Myopia Control: A Review

The Trends in Prevalence of Blindness Caused by Refraction Disorders in China from 1990 to 2019 and Its Predictions: Findings from the Global Burden of Disease Study 2019

PURPOSE

To examine the burden of blindness caused by refraction disorders (BCRD) in China over the past 30 years by year, age, and sex, and to estimate future projections.

METHODS

Data from the Global Burden of Diseases (GBD) 2019 database were used to analyze the number of cases and age-standardized prevalence rates (ASPRs) of BCRD in China from 1990 to 2019. We focused on changes over time using estimated annual percentage changes (EAPCs). In addition, we performed the Nordpred analysis and the Bayesian Age-Period-Cohort (BAPC) model with integrated nested Laplace approximations to predict the BCRD burden from 2020 to 2034.

RESULTS

The number of prevalent cases due to BCRD increased from 750,956.7 (95% uncertainty interval [UI] 636,381.24-872,040.62) in 1990 to 1,145,881.76 (95% UI 931,966.43-1,342,338.18) in 2019. The ASPRs of BCRD showed a decreasing trend, with EAPCs of -0.58 (95% confidence interval [CI] -0.81-0.36). The older and female populations had a higher BCRD burden. The number of prevalent cases due to BCRD is projected to continue to increase from 1.33 million in 2020 to 1.86 million in 2034. The ASPR also showed an increasing trend over the next 15 years.

CONCLUSION

Over the past three decades, the prevalence of BCRD in China has improved in both sexes and will continue to increase in the next 15 years. This study highlights the importance of prevention of BCRD, especially for women and the elderly.

Soft peripheral contact lens for eye elongation control (SPACE): 1-year results of a double-blinded randomized controlled trial

PURPOSE

To examine the safety and efficacy of soft multifocal contact lenses on slowing the rate of myopia progression.

METHODS

A prospective, randomized, double-masked clinical trial was conducted including 115 children (55 boys and 60 girls) aged 8 to 15 years. Children were assigned to wear one of two daily disposable soft contact lens designs; a multifocal design (Pegavision) or a dual-focus design (MiSight, Coopervision) in both eyes for at least 8 h per day for one year. All contact lenses were replaced on a daily basis. Measurements were obtained using a logMAR vision meter, including objective refraction, handheld retinoscopy, high (96 %) and low (12 %) contrast sensitivity, and distance and near visual acuity. Axial length was measured every 6 months.

RESULTS

After one year, the spherical equivalent refractive error and axial length of the experimental group (Pegavision) increased by -0.50 ± 0.48 D and 0.24 ± 0.16 mm, respectively, in the right eye and -0.47 ± 0.37 D and 0.23 ± 0.16 mm, respectively, in the left eye. The spherical equivalent refractive error and axial length of the control group (MiSight) increased by -0.48 ± 0.47 D and 0.22 ± 0.13 mm, respectively, in the right eye and by -0.50 ± 0.44 D and 0.23 ± 0.14 mm, respectively, in the left eye, with no significant differences observed between the two lens types.

CONCLUSIONS

The one-year results from this clinical trial show that the multifocal soft contact lenses used in the experimental group have a similar myopia control efficacy with respect to spherical equivalent refraction and axial length elongation as a commercially available dual focus soft contact lens design.

Absorption and attachment of atropine to etafilcon A contact lenses

PURPOSE

Myopia (short-sightedness) is a growing vision problem worldwide. Currently atropine eye drops are used to control the progression of myopia but these suffer from potential lack of bioavailability and low ocular residence time. Commercially available myopia control contact lenses are also used to limit myopia progression, but neither atropine nor contact lenses individually completely stop progression. Development of myopia control contact lenses which could deliver therapeutic doses of atropine is thus desirable and may provide increased efficacy. This study was designed to explore the feasibility of attaching atropine to etafilcon A contact lenses through an esterification reaction.

METHODS

Carboxylic acid groups on etafilcon A contact lenses were quantified using Toluidine Blue O. The carboxylic acid groups in etafilcon A contact lenses were activated using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC-HCl) and N-hydroxysuccinimide (NHS) crosslinkers after which atropine was added to undergo potential binding via esterification. Atropine was released from lenses by alkaline hydrolysis. Reverse phase high performance liquid chromatography (HPLC) was used to detect and quantify the released atropine and its degradation products in solution. Contact lenses that had not been activated by EDC-NHS (controls) were also examined to determine the amount of atropine that could be absorbed rather than chemically bound to lenses.

RESULTS

Each etafilcon A contact lens contained 741.1 ± 5.5 µg carboxylic acid groups which may be available for esterification. HPLC had a limit of detection for atropine of 0.38 µg/mL and for tropic acid, an atropine degradation product, of 0.80 µg/mL. The limits of quantification were 1.16 µg/mL for atropine and 2.41 µg/mL for tropic acid in NH4HCO3. The etafilcon A lenses adsorbed up to 7.69 μg atropine when incubated in a 5 mg/mL atropine solution for 24 h. However, there was no evidence that atropine could be chemically linked to the lenses, as washing in a high concentration of NaCl removed all the atropine from the contact lenses with no atropine being subsequently released from the lenses after incubating in 0.01 N NH4HCO3.

CONCLUSIONS

Etafilcon A contact lenses contain free carboxylic acids which may be an appropriate option for attaching drugs such as atropine. Etafilcon A lenses adsorbed up to 7.69 μg atropine, which would be more than enough to deliver atropine to eyes to control myopia. However, atropine could not be chemically bound to the carboxylic acids of the etafilcon A lenses using this methodology.

Assessment of Eye Care Apps for Children and Adolescents Based on the Mobile App Rating Scale: Content Analysis and Quality Assessment

BACKGROUND

In China, the current situation of myopia among children and adolescents is very serious. Prevention and control of myopia are inhibited by the lack of medical resources and the low awareness about eye care. Nevertheless, mobile apps provide an effective means to solve these problems. Since the health app market in China is still immature, it has become particularly important to conduct a study to assess the quality of eye-care apps to facilitate the development of better eye-care service strategies.

OBJECTIVE

This study aimed to evaluate the quality, functionality, medical evidence, and professional background of eye-care apps targeting children and adolescents in the Chinese app stores.

METHODS

A systematic search on iOS and Android app stores was performed to identify eye-care apps for children and adolescents. The general characteristics, development context, and functional features of the apps were described. Quality assessment of the apps was completed by 2 independent researchers using the Mobile App Rating Scale.

RESULTS

This study included 29 apps, of which 17 (59%) were developed by commercial organizations and 12 (41%) had a design with relevant scientific basis. The main built-in functions of these apps include self-testing (18/29, 62%), eye exercises (16/29, 55%), and eye-care education (16/29, 55%). The mean overall quality of eye-care apps was 3.49 (SD 0.33), with a score ranging from 2.89 to 4.39. The overall Mobile App Rating Scale score exhibited a significant positive correlation with the subscale scores (r=0.81-0.91; P<.001). In addition, although most apps provided basic eye-care features, there are some deficiencies. For example, only a few apps were developed with the participation of medical organizations or professional ophthalmologists, and most of the apps were updated infrequently, failing to provide the latest eye-care information and technology in a timely manner.

CONCLUSIONS

In general, the quality of eye-care apps for children and teenagers in Chinese app stores is good. These apps fulfill users' needs for eye-care services to a certain extent, but they still suffer from insufficient medical background, low user engagement, and untimely updates. In order to further improve the effectiveness of eye-care apps, cooperation with medical institutions and professional ophthalmologists should be strengthened to enhance the scientific and authoritative nature of the apps. At the same time, interactive features and regular updates should be added to enhance user participation and the continuity of the apps. This study provides a reference for future development or improvement of eye-care apps, which can help promote myopia prevention and control.

Efficacy of orthokeratology lens with the modified small treatment zone on myopia progression and visual quality: a randomized clinical trial

BACKGROUND

To evaluate the long-term effectiveness of orthokeratology (ortho-K) lenses with small treatment zone (STZ) or conventional treatment zone (CTZ) in controlling axial elongation in children with myopia as well as the impact on visual quality. We also sought to determine the effect of retinal visual signal quality on axial elongation.

METHODS

This is a prospective randomized controlled study. A total of 140 participants (age ranging from 8 to 12 years) were randomly assigned to wear either STZ or CTZ ortho-K lenses. STZ ortho-K lenses design was achieved by changing the depth of reverse zone and the sagitta height of the optical zone. Using the IOL-Master 500, axial length (AL) was measured at baseline and after 6, 12 and 18 months of ortho-K treatment. Spherical aberration (SA) and corneal topographic parameters were obtained by the Pentacam anterior segment analyzer at baseline and the 1-month follow-up visit, and optical qualities were assessed by optical quality analysis system-II (OQAS-II) at baseline and after 1 month of lens wearing. Optical quality parameters mainly included the modulation transfer function (MTF) cutoff, Strehl ratio (SR), objective scattering index (OSI), and predicted visual acuity (PVA).

