LEARNING DIFFICULTIES

Dyslexia,or specific learning disability, learning difficulties or reading difficulties commonly cause children to progress poorly at school.

BACKGROUND:

My interest in learning difficulties and vision therapy commenced in 1979 when I researched and published a number of papers on dyslexia and reading difficulties.

Subsequently in the early 80s at the instigation of the Royal Australian College of Ophthalmologists I reviewed the literature on dyslexia and learning difficulties -over 900 papers were researched- claims and counterclaims were reviewed. Few papers claiming success of therapy passed the most basic scrutiny of their scientific methods. Invariably a hypothesis was floated, not proven and then used as the foundation for uncontrolled or poorly controlled studies and the subsequent claimed success in the treatment of reading difficulties or dyslexias .

Theories involving an ocular mechanism in the causation or management of learning disabilities that were proved invalid and dismissed- resurfaced a little later with a thin veneer of disguise. These included papers by ophthalmologists, optometrists, psychologists and others. None bore true scientific scrutiny.

The position today has changed little.

The influence of visual disorders in the management of learning disability is discussed in detail in the linked page. The role of Vision Therapy and the use of Irlen Lenses for this condition is covered.


Detailed description of Dyslexia, Learning Disability, Reading difficulties

Background

In the  early 1980s the Royal Australian College of Ophthalmologists supported a review of  the literature on this topic -over 900 papers were researched- claims and counterclaims were reviewed.

Few papers, claiming therapeutic success, passed the most basic scrutiny of their scientific methods. Invariably in these papers a hypothesis was floated, not proven and then used as the foundation for uncontrolled or poorly controlled studies and the subsequent claimed success of therapy.

Theories involving an ocular mechanism in the causation or management of learning disabilities that were proved invalid and dismissed- resurfaced a little later with a thin veneer of disguise. These included papers by ophthalmologists, optometrists, psychologists and others. None bore true scientific scrutiny.

The position has changed little today.

Statements

Excellent statements of the current position succinctly summarising the situation are now available.
1. A statement from the American Academy of Ophthalmology   http://www.aapos.org/associations/5371/files/VisionTherapyPolicy.pdf  2001

2. A conjoint one issued by the American Academy of Pediatrics, American Association of Pediatric Ophthalmology and Strabismus and American Academy of Ophthalmology.  
I will include a brief excerpt from this statement

This combined statement states:

Learning disabilities are very common but "Visual problems are rarely responsible for learning difficulties" and "No scientific evidence exists to support the use of eye exercises, "vision therapy" or coloured lenses in the remediation of these complex paediatric neurological conditions."

You can see the full statement on the following website:
http://www.aapos.org/displaycommon.cfm?an=1&subarticlenbr=53

NH&MRC STATEMENT
In Australia The National Health and Medical Research Council is in agreement.

In view of these statements from these esteemed bodies why is there such confusion regarding Visual therapies in the management of children with learning disabilities?

This confusion exists because much misinformation is provided to parents and teachers regarding Visual therapies.

Visual Therapies

Learning Difficulties cause very significant parental concern. They also trouble teachers who are concerned for the welfare of their students.

The importance of correcting the problem is so great that a proliferation of diagnostic and remedial treatment procedures have proliferated.

These are invariably anecdotal, based on shaky hypotheses with no true scientific evidence of validity or efficacy.

They are widely advertised and promoted.

Hence teachers and parents become confused.

They will pursue any avenue to assist their children and are frequently persuaded to spend large sums of money on useless "Visual training, spectacles or eye exercises."

Practitioners who stand to gain much from their implementation promote these therapies to preschools and primary schools.

To discuss these issues and understand what is involved I would like to first define a number of terms to facilitate discussion.

