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To investigate the efficacy and safety of repeated low-level red-light (RLRL) therapy combined with orthokeratology among children who, despite undergoing orthokeratology, exhibited an axial elongation of at least 0.50 mm over 1 year. Multicenter, randomized, parallel-group, single-blind clinical trial (ClinicaTrials.gov identifier, NCT04722874). Eligible children were 8–13 years of age with a cycloplegic spherical equivalent refraction of –1.00 to –5.00 diopters at the initial orthokeratology fitting examination and had annual axial length (AL) elongation of ≥0.50 mm despite undergoing orthokeratology. Forty-eight children were enrolled from March 2021 through January 2022, and the final follow-up was completed in March 2023. Children were assigned randomly to the RLRL therapy combined with orthokeratology (RCO) group or to the orthokeratology group in a 2:1 ratio. The orthokeratology group wore orthokeratology lenses for at least 8 hours per night, whereas the RCO group received daily RLRL therapy twice daily for 3 minutes in addition to orthokeratology. The primary outcome was AL change measured at 12 months relative to baseline. The primary analysis was conducted in children who received the assigned intervention and completed at least 1 follow-up after randomization using the modified intention-to-treat principle. Forty-seven children (97.9%) were included in the analysis (30 in the RCO group and 17 in the orthokeratology group). The mean axial elongation rate before the trial was 0.60 mm/year and 0.61 mm/year in the RCO and orthokeratology groups, respectively. After 12 months, the adjusted mean AL changes were –0.02 mm (95% confidence interval [CI], –0.08 to +0.03 mm) in the RCO group and 0.27 mm (95% CI, 0.19–0.34 mm) in the orthokeratology group. The adjusted mean difference in AL change was –0.29 mm (95% CI, –0.44 to –0.14 mm) between the groups. The percentage of children achieving an uncorrected visual acuity of more than 20/25 was similar in the RCO (64.3%) and orthokeratology (65.5%) groups (P = 0.937). Combining RLRL therapy with orthokeratology may offer a promising approach to optimize axial elongation control among children with myopia. This approach also potentially allows children to achieve satisfactory visual acuity, reducing daytime dependence on corrective eyewear. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article. [ABSTRACT FROM AUTHOR]

In 2019, an international survey was conducted to evaluate strategies and attitudes in the management of myopia in clinical practice worldwide. This study reports on the results found in Spain and how these results compare with those from other regions of the world. A self-administrated, internet-based questionnaire was distributed to eye care professionals around the world through professional associations. The questions examined were based on the available strategies and their use. A total of 173 Spanish optometrists, of the 1,336 practitioners from the five different continents who participated in the study, responded to the online survey. Spain, Asia and South America were found among the regions with the highest concern regarding the increased incidence of myopia (p ≤ 0.001). However, in these regions, the prescription of single-vision spectacles and single-vision contact lenses continues to be the main methods of visual correction prescribed to young myopic patients (p ≤ 0.001). Spanish practitioners, like those from other regions, considered orthokeratology to be the most effective treatment to control myopia progression (p ≤ 0.001). The major reasons why Spanish practitioners were not prescribing myopia control strategies were increased cost, inadequate information and unpredictable outcomes (p < 0.05). The uptake of myopia control methods by Spanish practitioners is relatively low, despite the increase in the prevalence of paediatric myopia as well as increased concern and perceived clinical activity in the area in recent years. [ABSTRACT FROM AUTHOR]

Background/purpose: Orthokeratology (Ortho-K), atropine eye drops and combined atropine with Ortho-K are proven to be effective ways to prevent myopic progression in many studies, but there is scarce evidence regarding the comparative efficacy of different dosages of atropine,Ortho-K, and combined atropine with Ortho-K for childhood myopia.Methods: We performed a network meta-analysis (NMA) to assess the relative efficacy of the aforementioned interventions for myopic progression; moreover, we calculated the surface under cumulative ranking area (SUCRA) to determine the relative ranking of treatments.Results: We identified 19 randomized controlled trials (3435 patients). NMA revealed that 0.01%-1% atropine, Ortho-K, and 0.01% atropine combined with Ortho-K inhibited axial elongation (AL) over one year. For refractive change, SUCRA analysis revealed that the hierarchy was high-dose (0.5%-1%), moderate-dose (0.1%-0.25%), and low-dose (0.01%-0.05%) atropine. Regarding AL, SUCRA analysis revealed the following hierarchy: Ortho-K combined with 0.01% atropine, high-dose atropine, moderate-dose atropine, Ortho-K, and low-dose atropine.Conclusion: In conclusion, we found that atropine (0.01%-1%), Ortho-K, and 0.01% atropine combined with Ortho-K could significantly slow down myopia progression. The atropine efficacy followed a dose-related pattern; moreover, Ortho-K and low-dose atropine showed similar efficacy. There was a synergistic effect of using 0.01% atropine combined with Ortho-K, and it showed comparable efficacy to that of high-dose atropine. [ABSTRACT FROM AUTHOR]

Rigid contact lenses have an important role in contact lens practice. The purpose of this work is to update earlier surveys by describing global trends in rigid lens fitting between 2000-2023. An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023. Data relating to 342,500 fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of rigid lens fitting, defined as the fitting of any design of a contact lens manufactured in a rigid material. Overall, rigid lens prescribing increased slightly over time, from 14.2 % of lens fits in 2000 to 15.2 % in 2023 (p < 0.0001). However, post-hoc analysis shows that the change over time is best described as a decline between 2000 and 2012, followed by a steady increase subsequently. There were significant differences in rigid lens prescribing between countries (p < 0.0001). The difference between the percentage of males fitted with rigid lenses, as a proportion of all contact lenses (12.7 %), and females (12.0 %) is significant (p < 0.0001), although not clinically meaningful. Rigid lens wearers are older at fitting than soft lens wearers (38.7 vs 31.3 years, respectively) (p < 0.0001). Analysis of 5,994 rigid lens fits prescribed currently (2019–2023) were categorised as: corneal sphere – 30 %; scleral and corneo-scleral – 28 %; corneal myopia control/orthokeratology – 21 %; and corneal complex (including toric, multifocal and monovision) – 16 %. There has been a slight increase in rigid lens fitting during the second decade of this century. This increase is apparently due to a 'repurposing' of rigid lenses, with the growth of scleral/corneo-scleral and myopia control/orthokeratology lens fits essentially replacing conventional spherical corneal lens fits. [ABSTRACT FROM AUTHOR]

To evaluate the efficacy of orthokeratology contact lens wear in slowing the axial elongation of the eye in myopic children. Data from three prospective studies, which evaluated the use of orthokeratology for slowing myopia progression in children in comparison to a parallel control group of distance, single-vision spectacle lens wearers over a 2-year period, were pooled together for analysis. Collectively, data from 125 orthokeratology and 118 control subjects were analyzed in this study. Of these, 101 (81 %) and 88 (75 %) orthokeratology and control subjects completed the 2-year follow-up period, respectively. Statistically significant differences in the change in axial length from baseline were found over time, between groups and for the time*group interaction (all p < 0.001), indicating that the rate of increase in axial length over time was significantly lower in the orthokeratology versus the control group. The lower axial elongation of the orthokeratology versus the control group was statistically significant at all time points (all p < 0.001), with significant differences being also present between each of the different pairs of time points (all p < 0.001). The interactions of group with age, gender, mean spherical refractive error and ethnicity at baseline were not significant (p > 0.05). The change in axial length at the 2-year visit in comparison to baseline for the orthokeratology and control groups were 0.41 ± 0.25 and 0.65 ± 0.30 mm, respectively, thus providing a treatment effect following 2-years of lens wear of 0.24 mm (95 % confidence intervals: 0.15 to 0.34 mm). About 40 % and 25 % of the orthokeratology subjects experienced remarkably low and high levels of myopia progression, respectively (2-years axial elongation: ≤0.30 mm and >0.59 mm, respectively). Orthokeratology lens wear slows the axial elongation of the eye in comparison to spectacle lens wear in myopic children. The use of these lenses for slowing myopia progression appears to be very effective and not effective at all in 40% and 25% of orthokeratology lens wearers, respectively. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

