Technical and Clinical Approaches for Implementing a Vision Screening Tool

Abstract

Detecting vision problems in children is a challenging task, especially in large populations. Thisis in part due to the difficulty of obtaining useful indications of vision problems which may cause a child to be sent to an eye doctor. Modern vision screening approaches, intended to solve this problem, are either hard to scale, expensive, or limited in applicability. The aim of this thesis was to continue the development of and clinically test a vision screening mobile application aimed at wide distribution among Washington state school nurses and determine future development and testing plans based on the results of those tests. The QuickCheck vision screening application was tested against the FrACT vision screening application and near vision screening cards using accuracy, specificity, sensitivity, and other statistical measures. Using QuickCheck’s best testing policy the application is currently able to detect subjects with any vision problems with an average sensitivity of 0.91 ± 0.11, although performance by eye is much lower (average sensitivity of 0.83 ± 0.06). Accuracy by subject is 0.95 ± 0.07, and again average accuracy by eye is lower, at 0.84 ± 0.09. Additionally, QuickCheck is worse at detecting distance vision problems (sensitivity 0.83 ± 0.11) than near vision problems (sensitivity 0.875 ± 0.10), although this is more than offset by a corresponding difficulty with detecting a lack of near vision problems as compared to distance vision problems. A modification plan for QuickCheck, including methods to decrease the application’s false negative rate for distance vision tests and decrease acuity test time by half was established. However, given the small sample size of the clinical test, further testing of the QuickCheck application is required to demonstrate its effectiveness to a degree allowing widespread distribution. In addition to gathering more data to confirm the results of this work, future research directions include an examination of how the suggested changes improve performance and how well QuickCheck can detect the vision problems of very young (kindergarten-aged) children.