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Report

A super showing

30/05/2019By Lewis Williams PhD
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Optometry Australia NSW/ACT held its annual Super Sunday 2019 education event at Sydney’s Luna Park Big Top on March 10. In Part 2 of his report, LEWIS WILLIAMS details the event’s remaining presentations.

Associate Professor Jennifer Craig from the University of Auckland took the lectern to discuss Meibomian Gland Dysfunction (MGD) and its clinical ramifications.

The latest definition of MGD is a product of a report by the International Workshop on Meibomian Gland Dysfunction (2011), whose Definition and Classification sub-committee included Craig as a member.

The group defined MGD as a chronic, diffuse abnormality of the meibomian glands, characterised chronically by terminal duct obstruction and/or qualitative/quantitative changes in the glandular secretion. Those changes can result in alterations of the tear film, symptoms of eye irritation, inflammation that is apparent clinically, and ocular surface disease.

She noted that MGD is a major contributor to evaporative dry eye, posterior lamellar blepharitis, lid-margin thickening and keratinisation, hyperaemia, telangiectasia, and notching. Commonly, it is associated with anterior blepharitis. Meibomian gland blockage due to hyperkeratinisation, ductal stenosis, and the stagnation of oils can lead to gland atrophy. MGD is chronic and progressive, and affects Asian races more commonly.

Estimates from her New Zealand-based research suggests that up to 35% of people consulting an optometrist exhibit signs of MGD, and an estimated 15% exhibit signs of anterior blepharitis. Symptoms of the condition include: red-rimmed eyes, heavy and swollen eyelids, photophobia, tearing, discharge, discomfort, and blurred vision. An infestation of Demodex spp. in the lash follicles should be checked for if lid margins are itchy.

Overall, patients suffering from MGD are typically unhappy. The discomfort or pain caused by MGD is significant, and has been likened to angina or undergoing dialysis. Impacts include lower productivity, an association with depression and a lingering financial burden. As the Meibomian glands are the principal source of lipid and absence of the tear film’s lipid layer can result in the aqueous phase of the tears evaporating at up to 4x the normal rate, symptoms are sure to follow.



"Worryingly, up to 25% of those with cataracts drive despite not complying with legally required minimum driving vision"
Joanne Wood, staff member at School of Optometry and Vision Science

Risk factors for MGD include: advancing age, environment factors such as air-conditioning, CL wear, and use of digital devices. Other factors include eyes with higher bacterial loads, anterior blepharitis, Demodex infestation, and being of Asian ethnicity. Prevalence of MGD among Asian people is 60%, as opposed to less than 30% among non-Asians.

Following a three-step treatment plan, Craig started with: 'Dealing with the lid margins'.

In moderate to severe dry eye, lid hygiene is the most common treatment in Australia and the UK. Steps include lid-margin debridement using a golf club spud, a topical anaesthetic to soften the lid tissue, and Lissamine Green to disclose the effects of the treatment.

Despite it still being a relatively common recommendation, Craig counselled against the use of baby shampoo, even as a 10% solution, because it affects the lipid layer and goblet cell function adversely. It can also contribute to meibomian gland orifice obstruction. Special lid cleanser products, such as SteriLid and OCuSOFT HypoChlor, are preferred.

The BlephEx motorised debridement tool was recommended for the deep cleaning of the lid margins and meibomian gland orifices. Bacterial load reduction requires a topical antibiotic, such as fusidic acid 1%, or a Manuka honey gel such as Optimel.

A University of Auckland development of a complexing of cyclodextrin and Manuka honey has shown promising clinical results, and a laboratory assessment of inflammatory markers is now under way. Current recommendations for Demodex spp. treatment include lid hygiene with a tea tree-based daily cleanser with or without heat treatment, and a weekly treatment with a 1:1 tea tree oil and bland oil mix for 6 weeks.

The next treatment step is 'Encouraging meibum outflow'. Heat therapy, either patient-applied by warm compresses or in-office via pulsation therapy were suggested. Craig also recommended intense pulsed light (IPL), the use of a latent heat device, and therapeutic gland expression with a special tool.

The final step is 'Improving meibum quality'. Altering meibum composition can require systemic anti-inflammatory therapy and supplementation with essential fatty acids. In particular, omega-3 is used to address the common imbalance between omega-6 and omega-3.

A tetracycline, such as a 50 mg daily treatment of doxycycline for 2 to 3 months, can improve lipid quality by the inhibition of bacterial lipases on the anterior eye. However, this treatment is unsuited to growing children or pregnant women.

Topical or systemic azithromycin (1%) has also been shown to be beneficial. Topical lipid supplementation, such as liposomal sprays or drops, has also been shown to be beneficial by Craig and others in clinical trials. She summarised that practitioners need to do more than just palliative care; they need to treat dry eye.

The Josef Lederer Award for Excellence

Optometry NSW/ACT presents the Josef Lederer Award for Excellence to a member who has demonstrated outstanding achievement, commitment, and a furtherance of the optometric profession’s ideals. It is named after the late Professor Josef Lederer, founding Head of Department of Optometry, University of NSW (UNSW), and the first Professor of Optometry in the British Commonwealth.