To compare the efficacy and safety between traditional lens fitting and computer-aided fitting methods for orthokeratology (OrthoK) in the Chinese population. 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. 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. 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. [ABSTRACT FROM AUTHOR]

Corneal techniques for enhancing near and intermediate vision to correct presbyopia include surgical and contact lens treatment modalities. Broad approaches used independently or in combination include correcting one eye for distant and the other for near or intermediate vision, (termed monovision or mini-monovision depending on the degree of anisometropia) and/or extending the eye's depth of focus [1]. This report reviews the evidence for the treatment profile, safety, and efficacy of the current range of corneal techniques for managing presbyopia. The visual needs and expectations of the patient, their ocular characteristics, and prior history of surgery are critical considerations for patient selection and preoperative evaluation. Contraindications to refractive surgery include unstable refraction, corneal abnormalities, inadequate corneal thickness for the proposed ablation depth, ocular and systemic co-morbidities, uncontrolled mental health issues and unrealistic patient expectations. Laser refractive options for monovision include surface/stromal ablation techniques and keratorefractive lenticule extraction. Alteration of spherical aberration and multifocal ablation profiles are the primary means for increasing ocular depth of focus, using surface and non-surface laser refractive techniques. Corneal inlays use either small aperture optics to increase depth of field or modify the anterior corneal curvature to induce corneal multifocality. In presbyopia correction by conductive keratoplasty, radiofrequency energy is applied to the mid-peripheral corneal stroma, leading to mid-peripheral corneal shrinkage and central corneal steepening. Hyperopic orthokeratology lens fitting can induce spherical aberration and correct some level of presbyopia. Postoperative management, and consideration of potential complications, varies according to technique applied and the time to restore corneal stability, but a minimum of 3 months of follow-up is recommended after corneal refractive procedures. Ongoing follow-up is important in orthokeratology and longer-term follow-up may be required in the event of late complications following corneal inlay surgery. [ABSTRACT FROM AUTHOR]

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). 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. 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). 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. [ABSTRACT FROM AUTHOR]

To compare the effectiveness of myopia control in Chinese children, who had been wearing either orthokeratology (ortho -k) lenses or myopia control spectacles (MCS) for one year. Relevant data were retrieved from 212 patients, with baseline myopia of −5.00 to −0.75 D, astigmatism ≤ 1.50 D, who had been undergoing myopia control treatment with either ortho -k (Euclid (OK1) or CRT (OK2)) or MCS (Stellest (MCS1) or DIMS (MCS2)) for at least one year. Myopia control effectiveness among the four groups was compared based on the change in spherical equivalent refraction (SER) (for the spectacle groups) and axial length (AL) (for all groups). Data retrieved, from the right eye only, included best corrected visual acuity (BCVA), SER, and AL at both the initial clinic visit (baseline) and the one-year visit was analysed. Although no significant differences in gender, cylindrical power, or BCVA were observed at the baseline visit (P > 0.05), there were significant differences in baseline age, myopia, and AL among the four groups (P < 0.05). No significant difference in axial elongation (AE) was found among the four groups after one year of treatment (P = 0.49). AE, adjusted for baseline age and spherical power, were 0.19 ± 0.15, 0.18 ± 0.14, 0.19 ± 0.19, 0.20 ± 0.18 mm for OK1, OK2, MCS1, MCS2, respectively. Only age was a significantly factor associated with AE and SER increase (P < 0.05), with negative associations between AE and age in all groups and positive association between SER increase and baseline age in the spectacle groups observed. Both brands of ortho -k lenses and MCS had similar myopia control effectiveness for mild to moderate myopic children treated in a real-world setting in China. Average AE in one year ranged from 0.18 to 0.20 mm, comparable to previous reports on myopia control using ortho -k. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

To assess accommodation and spherical aberration changes during one year of orthokeratology lens wear and one month after lens cessation. A prospective, randomized, longitudinal study was conducted on forty-seven young healthy subjects at the Optometry Clinic of the Complutense University of Madrid (Spain). Non-cycloplegic refraction, high and low uncorrected visual acuity, high and low best corrected visual acuity, accommodative lag, horizontal near phoria, corneal topography, and high-order aberrations were performed at baseline, 1-day, 1-week, 1-, 6- and 12-months of lens wear and after one month of wash out period. p < 0.05 was considered as statistically significant. Spherical equivalent refraction (SE) was −3.23 ± 1.57D at baseline and –0.36 ± 0.64D after 12-months of lens wear, while accommodative lag changed from 0.53 ± 0.39D to 0.15 ± 0.29D after one year of lens wear. No significant differences were found when comparing SE at baseline and after one month of lens cessation (p > 0.05). A high correlation was found between the accommodative lag at baseline and after 12 M of lens wear. 22 out of 25 subjects with exophoria at baseline showed a significant reduction in the deviation at 12-months (p < 0.05). Total spherical aberration increased during all visits due to the lens wear (p < 0.05) although internal spherical aberration showed a significant decrease for 1-week, 1-month and 12-month visits (p < 0,05). Orthokeratology lenses may change the accommodative response of the patient as a reduction on accommodative lag on exophoric patients and an overall increase on the internal spherical aberrations was found during treatment but return to nearly baseline values when cessation. [ABSTRACT FROM AUTHOR]

Background: The effectiveness of orthokeratology in retarding anisometropic progression has been investigated in several small-sample studies. This quantitative analysis aimed to elucidate the efficacy of orthokeratology for anisometropia control.Methods: We searched PubMed, Embase, and Cochrane databases for relevant studies through September 2020. Axial length (AL) data at baseline and final follow-up were extracted, and AL elongation and difference were calculated. Methodological quality was evaluated using the risk of bias in non-randomized studies of interventions (ROBINS-I) tool. Meta-analyses were performed using a fixed-effect model based on the heterogeneity.Results: A total of 10 cohort studies (nine retrospective studies; one prospective study) were included. The pooled results for the unilateral myopia group showed that the mean AL elongation difference between myopic and emmetropic eyes was -0.27 mm (95% CI, -0.31 to -0.22; p < 0.01) at the one-year follow-up (four studies) and -0.17 mm (95% CI, -0.33 to -0.02; p = 0.03) at the two-year follow-up (two studies). In the bilateral anisomyopic group, mean AL elongation difference between high and low myopic eyes was -0.06 mm (95% CI, -0.09 to -0.04; p < 0.01) at the one-year follow-up (seven studies) and -0.13 mm (95% CI, -0.21 to -0.06; p < 0.01) at the two-year followup (three studies).Conclusion: This study demonstrated that orthokeratology can effectively retard myopic progression and reduce anisomyopic values. However, additional wellstructured randomized controlled trials or prospective studies with longer follow-up periods are warranted to address this topic in more detail. [ABSTRACT FROM AUTHOR]

[Display omitted] To develop gold nanoparticles-loaded contact lens ("GoldinLens") to bind a significant mass of cystine on the surface of the gold nanoparticles (GNPs) for cystinosis treatment due to the reaction between cystine and gold. The GoldinLens was manufactured by synthesizing GNPs inside the preformed contact lens matrix by first loading the lenses (Moist and TrueEye) with gold precursor followed by reduction (with sodium borohydride or trisodium citrate) to gold atoms, which nucleated to GNPs inside the polymeric matrix. The lenses were characterized by SEM, XRD, UV–Vis spectroscopy and mass of GNPs loaded in the lens was determined by direct measurement of mass. Manufactured lenses were soaked in cystine solution for cystine uptake in vitro. Results show that gold loading in the contact lens increases linearly with gold precursor concentration and number of repetitions of the manufacturing process. The stronger reducing agent sodium borohydride resulted in higher gold loading, with the loading being higher in the Moist lenses due to higher diffusivity of the reducing agent into the lens. However, GNPs were smaller in size and relatively monodispersed in TruEye GoldinLens, resulting in higher cystine uptake of 47 μg/lens over 24 h (vs. 33 μg/lens for Moist GoldinLens). However, the rate of this uptake was higher for Moist GoldiLens (8.25 vs. 2.35 μg/h), with the maximum uptake occurring in one hour (vs. five hours). A method for manufacturing GoldinLens, wherein small gold nanoparticles are trapped in contact lenses, has been developed for drugless cystinosis treatment. The lenses withdraw cystine molecules from the surrounding milieu, with the TrueEye GoldinLens being superior for the extent of, while Moist GoldinLens is superior for rate of cystine removal. GoldinLenses of this study can be used for drugless cystine removal cystinosis treatment with one- or five-hour wear at a time. [ABSTRACT FROM AUTHOR]

