Reducing the Global Burden of Myopia by Delaying the Onset of Myopia and Reducing Myopic Progression in Children: The Academy's Task Force on Myopia

Effect of Low-Concentration Atropine Eye Drops in Controlling the Progression of Myopia in Children: A One- and Two-Year Follow-Up Study

PURPOSE

Atropine eye drops have been shown to slow the progression of myopia, but there has been limited research on the effectiveness of 0.05% atropine in treating myopia. This study aimed to investigate the safety and efficacy of 0.05% atropine eye drops in controlling myopia in children.

METHODS

The study included 424 participants aged 6 to 12 years between January 1, 2015, and January 1, 2021. Of these, 213 were randomly assigned to the 0.05% atropine group and 211 to the placebo group. The cycloplegic spherical equivalent (SE), axial length (AL), corneal curvature (K), and anterior chamber depth (ACD) were measured using IOLMaster. The lens power and corneal astigmatism were also determined. The changes in ocular biometric parameters were compared between the two groups, and the contributions of ocular characteristics to SE progression were calculated and compared.

RESULTS

Over a 12-month period, the changes in spherical equivalent were -0.03 ± 0.28 and -0.32 ± 0.14 in the atropine and placebo groups, respectively (P = .01). The changes in axial length were 0.06 ± 0.11 and 0.17 ± 0.12, respectively (P = .01). At 18 and 24 months, there were significant differences in axial length and spherical equivalent between the atropine and placebo groups. Multiple regression models accounting for changes in AL, K, and lens magnification explained 87.23% and 98.32% of SE changes in the atropine and placebo groups, respectively. At 1 year (p = .01) and 2 years (p = .03), there were significant differences in photophobia between the atropine and placebo groups.

CONCLUSIONS

This two-year follow-up study demonstrates that 0.05% atropine eye drops are safe and effective in preventing the development of myopia in school-aged children.

How can we better evaluate paediatric progression of myopia and associated risk factors? Lessons from the COVID-19 pandemic: A systematic review

PURPOSE

During the COVID-19 pandemic, home-based and remote learning-particularly using electronic devices-was rapidly pushed out. Increased near-work, screen time exposure and lack of outdoor time are risk factors that contribute to childhood myopia, but it is difficult to adopt recommendations from prior publications as a consistent limitation in the literature is the heterogeneity of research methodology. This review seeks to systematically evaluate how observational studies published during the pandemic have quantified and measured risk factors and myopia in school-going children and adolescents.

METHODS

Three scientific databases (PubMed, CINAHL, Scopus) were systematically searched from March 2020 to April 2022. Findings from relevant studies were descriptively summarised in relation to the PICOS-based objective of the review.

RESULTS

The final sample of 13 studies included research from six countries and comprised 1 411 908 children and adolescents. The majority of studies (N = 10; 76.9%) used spherical equivalent refraction (SER) of -0.5 dioptres or lower as a common definition of myopia. Most studies (77.8%) measuring screen time exposure found it higher during COVID-19 compared to pre-COVID, but only one study used objective measurement of screen time. The average critical appraisal score of the sample was only 66.1%, with a considerable number of studies failing to identify and adjust for potential confounders.

CONCLUSION

Future studies should consider emergent objective and validated measures of risk factors, account for potential a priori confounders and covariates and ensure more representativeness in the sociodemographic makeup of their samples.

Quantitative Assessment of Fundus Tessellated Density in Highly Myopic Glaucoma Using Deep Learning

Purpose

To characterize the fundus tessellated density (FTD) in highly myopic glaucoma (HMG) and high myopia (HM) for discovering early signs and diagnostic markers.

Methods

This retrospective cross-sectional study included hospital in-patients with HM (133 eyes) and HMG (73 eyes) with an axial length ≥26 mm at Zhongshan Ophthalmic Center. Using deep learning, FTD was quantified as the average exposed choroid area per unit area on fundus photographs in the global, macular, and disc regions. FTD-associated factors were assessed using partial correlation. Diagnostic efficacy was analyzed using the area under the curve (AUC).

Results

HMG patients had lower global (0.20 ± 0.12 versus 0.36 ± 0.09) and macular FTD (0.25 ± 0.14 vs. 0.40 ± 0.09) but larger disc FTD (0.24 ± 0.11 vs. 0.19 ± 0.07) than HM patients in the tessellated fundus (all P < 0.001). In the macular region, nasal FTD was lowest in the HM (0.26 ± 0.13) but highest in the HMG (0.32 ± 0.13) compared with the superior, inferior, and temporal subregions (all P < 0.05). A fundus with a macular region nasal/temporal (NT) FTD ratio > 0.96 (AUC = 0.909) was 15.7 times more indicative of HMG than HM. A higher macular region NT ratio with a lower horizontal parapapillary atrophy/disc ratio indicated a higher possibility of HMG than HM (AUC = 0.932).

Conclusions

FTD differs in degree and distribution between HMG and HM. A higher macular NT alone or with a lower horizontal parapapillary atrophy/disc ratio may help differentiate HMG.

Translational Relevance

Deep learning-based FTD measurement could potentially assist glaucoma diagnosis in HM.

Association Between Physical Indicators and Myopia in American Adolescents: National Health and Nutrition Examination Survey 1999-2008

PURPOSE

Myopia is the most prevalent refractive error, imposing a substantial economic burden. Physical indicators constitute significant influencing factors for myopia. The National Health and Nutrition Examination Survey (NHANES) investigates the health and nutritional status of both children and adults in the United States. This study leveraged NHANES to explore the association between physical indicators and myopia among American adolescents.

DESIGN

Retrospective case-control study.

METHODS

The final study cohort consisted of 9008 adolescents. Demographic data, physical indicators, and vision data were extracted. The association between myopia and demographic factors, as well as physical indicators, employed weighted methods. Regression models were utilized to identify the associations between physical indicators and myopia. Cumulative odds logistic regression analysis was employed to investigate the association between physical indicators and the degree of myopia. Restricted cubic spline analysis was employed to examine the potential nonlinear relationship between physical indicators and the risk of myopia.

RESULTS

The occurrence of myopia was significantly correlated with age (P < .001) and race (P = .019). Adolescents in the fourth percentile for weight (odds ratio [OR] 1.38, 95% confidence interval [CI] 1.13-1.70) and body mass index (BMI) (OR 1.26, 95% CI 1.05-1.51) exhibited an increased possibility of myopia. The highest risk of myopia was observed when the BMI approached 30. Height emerged as a risk factor for the degree of myopia (OR 1.02, 95% CI 1.01-1.03).

CONCLUSIONS

A certain association existed between physical indicators and myopia. Weight and BMI were related to the occurrence of myopia, while height and race were associated with the degree of myopia.

Efficacy and Safety of Low-Dose Atropine on Myopia Prevention in Premyopic Children: Systematic Review and Meta-Analysis

Background: Early-onset myopia increases the risk of irreversible high myopia. Methods: This study systematically evaluated the efficacy and safety of low-dose atropine for myopia control in children with premyopia through meta-analysis using random-effects models. Effect sizes were calculated using risk ratios (RRs) with 95% confidence intervals (CIs). Comprehensive searches of PubMed, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov were conducted until 20 December 2023, without language restrictions. Results: Four studies involving 644 children with premyopia aged 4-12 years were identified, with atropine concentrations ranging from 0.01% to 0.05%. The analysis focused on myopia incidence and atropine-related adverse events. Lower myopia incidence (RR, 0.62; 95% CI, 0.40-0.97 D/y; p = 0.03) and reduction in rapid myopia shift (≥0.5 D/1y) (RR, 0.50; 95% CI, 0.26-0.96 D/y; p < 0.01) were observed in the 12-24-month period. Spherical equivalent and axial length exhibited attenuated progression in the atropine group. No major adverse events were detected in either group, whereas the incidence of photophobia and allergic conjunctivitis did not vary in the 12-24-month period. Conclusions: Our meta-analysis supports atropine's efficacy and safety for delaying myopia incidence and controlling progression in children with premyopia. However, further investigation is warranted due to limited studies.

Trends in Myopia and High Myopia from 1966 to 2019 in Olmsted County, Minnesota

PURPOSE

To investigate the prevalence of myopia and high myopia in Olmsted County, Minnesota, from 1966 to 2019.

DESIGN

Retrospective, cross-sectional, trend study.

METHODS

Manifest refractions or lens prescription were converted to spherical equivalent (SE) to estimate the prevalence of adult myopia and high myopia. Age, sex, race, and visual acuity were recorded. Subjects with an SE of -0.5 diopters (D) or less were considered to have myopia; those with an SE of -6.0 D or less were considered to have high myopia. Exclusion criteria included visually significant cataract, pseudophakia, prior refractive surgery, or age less than 18 years.

