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Investigation of the Effect of Short-term Orthokeratology With Increased Compression Factor on Ocular Parameters

NCT02643875 · Status: COMPLETED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 36

Last updated 2020-09-18

Study results available
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Summary

Orthokeratology (ortho-k) is a clinical technique that uses reverse geometry rigid gas permeable contact lens exerting positive pressure on the central cornea to temporary reduce refractive error. Researchers have shown that this treatment is effective for myopia control in low to high myopes, with and without astigmatism. Most designs of ortho-k lenses in the market are fitted based on the Jessen formula. The compression factor was introduced to compensate for the regression of the ortho-k effect during the no lens-wear period, so that the wearer can obtain clear distance vision throughout the day and most lens designs use a compression factor of 0.50-0.75 D. However, in a retrospective study (mixed brands of ortho-k lenses), it showed that most patients did not achieve an over-correction of 0.75 D. In order to achieve an over-correction of 0.75 D, an extra flattening power of about 1.50 D instead of 0.75 D should be be targeted. The increased compression factor is expected to increase the target reduction and it may play a role in myopic control and providing a higher successful rate in fitting ortho-k lenses.

Conditions

  • Myopic Progression

Interventions

DEVICE

Orthokeratology

It is a kind of rigid permeable lens.

Sponsors & Collaborators

  • Menicon Co., Ltd.

    collaborator INDUSTRY

  • Queensland University of Technology

    collaborator OTHER

  • Aston University

    collaborator OTHER

  • The Hong Kong Polytechnic University

    lead OTHER

Principal Investigators

  • Pauline Cho, PhD · The Hong Kong Polytechnic University

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Model
SINGLE_GROUP

Eligibility

Min Age
6 Years
Max Age
10 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2016-02-26
Primary Completion
2016-11-18
Completion
2016-11-18

Countries

  • China

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT02643875 on ClinicalTrials.gov