October 2020
Volume 20, Issue 11
Open Access
Vision Sciences Society Annual Meeting Abstract  |   October 2020
Eye on the prize: Fixational stability as a metric for the recovery of visual acuity in amblyopia
Author Affiliations & Notes
  • Avi Aizenman
    UC Berkeley
  • Dennis Levi
    UC Berkeley
  • Footnotes
    Acknowledgements  This work was funded by the Berkeley Fellowship to AMA and by grant RO1EY020976 from the National Eye Institute (to DML).
Journal of Vision October 2020, Vol.20, 558. doi:https://doi.org/10.1167/jov.20.11.558
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Avi Aizenman, Dennis Levi; Eye on the prize: Fixational stability as a metric for the recovery of visual acuity in amblyopia. Journal of Vision 2020;20(11):558. https://doi.org/10.1167/jov.20.11.558.

      Download citation file:

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

  • Supplements

Amblyopia is a developmental disorder which leads to impaired form vision and oculomotor abnormalities including eccentric and unsteady fixation. Increased fixational unsteadiness is associated with poor visual acuity and stereopsis. In this study, we investigated whether improvements in visual function with treatment are accompanied by changes in fixational stability, i.e., whether changes in fixation stability can serve as an objective proxy for changes in visual acuity in children undergoing treatment for amblyopia. Five children with amblyopia currently undergoing patching treatment or vision therapy (3 strabismic, 2 anisometropic, mean age 8.2 years) and five normally sighted children (control group, mean age 9.4 years) participated in 3 sessions over 3 months. During each session, we measured visual acuity and stereopsis. To measure fixational stability, observers were asked to look at a 1-degree colorful smiley face on a black screen for 20-second intervals. To ensure attention, the smiley face changed color after 10 (+/-3) seconds and observers responded when the color changed. There were ten 20 second trials in total. Eye movements were recorded with an Eyelink II eyetracker. We calculated the 68% isoline area (ISOA) values (similar to the more common bivariate contour ellipse metric, but without assumptions of normality) as a measure of fixational stability, and computed correlations between clinical measurements and ISOA. ISOA showed a correlation with visual acuity (r-squared=.41), and stereopsis (r-squared=.46) replicating previous work. Importantly, the change (pre/post ratio) in ISOA showed a correlation with changes in visual acuity (r-squared=.59), but not stereopsis (r-squared=.02). Although stereopsis is correlated with fixational stability by session, the changes in fixational stability during the treatment of amblyopia do not track changes in stereopsis. As improvements in visual acuity are accompanied by changes in fixational stability, novel interventions for amblyopia may consider tracking eye movements as a measure of recovery of visual function.


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.