Definition of Terms

  • LEARNING DISABLED - FAILURE TO ACQUIRE SKILLS TO A PREDICTABLE LEVEL
  • DELAYED READER - 2 OR MORE YEARS BELOW CURRENT GRADE
  • DYSLEXIA - EXTRAORDINARY DIFFICULTY IN LEARNING TO IDENTIFY PRINTED WORDS BY OTHERWISE NORMAL CHILDREN (Vellutino)

Vellutino F R Sci Amer 1987,vol 256 no3 20-27

OTHER FACTORS WHICH MAY AFFECT LEARNING INCLUDE:

  • IQ
  • NEUROLOGICAL & PHYSICAL DISORDERS
  • SOCIAL AND EMOTIONAL DISORDERS
  • ENVIRONMENTAL FACTORS
  • CULTURAL INFLUENCES
  • INAPPROPRIATE INSTRUCTION
  • PSYCHOGENIC FACTORS

 When these factors are considered it is easy to see that before any child is considered for eye evaluation all other factors that may contribute to the problem should be excluded.

It is disappointing that these factors are rarely controlled in any series of visual therapy patients. This makes the claimed results even more meaningless.

When True Dyslexia is considered it is found to have a multi-factorial aetiology reflecting genetic influences and abnormality of brain structure and function as shown by brain mapping.

What Causes Dyslexia

AETIOLOGY OF DYSLEXIA -

It is a subtle language deficiency that results in:

  • PHONOLOGICAL-CODING DEFECTS
  • DEFICIENT PHONEMIC SEGMENTATION
  • VOCABULARY & GRAMMATICAL DEFECTS

 Therefore it represents a subtle language deficiency which causes:

1. An inability to represent and access sounds of words in order to remember them.
2. An inability to divide words into composite sounds
3. Poor vocabulary and poor grammatical syntax

It is therefore a disorder of speech, memory and sounds with minimal visual causation.

Thus the dyslexic has a limited ability in using language to code other types of knowledge.

Image24Vellutino* compares the mind to a sophisticated reference library and states dyslexia is as closely aligned with cross referral and retrieval of coded information already stored in memory as it is with storage and coding of new information which decreases further any visual role in its production. Dyslexia is thus a function of memory and speech not a visual defect.

*Vellutino F R Sci Amer . 256 (3) 20-27 1987

Vellutino F R J Experimental Psychology. 59(1):76-123 1995 Feb


 

i.e. DYSLEXIA IS A DYSFUNCTION OF STORAGE & RETRIEVAL OF LINGUISTIC INFORMATION NOT A VISUAL DEFECT!

Visual Theraphy Claims

Where does confusion arise?

With the understanding of learning problems as expressed above this paper should be complete. But as stated previously the importance of correcting the problem is such that parents and teachers will search for any possible assistance and therefore can fall prey to any claims.

This has resulted in a proliferation of so-called diagnostic and remedial treatment procedures which make claim to amazing assistance for children. These confuse parents, teachers and practitioners and distract from the more appropriate assistance of extra remedial aid.

This information commenced with a Hypothesis of Orton.

ORTON 1925- LETTER REVERSAL, WORD REVERSAL
There is nothing new in the claims or the therapy of today. They can be traced back to Orton’s Hypothesis of 1925. Most theories and therapies have surfaced been discredited and rediscovered many times.

Orton hypothesised that a defect in Visual perception and visual memory characterised by a tendency to see letters and words in reverse caused dyslexia.

Other related hypotheses suggest motor & visual defects and eye movement disorders affect binocular coordination, eye-tracking and directional scanning. These concepts of a visual problem and its presumed association with uncertain cerebral dominance underlie the visual therapeutic approaches to learning disabilities.

VISUAL THERAPIES

These therapies may include -visual training and coloured lenses.

Note: Proponents of these therapies claim reading improvement almost invariably in 80% of cases whether they are using Irlen's coloured lenses or the most recently "discovered" therapy.

Benton in the seventies in a huge series of patients- several thousand- achieved similar results. He then disproved totally his own therapy methods and recommended they be discarded. Thus there is a placebo effect of 80% for all therapies.

