Discontinuation of Orthokeratology on Eyeball Elongation in Myopic Children
Information source: The Hong Kong Polytechnic University
ClinicalTrials.gov processed this data on August 23, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Myopia
Intervention: ortho-k lenses (Device); single-vision glasses (Device)
Phase: N/A
Status: Active, not recruiting
Sponsored by: The Hong Kong Polytechnic University Official(s) and/or principal investigator(s): Pauline Cho, PhD, Principal Investigator, Affiliation: The Hong Kong Polytechnic University
Summary
The primary aim of this study is to compare eyeball elongation in existing ortho-k subjects
who stop the treatment with subjects who continue ortho-k lens wear and control subjects
wearing single-vision glasses.
Clinical Details
Official title: Discontinuation of Orthokeratology on Eyeball Elongation (DOEE) Study. (1) Discontinuation of Lens Wear in Existing Ortho-k Children
Study design: Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment
Primary outcome: Axial length
Secondary outcome: Incidence of adverse effects
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). Both studies showed that the effect of myopic control was most significant during the
first six months of the treatment. It is unknown whether the myopic control effect would
dissipate upon the discontinuation of the treatment or whether the myopic control effect
only happened in the first six month of lens wear and was maintained thereafter. The current
study aims at evaluating the effect of discontinuation of ortho-k treatment on myopic
control in children who are currently on the treatment. This knowledge is necessary and
important as patients/parents have concerns about the permanent dependency on ortho-k once
they enrolled in the treatment.
Children who have been on the treatment for two years and have recently completed the myopic
control studies at The Hong Kong Polytechnic University, i. e. the ROMIO, TO-SEE and HM-PRO
studies, will be invited to participate in this 14-month study. Ortho-k subjects will be
randomly assigned to study group or the ortho-k control group. The study group subjects will
be required to stop lens wear for 7 months at the completion of the previous study (Phase I)
and resume lens wear for next 7 months (Phase II). The ortho-k control group subjects will
be required to continue the current treatment for another 14 months. Control subjects in the
existing myopic control studies will be required to continue using the same treatment, i. e.
single-vision glasses, for another 14 months. Rate of myopic progression among the 3 groups
and at the two study phases will be determined and compared.
Eligibility
Minimum age: 8 Years.
Maximum age: 14 Years.
Gender(s): Both.
Criteria:
Inclusion Criteria:
- Age 8-14 years old (inclusive)
- Subjects who have completed the ROMIO, TO-SEE or HM-PRO studies at The Hong Kong
Polytechnic University
- Willingness to be randomized into groups (for ortho-k subjects)
- Availability for follow-up for at least 14 months
Exclusion Criteria:
- Non-compliance to the follow up schedule
- Non-compliance to the assigned optical correction (i. e. single-vision glasses or
ortho-k lenses)
- 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)
Locations and Contacts
School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong, China
Additional Information
Related publications: Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. Curr Eye Res. 2005 Jan;30(1):71-80. Walline JJ, Jones LA, Sinnott LT. Corneal reshaping and myopia progression. Br J Ophthalmol. 2009 Sep;93(9):1181-5. doi: 10.1136/bjo.2008.151365. Epub 2009 May 4.
Starting date: July 2010
Last updated: July 10, 2013
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