pandemic and the conversion of in-person clinical evaluations to remote telemedicine encounters. Patients and providers want to do as much as possible remotely. The aim of this study was to conduct a systematic literature review of the accuracy and effectiveness of available portable automated refractors compared to the current standard of care, subjective refraction (SR). Methods A literature search of PubMED, Embase and ClinicalTrials.gov 97 unique publications in English on portable autorefractors. Twelve studies comparing a portable AR device to at least one form of SR were systematically included in this review. Results There were four portable autorefractors (Netra, Quicksee, Retinomax and SVOne) studied against SR. There was high patient acceptance of glasses prescriptions by the Quicksee alone, with 87% subjects seeing the same or better than SR. Quicksee was more accurate than Netra and Retinomax. SVOne was preferred over Netra and outperformed Retinomax in multiple measures, despite Retinomax being the fastest test. Discussion There are numerous portable autorefractors available, but few were compared against SR. Quicksee and SVOne are the most accurate and patient-preferred devices. Quicksee was the most accurate, and it performed clinically the same as SR in some reports.