RESULTS

Among 81,706 sampled subjects, the myopia prevalence increased from 33.9% (95% CI, 31.1-36.8) in the 1960s to 57.1% (95% CI, 56.6-57.6) in the 2010s (P < .001). The high myopia prevalence increased from 2.8% (95% CI, 1.95-3.98) in the 1960s to 8.3% (95% CI, 8.08-8.62) in the 2010s (P < .001). Both male (32.0%-55.1%, P < .001) and female (40.6%-58.5%, P < .001) subjects experienced increasing myopia prevalence from the 1960s to the 2010s; both male (2.6%-7.4%, P < .001) and female (3.4%-9.1%, P < .001) subjects also had higher high myopia prevalence rates from the 1960s through the 2010s. Increasing myopia and high myopia prevalence was detected by decade in nearly all age groups (excluding 18- to 24-year-old high myopia subjects). White and Asian subjects had the highest myopia prevalence, whereas Black subjects had the lowest. From the 2000s to the 2010s, White (53.3%-57.0%, P < .001) and Black (41.0%-47.0%, P = .001) subjects had significant increases in myopia prevalence. The mean SE decreased from the 1960s (-0.42 D; 95% CI, -0.59 to +2.49) to the 2010s (-1.85 D; 95% CI, -1.88 to +2.96) (P < .001).

CONCLUSIONS

From 1966 to 2019 in Olmsted County, Minnesota, there was a 68% and 199% increase in myopia and high myopia prevalence, respectively.

Four-Year Progression of Myopic Maculopathy in Children and Adolescents With High Myopia

Importance

Individuals with high myopia younger than 18 years are at relatively high risk of progressively worsening myopic maculopathy. Additional studies are needed to investigate the progression of myopic maculopathy in this age group, as well as the risk factors associated with progression.

Objective

To investigate the 4-year progression of myopic maculopathy in children and adolescents with high myopia, and to explore potential risk factors.

Design, Setting, and Participants

This hospital-based observational study with 4-year follow-up included a total of 548 high myopic eyes (spherical power -6.00 or less diopters) of 274 participants aged 7 to 17 years. Participants underwent comprehensive ophthalmic examination at baseline and 4-year follow-up. Myopic maculopathy was accessed by the International Photographic Classification and Grading System. The data analysis was performed from August 1 to 15, 2023.

Main Outcomes and Measures

The progression of myopic maculopathy progression over 4 years and associated risk factors.

Results

The 4-year progression of myopic maculopathy was found in 67 of 548 eyes (12.2%) of 274 participants (138 girls [50.4%] at baseline and 4-year follow-up) with 88 lesion changes, including new signs of the tessellated fundus in 16 eyes (18.2%), diffuse atrophy in 12 eyes (13.6%), patchy atrophy in 2 eyes (2.3%), lacquer cracks in 9 eyes (10.2%), and enlargement of diffuse atrophy in 49 eyes (55.7%). By multivariable analysis, worse best-corrected visual acuity (odds ratio [OR], 6.68; 95% CI, 1.15-38.99; P = .04), longer axial length (AL) (OR, 1.73; 95% CI, 1.34-2.24; P < .001), faster AL elongation (OR, 302.83; 95% CI, 28.61-3205.64; P < .001), and more severe myopic maculopathy (diffuse atrophy; OR, 4.52; 95% CI, 1.98-10.30; P < .001 and patchy atrophy; OR, 3.82; 95% CI, 1.66-8.80; P = .002) were associated with myopic maculopathy progression.

Conclusions and Relevance

In this observational study, the progression of myopic maculopathy was observed in approximately 12% of pediatric high myopes for 4 years. The major type of progression was the enlargement of diffuse atrophy. Risk factors for myopic maculopathy progression were worse best-corrected visual acuity, longer AL, faster AL elongation, and more severe myopic maculopathy. These findings support consideration of follow-up in these individuals and trying to identify those at higher risk for progression.

Evaluation of changes in corneal biomechanics after orthokeratology using Corvis ST

PURPOSE

To investigate the alterations in corneal biomechanical metrics induced by orthokeratology (ortho-k) using Corvis ST and to determine the factors influencing these changes.

METHOD

A prospective observational study was conducted to analyze various Corvis ST parameters in 32 children with low to moderate myopia who successfully underwent ortho-k lens fitting. Corneal biomechanical measurements via Corvis ST were acquired at six distinct time points: baseline (pre) and 2 h (pos2h), 6 h (pos6h), and 10 h (pos10h) following the removal of the first overnight wear ortho-k, one week (pos1w) and one month (pos1m) subsequent to the initiation of ortho-k.

RESULT

Significant differences were observed in Corvis ST Biomechanical parameters DAR2, IIR, CBI, and cCBI post ortho-k intervention. The integration of covariates (CCT, SimK, and bIOP) mitigated the differences in DAR2, IIR, and cCBI, but not in CBI. Initially, the stiffness parameter at first applanation, SP-A1, did not demonstrate significant variations, but after adjusting for covariates, noticeable differences over time were observed. The Stress-Strain Indeces, SSIv1 and SSIv2, did not manifest considerable changes over time, irrespective of the adjustment for covariates. No significant disparities were identified among different ortho-k lens brands.

CONCLUSION

Corneal biomechanics remained consistent throughout the one-month period of ortho-k lens wear. The observed changes in Corvis ST parameters subsequent ortho-k are primarily attributable to alterations in corneal pachymetry and morphology, rather than actual alterations in corneal biomechanics. The stability of corneal biomechanics post ortho-k treatment suggests the safety of this approach for adolescents from a corneal biomechanics perspective.

Juvenile-onset myopia-who to treat and how to evaluate success

The risk of eye diseases such as myopic macular degeneration increases with the level of myopia, but there is no safe level of myopia and the burden of lower degrees of myopia remains considerable. Effective treatments are available that slow progression and thus limit the final degree of myopia. In this review, the rationale for slowing progression is summarized, and a case made for treating all myopic children. Measurement of refractive error and axial length is reviewed, stressing the precision of optical biometry, but also the need for cycloplegic autorefraction. The factors influencing progression are considered and the available tools for interpretation of progression rate are discussed. Finally, the need to set attainable treatment goals is emphasized.

The influence of the environment and lifestyle on myopia

BACKGROUND

Myopia, commonly known as near-sightedness, has emerged as a global epidemic, impacting almost one in three individuals across the world. The increasing prevalence of myopia during early childhood has heightened the risk of developing high myopia and related sight-threatening eye conditions in adulthood. This surge in myopia rates, occurring within a relatively stable genetic framework, underscores the profound influence of environmental and lifestyle factors on this condition. In this comprehensive narrative review, we shed light on both established and potential environmental and lifestyle contributors that affect the development and progression of myopia.

MAIN BODY

Epidemiological and interventional research has consistently revealed a compelling connection between increased outdoor time and a decreased risk of myopia in children. This protective effect may primarily be attributed to exposure to the characteristics of natural light (i.e., sunlight) and the release of retinal dopamine. Conversely, irrespective of outdoor time, excessive engagement in near work can further worsen the onset of myopia. While the exact mechanisms behind this exacerbation are not fully comprehended, it appears to involve shifts in relative peripheral refraction, the overstimulation of accommodation, or a complex interplay of these factors, leading to issues like retinal image defocus, blur, and chromatic aberration. Other potential factors like the spatial frequency of the visual environment, circadian rhythm, sleep, nutrition, smoking, socio-economic status, and education have debatable independent influences on myopia development.

CONCLUSION

The environment exerts a significant influence on the development and progression of myopia. Improving the modifiable key environmental predictors like time spent outdoors and engagement in near work can prevent or slow the progression of myopia. The intricate connections between lifestyle and environmental factors often obscure research findings, making it challenging to disentangle their individual effects. This complexity underscores the necessity for prospective studies that employ objective assessments, such as quantifying light exposure and near work, among others. These studies are crucial for gaining a more comprehensive understanding of how various environmental factors can be modified to prevent or slow the progression of myopia.

Delayed melatonin circadian timing, lower melatonin output, and sleep disruptions in myopic, or short-sighted, children

STUDY OBJECTIVES

This study investigated the differences in melatonin circadian timing and output, sleep characteristics, and cognitive function in myopic and non-myopic (or emmetropic) children, aged 8-15 years.

METHODS

Twenty-six myopes (refractive error [mean ± standard error mean] -2.06 ± 0.23 diopters) and 19 emmetropes (-0.06 ± 0.04 diopters), aged 11.74 ± 2.31 years were recruited. Circadian timing was assessed using salivary dim-light melatonin onset (DLMO), collected half-hourly for 7 hours, beginning 5 hours before and finishing 2 hours after individual average sleep onset in a sleep laboratory. Nocturnal melatonin output was assessed via aMT6s levels from urine voids collected from 05:30 pm to 8:00 am the following morning. Actigraphy-derived objective sleep timing were acquired for a week prior to the sleep laboratory visit. Cognitive assessments of sustained attention (using psychomotor vigilance task [PVT]) and working memory (using digit spans) were performed on the night of sleep laboratory.

