THE ROLE OF VISUAL THERAPIES IN THE MANAGEMENT
of
CHILDREN WITH LEARNING DIFFICULTIES*
Clin. Assoc. Prof. Denis Stark.
*
Lecture presented By Invitation to The Annual conference of the Australian College of Paediatricians (Qld) October 1999
BACKGROUND:
My interest in learning difficulties and visual therapies commenced in 1979 when I researched and published a number of papers.
Subsequently in the early 80s at the instigation of the Royal Australian College of Ophthalmologists I reviewed the literature on this topic -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.
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.
Again, after extensive reading I considered stating my thoughts on the current position but, as so often happens, the Americans have already issued an excellent statement of the current position which succinctly summarises the situation.
This authoritative statement was 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 by clicking on the Heading (
http://med-aapos.bu.edu/AAPOS/ld.html )
In Australia The National Health and Medical Research Council is in agreement.
The NH&MRC summarised the position as shown: 
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 of much misinformation is provided to parents and teachers regarding 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.
- 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)
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.
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:
- 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.
.
Vellutino 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
i.e. DYSLEXIA IS A DYSFUNCTION OF STORAGE & RETRIEVAL OF LINGUISTIC INFORMATION NOT A VISUAL DEFECT!
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 fiances should be marshalled and applied to remedial help or programmes which will have a direct beneficial effect.
WHAT VISION IS REQUIRED TO READ?
This is a photo of a boy, JB. JB is legally blind!
Even with his very thick glasses he cannot read the top letter on the 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.
What then are claims frequently made?
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.
- VISUAL PROCESSES IN LEARNING DIFFICULTIES?
- IS THE DEFICIENCY VISUO-SPATIAL?
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 RELATION |
| LENNESTRAND | NO RELATIONSHIP OCULAR DISORDERS AND DYSLEXIA |
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.
I have not been able to duplicate this disorder in any patient I have seen.
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).
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. If these are prescribed they merely result in the child under utilising the ability to focus up close. This is graphed to demonstrate the unused accommodative power with these glasses.
ACTION: If your child has been given glasses, to assist "focussing", look through them. If they do little to help your vision they are not assisting your child!
These glasses do not help Children!
You might ask whom benefits from their prescription!
What Visual Assessment is necessary in Children with learning disabilities?
- ROUTINE SCREENING:
This can be performed by a GP 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
An assessment of distance and near acuity can be made.
While it is often stated that it is essential to assess reading acuity when I examined 1000 children of 5-7 years all children with significant difficulty with close work also had abnormal distance Visual Acuity.
THERE IS NO KNOWN EYE OR VISUAL CAUSE FOR LEARNING DISABILITIES.
THERE IS NO KNOWN EFFECTIVE VISUALTHERAPY
ANY CLAIM FOR A THERAPY MUST BE BACKED WITH OBJECTIVE SCIENTIFIC METHODOLOGY.
DO NOT ACCEPT ANECDOTAL ACCOUNTS OF RESULTS.
Summary: The AAP, AAO and AAPOS do summarise the position very well:
