An interventional study of Orthokeratology with 5.0mm back optical zone diameter and Orthokeratology with a 6.2 mm back optical zone diameter in Myopia and Myopia; Refractive Error, sponsored by Xiaoyan Yang. Completed at 1 site in China. Open to participants aged 8 Years to 13 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-02-13.
Sponsored by Xiaoyan Yang · Not applicable, Interventional, and Treatment
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).
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.
1,007 studies on the registry are indexed under Myopia; 210 are open to participants now.
This study's enrollment of 60 is below the median of 80 across 803 interventional studies indexed under Myopia.
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Exclusion Criteria:
Myopic children who need OK lens treatment
Device: Orthokeratology with 5.0mm back optical zone diameter
Myopic children who need OK lens treatment
Device: Orthokeratology with a 6.2 mm back optical zone diameter
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.
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.
Changes in axial length
Axial length was measured with a biometer
Time frame: The change of baseline and 1years
Change of visual quality
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.
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.
Change of wavefront aberrations
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.
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.
Change of contract sensitivity
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.
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.
This study is completed, as verified in Feb 2025. You cannot join it, but the record below documents what was studied.
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