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More evidence that outdoor time may help prevent nearsightedness

Kids who spend more time outdoors and who play sports are less likely to be near-sighted, according to a recent study in a large, diverse group of urban 6-year-olds.

“Lifestyle in early youth is very much associated with onset of myopia,” says Dr. Caroline Klaver of Erasmus Medical Center in Rotterdam.

“Not being outside, and performing lots of near work will increase risk a lot.”

While factors like being highly educated and of non-European heritage have traditionally been linked to nearsightedness, the new study suggests that how young children spend their time is likely to be the underlying source of these differences, the study team writes in the British Journal of Ophthalmology.

The researchers looked at 5,711 children in Rotterdam who have been participating since birth, along with their mothers, in a long-term study. At age 6, prevalence of myopia was 2.4% (n=137). Myopic children spent more time indoors and less outdoors than non-myopic children (p<0.01), had lower vitamin D (p=0.01), had a higher body mass index and participated less in sports (p=0.03).

The researchers used statistical techniques to analyze a wide variety of factors, including social and economic aspects of the household, ethnicity, lifestyle, parents’ education levels, children’s’ activities and any links between these and the likelihood a child would be nearsighted.

The study team found that myopic children spent less time outdoors, had lower levels of vitamin D, had a higher body mass index and were less likely to play sports than children who weren’t nearsighted. While being of non-European descent, having a mother with a low education level and low family income were also associated with myopia, the researchers found that lifestyle factors explained most of these risks.

The study was limited by the low number of children with myopia and the lack of information about parents’ nearsightedness – “a well-known myopia risk factor,” the authors note.

“Differences in myopia prevalence between ethnic groups that have commonly been assumed to be down to genetics may in fact be due to differences in lifestyle between ethnic groups,” Dr. Jeremy Guggenheim, an optometry professor at Cardiff University in the UK, told Reuters Health in an email.

“The new study and other recent work suggests that this preventative effect of time outdoors is beneficial even at very young ages, e.g. 3 – 6 years-old,” said Guggenheim, who studies the causes of myopia and sometimes collaborates with Klaver’s team, but was not involved in the current study.

“Too much close work, such as reading and using hand-held devices, may also be a risk – although the jury is still out on this question,” he added.

To help prevent myopia, Klaver said, parents should have children play outside for 15 hours a week, and limit “near work” to no longer than 45 continuous minutes.

“It’s important to keep in mind that this type of study can never pin-point the precise causes of myopia in the way that is possible using purpose-designed clinical trials,” Guggenheim said. “Nevertheless, the risk factors that were identified in the new study fit neatly with what has been learned in recent years from such trials.”

“Basically this study adds very nicely to the evidence that we already see from many other studies and many other countries that there is definitely a connection between outdoor activity and myopia in children,” said Susan Vitale at the U.S. National Eye Institute.

“The main thing to remember is that if parents have any concerns about their child’s vision it’s very important that they get a dilated eye exam from a health care professional,” Vitale said. Regular eye care is the most important thing people can do to maintain their eye health, she added.

(Reuters Health)

Pictures: https://commons.wikimedia.org

SOURCE: Tideman JWL, Polling JR, Hofman A, Jaddoe VW, Mackenbach JP, Klaver CC. Environmental factors explain socioeconomic prevalence differences in myopia in 6-year-old children. Br J Ophthalmol. 2017 Jun 12. pii: bjophthalmol-2017-310292. doi: 10.1136/bjophthalmol-2017-310292.

Other studies have also looked at the relationship between time outdoor and myopia (and many more…):

• Wu PC, Huang HM, Yu HJ, Fang PC, Chen CT. Epidemiology of Myopia. Asia Pac J Ophthalmol (Phila). 2016 Nov/Dec;5(6):386-393.

• Deng L, Pang Y. The role of outdoor activity in myopia prevention. Eye Sci. 2015 Dec;30(4):137-9.

• Isaacs D, Wood N. Let’s not be short-sighted: Increased outdoor activity reduces myopia. J Paediatr Child Health. 2016 Oct;52(10):969. doi: 10.1111/jpc.13358.