RESULTS

Myopic children (9:07 pm ± 14 minutes) exhibited a DLMO phase-delay of 1 hour 8 minutes compared to emmetropes (7:59 pm ± 13 minutes), p = 0.002. aMT6s melatonin levels were significantly lower among myopes (18.70 ± 2.38) than emmetropes (32.35 ± 6.93, p = 0.001). Myopes also exhibited significantly delayed sleep onset, delayed wake-up time, poor and reduced sleep, and more evening-type diurnal preference than emmetropes (all p < 0.05). Finally, myopes showed a slower reaction time in the PVT (p < 0.05), but not digit span tasks at night.

CONCLUSIONS

These findings suggest a potential association between circadian rhythm dysfunction and myopia in children.

Sleep and its association with dental caries or myopia in first graders

AIM

First grade is a transition from pre-school to school-age. The change in lifestyle behaviours such as sleep may have a physiological response, which contributes to the presence or absence of two highly incident diseases: dental caries or myopia. The aim of the study was to examine the association between sleep and myopia as well as sleep and dental caries in first graders.

DESIGN

It is a cross-sectional study.

METHODS

This was a recruitment phase of an interventional study. A total of 338 children whose caregivers completed a Children's Sleep Habits Questionnaire. Caregivers also provided information regarding myopia and caries status of children and their parents. Binary logistic regression was applied to analyse the potential risk factors.

RESULTS

Dental caries and myopia rates were 45.9% and 9.5%, respectively. After adjusting for children's gender, children's age, fathers with caries and mothers with caries, the odds ratio for dental caries in children who slept less than 9 h when compared to those who slept for nine and more hours was 1.94. Mothers with caries were 3.37 times more likely to have children with caries than mothers without caries. However, sleep was not associated with myopia in first graders.

CONCLUSION

Sleeping less than 9 h and maternal caries were risk factors of children developing dental caries. Future sleep and myopia studies can be conducted on higher graders who may present prolonged exposure and accumulations of myopic risk factors.

IMPLICATIONS

Screening of children with insufficient sleep is needed for nurses to enable the early identification of high-risk groups for dental caries in school settings. Family nurses are encouraged to work with family members to implement tailored sleep interventions, in order to facilitate better sleep and oral health practices in both school and home settings.

REGISTRATION

This study protocol was registered on ClinicalTrials.gov (Registration number: Redacted).

Topical Atropine for Childhood Myopia Control: The Atropine Treatment Long-Term Assessment Study

Importance

Clinical trial results of topical atropine eye drops for childhood myopia control have shown inconsistent outcomes across short-term studies, with little long-term safety or other outcomes reported.

Objective

To report the long-term safety and outcomes of topical atropine for childhood myopia control.

Design, Setting, and Participants

This prospective, double-masked observational study of the Atropine for the Treatment of Myopia (ATOM) 1 and ATOM2 randomized clinical trials took place at 2 single centers and included adults reviewed in 2021 through 2022 from the ATOM1 study (atropine 1% vs placebo; 1999 through 2003) and the ATOM2 study (atropine 0.01% vs 0.1% vs 0.5%; 2006 through 2012).

Main Outcome Measures

Change in cycloplegic spherical equivalent (SE) with axial length (AL); incidence of ocular complications.

Results

Among the original 400 participants in each original cohort, the study team evaluated 71 of 400 ATOM1 adult participants (17.8% of original cohort; study age, mean [SD] 30.5 [1.2] years; 40.6% female) and 158 of 400 ATOM2 adult participants (39.5% of original cohort; study age, mean [SD], 24.5 [1.5] years; 42.9% female) whose baseline characteristics (SE and AL) were representative of the original cohort. In this study, evaluating ATOM1 participants, the mean (SD) SE and AL were -5.20 (2.46) diopters (D), 25.87 (1.23) mm and -6.00 (1.63) D, 25.90 (1.21) mm in the 1% atropine-treated and placebo groups, respectively (difference of SE, 0.80 D; 95% CI, -0.25 to 1.85 D; P = .13; difference of AL, -0.03 mm; 95% CI, -0.65 to 0.58 mm; P = .92). In ATOM2 participants, the mean (SD) SE and AL was -6.40 (2.21) D; 26.25 (1.34) mm; -6.81 (1.92) D, 26.28 (0.99) mm; and -7.19 (2.87) D, 26.31 (1.31) mm in the 0.01%, 0.1%, and 0.5% atropine groups, respectively. There was no difference in the 20-year incidence of cataract/lens opacities, myopic macular degeneration, or parapapillary atrophy (β/γ zone) comparing the 1% atropine-treated group vs the placebo group.

Conclusions and Relevance

Among approximately one-quarter of the original participants, use of short-term topical atropine eye drops ranging from 0.01% to 1.0% for a duration of 2 to 4 years during childhood was not associated with differences in final refractive errors 10 to 20 years after treatment. There was no increased incidence of treatment or myopia-related ocular complications in the 1% atropine-treated group vs the placebo group. These findings may affect the design of future clinical trials, as further studies are required to investigate the duration and concentration of atropine for childhood myopia control.

Comparison of 0.02% atropine eye drops, peripheral myopia defocus design spectacle lenses, and orthokeratology for myopia control

CLINICAL RELEVANCE

There are many methods to control the progression of myopia. However, it is currently unknown which method could better control myopia progression: 0.02% atropine eye drops, peripheral myopic defocus design spectacle lenses (PMDSL), or orthokeratology (OK).

BACKGROUND

To compare the efficacy of 0.02% atropine, PMDSL, and OK to control axial length (AL) elongation in children with myopia.

METHODS

This study was analysed based on a previous cohort study (0.02% atropine group) and retrospective data (PMDSL and OK group). Overall, 387 children aged 6-14 years with myopia - 1.00D to - 6.00D in the three groups were divided into four subgroups according to age and spherical equivalent refraction (SER). The primary outcome was changed in AL over 1-year.

RESULTS

The mean axial elongation was 0.30 ± 0.21 mm, 0.23 ± 0.16 mm, and 0.17 ± 0.19 mm in the 0.02% atropine, PMDSL, and OK groups, respectively. Multivariate linear regression analyses showed significant differences in axial elongation among the three groups, especially in children aged 6-10, but not in children aged 10.1-14; the corresponding axial elongation was 0.35 ± 0.21 mm, 0.23 ± 0.17 mm, and 0.21 ± 0.20 mm (P < 0.05 between any two groups, except between PMDSL and OK groups at P > 0.05) and 0.22 ± 0.20 mm, 0.21 ± 0.13 mm, and 0.13 ± 0.18 mm (P < 0.05 between any two groups, except between 0.02% atropine and PMDSL groups at P > 0.05) in children with SER from - 1.00D to - 3.00D and from - 3.01D to - 6.00D, respectively.

CONCLUSIONS

Within the limits of this study design and using only the current brand of PMDSL, OK appeared to be the best method, followed by PMDSL and then 0.02% atropine, for controlling AL elongation over one year. However, different effects were found in the various age and SER subgroups.

The SNTB1 and ZFHX1B gene have susceptibility in northern Han Chinese populations with high myopia

The aim of this study was to explore the association between SNTB1 and ZFHX1B polymorphisms and high myopia (HM) in a Northern Han Chinese population. This case-control study included 457 HM and 860 healthy subjects from the Northern Han Chinese population. Four single nucleotide polymorphisms (SNPs) (rs7839488, rs4395927, rs4455882, and rs6469937) in SNTB1 and one SNP in ZFHX1B (rs13382811)were selected based on two previous genome-wide association study (GWAS) studies. The allele and genotype distributions of SNPs in SNTB1 and ZFHX1B were compared between the two groups using the chi-square test. The allele results were adjusted for age and sex using Plink software (Plink 1.9). Pairwise linkage disequilibrium (LD) and haplotype analyses were performed using SHEsis software. For HM subjects, the mean age was 44.80 ± 17.11 years, and for the control subjects, it was 44.41 ± 14.26 years. For rs7839488 of the SNTB1 gene, the A allele is a risk allele and the G allele is a wild allele. The A allele had no statistical significance with the HM cases and controls (OR = 0.90, 95% CI = 0.74-1.09, aP = 0.273, Pc = NS). There was a LD in SNTB1 (rs7839488, rs4395927, rs4455882, and rs6469937). The G-C-A-G haplotype frequency was higher in HM subjects than that of the controls (OR = 1.31, 95% CI = 1.07-1.60, P = 0.008). Meanwhile, the A-T-G-A haplotype frequency was slightly lower in the HM group (OR = 0.81, 95% CI = 0.66-0.99, P = 0.048). In the ZFHX1B gene, the frequency of the minor T allele of rs13382811 was significant higher in the HM group than in the control group (OR = 1.34, 95% CI = 1.11-1.61, aP = 0.001, Pc = 0.009). Furthermore, compared to the CC genotype, there were significant differences in the CT genotype (OR = 1.57, 95% CI = 1.23-2.00, aP < 0.001, Pc = 0.002). In conclusion, G-C-A-G is a risk haplotype from the SNTB1 gene in high myopia patients. The minor T-allele of ZFHX1B rs13382811 is a risk factor for high myopia. SNTB1 and ZFHX1B are both risk genes associated with increased susceptibility to high myopia in the Northern Han Chinese population.

