Orthokeratology for Myopia Control: A Meta-analysis

Proinflammatory and angiogenesis-related cytokines in vitreous samples of highly myopic patients

PURPOSE

To determine the concentrations of vitreous proinflammatory cytokines and angiogenesis-related growth cytokines in highly myopic (HM) patients and controls.

METHODS

Vitreous humor (VH) was obtained from patients during vitrectomy for rhegmatogenous retinal detachment (RRD), myopic retinoschisis (MRS), idiopathic epiretinal membrane (ERM), or macular hole (MH). High myopia was defined as an axial length (AL) of ≥26.0 mm and a spherical equivalent refractive error more negative than -6.0 D. A multiplex fluorescent-bead-based immunoassay was employed to measure the levels of 29 designated cytokines. The results were compared across groups.

RESULTS

Seventy-eight VH samples were collected from 78 patients (36 HM versus 42 controls). Vascular endothelial growth factor (VEGF) was significantly higher in the VH samples from HM patients than in those from the controls. Five inflammation-related factors, interferon γ (IFN-γ), interleukin 6 (IL6), IFN-γ-induced protein 10 (IP-10), eotaxin, and macrophage inflammatory protein 1α (MIP-1α), were significantly higher in the HM group than in the control group. The vitreous concentrations of well-known angiogenic growth factors monocyte chemoattractant protein 1 (MCP1) and IL5 were significantly elevated in the VH samples from HM patients.

CONCLUSIONS

Proinflammatory cytokines and angiogenic growth factors were elevated in the VH of HM patients, suggesting that an elevated inflammatory status and higher levels of angiogenic factors are present in eyes with HM.

Additive effect of atropine eye drops and short-term retinal defocus on choroidal thickness in children with myopia

Atropine eye drops and myopic retinal defocus each slow progression of myopia (short-sight). They also cause thickening of the choroid, and it has been suggested that the thickening is a precursor for reduced eye growth and slowed myopia progression. We investigated whether choroidal thickening due to optical defocus would add to thickening due to atropine when both were applied simultaneously. Addition would suggest that combining the two clinical treatments may improve efficacy of myopia control. We studied 20 children receiving 0.3% atropine daily for myopia control, over a period of 6 months. We imposed short periods of retinal defocus (1 h of myopic or hyperopic defocus (± 2.00D)) both before, and after 1 week and 3 and 6 months of atropine treatment. Prior to atropine, myopic or hyperopic defocus caused significantly thicker or thinner choroids respectively (± 12 µm, p < 0.001). After one week of atropine alone, thickness had increased (+ 21 µm; SD 17 µm; p < 0.001), and it increased further (by + 13 µm; SD 6 µm; p < 0.001) when exposed to myopic defocus. Atropine abolished choroidal thinning in response to hyperopic defocus. These effects remained the same after 3 and 6 months of atropine treatment. Our results show that additive effects of atropine and optical defocus are present at the level of the choroid, and suggest that combining optical and pharmaceutical treatments is likely to enhance efficacy of clinical myopia control.

Retinal Response of Low Myopes during Orthokeratology Treatment

The aim of this study was to evaluate the changes in retinal activity during orthokeratology (OK) treatment in 20 myopic eyes. Pattern electroretinography (PERG) and visual evoked potential (VEP) were assessed with the RETI-port/scan21 (Roland Consult, Wiesbaden, Germany). Measurements were taken at baseline (BL) and 1 night (1N), 15 nights (15N), 30 nights (30N), and 60 nights (60N) of OK lens wear. Repeated measures analysis of variance (ANOVA) and the Friedman test were used. Twenty eyes (23.20 ± 3.46 years, 70% female) with visual acuity ≤ 0.00 logMAR in post-treatment showed that despite a slight increase in retinal and cortical response amplitude, observed with both PERG and VEP, respectively, immediately after the initial treatment, these differences found were not statistically significant during the 60 days of OK treatment, despite a statistically significant increase in N95 response with PERG. This shows that retinal and cortical visual-related electrical activity is maintained or slightly increased during OK treatment.

Combined Orthokeratology with Atropine for children with Myopia: A Meta-analysis

BACKGROUND

Myopia has become a worldwide public health issue, which is occurring at a younger age, leading to an increased risk of high myopia. Ocular complications associated with high myopia can lead to irreversible vision loss. It is urgent and critical to explore effective treatment to slow or even stop the progression of myopia in young children.

OBJECTIVE

To evaluate the additive effects of orthokeratology (OK) and 0.01% atropine ophthalmic solution for myopia in children.

METHODS

We searched PubMed, Cochrane Library, EMBASE, MEDLINE, Web of science, Ovid, EBSCO host, CNKI, CBM to collect eligible studies. Efficacy and safety were evaluated in terms of the axial length, uncorrected distant visual acuity, corneal endothelial cell density, and intraocular pressure. We calculated the weighted mean difference (WMD) and the 95% confidence intervals (CIs) of all outcomes, and plotted on forest plots.

RESULTS

Four studies were ultimately included, involving a total of 267 subjects. This meta-analysis revealed that the mean axial length of the subjects in the experimental group was 0.09 mm less than that of subjects in the control group [WMD=-0.09, 95%CI (-0.15, -0.03), P=0.003]. There was no significant difference in uncorrected distant visual acuity, corneal endothelial cell density, and intraocular pressure between the two groups [WMD was -0.01 (95% CI: -0.03, 0.01), 11.75 (95% CI: -4.09, 27.58), 0.12 (95% CI: -0.40, 0.63), respectively]. None of the studies reported severe adverse events.

CONCLUSION

Our study suggests that the combination of OK and 0.01% atropine is more effective in slowing axial elongation than OK monotherapy in children with myopia in a relatively short duration of treatment. In addition, the combination therapy has no negative influence on uncorrected distant visual acuity, corneal endothelial cell density, and intraocular pressure.

Choroidal Thickness Changes after Orthokeratology Lens Wearing in Young Adults with Myopia

INTRODUCTION

Recently in South Korea, there are increasing number of young adults undergoing orthokeratology treatment for myopia control. They prefer orthokeratology treatment more than wearing spectacles or having a refractive surgery for several reasons. However, there is little research on the effect of orthokeratology treatment on choroids.

OBJECTIVE

The aim of this study was to analyze the change in choroidal thickness (CT) in the horizontal axis in young myopic adults after orthokeratology treatment.

METHODS

This was a retrospective research among young myopic patients (-1.0 to -5.0 diopters) aged 19-29 years (n = 36; 23.6 ± 2.5 years). We selected patients who were treated with orthokeratology for 12 months. CT values of the horizontal axis near the fovea before and after orthokeratology treatment were analyzed using optical coherence tomography. The value was measured at the beginning of treatment and at 3, 6, and 12 months after orthokeratology treatment. Three regional areas of choroid on the horizontal plane including fovea were analyzed.

