Evaluation of the Amblyopia tracker app

Abstract

Purpose: The Amblyopia tracker app has been developed to be a tool for parents to monitor changes in vision at home during amblyopia treatment. The aims of this study were to evaluate the feasibility and repeatability of parents testing their children at home and to compare home test results to an assessment in clinic by an orthoptist.

Methods: Children (age < 18 years) with amblyopia (interocular acuity difference of ≥ 0.2logMAR) were recruited. Parents were asked to test their child with the app three times during a two week period followed by an online questionnaire about the usability. Participants also tested within 48 h of their appointment where the measurement was repeated by an orthoptist.

Results: Out of 277 potential participants contacted, 37 completed three home measurements, mean age 6.8 years (SD 2.94). Home tests comparisons were made between test two and three to ensure familiarity with the process. Paired t-tests showed no statistically significant difference for either eye or the interocular acuity difference (IAD). However, 29% had a difference in IAD of more than 0.1logMAR on repeated testing, with a maximum of 0.4logMAR difference in the IAD. Questionnaire responses from the parents who participated were predominantly positive with 97% of respondents saying they would use it if were available. Comparison of home and clinical measurements (n = 23, mean age 6.72 SD 2.60) showed no statistically significant differences for either eye or interocular acuity difference (paired t-test, p > 0.3 in all cases).

Conclusion: Results show no statistically significant differences for the Amblyopia tracker app when used by parents at home on repeated testing, or between the home test by a parent and the test by a clinician. However, variability in the results does indicate that further improvements are required to ensure the results can be used as a reliable clinical tool.

Keywords: Amblyopia; App; Telehealth; Vision; Visual acuity.

Fig. 1

Bland Altman plot of the amblyopic eye (A) and non-amblyopic eye (B) comparing tests two and three. The solid black line indicates the mean bias and the dashed lines show the upper and lower limits of agreement

Fig. 2

Bland Altman plot of the interocular acuity difference comparing tests two and three

Fig. 3

Bland Altman plot of the amblyopic eye (A) and non-amblyopic eye (B) comparing the home and clinic measurements using the Amblyopia tracker app

Fig. 4

Bland Altman plot of the interocular acuity differences comparing the home and clinic measurements using the amblyopia tracker app