In 2019, the American Academy of Ophthalmology (AAO) created the Task Force on Myopia in recognition of the substantial global increases in myopia prevalence and its associated complications. The Task Force, led by Richard L. Abbott, MD, and Donald Tan, MD, comprised recognized experts in myopia prevention and treatment, public health experts from around the world, and organization representatives from the American Academy of Family Physicians, American Academy of Optometry, and American Academy of Pediatrics. The Academy's Board of Trustees believes that myopia is a high-priority cause of visual impairment, warranting a timely evaluation and synthesis of the scientific literature and formulation of an action plan to address the issue from different perspectives. This includes education of physicians and other health care providers, patients and their families, schools, and local and national public health agencies; defining health policies to ameliorate patients' access to appropriate therapy and to promote effective public health interventions; and fostering promising avenues of research. [ABSTRACT FROM AUTHOR]

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. 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. The TZA was 12.90 ± 5.15 mm2 and 20.61 ± 4.54 mm2, 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). 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. [ABSTRACT FROM AUTHOR]

• The dynamic changes in DCRs of OK lens users were observed at various time points. • Most DCRs changes significantly within the initial 6 months after OK lenses usage. • The stability period for DCRs occurs later than for optometry parameters. • Minimal variation in DCRs is observed at the same follow-up time point among OK lens users of different ages. • Certain DCR might serve as predictors of myopic progression in children. To investigate the effects of orthokeratology lenses (OK lenses) on corneal biomechanics in subjects of different ages. 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. 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. 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. [ABSTRACT FROM AUTHOR]

RigidCare is an electrolysis-based device that recently obtained approval from the US's FDA to sterilise microorganisms and remove proteins for orthokeratology (O-K) lenses. The study was conducted to investigate the device's performance in varied clinical circumstances. Trial lenses and private lenses were employed by O-K lens wearers from five hospitals for an evaluation of disinfection and sterilisation and an assessment of protein removal, respectively. Menicon multipurpose solution and protein remover were selected for use with the control group. Following the instructions, pre-cleaning lens samples, post-cleaning lens samples and residual solution samples of trial lenses of the experimental and control groups were collected for microorganism examinations by an experienced third-party testing organisation. The levels of protein deposition for these two approaches were rated by senior O-K experts. Categorical variables were analysed using statistical tests, such as the chi-squared test and Fisher's exact test. The microbial positive rate detected from the pre-cleaning and post-cleaning lens samples and the residual solution of the trial lenses for the experimental and control group was 4/76 vs 1/74 (P = 0.37), 1/76 vs 0/74 (P = 1.00) and 0/76 vs 8/74 (P = 0.006), respectively. Following protein removal, the experimental group exhibited a significantly higher overall proportion of lenses rated as 'clean' or with a 'mild deposit' (96.4 %, 79/82) compared to the control group (85.7 %, 66/77), with a significant difference (P < 0.05). This multi-center study demonstrated that RigidCare exhibited superior efficacy in disinfection, sterilisation and protein removal as compared to Menicon multipurpose solution and protein remover. [ABSTRACT FROM AUTHOR]

To compare the efficiency of orthokeratology (OK) and defocus-incorporated multiple segment (DIMS) lenses in myopia control in children. 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. 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). 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. [ABSTRACT FROM AUTHOR]

The purpose of this study was to explore the impact of several contact lens (CL) care solutions on the removal of proteins and lipids, and how deposit removal impacts bacterial adhesion and solution disinfection. Lysozyme and lipid deposition on three ortho -k (rigid) and two soft CL materials were evaluated using an ELISA kit and gas chromatography respectively. Bacterial adhesion to a fluorosilicone acrylate material using Pseudomonas aeruginosa with various compositions of artificial tear solutions (ATS), including with denatured proteins, was also investigated. The impact of deposition of the different formulations of ATS on biofilm formation was explored using cover slips. Finally, the lysozyme and lipid cleaning efficacy and disinfection efficacy against P. aeruginosa and Staphylococcus aureus of four different contact lens care solutions were studied using qualitative analysis. While maximum lysozyme deposition was observed with the fluorosilicone acrylate material (327.25 ± 54.25 µg/lens), the highest amount of lipid deposition was recorded with a fluoro-siloxanyl styrene material (134.71 ± 19.87 µg/lens). Adhesion of P. aeruginosa to fluorosilicone acrylate lenses and biofilm formation on cover slips were significantly greater with the addition of denatured proteins and lipids. Of the four contact lens care solutions investigated, the solution based on povidone-iodine removed both denatured lysozyme and lipid deposits and could effectively disinfect against P. aeruginosa and S. aureus when contaminated with denatured proteins and lipids. In contrast, the peroxide-based solution was able to inhibit P. aeruginosa growth only, while the two multipurpose solutions were unable to disinfect lenses contaminated with denatured proteins and lipids. Bacterial adhesion and biofilm formation is influenced by components within artificial tear solutions depositing on lenses, including denatured proteins and lipids, which also affects disinfection. The ability of different solutions to remove these deposits should be considered when selecting systems to clean and disinfect ortho -k lenses. [ABSTRACT FROM AUTHOR]

To study topographic epithelial and total corneal thickness changes in myopic subjects undergoing successful orthokeratology treatment in connection with the objective assessment of contact lens decentration. A prospective-observational and non-randomized study in 32 Caucasian myopic eyes undergoing Ortho-k for 3 months. Total, epithelial, and stromal thicknesses were studied before and after Ortho-k treatment, using optical coherence tomography with anterior segment application software. Central, paracentral, and mid-peripheral values are taken along 8 semi-meridians. The central average total corneal thickness was 4.72 ± 1.04 μm thinner after Ortho-K. The paracentral corneal thickness showed no significant changes (p = 0.137), while the mid-peripheral corneal thickness was increased by 3.25 ± 1.6 μm associating this increase exclusively to the epithelial plot (p <0.001). When lens centration was assessed, a lens fitting decentration less than 1.0 mm was found for the whole sample, predominantly horizontal-temporal (87.5%) and vertical-inferior (50%) decentring. Corneal topographical analysis revealed a horizontal and vertical epithelial thickness asymmetric change profile with paracentral temporal thinnest values, and mid-peripheral nasal thickest values. The present study found a central corneal thinning induced by Ortho-k lenses in subjects with moderate myopia, only associated with a change in epithelial thickness, as well as mid-peripheral thickening, that seems to be mainly epithelial in origin. The authors also found a tendency of contact lens decentration toward temporal and inferior areas conditioning an asymmetric epithelial redistribution pattern. [ABSTRACT FROM AUTHOR]

Orthokeratology (ortho-k) is the process of deliberately reshaping the anterior cornea by utilising specialty contact lenses to temporarily and reversibly reduce refractive error after lens removal. Modern ortho-k utilises reverse geometry lens designs, made with highly oxygen permeable rigid materials, worn overnight to reshape the anterior cornea and provide temporary correction of refractive error. More recently, ortho-k has been extensively used to slow the progression of myopia in children. This report reviews the practice of ortho-k, including its history, mechanisms of refractive and ocular changes, current use in the correction of myopia, astigmatism, hyperopia, and presbyopia, and standard of care. Suitable candidates for ortho-k are described, along with the fitting process, factors impacting success, and the potential options for using newer lens designs. Ocular changes associated with ortho-k, such as alterations in corneal thickness, development of microcysts, pigmented arcs, and fibrillary lines are reviewed. The safety of ortho-k is extensively reviewed, along with an overview of non-compliant behaviours and appropriate disinfection regimens. Finally, the role of ortho-k in myopia management for children is discussed in terms of efficacy, safety, and potential mechanisms of myopia control, including the impact of factors such as initial fitting age, baseline refractive error, the role of peripheral defocus, higher order aberrations, pupil size, and treatment zone size. [ABSTRACT FROM AUTHOR]

