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 myopia control. Currently, research is underway to understand centration of OK lenses and the optical effects as a result of centration which may promote myopia control. Although optometrists will typically assess the centration of the lens in the open eye, it is not clear how much this influences treatment zone centration after overnight wear in the closed eye, and this warrants investigation. The aim of this project is to compare open eye lens centration with treatment zone centration after 3 nights of overnight wear of OK lenses. We will investigate open eye lens centration with and without eyelid interactions, as well as lens centration immediately after eye opening following short-term eye closure. Our intent is to determine how these measurements can be used clinically to predict treatment zone centration after overnight OK lens wear.
Interventions
Description of intervention: BE Orthokeratology contact lenses (Capricornia Contact Lens, Brisbane, Australia) in Boston XO material with 100 Dk units ISO/Fatt 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 3 nights with no need for day time lens wear.
Delivery: The research team will initially insert the lens on the
Description of intervention: BE Orthokeratology contact lenses (Capricornia Contact Lens, Brisbane, Australia) in Boston XO material with 100 Dk units ISO/Fatt 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 3 nights with no need for day time 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 investigation team advising participants to complete a "Ortho-K Wear Time Journal” to record your OK lens insertion and removal times as well as sleep and waking up times.
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
• Males and females over 18 years of age • Good ocular and general health • Refractive error -1.00D to -6.00D and corneal toricity (astigmatism) <1.50D • Anisometropia (difference spectacle power between the two eyes) <1.00D
Exclusion criteria
• Any previous rigid gas permeable, including orthokeratology lens wearers • Soft contact lens wear in the past week • Contraindications to rigid lens wear, including orthokeratology lens wearers
Outcome results
None listed