MyopiaTO-SEENCT00978692
Toric Orthokeratology - Slowing Eye Elongation
A study testing Toric Orthokeratology lenses and Single-vision spectacles in people with Myopia and Astigmatism, run by The Hong Kong Polytechnic University at 1 site in China.
Trial summary
The aims of this study are to investigate the effects of ortho-k for astigmatic and myopic reduction and myopic control in children, and the long term effects on corneal curvatures and biomechanics. Read more about this study
- Who is it for?
- Ages 6 to 12 yearsHealthy volunteers can take part
- Conditions the study is for
- Myopia, Astigmatism
- What is being tested?
- Toric Orthokeratology lenses and Single-vision spectacles
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 80 participants
- Where
- 1 siteChina
- Study dates
- May 2008to Dec 2012
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 to 12 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Myopia (refractive sphere): more than -0.50DS to -5.00DS
- Astigmatism: with-the-rule astigmatism more than -1.25DC
- Anisometropia: ≤ 1.50D in both refractive sphere
- Best corrected monocular visual acuity: equal to or better than 0.10 in logMAR scale in both eyes
- Availability for follow-up for at least 2 years
Who cannot join
- Strabismus at distance or near
- Contraindication for contact lens wear and orthokeratology (e.g. limbus to limbus corneal cylinder and dislocated corneal apex
- Prior experience with the use of rigid lenses (including orthokeratology)
- Prior experience with myopia control treatment (e.g. refractive therapy or progressive spectacles)
- 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)
Trial locations and contacts
1 site in 1 country.
China1 site
School of Optometry, The Hong KOng Polytechnic University
Hong Kong SAR
About this study
Official title: Toric Orthokeratology for Slowing Eye Elongation in Astigmatic Children
The aims of this study are to investigate the effects of ortho-k for astigmatic and myopic reduction and myopic control in children, and the long term effects on corneal curvatures and biomechanics.
Read the detailed description
Ortho-k has been shown to be effective in correcting low myopia but relatively ineffective for astigmatism, using spherical reverse geometry lens designs. Toric ortho-k lenses have been introduced in recent years but the efficacy for astigmatic reduction and for myopic control in children have not been confirmed. The mechanism of myopic reduction in ortho-k cannot be fully explained by changes to the anterior corneal curvatures. It is therefore possible that other corneal parameters such as posterior corneal curvature and corneal biomechanics may contribute to the mechanism.
The current study aims at investigating the efficacy of toric ortho-k lenses for correcting myopic astigmatism and for retarding myopic progression in children compared to children wearing single-vision spectacles. Long term changes to other corneal parameters such as posterior cornea curvatures, topographical corneal thickness, corneal hysteresis, corneal resistance factor, with and without ortho-k lens wear will also be investigated.
- Conditions
- Myopia, Astigmatism
- Being tested
- Toric Orthokeratology lenses, Single-vision spectacles
- Keywords
- Myopia, Astigmatism, Orthokeratology, Corneal thickness, Corneal curvatures, Corneal biomechanics
- Medical subject headings
- Myopia, Astigmatism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Toric Orthokeratology lensesDevice
Also called corneal reshaping therapy
Children wearing toric orthokeratology at night for correcting astigmatism and myopia will be the study group
Single-vision spectaclesDevice
Also called glasses
Children wearing single-vision spectacles in the daytime for correcting the refractive errors will serve as the control group
| Study group | Role | What they receive |
|---|---|---|
| Toric orthokeratology lenses | Experimental | Children wearing toric ortho-k lenses at night for correcting astigmatism and myopia will be the study group Receives: Device: Toric Orthokeratology lenses |
| Single-vision spectacles | Other | Children wearing single-vision spectacles in the daytime for correcting the refractive error will be serve as control group Receives: Device: Single-vision spectacles |
What is being measured
The primary outcome is the main question the study is designed to answer.
To determine the eyeball elongation in children wearing ortho-k lenses
Measured: Before lens wear, 6, 12,18, 24 months after lens wear
Secondary outcomes (2)
To determine the posterior corneal curvatures, topographic corneal thickness, corneal volume, corneal hysteresis and corneal resistance factor in a group of children and compare these parameters with the ortho-k children
Measured: Before lens wear, 6, 12,18, 24 months after lens wear
To investigative the efficacy of toric orthokeratology for correcting astigmatism and myopia
Measured: Before lens wear, 6, 12,18, 24 months after lens wear
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Sep 2009 (estimated)
- Study startMay 2008
- Primary completionJul 2012
- Study completionDec 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for MyopiaStudies of the same condition, open and under way.
- More trials run by The Hong Kong Polytechnic UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 80 participants (actual)
Sponsor and investigators
- Lead sponsor
- The Hong Kong Polytechnic University
- Sponsor type
- University, hospital or other
- Collaborators
- Menicon Co., Ltd.
- Responsible party
- Principal investigator, Pauline Cho, The Hong Kong Polytechnic University
- Investigators
- Pauline Cho, PhD, Principal investigator, The Hong Kong Polytechnic University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00978692
- Sponsor's protocol ID
- H-ZG30
- Acronym
- TO-SEE
- Status last verified
- Feb 2016
- First submitted
- 16 Sep 2009
- Last updated
- 22 Feb 2016
- Results posted
- No
- Data monitoring committee
- No
Publications
Chen C, Cheung SW, Cho P. Myopia control using toric orthokeratology (TO-SEE study). Invest Ophthalmol Vis Sci. 2013 Oct 3;54(10):6510-7. doi: 10.1167/iovs.13-12527.
