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.
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.
Authors: Thomas G Beach; Charles H Adler; Lucia I Sue; Geidy Serrano; Holly A Shill; Douglas G Walker; LihFen Lue; Alex E Roher; Brittany N Dugger; Chera Maarouf; Alex C Birdsill; Anthony Intorcia; Megan Saxon-Labelle; Joel Pullen; Alexander Scroggins; Jessica Filon; Sarah Scott; Brittany Hoffman; Angelica Garcia; John N Caviness; Joseph G Hentz; Erika Driver-Dunckley; Sandra A Jacobson; Kathryn J Davis; Christine M Belden; Kathy E Long; Michael Malek-Ahmadi; Jessica J Powell; Lisa D Gale; Lisa R Nicholson; Richard J Caselli; Bryan K Woodruff; Steven Z Rapscak; Geoffrey L Ahern; Jiong Shi; Anna D Burke; Eric M Reiman; Marwan N Sabbagh Journal: Neuropathology Date: 2015-01-26 Impact factor: 1.906
Authors: Charles H Adler; Thomas G Beach; Joseph G Hentz; Holly A Shill; John N Caviness; Erika Driver-Dunckley; Marwan N Sabbagh; Lucia I Sue; Sandra A Jacobson; Christine M Belden; Brittany N Dugger Journal: Neurology Date: 2014-06-27 Impact factor: 9.910
Authors: Alison Fellgett; C Adam Middleton; Jack Munns; Chris Ugbode; David Jaciuch; Laurence G Wilson; Sangeeta Chawla; Christopher J H Elliott Journal: J Parkinsons Dis Date: 2021 Impact factor: 5.568