Peripheral Optics in Myopia and Orthokeratology

Sponsor

The Hong Kong Polytechnic University (Other)

Overall Status

Completed

CT.gov ID

NCT00978679

Collaborator

Menicon Co., Ltd. (Industry)

Enrollment

Location

Arms

Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The primary objective of the current study is to investigate changes in peripheral refraction and aberration in children wearing orthokeratology lenses and single-vision spectacles.

Condition or Disease	Intervention/Treatment	Phase
Myopia	Device: Orthokeratology lenses Device: Spectacles	N/A

Detailed Description

Apart from being effective in reducing low to moderate myopia, orthokeratology has been shown to have potential in retarding myopic progression. The central cornea is flattened and peripheral optics altered in orthokeratology and it has been suggested that orthokeratology slows myopic progression through the alteration of peripheral optics. The aim of the current study is to investigate the changes in peripheral refraction and aberration in children wearing orthokeratology (study group) and single-vision spectacles (control group).

Study Design

Study Type:

Interventional

Actual Enrollment :

90 participants

Allocation:

Non-Randomized

Intervention Model:

Parallel Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

Peripheral Refraction and Aberration in Myopic Progression and Myopic Control

Study Start Date :

Mar 1, 2008

Actual Primary Completion Date :

Dec 1, 2015

Actual Study Completion Date :

Dec 1, 2015

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Orthokeratology Myopic children wearing orthokeratology at night will be the study group	Device: Orthokeratology lenses Nightly use of orthokeratology lenses to correct the refractive errors Other Names: Menicon Z Night Lens 2 Menicon Z Night Lens 2 Toric
Other: Others Myopic children wearing single-vision spectacles in the daytime will serve as control group	Device: Spectacles Daily use of single vision lenses to correct refractive errors Other Names: Glasses Eyeglasses

Arm

Intervention/Treatment

Experimental: Orthokeratology

Myopic children wearing orthokeratology at night will be the study group

Device: Orthokeratology lenses

Nightly use of orthokeratology lenses to correct the refractive errors

Other Names:

Menicon Z Night Lens 2

Menicon Z Night Lens 2 Toric

Other: Others

Myopic children wearing single-vision spectacles in the daytime will serve as control group

Device: Spectacles

Daily use of single vision lenses to correct refractive errors

Other Names:

Glasses

Eyeglasses

Outcome Measures

Primary Outcome Measures

Changes in cycloplegic off-axial auto-refraction, aberration and eyeball length [2 years]

Eligibility Criteria

Criteria

Ages Eligible for Study:

6 Years to 9 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Myopia (refractive sphere): > 0.50D and ≤ 6.00D
Astigmatism: with-the-rule astigmatism (axes 180 +/- 30) ≤ 1.50D; astigmatism of other axes ≤ 0.50D
Spherical equivalent (SE): > 0.50D and ≤ 6.75D (myopia)
Best corrected monocular visual acuity: equal to or better than 6/7.5 in Snellen scale
Willingness to wear contact lenses or spectacles on a daily basis
Availability for follow-up for at least 2 years

Exclusion Criteria:

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 myopic 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)