Trial Review

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12620000347965
Ethics application status
Approved
Date submitted
15/02/2020
Date registered
12/03/2020
Date last updated
3/03/2023
Date data sharing statement initially provided
12/03/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Optimising orthokeratology lens fitting to improve quality of vision
Scientific title
Does fitting OK lenses based on entrance pupil improve clinic outcomes of OK when compared to fitting to vertex normal for Myopia?
Secondary ID [1] 300559 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Myopia 316281 0
Condition category
Condition code
Eye 314558 314558 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Description of intervention: Paragon CRT lenses (CooperVision Specialty EyeCare, Arizona, USA) in HDS100 material are used in this study. This is one of the most common materials used for conventional orthokeratology in Australia and abroad.
The lenses will be fitted to the entrance pupil by basing the lens fitting on topography measurements based on the default map centre. This will differ from the ‘no treatment’ condition where the fitting will be based on topography measurements obtained at the alternative reference centre.
Both eyes will receive the same type of lens at the same time and participants will receive both intervention and control treatments. There will be a minimum 1 week period of no overnight lens wear during sleep between the wear of the study lens and the lens fit to vertex normal.

Exposure: Study lenses are worn overnight during sleep (for minimum of 7-8 hours) over a period of 14 nights with each fitting method with no need for daytime lens wear.

Delivery: The research team will initially insert the lens on the subject's eye at the School of Optometry and Vision Science, UNSW, Sydney. Research participants will then be taught one-on-one face-to-face how to insert, remove, clean and maintain orthokeratology lenses so that subjects can safely wear contact lenses during the trial period. Adherence to the study protocol will be ensured by the investigation team advising participants to complete an "Ortho-K Wear Time Journal” to record their OK lens insertion and removal times as well as sleep and waking up times.
Intervention code [1] 316858 0
Treatment: Devices
Comparator / control treatment
Description of intervention: Paragon CRT lenses (CooperVision Specialty EyeCare, Arizona, USA) in HDS100 material are used in this study. This is one of the most common materials used for conventional orthokeratology in Australia and abroad.

Exposure: Study lenses are worn overnight during sleep (for minimum of 7-8 hours) over a period of 14 nights with each fitting method with no need for daytime lens wear.

Delivery: The research team will initially insert the lens on the subject's eye at the School of Optometry and Vision Science, UNSW, Sydney. Research participants will then be taught one-on-one face-to-face how to insert, remove, clean and maintain orthokeratology lenses so that subjects can safely wear contact lenses during the trial period. Adherence to the study protocol will be ensured by the investigation team advising participants to complete an "Ortho-K Wear Time Journal” to record your OK lens insertion and removal times as well as sleep and waking up times.

The comparator is the 'no treatment' situation therefore the lens fit will be based off conventional fitting methods to the vertex normal of the cornea (no treatment). The lens fitting will be based on topography measurements obtained at the alternative reference centre. This differs from the intervention where the lenses are fitted to the entrance pupil by basing the lens fitting on topography measurements based on the default map centre. The clinical outcomes following the lens fit to vertex normal (no treatment) will be measured and compared to clinical outcomes with the lens fit to the entrance pupil. There will be a minimum 2 week period of no overnight lens wear during sleep between the wear of the study lens and the lens fit to vertex normal (no treatment).
Control group
Active

Outcomes
Primary outcome [1] 322884 0
Difference in contrast sensitivity of an eye following 1 night of overnight wear of lenses fit to entrance pupil compared to lenses fit to vertex normal (no treatment).
In the contrast sensitivity test, a series of black and white stripes (sine wave gratings) of different contrast and varying number of stripes will be presented to the participant on a computer screen until a threshold of minimum contrast is detected.
Timepoint [1] 322884 0
Following one night of overnight lens wear.

The contrast sensitivity values measured following 1 night of overnight lens wear for both sets of lenses will be compared.
Primary outcome [2] 322885 0
Contrast sensitivity of an eye following 14 nights of overnight wear of lenses fit to entrance pupil compared to lenses fit to vertex normal (no treatment). In the contrast sensitivity test, a series of black and white stripes (sine wave gratings) of different contrast and varying number of stripes will be presented to the participant on a computer screen until a threshold of minimum contrast is detected.
Timepoint [2] 322885 0
Following 14 nights of overnight lens wear. The contrast sensitivity values measured following the 14 nights of overnight lens wear for both sets of lenses will be compared.
Secondary outcome [1] 380141 0
Changes in visual acuity following 14 nights of overnight wear of lenses fit to entrance pupil compared to lenses fit to vertex normal (no treatment). Visual acuity will be measured using computerized visual acuity charts (Test Chart 2000 Pro, UK). Participants will be asked to read out letters from a chart where the letters get increasingly smaller. The line of smallest letters correctly identified will be recorded.
Timepoint [1] 380141 0
Following 14 nights of overnight lens wear in both sets of lenses
Secondary outcome [2] 380142 0
Changes in optical aberrations following 14 nights of overnight wear of lenses fit to entrance pupil compared to lenses fit to vertex normal (no treatment). Ocular aberration assessment will be performed using ocular aberrometry (IVS Discovery aberrometry Innovative Visual Systems, U.S.A). This device measures subtle optical imperfections in the eye. The method of assessment is similar to corneal topography assessment performed during screening visit.
Timepoint [2] 380142 0
Following 14 nights of overnight lens wear in both sets of lenses.

