Impact of Various Concentrations of Low-Dose Atropine on Pupillary Diameter and Accommodative Amplitude in Children with Myopia

Purpose: To assess over 2 weeks, the effect of 3 different low concentrations of atropine on pupillary diameter and accommodative amplitude in children with myopia. Methods: Fifty-eight children with myopia [spherical equivalent (SE) of -0.50 diopters (D) or worse, astigmatism of less than or equal to 2.00 D] were randomly allocated to 3 groups receiving 0.01%, 0.02%, or 0.03% atropine eye drops, once nightly for 2 weeks. The primary outcome was the change from baseline in pupillary diameter and accommodative amplitude with each of the concentrations. Results: Fifty-seven participants (114 eyes), aged between 6 and 12 years, completed the 2-week trial (mean age 9.3 ± 1.7 years and mean SE -3.53 ± 1.79 D). After 2 weeks of use, all the 3 concentrations were found to have a statistically significant effect on both the pupillary diameter and accommodative amplitude. Accommodative amplitude reduced by an average of 5.23 D, 9.28 D, and 9.32 D, and photopic pupil size increased by an average of 0.95 ± 1.05 mm, 1.65 ± 0.93 mm, and 2.16 ± 0.88 mm with 0.01%, 0.02%, and 0.03%, respectively. Of the eyes, a total of 5.3% and 5.9% of the eyes on 0.02% and 0.03% atropine had a mean residual accommodative amplitude of <5 D. The percentage of eyes having a pupillary dilation >3 mm were 4.8%, 10.5%, and 23.5% for 0.01%, 0.02%, and 0.03% atropine, respectively. Conclusions: Low-dose atropine had an effect on pupillary diameter and accommodative amplitude. With the highest concentration assessed, that is, 0.03% nearly 1 of 4 eyes had pupillary dilation of >3 mm. Clinical Trial Registration number: NCT03699423.

Two-Year Myopia Management Efficacy of Extended Depth of Focus Soft Contact Lenses (MYLO) in Caucasian Children

PURPOSE

To evaluate the progression of myopia as assessed by change in axial length (AL) and spherical equivalent (SE) from baseline in Caucasian children wearing extended depth of focus soft contact lenses (CLs) compared to distance single-vision spectacles.

DESIGN

Prospective non-randomized comparative clinical trial.

METHODS

A total of 90 children (6-13 years of age) with SE ranging from -0.75 to -10.00 diopters (D) were recruited. Of these children, 45 were fitted with CLs (MYLO, mark´ennovy), whereas 45 children wore spectacles. Cycloplegic refraction was measured with an auto-refractometer (Topcon-TRK-2P) and AL with an IOLMaster-700 (Zeiss) at 6-month intervals. Subjective responses after 1 month of CL wear related to vision and comfort were determined using a questionnaire with a scale from 1 (very poor) to 10 (excellent). High-contrast visual acuity (HCVA) and contrast sensitivity (CS) were evaluated at baseline, 12, and 24 months.

RESULTS

After 2 years, mean change in SE/AL in the CL group was -0.62 ± 0.30 D/0.37 ± 0.04 mm and -1.13 ± 0.20 D/0.66 ± 0.03 mm in the spectacles group (P < .001). Cumulative absolute reduction in axial elongation (CARE) was 0.29 ± 0.06 mm. Difference in SE change was -0.50 ± 0.34 D. Although 100% of CL group had an AL increase ≤0.50 mm, all participants increased ≥0.50 mm in the spectacles group. In all, 53% of the CL group and 1% in the spectacles group showed a progression in SE ≤ -0.50D. All questionnaire items showed a mean value ≥9. There was a reduction logMAR HCVA in the CL compared to the spectacles group but it was less than 1 line (P < .001).

CONCLUSIONS

Use of MYLO CLs reduced axial elongation and myopia progression compared to use of distance single-vision spectacles.

Using choroidal thickness to detect myopic macular degeneration

AIM

To explore the usage of choroidal thickness measured by swept-source optical coherence tomography (SS-OCT) to detect myopic macular degeneration (MMD) in high myopic participants.

METHODS

Participants with bilateral high myopia (≤-6 diopters) were recruited from a subset of the Guangzhou Zhongshan Ophthalmic Center-Brien Holden Vision Institute High Myopia Cohort Study. SS-OCT was performed to determine the choroidal thickness, and myopic maculopathy was graded by the International Meta-Analysis for Pathologic Myopia (META-PM) Classification. Presence of MMD was defined as META-PM category 2 or above.

RESULTS

A total of 568 right eyes were included for analysis. Eyes with MMD (n=106, 18.7%) were found to have older age, longer axial lengths (AL), higher myopic spherical equivalents (SE), and reduced choroidal thickness in each Early Treatment Diabetic Retinopathy Study (ETDRS) grid sector (P<0.001). The area under the receiver operating characteristic (ROC) curves (AUC) for subfoveal choroidal thickness (0.907) was greater than that of the model, including age, AL, and SE at 0.6249, 0.8208, and 0.8205, respectively. The choroidal thickness of the inner and outer nasal sectors was the most accurate indicator of MMD (AUC of 0.928 and 0.923, respectively). An outer nasal sector choroidal thickness of less than 74 µm demonstrated the highest odds of predicting MMD (OR=33.8).

CONCLUSION

Choroidal thickness detects the presence of MMD with high agreement, particularly of the inner and outer nasal sectors of the posterior pole, which appears to be a biometric parameter more precise than age, AL, or SE.

Normative data for axial elongation in Asian children

AIM

To determine the influence of refractive error (RE), age, gender and parental myopia on axial elongation in Chinese children and to develop normative data for this population.

METHODS

This is a retrospective analysis of eight longitudinal studies conducted in China between 2007 and 2017. Data of 4701 participants aged 6-16 years with spherical equivalent from +6 to -6D contributed to one, two or three annualised progression data resulting in a dataset of 11,262 eyes of 26.6%, 14.8% and 58.6% myopes, emmetropes and hyperopes, respectively. Longitudinal data included axial length and cycloplegic spherical equivalent RE. Axial elongation was log-transformed to develop an exponential model with generalised estimating equations including main effects and interactions. Model-based estimates and their confidence intervals (CIs) are reported.

RESULTS

Annual axial elongation decreased significantly with increasing age, with the rate of decrease specific to the RE group. Axial elongation in myopes was higher than in emmetropes and hyperopes but these differences reduced with age (0.58, 0.45 and 0.27 mm/year at 6 years and 0.13, 0.06 and 0.05 mm/year at 15 years for myopes, emmetropes and hyperopes, respectively). The rate of elongation in incident myopes was similar to that in myopes at baseline (0.33 vs. 0.34 mm/year at 10.5 years; p = 0.32), while it was significantly lower in non-myopes (0.20 mm/year at 10.5 years, p < 0.001). Axial elongation was greater in females than in males and in those with both parents myopic compared with one or no myopic parent, with larger differences in non-myopes than in myopes (p < 0.01).

CONCLUSIONS

Axial elongation varied with age, RE, gender and parental myopia. Estimated normative data with CIs could serve as a virtual control group.

Establishing a method to estimate the effect of antimyopia management options on lifetime cost of myopia

BACKGROUND

Informed decisions on myopia management require an understanding of financial impact. We describe methodology for estimating lifetime myopia costs, with comparison across management options, using exemplars in Australia and China.

METHODS

We demonstrate a process for modelling lifetime costs of traditional myopia management (TMM=full, single-vision correction) and active myopia management (AMM) options with clinically meaningful treatment efficacy. Evidence-based, location-specific and ethnicity-specific progression data determined the likelihood of all possible refractive outcomes. Myopia care costs were collected from published sources and key informants. Refractive and ocular health decisions were based on standard clinical protocols that responded to the speed of progression, level of myopia, and associated risks of pathology and vision impairment. We used the progressions, costs, protocols and risks to estimate and compare lifetime cost of myopia under each scenario and tested the effect of 0%, 3% and 5% annual discounting, where discounting adjusts future costs to 2020 value.

