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Report

Diverse program powers SRC

02/07/2018By Lewis Williams PhD
The unseasonably warm weather at this year's Southern Regional Congress matched the packed program, as organisers turned up the heat with a wide array of speakers and topics. LEWIS WILLIAMS details some of the more engaging presentations in part one of his special report.

As it has done previously, Optometry Victoria, the Victorian division of Optometry Australia, held its annual Southern Regional Conference 2018 (SRC2018) at the Pullman and Mercure Hotels at Albert Park using its usual dual-stream format for most of the conference.

Despite an increase in cost, the diverse program and the attraction of acquiring enough CPD points in one weekend to satisfy national registration requirements seems to have been enough to maintain overall delegate numbers in the 700–800 range, including exhibitors. The only hiccup was a problem with the complex attendance and CPD MCQ monitoring system, which was not resolved completely until after the conference ended.

In the end, the root cause was announced to be an interstate server problem.

KEYNOTE SPEAKERS

Tim Thurn

Sujan Hong

Mark Koszek

Kate Gifford

Laura Downie

Essilor breakfast

The program proper was opened by two concurrent breakfast sessions – one provided by Essilor Australia, the other by Rodenstock Australia.

Essilor’s breakfast, a look at the future of optometry, was presented by well-known optometrist and veteran speaker on spectacle lens matters, Mr Tim Thurn, Essilor Australia’s director of professional services.

Thurn said he saw the market being driven by three interrelated factors; vision care, fashion, and price. Growth drivers, such as advertising and industry promotion by companies and relevant associations, give rise to a 2–3% per annum increase, while the increase in average needs, explained as increasing market sophistication and expectations, adds a further 1–3%. Finally, increased marketing by optometrists and practices to their patient base adds a further 2% per annum.

The fashion factor has already had the effect of decreasing the ‘own frame’ rate from historical levels of around 35% to the current rate of around 25%. About 75% of gross practice income relates to clinic-based factors, such as CLs, eye exams and optical appliances, and of that 75%, about 44% is derived from spectacle lenses.

However, in what Thurn referred to as ‘troubling costs’, he also categorised remakes, credits, and returns (RCRs). Industry estimates put that cost at about $17.5 million at the wholesale level, which translates roughly to about $55 million at retail.

At the wholesale level, those figures translate to about $2.20 per lens sold and at the retail level they amount to around $20,000 per practice per annum, excluding intangible costs such as reputational damage. He noted that the best practices kept their RCRs within the 0.5–1.5% range – zero being unrealistic while humans remain in the prescribing, selecting, manufacturing, and supplying chain.

"Unlike many research pursuits, Essilor’s approach is to work in 3D and the body/eye activities within a 3D volume are studied as part of their research approach."

Importantly, dispensing errors at the practice account for 40–50% of the errors and he singled out the use of ‘dartboard dotting-up’ of PPLs for special mention. Between the cessation of registration of optical dispensers nationwide, the growing optometric focus on therapeutics, and the increasing sophistication of modern spectacle lenses (and the knowledge demanded when prescribing them), it is difficult to see how this scenario will improve, at least in the short term.

In addition to the lack of need for formal dispenser education, practice factors such as being too busy, insufficient process control, rising patient expectations (fanned somewhat by the cost of sophisticated appliances), and ongoing practice beliefs in crude fitting techniques such as PD rules and dartboard PPL ordering, all combine to maintain the less-than-exemplary status quo.

Thurn also noted that almost 80% of frames present the dispenser/practitioner with parameters that are outside default (fall back on) parameters common in dispensaries. In Australia, only about 4% of PPLs are customised, yet around 80% of appliances dispensed are sub-optimal according to industry data.

He reminded the audience that personalised (so-called customer-facing) marketing was now relatively common and becoming more so, giving Foot Locker and RM Williams outlets as examples of trendsetters. Thurn reported that when surveyed, 36% of people expressed interest in personalised products and that in the main, price was not a barrier (a premium of up to 20% was considered acceptable). Additionally, those over 55 years of age were more likely to be interested in personalisation.

Increases in business of 6–10% have been attributed to personalisation. It’s also more likely to engage the patient, increase patient acquisition (spread by word-of-mouth), more likely to result in engaging conversations conducive to explaining the benefits, and more likely to increase patient retention.

Thurn then went on to explain some of the science/psychophysics behind Essilor’s lens research using pseudo-reading tasks and whole-body, motion-capture technology as used in movie making and CGI. Unlike many research pursuits, Essilor’s approach is to work in 3D and the body/eye activities within a 3D volume are studied as part of their research approach.

