Contrast Acuity With Different Colors in Parkinson's Disease

Harsh V. Gupta, Nan Zhang, Erika Driver-Dunckley, Shyamal H. Mehta, Thomas G. Beach, Charles H. Adler

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Background: Abnormal color vision and contrast acuity may have significant impact on daily activities. Objective: Evaluate color visual acuity, at high and low contrast, in Parkinson's disease (PD) and controls using an iPad application. Methods: Color visual acuity was tested with the Variable Contrast Acuity Chart (King-Devick Test LLC, Oakbrook Terrace, IL) on an iPad 2 at 40 cms using five colors (red, green, blue, yellow, and black) at low (2.5%) and high (100%) contrast. A numerical score (0–95) was assigned based on the number of correctly identified letters. Results: Thirty-six PD (mean ± standard deviation age 68 ± 10 years) and 36 controls (72 ± 11.2 years) were studied. PD disease duration was 6.4 ± 4.6 years; MDS-UPDRS part II was 11.7 ± 7.0, and part III was 24.5 ± 9.9. After adjusting for age and sex, PD patients had significantly (P < 0.05) lower scores at high (100%) as well as low (2.5%) contrast for all five colors tested (red, green, blue, yellow, and black), except yellow low contrast (2.5%; P = 0.10). The largest effect size (0.88) was with yellow high contrast, and the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy using a cut-off score of 82 was 31%, 97%, 92%, 58%, and 64%, respectively. No correlation to disease duration was found. Conclusions: This iPad application may be a simple-to-use biomarker for assessing color vision in PD. Further research is needed to determine disease specificity and whether there is a role in monitoring disease progression, treatment response, and identifying prodromal PD.

Original languageEnglish (US)
Pages (from-to)672-677
Number of pages6
JournalMovement Disorders Clinical Practice
Issue number8
StatePublished - Nov 1 2019


  • King-Devick test
  • Parkinson's disease
  • contrast sensitivity
  • visual acuity

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology


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