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Trial registered on ANZCTR


Registration number
ACTRN12619001476123
Ethics application status
Approved
Date submitted
24/09/2019
Date registered
24/10/2019
Date last updated
24/10/2019
Date data sharing statement initially provided
24/10/2019
Date results provided
24/10/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
Investigating compliance and effectiveness of gamified and conventional vision training for people with convergence insufficiency.
Scientific title
Investigating compliance and effectiveness of gamified virtual reality and conventional training for people with convergence insufficiency.
Secondary ID [1] 297471 0
nil
Universal Trial Number (UTN)
U1111-1228-9819
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
convergence insufficiency 311664 0
Condition category
Condition code
Eye 310285 310285 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Materials - Computerised virtual reality gaming head set with software for convergence insufficiency training in the form of a game of Snakes. The prescribed training regimen was 20 minutes, 3 times per week for 6 weeks. Participants were instructed to spend half the time in the converged position (where the two eyes are pointed inwards towards the nose, achieved by making the right eye image appear to the left and the left eye image appear to the right) and half the time in the diverged position (where the two eyes are pointed away from the nose achieved by making the right eye image appear to the left and the left eye image appear to the right) and to progressively increase the difficulty level whenever they felt the game became too easy. The task was the game of snakes (where a snake eats items and grows progressively longer and must avoid hitting its own growing body or the wall). The following modification enabled it to train convergence: items were cubes scattered on a sandpit with arrows drawn on them and the snake must eat the cubes from the correct approach direction as indicated by the arrows. Half the arrow was presented to the right eye view and the other half of the arrow was presented to the left eye view. Therefore, the participant must use both eyes to see the whole arrow and to correctly determine the approach angle. For patients who could not view both halves of the arrow, patients could lower the contrast of the half that is seen until the other half is visible, due to decreased suppression of one eye's view over the other eye's view. Patients control the movement of the snake using arrow keys on a regular computer keyboard. Patients change settings also using keys on a regular computer keyboard. Difficulty level was increased in 3 ways. Firstly by the game mechanics (must avoid the gradually increasing body length of the snake), by increasing the velocity of the snake and by increasing the level of convergence and divergence. Adherence was monitored by firstly observing whether the participant could carry out the tasks correctly after training, then assigning unique log ins to each participant and the computer software logging time spent in training and the settings used the participant for training. A phone number of the researcher who did the training was provided in case of difficulties next to the equipment, which was located in a university research laboratory that was left unlocked during business hours. Written instructions were also provided next to the equipment. Treatment assignment was determined by alternating the intervention based on the time of enrolment, however this was not the same as visit 1 hence it was not possible for the researcher assigned to assessing function before and after the intervention to predict the intervention on this basis. Care was taken so that there was no other identifying information of intervention in the record sheets of the participants.
Intervention code [1] 313726 0
Treatment: Other
Comparator / control treatment
Conventional therapy of anaglyphs whereby red-green glasses are worn when viewing red and green anaglyphs against a white background showing stimuli required to be fused in order to be seen completely and in three dimensions. The prescribed training regimen was 20 minutes, 3 times per week for 6 weeks. Participants were instructed to spend half the time in the converged position and half the time in the diverged position and to progressively increase the difficulty level whenever they felt the game became too easy. The main differences from the intervention are that 1) this is a regular clinical test, 2) it is conducted in real space, rather than virtual space, 3) the right and left eye views are produced through red and green filters placed over the two eyes that filter out different wavelengths so that the eye looking through the red filter can see the white background of the anaglyph as red and the green image as black. Alternatively, the eye looking through the green filter can see the white background as green and the red image as black, 4) convergence and divergence is increased by sliding the red and green anaglyphs either closer together or farther apart to move the images seen by the right and left eye (this is also how difficulty level is increased and decreased, there is no speed element, 5) the intervention is designed as a game whereas this intervention is not a game and 6) adherence was monitored by firstly observing whether the participant could carry out the task correctly, written instructions and phone number of the training researcher were provided next to the equipment and participants filled in a manual log of time started and time finished training.
Control group
Active

