A pilot study of anisometropic amblyopia improved in adults and children by perceptual learning: an alternative treatment to patching

Abstract

Visual acuity can be improved with perceptual learning and patching in older children and adult patients with anisometropic amblyopia. The improvements in visual acuity achieved with patching were one line better than those achieved with perceptual learning. Perceptual learning might provide an alternative treatment in patients with anisometropic amblyopia.

A dichoptic custom-made action video game as a treatment for adult amblyopia

“…This sustained improvement in VA is in line with several previous reports in the literature, showing that VA improvements are retained for at least a year (Chen et al, 2008; e.g. Li & Levi, 2004; Polat et al, 2004) or even 18 months (Zhou et al, 2006) following training (see Levi & Li, 2009 for review).…”

The Pattern of Learned Visual Improvements in Adult Amblyopia

“…Consistent with this notion, when gratings are used in a spatial frequency discrimination task, learning can be substantial. 40 Other studies (also using contrast based tasks) have achieved PPR Ն 0.34 (PPR found for letter contrast task), [41][42][43] although subjects received more training. We suspect that the very rapid rate of learning and degree of generalization in our letter contrast group is due to optimization of the stimulus configuration and procedural demands.…”

The challenges of developing a contrast-based video game for treatment of amblyopia

“…Psychophysical tasks on the other hand, call for sustained focus on a single attribute of a stimulus, which although not as stimulating, may evoke types of learning that are absent or diffuse in video games. Contrast-based laboratory tasks that thus far have produced improvement in acuity in amblyopia, have required discrimination of foveated, static targets in clearly defined spatial or temporal intervals, that is, in stimulus conditions optimized for producing low thresholds (Polat et al, 2004; Zhou et al, 2006; Chen et al, 2008; Huang et al, 2008; Astle et al, 2011). Insofar as dynamic target pursuit remains an objective of a game, threshold tasks (and especially contrast-based tasks) are not easily adapted to video games because pursuit of targets is difficult or impossible near threshold.…”

“…Practice of visual tasks can enhance visual function in amblyopic children and adults (Levi and Polat, 1996; Levi et al, 1997; Polat et al, 2004; Chen et al, 2008; Astle et al, 2011; To et al, 2011; Hussain et al, 2012b; Li et al, 2013). Such improvements in visual function after practice are classed under the phenomenon of “perceptual learning” and are attributed to residual plasticity in primary- and higher sensory cortices.…”

“…Whilst psychophysical tasks help to isolate particular dimensions of improvement (e.g., resolution vs. contrast), video games provide more stimulating conditions that elicit the reward mechanisms associated with learning (Koepp et al, 1998; Suzuki et al, 2001; Dommett et al, 2005; Seitz et al, 2009; Rokem and Silver, 2010). From the psychophysical tasks tested to date, there is evidence that contrast sensitivity tasks are associated with the largest improvements on the trained task, and with the largest transfer of benefits to visual acuity (e.g., Polat et al, 2004; Chen et al, 2008; Astle et al, 2011, see Levi, 2012 for review). Practice need not be on contrast detection or discrimination per se , but on a visual judgment in which stimulus contrast is the dependent variable (e.g., Landolt C discrimination, Astle et al, 2011).…”