Interactive, engaging and entertaining, The Western Australian Vision Education (WAVE) Conference in March was a great reminder of just how effective boutique conferences can be.
Described by delegates as “really awesome”, “amazing” and “the best vibe”, the event took place at the Esplanade Hotel in the picturesque coastal town of Freemantle in WA and was live streamed. This year a total of 150 delegates attended the conference with a further 300 dialling in from Bahrain, America, Shanghai, Singapore, and the east coast of Australia. A broad range of topics were covered, from contact lens fitting through to diet for eye health, Alzheimer’s Disease and myopia management. We review a selection of the presentations here.
BLOOD VESSELS AND EYE DISEASE
Optical coherence tomography (OCT) has made it significantly easier to detect even the smallest amount of intraretinal fluid. In a lively presentation, Michael Yapp, Head of Clinical Operations and teaching at Centre For Eye Health, University of New South Wales, spoke about the detection and optometric management of intraretinal fluid, detailing the underlying causes and discussing how to determine when to refer patients on.
Every visit is an opportunity to emphasise the importance of outdoor activity and minimising near work
He said to maximise the potential of OCT, optometrists really need a thorough understanding of the anatomy. “This will enable you to better understand and determine where the associated fluid is coming from to assist with determining the disease diagnosis and treatment planning,” he said.
Continuing the theme, Dr Bang Bui (deputy head of Department of Optometry and Vision Sciences, University of Melbourne), delved into the vasculature of the eye and how blood vessels are controlled.
Every time we blink, move our eyes or head, our intraocular pressure (IOP) changes, altering blood flow to the eye. Whether the eye is healthy or disease affected, the blood vessels that supply the eye with oxygen and sugar are constantly coping with the stress of changes in blood, eye and intracranial pressure. The vascular system attempts to adjust for these pressure changes with classical autoregulation and neurovascular coupling.
Through classical autoregulation, blood vessels dilate when blood pressure is low and constrict to decrease the volume of blood flow when blood pressure is high, much as occurs in the brain.
All images copyright of Pete Gardner Photography.
Neurovascular coupling occurs when neurons are activated in response to stimulation, delivering more blood as more energy is used. The latest evidence suggests that immune cells called microglia in the retina identify and interact with capillaries to change their capacity to cope with stress. When microglia are unwell, as might occur in very early diabetes or glaucoma, the control of blood flow is altered. Thus interactions between immune cells, neurons and blood vessels may be altered early in the development of retinal disease.
Sophisticated technology, such as OCT-A, is enabling clinicians to look for changes to capillaries which can indicate damage to the retina well before patients become symptomatic of disease. OCT-A, at present, is good at picking up loss of capillaries, even earlier than this, when capillaries may still be there but not working well.
By using Functional-OCTA we can study vessel and capillary responses to flickering light for example, which may enable us to detect very early capillary and microglia dysfunction. This might help us detect diabetic eye disease earlier and perhaps prognosticate as to who might go on to need anti-VEGF treatment and who may not.
In a separate presentation, Dr Bui spoke about detection of early signs of Alzheimer’s Disease (AD) via the retina.
Australia’s growing ageing population demands greater attention to AD. As the most common form of dementia, it affects one in five people 85 years and over – around the world, 50 million people now live with dementia, and 10 million are diagnosed each year.
AD causes disability and loss of independence and is predicted to cost Australia AU$83 million by 2026, surpassing all other diseases plaguing our country.
Being a multifactorial disease, we don’t fully understand what’s going on but we know what the risk factors are and have a role to encourage those at risk to modify their behaviours. Factors that collectively increase the risk of developing AD by 50% are a lack of social engagement, depression, physical inactivity, hypertension, obesity, smoking, diabetes, and low education.
Positron emission tomography (PET) scan with a contrast agent, magnetic resonance imaging (MRI) and cerebral spinal fluid (CSF) taps are reasonably good biomarkers, however they are expensive and invasive. Furthermore, because detection requires a reasonable build-up of plaques, these tests don’t stage the disease early enough to allow investigation of effective interventions.
