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Myopia: a world tour

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.

Myopia

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.

Asia

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%.

Europe

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%.

Australia

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.


Singapour

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

 

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Myopia and outdoor activities: new study

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.

myope-enfant

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.

myope-enfant2

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.

Reading processes and visual or surface «dyslexia» – part 2

Photo JPL-blogue

Lexical or whole-word reading

Competent reading essentially involves the whole-word or lexical process of reading which ensures fluent reading and a “direct” access to meaning. It recognizes the shape of the word and immediately find its sound correspondence in memory (or phonological), the meaning of the word being evoked, which is the ultimate goal of reading.

The whole-word process (or eidetic = photographic), both more automatic and faster, can even bypass the phonological pathway, which is more controlled and slower. Most of the time, the expert reader would not need to use his phonological knowledge to recognize written words. The observation of a double dissociation between visual and phonological dyslexia in patients with brain damage is an argument in favor of the neuropsychological existence of the two independent procedures for the recognition of written words (Coltheart, Masterson, Byng, Prior & Riddoch, 1983; Funnell, 1983; Shelton & Weinrich, 1997). Numerous studies supporting these models have also emphasized the optional phonological code while reading (Peereman, 1991, for a review).

Coltheart M, Masterson J, Byng S, Prior M, Riddoch J. Surface dyslexia. Q J Exp Psychol A. 1983 Aug;35(Pt 3):469-95.

Funnell E. Phonological processes in reading: new evidence from acquired dyslexia. Br J Psychol. 1983 May;74 (Pt 2):159-80.                     

Weinrich M, Shelton JR, McCall D, Cox DM. Generalization from single sentence to multisentence production in severely aphasic patients. Brain Lang. 1997 Jun 15;58(2):327-52.

Peereman R. Phonological assembly in reading: lexical contribution leads to violation of graphophonological rules. Mem Cognit. 1991 Nov;19(6):568-78.

When the child becomes able to recognize a word as a unit, he gradually builds his orthographic lexicon. The operation of this lexicon is not yet fully known, but it seems to be like a dictionary which exists in our brain, allowing rapid identification (the faster the more familiar word) and immediate access to meaning.

This procedure then develops to become more and efficient as reading becomes more competent. Ultimately, the adult reader would only use the “photographic” procedure, which is obviously much faster than going through words syllable by syllable (which remains necessary when we must read for example, new or meaningless words or of a foreign language).

http://www.coridys.asso.fr/pages/base_doc/txt_habib/entree.html

Imagine a child who reads the following sentence:

The locomotive arrives at the station

versus

The-lo-co-mo-ti-ve-ar-ri-ves-at-the-sta-tion“.

(or syllable by syllable)

 

Surface_01_en

In the first case, the child immediately recognizes the words and understands what he reads. In the second case, the child does not read words but syllables one by one. Difficult to quickly understand what is read.

Surface_02_en

Surface dyslexia

Surface dyslexia, in its pure form, is characterized by a selective impairment of reading irregular words while reading regular words and pseudo-words is relatively preserved. This selective difficulty reading irregular words translates a dysfunctionnal lexical reading procedure.

These children do not present associated disorders of oral language and have good capabilities in short term verbal and workong memory and have good phonological awareness. They also have difficulties in visual processing that make comparing sequences of letters or identify targets among others.

It is said that pure forms of surface dyslexia are relatively rare in clinical practice. But I can assure you that in my optometric practice, these children are much more numerous than the statistics show.

Visuo-attentional dyslexia

There is also, according to some authors, another form of dyslexia, called “visual-attentional” where the child has a good memory of the spelling of words and is able to transcribe sounds into words. For cons, the type of errors encountered in this disorder is reversals in groups of letters, omissions, additions, approximate reformulations, skippng lines while they read.  line breaks. The child may confuse letters and words with others closely resembling it. It would be a disorder affecting necessary attention for an effcient reading activity.

(In : http://www.ac-grenoble.fr/ia73/spip/IMG/pdf/dys_apedys.pdf)

These children also have oculomotor (eye movement) and visual discrimination problems, difficulties in visual attention, difficulties in copying material from a book or the blackboard.

