April 2011
Volume 52, Issue 14
Free
ARVO Annual Meeting Abstract  |   April 2011
Effect of Parkinson’s Disease on Eye Movements During Reading
Author Affiliations & Notes
  • Paul A. Wetzel
    Biomedical Engineering,
    Virginia Commonwealth University, Richmond, Virginia
  • George T. Gitchel
    Biomedical Engineering,
    Virginia Commonwealth University, Richmond, Virginia
    Parkinson's Disease Research, Education and Clinical Center, McGuire Veterans Affairs Medical Center, Richmond, Virginia
  • Mark S. Baron
    Neurology,
    Virginia Commonwealth University, Richmond, Virginia
    Parkinson's Disease Research, Education and Clinical Center, McGuire Veterans Affairs Medical Center, Richmond, Virginia
  • Footnotes
    Commercial Relationships  Paul A. Wetzel, None; George T. Gitchel, None; Mark S. Baron, None
  • Footnotes
    Support  Southeast/Richmond Parkinson's Disease Research, Education and Clinical Center, Hunter Holmes McGuire Veterans Affairs Medical Center
Investigative Ophthalmology & Visual Science April 2011, Vol.52, 4697. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Paul A. Wetzel, George T. Gitchel, Mark S. Baron; Effect of Parkinson’s Disease on Eye Movements During Reading. Invest. Ophthalmol. Vis. Sci. 2011;52(14):4697.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: : Reading requires accurate eye movement control and stability during fixation. Parkinson’s disease patients (PDs) often report difficulty with reading or have altogether stopped. To investigate these reports, the eye movements of PDs and aged matched controls were compared during reading.

Methods: : Eye movements of 36 medication confirmed PDs from 57 to 88 years old (mean 68 ± 7.5 yrs) and 20 similarly age-matched controls from 49 to 81 years old (62.9 ± 6.9 yrs) were recorded during reading. Patients with dementia (Mini-Mental State Exam scores <24) were excluded. On the day of testing, PDs were evaluated using the Unified Parkinson’s Disease Rating Scale (mean score 12.1 ± 9.7). Each subject read 10 out of 35 available texts ranging from easiest to most difficult and of equivalent difficulties. All texts were of equal line number, character style, character width with nearly equal numbers of total characters. From the reading distance, text boundaries were ±10° H by ±6° V. Texts were presented in a randomized order on a computer display while binocular eye movements were measured at 500 Hz from a two-dimensional eye tracking system (SR Research). Head movement was not restricted, but showed no measurable changes in position or orientation while reading. Eye position subject data were analyzed for the number of forward saccades and regressions including their respective amplitudes and durations, the number of fixations, their duration and stability, reading speed measured in characters/sec and the number of lines read.

Results: : Statistically significant differences between PDs and controls were found in nearly all eye measurement parameters except in the number of regressions and saccadic durations. PDs produced a greater number of smaller amplitude saccades than controls. Main sequence data for both groups appeared normal and similar to each other. The fixation durations of PDs were longer and less stable compared to controls. The visual span during reading was significantly less for PDs compared to the control group. For controls, reading speed was unaffected by text difficulty level compared to a downward slowing trend among PDs.

Conclusions: : PD negatively affects nearly all aspects of normal reading behavior related to eye movements primarily through reduced visual span and increased instability during fixation.

Keywords: eye movements • reading • neuro-ophthalmology: diagnosis 
×
×

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.

×