Examining the eye for biomarkers of AD offers a distinct advantage – it is the only area where we can clearly image blood vessels and neurons.
This idea is supported by studies of animal models of AD, which show that as the animal ages, the retina, like the brain, manifests both soluble and insoluble amyloid beta and tau which produces a range of structural and functional deficits. Importantly, soluble amyloid oligomers are appearing at the same time as they are appearing in the brain.
In addition to the presence of amyloid, when comparing the eyes of people with AD against people without AMD, studies have reported a range of differences in eye movements, pupils, tears, the crystalline lens, and choroidal thickness. People with AD experience decreased visual acuity in low luminance and contrast sensitivity, reduced reading speed at lower contrast; visual field loss, and reduced stereopsis. They have poorer colour discrimination and a higher threshold for motion detection. We are continuing to learn about the range of visual signs and symptoms that provide a specific picture of AD.
Perhaps moving forward, deep learning approaches can help with early detection of AD by combining information across a range of modalities, such OCT, OCT-A and other. If we have tools to detect the very early signs of disease – before toxic amyloid plaques build up and patients’ cognition goes into decline, we can begin to work out whether interventions can slow or even halt disease progression.
MYOPIA: CONTROVERSY VS CONUNDRUM
Mark Koszek, founding partner and professional education officer at EyeQ Optometrists, spoke on controversies and conundrums in myopia management.
Conundrum being a “confusing and difficult problem or question” and controversy being “a prolonged public disagreement or heated discussion”… with conundrums leading to controversy.
Demonstrating the point he pondered, “which is the best way to measure myopia progression: axial length or refraction?”.
“At various points of development”, Mr Kozsek said, “axial length progresses faster than myopia, however at other times, the reverse happens.”
He continued, “Axial length measurement allows us to predict myopia development and the risk of associated pathology for any patient and evaluate the effectiveness of myopia management treatments.”
Mr Koszek said using axial measurement charts can be a very effective way to educate parents of children with myopia as it clearly demonstrates the expected rates of progression based on age.
Similarly, he said, we know that myopia often progresses most quickly (>1D) in children aged six to nine-years, as does IOP – but is there a correlation? And, if there is, does increased IOP cause myopia? He highlighted a study that found after 20 minutes of looking at a smartphone, IOP increased, especially in low light; increasing IOP may make the sclera stretch, which in turn causes myopia to progress.
Another conundrum/controversy raised was, “which is the most effective treatment for myopia – atropine 0.01%, orthokeratology, or myopia control spectacle, contact lenses or even combination therapies?”.
On this topic, Mr Koszek introduced a number of studies, demonstrating just how confusing it can be to make a decision on which treatment path to follow. MiSight contact lenses as a stand-alone treatment have been found to slow 59% progression and 56% axial length over three years; DIMS spectacles, introduced in 2020, slowed myopia progression by 52% and axial length by 62%. A study in 2020 (Konshita) found combination therapies to be more effective, though in 2018 Wan et al found a combination of orthokeratology and atropine was slightly more effective than orthokeratology alone, but had better efficacy in lower myopes (less than -6D).
“We don’t know which is the most effective treatment yet – things are changing over time with new treatments and even results between studies show different results,” he concluded.
The key messages Mr Koszek imparted were to start measuring axial length, use eye growth charts as they’re effective for explaining to parents their children’s risk of myopia progression, and counsel patients about their near work behaviours. Encourage regular breaks, look into the distance, ensure a working distance no closer than 40cm, and read in good light… Consider multiple therapies for high risk patients.
Continuing the theme of myopia management, Dr Antony Clark spoke about treatment with atropine, which is currently only available through compounding pharmacies.
Most patients have already tried contact lenses and orthokeratology by the time they visit Dr Clark, and are eager to try atropine, although he acknowledged that some parents see it as a ‘set and forget’. In fact atropine requires that they commit to instilling eye drops, regular reviews and encouraging children to change their behaviour by spending more time outdoors and less time on screens.
Dr Clark acknowledged that while we know low dose atropine is safe and effective in the short term, more research is needed to gain a better understanding of its mechanism of action, the optimal dosage, duration and strategies for cessation.
