The 25th Australian Society of Cataract and Refractive Surgeons (AUSCRS) conference – Code to Success – took place virtually on 23 October 2021, after the planned face-to-face event in Noosa was cancelled due to ongoing restrictions.
As can be expected from an event distilled down to one day from the usual three, the surgical videos and content were more specialised and focussed with less repetition than previously. There was less coverage of basic cataract and refractive surgery, but many great pearls when it comes to dealing with more complex cases. Planning cataract surgery for cases of corneal scarring, keratoconus, irregular astigmatism, post-refractive surgery cases, zonular dehiscence and more, were well covered.
Never failing to impress, AUSCRS 2021 kicked off with a high energy session chaired by co-founder and president, Professor Graham Barrett, titled What’s new? – when the going gets tough – keeping your cool…
It’s important to understand the patient, balance expectations and risk, and plan the best lens for the patient first time round
Dr Lewis Levitz was in good form, with a presentation that revolved around cases of unstable capsular bags. He showed how he had used capsular hooks to stabilise a bag with inferior zonular dialysis, while deliberately avoiding using a capsular tension ring. He noted that having a tension ring in the bag made it hard to remove the hooks.
Dr Georgia Cleary focussed on the importance of pre-op chair time with discussion relating to potential dysphotopsia, and managing unhappy multifocal intraocular lens (IOL) patients. Often touted as a potential solution, IOL exchange is not trivial. Although lens replacement surgery can go smoothly, it can be very complex, a view supported by Prof Barrett. With up to 50% capsular complication rates, this procedure comes at a greater risk than primary IOL procedures. It’s important to understand the patient, balance expectations and risk, and plan the best lens for the patient first time round.
Dr Ben LaHood described a torn posterior capsule during surgery on a retired engineer. He questioned whether he should “hold ‘em, fold ‘em, walk away or run?” While keen to grab his Kiwi passport and a oneway ticket to Mexico, he chose instead to face reality. With an on axis toric lens in the bag, he had to decide to either stay with the trifocal he’d implanted and accept the risk, or explant, replace with a monofocal in the sulcus, and treat residual astigmatism later. In this case he left the lens in the torn capsule with a good result.
In the final presentation of the opening session, Prof Barrett detailed previous phakic IOL refractive surgery procedures for high myopia. In one case, a patient with anterior chamber (AC) IOLs, implanted in 1998, had developed dense brunescent cataract and significant myopia. Coupled with thin corneas and low endothelial cell count, he stressed the added complications and noted that normal IOL formulae don’t work too well when planning end points in such cases. Intraocular contact lenses (ICLs) are easier to explant than AC IOLs but are still challenging. Prof Barrett mentioned monovision with monofocal IOLs as good considerations, and recommended a second incision for implanting replacement IOLs. Surgically induced astigmatism was discussed, as was the importance of data review and surgeon-specific tweaks to the calculations, to improve outcomes.
WHAT’S NEW?
The What’s new? – choosing the right balance – EDOF IOL selection session was hosted by Professor Gerard Sutton.
Dr Brian Harrisberg discussed cases of RayOne EMV (enhanced monovision) extended depth of focus (EDOF) lenses, which were developed in conjunction with Prof Barrett. He mentioned mini monovision in one eye with slight under correction. The EMV IOLs induce controlled spherical aberration to achieve about 1.25D of extended range of vision. Acknowledging that he likes to ‘mix and match’, in one case he used an EMV IOL and a Vivity EDOF design, as he needed a toric lens. He reported no clinically significant difference between the different designs. Another surgeon commented that correcting astigmatism is important in EDOF IOLs, and that better-quality vision, with larger degrees of monovision, can be achieved with monofocal IOLs.
In a presentation titled Peeping through the hole – IC-8 pinhole optics, Dr Uday Bhatt detailed the IC-8 lens design and the advantages of small aperture IOLs for irregular corneas and young traumatic cases. Benefits of small aperture IOLs included ‘pseudo-accommodation’ (depth of field via pinhole), masking of some astigmatism and minimising the effects of aberrations. He advised caution with corneal opacities, especially central ones, as well as cases of macular pathology, large mesopic pupils and cases of reduced contrast sensitivity.