RESULTS

A total of 131 participants completed the study, including 68 in the STZ group and 63 in the CTZ group. The STZ group had significantly reduced AL elongation compared to the CTZ group after treatment (12 months: 0.07 ± 0.11 mm vs. 0.14 ± 0.12 mm, P = 0.002; 18 months: 0.17 ± 0.15 mm vs. 0.26 ± 0.16 mm, P = 0.002). The topography in the STZ group showed a smaller treatment zone (TZ) diameter (2.50 ± 0.23 mm vs. 2.77 ± 0.18 mm, P < 0.001), a wider defocus ring width (2.45 ± 0.28 mm vs. 2.30 ± 0.30 mm, P = 0.006), and larger values of total amount of defocus (119.38 ± 63.71 D·mm2 vs. 91.40 ± 40.83 D·mm2, P = 0.003) and total SA (0.37 ± 0.25 μm vs. 0.25 ± 0.29 μm, P = 0.015), compared with the CTZ group. Objective visual quality decreased in both groups (P < 0.001). This was evidenced by a greater decrease in MTF cutoff (- 14.24 ± 10.48 vs. - 10.74 ± 9.46, P = 0.047) and SR values (- 0.09 ± 0.07 vs. - 0.06 ± 0.07, P = 0.026), and an increase in OSI value (0.84 ± 0.72 vs. 0.58 ± 0.53, P = 0.019). PVA9% decreased significantly in the STZ group but not the CTZ group. A statistically significant negative correlation was found between the changes in total SA and MTF cutoff values (r =  - 0.202, P = 0.025). AL changes were associated with sex, change of MTF cutoff value, increment of total SA and TZ area.

CONCLUSIONS

Compared with CTZ ortho-K lenses, STZ ortho-K lenses significantly inhibited axial elongation in children with myopia while moderately reducing their objective visual quality. Axial elongation was affected by retinal visual quality, and it may be a possible mechanism for ortho-K slowing myopia progression. Trial registration This trial is registered at Chinese Clinical Trial Registry on November 5, 2019 with trial registration number: ChiCTR1900027218. https://www.chictr.org.cn/showproj.html?proj=45380.

Myopia Control: Are We Ready for an Evidence Based Approach?

INTRODUCTION

Myopia and its vision-threatening complications present a significant public health problem. This review aims to provide an updated overview of the multitude of known and emerging interventions to control myopia, including their potential effect, safety, and costs.

METHODS

A systematic literature search of three databases was conducted. Interventions were grouped into four categories: environmental/behavioral (outdoor time, near work), pharmacological (e.g., atropine), optical interventions (spectacles and contact lenses), and novel approaches such as red-light (RLRL) therapies. Review articles and original articles on randomized controlled trials (RCT) were selected.

RESULTS

From the initial 3224 retrieved records, 18 reviews and 41 original articles reporting results from RCTs were included. While there is more evidence supporting the efficacy of low-dose atropine and certain myopia-controlling contact lenses in slowing myopia progression, the evidence about the efficacy of the newer interventions, such as spectacle lenses (e.g., defocus incorporated multiple segments and highly aspheric lenslets) is more limited. Behavioral interventions, i.e., increased outdoor time, seem effective for preventing the onset of myopia if implemented successfully in schools and homes. While environmental interventions and spectacles are regarded as generally safe, pharmacological interventions, contact lenses, and RLRL may be associated with adverse effects. All interventions, except for behavioral change, are tied to moderate to high expenditures.

CONCLUSION

Our review suggests that myopia control interventions are recommended and prescribed on the basis of accessibility and clinical practice patterns, which vary widely around the world. Clinical trials indicate short- to medium-term efficacy in reducing myopia progression for various interventions, but none have demonstrated long-term effectiveness in preventing high myopia and potential complications in adulthood. There is an unmet need for a unified consensus for strategies that balance risk and effectiveness for these methods for personalized myopia management.

Low-level red-light therapy for myopia control in children: A systematic review and meta-analysis

INTRODUCTION

Low-Level Red-Light (LLRL) Therapy is a safe and natural way to promote healing and reduce inflammation in the body. When it comes to treating myopia in children, LLRL therapy is recent, and its efficacy and safety still are not clear.

METHODS

A systematic review and meta-analysis of the literature for LLRL was conducted in accordance with the PRISMA guidelines on November 5, 2022. Databases, including PUBMED, Cochrane Library, Web of Science, and Embase were queried. A meta-analysis of random effects was conducted. Inclusion criteria included Randomized Controlled Trials (RCTs) or observational studies where LLRL therapy was used in children (3‒15 years old) with myopia. Exclusion criteria were studies with other ocular abnormalities. Efficacy was evaluated through the mean change in Axial Length (AL) and cycloplegic Spherical Equivalent Error (SER), while safety was evaluated by monitoring adverse effects.

RESULTS

A total of 5 final studies were included (4 RCTs, and 1 observational), in which 685 total patients were analyzed. The mean age was 9.7 ± 0.66 years, with 48,2% female patients. The number of eyes in the LRLL arm is 714 and, in the control, arm is 656. LLRL showed better results in SER and AL mean change (OR = 0.58; 95% CI 0.33 to 0.83; p < 0.00001, and MD -0.33; 95% CI -0.52 to -0.13; p = 0.001, respectively), in comparison to the control group. There was no significant difference in adverse effects between groups (MD = 5.76; 95% CI 0.66 to 50.14; p = 0.11).

CONCLUSION

LLRL therapy is a non-invasive, effective, and safe short-term treatment option; however, long-term evaluation, particularly in comparison to other therapies, requires additional investigation.

Is Spending More Time Outdoors Able to Prevent and Control Myopia in Children and Adolescents? A Meta-Analysis

INTRODUCTION

Spending more time outdoors was treated as a safe and cost-effective method to prevent and control myopia. While prior research has established an inverse association between outdoor time and the risk of myopia onset, the effect of increasing outdoor time in delaying the progression of myopia remains a subject of debate. The present meta-analysis aimed to assess the relationship between outdoor time and the myopia onset, and further examine whether there is a dose-response relationship between outdoor time and the risk of myopia onset. Meanwhile, perform whether the outdoor time is related to delaying the progression of myopia.

METHODS

Studies were retrieved from PubMed, Web of Science, Embase, Medline, and the Cochrane Database, spanning from their inception to February 2023. Three cohort studies and 5 prospective intervention studies were included, with a total of 12,922 participants aged 6-16 years.

RESULTS

Comparing the highest with the lowest exposure levels of time spent outdoors, the highest outdoor time was strongly associated with a reduced risk of myopia onset (odds ratio [OR]: 0.53; 95% confidence interval [CI]: 0.34, 0.82). A nonlinear dose-response relationship was found between outdoor time and myopia onset risk. Compared to 3.5 h of outdoor time per week, an increase to 7, 16.3, and 27 h per week corresponded with a respective reduction in the risk of myopia onset by 20%, 53%, and 69%. Among children and adolescents who were not myopic, spending more time outdoors significantly slowed down the speed of change in spherical equivalent refractive (weighted mean difference [WMD] = 0.10D, 95% CI: 0.07, 0.14) and axial length (WMD = -0.05 mm, 95% CI: -0.06, -0.03). Among children and adolescents who were already myopic, spending more time outdoors did not slow myopia progression.

CONCLUSIONS

Overall, spending more time outdoors can prevent the onset of myopia, but it does not seem to slow its progression. Further studies are needed to better understand these trends.

Treating adolescent pseudomyopia and elevated intraocular pressure using chiropractic and moxibustion: A CARE-compliant case report

RATIONALE

This case report aims to provide clinical evidence on the effectiveness of integrating chiropractic and moxibustion techniques for treating pseudomyopia accompanied by elevated intraocular pressure resulting from cervical spine issues because the application of complementary medicine modalities for managing such vision disorders currently lacks adequate investigations.

PATIENT CONCERNS

A 6-year-old patient presented with blurred vision, intermittent ocular discomfort, and upper cervical discomfort.

DIAGNOSES

Spine-related increased intraocular pressure and pseudomyopia.

INTERVENTIONS

The patient received integrative treatment of chiropractic and walnut-shell moxibustion 3 times a week for a total of 10 treatment sessions.

