Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/16192
Title: Repeatability of the Waterloo Four-Contrast LogMAR visual acuity chart and near vision test card on a group of normal young adults
Authors: Cho, P 
Woo, GC 
Keywords: Contrast
LogMAR VA
Near acuity
Presentation
Repeatability
Issue Date: 2004
Publisher: Wiley-Blackwell
Source: Ophthalmic and physiological optics, 2004, v. 24, no. 5, p. 427-435 How to cite?
Journal: Ophthalmic and physiological optics 
Abstract: Purposes: To investigate the repeatability of logMAR visual acuity (VA) with the Waterloo Four-Contrast LogMAR Visual Acuity (FCLVA) chart and the Near Vision Test (NVT) card. The differences and agreements between near logMAR VA using horizontally- and vertically-presented letters were also determined. Methods: Visual acuity of one eye (55 subjects) was first assessed by using the FCLVA chart, comprising four charts of varying contrast, and then with the NVT card (comprising four charts of two contrasts and two presentations). Measurements were repeated after 3 or 4 weeks. Results: No significant between-visit differences were observed for any of the charts used. The repeatability coefficient for the distance 90, 60, 30 and 10% charts were 0.07, 0.11, 0.15 and 0.16 log units, respectively. The repeatability coefficients of the near vision charts were 0.06, 0.04 (high contrast), 0.11 and 0.10 (low contrast) log units. The agreements between horizontally- and vertically-presented letters were good. The differences were similar to the repeatability coefficient of each chart. Conclusions: The repeatability coefficient of the high contrast distance and near chart was about half a line. Repeatability coefficients increase with decreasing contrasts for both distance and near charts, with coefficients of one line or more for low contrast charts. Variabilities in both distance and near VA increase with decrease in contrast. The presentation of the letters does not affect near VA and the agreement between horizontally- and vertically-presented letters (both high and low contrast) was within the repeatability coefficient of each chart.
URI: http://hdl.handle.net/10397/16192
ISSN: 0275-5408
EISSN: 1475-1313
DOI: 10.1111/j.1475-1313.2004.00216.x
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

8
Last Week
0
Last month
0
Citations as of Nov 6, 2017

WEB OF SCIENCETM
Citations

8
Last Week
0
Last month
0
Citations as of Nov 24, 2017

Page view(s)

47
Last Week
5
Last month
Checked on Nov 20, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.