None listed
Conditions
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.
Interventions
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
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
Sponsors
University of New South Wales
Study design
Allocation
Non-randomised trial
Primary purpose
Treatment
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
No
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
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
Outcome results
None listed