Welcome to the world of children's vision!

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.


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

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.”



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/

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.



Photo JPL-blogueBy Charles Bankhead, Staff Writer, MedPage Today

Published: April 01, 2013

Parent behavior training (PBT) topped medication and other interventions for preschool children at risk of attention-deficit/hyperactivity disorder (ADHD), a systematic literature review showed.

Eight methodologically sound studies of PBT produced the best and most consistent strength of evidence for efficacy, reported Alice Charach, MD, of the Hospital for Sick Children in Toronto, and colleagues online in the journal Pediatrics.

However, the investigators found only one good study of medical treatment with methylphenidate (Ritalin), resulting in a low strength of evidence, while combined home and school/daycare interventions yielded inconsistent results.

“The evidence-based PBT interventions included in this review improve parenting skills and improve child disruptive behavior, including core symptoms of ADHD,” the authors concluded. “Community physicians are in an excellent position to initiate the assessments required, guide parents to evidence-based programs where available, monitor these conditions over time, and advocate for increased resources in communities where they do not yet exist.”

A variety of interventions for ADHD have been developed and evaluated in children and adolescents. However, no information about the comparative efficacy of PBT and other types of interventions has been reported.

Given the paucity of evidence to inform decision making, the Agency for Healthcare Research and Quality sponsored a review and critical examination of published studies involving interventions for ADHD. Specifically, the authors were charged with evaluating the comparative effectiveness of, and adverse events associated with, interventions for preschool children at high risk of ADHD.

To enhance the generalizability of the review, Charach and colleagues included studies of children who met criteria for clinically impairing symptoms of disruptive behavior, including ADHD symptoms.

A single key question guided the review: among children younger than 6 years with ADHD or disruptive behavior disorder, what are the effectiveness and adverse-event outcomes after treatment?

Charach and colleagues searched several databases for relevant studies reported from 1980 to Nov. 24, 2011. They limited the review to interventions for children younger than 6 with “clinically significant” disruptive behavior, as determined by:

  • Referral for treatment
  • Reliable and valid screening instruments
  • A diagnosis of ADHD, oppositional defiant disorder, or conduct disorder (following accepted criteria in appropriate books)

Most of the studies included were randomized controlled trials. Interventions reviewed included pharmacologic and nonpharmacologic treatment. Alternative/complementary interventions were excluded.

The review identified 55 publications that met inclusion criteria: 34 described PBT interventions, 15 involved treatment with psychostimulants (primarily immediate-release methylphenidate), and six described combinations of PBT and day care- or school-based interventions. The investigators included all 55 publications in a qualitative synthesis and 14 of the 55 in a meta-analysis.

Analysis of 13 good or fair-quality trials of PBT involving 558 children resulted in a moderate effect size (SMD -0.75) in favor of the intervention. An analysis limited to eight good-quality studies produced an SMD of -0.68 in favor of the intervention. The investigators found minimal heterogeneity among the studies.

The authors acknowledged that the PBT trials had some limitations in methodology including small sample sizes, use of wait-list controls, and reliance on parent report for child behavior outcomes, with minimal information about child behavior in classroom or daycare settings.

The 15 articles on psychostimulants involved 10 separate studies, the largest being the Preschool ADHD Treatment Study (PATS), which involved 165 patients. PATS was the only study that the authors considered high-quality evidence.

PATS evaluated several doses of methylphenidate with the objective of identifying the optimal dose. The best dose was associated with a small positive effect for teacher- but not parent-rated ADHD symptoms, no improvement in parental stress, and worsening of parent-rated child mood. Clinicians rated the children improved with a moderate to large effect.

For more information concerning parent training:


Source: Charach A, et al. “Interventions for preschool children at high risk for ADHD: a comparative effectiveness review” Pediatrics 2013.


Photo JPL-blogueThe eye’s shape depends on growth that occurs primarily during infancy, and to a lesser extent through adolescence. We think that growth is ruled in part by genetic instructions that humans have evolved over many millennia; if the genetic blueprint is defective, eyesight can certainly suffer. But growth of the eye also depends heavily on external cues — what scientists call visual feedback. The bombardment of light, with its colors and contrasts, and use of the eyes (reading, computer work, etc.) help guide proper or improper eye growth.

Scientists are now convinced that something about the visual environment and the use of the eys in this environment has changed drastically in recent decades, and those changes are driving the onslaught of nearsightedness seen in teens and young adults. From the early 1970s to the turn of the century, myopia prevalence in the United States rose from 25 percent to nearly 42 percent among people ages 12 to 54, a substantial shift in just one generation. The rate among U.S. young adults is 38 percent, up from 28 percent in the 1970s. On the other side of the globe, myopia rates in Singapore, which has gone from a sleepy port city to a center for international commerce, have risen from 43 percent among military conscripts (all young men) in the late 1980s to more than 80 percent today.