OUTCOMES

The patient exhibited progressive improvements in visual acuity and reductions in intraocular pressure over the treatment period, with unaided vision exceeding 2 lines of improvement in visual acuity charts and normalized intraocular pressure after 10 treatment sessions. These therapeutic effects were sustained at 3-month follow-up.

LESSONS

The integrative use of chiropractic and walnut-shell moxibustion demonstrates considerable potential in alleviating symptoms of pseudomyopia, reducing intraocular pressure, and restoring visual function in spine-related pseudomyopia cases.

Assessing the rebound phenomenon in different myopia control treatments: A systematic review

PURPOSE

To review the rebound effect after cessation of different myopia control treatments.

METHODS

A systematic review that included full-length randomised controlled studies (RCTs), as well as post-hoc analyses of RCTs reporting new findings on myopia control treatments rebound effect in two databases, PubMed and Web of Science, was performed according to the PRISMA statement. The search period was between 15 June 2023 and 30 June 2023. The Cochrane risk of bias tool was used to analyse the quality of the selected studies.

RESULTS

A total of 11 studies were included in this systematic review. Unifying the rebound effects of all myopia control treatments, the mean rebound effect for axial length (AL) and spherical equivalent refraction (SER) were 0.10 ± 0.07 mm [-0.02 to 0.22] and -0.27 ± 0.2 D [-0.71 to -0.03] after 10.2 ± 7.4 months of washout, respectively. In addition, spectacles with highly aspherical lenslets or defocus incorporated multiple segments technology, soft multifocal contact lenses and orthokeratology showed lower rebound effects compared with atropine and low-level light therapy, with a mean rebound effect for AL and SER of 0.04 ± 0.04 mm [0 to 0.08] and -0.13 ± 0.07 D [-0.05 to -0.2], respectively.

CONCLUSIONS

It appears that the different treatments for myopia control produce a rebound effect after their cessation. Specifically, optical treatments seem to produce less rebound effect than pharmacological or light therapies. However, more studies are required to confirm these results.

The Effect of Myopic Control between the Dual-Focus Contact Lenses and High-Concentration Atropine in an Asian Population

We aim to investigate the myopic control effect of high-concentration atropine (ATR) and dual-focus contact lenses (DFCLs). A retrospective cohort study was conducted. A total of 182 eyes in 91 individuals who used high-concentration ATR (0.125%) and another 70 eyes in 35 individuals who used DFCLs were enrolled in the ATR and DFCL groups, respectively. The primary outcomes were spherical equivalent refraction (SER) progression and axial length (AXL) elongation. The generalized estimate equation was utilized to yield the adjusted odds ratio (aOR) and 95% confidence interval (CI) of cycloplegic SER progression and AXL elongation between groups. According to the multivariable analysis, the change in cycloplegic SER progression was similar between the DFCL and ATR groups (aOR: 1.305, 95% CI: 0.247-2.515, p = 0.803). The DFCL group demonstrated a numerically higher rate of AXL elongation compared to the ATR group (aOR: 1.530, 95% CI: 0.980-1.894, p = 0.051). In the subgroup analysis, cycloplegic SER progression was insignificant between ATR and DFCL users in different subgroups (all p > 0.05). The DFCL patients with moderate astigmatism and high AXL (both p < 0.001) presented a high risk of AXL elongation. In conclusion, DFCL usage demonstrated similar myopic control of cycloplegic SER and AXL compared to high-concentration ATR, while DFCLs showed lower AXL control, mainly in patients with moderate astigmatism and high AXL.

Myopia Controlling using Low Dose Atropine Eye Drop

Purpose

To determine myopic progression, axial length elongation, best-corrected visual acuity (BCVA), pupil dilation, and accommodation amplitude following 24 months of Atropine 0.01% usage among progressive myopic patients.

Methods

Fifty-one progressive myopic patients (age range, 3.5-17 years) were included in the present study. Fifteen patients were excluded due to loss to follow-up (eight patients) and Atropine complications (seven patients) and 36 patients continued therapy. Myopic progression, axial length, far and near BCVA, pupil diameter, and accommodation amplitude were measured at baseline examination and repeated every 6 months up to 2 years. All patients were recommended to instill one drop of Atropine 0.01% in each eye every night. Absolute success of therapy was defined as myopic progression ≤0.50 diopter (D) and axial length growth ≤0.2 mm per year.

Results

Mean myopic progression was 0.16 and 1.28 D and mean axial length change was 0.05 and 0.69 mm at months 12 and 24, respectively. Pupil dilation was 1.26 and 1.84 mm and accommodation reduction was 3.38 and 3.37 D at the same follow-ups, while BCVA was not changed. Absolute success rate for myopic progression control was 56.8% at 12 months and 70.8% at 24 months follow-up. In addition, the success rate in respect to axial length changes was 44.4% and 58.3% at the same time points.

Conclusions

Atropine 0.01% can slow myopic progression and axial length elongation at least in 50% of myopic cases at 12- and 24-month follow-up with no significant complications. Therefore, Atropine therapy is recommended in cases of progressive myopia in children and teenagers.

Efficacy and safety of atropine in myopic children: A meta-analysis of randomized controlled trials

PURPOSE

To evaluate the safety and efficacy of atropine for childhood myopia and further explore the optimal concentration of atropine, so as to provide more reference for clinical application.

METHODS

PubMed, Embase, Cochrane Library and ClinicalTrials.gov were comprehensively searched for randomized controlled trials (RCTs) up to October 14, 2021. The efficacy outcomes were progression of spherical equivalent (SE) and axial length (AL). The safety outcomes included accommodation amplitude, pupil size and adverse effects. The meta-analysis was performed using Review Manager 5.3.

RESULTS

Eighteen RCTs involving 3002 eyes were included. The results showed that at 6-36 months of treatment, atropine was effective in slowing the progression of myopia in children. At 12 months, the WMD of SE and AL of low-dose atropine was 0.25 diopters (D) and 0.1 millimeter (mm), moderate-dose atropine was 0.44 D and 0.16mm, high-dose atropine was 1.21 D and 0.82mm, respectively, compared with the control group. Similarly, at 24 months, low-dose atropine was 0.22 D and 0.14mm, moderate-dose atropine was 0.60 D, high-dose atropine was 0.66 D and 0.24mm, respectively. Interestingly, we also found that there was no significant difference in the effects of low-dose atropine on accommodation amplitude and photopic pupil size compared with the control group, and the rate of photophobia, allergy, blurred vision and other side effects was similar between the low-dose atropine group and the control group. In addition, atropine appears to be more effective in myopic children in China than in other countries.

CONCLUSIONS

Atropine in various concentrations can effectively slow myopia progression in children, and its effect is dose-dependent, while low-dose atropine (0.01% atropine) appears to be safer.

Clinically Significant Axial Shortening in Myopic Children After Repeated Low-Level Red Light Therapy: A Retrospective Multicenter Analysis

INTRODUCTION

Myopia is recognized as a progressive eye disease. The aim of this study was to evaluate the frequency and associated factors of clinically significant axial length (AL) shortening among myopic children following repeated low-level red light (RLRL) therapy.

METHODS

The clinical data that were collected for the myopic children aged 3-17 years who received an RLRL therapy delivered by home-use desktop light device that emitted light at 650 nm for at least 1 year, were reviewed. The clinical data included AL, spherical equivalent refraction (SER), and visual acuity measured at baseline and follow-up. The primary outcomes were frequency of AL shortening of > 0.05 mm, > 0.10 mm, and > 0.20 mm per year, and associated factors of AL shortening per year.

RESULTS

A total of 434 myopic children with at least 12 months of follow-up data were included. The mean age of participants was 9.7 (2.6) years with SER of -3.74 (2.60) diopters. There were 115 (26.50%), 76 (17.51%), and 20 (4.61%) children with AL shortening based on cutoffs of 0.05 mm/year, 0.10 mm/year, and 0.20 mm/year, respectively. In the multivariable model, AL shortening was significantly associated with older baseline age, female gender, and longer baseline AL or greater spherical equivalent refraction (all P < 0.05). Among AL shortened eyes, the mean AL difference (standard deviation, SD) was -0.142 (0.094) mm/year. Greater AL shortening was observed among children who were younger and had longer baseline AL (all P < 0.05).

CONCLUSIONS

More than a quarter of children had AL shortening > 0.05 mm following RLRL therapy, and the overall mean AL change was -0.142 mm/year. Further studies should explore the mechanisms underlying AL shortening.

Axial Shortening in Myopic Children after Repeated Low-Level Red-Light Therapy: Post Hoc Analysis of a Randomized Trial

INTRODUCTION

Axial length (AL) elongation in myopia is considered irreversible. We aimed to systemically report unexpected AL shortening observed in a randomized clinical trial (RCT) after repeated low-level red-light (RLRL) therapy.