Therefore to evaluate any therapy this 80% placebo effect must be discounted. This improvement occurs because of the following effects:

Externalising the problem  
Increased parental involvement
Increased teacher involvement
Normal maturation process

The prescription of unneeded glasses or recommendation of 'eye training' allows a child to have a psychological boost which can in itself boost esteem and result in an improvement in performance at school.

The increased interest and awareness of parents and teachers related to a child's participation in a programme whether visual or otherwise can result in an improved performance at school. Most children's reading and learning ability will improve with time. So the involvement in any programme for a period will be associated with improved skills regardless of the effects of the programme.

Visual or other programmes cannot be justified on the basis of this placebo effect. The financial resources of parents is limited and these finances should be marshalled and applied to remedial help or programmes which will have a direct beneficial effect.

Evaluation of Visual Therapies

To evaluate these therapies further it is important to find how much vision is necessary to read and what do the so called visual defects really mean.

WHAT VISION IS REQUIRED TO READ?

This is the story of a boy, JB.   

JB is legally blind!

Even with his very thick glasses he cannot read the top letter on the distance vision chart.

But, JB is one of the best readers in his class!

This is not unusual and if we go back to the explanation of the causes of learning disabilities the reason for this is obvious. Perfect vision is not required to allow us to read.

Minor defects in vision do not cause reading difficulties.

LETTER & WORD REVERSAL

This is evidence of immaturity and is very common in the younger child. It may persist in poor readers it is not visual as only graphemic symbols are reversed.

IN NORMALLY DEVELOPING READERS
PERSISTS A SYMPTOM NOT CAUSE OF POOR READING
It is therefore not a cause but an effect of reading difficulty. Its presence is to be expected in young children and will usually disappear as reading improves. It is not caused by a visual defect or a visual perception defect.

EYE MOVEMENT DISORDERS:

Subtle defects of eye movement control eg latent squints etc are often cited as a cause for learning problems. But children with manifest squints do not have an increased incidence of reading problems!

Many studies have firmly confirmed this:

CASSIN* STRABISMUS NOT increased in learning disabilities
HELVESTON** 2000 CHILDREN OCULAR FUNCTION & ACADEMIC ACHIEVEMENT- NO RELATIONSHIP
LENNESTRAND NO RELATIONSHIP OCULAR DISORDERS AND DYSLEXIA

 * Cassin B Am Orthop J.Vol25 1975

** Helveston et al; Visual Function and Academic Performance, New Eng J of Medicine 1984

*** Lennestrand G Ygge J : Dyslexia; Ophthalmological Aspects 1991, Acta Ophthalmologica. 70(1):3-13 1992;                                                                                     Ygge J Lennerstrand et al: Oculomotor functions in a Swedish Population of Dyslexic & Normally Reading Children, acta Ophthalmologica 71 (1); 10-21, 1993

True Convergence Insufficiency is rarely present in these children but many of these children, who rarely read, do not pass convergence tests- a result of and not a cause of poor reading. The tests need to be modified to test true convergence ability.

ACCOMMODATION DEFECTS are frequently diagnosed.

Children with learning problems are frequently told they have a difficulty refocussing from board to books. This is described as difficulty in accommodation and glasses are prescribed.

Special tests -flipper tests, dynamic refraction etc are prone to subjective error and misinterpretation because of varying accommodative efforts by the child.

These children are commonly given weak glasses - (+0.50).

If appropriate tests are performed normal accommodative ability can invariably be demonstrated. These children can be shown to have 10-12 Dioptres of accommodation. This makes the prescription of weak spectacles a questionable practice.

Question: WHAT DO WEAK SPECTACLES ACHIEVE?

Answer: Nothing!

Why are these Spectacles of no benefit?

Children are able to focus on close objects much better than adults. They rarely require glasses just for reading or bifocals. If these are prescribed they merely result in the child under utilising the innate ability to focus on close work.

ACTION: If your child has been given glasses, to assist "focussing", look through them. If they do little to help or blur your vision they are not assisting your child!

