Preventing Myopia

Exploratory study of ultraviolet B (UVB) radiation and age of onset of bipolar disorder

BACKGROUND

Sunlight contains ultraviolet B (UVB) radiation that triggers the production of vitamin D by skin. Vitamin D has widespread effects on brain function in both developing and adult brains. However, many people live at latitudes (about > 40 N or S) that do not receive enough UVB in winter to produce vitamin D. This exploratory study investigated the association between the age of onset of bipolar I disorder and the threshold for UVB sufficient for vitamin D production in a large global sample.

METHODS

Data for 6972 patients with bipolar I disorder were obtained at 75 collection sites in 41 countries in both hemispheres. The best model to assess the relation between the threshold for UVB sufficient for vitamin D production and age of onset included 1 or more months below the threshold, family history of mood disorders, and birth cohort. All coefficients estimated at P ≤ 0.001.

RESULTS

The 6972 patients had an onset in 582 locations in 70 countries, with a mean age of onset of 25.6 years. Of the onset locations, 34.0% had at least 1 month below the threshold for UVB sufficient for vitamin D production. The age of onset at locations with 1 or more months of less than or equal to the threshold for UVB was 1.66 years younger.

CONCLUSION

UVB and vitamin D may have an important influence on the development of bipolar disorder. Study limitations included a lack of data on patient vitamin D levels, lifestyles, or supplement use. More study of the impacts of UVB and vitamin D in bipolar disorder is needed to evaluate this supposition.

Effects of behaviors and surrounding environment on myopia before and during the COVID-19 pandemic: a longitudinal analysis of children and adolescents in China

Aim

To investigate the relationship between related factors and visual acuity of Chinese school students before and during the COVID-19 pandemic.

Subject and methods

Chinese students from primary and secondary schools were included from the Chinese National Surveys on Students' Constitution and Health CNSSCH (2019). A total of 1496 participants completed follow-ups in June and December 2020, respectively. Generalized estimating equations were used to test the differences in visual environment. Logistic regression models were utilized to examine the roles of behaviors and surrounding environment changes associated with myopia before and during the pandemic.

Results

The prevalence of myopia was 47.7%, 55.6%, and 57.2% in baseline and two follow-ups, respectively. Significant differences existed for gender, learning level, and region (all P < 0.05). The proportion of new myopia and myopia torsion was the highest in the primary schools. Multivariate logistic regression analysis found that screen time ≥ 4h/d (OR = 2.717), poor eye habits (OR = 1.477), insufficient lighting for studying at night (OR = 1.779), desk or roof lamps only (OR = 1.388), and poor sleep quality (OR = 4.512) were the risk factors for myopia (all P < 0.05), and eye exercises (OR = 0.417), milk intake (OR = 0.758), and eggs intake (OR = 0.735) were the protective factors for myopia (all P < 0.05).

Conclusion

Prevalence of myopia increased among Chinese students before and during the COVID-19. It is necessary to pay more attention to the pupils' visual acuity, especially in primary school students, in the future.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-023-01900-w.

Current Insights into Optimal Lighting for Promoting Sleep and Circadian Health: Brighter Days and the Importance of Sunlight in the Built Environment

This perspective considers the possibility that daytime's intrusion into night made possible by electric lighting may not be as pernicious to sleep and circadian health as the encroachment of nighttime into day wrought by 20th century architectural practices that have left many people estranged from sunlight.

A Three-Dimensional-reconstruction-based study on the ocular volume of Chinese children with high myopia

BACKGROUND

Highly myopic eyes differ in morphology from emmetropic eyes, and the correct estimation of the vitreous volume is difficult. To explore an effective method to estimate ocular volume using refractive factors in children.

METHODS

This is a retrospective study of children with high myopia who visited the Shenzhen Shekou People's Hospital (July-December 2018) before undergoing posterior scleral reinforcement surgery. Data on refractive factors and ocular 3D reconstruction imaging based on high-end CT were collected for linear correlation and linear regression analyses.

