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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.

 

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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

Concussions and Vision – 2

Photo JPL-blogueA concussion is a traumatic brain injury that alters the way your brain functions. Effects are usually temporary but can include headaches and problems with concentration, memory, balance and coordination. Although concussions usually are caused by a blow to the head, they can also occur when the head and upper body are violently shaken. These injuries can cause a loss of consciousness, but most concussions do not. Because of this, some people have concussions and don’t realize it. Concussions are common, particularly if you play a contact sport, such as football. But every concussion injures your brain to some extent. This injury needs time and rest to heal properly. Most concussive traumatic brain injuries are mild, and people usually recover fully. The signs and symptoms of a concussion can be subtle and may not be immediately apparent. Symptoms can last for days, weeks or even longer. Concussion01Common symptoms after a concussive traumatic brain injury are headaches, loss of memory (amnesia) and confusion. The amnesia, which may or may not follow a loss of consciousness, usually involves the loss of memory of the event that caused the concussion. The post-concussion syndrome is a complex disorder in which various symptoms such as headaches and dizziness pain can last for weeks and sometimes months after the injury that caused the concussion. A concussion is a mild traumatic brain injury, usually following a blow to the head.

Loss of consciousness is not necessary for a diagnosis of concussion or post-concussion syndrome. In fact, the risk of post-concussion syndrome brain does not appear to be associated with the severity of the initial injury. In most people, symptoms of post-concussion syndrome occur in seven to ten days after the blow and may disappear within three months, but may also persist for a year or more.

Reduced cognitive abilities with visual activities

Visual perceptual deficits can be caused by concussions and have dramatic effects on school and even athletic success. Speed of visual processing and visual reaction time can be reduced. Processing speed may slow in an athlete both on and off the field. The speed with which an athlete processes visual information affects many aspects of competitive sport, including reading of the playing field, the judgment of the speed of a moving ball or puck, and judgment the speed of the other players in the field.

Post-traumatic visual syndrome and midline shift syndrome

Following a neurological event such as a traumatic brain injury, cerebrovascular accident, multiple sclerosis, cerebral palsy, etc., it has been noted by clinicians that persons frequently will report visual problems such as seeing objects appearing to move that are known to be stationary; seeing words in print run together; and experiencing intermittent blurring. More interesting symptoms are sometimes reported, such as attempting to walk on a floor that appears tilted and having significant difficulties with balance and spatial orientation when in crowded moving environments. These types of symptoms are not uncommon. Frequently, persons reporting these symptoms to eye care professionals (optometrists and ophthalmologists) have been told that their problems are not in their eyes and that their eyes appear to be healthy. What is often overlooked is dysfunction of the visual process causing one of two syndromes: Post Trauma Vision Syndrome (PTVS) and/or Visual Midline Shift Syndrome (VMSS). Recent research has documented PTVS utilizing Visual Evoked Potentials (VEP). This documentation concludes that the ambient visual process frequently becomes dysfunctional after a neurological event such as a TBI or CVA. Persons can often have visual symptoms that are related to dysfunction between one of two visual processes: ambient process and focal process. These two systems are responsible for the ability to organize ourselves in space for balance and movement, as well as to focalize on detail such as looking at a traffic light.

Post Trauma Vision Syndrome results when there is dysfunction between the ambient and focal process causing the person to over emphasize the details. Essentially individuals with PTVS begin to look at paragraphs of print almost as isolated letters on a page and have great difficulty organizing their reading ability. It has been found that the use of prisms and binasal occlusion can effectively demonstrate functional improvement, while also being documented on brain wave studies by increasing the amplitude (this is like turning up the volume on your radio). Concussion02 Visual Midline Shift Syndrome also results from dysfunction of the ambient visual process. It is caused by distortions of the spatial system causing the individual to misperceive their position in their spatial environment. This causes a shift in their concept of their perceived visual midline. This will frequently cause the person to lean to one side, forward and/or backward. It frequently can occur in conjunction with individuals that have had a hemiparesis (paralysis to one side following a TBI or CVA). The shifting concept of visual midline actually reinforces the paralysis, by using specially designed yoked prisms that can be prescribed, the midline is shifted to a more centered position thereby enabling individuals to frequently begin weight bearing on their affected side. This works very effectively in conjunction with physical and occupational therapy attempting to rehabilitate weight bearing for ambulation.

The symptoms of the syndrome shift of midline visual may include:

  • dizziness or nausea
  • spatial disorientation
  • always heading towards the right or left along a corridor
  • locomotion or posture problems as to lean back on your heels, forward or to one side when walking, either standing or sitting in a chair
  • perception of uneven pavement (or having a sloping side or the other)
  • neuromotor difficulties associated with balance, coordination and posture

Fortunately, many vision problems after a concussion can be resolved with rest and by allowing the brain to heal. But there are still many problems that can linger even after years, especially regarding spatial localization. Vision therapy, also called neuro-optometric rehabilitation, can be very effective in cases where visual symptoms persist, even when other symptoms such as dizziness or balance problems are solved.

