SCC6: Delegate numbers are still increasing

Specsavers Clinical Conference (SCC6) was held in early Septber at Melbourne’s Convention and Exhibition Centre. The programme was divided into a half-day Clinical Education Sessions programme on the Saturday and the all-day main programme on the Sunday.In opening the Saturday session, which was focused on OCT, Specsavers’ Head of Optometry Australia and New Zealand, Dr Ben Ashby, announced that Specsavers ANZ was investigating the possibility of installing OCT instruments in all their major stores.The pilot study of the utility of an OCT in-store suggested that the number of glaucoma referrals alone tripled. The availability of OCT machines also dovetailed well with the 2016 MOU between RANZCO and Specsavers regarding referral pathways between the two healthcare professions involved.The business model to be applied to the considerable total cost of ownership of an in-store OCT device was not discussed but will make interesting reading once revealed. Specsavers’ stated aims were to improve public health aspects of eyecare and to reduce avoidable blindness.OCT Screening is the futureThe first speaker on Saturday’s programme was brought to Australia to support Specsavers’ OCT investigations. Viennese medical retina ophthalmologist, Dr Carl Glittenberg, senior clinical advisor to Topcon Europe gave a presentation on why OCT screening was the future of eyecare. He is also involved in retinal and ocular imaging research.Glittenberg revealed that in a busy practice, the decision cycle of what path a patient’s care should follow occupies just 3–4 minutes. Issues relevant to OCT include: instrument versatility, the space occupied by it, speed and efficiency, and ease-of-use. It needed to provide clinically valid and legally admissible documentation with a lifetime of at least 30 years, the duration of legal liability in many jurisdictions.{{quote-A:R-W:450-Q: Glaucoma managent should include examinations of the patient’s immediate family. }}The issue of readability of ‘digital’ files 30 years into the future was not aired but rains an issue. Needless to say, Topcon’s leading OCT device, the 3D OCT-1 Maestro, met all the criteria mentioned including its space-saving, swivelling, touch-screen monitor, which allows it to be placed in small, little used areas in a consulting room.The Maestro also offers the advantage of taking real, full-colour fundus photographs as opposed to fundus ‘images’ cobbled using digital data and false colour rendering. True fundus photography was stated to be important in diabetic macular oeda (DMO) and clinically-significant macular oeda (CSMO).A brief animation created by Glittenberg illustrated the versatility of the Topcon offering and its location possibilities in confined spaces. Ease-of-use is taken to the extre and the device has no joystick and uses automated, self-optimising alignment. Two eyes can be scanned and photographed in under two minutes.Importantly, its OCT function can uncover probls earlier than would otherwise be revealed, eventually, by its fundus photography function, e.g. central serous chorio-retinopathy and macular holes. The Maestro ploys 12 mm x 9 mm scans and an optional anterior segment module is also available. The only RANZCO referral pathway function not offered by the Maestro is visual fields assessment.Practical OCT interpretation for diabetic retinopathyMelbourne ophthalmologist Dr Elaine Chang has sub-specialties in both medical retina and corneal, cataract, and refractive surgery. By her estimates, there are 382 million diabetics worldwide, a number she expects to double in the next 20 years.Australia is not immune to the high prevalence of diabetes, nor the expected increase in numbers, and about one-third of diabetics develop diabetic retinopathy (DR). Approximately 90% of diabetics are Type 2 cases and the rest are either Type 1 or gestational (often transient). Individuals with Type 1 diabetes are more likely to develop DR than Type 2 sufferers, as are those whose diabetes was of early onset (before 30 years of age).In other words, the longer diabetes is present, the greater the chance the patient has of developing DR.Treatment of DR with anti-VEGF will usually improve VA by 10–13 letters by 12 months. The PBS criteria for anti-VEGF usage require BCVA of 6/9–6/48 and 78–39 ETDRS letters. DR risk factors include elevated BP, elevated cholesterol, poor diabetes control, and pregnancy. A decreased HbA1c level will result in decreased DR. Generally, the systic control