To report the practice of orthokeratology (OK) in Algeria and to investigate the visual outcomes, safety and subjective responses with this technique in myopes. A retrospective chart review of 48 participants using OK lenses since January 2010 were included in the study. Lenses were selected and fitted according to the manufacturer's recommendations using their respective software and the number of lenses required for a successful fit was recorded. Visual acuity (VA) in logMAR units and biomicroscopic findings were recorded for each visit. Subjective ratings was determined with analogue rating scale was filled in by the investigator, the participants were divided into Group 1 (> 4.00D) and Group 2 (< 3.75D) myopic groups for analysis. First lens fitting success rate of 64.58%. There was also a significant difference between the BCVA at baseline and VA at Day 1 (P < 0.05), and no significant difference at Day 7, Day 30 and the final visit (P = 0.51, P = 0.93, P = 0.62, respectively), for Group 2. There was a significant difference between the BCVA at baseline and VA at Day 1, 7, 30 and the final visit (P < 0.05), for Group 1. the patients of the second group were happier but the results from the survey were not statistically significant (P = 0.10), no serious complication was reported. the technique was efficient and safe as we didn't have any serious complication, with a high success rate for first lens fitting. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the safety of overnight orthokeratology (OK) wear and explore whether factors such as age, refraction and allergic conjunctivitis (AC) history were associated with corneal adverse events (AEs) incidence.Methods: Medical records of consecutive patients who started OK for myopia correction and continued for more than one year were retrospectively reviewed. Clinical data including sex, baseline age, spherical equivalent refraction (SER), and related medical histories were retrieved. A total of 489 eyes from 260 patients (age: 8-15 years; SER: -1.00 to -6.00 D) were included. Corneal adverse events were the primary outcome. The generalized estimating equations model was used to evaluate the effects of sex, age, SER, and allergic conjunctivitis history on corneal AE incidence over the one-year period.Results: A total of 111 eyes (22.7%) had corneal AE during the one-year follow-up (corneal staining [n = 106], corneal infiltration [n = 5]) and the incidence of significant AE was 6.9%. The corneal AE incidence was associated with age (OR = 0.874, 95%CI = 0.781-0.978, p = 0.019); SER (OR=0.632, 95%CI=0.531-0.754, p < 0.001); and AC (OR=1.706, 95%CI=1.017-2.860, p = 0.043). High refraction was the key risk factor for significant AE (OR=0.542, 95%CI=0.401-0.732, p < 0.001).Conclusions: Orthokeratology is a safe option for children with myopia. Younger age, higher myopia, and AC were risk factors for corneal AE in OK wearers. Whereas, only higher myopia was a risk factor for significant AE. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of overnight orthokeratology (OOK) on the ocular surface and dry eye-related cytokines in children.Methods: A non-randomized, prospective pilot study was conducted including sixty myopes treated with OOK and sixty age-matched spectacle wearing participants. The following tests were performed before and after 1, 3, 6 and 12 months: ocular surface disease index (OSDI), noninvasive tear breakup time (NITBUT), tear meniscus height (TMH), corneal fluorescein staining (CFS), meiboscore using noncontact meibography. Then the concentrations of interleukin-17A (IL-17A), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) in tear samples were detected with a multiplex immunobead assay at different time points.Results: All parameters had no statistical differences between the two groups prior to treatment. No adverse events were observed except trace to moderate corneal staining and allergic conjunctivitis in the treatment group. NITBUT significantly decreased after 6 and 12 months OOK wearing (P = 0.003 and P = 0.001, respectively). After wearing OOK there was a significant increase in CFS at each follow-up time point compared with baseline (P = 0.023, P = 0.016, P = 0.001, and P < 0.001at 1, 3, 6, and 12 months, respectively). The upper meiboscore and the total meiboscore increased gradually and peaked at 12 months of OOK (both P < 0.001). The concentration of the three cytokines in the treatment group significantly increased after OOK wearing. These increases occurred at different time points: IL-17A increased significantly 3 months after OOK, IL-6 at 6 months, and PGE2 at 12 months (all P < 0.001). However, there were no significant changes in the above parameters in the control group. There were no significant differences in the OSDI or TMH at any follow-up time point compared to baseline in both groups (both P > 0.05).Conclusions: Short-term OOK may reduce the stability of the tear film and increase damage to the corneal epithelium. Long-term OOK could induce ocular inflammation through the disruption of meibomian glands. [ABSTRACT FROM AUTHOR]

Objective: To report the study design and one month's preliminary results of a randomized, single-masked, one-year prospective study of orthokeratology (ortho-k) in adults wearing lenses of different compression factors.Methods: Adults aged 18-38 years, with myopia of -0.75 to -5.00 D and astigmatism < 1.50 D, were recruited and randomly assigned into two groups: a conventional compression factor or Jessen Factor (CCF) group (compression factor = 0.75 D) and an increased (extra 1.00D) compression factor (ICF) group. Clinical outcomes, including spherical equivalent refraction (SER) reduction, visual acuity, corneal hysteresis (CH) and corneal resistance factor (CRF), and signs and symptoms were collected at the one-month follow-up visit. Indicators of the level of satisfaction and quality of life after commencing treatment were determined via a satisfaction questionnaire and the NEI-RQL-42 questionnaire.Results: Baseline data from 26 CCF and 24 ICF participants were analysed and no significant differences were observed between the two groups (p > 0.05). The first fit success rates were 90 % for CCF group and 83 % for the ICF group, SER reductions were 97 % and 95 % for the CCF and ICF group, respectively, with uncorrected high-contrast visual acuity of -0.06 (-0.18 to 0.42) and 0.00 (-0.16 to 0.52), respectively (p > 0.05) at the 1-month visit. Overall, the incidence of corneal staining was 77 % in the CCF and 79 % in ICF group; central corneal staining was 15 % and 33 %, respectively. However, the differences of corneal staining between the groups did not reach significance in any visit (p > 0.05). The main complaint from participants was glare (both groups). No significant differences in CRF and CH were found in the first month (p > 0.05). Both groups recorded high scores in the level of satisfaction questionnaire, with no significant differences between groups (p > 0.05). Compared with baseline scores, 1-month NEI-RQL-42 subscales of dependence on correction, appearance, and satisfaction with correction significantly increased, and the glare score significantly decreased in both groups (all p < 0.05).Conclusions: The majority of participants were satisfied with the treatment and no serious corneal adverse effects were observed. These results demonstrate that ortho-k lenses of default and increased compression factor (1D) demonstrated similar clinical performance and ortho-k can be a safe and well-accepted option for myopia correction in adults, but long-term observation is warranted. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical effect of orthokeratology in controlling myopia and treating anisometropia among children with myopic anisometropia.Methods: A total of 108 myopic anisometropic children aged 8-16 years old who wore orthokeratology lenses in both eyes were enrolled in this study and followed up for over 1 year. The more severely myopic eye of each patient was assigned to the more myopic group (108 eyes), with a mean spherical equivalent refraction of -4.25 (-5.00, -3.38) D; the opposite eye of each patient was assigned to the less myopic group (108 eyes), with a refraction of -2.75 (-3.63, -1.88) D. This study observed and analyzed changes in ocular parameters after orthokeratology (Wilcoxon signed-rank test).Results: In children who wore orthokeratology lenses for approximately 1 year, the level of anisometropia significantly dropped from 1.38 (1.13, 1.75) D to 1.25 (1.13, 1.75) D (P = .005). The difference between the axial lengths of the two eyes significantly dropped from 0.54 (0.37, 0.74) mm to 0.46 (0.28, 0.67) mm (P< .0001).Conclusions: Orthokeratology seemed to be more effective at delaying the progression of myopia in the more myopic eyes than in the less myopic eyes of myopic anisometropic children. Orthokeratology lenses are suitable for anisometropic children, although the effectiveness of orthokeratology against anisometropia requires additional follow-up time for further observation and study. [ABSTRACT FROM AUTHOR]