Sleep Quality is Associated with Axial Length Elongation in Myopic Children Receiving Orthokeratology: A Retrospective Study

Purpose

To identify potential demographic and lifestyle factors associated with progression of myopia with orthokeratology (ortho-k) treatment via follow-up of axial length (AL).

Methods

In this retrospective observational study, demographics, ocular parameters, near-work distance, outdoor activities, and sleep quality were analyzed in 134 children with myopia aged 8~15 years using ortho-k and a follow-up for one year.

Results

Compared with the slow progression group, the participants in the fast progression group were younger in age (10.55 ±1.70 years vs 9.90 ±1.18 years, P = 0.009), demonstrated higher spherical equivalent (SE) value (-2.52 ±0.63 diopters (D) vs -3.05 ±0.89 D, P < 0.001), shorter near-work distance (P = 0.010), and poorer sleep quality (Pittsburgh sleep quality index [PSQI], 4.79 ±1.29 vs 3.81 ±1.38, P < 0.001) in the one-year follow-up. Furthermore, multivariate linear regression analyses showed that baseline age (B =-0.020, P = 0.020), SE (B = 0.0517, P < 0.001), and total PSQI (B=0.026, P = 0.001) were associated with axial elongation. Advanced logistic regression analyses demonstrated that shorter average near-work distance (P = 0.034), higher SE value (P = 0.023), and poorer sleep quality (P = 0.003) were associated with fast axial elongation.

Conclusion

Sleep quality is one of the key factors associated with axial elongation in children with myopia after using ortho-k for one year. Further studies are required to confirm this observation and expand its practical applications.

Associations between systemic melatonin and human myopia: A systematic review

PURPOSE

Experimental models have implicated the role of melatonin circadian rhythm disruption in refractive error development. Recent studies have examined melatonin concentration and its diurnal patterns on refractive error with equivocal results. This systematic review aimed to summarise the literature on melatonin circadian rhythms in myopia.

RECENT FINDINGS

PubMed, EMBASE, Web of Science, Scopus, ProQuest Central, LILACS, Cochrane and Medline databases were searched for papers between January 2010 and December 2022 using defined search terms. Seven studies measured melatonin and circadian rhythms in three biological fluids (blood serum, saliva and urine) in both myopes and non-myopes. Morning melatonin concentrations derived from blood serum varied significantly between studies in individuals aged 10-30 years, with a maximum of 89.45 pg/mL and a minimum of 5.43 pg/mL using liquid chromatography and mass spectrometry. The diurnal variation of salivary melatonin was not significantly different between myopes and emmetropes when measured every 4 h for 24 h and quantified with enzyme-linked immunosorbent assay. Significantly elevated salivary melatonin concentrations were reported in myopes compared with emmetropes, aged 18-30 years when measured hourly from evening until their habitual bedtime using liquid chromatography. However, the relationship between dim light melatonin onset and refractive group was inconsistent between studies. The 6-sulphatoxymelatonin concentration derived from overnight urine volume, measured using a double antibody radioimmunoassay, was found to be significantly lower in myopes (29.17 pg/mL) than emmetropes (42.51 pg/mL).

SUMMARY

The role of melatonin concentration and rhythm in myopia has not been studied extensively. This systematic review confirms conflicting findings across studies, with potential relationships existing. Future studies with uniform methodological approaches are required to ascertain the causal relationship between melatonin dysregulation and myopia in humans.

Addressing Glaucoma in Myopic Eyes: Diagnostic and Surgical Challenges

Epidemiological and genetic studies provide strong evidence supporting an association between myopia and glaucoma. The accurate detection of glaucoma in myopic eyes, especially those with high myopia, remains clinically challenging due to characteristic morphologic features of the myopic optic nerve in addition to limitations of current optic nerve imaging modalities. Distinguishing glaucoma from myopia is further complicated by overlapping perimetric findings. Therefore, longitudinal follow-up is essential to differentiate progressive structural and functional abnormalities indicative of glaucoma from defects that may result from myopia alone. Highly myopic eyes are at increased risk of complications from traditional incisional glaucoma surgery and may benefit from newer microinvasive glaucoma surgeries in select cases.

The underestimated role of myopia in uncorrectable visual impairment in the United States

We estimate the US prevalence of uncorrectable visual impairment in 2050 accounting for the changing distribution of both age and myopia. Age projections of the US population (from an estimated total of 379 million in 2050), were taken from the US census website. The distribution of myopia, by severity, was calculated from literature-derived prevalence estimates of 58.4% (≤ - 0.50 D, 2050 projection) and 33.1% (≤ - 1.00 D, 1999-2004 estimate) to provide predicted and conservative estimates, respectively. Uncorrectable visual impairment as a function of age and refractive error was modelled by multiple linear regression. Finally, the likely number of individuals in the US with visual impairment in 2050 was calculated. For a projected myopia prevalence of 58.4%, 222 million are projected to be myopic and 48 million will have high myopia (- 5 D or worse). The projected total number with uncorrectable visual impairment is 11.4 million of which 4.9 million cases (43%) of visual impairment will be directly attributed to increased risk of eye disease associated with myopia. For a projected myopia prevalence of 33.1%, 8.9 million are projected to have uncorrectable visual impairment of which 2.4 million cases (27%) will be directly attributed to myopia. It is predicted that between 27 and 43% of uncorrectable visual impairment in the US population in 2050 will be directly attributable to myopia. Failure to account for the increasing prevalence of myopia among the aging population leads to a substantial underestimate of the prevalence of visual impairment.

Implementing a digital comprehensive myopia prevention and control strategy for children and adolescents in China: a cost-effectiveness analysis

Background

Children and adolescents' myopia is a major public problem. Although the clinical effect of various interventions has been extensively studied, there is a lack of national-level and integral assessments to simultaneously quantify the economics and effectiveness of comprehensive myopia prevention and control programs. We aimed to compare the cost-effectiveness between traditional myopia prevention and control strategy, digital comprehensive myopia prevention and control strategy and school-based myopia screening program in China.

Methods

A Markov model was used to compare the cost-utility and cost-effectiveness among school-based myopia screening, traditional myopia prevention and control strategy, and digital comprehensive myopia prevention and control strategy among 6 to 18-year-old rural and urban schoolchildren. Parameters were collected from published sources. The primary outcomes were quality-adjusted life-year, disability-adjusted life-year, incremental cost-utility ratio, and incremental cost-effectiveness ratio. Extensive sensitivity analyses were performed to test the robustness and sensitivity of base-case analysis.

Findings

Compared with school-based myopia screening strategy, after implementing digital comprehensive myopia prevention and control strategy, the prevalence of myopia among 18-year-old students in rural and urban areas was reduced by 3.79% and 3.48%, respectively. The incremental cost-utility ratio per quality-adjusted life-year gained with the digital myopia management plan ($11,301 for rural setting, and $10,707 for urban setting) was less than 3 times the per capita gross domestic product in rural settings ($30,501) and less than 1 time the per capita gross domestic product in urban settings ($13,856). In cost-effectiveness analysis, the incremental cost-effectiveness ratio produced by digital comprehensive myopia management strategy ($37,446 and $41,814 per disability-adjusted life-year averted in rural and urban settings) slightly exceeded the cost-effectiveness threshold. When assuming perfect compliance, full coverage of outdoor activities and spectacles satisfied the cost-effectiveness threshold, and full coverage of outdoor activities produced the lowest cost ($321 for rural settings and $808 for urban settings).

Interpretations

Health economic evidence confirmed the cost-effectiveness of promoting digital comprehensive myopia prevention and control strategies for schoolchildren at the national level. Sufficient evidence provides an economic and public health reference for further action by governments, policy-makers and other myopia-endemic countries.

Funding

National Natural Science Foundation of China, NSFC (82171051), Beijing Natural Science Foundation (JQ20029), Capital Health Research and Development of Special (2020-2-1081), National Natural Science Foundation of China, NSFC (82071000), National Natural Science Foundation of China, NSFC (8197030562).

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.

Binocular imbalance in patients after implantable collamer lens V4c implantation or femtosecond laser-assisted in situ keratomileusis for myopia with presbyopia

Aim

To investigate the long-term safety, efficacy, and binocular balance of monovision surgery using Implantable Collamer Lens (ICL) V4c implantation and Femtosecond Laser-Assisted in situ Keratomileusis (FS-LASIK) for the treatment of myopic patients with presbyopia.