It is difficult to conceive a child who has a serious visuo-attentional problem would not show a form of surface dyslexia. There is certainly a very close relationship between the two since both can prevent the establishment of a proper orthographic lexicon. They may also be different manifestations of the same problem called “visual dyslexia”. This close relationship between visual and attentional problems is reinforced by the significant progress in reading and spelling seen in a child with surface dyslexia following a trainign program focused on visual processing capabilities (Launay and Valdois , 1999)

Valdois S, Launay L. Évaluation et rééducation cognitives des dyslexies développementales: illustration à partir d’une étude de cas.  In : La rééducation neuropsychologie : Études de cas. AZOUVI P, PERRIER D, VAN DER LINDEN M (eds). Marseille, Solcoll, 1999 : 95-116).

 Visual-perceptual skills essential to insure adequate whole-word reading

It is probably unnecessary to say that the best readers are those who read in a whole-word fashion, this  method of reading is fast and understanding is also much better. But what is the action to take if a child uses no or has a poor orthographic lexicon? We must ensure that the related visual and perceptual skills are adequate. Otherwise, visual training will be needed to improve these skills.

What are the skills that have a close relationship with the development of orthographic lexicon? First, eye movements: reading requires a constant movement of the eyes along a line of text, which is done by a series of short jumps (saccades) interspersed with longer breaks during which takes place all intake of visual information. These jumps between fixations are very short, about one-thirtieth of a second. Saccades take approximately 250 to 300ms. Saccades are also an index of visual attention. We have tests that evaluate the speed, accuracy and fluency of reading. Eye movement problems hamper efficient learning and reading quality (failure to follow the text, loss of place, jump words or lines, etc.). For reading to be effective, eye movements must be flexible, fast and accurate.

Then visual attention and concentration allow the child to remain focused and attentive to every detail of what we see and as long as necessary. Attention and concentration are a preqequisite to good visual discrimination. In addition, visual attention is the link between perception (making information available) and cognition (use this information). It ensures maximum reception all the information from our visual environment. Visual concentration promotes maximum use of working memory to collect, store, retrieve and process the relevant information. It facilitates the work and especially the intellectual performance.

Short-term and sequential visual memories allow the child to recognize an item after a brief exposure, or to recall items in the same order and in the same sequence. For example, remembering the order of letters in a word or words in a sentence with a quicker understanding of what is read. Children who show difficulties in visual sequential memory may have difficulties copying information from the board or a book, to learn to read mulriple words or sentences and remember what they read. They may also have difficulties in creating their orthographic lexicon, which affects fluency and reading comprehension.

Visualization or mental imagery is the ability to create images of a word, a sentence or a paragraph in our head (our mental picture). This ensures good understanding of what is read and allows a better organization of information, making it easier to retain and build an efficient orthographic lexicon. This perceptual skill is also essential for mental arithmetic and spelling of words. If a child reads a story without being able to mentally see the scene described in the text, then this will influence contextual

In summary, the eyes must move effectively to ensure high quality of visual information, and the child must be able to remain attentive and focused on what he reads. Visual memory will also allow to recognize the same words in a text. Many children can not build a orthographic lexicon because they can not even recognize a word they just read and read again a few lines later. Visualization allows the child to “juggle with words” in his head. And finally, it is practicing reading every day that ensures efficiency in reading. More often we see the same words, the faster they will be included in the orthographic lexicon.

Conclusion

According to scientific research, three basic skills (among others) will thus directly influence reading performance in children: visual memory, visual attention and visualization. The best readers are capable of recognizing whole words easily (eidetic, global or whole-word reading). This accelerates visual decoding, requires less energy and promotes better understanding. Reading phonologically (syllable by syllable) slows down the reading process and does not guarantee an adequate understanding of a text. The best readers need not phonological awareness to read and can recognize most words without having to dissect them. That is why we have developed a particular portion of our vision therapy to enhance these perceptual abilities. We try to develop better whole-word reading to improve reading efficiency and comprehension.

Reading processes and visual or surface «dyslexia» – part 1

Photo JPL-blogue

“True“dyslexia is seemingly a “neurological” dysfunction (of course, we read with our brain, not just the eyes!) marked by the inability of the brain centers to efficiently decode print or phonetically make the connection between written symbols and their appropriate sounds. The connotation of the word “neurological” can be confusing: this word is too easily understood or related to a nervous system disease. Dyslexia may be caused by a nervous system dysfonction, but surely not a disease!

