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Trial registered on ANZCTR


Registration number
ACTRN12609000102279
Ethics application status
Approved
Date submitted
16/12/2008
Date registered
13/02/2009
Date last updated
4/07/2012
Type of registration
Retrospectively registered

Titles & IDs
Public title
Comparison of adaptation characteristics in two reverse-geometry lens systems for orthokeratology
Scientific title
A comparison of human corneal adaptation characteristics between empirical and diagnostic orthokeratology lens designs for myopia
Secondary ID [1] 770 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Myopia 4136 0
Condition category
Condition code
Eye 4336 4336 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Unlike conventional rigid gas permeable contact lenses that are steeper in curvature in the centre and flatten towards the periphery, reverse geometry lenses are designed to have a flatter central portion and become steeper in the periphery, in order to alter the shape of the cornea in the process known as orthokeratology. Reverse geometry lenses will be worn in both eyes of each subject, but each eye will wear a different proprietary orthokeratology lens design (either Capricornia BE lens, or Paragon CRT lens) selected in a randomised manner. The participants will be required to wear the lenses overnight for 14 days.
Intervention code [1] 3847 0
Treatment: Devices
Comparator / control treatment
Two proprietary reverse geometry contact lens designs will be compared in this study, one which uses an empirical fitting strategy, where the lens fit is selected on the basis of corneal topographical maps, and the other which uses a diagnostic fitting set, which relies on the clinician to evaluate fluorescein patterns beneath the lenses when in situ, in order to select the appropriate lens. One lens of each type will be fitted to each eye of the patient (so that both eyes are fitted with lenses, one of each proprietary design). Both lenses will be worn overnight for 14 days.
Control group
Active

Outcomes
Primary outcome [1] 5219 0
Corneal topography changes
Timepoint [1] 5219 0
at baseline and at one day, three days, seven days and fourteen days after randomisation
Primary outcome [2] 5220 0
High contrast visual acuity will be measured on a standard 4m LogMAR visual acuity chart and the refractive error of the subject will be measured by subjective over-refraction with standard trial lenses.
Timepoint [2] 5220 0
at baseline and at one day, three days, seven days and fourteen days after randomisation
Secondary outcome [1] 8791 0
Pachymetry will be measured using a slit-scanning elevation topographer (Orbscan, Bausch & Lomb, NY, USA)
Timepoint [1] 8791 0
at baseline and at one day, three days, seven days and fourteen days after randomisation
Secondary outcome [2] 8792 0
Peripheral visual acuity will be estimated with an open-field autorefractor (Shin-Nippon, Japan) at 10, 20 and 30 degrees on either side of centre
Timepoint [2] 8792 0
at baseline and at one day, three days, seven days and fourteen days after randomisation
Secondary outcome [3] 8793 0
Higher order aberrations will be quantified by aberrometry (Zywave, Bausch & Lomb, NY, USA)
Timepoint [3] 8793 0
at baseline and at one day, three days, seven days and fourteen days after randomisation
Secondary outcome [4] 8794 0
Low contrast visual acuity will be measured at 1m using the BEGAT (Brightness Equivalence Glare Acuity Tester, Tawa Holdings, Wellington, NZ)
Timepoint [4] 8794 0
at baseline and at one day, three days, seven days and fourteen days after randomisation
Secondary outcome [5] 8795 0
High and low contrast glare acuity will be measured using the BEGAT (Brightness Equivalence Glare Acuity Tester, Tawa Holdings, Wellington, NZ)
Timepoint [5] 8795 0
at baseline and at one day, three days, seven days and fourteen days after randomisation

Eligibility
Key inclusion criteria
Low myopia (<4.00D)
Low with-the-rule astigmatism (<0.75DC)
No against-rule-astigmatism
Anisometropia <0.50D
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Myopia >4.00D
High with-the-rule astigmatism >0.75DC
Against-rule-astigmatism
Anisometropia >0.50DS

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)
The study was advertised in the University of Auckland using posters. Subjects who volunteer will be assessed to ensure they meet the inclusion criteria. Subjects will be fitted with two different proprietary orthokeratology lenses, one in each eye. Allocation of the lens type to the right and left eyes will be randomised centrally by computer. The subjects will not know which lens is in which eye but will be advised not to swap lenses between eyes.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Subjects and lenses will be randomised using computer generated Latin squares
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
22/12/2008
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
12
Accrual to date
Final
Recruitment outside Australia
Country [1] 1476 0
New Zealand
State/province [1] 1476 0

Funding & Sponsors
Funding source category [1] 4305 0
University
Name [1] 4305 0
Faculty of Medical and Health Sciences, The University of Auckland
Country [1] 4305 0
New Zealand
Primary sponsor type
University
Name
Faculty of Medical and Health Sciences, The University of Auckland
Address
Faculty of Medical and Health Sciences
85 Park Road
Grafton
Auckland 1023
Country
New Zealand
Secondary sponsor category [1] 3876 0
None
Name [1] 3876 0
Address [1] 3876 0
Country [1] 3876 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 6352 0
The University of Auckland Human Participants Ethics Committee
Ethics committee address [1] 6352 0
The University of Auckland Human Participants Ethics Committee, The University of Auckland, 3rd Floor, 76 Symonds St, Private Bag 92019, Auckland 1142
Ethics committee country [1] 6352 0
New Zealand
Date submitted for ethics approval [1] 6352 0
Approval date [1] 6352 0
28/08/2008
Ethics approval number [1] 6352 0
UAHPEC 2008 / 288

Summary
Brief summary
To compare the short-term effects (2 weeks) of two different orthokeratology lens systems. Orthokeratology is the application of specially designed rigid contact lenses overnight, to change the corneal shape and reversibly and temporarily reduce short-sightedness. The purpose is to reduce your myopia with two different types of orthokeratology contact lenses and observe the changes in the eyes with advanced clinical instruments.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 35044 0
Address 35044 0
Country 35044 0
Phone 35044 0
Fax 35044 0
Email 35044 0
Contact person for public queries
Name 12391 0
Ryan Mahmoud
Address 12391 0
Department of Optometry and Vision Science, Private Bag 92019, Auckland 1142
Country 12391 0
New Zealand
Phone 12391 0
+64 211665899
Fax 12391 0
Email 12391 0
[email protected]
Contact person for scientific queries
Name 3319 0
Jennifer Craig
Address 3319 0
Department of Optometry and Vision Science, Private Bag 92019, Auckland 1142.
Country 3319 0
New Zealand
Phone 3319 0
+64 9 3737599 ext 88173
Fax 3319 0
Email 3319 0
[email protected]

No information has been provided regarding IPD availability


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
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