RESULTS

Low-dose atropine, antimyopia spectacles, antimyopia multifocal soft contact lenses and orthokeratology met our AMM inclusion criteria. Lifetime cost for TMM with 3% discounting was US$7437 (CI US$4953 to US$10 740) in Australia and US$8006 (CI US$3026 to US$13 707) in China. The lowest lifetime cost options with 3% discounting were antimyopia spectacles (US$7280, CI US$5246 to US$9888) in Australia and low-dose atropine (US$4453, CI US$2136 to US$9115) in China.

CONCLUSIONS

Financial investment in AMM during childhood may be balanced or exceeded across a lifetime by reduced refractive progression, simpler lenses, and reduced risk of pathology and vision loss. Our methodology can be applied to estimate cost in comparable scenarios.

IMI 2023 Digest

Myopia is a dynamic and rapidly moving field, with ongoing research providing a better understanding of the etiology leading to novel myopia control strategies. In 2019, the International Myopia Institute (IMI) assembled and published a series of white papers across relevant topics and updated the evidence with a digest in 2021. Here, we summarize findings across key topics from the previous 2 years. Studies in animal models have continued to explore how wavelength and intensity of light influence eye growth and have examined new pharmacologic agents and scleral cross-linking as potential strategies for slowing myopia. In children, the term premyopia is gaining interest with increased attention to early implementation of myopia control. Most studies use the IMI definitions of ≤-0.5 diopters (D) for myopia and ≤-6.0 D for high myopia, although categorization and definitions for structural consequences of high myopia remain an issue. Clinical trials have demonstrated that newer spectacle lens designs incorporating multiple segments, lenslets, or diffusion optics exhibit good efficacy. Clinical considerations and factors influencing efficacy for soft multifocal contact lenses and orthokeratology are discussed. Topical atropine remains the only widely accessible pharmacologic treatment. Rebound observed with higher concentration of atropine is not evident with lower concentrations or optical interventions. Overall, myopia control treatments show little adverse effect on visual function and appear generally safe, with longer wear times and combination therapies maximizing outcomes. An emerging category of light-based therapies for children requires comprehensive safety data to enable risk versus benefit analysis. Given the success of myopia control strategies, the ethics of including a control arm in clinical trials is heavily debated. IMI recommendations for clinical trial protocols are discussed.

Time outdoors positively associates with academic performance: a school-based study with objective monitoring of outdoor time

BACKGROUND

To explore the relationship between outdoor time and academic performance among school-aged children.

METHODS

This study was designed as a cross-sectional study. Data were derived from a school-based prospective children myopia intervention study (STORM). Outdoor time was recorded by self-developed algorithm-validated wristwatches in real-time and calculated as the cumulative average of 10 months. The academic performance was recorded and provided by the participating schools and further standardized. Other information was collected using an online standardized questionnaire. Mixed-effects model and B-Spline method were used to investigate the association between time spent on different types of daily activity, including outdoor activity and academic performance.

RESULTS

A total of 3291 children with mean age 9.25 years were included in the final analysis. Overall, outdoor time was associated with academic performance in a non-linear manner; specifically, not exceeding 2.3 h per day, outdoor time was positively associated with academic performance; exceeding 2.3 h per day, this association became non-significant. Likewise, daily sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner, resulting in turning points of 11.3 and 1.4 h per day, respectively. Separate analysis showed that outdoor time and sleep duration but not out-of-school learning time were positively associated with academic performance in Chinese, mathematics and English.

CONCLUSION

Outdoor time, sleep duration and out-of-school learning time were associated with academic performance in a non-linear manner. Promotion of outdoor time may not negatively impact on academic performance.

TRIAL REGISTRATION

Our study was registered in ClinicalTrials.gov (Identifier: NCT02980445).

Normative data and percentile curves for axial length and axial length/corneal curvature in Chinese children and adolescents aged 4-18 years

PURPOSE

To develop age-specific and gender-specific reference percentile charts for axial length (AL) and AL/corneal radius of curvature (AL/CR) and, to use percentiles to determine probability of myopia and estimate refractive error (RE).

METHODS

Analysis of AL, cycloplegic RE and CR of 14 127 Chinese participants aged 4-18 years from 3 studies. AL and AL/CR percentiles estimated using Lambda-Mu-Sigma method and compared for agreement using intraclass correlation (ICC). Logistic regression was used to model risk of myopia based on age, gender, AL and AL/CR percentiles. Accuracy of AL progression and RE estimated using percentiles was validated using an independent sample of 5742 eyes of children aged 7-10 years.

RESULTS

Age-specific and gender-specific AL and AL/CR (3rd, 5th, 10th, 25th, 50th, 75th, 90th and 95th) percentiles are presented. Concordance between AL and AL/CR percentiles improved with age (0.13 at 4 years to >0.75 from 13 years) and a year-to-year change was observed for all except <10th percentile from 15 years. Increasing age, AL and AL/CR was associated with a more myopic RE (r²=0.45,0.70 and 0.83, respectively). The sensitivity and specificity of the model to estimate probability of myopia was 86.0% and 84.5%, respectively. Estimation of 1-year change in AL using percentiles correlated highly with actual AL (ICC=0.98). Concordance of estimated to actual RE was high (ICC=0.80) and within ±0.50D and ±1.0D of actual RE for 47.4% and 78.9% of eyes, respectively.

CONCLUSION

Age-specific and gender-specific AL and AL/CR percentiles provide reference data, aid in identifying and monitoring individuals at risk of myopia and have utility in screening for myopia. AL/CR percentiles were more accurate in estimating probability of myopia in younger children.

Prevalence and Patterns of Refractive Errors in Children and Young Adults in an Urban Region in South India: the Hyderabad Eye Study

PURPOSE

To determine the prevalence of refractive error (RE) and associated risk factors for myopic refractive errors in children and young adults from the urban region of Hyderabad, South India.

METHODS

Four thousand sixty-five (4,065) participants aged 6-22 years were enrolled and examined in this cross-sectional study conducted from October 2013 to January 2015. Participants were enrolled from a random sample of schools and universities in regions representative of urban Hyderabad. RE was determined using cycloplegic autorefraction. The association of demographic factors such as age, gender, and socio-economic category (SEC) (low/mid/high) with myopia was explored with logistic regression with robust standard error.

RESULTS

Of the total participants, 2,259 were children aged 6-15 years and 1,806 were adolescents and young adults aged 16-22 years. Overall prevalence of myopia, high myopia (≤ -5.00D and ≤ -6.00 D), hyperopia, emmetropia, and astigmatism was 29.8% (95% CI: 26.0% to 33.6%, n = 1,216), 2.9% (95% CI: 1.9% to 3.9%, n = 120), 1.1% (95%CI: 0.7% to 1.5%, n = 46), 14.7% (95% CI: 12.4% to 17.0%, n = 599), 46.9% (95% CI: 43.7% to 50.1%, n = 1913) and 8.6% (95% CI: 7.4% to 9.9%, n = 352) respectively. A strong correlation existed between age and prevalence of myopia (R² = 0.88, p < .001) and high myopia (R² = 0.71, p < .001). Children from schools of low SEC (34.7%) had higher prevalence of myopia compared to the mid SEC (16.8%) (p = .043).

CONCLUSION

Myopia was the most prevalent refractive error and increased with age in this urban population. More myopia was observed in schools of low SEC.

