Gathering of minds at ANZGS 2018

Almost 120 delegates attended the two-day, packed program at Sydney’s Radisson Blu Hotel, which was headlined by glaucoma surgeon and acadic Mr John Salmon (UK).Salmon is well known in glaucoma circles for his publications on the topic, and his erudite and engaging style when presenting on his area of expertise. His links to Australia are more than coincidental, as he has mentored a number of RANZCO fellows doing glaucoma subspecialty fellowships in the UK, principally at the Oxford Eye Hospital where he is the director of glaucoma services.Several of those fellows were at the meeting. An expatriate South African, he has been immersed in ophthalmology since 1980 and became a Fellow of the Royal College of Ophthalmologists (RCO) in 1988. His doctoral research at the University of Cape Town (conferred 1993) was on chronic angle-closure glaucoma (CACG).He has filled numerous acadic positions including senior lecturer at the University of Oxford; tutor, and later, program director and clinical supervisor with the RCO. He is still an RCO examiner and holds awards from Oxford (including the Ida Mann Gold Medal), University of Witwatersrand, the South African Glaucoma Society, and, presented at this meeting, the Ronald Lowe Medal named after the noted Melbourne ophthalmologist and researcher (1913–1998).Lowe spent time at the University of Melbourne, Moorfields Eye Hospital (London), and eventually the Royal Victorian Eye and Ear Hospital (RVEEH), culminating in the position of eritus Ophthalmic Surgeon in 1973.Importantly, Lowe became the second head of the RVEEH’s Glaucoma Research Unit (founded 1957 as the first such unit in Australia, Lowe’s tenure spanned 1963–1975). He too was focused on angle-closure glaucoma, possibly because of its acute presentation and the attention that draws.It became apparent during the meeting that despite the large body of knowledge pertaining to glaucoma, we have a long way to go before anything approaching a complete understanding is achieved. It appears as if the more we know, the more we realise how much rains unknown, and most presentations involved interaction between speaker, session expert panels, and the audience.This writer was rinded of the early days of soft contact lenses in Australia, during which ophthalmic practitioners met regularly to learn and to relate experiences. As we were all on a learning curve, a mutual self-help ethos developed to deal with complications arising from, and issues related to lens care, etc., and advances were made through practitioner ‘parallel processing’ with considerable success.Case presentationsDr Anmar Abdul-Rahman (NZ) began his presentation by revealing that images from a confocal scanning laser ophthalmoscope were not only useful for revealing retinal nerve fibre layer (RNFL) changes, but could also be used to disclose eye cyclotorsion and the presence of intra-retinal fluid. Additionally, knowing the width of confocal scanning laser ophthalmoscope (CSLO) scans (six millimetres in his instrument’s case) allowed useful scaling of image features.In his case of peripapillary retinoschisis in a glaucoma patient, Abdul- Rahman noted that the pits seen in the optic disc could often be resolved by a vitrectomy for reasons no one understood. He raised a developmental boundary defect between disc and retina or a disruption of development pathways as possible aetiologies of the retinoschisis.Dr David Manning (ophthalmologist, NSW) presented a case of a myope (around –4 D) who was diagnosed with glaucoma in his 40s in 1992. The patient went on the have LASIK performed in 1998 (well before Manning got involved) with a monovision approach to vision correction. At that point, Salmon offered the simple yet sage advice that, “Glaucoma and LASIK was a no no”. With that in mind, it was hardly surprising that, in the 2000s, the patient’s IOP started to rise and Drance haorrhages were also noted.The patient was prescribed Lumigan and Timolol, and his IOP rained around 21 mm (of Hg pressure). Salmon suggested surgery for the case, as very low pressures were needed to preserve vision. The discs’ appearance was noted to be worse than the visual field defects measured would suggest.Salmon then suggested that 12 mm IOPs were required and he recommended a trabeculectomy with the application of mitomycin C (MMC), a chotherapeutic agent that possesses anti-tumour and anti-scarring properties (by inhibiting DNA synthesis). He counselled against the installation of a tube or a tube and medication combination, a recommendation partly related to the scleral thinning in myopia.He went on to recommend that the other eye be treated similarly, prophylactically.Manning revealed that he had done just what Salmon recommended, a trabeculectomy early on, despite the patient’s resistance to the idea.

