Abstract
Purpose: :
Pseudoisochromatic Ishihara plates are most commonly used to screen for color vision deficits in ophthalmic offices. Although there are many electronic versions of this test available, to our knowledge, no study has documented the comparison of the book versus electronic versions. This study was conducted to evaluate and compare pseudoisochromatic Ishihara plate test booklet with electronic plates using the iPad.
Methods: :
A standard 15-plate Ishihara booklet was used for testing color vision deficit in all subjects. The same plates were individually photographed and transferred to an iPad to be used as an electronic version of the test. During testing, the iPad was set to the highest brightness setting without any screen protector. Forty subjects, 18 years of age or older and with best-corrected visual acuity of 20/40 or better were evaluated for color vision deficits using the book version and then repeated using the electronic version of the Ishihara charts. Subjects using tinted glasses were excluded from the study. The total correct responses for the iPad (left and right eyes combined) were compared to those obtained for the booklet. The concordance rate was calculated.
Results: :
Color vision was tested by both methods in 40 subjects. Five subjects had poor vision in one eye and hence that eye was not tested, Hence, responses were obtained from 75 eyes and results evaluated. A maximum score of 1125 could possibly be obtained (75 eyes and 15 plates each) - the score for correct responses by iPad was 1032 as compared to 1051 by Ishihara booklet - a concordance rate of 98.2%.
Conclusions: :
Compared to the gold standard of Ishihara testing with a booklet, color vision can reliably be tested on iPad version.
Keywords: color vision • imaging/image analysis: clinical