Efficacy of contact lenses for myopia control: Insights from a randomised, contralateral study design

PURPOSE

To determine the efficacy of two myopia control contact lenses (CL) compared with a single-vision (SV) CL.

METHODS

Ninety-five Chinese children with myopia, aged 7-13 years in a 1-year prospective, randomised, contralateral, cross-over clinical trial with 3 groups; bilateral SVCL (Group I); randomised, contralateral wear of an extended depth of focus (EDOF) CL and SVCL (Group II) and MiSight® CL and SVCL (Group III). In Groups II and III, CL were crossed over at the 6-month point (Stage 1) and worn for a further 6 months (Stage 2). Group I wore SVCL during both stages. At baseline and the end of each stage, cycloplegic spherical equivalent refractive error (SE) and axial length (AL) were measured. Six-monthly ΔSE/ΔAL across groups was analysed using a linear mixed model (CL type, stage, eye and eye* stage included as factors). Intra-group paired differences between eyes were determined.

RESULTS

In Group I, mean (SD) ΔSE/ΔAL with SVCL was -0.41 (0.28) D/0.13 (0.09) mm and -0.25 (0.27) D/0.16 (0.09) mm for stages 1 and 2, with a mean paired difference between eyes of 0.01 D/0.01 mm and 0.05 D/-0.01 mm, respectively. ΔSE/ΔAL with SVCL was similar across Groups I to III (Stage 1: p = 0.89/0.44, Stage 2: p = 0.70/ 0.64). In Groups II and III, ΔSE/ΔAL was lower with the EDOF and MiSight® CL than the contralateral SVCL in 68% to 94% of participants, and adjusted 6-month ΔSE/ΔAL with EDOF was similar to MiSight® (p = 0.49/0.56 for ΔSE/ΔAL, respectively). Discontinuations across the three groups were high, but not different between the groups (33.3%, 48.4% and 50% for Groups I to III, respectively [p = 0.19]) and most discontinuations occurred immediately after baseline.

CONCLUSIONS

Extended depth of focus and MiSight® CL demonstrated similar efficacy in slowing myopia. When switched from a myopia control CL to SVCL, myopia progression was similar to that observed with age-matched wearers in SVCL and not suggestive of rebound.

Accelerated loss of crystalline lens power initiating from emmetropia among young school children: a 2-year longitudinal study

Purpose

To determine the characteristics of crystalline lens with varying refractive errors and relationship with axial elongation in young school children.

Methods

A total of 1465 children aged 6–8 years were examined annually for 2 years. Each participant underwent a series of ophthalmic examinations, including cycloplegic autorefraction, crystalline lens and axial length measurement. Crystalline lens power was determined, and factors associated with different refractive statuses were investigated.

Results

Crystalline lens power decreased with time; reduction in lens power in Year 1 was greater in children with emmetropia (−0.69 ± 0.59 dioptre [D]) than in those with hyperopia (−0.49 ± 0.56 D) or myopia (−0.45 ± 0.55 D) (p < 0.001). Among the emmetropes, there were no differences in loss of crystalline lens power between those who remained emmetropic (−0.63 ± 0.59 D) and those who became myopic at Year 1 (−0.74 ± 0.61 D) and Year 2 (−0.77 ± 0.57 D, p > 0.05) visits. Among myopes at Year 1 visit, there was a greater reduction at Year 2 in those who had baseline emmetropia (−0.61 ± 0.51 D) than those who had baseline myopia (−0.26 ± 0.49 D, p < 0.001). The trend was similar among children of the same age. There was a significant correlation between changes in lens power and axial elongation in non‐myopia (β = −0.954, p < 0.001) and new myopia (β = −1.178, p < 0.001), but not in established myopia (β = −0.001, p = 0.539).

Conclusions

There is accelerated loss of lens power in emmetropia and early stage of myopia. However, this loss is retarded when myopia persists and is accompanied by disappearance of the compensatory effect of lens power against axial elongation. These findings provide new insights into human refractive development.

Prevalence of myopia and high myopia, and the association with education: Shanghai Child and Adolescent Large-scale Eye Study (SCALE): a cross-sectional study

OBJECTIVES

To report on: (a) overall myopia and high myopia prevalence, and (b) the impact of education on the spherical equivalent refractive error in children across Shanghai.

DESIGN

Cross-sectional study.

SETTING

Across all 17 districts of Shanghai.

PARTICIPANTS

910 245 children aged 4-14 years from a school-based survey conducted between 2012 and 2013.

MAIN OUTCOME MEASURES

Data of children with non-cycloplegic autorefraction, visual acuity assessment and questionnaire were analysed (67%, n=6 06 476). Prevalence of myopia (≤-1.0 D) and high myopia (≤-5.0 D) was determined. We used a regression discontinuity design to determine the impact of school entry cut-off date (1 September) by comparing refractive errors at each age, for children born pre-September to post-1 September, and performed a multivariate analysis to explore risk factors associated with myopia. Data analysis was performed in 2017-2018.

RESULTS

Prevalence rates of myopia and high myopia were 32.9% (95% CI: 32.8% to 33.1%) and 4.2% (95% CI: 4.1% to 4.2%), respectively. From 6 years of age onwards, children born pre-September were more myopic compared with those born post-1 September (ahead in school by 1 year, discontinuity at 6 years: -0.19 D (95% CI: -0.09 to -0.30 D); 14 years: -0.67 D (95% CI: -0.21 to -1.14 D)).

CONCLUSIONS

Our findings suggest that myopia is associated with education, that is primarily focused on near-based activities. Efforts to reduce the burden should be directed to public awareness, reform of education and health systems.

A Meta-Analysis Assessing Change in Pupillary Diameter, Accommodative Amplitude, and Efficacy of Atropine for Myopia Control

PURPOSE

To determine the effect of atropine on pupillary diameter, accommodative amplitude as well as myopia progression.

METHODS

Medical databases and Cochrane Library were systematically searched for studies from 1980 until June 2020. The primary and secondary outcomes were: a) change in pupillary diameter (PD) and accommodative amplitude (AA) and b) annualized mean change in spherical equivalent and axial length with various concentrations of atropine compared to control.

RESULTS

Thirteen trials (6 RCTs, 7 observational studies) that studied 9 atropine concentrations (0.01-1.0%) were included. The relation between atropine and change in PD and AA was nonlinear; at < 0.10% atropine, the slope of the curve was steep but the change in PD (+0.7 mm; 95% CI: +0.1 to +1.4) and AA (-1.6D; 95% CI: -3.9 to +0.7) was smaller whereas at ≥0.10% atropine, the slope plateaued but change in PD (+3.2 mm, 95% CI: +2.8 to +3.5) and AA (-10.7D; 95% CI: -12.2 to -9.2) was high.Reduction in myopia progression with atropine at <0.10% and ≥0.10% as compared to controls was 0.37D (95% CI: 0.16 to 0.58) versus 0.75D (95% CI: 0.17 to 1.33) for spherical equivalent and -0.10 mm (95% CI: -0.24 to 0.05) versus -0.23 mm (95% CI: -0.34 to -0.13) for axial length.

CONCLUSIONS

A nonlinear dose-response relationship exists between atropine and PD and AA. Further work is warranted to determine the concentration that provides maximal efficacy with tolerable side effects.

IMI 2021 Yearly Digest

Purpose

The International Myopia Institute (IMI) Yearly Digest highlights new research considered to be of importance since the publication of the first series of IMI white papers.

Methods

A literature search was conducted for articles on myopia between 2019 and mid-2020 to inform definitions and classifications, experimental models, genetics, interventions, clinical trials, and clinical management. Conference abstracts from key meetings in the same period were also considered.