Dr Clark said dosage will depend on the individual’s race and tolerability.
- 0.01% is not likely to be enough for Asians,
- 0.05% is probably most effective in Asians, perhaps due to dark irises, and
- 0.05% is probably too much for Caucasians, perhaps due to light irises.
While 1% has been shown to be effective, it is not well tolerated and causes unpleasant symptoms, including light sensitivity. Additionally, the Singapore trial showed a massive rebound effect with 1% atropine – it became the worst performer at three years and 0.01% became the hero performer, holding out for five years.
Dr Clark said we can expect myopia progression to reduce by about half a dioptre a year. “If the patient is progressing at a rate of 1D per year, I go for a higher dose (0.025%) to stop the progression, then bring the dose down. If they’re tolerating the dose really well, and still there is significant progression, I consider escalating the dose. If the patient continues to progress, I consider other options such as orthokeratology.”
When myopia progression has sufficiently reduced over two years, cessation should be achieved with dose tapering and follow-up reviews every six to 12 months.
“Every visit is an opportunity to emphasise the importance of outdoor activity and minimising near work (remind parents their kids get enough screen time at school),” Dr Clark said.
KERATOCONUS AND COMMON CONTACT LENS FITTING TRAPS
Queensland optometrist David Foresto spoke on optometrists’ role in managing keratoconus via early detection and vision correction.
Corneal cross-linking has been a great step forward but optometrists need to be aware that a small percentage of patients still steepen after cross-linking and may require re-treatment. Additionally, there is strong evidence now that many cross-linked patients will exhibit progressive flattening afterwards, so optometrists should still ensure to monitor these patients regularly.
Evidence based guidelines recommend that glasses or contact lenses should be the primary form of correction and surgery should only occur when these are unsuccessful.
There have been great steps forward in the success of contact lenses, namely in scleral lenses which can now also incorporate toric and wavefront level corrections to give better vision than ever before.
In a second presentation Mr Foresto provided some practical, well received tips on contact lens fitting. Moving from the simple to the complex, he said the aim of the tips was to decrease chair time and stress.
Speaking about fitting presbyopes with multifocal contact lenses he said, it is most important to set realistic expectations and that painting an accurate picture of a patient’s vision with these lenses has been key to his practice’s high fitting success rate.
“Referrals for multifocal soft contact lenses are on the increase and setting realistic expectations makes all the difference.
“It generally takes three weeks to adapt to multifocal contact lenses and full visual adaptation takes three months. If your patient feels their vision is better at the end of the first week than it was on day one, they’re probably going to get better – if not, we need to try something else.”
Mr Foresto said patients can be confused by the term ‘multifocal’ because it is used in relation to both spectacle and contact lenses. “We need to explain they don’t work in the same way, and reassure them that multifocal contact lenses won’t cause balance issues, which can be the case with multifocal spectacle lenses – so if they failed the latter, they won’t necessarily fail wearing multifocal contact lenses.” Mr Foresto explained that a patient’s ability to visually adapt can be influenced by how their visual system developed as a child.
NUTRITION AND THE EYE
Associate Professor Laura Downie (University of Melbourne) presented a fascinating lecture highlighting the capacity of diet to impact ocular health and optometrists’ role in educating patients on this topic.
While focusing on age-related macular degeneration and dry eye disease, she said diet can affect cataract and glaucoma as well. While many optometrists question how to provide evidence based advice to patients, Assoc/Prof Downie’s research indicates that patients would be receptive to advice they offer.
Indeed, it seems that the general population would benefit from education in this area as adherence to the Australian Dietary Guidelines is poor. A/Prof Downie reported that energy-dense, nutrition-poor foods makes up 30% of most people’s diet.
Assoc/Prof Downie presented conflicting results from studies that indicate opportunities for more targeted patient education on eating for eye health in practice.
Encouragingly, a 2015 survey attracting responses from 283 Australian optometrists, found 60% of respondents self-reported routinely asked their patients about diet and nutritional supplement behaviours, and 80% routinely advised on supplemental intake.