Optometry NSW/ACT President Mr Luke Cahill presented the Josef Lederer Award for Excellence to Emeritus Professor Stephen Dain.
Optometry NSW/ACT President Mr Luke Cahill presented the Josef Lederer Award for Excellence to Emeritus Professor Stephen Dain.

Emeritus Professor Stephen Dain was announced as the 2019 recipient of the award before Super Sunday, but its formal presentation was conducted at the event. Dain is a former Head of School who was responsible for expanding the institution’s scope and renaming it the School of Optometry and Vision Science.

He is also the founder of the National Association of Testing Authorities-registered Optics and Radiometry Laboratory at UNSW; a comprehensive calibration and testing laboratory catering for standards testing of ophthalmic appliances and other safety equipment, as well as light and colour calibration. The laboratory also maintains a research function. Despite retiring from the laboratory’s day-to-day activities, Dain is still involved in its operation.

Optometry NSW/ACT President Mr Luke Cahill presented the award.

Driver vision testing challenges

Queensland University of Technology, School of Optometry and Vision Science staff member Professor Joanne Wood delivered a lecture on the current visual requirements for driving, how various ocular conditions impact driving ability, and how to convey that information to the affected drivers.

She described driving as a highly complex and demanding task that encompasses the co-ordination of visual, cognitive, and motor skills. The visual tasks involve monitoring the road, mirrors, and the car’s dashboard, all while a driver’s attention alternates between driving and non-driving tasks.

Factors affecting driving performance include age, actual vision function, refractive errors and corrections, light conditions, and glare, especially at night. Eye diseases are also a factor, particularly glaucoma, age-related macular degeneration (AMD), and cataracts. Age-related changes reduce visual acuity (VA), contrast sensitivity, visual fields, and motion sensitivity while also increasing glare sensitivity.

Worryingly, up to 25% of those with cataracts drive despite not complying with legally required minimum driving vision. Those in that category have a 2.5x higher crash risk. Cataract surgery halves the crash risk. Wood nominated the Pelli-Robson test as the best gauge of visual performance. Predictably, the drivers’ perceptions of their driving skills were variable and included over and under estimates, often by wide margins.

Glaucoma is now one of the most common reasons for driving cessation. Unfortunately, that was linked subsequently with social isolation and depression. With 3.6 times increased crash risk, largely connected to visual field loss, the problem is obvious. In closed-road circuit testing, glaucoma patients required twice the number of driving instructor interventions than control patients did, with the greatest problems being drifting out of lanes and issues with traffic lights.

AMD patients are usually aware of their visual shortcomings and, at least initially, avoid challenging driving situations while reducing the amount of driving undertaken overall. Surprisingly, studies of crash risk have delivered mixed results. Their most difficult tasks are general observation, including of traffic lights and what they are indicating, lane position, and gap selection when changing car position on the road. Driver safety was associated strongly with motion sensitivity, but not VA or contrast sensitivity.

While standard licensing requirements are relatively straightforward, conditional licensing is far more complex. Regardless, the VA in the better eye must not be worse than 6/24. Although the state of the visual field is not quantified specifically for conditional licensing, the fact that an ophthalmologist or optometrist can recommend a conditional licence means that deviations too far from the requirement for an unconditional licence (≥110 ° horizontally, an ≥10 ° and no significant loss out to ±20 ° above and below the horizontal meridian) are unlikely to be encountered on the road. Importantly, no leeway is offered for commercial licences as far as fields are concerned, and a more stringent VA standard usually applies.

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Wood advised that delegates make themselves familiar with local regulations due to small variations between the states. She also noted that some states mandate practitioner reporting of those drivers who fail to meet vision standards. Only severe field losses have been shown to increase crash risk, meaning that a simple, targeted confrontation test is probably adequate. However, Wood recommended the binocular Humphrey Esterman visual field test.

Optical blur, whether due to uncorrected refractive error, incompletely corrected refractive error, or other causes is known to increase reaction times, and therefore the risk of an accident. Blur as low as 0.50 D has been shown to impair driving performance. The effects are worse at night, as the increased pupil size enlarges retinal blur circles.

Uncorrected astigmatism also has deleterious effects on both day and night driving, especially when low-contrast hazards are present alongside shorter pedestrian recognition distances. Although monovision contact lens corrections are now less common, the impaired stereopsis they deliver is a problem when driving. This is worse at night, when up to 80% of monovision CL wearers report difficulties. Multifocal CL wearers report ghosting around lights at night leading to vision difficulties, especially reading street signs. Presbyopic spectacle corrections perform well generally but single vision distance corrections performed poorly when a car’s dashboard was viewed.

Wood’s final topic was glare of either the discomfort or disability variety In a driving context. Glare can occur when there is too much light overall and/or when the luminance range is too large. Furthermore, adaptation to low light levels after exposure to glare sources takes time, and visual function is reduced in the interim. The biggest glare sources at night are the headlights of oncoming cars.

