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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Using eye movements to measure vision in children
Scientific title
Objective Assessment of Visual Performance Using Optokinetic Nystagmus in Young Children
Secondary ID [1] 290610 0
Universal Trial Number (UTN)
Trial acronym
OKN (optokinetic nystagmus) study
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Amblyopia 301102 0
Anisometropia 301103 0
Significant refractive error 301104 0
Visual impairment 301105 0
Strabismus 301106 0
Condition category
Condition code
Eye 300873 300873 0 0
Normal eye development and function
Eye 300874 300874 0 0
Diseases / disorders of the eye

Study type
Description of intervention(s) / exposure
The intervention is a clinical device designed by Dr. Jason Turuwhenua, and consists of multiple components: a stimulus display unit, infrared (IR) camera for optokinetic nystagmus (OKN) video recording, IR illumination, and a computer. Data collection will be done with a prototype device by Objective Acuity Ltd, a UniServices (University of Auckland) start-up company co-founded by Lead investigator, Dr. Jason Turuwhenua, and A/Prof. Ben Thompson. The overall aim of this study is to accurately test visual acuity in young children to allow for the early detection and treatment of vision problems. The OKN device assesses visual acuity by inducing and measuring an involuntary, reflexive eye movement known as OKN. This eye movement only occurs when a moving target is visible. The intervention will be done one eye at a time, and the eye not being tested is covered by an eye patch.

The intervention will be delivered by optometrist(s), orthoptist(s), ophthalmologist(s), and vision researcher(s) with minimum 2 years' clinical/clinical research experience. The mode of delivery is face to face, one participant at a time, in an optometry/ophthalmology clinic or a clinic in vision research institution..

Children will undergo the intervention once, but in the event of technical difficulties or child unable to cooperate, we will invite children and their parents to reschedule for a second attempt. The duration of intervention is approximately 10 minutes (5 minutes per eye).
Intervention code [1] 297337 0
Early detection / Screening
Comparator / control treatment
The sensitivity and specificity of the OKN device will be compared against the clinical gold-standard crowded HOTV visual acuity test using the EVA (electronic visual acuity) system. Children will be shown letters on the EVA monitor one eye at a time, and asked to identify the letter verbally or by letter-matching. The eye not being tested is covered by an eye patch. All children enrolled in this trial will have their visual acuity measured using both the gold-standard and OKN device.
Control group

Primary outcome [1] 300302 0
To assess the sensitivity and specificity of the OKN device for detecting uncorrected monocular visual acuity impairment caused by strabismic amblyopia, anisometropic amblyopia or refractive error in developmentally normal children from 3-6-years of age. The HOTV test delivered using the Electronic Visual Acuity (EVA) system will be used as the gold-standard comparison.

Uncorrected monocular visual acuity impairment will be defined using the ATS-HOTV test in the absence of refractive correction according to age-specific visual acuity cutoffs for vision screening provided by the American Association for Pediatric Ophthalmology and Strabismus (AAPOS, 2014): 36-47 months, >0.4 LogMAR; 49-59 months, >0.3 LogMAR; 60-83 months, >0.2 LogMAR.
Timepoint [1] 300302 0
Data analysis will be conducted between March 19th to 31st 2018.
Secondary outcome [1] 329655 0
Testability of the OKN device (proportion of completed measurements vs. attempts) compared to the ATS-HOTV test. A complete measurement is defined as a visual acuity measurement at the age-appropriate cut-off LogMAR level for each eye separately.
Timepoint [1] 329655 0
The proposed timepoint for calculation and presentation of secondary outcome is January-March 2018.
Secondary outcome [2] 329656 0
To assess the specificity and sensitivity of OKN in the detection of impaired visual acuity for pre-specified subgroups, if sufficient number of children can be recruited for each category:
* Study sites (Auckland vs Melbourne vs Texas)
* Age groups (36-47, 48-59, 60-83 months of age)
* Sex (Male, Female)
* Hyperopes vs. Myopes
* High astigmatism vs. low/no astigmatism
* Strabismic vs. non-strabismic
Timepoint [2] 329656 0
The proposed timepoint for calculation and presentation of secondary outcome is January-March 2018.

Key inclusion criteria
* Aged 3-6 years old (36-83 months at the time of registration)
* Have parent(s)/guardian(s) willing to provide informed consent
* Had paediatric eye examination, including cycloplegic refraction within the past 6 months OR is a child for whom the parent consents to having a paediatric eye examination including cycloplegic refraction at the time of registration.
Minimum age
36 Months
Maximum age
83 Months
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
* Infantile nystagmus syndrome
* Eye muscle surgery within the past 6 months
* Current eye disease
* Developmental delay (known or suspected)
* Systemic disease or syndrome

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Statistical analysis will be performed using SAS version 9.4 (SAS Institute Inc., Cary, NC, USA) and R version 3.3 (R Foundation for Statistical Computing). All statistical tests will be two-sided at 5% significance level. The STROBE statement will be used as the guidelines for reporting observational studies.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 15480 0
3010 - University Of Melbourne
Recruitment outside Australia
Country [1] 8415 0
New Zealand
State/province [1] 8415 0
Country [2] 8416 0
United States of America
State/province [2] 8416 0

