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Generation Next: Optometry graduates put on a show

08/02/2018By Lewis Williams PhD
UNSW optometry graduates and some early post-graduate degree candidates provided a snapshot of their work at two recent events attended by LEWIS WILLIAMS. Myopia control featured heavily, along with topics including limbal stem cell dysfunction, miniscleral contact lenses, and orthokeratology.

At the conclusion of UNSW’s most recent semester, the School of Optometry and Vision Science (SOVS) hosted two events to wind-up its 2017 activities. The first event was a day-long series of presentations by fifth-year optometry students delivering the outcomes of their final-year research projects.

Those projects serve multiple purposes. In particular, they form an assessable component of their degree, while also providing a taste of research as a career possibility. They also double as pilot projects for more detailed and in-depth projects to be undertaken by the original student(s) at a post-graduate level, another post-graduate student, or the project’s academic supervisor.

The second event was an Alumni Evening at which several post-graduate students delivered progress reports on their research. Those presentations were followed by myopia-related lectures by Drs Pauline Kang and Kathleen Watt (jointly), and Professor Padmaja Sankaridurg.

Projects presentation day


A wide range of topics was covered in the 33 presentations, which focused on projects executed mostly by either a duo or trio of final year students. There were presentations on all aspects of vision, including performance and its assessment, clinical issues such as grading iris colour and the use of OCT to image corneal epithelial cells, ocular physiology and microbiology, and specialty contact lenses.

A panel of academic staff assessed all presentations and at the end of the day prizes were awarded for the Best Rapid Fire presentation, the Best Poster, and the Best Talk.

The Best Talk was awarded to Ms Celine Zhang and Mr Charles Wu for their project, ‘Comparison of standardised patients and record audit in measuring appropriateness of optometric care delivery in a university practice’. Using a trained (standardised) actor as an undercover patient, the students and supervising staff were unaware of who they were dealing with.

Generally, students did well (rated at 90%) for completeness and accuracy whereas qualified staff made decisions about what to include, resulting in only a 65% rating (all staff results fell between 76% and 97%). It was also found that record cards can sometimes be inaccurate.

An expressed wish of the team was that their findings would lead to improvements in eye tests and recording of data by all involved.


A project looking at managing spectacles and falls in older patients, co-supervised by Associate Professor Lisa Keay of the George Institute for Global Health, revealed that almost one-third of adults over the age of 65 fall each year.

One issue affecting ‘safety’ is the employment of full or partial Rx changes in new spectacles. The advice from the study was that multifocal and PPL spectacle lenses were probably inappropriate if the patient was frail and/or a user of a walker, as spectacles worn while moving about can affect the fall rate, especially those using bifocal or PPL lenses.

A confocal microscope study of limbal stem cell (LSC) dysfunction supervised by Dr Nicole Carnt, which used subjects who either did not wear CLs or wore EW CLs, showed that despite the relatively distal corneal location of LSCs, LSC dysfunction was capable of affecting the morphology of central corneal cells.

Changes found in the EW CL subjects included: an increase in sub-basal dendrites, a slight increase in the prominence of sub-basal nerves, and a slight alteration of the mid-limbal palisades of Vogt.

The Best Poster was awarded to Ms Anna Yang and Mr Tyson Xu for their research on, ‘Why do miniscleral contact lenses settle on the eye?’ PhD candidate, Ms Rajini Peguda, supervised their project.


Although some view minisclerals as a panacea CL, that is far from the case. However, there are some cases where a CL that vaults the whole of the cornea-limbus area is necessary. They are known to settle back towards the anterior eye after dispensing, often by a considerable amount – in some instances >100 microns, with an average of about 65 microns.

The duo’s research suggests there is compression and a spreading of bulbar conjunctival epithelial cells (KATT CLs with a TD of 16.5 mm were used). In other words, settling is due to a thinning of cells in the bearing areas.

In some cases, that can lead to an increase in inflammatory markers being observed in the miniscleral-wearing eye. The cell densities in the superior and temporal areas (the only areas assessed) were affected, along with an increase in cell diameter.