of diabetes needs to be optimised, blood pressure limited to around 130/90, total cholesterol levels <5 mmol/L, and HbA1c <7%.Chong reiterated that anatomical and OCT layers were not identical. Swept-source spectral domain OCT instruments have the advantage of deeper penetration of outer eye structures, especially the choroid. OCT ‘images’ can be read as 2D or 3D images, multi-slide animations are possible, and colour coding can facilitate comparisons.She introduced the term DRIL (disorder of the retina’s inner layers), which are accompanied by minimal or no changes in VA. The efficacy of anti-VEGF injections can be donstrated by thinning of the macula from 400–600 microns initially, to just 250 microns following a sixth injection.Chong finds 3D presentations tend to distract the viewer from what is being investigated, and suggests the use of 2D, line scroll-throughs instead – especially if detail capture in the macular area is to be maximised. If necessary, the image can be switched between colour and B&W/greyscale. In the latter, brighter features are a sign of greater reflectance. The presence of retinal oeda and hard exudates indicate a greater risk of lipid dumping in the central retina, which decreases VA, most likely permanently.She suggested that the retina be monitored for 3–4 months using OCT line tracking before undertaking anti-VEGF pan retinal photocoagulation (PRP), in order to achieve accurate repetition of the assessment. For the uninitiated, Chong warned that it’s possible for proliferative diabetic disease to be present, despite the OCT scan appearing to be apparently ‘normal’.Chong also cautioned that it was possible to have DMO with little DR, proliferative DR and no DMO, and that DMO was usually worsened by any concurrent ocular surgery. She noted that almost nothing happens in isolation and seeking the ramifications was part of diabetic eye care. Ultra-wide field imaging was strongly recommended as the tool of choice.Her attention then shifted to the evolving field of OCTA, with the caveat that it did not detect vessels leaks, and was instead imaging based on the movent of erythrocytes through the retinal vasculature. She recommended referral upon detection of any OCT abnormality, but should AMD or a RVO be detected, referral within 1–2 weeks was recommended – the exception being longstanding cases, in which case a 4–8 weeks’ timeframe was adequate.Referral in less than two weeks was recommended for non-proliferative DR or proliferative DR with or without DMO. Once cleared by an ophthalmologist (often in collaboration with an endocrinologist), Chong is comfortable with optometric monitoring of diabetics. However, she did recommend 3-monthly monitoring for cases with mild DMO and 6-monthly monitoring for quiescent proliferative DR cases.


Ben Ashby Peter Larsen Carl Glittenberg Elaine Chong Lance Liu Mitchell Lawlor Peter van Wijngaarden

OCT interpretation for glaucomaMelbourne ophthalmologist and cataract and glaucoma surgeon Dr Lance Liu is probably well known to many through his online magazine Eye Health Research Review. Apart from the obvious roles that slit-lamps and gonioprisms play in examining the anterior segment in detail, and the various ways of examining the posterior pole, Liu sees a role for anterior segment OCT to assess the anterior angle – especially in cases of possible angle-closure glaucoma.Not only can OCT confirm a diagnosis, but it can also exclude other pathologies. Because glaucoma is a progressive optic neuropathy, Liu saw a role for the Topcon Maestro’s real, colour fundus photo feature as a way of monitoring the centro-coecal retina, including the optic disc and the optic nerve head. However, regardless of the imaging syst used, he warned that the neuro-retinal rim may actually be thinner than it appeared.Liu traced the evolution of glaucoma detection and monitoring from the measurent of IOP in the 1970s, through the use of visual field assessment of the 1980s, to the use of OCT in the mid-1990s. He regards images as being case documentation, but not diagnostic material, and noted in passing that the presence of myopia can confound the appearance of the optic disc. His technique is basically one of correlating images with other clinical findings.Despite the proliferation of useful imaging devices, Liu still recommended looking with conventional instruments (BIO, direct ophthalmoscope, fundus camera, gonioprisms, etc.) because the quality of the images available still relies on patient fixation, pupil size, regularity, the