Comparing performance on the MNREAD iPad application with the MNREAD acuity chart

Abstract

Our purpose was to compare reading performance measured with the MNREAD Acuity Chart and an iPad application (app) version of the same test for both normally sighted and low-vision participants. Our methods included 165 participants with normal vision and 43 participants with low vision tested on the standard printed MNREAD and on the iPad app version of the test. Maximum Reading Speed, Critical Print Size, Reading Acuity, and Reading Accessibility Index were compared using linear mixed-effects models to identify any potential differences in test performance between the printed chart and the iPad app. Our results showed the following: For normal vision, chart and iPad yield similar estimates of Critical Print Size and Reading Acuity. The iPad provides significantly slower estimates of Maximum Reading Speed than the chart, with a greater difference for faster readers. The difference was on average 3% at 100 words per minute (wpm), 6% at 150 wpm, 9% at 200 wpm, and 12% at 250 wpm. For low vision, Maximum Reading Speed, Reading Accessibility Index, and Critical Print Size are equivalent on the iPad and chart. Only the Reading Acuity is significantly smaller (I. E., better) when measured on the digital version of the test, but by only 0.03 logMAR (p = 0.013). Our conclusions were that, overall, MNREAD parameters measured with the printed chart and the iPad app are very similar. The difference found in Maximum Reading Speed for the normally sighted participants can be explained by differences in the method for timing the reading trials.

Benefits of low vision aids to reading accessibility

“…In this sample of visually impaired people attending for low vision assessment, average clinical reading accessibility (ACC) was 0.31, comparable with other samples of visually impaired observers (0.35-0.36; (Calabrèse et al, 2018;Tarita-Nistor et al, 2018)), and lower than that seen for people with surgically-significant cataract (0.65; (Calabrèse, Owsley, et al, 2016)). The ACC for the majority of observers (92%) improved with use of an LVA, with an average improvement of 0.16.…”

“…Since ACC is a relatively recently proposed parameter, it has previously been determined in only three other samples of observers with some form of visual loss (Table 4). These have been one group with cataract (Calabrèse, Owsley, et al, 2016) and two groups with visual impairment, either from mixed causes of visual loss (Calabrèse et al, 2018), or central field loss specifically (Tarita-Nistor et al, 2018). It is clear that visual impairment has a marked impact on reading accessibility (0.31 -0.36 across studies) as compared to a normative value of 1.0, and also compared to the sample with cataract (0.65).…”

“…However, derivation of the Reading Index in this way relies on accurate identification of the CPS, which can often be difficult when an observer is visually impaired (Rubin, 2013). Different methods of CPS calculation result in different values (Patel, Chen, da Cruz, Rubin, & Tufail, 2011), and variability in reading speed with print size in the low vision observer can mean that standard algorithms fail to identify an appropriate CPS (Calabrèse et al, 2018). A 'Reading Accessibility Index' (ACC) has recently been proposed (Calabrèse, Owsley, McGwin, & Legge, 2016), which is a single value representing an individual's mean reading speed across the 10 largest print sizes on the MNREAD Acuity Chart (1.3-0.4 logMAR at 40cm in angular terms, or 8-1 Sloan M in physical terms), normalised by 200wpm (the average reading speed for normally sighted young adults).…”

Benefit of an electronic head‐mounted low vision aid

“…Reading performance (near visual acuity, critical print size, reading speed) was measured using the iPad version of the MNREAD test (http://www.apps.apple.com/us/app/mnread/id1196638274). Visual field data were extracted from the participant’s medical records. Those with loss only within the central 15 degrees were classified as having central loss, those with loss only beyond 15 degrees as peripheral loss, those with loss in both regions as mixed, and without field loss as no field loss.…”

How many words do we read per minute? A review and meta-analysis of reading rate

“…There are reasons to believe that the manual administration leads to an overestimate of the true reading rate by some 10%. This is because the participant can see the chart a few 100 ms before the timer is started (Calabrèse, To, He, Berkholtz, Rafian, & Legge, 2018). A final difference is that the texts are not followed by questions, as is customary in silent reading studies.…”