Axial Length and Prevalence of Myopia among Schoolchildren in the Equatorial Region of Brazil

Myopia Is Suppressed by Digested Lactoferrin or Holo-Lactoferrin Administration

Myopia is becoming a leading cause of vision impairment. An effective intervention is needed. Lactoferrin (LF) is a protein that has been reported to inhibit myopia progression when taken orally. This study looked at the effects of different forms of LF, such as native LF and digested LF, on myopia in mice. Mice were given different forms of LF from 3 weeks of age, and myopia was induced with minus lenses from 4 weeks of age. Results showed that mice given digested LF or holo-LF had a less elongated axial length and thinned choroid, compared to those given native-LF. Gene expression analysis also showed that the groups given native-LF and its derivatives had lower levels of certain cytokines and growth factors associated with myopia. These results suggest that myopia can be more effectively suppressed by digested LF or holo-LF than native-LF.

Seasonal Variations in Ocular Axial Length Increase among Children in the Czech Republic

In recent decades, the prevalence of myopia has increased worldwide as well as in European countries, and it has become an important medical and socioeconomic problem. Our prospective single-center study analysed the changes in ocular axial length (AXL) in a population of Central European schoolchildren from 2016 to 2019. The study included 528 eyes of 264 children with a mean age of 12.2 years at the beginning of the study. Visual acuity, ocular AXL, anterior chamber depth, and the questionnaire were examined at 6-month intervals (in spring and autumn, following the winter and summer periods, respectively). The average ocular AXL was 23.329 mm (median: 23.315 mm) at the beginning of the study and 23.525 mm (median: 23.505 mm) at the end of the study. The change in ocular AXL per month was significantly higher (p < 0.0001) during the winter period (average: 0.013 mm, median: 0.011 mm) than during the summer period (average: -0.001 mm, median: 0.000 mm). We observed a significantly higher increase in ocular AXL in a Caucasian population during the winter period (with lower daylight exposure) than the summer period.

Global, Regional, and National Burdens of Blindness and Vision Loss in Children and Adolescents from 1990 to 2019: A Trend Analysis

PURPOSE

To provide estimates for regional and national burdens of blindness and vision loss among children and adolescents between 1990 and 2019 by disease, age, and sociodemographic index (SDI).

DESIGN

This was a retrospective demographic analysis based on aggregated data.

METHODS

This was a population-based study using 1990-2019 data on the burden of vision loss and blindness from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. The burden of vision loss and blindness was evaluated in terms of case numbers, rates per 100 000 population, and average annual percentage changes (AAPCs) in prevalence rates and years lived with disability (YLDs).

RESULTS

Globally, the rates of blindness and vision loss per 100 000 population decreased in all age groups between 1990 and 2019, with prevalence rates decreasing from 1091.4 (95% uncertainty interval [UI], 895.2-1326.1) to 1036.9 (95% UI, 847.8-1265.9, AAPC, -0.2) and YLDs decreasing from 44.5 (95% UI, 28.1-66.5) to 40.2 (95% UI, 25.1-60.7, AAPC, -0.4). Most of these reductions in prevalence rates (AAPC, -0.2, 95% confidence interval [CI], -0.2 to -0.1) and YLDs (AAPC, -0.2, 95% CI, -0.3 to -0.2) were due to decreases in refractive disorder. Notably, near-vision loss prevalence (AAPC, 0.3, 95% CI, 0.2-0.4) and YLDs (AAPC, 0.3, 95% CI, 0.2-0.4) substantially increased in all age groups. Children and adolescents in low- and low-middle SDI countries exhibited substantial decreases in the prevalence rates and YLDs of blindness and vision loss, but their counterparts in high- and middle-high SDI countries experienced a substantial increase in prevalence.

CONCLUSIONS

Globally, efforts in the past 3 decades have substantially decreased the burdens of blindness and vision loss among children and adolescents. However, there is extensive variation according to the kind of impairment, age group, and country SDI.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Myopia and Near Work: A Systematic Review and Meta-Analysis

BACKGROUND

Myopia is a global public health problem affecting quality of life and work productivity. Data is scarce regarding the effects of near work on myopia. Providing a larger meta-analysis with life-long perspective, including adults and occupational exposure seemed needed.

METHODS

We searched PubMed, Cochrane Library, Embase and Science Direct for studies reporting myopia prevalence in near work. Myopia was defined as a mean spherical equivalent ≤ -0.50 diopter. We performed a meta-analysis using random-effects model on myopia prevalence, myopia progression per year, and odds ratio (OR) of myopia in near work, completed by subgroup analyses and meta-regressions on patients' characteristics, type of work in adults, geographic zones, time and characteristics of near work.