• Suhr Thykjaer A, Lundberg K, Grauslund J. Physical activity in relation to development and progression of myopia – a systematic review. Acta Ophthalmol. 2016 Dec 14. doi: 10.1111/aos.13316.

• Guo Y, Liu LJ, Tang P, Lv YY, Feng Y, Xu L, Jonas JB. Outdoor activity and myopia progression in 4-year follow-up of Chinese primary school children: The Beijing Children Eye Study. PLoS One. 2017 Apr 27;12(4):e0175921. doi: 10.1371/journal.pone.0175921. eCollection 2017.

 

Does handwriting matter?

Not very much, according to many educators. The Common Core standards, which have been adopted in most states, call for teaching legible writing, but only in kindergarten and first grade. After that, the emphasis quickly shifts to proficiency on the keyboard.

But neuroscientists say it is far too soon to declare handwriting a relic of the past. New evidence suggests that the links between handwriting and broader educational development run deep.

Children not only learn to read more quickly when they first learn to write by hand, but they also remain better able to generate ideas and retain information. In other words, it’s not just what we write that matters — but how.

“When we write, a unique neural circuit is automatically activated,” said Stanislas Dehaene, from the Collège de France in Paris. “There is a core recognition of the gesture in the written word, a sort of recognition by mental simulation in your brain.

“And it seems that this circuit is contributing in unique ways we didn’t realize,” he continued. “Learning is made easier.”

A 2012 study led by Karin James, from Indiana University, lent support to that view. Children who had not yet learned to read and write were presented with a letter or a shape on an index card and asked to reproduce it in one of three ways: trace the image on a page with a dotted outline, draw it on a blank white sheet, or type it on a computer. They were then placed in a brain scanner and shown the image again.

The researchers found that the initial duplication process mattered a great deal. When children had drawn a letter freehand, they exhibited increased activity in three areas of the brain that are activated in adults when they read and write: the left fusiform gyrus, the inferior frontal gyrus and the posterior parietal cortex.

By contrast, children who typed or traced the letter or shape showed no such effect. The activation was significantly weaker.

Dr. James attributes the differences to the messiness inherent in free-form handwriting: not only must we first plan and execute the action in a way that is not required when we have a traceable outline, but we are also likely to produce a result that is highly variable.

In another study, Dr. James is comparing children who physically form letters with those who only watch others doing it. Her observations suggest that it is only the actual effort that engages the brain’s motor pathways and delivers the learning benefits of handwriting.

The effect goes well beyond letter recognition. In a study that followed children in grades two through five, Virginia Berninger, a psychologist at the University of Washington, demonstrated that printing, cursive writing, and typing on a keyboard are all associated with distinct and separate brain patterns — and each results in a distinct end product. When the children composed text by hand, they not only consistently produced more words more quickly than they did on a keyboard, but expressed more ideas. And brain imaging in the oldest subjects suggested that the connection between writing and idea generation went even further. When these children were asked to come up with ideas for a composition, the ones with better handwriting exhibited greater neural activation in areas associated with working memory — and increased overall activation in the reading and writing networks.

Samples of handwriting by young children. Dr. James found that when children drew a letter freehand, they exhibited increased activity in three significant areas of the brain, which didn’t happen when they traced or typed the letter. Credit Karin James

It now appears that there may even be a difference between printing and cursive writing — a distinction of particular importance as the teaching of cursive disappears in curriculum after curriculum. In dysgraphia, a condition where the ability to write is impaired, usually after brain injury, the deficit can take on a curious form: In some people, cursive writing remains relatively unimpaired, while in others, printing does.

Dr. Berninger goes so far as to suggest that cursive writing may train self-control ability in a way that other modes of writing do not, and some researchers argue that it may even be a path to treating dyslexia. A 2012 review suggests that cursive may be particularly effective for individuals with developmental dysgraphia — motor-control difficulties in forming letters — and that it may aid in preventing the reversal and inversion of letters.

Two psychologists, Pam A. Mueller of Princeton and Daniel M. Oppenheimer of the University of California, Los Angeles, have reported that in both laboratory settings and real-world classrooms, students learn better when they take notes by hand than when they type on a keyboard. Contrary to earlier studies attributing the difference to the distracting effects of computers, the new research suggests that writing by hand allows the student to process a lecture’s contents and reframe it — a process of reflection and manipulation that can lead to better understanding and memory encoding.