METHODS

This is a post hoc analysis of a multicenter, single-masked RCT. Two hundred sixty-four myopic children aged 8-13 years allocated to RLRL treatment (intervention group) or a single vision spectacle (SVS, control group) were included. AL was measured using an IOL-master 500 at baseline, 1-, 3-, 6-, and 12-month follow-up visits. AL shortening was defined as AL reduction from baseline to follow-up visits at three cutoffs: > 0.05 mm, > 0.10 mm, and > 0.20 mm. Frequency of AL shortening at different cutoffs was calculated. Analysis was done with intent to treat (ITT).

RESULTS

At 12-months follow up, frequency of AL shortening > 0.05 mm was 26/119 (21.85%) and 2/145 (1.38%) for the RLRL group versus the control group, respectively. The frequency was 18/119 (15.13%) versus 0/145 (0%) for AL shortening > 0.10 mm, and 7/119 (5.88%) versus 0/145 (0%), for AL shortening > 0.20 mm, respectively (p < 0.001). Mean AL shortening after 12 months (SD) was -0.156 (0.086) mm in the RLRL group and -0.06 mm in the control group. Age was significantly associated with AL shortening in the multivariable analysis. For the RLRL group that exhibited AL shortening (n = 56), choroidal thickness (ChT) thickening (0.056 mm) could only explain 28.3% of AL shortening (-0.20 mm).

CONCLUSION

Nearly a quarter of children had > 0.05 mm AL shortening following 12 months of RLRL therapy, whereas AL shortening rarely occurred among controls.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04073238).

Myopia Management in Daily Routine - A Survey of European Pediatric Ophthalmologists

PURPOSE

Assessment of diagnostic and therapeutic strategies currently used in routine practice for myopia management in Europe.

METHODS

Online survey study including 11 main questions. The questionnaire was sent to members of the European Paediatric Ophthalmology Society (EPOS). The following items and questions were surveyed: I. Profession and workplace of the survey participants. II. Preventive measures and recommendations for myopia management, a) regarding reading distance and near work, b) optical tools, i.e., application of Defocus Incorporated Multiple Segments (DIMS) glasses, near additions, or contact lenses, and c) the application of atropine eye drops. III. Application of additional diagnostic tools.

RESULTS

Forty-eight individuals completed the survey. Of the respondents, 88% (n = 42) affirmed that they generally gave advice on strategies for myopia prevention and management strategies. Almost all study participants (n = 41; 85%) recommend outdoor time as a preventive measure. The recommendation on near distance is given less frequently, with 28 (58%) participants confirming that they do recommend a "safe" reading distance, and 15 (31%) negating this. Eight (17%) survey participants recommend using near addition glasses, while 36 (75%) do not. Similarly, 35 (73%) respondents do not apply DIMS glasses and 8 (17%) apply them. Fourteen (29%) participants recommend myopia-reducing contact lenses while 30 (63%) do not, and 29 (60%) confirmed that they applied atropine eye drops to slow myopia progression while 14 (29%) do not prescribe these eye drops. The majority of respondents (n = 25; 86%) who prescribe atropine eye drops use atropine 0.01% eye drops.

CONCLUSIONS

Prevention and therapeutic management of childhood myopia is an essential part in the daily routine of pediatric ophthalmologists. Substantial agreement was found for the protective role of outdoor time (85%). The only common therapeutic approach is the administration of atropine eye drops (60%).

The association between time spent on screens and reading with myopia, premyopia and ocular biometric and anthropometric measures in 6- to 7-year-old schoolchildren in Ireland

PURPOSE

More time spent on near tasks has consistently been associated with the promotion of myopia. The World Health Organization advises limiting daily screentime to less than 2 h for children aged five and over. This study explored the relationship between time spent on screens and reading/writing with refractive status, ocular biometric and anthropometric factors in 6- to 7-year-olds in Ireland.

METHODS

Participants were 723 schoolchildren (377 boys [51.8%]), mean age 7.08 (0.45) years. The examination included cycloplegic autorefraction (1% cyclopentolate hydrochloride), ocular biometry (Zeiss IOLMaster), height (cm) and weight (kg). Screentime and reading/writing time were reported by parents/legal guardians by questionnaire. Myopia (≤-0.50D) and premyopia (>-0.50D ≤ 0.75D) risk assessments were performed using logistic regression, and multivariate linear regression was used to analyse continuous variables.

RESULTS

Reported daily screentimes were 31% <1 h, 49.5% 1-2 h, 15.6% 2-4 h and 3.9% >4 h. Reading/writing times were 42.2% frequently, 48.0% infrequently and 9.8% seldom/never. Linear regression, controlling for age and ethnicity, revealed >2 h/day on screens was associated with a more myopic spherical equivalent [β = -1.15 (95% confidence intervals {CIs}: 1.62-0.69, p < 0.001)], increased refractive astigmatism (β = 0.29, CI: 0.06-0.51, p = 0.01), shorter corneal radius (β = 0.12, CI: 0.02-0.22, p = 0.02), higher axial length/corneal radius (β = 0.06, CI: 0.03-0.09, p < 0.001), heavier weight (β = 1.60, CI: 0.76-2.45, p < 0.001) and higher body mass index (BMI) (β = 1.10, CI: 0.28-1.12, p < 0.001). Logistic regression, controlling for age and ethnicity, revealed daily screentime >2 h was associated with myopia (OR = 10.9, CI: 4.4-27.2, p = 0.01) and premyopia (OR = 2.4, CI: 1.5-3.7, p < 0.001). Frequent reading/writing was associated with screentime ≤2 h/day (OR = 3.2, CI: 1.8-5.8, p < 0.001).

CONCLUSION

Increased screentime was associated with a more myopic refraction, higher axial length/corneal radius ratio, increased odds of myopia, premyopia, higher degrees of astigmatism, increased weight, BMI and decreased reading/writing time. Dedicated education programmes promoting decreased screentime in children are vital to prevent myopia and support eye and general health.

Changes in corneal thickness, corneal volume, and densitometry after long-term orthokeratology wear

PURPOSE

To investigate changes in the corneal volume, corneal densitometry and pachymetry of young myopes wearing over-night orthokeratology (OK) contact lenses.

METHODS

The medical records of 28 right eyes of young myopes wearing OK between 2013 and 2018 were reviewed retrospectively. The baseline refractive error, best corrected visual acuities at baseline and uncorrected visual acuity at the most recent visit were recorded. Corneal volume of the central 10 mm cornea; densitometry at central, nasal and temporal cornea; and pachymetry along the horizontal and vertical meridians were collected from the Pentacam® HR at baseline, after one night of lens wear, and at the latest visit.

RESULTS

The mean age of subjects was 12.03 ± 3.80 years at the time of OK lens fitting and wore OK overnight for a mean duration of 666 days (range 206-1736 days). The baseline spherical equivalent refractive error was -3.03 ± 1.56 D (range -1.00 to -6.00 D). The corneal volume increased significantly after OK wear (p = 0.001). Corneal densitometry increased after OK wear, but the change did not reach statistical significance (p = 0.113). Pachymetry in the central cornea did not change significantly across all visits (p > 0.05) but increased significantly in the mid-peripheral regions of the cornea. Baseline refractive error was not found to be correlated with the changes in corneal volume, corneal densitometry, or pachymetry.

CONCLUSION

The increase in corneal volume and densitometry and no significant change in the central corneal thickness may indicate the presence of corneal oedema from long-term OK wear. The baseline refraction was not correlated with the changes in corneal volume, densitometry or pachymetry.

A Review of the Role of the School Spatial Environment in Promoting the Visual Health of Minors

Rising childhood myopia rate has detrimental health consequences that pose a considerable challenge to health systems. The school spatial environment, which is where students are for the longest period of time, has a high health value for myopia systematic intervention. While research has demonstrated associations between physical daylight environments, medical gene and visual health, the literature currently lacks a synthesis of evidence that will act as a spatially-organized resource for school designers. This study is based on literature from the period 2000-2022 and has been taken from the Web of Science, scopus, Medline and CNKI core collection database. Collaboration, literature co-citation and quantitative and qualitative analysis, in addition to keyword co-occurrence are adopted to conduct a visual health research review. The results indicate that intensive near work activity (as a risk factor) and longer time spent outdoors (as a protective factor), are involved in visual health factors. Two main research themes are obtained and relate to: (1) The environment of visual work behavior (especially the near work learning environment) and adaptable multimedia learning environment; and (2) the environment of outdoor exposure behavior. Furthermore, with the variation of educational demands, models and concepts, there are different demands for near work behavior, and this study makes an important contribution by pointing to two future research directions, including the accurate and controllable environment of near work behavior, which operate in accordance with various educational mode requirements and the active design of the environment of outdoor exposure behavior. In referring to differences between regions and countries, as well as the development of the educational environment, it provides insight into how these demands can be controlled.