RESULTS

We included 78 studies, representing a total of 254,037 participants, aged from 6 to 39 years. The global prevalence of myopia in near work was 35% (95% CI: 30 to 41%), with a prevalence of 31% (95% CI: 26 to 37%) in children and 46% (95% CI: 30 to 62%) in adults. Myopia progression was -0.39 diopters per year (-0.53 to -0.24 D/year), ranging from -0.44 (-0.57 to -0.31) in children to -0.25 D/year (-0.56 to 0.06) in adults. The odds of myopia in workers exposed vs. non-exposed to near work were increased by 26% (18 to 34%), by 31% (21 to 42%) in children and 21% (6 to 35%) in adults. Prevalence of myopia was higher in adults compared to children (Coefficient 0.15, 95% CI: 0.03 to 0.27).

CONCLUSIONS

Near work conditions, including occupational exposure in adults, could be associated with myopia. Targeted prevention should be implemented in the workplace.

Choroidal Thickness in Correlation with Axial Length and Myopia Degree

Background: Myopia is a condition in which the visual images come to a focus in front of the retina of the eye. This disease is a major cause of visual disability, which presents in 108 million persons globally. Purpose: This study aims to determine the relationship between the degree of myopia, the axial length, and the choroidal thickness (CT). Methods: This is an observational analytical study that made use of a cross-sectional design. A total of 59 participants with refractive errors underwent treatment at Hasanuddin University Hospital and 116 eyes were measured and analyzed. The choroidal thickness was measured using the Enhance Depth Imaging OCT (EDI-OCT) tool, which is divided into nine observational areas. Furthermore, all data obtained were compared using statistical analysis, such as the one-way ANOVA and Pearson correlation test (p < 0.05). Results: There was a significant relationship between the choroidal thickness with axial length (p < 0.05) and myopia degrees (p < 0.05). Conclusions: The thickness of the choroid decreases with an increase in the axial length and degree of myopia, which further indicates that the higher the myopia degree, the thinner the choroidal vasculature.

Relationship between axial length and spherical equivalent refraction in Chinese children

Purpose

To evaluate the relationship between axial length (AL) and spherical equivalent refraction (SER) in Chinese children.

Methods

This hospital-based cross-sectional study included 1208 eyes (from 617 Chinese boys and 591 Chinese girls), ranging between 2 and 12 years. All subjects were divided into subgroups according to the spherical equivalent refraction (SER) (hyperopia, emmetropia, and myopia) and age (2-6 years, 7-9 years, and 10-12 years). Comparisons were made between age, sex, and SER groups. Multiple linear regression analysis was used to evaluate the correlation of AL and SER for all groups.

Results

The mean AL and SER were significantly different among the three age groups: 2-6 years group (AL: 22.24 ​± ​1.59 ​mm; SER: 0.73 ​± ​2.67 D); 7-9 years group (AL: 23.49 ​± ​1.10 ​mm; SE: -0.68 ​± ​1.97 D) and 10-12 years group (AL: 24.33 ​± ​1.02 ​mm; SER: -1.72 ​± ​1.86 D). Boys showed longer AL compared with the girls (23.66 ​± ​1.51 ​mm vs 23.05 ​± ​1.32 ​mm). However, as for SER, the girls (-0.70 ​± ​2.17 D) showed smaller SER (more myopia) compared with the boys (-0.4 ​± ​2.48 D). After adjusting for age and sex, the SER tended to decrease (became more myopic) 1.23 D (95% CI: 1.15-1.30D) with a 1 ​mm increase of AL. Among the different SER groups, the SER tended to become more myopic per mm of AL by 1.09 D (95% CI: 0.97-1.21D) for the myopia group, 1.38 D (95% CI: 1.23-1.54 D) for the hyperopia group, and 0.05 D (95% CI: 0.02-0.08 D) for the emmetropic group. In addition, an increase of 1 ​mm elongation of AL showed a decrease of SER by 1.05 D (95% CI: 0.90-1.20 D) among 2 - 6-year-olds, by 1.40 D (95% CI: 1.30-1.51 D) among 7 - 9-year-olds, and by 1.37 D (95% CI: 1.21-1.52 D) among 10-12-year-olds. As for sexual differences, the girls 1.68 D, (95% CI: 1.57-1.79 D) showed a more significant myopic shift of SER with a 1 ​mm increase of AL compared with the boys (0.94 D, 95% CI: 0.84-1.04 D).

Conclusions

Our results indicated a strong linear relationship between SER and AL and an early-rising trend of myopia in Chinese children.