Perceptual learning in enhanced amblyopia treatment

INTERVENTION: Perceptual learning treatment administered using a computer and eMagin gaming goggles You will be randomised to one of three treatment groups using an automated telephone service provided by the Robertson Centre of Biostatistics at the University of Glasgow. After obtaining informed consent, a telephone number is called which provides a unique participant number, which determines your treatment group. All of you will play the same child‐friendly fun video game and wear the same eMagin gaming goggles, it is how you view the game through the gaming goggles that is being compared. You will be randomised to viewing the game with one eye only, with both eyes, or with both eyes and different game elements are presented to each eye to encourage binocular cooperation. You will play the video game for an hour each day, for 10 days spread over 2 weeks. If you don't experience any improvement in the quality of vision in your the lazy eye or how well you can use your eyes together, you will be offered an extra 10 days of playing the video game, this time using the special viewing mode through the gaming goggles that encourages binocular cooperation. After the computer game training is completed, if you've had an improvement in vision in your lazy eye or can use your eyes together better than you could before, you will be asked to come back for a check‐up of these things 3 months later, and then again another 3 months later so it will have been 6 months since you finished the computer game training. This is so we can check to see if the improvement you gained is retained over time. After this 6 month check we don't need to see you again. If you haven't had an improvement and want to do the extra 10 days of training then this is done separately from the rest of the study and we won't need to see you for any check‐ups after the training is all finished. CONDITION: Amblyopia ; Eye Diseases PRIMARY OUTCOME: Proportion of patients with visual acuity improvement of 0.1 log units or better in the amblyopic eye at the end of the training period SECONDARY OUTCOME: 1. Sensory fusion status (assessed with Bagolini glasses) ; 2. Motor fusion reserves (measured using horizontal prism bar); 3. Stereoacuity (measured using Frisby and/or Preschool Randot Stereotest); 4. Interocular suppression density (measured using Sbisa bar); 5. Angle of strabismus (measured using prism cover test) ; 6. Severity of perceptual visual distortions (measured using a 5 minute computer game that has been extensively piloted with amblyopic and visually normal children); ; These are measured at the end of training. INCLUSION CRITERIA: 1. Age 5 to 17 years 2. Visual acuity of 0.2 log units or lower in worst eye and/or interocular difference of at least 0.1 log units 3. Presence of anisometropia >1.00 MSE and/or strabismus/microtropia. 4. Not receiving any active conventional amblyopia treatment 5. Participants will all have a refraction, fundus and media check within 6 months prior to enrolment and will wear their up‐to‐date refractive correction for testing and training. It is important to establish that full spectacle adaptation has occurred.