None listed
Conditions
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 called myopia control. This benefit is likely due to changes in mid-peripheral corneal shape and corresponding changes in peripheral vision induced by OK lenses. It has been proposed that greater changes in peripheral vision may induce better myopia control. Hence this prospective study aims to compare the effect of two different OK lens designs on mid-peripheral corneal shape changes to determine whether corneal shape changes can be predictably made through lens parameter changes. Outcomes of this study can be assist in future studies that investigate myopia control using OK lenses.
Interventions
Medical device/intervention: orthokeratology contact lenses with modified lens design (custom orthokeratology lenses). Lenses will be made of Boston XO material with high oxygen permeability (100 Dk units ISO/Fatt). This material is the most common material used for conventional orthokeratology lens designs in Australia and internationally.
Exposure: 1 week of overnight lens wear during sleep (for minimum 7-8 hours) with no daytime lens wear. This is a cross-over trial where the order of lens w
Medical device/intervention: orthokeratology contact lenses with modified lens design (custom orthokeratology lenses). Lenses will be made of Boston XO material with high oxygen permeability (100 Dk units ISO/Fatt). This material is the most common material used for conventional orthokeratology lens designs in Australia and internationally. Exposure: 1 week of overnight lens wear during sleep (for minimum 7-8 hours) with no daytime lens wear. This is a cross-over trial where the order of lens wear (standard or custom orthokeratology lenses) will be randomised and there will be a minimum 1 week washout period of no lens wear between the two lens wearing periods. Delivery: The research team will initially insert the lens on the subject's eye at the School of Optometry and Vision Science, UNSW, Sydney. Reseach participants will then be taught one-on-one face-to-face how to insert, remove, clean and maintain the orthokeratology lenses so that they can safely wear contact lenses during the trial period. Compliance: Text-message reminders will be sent to monitor adherence to the intervention.
Sponsors
University of New South Wales
Study design
Allocation
Randomised controlled trial
Primary purpose
Treatment
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
No
Inclusion criteria
1. Healthy individuals aged between 18-40 2. Have short-sightedness (myopia) between -1.00D and -4.00D and less than -1.50D of corneal astigmatism 3. No previous rigid contact lens wear 4. Have good ocular health and general health 5. No contraindications to rigid contact lens wear
Exclusion criteria
1. 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. Ocular or systemic medication use that may interfere with contact lens wear or ocular surface 5. Not willing to comply with the allocated treatment and follow-up schedule
Outcome results
None listed