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HomemipatientBehavioural Optometry: Reviewing the Evidence

Behavioural Optometry: Reviewing the Evidence

Recent intense focus on behavioural optometry has generated discussion about whether its practice is based on a sound, evidence-based, clinical approach.

When evidence abounds for a particular therapy or intervention, in randomised controlled trials, or case study groups, it becomes adopted in mainstream optometry, orthoptics and ophthalmology methodology.

In this context, I asked Shaun Chang, my local behavioural optometrist, and Stephen Leslie, current president of the Australian College of Behavioural Optometrists (ACBO), the peak body of behavioural optometrists, some important questions about their field, and the evidence for the way they practice.

In doing so, I found there was significant overlap between optometry, ophthalmology, behavioural optometry and paediatric optometry.

Education is the most powerful weapon which you can use to change the world

Q: What is behavioural optometry?

Shaun Chang: “Behavioural optometry aims to determine if there are learning-related vision problems, as well as vision problems affecting other areas of daily living. This involves an assessment for visual defects, which can be thought of as ‘hardware problems’ such as refractive error, strabismus, and ocular health. Additionally, there is an assessment of visual deficits, which can be thought of as ‘software problems,’ such as visual processing.

“Behavioural optometry involves comprehensive assessment of distance and near binocular vision, accommodation, eye movement, refraction, and visual processing development, to detect and treat vision problems that can interfere with reading, computer use, learning to read, and other activities of daily living. Treatment may include lenses, prisms and vision therapy.”

Q: What is the difference between behavioural optometry and paediatric optometry?

Stephen Leslie: “The concepts and practice of behavioural optometry do not apply only to kids but adults as well. Children have to learn to read, and then use their vision for longer periods in reading to learn over the next 12 years of school. Children and adults are increasing their use of digital devices.

“Behavioural optometry concentrates intensively on binocular vision, accommodation and convergence problems, which can seriously impact on their ability to use vision for these tasks. While many of our patients are children, we also see many adults struggling with the visual demands of university or working at a computer eight hours a day, as well as older adults whose vision systems cannot cope without eyestrain associated with their work and computer use as they age.

“So behavioural optometry is not confined to children, it involves testing and treatment of vision problems at all ages.’

Q: Some cite studies that say behavioural optometry has no evidence base to its treatment methodology or its effectiveness. What would you say in response?

Shaun Chang: “The efficacy of vision training for convergence insufficiency (also known as accommodative convergence dysfunction) has been confirmed by multicentered randomised control studies by the Convergence Insufficiency Treatment Trial (CITT) group. Scheiman and Wick’s Clinical Management of Binocular Vision also provides an excellent review of assessment, management and prognosis for the clinical management of binocular vision disorders of heterophoria, accommodation, fusional vergence, or ocular movement control. Behavioural optometry does not diagnose or treat specific learning disabilities.

“However comorbid visual problems have been reported and they can exacerbate the condition. There are aspects of our care where evidence is well established and other areas where evidence needs to increase.

“We have to make sure the treatment we prescribe results in benefits that are measurable. For many decades, evidence supporting monocular patching for amblyopia treatment and binocular treatment was controversial. Now it is widely utilised and well established as being beneficial for visual development.”

Stephen Leslie: “This question is like asking, ‘Is there any evidence for optometry, or ophthalmology?’ There is extensive evidence for assessment and treatment of each area of clinical practice; for instance treatment of convergence insufficiency, myopia development and progression, intermittent exotropia, accommodation dysfunction, and visual processing assessment and treatment.

“Gold standard, multicentre studies carried out and reported in the US by the Paediatric Eye Disease Investigative Group (PEDIG), involving optometrists and ophthalmologists, have provided irrefutable evidence that myopia is primarily a result of near visual dysfunction and less outside time, with hereditary a lesser issue, which is a long-standing principle of behavioural optometry.

“Similarly, PEDIG studies have shown that in-office vision therapy is the best treatment for convergence insufficiency, another long-standing practice of behavioural optometrists, with push-up exercises shown to be useless, and yet many practitioners persist with this non-evidence-based practice. Sue Cotter, one of the coordinators of the PEDIG studies, presented all the latest evidence at the National conference of ACBO this year.

“Sadly, critics make false claims about behavioural optometry. For instance, behavioural and developmental optometrists do not claim to treat learning problems and dyslexia, and we do not treat vision-related learning problems, but we do treat learning-related vision problems of function and visual processing development which can interfere with the learning process.”

Q: Some eye care professionals do not recognise behavioural optometry because the discipline does not have a standardised treatment methodology that is universally applied for patients. This means, for example, one behavioural optometrist might treat a condition in a completely different way to another, and as a result, there can be considerable differences in patient outcomes. What are your comments?

Stephen Leslie: “There are different antibiotics for treating an infection, and the choice depends on the severity and chronicity of the condition, as well as on the preferences of the practitioner. In the same way, treatment of particular visual conditions depends on how long the problem has been going on, and its severity. In some cases, spectacle lenses alone may be sufficient, and in others, vision therapy may be necessary. Once you accept that vision problems change over time, and do not just occur with no explanation, there are logical and evidence-based options for treatment which will be considered by the practitioner as most appropriate.”

Q: In the current climate, is there more focus on creating more of an evidence based approach for behavioural optometry?

Shaun Chang: “Yes. The most recent NACBO conference was a testimony to that. Susan Cotter who is part of the CITT group presented her life’s work. Stephen Leslie presented the evidence for the use of coloured lenses specifically in pattern glare. The current climate for evidence can only be a good thing. It will allow us to look at our practice and be better. It also allows us to look at our colleagues and help them be better too.

Stephen Leslie: “The evidence for behavioural optometry has been rapidly increasing to catch up with constantly evolving clinical practice. However, we recognise that it has not been communicated as well as possible, and we have taken steps to ensure that the evidence for specific visual conditions and treatment options is communicated to optometrists and the community in more effective ways. The ACBO website has an extensive list of evidence summaries, and members are provided with evidence-based communications for clients and their referrers.

“ACBO provides an extensive range of evidence-based educational courses involving assessment of visual dysfunctions, strabismus and amblyopia, learning related vision problems, and special needs and acquired brain injury.”

Time for a Collaborative Approach

At the start of the journey, I mentioned that there was more overlap than I expected between optometry, ophthalmology, behavioural optometry and paediatric optometry. When evidence abounds for a particular therapy or intervention, it very much becomes adopted in mainstream eye care.

I think we owe it to our colleagues to understand there is always room for improvement in evidence base for clinical practice. As a profession, we should all accept responsibility for continuously contributing to this collective wisdom through collaboration. And we should resist making judgements on aspects of practice before we have undertaken extensive research.

I quote Nelson Mandela in saying, “Education is the most powerful weapon which you can use to change the world”.

Greater awareness and education will turn the focus away from working in silos, and towards collaboration.