An A4-sized tablet computer was used not only as reading material, but also as part of the measuring/monitoring system that can span the Rx range from –10 to +7.5 D. Using a lens-less frame equipped with eye movement sensors, they were able to confirm that reading was not a smooth eye-movement task.

Furthermore, in a paper presented at the American Academy of Optometry in November 2016, Essilor showed that, while not exactly the same as real reading, their pseudo-reading system correlated highly with it. The company’s Varilux X series of PPLs is the result of that research.


TFOS DEWS II

An update on the DEWS II report (Tear Film and Ocular Surface Society Dry Eye WorkShop 2) released in 2017 was delivered by Dr Laura Downie, senior lecturer in the Department of Optometry and Vision Sciences at the University of Melbourne. Downie was a member of the TFOS DEWS II Management and Therapy Committee, so she was well placed to deliver clinical pearls for the optimisation of the diagnosis and management of dry eye.

The new 2017 definition admits that dry eye (DE) is a multifactorial ocular surface disease (OSD) accompanied by symptoms, tear film instability, OS inflammation/damage, and neurosensory abnormalities. Although DE has been divided previously into two separate categories (aqueous deficiency and evaporative) DEWS II took a different path, with the expressed purpose of improving patient care and the inclusion of a ‘normal’ diagnosis – notably absent in the previous edition (DEWS I, 2007).

Taking the approach that DE is more of a continuum, its flow chart starts with the presence or absence of symptoms, then the presence or absence of signs of OSD within those categories. Acknowledging that there is still often a perplexing disconnect between the signs and symptoms of DE, the flow chart attempts to deal with symptomatic patients without signs of OSD on the basis that DE is probably imminent.

The result is a continuum of DE disease ranging from aqueous deficiency to evaporative DE, with a mixed form between those extremes. Any disruption to one or more of the so-called lacrimal function unit (lacrimal gland, OS, meibomian glands, lids, and relevant sensory and autonomic nerves) can affect tear homeostasis adversely.

Central to the OS’ innervation are the epithelium’s anterior sub-basal nerve plexus and intraepithelial terminals. Pain sensing (nociceptive – pain resulting from stimulation of sensory nerve cells) and neurotrophic pain (pain resulting from damage to the somatosensory nerve system itself), while once thought of as two distinct pain types are now considered to also be part of a continuum.

Generally, signs and symptoms are related in nociceptive pain whereas neurotrophic pain can occur without staining, for example. Neurotrophic pain is more likely to be reported as prickling or heat sensations. When a topical anaesthetic fails to relieve pain, it is suggestive of a peripheral or a neurotrophic origin. In a pilot study, omega-3 fatty acids were shown to increase basal nerve density by corneal nerve regeneration.

Regardless of the DE type, tear osmolality is increased (hyperosmolality) and a vicious cycle of OS damage is commenced. Starting with various tear film factors being altered, the OS’ goblet cells and glycocalyx mucin are affected adversely, and epithelial damage and apoptosis ensue. They in turn destabilise the tears, exacerbating the hyperosmolality issue further – and around it goes.

While various patient questionnaires exist to assess the likelihood of DE being present, the two most commonly featured at SRC were DEQ-5 and the OSDI. Downie also suggested that patients be screened for Sjögren’s syndrome, especially if mouth dryness was obvious or reported.

Unfortunately, there are a significant number of non-modifiable risk factors in DE including: age (>40), being female, being Asian, suffering from some systematic conditions, such as diabetes mellitus, rosacea, rheumatoid arthritis, lupus, Sjögren’s syndrome, and some thyroid disorders. Modifiable factors are the usual culprits: cigarettes, CL wear, some medications, inadequate water consumption, computer usage, air-conditioning, and elective ocular surgery.

When assessing tear stability, Downie recommended against the use of sodium fluorescein when assessing tear break-up time, i.e., NIBUT. She also recommended that the meibomian gland secretions be assessed, including the possible use of a constant-pressure expression tool, such as the TearScience Meibomian Gland Evaluator, or other meibomian gland compression devices, e.g. roller forceps or a Mastrota paddle.

Despite our better understanding of DE and related issues, the mainstay of therapy remains ocular lubricants/artificial tears, many of which are still preserved. Omega-3 has been shown to produce, albeit indirectly, an increase in anti-inflammatory mediators, but consumption for up to three months may be required before benefits are detected.

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While highly desirable, the measurement of tear film osmolality is likely to remain outside the realm of routine clinical practice for the foreseeable future, due to the cost and complexity of osmolality-measuring devices. Some DE questionnaires are available as apps at little or no charge. Meanwhile, older methods of tear volume assessment, e.g., Schirmer strips and the phenol-red thread test, still have a role to play, as do simple tests such as measuring tear prism height (a proxy for tear volume).