Results

One thousand articles on myopia have been published between 2019 and mid-2020. Key advances include the use of the definition of premyopia in studies currently under way to test interventions in myopia, new definitions in the field of pathologic myopia, the role of new pharmacologic treatments in experimental models such as intraocular pressure-lowering latanoprost, a large meta-analysis of refractive error identifying 336 new genetic loci, new clinical interventions such as the defocus incorporated multisegment spectacles and combination therapy with low-dose atropine and orthokeratology (OK), normative standards in refractive error, the ethical dilemma of a placebo control group when myopia control treatments are established, reporting the physical metric of myopia reduction versus a percentage reduction, comparison of the risk of pediatric OK wear with risk of vision impairment in myopia, the justification of preventing myopic and axial length increase versus quality of life, and future vision loss.

Conclusions

Large amounts of research in myopia have been published since the IMI 2019 white papers were released. The yearly digest serves to highlight the latest research and advances in myopia.

IMI Impact of Myopia

The global burden of myopia is growing. Myopia affected nearly 30% of the world population in 2020 and this number is expected to rise to 50% by 2050. This review aims to analyze the impact of myopia on individuals and society; summarizing the evidence for recent research on the prevalence of myopia and high myopia, lifetime pathological manifestations of myopia, direct health expenditure, and indirect costs such as lost productivity and reduced quality of life (QOL). The principal trends are a rising prevalence of myopia and high myopia, with a disproportionately greater increase in the prevalence of high myopia. This forecasts a future increase in vision loss due to uncorrected myopia as well as high myopia-related complications such as myopic macular degeneration. QOL is affected for those with uncorrected myopia, high myopia, or complications of high myopia. Overall the current global cost estimates related to direct health expenditure and lost productivity are in the billions. Health expenditure is greater in adults, reflecting the added costs due to myopia-related complications. Unless the current trajectory for the rising prevalence of myopia and high myopia change, the costs will continue to grow. The past few decades have seen the emergence of several novel approaches to prevent and slow myopia. Further work is needed to understand the life-long impact of myopia on an individual and the cost-effectiveness of the various novel approaches in reducing the burden.

IMI Prevention of Myopia and Its Progression

The prevalence of myopia has markedly increased in East and Southeast Asia, and pathologic consequences of myopia, including myopic maculopathy and high myopia-associated optic neuropathy, are now some of the most common causes of irreversible blindness. Hence, strategies are warranted to reduce the prevalence of myopia and the progression to high myopia because this is the main modifiable risk factor for pathologic myopia. On the basis of published population-based and interventional studies, an important strategy to reduce the development of myopia is encouraging schoolchildren to spend more time outdoors. As compared with other measures, spending more time outdoors is the safest strategy and aligns with other existing health initiatives, such as obesity prevention, by promoting a healthier lifestyle for children and adolescents. Useful clinical measures to reduce or slow the progression of myopia include the daily application of low-dose atropine eye drops, in concentrations ranging between 0.01% and 0.05%, despite the side effects of a slightly reduced amplitude of accommodation, slight mydriasis, and risk of an allergic reaction; multifocal spectacle design; contact lenses that have power profiles that produce peripheral myopic defocus; and orthokeratology using corneal gas-permeable contact lenses that are designed to flatten the central cornea, leading to midperipheral steeping and peripheral myopic defocus, during overnight wear to eliminate daytime myopia. The risk-to-benefit ratio needs to be weighed up for the individual on the basis of their age, health, and lifestyle. The measures listed above are not mutually exclusive and are beginning to be examined in combination.

IMI Risk Factors for Myopia

Risk factor analysis provides an important basis for developing interventions for any condition. In the case of myopia, evidence for a large number of risk factors has been presented, but they have not been systematically tested for confounding. To be useful for designing preventive interventions, risk factor analysis ideally needs to be carried through to demonstration of a causal connection, with a defined mechanism. Statistical analysis is often complicated by covariation of variables, and demonstration of a causal relationship between a factor and myopia using Mendelian randomization or in a randomized clinical trial should be aimed for. When strict analysis of this kind is applied, associations between various measures of educational pressure and myopia are consistently observed. However, associations between more nearwork and more myopia are generally weak and inconsistent, but have been supported by meta-analysis. Associations between time outdoors and less myopia are stronger and more consistently observed, including by meta-analysis. Measurement of nearwork and time outdoors has traditionally been performed with questionnaires, but is increasingly being pursued with wearable objective devices. A causal link between increased years of education and more myopia has been confirmed by Mendelian randomization, whereas the protective effect of increased time outdoors from the development of myopia has been confirmed in randomized clinical trials. Other proposed risk factors need to be tested to see if they modulate these variables. The evidence linking increased screen time to myopia is weak and inconsistent, although limitations on screen time are increasingly under consideration as interventions to control the epidemic of myopia.

IMI 2021 Reports and Digest - Reflections on the Implications for Clinical Practice

The International Myopia Institute's (IMI) mission is to advance research, education, and management of myopia to decrease future vision impairment and blindness associated with increasing myopia. Its approach is to bring together scientists, clinicians, policymakers, government members, and educators into the field of myopia to stimulate collaboration and sharing of knowledge. The latest reports are on pathologic myopia, the impact of myopia, risk factors for myopia, accommodation and binocular vision in myopia development and progression, and the prevention of myopia and its progression. Together with the digest updating the 2019 International Myopia Institute white papers using the research published in the last 18 months, these evidence-based consensus white papers help to clarify the imperative for myopia control and the role of environmental modification initiatives, informing an evidence-based clinical approach. This guidance includes who to treat and when to start or stop treatment, and the advantages and limitations of different management approaches.

CLEAR - Contact lens technologies of the future

Contact lenses in the future will likely have functions other than correction of refractive error. Lenses designed to control the development of myopia are already commercially available. Contact lenses as drug delivery devices and powered through advancements in nanotechnology will open up further opportunities for unique uses of contact lenses. This review examines the use, or potential use, of contact lenses aside from their role to correct refractive error. Contact lenses can be used to detect systemic and ocular surface diseases, treat and manage various ocular conditions and as devices that can correct presbyopia, control the development of myopia or be used for augmented vision. There is also discussion of new developments in contact lens packaging and storage cases. The use of contact lenses as devices to detect systemic disease has mostly focussed on detecting changes to glucose levels in tears for monitoring diabetic control. Glucose can be detected using changes in colour, fluorescence or generation of electric signals by embedded sensors such as boronic acid, concanavalin A or glucose oxidase. Contact lenses that have gained regulatory approval can measure changes in intraocular pressure to monitor glaucoma by measuring small changes in corneal shape. Challenges include integrating sensors into contact lenses and detecting the signals generated. Various techniques are used to optimise uptake and release of the drugs to the ocular surface to treat diseases such as dry eye, glaucoma, infection and allergy. Contact lenses that either mechanically or electronically change their shape are being investigated for the management of presbyopia. Contact lenses that slow the development of myopia are based upon incorporating concentric rings of plus power, peripheral optical zone(s) with add power or non-monotonic variations in power. Various forms of these lenses have shown a reduction in myopia in clinical trials and are available in various markets.

