Comparing the Effectiveness of Printed Versus iPad Ishihara Plates in Diagnosis of Congenital Red-green Color Deficiency in Thai Male Population

Abstract

Objective : To compare the Effectiveness Between Ishihara plates on iPad Air2 and traditional printed standard Ishihara test for screening red-green color vision deficiency in male population

Design : Case-control Diagnostic Study

Methods : Male volunteers (patients and relatives) from Thammasat hospital and students from grades 3-6 at Buengkhaoyorn school, Pathumtani province were recruited. All volunteers were initially examined for red-green color deficiency by standard Ishihara test, and Pseudochromatic color test application in iPad Air2 at 100% brightness. 49 participants who had positive standard Ishihara test and 264 participants who had negative standard Ishihara test were asked to take the Pseudochromatic color test application on iPad Air2, comparing the two results to determine the latter test’s effectiveness in screening red-green color deficiency.

Results  : A total of 313 selected volunteers were examined, age ranged from 6 to 80 years old. 49 participants who tested positive for red-green color vision deficiency using the Standard Ishihara test were also positive for red-green color vision deficiency using the Pseudochromatic color test application in iPad Air2. Another 264 volunteers who tested negative red-green color vision deficiency using the Standard Ishihara test also had negative red-green color vision deficiency using the Pseudochromatic color test application in iPad Air2. The sensitivity, specificity and positive predictive value for the Pseudochromatic color test was 100%, 100% and 100%.

Discussion : The Pseudochromatic color test is a suitable substitute to the standard Ishihara test when used on an iPad Air2 at optimal lighting conditions.  The use of free standard Ishihara test substitute applications on tablets may be suitable for screening color deficiency in resource limited settings.