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Purpose: To investigate axial elongation (AE) and changes in relative peripheral refraction (RPR) in anisomyopic children undergoing orthokeratology (ortho-k)., Methods: Bilateral anisomyopic children, 7-12 years of age, were treated with ortho-k. Axial length (AL) and RPR, from 30° nasal (N30°) to 30° temporal (T30°), were measured at baseline and every 6 months over the study period. AE, changes in RPR and changes in the interocular AL difference were determined over time., Results: Twenty-six of the 33 subjects completed the 2-year study. The AE of the higher myopic (HM) eyes (at least 1.50 D more myopia than the other eye) (0.26 ± 0.29 mm) was significantly smaller than for the less myopic (LM) eyes (0.50 ± 0.27 mm; p = 0.003), leading to a reduction in the interocular difference in AL (p = 0.001). Baseline RPR measurements in the HM eyes were relatively more hyperopic at T30°, N20° and N30° (p ≤ 0.02) and greater myopic shifts were observed at T20° (p < 0.001), T30° (p < 0.001), N20° (p = 0.02) and N30° (p = 0.01) after lens wear. After 2 years of ortho-k lens wear, temporal-nasal asymmetry increased significantly, being more myopic at the temporal locations in both eyes (p < 0.001), while AE was associated with the change in RPR at N20° (β = 0.134, p = 0.01). The interocular difference in AE was also positively associated with the interocular difference in RPR change at N30° (β = 0.111, p = 0.02)., Conclusions: Ortho-k slowed AE in bilateral anisomyopia, with slower growth in the HM eyes leading to a reduction in interocular AL differences. After ortho-k, RPR changed from hyperopia to myopia, with greater changes induced in the HM eyes, and slower AE was associated with a more myopic shift in RPR, especially in the nasal field of both eyes., (© 2024 College of Optometrists.)

Objectives: To evaluate the effect of peripheral defocus soft contact lenses (PDSCLs) on controlling myopia progression in children and adolescents, and to compare it with orthokeratology (Ortho-K) and single vision lenses (SVLs)., Methods: We conducted a systematic search of PubMed, the Cochrane Library, Medline, CNKI, CBM, VIP, and WanFang Data databases for randomized controlled trials (RCTs) and cohort studies that investigated the effects of PDSCLs on myopia control in children and adolescents. The published languages were limited to English and Chinese. The risk bias tool provided by the Cochrane risk-of-bias tool and Newcastle-Ottawa Scale were used to assess the risk bias of included studies of RCTs and CTs. The published biases of included studies were assessed by Egger`s test., Results: We included 21 studies, comprising 13 RCTs and 8 cohort studies, with a total of 1337 participants in the PDSCLs group, 428 in the Ortho-K group, and 707 in the SVLs group. The meta-analysis indicated no significant difference between PDSCLs and Ortho-K in controlling the increase of diopter ( MD  = 0.01, 95% CI : -0.06, 0.09; P  = 0.69) and axial length ( MD  = -0.01, 95% CI : -0.02, 0.00; P  = 0.28). Compared with SVLs, PDSCLs had a better effect in controlling the increase of diopter ( MD  = 0.23, 95% CI : 0.17, 0.28; P  < 0.00001) and axial length ( MD  = -0.11, 95% CI : -0.12, -0.09; P  < 0.00001) in children and adolescents., Conclusions: Children and adolescents wearing PDSCLs can achieve better myopia control than those wearing SVLs, and their effect is comparable to that of Ortho-K., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: This study aimed to investigate the 6-month effects of wearing orthokeratology (OK) lenses on the retina vessel density (VD), vessel diameter index (VDI), and foveal avascular zone (FAZ) of myopia children using optical coherence tomography angiography, and to further investigate the underlying mechanisms of Orthokeratology in myopia control., Methods: Sixty-two eyes form 62 subjects were included in the study. Baseline and 6-month measurements of axial length (AL), anterior chamber depth (ACD), FAZ area, FAZ perimeter, FAZ circularity, vessel density (VD) and VDI from both the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were obtained., Results: The mean age of the participants was 11.02 years (range: 8 years to 15 years), with 41.9% males and 58.1% females. Six months after orthokeratology, ACD decreased significantly, and AL remain unchanged. SCP-VD and DCP-VD significantly increased after treatment without obvious change of VDI, and FAZ parameters remained unchanged. During follow-up period, SCP-VD increased in all subgroups especially in mild myopia group, and DCP-VD increased significantly in all subgroups except for the group 8-10 years., Conclusion: After the 6-month treatment of orthokeratology in myopia children, the macular microvasculature changed significantly. We observed a significant increase of vessel densities in both SCP and DCP without obvious effect on vascular morphology. The changes of DCP-VD tended to be more sensitive in the elder subgroup, and the efficacy of orthokeratology might be greater in mild myopia group. OCT-A may provide additional information on myopia progression and the mechanisms of controlling myopia with OK lens treatment., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Aims: This study aimed to synthesize the variations in subfoveal choroidal thickness (SFCT) observed at different follow-up intervals in myopic children undergoing orthokeratology treatment., Materials and Methods: Relevant articles were systematically retrieved from databases such as PubMed, EMBASE, Web of Science, and Cochrane Library. The retrieval period extended from the inception of these databases to November 2023. Means and standard deviations (SD) of baseline and post-treatment SFCT were selected as the results for analysis and calculation., Results: A total of eight articles involving 478 eyes fulfilled the inclusion criteria. At 1 month, 3 months, and 6 months intervals, the SFCT demonstrated significant increases by 16.74 μm (95% CI: 8.66, 24.82; p  < 0.0001), 13.41 μm (95% CI: 4.36, 22.45; p  = 0.004), and 17.57 μm (95% CI: 8.41, 26.73; p  = 0.0002), respectively. Besides, children treated with orthokeratology exhibited a notably thicker change of SFCT in comparison with children with single-vision spectacles (SVL) (WMD = 13.50, 95% CI: 11.69, 15.13; p  < 0.0001)., Conclusion: Myopic children undergoing orthokeratology treatment experience a discernible increase in SFCT at 1 month, 3 months, and 6 months. Furthermore, compared to children utilizing SVL, those undergoing orthokeratology manifest a more pronounced thickening of SFCT.

Myopia is becoming increasingly common in young generations all over the world, and it is predicted to become the most common cause of blindness and visual impairment in later life in the near future. Because myopia can cause serious complications and vision loss, it is critical to create and prescribe effective myopia treatment solutions that can help prevent or delay the onset and progression of myopia. The scientific understanding of myopia's causes, genetic background, environmental conditions, and various management techniques, including therapies to prevent or postpone its development and slow its progression, is rapidly expanding. However, some significant information gaps exist on this subject, making it difficult to develop an effective intervention plan. As with the creation of this present algorithm, a compromise is to work on best practices and reach consensus among a wide number of specialists. The quick rise in information regarding myopia management may be difficult for the busy eye care provider, but it necessitates a continuing need to evaluate new research and implement it into daily practice. To assist eye care providers in developing these strategies, an algorithm has been proposed that covers all aspects of myopia mitigation and management. The algorithm aims to provide practical assistance in choosing and developing an effective myopia management strategy tailored to the individual child. It incorporates the latest research findings and covers a wide range of modalities, from primary, secondary, and tertiary myopia prevention to interventions that reduce the progression of myopia., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: JBJ discloses European patent EP 3 271 392, JP 2021-119187, and US 2021 0340237 A1: „Agents for use in the therapeutic or prophylactic treatment of myopia or hyperopia”; AG discloses grants from Alcon, Bausch&Lomb, Zeiss, Teleon, J&J, CooperVision, Hoya, Essilor, Thea, Polpharma, Viatris, consultation: Polpharma, Eyerising, lectures: Thea, Polpharma, Viatris, member of Advisory Boards: Nevakar, GoCheckKids and Thea; JAG discloses editorial board memberships: IOVS, TVST, OPO, grants panel: Fight for Sight UK, consultant for several companies, however the consultancy fee is paid directly by the company to an eye research charity chosen by the company; RCB discloses editorial board memberships: Investigative Ophthalmology and Visual Science (IOVS), Current Eye Research, Scandinavian Journal of Optometry and Visual Science (SJOVS). JRP discloses consultant: Essilor, Hoya, Sightglass, Vyluma, Government funding by ZonMw; JSW discloses consultant: Alcon, Allergan, AOS, Bausch & Lomb, CooperVision, CSIDryEye, DopaVision, M2C Pharmaceuticals, Medmont, Novartis, NuVision, Santen, Scope Ophthalmics, SightGlass, Théa, shares in AstonVision Sciences, Eyoto, Wolffsohn Research Limited, and funding by Alcon, Allergan, Johnson & Johnson Vision, Rayner, M2C Pharmaceuticals, Novartis, NuVision, Scope Ophthalmics, SightGlass, Théa, Topcon, The Eye Doctor; SW is employee of Carl Zeiss Vision International GmbH; SR discloses consultant: BHVI (C), Thea (C); DIF discloses trial support from CooperVision, Topcon and Vyluma Inc., consultant: Coopervision, Thea, Vyluma, EssilorLuxottica, Sightglass, Johnson and Johnson, and commercial interest in Ocumetra Ltd.KJS is in receipt of research funding from Hoya Vision and Vyluma Inc; SJM Is in receipt of research funding from Hoya Vision; HK is consultant for Hoya and Haag-Streit. The other authors declared no potential conflicts of interest with respect to the authorship, and/or publication of this article.