Design and assessment of amblyopia, strabismus, and myopia treatment and vision training using virtual reality

Background

Virtual reality is a relatively new intervention that has the potential to be used in the treatment of eye and vision problems. This article reviews the use of virtual reality-related interventions in amblyopia, strabismus, and myopia research.

Methods

Sources covered in the review included 48 peer-reviewed research published between January 2000 and January 2023 from five electronic databases (ACM Digital Library, IEEE Xplore, PubMed, ScienceDirect and Web of Science). To prevent any missing relevant articles, the keywords, and terms used in the search included "VR", "virtual reality", "amblyopia", "strabismus," and "myopia". Quality assessment and data extraction were performed independently by two authors to form a narrative synthesis to summarize findings from the included research.

Results

Total number of 48 references were reviewed. There were 31 studies published on amblyopia, 18 on strabismus, and 6 on myopia, with 7 studies overlapping amblyopia and strabismus. In terms of technology, smartphone-based virtual reality headset viewers were utilized more often in amblyopia research, but commercial standalone virtual reality headsets were used more frequently in myopia and strabismus-related research. The software and virtual environment were mostly developed based on vision therapy and dichoptic training paradigms.

Conclusion

It has been suggested that virtual reality technology offers a potentially effective tool for amblyopia, strabismus, and myopia studies. Nonetheless, a variety of factors, especially the virtual environment and systems employed in the data presented, must be explored before determining whether virtual reality can be effectively applied in clinical settings. This review is significant as the technology in virtual reality software and application design features have been investigated and considered for future reference.

Contact Lens Safety for the Correction of Refractive Error in Healthy Eyes

ABSTRACT

Contact lenses are a safe and effective method for correction of refractive error and worn by an estimated 45 million Americans. Because of the widespread availability and commercial popularity of contact lenses, it is not well appreciated by the public that contact lenses are U.S. Food and Drug Administration (FDA)-regulated medical devices. Contact lenses are marketed in numerous hard and soft materials that have been improved over decades, worn in daily or extended wear, and replaced in range of schedules from daily to yearly or longer. Lens materials and wear and care regimens have impact on the risks of contact lens-related corneal inflammatory events and microbial keratitis. This article reviews contact lens safety, with specific focus on the correction of refractive error in healthy eyes.

Immediate Effect in the Retina and Choroid after 650 nm Low-Level Red Light Therapy in Children

INTRODUCTION

The objective of this study was to investigate the changes in the retina and choroid of children after 650 nm low-level red light therapy (LLRLT).

METHODS

In this prospective study, 25 subjects in the Shanghai Eye and ENT Hospital of Fudan University were included from August 2021 to September 2021. One eye was randomly selected to receive LLRLT for 3 min. Swept-source optical coherence tomography (OCT) and OCT angiography were used to measure retinal fovea perfusion density (RFPD), retinal fovea thickness (RFT), choroidal fovea blood flow (CFBF), and choroidal fovea thickness (CFT) before LLRLT, 5 min and 1 h after LLRLT. Baseline characteristics between LLRLT and non-LLRLT eyes were compared. Changes in the retinal and choroidal parameters were analyzed by ANCOVA models. SAS software was used for data analysis. The difference was considered statistically significant if p < 0.05.

RESULTS

There was no difference in baseline characteristics between LLRLT eyes and non-LLRLT eyes. The RFPD in LLRLT eyes significantly increased 5 min after LLRLT, and the increment was 1.70 ± 0.83% (p = 0.0389). The RFPD significantly decreased from 5 min to 1 h after LLRLT with a mean of -2.62 ± 0.86% decrement (p = 0.0031). The RFPD levels returned to baseline at 1 h after LLRLT (p = 0.8646). However, compared with insignificant RFPD changes in non-LLRLT eyes, there was no significant difference in RFPD changes at any sampling point. No significant changes in RFT, CFBF, and CFT were found in LLRLT eyes at each sampling point.

CONCLUSION

Although 3 min of LLRLT has no effect on the choroid, it may cause a short-term transient increase in RFPD. It will provide theoretical support for the role of LLRLT in myopia control.

Retardation of Myopia by Multifocal Soft Contact Lens and Orthokeratology: A 1-Year Randomized Clinical Trial

OBJECTIVES

This randomized, single-blind, clinical trial compared the effectiveness of multifocal soft contact lenses (MFSCLs), orthokeratology contact lenses (Ortho-kCLs), and single vision spectacles (SVSs) for myopia control.

METHODS

Sixty-six eligible Chinese subjects, aged 7 to 15 years old with cycloplegic refraction measurements between -1.00 and -8.00 diopters (D), astigmatism not more than 1.00 D, and no history of myopia control treatment, were randomly assigned to wear MFSCLs, Ortho-kCLs, or SVSs for 1 year. For all three groups, baseline measurements of cycloplegic refraction, axial length (AL), and corneal endothelial cell density (CECD) were made. At the 6- and 12-month follow-up visits, changes in cycloplegic refraction, AL, and CECD were measured in the MFSCL and SVS groups. For the Ortho-kCL group, only changes in the AL were measured at 6 and 12 months, and CECD was measured at the 12-month follow-up visit.

RESULTS

After 1 year of lens wear, myopia progression of the SVS group, -0.938±0.117 D, was greater than that of the MFSCLs group, -0.591±0.106 D (P=0.032). Thus, MFSCLs reduced the rate of myopia progression by 37.0% compared with the SVSs. The AL elongations after 1 year were 0.30±0.03 mm for MFSCLs (P=0.027 vs SVSs), 0.31±0.04 mm for Ortho-kCLs (P=0.049 vs SVSs), and 0.41±0.04 mm for SVSs. Compared with the SVS group, the reduction in AL elongation was 26.8% and 24.4% in the MFSCL and Ortho-kCL groups, respectively. There were no significant differences in CECD among the three groups (P>0.05).

CONCLUSIONS

Compared with SVSs, wearing MFSCLs and Ortho-kCLs significantly delayed myopia progression. MFSCLs and Ortho-kCLs are safe and promising methods of myopia control (chictr.org number, ChiCTR2100048452).

Effects of Extended Viewing Distance on Accommodative Response and Pupil Size of Myopic Adults by Using a Double-Mirror System

Purposes: This study discussed the accommodative response and pupil size of myopic adults using a double-mirror system (DMS). The viewing distance could be extended to 2.285 m by using a DMS, which resulted in a reduction and increase in the accommodative response and pupil size, respectively. By using a DMS, the reduction of the accommodative response could improve eye fatigue with near work. Method: Sixty subjects aged between 18 and 22 years old were recruited in this study, and the average age was 20.67 ± 1.09. There were two main steps in the experimental process. In the first step, we examined the subjects’ refraction state and visual function, and then fitted disposable contact lenses with a corresponding refractive error. In the second step, the subjects gazed at an object from a viewing distance of 0.4 m and at a virtual image through a DMS, respectively, and the accommodative response and pupil size were measured using an open field autorefractor. Results: When the subjects gazed at the object from a distance of 0.4 m, or gazed at the virtual image through a DMS, the mean value of the accommodative response was 1.74 ± 0.43 or 0.16 ± 0.47 D, and the pupil size was 3.98 ± 0.06 mm or 4.18 ± 0.58 mm, respectively. With an increase in the viewing distance from 0.4 m to 2.285 m, the accommodative response and pupil size were significantly reduced about 1.58 D and enlarged about 0.2 mm, respectively. For three asterisk targets of different sizes (1 cm × 1 cm, 2 cm × 2 cm, and 3 cm × 3 cm), the mean accommodative response and pupil size through the DMS was 0.19 ± 0.16, 0.27 ± 0.24, 0.26 ± 0.19 D; and 4.20 ± 1.02, 3.94 ± 0.73, 4.21 ± 0.57 mm, respectively. The changes of the accommodative response and pupil size were not significant with the size of the targets (p > 0.05). In the low or high myopia group, the accommodative response of 0.4 m and 2.285 m was 1.68 ± 0.42 D and 0.21 ± 0.48 D; and 1.88 ± 0.25 D and 0.05 ± 0.40 D, respectively. The accommodative response was significantly reduced by 1.47 D and 1.83 D for these two groups. The accommodative microfluctuations (AMFs) were stable when a DMS was used; on the contrary, the AMFs were unstable at a viewing distance of 0.4 m. Conclusions: In this study, the imaging through a DMS extended the viewing distance and enlarged the image, and resulted in a reduction in the accommodative response and an increase in the pupil size. For the low myopia group and the high myopia group, the accommodative response and pupil size were statistically significantly different before and after the use of the DMS. The reduction of the accommodative response could be applied for the improvement of asthenopia.