Background: To investigate changes in the corneal thickness profile in juvenile myopia after overnight wear of orthokeratology lenses (OK).Methods: A total of 53 juveniles (53 right eyes) successfully wore OK between January 2016 and July 2017 and they were reviewed one day, one week and one month after first wearing it. Epithelial and corneal data were obtained by optical coherence tomography (OCT). Changes in uncorrected visual acuity, refractive error, corneal refractive power, and epithelial and corneal thickness were analyzed before and after wear of OK.Results: The corneal epithelium was reshaped after 1 day of OK; the myopia degree was reduced, and uncorrected visual acuity reached 0 logMAR at 1 week. The central (2 mm) average epithelial thickness was 52.04 ± 2.35 μm, 49.25 ± 2.67 μm, 45.91 ± 2.80 μm, and 47.53 ± 3.44 μm before and after 1 day, 1 week, and 1 month of OK, respectively (t = 4.497, 9.741, and 7.340, respectively, P<0.001). The central epithelium was thinnest at 1 week, when the average thinning of 6.13 ± 1.67 μm accounted for approximately 11.78 % ± 3.21 % of the total epithelium thickness at baseline. The epithelial thickness of the reverse curve zone was 51.83 ± 2.49 μm, 57.62 ± 3.01 μm, 59.43 ± 3.19 μm, and 60.22 ± 2.75 μm before and after 1 day, 1 week, and 1 month of OK, respectively, showing a significant increase over time (t=-4.752, -6.208, and -6.848, respectively, P < 0.001).Conclusion: In the early stage of OK, the corneal epithelium was redistributed very quickly. The central epithelium became thin, while the epithelium of the reverse curve zone correspondingly thickened. Effectively reduced the refractive power of the cornea equivalent to the effect of adding a concave spectacle lens, which ensures uncorrected vision after removal of the lenses. [ABSTRACT FROM AUTHOR]

Purpose: To determine the intensity of corneal pigmented arc in orthokeratology (ortho-k)-treated children and its correlation with wide epithelial thickness map (ETM) obtained through anterior segment optical coherent tomography (AS-OCT).Methods: This retrospective case series reviews medical records of children who received ortho-k treatment for myopia control. Intensity of ortho-k-associated pigmented arc after wearing ortho-k lens more than 12 months and its correlation with each sector/zone of wide ETM obtained by AS-OCT was explored. Pigmented arcs were further divided into apparent and unapparent groups, and the clinical differences between groups were determined.Results: This study included 57 eyes of 29 children (mean age, 11.4 years, range 9-15); after initiating ortho-k treatment, the incidence of the corneal pigmented arc was 91.2% with mean lens wear duration of 26.1 months. Intensity of pigmented arc was significantly correlated with lens wear duration, target power, baseline degree of myopia, C zone and sectors I2, I3 and IT3 on wide ETM. Comparison between apparent and unapparent groups showed the same significant results except for C zone. After adjusting for lens wear duration and target power, sector I2 has the highest association with pigmented arc severity.Conclusion: Children treated with ortho-k are likely to develop ortho-k-associated pigmented arcs. The new wide ETM of AS-OCT can provide important information regarding the intensity of pigmented arc in these children. This can support customized pigmented arc-free ortho-k treatment for children in the future. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the risk factors associated with contamination of lens cases in a group of orthokeratology (ortho-k) lens wearers.Method: Ortho-k patients attending the Contact Lens Clinic of the Hospital were required to complete a checklist about their routine daily care and handling of lens cases. Their cases were then collected for analysis. Contamination was evaluated by determining the optical density (OD) of crystal violet stained biofilm present in the cases. OD values were divided into three groups, lower, middle, and upper tertiles, and associations between risk factors were determined by multivariate analysis.Results: A total of 194 subjects were recruited. Twenty-five subjects used cylindrical lens cases (CC), 98 flat cases with ridges (FCR), and 71 flat cases without ridges (FC). FCRs were the most heavily contaminated and CC showed least contamination (FCR > FC, OR 2.16, CI 1.11-4.18, p =  0.023; FCR > CC, OR 8.86, CI 2.97-26.44, p <0.001; FC > CC, OR 2.33, CI 1.35-12.45, p =  0.013). Replacing lens cases monthly significantly reduced the risk of high contamination (OR 0.013, CI 0.06-0.30, p <  0.001), compared to those used for three months. Cases that were not rinsed (OR 3.44, CI 1.50-7.86, p =  0.003) or rinsed by other methods (OR 4.07, CI 1.67-9.92, p =  0.002) had significantly more contamination, compared to those rinsed with multipurpose solution. Lens cases, which were not dried (OR 11.36, CI 2.06-62.93, p =  0.005) or air-dried (OR 8.71, CI 1.16-65.56, p =  0.036), showed more contamination compared to those wiped with tissue daily.Conclusion: Case design (cylindrical), monthly replacement, daily rinsing with MPS, and wiping with tissue daily can effectively reduce biofilm formation in contact lens cases. [ABSTRACT FROM AUTHOR]

Purpose: The relative risks of ocular pathology with increasing myopia have been described; the absolute lifetime risk of vision impairment from myopia is yet to be compared to the childhood and lifetime risks of contact lens wear for myopia control.Methods: Using peer-reviewed data, the absolute risks of microbial keratitis (MK) in daily disposable soft, reusable soft and orthokeratology contact lens (CL) wear were calculated over both a childhood (age 8-18) and a lifetime (age 8-65) of CL wear. This was compared to the previously published cumulative risk of vision impairment by age 75 based on increasing myopia and axial length. Data were converted utilizing the Council of International Organizations of Medical Sciences (CIOMS) classification system for frequency of adverse events, with 95 % confidence intervals included.Results: The lifetime risk of vision impairment in axial lengths over 26 mm and more than 6D of myopia is greater than the lifetime risk of MK in any CL modality, except for adult SCL extended wear. If axial length is below 26 mm and myopia lower than 3D, a lifetime of CL wear is more risky in comparison, except in the case of daily disposable wear. Ten years of childhood CL wear of any modality presents lower likelihood of MK than any comparable risk of vision impairment.Conclusion: The comparative lifetime risks of contact lens wear commenced at age 8 for myopia control are less than the lifetime risks of vision impairment with myopia more than 6D or axial length more than 26 mm. When only childhood CL wear is considered, the risk comparison is clearly skewed towards the positive impact of CL wear, especially in daily disposable wear. Clinicians should be confident to proactively recommend myopia control CL wear to younger children, as both the safety profile and potential preventative ocular health benefits are evident. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether orthokeratology (OK) induced treatment zone (TZ) diameter can be reduced by altering OK lens design, and if so the impact of modifying TZ diameter on relative peripheral refraction (RPR).Methods: 16 subjects (mean age 23.4 ± 1.5 years; 8 female) completed the study. Standard (Control) OK lens design (PJ, Capricornia, Australia) or a modified version (Test) where the back optic zone diameter was reduced, and back optic zone asphericity and intermediate lens curves were altered, were worn overnight only for 7-nights in a randomised double masked order, with a minimum 1-week wash out (no lens wear) between lens designs. Full correction of refractive error was targeted. Refraction; best corrected visual acuity (BCVA); RPR (Shin-Nippon NVision-k 5001) along the horizontal and vertical meridians; and corneal topography (Medmont E300) were measured before starting lens wear and in the morning after lens removal after the seventh night of lens wear for both lens designs. TZ diameter and decentration was calculated from corneal topography.Results: After 7-nights of wear both lens designs created -2.00D refraction effect with no significant difference in refractive effect or change to BCVA between the designs. The Test design created a significantly smaller horizontal (4.78 ± 0.37 vs 5.70 ± 0.37 mm, p < 0.001) and vertical (5.09 ± 0.51 vs 5.92 ± 0.51 mm p < 0.001) TZ diameter. The TZ was decentered inferior temporal with no significant difference between designs. There was no significant difference between the lens designs in RPR along the horizontal and vertical meridians at any measurement period.Conclusions: OK induced TZ diameter can be reliably reduced by altering OK lens design without detrimentally effecting lens centration or refractive effect. Reducing TZ diameter did not alter RPR, though measurement artifacts could be responsible for masking an effect. Longitudinal studies are needed to assess whether smaller TZ OK lens designs increase efficacy for slowing progression of myopia. [ABSTRACT FROM AUTHOR]

