Lifting the global focus on eye health

Keynote speakers Associate Professor Nitin Verma from Hobart and Dr Heather Mack from Melbourne headlined the 2016 Australian College of Optometry national conference, while the supporting presenters added to the quality of the event.Professor Konrad Pesudovs, currently Chair of Optometry and Vision Science at Flinders University was announced as the new President of the ACO’s governing council during the conference, which was held at Melbourne’s MCG in late October.Among the 2016 awards presented by the ACO were Life Mbership to Professor Erica Fletcher and Associate Professor Rod Watkins and Honorary Life Mbership to Professor Robert Augusteyn.Improving global eye healthAs the founder of the East Timor Eye Program [ETEP], Verma has always had an interest in increasing the standard of eye health in the developing world. His focus is now on cataracts – the largest cause of blindness globally, mainly due to the lack of suitable services in poorer parts of the world.{{image2-a:l-w:400}}There are significant optical benefits to intraocular lens (IOL) implantation after cataract surgery as they offer long-term financial benefits over the patient’s lifetime and are therefore the preferred option. However, Verma believes that manpower and not money is the key to improving eye health in developing economies. Unfortunately, non-medical factors often act as a deterrent to locating staff where they are most needed. He left his position in PNG in 1997 after one-too-many run-ins with PNG’s notorious raskol gangs.As a result, he moved to the Northern Territory where, along with Associate Professor Alex Hewitt (Tasmania), he operated mobile eye clinics supported by trained nurses and aboriginal health workers who undertook much of the patient screening. Those needing further care were referred to ophthalmology, optometry, or general medicine (especially for diabetes).Verma also managed a teledicine operation from Darwin because it was far more cost-effective than in-person consultations.After signing a morandum of understanding in 2000 with the International Red Cross to provide local ophthalmic services, he then travelled back to Timor-Leste with a team of three ophthalmologists, two optometrists, and two specialist nurses.Vitamin A deficiency was common along with the consequences such as xerophthalmia, corneal ulcers, conjunctival Bitot’s spots, and nyctalopia.The ETEP programme commenced in 2004 and the Fred Hollows NZ Foundation joined in 2005. There are up to 11 outreach eye centres now operating in Timor-Leste. One ophthalmologist from Timor-Leste has already been trained and seven more are in training and it’s expected that the program will start to hand-over to local managent this year (2017).Verma noted that in most countries, eye health was low on the list of national priorities in part because the local capacity to manage eye programs was limited as were the resources required. Limited training opportunities held programs back, and ill-defined referral pathways to other professionals hindered inclusiveness and continuity of care.St cell reseach with a retinal focusAssociate Professor Alice Pébay from the Centre for Eye Research Australia (CERA) provided an update on her research into induced pluripotent st cells (iPSCs). Her main focus is apoptosis (programmed cell death).According to Pébay, SC research is important to the study of disease, tissue/organ transplants, genetic error correction within cells, drug screening, and stalling diseases of ageing. Ocular pursuits, however, have proved to be more of a challenge.While functional RPE cells have been ‘grown’, the layered nature of the retina has been a barrier to success. Furthermore, photoreceptors have resisted in vitro attpts to grow th successfully. Retinal ganglion cells (RGCs) have proved to be even more difficult to replicate, probably because each body part has a unique form of neurons and converting SCs into the required form for the retina have failed so far.Gene editing using the nascent CRISPR technology is an ongoing pursuit in many research laboratories but before human trials are undertaken, great care is required to ensure that aberrant cells are not returned to the recipient lest a probl worse than the original disease occurs.Research targeting monogenic diseases is the focus of current research, with more complicated (polygenic) conditions having to wait for the discipline to evolve further. According to Pébay, gene editing is not genetic therapy.Currently, CERA has automated cell culturing to shorten the growth cycle of patient cell cultures and the cell lines of about 100 patients are either being cultured or stored already. While the technology holds much promise, it would se that human ocular uses are quite some way off.