Meanwhile, older generations haven’t experienced a sharp rise in the disorder. The rate in people over age 40 inChina and the United States is at about one-fourth.

Rural vs urban life

Studies suggest that rates of nearsightedness differ in ethnically related populations living in rural versus urban areas (data from country to country may not be comparable). City living appears to have a detrimental effect on visual problems (I. Morgan and K. Rose/Progress in Retinal and Eye Research 2005).

Because such increases also have not shown up in rural areas, scientists think the trend reflects new behaviors among young urbanites. With more people moving to cities, the trend is likely to worsen. For some, nearsightedness will be a mere inconvenience. But others, who develop high-degree myopia, will have worsening vision over time and a greater risk of cataracts, glaucoma or a detached retina later in life. Of those young men in Seoul and students in Shanghai who are nearsighted, roughly one in five already has high-degree myopia.

Vie rurale et urbaine

This graph shows the prevalence of myopia in China, Vietnam, India and Nepal whether people live in a rural or urban area. We see that the people who live in rural areas (with a school system probably more demanding) have a higher prevalence.

“There will be an epidemic of pathological myopia and associated blindness in the next few decades in Asia,” says Seang-Mei Saw, a physician and epidemiologist at the National University of Singapore.

The new wave isn’t genetic, Morgan says. “The gene pool can’t change that much in a generation, not even in several,” he says.

The other behavioral change that may not mesh well is near work. Human forebears didn’t read, and even those who chipped arrow points or did other fine work probably didn’t do it all day, every day. Frequent near work arrived with civilization; in many societies, it came about in the last century or two. A lot of myopia develops during childhood, and there may be some science behind the stereotypical bookworm with thick glasses. Myopia can also show up in adulthood, depending on the quantity of near work done. This is called occupational myopia.

Recent work by several researchers argues that “reading, writing and computer work will contribute to myopia, and that children who regularly spend much time on computers have a higher risk of myopia.”

 A world tour…

Source: Epidemiology (http://en.wikipedia.org/wiki/Myopia)

The global prevalence of refractive errors has been estimated from 800 million to 2.3 billion. The incidence of myopia within sampled population often varies with age, country, sex, race, ethnicity, occupation, environment, and other factors. Variability in testing and data collection methods makes comparisons of prevalence and progression difficult.

The prevalence of myopia has been reported as high as 70–90% in some Asian countries, 30–40% in Europe and the United States, and 10–20% in Africa. Myopia is less common in African people. In Americans between the ages of 12 and 54, myopia has been found to affect African Americans less than Caucasians.


In some parts of Asia, myopia is very common. Singapore is believed to have the highest prevalence of myopia in the world; up to 80% of people there have myopia, but the accurate figure is unknown. China’s myopia rate is 31%: 400 million of its 1.3 billion people are myopic. The prevalence of myopia in high school in China is 77.3%, and in college is more than 80%. However, some research suggests the prevalence of myopia in India in the general population is only 6.9%.


A recent study involving first-year undergraduate students in the United Kingdom found 50% of British whites and 53.4% of British Asians were myopic.

United States

Myopia is common in the United States, with research suggesting this condition has increased dramatically in recent decades. In 1971-1972, the National Health and Nutrition Examination Survey provided the earliest nationally representative estimates for myopia prevalence in the U.S., and found the prevalence in persons aged 12–54 was 25.0%. Using the same method, in 1999-2004, myopia prevalence was estimated to have climbed to 41.6%.


In Australia, the overall prevalence of myopia (worse than −0.50 diopters) has been estimated to be 17%. In one recent study, less than one in 10 (8.4%) Australian children between the ages of four and 12 were found to have myopia greater than −0.50 diopters. A recent review found 16.4% of Australians aged 40 or over have at least −1.00 diopters of myopia and 2.5% have at least −5.00 diopters.

Epidemic myopia in Asia

Source: http://blogs.discovermagazine.com/80beats/2012/05/12/why-are-90-of-asian-schoolchildren-nearsighted-from-doing-what-youre-doing-now/#.UTNmJ5aEXjY (Why Are 90% of Asian Schoolchildren Nearsighted? From Doing What You’re Doing Now –  By Sarah Zhang)

The sheer prevalence of nearsightedness, or myopia, among Asian schoolchildren (in Singapore, China, Taiwan, Hong Kong, Japan, and Korea) is stunning: 80 to 90% according to a recent review in the journal Lancet. In comparison, that number is just 20 to 30% in the UK. Myopia has also been on the rise in both Asia and Europe over the past few years.

In Singapore, myopia has shot up in the last 30 years among all three major ethnic groups—Chinese, Indian, and Malay—which highly suggests a environmental cause. Singaporean schoolchildren who read more than two books per week were also more likely to have myopia. How one reads physically, may have an impact too: ultra-orthodox Jewish boys, who study the Torah intensely and at a close distance while swaying, have higher myopia numbers than the girls, who don’t. Together, these observational studies suggest that high myopia rates in Asian schoolchildren are likely related to their intense educational systems.


