• Accommodation
• Myopia
• Orthokeratology
• Peripheral Refraction
• Refractive error

• Humans
• Orthokeratologic Procedures/methods
• Myopia/physiopathology
• Myopia/therapy
• Refraction, Ocular/physiology
• Male
• Accommodation, Ocular/physiology
• Female
• Young Adult
• Adult
• Visual Acuity/physiology

• 2023S141 Ningbo Science and Technology Plan Project

• aspherical lenslets
• myopia control
• peripheral eye length
• peripheral refraction

• 95020005 Collaborative research project with Essilor International in Wenzhou Medical University

• Corvis ST
• atropine
• corneal biomechanical properties
• myopia
• orthokeratology

• Humans
• Child
• Atropine/administration & dosage
• Orthokeratologic Procedures/methods
• Adolescent
• Female
• Male
• Cornea/physiopathology
• Disease Progression
• Prospective Studies
• Myopia/therapy
• Myopia/physiopathology
• Myopia/diagnosis
• Biomechanical Phenomena
• Refraction, Ocular/physiology
• Follow-Up Studies
• Mydriatics/administration & dosage
• Intraocular Pressure/physiology
• Axial Length, Eye
• Ophthalmic Solutions
• Dose-Response Relationship, Drug

• Back optic zone diameter
• Corneal refractive power
• Orthokeratology
• Peripheral defocus
• Treatment zone

• Humans
• Orthokeratologic Procedures
• Corneal Topography
• Male
• Female
• Child
• Retrospective Studies
• Cornea/pathology
• Myopia/therapy
• Myopia/physiopathology
• Refraction, Ocular/physiology
• Contact Lenses
• Visual Acuity/physiology

• myopia progression
• myopic defocus
• orthokeratology
• peripheral refraction

• corneal asymmetry vector
• myopia
• orthokeratology
• treatment zone decentration

• Humans
• Retrospective Studies
• Corneal Topography/methods
• Female
• Male
• Orthokeratologic Procedures/methods
• Myopia/therapy
• Myopia/physiopathology
• Myopia/diagnosis
• Cornea/diagnostic imaging
• Contact Lenses
• Refraction, Ocular/physiology
• Young Adult
• Adult
• ROC Curve
• Visual Acuity/physiology
• Adolescent

• axial elongation
• binocular anisomyopia
• myopia control
• orthokeratology
• relative peripheral refraction

• Humans
• Orthokeratologic Procedures/methods
• Child
• Myopia/physiopathology
• Myopia/therapy
• Male
• Refraction, Ocular/physiology
• Female
• Axial Length, Eye
• Visual Acuity/physiology
• Anisometropia/physiopathology
• Anisometropia/therapy
• Follow-Up Studies
• Prospective Studies

• HX-H2202035 West China Hospital of Sichuan University
• HXDZ22007 West China Hospital of Sichuan University

• Myopia
• atropine
• management algorithm
• myopia control interventions
• orthokeratology
• pre-myopia
• preventive medicine
• screening
• time spent outdoors

• Humans
• Algorithms
• Myopia/therapy
• Myopia/physiopathology
• Ophthalmology/organization & administration
• Societies, Medical
• Eyeglasses
• Disease Progression
• Europe
• Disease Management

• International Myopia Institute (IMI)

• Keratectasia, Refractive surgery
• LASIK
• Percent tissue altered
• Posterior cornea

• Humans
• Young Adult
• Adult
• Middle Aged
• Keratomileusis, Laser In Situ
• Retrospective Studies
• Corneal Topography
• Cornea/surgery
• Refraction, Ocular

• children
• myopia
• peripheral eye length
• peripheral refraction

• aspheric base curve
• axial elongation
• orthokeratology lens
• relative peripheral refraction

• 82070996 National Natural Science Foundation of China
• 2020HXBH167 Post-Doctoral Research Project, West China Hospital, Sichuan University
• HX-H2012261 Collaborative Research Agreement between West China Hospital, Sichuan University and Eyebright Corporation (Beijing)

• OCTA
• orthokeratology
• relative corneal refractive power shift
• retinal thickness
• retinal vascular density

• Biomarker
• Choroidal vasculature
• Myopia control
• Orthokeratology
• Prediction

• 82000931 National Natural Science Foundation of China
• 82025009 National Natural Science Foundation of China
• U20A20364 National Natural Science Foundation of China
• LQ21H120005 Natural Science Foundation of Zhejiang Province
• 2021C03053 Key Research and Development Program of Zhejiang Province
• 2021C03102 Key Research and Development Program of Zhejiang Province
• 2019-I2M-5-048 CAMS Innovation Fund for Medical Sciences