Methods

This case series study involved 90 eyes of 45 patients (male/female = 19/26; average age:46.27 ± 5.54 years; average follow-up time:48.73 ± 14.65 months) who underwent the aforementioned surgery to treat myopic presbyopes. Data on manifest refraction, corrected distance visual acuity, dominant eye, presbyopic addition, intraocular pressure, and anterior segment biometric parameters were collected. The visual outcomes and binocular balance at 0.4 m, 0.8 m, and 5 m were documented.

Results

The safety index for the ICL V4c and FS-LASIK groups were 1.24 ± 0.27 and 1.04 ± 0.20 (p = 0.125), respectively. Binocular visual acuity (logmar) for 0.4 m, 0.8 m, and 5 m were -0.03 ± 0.05, -0.03 ± 0.02, and 0.10 ± 0.03 for the ICL V4c group, and -0.02 ± 0.09, -0.01 ± 0.02, and 0.06 ± 0.04 for the FS-LASIK group, respectively. The proportions of all patients with imbalanced vision at 0.4 m, 0.8 m, and 5 m distances were 68.89, 71.11, and 82.22%, respectively (all p > 0.05 between the two groups). There were significant differences in refraction between the balanced and imbalanced vision for patients at 0.4 m distance (for non-dominant eye spherical equivalent [SE]: -1.14 ± 0.17D and -1.47 ± 0.13D, p < 0.001), 0.8 m distance (for preoperative ADD:0.90 ± 0.17D and 1.05 ± 0.11D, p = 0.041), and 5 m distance (for non-dominant SE: -1.13 ± 0.33D and -1.42 ± 0.11D, p < 0.001).

Conclusion

ICL V4c implantation and FS-LASIK monovision treatment demonstrated good long-term safety and binocular visual acuity at various distances. After the procedure, the imbalanced patients' vision is primarily related to the age-related presbyopia and anisometropia progression caused by the monovision design.

Incidence of Corneal Adverse Events in Children Wearing Soft Contact Lenses

OBJECTIVES

There is increasing interest in fitting children with soft contact lenses, in part due to the increase in prescribing of designs to slow the progression of myopia. This literature review summarizes large prospective and retrospective studies that include data on the incidence of microbial keratitis and corneal infiltrative events (CIEs) in children wearing soft contact lenses.

METHODS

Peer-reviewed prospective and retrospective studies that report contact lens-related complications in children with at least one year of wear and at least 100 patient years of wear were identified.

RESULTS

Seven prospective studies published between 2004 and 2022 were identified representing 3,752 patient years of wear in 1,756 children, nearly all of whom were fitted at age 12 years or younger. Collectively, they report one case of microbial keratitis and 53 CIEs, of which 16 were classified as symptomatic. The overall incidence of microbial keratitis was 2.7 per 10,000 patient years (95% CI: 0.5-15), and the incidence of symptomatic CIEs was 42 per 10,000 patient years (95% CI: 26-69). Two retrospective studies were identified representing 2,545 patient years of wear in 1,025 children, fitted at age 12 years or younger. One study reports two cases of microbial keratitis giving an incidence of 9.4 per 10,000 patient years (95% CI: 0.5-15).

CONCLUSIONS

Accurate classification of CIEs is challenging, particularly in retrospective studies. The incidence of microbial keratitis in children wearing soft lenses is no higher than in adults, and the incidence of CIEs seems to be markedly lower.

High Myopia Prevalence across Racial Groups in the United States: A Systematic Scoping Review

High myopia is a significant public health issue globally and in the United States (US), where it affects ~4% of the population or 13 million people. This is a potentially blinding condition, but complications can be prevented with early intervention in childhood. Several countries have developed robust data on high myopia, but the United States' data on high myopia remains lacking. Further, underrepresented populations are at particular risk of complications due to reduced access to optometric and ophthalmic care. We performed a systematic scoping review of population-based studies that investigated the prevalence of high myopia across racial and ethnic groups in the US to identify the impact of high myopia on underrepresented communities. Only four studies were identified that met inclusion criteria, which highlights the need to further investigate the topic in the United States. The prevalence of high myopia ranged from a low of 1.8% among Hispanic populations to a high of 11.8% among Chinese populations. Our study demonstrated a paucity of high myopia data in the United States and variable rates of high myopia depending on the time and location of each study. More complete prevalence data will help identify opportunities for community-based interventions to prevent debilitating and blinding complications of high myopia.

Prevention of myopia shift and myopia onset using 0.01% atropine in premyopic children - a prospective, randomized, double-masked, and crossover trial

This study aims to evaluate the efficacy of 0.01% atropine eye drops in preventing myopia shift and myopia onset in premyopic children. A prospective, randomized, double-masked, placebo-controlled, and crossover trial was conducted over 13 months. Sixty premyopic children aged 6-12 years with cycloplegic spherical equivalent refraction (SER) >  - 0.75 D and ≤  + 0.50 D in both eyes were assigned in a 1:1 ratio to receive one drop of 0.01% atropine or placebo once nightly for 6 months (period 1), followed by a 1-month recovery period. Then, the 0.01% atropine group was crossed over to the placebo group, and the latter was crossed over to the 0.01% atropine group for another 6 months (period 2). The primary outcomes were changes in SER and axial length (AL), and the secondary outcomes were the proportion of myopia onset (SER ≤  - 0.75D) and fast myopic shift (change in SER ≤  - 0.25D) in the two periods. Generalized estimating equation (GEE) model performed a statistically significant treatment effect of 0.01% atropine compared with placebo (p_SER = 0.02, p_AL < 0.001), with a mean SER and AL difference of 0.20D (- 0.15 ± 0.26D vs. - 0.34 ± 0.34D) and 0.11 mm (0.17 ± 0.11 mm vs. 0.28 ± 0.14 mm) in period 1, and 0.17D (- 0.18 ± 0.24D vs. - 0.34 ± 0.31D) and 0.10 mm (0.15 ± 0.15 mm vs. 0.24 ± 0.11 mm) in period 2. The GEE model showed that the proportion of myopia onset (p = 0.004) and fast myopic shift (p = 0.009) was significantly lower in the 0.01% atropine group than that in the placebo group. The period effect was not statistically significant (all p > 0.05). A total of 0.01% atropine significantly prevented myopic shift, axial elongation, and myopia onset in premyopic schoolchildren in central Mainland China.

CONCLUSION

Within the limits of only two consecutive 6-month observation period, 0.01% atropine eye drops effectively prevented myopic shift, axial elongation, and myopia onset in premyopic children.

TRIAL REGISTRATION

This trial was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2000034760). Registered 18 July 2020.

WHAT IS KNOWN

• Minimal studies on interventions for pre-myopia, despite the International Myopia Institute stating that preventing myopia is an "even more valuable target" for science and practice than reducing progression after onset.

WHAT IS NEW

• A total of 0.01% atropine eye drops may safely and effectively reduce the proportion of myopia onset and fast myopic shift in premyopic schoolchildren.

Extreme myopia is more susceptible to SOX2 gene than high myopia

PURPOSE

To explore the association between two single-nucleotide polymorphisms (SNPs) in the SOX2 gene and high and extreme myopia in the Han Chinese population.

MATERIALS AND METHODS

A genetic association study using a case-control method was performed with 139 high myopia, 318 extreme myopia, and 918 healthy participants from the Chinese Han population. Two SNPs (rs4459940 and rs4575941) near SOX2 gene were selected for genotyping. We compared the allelic frequencies and haplotypes of the SNPs to assess their association with high and extreme myopia. This study was adjusted for sex and age of participants in the groups.

RESULT

The mean ages of the extreme myopia and control subjects were 47.44 ± 15.59 and 44.15 ± 14.08 years, respectively. The rs4575941 SNP of the SOX2 gene and the GG and AG genotypes showed no significant association with the risk of high myopia as opposed to the AA genotype (GG, OR = 0.94, 95% CI = 0.55-1.60, P = 0.820, Pc = NS; AG, OR = 0.91, 95% CI = 0.54-1.52, P = 0.708, Pc = NS). However, the frequency of the risk G allele of rs4575941 was significantly higher in the extreme myopia group than in the control group (OR = 1.31, 95% CI = 1.08-1.59; P = 0.007; Pc = 0.014). Furthermore, there were significant differences in the GG genotype frequency between the extreme myopia and control groups (OR = 1.77, 95% CI = 1.45-2.74, P = 0.009, Pc = 0.036). The A-G haplotype frequency was higher in the extreme group (OR = 1.27, 95% CI = 1.05-1.55, P = 0.014), while there were no significant differences found in high myopia group (OR = 1.18, 95% CI = 0.77-1.31, P = 0.979).

CONCLUSION

The SOX2 rs4575941 polymorphism, in Chinese Han population, contributes to the susceptibility of extreme myopia. SOX2 may thus be implicated in extreme myopia rather than in high myopia.

