The Spatial Distribution of Relative Corneal Refractive Power Shift and Axial Growth in Myopic Children: Orthokeratology Versus Multifocal Contact Lens

Jiang, Fan; Huang, Xiaopeng; Xia, Houxue; Wang, Bingqi; Liu, Fan; Zhang, Bin; Jiang, Jun

doi:10.3389/fnins.2021.686932

Cited by 18 publications

(15 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…YangXY et al [ 13 ] demonstrated that a smaller X50 is significantly associated with smaller ALG in children wearing orthokeratology lenses with different peripheral curves. FanJ et al [ 34 ] reported that contact lenses with smaller Half_x induce RCRPS closer to the corneal center may exert better myopia control. The other is corneal asymmetry [ 9 , 35 ] which could be well quantified by the amplitude of a sinewave running one cycle over 360 degrees around the cornea.…”

Section: Discussionmentioning

confidence: 99%

The treatment zone decentration and corneal refractive profile changes in children undergoing orthokeratology treatment

Lin

Bai

et al. 2022

BMC Ophthalmol

Self Cite

View full text Add to dashboard Cite

Background To confirm the association between treatment-zone (TZ) decentration and axial length growth (ALG) in children who underwent orthokeratology; and to explore the association between TZ decentration and relative corneal refractive power (RCRP) profile, which was known to be significantly associated with ALG retardation. Methods Four hundred myopic children of age 12 years participated in the study, with 200 wearing orthokeratology lenses and the other 200 wearing single-vision spectacle as the controls. Cycloplegic refraction was performed at baseline. Axial length was measured at baseline and 12 months after initial lens wear, and ALG was defined as the difference. In the ortho-k group, TZ decentration and the RCRP map were calculated from the topography map obtained at the 12-month visit. RCRP were summed within various chord radii from the cornea center, and the association to TZ decentration, spherical equivalent (SE), ALG were analyzed with linear regressions. Results Compared to the controls, children wearing orthokeratology lenses had significantly smaller ALG over 1 year (0.1 ± 0.15 mm vs. 0.32 ± 0.17 mm, p < 0.001). ALG was significantly and negatively associated with summed RCRP within the central cornea of 2 mm in radius. The mean TZ decentration was 0.62 ± 0.25 mm, and the mean direction was 214.26 ± 7.39 degrees. ALG was negatively associated with the TZ decentration magnitude (p < 0.01), but not the direction (p = 0.905). TZ decentration caused an asymmetrical distribution of the RCRP with the nasal side plus power shifting towards the corneal center. For chord radius ranging 1-2 mm, the association between TZ decentration and the summed RCRP were significant, and the proportion of variance accountable increased with chord radius. For chord radius beyond 1.5 mm, the association between baseline spherical equivalent (SE) and summed RCRP was significant. The portion of variance accountable by SE increased and peaked in 2.5 mm chord radius. Conclusions A larger TZ decentration was associated with a larger summed RCRP in the central cornea. It may be one of the possible reasons why TZ decentration is beneficial to retarding myopia progression.

show abstract

Section: Discussionmentioning

confidence: 99%

The treatment zone decentration and corneal refractive profile changes in children undergoing orthokeratology treatment

Lin

Bai

et al. 2022

BMC Ophthalmol

Self Cite

View full text Add to dashboard Cite

show abstract

“…Participants with history of Ortho-K lens wear, contact lens contraindications, related eye systemic diseases, uncorrected visual acuity below 20/25, or unacceptable lens decentration (over 1 mm) after regular wear were excluded. These inclusion and exclusion criteria, along with details of the clinical care adopted, follow those presented in our earlier clinical study [ 27 ]. The study was approved by the Ethics Committee of the eye hospital and complied with the Declaration of Helsinki.…”

Section: Methodsmentioning

confidence: 99%

“…Finally, the Dreamlite lenses were manufactured with the Boston XO hexafocon-A material that had Dk of 100 × 10 –11 (cm 2 s −1 ) (mLO 2 ml −1 × mmHg). The lenses were fitted to both eyes by an experienced clinician (JJ) according to the manufacturer's guidelines, and participants were requested to wear the lenses for eight hours each night except in cases of illness or abnormal ocular symptoms [ 27 , 28 ].…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

