Research

Latest information on show as Brisbane hosts ARVO – Asia

For some years now, ARVO has also held smaller satellite meetings biennially in Asia and it was Brisbane’s turn to host ARVO-Asia in early February. It may be more than coincidence that Australia’s own, Professor Justine Smith (Flinders University, Adelaide), just happens to be the current ARVO president.The event attracted 650 delegates over a packed three and a half-day program while, coinciding with ARVO was a separate Translational Vision Summit, which had 130 delegates.Insight’s photographic coverage of both events was somewhat limited by ARVO’s policy of no photography. Naturally, its policy also applies to the actual slides and images used in presentations but, to use a Shakespearean phrase, that was more honoured in the breach than in the observance in the era of the ubiquitous smartphone.Myopia prevalence and outdoor activity{{image2-a:r-w:400}}The ARVO-Asia program included six concurrent subject streams offered for most of the meeting. Professor Kathryn Rose, from UTS and ANU’s Professor Ian Morgan, the lead authors of the sinal paper Rose et al., 2008 that linked inversely myopia prevalence and time spent outdoors, were the first two speakers.Rose presented graphical data spanning 1938 to 2011 that showed clearly an increase in the prevalence of myopia from around 1970 onwards. Such an apparent change suggests an environmental aetiology rather than a genetic one, although genetics may still play a part. More disturbing were figures from Taiwan that showed an increase in the prevalence of myopia from 6% to 20% for a group of seven-year-olds between 1983 and 2000.Factors correlated included; the number of years of schooling, the acadic level attained, children in accelerated learning environments such as cram schools – which had a significantly higher prevalence and probably magnitude of myopia – socioeconomic status, intelligence (albeit highly confounded according to Rose), parental myopia, and restrictions on time spent outdoors.In the Sydney Myopia Study, Dr Amanda French from UTS’ Discipline of Orthoptics has shown that dividing schools into categories based on background – eg, public, private, religious, and acadically selective – reveals differences.By 12 years of age, 40% in selective schools were myopic and by 17 years of age that figure had increased to 50%. From her study, she recommended that the last years of primary school were the ideal intervention point if myopia was to be stalled. Weekend-only outdoor activity was shown to be inadequate, suggesting a school-based intervention was the likely answer.{{image3-a:l-w:400}}Studies already underway in China and Taiwan are investigating 40, 80, and 120 minutes a day outdoors on school days. Even the shortest of those options has donstrated a 10% reduction in myopia prevalence. Currently, a tentative recommendation is 15 hours outdoors a week and wrist-watch-like devices are being developed to indicate actual time outdoors. However, when the winter outdoor tperature can be –15 °C or worse, resistance to spending time outdoors is understandable. Regardless, the exact underlying mechanism rains unclear.Despite the aspersions cast on digital devices, their relatively recent appearance does not correlate well with myopia prevalence rates. As Rose put it, digital devices are not the elephant in the room. So far, diet and body height changes, TV and computer use, the spectral characteristics of ambient light, vitamin D per se, and the use of a night light have been ruled-out as aetiological factors. Reading distance has some effect, but more work is required to tease out its contribution, and under-correction has already been donstrated to be myopigenic.Morgan presented similar figures to Rose using a Guangzhou study spanning 1980 to 2013, when the myopia prevalence increased from 20% to 80%. Triggers were the end of the so-called Cultural Revolution in China, increasing levels of education, and industrial development. Those factors led Morgan to call myopia a social disease. To reinforce the developing probl of high myopia (now defined as ≥–5 D), he gave Taiwanese figures showing that up to 20% of the population now have Rxs >–6 D. In his view, myopia has increased 3-4X, while high myopia has increased by about 10X.Later, optometrist Mr Choi Kai Yip from Hong Kong’s Polytechnic University showed another aspect of the social implications for myopia when he revealed that Hong Kong only has 161 sq m per person whereas the rest of the world has, on average, 960 sq m.{{image4-a:r-w:400}}That physical population density and restricted visual environment, combined with a less activity-based education syst, has seen a rise of myopia – especially high myopia.However, Professor Paul Baird of CERA has been investigating the contribution of genetics to the myopia issue and he described the environmental model as an incomplete explanation of the increasing prevalence of myopia. While environment is already accepted as an issue, other possible factors include; ethnic differences, genetics per se, interactions between genes and cultural features.Already, 21 myopia-related regions of genes have been identified as candidate genes and that number is expected to increase. Genome-wide association studies suggest that less than 40 different loci are associated with myopia, either singly or in combination with others, but ‘noisy’ data makes the picture difficult to clarify. He believes that less than 10% of myopia variation can be explained by genetic factors.Citing a Dutch paper (Tidan et al., 2016), it has been suggested that different genes at different ages are involved and some genes appear to be only involved in rapid progression myopia. Furthermore, there is now evidence that Europeans and Asians are different genetically in a myopia context, which could mean that a treatment that is successful in one group might not translate directly to other groups. On the possibility of gene-environment interactions, Baird believes that not enough time is spent outdoors to be useful to an analysis. An Odds Ratio of 5.42X was attributed to time spent reading for the progression of myopia.Australian-trained ophthalmologist, Adjunct Associate Professor Audrey Chia from the Singapore National Eye Centre detailed some of the investigations into the use of atropine at various concentrations (0.01% to 1%) as a myopia control strategy.
