An Active Approach to Treat Amblyopia: Perceptual Learning and Video Games

• Spatial vision [ Time Frame: 9 months ] [ Designated as safety issue: No ]
  Improvement in spatial vision (eg. contrast sensitivity, positional acuity and spatial attention)
• Temporal vision [ Time Frame: 9 months ] [ Designated as safety issue: No ]
  Improvement in temporal processing and temporal vision

Amblyopia, a developmental abnormality that impairs spatial vision, is a major cause of vision loss, resulting in reduced visual acuity and reduced sensitivity to contrast. This study uses psychophysical measures to study neural plasticity in both adults and children with amblyopia.

Amblyopia, a developmental abnormality that impairs spatial vision, is a major cause of vision loss, resulting in reduced visual acuity and reduced sensitivity to contrast. Our previous findings (see CITATIONS) show that the adult amblyopic brain is still plastic and malleable, suggesting that active approach is potential useful in treating amblyopia. The goal of this project is to assess the limits and mechanisms of neural plasticity in both normal and amblyopic spatial vision. This study uses psychophysical measures to study neural plasticity in both adults and children with amblyopia. Research participants will be asked to practice a visual discrimination task (perceptual learning) or to play video games with the amblyopic eye for a period of time. A range of visual functions will be monitored during the course of treatment.

• Behavioral: Perceptual learning
  Research participants will be asked to practice a visual discrimination task (e.g. position acuity, contrast sensitivity, stereoacuity etc) in our laboratory for a period of time (2 hrs/day, 5 days/week).
  Other Names:

  • vision therapy
  • vision training
• Behavioral: Video Games
  Research participants will be asked to play "off-the-shelf" video games in our laboratory for a period of time (2 hrs/day, 5 days/week).
  Other Names:

  • vision therapy
  • vision training
• Behavioral: Occlusion therapy
  Research participants will be required to cover the good eye during the day in order to push the brain to use the amblyopic eye (2 hrs/day, 5 days/week for 2-4 weeks).
  Other Names:

  • vision training,
  • vision therapy

• Li RW, Klein SA, Levi DM. Prolonged perceptual learning of positional acuity in adult amblyopia: perceptual template retuning dynamics. J Neurosci. 2008 Dec 24;28(52):14223-9.
• Li RW, Provost A, Levi DM. Extended perceptual learning results in substantial recovery of positional acuity and visual acuity in juvenile amblyopia. Invest Ophthalmol Vis Sci. 2007 Nov;48(11):5046-51.
• Li RW, Young KG, Hoenig P, Levi DM. Perceptual learning improves visual performance in juvenile amblyopia. Invest Ophthalmol Vis Sci. 2005 Sep;46(9):3161-8.
• Li RW, Levi DM. Characterizing the mechanisms of improvement for position discrimination in adult amblyopia. J Vis. 2004 Jun 1;4(6):476-87.
• Chung ST, Li RW, Levi DM. Identification of contrast-defined letters benefits from perceptual learning in adults with amblyopia. Vision Res. 2006 Oct;46(22):3853-61. Epub 2006 Aug 22.
• Chung ST, Li RW, Levi DM. Learning to identify near-threshold luminance-defined and contrast-defined letters in observers with amblyopia. Vision Res. 2008 Dec;48(27):2739-50. Epub 2008 Oct 18.
• Levi DM, Li RW. Improving the performance of the amblyopic visual system. Philos Trans R Soc Lond B Biol Sci. 2009 Feb 12;364(1515):399-407. Review.
• Levi DM, Li RW. Perceptual learning as a potential treatment for amblyopia: a mini-review. Vision Res. 2009 Oct;49(21):2535-49. Epub 2009 Feb 27. Review.

Inclusion Criteria:

• adults and children (>5 years old) with normal vision or amblyopia
• amblyopia: interocular VA difference of at least 0.1 logMAR

Exclusion Criteria:

• any ocular pathological conditions, nystagmus