The Best Rapid Fire presentation was awarded to Ms Laura Hou and Ms Rachael Kim for a presentation titled, ‘The effect of lens diameter on orthokeratology treatment zone centration’. The project, supervised by Dr Pauline Kang, reported that an increase in lens TD did not alter the centration of the treatment zone. It also found that treatment zone diameter and the refractive outcome were independent of Ortho-K CL TD.

KEYNOTE SPEAKERS

Anna Yang

Charles Wu

Marriette Khalil

Mary Tran

Myopia

Professor Sankaridurg is the Program Leader of the Myopia Program at the BHVI in Sydney. According to an Indian study, in 2015 36.4% of the population were myopic, 10.8% were hyperopic, and 52.8% were emmetropic.

In China, studies have shown that modern children reach myopic parity with their parents by the time they are just 11-years-old and, by 18 years of age they are, on average, 1.94 D more myopic than their parents. If that generation cycle was to continue, the problem becomes more obvious.

Already, some Chinese pre-schoolers are exhibiting myopia in the 5–6 D range. It has been estimated that by 2050 half of the world’s population will be myopic. What many fail to realise is that the biggest burden of myopia occurs later in life.

Very high myopes (≥–15 D) have reduced VA, even when corrected fully. Axial lengths (ALs) > 26 mm, and myopia ≥–10 D have attendant risks of vision impairment (VA worse than 6/18), POAG, and myopic maculopathy (MM). When older, some 68–73% of the latter group develop some form of MM.

Although not quite as effective as higher concentrations, 0.01% atropine seems to be firming as the weapon of choice in the war against myopia. Side-effects include allergic conjunctivitis and adverse effects on the ocular surface, especially if a BAK-preserved form of the pharmaceutical is used. As such, preservative-free forms are preferred.

The difficulty for many who might otherwise elect to use low-dose atropine is that its use is restricted to those optometrists who are endorsed to use therapeutics. Despite being used by UK optometry for the best part of a century, atropine has never been available to those Australian practitioners who are only endorsed to use diagnostic drugs.

Given the low concentrations envisaged, perhaps thought needs to be given to allowing more optometrists to use atropine for treating myopia. An added complication is that currently, there is no commercial manufacture of 0.01% atropine and the riskier process of compounding from higher concentrations of the drug is the only alternative.

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The high cost of registering such a concentration, despite the availability/ existing registration of stronger variants, probably means that it will be some time, if ever, that 0.01% is available commercially in Australia.

Although not quite as effective, optical management of myopia is, arguably, better established. Approaches include, bifocal/PPL CLs, bifocal/ PPL spectacles, special CLs and spectacles that modify the peripheral defocus, and Ortho-K CLs.

A recent possibility, not yet available commercially, is the extended depth-of-focus (EDOF) CLs designed by Dr Ravi Bakaraju and colleagues from the BHVI. The EDOF CLs use higher-order aberrations to degrade the image quality of images behind the retina to discourage myopic onset and/or progression.

Large US studies have already confirmed that children who use CLs as an anti-myopia method are no more prone to inflammatory events or MK than adult contact lens wearers.

KEYNOTE SPEAKERS

Tyson Xu

Padmaja Sankaridurg

Laura Hou

Minh Dinh

A problem that can be encountered is a rebound effect once treatment ceases. That effect has been found in Ortho-K and some drug studies. The duration of treatment required to avoid a rebound is the subject of ongoing research.

Benefits of Ortho-K include, improved QofL, VA, cosmesis, overall satisfaction, enhanced activities, academic achievement, and an improved perception of the wearer by their peers.

Environmental modifications, especially time outdoors, can reduce onset of myopia by up to 50% and a dose-response effect has been determined, i.e. more is better. As such, 40 minutes a day minimum has been recommended, with some suggesting extending that to nine hours per week or 80 minutes per day.

Unfortunately, outdoor exposure seems to have little benefit in those with existing myopia, rather outdoors is preventative not curative or retarding.