Distribution of intraocular pressure and related risk factors in a highly myopic Chinese population: an observational, cross-sectional study

Clinical relevance: Those with high myopia are more likely to have glaucoma compared to those without myopia and intraocular pressure was a key factor for developing glaucoma. Thus, investigating the distribution of intraocular pressure and associated factors among those with high myopia is of high importance.Background: The aim of this work is to investigate the distribution of intraocular pressure and the correlated risk factors in a highly myopic Chinese population.Methods: A total of 884 Chinese participants with bilateral high myopia (≤ -6.00 D spherical power) were included from the Zhongshan Ophthalmic Center-Brien Holden Vision Institute High Myopia Cohort Study. All participants underwent a comprehensive ocular examination, including ocular biometry, cycloplegic refractometry, and intraocular pressure measurement with Goldmann applanation tonometry. Information on smoking and drinking status was also collected.Results: The mean spherical equivalence of left eyes was -10.02 ± 3.58 D with a mean axial length of 27.48 ± 1.55 mm. The overall mean intraocular pressure was 15.1 ± 2.4 mmHg (95% confidence interval, 15.0 to 15.3 mmHg). The intraocular pressure in the -6.00D to -7.99D spherical equivalence group, -8.00D to -9.99D spherical equivalence group, and ≤ -10.00 D group were 15.3 ± 2.4 mmHg, 15.1 ± 2.5 mmHg, and 15.0 ± 2.4 mmHg, respectively (p = 0.979). In multiple regression models, intraocular pressure in high myopes was not associated with spherical equivalence (p = 0.354) or axial length (p = 0.601), but significantly higher in those who were younger (non-standardised beta, -0.018; p = 0.007), smoked tobacco (non-standardised beta, 1.085; p = 0.001) and had greater central corneal thickness (non-standardised beta, 0.021; p < 0.001).Conclusion: Intraocular pressure was 15.1 ± 2.4 mmHg among subjects with a mean age of 22.8 years in this highly myopia Chinese population. These findings suggested that highly myopic Chinese persons of a younger age and greater central corneal thickness were more likely to have higher intraocular pressure.

Refractive error, axial length, environmental and hereditary factors associated with myopia in Swedish children

Clinical relevance: Investigation of refractive errors amongst Swedish schoolchildren will help identify risk factors associated with myopia development.Background: Genetic and hereditary aspects have been linked with the development of myopia. Nevertheless, in the case of 'school myopia' some authors suggest that environmental factors may affect gene expression, causing school myopia to soar. Additional understanding about which environmental factors play a relevant role can be gained by studying refractive errors in countries like Sweden, where prevalence of myopia is expected to be low.Methods: Swedish schoolchildren aged 8-16 years were invited to participate. Participants underwent an eye examination, including cycloplegic refraction and axial length (AL) measurements. Predictors such as time spent in near work, outdoor activities and parental myopia were obtained using a questionnaire. Myopia was defined as spherical equivalent refraction (SER) ≤ -0.50D and hyperopia as SER ≥ +0.75D.Results: A total of 128 children (70 females and 58 males) participated in this study with mean age of 12.0 years (SD = 2.4). Based on cycloplegic SER of the right eye, the distribution of refractive errors was: hyperopia 48.0% (CI95 = 38.8-56.7), emmetropia 42.0% (CI95 = 33.5-51.2) and myopia 10.0%. (CI95 = 4.4-14.9). The mean AL was 23.1 mm (SD = 0.86), there was a correlation between SER and AL, r = -0.65 (p < 0.001). Participants with two myopic parents had higher myopia and increased axial length than those with one or no myopic parents. The mean time spent in near work, outside of school, was 5.3 hours-per-day (SD = 3.1), and mean outdoor time reported was 2.6 hours-per-day (SD = 2.2) for all the participants. The time spent in near work and outdoor time were different for different refractive error categories.Conclusion: The prevalence of myopia amongst Swedish schoolchildren is low. Hereditary and environmental factors are associated with refractive error categories. Further studies with this sample are warranted to investigate how refractive errors and environmental factors interact over time.

Exploring non-adherence to contact lens wear schedule: Subjective assessments and patient related factors in children wearing single vision and myopia control contact lenses

PURPOSE

To determine factors associated with non-adherence to contact lens wear schedule involving single vision and myopia control contact lenses in children.

METHODS

Data from 379 children enrolled in a prospective, double masked, randomized clinical trial, aged 8-13 years, cycloplegic spherical equivalent of -0.75 to -3.50D and wearing either: single vision silicone hydrogel (SiH) CL (control lens); two anti-myopia SiH CL that incorporated relative plus in the central and periphery in a stepped manner (test lens I and II); and two extended depth of focus hydrogel CL (test lens III and IV) was considered. A questionnaire was administered to the participants at every scheduled visit and gathered information on days of wear/week and subjective assessments of ocular comfort and visual quality on an analog scale of 1-10.Participants were categorized as "Adherent" when lens wear was ≥ 6 days/week or "Non-adherent" when lens wear ≤ 5 days/week. Categorized adherence data was summarized as a percentage across visits for each CL type. Differences between the two groups were analyzed using linear mixed model.

RESULTS

For the control lens, 79.6 % participants were adherent as compared to 63.7%-74.6% with test lenses (p=0.026). Non-adherence was greater in those that discontinued (p<0.001). Subjective ratings of visual quality for static and dynamic tasks were lower with non-adherent wearers and more variable between visits. Ocular comfort was also poorer in non-adherent wearers irrespective of lens material or lens design. Male gender, lower baseline myopia, lower high contrast visual acuity and esophoria were associated with a higher risk of non-adherence.

CONCLUSIONS

The study identified a wide range of factors associated with non-adherence to lens wear schedule. Paying specific attention to these factors when evaluating patients for CL wear and taking steps to ensure satisfaction in lens wear may promote longer term continuation of wear.

Choroidal thickness predicts progression of myopic maculopathy in high myopes: a 2-year longitudinal study

AIM

To prospectively determine the impact of choroidal thickness (CT) on the myopic maculopathy progression.

METHODS

This is a prospective, longitudinal, observational study. In total, 434 participants aged 7-70 years with bilateral high myopia (≤-6 D spherical error, range, -6 to -27.0 D) completed follow-up visits for 2 years. The baseline CT centred on the fovea was measured using a swept-source optical coherence tomography (OCT). Myopic maculopathy progression was determined by fundus photography. Logistic model was used to examine the impact of CT at baseline on the myopic maculopathy progression. Likelihood ratio test was adopted for model comparison.

RESULTS

The mean baseline age, spherical equivalence and subfoveal CT (SFCT) of the participants were 23.2±12.5 years, -10.50±3.18 D and 153.20±72.76 μm, respectively. Over 2-year's follow-up, 74 of 434 eyes (17.1%) had myopic maculopathy progression. Baseline SFCT was thinner in eyes with myopic maculopathy progression than those without (67.26±37.67 μm vs 170.95±65.45 μm; mean difference, 99.31 μm; 95% CI 83.61 to 115.01 μm; p<0.001). The same patterns of differences were observed in 7-18 years, 19-39 years and 40-70 years. In multivariate logistic regression model, SFCT was a significant risk factor (adjusted OR=0.97, p<0.005) when age, gender, axial length and baseline myopic maculopathy category were adjusted for. The addition of SFCT significantly improved the predictive discrimination of myopic maculopathy progression in comparison with that included established risk factors alone (area under the receiver operating characteristic curve, 0.899 vs 0.942, p<0.001).

CONCLUSION

CT is an independent predictor for myopic maculopathy progression.

Progression and Longitudinal Biometric Changes in Highly Myopic Eyes

Purpose

To examine 2-year progression rate and associated biometric changes in highly myopic eyes.

Methods

This is a longitudinal, observational cohort study that included 657 participants aged 7 to 70 years with bilateral high myopia (≤-6.00 diopters [D]) and followed for 2 years. All participants underwent ocular biometry and cycloplegic refraction examinations. Main outcome measures were changes in spherical equivalent refraction (SE) and ocular biometry in the right eyes.