Purpose: A survey in 2015 identified a high level of eye care practitioner concern about myopia with a reported moderately high level of activity, but the vast majority still prescribed single vision interventions to young myopes. This research aimed to update these findings 4 years later.Methods: A self-administrated, internet-based questionnaire was distributed in eight languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy of available strategies and adoption levels of such strategies, and reasons for not adopting specific strategies.Results: Of the 1336 respondents, concern was highest (9.0 ± 1.6; p < 0.001) in Asia and lowest (7.6 ± 2.2; p < 0.001) in Australasia. Practitioners from Asia also considered their clinical practice of myopia control to be the most active (7.7 ± 2.3; p < 0.001), the North American practitioners being the least active (6.3 ± 2.9; p < 0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by pharmaceutical approaches and approved myopia control soft contact lenses (p < 0.001). Although significant intra-regional differences existed, overall, most practitioners did not consider single-vision distance under-correction to be an effective strategy for attenuating myopia progression (79.6 %), but prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients (63.6 ± 21.8 %). The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (20.6 %) and inadequate information (17.6 %).Conclusions: While practitioner concern about myopia and the reported level of activity have increased over the last 4 years, the vast majority of eye care clinicians still prescribe single vision interventions to young myopes. With recent global consensus evidence-based guidelines having been published, it is hoped that this will inform the practice of myopia management in future. [ABSTRACT FROM AUTHOR]

Purpose: To compare axial length (AL) elongation in myopic children with four Orthokeratology (OrthoK) lenses and spectacles.Methods: The medical records of 266 patients (532 eyes) who were fitted with OrthoK lenses or spectacles (control group) were reviewed. Data collection included baseline age, gender, baseline objective sphere and cylinder, baseline flat and steep corneal meridian power, corneal asphericity coefficient (Q value), AL at baseline and after 1-year, and 2-years of OrthoK or spectacle wear analyzed using analysis of repeated measures data ANOVA. Stepwise linear regressions between the changes in AL after 2 years relative to baseline parameters were calculated for the OrthoK and control groups separately.Results: The baseline subject parameters for each of the four OrthoK lenses were not statistically different. Statistically significant differences between time points were found between 12- and 24- months (all P < 0.05). AL growth was slower in all OrthoK groups than in the control group (all P < 0.05). AL grew 0.081±0.034 mm per year slightly less than average with Essence compared to the Mouldway OrthoK group (P = 0.019). The coefficient of regression weakly expressed between the increases in AL over 2-years study period and baseline spherical equivalent refraction was 0.065 in Essence, 0.079 in Euclid and 0.087 in Mouldway. The coefficient of regression was also weakly between age and the increases AL over 2-years study period and baseline age in all groups.Conclusion: Different OrthoK lenses differ minimally in slowing axial elongation effectively in myopic children during 2-years lens wear. [ABSTRACT FROM AUTHOR]

Purpose: Orthokeratology (OK) is known to alter relative peripheral refraction (RPR) with this presumed to be its key myopia control mechanism. A prospective, longitudinal study was performed to examine stability of OK-induced RPR changes in myopic children and young adults.Methods: RPR of twelve children (C)(8-16 years) and eight adults (A)(18-29 years) with spherical equivalent refraction of -0.75 to -5.00D were measured unaided and while wearing single vision soft contact lenses (SCL). Measurements were repeated after 1, 6 and 12 months of OK wear. RPR was measured using an open-field Shin Nippon SRW-5000 autorefractor at 10, 20 and 30 degrees nasally (N) and temporally (T), converted into power vectors M, J0 and J45. On-axis refractions and axial lengths (IOL Master) were also measured.Results: Compared to the unaided state, 1-month of OK wear shifted the RPR in the myopic direction at 30 T (C: p = 0.023; A:, p = 0.002) and 30 N (C&A, p = 0.003) and was stable thereafter, with similar changes compared to SCL wear. J0 showed a myopic shift in comparison to both unaided and SCL correction in children but not adults, and J45 did not change in either group. The on-axis OK correction was predictive of the RPR shift in both children and adults at 30 T (C: r=-0.58, p = 0.029; A: r=-0.92, p < 0.001) and 30 N (C: r=-0.60, p = 0.024; A: r=-0.74, p = 0.013) with symmetry of RPR shifts (C: r = 0.67, p = 0.008; A: r = 0.85, p = 0.004). No relationships between changes in RPR and axial length were found after twelve months of OK wear; level of myopia was stable in both groups.Conclusion: Relative to both unaided and single vision SCL correction, OK shifted the RPR in the myopic direction; the RPR was stable from 1 to 12 months. The RPR shift in OK wear varied with the degree of myopia but was not correlated with myopia progression. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate changes in refractive and corneal responses in myopic children wearing orthokeratology (ortho-k) lenses with conventional compression factor (CCF, 0.75 D) and increased compression factor (ICF, 1.75 D).Methods: This was a double-blind self-controlled study. Subjects were randomly fitted with CCF in one eye and ICF in the fellow eye. Weekly monitoring of refraction, visual acuity (VA), external ocular health, and corneal responses were performed over one month of lens wear and after discontinuation of lens wear until stabilization was achieved.Results: Twenty-five subjects, aged 9.4 ± 1.0 years, completed one-month lens wear, of whom 23 completed the washout period. The first fit success rates for CCF and ICF were 93% and 96%, respectively. Myopia, unaided VA, central corneal thickness, anterior corneal curvatures (K), apical power (AP), and corneal resistance factor (CRF) all changed significantly during the study period (P <  0.003). Between-eye difference was significant only for myopia reduction (P =  0.001). About 4% and 8% of ICF and CCF eyes were under-corrected. The attempted target was achieved in about 80% of CCF and 60% of ICF eyes at week 4. At the end of the washout period (3 weeks), myopia, K, and AP were significantly different compared to baseline (P <  0.001).Conclusion: Increasing the compression factor did not affect the first fit success rate and external ocular health, but did allow faster correction of refractive error within one month of lens wear. Further investigation is warranted to investigate the long-term effects of ICF on myopia control compared to CCF. [ABSTRACT FROM AUTHOR]

Purpose: To report a case of reduced aniseikonia in a myopic axial anisometrope during orthokeratology (OK) lens wear.Case Report: A 19-year-old female university student with myopic anisometropia presented for an OK lens fitting consultation. At baseline, perceptual interocular image size difference or aniseikonia of 1.45% was found, with a smaller image seen by the right eye compared to the left eye. The patient was fitted with a pair of OK lenses and interocular image size differences, subjective refraction and corneal topography were measured after 7, 14 and 47 days of overnight lens wear. Hyperopic shifts in central refraction and corresponding flattening of the central cornea was measured during OK treatment. Aniseikonia reduced after OK wear with the most significant change measured from baseline to day 7. Aniseikonia recorded after 7, 14 and 47 nights of lens wear was 0.05%, 0.35% and 0.85%, respectively. Although minimum differences in refractive error between eyes was reached after 47 days of OK, aniseikonia was greater than that measured after 7 and 14 days of OK.Conclusion: This case report demonstrates reduction in aniseikonia with OK lens wear in a myopic patient with axial anisometropia, although this effect was not sustained beyond 1 week of lens wear. As the impact of corneal curvature changes on aniseikonia is not well understood, future studies on the impact of OK on aniseikonia and associated asthenopia is required. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of overnight orthokeratology (OK) lens wear on axial growth in anisometropic children.Methods: The study involved 17 males and 12 females with an average age of 11.4 ± 2.9 years. Cycloplegic spherical equivalent error (SER) was -0.50D to -6.00D, and anisometropia ≥1.00D. The eyes with greater myopia were assigned to the G eye group and the fellow eyes with less myopia to the L eye group. All eyes were fitted with OK lenses. Axial length (AL) was measured at the beginning of the study and at 6-, 12-, 18-, and 24-month follow-up visits. Refractive error was measured at the beginning and at the 24-month visit. Linear mixed model analysis was used to evaluate the effect of time, group, and time*group on axial growth. Paired t test was used to compare the myopia increase over 24 months between the two groups.Results: The mean baseline AL was 25.06 ± 0.61 mm for the G eyes and 24.48 ± 0.61 mm for the L eyes. After 24 months, AL had increased by 0.31 ± 0.23 mm in the G eye group and by 0.41 ± 0.31 mm in the L eye group. Axial growth of the L eyes was significantly greater than that of the G eyes (p = 0.006). The mean baseline myopia of the G eye and the L eye was -3.62 ± 1.27D [-5.75D to -1.75D] and -1.93 ± 1.02D [-4.00D to -0.50D] respectively. At 24 months, the increase in myopia in the G eyes was significantly less than that in the L eyes (-0.84 ± 0.63D vs, -1.21 ± 0.89D, p < 0.001).Conclusions: In anisometropic children who wore OK lenses, axial growth was greater in the eye with less baseline myopia than in the fellow eye with greater baseline myopia after 2 years. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