RESULT AND CONCLUSIONS

In the beginning of orthokeratology treatment, CT of the horizontal axis was 248.9 ± 45.7 μm in the temporal region, 259.9 ± 55.3 μm in the macular region, and 219.2 ± 46.4 μm in the nasal region. Three months after orthokeratology treatment, thickness values of choroids in the 3 divided areas increased significantly (p < 0.05). Mean CT at 6 or 12 months after orthokeratology treatment was greater than before ortho<X00_Del_TrennDivis>--</X00_Del_TrennDivis>keratology treatment. CT increased after 3 months of orthokeratology treatment in each regional area. In young myopic adults, CT in nasal area was thinner than that in foveal or temporal area before treatment. CT recovered to near baseline when it was observed for more than 6 months after orthokeratology treatment.

Effect of Defocus Incorporated Multiple Segments Spectacle Lens Wear on Visual Function in Myopic Chinese Children

Purpose

To compare visual function of myopic children who had worn either defocus incorporated multiple segment (DIMS) spectacle lenses or single vision (SV) spectacle lenses over two years.

Methods

We included 160 Chinese myopic (−1 diopter [D] to −5 D) children aged 8 to 13 years in a randomized clinical trial; they wore either DIMS lenses (DIMS; n = 79) or regular SV spectacles lenses (n = 81) full time for 2 years. Visual function, including high-contrast visual acuity (VA) and low-contrast VA at distance and near, binocular functions, and accommodation, before, during, and after 2 years of spectacle wear were assessed when both groups wore SV corrections. Changes of visual function between the two groups and within groups were compared.

Results

There were no statistically significant differences in the 2-year visual function changes between DIMS and SV groups (repeated measures analysis of variance with group as factor; P > 0.05). Statistically significant improvement in the best-corrected distance high-contrast VA (P < 0.001) and stereoacuity score (P < 0.001) were found after DIMS lens wear over 2 years. Similar findings were observed after SV spectacle lens wear. For both the DIMS and SV groups, there were statistically significant decreases in accommodative lag, monocular and binocular amplitude of accommodation after two years (P < 0.01), but not in the changes in distance low-contrast VA, near high-contrast VA, near low-contrast VA, or phoria.

Conclusions

Although changes in some visual function were shown during 2 years of DIMS lens wear, similar changes were found with SV lens wear. Wear of DIMS spectacle lenses for 2 years does not adversely affect major visual function when children return to SV corrections.

Translational Relevance

DIMS spectacle lenses did not cause any adverse effects on visual function.

Myopia and its progression in children in London, UK: a retrospective evaluation

PURPOSE

Worldwide, the prevalence of myopia is increasing. Myopia begins at younger ages and progresses faster, leading to more adults with high myopia and risk of sight-threatening complications. No data are available about myopia trends in children in urban areas in the UK. We present a 10-year review of children attending a secondary and tertiary eye care facility in London, focussing on the proportion of glasses prescriptions for myopia and progression rates.

METHODS

We collated refraction and demographic data from children under the age of 17 years seen at Moorfields Eye Hospital, London, UK, between 2008 and 2017.

RESULTS

We included 63,854 datasets from 23,593 children (51.2% boys, median age 5.4 years, interquartile range IQR 3.8-7.1). The proportion of myopic prescriptions increased from 24 to 32%. In n = 3355 with initial mild/moderate myopia, median progression rate was -0.16 (-0.5 to 0.04) D/year. In those with progression (n = 2095), the rate was -0.40 (-0.19 to -0.74) D/year, slightly higher in girls than in boys (-0.42 vs -0.38 D/year; p = 0.02). Progression was faster in initial moderate than initial mild myopia (-0.54 vs -0.37 D/year; p < 0.001), and before than after average age of onset of puberty (-0.41 vs -0.35 D/year; p = 0.013). There was no statistically significant difference between children of different ethnic backgrounds.

CONCLUSIONS

In this cohort, the proportion of glasses prescriptions for myopia and the rate of progression are higher than previously reported for European countries. Living in an urban environment may result in similar progression rates despite different genetic backgrounds.

Overnight orthokeratology

Overnight orthokeratology lenses are approved in countries all over the world for the temporary reduction in myopia, and recently, one lens design has received regulatory approval for myopia control in Europe. The modern orthokeratology lens has a substantial history from its origins of attempting to flatten the corneal curvature with a spherical rigid contact lens to sophisticated gas permeable lenses, designed to reshape the cornea. These lenses are predominantly prescribed for children to slow myopia progression and limit axial elongation of the eye. This article reviews the peer-reviewed literature on the efficacy of orthokeratology for myopia control, sustainability after treatment is discontinued, and the safety concerns of overnight contact lens wear. Future avenues of research are discussed.

Bifocal & Atropine in Myopia Study: Baseline Data and Methods

SIGNIFICANCE

The Bifocal & Atropine in Myopia (BAM) study aims to determine whether combining 0.01% atropine and +2.50-diopter add center-distance soft bifocal contact lenses (SBCL) slows myopia progression more than SBCL alone. The results could provide significant information on the myopia control effect of combining optical and pharmacological treatments.

PURPOSE

This article describes the subject characteristics at baseline, the study methods, and the short-term effects of this combination treatment on visual acuity (VA) and vision-related outcomes.

METHODS

Subjects from the BAM study who met the baseline eligibility criteria were dispensed the combination treatment for 2 weeks to determine final eligibility. Outcome measures included VA at near and distance (Bailey-Lovie logMAR charts), near phoria (modified Thorington), accommodative lag (Grand Seiko WAM-5500), and pupil size (NeurOptics VIP-200 Pupillometer). Compliance was monitored using surveys. Two subgroups in the Bifocal Lenses In Nearsighted Kids study, single-vision contact lens wearers and those who wore +2.50-diopter add SBCL, will serve as the age-matched historical controls for BAM study.

RESULTS

Forty-nine BAM subjects (9.6 ± 1.4 years) were enrolled; mean spherical equivalent cycloplegic autorefraction was -2.33 ± 1.03 diopters. After 2 weeks of treatment, the best-corrected low-contrast (10% Michelson) distance VA was reduced (pre-treatment, +0.09 ± 0.07; post-treatment, +0.16 ± 0.08; P < .0001), but the high-contrast VA at near or distance was unaffected. Near phoria increased by approximately 2 in the exo direction (P = .01), but the accommodative lag was unchanged. The pupil size was not significantly different between pre-treatment and post-treatment of either the photopic or mesopic condition. Surveys indicated that the subjects wore SBCL 77 ± 22% of waking hours and used atropine 6.4 ± 0.7 days per week.

CONCLUSIONS

Two weeks of combination treatment reduced low-contrast distance VA and increased near exophoria slightly, but the subjects were compliant and tolerated the treatment well.

Changes in axial length after orthokeratology lens treatment for myopia: a meta-analysis

PURPOSE

Orthokeratology (OK) lens is a popular optical method to control myopia progression. This study aimed to assess the effect of OK lens on axial length change compared with glasses.

METHODS

PubMed, Web of Science, and Embase were searched to retrieve the related articles. Then, the articles were selected according to predefined criteria. Standardized mean difference (SMD) and 95% confidence interval (CI) were selected as effect size for combining and analyzing the change in axial length.