Reflection: Instead of giving a computer for continuous use to children with academic difficulties, such as dysgraphia, the child may have to be trained to write as well as he can (while using his computer) instead of giving up! Motor training can only help the child to write better. But as today, things that do not require any effort seem to take precedence. So, it is up to you, parents, to lead this battle!

From:
Karin H. James KH, Engelhardt L. The effects of handwriting experience on functional brain development in pre-literate children. Trends in Neuroscience and Education. Volume 1, Issue 1, December 2012, Pages 32–42

Video Displays and Dry Eye in Children

Photo JPL-blogueSource: http://www.practiceupdate.com/journalscan/9378

In a population of Korean children in grades 5 and 6 (ages 9–11), the authors compared symptoms and use of video display terminals in those with dry eye disease (9.7%, as determined by ophthalmic exam) with children without clinically determined dry eye. The risk factors for dry eyes in this population were related more to smartphone use (including mean duration of use, as reported by questionnaire) than to either computer or television viewing.

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Photograph from Thomas PLESSIS (T.P Photographie)
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The authors remind to keep the possibility of dry eye, which seems to be related to increased smartphone use, in mind in this population.

It is not uncommon for children between the ages of 9 and 11 — the population studied here — to exhibit potential signs of dry eye, which might include frequent blinking. Parents of children in this age range might also notice frequent or deep blinking behaviors that can be associated with tics or spasmodic blinking due to stress or anxiety.

The authors provide evidence that some of the signs and symptoms of ocular or visual discomfort can be associated with dry eyes. However, the jury is out on correlation or causation because the rate of dry eye signs was significantly greater in children with more smartphone use. The authors note that other visual factors have been reported as potentially associated with sustained smartphone use, such as accommodative issues and transient myopia. Because dry eye disease is not widely recognized as a potential problem in this age range, it adds to considerations in differential diagnosis of visual and ocular problems in childhood.

Two-hundred eighty-eight children were classified in either a dry eye disease group or control group according to the diagnostic criteria of dry eye disease. The results of ocular examinations, including best-corrected visual acuity, slit-lamp examination, and tear break-up time, were compared between groups. The results of questionnaires concerning video display terminal use and ocular symptoms were also compared.

Twenty-eight children were included in the dry eye disease group and 260 children were included in the control group. Gender and best-corrected visual acuity were not significantly different between the two groups. Smartphone use was more common in the dry eye disease group (71%) than the control group (50%) (P = .036). The daily duration of smartphone use and total daily duration of video display terminal use were associated with increased risk of dry eye disease (P = .027 and .001, respectively), but the daily duration of computer and television use did not increase the risk of dry eye disease (P = .677 and .052, respectively).

The results showed that smartphone use is an important dry eye disease risk factor in children. Close observation and caution regarding video display terminal use, especially smartphones, are needed for children.

Study source: JH Moon, MY  Lee, NJ Moon. Association Between Video Display Terminal Use and Dry Eye Disease in School Children. J Pediatr Ophthalmol Strabismus 2014 Mar 01;51(2)87-92.

Mayo Clinic Study: In-School Eye Movement Training Improves Early Reading Fluency

Photo JPL-blogueIn a new Mayo Clinic study, researchers examined the physical act of reading to see if practicing eye movements in school could lead to better early reading fluency.

Reading fluency is defined as the ability to read easily, quickly, without errors and with good intonation.

Saccades or rapid eye movements are required for the physical act of reading. Previous studies have shown that the ability to perform complex tasks such as saccadic eye movements are not fully developed at the age when children begin to learn to read. Eye movements in younger children are imprecise, resulting in the need for the eyes to go back to re-read text, leading to slower performance. When translated into the task of reading, it slows the reading rate and leads to poor reading fluency and may affect reading comprehension and academic performance.

“There are studies that show that 34 percent of third graders are not proficient in reading, and if you are not proficient in reading by third or fourth grade there is a four times higher likelihood that you will drop out of high school,” says Amaal Starling, M.D., Mayo Clinic neurologist and co-author of the study published in Clinical Pediatrics.