Purpose: To compare the efficacy and safety between traditional lens fitting and computer-aided fitting methods for orthokeratology (OrthoK) in the Chinese population., Methods: A multi-center, examiner-masked, randomized controlled study was conducted with a one-year follow-up period, enrolling 280 participants with spherical equivalent (SE) ranging from -0.5D to -4.0D. Participants were assigned to either the computer-aided orthokeratology fitting group (trial group) or the traditional lens fitting group (control group) using stratified randomization based on age (8 to 13 years, 13 to 18 years, and ≥ 18 years) to ensure a minimum of 30 cases in each sub-age group. Ocular examinations included visual acuity, objective and subjective refraction, corneal endothelial cell density, corneal topography, intraocular pressure, axial length, and ocular health assessment. Successful lens-correction was defined as the residual refraction with the OK lens, which should not exceed ± 0.5D, and/or an uncorrected visual acuity of no worse than 0.1 logMAR. Statistical analysis involves t-tests, analysis of variance, and Chi-squared tests., Results: 215 subjects were included in the statistical analysis (109 in the trial group and 106 in the control group). In both groups, compared to baseline data, the uncorrected visual acuity (UCVA) improved significantly, with SE reduced and central corneal curvature flattened greatly after wearing OrthoK lens (P < 0.05 for all). Compared to the control group, the trial group exhibited a higher successful rate in correcting UCVA (93.6 % vs. 84.0 %, P = 0.03) and slightly better correction in refraction (77.1 % vs. 66.0 %, P = 0.07) at 1-month follow-up. However, no significant differences were observed in the axial length elongation, corneal changes, or the incidence of adverse events between the two groups., Conclusion: These findings indicate the higher efficiency and slightly better performance in correcting myopia and improving UCVA of computer-aided lens fitting approach compared to the traditional one, but similar outcomes in controlling axial elongation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Purpose: To investigate bilateral axial length (AL) growth patterns and interactions of myopic eyes in anisometropic children during unilateral orthokeratology (OK) treatment in their singularly myopic eyes (Eyes1), followed by bilateral treatment when their second eyes (Eyes2) developed myopia., Methods: This study enrolled 94 eyes from 47 anisometropes (20 males). All patients had undergone monocular OK treatment for > 1 year followed by binocular treatment for > 1 year. Axial growth of Eyes1 and Eyes2 during the first year of monocular treatment (Stage 1), average annual axial elongation during the monocular treatment period, and axial elongation during the first year of binocular treatment (Stage 2) were respectively termed: S1E1 and S1E2, Annual E1 and Annual E2, and S2E1 and S2E2. Associations between AL growth and age, sex, interval time, and ocular parameters were analysed using correlation and generalised estimating equation (GEE) analysis., Results: During the monocular period, Eyes1 showed less AL growth (S1E1: 0.05 ± 0.18 mm; Annual E1: 0.05 ± 0.21 mm) than Eyes2 (S1E2: 0.51 ± 0.24 mm; Annual E2: 0.52 ± 0.25 mm) (all p < 0.001). During the binocular period, there was no significant difference between S2E1 and S2E2(0.21 ± 0.14 mm v. 0.19 ± 0.17 mm, p = 0.951). Between monocular and binocular periods, Eyes1 had significantly higher S2E1 compared to S1E1 and Annual E1 (both p < 0.001), and Eyes2 had significantly lower S2E2 than S1E2 and Annual E2 (both p < 0.001). In the GEE model, spherical equivalent refraction (SER) and between periods interval time showed independently significant associations with AL growth after adjusting for age and sex., Conclusion: Orthokeratology can significantly control AL growth in unilateral myopia. AL growth of the initial myopic OK-treated eyes accelerated relative to the monocular period when contralateral eyes developed myopia and assumed OK treatment. During the binocular treatment phase, OK lenses showed moderate and comparable effects on AL retardation across both eyes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: This meta-analysis reviews the evidence for the risks and benefits associated with orthokeratology (OK) treatment compared with other methods of myopia control in children and adults., Methods: A systematic search of Cochrane Central Register of Controlled Trials, Pubmed, Embase and Ovid was conducted from database inception to 22nd August 2021. Studies that reported on risks, visual and ocular biometric effects of OK in patients > 5 years of age with myopia (- 0.75 to - 6.00D) were included. Main outcomes are change in axial length and any adverse event., Results: Fourty-five papers were included in this systematic review and meta-analysis. The quality of data was variable and of moderate certainty, and selection bias likely skewed the results towards a relative benefit for OK. The rate of axial elongation in children was lower for OK treatment compared to other treatment modalities at one year (MD - 0.16 mm, 95% CI - 0.25 to - 0.07). Rate of change in axial length in children rebounded after OK discontinuation compared to participants who continued treatment (MD 0.10 mm, 95% CI 0.06 to 0.14). Adults and children wearing OK were up to 3.79 times more likely to experience an adverse event when compared with conventional contact lenses (OR 3.79, 95% CI 1.24 to ll.), though this evidence base is underdeveloped and requires additional well-designed studies for substantial conclusions to be drawn., Conclusions: OK arrests myopia progression while in use, however, there remain unanswered questions about the optimal duration of treatment, discontinuation effects and long-term risk for adverse events., (© 2024. The Author(s).)

Purpose: To assess the impact of 3 months of orthokeratology (ortho-k) contact lenses (CLs) for myopia correction on the corneoscleral profile, as changes in scleral geometry could serve as indirect evidence of alteration in the corneal biomechanical properties., Methods: Twenty subjects (40 eyes) were recruited to wear ortho-k lenses overnight; however, after discontinuation (two CL fractures, one under-correction and two non-serious adverse events), 16 subjects (31 eyes) finished a 3-month follow-up. Corneoscleral topographies were acquired using the Eye Surface Profiler (ESP) system before and after 3 months of lens wear. Steep (SimKs) and flat (SimKf) simulated keratometry and scleral sagittal height measurements for 13-, 14- and 15-mm chord lengths were automatically calculated by the ESP software. Additionally, sagittal height and slope were calculated in polar format from 21 radii (0-10 mm from the corneal apex) at 12 angles (0-330°). Linear mixed models were fitted to determine the differences between visits., Results: SimKs and SimKf were increased significantly (p ≤ 0.02). The sagittal height in polar format increased significantly (p = 0.046) at a radius of 2.5 mm for 150°, 180°, 210° and 240° orientations and at a radius of 3.0 mm for 210°. Additionally, the slope in polar format significantly decreased (p ≤ 0.04) at radii ranges of 0.0-0.5, 0.5-1.0 and 1.0-1.5 mm for multiple angles and at a radii range of 5.0-5.5 mm for 90°. It also increased significantly (p ≤ 0.045) at a radii range of 1.5-2.0 mm for 30° and at radii ranges of 2.0-2.5, 2.5-3.0 and 3.0-3.5 mm for multiple angles. No significant changes were found for any parameter measured from the scleral area., Conclusions: Three months of overnight ortho-k lens wear changed the central and mid-peripheral corneal geometry as expected, maintaining the peripheral cornea and the surrounding sclera stability., (© 2024 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Purpose: To investigate the effect of COVID-19 home confinement on the efficacy of the interventions for controlling myopia, and to select effective therapies to control myopia during COVID-19 confinement., Method: Children (n = 164) aged 8-12 years with spherical equivalent refraction of -1.00 to -6.00 diopters were stratified into two age subgroups and randomly allocated into the control, 0.01% atropine, orthokeratology (ortho-k) and atropine combined ortho-k (ACO) groups. Axial length (AL) was measured at baseline, 6-, 12-, 18- and 24-month visits. The follow-up spanned the period before the COVID-19 outbreak, the period of the home confinement, and the period of the school reopening. Hence, the AL change in different periods was collected and compared. Data analysis was performed following the criteria of intention to treat (ITT)., Results: All 164 children were involved in the ITT analysis. Compared to control, all interventions can still reduce the AL elongation during the COVID-19 home confinement period (all p < 0.05). However, the efficacy was compromised: individuals experienced more AL elongation during the COVID-19 home confinement period in the control, 0.01% atropine and ACO groups (all p < 0.05). Interestingly, in the ortho-k group, the difference was insignificant (p = 0.178), and the interaction between the intervention type (control vs. ortho-k) and the confinement severity was significant (p for interaction = 0.041), which is different from the atropine (p for interaction = 0.248) or ACO group (p for interaction = 0.988). These results were stable after being adjusted by other variables based on the multivariable regression model., Conclusion: Ortho-k was less affected by the COVID-19 home confinement, which is potentially a better therapy for children in this high-risk environment. Further investigations are warranted to validate this issue., (© 2023 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Purpose: To investigate the effects of modifications in back optical zone diameter (BOZD), reverse curve width (RCW), and compression factor (CF) on refractive error changes and axial elongation in myopic children undergoing orthokeratology (ortho-k) over a 12-month period., Method: In this retrospective study, data from 126 myopic children undergoing ortho-k fitting were analyzed. Subjects were categorized into four distinct groups based on lens design parameters: Group A (BOZD 6.0 mm, RCW 0.6 mm, CF 0.75 D); Group B (BOZD 6.0 mm, RCW 0.6 mm, CF 1.25 D); Group C (BOZD 5.4 mm, RCW 0.9 mm, CF 1.25 D); and Group D (BOZD 5.0 mm, RCW 1.1 mm, CF 1.25 D). The study evaluated uncorrected visual acuity (UCVA), corneal topography, and axial length (AL) at intervals, using Linear Mixed Models (LMMs) for time-based changes, and ANOVA or Kruskal-Wallis tests for group differences in AL elongation. A multivariable regression analysis identified factors independently associated with AL elongation., Results: Within the first day and week, all four groups displayed significant improvements in UCVA and alterations in corneal curvature, which subsequently stabilized. Although UCVA variations between groups were subtle, Group D had less corneal curvature change than Groups A and B initially and exhibited significantly less AL elongation after one year. No significant difference in corneal curvature change or AL elongation was observed between Group C and the other groups. Multiple regression analysis indicated that older baseline age, greater baseline spherical equivalent refractive error, and smaller BOZD were associated with less AL elongation., Conclusion: The study reveals a positive correlation between BOZD and axial length growth over the 12-month period. A pure 0.5 D CF increment demonstrates a nonsignificant impact. This study provides new ideas into optimizing the parameters of ortho-k lenses., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Purpose: To determine the relationship between changes in accommodative and binocular function with myopia progression in myopic children over a two-year follow-up period, and to determine when changes in visual functions stabilized after switching from spectacles to orthokeratology (Ortho-K)., Methods: This prospective, self-controlled study followed thirty-six participants (aged 8-14 years) for two years after they switched from spectacles to Ortho-K. Accommodative and binocular function were assessed prior to and 1, 3, 6, 12, 18 and 24 months after commencing Ortho-K. Measurements included accommodative amplitude, accommodative response, accommodative facility, accommodative convergence/accommodation (AC/A), ocular alignment, positive relative accommodation (PRA), negative relative accommodation (NRA), horizontal vergence range, reading ability and stereoacuity. Myopia progression was quantified by the change in axial length., Results: Ocular alignment, monocular and binocular accommodative facility, and PRA stabilized after 1 month. The distance blur point in the convergence range, the distance break and recovery point in the divergence range, accommodative amplitude, calculated AC/A, stereoacuity and reading ability stabilized within 6 months. After two years of Ortho-K, NRA significantly increased (p = 0.044), while it showed no significant difference after one-year of lens wear (p = 0.49). The distance break point in the convergence range showed no significant difference (p = 0.20), but significantly decreased after one-year (p = 0.005). There were no significant correlations between the change in axial length with changes in accommodative or binocular function (p > 0.05)., Conclusion: Accommodative and binocular function changed significantly after switching from spectacles to Ortho-K and most of the parameters stabilized within the first 6 months. There was no association between the change in accommodative or binocular function and myopia progression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Purpose: The purpose of this study was to compare the differences in myopic control effects between orthokeratology (OK) contact lenses and defocus incorporated multiple segments (DIMS) spectacle lenses. Methods: A retrospective cohort study was conducted that included patients who had received OK lens, DIMS spectacle lens or single-vision spectacle treatments. A total of 54 eyes from 27 individuals, 38 eyes from 19 individuals and 42 eyes from 21 individuals were enrolled into the OK lens, DIMS and control groups, respectively. The primary outcomes were the changes in the spherical equivalent refraction (SER) and axial length (AXL) among the groups. A repeated-measure ANCOVA was adopted to calculate the SER progression and AXL elongation of the OK lens group compared with the DIMS group. Results: The difference in the SER progression was clinically non-significant in the OK lens group compared with the DIMS and control groups (P = 0.001). The total AXL elongation results were similar between the OK lens and DIMS groups, but these were lower than in the control group (P = 0.005). The repeated-measure ANCOVA revealed that the SER progression difference during the study interval was clinically non-significant in the OK lens group when compared with the DIMS group (P = 0.028). The AXL elongation results between the OK lens and DIMS populations did not illustrate a significant difference (P = 0.607). In a subgroup analysis of moderate astigmatism, better AXL control was observed in the DIMS subgroup compared with the OK lens subgroup (P = 0.016). Conclusions: The OK lens demonstrated a clinically non-significant effect on the SER and AXL controls compared with the DIMS spectacle lens., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Clinical Relevance: Identification of the baseline chracteristics for children undergoing orthokeratology with relatively fast myopia progression can allow a more accurate determination of the risk/benefit ratio., Background: This study aimed to investigate if baseline corneal biomechanics can classify relatively slow and fast myopia progression in children., Methods: Children aged six to 12 years with low myopia (0.50 to 4.00 D) and astigmatism (less than or equal to 1.25 D), were recruited. Participants were randomised to be fitted with orthokeratology contact lenses with a conventional compression factor (0.75 D, n  = 29) or an increased compression factor (1.75 D, n  = 33). Relatively fast progressors were defined as participants who had axial elongation of 0.34 mm or above per 2 years. A binomial logistic regression analysis and a classification and regression tree model were used in the data analysis. The corneal biomechanics were measured with a bidirectional applanation device. The axial length was measured by a masked examiner., Results: As there were no significant between-group differences in the baseline data (all p  > 0.05), data were combined for analysis. The mean ± SD axial elongation for relatively slow ( n  = 27) and fast ( n  = 35) progressors were 0.18 ± 0.14 mm and 0.64 ± 0.23 mm per 2 years, respectively. The area under the curve (p2area1) was significantly higher in relatively fast progressors ( p  = 0.018). The binomial logistic regression and classification and regression tree model analysis showed that baseline age and p2area1 could differentiate between slow and fast progressors over 2 years., Conclusions: Corneal biomechanics could be a potential predictor of axial elongation in orthokeratology contact lens-wearing children.