When the 0.01% alternative was used in the two-year Atropine for Treatment Of Myopia (ATOM) study, there was some myopia progression during the first four months of use, after which the level of myopia seed to stabilise. Meanwhile, the 0.5% and 0.1% concentrations were more effective, donstrating 75% and 70% reductions respectively compared with the control group.Following cessation of the trial at 24 months and a 12-month monitoring period thereafter, a rebound effect was observed in the test group. As a direct result, the 0.01% treatment proved to be less effective once the rebound was factored in. Interestingly, in the 0.01% group over the 24 months of the trial, only 24% progressed more than 0.5 D per year.{{image5-a:l-w:400}}As the lower dose regimen has obvious attractions – such as little effect on accommodation and pupil size, no near vision loss, and is a more conservative medication – Chia suggested continuation of a low-dose regimen for at least one, but preferably two years, if the myopia is still progressing at the end of 24 months usage (for results of the ATOM 2 study see Chia et al., 2015 Ophthalmology in-press).Trial cessation was based on a flattening of the progression curve. Most children started in the 6-8 year age band finished treatment by 8-10 years of age, but some needed to continue to about 12 years of age. Myopia retardation is generally greater in younger subjects. Predictably, about 4% of subjects on the 1% regimen developed an allergy to the product whereas only 1% of the 0.01% group did.Sudden discontinuation of a high-dose regimen is not recommended; rather a shift to a lower dose or a decrease in frequency of application is preferred. Due to the known disconnect between changes in axial length and myopia progression, Chia and others have suggested that the ratio of axial length to corneal radius (derived from an IOLMaster for example) is a better clinical measure of myopia trial outcomes.Tracking keratoconus treatment outcomesClinical Professor Stephanie Watson from Sydney’s Save Sight Institute, detailed its latest registry, the Keratoconus Module. Its prime aim is to track outcomes from treatments administered in the real world, including so-called off-label treatments, and compare th to relevant clinical trials and other research endeavours.The web-based software tool is designed to require a minimum of effort from those entering data, so that the latter does not constitute a ‘barrier to entry’ onto the register. Data is anonymised by the syst and estimates of 60 seconds for initial case entry and 30 seconds for subsequent entries were aired. The keratoconus registry was modelled on the existing AMD registry, now 7,000 cases strong.Ophthalmologist Professor Dipika Patel from New Zealand’s University of Auckland gave a lecture on imaging in keratoconus, a topic she and colleagues are all too familiar with as a result of the prevalence of keratoconus among the Pacifica people in New Zealand and surrounding islands. She gave the uses of imaging as the diagnosis, screening, progression managent, and corneal cross-linking (CXL) treatment decisions in keratoconus.While several instruments have their own keratoconus prediction systs, most are peculiar to the originating instrument. Patel made specific mention of Reichert’s Ocular Response Analyser and the OCULUS Corvis ST tonometer, both of which use pressured air pulses to impact the cornea, which is then monitored in real time for its response to, and recovery from, the pressure applied.Because of the keratoconic cornea’s altered (inferior) physical properties, the analysers cause greater corneal distortions than those donstrated by a normal cornea. Despite offering useful information, Patel stated that they are not stand-alone tools for keratoconus diagnosis and quantification.Focusing on the RTVue OptoVue OCT with its anterior module, she noted it was possible to assess the corneal epithelial thickness over a 6 mm diameter of the cornea. Although some characteristic apical thinning patterns have been identified, that instrument too was still not a definitive means of diagnosing keratoconus. However, other useful findings include the ability to image tears in Descet’s mbrane, eg, in hydrops, and the darcation between CXL’d and un-CXL’d corneal zones after a cross-linking procedure.Patel and colleagues have published widely on in vivo confocal microscopy. This technique can reveal breaks in Bowman’s layer, corneal nerve networks below the central cornea, and also the more tortuous pattern those nerves take up in keratoconus, which tends to be arranged concentrically with the cone’s base. Additionally, the corneal keratocyte density and distribution can be visualised, as can acanthamoebae in Acanthamoeba keratitis. In corneal hydrops, some features observed can predict neovascularisation.Meanwhile, according to Professor Charles McGhee, the difficult and expensive lamellar corneal procedure Deep Automated Lamellar Keratoplasty (DALK), which eliminates the possibility of endothelial rejection, is becoming more popular despite it having a lower apparent survival rate in the 5-10-year long-term. He also stated that DALK has twice as much risk of failure compared with alternative procedures, as well as a higher risk of infection – often due to patient compliance issues.