Results

Mean age of participants was 21.6 ± 12.2 years. At baseline, mean SE was -9.82 ± 3.28 D and ocular biometric measurements were 27.40 ± 1.56 mm for axial length, 3.16 ± 0.27 mm for anterior chamber depth, 3.60 ± 0.35 mm for lens thickness, and 20.09 ± 1.50 mm for vitreous chamber depth. After 2 years of follow-up, there was a trend toward more myopia and greater axial elongation in all age groups. Younger participants (≤20 years) had significantly (P < 0.001) greater rates of myopic shift and axial elongation compared with older participants (>20 years). However, highly myopic adults aged 40 to 70 years continued to demonstrate refractive progression, particularly if they had extremely high myopia (≤-10.00 D). In the multiple regression analysis, each additional diopter of myopia at baseline was associated with a 11% higher risk of a >1.00-D/y myopic shift (odds ratio, 1.11; 95% confidence interval, 1.04-1.18; P = 0.002).

Conclusions

Longitudinal data from this large Chinese cohort suggest that highly myopic eyes continue to progress in SE throughout life, with the greatest rates of progression observed in younger participants. Axial elongation rates appeared to stabilize after 20 years of age and were predominantly due to an increase in the vitreous chamber depth. Other risk factors for a myopic shift included a higher degree of myopic refraction at baseline.

Progression of diffuse chorioretinal atrophy among patients with high myopia: a 4-year follow-up study

AIMS

To investigate the progression pattern of diffuse chorioretinal atrophy (DCA) among Chinese participants with high myopia.

METHODS

This is a longitudinal, non-interventional study. Participants with high myopia, defined as ≤-6 diopters spherical power, were included and followed up for 4 years, and underwent cycloplegic autorefraction, best-corrected visual acuity (BCVA) and fundus photography examinations. Newly established DCA, enlargement of existing DCA and development of other lesions of myopic maculopathy were regarded as DCA progression.

RESULTS

Of the 484 participants with a mean age of 21.5±12.7 years (range, 6.8-69.7 years), 68 eyes (14.0%) showed DCA progression, with 88 lesion changes. The first appearance of DCA was identified in 21 eyes (23.9%). Of 88 eyes with DCA at baseline, 47 eyes (53.4%) showed progression, with 67 lesion changes, including 45 eyes (67.2%) with enlargement of DCA, 17 (25.3%) with a first appearance of lacquer cracks, 4 (6.0%) with development of patchy chorioretinal atrophy and 1 (1.5%) with increased numbers of lacquer cracks. Longer axial length (p<0.001), baseline DCA (p=0.005) and baseline DCA closer to the fovea (p=0.013) predicted DCA progression. Eyes had poorer BCVA at the follow-up if DCA was enlarging (p<0.001) or DCA was closer to the fovea at baseline (p=0.028) after adjusting for age,gender and cataract.

CONCLUSION

Approximately half of the participants with DCA had progression over a 4-year follow-up. Enlargement and newly developed DCA were common progression patterns. Larger areas of DCA and foveal involvement with DCA could be indicators of a worse BCVA later.

Highlights from the 2019 International Myopia Summit on 'controversies in myopia'

Myopia is an emerging public health issue with potentially significant economic and social impact, especially in East Asia. However, many uncertainties about myopia and its clinical management remain. The International Myopia Summit workgroup was convened by the Singapore Eye Research Institute, the WHO Regional Office for the Western Pacific and the International Agency for the Prevention of Blindness in 2019. The aim of this workgroup was to summarise available evidence, identify gaps or unmet needs and provide consensus on future directions for clinical research in myopia. In this review, among the many 'controversies in myopia' discussed, we highlight three main areas of consensus. First, development of interventions for the prevention of axial elongation and pathologic myopia is needed, which may require a multifaceted approach targeting the Bruch's membrane, choroid and/or sclera. Second, clinical myopia management requires co-operation between optometrists and ophthalmologists to provide patients with holistic care and a tailored approach that balances risks and benefits of treatment by using optical and pharmacological interventions. Third, current diagnostic technologies to detect myopic complications may be improved through collaboration between clinicians, researchers and industry. There is an unmet need to develop new imaging modalities for both structural and functional analyses and to establish normative databases for myopic eyes. In conclusion, the workgroup's call to action advocated for a paradigm shift towards a collaborative approach in the holistic clinical management of myopia.

Visual impairment in highly myopic eyes: The ZOC-BHVI High Myopia Cohort Study

IMPORTANCE

Understanding visual impairment (VI) under different definitions and potential risk factors in high myopic is important for future myopia control.

BACKGROUND

Limited studies exists investigating the VI among high myopic and with varying VI definitions.

DESIGN

Registry cohort study.

PARTICIPANTS

Eight hundred and eighty-four participants were from ZOC-BHVI study.

METHODS

Subjects aged 7 to 70 years with high myopia were enrolled. Uncorrected visual acuity and best-corrected visual acuity (UCVA and BCVA), cycloplegic refraction, axial length (AL), corneal curvatures, anterior chamber depth and lens thickness were measured. Axial length/corneal radius of curvature ratio (AL/CR ratio) was calculated. Fundus lesions were graded into five categories. VI and blindness were defined based on the better-seeing eye according to the World Health Organization (WHO) criteria and US criteria. Multiple logistic regression analysis was used to assess risk factors for VI.

MAIN OUTCOME MEASURES

Rates of VI and blindness.

RESULTS

A total of 884 participants were included, with mean (SD) age 18.5 (12.4) years and 46.4% male. Rate of UCVI/blindness were 72.6%/27.3% and 17.9%/82.1% based on WHO and US criteria. With respect to BCVA, 4.1%/5.9% of participants had BCVI using two definitions, whereas the rate for blindness was 0.2% and 0.6%. After adjusting confounders, multiple logistic regression showed that more severe fundus lesions, greater AL/CR ratio were at a higher risk of being VI, both in two definitions (P < .005).

CONCLUSIONS AND RELEVANCE

The rate of VI and blindness in highly myopic patients varies significantly using different definition. Severe fundus lesions and greater AL/CR ratios were associated with a higher risk of VI.

Posterior segment conditions associated with myopia and high myopia

Myopia, and especially high myopia, is associated with a number of posterior segment changes that are considered to be mostly a consequence of the increased axial elongation. This can result in mechanical strain, attendant vascular changes, stretching and thinning of tissues, and atrophy/deformation of tissues in later or more advanced stages. Such myopia-related changes are observed as changes and/or abnormalities in the vitreous, choroid, retina and peripheral retina, sclera and/or optic disc. Although many of these changes are benign, at times they may be associated with significant vision impairment that either requires active intervention or may suggest future progression of the disease. This review systematically addresses the posterior segment conditions seen in myopic eyes, describes the features associated with the condition and details management pathways.

Review: Myopia control strategies recommendations from the 2018 WHO/IAPB/BHVI Meeting on Myopia

Myopia is a major public health problem, particularly in East Asia. In this summary report, we present key findings and recommendations on strategies for myopia control discussed during the meeting jointly organised by the WHO Regional Office for the Western Pacific, the International Agency for the Prevention of Blindness and the Brien Holden Vision Institute. First, myopia prevalence was reported to be increasing, with up to 80% of junior school students with myopia in East Asia. However, common challenges in implementing myopia control strategies on a national level included lack of school screening programme, and paucity of accurate prevalence data. Second, there continues to be broad public misconception about myopia and myopia control, including lack of parental awareness and resistance to wearing spectacles. Third, best practices for myopia management were shared, and recommendations for policy implementation are presented in this review. Key recommendations from this meeting include increased public education to raise parent and teacher awareness; encouragement of increased outdoor time of 2-3 hours per day for schoolchildren-as a practical public health intervention that has been shown to potentially reduce onset and progression of myopia. Governments and non-governmental organisations are encouraged to collaborate, especially education and health ministries to develop national myopia prevention programme. Lastly, it is important to emphasise that the key recommendations, such as increasing outdoor time for schoolchildren, are specific for East Asian nations in the Western Pacific region and may not be entirely applicable for Western nations.

