Contrast Sensitivity and Visual Acuity among the Elderly THESIS Presented in Partial Fulfillment of the Requirements for the Degree Master of Science in the Graduate School of The Ohio State University By Mawada Osman Graduate Program in Vision Science The Ohio State University 2020 Master's Examination Committee: Angela M. Brown, PhD, Advisor Bradley E. Dougherty, OD, PhD Heidi A. Wagner, OD, MPH Copyright by Mawada Osman 2020 Abstract Purpose: To establish the clinical utility and strengthen the validity of the Ohio Contrast Cards (OCC), expand the use of the OCC in a healthy elderly population, and form a baseline dataset of patients to be compared to patients with dementia. Method: Participants ages 65 and over (N = 51) were recruited from the Ohio State University Primary Vision Care (PVC). We assessed the visual function of each patient using four visual tests which include: OCC, Pelli-Robson Chart (PR), Teller Acuity Cards (TAC) and Clear Chart. The contrast sensitivity tests (OCC and PR) were assessed twice, once by each tester. The PR contrast levels were also evaluated at two different distances 1 meter and 3 meters (0.50 meter if visual acuity worse than 6.0 cy/cm). Cognitive abilities were evaluated using the 6-Item Cognitive Impairment Test (6-CIT). Results: A significant effect of test was revealed (p < 0.005), in favor of OCC, yielding consistently higher average LogCS scores than PR, average difference of 0.412 LogCS. The PR and OCC revealed similar repeatability with 95% LoA of ± 0.28 log units and 95% LoA of ± 0.27 log units, respectively. No statistically significant effect of testing distance was found. Strong statistically significant correlations were found between grating CS (OCC) vs. grating VA (TAC), letter CS (PR) vs. letter VA (Clear Chart), Grating CS (OCC) vs. letter CS (PR), and Grating VA (TAC) vs. letter VA (Clear Chart). No statistically significant association between cognitive impairment scores and age vs. our four tests (PR, OCC, TAC, Clear Chart) was found. Conclusion: The Ohio Contrast Cards serve as an alternative to the Pelli-Robson chart and show greater potential in uninstructable patients (e.g. dementia patients). i Dedication This document is dedicated to my family and friends. ii Acknowledgments Dr. Angela Brown has been a great mentor and advisor to me throughout this project. I am grateful for her guidance and support as I learned to grow as a researcher and developed a deeper understanding of vision science. I would like to acknowledge Faustina Ottie Opoku for her dedication to collecting data and for always keeping me motivated . I must thank the Ohio State College of Optometry’s Primary Vision Care Clinic, especially Dr. Dawn Goedde, chief, and the check-in and scheduling staff, for helping with recruiting and for their tremendous support and encouragement. Finally, I would like to thank my committee members Dr. Bradley E. Dougherty and Dr. Heidi A. Wagner for serving on my committee and providing me with advice on how to perfect my work. iii Vita 2012................................................................Gahanna Lincoln High School 2016................................................................B.S. Biology, The Ohio State University 2016 to present ..............................................O.D./M.S. student, College of Optometry, The Ohio State University Fields of Study Major Field: Vision Science iv Table of Contents Abstract ................................................................................................................................ i Dedication ........................................................................................................................... ii Acknowledgments.............................................................................................................. iii Vita ..................................................................................................................................... iv Fields of Study ................................................................................................................... iv Table of Contents ................................................................................................................ v List of Tables ................................................................................................................... viii List of Figures .................................................................................................................... ix Chapter 1: Introduction ...................................................................................................... 1 1.1: Visual Acuity .......................................................................................................... 2 1.1.1: Bailey Lovie Chart .......................................................................................... 2 1.1.2: Clear Chart ® 4 Digital Acuity System ......................................................... 4 1.1.3: Teller Acuity Cards ......................................................................................... 6 1.2.1: Pelli-Robson Chart .......................................................................................... 9 1.2.2: The Ohio Contrast Cards ............................................................................. 12 1.3: Cognitive Impairment ......................................................................................... 14 1.3.1: Six-Item Cognitive Impairment Test ........................................................... 14 v 1.4: Overview of this project ...................................................................................... 16 Chapter 2: Methods ........................................................................................................... 17 2.1: Power Analysis ..................................................................................................... 17 2.2: Participants ........................................................................................................... 19 2.3: Visual Acuity Procedures .................................................................................... 19 2.3.1: Letter acuity ................................................................................................... 19 2.3.2: Grating acuity ................................................................................................ 20 2.4: Contrast Sensitivity Procedures ......................................................................... 20 2.4.1: Letter Contrast .............................................................................................. 20 2.4.2: Grating Contrast ........................................................................................... 21 2.5: Mental Status Assessment ................................................................................... 21 2.5.1: Six-Item Cognitive Impairment Test ........................................................... 21 2.6: Randomization: .................................................................................................... 22 Chapter 3: Analysis......................................................................................................... 24 Chapter 4: Results........................................................................................................... 25 4.1: Pelli-Robson and Ohio Contrast Cards Performance ...................................... 25 4.2: Test-Retest Reliability ......................................................................................... 28 4.3: Testing Distance of PR......................................................................................... 31 4.4: Contrast Sensitivity vs. Visual Acuity ................................................................ 32 vi 4.5: Gratings vs. Letters .............................................................................................. 34 4.6: Cognitive impairment Test ................................................................................. 35 Chapter 5: Discussion ..................................................................................................... 37 5.1: Test-Retest Reliability of the OCC and PR chart ............................................. 37 5.2: Testing Distance of the Pelli-Robson Chart....................................................... 37 5.3: Contrast Sensitivity vs. Visual Acuity ................................................................ 38 5.4: Grating vs. Letter ................................................................................................. 39 5.5: Cognitive test results: .......................................................................................... 40 5.6: Future work .......................................................................................................... 40 Appendix A: Study Materials ........................................................................................ 41 References:....................................................................................................................... 61 vii List of Tables Table 1.1: Snellen Standard and LogMAR size progression of the Clear Chart ® Digital Acuity System ..................................................................................................................... 6 Table 2.1: Chosen Standard Deviations for power analysis ............................................. 18 Table 4.1: Average contrast sensitivity scores for each test (PR1m,