Disability glare from sunlight can be reduced by the use of sunvisors but not sunglasses, which reduce the brightness of everything including the road ahead. Intraocular light scatter, and therefore disability glare, remains fairly constant among most people until about 40 to 50 years of age. However, by the age of 70, even with a healthy ocular media, the light scatter is twice that of a healthy 20 year old. Discomfort glare is not uniform across the visible spectrum and is worst at the shorter wavelengths around 480 nm (blue). Pedestrian detection at night was the factor most affected by glare, and glare sensitivity was the best predictor of night driving performance.

When assessing patients, document any advice given to cover the practice and practitioner in case of litigation or disputes over what was said in the consulting room. It is also prudent to advise drivers that even when visual standards are met, there is no guarantee they have good vision for driving and they should drive within their limits.

They should be more familiar with these limits by the end of any consultation. The importance of regular eye examinations, especially when issues have already been identified, needs to be emphasised to the patient. Patients also need to be made aware that their vision and driving performance can change over time.

Wood also advised the audience to refrain from assuming that other professionals provide appropriate advice.

Some might even withhold crucial information because they do not want to be the bringer of bad news, while others feel that they should ‘test’ other practitioners to confirm their findings without priming them to the possibilities.

Optometry's Future: Brink of Extension or a Brave New World?

Optometrist Mr Daryl Guest delivered the final presentation of the conference.

He is the clinic director of the University of Melbourne’s Eyecare Clinic and an experienced practitioner.

He opened by stating that artificial intelligence (AI) is on the way; a fact that most people no longer find difficult to accept. It is a topic raised regularly in discussions about future technologies and the effects those issues are likely to have on most aspects of life. He argued that AI was not that new, and elements of it are already in use in visual field analysers.

As an example of the current state of ophthalmic AI, he cited Google’s use of AI and deep learning to diagnose diabetic retinopathy (DR) efficiently and accurately, with a specificity of 90.5% and a sensitivity of 91.1%. Given that DR remains the leading cause of blindness, it is easy to imagine that AI will not just be useful in the future, but essential for detecting and treating all cases, especially given that qualified manpower is a limited resource.

In its current form, AI can detect as few as three microaneurysms in a diabetic’s retina, but at that sensitivity there is now the need for ‘cheaper’ personnel to triage the increased number of ‘AI referrals’. This is due to the reality that there would be too many diagnosed cases of DR competing with one another for an ophthalmologist’s time – essentially a case of overkill initially.

In the same vein, the wider usage of OCTs, including by optometry, has tended to create an over-referral problem with the help of so-called ‘red disease’; instances where non-existent disease is identified incorrectly. If retinal vascular changes need detecting or monitoring, OCT-A is the current tool of choice and further improvements are expected.

Optometrist Mr Daryl Guest
Optometrist Mr Daryl Guest

Guest also admitted that AI does not always work, a situation that is likely to improve with time. He also saw improvements in eye scanning technologies, greater utility in big data, and evolving pharmacological agents and treatments all of which are likely to impact optometry. His bottomline was whether such changes in technology and data usage would replace optometry’s evolving roles, whether optometry is well-placed to utilise and benefit from the inevitable changes in health care, and where the profession sits between those two extremes.

Ultimately, the overall aim is to maximise patient outcomes. Guest’s timeframes were 5, 10, and 20 years. The latter aligns with Optometry Australia’s ambitious Optometry 2040 initiative.

Returning to his clinical roots, he offered some advice to the audience on when to ‘hold’ and when to refer in several conditions.

Retinal detachment that did not happen recently: same day or early next day,

Macular oedema: same-day referral is not necessary,

CSR: review at 6 weeks, refer at 3 months, in the meantime prepare a management plan. Measure the ‘gap’ in OCT of a CSR case, be wary of separations >250 microns (about half corneal thickness),

CRVO: essentially a systemic problem, not an ophthalmological one, and referral to the patient’s GP initially was recommended within a 2-4 week window,

Diabetic macular oedema: requires referral, albeit not as an emergency, anti-VEGF therapy will be required until resolved.

Looking towards the future, Guest touched on other possible issues including the faster and better production of 3D printed spectacle frames, the risks associated with MIGS devices such as the CyPass, low-concentration atropine for myopia progression (LAMP) therapy, and the crowdfunding of eye care.

Manpower issues were alluded to, but with nascent optometry courses yet to produce their first graduate, the likely collective output of optometric academia in Australia cannot be determined accurately. Significantly, the number of ophthalmologists has remained relatively static and is almost certainly at inadequate levels.

The main limiting factor remains the number of hospital registrar positions available which, when compounded by the justifiable philosophy of turning out ophthalmologist that have undergone a comprehensive training programme rather than a hyper-specialised one at the time of graduation, means ophthalmologist numbers seem unlikely to change in the foreseeable future.

The Super Sunday 2020 event will return to Luna Park’s Big Top once again on 8 March 2020.

 

More reading:

Super Sunday 2019

 

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