The origin of this problem, yet ardently debated in the literature, is probably multi-causal. It is unfortunate that the researchers are constantly looking at only a small aspect of dyslexia in their studies. We also know that not all children who have difficulty reading, however, suffer from phonological processing. Although the symptoms are similar, they may also have visual and perceptual problems that interfere with adequate learning, not just a deficit-based language, as some would have us believe…

Margaret Livingstone, et al, from the Department of Neurobiology, Harvard Medical School and the Dyslexia Research Laboratory, Beth Israel Hospital in Boston reports that poor visual processing plays a significant role in a large majority of children who struggle to read:   “Several perceptual studies have suggested that dyslexic subjects process visual information more slowly than normal subjects.  Such visual abnormalities were reported to be found in more than 75% of the reading-disabled children tested.”

Livingstone MS, Rosen GD, Drislane FW, et al. Physiological and anatomical evidence for a magnocellular defect in developmental dyslexia. Proc Natl Acad Sci USA 1991; 88:7943-7.

Moreover, all children with learning difficulties in primary school are not dyslexic, and vice versa, a child may be dyslexic without it being prolonged failure (especially if dyslexia is mild and if it can be compensated by the development of other skills intact).

Essentially, there is also a problem in the clinical definition of dyslexia. Everyone has their own definition and tests used in the diagnosis of such a condition do not always lead to a clear diagnosis… This imprecision in diagnosis can also certainly explain the variability in prevalence rates reported in the literature (this rate may actually increase from 4% (Yule and Rutter, 1973) to 20% (Shaywitz, 1996)).

Yule W, Rutter M, Berger M, Thompson J. Over- and under-achievement in reading: distribution in the general population. Br J Educ Psychol. 1974 Feb;44(1):1-12. 

Shaywitz SE. Dyslexia. Sci Am. 1996 Nov;275(5):98-104.

A child in early primary school may have some difficulty learning to read, this situation is common and there is no question of going overboard and put a label of  “dyslexia” for all these children.

Decoding process of reading: the dual-route model

The dual-route model is very frequently used as a reference model for decoding during reading. This model postulates the existence of two procedures involved in both reading and writing.

Odédys_en

Dual-route reading process

From : http://www.cognisciences.com: Outil de Dépistage des Dyslexies – Odedys2 – 2009

Phonological process

The phonological process is characterized by a sequential analytical processing or syllabic of a word or pseudo-word (invented word). It involves a system of rules for grapheme (a letter or two, sometimes three) – phoneme (sound related) explicitly learned in school.

The word “camel” when processed through this system will be segmented into graphemes <CA – MEL>, then each grapheme will be assigned to a phoneme which is most frequently associated in the language This allows to generate the sequence of the word.

Only the phonological process allows the processing of new words (words not previously learned or “pseudo-words” which are words invented for the purposes of experiment, for example: famsled, posvent or rolted).

Insofar as the treatment of new words is dedicated to this system, lists of pseudo-words are systematically tested for reading and dictation for children with difficulties, to test the integrity of the phonological process. Good performance in reading invented words indicates that the phonological process is operational, poor performance involves an inadequacy of this pathway.

It is known that the analytical (phonological) route plays a major role in early learning as it is chronologically the first. If we conceive that in adults both channels are relatively autonomous, it seems unlikely that these two pathways are also distinct in children who are learning to read.

Whole-word or eidetic process

The lexical procedure (or whole-word process) performs simultaneous processing of all the elements of the word. All units which compose the word are processed in parallel, leading to the activation of the orthographic lexicon stored in the brain and learned previously. The child sees the word and understands it immediately.

In reading, and after some visual processing, the representation of the word as a whole is activated in our orthographic lexicon (the “dictionary within our head”) and gives a very rapid access to the sound structure (phonology) corresponding to this word and its meaning. No need to decode the word syllable by syllable.

The way this lexicon functions is not yet fully known, but it seems to be like a dictionary to which we would refer for each word read, according to a “photographic” procedure, allowing rapid identification (the faster the more familiar is the word) and immediate access to meaning.