RESULTS

A total of 13 articles were included in the present study. Different models were selected according to the heterogeneity of each analysis. The axial length change in OKs group was significantly smaller than control group; SMD (95% CI) of change in axial length was - 0.857 (- 1.146, - 0.568), p < 0.001 at the end of 1 year and - 0.701 (- 1.675, 0.272), p < 0.001 at the end of 2 years or longer time.

CONCLUSIONS

OK lens treatment appears more effective in slowing axial elongation than glasses during the early treatment of myopia in children.

Stability of peripheral refraction changes in orthokeratology for myopia

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.

Reducing treatment zone diameter in orthokeratology and its effect on peripheral ocular refraction

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.

Influence of Overnight Orthokeratology Lens Treatment Zone Decentration on Myopia Progression

Purpose

To investigate the effect of OK lens treatment zone decentration on myopia control.

Methods

We retrospectively selected 30 OK lens wearers who met the following conditions in our hospital from more than 1300 cases: wearing lens in both eyes and only one eye was off-center while the other one was centric for more than 12 months. During the period of follow-up, the UCVA of each eye was better than 0.1 of logMAR and there were no obvious tropia, Kappa angle, and complications such as glare and diplopia.

Result

Among 30 cases, 15 are males and 15 are females, with an average age of 9.3 ± 1.51Y. There were no significant differences in equivalent spherical lens, astigmatism, e value, flat K, steep K, astigmatism, lens diameter, and toric between the two groups (p > 0.05). The average distance of decentration was 0.73 ± 0.25 mm. Axis growth per year in was 0.20 ± 0.24 mm the OK-lens-decentered group and 0.29 ± 0.20 mm in the OK-lens-centric group, which shows significant difference between them (p < 0.05). According to the direction of decentration, 30 decentered eyes were divided into temporal group (20 eyes) and other direction group (10 eyes). The efficiency of myopia control (the growth of AL per year in OK-lens-decentered eye/the growth of AL per year in the contralateral OK-lens-centric eye) was 0.69 ± 0.50 in the temporal decentration group and 0.75 ± 0.52 in the other direction group, showing no significant difference between them (p > 0.05). There was no significant correlation between the efficiency of myopia control and the degree of decentration among temporal decentration group (p > 0.05).

Conclusion

This self-control study without much interference factors shows that the decentration of OK lens can delay the development of myopia more effectively than being centric when uncorrected visual acuity was acceptable without obvious corneal complications, glare, or ghosting.

Multifocal spectacles in childhood myopia: Are treatment effects maintained? A systematic review and meta-analysis

We evaluate the impact of duration on the treatment effect of multifocal spectacle lenses used to inhibit myopia progression in children. A systematic literature search identified randomized controlled trials where multifocal lenses were prescribed as the intervention, with single-vision lenses as the control. Nine randomized control trials involving 1,701 children aged 8-13 years were included in the meta-analysis. Treatment effects, that is, differences in spherical equivalent refraction between intervention and nonintervention groups, were analyzed over both 6- and 12-month intervals. As treatment duration increased, effectiveness reduced. In 6-month intervals, treatment effects were 0.07 D (95 % CI 0.02, 0.13), 0.03 D (95% CI -0.02, 0.08), and 0.02 D (95% CI -0.05, 0.11) for baseline to 6, 6-12, and 12-18 months, respectively. For 12-month intervals, treatment effects were 0.21 D (95% CI 0.12, 0.29), 0.11 D (95% CI 0.03, 0.19), and 0.12 D (95% CI -0.01, 0.25) for baseline to 12, 12-24, and 24-36 months, respectively. Even during the second 6 months of wear, the ability of multifocal spectacle lenses to inhibit myopia progression was reduced. It is not appropriate to extrapolate the treatment effect observed in the first 6 months or 12 months to estimate the likely future benefit of treatment.

Association between long-term orthokeratology responses and corneal biomechanics

Myopia is very prevalent worldwide, especially among Asian populations. Orthokeratology is a proven intervention to reduce myopia progression. The current study investigated association between baseline corneal biomechanics and orthokeratology responses, and changes of corneal biomechanics from long-term orthokeratology. We fitted 59 adult subjects having myopia between −4.00D to −5.00D with overnight orthokeratology. Corneal biomechanics was measured through dynamic bidirectional corneal applanation (in terms of corneal hysteresis, CH and corneal resistance factor, CRF) and corneal indentation (in terms of corneal stiffness, S and tangent modulus, E). Subjects with poor orthokeratology responses had lower E (mean 0.474 MPa) than subjects with good orthokeratology responses (mean 0.536 MPa). Successful orthokeratology for 6 months resulted in reducing CH (reduced by 5.8%) and CRF (reduced by 8.7%). Corneal stiffness was stable, but E showed an increasing trend. Among subjects with successful orthokeratology, a higher baseline S resulted in greater myopia reduction (Pearson correlation coefficient, r = 0.381, p = 0.02).

IMI - Myopia Control Reports Overview and Introduction

With the growing prevalence of myopia, already at epidemic levels in some countries, there is an urgent need for new management approaches. However, with the increasing number of research publications on the topic of myopia control, there is also a clear necessity for agreement and guidance on key issues, including on how myopia should be defined and how interventions, validated by well-conducted clinical trials, should be appropriately and ethically applied. The International Myopia Institute (IMI) reports the critical review and synthesis of the research evidence to date, from animal models, genetics, clinical studies, and randomized controlled trials, by more than 85 multidisciplinary experts in the field, as the basis for the recommendations contained therein. As background to the need for myopia control, the risk factors for myopia onset and progression are reviewed. The seven generated reports are summarized: (1) Defining and Classifying Myopia, (2) Experimental Models of Emmetropization and Myopia, (3) Myopia Genetics, (4) Interventions for Myopia Onset and Progression, (5) Clinical Myopia Control Trials and Instrumentation, (6) Industry Guidelines and Ethical Considerations for Myopia Control, and (7) Clinical Myopia Management Guidelines.

IMI - Industry Guidelines and Ethical Considerations for Myopia Control Report

Purpose

To discuss guidelines and ethical considerations associated with the development and prescription of treatments intended for myopia control (MC).

Methods

Critical review of published papers and guidance documents was undertaken, with a view to carefully considering the ethical standards associated with the investigation, development, registration, marketing, prescription, and use of MC treatments.

Results

The roles and responsibilities of regulatory bodies, manufacturers, academics, eye care practitioners, and patients in the use of MC treatments are explored. Particular attention is given to the ethical considerations for deciding whether to implement a MC strategy and how to implement this within a clinical trial or practice setting. Finally, the responsibilities in marketing, support, and education required to transfer required knowledge and skills to eye care practitioners and academics are discussed.

Conclusions

Undertaking MC treatment in minors creates an ethical challenge for a wide variety of stakeholders. Regulatory bodies, manufacturers, academics, and clinicians all share an ethical responsibility to ensure that the products used for MC are safe and efficacious and that patients understand the benefits and potential risks of such products. This International Myopia Institute report highlights these ethical challenges and provides stakeholders with recommendations and guidelines in the development, financial support, prescribing, and advertising of such treatments.

