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Trial registered on ANZCTR


Registration number
ACTRN12618000671268
Ethics application status
Approved
Date submitted
9/04/2018
Date registered
24/04/2018
Date last updated
24/04/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effect of lens diameter on orthokeratology lens centration
Scientific title
The effect of lens diameter on orthokeratology lens centration
Secondary ID [1] 294538 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
myopia
307317 0
Condition category
Condition code
Eye 306425 306425 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Intervention: standard orthokeratology rigid contact lenses with 10.5 mm total lens diameter
Materials: Lenses will be made from paragon HDS 100 material with high oxygen permeability (100 Dk units ISO/Fatt). This is a material that is commonly used for conventional orthokeratology lens designs.
Exposure: 2 weeks of overnight lens wear during sleep (for minimum 7-8 hours) with no day time lens wear. Following this 2 week lens wear period, this trial will involve a minimum 2 week wash out period of no lens wear after which the comparator orthokeratology lenses will be worn for another 2 weeks.
Delivery and location: The research team will initially insert the lens on the research participants's eye at the School of Optometry and Vision Science, UNSW, Sydney. Lenses will be provided individually and once at the beginning of the trial.
Supporting procedures: Research participants will then be taught one-on-one face-to-face how to insert, remove clean and maintain orthokeratology lenses so that they can safely wear the contact lenses during the trial period
Intervention code [1] 300838 0
Treatment: Devices
Comparator / control treatment
Intervention: comparator orthokeratology rigid contact lenses with either 10.0 mm or 11.0 mm total lens diameter. Research participants with horizontal visible iris diameter 11.5 mm will be given lenses with 11.0 mm total lens diameter. Those with horizontal visible iris diameter of less than 11.5 mm will be given lenses with 10.0 mm total lens diameter.
Materials: Lenses will be made from paragon HDS 100 material with high oxygen permeability (100 Dk units ISO/Fatt). This is a material that is commonly used for conventional orthokeratology lens designs.
Exposure: After 2 weeks of overnight lens wear during sleep of the standard orthokeratology lens, research participants will undergo a minimum 2 week wash out period of no lens wear. Following this wash out period, research participants will be given the comparator orthokeratology lenses will be worn for another 2 weeks during sleep (for minimum 7-8 hours) with no day time lens wear.
Delivery and location: The research team will initially insert the lens on the Research participants's eye at the School of Optometry and Vision Science, UNSW, Sydney. Lenses will be provided individually and once at the beginning of the trial.
Supporting procedures: Research participants will then be taught one-on-one face-to-face how to insert, remove clean and maintain orthokeratology lenses so that they can safely wear the contact lenses during the trial period
Control group
Uncontrolled

Outcomes
Primary outcome [1] 305442 0
Anterior eye shape (corneal refractive power) changes measured using the Medmont E300 corneal topographer.
Timepoint [1] 305442 0
Measurements will be taken at baseline before any lens wear, then after 1, 7, and 14 nights (primary timepoint) of orthokeratology lens wear of both the standard and comparator designs
Secondary outcome [1] 345242 0
Central refraction will be measured using the Shin-Nippon NVision-K 5001 autorefractor.
Timepoint [1] 345242 0
Measurements will be taken at baseline before any lens wear, then after 1, 7, and 14 nights of orthokeratology lens wear of both the standard and comparator designs
Secondary outcome [2] 345243 0
Visual acuity will be measured using a computerised vision chart.
Timepoint [2] 345243 0
Measurements will be taken at baseline before any lens wear, then after 1, 7, and 14 nights of orthokeratology lens wear of both the standard and comparator designs

Eligibility
Key inclusion criteria
1. Healthy individuals aged 18 to 40 years
2. Have short sightedness between -1.00D and -6.00D and less than -1.50D of corneal astigmatism
3. Have good ocular and general health
4. No contraindications for rigid contact lens wear and have not previously worn rigid contact lenses
5. Horizontal visible iris diameter 11 mm or greater
Minimum age
18 Years
Maximum age
40 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. No strabismus or amblyopia
2. Systemic or ocular conditions that may affect tear quality or contact lens wear
3. Previous history of ocular surgery, trauma or chronic ocular disease
4. Not willing to comply with allocated treatment and follow-up schedules

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)
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
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW

Funding & Sponsors
Funding source category [1] 299164 0
University
Name [1] 299164 0
University of New South Wales
Address [1] 299164 0
School of Optometry and Vision Science
University of New South Wales
Gate 14, Barker St
Rupert Myers Building (North Wing)
Kensington, NSW, 2033
Country [1] 299164 0
Australia
Primary sponsor type
University
Name
University of New South Wales
Address
School of Optometry and Vision Science
University of New South Wales
Gate 14, Barker St
Rupert Myers Building (North Wing)
Kensington, NSW, 2033
Country
Australia
Secondary sponsor category [1] 298424 0
None
Name [1] 298424 0
Address [1] 298424 0
Country [1] 298424 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 300088 0
UNSW Human Research Ethics Committee
Ethics committee address [1] 300088 0
UNSW Human Research Ethics Committee
University of New South Wales
Gate 14, Barker St
Rupert Myers Building (South Wing)
Kensington, NSW, 2033
Ethics committee country [1] 300088 0
Australia
Date submitted for ethics approval [1] 300088 0
28/03/2017
Approval date [1] 300088 0
09/05/2017
Ethics approval number [1] 300088 0
HC17228

Summary
Brief summary
Orthokeratology (OK) lenses are specialised rigid contact lenses that are worn overnight during sleep in order to reshape the front surface of the eye to temporarily correct short-sightedness or myopia. The traditional approach to improve centration of conventional rigid contact lenses on the eye involves increasing total lens diameter. Similarly, it has been proposed that increasing the diameter of an OK lens will improve lens centration. However, this has not yet been comprehensively investigated. Therefore this research study aims to explore the influence of OK lens diameter on lens centration. This study is significant, as it will provide insight into methods to improve the fitting and efficacy of orthokeratology lenses for myopia correction.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 82530 0
Dr Pauline Kang
Address 82530 0
School of Optometry and Vision Science
University of New South Wales
Gate 14, Barker St
Rupert Myers building (North Wing)
Kensington, NSW, 2033
Country 82530 0
Australia
Phone 82530 0
+61 2 9385 9816
Fax 82530 0
Email 82530 0
p.kang@unsw.edu.au
Contact person for public queries
Name 82531 0
Dr Pauline Kang
Address 82531 0
School of Optometry and Vision Science
University of New South Wales
Gate 14, Barker St
Rupert Myers building (North Wing)
Kensington, NSW, 2033
Country 82531 0
Australia
Phone 82531 0
+61 2 9385 9816
Fax 82531 0
Email 82531 0
p.kang@unsw.edu.au
Contact person for scientific queries
Name 82532 0
Dr Pauline Kang
Address 82532 0
School of Optometry and Vision Science
University of New South Wales
Gate 14, Barker St
Rupert Myers building (North Wing)
Kensington, NSW, 2033
Country 82532 0
Australia
Phone 82532 0
+61 2 9385 9816
Fax 82532 0
Email 82532 0
p.kang@unsw.edu.au

No data has been provided for results reporting
Summary results
Not applicable