Downie also broached the topic of lid warmers used to soften thickened meibum before expression. Many have been shown to have very short-lived effects, especially hot compresses using hot water in a face washer, which are effective for about one minute only.

Most special purpose aids, such as a Bruder Mask, The Eye Doctor, and Thera Pearl are more effective. The temperature required needs to be maintained within the range 40–42.5°C for some time to be useful.

Contact lens comfort


Professional affairs manager for Alcon Laboratories Australia, Ms Sujan Hong, teamed up with Sydney optometrist and EyeQ Optometrists’ professional education officer, Mr Mark Koszek, to address CL comfort and tear film issues.

Hong reported that in company-sponsored trials, up to 60% of patients offered CLs went on to purchase them, suggesting that failure to offer the option for vision correction was a major factor in the relatively low market penetration of CLs in Australia (and probably many other parts of the world). She also suggested that practitioners tell prospective wearers that CLs are more comfortable than spectacles, a consequence of the evolution of modern CL materials, especially gradient-water-content materials.

Koszek traced the evolution of CL materials from the original PMMA to the better RGP material starting with the silicone acrylates of the late 1970s, the Permalens hydrogel CLs with improved physiological performance used experimentally in the formative CCLRU (UNSW) in the mid to late 1970s, and the milestone of the J&J Acuvue disposable hydrogel in 1987, which was followed closely by similar offerings from B+L and CIBA Vision.

The current era of SiHy CLs was launched by CIBA Vision’s Focus Night & Day CLs in 1998. Along the way, our understanding of the tear film has gone from a simple tri-laminate model (lipid, aqueous, mucin) to a more complex model involving more of a continuum from polar and non-polar meibum lipids (outermost), to a mucin/glycoprotein layer (innermost).

Importantly, it is now widely accepted that the presence of a contact lens ‘splits’ the tear film into a pre-lens tear film (lipids and aqueous) and a post-lens tear film (the mucoaqueous layer), which contains at least four major mucins and over 1,500 different proteins and peptides that overlay the glycocalyx of the apical epithelium (DEWS II, 2017).

The lipid layer thins in the presence of a CL from around 170 nm to 40–70 nm. Koszek also reported that wet-dry-wet cycles of CL surfaces can produce irreversible decreases in CL surface wettability, from 25° (more wettable) up to 100° (less wettable). He then gave technical details of Alcon’s Dailies Total 1 CL and its material, which has nearly 100% water content in its surface skin just six microns thick.

A low modulus of elasticity and a high lubricity are claimed, the latter being sustained for 14 hours of wear. The hysteresis demonstrated by the CL’s wetting contact angles (advancing vs receding) is claimed to be just 10° and the non-invasive break-up time was given as 7.1 seconds, compared with 5–6 seconds for competing products (all of which are well short of the desired 10–20 sec).

Up to 93% of Dailies Total 1 wearers claim good end-of-day wearing comfort. Currently, the water-holding ability of the gradient-water-content material is being investigated as a drug-delivery system for glaucoma and antimicrobial drugs, and it has already demonstrated an ability to deliver a full dose over 1–2 hours of CL wear.

Binocular vision, contact lenses, and kids


Brisbane optometrist, myopia guru (44 publications and 90 presentations), part-time academic, and paediatric binocular vision practitioner, Dr Kate Gifford gave a presentation that looked at the safety of CLs in children, binocular vision (BV) and CL optics, and the reasons for fitting kids.

Supported by published data, especially the work of Professor Mark Bullimore (Dean, Southern California College of Optometry) she reported that corneal infiltrative events (CIEs) and microbial keratitis (MK) rates were similar in children and adults. Interestingly, Bullimore (2017) published data that suggests that children between the ages of 8–12 years had a lower risk of adverse events, possibly due to parent-enforced compliance.

Several papers from the likes of Stapleton, Sankaridurg, and Bullimore show that the risk in Ortho-K CLs, a reasonably common anti-myopia measure in children, carries the same risk as SiHy CLs worn on a daily wear (DW) basis by wearers other than kids. That risk translates to one case of MK per 1,000 years of CL wear. DW SiHy CLs worn by kids have an almost zero risk however.

Not surprisingly, Walline et al., 2010 reported that the 8–12 year group recalled less information correctly after three months than teens instructed similarly. Chalmers et al., 2010 published data that showed 3% of 8–13-year-olds and 5% of 14–25-year-olds experienced interrupted CL wear as a result of an adverse event.