IMI - Interventions Myopia Institute: Interventions for Controlling Myopia Onset and Progression Report

Myopia has been predicted to affect approximately 50% of the world's population based on trending myopia prevalence figures. Critical to minimizing the associated adverse visual consequences of complicating ocular pathologies are interventions to prevent or delay the onset of myopia, slow its progression, and to address the problem of mechanical instability of highly myopic eyes. Although treatment approaches are growing in number, evidence of treatment efficacy is variable. This article reviews research behind such interventions under four categories: optical, pharmacological, environmental (behavioral), and surgical. In summarizing the evidence of efficacy, results from randomized controlled trials have been given most weight, although such data are very limited for some treatments. The overall conclusion of this review is that there are multiple avenues for intervention worthy of exploration in all categories, although in the case of optical, pharmacological, and behavioral interventions for preventing or slowing progression of myopia, treatment efficacy at an individual level appears quite variable, with no one treatment being 100% effective in all patients. Further research is critical to understanding the factors underlying such variability and underlying mechanisms, to guide recommendations for combined treatments. There is also room for research into novel treatment options.

Efficacy and safety of interventions to control myopia progression in children: an overview of systematic reviews and meta-analyses

Background

Myopia is a common visual disorder with increasing prevalence. Halting progression of myopia is critical, as high myopia can be complicated by a number of vision-compromising conditions.

Methods

Literature search was conducted in the following databases: Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica dataBASE (EMBASE), Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE) and Centre for Reviews and Dissemination (CRD) Health Technology Assessment (HTA) database. Systematic reviews and meta-analyses investigating the efficacy and safety of multiple myopia interventions vs control conditions, were considered. Methodological quality and quality of evidence of eligible studies were assessed using the ROBIS tool and GRADE rating. The degree of overlapping of index publications in the eligible reviews was calculated with the corrected covered area (CCA).

Results

Forty-four unique primary studies contained in 18 eligible reviews and involving 6400 children were included in the analysis. CCA was estimated as 6.2% and thus considered moderate. Results demonstrated the superior efficacy of atropine eyedrops; 1% atropine vs placebo (change in refraction: -0.78D, [− 1.30 to − 0.25] in 1 year), 0.025 to 0.05% atropine vs control (change in refraction: -0.51D, [− 0.60 to − 0.41] in 1 year), 0.01% atropine vs control (change in refraction: -0.50D, [− 0.76 to − 0.24] in 1 year). Atropine was followed by orthokeratology (axial elongation: − 0.19 mm, [− 0.21 to − 0.16] in 1 year) and novel multifocal soft contact lenses (change in refraction: -0.15D, [− 0.27 to − 0.03] in 1 year). As regards adverse events, 1% atropine induced blurred near vision (odds ratio [OR] 9.47, [1.17 to 76.78]) and hypersensitivity reactions (OR 8.91, [1.04 to 76.03]).

Conclusions

Existing evidence has failed to convince doctors to uniformly embrace treatments for myopic progression control, possibly due to existence of some heterogeneity, reporting of side effects and lack of long-term follow-up. Research geared towards efficient interventions is still necessary.

Electronic supplementary material

The online version of this article (10.1186/s12886-019-1112-3) contains supplementary material, which is available to authorized users.

Repeatability of choroidal thickness measurements with Spectralis OCT images

Objective

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

Methods and analysis

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

Results

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

Conclusion

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

Short-Term Effects of Overnight Orthokeratology on Corneal Sensitivity in Chinese Children and Adolescents

Purpose

To assess the effects of the 3-month period of orthokeratology (OK) treatment on corneal sensitivity in Chinese children and adolescents.

Methods

Thirty subjects wore overnight OK lenses in both eyes for 3 months and were assessed at baseline, 1 day, 1 week, 1 month, and 3 months after the treatment. Changes in corneal sensitivity were measured by the Cochet–Bonnet (COBO) esthesiometer at the corneal apex and approximately 2 mm from the temporal limbus. Changes in refraction and corneal topography were also measured.

Results

Central corneal sensitivity suffered a significant reduction within the first month of the OK treatment period but returned to the baseline level at three months (F = 3.009, P=0.039), while no statistically significant difference occurred in temporal sensitivity (F = 2.462, P=0.074). The baseline of central corneal sensitivity correlated with age (r = −0.369, P=0.045). A marked change in refraction (uncorrected visual acuity, P < 0.001; spherical equivalent, P < 0.001) and corneal topographical condition (mean keratometry reading, P < 0.001; eccentricity value, P < 0.001; Surface Regularity Index, P < 0.001) occurred, but none of these measurements were correlated with corneal sensitivity.

Conclusions

A 3-month period OK treatment causes a reduction in central corneal sensitivity in Chinese children and adolescents but with a final recovery to the baseline level, which might be because neuronal adaptation occurred earlier in children and adolescents than in adults.

Assessment of Tear Film and Bulbar Redness by Keratograph 5M in Pediatric Patients After Orthokeratology

OBJECTIVES

To assess the tear meniscus height (TMH), noninvasive tear breakup time (NITBUT), and bulbar redness in pediatric patients after orthokeratology (OK).

METHODS

Pediatric patients who underwent overnight OK between December 2014 and November 2017 were retrospectively investigated. According to the time of wearing, subjects were divided into three groups: 1-week, 1-month, and over 1-year. Age-matched subjects were recruited as a control group. Keratograph 5M was used to assess TMH, NITBUT-first, NITBUT-average, and bulbar redness score.

RESULTS

A total of 106 subjects aged from 7 to 15 years were included. Compared with control group, NITBUT-first was significantly lower in 1-week group (P=0.036) and NITBUT-average was significantly lower in 1-month group (P=0.019). Compared with over 1-year group, NITBUT-first was significantly lower in 1-week and 1-month groups (P=0.014, P=0.035, respectively), and NITBUT-average was significantly lower in 1-month group (P=0.022). Bulbar redness score was significantly lower in 1-month group than 1-week group (P=0.004). No significant difference in TMH was found between all groups. Significant correlation was found between NITBUT-first and NITBUT-average in all subjects (R=0.812, P<0.001). No other significant correlations were found between variables included TMH, NITBUT, bulbar redness score, or target correction.

CONCLUSIONS

As a noninvasive method, Keratograph 5M was easily to be applied on pediatric patients. The OK lens did not induce significant tear deficiency or bulbar redness, but might affect tear film stability in a short term after wearing.

Comparison Between Viscous Teardrops and Saline Solution to Fill Orthokeratology Contact Lenses Before Overnight Wear

OBJECTIVE

To compare, in terms of efficacy, the differences between the use of saline solution and a viscous artificial tear to fill the lens during the first month of orthokeratology wear.