The Incidence and Severity of Myopia in the Population of Medical Students and Its Dependence on Various Demographic Factors and Vision Hygiene Habits

(1) Background: Myopia is one of the leading causes of visual impairment. Visual work and usage of electronic devices are known risk factors of myopia. Many education systems were forced to apply online and hybrid teaching methods, to reduce the number of new cases of COVID-19. Medical students are a population well-known for intense visual work in the form of learning; (2) Methods: Visual acuity and refractive error were measured in the population of medical students. Participants also filled out the survey that included their population characteristic and their habits related to the hygiene of vision; (3) Results: We found a correlation between the age of the first diagnosis of myopia and current values of refractive error. The majority of participants believe that the COVID-19 pandemic had an impact on the health of their vision. Among methods of studying, usage of the computer screen was less preferred by myopic students; (4) Conclusions: In the population of medical school students in Eastern Poland, visual acuity was lower than 1.0 in 232 (52.97%) in the right eye and 234 (53.42%) in the left eye. Early recognition of refractive error has influenced its current values. Among methods of studying, usage of the computer screen was less preferred by myopic students. More population-based studies should focus on the impact of the COVID-19 pandemic on the health of vision.

Flash Electroretinography as a Measure of Retinal Function in Myopia and Hyperopia: A Systematic Review

Refractive errors (myopia and hyperopia) are the most common visual disorders and are severe risk factors for secondary ocular pathologies. The development of refractive errors has been shown to be associated with changes in ocular axial length, suggested to be induced by outer retinal elements. Thus, the present study systematically reviewed the literature examining retinal function as assessed using global flash electroretinograms (gfERGs) in human clinical refractive error populations. Electronic database searching via Medline, PubMed, Web of Science, Embase, Psych INFO, and CINAHL retrieved 981 unique records (last searched on the 29 May 2022). Single case studies, samples with ocular comorbidities, drug trials, and reviews were excluded. Demographic characteristics, refractive state, gfERG protocol details, and waveform characteristics were extracted for the eight studies that met the inclusion criteria for the review and were judged to have acceptable risk of bias using the OHAT tool (total N = 552 participants; age 7 to 50). Study synthesis suggests that myopia in humans involves attenuation of gfERG photoreceptor (a-wave) and bipolar cell (b-wave) function, consistent with the animal literature. Meaningful interpretation of the overall findings for hyperopia was limited by inconsistent reporting, highlighting the need for future studies to report key aspects of gfERG research design and outcomes more consistently for myopic and hyperopic refractive errors.

Ocular Rigidity and Current Therapy

Purpose: Ocular rigidity (OR) is an important biomechanical parameter of the eye accounting for the material and geometrical properties of the corneoscleral shell.Methods: This study used a literature search to review the role of ocular rigidity and the application of potential therapies targeting this parameter in glaucoma and myopia.Conclusion: Biomechanical modeling and improved understanding of the biochemistry, and molecular arrangement of sclera and its constituents have yielded important insights. Recent developments, including that of a non-invasive and direct OR measurement method and improved ocular imaging techniques are helping to elucidate the role of OR in healthy and diseased eyes by facilitating large scale and longitudinal clinical studies. Improved understanding of OR at the initial stages of disease processes and its alterations with disease progression will undoubtedly propel research in the field. Furthermore, a better understanding of the determinants of OR is helping to refine novel therapeutic approaches which target and alter the biomechanical properties of the sclera in sight-threatening conditions such as glaucoma and myopia.

Topical Review: Studies on Management of Myopia Progression from 2019 to 2021

SIGNIFICANCE

Myopia is a common eye condition that increases the risk of sight-threatening complications. Each additional diopter increases the chance of complications. The purpose of this review was to make an overview of myopia control treatment options for children with myopia progression.In this nonsystematic review, we searched PubMed and Cochrane databases for English-language studies published from 2019 to September 2021. Emphasis was given to selection of randomized controlled trials. Nineteen randomized controlled trials and two retrospective studies were included. Topical atropine and orthokeratology remain the most used treatments, whereas lenses with novel designs are emerging treatments. Overall myopia progression in the treatment groups for low-dose atropine and orthokeratology was lower than in the control groups, and their efficacy was reported in several randomized controlled trials and confirmed by various systematic reviews and meta-analysis. The findings of myopia progression and axial elongation for the MiSight, defocus incorporated multiple segment spectacle lens, highly aspherical lenslets, and diffusion optics technology spectacle lens were comparable. Public health interventions to optimize environmental influences may also be important strategies to control myopia. Optimal choice of management of myopia depends on treatment availability, acceptability to child and parents, and specific patient features such as age, baseline myopia, and lifestyle. Eye care providers need to understand the advantages and disadvantages of each therapy to best counsel parents of children with myopia.

The relationship between baseline axial length and axial elongation in myopic children undergoing orthokeratology

PURPOSE

To investigate the correlation between the baseline axial length (AL) and axial elongation in myopes undergoing orthokeratology (ortho-k).

METHODS

This was a retrospective study. During the 1-year follow-up, 1176 children (aged 8-14 years) were included and divided into an ortho-k group (n = 588) and a single-vision spectacle group (n = 588). The ortho-k group participants (8-11 years of age) who completed the 3-year follow-up (n = 150) were further divided into three subgroups stratified by their baseline AL: subgroup 1 (AL < 24.5 mm), subgroup 2 (24.5 ≤ AL < 26 mm) and subgroup 3 (AL ≥ 26 mm). AL was measured at baseline and during the annual visit.

RESULTS

The ortho-k group exhibited slower 1-year axial elongation (39% reduction) than the spectacle group. The 1-year axial elongation was negatively correlated with initial age in both groups. A negative association between 1-year axial elongation and baseline AL was observed in the ortho-k group but not in the spectacle group. However, this relationship only existed in ortho-k participants 8-11 years of age. For the younger ortho-k participants who completed the 3-year follow-up, the annual axial elongation was significantly higher in subgroup 1 for the first and second years but not in the third year compared with subgroups 2 and 3.

CONCLUSION

Axial elongation was negatively correlated with baseline AL in the ortho-k group. Children aged 8-11 years with longer baseline AL (≥24.5 mm) demonstrated slower annual axial elongation during the first 2 years of ortho-k treatment, which may provide insight into establishing individual guidelines for controlling myopia using ortho-k in children with different baseline characteristics.

Cataract surgery in myopic eyes

PURPOSE OF REVIEW

We discuss the preoperative, intraoperative, and postoperative considerations for cataract surgery in eyes with high myopia. We also reviewed the recent literature on refractive outcomes and complications of cataract surgery in myopic eyes.

RECENT FINDINGS

Several novel intraocular lens (IOL) power calculation formulas have recently been developed to optimize refractive outcomes. Haigis formula is the most accurate among the third-generation IOL formulas. Novel formulas such as Barrett Universal II, Kane, and modified Wang-Koch adjustment for Holladay I formula provide a better refractive prediction compared with old formulas. Intraoperatively, the chopping technique is preferred to minimize pressure on weak zonules and reduce the incidence of posterior capsule rupture. Anterior capsular polishing is recommended to reduce the risk of postoperative capsular contraction syndrome (CCS). Postoperatively, complications such as refractive surprises, intraocular pressure spikes, and CCS remain higher in myopic eyes. Only 63% of myopic patients with axial length more than 26 mm achieve a visual acuity at least 20/40 after cataract surgery, mainly because of coexisting ocular comorbidities.

SUMMARY

There are multiple preoperative, intraoperative, and postoperative considerations when performing cataract surgery in myopic eyes. Further research is needed to optimize the refractive outcomes in these eyes and determine the best IOL formula. Surgeons should be adept and knowledgeable with different techniques to manage intraoperative complications.

Myopia and Its Association with Near Work, Outdoor Time, and Housing Type among Schoolchildren in South India

SIGNIFICANCE

In this comprehensive assessment of environmental associations with refractive status among schoolchildren in India, outdoor time was the key modifiable risk factor associated with myopia rather than time spent on near work.

PURPOSE

This study aimed to investigate the environmental risk factors associated with myopia among adolescent schoolchildren in South India.

METHODS

Children in grades 8 to 10 from 11 schools in Tamil Nadu, South India, underwent eye examination and risk factor assessments through a modified version of the Sydney myopia questionnaire. Time spent on near work and outdoors was analyzed after division into three groups based on tertiles. Mixed-effects logistic regression was performed to assess the factors associated with myopia.