Update on Myopia Control: The US Perspective

ABSTRACT

Myopia is a global epidemic on the rise, garnering increased attention, particularly in therapeutics and prevention, and the field of myopia control. This study reviews the current management options including contact lenses, spectacles, atropine, and environmental and behavioral modifications. Particular attention is given to the US perspective.

Efficacy and Safety of 8 Atropine Concentrations for Myopia Control in Children: A Network Meta-Analysis

TOPIC

Comparative efficacy and safety of different concentrations of atropine for myopia control.

CLINICAL RELEVANCE

Atropine is known to be an effective intervention to delay myopia progression. Nonetheless, no well-supported evidence exists yet to rank the clinical outcomes of various concentrations of atropine.

METHODS

We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov on April 14, 2021. We selected studies involving atropine treatment of at least 1 year's duration for myopia control in children. We performed a network meta-analysis (NMA) of randomized controlled trials (RCTs) and compared 8 atropine concentrations (1% to 0.01%). We ranked the atropine concentrations for the corresponding outcomes by P score (estimate of probability of being best treatment). Our primary outcomes were mean annual changes in refraction (diopters/year) and axial length (AXL; millimeters/year). We extracted data on the proportion of eyes showing myopia progression and safety outcomes (photopic and mesopic pupil diameter, accommodation amplitude, and distance and near best-corrected visual acuity [BCVA]).

RESULTS

Thirty pairwise comparisons from 16 RCTs (3272 participants) were obtained. Our NMA ranked the 1%, 0.5%, and 0.05% atropine concentrations as the 3 most beneficial for myopia control, as assessed for both primary outcomes: 1% atropine (mean differences compared with control: refraction, 0.81 [95% confidence interval (CI), 0.58-1.04]; AXL, -0.35 [-0.46 to -0.25]); 0.5% atropine (mean differences compared with control: refraction, 0.70 [95% CI, 0.40-1.00]; AXL, -0.23 [-0.38 to -0.07]); 0.05% atropine (mean differences compared with control: refraction, 0.62 [95% CI, 0.17-1.07]; AXL, -0.25 [-0.44 to -0.06]). In terms of myopia control as assessed by relative risk (RR) for overall myopia progression, 0.05% was ranked as the most beneficial concentration (RR, 0.39 [95% CI, 0.27-0.57]). The risk for adverse effects tended to rise as the atropine concentration was increased, although this tendency was not evident for distance BCVA. No valid network was formed for near BCVA.

DISCUSSION

The ranking probability for efficacy was not proportional to dose (i.e., 0.05% atropine was comparable with that of high-dose atropine [1% and 0.5%]), although those for pupil size and accommodation amplitude were dose related.

Ten Years of Knowledge of Nano-Carrier Based Drug Delivery Systems in Ophthalmology: Current Evidence, Challenges, and Future Prospective

The complex drug delivery barrier in the eye reduces the bioavailability of many drugs, resulting in poor therapeutic effects. It is necessary to investigate new drugs through appropriate delivery routes and vehicles. Nanotechnology has utilized various nano-carriers to develop potential ocular drug delivery techniques that interact with the ocular mucosa, prolong the retention time of drugs in the eye, and increase permeability. Additionally, nano-carriers such as liposomes, nanoparticles, nano-suspensions, nano-micelles, and nano-emulsions have grown in popularity as an effective theranostic application to combat different microbial superbugs. In this review, we summarize the nano-carrier based drug delivery system developments over the last decade, particularly review the biology, methodology, approaches, and clinical applications of nano-carrier based drug delivery system in the field of ocular therapeutics. Furthermore, this review addresses upcoming challenges, and provides an outlook on potential future trends of nano-carrier-based drug delivery approaches in ophthalmology, and hopes to eventually provide successful applications for treating ocular diseases.

Reduction in Accommodative Response of Schoolchildren by a Double-Mirror System

PURPOSE

This study first proposed the application of a double-mirror system (DMS) to extend viewing distance and investigate the accommodative response of schoolchildren under a DMS.

METHOD

Fifty-seven subjects aged between 7 and 12 years old were recruited in this study, and the experiment was divided into two stages. The first stage consisted of a case history inquiry, a refraction state, and a visual function examination. In the second stage, the subjects gazed at an object at distances of 0.4 m, 2.285 m, and through a DMS, respectively, and their accommodative responses were measured using an open-field autorefractor.

RESULTS

There was no significant difference in the schoolchildren's accommodative response between subjects gazing at an object at 2.285 m (0.14 ± 0.35 D, p > 0.05) and those gazing at it through a DMS (0.20 ± 0.35 D). However, their accommodative response showed a significant difference between subjects gazing at an object at 0.4 m and 2.285 m and those gazing at it at 0.4 m and through a DMS.

CONCLUSION

In this experiment, the results of the children's accommodative response measured at 2.285 m or through a DMS are very similar. The viewing distance can be extended by a DMS, resulting in accommodative relaxation. This result may have potential applications in myopia control.

Alterations in peripheral refraction with spectacles, soft contact lenses and orthokeratology during near viewing: implications for myopia control

CLINICAL RELEVANCE

The peripheral refraction profile in myopes with different corrective modalities varies significantly for both distance and near viewing and will have implications in managing myopia.

BACKGROUND

This study investigated how the magnitude of peripheral myopic defocus induced by Ortho-K varies with and without accommodation, and how this compares to single vision spectacles and soft-contact-lenses (SCL).

METHODS

Relative peripheral refraction (RPR) of 18 young adults (spherical equivalent -1.00 D to -4.50 D) was determined along the horizontal meridian (±10°, ±20°, ±25°) during distance (3-metres) and near viewing (0.2-metres), and along vertical meridian (±10°, ±15°) for distance viewing alone. Measurements were obtained in an uncorrected state and with single vision spectacles, soft contact lens and Ortho-K. Changes in RPR and astigmatic components were compared between distance and near viewing with all different modalities.

RESULTS

A significant interaction (p = 0.02) between relative peripheral refraction and the target distance (distance and near viewing) was found among different refractive modalities. Single overnight Ortho-K lens wear alone led to relative peripheral myopia for both distance (mean RPR ± SE: -0.92 ± 0.21D and -1.04 ± 0.22D) and near viewing (-0.71 ± 0.17D and -0.76 ± 0.20D). Comparisons of relative peripheral refraction between different corrective modalities at each eccentricity indicated statistical significance of RPR at extreme locations along both temporal and nasal meridian (±20 and ±25°, p < 0.05). RPR with soft contact lenses and spectacles were similar for both distance and near viewing (p > 0.05).

CONCLUSION

Single overnight Ortho-K lens wear alone shifted the RPR in the myopic direction for both distance and near viewing in comparison with single vision spectacles and soft contact lenses. The Ortho-K lens designs that offer a large amount of mid-peripheral corneal steeping, in-turn leading to high relative peripheral myopia for both distance and near viewing and might offer beneficial effects on myopia control.

Myopia management in the Netherlands

PURPOSE

A trend that myopia is becoming gradually more common is shown in studies worldwide. Highest frequencies have been found in East Asian urban populations (96.5%) but also a study in Europe shows that nearly half of the 25-29 year olds has myopia. With the increase in prevalence, high myopia, i.e. a spherical equivalent of -6 or more and an axial length of 26 mm or more is also on the rise. High myopia particularly carries a significant risk of ocular pathology related to the long axial length. This highlights the need for myopia management in children with progressive myopia, in particular progression to high myopia.

RECENT FINDINGS

During the last decade, many intervention studies for myopia progression have emerged. Although lifestyle adjustments are effective, pharmacological and optical interventions have shown the highest efficacy on reduction of eye growth. High concentration atropine (0.5%-1.0%) shows the most reduction in axial length progression, but has drawbacks of light sensitivity and loss of accommodation. Nevertheless, when these side effects are mitigated by multifocal photochromatic glasses, the long-term adherence to high dose atropine is high. Lower concentrations of atropine are less effective, but have less side effects. Studies on optical interventions have reported reduction of progression for Ortho-K and multifocal contact lenses, but are in need for replication in larger studies with longer duration.

SUMMARY

The field of myopia management is rapidly evolving, and a position on the best approach for daily clinics is desirable. Over the last 10 years, our team of clinical researchers has developed a strategy which involves decision-making based on age, axial length, position on the axial length growth chart, progression rate, risk of high myopia, risk profile based on lifestyle and familial risk, side effects, and individual preference. This personalised approach ensures the most optimal long-term myopia control, and helps fight against visual impairment and blindness in the next generations of elderly.