METHODS

A pilot, double-masked, crossed, randomized, and prospective study was conducted. In this study, 20 subjects (14 males and 6 females) with a mean age of 16.29±6.22 years (range, 10-26) were fitted with orthokeratology contact lenses. For the study, nonpreserved 0.9% NaCl commercial saline solution (Avizor, Madrid, Spain) and nonpreserved artificial teardrops with 0.3% of hyaluronic acid (Ocudry 0.3%; Avizor, Madrid, Spain) were used. Corneal staining, tear break up time (TBUT), topography, refraction, visual acuity, and subjective comfort and vision with the visual analog scale (score from 0 to 10, being 10 better comfort and vision) were evaluated at 1 day, 1 week, and 1 month of contact lens wear.

RESULTS

The corneal staining was statistically greater in the saline group than in the Ocudry group for the first day and during 1 week of wear (P<0.05). Comfort was found to be statistically better, with Ocudry 0.3% than saline solution, being 7.17±1.94 and 6.37±1.63, for the first day, and 8.78±0.43 and 8.15±0.62 for the day 28, respectively (P<0.05). However, no differences were found for subjective vision scores, TBUT, spherical equivalent, best-corrected visual acuity and uncorrected visual acuity, and mean keratometry between groups for any visit (P>0.05).

CONCLUSION

Viscous artificial tears improve the subjective comfort of patients and reduce the corneal staining, compared with saline solution during the orthokeratology lenses fitting process. However, no differences between solutions for the treatment efficacy, in vision and corneal topography, were found.

Case Series Analysis of Myopic Progression Control With a Unique Extended Depth of Focus Multifocal Contact Lens

OBJECTIVES

To determine the rate of myopia progression in children fit with a commercially available extended depth of focus (center distance) multifocal soft contact lens with attributes theoretically expected to slow the progression of myopia.

METHODS

A retrospective case series analysis of 32 patients (ages 6-19 years, mean 10.98±2.95) from 10 practice locations was performed. At initial presentation, 44% wore spectacles, 37.5% spherical soft contact lenses, 15.6% a different soft multifocal contact lens, and 3% orthokeratology lenses. All participants showed progression of at least -0.50 diopter with current corrections and were fit with an extended depth of focus (center distance) multifocal soft contact lens (NaturalVue Multifocal 1 Day Contact Lenses; Visioneering Technologies, Inc., Alpharetta, GA). Follow-up time was 6 to 25 months (mean: 10.94±4.76).

RESULTS

Reductions in the annualized rate of myopic progression from -0.85 D per year ±0.43 D to -0.04 D per year ±0.18 D (P<0.00000) OD, -0.90 D per year ±0.57 D to -0.03 D per year ±0.17 D (P<0.00000) OS were observed. These data represent a reduction of 95.4% OD and 96.25% OS. Approximately 98.4% of the children showed reduction of annualized myopic progression; 91% showed a decrease of 70% or greater. Overall, 81.25% showed complete halting of myopic progression, including 6.25% demonstrating myopic regression.

CONCLUSIONS

This unique extended depth of focus (center distance) daily disposable multifocal contact lens was effective in slowing myopic progression in these children. These findings add to the growing evidence that center distance multifocal soft contact lenses may slow the progression of myopia.

Prevention of Progression in Myopia: A Systematic Review

The prevalence of myopia has increased worldwide in recent decades and now is endemic over the entire industrial world. This increase is mainly caused by changes in lifestyle and behavior. In particular, the amount of outdoor activities and near work would display an important role in the pathogenesis of the disease. Several strategies have been reported as effective. Spectacles and contact lenses have shown only slight results in the prevention of myopia and similarly ortokerathology should not be considered as a first-line strategy, given the high risk of infectious keratitis and the relatively low compliance for the patients. Thus, to date, atropine ophthalmic drops seem to be the most effective treatment for slowing the progression of myopia, although the exact mechanism of the effect of treatment is still uncertain. In particular, low-dose atropine (0.01%) was proven to be an effective and safe treatment in the long term due to the lowest rebound effect with negligible side effects.

The Adenosine Receptor Antagonist, 7-Methylxanthine, Alters Emmetropizing Responses in Infant Macaques

Purpose

Previous studies suggest that the adenosine receptor antagonist, 7-methylxanthine (7-MX), retards myopia progression. Our aim was to determine whether 7-MX alters the compensating refractive changes produced by defocus in rhesus monkeys.

Methods

Starting at age 3 weeks, monkeys were reared with −3 diopter (D; n = 10; 7-MX −3D/pl) or +3D (n = 6; 7-MX +3D/pl) spectacles over their treated eyes and zero-powered lenses over their fellow eyes. In addition, they were given 100 mg/kg of 7-MX orally twice daily throughout the lens-rearing period (age 147 ± 4 days). Comparison data were obtained from lens-reared controls (−3D/pl, n = 17; +3D/pl, n = 9) and normal monkeys (n = 37) maintained on a standard diet. Refractive status, corneal power, and axial dimensions were assessed biweekly.

Results

The −3D/pl and +3D/pl lens-reared controls developed compensating myopic (−2.10 ± 1.07 D) and hyperopic anisometropias (+1.86 ± 0.54 D), respectively. While the 7-MX +3D/pl monkeys developed hyperopic anisometropias (+1.79 ± 1.11 D) that were similar to those observed in +3D/pl controls, the 7-MX −3D/pl animals did not consistently exhibit compensating myopia in their treated eyes and were on average isometropic (+0.35 ± 1.96 D). The median refractive errors for both eyes of the 7-MX −3D/pl (+5.47 D and +4.38 D) and 7-MX +3D/pl (+5.28 and +3.84 D) monkeys were significantly more hyperopic than that for normal monkeys (+2.47 D). These 7-MX–induced hyperopic ametropias were associated with shorter vitreous chambers and thicker choroids.

Conclusions

In primates, 7-MX reduced the axial myopia produced by hyperopic defocus, augmented hyperopic shifts in response to myopic defocus, and induced hyperopia in control eyes. The results suggest that 7-MX has therapeutic potential in efforts to slow myopia progression.

A Review of Current Concepts of the Etiology and Treatment of Myopia

Myopia occurs in more than 50% of the population in many industrialized countries and is expected to increase; complications associated with axial elongation from myopia are the sixth leading cause of blindness. Thus, understanding its etiology, epidemiology, and the results of various treatment regiments may modify current care and result in a reduction in morbidity from progressive myopia. This rapid increase cannot be explained by genetics alone. Current animal and human research demonstrates that myopia development is a result of the interplay between genetic and the environmental factors. The prevalence of myopia is higher in individuals whose both parents are myopic, suggesting that genetic factors are clearly involved in myopia development. At the same time, population studies suggest that development of myopia is associated with education and the amount time spent doing near work; hence, activities increase the exposure to optical blur. Recently, there has been an increase in efforts to slow the progression of myopia because of its relationship to the development of serious pathological conditions such as macular degeneration, retinal detachments, glaucoma, and cataracts. We reviewed meta-analysis and other of current treatments that include: atropine, progressive addition spectacle lenses, orthokeratology, and multifocal contact lenses.

Vision Improvement and Compliance With the Use of Orthokeratology Lenses in School Children: A Sample From Five Primary Schools in Northern Taiwan

PURPOSE

To assess the visual acuity and compliance with the use of orthokeratology lenses (OrthoK) in school children.

