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Journal of Biomedical Optics • Open Access

Psychophysics, reliability, and norm values for temporal contrast sensitivity implemented on the two alternative forced choice C-Quant device
Author(s): Thomas J. T. P. van den Berg; Luuk Franssen; Bastiaan Kruijt; Joris Coppens

Paper Abstract

The current paper describes the design and population testing of a flicker sensitivity assessment technique corresponding to the psychophysical approach for straylight measurement. The purpose is twofold: to check the subjects' capability to perform the straylight test and as a test for retinal integrity for other purposes. The test was implemented in the Oculus C-Quant straylight meter, using homemade software (MATLAB). The geometry of the visual field lay-out was identical, as was the subjects' 2AFC task. A comparable reliability criterion ("unc") was developed. Outcome measure was logTCS (temporal contrast sensitivity). The population test was performed in science fair settings on about 400 subjects. Moreover, 2 subjects underwent extensive tests to check whether optical defects, mimicked with trial lenses and scatter filters, affected the TCS outcome. Repeated measures standard deviation was 0.11 log units for the reference population. Normal values for logTCS were around 2 (threshold 1%) with some dependence on age (range 6 to 85 years). The test outcome did not change upon a tenfold (optical) deterioration in visual acuity or straylight. The test has adequate precision for checking a subject's capability to perform straylight assessment. The unc reliability criterion ensures sufficient precision, also for assessment of retinal sensitivity loss.

Paper Details

Date Published: 1 August 2011
PDF: 8 pages
J. Biomed. Opt. 16(8) 085004 doi: 10.1117/1.3613922
Published in: Journal of Biomedical Optics Volume 16, Issue 8
Show Author Affiliations
Thomas J. T. P. van den Berg, The Netherlands Ophthalmic Research Institute (Netherlands)
Luuk Franssen, The Netherlands Ophthalmic Research Institute (Netherlands)
Bastiaan Kruijt, The Netherlands Ophthalmic Research Institute (Netherlands)
Joris Coppens, The Netherlands Ophthalmic Research Institute (Netherlands)

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