Data from Sankaridurg et al., 2013 and Bullimore et al., 2013 showed that the most common complications were CLPC (4%) and infiltrative keratitis (IK) (1%). Ocular allergies that occur in about 10% of children, have an attendant 9% risk of an adverse event.

Itemising the relevance of particular ocular pharmaceuticals to children, Gifford advised that most medications were safe once a child reached two years of age, with the exception of Patinol and Zaditen (≥3 yr), and the stronger vasoconstrictors (≥6 yr). Before moving to the next part of her presentation, Gifford estimated that children consumed 15 minutes more chair time than teens, and that just 10 minutes were required for CL insertion and removal instruction. Furthermore, she said when planting the seed for the idea that CLs were usually an option, it helped to let them play with a real CL if possible.

Gifford took a two-system approach to BV, accommodation (focusing) and vergence (aiming) – the latter encompassing phorias, NPC, and fusional reserves at distance and near. She sought to confirm, or to work towards creating, stamina, stability, and the ability to perform without fatigue at all distances.

With myopia, the most common refractive error in children and teens, it is perhaps somewhat unfortunate that converting those age groups to CLs does not always work in the wearer’s favour with respect to BV. If they are esophoric, the effect is beneficial but if they are exophoric, their exophoria and their accommodative lag can get worse.

The difference is largely due to the Base IN prismatic effect of minus spectacle lenses, an effect not present in CLs. Hyperopic cases experience the opposite effects. Those points were illustrated by a few simple cases from her practice.

However, some benefit can be attributed to a conversion to CLs and the larger image size CLs present in myopia – especially if the myopia is all or mostly refractive in nature, a fact that is difficult to determine. Unfortunately, it seems that most case of the myopia ‘epidemic’ are axial in nature.

From Gifford’s experience with myopia, she equates much of it to inaccurate BV behaviour, i.e., near eso, accommodative lag, higher AC/A ratios, and increased variability in accommodative responses. To that end, she postulated that myopia control might require BV management rather than myopia ‘control’.

Gifford reported that following numerous studies over the last decade, the efficacy of high (1%) and low (0.01%) concentration atropine eyedrops, Ortho-K, and special-purpose multifocal CLs all have similar anti-myopia properties with efficacies around 50% (some studies have shown high-dose atropine can be as high as 75%, but the side-effects curb enthusiasm for the modality). She went on to describe the resulting differences in those with a normal accommodative response and those with a reduced accommodative response when MF SCLs are used.

Her conclusion was that those with normal accommodation were suited to MF SCLs, and those with poor accommodation and/or esophoria were better suited to Ortho-K or MF SCLs with larger central optic zones (Centre-Distance designs assumed). Those recommendations are based on a desire to avoid providing hyperopic defocus under most circumstances.

In cases involving reduced vergence facility, the most likely effects seen are reduced reading speed and increased eye movements. Learning difficulties can also be reported because convergence insufficiency leads to avoidance behaviour, an undesirable outcome as up to 58% of school class time is at near, including computer screen time.

Confounding factors such as anisometropia (≥2 D difference) affect up to 1.5% of the population. If amblyopia is detected and the child is younger than seven years, they are usually responsive to patching. Unfortunately, those from 7–13 years are less responsive, although modern techniques have registered some success even in adults, especially if they are not strabismic. Irrespective of age, 22% of amblyopes simply need a full Rx and no patching.

The computer-era problem of easier bullying was also addressed by Gifford. While 31% of children experience bullying (probably an evergreen childhood problem), spectacle wearers are some 35% more likely to be bullied, giving rise to a possible CL solution to the problem.

While about 56% of adults experience DE, just 4% of children, and probably slightly more teens, experience the same.

The relatively recent arrival of screen-based devices has compounded existing DE problems by reducing blink rate, among other effects. Additionally, systemic medications including antihistamines, antidepressants/antianxiety medications, and acne treatments can confound existing DE issues or create new ones.

Estimates of the allergy rate in the general Australian population go as high as 20% and that figure is expected to increase to 25% by 2050. In children, about 90% of cases of allergic conjunctivitis are associated with allergic rhinitis (hayfever). Of the 13% of patients reporting ocular allergy, only 11% consult their optometrist (that figure will rise as more therapeutically endorsed practitioners come on stream), 53% consult a GP, 41% a pharmacist, and 18% consult a friend or relative (and possibly use their medications without any considered professional advice).

Wolffsohn et al., 2011 demonstrated that when daily disposable (DD) CLs were used by ocular allergy cases there were reductions in burning and stinging, the duration of symptoms, bulbar, limbal, and palpebral hyperaemia, and surface staining.

 

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