RESULTS

Ten patients (20 eyes) were included. There are nine males and one female. They were 4 to 12 years of age. The spherical equivalent ranges from + 0.25 to -20.00 D. The cylindrical equivalent ranges from - 0.50 to -6.25 D. The AL(axial length, AL) ranges from 21.78 to 33.90 mm. The corneal curvature (mean) ranges from 42.44 to 46.75. The 3D reconstruction of the CT images shows that the ocular volume ranges from 4.591 to 10.988 ml. The ocular volume of the 20 eyes decreases with the increase of diopter and total curvature, both presenting a linear trend, with the Pearson correlation coefficients being - 0.776 (P < 0.001) and - 0.633 (P = 0.003), respectively. The ocular volume of the 20 eyes increases with the increasing AL, also presenting a linear trend, with the Pearson correlation coefficient being 0.939 (P < 0.001).

CONCLUSIONS

In children, the ocular volume is negatively and linearly correlated with the diopter and curvature, and positively and linearly correlated with the AL.

Energy Savings in an Office Building with High WWR Using Glazing Systems Combining Thermochromic and Electrochromic Layers

This paper assesses energy savings in terms of heating, cooling, and artificial lighting achieved in an office building with a high Window to Wall Ratio (WWR), located in Athens and Stockholm. Six different configurations of triple pane windows combining thermochromic, electrochromic, and low-e coatings in Insulated Glass Units (IGUs) are examined to quantify the potential of increasing energy savings in office buildings. The combination of electrochromic and thermochromic layers on the outer pane of the triple IGU, achieved an 18.5% and 8.1% reduction in annual primary energy use for Athens and Stockholm, respectively. The used switching strategy ensured the visual comfort of the employees and provided adequate daylight in both cases. It was found that in Stockholm the cooling system can be downsized considerably, achieving important cost reduction in the HVAC system. The analysis also takes into account the reduction of thermal storage in the building envelope due to the switchable windows. This reduction is beneficial in the case of Athens, but it can reduce energy savings in Stockholm. Therefore, for colder climates, it is important to increase window heat gains through the development of layers with higher g-value in the clear state and through the application of appropriate switching strategies.

A Pilot Study on the Efficacy and Safety of 0.01% Atropine in German Schoolchildren with Progressive Myopia

INTRODUCTION

Although the interest is growing in topical low-dose atropine to control myopia in schoolchildren worldwide, its use in children of European ancestry remains controversial and solid evidence is sparse. The Oxford Centre for Evidence Based Medicine (OCEBM) classifies the evidence for this therapy as level I for East Asian populations, but only level IV in non-Asian populations.

METHODS

Fifty-six children, aged a median of 11 years (range 6-17), were analysed after 12 months of topical treatment with 0.01% preservative-free atropine in both eyes at bedtime every day. Efficacy was assessed during treatment every 6 months. In a subset of 20 patients, treatment of the second eye was delayed by 1 day to enable a controlled safety assessment of side effects such as pupil dilation, hypoaccommodation, and near vision reduction.

RESULTS

Prior to treatment, the mean myopic progression was estimated as 1.05 D/year; after 12 months of treatment with 0.01% atropine, it was 0.40 D/year (p < 0.0001). The only consistently measurable side effect was the induction of 1 mm pupil dilatation, which was only noticeable in comparison to the non-treated eye during the safety investigation.

CONCLUSIONS

Topical low-dose atropine appears to be safe and efficacious also in a cohort of European schoolchildren. These data should motivate researchers to conduct more randomised clinical trials.

Reading and Myopia: Contrast Polarity Matters

In myopia the eye grows too long, generating poorly focused retinal images when people try to look at a distance. Myopia is tightly linked to the educational status and is on the rise worldwide. It is still not clear which kind of visual experience stimulates eye growth in children and students when they study. We propose a new and perhaps unexpected reason. Work in animal models has shown that selective activation of ON or OFF pathways has also selective effects on eye growth. This is likely to be true also in humans. Using custom-developed software to process video frames of the visual environment in realtime we quantified relative ON and OFF stimulus strengths. We found that ON and OFF inputs were largely balanced in natural environments. However, black text on white paper heavily overstimulated retinal OFF pathways. Conversely, white text on black paper overstimulated ON pathways. Using optical coherence tomography (OCT) in young human subjects, we found that the choroid, the heavily perfused layer behind the retina in the eye, becomes about 16 µm thinner in only one hour when subjects read black text on white background but about 10 µm thicker when they read white text from black background. Studies both in animal models and in humans have shown that thinner choroids are associated with myopia development and thicker choroids with myopia inhibition. Therefore, reading white text from a black screen or tablet may be a way to inhibit myopia, while conventional black text on white background may stimulate myopia.