RESULTS

A total of 3429 children (response rate, 78.4%) provided both questionnaire and refraction data. The mean (standard deviation) age was 14 (0.93) years with an equal distribution of sexes. Myopia was present among 867 children (noncycloplegic spherical equivalent refraction, ≤-0.75 D). Refraction was not associated with near work tertiles ( P = .22), whereas less time outdoors was associated with higher myopic refractions ( P = .01). Refraction shifted toward increased myopia with an increase in the near-work/outdoor time ratio ( P = .005). Children living in apartment housing had a higher prevalence of myopia compared with other types of housing ( P < .001). In multivariate analysis, increased time outdoors was a protective factor against myopia (odds ratio, 0.79; 95% confidence interval, 0.63 to 0.99; P = .04), whereas living in apartment housing (odds ratio, 1.27; 95% confidence interval, 1.04 to 1.55; P = .02) was a significant risk factor.

CONCLUSIONS

In this cohort of Indian children, outdoor time, increased near-work/outdoor time ratio, and type of housing were the factors associated with myopia. Policies should target implementing a balance between near-work and outdoor time among children.

Prevalence of refractive error in Portugal estimated from ophthalmic lens manufacturing data: Ten-years analysis

PURPOSE

To investigate the prevalence, distribution and trends of refractive error from ophthalmic lens manufacturing data over a ten-year period.

METHODS

Fully anonymized data from ophthalmic lenses, for the years between 2010 and 2020, provided by the leading ophthalmic lens manufacturer operating in Portugal were analysed (no human participants were involved in the research). Prescriptions delivered were divided in single vision prescriptions and progressive/multifocal prescriptions and categorized into 14 spherical equivalent ranges. Given the lack of absolute values, indirect estimates and a qualitative analysis of the current situation and trends on refractive error epidemiology was carried out.

RESULTS

Dataset from manufacturer comprises percentage values of ophthalmic lenses dispensed in Portugal. The distribution of ophthalmic prescriptions for single vision prescriptions presents most of the observations in the range [-1.49, -0.50] diopters, in every year from 2010 to 2020. For the progressive prescription's lenses, most of the observations is in an interval of two ranges, [0.50, 1.49] and [1.50, 2.99] diopters. From 2010 to 2020 the proportion of single vision ophthalmic lens prescriptions for myopia increased from 38.13% to 46.21%; the proportion for high myopia increased from 2.76% to 4.45%; and the proportion for hyperopia decreased from 40.85% to 31.36%.

CONCLUSIONS

Ophthalmic lens manufacturing data can be a valuable source for long-term analysis of refractive error prescription and trends over time. It was possible to observe a trend of increasing prevalence of myopia and high myopia from 40.89% in 2010 to 50.66% in 2020. That increase trend has important implications for public health and in the planning of services.

Implantable collamer lens implantation (ICL) versus small incision lenticule extraction (SMILE) in low to moderate myopia: study protocol for a randomized, non-inferiority trial

BACKGROUND

Implantable collamer lens implantation (ICL) is a form of 'foldable' posterior chamber phakic intraocular lens refractive surgery that generally does not impair cornea and natural accommodation. The potential advantages of the ICL over keratorefractive laser procedures include less induction of higher-order aberrations (HOAs) and enhanced retinal image magnification. On the other hand, small incision lenticule extraction (SMILE), currently, one of the most popular refractive surgery procedures, also offers excellent visual outcomes, particularly for eyes with low to moderate amounts of myopia. The aim of this study is to evaluate whether ICL/TICL (toric ICL) is comparable to SMILE for low to moderate myopia in terms of refractive outcomes at 3 and 18 months post-operatively.

METHODS/DESIGN

This is a prospective randomized study. A total of 300 participants will be randomized into two groups, the ICL/TICL group and SMILE group. Eligible participants with spherical equivalent (SE) less than - 6.0 diopter (D) will be recruited. Following randomization, participants will be followed at 1, 3, 6, 12, and 18 months. The primary outcome is the refractive predictability at every postoperative point after surgery, which is the proportion of the number of eyes achieving a postoperative SE within ± 0.5 D and ± 1.0 D of the intended target. Secondary outcome parameters include visual acuity, refraction, adverse events, and quality of vision measurements.

DISCUSSION

This trial will provide information on whether ICL has comparable, if not superior, refractive outcomes compared to the established SMILE for low to moderate myopia, thus providing evidence for translation into clinical practice.

TRIAL REGISTRATION

Chinese clinical trial registry (ChiCTR) 2200055372. Registered on 08 January 2022.

Exploring the Relationship Between Binocular Imbalance and Myopia: Refraction with a Virtual Reality Platform

To explore the relationship between binocular imbalance (BI) and the abnormal development of binocular refraction. BI data were collected by enrolling the first 1,000 adolescents and children aged 6-18 years in Shenzhen Eye Hospital from April 2020 to January 2021. In this cross-sectional study, the imbalance value (IV) did not show a statistical correlation with the spherical equivalent (SE) (oculus dexter [OD]: r = 0.022, p = 0.586; oculus sinister [OS]: r = -0.021, p = 0.606), and had little correlation with the uncorrected visual acuity (VA) (OD: r = -0.084, p = 0.039; OS: r = -0.034, p = 0.408). The proportion of binocular contrast imbalance (BCI) (the absolute value) maintained the highest level (from 54.42 to 79.17 percent) with the increase of bilateral SE difference in the four subcategories (binocular balance, monocular suppression, binocular rivalry, and BCI). From -100 to +100 of IV, the SE of the left eye tends to increase negatively when compared with the right eye (from -95 < IV ≦ -80, SE difference = -0.83 ± 1.58, to -20 < IV ≦ -10, SE difference = -0.14 ± 0.61; from 10 ≦ IV <20, SE difference = -0.05 ± 0.80, to 80 ≦ IV <95, SE difference = 1.48 ± 2.77). BI widely exists within the general pediatric population. The BI did not show significant correlation with the unilateral eye refractive state and the VA. However, the BI may be accompanied by imbalanced development of the eye refractive system. Furthermore, the SE of the dominant eye (from the prospective of BI) tends to be more negative than that of the opposite eye as the value increases. Clinical Trial Registration number: ChiCTR2100045457.

Outdoor exposure in children from Buenos Aires Province, Argentina

OBJECTIVES

To evaluate myopia risk factors, mainly outdoor exposure and reading habits, in a country with low prevalence of myopia (Buenos Aires Province, Argentina).

METHODS

Consecutive children interviewed in a clinical private practice setting were autorefracted under cycloplegia with cyclopentolate 1%. Their parents consented to fill a questionnaire about schooling, tutorial classes, outdoor exposure, reading habits, and cellphone use, both on weekdays and weekends. The Spanish questionnaire was based on past English questionnaires of myopia clinical trials. The spherical equivalent of the right eye was used for the refractive distribution. The average daily hours spent for each activity were calculated.

RESULTS

This study involved 115 children aged 10.48 ± 3.65 years (range 5-18 years), with 56.5% being girls. Children had 8 h of schooling per day in 62.6% of cases, and only 14.8 % had tutorial classes after school. There were 38.3% myopes (<-0.50 D), 24.3% hyperopes (>+2.00 D) and the rest were emmetropes. The mean time that these children spent outdoors per day was 3.94 ± 1.45 h (27.60 ± 10.16 h per week). The total mean time spent reading and writing per day was 1.50 ± 0.98 h, and that spent using cellphones and tablets was 2.43 ± 1.66 h.

CONCLUSION

In an environment with low myopia prevalence, children spend almoast 4 h per day outdoors, much more than the usual recommendation of 2 h a day for myopia prevention.

Exposure to the Life of a School Child Rather Than Age Determines Myopic Shifts in Refraction in School Children

Purpose

The prevalence of myopia increases with both age and grade for children attending school. The current study aimed to distinguish the effects of aging and grade on myopia.

Methods

Grade 1 students (706 at baseline in 2009, mean age 6.56 ± 0.29 years, range 6.00 to 6.99 years old, 55.5% boys) were followed up until 2012. Cycloplegic spherical equivalent (SE) was measured annually.

Results

The sample in a grade was divided into three 4-month age blocks according to their birth month. Within each grade, there were no significant differences in SE between age blocks (all P > 0.05), despite an age range of one year. More myopic SE was observed in the youngest block of grade 2 compared to the oldest block of grade 1 (difference, -0.36 ± 0.08 D; P < 0.001), although age of the two blocks only differed by four months. Similarly, more myopic SE were found in the youngest block in grade 3 than the oldest block in grade 2 (differences, -0.50 ± 0.10 D; P < 0.001) and in the youngest block in grade 4 than the oldest block in grade 3 (differences, -0.82 ± 0.14 D; P < 0.001).

Conclusions

Exposure to schooling, rather than age, appears to be the major driver of refractive development, at least in the early years of schooling. Interventions during this period, involving reductions in educational pressure and increased time outdoors may have major effects on the subsequent development of myopia.

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.

Correlation of myopia onset and progression with corneal biomechanical parameters in children

BACKGROUND

Recent epidemiological studies have shown that general eye measurement parameters and corneal biomechanical properties can predict the speed of myopic progression in children.

AIM

To investigate the correlation between the onset and progression of myopia and corneal biomechanical parameters in children.