Purpose: To compare the efficiency of orthokeratology (OK) and defocus-incorporated multiple segment (DIMS) lenses in myopia control in children., Methods: This prospective study involved 540 subjects (7-14 years) categorized into three groups: DIMS lenses (180 cases), OK lenses (180 cases), or single-vision spectacles (SVS) (180 cases). After a one-year follow-up, changes in axial length (AL) and differences among the groups were analyzed. The subjects were further divided into a low myopia degree subgroup (LM, -1.50 D ≤ SE ≤ -0.50 D), a moderate myopia degree subgroup (MM, -3.00 D ≤ SE ＜ -1.50 D), and a high myopia degree subgroup (HM, -5.00 D ≤ SE ＜ -3.00 D). A one-way ANOVA and multiple linear regression analysis were used to compare AL elongation and the factors influencing the different groups., Results: A total of 496 (92 %) subjects completed the study. The mean AL change in the OK lenses, DIMS lenses, and SVS were 0.20±0.18 mm, 0.30±0.22 mm, and 0.38±0.19 mm, respectively (P < 0.001). In the LM subgroup, the OK and DIMS groups showed similar AL changes, but both exhibited slower changes than the SVS group (P = 0.001). In the MM and HM subgroups, the OK lens performed the shortest AL elongation compared with the DIMS lenses and SVS (P < 0.001). Multiple regression analysis showed that the AL change was associated with age (β = -0.038 and P = 0.005), initial AL (β = -0.010 and P = 0.011), initial SE (β = 0.028 and P = 0.007), and interventions using OK lenses (β = -0.172 and P = 0.020) and DIMS lenses (β = -0.089 and P = 0.020)., Conclusion: Over a one-year treatment period, OK and DIMS lenses can significantly retard AL elongation compared with SVS. In addition, the OK lenses were more effective than the DIMS lenses in controlling AL in patients with higher degrees of myopia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Objective: To investigate the effects of orthokeratology lenses (OK lenses) on corneal biomechanics in subjects of different ages., Methods: Fifty subjects with mild to moderate myopia were categorized into three groups (Group I-III) based on their age. Corvis ST was used to collect dynamic corneal response parameters (DCRs) at different follow-up time points. Repeated measures analysis of variance combined with simple effect analysis was used to analyze the changes in DCRs in different groups during the follow-up period. Multiple linear regression analysis was used to analyze the correlations between axial length growth (ALG) at 6 months (ALG-6M) or 12 months (ALG-12M) and sex, baseline spherical equivalent refraction (SER), and DCRs., Results: The DCRs changed in all three groups after wearing OK lenses. Most DCRs showed significant differences between baseline and 6 months after wearing OK lenses, while the differences between DCRs at 6 months and 12 months were not statistically significant. No significant differences in DCRs were observed among the three groups at the same follow-up time point. Additionally, at 6 months post-OK lens wear, ALG-6M was significantly correlated with velocity of the corneal apex at the first applanation (A1V-6M) (P = 0.002), Corvis biomechanical index (CBI-6M) (P = 0.004), the maximum amount of corneal movement (DAM-6M) (P = 0.010), deformation amplitude ratio of 2 mm (DAR2-6M) (P = 0.010), and stress-strain index (SSI-6M) (P = 0.038) in Group I. Furthermore, ALG-12M showed significant correlations with SSI-6M (P = 0.031), peak distance at the DAM (PD)-6M (P = 0.037), baseline Ambrósio Relational Thickness to the horizontal profile (P = 0.013) in Group I., Conclusions: The majority of DCRs displayed significant changes within the initial 6 months of OK lens wear. Minimal variation in DCRs was observed across different age groups at the same follow-up time point. Certain DCR parameters exhibited correlations with ALG, suggesting their potential in predicting ALG in myopic children undergoing OK lenses correction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To investigate the relationship between relative corneal refractive power shift (RCRPS) and axial length growth (ALG) in bilateral myopic anisometropes treated with orthokeratology., Methods: A total of 102 children with myopic anisometropia in this prospective interventional study were randomly assigned to the spectacle group and orthokeratology group. Axial length (AL) and corneal topography was measured at baseline and the 12-month follow-up visit. ALG was defined as the difference between the two measurements, and RCRPS profiles were calculated from two axial maps obtained., Results: In the orthokeratology group, the ALG in the more myopic eye (0.06 ± 0.15 mm) was significantly smaller than that in the less myopic eye (0.15 ± 0.15 mm, p < 0.001), and the interocular difference in AL significantly decreased following 1-year treatment, from 0.47 ± 0.32 to 0.38 ± 0.28 mm (p < 0.001). However, in the spectacle group, the ALG was similar between the two eyes, and the interocular difference in AL did not change significantly over one year (all p > 0.05). The interocular difference in ALG in the orthokeratology group was significantly correlated with the interocular difference in RCRPS (dRCRPS, β=-0.003, p < 0.001) and the interocular difference in baseline AL (β=-0.1179, p < 0.001), with R 2 being 0.6197., Conclusion: Orthokeratology was effective in decreasing the magnitude of anisometropia. The interocular variation in RCRPS is an important factor accounting for the reduction of interocular ALG difference in anisomyopic children post-orthokeratology. These results provide insight into establishing eye-specific myopia control guidelines during orthokeratology treatment for myopic anisometropes., (© 2023. The Author(s).)