The Association between Fourier Parameters and Clinical Parameters in Myopic Children Undergoing Orthokeratology

Purpose: To explore how Fourier parameters are associated with axial length growth (ALG) and clinical parameters in children who underwent orthokeratology.Materials and Methods: A total of 267 children received orthokeratology. Baseline cycloplegic autorefraction was performed. Axial length was measured at baseline and one year after the lens dispatch, and the difference was defined as ALG. Corneal topography was performed at the same two visits. Central treatment zone (CTZ) was identified from the difference between the two tangential maps, and its center distance to corneal center was defined as decentration. A relative refractive corneal power (RCRP) map was derived by subtracting the center value from every point on the one-year axial map. It was decomposed into 3 Fourier components: a mean (F0), a single-cycle sinewave (F1), and a double-cycle sinewave (F2). Linear regressions were used to reveal the association between ALG and these parameters.Results: At baseline, the age was 10.18 ± 1.48 year, spherical equivalent (SE) was - 3.10 ± 1.15D, astigmatism was 1.17 ± 0.58D, and axial length was 24.69 ± 0.81 mm. The mean ALG was 0.181 ± 0.22 mm. In multiple regression, ALG was negatively associated with F1 (p < .001), not F0 and F2. Amplitude-wise, F0 and F1 were correlated with decentration (p < .01) and SE (p < .01), and F2 was associated with astigmatism (p < .001). Direction-wise, F1 was correlated with decentration (p < .001) and F2 was associated with astigmatism (p < .001).Conclusions: Among Fourier parameters, F0 and F1 were negatively associated with ALG in myopic children undergoing orthokeratology. Their associations to SE and CTZ decentration may partially explain the effect on ALG retardation.

Flitcroft's model of refractive development in childhood and the possible identification of children at risk of developing significant myopia

PURPOSE

To better understand juvenile myopia in the context of overall refractive development during childhood and to suggest more informative ways of analysing relevant data, particularly in relation to early identification of those children who are likely to become markedly myopic and would therefore benefit from myopia control.

METHODS

Examples of the frequency distributions of childhood mean spherical refractive errors (MSEs) at different ages, taken from previously-published longitudinal and cross-sectional studies, are analysed in terms of Flitcroft's model of a linear combination of two Gaussian distributions with different means and standard deviations. Flitcroft hypothesises that one, relatively-narrow, Gaussian (Mode 1) represents a "regulated" population which maintains normal emmetropisation and the other, broader, Gaussian (Mode 2) a "dysregulated" population.

RESULTS

Analysis confirms that Flitcroft's model successfully describes the major features of the frequency distribution of MSEs in randomly-selected populations of children of the same age. The narrow "regulated" Gaussian typically changes only slightly between the ages of about 6 and 15, whereas the mean of the broader "dysregulated" Gaussian changes with age more rapidly in the myopic direction and its standard deviation increases. These effects vary with the ethnicity, environment and other characteristics of the population involved. At all ages there is considerable overlap between the two Gaussians. This limits the utility of simple refractive cut-off values to identify those children likely to show marked myopic progression.

CONCLUSIONS

Analysing the frequency distributions for individual MSEs in terms of bi-Gaussian models can provide useful insights into childhood refractive change. A wider exploration of the methodology and its extension to include individual progression rates is warranted, using a range of populations of children exposed to different ethnic, environmental and other factors.

Established soft contact lens wearers' awareness of and initial experiences with orthokeratology

OBJECTIVES

To understand the initial awareness of and experience with orthokeratology in a group of adult, symptomatic, soft contact lens (CL) wearers.

METHODS

This was a prospective, 3-month, open-label study of symptomatic soft CL wearers who were between the ages of 18 and 45 years. Baseline measurements were taken and then all subjects were treated with orthokeratology. A dry eye evaluation was completed at baseline prior to orthokeratology treatment. This same dry eye evaluation was completed 1 week and 1 month after orthokeratology treatment. An investigator-designed questionnaire that aimed to understand the subject's initial awareness of and experience with orthokeratology was also administered at the baseline, 1-week, 1-month and 3-month visits (perceptions, knowledge, tolerance and ability to apply and remove orthokeratology lenses).

RESULTS

Twenty-nine out of 40 subjects completed this study. Completed subjects (age = 24.28 ± 3.75 years) had significant improvements in ocular comfort over the course of the study compared to their soft CLs. Most subjects were unfamiliar with orthokeratology before the study, were able to quickly adapt to the treatment and were likely to recommend orthokeratology to friends or children for myopia management.

CONCLUSIONS

This study found that few subjects knew about orthokeratology before learning about it through this investigation, suggesting that patients should be offered this treatment more regularly. This conclusion is supported by the ability of the subjects to learn and adapt to orthokeratology with ease, and their likelihood to recommend it to a friend or child.

Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute

The prevalence of myopia is increasing extensively worldwide. The number of people with myopia in 2020 is predicted to be 2.6 billion globally, which is expected to rise up to 4.9 billion by 2050, unless preventive actions and interventions are taken. The number of individuals with high myopia is also increasing substantially and pathological myopia is predicted to become the most common cause of irreversible vision impairment and blindness worldwide and also in Europe. These prevalence estimates indicate the importance of reducing the burden of myopia by means of myopia control interventions to prevent myopia onset and to slow down myopia progression. Due to the urgency of the situation, the European Society of Ophthalmology decided to publish this update of the current information and guidance on management of myopia. The pathogenesis and genetics of myopia are also summarized and epidemiology, risk factors, preventive and treatment options are discussed in details.

Practice of orthokeratology in Algeria: a retrospective study

PURPOSE

To report the practice of orthokeratology (OK) in Algeria and to investigate the visual outcomes, safety and subjective responses with this technique in myopes.

METHODS

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.

RESULTS

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.

CONCLUSION

the technique was efficient and safe as we didn't have any serious complication, with a high success rate for first lens fitting.

Biological Mechanisms of Atropine Control of Myopia

Myopia is a global problem that is increasing at an epidemic rate in the world. Although the refractive error can be corrected easily, myopes, particularly those with high myopia, are susceptible to potentially blinding eye diseases later in life. Despite a plethora of myopia research, the molecular/cellular mechanisms underlying the development of myopia are not well understood, preventing the search for the most effective pharmacological control. Consequently, several approaches to slowing down myopia progression in the actively growing eyes of children have been underway. So far, atropine, an anticholinergic blocking agent, has been most effective and is used by clinicians in off-label ways for myopia control. Although the exact mechanisms of its action remain elusive and debatable, atropine encompasses a complex interplay with receptors on different ocular tissues at multiple levels and, hence, can be categorized as a shotgun approach to myopia treatment. This review will provide a brief overview of the biological mechanisms implicated in mediating the effects of atropine in myopia control.

Pharmacotherapeutic candidates for myopia: A review

This review provides insights into the mechanism underlying the pathogenesis of myopia and potential targets for clinical intervention. Although the etiology of myopia involves both environmental and genetic factors, recent evidence has suggested that the prevalence and severity of myopia appears to be affected more by environmental factors. Current pharmacotherapeutics are aimed at inhibiting environmentally induced changes in visual input and subsequent changes in signaling pathways during myopia pathogenesis and progression. Recent studies on animal models of myopia have revealed specific molecules potentially involved in the regulation of eye development. Among them, the dopamine receptor plays a critical role in controlling myopia. Subsequent studies have reported pharmacotherapeutic treatments to control myopia progression. In particular, atropine treatment yielded favorable outcomes and has been extensively used; however, current studies are aimed at optimizing its efficacy and confirming its safety. Furthermore, future studies are required to assess the efficacy of combinatorial use of low-dose atropine and contact lenses or orthokeratology.