Each of the two procedures for reading (or writing) is implemented specifically for the treatment of certain types of words: the lexical route or process can only deal with words already learned and whose representations are available within the orthographic lexicon and its phonological correspondence. It is needed when reading or writing irregular words that are not pronounced the way they are written (for example, rough, soared, laugh). Irregular words that can only be handled by the lexical route is used in the evaluation of children with learning disabilities. Lists of irregular words are proposed or presented to test the integrity of the lexical route: a good performance when reading these words shows that the lexical procedure is operational; poor performance in reading irregular words compared to reading regular words or pseudo-words suggests a failure of the lexical procedure.

(Part 2 in next blog)

Headaches, again…

In the previous text, we shared a study on headaches in children and the lack of relevance to either having to wear glasses or changing the lens power of the glasses. One of the issues discussed was the biased scientific methodology and the art of making such statements without seeing further than one’s nose…

Contrary to the statement of the authors and of the American Association of Ophthalmology, there is a source more relevant and of more scientific relevance about headaches and vision of children that is free of any bias examiner. In 2009, a major study both from optometrists and ophthalmologists concerning convergence insufficiency and its symptoms, the CITT study (Convergence Insufficiency Treatment Trial) began. They created a questionnaire called CISS (Convergence Insufficiency Symptom Survey) to link the symptoms to convergence insufficiency. All one has to do to determine if the visual requirements are linked to headaches is to ask! The CISS questionnaire showed that it could be done reliably. You will find the questionnaire at the end of the text. Note the number of items that relate to visual discomfort. You can also download it from: http://www.aoa.org/x13917.xml

Q1: Do your yes feel tired when reading or doing close work?

Q2: Do your eyes feel uncomfortable when reading or doing close work?

Q3: Do you have headaches when reading or doing close work?

Wait a second! Why is it that the best standardized questionnaire in the history of joint studies of optometry and ophthalmology, studies funded by the U.S. government, directly ask a question about headaches associated with visual tasks, while the recent study talked about “proofs beyond doubt” that it is not relevant?

Let’s dispense with the simplistic notions of the latest press release, and set the record straight:

  1. Headaches can be associated with vision problems.  Unless you ask the question, you can’t get an answer.
  2. Pediatrician screening is not a substitute for a complete eye exam performed by an optometrist. A child who complains of headache associated with visual tasks near (reading, writing, drawing, etc.) might show a functional problem (alignment problem like convergence and/or focusing), while having no problem with distance visual acuity (vision of 20/20 or 100%).
  3. A change in glasses may sometimes not completely solve the headache. But often wearing new glasses for an individual who was not wearing any will solve the problem.
  4. If the underlying cause of headaches is a functional problem, the treatment of choice according to proved scientific studies is proven optometric vision therapy.

Adapted from VisionHelp Blog (a super blog!): http://visionhelp.wordpress.com/

The abstract of the study on the CISS questionnaire can be found here: http://www.ncbi.nlm.nih.gov/pubmed/19289977

Even in ophthalmology, here is what is said about eyestrain and headaches:

“The visual symptoms are caused by because focusing of the eyes becomes increasingly difficult due to fatigue especially at the end of the day after prolonged reading. Vision becomes blurred and sometimes even double. Vision at near can be uncomfortable.

Eyestrain occurs mainly in the late afternoon as near vision is constantly at work by efforts of focusing in work and in leisure with particularly computer screens, mobile phones, television, console games…

Eye symptoms reflecting visual fatigue include a feeling of discomfort, tension, and heaviness in the region of the eye, orbit or eyelids. There may be feeling of irritation, burning, stinging, and itching, sometimes with red eyes, some tearing or irritation due to dry eye. The subject may feel dull pain but not very intense that may become acute generally behind the eyes.

Headaches can be felt around the eyes, on the forehead above the eyebrow line, temples or behind the head. These headaches are related to eye strain, occur after a certain period of work at the end of the day, fade and disappear after cessation of work.” (Source: http://www.ophtalmologie.fr/fatigue-visuelle-yeux.html)

Glasses and headaches: confusion for all!

Does your child wear glasses? If so, has he or she ever complained of headaches that improved or were eliminated with a change of prescription glasses or wearing a pair of glasses for the first time? That would be very rare, at least according to a “study” presented at the meeting of the American Academy of Ophthalmology.