Funding & Sponsors
Funding source category [1] 295056 0
Government body
Name [1] 295056 0
Ministry of Business, Innovation and Employment
Address [1] 295056 0
15 Stout Street, Wellington 6011
Country [1] 295056 0
New Zealand
Funding source category [2] 298621 0
Commercial sector/Industry
Name [2] 298621 0
Objective Acuity Ltd (University of Auckland UniServices company)
Address [2] 298621 0
Objective Acuity Limited
c/o Lumberlink Ltd
P.O. Box 105193
Auckland City 1143
New Zealand
Country [2] 298621 0
New Zealand
Primary sponsor type
University of Auckland
Auckland Bioengineering Institute
70 Symonds Street
Auckland 1010
School of Optometry & Vision Science
85 Park Road
Auckland 1023
New Zealand
Secondary sponsor category [1] 293870 0
Name [1] 293870 0
Address [1] 293870 0
Country [1] 293870 0
Other collaborator category [1] 279322 0
Name [1] 279322 0
Dr. Shuan Dai (Eye Doctors)
Address [1] 279322 0
Eye Doctors Ltd
Level 2, 90 Greenlane Rd East
Auckland, 1050
Country [1] 279322 0
New Zealand
Other collaborator category [2] 279323 0
Name [2] 279323 0
Prof. Eileen Birch (Retina Foundation of the Southwest)
Address [2] 279323 0
Retina Foundation of the Southwest
9600 N Central Expy #200, Dallas, TX 75231
Country [2] 279323 0
United States of America
Other collaborator category [3] 279407 0
Name [3] 279407 0
Ms Christine Nearchou (University of Melbourne Eye Care Clinic)
Address [3] 279407 0
University of Melbourne Eye Care Clinic
2/800 Swanston St
University of Melbourne
VIC 3010
Country [3] 279407 0
Other collaborator category [4] 279931 0
Name [4] 279931 0
A/Prof. Ben Thompson (University of Waterloo)
Address [4] 279931 0
School of Optometry and Vision Science
University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada
N2L 3G1
Country [4] 279931 0

Ethics approval
Ethics application status
Ethics committee name [1] 296402 0
The University of Auckland Human Participants Ethics Committee (UAHPEC)
Ethics committee address [1] 296402 0
The University of Auckland Research Office
Level 10, Building 620
49 Symonds Street
Auckland 1010
Ethics committee country [1] 296402 0
New Zealand
Date submitted for ethics approval [1] 296402 0
Approval date [1] 296402 0
Ethics approval number [1] 296402 0

Brief summary
If eye problems occur in early childhood, they can affect the development of the brain areas that are responsible for sight and cause lifelong visual impairment. In addition, vision problems can affect the development of fine control over arm and hand movements and, in older children, impact on education. Many of the eye problems that affect young children can be treated effectively, however detecting these problems is challenging. Young children find it difficult to complete standard tests of vision because these tests require high levels of attention. Many tests also involve recognising shapes and letters and are therefore not suitable for young children.

To address this problem we are developing a new computer-based vision test suitable for use with children as young as 2-years old. The test is simple and easy to use; carefully designed moving patterns are shown to the child that causes a reflexive, involuntary movement of the eyes if the child is able to see the pattern (which thereby yields a measure of visual performance). At the same time we record the movement of the eyes with a video camera attached to a computer and the software we are developing will identify whether the child is able to see the pattern or not. Finally, the visibility of the pattern will be varied to measure how well the child can see.

In this project, we will develop and perform clinical validation tests in ophthalmology and optometry clinics in New Zealand and the USA. The overall aim of this research is to validate a device that we envisage could be used to rapidly and accurately test visual acuity in young children to allow for the early detection and treatment of vision problems.

We propose here to conduct data collection of OKN eye movement using our prototype system developed from our own research to date. This study will involve three clinical sites: (1) the University of Auckland Optometry research clinic, (2) a private ophthalmology clinic (Eye Doctors, Ascot Hospital) led by co-investigator and ophthalmologist Dr Shuan Dai and his research assistant (orthoptist, Nia Stonex), and (3) the Retina Foundation of the Southwest (a non-profit eye research institute in Texas, USA) led by co-investigator Prof. Eileen Birch and her research team.
Trial website
Trial related presentations / publications
Public notes
Attachments [1] 1354 1354 0 0
Attachments [2] 1355 1355 0 0
Attachments [3] 1541 1541 0 0
/AnzctrAttachments/371914-child_PIS CF_018420_ANZCTR.pdf (Participant information/consent)
Attachments [4] 2417 2417 0 0

Principal investigator
Name 70714 0
Dr Jason Turuwhenua
Address 70714 0
Auckland Bioengineering Institute
The University of Auckland
Private Bag 92019
Auckland 1142
Country 70714 0
New Zealand
Phone 70714 0
+64 9 923 5807
Fax 70714 0
Email 70714 0
Contact person for public queries
Name 70715 0
Dr Lily Yu-Li Chang
Address 70715 0
Auckland Bioengineering Institute
The University of Auckland
Private Bag 92019
Auckland 1142
Country 70715 0
New Zealand
Phone 70715 0
+64 9 923 1689
Fax 70715 0
Email 70715 0
Contact person for scientific queries
Name 70716 0
Dr Jason Turuwhenua
Address 70716 0
Auckland Bioengineering Institute
The University of Auckland
Private Bag 92019
Auckland 1142
Country 70716 0
New Zealand
Phone 70716 0
+64 9 923 5807
Fax 70716 0
Email 70716 0

No information has been provided regarding IPD availability
Summary results
No Results