Purpose: To investigate the influence of corneal parameters on the treatment zone area (TZA) after Corneal Refractive Therapy (CRT) with a 5.0-mm back optical zone diameter (BOZD) were worn and to compare changes in the axial length (AL) with traditional 6.0-mm BOZD lenses., Methods: This retrospective study involved 146 subjects (7-12 years) who wore orthokeratology (ortho-K) lenses for one year: 86 subjects were treated with CRT 5.0-mm lenses, and 60 subjects were treated with CRT 6.0-mm lenses. The TZA was measured after one year of ortho-K treatment. Both TZA and AL elongation after wearing the two kinds of lenses was compared. The parameters were recorded in the CRT 5.0 group: flat K, steep K, corneal toricity, e value, and anterior corneal elevation values at the 3-, 4-, and 5-mm chords along the principal meridians of the superior, inferior, nasal, and temporal sides. The relationships between these data and the TZA were analyzed., Results: The TZA was 12.90 ± 5.15 mm 2 and 20.61 ± 4.54 mm 2 , and the AL elongation was 0.15 ± 0.18 mm and 0.26 ± 0.18 mm in the CRT 5.0 group and the CRT 6.0 group, respectively (all p < 0.001). The one-year AL elongation was significantly associated with initial age and the TZA (r =  - 0.394, 0.393; all p < 0.001) in the CRT 5.0 group. The following corneal parameters were found to have statistically significant correlations with the TZA: the e value, difference in corneal elevation (nasal-temporal at the 3-, 4-, and 5-mm chord), and the absolute value of elevation difference (nasal-temporal at the 3- and 4-mm chord and inferior-superior at the 3-, 4-, and 5-mm chord). The e value was the only relevant factor for the TZA by multiple regression analysis (unstandardized β = 14.219, p = 0.008). In the CRT 6.0 group, the one-year AL elongation was statistically significantly associated only with initial age (r =  - 0.605, p = 0.005), but not with the TZA (p = 0.161)., Conclusions: A smaller TZA induced by a smaller BOZD may be beneficial for retarding AL elongation in children undergoing ortho-K treatment. The morphology and eccentricity of the cornea may show effects on the TZA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: With the rising prevalence of myopia, especially among the young, orthokeratology (Ortho-K) stands out as a promising approach, not only to reduce myopia but also to control the progression of axial length (AL). This study examined how the intersection area between the pupil and defocus ring influenced retinal defocus and axial growth after Ortho-K., Methods: A case-control study was conducted with 100 participants (100 eyes). Both AL and the refraction difference value (RDV), that is, the peripheral refractive error measured with respect to the central value after wearing Ortho-K lenses, were determined. Subjects were categorised into two groups based on the size of the intersection area after 3 months of lens wear: Group A (<4.58 mm 2 ) and Group B (≥4.58 mm 2 )., Results: Group B demonstrated significantly lower changes in AL and RDV at 30-40° and 40-53° compared with Group A after 3 months of lens wear (all p < 0.05). After 6 months of lens wear, Group B showed significantly lower changes in AL and RDV in the 40-53° region compared with Group A (all p < 0.05). Correlation analysis revealed that as the intersection area increased, the changes in AL and RDV at 0-53°, 30-40° and 40-53° eccentricity decreased after both 3 and 6 months of lens wear (all p < 0.01)., Conclusions: A larger intersection area between the pupil and defocus ring within a certain time period can cause a greater amount of myopic defocus at 30-53° from the fovea. The results suggest that a larger intersection area might lead to more effective control of axial growth., (© 2024 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Purpose: Wearing ortho-k lenses overnight may not fully correct their daytime refractory errors of adolescents with moderate to high myopia. There are three common ways to deal with the daytime residual refractive error (RRE): 1) wearing spectacles to correct the RRE; 2) wear ortho-k lenses during the daytime instead of overnight.; 3) not correcting the residual refractive error. According to previous laboratory studies, myopic peripheral refraction is associated with better myopic control. This study had two aims:1) to compare relative peripheral refractive error (RPRE) among these ways after one-month stabilization; 2) to assess the axial length changes over 2 years of ortho-k lens overnight wear combined with spectacle glasses., Methods: This was a prospective, non-controlled, non-randomized, observational study in which a total of 27 subjects (20 females, 7 males, mean age 12.48 ± 2.23Y) with spherical equivalent refractive error from -5.00 to -8.25D were enrolled. All participants in the study wore orthokeratology (ortho-k) lenses overnight for a minimum of one month. Subsequently, their peripheral refractive error (PRE) was assessed using an open-field autorefractor. During the assessment, the participants underwent three conditions in a random order in a same morning: 1) unaided eye after orthokeratology (referred to as the Unaided-eye condition), 2) wearing glasses to correct any remaining refractive errors after orthokeratology (referred to as the Spec-RE condition), and 3) wearing ortho-k lenses during the daytime (referred to as the Continuous OK wear condition). After testing, all subjects were instructed to wear ortho-k lenses overnight and glasses during the daytime to correct their RRE for the next 2 years, during which time the progression of their axial length was followed up., Results: 1) RPRE in either Unaided-eye or Spec-RE condition subjects were significantly more myopic than those in the Continuous OK wear condition. 2) No difference in RPRE was seen between Unaided-eye and Spec-RE conditions. 3) Axial length growth was 0.05 ± 0.20 mm and 0.17 ± 0.32 mm (mean ± standard deviation) at 1-year and 2-year follow-ups after the initial visit, respectively, which were comparable to mild myopia patients after orthokeratology. 4) After orthokeratology, axial length change had negative correlation with the initial age (p = 0.001, r = -0.616) and residual diopter (p = 0.022)., Conclusions: For myopes above refraction < -5.00D, wearing Ortho-k lenses overnight and glasses to correct the RRE in the daytime is recommended to ensure good visual quality and have more myopic RPRE for potential myopia control., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Purpose: The aim of this study is to develop an automatic model based on deep learning techniques for determining the Treatment Zone (TZ) and Peripheral Steepened Zone (PSZ) following Orthokeratology (OK) treatment., Methods: A total of 1346 corneal topography maps were included in the study. A deep neural network based on the Segformer architecture was constructed to automatically detect TZ and PSZ. The model was optimized and trained multiple times, and the areas of TZ, PSZ, and TZ decentration were calculated based on the segmentation results., Results: The mean Intersection over Union (mIoU) of the overall segmentation results of the model reached over 97% after multiple training with different optimization methods, and the IoU for the TZ and PSZ segmentation tasks were 98.08% and 94.54% in test set, respectively. Moreover, the model demonstrated high consistency with the expert annotation for the TZ segmentation, while a significant difference was found in the PSZ segmentation and expert annotation due to several interference factors., Conclusion: This study presents an efficient and repeatable system for clinical research, based on a deep neural network that accurately determines TZ and PSZ after OK treatment using the Segformer architecture. However, further deployment validation may be necessary., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: To investigate the knowledge, training and clinical practice of Spanish optometrists about preventing and controlling myopia progression., Methods: A web-based questionnaire was distributed to Spanish optometrists through social networks, optometric professional bodies and one of the major Spanish optometrists' associations to assess practitioner perception, understanding, and self-reported clinical practice behavior related to myopia diagnosis and management., Results: A total of 534 optometrists with a mean age of 40.8 ± 10.3 years completed the survey. Most respondents have been practicing optometry for more than 20 years (89.8%), report having actively treated childhood myopia (82.4%), and are very concerned about the increasing frequency of pediatric myopia in their daily practice (85.3%). Almost all of the respondents (97.3%) agreed that the efficacy of treatment is related to the age at which it is prescribed, and more than half (53.6%) considered a progression higher than - 0.50 and up to - 1.00D as the minimum necessary to consider a myopia management option. Respondents who reported actively managing childhood myopia considered orthokeratology, atropine and soft-defocus contact lenses the most effective myopia control interventions. However, the most frequently prescribed form of myopia correction by Spanish optometrists was single-vision spectacles, followed by orthokeratology and soft-defocus contact lenses., Conclusions: Spanish optometrists are very active in the management of myopia, especially by fitting orthokeratology lenses or dual-focus soft contact lenses for myopia control, but there is still potential for improvement in the methodology they follow for both the diagnosis and management of myopia., (© 2023. The Author(s).)

Background: Delaying the development and lowering the progression of myopia in children is the focus of current ophthalmology researches. We aimed to evaluate the role of orthokeratology in controlling myopia of children, to provide insights to the clinical treatment and care of children with myopia., Methods: Two investigators searched the The Cochrane Library, Embase, Pubmed, China national knowledge infrastructure, China biomedical literature database, WanFang and Weipu databases for randomized controlled trials(RCTs) on the role of orthokeratology in controlling myopia of children up to November 5, 2022. Two researchers independently searched, screened and extracted the studies according to the inclusion and exclusion standards. RevMan5.3 software was used for statistical analysis., Results: A total of 14 RCTs involving 2058 children were included in this meta-analysis. Synthesized outcomes indicated that orthokeratology improved the uncorrected visual acuity(MD = 0.40, 95%CI: 0.05 ~ 0.74), reduced the diopter change(MD=-3.19, 95%CI: -4.42~-1.95), changes of corneal curvature(MD=-3.21, 95%CI: -3.64~-2.79), the length of ocular axis (MD=-0.66, 95%CI: -1.27~-0.06) and amount of ocular axis change(MD=-0.42, 95%CI: -0.64~-0.21) after 1 year of wearing orthokeratology(all P < 0.05). Besides, orthokeratology reduced the diopter change (MD=-3.22, 95%CI: -4.86~-1.58), the length of ocular axis (MD=-1.15, 95%CI: -2.25~-0.06) and the amount of ocular axis change after 2 year of wearing orthokeratology (MD=-0.53, 95%CI: -0.96~-0.11) after 2 year of wearing orthokeratology (all P < 0.05). No publication biases were found amongst the synthesized outcomes (all P > 0.05)., Conclusions: Orthokeratology delays the progression of myopia in children, the long-term effects of orthokeratology need further investigations in future studies., (© 2023. The Author(s).)

Background: To evaluate the relationship between amount of corneal refractive change (CRC) after wearing orthokeratology (Ortho-K) lenses and axial length (AL) growth., Methods: We retrospectively enrolled 77 patients (77 eyes) aged 8-14 years who wore Ortho-K lenses more than 12 months. We divided the patients into 2 subgroups: spherical equivalent (SE) ≤ -3.0 D and SE > -3.0 D subgroup. The sagittal and tangential curvature maps and corneal topographic data within the 8-mm diameter ring at the baseline and during follow-up visits after wearing Ortho-K lens were recorded in addition to the area, height, and volume of the CRC region. The AL data were recorded at the baseline and during follow-up visits. Multivariate linear regression was conducted to analyze associations between the area, height, and volume of the CRC region, AL elongation, and SE., Results: The average change in the CRC region was 9.77 ± 0.60 D in height, 16.66 ± 3.61 mm 2 in area, and 87.47 ± 8.96 D*mm 2 in volume on the tangential diagram after wearing Ortho-K lenses for 3 months. The AL showed a change of 0.19 ± 0.14 mm after 1 year of Ortho-K lens wear (P < 0.05). At 1 year, AL elongation was negatively correlated with the area (P = 0.019) and volume (P < 0.001) of the CRC region. At 1 year, for every 1-mm 2 increase in the area and every 1-D*mm 2 increase in the volume of the CRC region, the average AL elongation decreased by 0.01 mm and 0.002 mm, respectively, in the multivariate analysis. In patients with SE ≤ -3.0 D, AL elongation was negatively correlated with the CRC-region volume (β = -0.002, P = 0.018), and in patients with SE > -3.0 D, AL elongation was negatively correlated with the CRC-region area (β = -0.017, P = 0.016)., Conclusions: The AL elongation-control efficacy of Ortho-K lenses may be related to the area and volume of the CRC region., (© 2023. The Author(s).)