• Axial length
• Contact lens
• Crystalline lens thickness
• Myopia
• Orthokeratology

• Myopia
• Orthokeratology

• Myopia
• myopia control
• orthokeratology
• peripheral refraction
• randomized
• relative peripheral refraction

• Aspheric base curve
• Orthokeratology lens
• Relative corneal refractive power change
• Relative peripheral refraction

• myopia
• astigmatism
• peripheral refraction
• orthokeratology
• soft multifocal

• Adult
• Astigmatism/therapy
• Contact Lenses, Hydrophilic
• Humans
• Myopia/therapy
• Refraction, Ocular
• Retina

• P30 EY007551 NEI NIH HHS

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.

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.

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.

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.

• Corneal refractive power
• Myopia control
• Orthokeratology
• Treatment zone decentration

To analyze the factors influencing the progression of myopia in adolescents receiving orthokeratology.

This prospective cohort study collected the data of 378 myopia patients receiving orthokeratology. The follow-up time was 12 months ranging from December 2015 to December 2019. The group-based trajectory modeling (GBTM) was used to identify similar developmental trajectories in the levels of uncorrected visual acuity and changes of axial length elongation. Univariate and multivariate logistic regression analyses were conducted to explore the influencing factors of myopia development in patients wearing orthokeratology.

There was no factor having effect on visual acuity (left) and visual acuity (right) in different trajectories (all P>0.05). The corneal curvature K1 (left) (OR=0.382, 95% CI: 0.188–0.776), corneal curvature K2 (left) (OR=0.362, 95% CI: 0.187–0.699), degree of spherical refraction (left) (OR=0.139, 95% CI: 0.082–0.235) and spherical equivalent (left) (OR=7.276, 95% CI: 3.724–14.215) were factors associated with the changes of axial length elongation (left). The corneal curvature K1 (right) (OR=0.260, 95% CI: 0.116–0.585), corneal curvature K2 (left) (OR=0.272, 95% CI: 0.121–0.610) and degree of spherical refraction (right) (OR=0.129, 95% CI: 0.068–0.244) were correlated with the changes of axial length elongation (right). All P<0.05.

Orthokeratology is a promising method for controlling the progression of myopia. The corneal curvature, degree of spherical refraction and spherical equivalent were factors influencing the changes of axial length elongation in myopia patients wearing orthokeratology. The findings might give a reference for the application of orthokeratology in clinic.

• received no funding

• Contact lens
• Contact lens complications
• Corneal staining
• Microbial keratitis
• Orthokeratology

• Myopia progression
• Orthokeratology
• Peripheral eye length
• Peripheral refraction
• Retinal shape

Myopia, as one of the common ocular diseases, often occurs in adolescence. In addition to the harm from itself, it may also lead to serious complications. Thus, prevention and control of myopia are attracting more and more attention. Previous research revealed that single-focal glasses and orthokeratology lenses (OK lenses) played an important part in slowing down myopia and preventing high myopia.

To compare the clinical effects of OK lenses and frame glasses against the increase of diopter in adolescent myopia and further explore the mechanism of the OK lens.

Changes in diopter and axial length were collected among 70 adolescent myopia patients (124 eyes) wearing OK lenses for 1 year (group A) and 59 adolescent myopia patients (113 eyes) wearing frame glasses (group B). Refractive states of their retina were inspected through multispectral refraction topography. The obtained hyperopic defocus was analyzed for the mechanism of OK lenses on slowing down the increase of myopic diopter by delaying the increase of ocular axis length and reducing the near hyperopia defocus.

Teenagers in groups A and B were divided into low myopia (0D - -3.00 D) and moderate myopia (-3.25D - -6.00 D), without statistical differences among gender and age. After 1-year treatment, the increase of diopter and axis length and changes of retinal hyperopic defocus amount of group A were significantly less than those of group B. According to the multiple linear analysis, the retinal defocus in the upper, lower, nasal, and temporal directions had almost the same effect on the total defocus. The amount of peripheral retinal defocus (15°-53°) in group A was significantly lower than that in group B.

Multispectral refraction topography is progressive and instructive in clinical prevention and control of myopia.