A new approach for quantifying epithelial and stromal thickness changes after orthokeratology contact lens wear

et al. 2021

Self Cite

View full text Add to dashboard Cite

The aim of the study was to develop an automatic segmentation approach to optical coherence tomography (OCT) images and to investigate the changes in epithelial and stromal thickness profile and radius of curvature after the use of orthokeratology (Ortho-K) contact lenses. A total of 45 right eyes from 52 participants were monitored before, and after one month of, uninterrupted overnight Ortho-K lens wear. The tomography of their right eyes was obtained using optical OCT and rotating Scheimpflug imaging (OCULUS Pentacam). A custom-built MATLAB code for automatic segmentation of corneal OCT images was created and used to assess changes in epithelial thickness, stromal thickness, corneal and stromal profiles and radii of curvature before, and after one month of, uninterrupted overnight wear of Ortho-K lenses. In the central area (0–2 mm diameter), the epithelium thinned by 12.8 ± 6.0 µm (23.8% on average, p < 0.01) after one month of Ortho-K lens wear. In the paracentral area (2–5 mm diameter), the epithelium thinned nasally and temporally (by 2.4 ± 5.9 µm, 4.5% on average, p = 0.031). The stroma thickness increased in the central area (by 4.8 ± 16.1 µm, p = 0.005). The radius of curvature of the central corneal anterior surface increased by 0.24 ± 0.26 mm (3.1%, p < 0.01) along the horizontal meridian and by 0.34 ± 0.18 mm (4.2%, p < 0.01) along the vertical meridian. There were no significant changes in the anterior and posterior stromal radius of curvature. This study introduced a new method to automatically detect the anterior corneal surface, the epithelial posterior surface and the posterior corneal surface in OCT scans. Overnight wear of Ortho-K lenses caused thinning of the central corneal epithelium. The anterior corneal surface became flattered while the anterior and posterior surfaces of the stroma did not undergo significant changes. The results are consistent with the changes reported in previous studies. The reduction in myopic refractive error caused by Ortho-K lens wear was mainly due to changes in corneal epithelium thickness profile.

show abstract

“…In recent years, many studies have attempted to quantitatively assess the effectiveness of Ortho-K for AL control based on the defocus characteristics produced during the treatment. However, the methods of existing studies remain incomprehensive as they consider only certain axis directions [12,13], specific regions [14,15] or profiles [16] and do not fully reflect the morphology of the cornea in its entirety and the overall defocus characteristics in a three-dimensional space. In addition, it has been demonstrated that Ortho-K for myopia control significantly increases the Zernike coefficients and ocular higher-order aberrations in children [17,18].…”

Section: Introductionmentioning

confidence: 99%

Weighted Zernike defocus coefficient of treatment zone is a meaningful indicator for myopia control efficacy of Ortho-K lenses

Fan

Wang

et al. 2022

Eye and Vis

View full text Add to dashboard Cite

Background The goal of this study was to reproduce a three-dimensional representation of corneal defocus characteristics after orthokeratology (Ortho-K) treatment via an indicator defined as the weighted Zernike defocus coefficient of the treatment zone (Cweighted defocus). This could be used to predict the effectiveness of Ortho-K treatment quantitatively in a timely manner after the one-month visit. Methods Seventy myopic children with axial length (AL) elongation after Ortho-K treatment (group A) and 63 myopic children with AL shortening after Ortho-K treatment (group B) were included in this one-year retrospective study. The proposed indicator was calculated by a customized MATLAB program. Multivariate binomial logistic regression and multivariate linear regression analyses were used to explore the association between AL change and the Cweighted defocus, age, sex, and other ocular biometric parameters. Results The 12-month AL change, age, pupil diameter, and vertical decentration of the Ortho-K lens were significantly different between the two groups. Multivariate logistic regression analysis showed that a larger Cweighted defocus (≥ 0.35 D/mm2) (OR: 0.224; 95% CI: 0.078–0.646; P = 0.006) was correlated with the emergence of AL shortening after orthokeratology treatment. A multivariate linear regression model showed that a greater Cweighted defocus was associated with slower 12-month AL elongation (β = − 0.51, P = 0.001). Conclusions The Cweighted defocus is an effective predictive indicator of myopia control, and a larger Cweighted defocus may lead to slower elongation of AL. This meaningful indicator may help in the evaluation and adjustment of Ortho-K lens parameters in a timely manner and minimize the cost of clinical trial and error.

show abstract

The Spatial Distribution of Relative Corneal Refractive Power Shift and Axial Growth in Myopic Children: Orthokeratology Versus Multifocal Contact Lens

Cited by 18 publications

References 34 publications

The treatment zone decentration and corneal refractive profile changes in children undergoing orthokeratology treatment

The treatment zone decentration and corneal refractive profile changes in children undergoing orthokeratology treatment

A new approach for quantifying epithelial and stromal thickness changes after orthokeratology contact lens wear

Weighted Zernike defocus coefficient of treatment zone is a meaningful indicator for myopia control efficacy of Ortho-K lenses

Contact Info

Product

Resources

About