This study from the Albany Medical Center in New York believes that vision problems or eye are rarely the cause of recurrent headaches in children, although headaches usually strike while the child is doing schoolwork or other visual tasks.

Photo: www.visionhelp.wordpress.com

If this sounds suspicious to you, it should.

The biggest problem: the study was retrospective. Scientists agree that only prospective studies (see below) constitute real scientific evidence. This press release claims clear evidence that vision or eye problems are rarely the cause of headaches, and that there is no correlation between the need for glasses and headaches. And what kind of study is it? A retrospective study!

Prospective studies usually have fewer potential sources of bias and confounding than retrospective studies. For this reason, retrospective investigations are often criticised.

There seems fishy, does it not? Of course! This is another effort by the association of ophthalmologists in the United States to convince the public that glasses are prescribed unnecessarily. The press release highlights the hope that this study will help to reassure parents that most cases of headaches in children are not associated with vision or eye problems, and that most headaches will disappear with time, even if the headaches usually strike while the child is doing schoolwork or other visual tasks. My eye!

A statement of this nature has broad implications, and it intended (?) to assure parents that headaches are not likely to be causes by use of vision. The authors prefer to direct the public to a pediatrician that will decide if a visual examination is necessary rather than consult an optometrist!

The burden of proof for such claims is on the investigators, because it runs counter to gold standard published research.  Acknowledged by all parties to be one of the best studies ever published jointly by Optometry and Ophthalmology regarding children’s visual symptoms, the CITT noted that 32% of all children with convergence insufficiency (CI) reported headaches occurring fairly often or always while reading or doing close work.  Given that the prevalence of CI occurs to a greater degree in the population studied than strabismus, amblyopia, and high ametropia combined, and that no provision is made in vision screenings by pediatricians or school nurses to detect the condition, this study stands to confuse rather than clarify the role of vision conditions regarding headaches in children.

Photo : http://www.freedigitalphotos.net/

The authors report that 13.9% (22 children) of their population experienced headaches associated with visual tasks.  This means that 86.1% (136 children of a total of 158) of their population had a headache type for which visual input was not a factor, and therefore a severely skewed population in which one would not expect to find that glasses had more than a chance influence.

The authors did not even look at reasons for the disappearance of headaches in children over time. We must understand that headaches are mostly caused by the use of near vision (reading, writing, video games, etc.), often there is an eye alignment problem or a focusing problem. If the problem persists, the visual system will make significant concessions to solve the problem. Most of the time, as an adaptation to visual stress, we will see the child becoming myopic. Headaches do not go away without other visual problems appearing. But the authors did not take this into account…

It is unfortunate that a study so scientifically questionable has made ​​so many headlines everywhere…

Here is the link to the study:

http://www.aao.org/newsroom/release/20121112a.cfm

Adapted from the VisionHelp Blog: http://visionhelp.wordpress.com/

Vision Problems of Children with Individualized Education Programs

Much of learning is associated with visual cues, so children with vision-related problems may find it difficult to keep up with their peers in an academic setting. In order to assess the relationship between success in an academic setting and vision-related problems, we compared the prevalence of vision-related problems between children with Individualized Education Programs (IEPs) to population-based samples from the literature.

An IEP is a written statement that includes a child’s present levels of academic achievement and functional performance, measurable academic and functional goals, alternate assessments aligned to alternate achievement standards (if necessary), and a description of necessary special education services, supplementary aids, and accommodations. An IEP is written by a team of professionals that may include school psychologists, teachers, school nurses, speech and language teachers, and medical specialists in order to set measurable goals and establish a guide for the child’s special learning needs.

Eye care professionals completed a visual examination on children with an IEP. The prevalence of a variety of conditions exhibited by children with IEPs was compared to prevalence rates reported in the literature.

Data were analyzed for 255 children reported to have an IEP. The average age of the children was 9.6 years.

Higher prevalence rates were reported for IEP patients than for samples from the literature for myopia (9 of 13 studies), hyperopia (10 of 13 studies), astigmatism (6 of 9 studies), anisometropia (myopia oy hyperopia different in each eye) (3 of 4 studies), and strabismus (6 of 6 studies). The entering distance visual acuity of IEP patients was 20/40 or worse for 23.7% of them, but 7.2% of eyes still had a visual acuity worse than 20/40 after correcting their problem. Of the children who required some form of treatment, 124 (69.3%) had better than 20/40 entrance visual acuity in both eyes.