• The changes in Corvis ST parameters post orthokeratology lens wear are primarily related to alterations in corneal shape, rather than variations in corneal biomechanical properties. To investigate the alterations in corneal biomechanical metrics induced by orthokeratology (ortho -k) using Corvis ST and to determine the factors influencing these changes. A prospective observational study was conducted to analyze various Corvis ST parameters in 32 children with low to moderate myopia who successfully underwent ortho -k lens fitting. Corneal biomechanical measurements via Corvis ST were acquired at six distinct time points: baseline (pre) and 2 h (pos2h), 6 h (pos6h), and 10 h (pos10h) following the removal of the first overnight wear ortho -k, one week (pos1w) and one month (pos1m) subsequent to the initiation of ortho -k. Significant differences were observed in Corvis ST Biomechanical parameters DAR2, IIR, CBI, and cCBI post ortho -k intervention. The integration of covariates (CCT, SimK, and bIOP) mitigated the differences in DAR2, IIR, and cCBI, but not in CBI. Initially, the stiffness parameter at first applanation, SP-A1, did not demonstrate significant variations, but after adjusting for covariates, noticeable differences over time were observed. The Stress-Strain Indeces, SSIv1 and SSIv2, did not manifest considerable changes over time, irrespective of the adjustment for covariates. No significant disparities were identified among different ortho -k lens brands. Corneal biomechanics remained consistent throughout the one-month period of ortho -k lens wear. The observed changes in Corvis ST parameters subsequent ortho -k are primarily attributable to alterations in corneal pachymetry and morphology, rather than actual alterations in corneal biomechanics. The stability of corneal biomechanics post ortho -k treatment suggests the safety of this approach for adolescents from a corneal biomechanics perspective. [ABSTRACT FROM AUTHOR]

To compare the clinical efficacy of orthokeratology (ortho-k) and 0.01% atropine for retardation of myopia progression in myopic children. This was a retrospective cohort study. A total of 282 patients, aged 8–17 years, were enrolled, including 100 children treated with ortho-k, 84 with 0.01% atropine, and 98 with single-vision spectacles. During the follow-up of 1 year, ortho-k wearers were examined at 1 day, 1 week, 1 month, 3 months after treatment, and thereafter every 3 months, while the others were examined every 3 months by measurements of uncorrected vision, intraocular pressure, refractive power, slit-lamp microscopy, corneal topography, and the lens fitting when necessary. The axial length was measured every 6 months. Patients with ortho-k had stable uncorrected vision after 1 month of lens wear, all reaching 0 logMAR. The annual axial elongation was 0.23 ± 0.19 mm, 0.22 ± 0.20 mm, and 0.39 ± 0.27 mm in the ortho-k, atropine, and spectacle groups, respectively, with significant difference (F = 23.251, P = 0.000). The axial length was delayed to increase by 41.03% and 43.59% within a year in patients with ortho-k and atropine, respectively, as compared to patients with spectacles (F = 0.006, P = 0.936). The elongation was ≤ 0.3 mm in 69.0% and 66.7% of patients in the two groups, respectively, versus 38.8% in the spectacle group (χ2 = 17.251, P = 0.000). During the follow-up, the rate of corneal staining was 11.0% and 2.0% in the ortho-k and spectacle groups, respectively (χ2 = 8.076, P = 0.003). The use of atropine did not increase corneal staining, but the incidence of related photophobia was 4.8%. No other serious complications were observed. Ortho-k lenses and 0.01% atropine can achieve similar efficacy of myopia retardation, which was significantly better than that obtained with single-vision spectacles, in myopic children. The risk of corneal staining after ortho-k wear may be slightly higher than that with spectacles, but could be well controlled. [ABSTRACT FROM AUTHOR]

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. 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. 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). 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. [ABSTRACT FROM AUTHOR]

To compare the changes in corneal biomechanics after orthokeratology (OK) lens and Defocus Incorporated Soft Contact (DISC) lens treatment. Of 28 myopic children were recruited, with one eye wearing OK lens and the other eye wearing DISC lens for one year, and the data after discontinued for 4 weeks were also collected. Major outcomes were corneal biomechanics and axial length (AL) elongation. Throughout the follow-up period, the DISC group had longer the first applanation (A1) time, larger A1 deformation amplitude, A1 deflection length (A1 DLL), and A1 deflection amplitude than the OK group. AL elongation was less in the OK group at each visit (all P < 0.05) but faster in the OK group than in the DISC group after discontinuation (P = 0.006). Moreover, AL elongation was related to baseline A1 time, A1 velocity and whole eye movement max in the DISC group, and in the OK group, was related to the baseline the second applanation (A2) DLL, A2 delta arc length and stiffness parameter A1 (all P < 0.05). The cornea was more deformable after wearing DISC lens than OK lens, and corneal biomechanical parameters were associated with AL elongation. Eyes showed less AL elongation during OK lens treatment while faster AL elongation after discontinuation than DISC lens. The baseline corneal biomechanics may help to predict AL elongation in myopic control strategies. [ABSTRACT FROM AUTHOR]

A hospital-based survey to explore lens rinsing habits of orthokeratology (ortho -k) patients, including the solution used for rinsing. An anonymous survey, via an online questionnaire, was administered to ortho -k lens wearers or their parents when they attended Fudan University Eye and ENT Hospital for routine follow-up visits. Three major issues were investigated: basic demographics, lens rinsing solution used, and specific rinsing habits. Relationships between demographics and rinsing solution used and rinsing behaviours were explored. Of the total of 541 online questionnaires delivered, 296 were completed and returned. The respondents were the person responsible for lens care, either the ortho -k users themselves, or their parents. The median age of the lens wearers was 12.0 years (range: 8–22 years), and the median period of ortho -k lens wear was 18.0 months (range: 1–109 months). The most common rinsing solutions reported were a particular brand of multidose preserved saline (28.4%), cooled boiled water (23.3%), and non-preserved multidose saline (16.2%). Overall, the main reason for choice of rinsing solution was recommendation of eye care practitioners (90.2%). The respondents with a longer lens wear history tended to use commercially available bottled water, drinking water, or cooled boiled water rather than non-preserved saline (unidose or multidose) (p ≤ 0.009) and were more likely to use the rinsing solution to soak their lenses (p = 0.009). Lens wearers who rinsed the lenses themselves tended to use tap water compared to those whose lenses were handled by parents (p = 0.040). Inappropriate choice and usage of rinsing solution appeared to be a common issue among ortho -k lens wearers in Shanghai, China. The problem was more pronounced in long-term wearers and in those who performed rinsing themselves. [ABSTRACT FROM AUTHOR]