Outcomes
Primary outcome [1] 321500 0
Positive fusional vergences for the control and intervention group as measured by a prism bar
Timepoint [1] 321500 0
Baseline and 6 weeks after commencement of treatment
Secondary outcome [1] 375143 0
Duration of training as assessed by time logged training, recorded by the VR Snake Game software and manually for the control group
Timepoint [1] 375143 0
Baseline and 6 weeks after commencement of treatment

Eligibility
Key inclusion criteria
Participant inclusion criteria were (1) aged at least 18 years, (2) visual acuity of at least 0.1 logMAR vision in both eyes, (3) less than 0.1 logMAR difference in visual acuity between eyes and (4) a diagnosis of convergence insufficiency, defined as showing at least one of the following signs: near exophoria greater than or equal to 4 prism diopters (PD) larger than far exophoria, near point of convergence break of greater than or equal to 6 cm, insufficient positive fusional reserves (PFR) at near (defined as PFR break or blur less than 2 times the near phoria), or PFR break less than or equal to 15 PD.
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Exclusion criteria were having a history of extraocular muscle surgery, strabismus, amblyopia, significant under-correction with current spectacles (defined as greater than or equal to 0.75DS undercorrection for myopes; greater than or equal to 1.00DS undercorrection for hyperopes; greater than or equal to 1.00DC undercorrection for astigmatism per eye) and no diagnosis of convergence insufficiency.

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation was not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
All data analyses were performed using SPSS (IBM SPSS Statistics 23). The Shapiro-Wilk test confirmed that all data were normally distributed and therefore a repeated measure ANOVA was used to determine if there was a significant effect of visit or group on the PFV and NPC. An independent t test was used to compare compliance between the two groups. The feedback questionnaire on the core elements of gaming was analysed descriptively. Sample size was based on a previous paper Boon, M. Y., Asper, L., Jiao, N., & Ryan, M. (2017). Vision training: comparing a novel virtual reality game of snakes with a conventional clinical therapy. In 2017 IEEE Life Sciences Conference, LSC 2017 (pp. 43-46). Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE). https://doi.org/10.1109/LSC.2017.8268139 with 18 participants.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
10/08/2017
Date of last participant enrolment
Anticipated
Actual
14/09/2017
Date of last data collection
Anticipated
Actual
26/10/2017
Sample size
Target
18
Accrual to date
Final
18
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 28113 0
2052 - Unsw Sydney

Funding & Sponsors
Funding source category [1] 302040 0
University
Name [1] 302040 0
University of New South Wales
Country [1] 302040 0
Australia
Primary sponsor type
University
Name
University of New South Wales
Address
UNSW, Sydney, NSW, 2052, Australia
Country
Australia
Secondary sponsor category [1] 301841 0
University
Name [1] 301841 0
Macquarie University
Address [1] 301841 0
Balaclava Rd, Macquarie Park NSW 2109
Country [1] 301841 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 302722 0
University of New South Wales, Human Research Ethics Committee
Ethics committee address [1] 302722 0
Ethics committee country [1] 302722 0
Australia
Date submitted for ethics approval [1] 302722 0
26/04/2017
Approval date [1] 302722 0
16/05/2017
Ethics approval number [1] 302722 0
HC16710

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 91162 0
Dr Mei Ying Boon
Address 91162 0
School of Optometry and Vision Science, UNSW, Sydney, NSW, 2052, Australia
Country 91162 0
Australia
Phone 91162 0
+61 293854621
Fax 91162 0
Email 91162 0
m.boon@unsw.edu.au
Contact person for public queries
Name 91163 0
Mei Ying Boon
Address 91163 0
School of Optometry and Vision Science, UNSW, Sydney, NSW, 2052, Australia
Country 91163 0
Australia
Phone 91163 0
+61 293854621
Fax 91163 0
Email 91163 0
m.boon@unsw.edu.au
Contact person for scientific queries
Name 91164 0
Mei Ying Boon
Address 91164 0
School of Optometry and Vision Science, UNSW, Sydney, NSW, 2052, Australia
Country 91164 0
Australia
Phone 91164 0
+61 293854621
Fax 91164 0
Email 91164 0
m.boon@unsw.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Individual participant data will not be included in a database due to the terms of ethics approval for this study. However, data in other forms will be presented in publications.


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.