Dr. Starling says that the purpose of the new study was to determine the effect of six weeks of in-school training using the King-Devick remediation software on reading fluency. This software allows people to practice rapid number naming which requires eye movements in a left to right orientation. It teaches the physical act of reading.

In this study, standardized instructions were used, and participants in the treatment group were asked to read randomized numbers from left to right at variable speeds without making any errors. The treatment protocol consisted of 20-minute individual training sessions administered by laypersons, three days each week for six weeks, for a total of six hours of training.

Randomized numbers are presented at variable speeds from left to right; the participants read the numbers as quickly as possible.


Examples of pages taken from the King-Devick Test

(Images deleted following a call from the company)

 

Students in the treatment group had significantly higher reading fluency scores after treatment and post-treatment scores were significantly higher compared with the control group. At the one-year follow-up, reading fluency scores were significantly higher than post-treatment scores for students in first grade. Additionally, these one-year follow-up scores were higher than pretreatment scores across all grades, with an average improvement of 17 percentile rank points in the treatment group.

“The results of this pilot study suggest that the King-Devick remediation software may be effective in significantly improving reading fluency through rigorous practice of eye movements,” says Dr. Starling. “What our study also found was that there was an even greater improvement between first and third grade versus third and fourth graders, which means there may be a critical learning period that will determine reading proficiency.”

“The outcome of this study suggests that early childhood intervention with a simple methodology of eye movement training via the remediation software, which is inexpensive and can be implemented in developed or developing cultures easily, might allow a lasting improvement in ability to read, with clear sociologic ramifications,” says Craig H. Smith, M.D., neuro-ophthalmologist, Chief Medical Officer, Aegis Creative, and Senior Advisor, Bill and Melinda Gates Foundation, and a co-author of the study.

The authors hypothesize that this improvement in reading fluency is a result of rigorous practice of eye movements and shifting visuospatial attention, which are vital to the act of reading.

Commentary:

Training activities by computer undoubtedly bring improvements, at least in regard to eye movements, but vision therapy performed in real space would probably be much more effective.

In addition, the recognition by the medicine (or at least the group of physicians who participated in this study) the effectiveness of vision therapy is a big step for optometry.

Those who dispute the link between vision and academics must critically review and change these misguided beliefs. We cannot afford to let unfounded, dogmatic opinions, professional animosities and political agendas stop our children from achieving single, clear, comfortable and binocular vision while attaining their highest academic level possible.

Yes, there is a link between vision and learning. And yes, vision therapy improves academic performance.

Source: http://www.ncbi.nlm.nih.gov/pubmed/24790022

Researchers recommend increasing time spent outdoors during school

Photo JPL-blogueDecidedly, studies on myopia and vitamin D or activities spent outside keep coming!

Results of a study involving 2,000 first-grade students prompted the researchers to suggest mandatory targets for the amount of time children spend outside during school hours.

Ian G. Morgan, PhD, of the Research School of Biology, Australian National University, Canberra, and the Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China, reported results of the Guangzhou Outdoor Activity Longitudinal Study here at the Association for Research in Vision and Ophthalmology meeting.

“The prevalence of myopia in East Asia has increased dramatically in the last 50 years, and a slower increase has been seen in Europe and North America,” Morgan said in his presentation.

The prevalence of high myopia, considered to be at least -6 D, is 20% in East Asia, he said, and prevention becomes essential.

The researchers recruited more than 2,000 first-grade students in 12 primary schools in Guangzhou. The school had been involved in previous studies, so records on visual acuity assessment dating back 20 years were available for children from this school, Morgan said.

One 45-minute class of outdoor activity was added at the end of the day, and children in the control group went home at the normal time, he said. The two groups of children were matched for prevalence of myopia, mean spherical equivalent and axial length.

Over the 3-year period, cumulative incident myopia was 39.5% in the control group and 30.4% in the intervention arm, a reduction of 23%, according to the study abstract.

“Differences in axial length did not quite reach statistical significance,” Morgan said. “It seemed to indicate that by increasing the amount of time outdoors, we were able to lower the level of incident myopia and prevalence of myopia. This is apparently a dose-response relationship.”

