None listed
Conditions
Brief summary
The purpose of this trials is to assess the effect on visual performance when spectacles lenses are prescribed in 0.05 D steps compared to when they are prescribed in 0.25 D steps
Interventions
This trial will be a prospective, bilateral, randomized, double-masked, cross-over clinical trial.
Participants will wear two single-vision spectacle lenses mounted in the same pair of frames for one week each.
The power of each single-vision spectacle lens is matched to correct the participant’s myopia. The difference between designs is the control spectacle lens is available in the traditional increments of 0.25 D while the test spectacle lens is available in finer increments of 0.05 D steps.
This trial will be a prospective, bilateral, randomized, double-masked, cross-over clinical trial. Participants will wear two single-vision spectacle lenses mounted in the same pair of frames for one week each. The power of each single-vision spectacle lens is matched to correct the participant’s myopia. The difference between designs is the control spectacle lens is available in the traditional increments of 0.25 D while the test spectacle lens is available in finer increments of 0.05 D steps. All spectacles will be worn daily. There will four visits comprising visit 1 (Baseline), visit 2 (collection of first randomly allocated spectacles), visit 3 (assessment of first randomly allocated spectacles and collection of second randomly allocated spectacles), and visit 4 (assessment of second randomly allocated spectacles). All visits will be performed by a masked investigator. Visit 1 will be approximately 90 minutes in duration, visit 3 approximately 60 minutes, and visits 2 and 4 approximately 30 minutes each. Visit 1 will comprise subjective refraction in both 0.25 D and 0.05 D steps and measurement of visual acuity for both subjective refractions. Participants will be asked to rate their quality of vision with habitual spectacles on a numeric rating scale. The numeric rating used in this study is a non-validated metric. Visit 2 will comprise dispensing of first randomly allocated study spectacles. Visual acuity will be measured, and quality of vision will be assessed via a numeric rating scale, with first study spectacles. Visit 3 will comprise measurement of visual acuity and assessment of quality of vision via a numeric rating scale with first study spectacles. The first study spectacle lenses will be collected from the participant. The second study spectacles will be dispensed to the participant. Visual acuity will be measured, and quality of vision will be assessed via a numeric rating scale, with second study spectacles. There is no 'wash-out' period between treatments. Visit 4 will comprise measurement of visual acuity and assessment of quality of vision via a numeric rating scale with second study spectacles. The second spectacle lenses will be collected at the completion of the visit. All study spectacle lenses will be prescribed, and all assessments will be carried out by an optometrist. Participants will be instructed to bring study spectacles to each visit. Compliance will be assessed by verbal questioning of the participant.
Sponsors
nthalmic Pty Ltd
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to 45 Years
Healthy volunteers
No
Inclusion criteria
Able to read and comprehend English and give informed consent as demonstrated by signing a record of informed consent. Healthy adults aged 18 to 45 years of age (inclusive). Willing to refrain from using soft contact lenses for the duration of the study. Spherical refractive error between -1.00 and -6.00 D (inclusive) with cylinder power less than or equal to 1.00 D. Can attain good vision: Best corrected visual acuity of 6/6 or better in each eye. Willing to wear the study spectacles provided daily in lieu of their habitual spectacles for the duration of the study. Willing to attend the scheduled study visits and adhere to instructions.
Exclusion criteria
Be currently using topical ocular medication or have used topical ocular medication within 2 weeks of the first visit. Patients who are being treated bilaterally with marketed artificial tears can be considered, provided they discontinue use for 24 hours prior to each visit. History of clinically significant or progressive ocular disease in either eye that would affect vision e.g. keratoconus. Clinically significant anisometropia (difference in refractive power between the two eyes) of > 1.00D. Rigid gas permeable lens wearer (including orthokeratology). Any systemic disease that may affect ocular health e.g. Graves disease, and auto-immune diseases such as ankylosing spondylitis, multiple sclerosis and systemic lupus erythematosus. History of eye surgery or eye trauma within 6 months prior to enrolment in the study. History of corneal refractive surgery. The Investigator may, at his/her discretion, exclude anyone else who they believe may not be able to fulfil the study requirements, or if it is believed to be in the participant’s best interests.
Outcome results
None listed