None listed
Conditions
Brief summary
To determine the effectiveness of a specially designed spectacle lens in the control of myopia progression in children.
Interventions
Custom designed Progressive Addition Lenses worn binocularly during normal waking hours and for all tasks where spectacles can and normally would be worn. There are two designs: a 1.00 D addition and the 1.50 D addition power, subjects are assigned to either of these designs or a single-vision lens control condition according to a pre-defined randomized sequence assigned on an incremental recruitment number. The study will compare the effectiveness of these two addition powers. The addition powe
Custom designed Progressive Addition Lenses worn binocularly during normal waking hours and for all tasks where spectacles can and normally would be worn. There are two designs: a 1.00 D addition and the 1.50 D addition power, subjects are assigned to either of these designs or a single-vision lens control condition according to a pre-defined randomized sequence assigned on an incremental recruitment number. The study will compare the effectiveness of these two addition powers. The addition power reduces the accommodative demand of the wearer while doing near vision tasks (< 75 cm). The lens has a progressively increasing addition power starting at the distance viewing reference point and reaching the prescribed addition at approximately 14 mm below the fitting cross. The patient's regular prescription is additionally surfaced on the back surface of these lenses to correct any ocular errors of the eye. This may include Sphere and / or Cylinder corrections. Patients wear the lenses during normal waking hours and for all tasks where spectacles can be worn for a period of 24 months.
Sponsors
Carl Zeiss Vision
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Blinded (masking used)
Eligibility
Sex/Gender
All
Age
6 Years to 12 Years
Healthy volunteers
Yes
Inclusion criteria
1. Spherical equivalent refractive error (SER) of –0.50 to -4.50 D. 2. Astigmatism of not more than -1.50 D. 3. Anisometropia of not more than -1.50 D in spherical or cylindrical error. 4. Visual acuity with best subjective correction of 0.00 LogMAR or better. 5. Normal ocular health other than myopia. 6. No prior use of bifocal or progressive lenses in the last 12 months. 7. No rigid contact lenses or Bi-Focal contact lens experience and must be willing not to wear contact lenses. 8. In satisfactory health. 9. Willing and able to tolerate cycloplegia. 10. Informed parental consent.
Exclusion criteria
1. Outside the age range 6 to 12 years at time of recruitment. 2. Not willing to wear spectacles continuously. 3. Not available for follow-up for at least 2 years. 4. Absence of parental consent to the random assignment of their child to one of three spectacle lens groups. 5. Any systemic condition which might affect refractive development or systemic diseases which may affect vision or refractive error. 6. Previous use of contact lens/PALs or other treatment for myopia within the last 12 months. 7. Defective binocular function. 8. Amblyopia and or manifested squint. 9. Vestibular disorders or motor imbalance. 10. Any other conditions precluding adherence to the Protocol.
Outcome results
None listed