eye’s optics, media transparency and regularity, and instrument reliability.He also raised an issue mentioned by others over the weekend of lectures – the so-called red pixel disease – the automatic assignation of red colour to data points or features outside normative data. While intended to draw attention to abnormal data, it sometimes results in false positive findings when taken at face value, meaning the patient unwittingly becomes a victim of imaging technology.The role of OCT in glaucoma must be considered with the knowledge that it is the end stage of a slowly progressive disease. Glaucoma is a continuum that progresses from the early stages, in which any structural changes are undetectable, through to structural changes affecting function that range from pre-perimetric retinal changes to perimetric changes that can be assessed and recorded.Thinning of the neural retinal rim (applying the ISNT order), baring of circumlinear vessels that once resided at the rim margin, exposure of the lamina cribrosa, Drance haorrhages at the optic disc, and later, peripapillary atrophy, are all signs of the disease.{{quote-A:L-W:450-Q: Without baseline data, the whole process of assessing or diagnosing a case is more difficult. }}As the cup/disc ratio changes by about 0.1 over a span of 40 years and the RNFL thickness decreases between 0.2–0.5 microns per year, or 2–5 microns per decade, there is a need to try to accommodate normal anatomical, age-related changes. Importantly, functional loss follows losses of the RNFL. For that reason, among others, structure and function need to be tested when monitoring actual or suspect glaucoma cases.Risk factors such as elevated IOP, fluctuating IOP, pigment-dispersion syndrome (PDS), and pseudoexfoliation syndrome (PxF) need to be considered when assessing a primary angle-closure glaucoma suspect. Glaucoma cases involving thin (<500 microns) central corneal thicknesses are likely to progress faster and can result in worse effects.Without baseline data, the whole process of assessing or diagnosing a case is more difficult. A fundus photo, an assessment of the RNFL thickness, gonioscopy, OCT, and detailed visual fields (VFs) are all useful baseline data. A fundus image and VFs review are central to any risk assessment at each subsequent visit. Other structural tests should be repeated at 1–2 year intervals, depending on the results of earlier assessments.NHMRC guidelines (2010) suggest that a baseline fundus photo, gonioscopy, and VFs are required for low risk glaucoma cases, followed by a review 1–3 months later and annually thereafter – unless changes are detected. High-risk cases, especially if PDS or PxF are known to be present, follow a similar regimen but with 6–9 month re-assessments, until two consecutive VF assessments show no change, after which the interval can be extended. About 52% of cases show VF progression, while about 12% show progression of optic disc changes.Eventually (<6 years), about 60% of glaucoma suspects donstrate RNFL defects that result in VF defects. Despite that, Liu does not regard VFs as the best test we have. Despite the tools available, he still regards gonioscopy as the gold standard and he also suggested that various ambient light levels be used while attpting to observe the anatomy of the anterior angle in vivo.He also believes strongly that glaucoma managent should include examinations of the patient’s immediate family. Unfortunately, all glaucoma treatments can cause cataracts eventually, as well as ocular surface disease, and blepharitis. Preservative-free drugs were recommended.From his experience, constructive feedback to referring practitioners is not only educational, but also effective in reducing the number of false positive cases he sees. If the risk of glaucoma is low, he suggested the optometrist monitors the patient, however, if the risk is high or the case is a glaucoma suspect, he recommended a timely referral until the case is stable.Liu also made comments on collaborative care; in his view OCT, Goldmann applanation tonometry, and VFs were core requirents, but the different instruments targeting the same outcomes varied from practice to practice. He stated that OCT was here to stay and practitioners so equipped needed to correlate their clinical findings with OCT imaging and data sets.The optometrist’s role was recording baseline data and monitoring any changes subsequently, paying particular attention to the width of the neuroretinal rim, IOP, and the presence of Drance haorrhages.