KEYNOTE SPEAKERS
Anne Brooks	David Manning	Annie Gibbins	John Landers	Ridia Lim	Nathan Kerr

Colour visionColour vision in glaucoma was the topic presented by Dr Ellie Bowditch (RVEEH, Melbourne). While colour vision is a common assessment in optic neuropathy, its role in glaucoma assessment is not as well established and the possibilities poorly understood.In an effort to rectify that gap in knowledge, Bowditch and colleagues undertook to assess the nature and prevalence of colour vision defects (colour dyschromatopsias) in a glaucoma population using the so-called desaturated panel D-15 test, a.k.a. Lanthony’s Desaturated 15-Hue Test.Their prospective study enrolled 110 subjects who had already been diagnosed with glaucoma, including seven with compressive optic neuropathy (CON). A control group of 15 normals was also recruited. They found significant differences in test scores across all glaucomas (POAG, OHT, PACG, secondary glaucoma, and CON).The glaucomas could not be distinguished from CON cases by severity of score deviations from normal. However, they did find that more CON cases exhibited mixed-type defects (B-Y and R-G), whereas the other cases tended to have simple B-Y defects. They concluded that the D-15 test used was a simple tool for assessing colour vision defects in glaucoma patients.Visual field assessmentDr Lukas Sahhar (RVEEH) and colleagues compared the Melbourne Rapid Fields (MRF) test performed on two sizes of Apple’s iPad tablet computer (at 33 cm) – a 9.7” iPad (MRF-s), and the 12.5” iPad Pro (MRF-p) – with the more common Humphrey Visual Field Analyzer (HFA) using the 24-2 Swedish Interactive Threshold Algorithm.{{quote-A:R-W:450-I:2-Q:"While diabetes-screening programs are expensive, I believe that they are cost-effective."-WHO:John Salmon, Glaucoma surgeon and acadic}}The MRF app is the brainchild of Professor Algis Vingrys from UniMelb’s Department of Optometry and Vision Sciences, and ophthalmologist Dr George Kong (RVEEH). A total of 44 patients were recruited – nine normals to act as a control group, six glaucoma suspects, 10 with mild glaucoma, and 19 moderate to severe glaucoma cases.Earlier, some cases were rejected because of poor VA, intraocular surgery within six months of the study, or generally poor performance on one or more of the ‘instruments’. The smaller iPad requires four changes of fixation to cover the field size required, whereas the larger iPad Pro required only one change.Both iPad devices were significantly faster than the HFA, with the MRF-p being faster at 4.01 min vs. 5.29 min, while the HFA took 6.56 min. Statistical analyses confirmed a high correlation between the MRFs and the HFA.The team concluded that in particular, the iPad Pro with the MRF app was an efficient method of assessing visual fields rapidly in a clinical setting. However, one admitted drawback under investigation still is the control and monitoring of patient fixation.The prospect of ‘DIY at home’ visual fields was raised during the discussions that followed the presentation. The app provides multilingual guidance and instructions, while it costs $29 from GLANCE Optical or $100 for a subscription with updates included. A free trial version is available from the Apple App Store.For reasons related to either the operating syst or syst architecture, it is unlikely that an Android version will be released in the near future (writer’s conversation with one of the developers circa 2016).

A novel challenge testFlawed though they may be, most will be familiar with the water-drinking and dark-room provocative tests for glaucoma, along with the possibility of accidental provocation when a mydriatic is instilled. However, in a novel update, a team of researchers from Adelaide’s Flinders Medical Centre, headed by Associate Professor John Landers, has trialled a new test using ibopamine, a topical drug that induces a tporary increase in aqueous production in order to stress the test eye’s outflow facility.In their context of glaucoma differentiation rather than detection, 119 glaucoma suspects and early-stage glaucoma patients were exposed to two drops of ibopamine 2%. The pharmaceutical achieves maximum effect by about 45 minutes but overall, its activity lasts 2–6 hours.The team’s aim was to determine if changes induced by the challenge were associated with progression of RNFL thickness losses, or visual field changes.The group of 119 was comprised of 95 glaucoma suspects and 24 early-stage cases. The mean IOP elevation was two millimetres (0–11 mm Hg) but 29% of cases showed a greater than four millimetre elevation. While the latter group was 4x more likely to show progression of field losses, statistical significance was not reached.Similarly, among the glaucoma suspects, there was a trend towards a more rapid rate of recent RNFL loss (thinning). Having a positive test was associated with a more rapid rate of recent RNFL loss among early-stage cases that was significant. While the original study is ongoing, according to Landers, it is probable that a study of some 200–500 patients may be required to reach valid conclusions.Tonometry at homeDr Mona Awadalla from Flinders Medical Centre provided details of a study in which the iCare HOME impact-rebound tonometer was used by glaucoma patients to measure diurnal variation in their IOP and to determine if the data was associated with the disease’s progression. Training was estimated to take 10–20 minutes and patients were required to use the device four times daily for 2–4 consecutive days.Of those that accepted the invitation to participate, 153 (84%) completed the requirents fully, of which 12 (7.8%) exhibited elevated IOP outside office hours, elevations that would have gone unnoticed otherwise (out-of-hours: 35.6 mm, in-office: 21.4 mm). That sub-group of 12 showed significant progression of RNFL loss.While some right-handed patients expressed some difficulty measuring the left eye, Awadalla claimed that her preliminary study donstrated monitoring diurnal IOP was important. During the discussions that followed, Professor Ivan Goldberg suggested that ‘spikers’ be given a water-drinking test.

More reading: Fighting 'the silent thief of sight': Report Part 2