Use of Mobile Apps for Visual Acuity Assessment: Systematic Review and Meta-analysis

Abstract

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.

The effectiveness of using peek acuity in vision screening for the admission of elementary school students

“…There was no significant difference in the examination of the right and left eyes. 25 Tests that can be considered good hold a sensitivity and specificity between 80-90%. 26 Therefore, the sensitivity of this application is considered still lacking.…”

“…Peek Acuity application tends to give higher examination results than the real one because the population studied are children whose literacy power is lower, and there is no time limit feature in order for children to guess which way the letters appear on the screen. [25][26][27] This can be assessed if the child answers in a longer time than the others, and there is a possibility that the child's guess is correct and therefore is able to reduce the sensitivity of the test. However, the high specificity of Peek Acuity significantly predicts the number of children who do not require further evaluation, and it can indeed help screening programs in areas with limited resources.…”

“…The duration of the peek acuity check was 136.59 seconds, and the Snellen card was 309.16 seconds. 7, 25 Peek acuity also improves adherence to hospital referrals compared to the standard approach in children at school and can be used in patients who are unfamiliar with the letters of the alphabet. This shows the potential of technology in improving health services in real-time and helping to target resources.…”

Evaluation of a Digital Amsler Grid (PocDoc) for Macular Disease Screening: A Comparative Analysis with the Conventional Method

“…The number is expected to increase with increasing life expectancy, leading to greater burden on resources in the hospitals and clinics. To address this, mobile applications such as E-health apps which contain various eye tests have been developed to allow for self-monitoring, early detection and monitoring progression [ 2 – 6 ].…”

Validity and Reliability of Vis-Screen Application: A Smartphone-Based Distance Vision Testing for Visual Impairment and Blindness Vision Screening

“…Various distance vision testing apps have utilized different forms of charts in their algorithm for screening assessment to mimic the frequent routine practices. These include the most popular Tumbling E, followed by Early Treatment Diabetic Retinopathy Study (ETDRS), and Snellen charts [ 5 ]. Even though these existing apps could provide another option for vision screening, most of them need to be appropriately validated, thus raising the biggest concern toward their safety and accuracy [ 3 , 6 ].…”