A comparative study on visual acuity and stereopsis outcomes between perceptual learning based on cloud services and conventional therapy for amblyopia
Background
Amblyopia is a developmental disorder of spatial vision that results in both monocular and binocular deficits.Conventional therapy for amblyopia which focuses on monocular training can improve visual acuity.However, how to improve the binocular function, especially stereopsis is rarely studied.


Objective
This study was to evaluate the outcome of perceptual learning based on cloud services of improving stereopsis and visual acuity for amblyopia.


Methods
A randomized-controlled clinical study was performed.One hundred and seven amblyopic patients (178 eyes) with the age of 5—18 years old were recruited in The Second Affiliated Hospital of Anhui Medical University from July 2013 to March 2014.The patients were randomized into the perceptual learning group and the conventional therapy group.A perceptual learning based on cloud services with computer under the best corrected visual acuity was carried out in the perceptual learning group with 30-day duration as a course for 5—6 cycles, and training feedback data was obtained after each cycle for the regulation of following treatment.The dominant eye was covered during the training process.In the conventional therapy group, a training regimen of health eye covering that combined with eyesight training of amblyopic eye was performed.The stereopsis and visual acuity of the patients were estimated after training.Written informed consent was obtained from the parents or custodians of the children before entering the cohort.


Results
The total effective rate of visual acuity improvement is significantly higher in the perceptual learning group than that in the conventional therapy group after training (Z=6.368, P=0.012). The mean stereopsis value of the amblyopic eyes in the perceptual learning group and the conventional therapy group was (127±53)″ and (174±67)″ after training, which was significantly higher than (273±95)″ and (311±103)″ before training, respectively, and the increasing range of the mean stereopsis was considerably larger in the perceptual learning group than that in the conventional therapy group(t=12.329, 9.557, 15.649; all at P<0.05). In the perceptual learning group, the improving range of mean stereopsis was larger in the severe or moderate amblyopic eyes than that in the mild amblyopic eyes, and the improving range of mean stereopsis in ametropic amblyopia was larger than that in anisometropic amblyopia (all at P<0.05).


Conclusions
Both perceptual learning based on cloud services and conventional therapy can improve stereopsis and visual acuity in amblyopic eyes.However, perceptual learning based on cloud services can improve the treating compliance of children.


Key words: 
Amblyopia/physiopathology; Vision, binocular/physiology; Visual acuity/physiology; Amblyopia/therapy; Children; Randomized controlled trials; Cloud services; Perceptual learning