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Steve Njeru - MS Thesis Final.pdf (1.41 MB)

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Contrast Sensitivity and Visual Acuity in Low-Vision Students

Njeru, Steve Murimi Mathenge
http://rave.ohiolink.edu/etdc/view?acc_num=osu1586966057072378

Abstract Details

2020, Master of Science, Ohio State University, Vision Science.
Purpose: This study primarily compared the test-retest reliability of the Pelli-Robson chart (PR) and Ohio Contrast Cards (OCC) amongst testers. The secondary goal of this study was to examine the impact on contrast sensitivity if the testing distance for the Pelli-Robson chart were to be changed. An additional goal was to evaluate the relationship between visual acuity (VA) and contrast sensitivity (CS) when using letter-based charts and grating cards. Methods: Thirty low-vision students were tested, ranging from 7-20 years old. Each student was tested with both VA and CS tests in randomized order, which included: the Bailey-Lovie chart (BL), Pelli-Robson chart, Teller Acuity Cards (TAC), and Ohio Contrast Cards. Each student repeated both the PR chart and OCC in separate rooms, but neither the BL chart nor TAC was repeated. The PR chart was also tested at closer testing distance, based on the student’s logMAR acuity from the BL chart. For the letter charts, a letter-by-letter scoring method was used. For grating cards, these were both scored as preferential looking tests. Results: The Limits of Agreement for the OCC and PR chart were +/- 0.451 and +/- 0.536, respectively. There was no statistically significant difference between tester or order of testers for the PR chart and OCC. Using the PR chart at a closer distance yielded an improvement in contrast threshold performance when compared to the standard testing distance. Students performed better on grating cards than letter charts, regardless of VA testing or CS testing. Conclusions: The Ohio Contrast Cards are a promising diagnostic tool for evaluating CS on low-vision patients and other patients who cannot be tested using letter-based charts. Clinicians using the Pelli-Robson chart for low-vision patients should consider testing closer than the standard testing distance.
Angela Brown, PhD (Advisor)
Bradley Dougherty , OD, PhD (Committee Member)
Deyue Yu, PhD (Committee Member)
59 p.
Health Care; Ophthalmology
contrast sensitivity, visual acuity, low-vision

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Citations

  • Njeru, S. M. M. (2020). Contrast Sensitivity and Visual Acuity in Low-Vision Students [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1586966057072378

    APA Style (7th edition)

  • Njeru, Steve . Contrast Sensitivity and Visual Acuity in Low-Vision Students. 2020. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1586966057072378.

    MLA Style (8th edition)

  • Njeru, Steve . "Contrast Sensitivity and Visual Acuity in Low-Vision Students." Master's thesis, Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1586966057072378

    Chicago Manual of Style (17th edition)

osu1586966057072378
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This open access ETD is published by The Ohio State University and OhioLINK.