• Multispectral refraction topography
• Myopia
• Retinal hyperopic defocus
• Eye axis
• Diopter
• Orthokeratology lens
• Frame glasses

• Myopia control
• Orthokeratology
• Treatment zone decentration
• Treatment zone size

This study aimed to characterise corneal refractive power (CRP) changes along the principal corneal meridians during orthokeratology (OK). Nineteen myopes (mean age 28 ± 7 years) were fitted with OK lenses in both eyes. Corneal topography was captured before and after 14 nights of OK lens wear. CRP was calculated for the central 8 mm cornea along the horizontal and vertical meridians. The central-paracentral (CPC) power ratio was calculated as the ratio between maximum central and paracentral CRP change from individual data. There was a significant reduction in CRP at all locations in the central 4 mm of the cornea (all p < 0.001) except at 2 mm on the superior cornea (p = 0.071). A significant increase in CRP was evident in the paracentral zone at 2.5, 3 and 3.5 mm on the nasal and superior cornea and at 3.5 and 4 mm on the temporal cornea (all p < 0.05). No significant change in CRP was measured in the inferior cornea except decreased CRP at 2.5 mm (p < 0.001). CPC power ratio in the nasal and temporal paracentral regions was 2.49 and 2.23, respectively, and 2.09 for both the inferior and superior paracentral corneal regions. Our results demonstrates that OK induced significant changes in CRP along the horizontal and vertical corneal meridians. If peripheral defocus changes are inferred from corneal topography, this study suggests that the amount of myopia experienced on the peripheral retina was greater than twice the amount of central corneal power reduction achieved after OK. However, this relationship may be dependent on lens design and vary with pupil size. CPC power ratios may provide an alternative method to estimate peripheral defocus experienced after OK.

To determine if the spatial distribution of the relative corneal refractive power shift (RCRPS) explains the retardation of axial length (AL) elongation after treatment by either orthokeratology (OK) or multifocal soft contact lenses (MFCLs).

Children (8–14 years) were enrolled in the OK (n = 35) or MFCL (n = 36) groups. RCRPS maps were derived by computing the difference between baseline and 12-month corneal topography maps and then subtracting the apex values. Values at the same radius were averaged to obtain the RCRPS profile, from which four parameters were extracted: (1) Half_x and (2) Half_y, i.e., the x- and y-coordinates where each profile first reached the half peak; (3) Sum4 and (4) Sum7, i.e., the summation of powers within a corneal area of 4- and 7-mm diameters. Correlations between AL elongation and these parameters were analyzed by multiple linear regression.

AL elongation in the OK group was significantly smaller than that in the MFCL group (p = 0.040). Half_x and Half_y were also smaller in the OK group than the MFCL group (p < 0.001 each). Half_x was correlated with AL elongation in the OK group (p = 0.005), but not in the MFCL group (p = 0.600). In an analysis that combined eyes of both groups, Half_x was correlated with AL elongation (β = 0.161, p < 0.001).

The OK-induced AL elongation and associated RCRPS Half_x were smaller than for the MFCL. Contact lenses that induce RCRPS closer to the corneal center may exert better myopia control.

• axial length
• corneal refractive power
• multifocal soft contact lens
• myopia
• orthokeratology

• Keratoectasia
• Percent tissue altered
• Posterior cornea
• Refractive surgery

This study aimed to evaluate the effects of two months of orthokeratology (OK) treatment in the accommodative response of young adult myopes. Twenty eyes (21.8 ± 1.8 years) were fitted with the Paragon CRT^® 100 LENS to treat myopia between −1.00 and −2.00 D. Low- and high-contrast visual acuity (LCDVA and HCDVA), central objective refraction, light disturbance (LD), and objective accommodative response (using the Grand Seiko WAM-5500 open-field autorefractometer coupled with a Badal system) were measured at baseline (BL) before lens wear and after 1, 15, 30, and 60 nights of OK. Refractive error correction was achieved during the first fifty days of OK lens wear, with minimal changes afterwards. LD analysis showed a transient increase followed by a reduction to baseline levels over the first 30 nights of treatment. The accommodative response was lower than expected for all target vergences in all visits (BL: 0.61 D at 1.00 D to 0.96 D at 5.00 D; 60 N: 0.36 D at 1.00 D to 0.79 D at 5.00 D). On average, the accommodative lag decreases over time with OK lens wear. However, these differences were not statistically significant (p > 0.050, repeated-measures ANOVA and Friedman test). This shows that overnight OK treatment does not affect objectively measured the accommodative response of young, low myopic eyes after two months of treatment stabilization.