METHODS

A retrospective study was conducted to determine the education-related factors influencing the improvement in visual acuity in myopic students using OrthoK in five primary schools in Taiwan.

RESULTS

Of the 5,173 eligible students from five primary schools, 1906 (36.8%) students were diagnosed with myopia. Among 201 (10.6%) students wearing OrthoK, 69.7% had used them for at least 1 year, 53.2% achieved visual acuity greater than 0.8 (6/7.5, log of minimal angle of resolution 0.1) in school, and 49.8% had received health education related to OrthoK care. Multiple logistic regression analysis showed that a higher possibility to achieve visual acuity greater than 0.8 was associated with more than 1-year use of OrthoK, good compliance, and receiving health education from an ophthalmologist.

CONCLUSION

It is important that children wearing OrthoK receive education and comply with the use of OrthoK for visual acuity improvement.

Short term effect of choroid thickness in the horizontal meridian detected by spectral domain optical coherence tomography in myopic children after orthokeratology

AIM

To investigate choroidal thickness changes in the horizontal meridian after orthokeratology.

METHODS

This is a prospective cross-sectional observed study. Subjects (n=30; 11.3±1.7y) with low-to-moderate myopia (-1.0 to -6.0 diopters), wore orthokeratology (Ortho-K) lenses for 3mo. Before and after Ortho-K, OCT scans were made through the fovea in the horizontal meridian. Choroid thickness around the fovea was acquired by custom software. The analyzed regions along the horizontal meridian were divided into 7 equal zones. Ocular parameters were measured by Lenstar LS 900 non-contact biometry.

RESULTS

Only the right eye ocular parameters were analyzed in this study. Before Ortho-K, choroidal thickness along the horizontal meridian was 273.7±31.8 µm in the temporal zone, 253.1±38.6 µm in the macula zone, and 194.8±52.2 µm in the nasal zone. After Ortho-K, the choroid was thicker in each horizontal zone (P<0.05). The increased thickness was greatest in the temporal zone (13.5±22.5 µm) and least in the nasal zone (8.4±14.2 µm). The axial length (AL) increased 0.02 mm (P>0.05). The choroid thickness change in each horizontal zone was negatively correlated with AL (r, -0.3 to -0.4; P<0.05) except one of the nasal zones.

CONCLUSION

In myopic children, the thickness of the choroid is greatest in the temporal zone and thinnest in the nasal zone. After nightly Ortho-K for 3mo, the thickness increase along the horizontal meridian. The choroid thickness changes are negatively correlated with the change of AL.

Predictive Role of Paracentral Corneal Toricity Using Elevation Data for Treatment Zone Decentration During Orthokeratology

PURPOSE

To investigate the influence of paracentral corneal toricity using elevation data on the treatment zone decentration of spherical and toric orthokeratology (Ortho-k) lens.

METHODS

Corneal elevation difference (CED) was defined as the difference of corneal elevation between the two principle meridians at 8-mm chord, representing the paracentral corneal toricity. Seventy-five subjects included in this prospective study were divided into a low CED (LCED) group (LCED<30μm, n = 25) and a high CED (HCED) group (HCED≥30μm, n = 50). All subjects in the LCED group and 25 subjects in the HCED group (HCED I) were fitted with spherical Ortho-k; the other 25 subjects in the HCED group (HCED II) were fitted with toric Ortho-k. Corneal topography data from the right eyes were obtained at baseline and after 1 month of lens wear. The amount and direction of treatment zone decentration among the three groups were compared, and their relationships with corneal shape parameters, including central and paracentral corneal toricity, corneal asymmetry, flat-k and eccentricity, and lens diameter were analyzed using univariable and multivariate linear regression models.

RESULTS

The magnitude of treatment zone decentration was the greatest in the HCED I group ((LCED vs. HCED I vs. HCED II: 0.47 ± 0.15mm vs. 0.73 ± 0.15mm vs. 0.47 ± 0.19mm, respectively; ANOVA, p < 0.01). Among participants fitted with spherical Ortho-k, the magnitude of treatment zone decentration was significantly correlated to paracentral CED after adjusting for the other corneal parameters and lens diameter (standard β = 0.599, p < 0.01). No significant correlation between these parameters was found among those fitted with toric Ortho-k.

CONCLUSIONS

Eyes with greater paracentral CED tend to have increased decentration of spherical Ortho-k lens, whereas toric Ortho-k appears to reduce the amount of lens decentration in eyes with CED at 8-mm chord above 30 μm.

Influence of overnight orthokeratology lens fitting decentration on corneal topography reshaping

Background

This retrospective study was designed to investigate the sole influence of orthokeratology (OK) lens fitting decentration on the Zernike coefficients of the reshaped anterior corneal surface.

Methods

This study comprised a review of 106 right eyes and measurements of corneal topography both before OK and at 1-month follow-up visit. A routine was designed to calculate local corneal surface astigmatism and assist the determination of OK lens fitting decentration from pupil center. The pupil-centered corneal Zernike coefficients of baseline (PCCB) and post-treatment (PCCP) were calculated. Meanwhile, the OK-lens-centered corneal Zernike coefficients of post-treatment (OCCP) were also calculated and considered as the presumptive ideal fitting group without decentration. Relationships between lens fitting decentration and the change of Zernike coefficients including (PCCP − PCCB) and (PCCP − OCCP) were analyzed.

Results

Patients with a mean age of 11 ± 2.36 years old had an average spherical equivalent refractive error of −3.52 ± 1.06 D before OK. One month after treatment, OK lens fitting decentration from pupil center was 0.68 ± 0.35 mm. RMS of 3rd-order (P < 0.05), RMS of 4th-order (P < 0.001) and RMS of total high order (P < 0.001) corneal Zernike coefficients were increased in PCCP by comparing with OCCP, which was solely caused by lens fitting decentration. Nevertheless, no significant difference was observed in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_2^0 $$\end{document}C20 (P > 0.05). For the high order corneal Zernike coefficients in (PCCP – OCCP), radial distance of decentration was correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_3^{-1} $$\end{document}C3−1 (r = −0.296, P < 0.05), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_3^1 $$\end{document}C31 (r = −0.396, P < 0.001), and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_4^0 $$\end{document}C40 (r = 0.449, P < 0.001), horizontal decentration was significantly correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_3^1 $$\end{document}C31 (r = 0.901, P < 0.001) and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_5^1 $$\end{document}C51 (r = 0.340, P < 0.001), and vertical decentration was significantly correlated with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_3^{-1} $$\end{document}C3−1 (r = 0.904, P < 0.001).

Conclusions

OK lens fitting decentration within 1.5 mm hardly influenced the change of corneal spherical power for myopia correction, but significantly induced additional corneal high order Zernike coefficients including \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_3^{-1} $$\end{document}C3−1, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_3^1 $$\end{document}C31, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_4^0 $$\end{document}C40, and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {C}_5^1 $$\end{document}C51.