Dr Andrea Ang presented Multiple rings – Symfony diffractive optics, noting that we must be aware of compromises: more focal points and avoidance of spectacles means more side effects. She discussed diffractive optics to achieve increased depth of focus via the Symfony IOL, which is designed for an extended range of distance and intermediate vision, using a ‘diffractive echelette’ to create an elongated focus. Dr Ang shared a review of 50 cases with good distance vision around 6/6, and better than expected near vision, with 50% needing top up glasses for near vision in dim light/small print. Mild night time glare/haloes were reported by most patients. ‘Micro-monovision’ can be used to tweak the range of vision.
Professor Sutton wrapped up session two with his presentation, Is this just a phase? – Vivity Optics, during which he explained how the Alcon Vivity IOL uses wavefront shaping optics that advance or delay the wavefront to ‘stretch’ the range of focus. Again, minimonovision was used to enhance outcomes with most post-op outcomes within 0.50D of target. Distance vision was 6/7.5 or better in 95% of patients with good intermediate vision in 100%, but only 77% were satisfied with near vision (without top up readers). The lenses generally provided decent ‘social vision’. Pupil size was noted to be significant, which might explain the variation in near vision between cases. Vivity is currently his lens of choice for uncomplicated patients. Proper discussion and realistic expectations are important.
The importance of a stable tear film was discussed in the panel session, as was the need to be cautious around dry eye in EDOF cases, as this might affect night time dysphotopsia. Treat cases of dry eye and monitor osmolarity. Severe cases like Sjogren’s are best managed with monofocal IOLs.
Careful selection is important, targeting uncomplicated eyes, but overall the surgeons noted the ‘wow factor’ when things were ideal. Dr Audrey Rostov from Seattle was one of two international presenters who spoke about aberration neutral IOLs in complex cases, as the Bausch + Lomb platinum sponsor speaker. She gave one of the best take-home comments stating that, “we should not use multifocal lenses in multifocal corneas”, such as keratoconus, and also mentioned previous refractive surgery, retinal pathology, traumatic cataracts, missing zonules, multifocal IOLs, glistenings and corneal scars. Dr Rostov discussed the Bausch + Lomb enVista family of IOLs, which are aspheric and aberration-free. As no aberrations are induced with the enVista platform, surgeons are able to preserve the cornea’s natural positive aspherical aberration of, on average, +0.274 } 0.089μm for a 6mm pupil size. This is important for patients’ visual function because there is a strong correlation between spherical aberration and depth of focus. There are benefits to eyes having a specific amount of spherical aberration to enhance depth of focus. A great panel discussion between Dr Rostov, Prof Barrett and Dr Rick Wolfe ensued, continuing in the breakout rooms in the virtual world. Again, monovision was discussed with Prof Barrett defining micromonovision as -0.25D under-correction, mini-monovision as -0.50 to -0.75D and moderate-monovision as -1.00 to -1.50D.
CUTTING CORNEAS
Dr Jacqui Beltz chaired the session What’s new? – cutting corners/corneas, during which Dr David Kent delivered a presentation titled, Creating an even surface – intra-corneal ring segments (ICRS) for patients with keratoconus.
Stating, “give them realistic expectations before they start’, he discussed the types of ICRSs and suggested they be considered in cases where all else has failed (like cases of contact lens intolerance) and where the only other surgical option was a corneal graft. The goal is to flatten the cornea, reduce astigmatism and make the cornea more symmetrical. Complications include infiltrates, low light problems, infective keratitis and corneal melt if rings are too shallow. He noted that cases often only had around one-line improved acuity but that they were more likely to obtain a reasonable spectacle correction than before. Dr Kent suggested avoiding very steep, thin, irregular corneas and central scarring.
