Discontinuation of Lens Wear in New Ortho-k Children (DOEE2)
This study aims at investigating the efficacy of myopic control using ortho-k in younger and older children.
|Study Design:||Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Discontinuation of Orthokeratology on Eyeball Elongation (DOEE) Study. (2) Discontinuation of Lens Wear in New Ortho-k Children|
- Axial length [ Time Frame: 14 months ] [ Designated as safety issue: No ]To determine and compare the rate of axial elongation in spectacle lens and contact lens wear periods
- Incidence of adverse effects [ Time Frame: 14 months ] [ Designated as safety issue: Yes ]To determine the incidence of adverse effects of the cornea, the palpebral, bulbar and tarsal conjunctiva
|Study Start Date:||October 2010|
|Estimated Study Completion Date:||October 2013|
|Estimated Primary Completion Date:||July 2013 (Final data collection date for primary outcome measure)|
Experimental: from single-vision glasses to ortho-k
Children will be required to wear single-vision glasses for the first 7 months of the study and will be switched to wear ortho-k lenses in the next 7 months
Device: single-vision glasses
Daily wear of glasses to correct vision
Other Name: CR-39 lensesDevice: ortho-k lenses
Nightly wear of lenses to correct vision in day time
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.
|China, Hong Kong|
|School of Optometry, The Hong Kong Polytechnic University|
|Hong Kong, Hong Kong, China|
|Principal Investigator:||Pauline Cho, PhD||The Hong Kong Polytechnic University|