PubMed 24003088Chen CC, Cheung SW, Cho P. Toric orthokeratology for highly astigmatic children. Optom Vis Sci. 2012 Jun;89(6):849-55. doi: 10.1097/OPX.0b013e318257c20f.
PubMed 22561203Chen C, Cho P. Toric orthokeratology for high myopic and astigmatic subjects for myopic control. Clin Exp Optom. 2012 Jan;95(1):103-8. doi: 10.1111/j.1444-0938.2011.00616.x. Epub 2011 Sep 5. No abstract available.
PubMed 21895768
Study at a glance
From the registry record, last updated by the sponsor on 22 Feb 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Toric Orthokeratology for Slowing Eye Elongation in Astigmatic Children
- ClinicalTrials.gov ID
- NCT00978692
- Acronym / sponsor ID
- TO-SEE / H-ZG30
- Conditions
- Myopia, Astigmatism
- Keywords
- Myopia, Astigmatism, Orthokeratology, Corneal thickness, Corneal curvatures, Corneal biomechanics
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 80 participants (actual)
- Lead sponsor
- The Hong Kong Polytechnic UniversityUniversity, hospital or other
- Collaborators
- Menicon Co., Ltd.
- Study start
- May 2008
- Primary completion
- Jul 2012 (actual)
- Study completion
- Dec 2012 (actual)
- First posted
- 17 Sep 2009 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aims of this study are to investigate the effects of ortho-k for astigmatic and myopic reduction and myopic control in children, and the long term effects on corneal curvatures and biomechanics.
Detailed description
Ortho-k has been shown to be effective in correcting low myopia but relatively ineffective for astigmatism, using spherical reverse geometry lens designs. Toric ortho-k lenses have been introduced in recent years but the efficacy for astigmatic reduction and for myopic control in children have not been confirmed. The mechanism of myopic reduction in ortho-k cannot be fully explained by changes to the anterior corneal curvatures. It is therefore possible that other corneal parameters such as posterior corneal curvature and corneal biomechanics may contribute to the mechanism.
The current study aims at investigating the efficacy of toric ortho-k lenses for correcting myopic astigmatism and for retarding myopic progression in children compared to children wearing single-vision spectacles. Long term changes to other corneal parameters such as posterior cornea curvatures, topographical corneal thickness, corneal hysteresis, corneal resistance factor, with and without ortho-k lens wear will also be investigated.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Toric orthokeratology lenses | Experimental | Device: Toric Orthokeratology lensesChildren wearing toric ortho-k lenses at night for correcting astigmatism and myopia will be the study group |
| Single-vision spectacles | Other | Device: Single-vision spectaclesChildren wearing single-vision spectacles in the daytime for correcting the refractive error will be serve as control group |
Who may qualify
- Ages
- 6 to 12 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (5 listed)
- Myopia (refractive sphere): more than -0.50DS to -5.00DS
- Astigmatism: with-the-rule astigmatism more than -1.25DC
- Anisometropia: ≤ 1.50D in both refractive sphere
- Best corrected monocular visual acuity: equal to or better than 0.10 in logMAR scale in both eyes
- Availability for follow-up for at least 2 years
Key exclusion criteria (6 listed)
- Strabismus at distance or near
- Contraindication for contact lens wear and orthokeratology (e.g. limbus to limbus corneal cylinder and dislocated corneal apex
- Prior experience with the use of rigid lenses (including orthokeratology)
- Prior experience with myopia control treatment (e.g. refractive therapy or progressive spectacles)
- Systemic or ocular conditions which may affect contact lens wear (e.g. allergy and medication)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Toric Orthokeratology lensesAlso: corneal reshaping therapyChildren wearing toric orthokeratology at night for correcting astigmatism and myopia will be the study group | Device | Toric orthokeratology lenses |
| Single-vision spectaclesAlso: glassesChildren wearing single-vision spectacles in the daytime for correcting the refractive errors will serve as the control group | Device | Single-vision spectacles |
Primary outcome
To determine the eyeball elongation in children wearing ortho-k lenses
Time frame: Before lens wear, 6, 12,18, 24 months after lens wear
2 secondary outcomes
To determine the posterior corneal curvatures, topographic corneal thickness, corneal volume, corneal hysteresis and corneal resistance factor in a group of children and compare these parameters with the ortho-k children
Time frame: Before lens wear, 6, 12,18, 24 months after lens wear
To investigative the efficacy of toric orthokeratology for correcting astigmatism and myopia
Time frame: Before lens wear, 6, 12,18, 24 months after lens wear
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Feb 2016.
- Background: PubMed 24003088Chen C, Cheung SW, Cho P. Myopia control using toric orthokeratology (TO-SEE study). Invest Ophthalmol Vis Sci. 2013 Oct 3;54(10):6510-7. doi: 10.1167/iovs.13-12527.
- Background: PubMed 22561203Chen CC, Cheung SW, Cho P. Toric orthokeratology for highly astigmatic children. Optom Vis Sci. 2012 Jun;89(6):849-55. doi: 10.1097/OPX.0b013e318257c20f.
- Background: PubMed 21895768Chen C, Cho P. Toric orthokeratology for high myopic and astigmatic subjects for myopic control. Clin Exp Optom. 2012 Jan;95(1):103-8. doi: 10.1111/j.1444-0938.2011.00616.x. Epub 2011 Sep 5. No abstract available.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Pauline Cho, PhD principal investigator
The Hong Kong Polytechnic University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Toric Orthokeratology lenses and Single-vision spectacles in people with Myopia and Astigmatism, run by The Hong Kong Polytechnic University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Feb 2016. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To determine the eyeball elongation in children wearing ortho-k lenses (time frame: Before lens wear, 6, 12,18, 24 months after lens wear). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00978692, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Feb 2016.