“We, therefore, recommend that myopia control programs based on increased time outdoors be developed in primary schools, at least in countries with currently high prevalence rates for myopia, with evidence-based mandatory targets for the amount of time children spend outdoors,” the authors concluded in their abstract.

 ?

Morgan asked: “Is the mechanism brighter light and increased dopamine release outdoors, or is it increased UV exposure outdoors? Evidence from animal studies favor the light-dopamine hypothesis, but a clinical trial of vitamin D needs to be done.”

From:

http://www.healio.com/optometry/optics/news/online/%7B5f21032e-c14c-4e33-96c2-345d7beaa63a%7D/researchers-recommend-increasing-time-spent-outdoors-during-school

New study finds vitamin D may be related to myopia in adolescents

Photo JPL-blogueRecently, researchers in South Korea have found that vitamin D levels may relate to severity of myopia.

Previous research has found that spending more time outdoors may help protect against developing myopia. This has led some researchers to speculate that vitamin D may play a role in myopia, as outdoor sun exposure is the main way for humans to produce vitamin D.

In the present study, researchers at the Catholic University of Korea in Seoul, South Korea looked at data from a national sample to determine if vitamin D relates to myopia. They used data from the Korea National Health and Nutrition Examination Survey (KNHANES). KNHANES is an ongoing population-wide survey that collects data on health and nutritional status of people in South Korea.

The researchers looked at data from 2,038 people aged 13 to 18 years old who had participated in KNHANES. The researchers examined their vitamin D levels, and noted whether they had myopia, and how severe their myopia was.

They wanted to know if vitamin D levels were related to the prevalence and severity of the condition. Of the 2,038 participants, 80.1% had myopia and 8.9% had very severe myopia. The researchers found that vitamin D levels were related to severity of myopia. This means lower vitamin D levels were related to more severe myopia among the participants.

“We found a significant association between low serum [vitamin D] concentration and myopia in Korean adolescents aged 13 to 18 years,” the researchers stated.

The researchers called for efforts to raise vitamin D levels among children through supplementation and outdoor activity in order to prevent the development of myopia.

To be followed…

Source:  http://www.vitamindcouncil.org/

Multifocal Contact Lens Myopia Control

Photo JPL-bloguePrevious studies on soft multifocal contact lens myopia control published in the peer-reviewed literature reported findings of noncommercial contact lenses worn for 1 year or less. This study sought to determine the progression of myopia and axial elongation of children fitted with commercially available distance center soft multifocal contact lenses for 2 years.

Eight- to eleven-year-old children with −1.00 D to −6.00 D spherical component and less than 1.00 D astigmatism were fitted with soft multifocal contact lenses with a +2.00 D add (Proclear Multifocal “D”; CooperVision, Fairport, NY). They were age- and gender-matched to participants from a previous study who were fitted with single-vision contact lenses (1 Day Acuvue; Vistakon, Jacksonville, FL). A-scan ultrasound and cycloplegic autorefraction were performed at baseline, after 1 year, and after 2 years. Multilevel modeling was used to compare the rate of change of myopia and axial length between single-vision and soft multifocal contact lens wearers.

Forty participants were fitted with soft multifocal contact lenses, and 13 did not contribute complete data (5 contributed 1 year of data). The adjusted mean ± standard error spherical equivalent progression of myopia at 2 years was −1.03 ± 0.06 D for the single-vision contact lens wearers and −0.51 ± 0.06 for the soft multifocal contact lens wearers (p < 0.0001). The adjusted mean axial elongation was 0.41 ± 0.03 and 0.29 ± 0.03 for the single-vision and soft multifocal contact lens wearers, respectively (p < 0.0016).

Soft multifocal contact lens wear resulted in a 50% reduction in the progression of myopia and a 29% reduction in axial elongation during the 2-year treatment period compared to a historical control group. Results from this and other investigations indicate a need for a long-term randomized clinical trial to investigate the potential for soft multifocal contact lens myopia control.

Source: Walline JJ, Greiner KL, McVey ME, Jones-Jordan LA. Multifocal contact lens myopia control. Optom Vis Sci. 2013 Nov;90(11):1207-14. doi: 10.1097/OPX.0000000000000036.