Myopia
Conditions
Keywords
children, corneal reshaping, myopia, myopia progression, orthokeratology
Brief summary
This study aims at investigating the efficacy of myopic control using ortho-k in younger and older children.
Detailed description
Children wearing ortho-k have been shown to have slower rate of myopic progression than those wearing single-vision spectacles (Cho et al. 2005) or soft lenses (Walline et al. 2009). Younger myopic children (aged 6-10 years old) may have the faster increase in myopia than old myopic children (aged 11-15 years old), i.e. the rate of myopic progression may be different in different age groups and in children with different refractive status (Edwards 1999; Fan et al. 2004; Cheng et al. 2007). Although the refractive correction with ortho-k has been well documented, it is unknown whether the efficiency and reversibility of ortho-k for myopic reduction as well as myopic control are similar in children of different age and refractive groups. In this 14-month study, the eyeball length in 45 younger (6-10 years old) and 45 older (11-15 years old) myopic children before and after ortho-k will be evaluated. Eyeball elongation will be determined for the first 7 months when single-vision glasses will be prescribed (Phase I) and the next 7 months when ortho-k will be prescribed (Phase I). Rate of myopic progression will be determined and compared between the two groups of children in the two phases.
Interventions
DEVICEsingle-vision glasses
Daily wear of glasses to correct vision in the first seven months of the study
DEVICEortho-k lenses
Nightly wear of lenses to correct vision in day time in the second seven months of the study
Sponsors
Menicon Co., Ltd.
The Hong Kong Polytechnic University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
SINGLE
Masking description
The outcome assessor was responsible for measuring the axial length and was unaware of the intervention (i.e. spectacles or orthokeratology) used by the subjects
Intervention model description
All subjects were prescribed with a pair of glasses for seven months and switched to orthokeratology for another seven months
Eligibility
Sex/Gender
ALL
Age
6 Years to 15 Years
Healthy volunteers
Yes
Inclusion criteria
* Age: between 6 to 15 years old * Myopia: between 1.50D and 4.50D in at least one eye * Spherical equivalent (SE): between -1.00D to -4.50D in both eyes * Astigmatism: ≤ 3.00D of axes 180 +/- 30 or ≤ 1.00D of other axes; and the amount is less than refractive sphere * 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 to wear contact lenses or spectacles on a daily basis * Can obtain good ortho-k results with the study lenses * Availability for follow-up for at least 14 months
Exclusion criteria
* Strabismus at distance or near * Contraindication for contact lens wear and ortho-k (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) * Prior experience with the use of rigid lenses (including ortho-k) * Prior experience with myopia control treatment (e.g. refractive therapy or progressive spectacles) * Non-compliance to the follow up schedule * Non-compliance to the use of the prescribed optical correction * Poor ocular response to ortho-k lens wear * Significant residual refractive error after ortho-k treatment resulting in poor unaided vision (worse than 0.18 in logMAR scale)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Axial Elongation in the Two Study Phases | 14 months | Axial elongation in children during the two study phases. Phase I: 7 months wearing single-vision spectacles. Phase II: 7 months wearing orthokeratology |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With Serious Adverse Effects | 14 months | Number of subjects with serious adverse effects of the cornea, the palpebral, bulbar and tarsal conjunctiva |
Countries
China
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Subjects Completed the 14-month Study Subjects who have completed the study in which they used single-vision spectacles every day for 7 months in Phase I and ortho-k lenses every night for the next 7 months in Phase II to correct their vision. | 66 |
| Total | 66 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Orthokeratology Wearing Phase | Poor Refractive Correction / Centration | 3 |
| Orthokeratology Wearing Phase | Withdrawal by Subject | 5 |
| Spectacles Wearing Phase | Lost to Follow-up | 9 |
| Spectacles Wearing Phase | Withdrawal by Subject | 8 |
Baseline characteristics
| Characteristic | Subjects Completed the 14-month Study |
|---|---|
| Age, Continuous | 11.3 years STANDARD_DEVIATION 2.3 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 66 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Region of Enrollment Hong Kong | 66 participants |
| Sex: Female, Male Female | 39 Participants |
| Sex: Female, Male Male | 27 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 66 |
| other Total, other adverse events | 0 / 66 |
| serious Total, serious adverse events | 0 / 66 |
Outcome results
Primary
Change in Axial Elongation in the Two Study Phases
Axial elongation in children during the two study phases. Phase I: 7 months wearing single-vision spectacles. Phase II: 7 months wearing orthokeratology
Time frame: 14 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Axial Elongation in Spectacle and Ortho-k Wearing Phases | Change in Axial Elongation in the Two Study Phases | spectacles wearing phase | 0.163 mm | Standard Deviation 0.121 |
| Axial Elongation in Spectacle and Ortho-k Wearing Phases | Change in Axial Elongation in the Two Study Phases | orthokeratology wearing phase | 0.047 mm | Standard Deviation 0.112 |
Secondary
Number of Participants With Serious Adverse Effects
Number of subjects with serious adverse effects of the cornea, the palpebral, bulbar and tarsal conjunctiva
Time frame: 14 months
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Axial Elongation in Spectacle and Ortho-k Wearing Phases | Number of Participants With Serious Adverse Effects | spectacles wearing phase | 0 Participants |
| Axial Elongation in Spectacle and Ortho-k Wearing Phases | Number of Participants With Serious Adverse Effects | orthokeratology wearing phase | 0 Participants |