None listed
Conditions
Brief summary
The main aim of this research is to assess how Orthokeratology (OK) lenses accumulate surface deposits and scratches under regular cleaning and disinfection practices, in order to determine the optimal time for replacing the lenses. Additionally, we will evaluate the health of the front surface of the eye and the comfort of the lenses during one year of overnight use. We hypothesize that the OK lens spoilage, including scratches and surface deposits, as well as eye discomfort levels, will progressively worsen across the visits at the baseline visit, 6 months and 12 months visit. The primary outcome: OK lens spoilage grading scores. Secondary outcomes: Comfort (Ocular Surface Disease Index, OSDI and Contact Lens Dry Eye Questionnaire-8, CLDEQ-8) and ocular surface changes (corneal and conjunctival staining). The proposed study uses a prospective, observational quasi-experimental research design where the contact lens spoilage from the same participants will be observed over the time before and after contact lens wear. Individuals (between 18 to 40 years of age) with a refractive error between -1.00 and -4.00D of sphere and astigmatism = 2.50D will be recruited in the study. The eligible participants will receive study OK lenses during the dispensing visit, following the screening visit. Participants will attend a total of eight visits, including a follow-up visit 2 weeks after the lens cessation.
Interventions
All participants will be fitted with orthokeratology lenses (Menicon Z Night lenses) following the manufacturer's guidelines. These lenses are made from Tisilfocon A, a safe and rigid gas-permeable material with a reverse geometry design, which are approved by the Therapeutic Goods Administration (TGA) in Australia (ARTG number: 226883) for overnight wear. They are designed to be worn while sleeping to help correct short-sightedness, also known as myopia. The power of these lenses will slightly
All participants will be fitted with orthokeratology lenses (Menicon Z Night lenses) following the manufacturer's guidelines. These lenses are made from Tisilfocon A, a safe and rigid gas-permeable material with a reverse geometry design, which are approved by the Therapeutic Goods Administration (TGA) in Australia (ARTG number: 226883) for overnight wear. They are designed to be worn while sleeping to help correct short-sightedness, also known as myopia. The power of these lenses will slightly differ from spectacle power, as they sit close to the eye surface. Participants will be instructed to wear the lenses overnight for at least 6 hours. Participants will be reviewed at regular visits (Screening visit, baseline visit, 1 day, 7 days, 21 days, 6 months, 12 months and 2 weeks lens cessation visit). Both lenses will be worn continuously for six months. At the six-month visit, a new lens with similar parameters will be dispensed for the right eye, while the original lens will undergo quantitative surface assessment. The left eye lens will continue to be worn until the 12-month visit, where it will also undergo a similar assessment. Participants will receive handouts detailing insertion, removal, and cleaning instructions, along with an "O-K Wear Time Journal" to log their lens usage, including bedtime and wake times. All visits will be scheduled in the morning, approximately 45–60 minutes in duration, within two hours of waking. During these visits, the lens care regimen and hygiene practices will be reinforced, and the 'O-K Wear Time Journal' will be reviewed. At each visit, the anterior surface of the eye will be examined using clinical microscope, and lens comfort levels will be assessed using Ocular Surface Disease Index questionnaire (OSDI) and Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8). Additionally, lens spoilage will be qualitatively assessed through photography at each visit. During the lens dispensing, six-month, and one-year visits, lens deposition will also be quantitatively evaluated using established standard laboratory procedures.
Sponsors
Prof Mark Willcox, University of New South Wales
Study design
Allocation
Non-randomised trial
Primary purpose
Prevention
Eligibility
Sex/Gender
All
Age
18 Years to 40 Years
Healthy volunteers
No
Inclusion criteria
• Age between 18 to 40 • Have refractive error between -1.00 and -4.00D of Sphere, Astigmatism less than or equal to 2.50D. • Good eye health with no history of eye trauma or surgery, no eye disease • Soft contact lens wearers willing to discontinue lens wear for at least 24 hours before participation. Individuals with or without a history of wearing rigid lenses (including orthokeratology) for a short-term (less than or equal to 3months) and have discontinued wearing them for one month. • Good general health and no medications which may influence eye health. • Willing and able to comply with the research procedures and follow-up schedule.
Exclusion criteria
• Age less than 18 years-old and more than 40 years-old • Refractive error between less than -1.00D and more than -4.00D, astigmatism >2.50
Outcome results
None listed