KEYNOTE SPEAKERS

Jacki Trad

Mark Radford

Malvina Eydelman

Robyn Ward

Medical research gender gapRenowned oncologist Professor Robyn Ward, Deputy Vice-Chancellor and Vice President of Research at the University of Queensland, gave an engaging presentation about the gender gap in research and medicine.Ward believes that one reason for the apparent gap was the ‘leaking’ of women from the ‘syst’. The opportunities are there because knowledge-based occupations have enjoyed an 8% growth rate compared with just 2% for other occupations.She estimated that by 2020 there would be a worldwide shortage of 40 million workers, especially fale workers, in professional occupations, in particular the ST subjects – science, technology, engineering and mathatics/medicine – all of which overlap with medicine and medical research.Given that likely need, Ward said the inclusion of women in ST subjects was essential, rather than an optional inclusion. Ironically, studies of TAFE and university courses suggest that women are performing proportionally better in ST subjects meaning, arguably, they should be dominating ST occupations because of greater suitability/ability.Regardless of this, figures show there is declining interest in the ST areas by fale students at school and tertiary levels, which is resulting, once again, in an increasing gender disparity in the workforce.An analysis of university acadic positions shows approximate parity up to the position of Lecturer, after which fale numbers decrease significantly while male numbers rise to make up the difference. At the full Professorial level, fale numbers are seriously under-represented.According to Ward, pipeline leakage can be attributed to: intentional bias, something wrong with women – eg, a lack of suitable skills and experience – women opting-out due to lack of ambition, and unintentional gender bias resulting from cultural or organisational beliefs and practices.Often implicit in society’s thinking is the male leader-fale caretaker dichotomy. Also not helping the situation is the design of the ‘syst’ – by males for males – in which its norms and practices se ‘normal’ to those within.Ward also warned against organisations claiming meretricious ployment and career paths because she believes it has been shown that the more such claims are made, the greater is the male bias within th. Such organisations believe they are objective and therefore don’t examine or re-examine their behaviour leading to a paradox of meritocracy.Overcoming the probls Ward raised is difficult and likely to rain so for some time to come. In some UK contexts, government funding is reliant, at least partially, on deploying the principles of equity and inclusion in the workplace. In Australia, SAGE (Science in Australian Gender Equity) – Equity and Diversity is a 4–year action plan to address and enhance gender equity in ST areas using both qualitative and quantitative data.It is driven by a peer-review panel and awards ratings to institutions meeting their criteria that are valid for four years. The program is intensive to complete, taking some two years just to collect the initial data. It is hoped that the number of women in mid-level and senior positions will increase as a direct result.<>* The Translational Vision Summit will be covered next month.

ARVO Asia gallery


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