Myopia
Conditions
Keywords
children, corneal reshaping, myopia, myopia control, orthokeratology
Brief summary
The purpose of this study is to evaluate and compare the eyeball elongation in high myopic children using partial correction orthokeratology and single-vision spectacles.
Detailed description
Orthokeratology (ortho-k) has been shown to have strong potential for retardation of myopic progression in low myopes. To date, clinical experience has shown the technique to be less effective in achieving full myopic reduction in high myopes. Would myopic control be possible for high myopes undergoing partial correction ortho-k treatment? A randomized, longitudinal study is designed to investigate the efficacy of partial correction ortho-k in retardation of myopic progression in high myopic children. Eye growth in terms of axial length elongation in children wearing ortho-k and over-spectacles (to correct residual refractive errors) (study group) and those wearing single-vision spectacles (control group) will be evaluated and compared.
Interventions
DEVICEOrthokeratology lenses
Nightly use of orthokeratology to correct the refractive error and over-specs for a period of two years
Daily use of spectacles to correct the refractive error for a period of two years
Sponsors
Procornea Nederland B.V.
The Hong Kong Polytechnic University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Age
8 Years to 11 Years
Healthy volunteers
Yes
Inclusion criteria
* Myopia (refractive sphere): \> 5.75D * Astigmatism: \< ½ of myopia; with-the-rule astigmatism (axes 180 +/- 30) ≤1.25D; astigmatism of other axes ≤ 0.50D * Spherical equivalent (SE): \> 5.75D * Anisometropia: ≤ 1.50D in both refractive sphere, refractive cylinder and SE * Best corrected monocular visual acuity: equal to or better than 0.10 in logMAR scale in both eyes * Willingness for randomization * Availability for follow-up for at least 2 years
Exclusion criteria
* Strabismus at distance or near * Contraindication for contact lens wear and orthokeratology (e.g. limbus to limbus corneal cylinder and dislocated corneal apex * Systemic or ocular conditions which may affect contact lens wear (e.g. allergy and medication) * Systemic or ocular conditions which may affect refractive development (e.g. Down syndrome, ptosis)
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Determine the change in cycloplegic axial length in the study and control groups | 2 years |
Secondary
| Measure | Time frame |
|---|---|
| Determine the incidence of adverse effects in cornea, the palpebral, bulbar and tarsal conjunctiva in the study and the control groups | 2 years |
| Rate of regression during the daytime | 2 years |
Countries
China
Outcome results
None listed