Reading problems and concussion Reading deficits can come from various problems after stroke or injury or a blow to the head. It is crucial that the type of reading problem is diagnosed. Problems can occur individually or as part of a constellation of related problems PTVS. The treatment of PTVS by various neuro-optometric rehabilitation interventions can solve many of the problems. In the next article, we will continue discussing visual problems and concussions.

Source : Lagacé JP. Les commotions cérébrales et la vision – généralités. Revue L’Optométriste – Volume 37 No 2, Mars-avril 2015.

British study examines mobile phone effects on children

Photo JPL-blogueBritish scientists launched a major government-commissioned study on Tuesday into the effects of mobile phone usage on the developing brains of children.

About 2,500 children from London will be tested at the age of 11 and 12 and then again two years later, to assess how their cognitive abilities develop in relation to their changing use of phones and other wireless technologies.

blogue - fillette-iPhone

 Source : http://cypressinternalmedicine.com/wp-content/uploads/2011/11/photo-1.jpg

Professor Patrick Haggard, deputy director of the Institute of Cognitive Neuroscience at University College London, said it was the “largest follow-up study of its kind in adolescents worldwide”.

The World Health Organisation says there is no convincing evidence that mobile phones affect health, but existing data only goes back about 15 years.

In the study, the children will undertake classroom-based computerised tasks to measure cognitive abilities such as memory and attention.

“Cognition is essentially how we think, how we make decisions and how we process and recall information,” said Dr Mireille Toledano of Imperial College London, the principal investigator on the study.

Participants and their parents will also be asked questions about how they use mobile phones and other devices, and other aspects of their lifestyle.

An estimated 70 percent of all 11- to 12-year-olds in Britain now own a mobile phone, rising to 90 percent by the age of 14, according to the researchers.

The Study of Cognition, Adolescents and Mobile Phones (SCAMP) is being carried out by Imperial College London at the commission of the British Department of Health.

Letters were sent out to 160 different schools inviting them to enrol pupils, and tests will begin at the start of the new school year in September.

Imperial College is already involved in a separate international study, called Cosmos, into the possible long-term health effects of mobile phones on 290,000 adults in five European countries.

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.

Blogue - Apple Addict

Photograph from Thomas PLESSIS (T.P Photographie)
                               With permission
                     http://www.thomas-plessis.com

 

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.

Smartphones do affect vision in children

How to hold your phone so it doesn’t (completely) wreck your vision

Photo JPL-blogueSource:  http://www.marketwatch.com/story/dont-give-up-your-eyes-for-an-iphone-2013-08-23

Spending half the day staring into a 10 cm (four-inch) screen may also wreck one’s eyesight, new research suggests — and the devices may not be to blame so much as how we hold them.

David Allamby, an eye surgeon and the founder of Focus Clinics in London, recently coined the term “screen sightedness” and pointed out that according to his research, there has been a 35% increase in the number of people with advancing myopia since smartphones launched in 1997.

Allamby is concerned that use of portable devices could increase cases of myopia in children of another 50% in ten years!

Nearsightedness affects more than 30 % of the population of the U.S and more than 80% in Asia. The environmental factors that contribute include “close work,” or stress on the eye caused by reading or otherwise focusing on near visual tasks.

Using a smartphone strains the eyes in much the same way reading a book or staring at a computer monitor does, with one exception — the distance between the eye and the object. When a phone or other device is held close to one’s face, it forces the eye to work harder than usual to focus on text, says Mark Rosenfield, an optometrist. The discomfort can eventually result in fatigue.

enfant-iphone

Source: http://www.loupiote.com/photos/5391333755.shtml

People tend to hold smartphones considerably closer to their faces than they would a book or newspaper, even as close as seven or eight inches, Rosenfield says. And since smartphones have such a small screen, the importance of visual stress tends to be higher than for other devices.

Holding a smartphone farther away (but still using it the same amount) won’t necessarily prevent myopia entirely, Schaal said. But holding the phone at least 16 inches away from the face during use can be beneficial, Rosenfield says.

He also suggests taking breaks from using the phone. During those breaks, it is helpful to look into the distance, which relaxes the eye as it focuses on faraway detail instead of what is close.

Young children’s eyes may be spared early damage by limiting smartphone and tablet use, doctors say. Spending hours playing games or otherwise intently viewing a screen causes children’s eyes to exert effort for long periods. In the past, children focused on larger objects like blocks or toys, rather than such fine detail. They should be encouraged to engage in a variety of activities with different focusing targets of both near and far away objects.

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