May 2006
Volume 47, Issue 13
ARVO Annual Meeting Abstract  |   May 2006
Supra–Threshold Contrast Matching With Macular Disorders
Author Affiliations & Notes
  • M. Mei
    School of Optometry, University of Waterloo, Waterloo, ON, Canada
  • S.J. Leat
    School of Optometry, University of Waterloo, Waterloo, ON, Canada
  • Footnotes
    Commercial Relationships  M. Mei, None; S.J. Leat, None.
  • Footnotes
    Support  Macular Disease Society, UK.
Investigative Ophthalmology & Visual Science May 2006, Vol.47, 5828. doi:
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      M. Mei, S.J. Leat; Supra–Threshold Contrast Matching With Macular Disorders . Invest. Ophthalmol. Vis. Sci. 2006;47(13):5828.

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      © ARVO (1962-2015); The Authors (2016-present)

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Purpose: : To examine supra–threshold contrast perception in macular disorders.

Methods: : Two groups of control subjects (14 aged 20–49 and 15 aged 50+) and three groups of subjects with macular disorders (13 dry ARMD, 14 wet ARMD, and 8 macular dystrophy) participated. Contrast sensitivity (CS) up to 8 cycles per degree and supra–threshold contrast matching at 3.6% and 28% contrast were measured. Measurements were taken up to the highest spatial frequency that each subject could detect. CS was measured with a temporal 2AFC staircase procedure. A method of adjustment was used for contrast matching. A 0.5 cycle per degree sine–wave grating was the standard grating for contrast matching, the subject being asked to match the contrast of gratings of different spatial frequencies.

Results: : For both threshold and supra–threshold contrast matching there was no effect of diagnosis (repeated measures ANOVA, 3 x groups x 5 spatial frequency x 3 levels, p > 0.05). There was an effect of spatial frequency (p < 0.001) at all contrast levels. Although contrast matching for those with macular disorders was often outside the 95% of the normal range at the lower contrast (3.6%), at the higher contrast of 28% contrast matches were accurate and within the normal range. Contrast matching functions at 28% contrast are flatter compared with the threshold and the 3.6% matching functions.

Conclusions: : Patients with macular disorders performed similarly and all three groups showed evidence of contrast constancy. Supra–threshold contrast perception is less impaired than contrast thresholds in ARMD and macular dystrophy.

Keywords: low vision • macula/fovea • age-related macular degeneration 

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