Computerized method of visual acuity testing: Adaptation of the amblyopia treatment study visual acuity testing protocol

- PURPOSE: To report a computerized method for deter, mining visual acuity in children using the Amblyopia Treatment Study visual acuity testing proto col. - METHODS: A computerized visual acuity tester was developed that uses a pr ogrammed handheld device that uses the Palm operating system (Palm, Inc, Sa nta Clara, California). The handheld device communicates with a personal co mputer running a Linux operating system and 17-inch monitor. At a test dist ance of 3 m, single letters can be displayed from 20/800 to 20/12. A C prog ram on the handheld device runs the Amblyopia Treatment Study visual acuity testing protocol. Using this method, visual acuity was tested in both the right and left eyes, and then the testing was repeated in 156 children age 3 to 7 years at four clinical sites. - RESULTS: Test-retest reliability was high (r = .92 and 0.95 for and right and left eyes, respectively), with 88% of right eye retests and 94% of lef t eye retests within 0.1 logarithm of minimal angle of resolution (logMAR) units of the initial test. The 95% confidence interval for an acuity score was calculated to be the score +/- 0.13 logMAR units. For a change between two acuity scores, the 95% confidence interval was the difference +/- 0.19 logMAR units. - CONCLUSIONS: We have developed a computerized method for measurement of v isual acuity. Automation of the Amblyopia Treatment Study visual acuity tes ting protocol is an effective method of testing visual acuity in children 3 to 7 years of age. (C) 2001 by Elsevier Science Inc. All rights reserved.