DIFFUSE CHORIORETINAL ATROPHY IN CHINESE HIGH MYOPIA: The ZOC-BHVI High Myopia Cohort Study

PURPOSE

To explore the associations between diffuse chorioretinal atrophy (DCA) and age, sex, axial length, spherical equivalent, and best-corrected visual acuity (BCVA) among highly myopic eyes.

METHODS

This study included right eyes of 857 bilaterally highly myopic individuals from the ZOC-BHVI Cohort Study. Participants underwent examinations, including BCVA, ocular biometry, autorefraction, and color fundus photography. An Early Treatment Diabetic Retinopathy Study grid was applied on the fundus photographs to evaluate the location of DCA, which was graded into four categories (D0-D3). The characteristics and ocular biometry were compared between participants' eyes with and without DCA.

RESULTS

Diffuse chorioretinal atrophy was found in 177 (20.6%) eyes. The proportion of participants with DCA in age groups of 7 to 11, 12 to 18, 19 to 39, and ≥ 40 years old was 20.9%, 9.2%, 23.1%, and 52.9%, respectively. The proportion of DCA significantly increased with longer axial length and worse myopic spherical equivalent. Eyes with DCA had poorer BCVA (Snellen visual acuity 20/36, logarithm of minimal angle of resolution 0.26 ± 0.25) than those without DCA (Snellen visual acuity 20/23, logarithm of minimal angle of resolution 0.06 ± 0.14) (P < 0.001). The BCVA gradually declined as the lesion got closer to the fovea (P for trend < 0.001).

CONCLUSION

The proportion of DCA increased with older age, longer axial length, and more myopic spherical equivalent. Diffuse chorioretinal atrophy is a vision-threatening complication of high myopia where BCVA gradually worsens with foveal involvement.

Discrimination of indoor versus outdoor environmental state with machine learning algorithms in myopia observational studies

BACKGROUND

Wearable smart watches provide large amount of real-time data on the environmental state of the users and are useful to determine risk factors for onset and progression of myopia. We aim to evaluate the efficacy of machine learning algorithm in differentiating indoor and outdoor locations as collected by use of smart watches.

METHODS

Real time data on luminance, ultraviolet light levels and number of steps obtained with smart watches from dataset A: 12 adults from 8 scenes and manually recorded true locations. 70% of data was considered training set and support vector machine (SVM) algorithm generated using the variables to create a classification system. Data collected manually by the adults was the reference. The algorithm was used for predicting the location of the remaining 30% of dataset A. Accuracy was defined as the number of correct predictions divided by all. Similarly, data was corrected from dataset B: 172 children from 3 schools and 12 supervisors recorded true locations. Data collected by the supervisors was the reference. SVM model trained from dataset A was used to predict the location of dataset B for validation. Finally, we predicted the location of dataset B using the SVM model self-trained from dataset B. We repeated these three predictions with traditional univariate threshold segmentation method.

RESULTS

In both datasets, SVM outperformed the univariate threshold segmentation method. In dataset A, the accuracy and AUC of SVM were 99.55% and 0.99 as compared to 95.11% and 0.95 with the univariate threshold segmentation (p < 0.01). In validation, the accuracy and AUC of SVM were 82.67% and 0.90 compared to 80.88% and 0.85 with the univariate threshold segmentation method (p < 0.01). In dataset B, the accuracy and AUC of SVM and AUC were 92.43% and 0.96 compared to 80.88% and 0.85 with the univariate threshold segmentation (p < 0.01).

CONCLUSIONS

Machine learning algorithm allows for discrimination of outdoor versus indoor environments with high accuracy and provides an opportunity to study and determine the role of environmental risk factors in onset and progression of myopia. The accuracy of machine learning algorithm could be improved if the model is trained with the dataset itself.

Progression of Myopic Maculopathy in Highly Myopic Chinese Eyes

Purpose

To evaluate the 2-year changes in myopic maculopathy and its associations in highly myopic eyes.

Methods

This was a longitudinal, observational cohort study involving 657 Chinese participants with bilateral high myopia (≤ -6.00 diopters spherical power), who were followed for 2 years. The worst eye of each participant was considered for the analysis. Myopic maculopathy was graded based on fundus photographs, using the International Photographic Classification and Grading System for Myopic Maculopathy.

Results

The mean baseline age was 21.6 ± 12.2 years (range, 6.8-69.7 years). Myopic maculopathy progressed in 97 (14.8%) of 657 eyes, of which 24 eyes progressed to a higher category of myopic maculopathy, including from no maculopathy to tessellated fundus in 17 eyes, from tessellated fundus to diffuse atrophy in 6 eyes, and from diffuse to patchy atrophy in 1 eye. Among 122 lesion changes identified, the most common changes were enlargement of diffuse atrophy (n = 50, 41.0%), appearance of lacquer cracks (n = 28, 23.0%), enlargement of patchy atrophy (n = 10, 8.2%) and development of additional lacquer cracks (n = 7, 5.8%). In addition, we identified 1 eye with enlargement of a Fuch's spot, and 1 eye with active choroidal neovascularization. In multiple logistic regression analysis, myopic maculopathy progression was associated with older age, longer axial length, greater change in myopic spherical equivalent and more severe myopic maculopathy at baseline.

Conclusions

Myopic maculopathy progressed in approximately 15% of highly myopic eyes over a 2-year period. Further studies with longer follow up periods are required to confirm identified risk factors for progression.

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 - Clinical Management Guidelines Report

Best practice clinical guidelines for myopia control involve an understanding of the epidemiology of myopia, risk factors, visual environment interventions, and optical and pharmacologic treatments, as well as skills to translate the risks and benefits of a given myopia control treatment into lay language for both the patient and their parent or caregiver. This report details evidence-based best practice management of the pre-, stable, and the progressing myope, including risk factor identification, examination, selection of treatment strategies, and guidelines for ongoing management. Practitioner considerations such as informed consent, prescribing off-label treatment, and guides for patient and parent communication are detailed. The future research directions of myopia interventions and treatments are discussed, along with the provision of clinical references, resources, and recommendations for continuing professional education in this growing area of clinical practice.

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.

Myopia control with novel central and peripheral plus contact lenses and extended depth of focus contact lenses: 2 year results from a randomised clinical trial

PURPOSE

We aimed to determine myopia control efficacy with novel contact lenses (CL) that (1) reduced both central and peripheral defocus, and (2) provided extended depth of focus with better global retinal image quality for points on, and anterior to, the retina and degraded for points posterior to the retina.

METHODS

Children (n = 508, 8-13 years) with cycloplegic spherical equivalent (SE) -0.75 to -3.50D were enrolled in a prospective, double blind trial and randomised to one of five groups: (1) single vision, silicone hydrogel (SH) CL; (2) two groups wearing SH CL that imposed myopic defocus across peripheral and central retina (test CL I and II; +1.00D centrally and +2.50 and +1.50 for CL I and II at 3 mm semi-chord respectively); and (3) two groups wearing extended depth of focus (EDOF) hydrogel CL incorporating higher order aberrations to modulate retinal image quality (test CL III and IV; extended depth of focus of up to +1.75D and +2.50D respectively). Cycloplegic autorefraction and axial length (AL) measurements were conducted at six monthly intervals. Compliance to lens wear was assessed with a diary and collected at each visit. Additionally, subjective responses to various aspects of lens wear were assessed. The trial commenced in February 2014 and was terminated in January 2017 due to site closure. Myopia progression over time between groups was compared using linear mixed models and where needed post hoc analysis with Bonferroni corrections conducted.