Assuming they share an environment (within limits), if a child has one myopic parent they are 3x more likely to be myopic and if both parents are myopic, their chances rise to 6x. Sankaridurg referred the audience to the BHVI online calculator if an estimate of where particular cases are likely to head is required.

Drs Kang and Watt detailed the myopia clinic hosted within SOVS. It offers service and advice on myopia control, prevention, and arrest. Trials of 0.01% atropine are underway, Ortho-K and other CL options are also employed.

Given the equipment and the expertise available, the long-term results will be interesting to monitor. Email contact for the clinic is: optomclinic@ optometry.unsw.edu.au.

While we are probably ‘not there yet’ as far as definitive answers to myopia and its management are concerned, there are basic steps that can be taken by most involved. At this point in time, the availability of commercial 0.01% atropine and its use by all registered optometrists has appeal.

Alumni evening

Three post-graduate students gave presentations to the UNSW SOVS alumni that attended the evening. The first presenter was Mr Minh Dinh, who canvassed a possible role for coffee as a pharmacological myopia intervention in his presentation titled, ‘Coffee does more than keep you awake’. Optical intervention is the alternative route.


Although acknowledging the current push towards the use of atropine in increasingly dilute concentrations as the preferred pharmacological intervention, Dinh cited the downsides of the effects on pupil size and accommodation, among others. He also highlighted the unknown, long-term effects of atropine as motivation for exploring pharmaceutical alternatives.

Mechanisms affecting the progress of myopia include: scleral remodelling, scleral thinning, fibroblast proliferation, and a decrease in collagen fibril diameter. Dinh plans to use caffeine and atropine eyedrops, as well as a combination of the two, in a randomised controlled clinical trial (RCT).

The whole project will be conducted in Vietnam due to caffeine manufacture in the country, subject availability, and a streamlined ethics approval process. More than 43 student subjects between the ages of 8–12 years will be recruited for the study.

The second presenter was Ms Sidra Sarwat whose presentation, ‘Examining the tear film using quantum dots’, had a cutting-edge appeal because of the use of the magic word – nanotechnology.

Motivated by our poor understanding of the tear film’s lipid layer (LL) dynamics, she is set to use quantum dots (QDs), an optically active complex of hydrophobic and hydrophilic molecules surrounding an inner shell, to visualise lipids. Despite their complexity, the dots only measure some 2–10 nm in diameter.

Described as semiconductor particles, QDs have a property whereby they emit light at frequencies that are dot-size dependent when irradiated with light. They also have longer than average fluorescence times.

Sarwat is using optimised, surface-modified copper (Cu) and scandium (Sc) QDs. Until concentrations are lowered to around 1.33 μg/mL, those QDs can be cytotoxic. For that and other reasons, animal models will be trialled initially and the fluorescence profile over time will be assessed.


A slit-lamp-mounted camera fitted with an emissions filter will be used to monitor the QD’s optical activity. The camera has a sCMOS sensor with a resolution of 2560 x 2160 pixels. Currently, UV wavelengths are used as exciters but the hope is that, eventually, the use of visible wavelengths will be feasible.

The final post-graduate presenter was Ms Mahjabeen Khan, who posed the question; ‘Are contact lenses responsible for more frequent resistant Pseudomonas corneal infections?’ Over the period 2003–14, more organisms responsible for MK have demonstrated increasing resistance to even the supposedly more capable antimicrobials.

Khan is studying the organisms involved in CL-related and non-CL-related keratitis in Australia, India, and Taiwan. Despite having the same genus and species, Pseudomonas aeruginosa, phenotypic and genetic differences exist and some are known to affect the organism’s behaviour, virulence, and antibiotic resistance.

Other factors include: the type of CL and CL material used, antibiotic usage, lens cases, and lens care products employed in the maintenance of the CLs. Generally, drugs are clustered according to their mode of action, i.e. effect on microorganism cell walls, osmotic effects on cells, alterations to protein, RNA, and DNA synthesis, blockage of cell replication, and effects on metabolism including the metabolic pathways involved.

 

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