Adrian Bruce Josephine Li Michael Ibbotson Nitin Verma Simon Skalicky

Therapies for glaucomaDr Simon Skalicky an opthalmologist from the RVEEH described glaucoma as a progressive, irreversible, optic neuropathy related to the intraocular pressure (IOP), which is usually, but not always, high. He estimated that 300,000 Australians have glaucoma and that figure is expected to balloon to 400,000 over the next 10–15 years.Although glaucoma is a multi–factorial disease, the only modifiable risk factor rains IOP. Other factors include probls of optic nerve perfusion, free radicals/oxidative stress, glutamate-related neurotoxicity, immunopathological mechanisms, sleep apnoea, myopia, and genetic factors. IOP-lowering methods are surgery, laser, and ocular medications. After detailing the various IOP–lowering medications, their uses, side– effects and combinations, Skalicky raised the issue of compliance, a difficulty in glaucoma therapy.He then progressed to laser treatments including SLT (selective laser trabeculectomy) for use up to the moderate to severe stage of the openangle form of the disease, ALT (argon laser trabeculectomy) that uses a small spot size for irradiation (50 μm vs 400 μm), PI (peripheral iridotomy) for the narrow-angle/closed-angle form in which it has been shown that a tporal iris position reduces any dysphotopsia effect, and the various MIGS (minimally-invasive or micro-invasive glaucoma surgery) often performed at the same time as cataract surgery.The latter is known to reduce IOP significantly and has to be considered a confounding factor in any IOP reduction subsequently.The controversial links between glaucoma and sleep apnoea were admitted and Skalicky advised against various yoga movents involving body inversions. He finished his presentation with a brief overview of neuroprotection endeavours, the several methods under investigation that seek to protect the optic nerve from suffering damage in glaucoma. None are available commercially yet.Digital devices in low visionACO staff mbers Associate Professor Sharon Bentley and Ms Mae Chong presented a summary of the hi-tech devices now providing some relief to those with subnormal/low vision (LV). Many are affordable although some of the larger, more complex, feature–rich products are more expensive.They believe that technically advanced devices will dominate LV aids because they are affordable and are developing at a faster rate than lowertech (mainly optical) devices. Because many LV aid users and the vision impaired (VI) are older, the figures for technology usage are interesting.Some 60% of seniors these days have access to online services and they tend to use tablets, computers, and e-book readers rather than smartphones. About 81% of VI patients use a smartphone, 59% use text-to-speech conversion, 51% use the camera feature as a magnifier, 50% also use large print, and many have learned to use the smartphone camera flash as a torch.Bentley donstrated various EVES (electronic vision enhancent systs) ranging from hand-held to desktop systs. EVES are available offering magnifications from 1.9X to 170X – the latter ploying an X-Y table to move the reading material. Several sophisticated HumanWare devices ranging in price from around $3,000 to $4,000 were detailed, eg, SmartView 360 and Prodigi Connect 12.Newer devices such as talking GPS trackers and head-mounted text-tospeech cameras were also mentioned as were features such as font size/ text zoom, screen magnifier, contrast control, figure/background reversal, cursor enhancent, and voice-over.Both Bentley and Chong concluded that optometrists should better inform patients about their options, taking into account their specific needs, and trying to understand their individual situations.


Sharon Bentley Mae Chong Wilson Heriot Maureen O’Keefe Jolanda de Jong

Sudden vision lossAssociate Professor Wilson Heriot from the medical retina group at CERA delivered a lecture on sudden vision loss.In the era of anti-VEGF and OCT, Heriot described OCT as a tool for optometrists to find ‘invisible’ pathology that is useful when deciding whether or not to refer, what to tell the patient, and often identification of what is seen. He also saw central roles for OCT microangiography and microperimetry.In cases of CRVO, delayed detection/treatment results in worse outcomes. Unfortunately, anti-VEGF treatment can lower inner-retinal oxygen levels leading to ischaia and hypo-perfusion locally. Heriot also noted that hypoxia (low tissue oxygenation) and hypo-perfusion were not necessarily synonymous and recommended that the professions abandon the use of perfused (non-ischaic) and non-perfused (ischaic) terminology in CRVO.The best predictor of final VA in CRVO is the presence of sub–retinal fluid at three months (SRF at three months suggests a poorer outcome). Because radial peripapillary capillaries that supply the RGC layer drain into the CRV, any blockage of the latter leads to increased venous backpressure and capillary swelling. Any resulting RGC hypoxia can result in retinal neovascularisation.Anti-VEGF usage decreases capillary permeability and can make the probl worse. A complication of retinal vascular disease is paracentral acute middle maculopathy (PAMM – a variant of acute macular neuroretinopathy associated with retinal capillary ischaia) that can cause micro-scotomata at the macula resulting in reading difficulties.One possible treatment in retinal vessel blockages is to use a laser to join (shunt) retinal vessels to the underlying choroidal vasculature.Moving to macula holes, Heriot stated that full–thickness macula holes usually close without scars. The most interesting part of his presentation was the revelation that the foveal pit is lined with stellate astrocytes (starlike cells), an bryological residue. To date, textbooks have stated that Müller cells are located centrally in the foveal pit whereas new research shows th to be located more laterally.Astrocytes are arranged radially forming an astrocytic plate. Stellate astrocyte plate traction on the outer limiting mbrane (OLM) can result in the extraction of a full foveal-depth section of the retina.Astrocytes grow outwards (radially) forming a ‘lawn’ enmeshing everything nearby and the existence of an astrocytic plate can produce microholes at the fovea. The OLM is a malleable tissue with pores that open as cells enlarge in conditions such as diabetic hyperglycaia and Heriot likened the result to an elastic mesh used to restrain luggage on a roof-rack.Moving to the theoretical, using finite-elent analysis, the CERA team has been able to show that blunt trauma to an eye with vitreous attached to the astrocytic plate can result in traction on a ‘column’ of foveal tissue. Any resulting PVD can tug on, and lift, the column from the retina producing a hole.Because fault lines exist between foveal cones, predicting the outcome of such trauma is difficult and the fibre layer of Henle in the macular region (a layer of oblique axons in the central retina) can contribute to hole formation.To repair a macula hole, vitreous movent must be prevented to stop local hydraulic ‘jets’ exacerbating the situation. So-called pseudo-macula holes only involve the inner retina, leaving the outer retina intact. Patients should be referred if they are symptomatic, have reduced VA, or complain of metamorphopsia. While surgery for retinal hole closure is possible, closure can occur spontaneously. Referral is better sooner rather than later but is not an ergency.If holes are < 400 μm deep, 95% will close with surgery and a facedown posture is not required. Holes >600 μm are a surgical challenge and treatment may include a full-fill bubble (>95% of the vitreous cavity), which, by Pascal’s Principle, translates to uniform pressure inside the eye (closed syst) that is not posture-dependent.Because a vitrectomy usually leads to a cataract in the over 50s, some surgeons perform cataract surgery (IOL implantation later in the same session) before a vitrectomy in the long-term interest of vision. High myopia is now a serious complication because the posterior pole is stretched and abnormal.Once again, the ACO deserves congratulations for producing a quality entertaining and educational conference. Its next annual conference will be held late in 2017.

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