Chemotherapy is among the limited choices approved for the treatment of hepatocellular carcinoma (HCC) at intermediate and advanced stages. Preferential and prolonged drug exposure in diseased sites is required to maximize the therapeutic index of the drug. Here, we report an injectable supramolecular peptide hydrogel as an intraperitoneal depot for localized and sustained release of triptolide for the treatment of orthotopic HCC. We chose peptide amphiphile C 16 -GNNQQNYKD-OH-based nanofibers as gelators and carriers for triptolide. Sustained triptolide release from the hydrogel was achieved over 14 days in vitro , with higher accumulation in and cytotoxicity against human HCC Bel-7402 in comparison with L-02 fetal hepatocytes. After intraperitoneal injection, the hydrogel showed prolonged retention over 13 days and preferential accumulation in the liver, realizing HCC growth inhibition by 99.7 ± 0.1% and animal median survival extension from 19 to 43 days, without causing noticeable pathological changes in the major organs. These results demonstrate that injectable peptide hydrogel can be a potential carrier for localized chemotherapy of HCC. C 16 -N hydrogel containing triptolide was created as an intraperitoneal depot for the treatment of orthotopic hepatocellular carcinoma. After intraperitoneal injection, the hydrogel retained in the peritoneal cavity for more than 2 weeks with preferential drug accumulation in the liver, and doubled the median survival time of tumor-bearing mice without noticeable side effects to major organs. Image 1 [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to develop evidence-based guidelines for identifying suitable subjects for myopia control using orthokeratology (ortho-k).Methods: Changes in axial elongation (AE) in the worse eyes of 66 myopic children (myopia between -0.75 and -4.50 D and astigmatism <2.00D, and aged 6 to <16 years old) who wore single-vision spectacles for seven months before switching to orthokeratology treatment for another seven months were observed.Results: AE during ortho-k lens wear was affected by age and rate of progression during spectacle wear. The percentage of subjects with rapid, moderate, and slow AE (equivalent annual myopia progression; rapid: ≥1.00D; moderate: 0.50D to <1.00D; slow: <0.50D) during spectacle wear was 36.3%, 33.3% and 30.3%, respectively. Rapid progression was most common in subjects aged less than nine, but 25% of subjects aged 9 to <13 and 12.5% aged 13 to <16 also demonstrated rapid progression. All subjects with rapid AE during spectacle wear achieved a significant reduction in eye elongation with ortho-k lens wear. Guidelines for patient selection was proposed based on the initial age and history of myopia progression.Conclusions: Myopia control is indicated for children at risk of developing high myopia. The suggested guidelines can help practitioners to identify children for whom the benefits outweigh the risks of serious adverse events. [ABSTRACT FROM AUTHOR]

Purpose: . To determine the extent of orthokeratology (OK) contact lens fitting worldwide and to characterize associated demographics and fitting patterns.Methods: . Survey forms were sent to contact lens fitters in 45 countries between January and March every year for 14 consecutive years (2004 - 2017, inclusive). Practitioners were asked to record data relating to the first 10 contact lens fits or refits performed after receiving the survey form.Results: . Data were obtained for 295,044 contact lens fits, of which 2,702 were with OK lenses and 292,342 were with other lens types (non-OK). Overall, OK lenses represented 1.2% of all contact lens fits, with significant differences between nations (p < 0.0001), ranging from no fits recorded in Brazil, Egypt, Indonesia, Iran, Lithuania, Nepal and the United Arab Emirates, to 6.0% in The Netherlands. There has been a slight overall increase in OK lens fitting over the survey period (p < 0.0001). OK lenses were fitted to younger persons (OK, 25.0 ± 12.8 years vs. non-OK, 39.8 ± 14.9 years) (p < 0.0001). A higher proportion of males (55%) were fitted with OK lenses versus non-OK lenses (30%) (p < 0.0009). There was a skewed distribution towards OK lenses being fit with higher oxygen permeable materials (p < 0.0001) and on a planned replacement basis (p < 0.0001).Conclusions: . OK contact lens prescribing is a niche activity, with this lens type typically being fitted in high oxygen permeable materials on a planned replacement basis to younger males. The slightly increasing rate of OK fitting, albeit at a very low level, may be attributed to practitioner interest in the reported myopia control properties of this lens type. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the adjunctive effect of orthokeratology (ortho-k) and low-dose atropine eye drops on axial length elongation in fast-progressing myopic children.Methods: Axial elongation in 60 eyes of 60 subjects who completed two years of ortho-k treatment was retrospectively reviewed. They were aged between 5.6-11.6 (mean, 8.3 ± 1.5) years old when they started ortho-k treatment. During their first year of ortho-k treatment (Phase One), they all demonstrated a faster than 0.25 mm/yr axial elongation rate. They were then treated with nightly 0.01% atropine in addition to ortho-k treatment for another year (Phase Two). Annual axial elongation rates before and after atropine treatment were compared.Results: Baseline spherical equivalent refractive error was -2.65 ± 1.08 DS and axial length was 24.34 ± 0.92 mm for the study cohort. The mean axial elongation rate was 0.46 ± 0.16 mm/yr during Phase One, being significantly faster in younger children (t = -4.920, P < 0.001). When atropine was added, annual axial elongation rate significantly decreased to 0.14 ± 0.14 mm/yr (t = -11.988, P < 0.001), and those who were fast progressors in Phase One had a greater reduction in the rate of axial elongation during Phase Two (t = -8.052, P < 0.001).Conclusions: Axial elongation rate is faster in younger children undergoing ortho-k treatment. For fast myopia progressors, low dose atropine may significantly slow axial elongation in addition to ortho-k's treatment effect. Those who have faster axial elongation after ortho-k treatment will benefit more from the addition of low dose atropine, regardless of their refractive error and age. [ABSTRACT FROM AUTHOR]

Background: This study aimed at comparing the inter-eye axial elongation difference in order to evaluate the change of anisometropia in unilateral myopic children wearing monocular orthokeratology (Ortho-K) lens.Methods: In this retrospective cohort study, we recruited monocular myopic subjects treated with monocular Ortho-K lens from May 2012 to January 2017. The axial length (AL) of both eyes was recorded, and we calculated the AL difference as our primary outcome, to evaluate myopia progression. High anisometropia was defined as anisometropia more than 2.50D. The generalized estimating equations (GEE) model was used to assess the related risk factors.Results: A total number of 31 unilateral myopic patients were identified. The initial wearing age of the subjects was 12.32+/-3.07 years. In myopic eyes, the initial spherical equivalent was -2.73+/-0.95 diopter (D). The mean follow-up duration was 2.01+/-1.48 years. A significant reduction in the AL difference was found, from 0.83+/-0.45 millimeters at the baseline to 0.59+/-0.49 millimeters at 24 months (P = 0.039). Besides, after wearing Ortho-K lens for a long term, high anisometropic wearers showed more AL difference reduction than low anisometropic wearers in unilateral myopic children (P=0.002).Conclusion: This study demonstrated that the myopic eyes in unilateral myopic children had less AL growth than the companion emmetropic eyes when treated with monocular Ortho-K lenses. Wearing Ortho-K lens for a long time would present a more significant AL difference reduction in high anisometropic children. [ABSTRACT FROM AUTHOR]

Highlights • The synergistic PDT effects combining 405 nm and 505 nm light were highest in vitro. • ROS production was the highest with the combination of 405 nm and 505 nm light. • The PDT effect at 405 nm + 505 nm was the most effective in vivo. Abstract Background Photosensitizers used for photodynamic therapy (PDT) to treat dermatologic disease are metabolized into mainly protoporphyrin IX (PpIX), which has five absorption wavelength peaks: 410 nm, 510 nm, 545 nm, 580 nm, and 630 nm. Although only red light around 635 nm and blue light around 400 nm are used as light sources for PDT, the efficiency of PDT might be improved by using multiple wavelengths, including those that correspond to the other absorption peaks of PpIX. Furthermore, because the target disease often occurs on the face, a flexible-type light-source unit that can be fitted to the lesion without unnecessarily exposing the mucous membranes, e.g., the eyes, nostrils, and mouth, is preferred. Objective We investigated the efficacy of a flexible light-emitting diode (LED) unit that emits multiple wavelengths to improve PDT effects. Methods HaCaT cells were incubated with 5-ALA and subsequently irradiated with either a single wavelength or sequentially with two wavelengths. Cell viability and reactive oxygen species were analyzed. Nude mice were implanted with COLO679 cells by subcutaneous injection into the flank. 5-ALA was subcutaneously injected into the tumor. The tumor was irradiated with 50 J/cm2 (day 0) and assessed daily until day 21. Results The synergistic PDT effects of dual-wavelength irradiation and reactive oxygen species production were highest with the 405-nm and 505-nm wavelength combination. This dual wavelength combination was also the most effective in vivo. Conclusion We could therefore conclude that dual-wavelength PDT is an efficient strategy for improving the therapeutic effects of PDT. Using a flexible LED unit is expected to achieve more uniform irradiation of uneven areas. [ABSTRACT FROM AUTHOR]