Efficacy in myopia control

There is rapidly expanding interest in interventions to slow myopia progression in children and teenagers, with the intent of reducing risk of myopia-associated complications later in life. Despite many publications dedicated to the topic, little attention has been devoted to understanding 'efficacy' in myopia control and its application. Treatment effect has been expressed in multiple ways, making comparison between therapies and prognosis for an individual patient difficult. Available efficacy data are generally limited to two to three years making long-term treatment effect uncertain. From an evidence-based perspective, efficacy projection should be conservative and not extend beyond that which has been empirically established. Using this principle, review of the literature, data from our own clinical studies, assessment of demonstrated myopia control treatments and allowance for the limitations and context of available data, we arrive at the following important interpretations: (i) axial elongation is the preferred endpoint for assessing myopic progression; (ii) there is insufficient evidence to suggest that faster progressors, or younger myopes, derive greater benefit from treatment; (iii) the initial rate of reduction of axial elongation by myopia control treatments is not sustained; (iv) consequently, using percentage reduction in progression as an index to describe treatment effect can be very misleading and (v) cumulative absolute reduction in axial elongation (CARE) emerges as a preferred efficacy metric; (vi) maximum CARE that has been measured for existing myopia control treatments is 0.44 mm (which equates to about 1 D); (vii) there is no apparent superior method of treatment, although commonly prescribed therapies such as 0.01% atropine and progressive addition spectacles lenses have not consistently provided clinically important effects; (viii) while different treatments have shown divergent efficacy in the first year, they have shown only small differences after this; (ix) rebound should be assumed until proven otherwise; (x) an illusion of inflated efficacy is created by measurement error in refraction, sample bias in only treating 'measured' fast progressors and regression to the mean; (xi) decision to treat should be based on age of onset (or refraction at a given age), not past progression; (xii) the decreased risk of complications later in life provided by even modest reductions in progression suggest treatment is advised for all young myopes and, because of limitations of available interventions, should be aggressive.

Comparison between two autorefractor performances in large scale vision screening in Chinese school age children

AIM

To evaluate the effectiveness of Grand Seiko Ref/Keratometer WAM-5500 compared to Topcon KR800 autorefractor in detecting refractive error in large scale vision screening for Chinese school age children with the WHO criteria.

METHODS

A total of 886 participants were enrolled with mean age of 9.49±1.88y from Tianjin, China. Spherical equivalent (SE) was obtained from un-cycloplegic autorefraction and cycloplegic autorefraction. Topcon KR 800 (Topcon) and Grand Seiko WAM-5500 (WAM) autorefractors were used. Bland-Altman Plot and regression were generated to compare their performance. The overall effectiveness of detecting early stage refractive error was analyzed with receiver operating characteristic (ROC) curves.

RESULTS

The mean SE was -0.98±1.81 diopter (D) and the prevalence of myopia was 48.9% defined by WHO criteria according to the result of cycloplegic autorefraction. The mean SE of un-cycloplegic autorefraction with Topcon and WAM were -1.21±1.65 and -1.20±1.68 D respectively. There was a strong linear agreement between result obtained from WAM and cycloplegic autorefraction with an R² of 0.8318. Bland-Altman plot indicated a moderate agreement of cylinder values between the two methods. The sensitivity and specificity for detecting hyperopia were 90.52% and 83.51%; for detecting myopia were 95.60% and 90.24%; for detecting astigmatism were 79.40% and 90.21%; for detecting high myopia were 98.16% and 98.91% respectively.

CONCLUSION

These findings suggest that both Grand Seiko and Topcon autorefractor can be used in large-scale vision screening for detecting refractive error in Chinese population. Grand Seiko gives relatively better performance in detecting myopia, hyperopia, and high myopia for school age children.

A 3-year follow-up study of atropine treatment for progressive myopia in Europeans

BACKGROUND

Atropine is the most powerful treatment for progressive myopia in childhood. This study explores the 3-year effectiveness of atropine in a clinical setting.

METHODS

In this prospective clinical effectiveness study, children with progressive myopia ≥ 1D/year or myopia ≤ -2.5D were prescribed atropine 0.5%. Examination, including cycloplegic refraction and axial length (AL), was performed at baseline, and follow-up. Outcome measures were spherical equivalent (SER) and AL; annual progression of SER on treatment was compared with that prior to treatment. Adjustments to the dose were made after 1 year in case of low (AL ≥ 0.3 mm/year) or high response (AL < 0.1 mm/year) of AL.

RESULTS

A total of 124 patients were enrolled in the study (median age: 9.5, range: 5-16 years). At baseline, median SER was -5.03D (interquartile range (IQR): 3.08); median AL was 25.14 mm (IQR: 1.30). N = 89 (71.8%) children were persistent to therapy throughout the 3-year follow-up. Median annual progression of SER for these children was -0.25D (IQR: 0.44); of AL 0.11 mm (IQR: 0.18). Of these, N = 32 (36.0%) had insufficient response and were assigned to atropine 1%; N = 26 (29.2%) showed good response and underwent tapering in dose. Rebound of AL progression was not observed. Of the children who ceased therapy, N = 9 were lost to follow-up; N = 9 developed an allergic reaction; and N = 17 (19.1%) stopped due to adverse events.

CONCLUSION

In children with or at risk of developing high myopia, a starting dose of atropine 0.5% was associated with decreased progression in European children during a 3-year treatment regimen. Our study supports high-dose atropine as a treatment option for children at risk of developing high myopia in adulthood.

Optical and imaging properties of a novel multi-segment spectacle lens designed to slow myopia progression

PURPOSE

High sampling density optical metrology combined with pupil- and image-plane numerical analyses were applied to evaluate a novel spectacle lens containing multiple small zones designed to slow myopia progression.

METHODS

High-resolution aberrometry (ClearWave, www.lumetrics.com) was used to sample wavefront slopes of a novel spectacle lens, Defocus Incorporated Multiple Segments (DIMS) (www.hoya.com), incorporating many small, positive-powered lenslets in its periphery. Using wavefront slope and error maps, custom MATLAB software ('Indiana Wavefront Analyzer') was used to compute image-plane point-spread functions (PSF), modulation transfer functions (MTF), simulated images and power distributions created by the dual-focus optic for different pupil sizes and target vergences.

RESULTS

Outside of a central 10 mm zone containing single distance optical power, a hexagonal array of small 1 mm lenslets with nearest-neighbour separations of 0.5 mm were distributed over the lens periphery. Sagittal and curvature-based measures of optical power imperfectly captured the consistent +3.50 D add produced by the lenslets. Image plane simulations revealed multiple PSFs and poor image quality at the lenslet focal plane. Blur at the distance optic focal plane was consistent with a combination of diffraction blur from the distance optic and the approximately +3.50 D of defocus from the 1 mm diameter near optic zones.

CONCLUSION

Converging the defocused beams generated by the multiple small (1 mm diameter) lenslets to a blurred image at the distance focal plane produced a blur magnitude determined by the small lenslet diameter and not the overall pupil diameter. The distance optic located in between the near-add lenslets determines the limits of the optical quality achievable by the lens. When compared to the optics of a traditional concentric-zone dual-focus contact lens, the optics of the DIMS lens generates higher-contrast images at low spatial frequencies (<7 cycles per degree), but lower-contrast at high spatial frequencies.

Efficacy of combined orthokeratology and 0.01% atropine solution for slowing axial elongation in children with myopia: a 2-year randomised trial

Eighty Japanese children, aged 8–12 years, with a spherical equivalent refraction (SER) of − 1.00 to − 6.00 dioptres (D) were randomly allocated into two groups to receive either a combination of orthokeratology (OK) and 0.01% atropine solution (combination group) or monotherapy with OK (monotherapy group). Seventy-three subjects completed the 2-year study. Over the 2 years, axial length increased by 0.29 ± 0.20 mm (n = 38) and 0.40 ± 0.23 mm (n = 35) in the combination and monotherapy groups, respectively (P = 0.03). Interactions between combination treatment and age or SER did not reach significance level (age, P = 0.18; SER, P = 0.06). In the subgroup of subjects with an initial SER of − 1.00 to − 3.00 D, axial length increased by 0.30 ± 0.22 mm (n = 27) and 0.48 ± 0.22 mm (n = 23) in the combination and monotherapy groups, respectively (P = 0.005). In the − 3.01 to − 6.00 D subgroup, axial length increased by 0.27 ± 0.15 mm (n = 11) and 0.25 ± 0.17 mm (n = 12) in the combination and monotherapy groups, respectively (P = 0.74). The combination therapy may be effective for slowing axial elongation, especially in children with low initial myopia.

The Combined Effect of Low-dose Atropine with Orthokeratology in Pediatric Myopia Control: Review of the Current Treatment Status for Myopia

Pediatric myopia has become a major international public health concern. The prevalence of myopia has undergone a significant increase worldwide. The purpose of this review of the current literature was to evaluate the peer-reviewed scientific literature on the efficacy and safety of low-dose atropine treatment combined with overnight orthokeratology for myopia control. A search was conducted in Pubmed and Web of Science with the following search strategy: (atropine OR low-dose atropine OR 0.01% atropine) AND (orthokeratology OR ortho-k) AND (myopia control OR myopia progression). All included studies improved myopia control by the synergistic effect of orthokeratology with low-dose atropine, compared with orthokeratology treatment alone. All studies included a short or medium follow-up period; therefore longer-term studies are necessary to validate these results.