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. Hence this prospective study aims to understand the effects of peripheral corneal shape on lens decentration by determining treatment zone decentration resulted through lens decentration during OK lens wear. Outcomes of this study would help in designing OK lenses that help in achieving myopia control in a more desired manner.
Interventions
Description of intervention: Orthokeratology contact lenses with Paragon HDS 100 (paflufocon D) 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.
The lens overall diameter is selected based on study participants' corneal diameter. The overall diameter is calculated to encompass 95% of the participant's corneal diameter.
Exposure: Study lenses are worn overnight during sleep (fo
Description of intervention: Orthokeratology contact lenses with Paragon HDS 100 (paflufocon D) 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. The lens overall diameter is selected based on study participants' corneal diameter. The overall diameter is calculated to encompass 95% of the participant's corneal diameter. Exposure: Study lenses are worn overnight during sleep (for minimum of 7-8 hours) over a period of 2 weeks (or 14 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 sending regular text messages to participants as reminders at all stages of the study.
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. Individuals aged between 18 and 40 years 2. Have short sightedness between -1.00D and -5.00D with less than 1.50D of corneal astigmatism 3. Have horizontal visible iris diameter (corneal diameter) that is at least 11.5 mm 4. No contraindications for rigid contact lens wear and have not previously worn rigid contact lenses 5 Current wearers of soft contact lens will be required to discontinue 2 days prior to screening
Exclusion criteria
1. Persons with strabismus (squint or cross eyed) or amblyopia (lazy eye) 2. Systemic health conditions or other eye conditions that may affect the quality of tears or that may affect refractive development. 3. Previous history of eye operations, injury or chronic eye conditions. 4. Medications used for systemic or ocular health that may interfere with contact lens wear or ocular surface. 5. Not willing to comply with the located treatment and follow-up schedule.
Outcome results
None listed