None listed
Conditions
Brief summary
The purpose of the study is to investigate the effects of short-term imposed blur (optical defocus) on central and peripheral length and the vascular layer of the eye ( choroid) that may help to predict that an optical intervention can control myopia progression.
Interventions
This trial will be prospective.
Participants will wear two contact lens designs for 30 minutes, with a minimum 4 hours washout between lens types. One lens type is designed to correct myopia and hyperopia, while the other one is designed to correct presbyopia. The materials and parameters for each lens type are:
single vision lens: etafilcon A, base curve = 8.5 mm, diameter = 14.2 mm, with power of +3.00D, -3.00D for 1day AcuvueMoist;
multifocal lens: omafilcon, base curve = 8.7 mm, diamete
This trial will be prospective. Participants will wear two contact lens designs for 30 minutes, with a minimum 4 hours washout between lens types. One lens type is designed to correct myopia and hyperopia, while the other one is designed to correct presbyopia. The materials and parameters for each lens type are: single vision lens: etafilcon A, base curve = 8.5 mm, diameter = 14.2 mm, with power of +3.00D, -3.00D for 1day AcuvueMoist; multifocal lens: omafilcon, base curve = 8.7 mm, diameter = 14.4 mm, with power 0.00D /Add +2.50D. The minimum wearing time will be 30 minutes per visit with no maximum wearing time provided. After preliminary evaluation, three to five visits will be require for the study. The first three visits will be compulsory for every participant and will include wearing + 300D, -3.00D and the multifocal lens at visit 1, visit 2 and visit 3, respectively. The total number of visits will be determined based on the results (e.g. degree of refractive error, time of measurement, etc.) from the compulsory visits. The time between the visits will be from 4 hours to 30 days. The preliminary visit will be approximately 45 minutes in duration and will include auto-refraction, subjective refraction with visual acuity measurement and ocular assessment with a slit-lamp biomicroscope (a specialized microscope for viewing the eye). Each visit will be approximately 1h45 min each in duration and will include three sessions (of 15 minutes each): Session 1: Baseline measurement Session 2: Baseline measurement and contact lens fitting Session 3: Assessment measurement (taken after 30 min soon after removing the contact lens) The time interval between each session is 30 minutes. At the end of the second session, there will be a contact lens fitting followed by an assessment of contact lenses on the eye with a slit-lamp biomicroscope (a specialized microscope for viewing the eye). Between the second and third set of measurements, the participant will be required to wear the contact lens in one eye and will wear their normal prescription lens (on a trial frame) in the other eye and watch a video on a distant monitor for 30 minutes. The contact lens will be removed before the last set of measurements. All contact lenses will be provided and all assessments will be carried out by an optometrist.
Sponsors
Brien Holden Vision Institute
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
Inclusion criteria: • Any gender; • Aged more than 18 years; • Participant to provide informed consent; • Either has a refractive error of the eye (a condition that causes blur for either distance or near) or no refractive error • Have ocular health findings considered to be “normal” and no anterior segment or posterior segment condition other than refractive error; • Have best corrected visual acuity to at least 6/6 or better in each eye with spectacles or contact lenses; • No history of amblyopia or strabismus; • Can be an experienced soft contact lens wearer or a neophyte (no previous experience contact lens wearer); • No history of rigid contact lens wear; • Being able to read and communicate in English; • Be willing to comply with clinical trial visit schedule as directed by the investigator.
Exclusion criteria
Exclusion criteria: • Age < 18 years; • History of any systemic diseases including diabetes, hypertension, cardiac problems etc.; • History of any other ocular pathology; • History of any refractive or ocular surgeries; • History of using orthokeratology lenses.
Outcome results
None listed