Discontinuation of Lens Wear in New Ortho-k Children (DOEE2)

The Hong Kong Polytechnic University91 enrolled

Overview

This study aims at investigating the efficacy of myopic control using ortho-k in younger and older children.

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.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Myopia

Interventions

single-vision glassesDEVICE

Daily wear of glasses to correct vision in the first seven months of the study

ortho-k lensesDEVICE

Nightly wear of lenses to correct vision in day time in the second seven months of the study

Eligibility

Sex: ALLMin age: 6 YearsMax age: 15 YearsHealthy volunteers:

Medical Language ↔ Plain English

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)

Locations (1)

School of Optometry, The Hong Kong Polytechnic University

Hong Kong, Hong Kong, China

Outcomes

Primary Outcomes

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

Secondary Outcomes

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

Data from ClinicalTrials.gov

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