Purpose: To report the characteristics (prevalence, severity, and location) of corneal epithelial microcysts and investigate associated risk factors in children wearing orthokeratology (ortho-k) lenses., Method: Ninety-five myopic children wearing ortho-k lenses (examined by one of three independent investigators from March to September 2020) were included in this retrospective cross-sectional study. Pertinent data at baseline before ortho-k treatment and at the aftercare visits (the first visit when the microcysts were observed for children with microcysts, and the last visit before October 2020 for children without microcysts) were retrieved and analysed., Results: A microcystic response was observed in 52.6% of children wearing ortho-k lenses. Children with high myopia (≥ 5.00 D) had a higher prevalence (100.0%, 23/23) and severity (69.5% (16/23) > grade 2 Efron scale) compared to children with low myopia (≤ 4.00 D) (prevalence of 37.5% (27/72) and 7.0% (5/72) > grade 2, p < 0.001). Microcysts were predominantly (86.0%) observed in the region of the inferior pigmented arc, typically originating in the inferior mid-peripheral cornea, and expanding over time into a semi- or whole annulus. Baseline myopia and topographical change at the treatment zone centre were significantly greater (p < 0.05) in low myopic children with microcysts (univariate analyses)., Conclusions: During the COVID-19 pandemic, probably due to lifestyle changes, microcysts were frequently observed in children wearing ortho-k lenses and were associated with higher baseline myopia. Practitioners should examine ortho-k wearers with caution using a slit lamp with high magnification and illumination, especially the mid-peripheral cornea. The use of highly oxygen permeable lenses and frequent aftercare are necessary for ortho-k wearers, especially those with higher myopia., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Clinical Relevance: The changes in various biomechanical and tomographic characteristics of the cornea associated with orthokeratology may allow us to identify potential mid- and long-term structural alterations, resulting in a better understanding of the governing mechanisms of this procedure and in its optimisation., Background: The study aimed at describing short and mid-term changes in CORVIS ST® parameters and indices in orthokeratology (ortho-k), and their diurnal variations., Methods: A prospective observational study was designed in which several CORVIS ST® parameters of 75 new adult participants successfully fitted with overnight ortho-k Seefree® (Conóptica - Hecht Contactlinsen) contact lenses were explored. Measurements were conducted in baseline (BL) conditions and in the morning and evening at the one-night (1 NM/1NT), one-week (1WM/1 WT) and 3-month (3 MM/3MT) follow-up visits., Results: Statistically significant differences were found in DARatio&#95;2 mm, IntRad, ARTh, CBI and TBI following overnight ortho-k, when compared with BL values, with most values reaching stability at 1WM or reverting to BL values at 3 MM. The ARTh and CBI parameters showed some of the most significant temporal variations (both p < 0.001), probably reflecting the encountered differences in central corneal thickness between BL and 1WM (p = 0.010) and between BL and 3 MM (p = 0.016). In general, corneal rigidity was higher in the morning at all follow-up visits, and decreased during the day. No statistically significant changes in adjusted intraocular pressure values were found., Conclusion: Ortho-k in adults may be considered a safe procedure in terms of short and mid-term changes in CORVIS ST® parameters. The observed alterations in most of the parameters provided by the Corvis ST® probably responded to the well-described changes in corneal pachymetry and tomography, rather than to actual alterations in corneal rigidity.

Clinical Relevance: Orthokeratology (OK) lens is commonly used to control myopia progression of children. Understanding the relationship between relative peripheral refraction (RPR) and the growth rate of axial length (AL) may assist in explaining myopic progression., Background: The aim of this work is to investigate the RPR in myopic children wearing OK lenses, and to evaluate its relationship with the growth rate of AL., Methods: RPRs of 31 children wearing OK lenses and 31 children wearing single-vision glasses were measured with multispectral refraction topography (MRT). MRT shows the total RPR (TRPR), RPR in the superior area (RPR-S), RPR in the inferior area (RPR-I), RPR in the temporal area (RPR-T) and RPR in the nasal area (RPR-N), respectively. It also shows RPR in the visual field of 15° (RPR-15), 30° (RPR-30) and 45° (RPR-45), respectively. RPRs in the visual field from 15° to 30°, 30° to 45° and 15° to 45° are recorded as RPR-(30-15), RPR-(45-30) and RPR-(45-15), respectively. According to the growth rate of AL, children wearing OK lenses were further divided into slow and fast growth groups., Results: TRPR, RPR-I, RPR-T, RPR-N, RPR-15, RPR-30, RPR-45, RPR-(30-15), RPR-(45-30), and RPR-(45-15) of children in the OK lens group were significantly smaller than in the control group (all P < 0.05). TRPR, RPR-N, RPR-15, RPR-30, RPR-45, RPR-(30-15), and RPR-(45-15) of the slow growth group were significantly smaller than in the fast growth group (all P < 0.05). The growth rate of AL were positively correlated with TRPR (R = 0.383, P = 0.040), RPR-N (R = 0.395, P = 0.034), RPR-30 (R = 0.408, P = 0.028), RPR-45 (R = 0.377, P = 0.044), RPR-(30-15) (R = 0.390, P = 0.036)., Conclusions: RPRs of children show relative myopic defocus after wearing OK lenses. Furthermore, the growth rate of AL is smaller with more negative RPR.

Myopia has significantly risen in East and Southeast Asia, and the pathological outcomes of this condition, such as myopic maculopathy and optic neuropathy linked to high myopia, have emerged as leading causes of irreversible vision loss. Addressing this issue requires strategies to reduce myopia prevalence and prevent progression to high myopia. Encouraging outdoor activities for schoolchildren and reducing near-work and screen time can effectively prevent myopia development, offering a safe intervention that promotes healthier habits. Several clinical approaches can be employed to decelerate myopia progression, such as administering low-dose atropine eye drops (0.05%), utilizing orthokeratology lenses, implementing soft contact lenses equipped with myopia control features, and incorporating spectacle lenses with aspherical lenslets. When choosing an appropriate strategy, factors such as age, ethnicity, and the rate of myopia progression should be considered. However, some treatments may encounter obstacles such as adverse side effects, high costs, complex procedures, or limited effectiveness. Presently, low-dose atropine (0.05%), soft contact lenses with myopia control features, and orthokeratology lenses appear as promising options for managing myopia. The measures mentioned above are not necessarily mutually exclusive, and researchers are increasingly exploring their combined effects. By advocating for a personalized approach based on individual risk factors and the unique needs of each child, this review aims to contribute to the development of targeted and effective myopia prevention strategies, thereby minimizing the impact of myopia and its related complications among school-aged children in affected regions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Tariq, Mobeen, Wang, Lin, Bao, Liu and Gao.)