OCT interpretation for AMD{{image9-a:r-w:200}}Continuing the OCT the, Melbourne ophthalmologist and oculoplastic surgeon, Dr David van der Straaten, gave a presentation on correct interpretation of OCT images. He noted there are subtle differences between retinal anatomy as revealed by traditional staining/microscopy techniques and the reflected/scattered light (B-scans) imaging inherent in OCT imaging technology, ie. the two are not correlated precisely.Features that are more light reflective, e.g. the RNFL synapses and the so-called ellipsoidal zone of the photoreceptors – appear brighter in OCT images and the instrument usually renders th as ‘redder’ in the false-colour sche of an OCT. Purple indicates the top 1% of thickness measures.With increasing eccentricity from the fovea, the photoreceptors get shorter leading to the appearance of a ‘thinner’ retina in OCT images. For purposes of contributing to and using normative data, a circular 6 mm macular ‘grid’ is used according to the ETDRS (early treatment diabetic retinopathy study).Thinning or loss of layers, increased thickness of layers, separation of layers, obvious oeda, blood and exudates, and any outer retinal layer losses are all important features disclosed in OCT images. However, for obvious reasons, cataractous or other optical media changes are a probl to OCT imaging.In a normal OCT image, a complete retina can be confirmed by a lack of any shadowing. Shadowing in the choroid can be caused by the presence or absence of more anterior retinal features, such as peri-papillary atrophy or the loss of photoreceptors. Thickening of the outer retinal layers can be due to non-arteritic anterior ischaic optic neuropathy (NAION).Changes to the vitreo-retinal interface, e.g. an epiretinal mbrane (ERM), vitreo-macular traction, and separation of the inner retinal layers, can often be seen in OCT. Rhegmatogenous retinal detachment results in layer separation and sub-retinal fluid, and an apparent retinal pigment epithelium detachment (PED) is indicative of a separation of the RPE from Bruch’s mbrane. Given the interest in myopia, especially high myopia, OCT is useful in disclosing myopic macular schisis.In cases of recent cataract surgery, practitioners were advised to be aware of the possibility of post-surgical cystoid macular oeda (CMO). It is probable that any ocular surgery has the potential to cause macular thickening, possibly with sub-retinal fluid (SRF). Advanced uveitis and diabetes can also result in CMO and SRF.Van der Straaten divided AMD into non-neovascular, drusen, RPE pigmentary changes, geographic atrophy (GA), and PED. Intra-retinal fluid can be the result of polypoidal choroidal vasculopathy (PPV), characterised by the so-called double-layer sign, a separation within Bruch’s mbrane itself.The audience was advised to seek evidence of disturbances to central vision when screening for AMD, especially if the patient is a smoker or ex-smoker. An annual review was advised, along with potential lifestyle changes and an AREDS II-based supplent, whenever early AMD was detected. In late AMD, GA at the macula can be expected, there is an increased risk of CNV, and within 6–12 months the patient’s driving status can become borderline.Basically, the condition is a central macular disease and Amsler grid changes will usually be apparent, while OCT will show SRF or intra-retinal cysts. If the patient is asymptomatic, they should consult an ophthalmologist within two weeks because of the possibility of CNV. However, if they are symptomatic, an ophthalmologist should see th within one week, especially if there is evidence of haorrhages.From his experience, van der Straaten estimated that 50% of AMD patients improve with treatment, 36% might improve, and about 13% don’t improve despite the treatment(s) given. He summarised the clinical aspects of AMD as: look for changes in OCT, look for CNV, determine any changes in vision, and use an Amsler grid, noting pattern distortions, discontinuities, etc.

<>Part two of Lewis Williams’ report will detail the second day of the conference, which included presentations from the likes of glaucoma surgeon and neuro-ophthalmologist Dr Mitchell Lawler, renowned Sydney ophthalmologist Dr Simon Chen, and CERA researchers Dr Peter van Wijngaarden and Professor Robyn Guymer.
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