• accommodation
• contact lenses
• myopia control
• orthokeratology

• Orthokeratology
• axial Length
• myopia
• relative Corneal Refractive Power Shift (RCRPS)
• spatial Distribution

The objective of the present retrospective comparative cohort study was to compare the impact of wearing glasses versus an orthokeratology (Ortho-K) lens on peripheral optical properties and myopia progression in a population of South Korean children. Participants included children with myopia, between 8 and 12 years of age (n = 22 eyes), and divided into two groups: those who used glasses (Group I, n = 9) and those who used an Ortho-K lens (Group II, n = 13). Myopia progression over one year was quantified by changes in the central axial length of the eye. Keratometry and corneal aberrations on both the anterior and posterior surfaces of the eye were obtained using a Scheimpflug camera. A custom-developed Shack-Hartmann aberrometer was also used to measure peripheral aberrations across the horizontal visual field, up to 30°, and along the nasal-temporal meridian in 10-degree steps. Central axial elongation was larger in Group I (0.59 ± 0.21 mm) than in Group II (0.34 ± 0.18 mm) (P = .01). Relative peripheral spherical refractions at 10 and 20° nasally and at 10° temporally (P = 0.04, 0.049, and 0.042, respectively) relative to the fovea were positively correlated with central axial elongation in Group II. Group II exhibited an increase in peripheral ocular high order aberrations, such as horizontal coma and asymmetric trefoil. The use of Ortho-K lenses was found to slow the rate of central axis elongation in children with myopia. This effect might be related to an increase in both peripheral spherical refraction and peripheral ocular higher order aberrations with Ortho-K lens use.

• Aberrometry
• Child
• Clinical research
• Eye-ear-nose-throat
• Myopia
• Ophthalmology
• Physiology

To investigate the repeatability of choroidal thickness measurements determined from enhanced depth imaging optical coherence tomography (EDI-OCT) images of eyes after wearing single-vision spectacles (SV) and orthokeratology (ortho-k) lenses.

Two EDI-OCT images of 40 children (SV: 20, ortho-k: 20) taken at a single visit were analysed twice. Subjects in the ortho-k group had been wearing ortho-k for 1–4 weeks. The choroidal thickness was determined from each image using a graph theory-based software and, where appropriate, manual correction of choroidal boundaries was undertaken by an experienced examiner.

The mean (±SD) choroidal thickness was 227.3±42.2 µm for the SV subjects and 251.1±54.4 µm for the ortho-k subjects. The interimage differences in choroidal thickness were −0.99±3.54 and −1.14±5.03 µm for the SV and ortho-k subjects, respectively, and the limits of agreement were +5.96 to −7.93 and +8.72 to −11.00 µm, respectively.

The coefficients of repeatability of choroidal thickness measurements from two EDI-OCT images taken at a single visit were 7.08 µm (SV) and 10.06 µm (ortho-k), suggesting that a change in choroidal thickness of less than 10 µm may not indicate a real change resulting from ortho-k lens wear.

• choroidal thickness
• orthokeratology
• repeatability
• semi-automated segmentation

We present a new method for analyzing relative corneal refractive power (RCRP) in children undergoing orthokeratology and explore its potential association to effective myopic control

A total of 55 children aged 8 to 12 years participated in the study. Axial growth was calculated as the difference in axial length before and 1 year after orthokeratology. Growth <0.30 mm was considered as effective control. Corneal topography was obtained before and 4 months after lens dispatch. The topography was divided into 36 10° slices and the maximal RCRP (mRCRP) in each was calculated and fitted into a model that integrated the effects of mean refractive power (M), corneal asymmetry (f1), and astigmatism (f2). The relationship between the probability of achieving effective control and the modulation of mRCRP was analyzed with logistic regression.

A total of 45 subjects achieved effective control, but for 10 the treatment was ineffective. The M-values were not different between the groups. Modulations of mRCRP were significantly larger in the effective than the ineffective group (1.17 vs. 0.64 diopters [D] for f1, P = 0.02; 0.85 vs. 0.35 D for f2, P = 0.03). The probability to achieve effective control increased with modulation of mRCRP (P = 0.02). With a peak mRCRP > 4.5 D, a subject had an above 80% chance to achieve effective control.

The new method reveals that how the combination of spherical equivalent (SE), corneal asymmetry, and astigmatism determines modulation of the mRCRP and a large amplitude of modulation is associated with a higher probability of effective myopic control.

Our finding enables clinicians to estimate the outcome early and provides new insights to lens design.

• axial growth
• myopic progression
• orthokeratology lens
• probability
• relative corneal refractive power

• contact lenses
• multifocal spectacles
• myopia control
• optical
• orthokeratology
• pharmacology

• Axial Length, Eye
• Child
• Contact Lenses
• Corneal Topography
• Disease Progression
• Humans
• Myopia/physiopathology
• Myopia/therapy
• Orthokeratologic Procedures/methods
• Refraction, Ocular/physiology

• Contact lenses
• model eyes
• myopia
• myopia progression
• peripheral refraction