Background Vision impairments (VIs) and blindness are major global public health issues. A visual acuity (VA) test is one of the most crucial standard psychophysical tests of visual function and has been widely used in a broad range of health care domains, especially in many clinical settings. In recent years, there has been increasing research on mobile app–based VA assessment designed to allow people to test their VA at any time and any location. Objective The goal of the review was to assess the accuracy and reliability of using mobile VA measurement apps. Methods We searched PubMed, Embase, Cochrane Library, and Google Scholar for relevant articles on mobile apps for VA assessment published between January 1, 2008, and July 1, 2020. Two researchers independently inspected and selected relevant studies. Eventually, we included 22 studies that assessed tablet or smartphone apps for VA measurement. We then analyzed sensitivity, specificity, and accuracy in the 6 papers we found through a meta-analysis. Results Most of the 22 selected studies can be considered of high quality based on the Quality Assessment of Diagnostic Accuracy Studies–2. In a meta-analysis of 6 studies involving 24,284 participants, we categorized the studies based on the age groups of the study participants (ie, aged 3-5 years, aged 6-22 years, and aged 55 years and older), examiner (ie, professional and nonprofessional examiners), and the type of mobile devices (ie, smartphone, iPad). In the group aged 3 to 5 years, the pooled sensitivity for VA app tests versus clinical VA tests was 0.87 (95% CI 0.79-0.93; P=.39), and the pooled specificity was 0.78 (95% CI 0.70-0.85; P=.37). In the group aged 6 to 22 years, the pooled sensitivity for VA app tests versus clinical VA tests was 0.86 (95% CI 0.84-0.87; P<.001), and the pooled specificity for VA app tests versus clinical VA tests was 0.91 (95% CI 0.90-0.91; P=.27). In the group aged 55 years and older, the pooled sensitivity for VA app tests versus clinical VA tests was 0.85 (95% CI 0.55-0.98), and the pooled specificity for VA app tests versus clinical VA tests was 0.98 (95% CI 0.95-0.99). We found that the nonprofessional examiner group (AUC 0.93) had higher accuracy than the professional examiner group (AUC 0.87). In the iPad-based group, the pooled sensitivity for VA app tests versus clinical VA tests was 0.86, and the pooled specificity was 0.79. In the smartphone-based group, the pooled sensitivity for VA app tests versus clinical VA tests was 0.86 (P<.001), and the pooled specificity for VA app tests versus clinical VA tests was 0.91 (P<.001). Conclusions In this study, we conducted a comprehensive review of the research on existing mobile apps for VA tests to investigate their diagnostic value and limitations. Evidence gained from this study suggests that mobile app–based VA tests can be useful for on-demand VI detection.

BACKGROUND Vision impairments (VI) and blindness are one of the core global public health issues. Visual acuity (VA) is one of the most crucial standard psychophysical test of visual function, and used widely in a broad range of healthcare domain, especially in many clinical settings. OBJECTIVE To assess the accuracy and application of using Mobile devices-based visual acuity measurement apps. METHODS We searched Pubmed, Embase, Cochrane Library, and Google Scholar for relevant articles published between January 1, 2008 and July 1 2020. Two reviewers independently selected studies that assessed the mobile-based VA measurement apps. We included all studies that assessed a tablet and/or smartphone VA measurement apps. RESULTS Most of the enrolled 22 studies considered as high quality studies, evaluating by QUADAS-2. In meta-analysis, six studies involving 24284 participants were included. In 3~5 years old group, the pooled sensitivity was 0.87 (95% CI 0.79, 0.93); the pooled specificity was 0.78 (95% CI 0.70, 0.85); In 6~22 years old group, the pooled sensitivity was 0.86 (95% CI 0.84, 0.87); the pooled specificity was 0.91 (95% CI 0.90, 0.91). In ≥55 years old group, the pooled sensitivity was 0.85 (95% CI 0.55, 0.98); the pooled specificity was 0.98 (95% CI 0.95, 0.99). CONCLUSIONS In this study, we conducted a comprehensive review of the state-of-the-art research to investigate the diagnostic value and limitations of existing mobile-based VA test applications. Evidence from this study shows that mobile-based app VA measurements may be useful tools for VI detection.