Purpose: To investigate the variation trend of the treatment zone (TZ) during 12 months of Orthokeratology (Ortho-K) from the perspective of the treatment zone size (TZS), decentration (TZD) and the weighted Zernike defocus coefficient of the treatment zone (C weighteddefocus )., Methods: 94 patients were included in this retrospective study, who were fitted with a 5-curve vision shaping treatment (VST) lens (n = 44) or a 3-zone corneal refractive therapy (CRT) lens (n = 50). The TZS, TZD and C weighteddefocus up to 12 months were analyzed., Results: TZS (F(4,372) = 10.167, P＜0.001), TZD (F(4,372) = 8.083, P＜0.001) and C weighteddefocus (F(4,372) = 7.100, P＜0.001) were significantly increased with time during overnight Ortho-K treatment. The TZS increased sharply from 1 week to 1 month of overnight Ortho-K (F = 25.479, P <.001) and stayed smooth then. It showed growing tendency from 6 to 12 months (F = 8.407, P =.005). The TZD (F = 16.637, P <.001) and C weighteddefocus (F = 13.401, P <.001) increased significantly until 1 month and kept stable until 12 months (all P＞0.05). The univariant linear regression analysis showed that TZS of the last visit was correlated with baseline myopia (β = 0.219, P =.034). Also, the greater final C weighteddefocus was correlated with higher baseline myopia (β = -0.589, P＜0.001) and higher corneal astigmatism (β = -0.228, P =.007) at the onset of lens wear with the multiple linear regression., Conclusion: The TZS, TZD and C weighteddefocus kept stable after 1 month of Ortho-K while the TZS had an increasing trend after 6 months. Children with higher myopic eyes or higher corneal astigmatism at baseline tended to have smaller TZS and greater C weighteddefocus at 12 months., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Purpose: The aim of this study was to analyze the influence of corneal topography, contact lens parameters and degree of myopia on the treatment zone (TZ) and peripheral plus ring (PPR) size in orthokeratology., Methods: In this retrospective study the topographic zones of the right eyes of 106 patients (73 female, 22.16 ± 8.96 years) were analyzed in the tangential difference map of the Oculus Keratograph 5M (Oculus, Wetzlar, Germany). Using the MB-Ruler Pro 5.4 software (MB-Softwaresolutions, Iffezheim, Germany) the horizontal, vertical, longest, shortest diameters and area of the TZ; horizontal, vertical, total diameters and width of the PPR were measured. Correlations were determined between these zones and the subjects' baseline parameters (myopia; corneal diameter, radii, astigmatism, eccentricity, sagittal height; contact lens radii, toricity and total diameter) for three back optic zone diameter (BOZD) groups (5.5, 6.0 and 6.6 mm). A stepwise linear regression analysis was performed to test for TZ and PPR predictability., Results: In the group of BOZD 6.0 correlations were found between the amount of myopia and the short TZ diameter (r = -0.25, p = 0.025); the steep corneal radius and the vertical diameter (r = -0.244, p = 0.029), the longest diameter (r = -0.254, p = 0.023) and the area (r = -0.228, p = 0.042) of the TZ; the amount of astigmatism and PPR width (r = 0.266, p = 0.017); eccentricity of the steep corneal meridian and PPR width (r = -0.222, p = 0.047). BOZD correlated significantly positively with all zones (p < 0.05). The best prediction model (R 2  = 0.389) resulted with the TZ area as the outcome variable., Conclusion: The amount of myopia, topography and contact lens parameters influence TZ and PPR in orthokeratology. Describing the TZ by its area may provide the most accurate representation of its size., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Objective: To estimate the original corneal curvature after orthokeratology by applying a machine learning-based algorithm., Methods: A total of 497 right eyes of 497 patients undergoing overnight orthokeratology for myopia for more than 1 year were enrolled in this retrospective study. All patients were fitted with lenses from Paragon CRT. Corneal topography was obtained by a Sirius corneal topography system (CSO, Italy). Original flat K (K1) and original steep K (K2) were set as the targets of calculation. The importance of each variable was explored by Fisher's criterion. Two machine learning models were established to allow adaptation to more situations. Bagging Tree, Gaussian process, support vector machine (SVM), and decision tree were used for prediction., Results: K2 after one year of orthokeratology (K2 after ) was most important in the prediction of K1 and K2. Bagging Tree performed best in both models 1 and 2 for K1 prediction (R = 0.812, RMSE = 0.855 in model 1 and R = 0.812, RMSE = 0.858 in model 2) and K2 prediction (R = 0.831, RMSE = 0.898 in model 1 and R = 0.837, RMSE = 0.888 in model 2). In model 1, the difference was 0.006 ± 1.34 D (p = 0.93) between the predictive value of K1 and the true value of K1 (K1 before ) and was 0.005 ± 1.51 D(p = 0.94) between the predictive value of K2 and the true value of K2 (K2 before ). In model 2, the difference was -0.056 ± 1.75 D (p = 0.59) between the predictive value of K1 and K1 before and was 0.017 ± 2.01 D(p = 0.88) between the predictive value of K2 and K2 before ., Conclusion: Bagging Tree performed best in predicting K1 and K2. Machine learning can be applied to predict the corneal curvature for those who cannot provide the initial corneal parameters in the outpatient clinic, providing a relatively certain degree of reference for the refitting of the Ortho-k lenses., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Purpose: The aim of this study was to evaluate the short-term effects of peripheral gradient high-addition multifocal soft contact lenses (MFSCLs) and orthokeratology (Ortho-K lenses) on visual performance in myopic children., Methods: Thirty myopic children participated in this prospective study. Each participant wore different sets of lenses in the following sequence: single-vision spectacles (SVSPs) as a control, MFSCLs and Ortho-K lenses. Ocular aberrations, topography, high-contrast visual acuity (HCVA), low-contrast visual acuity (LCVA) and accommodation of the right eye were measured with each type of correction on a different day., Results: Compared with SVSPs, high-addition MFSCLs and Ortho-K lenses significantly increased all items of aberrations (all p < 0.05) except trefoil (p = 0.17). MFSCLs induced less coma, root mean square of the third-order aberration (RMS3) and higher order aberrations than Ortho-K lenses (all p < 0.05). No significant difference in HCVA was found across the three correction types (F = 1.19, p = 0.39). In terms of LCVA, MFSCLs performed significantly poorer than SVSPs (difference, 0.16 logMAR; p = 0.001) and slightly worse than Ortho-K lenses (difference, 0.08 logMAR; p = 0.35). No significant difference in decentration was found between the two types of contact lenses, and no associations were observed between decentration and visual acuity at both high- and low-contrast levels (all p > 0.05). For MFSCLs, decentration was positively related to coma (r = 0.43, p = 0.02) and RMS3 (r = 0.44, p = 0.02), which was not the case for Ortho-K lenses. Accommodative facility was worse with MFSCLs than Ortho-K lenses (p = 0.001)., Conclusion: Multifocal soft contact lenses differed from Ortho-K lenses in aberration profile and LCVA, although decentration was similar. Decentration <1 mm had minimal influence on both HCVA and LCVA for either type of correction, but significantly increased third-order aberrations for MFSCLs, but not Ortho-K lenses., (© 2023 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Background: Home confinement during the epidemic has a significant impact on the lifestyle and behavior of school-aged children, who have exhibited an increase in the prevalence and development of myopia. Our research will look at if home confinement will affect school-aged children on myopia control with orthokeratology., Method: Data on axial length was gathered from school-aged children who had received OK lenses treatment. The entire data was separated into subgroups based on gender, age, and initial refraction, and the AL changes for each period were calculated using the formula defined in our study. Finally, the acquired data will be examined using various statistical approaches, and the ideas of slow, moderate, and rapid myopia progression will be applied to our study., Result: A total of 258 study subjects met the requirements to be included in the study. We discovered that the percentage of rapid myopia growth increased during the epidemic. In addition, the AL changes before and during the epidemic were found to be statistically significant in 171 subjects in the overall data. (P = 0.041) In the high age group, the AL changes before and during the epidemic、(P = 0.033) before and after the epidemic (P = 0.023) were found to be statistically significant. The AL changes before and during the epidemic (P = 0.035) were shown to be statistically significant in the moderate myopia group. Finally, we did not find statistically significant results for other groups., Conclusion: We cannot conclude that home confinement did have a negative impact on myopia control with orthokeratology in school-aged children. But we found there was an increase in the percentage of patients with OK treatment that had fast myopia progression during the confinement. We also observed that older children with higher initial refraction were more likely to be affected by home confinement., (© 2023. The Author(s).)

Objective: To determine changes in various ocular parameters of adults wearing orthokeratology (ortho-k) lenses and their levels of satisfaction and quality of life (QoL) after commencing treatment., Methods: Adults aged 18-38 years, with mild to moderate myopia and astigmatism < 1.50D, were wearing ortho-k lenses for one year. Data collection, which included history taking, refraction, axial length (AL), corneal topography, corneal biomechanics, and biomicroscopy examination, was performed at baseline and every 6 months during the study period. The level of satisfaction with the treatment and QoL was determined via questionnaires., Results: Forty-four subjects completed the study. AL was shortened significantly at the 12-month visit: AL -0.03 (-0.45 to 0.13) mm compared to baseline (p < 0.05). A significant number of subjects in both groups presented with overall and central corneal staining, but the majority were mild (Grade 1). Central endothelial cell density was reduced by 40/mm 2 (loss rate 1.4 %) (p < 0.05). High scores were obtained in the satisfaction questionnaire, with no significant differences between visits. At the 12-month visit, NEI-RQL-42 total score, dependence on correction, activity limitation, appearance, and satisfaction with the treatment all significantly increased compared to baseline values., Conclusions: Results suggest that ortho-k can be an effective and safe myopia correction technique for adults with low to moderate myopia, improving daytime vision without serious adverse events. Satisfaction with ortho-k lens wear was high, particularly those who were dependent on vision correction and found spectacles or contact lenses limiting specific activities or cosmetically undesirable., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To develop and validate an ideal nomogram and an online calculator for predicting rapid myopia progression risk in children managed with orthokeratology (ortho-k)., Methods: Data of children undergoing ortho-k treatment at Shanghai Children's Hospitals between January 2018 and April 2021 were retrospectively assessed. Potential predictors were screened using univariable analyses and a bidirectional stepwise procedure based on Akaike's information criterion. The final model was constructed using multivariable logistic regression and validated using an internal validation cohort. A nomogram and an online calculator were used to present the final model., Results: In this retrospective study with 1051 eyes of 560 myopia patients, the training cohort included 735 eyes, and the validation cohort included 316 eyes. Among 11 potential predictors of rapid myopia progression considered, the following four variables identified as independent predictive factors were included in the nomogram: age (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.61-0.79), baseline spherical equivalent (OR, 1.53; 95% CI, 1.31-1.79), pupil diameter (OR, 0.56; 95% CI, 0.32-0.97), and horizontal visible iris diameter (OR, 0.57; 95% CI, 0.33-0.97). The mean concordance statistics for the training and validation cohorts were 0.705 (95% CI 0.664-0.747) and 0.707 (95% CI 0.639-0.774), respectively. The online calculator is publicly available (https://hycalculatoronline.shinyapps.io/dynnomapp/)., Conclusion: This study developed a simple-to-use nomogram and online calculator that predicted rapid myopia progression risk in children treated with ortho-k, who will likely benefit from early intervention and improved surveillance.