Many of these vision problems would solely be undetected by vision screenings based on distance visual acuity, illustrating the need for comprehensive vision examinations for children who are struggling academically.

(1)   Walline JJ, Johnson Carder ED. Vision Problems of Children with Individualized Education Programs Journal of Behavioral Optometry. Volume 23/2012/Number 4.

It has been estimated that 80% of learning is obtained through vision. Although there is no scientific evidence for this statement, few disagree with the assertion. Scientists have found significantly lower achievement test scores, as well as reduced letter and word recognition, receptive vocabulary, emergent orthography, and verbal and performance intelligence quotients among children with uncorrected hyperopia. Furthermore, children with learning disabilities exhibit a greater prevalence of vision-related problems than the entire population. Certain vision problems that may affect learning, but not all, are related to refractive problems (hyperopia, astigmatism and less with myopia), so vision examinations may provide helpful information in the management of children with learning disabilities.

Source: VisionHelp Blog – Dr Fortenbacher, OD FCOVD:

Conclusion

But, what if a child with an IEP also has a vision problem? Wouldn’t that pose a risk to the child responding effectively to their IEP?   To attempt to answer this question, 3 states in the US (Illinois, Kentucky and Missouri) have mandatory eye examinations for children before Kindergarten. Only Arkansas, North Carolina, Oklahoma and Massachusetts require examinations for children who fail a school vision screening. And only Ohio and Massachusetts require examinations for children with learning difficulties. Sixteen states do not even require vision screenings for children.  Regardless of the state laws, when an eye examination has not been performed by a qualified eye doctor, the school will typically provide a vision screening to determine that vision is functioning “normally”. However, here is where problems begin to surface. Vision screenings are predominantly an eye sight test. That is, if the child’s visual acuity (eye sight) is better than 20/40 they pass the vision screening!

Even more critical to the question of the validity of a school vision screening was another startling conclusion of the team which found that out of the 179 that required treatment, 124 (69%) of the children with IEPs would have passed the school vision screening test. That is to say, nearly 70% of those children with an IEP were identified with treatable vision problems and yet would pass the vision screening because their vision problem did not affect their distant eye sight!

If you are a teacher, insist that any child who has an IEP be seen by an eye doctor who will provide a thorough vision evaluation and provide you with feedback about the results.

If you are a parent, whose child struggles in reading and learning and/or has an IEP, it is imperative that you seek help by a doctor who is thorough, enjoys working with children and either provides office-based vision therapy or will refer you to a qualified doctor who provides office-base optometric vision therapy.

WHAT IS AN IEP?

http://www.edu.gov.on.ca/eng/general/elemsec/speced/guide/specedpartee.pdf

An IEP is a written plan. It is a working document that describes the strengths and needs of an individual exceptional pupil, the special education program and services established to meet that student’s needs, and how the program and services will be delivered. It also describes the student’s progress.

An IEP should be based on a thorough assessment of the student’s strengths, interests, and needs. It should identify specific goals and expectations for the student, and should explain how the special education program will help the student achieve the goals and expectations set out in the plan. The special education program and services the IEP describes should be modified as necessary by the results of continuous assessment and evaluation.

A student’s IEP should be developed, implemented, and monitored in a collaborative manner. The educational growth of a student is best accomplished through the mutual efforts of, and close communication among, the student, the student’s parent, the school, the community, and other professionals involved with the student. The IEP provides an opportunity for all those involved with the student to work together to provide a program that will foster student achievement and success.

In summary, an IEP is…

  • a summary of the student’s strengths, interests, and needs and of the expectations for a student’s learning during a school year that differ from the expectations defined in the appropriate grade level of the Ontario curriculum;
  • a written plan of action prepared for a student who requires modifications of the regular school program or accommodations;
  • a tool to help teachers monitor and communicate the student’s growth;
  • a plan developed, implemented, and monitored by school staff;
  • a flexible, working document that can be adjusted as necessary;
  • an accountability tool for the student, his or her parents, and everyone who has responsibilities under the plan for helping the student meet his or her goals and expectations;
  • an ongoing record that ensures continuity in programming;
  • a document to be used in conjunction with the provincial report card.