Change in prevalence of myopia among three ethnic groups in Singapore. The following numbers Figures are approximate and are taken from the illustration above.

                                       China             India              Malaysia

1987-1992                     48%                29%                  25%

1996-1997                     80 %              70%                  65%

2009-2010                     85%               75%                  70%

Also adapted from : http://www.sciencenews.org/view/feature/id/347738/description/Urban_Eyes – By Nathan Seppa


Photo JPL-blogueFor about 5 years, a new theory was launched: kids who do not play outdoors regularly are on average more myopic (or less farsighted) than those who practice outdoor activity on a regular and prolonged basis. Children with few outdoor activities and who practice activities requiring near vision (reading, video games on portable console, etc.) were three times more likely to be myopic as those who practice many outdoor activities and some reading activity.

Professor Ian Morgan (from the Australian National University), highlights another risk factor: for him the crucial factor is simply the lack of natural light. A neurotransmitter produced in the retina under the influence of light, dopamine, could avoid excessive growth of the eye in childhood. If spending hours reading, playing or working on a screen promotes myopia, according to Morgan, this is indirectly because children spend much less time outside {1}.

These data were corroborated with those of a study of adolescents in Singapore, which were much less myopic (or farsightedness) when they practiced much more outdoor activities. {2}

It seems that this is the time that is spent outside that protects against myopia, rather than the sport itself (no influence of indoor sports on the prevalence of myopia). This was corroborated by a more recent study by Guggenheim et al. {3}

  1. Rose et al. Outdoor activity reduces the prevalence of myopia in children. Ophhalmology 2008 115: 1279–1285.
  2. Dirani et al. Outdoor activity andmyopia in Singapore teenage children. Br J Ophthalmol. 2009; 93: 997–1000.
  3. Guggenheim JA, Northstone K, McMahon G, Ness AR, Deere K, Mattocks C, St Pourcain B, Williams C. Time outdoors and physical activity as predictors of incident myopia in childhood: A prospective cohort study Invest Ophthalmol Vis Sci. 2012 Apr 6.


Source: http://www.alancarlsonmd.com/wp-content/uploads/2011/06/im084057.jpg

New study

Another recent study (February 2013) conducted in Denmark shows that for children with myopia, vision deteriorated rapidly when the days were shorter (winter period) and more slowly during the summer months. This study aimed to determine whether daylight could slow the progression of myopia in children.

“Most likely it is the light exposure that causes the reduced myopia progression during periods with longer days,” said lead author Dr. Dongmei Cui, an ophthalmologist at SunYat-senUniversity in Guangzhou, China.

Cui and his colleagues analyzed data from a clinical trial that included more than 200 children aged 8 to 14 years old with myopia, or nearsightedness, in Denmark – where day length ranges from seven hours in winter to almost 18 hours in summer.

Over the six months with the least daylight, nearsightedness progressed by 0.32 diopter. In comparison, children’s vision deteriorated by 0.28 diopter over the sunniest months.

Accumulated hours of daylight ranged from 1660 to 2804 hours. Significant correlations were found between hours of daylight and myopia progression (P = 0.01). In children with an average of 2782 ±19 myopic progression was greater.

With the increase in the length of the eyeball (axial length) from the front to the back, myopia tends to worsen. During the winter period, the axial length among study participants increased by an average of 0.18 mm compared to 0.14 mm in the summer, according to results published in the journal Ophthalmology.

Note: if statistically there is a difference in the progression of myopia between the two groups, can we say that these results are clinically significant? No! Over a period of one year, we can estimate an increase of 0.60 diopter if the children of both groups react in the same way. The only difference is the seasonal variation during the year.


Source: http://www.cataract.com.sg/neuro.htm

The researchers did not analyze how much time the children spent outside, just how much they probably did based on the season. Danish children spend much more time outdoors in summer, and very little in winter, when temperatures hover around freezing for four months, according to Cui.

Past research on nearsightedness in children in the U.S. found the condition deteriorated more during the six months of the school year and less during the six months that include summer. But another study in Singapore, where days are about the same length all year, found no seasonal difference in the progression of nearsightedness.

The idea that daylight might protect children from worsening nearsightedness is a relatively new theory, said professor Jeffrey Cooper of the College of Optometry at the State University of New York in Manhattan.

Studies in mammals and birds have found that light exposure plays a role in the development of the eye, and that animals reared from a young age with frequent exposure to high intensity light may be somewhat protected from myopia. No similar effect has been seen with light exposure in adulthood.

The new study’s results can’t prove that daylight causes vision loss to slow down, Cooper said. “There is no evidence that increasing outside exposure will actually reduce the progression of myopia,” Cooper, who was not involved in the work.