May 2008
Volume 49, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2008
Agreement Between Psychophysical Orientation Discrimination and Observable Macular Changes That Precede Amd
Author Affiliations & Notes
  • H. E. Bedell
    College of Optometry, University of Houston, Houston, Texas
  • S. Y. Woo
    College of Optometry, University of Houston, Houston, Texas
  • J. Tong
    College of Optometry, University of Houston, Houston, Texas
  • J. R. House
    College of Optometry, University of Houston, Houston, Texas
  • T. Nguyen
    College of Optometry, University of Houston, Houston, Texas
  • T. C. Lien
    College of Optometry, University of Houston, Houston, Texas
  • Footnotes
    Commercial Relationships  H.E. Bedell, patent applied for, P; S.Y. Woo, patent applied for, P; J. Tong, patent applied for, P; J.R. House, None; T. Nguyen, None; T.C. Lien, None.
  • Footnotes
    Support  NEI T35 EY07088
Investigative Ophthalmology & Visual Science May 2008, Vol.49, 2252. doi:https://doi.org/
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      H. E. Bedell, S. Y. Woo, J. Tong, J. R. House, T. Nguyen, T. C. Lien; Agreement Between Psychophysical Orientation Discrimination and Observable Macular Changes That Precede Amd. Invest. Ophthalmol. Vis. Sci. 2008;49(13):2252. doi: https://doi.org/.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: : The retinal distribution of errors in a psychophysical orientation-discrimination task was compared to the observed location of subtle macular changes that precede early AMD.

Methods: : By comparing digital fundus photographs to Nidek-MP1 fundus images, a masked examiner specified the meridian of macular drusen and/or early RPE changes with respect to the retinal fixation locus in 26 eyes of 16 patients, aged 52 - 82. Visual acuities ranged from 20/15 to 20/30, with a median value of 20/20. To assess orientation discrimination, two 1-deg patches of 0.4-deg lines were presented for 200 ms on opposite sides of a central fixation spot. In one patch, all of the lines were parallel. In the other, each line varied from the mean orientation by a pre-determined angular standard deviation. After each presentation, the patient indicated which patch contained the more parallel lines. The orientation-discrimination threshold and the meridional distribution of errors were determined from the responses to 80 trials. Automated 10-2 perimetry, retinal micro-perimetry, and Amsler grid testing were performed also for each eye.

Results: : The average orientation-discrimination threshold in the eyes with subtle macular changes was 10.0 deg, similar to previous results. Meridians with ≥ 25% errors agreed with the meridian of one or more observable macular abnormalities in 62% of the eyes. In contrast, defects in the central 2 deg determined with automated perimetry (P < 0.05) and Nidek retinal micro-perimetry (sensitivity < 20 dB) agreed with the meridian of macular abnormalities (within +45 deg) in only 42% and 50% of eyes. Amsler grid responses were abnormal in just 2 eyes.

Conclusions: : The distribution of errors on a psychophysical test of orientation discrimination agrees better with the observed location of subtle macular abnormalities than do perimetry results.

Keywords: age-related macular degeneration • perception • visual fields 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×