However, asked whether their optometrist had asked about diet, a survey of 225 patients presenting for optometric care found only 25% recalled the conversation. Encouragingly, 80% said they felt comfortable discussing this topic with their optometrist.
Foods rich in anti-oxidants and with anti-inflammatory properties are proposed to limit retinal damage, specifically foods with zeaxanthin, lutein and omega-3 fatty acids.
To reduce the risks of age-related macular degeneration people should eat:
- Dark green leafy vegetables and fresh fruit daily,
- A serving of oily fish two to three times a week,
- Low GI carbohydrates,
- A handful of nuts a week, and
- Limit consumption of fats and oils.
High dose anti-oxidant vitamin and mineral supplements, such as those based on the AREDS formulation are only of potential benefit to patients with at least intermediate nAMD, and the benefits of taking them should be weighed up against the risks (such as the potential risk of lung cancer in current smokers with the use of high-dose beta carotene supplementation).
dry eye disease, Assoc/Prof Downie said the primary management goal is to restore homeostasis to the ocular surface.
As a chronic, multi-faceted condition, dry eye disease requires long term interventions and a step-wise approach (from low risk to more advanced therapeutics). Step one, includes the intake of omega-3 fatty acids for their inflammatory and neuroprotective metabolic products, either through diet or supplements.
Omega-3 fatty acids exist in short chain form in plant based foods such as chia and flax seed; and long chain EPA and DHA exist in oily fish such as salmon and to a lesser extent, seafood.
The National Health and Medical Research Council (NHMRC) recommends 500gm per day of consumed long chain omega-3 fatty acids, equating to two x 100g servings of oily fish per week; with an upper safety limit of 3,000mg/day. A study of 200 Australian and New Zealand optometrists, undertaken by Ceecee Zhang (PhD student of A/Prof Downie and Prof Jennifer Craig, University of Auckland), found 80% would recommend patients consume some form of omega 3, especially those with evaporative and severe forms of dry eye disease. Optometrists reported suggesting both omega-3 rich foods as well as supplements, with recommended supplement doses ranging from 250–6,000mg per day, indicating many weren’t aware of the potential risks of excessive intake. Almost no respondents used a quantitative tool to survey patient’s supplement intake, which meant optometrists were unable to monitor whether or not omega-3s in a patient’s blood levels was sufficient. While it is possible in practice to measure systemic omega-3 levels via a blood test, research undertaken in A/ Prof Downie’s lab has shown that a simple questionnaire asking patients to select how much and how often they ate particular foods and take dietary supplements, can achieve a meaningful estimation.
With respect to supplementation, A/Prof Downie recommended long-chain omega- 3s with re-esterified triglyceride over less expensive ethyl ester formulations; she said that although there remained some contention about the optimal daily dose, research undertaken by her team has shown that 1,000mg of EPA and 500mg of DHA per day can impart therapeutic effects in dry eye disease, and these supplements need to be appropriately stored to retain their effectiveness. She said it is important to capture a patient’s baseline omega-3 levels as a matter of routine and reminded optometrists that omega-3 takes about three months to build up in a person’s system.
WAVE 2022
Evan MacRae, executive officer of Optometry Western Australia, said feedback on the conference, which was attended by a record number of delegates, was “amazingly positive”.
Describing the conference as “a really awesome effort” one delegate added, “in 35 years of OWA conferences, this year’s conference had the best vibe, the best content and was best organised.”
Mr MacRae said, “The vibe, both face-toface and online was truly spectacular. Clearly the chance to catch up with colleagues face-to-face plus enjoy a drink and a bite to eat around the pool at the famous WAVE Sundowner (36 degrees and not a cloud in the sky) made for a very happy affair. Just as importantly, online delegates sharing tips and tricks along with ideas, and being genuinely interactive, was a side of WAVE we had never seen before – we look forward to facilitating this again in the future.”
The 2021 lectures are available online until 31 October 2021 (WAVE on Demand) for optometrists who registered to attend WAVE. Visit: wave.delegateconnect.co/ pages/recordings.
WAVE will return in 2022 as a hybrid event.