The effect of orthokeratology on axial length elongation in children with myopia: Contralateral comparison study

PURPOSE

To evaluate the effectiveness of the orthokeratology (OK) lens slowing myopic progression compared with no intervention in pediatric eyes METHODS: A retrospective review of medical records was performed on 45 monocular myopic subjects 7 to 13 years of age who were treated with monocular ortho-k lens and followed-up for more than 12 months. The monocular myopia in the subjects' eyes was -0.75 to -4.25 D (diopter), and near emmetropia in the contralateral and with-the-rule astigmatism no greater than -1.50 D. Axial elongation OU, reflecting the progression of myopia was measured at baseline using the same AL-Scan Optical Biometer and compared between the two eyes of each individual every six months for one year in all subjects and for two years in 9 subjects.

RESULTS

After 12 months of lens wear, axial length had increased by 0.36 ± 0.23mm in the control eyes (P < 0.001) but showed far less change (+0.07 ± 0.21 mm) in the OK eyes (P = 0.038). The nine subjects followed-up for 2 years showed no axial length change (+0.16 ± 0.25 mm) in the OK eyes (P = 0.095) after 24 months and significant axial length growth (+0.38 ± 0.26 mm; P = 0.002) in the control eyes. Control eyes showed progressive axial length growth throughout the study compared with the one OK lens eye.

CONCLUSIONS

Using a contralateral eye study design, which prevented the influence of potential confounding factors, Effectiveness of the OK lens was proved. Myopic progression within a subject was excellent compared with no intervention.

Optical and pharmacological strategies of myopia control

Recent increases in global myopia prevalence rates have raised significant concerns as myopia increases the lifelong risk of various sight-threatening ocular conditions. This growing public health burden has generated significant research interests into understanding both its aetiology and developing effective methods to slow down or stop its development, methods collectively termed 'myopia control'. The growing body of research has demonstrated benefits of various optical and pharmacological treatments resulting in myopia control management increasingly becoming a part of main stream clinical practice. This review will discuss the peer-reviewed literature on the efficacy of various myopia control interventions including multifocal spectacles and contact lenses, orthokeratology and pharmaceutical eye drops, as well as potential future research directions.

MiSight Assessment Study Spain (MASS). A 2-year randomized clinical trial

PURPOSE

To compare myopia progression in children randomized to MiSight contact lenses (CLs) versus children corrected with single-vision spectacles (SV) over a 2-year period.

METHODS

Subjects aged 8 to 12 with myopia (-0.75 to -4.00 D sphere) and astigmatism (< -1.00 D cylinder) were assigned to the lens study group (MiSight) or the control group (single vision). Measurements of visual acuity and subjective refraction were taken at 6-month intervals, and axial length, anterior chamber, corneal power, and cycloplegic autorefraction were measured at the baseline, 12-month, and 24-month visits.

RESULTS

Eighty-nine subjects were recruited. Forty-fix children were assigned to the MiSight group, and 33 to the single-vision spectacle group. In total, 74 children completed the clinical trial, with the following parameters at the beginning of the study: n =  41 in the MiSight group (age: 11.01 ± 1.23 years, spherical equivalent: -2.16 ± 0.94 D, gender: male: 21, female: 20) and n = 33 in the single-vision group (age: 10.12 ± 1.38 years, spherical equivalent: -1.75 ± 0.94 D, gender: male: 12, female: 21). After 2 years of follow-up, myopia progressed slowly in the MiSight group compared to the control group (0.45 D vs 0.74 D, p < 0.001) and there was less axial elongation in the MiSight group compared to the single-vision group (0.28 mm vs 0.44 mm, p < 0.001). Therefore, use of MiSight CLs produced lower myopia progression (39.32%) and lower axial growth of the eye (36.04%) at 2 years compared to spectacle use.

CONCLUSIONS

MiSight contact lens wear reduces axial elongation and myopia progression in comparison to distance single-vision spectacles in children. ClinicalTrials.gov Identifier: NCT01917110.

Influence of Overnight Orthokeratology on Corneal Surface Shape and Optical Quality

Purpose

To investigate the changes of corneal surface shape and optical quality during orthokeratology.

Methods

49 eyes of 26 patients (10.63 ± 2.02 years old) who underwent overnight orthokeratology for myopia were prospectively examined. The corneal surface shape parameters, including surface regularity index (SRI) and surface asymmetry index (SAI), were attained with an OPD-III SCAN. The higher-order aberrations and higher-order Strehl ratios were calculated under a 3 mm pupil diameter before orthokeratology, 1 month, 3 months, and 6 months after orthokeratology. A P value of less than 0.05 was statistically significant.

Results

Months after orthokeratology, SRI and SAI were both showing a significant increase in comparison with those before orthokeratology (P < 0.001). After orthokeratology, for a 3 mm pupil, the higher-order Strehl ratio presented a reduction of 0.217 μm (P < 0.001), and the higher-order aberration root mean square (HOA RMS) showed a mean increase of 0.100 μm (P < 0.001). There were significant increases in spherical aberration (P < 0.001) and coma (P = 0.044) after orthokeratology. Trefoil showed a slight reduction at month 6 after orthokeratology, but there was no statistical significance (P = 0.722).

Conclusion

Overnight orthokeratology for a correction of myopia resulted in a significant improvement in refractive error but increased corneal irregularity and ocular higher-order aberrations, especially in spherical aberration.

Choroidal thickness and axial length changes in myopic children treated with orthokeratology

PURPOSE

To analyze the change in subfoveal choroidal thickness (SFChT) and its relationship with changes in axial length (AL) in myopic children treated with Orthokeratology (Ortho-k).

METHODS

Fifty myopic children participated in this study: 29 subjects were treated with Ortho-k lenses and 21 with single vision distance spectacles. The SFChT and ocular biometrics, including AL, were measured at baseline, one month, and six months after lens wear in both groups.

RESULTS

AL significantly increased in both groups over time. In the Ortho-k group, SFChT also increased; however, there was no significant change in SFChT in the control group over time. At the six-month visit, the magnitude of eye growth was significantly reduced in the Ortho-k group compared to the control group (0.06±0.10mm vs. 0.17±0.10mm, P<0.001). SFChT was significantly thicker in the Ortho-k group compared to the control group at the one-month and six-month visits (15.78±11.37μm vs. -2.98±8.96μm, P<0.001 (one-month visit); 21.03±12.74μm vs. -2.50±14.43μm, P<0.001 (six-month visit)), although there was no significant difference between the two follow-up visits (P=0.102 for the Ortho-k group; P=0.898 for the control group). Changes in the large choroidal vascular layer (LCVL) accounted for the majority of subfoveal choroidal thickening (approximately 77% and 80% at one-month and six-month visits, respectively).

CONCLUSION

Ortho-k treatment induced significant choroidal thickening and a slowing of eye growth. LCVL thickening accounted for the majority of SFChT thickening. However, its potential mechanism in myopia control requires further investigation.

Interventions to control myopia progression in children: protocol for an overview of systematic reviews and meta-analyses

BACKGROUND

Myopia is a common visual disorder with increasing prevalence among developed countries of the world. Myopia constitutes a substantial risk factor for several ocular conditions that can lead to blindness. The purpose of this study is to conduct an overview of systematic reviews and meta-analyses in order to identify and appraise robust research evidence regarding the management of myopia progression in children and adolescents.

