Amblyopia treatment by means of computer-games with background stimulation:: a placebo controlled pilot study of 10 days

Background: Computer programmes for visual stimulation may give new impulses to the field of amblyopia treatment by offering an option to shift the apparative visual training into the domestic sphere, Regarding this aspect we report on a placebo controlled study on a newly developed vision training consisting of a background stimulation by a drifting sinusoidal grating combined with a foreground game aimed to maintain the attention. Materials and Methods: Fourteen amblyopia patients aged from 6 to 13 years participated in the study. Seven were allocated to a placebo and seven to a treatment group. Both groups had to train at the computer for a period of 10 working days by two sessions of about 20 minutes daily. Whilst the placebo group played in front of a neutral background, the treatment group did this with a drifting sinusoidal grating in the background. Results: The treatment condition resulted in a greater increase of visual acuity than the placebo condition. Near vision improved in the treatment group from 0.20 (SD +/-4.51 steps) to 0.39 (SD +/-3.06 steps), i.e. by 3.0 steps of Visual acuity (SD +/-1.8 steps), in the placebo group from 0.14 (SD +/-6.02 steps) to 0.17 (SD +/-5.85 steps), i.e. by 0.8 steps of visual acuity (SD +/-1.6 steps). Far vision improved in the treatment group from 0.29 (SD +/-2.57 steps) to 0.44 (SD +/-3.16 steps), i.e. by 1.9 steps of Visual acuity (SD +/-1.3 steps), in the placebo group from 0.24 (SD +/-5.20 steps) to 0.28 (SD +/-5.51 steps), i.e. by 0.7 steps of visual acuity (SD +/-1.1 steps). Conclusions: Stimulation with drifting sinusoidal gratings improves the visual acuity of amblyopic eyes in a specific way. The effect might be accounted for by a synergy of spatial and temporal frequency in form vs. motion channels. A preliminary hypothesis is discussed and will be the subject of ongoing research. The presented method has been developed for the treatment of "delayed" amblyopia in the elder child. It is aimed to support and complement occlusion therapy. However, the reported results obtained over 10 days should be estimated only within the context of evaluation. By no means should the results be interpreted as a renewed pledge for a short-term treatment of amblyopia.