These glasses do not help Children!

 You might ask whom benefits from their prescription!

Irlen tinted Lenses

Scotopic Sensitivity Syndrome (Irlen Syndrome) was a term coined, by Irlen, 25 years ago in an as yet an unproven hypothesis. This syndrome, it has been claimed, causes reading difficulties and can be relieved by wearing special tinted lenses.

There is confusion with terminology- “scotopic vision”=rod vision/vision at low levels of luminance (measured in terms of threshold/minimum intensity of detectable light)

 -Irlen’s definition of SSS has little to do with scotopic vision

-Central feature of syndrome is that some dyslexics respond dysfunctionally to certain wavelengths of light (this is actually defined as “photopic vision”)

SSS not identified through standardized educational and/or psychological evaluations, vision exams, medical check-ups or other diagnostic tests

Proponents of this therapy claim it can assist with learning disabilities, autism, migraine, driving fatigue. These lenses it is stated can be of benefit to 14% of the general population and 45% of the learning disabled. Sitch et al found that more than 80% of third graders, ninth graders and undergraduates (who had no learning difficuly) tested demonstrated characteristics of Irlen Syndrome/Scotopic Sensitivity

 ack of attention to placebo effect has been made-  positive results due to motivational factors, social factors,     (child now has a  vision problem and is not “stupid”), changed attitudes of parents, peers and teachers as well as affected child. Much of supportive literature for Irlen filter effectiveness in publications that do not use a peer review process.

No clinically controlled trial has been conducted to confirm these figures. Sitch et al* state the results of therapy are invariably reported in an anecdotal and subjective fashion e.g. . “I feel much better”,  “I can see the words more clearly”

Sitch et al state "These lenses represent a cash grab"• similar to other unproven therapies.

* •Sitch, S., Sperraza, A. and Schubert, M. (1994) Scotopic Sensitivity Syndrome

Many authors have attempted to prove the effectiveness of this therapy. None have been successful.**. An objective method of assessment of improvement by comparing improvement in reading comprehension failed to demonstrate any change with the use of these lenses**.

THESE LENSES HAVE NOT BEEN PROVEN TO WORK! All the evidence is to the contrary.

*Gole, G.A., et, (1989)Tinted lenses and dyslexics:  A controlled study Aus & N Z J Ophth, 17, 137-141

•*Cotton, M.M. & Evans, K.M. (1990).An evaluation of Irlen lenses as a treatment for specific reading disorders. Aus J Psych, 42, 1-12.

*Solan HA. Richman J . Irlen lenses: a critical appraisal  J Am Optom Assoc 1991Aug;62(8):585,

**Fletcher, J. and Martinez, G. (1994)An Eye-Movement Analysis of the Effects of Scotopic Sensitivity Correction on Parsing & Comprehension.J Learn Dis Vol. 27 No.1 p.67-70.

What Assessment of Vision is Required


ROUTINE SCREENING:
This can be performed by a GP or school nurse who will test:

 

VISION
EYE MOVEMENTS
OCULAR DISORDERS
A REFERRAL should be made if abnormal results are obtained.
If all appears normal then a learning problem is unlikely to be due to a visual problem 

Summary

Use of unproven therapy can delay application of more appropriate corrective measures.  Some researchers believe  a  non-invasive therapy that cannot physically harm patients, HOWEVER, an individual’s time and emotional and physical                     energy can be spent on unproven therapies this can be harmful to the individual’s sense of hope and self-esteem not to mention the financial drain on parents.

THERE IS NO KNOWN EYE OR VISUAL CAUSE FOR LEARNING DISABILITIES.

THERE IS NO KNOWN EFFECTIVE VISUAL THERAPY

ANY CLAIM FOR A THERAPY MUST BE BACKED WITH OBJECTIVE SCIENTIFIC METHODOLOGY.

DO NOT ACCEPT ANECDOTAL ACCOUNTS OF RESULTS.

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