Purpose: To evaluate the relative efficacy of peripheral defocus contact lenses (PDCLs) and orthokeratology (OK) in a real-world clinical population, and compare these results with previous randomised controlled clinical trials., Methods: Records from a university practice were reviewed to identify children who were treated with OK or PDCLs. The analysed sample contained 273 visits from 77 patients. Annualised rates of axial length (AL) progression were calculated and used as the response variable in both linear mixed-effects (LME) and nonlinear regression models., Results: On average, children were 10.7 years of age at baseline (p = 0.14 between treatments), and most patients were female. More Asian children wore OK lenses compared with PDCLs (p < 0.01). At baseline, children had ~3.00 D of myopia and 0.75 D of astigmatism in both treatment groups (p > 0.20 between treatments). LME regression models using only baseline covariates showed no evidence that the annualised change in AL differed between treatments, with or without the inclusion of age, race, sex, baseline AL or spherical equivalent refractive error. Across all possible subsets of models, age at baseline was the best predictor of annualised AL change. There was no statistical difference between parameters of an exponential decay model fitted within treatment using follow-up age as a time-varying predictor, indicating that the rate of annualised change in AL was similar for OK and PDCL., Conclusions: Retrospective analysis of real-world clinical data found no difference in annualised AL growth between PDCL and OK. Importantly, the AL progression from this clinical setting is consistent with that reported in randomised clinical trials. Therefore, continued research of real-world performance is warranted to understand the safety and efficacy of modern myopia control treatments in the broader population., (© 2023 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Purpose: To investigate the correlation between spatial corneal power distribution and one-year axial length (AL) elongation using three ortho-k lens designs by a unified mathematical method., Methods: A total of 137 subjects were included: 42 with Euclid lenses, 28 with DRL lenses, and 67 with CRT lenses. AL elongation, Xmax, Ymax and power exponent were compared among the three groups. One-year relative corneal refractive power change (RCRPC) was calculated by a polynomial function and a monomial function. Factors including age, baseline spherical equivalent refractive error (SER), Xmax, Ymax and power exponent was tested against one-year AL growth in a stepwise multiple linear regression model., Results: The power exponent (F = 7.29, P = 0.0012) and Xmax (F = 62.88, P < 0.0001) of the DRL group was significantly smaller than that of the other two lens groups. Ymax was not significantly different among three lens groups (F = 1.18, P = 0.31). The one-year AL elongation of the DRL group (0.09 ± 0.14 mm) was significantly slower than that of the Euclid group (0.26 ± 0.14 mm, P = 0.002) and CRT group (0.32 ± 0.18 mm, P < 0.0001). AL elongation was significantly correlated with Xmax (standardized β = 0.196, P = 0.003), power exponent (standardized β = 0.644, P < 0.001), and age (standardized β = -0.263, P < 0.001), with R 2 being 0.608., Conclusion: A smaller and more aspheric treatment zone may be beneficial for reducing axial elongation in children undergoing ortho-k treatment, regardless of their baseline myopic refractive error., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To investigate changes in peripheral and relative peripheral refraction (RPR) during orthokeratology lens (OKL) use in children, and predictors for myopia progression in a randomized controlled trial., Methods: Refraction and axial length (AL) were measured at baseline, 6, 12, and 18 months for children aged 6-12 years, with myopia of 0.5 to 4.75 dioptres (D) spherical component randomized to either OKL or single-vision spectacles (SVS) at baseline. Cycloplegic spherical equivalent refractive error (SEQ) was measured on-axis and eccentric at 10°, 20°, and 30° during nasal and temporal gaze in the horizontal plane with Shin-Nippon Nvision-K 5001. RPR was computed as SEQ (eccentricity) minus SEQ (on axis) . AL was measured with Lenstar LS900., Results: Twenty-one and 28 subjects from the OKL and SVS groups, respectively were available for analysis. OKL wear induced significant myopic RPR at all eccentricities (p ≤ 0.004) whereas peripheral refraction only changed in two out of six eccentric measuring points. Baseline peripheral refraction SEQ at all eccentricities, baseline on-axis SEQ, and baseline RPR at 30° nasal eccentricity were positively correlated to treatment efficacy defined as change in AL., Conclusion: We found no correlations between change in RPR and treatment efficacy defined as change in AL. Interestingly, our results suggest that the central emmetropisation that occurs during OKL-use accounts for most of the optical changes and to a lesser extent the mid-peripheral plus-zone of the lens., (© 2022 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Purpose: To investigate changes in the corneal volume, corneal densitometry and pachymetry of young myopes wearing over-night orthokeratology (OK) contact lenses., Methods: The medical records of 28 right eyes of young myopes wearing OK between 2013 and 2018 were reviewed retrospectively. The baseline refractive error, best corrected visual acuities at baseline and uncorrected visual acuity at the most recent visit were recorded. Corneal volume of the central 10 mm cornea; densitometry at central, nasal and temporal cornea; and pachymetry along the horizontal and vertical meridians were collected from the Pentacam® HR at baseline, after one night of lens wear, and at the latest visit., Results: The mean age of subjects was 12.03 ± 3.80 years at the time of OK lens fitting and wore OK overnight for a mean duration of 666 days (range 206-1736 days). The baseline spherical equivalent refractive error was -3.03 ± 1.56 D (range -1.00 to -6.00 D). The corneal volume increased significantly after OK wear (p = 0.001). Corneal densitometry increased after OK wear, but the change did not reach statistical significance (p = 0.113). Pachymetry in the central cornea did not change significantly across all visits (p > 0.05) but increased significantly in the mid-peripheral regions of the cornea. Baseline refractive error was not found to be correlated with the changes in corneal volume, corneal densitometry, or pachymetry., Conclusion: The increase in corneal volume and densitometry and no significant change in the central corneal thickness may indicate the presence of corneal oedema from long-term OK wear. The baseline refraction was not correlated with the changes in corneal volume, densitometry or pachymetry., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

Purpose: This study aimed to evaluate binocular vision in terms of vergence and accommodative measurements in children treated with 0.01% atropine combined with orthokeratology (OK)., Methods: This was a prospective and randomized controlled clinical trial involving participants aged 8 to 12 years, with a spherical equivalent (SE) ranging from - 1.00 to - 6.00D. Participants were randomly divided into four groups: 1) a combination group using 0.01% atropine solution and OK lens; 2) an OK group using placebo solution and OK lens; 3) an atropine group using 0.01% atropine solution and wearing spectacles; and 4) a control group using placebo solution and wearing spectacles. Binocular vision was determined at baseline and at 3-month visits, with evaluations including horizontal phoria, fusional vergence, the accommodative convergence/accommodation (AC/A) ratio, accommodative lag, and accommodative amplitude (AA). The Wilcoxon signed-rank test was used to compare the changes in binocular vision in each group, and the Kruskal-Wallis test was used for comparisons of four groups., Results: Sixty-two participants completed the study. There was no significant difference in baseline refraction, accommodation or vergence measurements among the groups (all P > 0.05). Three months later, the accommodative lag significantly decreased in the OK group (P = 0.002) but remained unchanged in the other three groups (all P > 0.05). In addition, binocular accommodative facilities and positive relative accommodations increased in the combination and OK groups (both P < 0.05) but remained unchanged in the atropine and control groups (both P > 0.05). Only the participants with esophoria in the OK group had a significant decrease in esophoria (P = 0.008). Moreover, the changes in fusional vergence and AC/A did not significantly differ between the four groups (all P > 0.05)., Conclusion: Accommodative measurements changed similarly in the groups treated with OK. Changes in vergence measurements after treatment with 0.01% atropine were not significant., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To investigate the effects of overnight orthokeratology (OK) lenses wear on the interocular axial length (AL) difference in anisomyopic children., Methods: Sixty anisomyopic children (8-14 years old) were enrolled in this one-year prospective, randomised controlled study. Subjects were randomly assigned to wear OK lenses (OK group) or single-vision spectacles (control group). AL was monitored at baseline and every six months using an IOL Master biometer, and axial elongation and interocular AL differences were compared between the groups., Results: In the control group, the more myopic eyes had similar axial elongation (0.36 ± 0.17 mm) to the less myopic eyes (0.37 ± 0.17 mm) at the one-year follow-up (P > 0.05). In the OK group, the less myopic eyes exhibited significantly greater axial elongation (0.24 ± 0.17 mm) than the more myopic eyes (0.13 ± 0.13 mm) at the one-year follow-up (P < 0.05). The mean interocular AL difference significantly decreased in the OK group over one year, from 0.47 ± 0.24 mm to 0.35 ± 0.22 mm (P < 0.05). However, the mean interocular AL difference decreased only slightly in the control group, from 0.56 ± 0.28 mm to 0.55 ± 0.28 mm (P > 0.05)., Conclusion: This randomised, controlled study demonstrated that OK reduces the interocular AL difference in anisomyopic children due to stronger myopic control of the more myopic eye., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Ltd.)