RESULTS

Myopia progressed with control CL -1.12 ± 0.51D/0.58 ± 0.27 mm for SE/AL at 24 months. In comparison, all test CL had reduced progression with SE/AL ranging from -0.78D to -0.87D/0.41-0.46 mm at 24 months (AL: p < 0.05 for all test CL; SE p < 0.05 for test CL III and IV) and represented a reduction in axial length elongation of about 22% to 32% and reduction in spherical equivalent of 24% to 32%. With test CL, a greater slowing ranging from 26% to 43% was observed in compliant wearers (≥6 days per week; Control CL: -0.64D/0.30 mm and -1.14D/0.58 mm vs test CL: -0.42D to -0.47D/0.12-0.18 mm and -0.70 to -0.81D/0.19-0.25 mm at 12 and 24 months respectively).

CONCLUSIONS

Contact lenses that either imposed myopic defocus at the retina or modulated retinal image quality resulted in a slower progression of myopia with greater efficacy seen in compliant wearers. Importantly, there was no difference in the myopia control provided by either of these strategies.

Distribution and Severity of Myopic Maculopathy Among Highly Myopic Eyes

Purpose

The purpose of this study was to document the distribution of the severity of myopic maculopathy in a cohort of highly myopic patients and to explore the associated risk factors.

Methods

A total of 890 Chinese highly myopes aged between 7 and 70 years (median age 19 years) and with spherical refraction -6.00 diopter (D) or worse in both eyes were investigated. All participants underwent detailed ophthalmic examination. Myopic maculopathy was graded into 5 categories according to the International Photographic Classification and Grading System using color fundus photographs: category 0, no myopic retinal lesions, category 1, tessellated fundus only; category 2, diffuse chorioretinal atrophy; category 3, patchy chorioretinal atrophy; category 4, macular atrophy. Category 2 or greater were further classified as clinically significant myopic maculopathy (CSMM).

Results

Data from 884 of 890 right eyes were available for analysis. The proportions of category 1, category 2, category 3, and category 4 were 20.0% (177 eyes), 20.2% (178 eyes), 2.6% (23 eyes), and 0.2% (2 eyes), respectively. The proportion of CSMM increased with more myopic refraction (odds ratio 1.57; 95% confidence interval: 1.46-1.68), longer axial length (odds ratio 2.97; 95% confidence interval: 2.50-3.53), and older age (40-70 years compared to 12-18 years, odds ratio 6.77; 95% confidence interval: 3.61-12.70). However, there was a higher proportion of CSMM in children aged 7 to 11 years than those aged 12 to 18 years (20.9% vs. 11.0%, P = 0.008).

Conclusions

Older age, more myopic refraction, and longer axial length were associated with more severe myopic maculopathy. Although CSMM was uncommon among younger participants, children with early-onset high myopia have a disproportionately increased risk.

Shanghai Time Outside to Reduce Myopia trial: design and baseline data

IMPORTANCE

Myopia is a major public health concern worldwide, while outdoor time is indicated to be protective against the onset of myopia.

BACKGROUND

To describe the methodology and baseline data of the Shanghai Time Outside to Reduce Myopia (STORM) trial.

DESIGN

A 2-year, school-based, prospective, cluster randomized trial.

PARTICIPANTS

Children from grade I and II classes of 24 schools from eight districts in Shanghai, China, were randomized to either a control group, a test group I (40-min outdoor time/day) or test group II (80-min outdoor time/day).

METHODS

At baseline and annual intervals, cycloplegic autorefraction and axial length measurement will be performed. Time outdoors and light exposure will be monitored via parent/carer questionnaires and a wearable device.

MAIN OUTCOME MEASURES

Spherical equivalent, prevalence of myopia and time outdoors in each group.

RESULTS

A total of 6295 eligible children (age 7.2 ± 0.7 y [6-9 y]) were randomized to control (n = 2037), test group I (n = 2329) and test group II (n = 1929). At baseline, spherical equivalent was +0.98 ± 1.02D, +1.02 ± 1.02D and +1.00 ± 0.99D (P = 0.708), myopia prevalence was 8.9, 7.7 and 7.8% (P = 0.270) and time outdoors was 58.5 ± 35.8, 59.8 ± 34.7 and 58.5 ± 35.3 min/d (P = 0.886) for control, test groups I and II, respectively.

CONCLUSIONS AND RELEVANCE

Myopia prevalence was high at nearly 8 to 9% in school children aged 7 years in Shanghai, China. The current trial will help evaluate if increased time outdoors has a role to play in reducing the incidence of myopia and/or slow the progression of myopia.

Controlling Progression of Myopia: Optical and Pharmaceutical Strategies

The burden associated with the rising prevalence of myopia and high myopia, and the associated vision impairment and sight-threatening complications, has triggered the need to evaluate strategies to control the progression of myopia. We provide an overview of the literature on the use of optical (spectacles, contact lenses, and orthokeratology) and pharmaceutical approaches to slow progress of myopia. The evidence indicates that myopia progression can be slowed by varying degrees using these strategies. All approaches play a role in the management of myopia as needs and requirements of an individual vary based on age, suitability, affordability, safety of the approach, subjective needs of the individual, and rate of progression. This review also identifies and discusses the lack of long-term efficacy data and rebound on discontinuation of myopia control products.

Tessellated fundus appearance and its association with myopic refractive error

The appearance of tessellated fundus in an eye may act as a marker in identifying visual performance, degree of myopia or risk of progression of myopia in a given eye. A systematic literature search using key words was performed using PubMed, Web of Science and Google Scholar and of the 832 studies identified, 10 full-length articles, which met the inclusion criteria, were considered for review. The primary outcome measures were association of tessellated fundus with: (i) visual acuity, (ii) refractive error, (iii) axial length, (iv) choroidal thickness and (v) future progression of myopia when compared to either no myopic maculopathy, or more severe myopic maculopathy. There was no significant difference in the visual acuity noted between eyes with normal fundus and tessellated fundus appearance. Compared to eyes with tessellated fundus, eyes with more severe myopic maculopathy had a four-line decrease in best-corrected visual acuity, more myopia (mean difference 2.75 D, range 0.28-5.78 D) and a longer axial length (mean difference 2 mm, range 2.29 to 1.71 mm). Eyes with tessellated fundus generally exhibited a significant decrease in choroidal thickness compared to eyes with no maculopathy. In mostly older individuals, eyes with tessellated fundus had a better outcome with respect to visual acuity, degree of myopia and axial length compared to other severe myopic maculopathies, but had a worse outcome for choroidal thickness and degree of myopia, compared to eyes with no myopic maculopathy. The features such as reduced choroidal thickness combined with a predilection to infra-temporal and parapapillary regions may indicate regions of stress that are prone to more stretching/atrophic changes. This systematic review demonstrated an association of tessellated fundus with visual acuity, refractive error, axial length and choroidal thickness and hence emphasises the documentation of the presence and location of tessellated fundus appearance that may help in predicting the progression of myopia.

A Review of Myopia Control with Atropine

Myopia is a global public health issue with a worldwide prevalence of ∼30% and is estimated to rise to 50% by 2050. In addition to the burden associated with routine management of the condition, high myopia predisposes the eye to sight-threatening complications such as myopic maculopathy and glaucoma in adult life. Controlling onset and progression of myopia at a young age can reduce the risk of morbidity associated with high myopia. Progression of myopia can be slowed with various optical, environmental, and pharmaceutical strategies, of which atropine has proven to be the most effective. High-dose atropine (0.5%-1%) is the most effective, but it has significant trade-offs with respect to rebound of myopia on discontinuation and side effects such as photophobia and difficulty with near work (decreased accommodation). Low doses of atropine have been trialed and show a dose-dependent efficacy. However, its mode of action on the ocular tissues leading to slowing eye growth remains unclear and multiple mechanisms and sites in the eye have been postulated to play a role. This review summarizes the role of atropine in controlling myopia and the mechanisms studied to date.