Refinement and preliminary evaluation of two tablet-based tests of real-world visual function

Tablet-based tests of everyday visual function in a diabetic macular oedema (DME) clinic waiting area: A feasibility study

PURPOSE

(1) To assess the feasibility of conducting tablet-based vision tests in hospital clinic waiting areas; (2) To test the hypothesis that increasing severity of diabetic macular oedema (DME) is associated with the performance of tablet-based surrogates of everyday tasks and self-reported visual function.

METHODS

Sixty-one people with mild (n = 28), moderate (n = 24) or severe (n = 9) DME performed two tablet-based tests of 'real-world' visual function (visual search and face recognition) while waiting for appointments in a hospital outpatient clinic. Participants also completed a tablet-based version of a seven-item, visual-functioning (VF-7) patient-reported outcome measure. Test performance was compared to previously published 99% normative limits for normally sighted individuals.

RESULTS

Thirty-four participants (56%; 95% confidence interval [CI] 43%-68%) exceeded normative limits for visual search, while eight (13%; 95% CI 65%-24%) exceeded normative limits for face discrimination. Search duration was significantly longer for people with severe DME than those with mild and moderate DME (p = 0.01). Face discrimination performance was not significantly associated with DME severity. VF-7 scores were statistically similar across DME severity groups. Median time to complete all elements (eligibility screening, both tablet-based tasks and the VF-7) was 22 (quartiles 19, 25) min. Further, 98% and 87% of participants, respectively, reported the search task and face discrimination task to be enjoyable, while 25% and 97%, respectively, reported finding the two tasks to be difficult.

CONCLUSIONS

Portable tablet-based tests are quick, acceptable to patients and feasible to be performed in a clinic waiting area with minimal supervision. They have the potential to be piloted in patients' homes for self-monitoring.

Evaluation of Predictive Motor Control With Two Touchscreen Tablet-Based Tests: Reliability and Validity in School-Aged Children

As predictive motor control is an important index of neuromotor development and maturation, we developed two touchscreen tablet-based tests of this function. Our aim was to investigate the reliability and validity of both a rapid manual interception test and a pursuit tracking test, using a sample of 124 children (62 boys and 62 girls) from two age groups (7-8-year-oldss and 9-10-year-olds). Participants performed both tablet tests with a stylus (sample rate 100 Hz) with both a visible and a temporarily invisible moving target. Confirmatory factor analyses and omega coefficients showed that both tests were univariate methods that provided a reliable assessment of the latent factor related to predictive visuomotor control. As would be expected, compared to younger children, older children performed better on both manual interception and pursuit tracking. The correlations between the latent factors of the two tests at 95% confidence intervals (-.276, -.608) suggested shared variance. Thus, the touchscreen-tablet based tests of rapid manual interception and manual pursuit tracking appear psychometrically suitable for assessing the neuromotor ability of predictive control in 7-10-year-old children.

Novel computer-based assessments of everyday visual function in people with age-related macular degeneration

PURPOSE

To test the hypothesis that the performance in novel computer-based tasks of everyday visual function worsens with disease severity in people with non-neovascular age-related macular degeneration.

METHODS

Participants with and without non-neovascular age-related macular degeneration (≥60 years, minimum logMAR binocular visual acuity 0.7) performed a series of standard visual function tests and two novel computer-based tasks. In a visual search task, participants had to locate an image of a single real-world object within an array of 49 distractor images. Next, in a series of simulated dynamic driving scenes, participants were asked to identify one or two approaching real-world road signs and then select these road signs from four options. Outcome measures were median response times and total correct responses.

RESULTS

Forty-nine participants had no macular disease (n = 11), early/intermediate age-related macular degeneration (n = 16) or geographic atrophy (n = 22). Groups were age-similar with median (interquartile range) logMAR visual acuity of 0.00 (-0.08,0.12), 0.13 (-0.08,0.70) and 0.32 (0.12,0.70) respectively. Median (interquartile range) visual search response times were 1.9 (1.0,2.4), 1.8 (1.1,3.7) and 2.4 (1.2,6.0) seconds respectively. Median (interquartile range) road sign response times (single road signs) were 1.2 (0.4,1.7), 1.5 (0.9,2.8) and 1.8 (1.0,5.5) seconds respectively. Median (interquartile range) road sign response times (double road signs) were 1.7 (0.7,2.4), 2.3 (1.2,3.1) and 2.5 (1.7,6) seconds respectively. Participants with geographic atrophy recorded slower response times in all tasks and over 50% performed outside the normative limit for task performance. There were no significant differences between groups in total correct responses across all tasks.

CONCLUSIONS

In a novel computer-based assessment, people with increasing severity of age-related macular degeneration take longer to perform visual search of everyday objects and take longer to identify road signs than those with no age-related macular degeneration. These novel assessments could be useful as patient-relevant, secondary outcomes for clinical trials.

Refinement and preliminary evaluation of two tablet-based tests of real-world visual function

Purpose

To describe, refine, evaluate, and provide normative control data for two freely available tablet‐based tests of real‐world visual function, using a cohort of young, normally‐sighted adults.

Methods

Fifty young (18–40 years), normally‐sighted adults completed tablet‐based assessments of (1) face discrimination and (2) visual search. Each test was performed twice, to assess test‐retest repeatability. Post‐hoc analyses were performed to determine the number of trials required to obtain stable estimates of performance. Distributions were fitted to the normative data to determine the 99% population‐boundary for normally sighted observers. Participants were also asked to rate their comprehension of each test.

Results

Both tests provided stable estimates in around 20 trials (~1–4 min), with only a further reduction of 14%–17% in the 95% Coefficient of Repeatability (CoR₉₅) when an additional 40 trials were included. When using only ~20 trials: median durations for the first run of each test were 191 s (Faces) and 51 s (Search); test‐retest CoR₉₅ were 0.27 d (Faces) and 0.84 s (Search); and normative 99% population‐limits were 3.50 d (Faces) and 3.1 s (Search). No participants exhibited any difficulties completing either test (100% completion rate), and ratings of task‐understanding were high (Faces: 9.6 out of 10; Search: 9.7 out of 10).

Conclusions

This preliminary assessment indicated that both tablet‐based tests are able to provide simple, quick, and easy‐to‐administer measures of real‐world visual function in normally‐sighted young adults. Further work is required to assess their accuracy and utility in older people and individuals with visual impairment. Potential applications are discussed, including their use in clinic waiting rooms, and as an objective complement to Patient Reported Outcome Measures (PROMs).