Purpose: To compare axial elongation, relative corneal refractive power (RCRP) distribution within the pupillary diameter, and corneal higher-order aberrations (HOAs) in myopic children wearing orthokeratology (ortho-k) lenses with different back optic zone diameters (BOZD)., Methods: Children aged 8-11 years were fitted with 5.0 or 6.2 mm-BOZD ortho-k lenses (groups A and B, respectively). Axial length (AL) and corneal topography were measured at baseline and during the annual visit. RCRP and corneal HOAs were compared between the two groups after one-year treatment. Multivariate linear regression analysis was performed to determine the association between AL elongation and RCRP parameters, corneal HOAs, and other variables between the groups., Results: After one-year treatment, axial elongation was slower in group A than in group B, with a difference of 0.15 mm. Children in group A showed smaller treatment zone size, smaller 3/4X value (describing the distance from the apex RCRP profile rising to its three-quarter-peak level), greater RCRP sum value within the pupillary area, and higher increases in corneal total HOAs and horizontal coma (Z 3 1 ). AL elongation was significantly correlated with baseline age, baseline spherical equivalent refraction (SER), treatment zone size, and 3/4X value., Conclusions: Ortho-k lenses designed with smaller BOZD increased myopia control efficacy, induced a steeper distribution of the RCRP profile within the pupillary diameter, and induced greater increases in corneal total HOAs and horizontal coma (Z 3 ). Lens-induced RCRP profile within pupillary diameter, rising to its three-quarter-peak level at a smaller distance, may show a better myopia control effect.1 ). Lens-induced RCRP profile within pupillary diameter, rising to its three-quarter-peak level at a smaller distance, may show a better myopia control effect., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: To investigate whether combining 0.01% atropine with orthokeratology (AOK) has a better effect in retarding axial elongation, compared with orthokeratology alone (OK) over two years., Methods: A total of 96 Chinese children aged six to < 11 years with myopia (1.00 - 4.00 D, inclusive) were randomized into either the AOK or OK group in a 1:1 ratio. Axial length (the primary outcome), and secondary outcomes (e.g. pupil size and choroidal thickness) were measured at 1-month and at 6-monthly intervals after commencement of treatment., Results: Both intention-to-treat and per-protocol analyses showed significantly slower axial elongation in the AOK group than OK group over two years (P = 0.008, P < 0.001, respectively). AOK subjects had statistically slower axial elongation (adjusted mean [standard error], 0.17 [0.03] mm vs 0.34 [0.03] mm, P < 0.001), larger increase in mesopic (0.70 [0.09] mm vs 0.31 [0.09] mm, P = 0.003) and photopic pupil size (0.78 [0.07] mm vs 0.23 [0.07] mm, P < 0.001), and greater thickening of the choroid (22.6 [3.5] µm vs -9.0 [3.5] µm, P < 0.001) than OK subjects over two years. Except for a higher incidence of photophobia in the AOK group (P = 0.006), there were no differences in the incidence of any other symptom or adverse events between the two groups. Slower axial elongation was associated with a larger increase in the photopic pupil size and a greater thickening in the choroid in the AOK group., Conclusions: Slower axial elongation following 2-year AOK treatment may result from increased pupil dilation and a thickening in the choroid observed in the AOK group., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: There are limited reports available on the impact of wearing Orthokeratology (ortho-K) lenses on the quality of life of Asian children. This study evaluated and compared vision-related quality of life (VRQoL) between myopic children wearing ortho-K lenses and single-vision spectacles (SVSs), living in Kuala Lumpur, using Paediatric Refractive Error Profile (PREP) questionnaires., Methods: This is a cross sectional study. Myopic children who had been wearing ortho-K and SVSs for 12 months were recruited, and the questionnaires were distributed online. The PREP scores were obtained using a summary scoring method. The Shapiro-Wilk test was used to determine data normality. Unpaired t-test was performed for normally distributed data, and the Mann-Whitney test for non-normally distributed data. P < 0.05 was considered significant., Results: A total of 70 subjects participated in this study (45 ortho-K and 25 SVSs), with a mean age of 10.86 ± 0.73 years. The mean scores for all the items were higher in ortho-K than SVS wearers (p < 0.05). With regard to symptoms during ortho-K lens wear at night, <10 % of the subjects reported difficulty falling asleep, itch/burning/dry eyes and foreign body sensation after lens insertion., Conclusion: Ortho-K improves the vision-related quality of life of myopic school children in Kuala Lumpur. Thus, it should be considered by more local optometrists when managing myopic children., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: To determine the frequency and severity of ocular symptoms and signs in new orthokeratology (ortho-k) subjects using a povidone iodine (PI) disinfecting system compared to those present before lens wear, and whether these were associated with cleaning regimes., Methods: This study recruited 80 subjects from two myopia control studies, who used a PI disinfecting solution for routine use. Ocular symptoms and signs at baseline, one- and six-month after lens wear were reported via questionnaires and ocular examination, respectively. To determine if rates of occurrence were attributable to differences in cleaning regime, subjects were randomly assigned into four groups with respect to routine care procedures, which involved various combinations of rubbing and use of a daily and/or enzymatic cleaner., Results: Sixty-eight subjects completed all aspects of the study. As there were no significant differences in incidence of signs and symptoms between the four groups before and after lens wear (Friedman tests, p > 0.07), data were combined for further analysis. Prior to lens wear, itchiness (69 %) and dryness (53 %) were the most commonly reported symptoms. The frequency and severity of all symptoms remained similar after lens wear (p > 0.10). Presence of follicles in the lower tarsal conjunctiva (22 %) and conjunctival injection (15 %) was frequently observed, but reduced significantly after lens wear (p < 0.01). Mild corneal staining, noted in 13 % of subjects at baseline, did not change significantly over time (p = 0.17). Ocular signs were not necessarily reflected in symptoms and vice versa., Conclusion: Use of a PI-based solution did not increase the frequency or severity of ocular signs and symptoms observed before lens wear. Absence of a difference in occurrence of ocular discomfort with respect to cleaning regimes indicated that the use of the PI-based solution may adequately clean the lenses over a 6-month period., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: To investigate the effectiveness of orthokeratology (ortho-k) lenses and corneal changes with increased compression factor for myopia control over a 2-year period., Methods: Young participants (age: 6-<12 years), with low myopia (0.50-4.00 D) and low astigmatism (≤1.25 D), were recruited and allowed to choose to wear either single-vision spectacles or ortho-k lenses (randomly assigned to compression factor of either 0.75 or 1.75 D). Axial length and cycloplegic refraction were measured at six monthly intervals for two years by a masked examiner. The myopia control effectiveness was determined by axial elongation., Results: A significant number of control (63 %) dropped out, mainly due to concern about myopia progression (58 %). A total of 75 participants (mean age: 9.3 ± 1.0 years; control: n = 11, ortho-k [0.75 D]: n = 29, ortho-k [1.75 D]: n = 35) completed the study. Considering ortho-k groups only, the mean axial elongation of participants wearing ortho-k lenses of conventional compression factor (0.75 D) and increased compression factor (1.75 D) were 0.53 ± 0.29 and 0.35 ± 0.29 mm, respectively, over the 2-year study period. The between-group differences in corneal health were not significant at all visits., Conclusion: Participants wearing ortho-k lenses of increased compression factor further slowed axial elongation by 34%, when compared with the conventional compression factor without compromising corneal health. Further investigations are warranted to confirm the potential mechanism of an increased compression factor for improved myopia control effectiveness., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To investigate the relationship between myopia progression and axial length (AL) elongation in orthokeratology (ortho-k) patients., Methods: This study investigated 184 patients (baseline age 9.0 ± 1.6 years), who underwent overnight ortho-k treatment for 12 to 72 months, and stopped lens wear for 1 to 2 months. Refractive sphere and cylinder after cycloplegia, corneal curvatures along both meridians, and AL were compared before the commencement and after discontinuation of ortho-k treatment. The effects of AL change, baseline AL, corneal curvature change, baseline age, and duration of ortho-k treatment on the change in spherical equivalent refractive error (SER) were analysed., Results: Myopia significantly progressed and AL increased following 32.8 ± 13.0 months of ortho-k lens wear and 1 to 2 months washout period, as compared to baseline (all P < 0.001). Corneal curvature along the flat meridian (FK) became significantly flatter (P < 0.001) and corneal curvature along the steep meridian (SK) became steeper (P = 0.036). In the first stepwise multiple linear regression model (R 2  = 0.696), the change in SER over time (ΔSER) is significantly correlated to the change in AL (ΔAL, P < 0.001), baseline AL (P < 0.001), baseline age (P = 0.028), change in SK (P = 0.002), and the duration of ortho-k lens treatment before discontinuation (P = 0.010). In a more simplified model (R 2  = 0.628), the regression equation using ΔAL to predict ΔSER is: ΔSER = -0.094-1.608*ΔAL., Conclusions: The change in SER was significantly correlated to the change in AL, change in SK, baseline AL, baseline age, and the duration of treatment among children undergoing ortho-k therapy. The ratio of axial elongation to myopia progression was approximately 1:1.6 between the ages of 6 to 14 years. A simplified equation was derived for clinical use to estimate myopia progression from repeated AL measurement in ortho-k patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Ltd.)

Purpose: This study compares the trends of changes in corneal asphericity, corneal and total aberrations and peripheral refraction in myopic eyes after excimer laser and orthokeratology correction., Material and Methods: Aberrometry (OPD-Scan III; Nidek, Japan) was performed in 63 patients (126 eyes) with moderate and high myopia before and after femtosecond laser-assisted in situ keratomileusis (Femto-LASIK; 88 eyes, group 1) and photorefractive keratectomy (PRK; 38 eyes, group 2). Peripheral refraction (Grand Seiko AutoRef/Keratometer) at 15° and 30° from the center of the fovea was observed in 12 patients of group 1 and in 18 patients with a background of orthokeratology correction (group 3)., Results: Corneal asphericity factor Q transitioned to positive values after PRK and Femto-LASIK. Corneal aberrations: root mean square higher order aberration (RMS HOA) increased in both groups, Tilt 1 increased in group 1 and became negative in group 2, Tilt 2 increased in group 2 and went negative in group 1. Trefoil 6 did not change in group 1 and decreased in group 2. Coma 7 and 8 increased synchronously in both groups. Spherical aberrations (SA) increased in group 1, and went negative in group 2. Total aberrations changed to a lower degree, and these changes were not synchronous with the corneal ones; RMS HOA decreased in group 1 (while corneal RMS increased significantly), and in the PRK group it increased, but much less than the corneal. Total SA increased in group 1 and did not change in group 2. Peripheral myopic defocus formed in all cases, after Femto-LASIK the maximum was in the zone of 30º, after orthokeratology lenses - in the zone of 15º., Conclusion: Using excimer laser and orthokeratology to reshape the cornea in full accordance with its different profiles have different effects on the wavefront and peripheral refraction of the eye. The internal optics of the eye partially compensates corneal aberrations induced by the excimer laser.

Clinical Relevance: Understanding the impact of home confinement on axial length in myopic children undergoing orthokeratology (OK) treatment facilitates the management of myopia control during coronavirus disease 2019 (COVID-19) lockdown., Background: The outbreak of COVID-19 and the corresponding home confinement measures have brought a considerable challenge to myopia control. The study aimed to investigate the influence of home quarantine on axial length in myopic children with OK treatment., Methods: Axial length measurements during and before COVID-19 home confinement were retrospectively collected from the myopic children treated with OK, and the children were prospectively followed up after finishing the quarantine. The monthly axial length growth before, during and after confinement was calculated and compared in the full dataset and subgroups stratified by age. Influencing factors for monthly axial length growth during confinement were analysed., Results: Ninety-two myopic children with OK treatment were enrolled in this study. In the full dataset, covariates adjusted (gender, time interval, baseline axial length and age) monthly axial length growth during confinement was not significantly different from that before ( P = 0.213) or after the home confinement ( P = 1.000). Multiple linear regression showed that the monthly axial length growth during confinement was negatively correlated with age ( P = 0.002). Subgroup analysis based on age demonstrated that the adjusted monthly axial length growth was not significantly different among three periods ( P > 0.05) for younger children. For children older than 12-year-old, the adjusted monthly axial length growth during home confinement was significantly slower than before the confinement ( P = 0.011), but not the monthly axial length growth after the confinement ( P = 1.000)., Conclusions: COVID-19 home confinement does not increase the myopic axial length elongation in children with OK treatment.

Objective: To evaluate the effects of long-term wear and discontinuation of the orthokeratology lenses (Orth-K) on the biological parameters of eyeballs in children with myopia. Methods: In this prospective study, a total of 308 subjects with myopia were randomized to receive Orth-K (n = 154) or single vision spectacles (SVS) (n = 154) for 12 months followed by a 1-month withdrawal period. The axial length (AL), the central corneal thickness (CCT), the anterior chamber depth (ACD) and the central lens thickness (CLT) were assessed at the baseline, 6 months, 12 months, and 13 months (1-month after lens withdrawal). Results: A total of 279 subjects completed the 13-month follow-up (142 in Orth-K group and 137 in SVS group). No statistical difference was noted in AL, CCT, ACD and CLT between the two groups at the baseline (all p > 0.05). However, compared with the baseline, the AL from the two groups became elongated 12 months after wearing Orth-K or SVS. The increase of AL in Orth-K group was 0.22 ± 0.11 mm, significantly smaller than 0.35 ± 0.08 mm in SVS group (p < 0.05). In addition, CCT in Orth-K group was 544.26 ± 11.69 µm at 12 months, significantly thinner than 550.49 ± 12.13 µm in SVS group (p < 0.05). Interestingly, the change in CCT between the baseline and 1-month after withdrawal of the lens was not statistically different in either group (all p > 0.05). Furthermore, at 12-months, CLT in Orth-K group was 3.35 ± 0.21 mm, significantly thicker than 3.31 ± 0.15 mm at baseline and thicker than 3.30 ± 0.05 mm in SVS group at 12 months (all p < 0.05). Lastly, ACD was not statistically different between Orth-K and SVS groups at any time point (p > 0.05). Conclusion: Orthokeratology lenses can effectively retard axial elongation, reversibly reduce CCT, increase CLT in myopic children, but have no obvious effect on ACD, indicating that Orth-K may significantly retard myopia without noticeable myopia rebound after interruption of Orth-K., Competing Interests: Competing interests: The authors have declared that no competing interest exists., (© The author(s).)