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Completed

NCT Number: NCT06825585

Efficacy and Visual Quality of Orthokeratology Lenses With Different Designs

Orthokeratology (ortho-k) lens is very effective in slowing down axial elongation in myopic children by 30% to 63% when compared to children wearing single-vision spectacles or contact lenses. More recently, it is reported that the children wearing orthok lens of smaller back optical zone diameter (BOZD) demonstrated a smaller axial elongation when compared to children wearing lens with larger BOZD. We aimed to explored the myopia efficacy and visual quality of ortho-k with different BOZD (5.0mm or 6.2mm).

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Key information

Conditions

Myopia Eye Diseases Myopia; Refractive Error Refractive Errors

Age range

8 year–13 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Tianjin Eye Hospital Opotometric Center

Tianjin, Tianjin Municipality, 300020, China

About this study

This prospective study aimed to evaluate the efficacy of orthokeratology lenses with different back optical zone diameters (BOZD) in slowing axial elongation. Additionally, visual quality will be assessed through measurements of wavefront aberrations, contrast sensitivity, and subjective visual quality using a validated questionnaire. The study seeks to explore the effectiveness of various Ortho-K lens designs and the potential factors influencing their outcomes.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age between 8 and 13 years.
  • Subjective refraction under cycloplegia: spherical power between -4.00 D and
  • 1.00 D, with cylindrical power≤ 1.50 D.
  • Best-corrected visual acuity (BCVA) of ≥ 1.0 based on subjective refraction.
  • Willing to participate in the clinical trial and provide signed informed consent.

Exclusion criteria

  • One eye met the inclusion criteria
  • Patients with systemic diseases causing immunocompromised or affecting orthokeratology
  • There are other eye diseases that affect orthokeratology lens wearing, such as dacryocystitis, blepharitis, various inflammation, glaucoma, etc
  • Abnormal cornea
  • Previous corneal surgery or corneal trauma history
  • Active keratitis (e.g., corneal infection)
  • Patients with best corrected distance visual acuity of less than 5.0
  • Patients with corneal flat curvature lower than 39.00D, or higher than 48.00D
  • Patients with refractive instability
  • Patients with overt strabismus
  • The corneal epithelium showed obvious fluorescent staining, which was not suitable for patients wearing orthokeratology lenses
  • Patients with dry eye are not suitable for orthokeratology
  • Patients with corneal endothelial cell density less than 2000 cells /mm2
  • Patients who had worn rigid contact lenses (including orthokeratology lenses) within the previous 30 days

Treatment and study plan

Orthokeratology with 5.0mm back optical zone diameter

Device

The orthokeratology lenses used in this study were Double Reservoir Lenses (DRL) manufactured by Precilens (Creteil, France). The lenses feature a dual reverse-curve design with a back optic zone diameter (BOZD) of 5.0 mm.

Orthokeratology with a 6.2 mm back optical zone diameter

Device

The orthokeratology lenses used were Euclid lenses manufactured by Euclid Systems (Herndon, VA, USA). These lenses feature a four-zone, five-curve design with a back optic zone diameter (BOZD) of 6.2 mm.

Primary outcomes

  1. Changes in axial length

    Time frame: The change of baseline and 1years

    Axial length was measured with a biometer

Other outcomes

  1. Change of visual quality

    Time frame: Follow-up evaluations were conducted at baseline, and at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months after lens wear. The differences from baseline were calculated for each follow-up period.

    The visual quality questionnaire used in this study was adapted from the questionnaire developed by Tilia et al. The questionnaire comprises five categories with a total of nine questions, each accompanied by descriptive text and illustrative images to assist participants in providing their responses. Participants were asked to select the image corresponding to each question, and their responses were converted into numerical scores ranging from 1 to 10, where a score of 1 represents the poorest visual quality.

  2. Change of wavefront aberrations

    Time frame: Follow-up evaluations were conducted at baseline, and at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months after lens wear. The differences from baseline were calculated for each follow-up period.

    Wavefront aberration data for the eye were obtained using a Hartmann-Shack wavefront sensor (i.Profiler plus, Carl Zeiss Co., Aalen, Germany). The data were analyzed using Zernike polynomial decomposition to calculate the root mean square (RMS) values of total higher-order aberrations (HOAs), spherical aberration, coma aberration, trefoil, astigmatism, and fourth-order aberrations.

  3. Change of contract sensitivity

    Time frame: Follow-up evaluations were conducted at baseline, and at 1 week, 1 month, 3 months, and 12 months after lens wear. The differences from baseline were calculated for each follow-up period.

    Contrast sensitivity was assessed using the OPTEC 6500P contrast sensitivity tester (OPTEC 6500P, Stereo Optical Company, Inc., Chicago, USA) at five spatial frequencies: 1.5, 3, 6, 12, and 18 cycles/degree. The contrast sensitivity scores were expressed in logarithmic units (base 10) following a logarithmic transformation.

Sponsors and collaborators

Lead sponsor

Xiaoyan Yang

Other

Registry information

Important dates

Study start
2021
Primary completion
2022
Study completion
2022
First posted
Feb 13, 2025
Registry last updated
Feb 13, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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