METHODS

A literature search will be conducted in MEDLINE, EMBASE, The Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE), and Health Technology Assessment (HTA) Database via Centre for Reviews and Dissemination (CRD). We will search for systematic reviews or meta-analyses that examine optical or pharmaceutical modalities for myopia control. Two independent overview authors will screen the titles and abstracts against the eligibility criteria. Individual study's methodological quality and quality of evidence for each outcome of interest will be assessed by two independent authors using the ROBIS tool and GRADE rating, respectively. In cases of disagreement, consensus will be reached with the help of a third author. Our primary outcomes will be the mean change in refractive error, mean axial length change, and adverse events. A citation matrix will be generated, and the corrected covered area (CCA) will be estimated, in order to identify overlapping primary studies. Possible meta-biases and measures of heterogeneity will be described, and cases of dual co-authorship will be identified and discussed. If any recently published randomized controlled trials (RCTs) are detected, these will be appraised and their findings will be presented. An overall summary of outcomes will be provided using descriptive statistics and will be supplemented by narrative synthesis.

DISCUSSION

This overview will examine the high level of existing evidence for treatment of myopia progression. Efficient interventions will be identified, and side effects will be reported. The expected benefit is that all robust recent research evidence will be compiled in a single study. The results may inform future research in this area, which should provide insight into the appropriate regimes for the administration of these modalities and contribute to future guideline development.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017068204.

The quality of systematic reviews about interventions for refractive error can be improved: a review of systematic reviews

BACKGROUND

Systematic reviews should inform American Academy of Ophthalmology (AAO) Preferred Practice Pattern® (PPP) guidelines. The quality of systematic reviews related to the forthcoming Preferred Practice Pattern® guideline (PPP) Refractive Errors & Refractive Surgery is unknown. We sought to identify reliable systematic reviews to assist the AAO Refractive Errors & Refractive Surgery PPP.

METHODS

Systematic reviews were eligible if they evaluated the effectiveness or safety of interventions included in the 2012 PPP Refractive Errors & Refractive Surgery. To identify potentially eligible systematic reviews, we searched the Cochrane Eyes and Vision United States Satellite database of systematic reviews. Two authors identified eligible reviews and abstracted information about the characteristics and quality of the reviews independently using the Systematic Review Data Repository. We classified systematic reviews as "reliable" when they (1) defined criteria for the selection of studies, (2) conducted comprehensive literature searches for eligible studies, (3) assessed the methodological quality (risk of bias) of the included studies, (4) used appropriate methods for meta-analyses (which we assessed only when meta-analyses were reported), (5) presented conclusions that were supported by the evidence provided in the review.

RESULTS

We identified 124 systematic reviews related to refractive error; 39 met our eligibility criteria, of which we classified 11 to be reliable. Systematic reviews classified as unreliable did not define the criteria for selecting studies (5; 13%), did not assess methodological rigor (10; 26%), did not conduct comprehensive searches (17; 44%), or used inappropriate quantitative methods (3; 8%). The 11 reliable reviews were published between 2002 and 2016. They included 0 to 23 studies (median = 9) and analyzed 0 to 4696 participants (median = 666). Seven reliable reviews (64%) assessed surgical interventions.

CONCLUSIONS

Most systematic reviews of interventions for refractive error are low methodological quality. Following widely accepted guidance, such as Cochrane or Institute of Medicine standards for conducting systematic reviews, would contribute to improved patient care and inform future research.

Relationship between higher-order wavefront aberrations and natural progression of myopia in schoolchildren

This study investigated the relationship between higher-order aberrations (HOAs) and myopia progression as well as axial elongation in schoolchildren. We examined cycloplegic refraction, axial length, and wavefront aberrations prospectively in 71 myopic children. Changes in cycloplegic refraction and axial length during a 2-year study period were assessed, and their correlations with HOA components were analyzed. Sixty-four subjects ([mean ± SD] 9.2 ± 1.6 years) completed the 2-year examinations. Cycloplegic refraction was significantly changed after 2 years (P < 0.0001), and the average change (myopia progression) was -1.60 ± 1.04 D. Axial length also increased significantly (P < 0.0001), and the average increase (axial elongation) was 0.77 ± 0.40 mm. Myopia progression and axial elongation showed significant correlations with many components of corneal HOA (P < 0.0001 to P = 0.0270). Multivariate analysis showed that the total HOA of the cornea was the most relevant variable to myopia progression and axial elongation (P < 0.0001). Eyes with larger amounts of corneal HOAs showed less myopia progression and smaller axial elongation, suggesting that corneal HOAs play a role in the refractive and ocular developments in children.

Efficacy and Adverse Effects of Atropine in Childhood Myopia: A Meta-analysis

Importance

Some uncertainty about the clinical value and dosing of atropine for the treatment of myopia in children remains.

Objective

To evaluate the efficacy vs the adverse effects of various doses of atropine in the therapy for myopia in children.

Data Sources

Data were obtained from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, from inception to April 30, 2016. The reference lists of published reviews and clinicaltrials.gov were searched for additional relevant studies. Key search terms included myopia, refractive errors, and atropine. Only studies published in English were included.

Study Selection

Randomized clinical trials and cohort studies that enrolled patients younger than 18 years with myopia who received atropine in at least 1 treatment arm and that reported the annual rate of myopia progression and/or any adverse effects of atropine therapy were included in the analysis.

Data Extraction and Synthesis

Two reviewers independently abstracted the data. Heterogeneity was statistically quantified by Q, H, and I2 statistics, and a meta-analysis was performed using the random-effects model. The Cochrane Collaboration 6 aspects of bias and the Newcastle-Ottawa Scale were used to assess the risk for bias.

Main Outcomes and Measures

The primary outcome was a difference in efficacy and the presence of adverse effects at different doses of atropine vs control conditions. The secondary outcomes included the differences in adverse effects between Asian and white patients.

Results

Nineteen unique studies involving 3137 unique children were included in the analysis. The weighted mean differences between the atropine and control groups in myopia progression were 0.50 diopters (D) per year (95% CI, 0.24-0.76 D per year) for low-dose atropine, 0.57 D per year (95% CI, 0.43-0.71 D per year) for moderate-dose atropine, and 0.62 D per year (95% CI, 0.45-0.79 D per year) for high-dose atropine (P < .001), which translated to a high effect size (Cohen d, 0.97, 1.76, and 1.94, respectively). All doses of atropine, therefore, were equally beneficial with respect to myopia progression (P = .15). High-dose atropine were associated with more adverse effects, such as the 43.1% incidence of photophobia compared with 6.3% for low-dose atropine and 17.8% for moderate-dose atropine (χ22 = 7.05; P = .03). In addition, differences in the incidence of adverse effects between Asian and white patients were not identified (χ21 = 0.81; P = .37 for photophobia).

Conclusions and Relevance

This meta-analysis suggests that the efficacy of atropine is dose independent within this range, whereas the adverse effects are dose dependent.