METHODS

The study included 102 cases in the emmetropia group, 207 cases in the myopic group, and 109 cases in the hyperopic group. The correlation between the change in corneal biomechanical indexes and the change in general ocular measurement parameters was analyzed. A one-way ANOVA test compared general ocular measurement and corneal biomechanical parameters. Pearson’s correlation coefficient was analyzed to correlate corneal biomechanical and general ocular measurement parameters.

RESULTS

The general ophthalmometric parameters: Spherical equivalent (SE), intraocular pressure (IOP), and axial length (AL), differed significantly among subjects in myopia, emmetropia, and hyperopic groups. Children’s SE positively correlated with corneal biomechanical parameters: Second velocity of applanation (A2V), peak distance (PD), and deformation amplitude (DA) (P < 0.05), and second applanation length (A2L) (P < 0.05). But it was negatively correlated with PD, DA and integral radius (IR) (P < 0.05). Also, IOP was negatively correlated with A2L and IR (P < 0.05). AL positively correlated with A2V and negatively correlated with second applanation time (A2T), highest concavity, and PD. Central corneal thickness positively correlated with first applanation length, first applanation time, first applanation deformation amplitude, A2V, A2L, A2T, second applanation deformation amplitude, central curvature radius at highest concavity (HCR), PD, DA, IR, ambrosia relational thickness-horizontal, first applanation stiffness parameter, corvis biomechanical index, topographic and biomechanics index and the first velocity of applanation. The general ocular Km in children positively correlated with corneal biomechanical parameters DA and IR and negatively correlated with A2L, HCR, and PD. There was a positive correlation between the general ocular measurement parameters ΔSE and corneal biomechanical parameters ΔA2V and ΔA2L, and a negative correlation with ΔIR. The increase in general ocular measurement parameter ΔKm positively correlated with changes in corneal biomechanical parameters, ΔDA and ΔIR, and negatively correlated with ΔHCR and ΔPD.

CONCLUSION

Myopia development in children was associated with multiple corneal biomechanical parameters.

Reappraisal of the historical myopia epidemic in native Arctic communities

PURPOSE

This study was developed to explain the extraordinary rise in myopia prevalence beginning after 1950 in Indigenous Arctic communities considering recent findings about the risk factors for school myopia development. Myopia prevalence changed drastically from a historical low of less than 3% to more than 50% in new generations of young adults following the Second World War. At that time, this increase was attributed to concurrent alterations in the environment and way of life which occurred in an aggressive programme of de-culturalization and re-acculturation through residential school programmes that introduced mental, emotional and physical stressors. However, the predominant idea that myopia was genetic in nature won the discussion of the day, and research in the area of environmental changes was dismissed. There may have also been an association between myopia progression and the introduction of extreme mental, emotional and physical stressors at the time.

RECENT FINDINGS

Since 1978, animal models of myopia have demonstrated that myopiagenesis has a strong environmental component. Furthermore, multiple studies in human populations have shown since 2005 how myopia could be produced by a combination of limited exposure to the outdoors and heavy emphasis on academic subjects associated with intense reading habits. This new knowledge was applied in the present study to unravel the causes of the historical myopia epidemics in Inuit communities.

SUMMARY

After reviewing the available published data on myopia prevalence in circumpolar Inuit populations in the 20th century, the most likely causes for the Inuit myopia epidemic were the combination of increased near work (from almost none to daily reading) and the move from a mostly outdoor to a much more indoor way of life, exacerbated by fewer hours of sunshine during waking hours, the lower illuminance in the Arctic and the extreme psychophysical stress due to the conditions in the Residential Schools.

The impact of spectacle lenses for myopia control on visual functions

Purpose

Spectacle lenses containing multiple small peripheral elements have been developed for myopia control in children. It is important that their effect on vision be quantified by (i) fixation through the peripheral portion, thereby using foveal vision and (ii) by fixation through the central portion and presentation of peripheral targets.

Methods

The above approaches were used in five studies to evaluate two novel spectacle lens designs: spectacle lenses with Highly Aspherical Lenslets (HAL) and Slightly Aspherical Lenslets (SAL). A single vision lens served as a control. Visually normal adults participated in each study. The first two studies had subjects fixate through the periphery of the lenses. High and low (10%) contrast visual acuity was measured with the Freiburg Vision Test and reading speed for high and low contrast words measured with a sentence generator. The other three studies assessed peripheral vision while subjects fixated through the central portion of the lens. Peripheral contrast sensitivity was measured using two cycles per degree drifting Gabor stimuli. Peripheral motion perception was further evaluated using random dot stimuli. Finally, attention was measured using an established test of useful field of view with three levels of complexity.

Results

The periphery of the HAL lens significantly reduced low contrast visual acuity, but not high contrast visual acuity, while the effect of the SAL lens was not significant for either. Neither test lens affected reading speed for high contrast words, but the HAL lens significantly affected performance for low contrast words. Neither test lens affected peripheral motion perception or useful field of view.

Conclusions

Low contrast visual acuity and reading was slightly reduced while high contrast visual acuity was unaffected when fixating through the periphery of the novel lens designs. None of the peripheral measures of vision was affected by the novel lens designs.

Familial Aggregation and Heritability of Myopia: A Local Population Survey in Shanxi, China

Purpose

To further determine the roles of environmental and genetic factors in the development of myopia, a comprehensive survey was performed. The guidance for myopia-susceptible people is established which might help prevent or delay the onset and development of myopia.

Methods

1,852 students were recruited using the multistage sampling approach from the Gaoping county in Shanxi. The refractive status of students was examined using an autorefractometer, and the refractive status of students' first-degree relatives was collected using a well-designed questionnaire. Family aggregation of myopia was analyzed according to the myopic status of the students (nonmyopic or myopic group). The prevalence and heritability of myopia in students and their first-degree relatives were further explored by subdividing into mild, moderate, and high myopia groups. Significance analysis among each group was performed by the χ² test using SPSS 25.0 software. Falconer's method was used to calculate the inheritability of myopia.

Results

A total of 1,852 subjects were recruited in this study, and 1,813 subjects were finally included. The family aggregation of myopia in the myopic student group (34.7%) was significantly higher than that in the nonmyopic group (8.5%). The prevalence of mild, moderate, and high myopia in children (students and siblings) was higher than that in their parents. The rate of high myopia (6.33%) was significantly higher among students with one or both myopic parents than those without myopic parents (3.85%). The heritability of mild, moderate, and high myopia among parents-offspring was 3.72%, 20.47%, and 48.00%, respectively. The heritability of mild, moderate, and high myopia among siblings was 17.50%, 86.09%, and 78.75%, which is significantly higher than that among parents-offspring. In addition to genetic factors, extensive near-work time, higher education pressure, and minimal outdoor activities contribute significantly to mild and moderate myopia.

Conclusions

Myopia is of high risk due to familial aggregation. Students with a family history of myopia are more likely to have high myopia than those without family history. The occurrence and development of high myopia are affected by both the genetic and environmental factors, which could either weaken or strengthen myopia. Therefore, students with a family history of myopia should pay close attention to their eye health to avoid the occurrence of myopia and the deepening of diopter, which may lead to high myopia and its related complications.

The Risks and Benefits of Myopia Control

PURPOSE

The prevalence of myopia is increasing around the world, stimulating interest in methods to slow its progression. The primary justification for slowing myopia progression is to reduce the risk of vision loss through sight-threatening ocular pathologic features in later life. The article analyzes whether the potential benefits of slowing myopia progression by 1 diopter (D) justify the potential risks associated with treatments.

METHODS

First, the known risks associated with various methods of myopia control are summarized, with emphasis on contact lens wear. Based on available data, the risk of visual impairment and predicted years of visual impairment are estimated for a range of incidence levels. Next, the increased risk of potentially sight-threatening conditions associated with different levels of myopia are reviewed. Finally, a model of the risk of visual impairment as a function of myopia level is developed, and the years of visual impairment associated with various levels of myopia and the years of visual impairment that could be prevented with achievable levels of myopia control are estimated.

RESULTS

Assuming an incidence of microbial keratitis between 1 and 25 per 10 000 patient-years and that 15% of cases result in vision loss leads to the conclusion that between 38 and 945 patients need to be exposed to 5 years of wear to produce 5 years of vision loss. Each additional 1 D of myopia is associated with a 58%, 20%, 21%, and 30% increase in the risk of myopic maculopathy, open-angle glaucoma, posterior subcapsular cataract, and retinal detachment, respectively. The predicted mean years of visual impairment ranges from 4.42 in a person with myopia of -3 D to 9.56 in a person with myopia of -8 D, and a 1-D reduction would lower these by 0.74 and 1.21 years, respectively.

CONCLUSIONS

The potential benefits of myopia control outweigh the risks: the number needed to treat to prevent 5 years of visual impairment is between 4.1 and 6.8, whereas fewer than 1 in 38 will experience a loss of vision as a result of myopia control.