Eligibility
Key inclusion criteria
• Males and females between 18 and 40 years of age
• Good ocular and general health
• Refractive error -0.75 to -5.00D, corneal toricity (astigmatism) <1.50D
• Anisometropia (spectacle difference between the two eyes) <0.75D
• Individuals with a history of wearing rigid lenses (including orthokeratology) for a short-term (<=3months) ) and have discontinued wearing them for one month
Minimum age
18 Years
Maximum age
40 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
*Any current rigid gas permeable (including orthokeratology) lens wearers
*Previous long-term (>3 months) rigid (including orthokeratology) lens wearers
*Soft contact lens wear in the past week
*Contraindications to rigid lens wear, including orthokeratology lens wearers
• Participants having eye turns or lazy eye.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled 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
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s

Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
15/03/2023
Actual
Date of last participant enrolment
Anticipated
14/03/2024
Actual
Date of last data collection
Anticipated
31/05/2023
Actual
Sample size
Target
12
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW

Funding & Sponsors
Funding source category [1] 304969 0
University
Name [1] 304969 0
University of New South Wales
Country [1] 304969 0
Australia
Primary sponsor type
University
Name
University of New South Wales
Address
School of Optometry and Vision Science Rupert Myer Building (North Wing) University of New South Wales
Gate 14, Barker Street Kensington, NSW 2033
Australia
Country
Australia
Secondary sponsor category [1] 305328 0
None
Name [1] 305328 0
Address [1] 305328 0
Country [1] 305328 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 305380 0
UNSW Human Research Ethics Advisory Panel
Ethics committee address [1] 305380 0
UNSW Research Ethics & Compliance Support
Rupert Myer Building (South Wing)
University of New South Wales Gate 14. Barker Street Kensington. NSW 2033
Ethics committee country [1] 305380 0
Australia
Date submitted for ethics approval [1] 305380 0
07/07/2020
Approval date [1] 305380 0
14/07/2020
Ethics approval number [1] 305380 0

Summary
Brief summary
Orthokeratology (OK) lenses are rigid contact lenses that are designed to be worn during sleep. Their purpose is to reshape the front surface of the eye (cornea) in order to temporarily correct short-sightedness, also known as myopia. Although their primary aim is to correct myopia and provide clear unaided vision during the day, studies have shown that they also have an effect on slowing or stopping the progression of short-sightedness in children, termed myopia control. Currently lenses are fit on the eye by optometrists by fitting the lens on the corneal topographic map centred over the vertex normal. However, anecdotal reports suggest improved clinical outcomes are achieved when lenses are fit based on the topographical maps centred over the entrance pupil centre rather than vertex normal. The aim of this project is to compare the clinical outcomes of lenses that were designed based on the entrance pupil centre after 7 nights of overnight wear. We will investigate visual acuity, contrast sensitivity as well as optical aberrations. Our intent is to determine how these measurements can guide best clinical practice in fitting OK lenses.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 100182 0
Dr Vinod Maseedupally
Address 100182 0
School of Optometry and Vision Science
University of New South Wales
Gate 14. Barker Street Kensington. NSW 2033
Country 100182 0
Australia
Phone 100182 0
+61 2 9385 9233
Fax 100182 0
Email 100182 0
[email protected]
Contact person for public queries
Name 100183 0
Dr Vinod Maseedupally
Address 100183 0
School of Optometry and Vision Science
University of New South Wales
Gate 14. Barker Street Kensington. NSW 2033
Country 100183 0
Australia
Phone 100183 0
+61 2 9385 9233
Fax 100183 0
Email 100183 0
[email protected]
Contact person for scientific queries
Name 100184 0
Dr Vinod Maseedupally
Address 100184 0
School of Optometry and Vision Science
University of New South Wales
Gate 14. Barker Street Kensington. NSW 2033
Country 100184 0
Australia
Phone 100184 0
+61 2 9385 9233
Fax 100184 0
Email 100184 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


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.