Dr David Gunn presented on the first corneal allogenic intrastromal ring segment (CAIRS) surgery in Australia, performed in May 2021, which is paving the way to better sight for keratoconus sufferers. An evolving technique with over 200 cases worldwide since 2017, CAIRS is an alternative to ICRS surgery or grafting, which uses donor stromal tissue implants, instead of the acrylic in ICRS. Because CAIRS can be implanted at a shallower depth than ICRS, it can be used in thinner and steeper corneas. CAIRS segments are sculpted on the day using femtosecond laser. In theatre, a similar femto-laser channel is created on the host, and the sculpted donor tissue is carefully implanted. Finding a ‘better’ implant material, thereby saving donor tissue, would be a great long-term evolution.
Associate Professor Michael Lawless presented Doctor, you did my LASIK… but what about my cataract? He discussed how to plan such cataract surgery, choose the right formulae, and average different results to enhance end points. He showed how post- LASIK ectasia-related aberrations shift as cataracts develop and talked about using an aspheric monofocal lens to enhance outcomes, using a toric lens where indicated, but avoiding torics in highly irregular eyes. He stressed that if a rigid gas permeable contact lens is still needed/desired post-op to use a non-toric and mentioned tweaking with topography guided PRK. He also discussed using pinhole IOLs with good outcomes, highlighting how challenging such cases can be.
Continuing the ‘irregular’ theme, Dr Tanya Trinh presented Smoothing the bumps – PRK for corneal ectasia, during which she elaborated on the challenges of severely aberrated corneas and/or a history of postrefractive surgery ectasia/complications. She explained that topography-guided PRK was indicated where wavefront-guided PRK was impossible due to the condition of the cornea, and noted the importance of refractive predictability, customised treatments, nomogram development and use of cross-linking to enhance stability. The current goal is to improve bestcorrected acuity, with the future goal being to improve uncorrected acuity. This represents a paradigm shift as previously, registrars and surgeons were told to avoid PRK in irregular eyes. Such techniques are worth considering to avoid or delay corneal grafts. She noted an excellent safety profile.
HOME RUN
AUSCRS co-founder Dr Rick Wolfe chaired the day’s closing session with What’s new? – perfect predictions – devices and planning.
Earlier in the day Alex Long of Alcon had taken time out from a family holiday in Arkansas to deliver a platinum sponsor presentation on Alcon’s innovative solutions for improved patient outcomes. Among the innovations he described was Alcon’s vision suite ecosystem including the sci-fi Ngenuity 3D visualisation system. The content of his presentation was elaborated on with a very interesting presentation from Dr Nathan Kerr titled, I’ve looked at things from both sides now… 3D in cataract surgery. The Ngenuity system is a virtual operating microscope, which uses a high dynamic range camera and provides a view for everyone in theatre to see, on a large 4K screen. It provides greater depth of field and increased magnification, allowing for much less refocussing – as well as facilitating less use of dyes by using digital filters to highlight specific tissues. Over and under-exposed image areas are enhanced for better viewing, while also improving patient safety through reduced illumination intensity, thereby reducing the risk of retinal phototoxicity. The Ngenuity system also potentially improves surgeon health and safety, as it helps improve posture, reducing the neck, back and arm problems many surgeons suffer. It seems that, like FLACS, this kind of new technology has protagonists and antagonists – regardless, it is likely to be increasingly found in operating theatres.
In another presentation titled Mission impossible – cataract surgery for keratoconus, Dr Anchal Gupta discussed the importance of topography when identifying keratoconus and the degree thereof, and of understanding the patient’s history and desired outcomes: if contact lenses are needed after surgery to provide decent vision, toric IOLs are not an option. If the condition can be managed by spectacles, then a toric IOL is a possibility. Time needed out of contact lenses before surgery is important to optimise refractive outcomes. IOL calculations are a critical part of the decision-making process and while not as reliable as they are in normal eyes, tweaked formulae like the Kane and Holladay 2 are useful. Dr Gupta drew on cases and an audit of her data to illustrate her approach, and how it helps with planning and achieving significant improvements in post-op visual acuity. The goal is providing driving vision, or better.
The plenary talks were wound up by a closing presentation from Dr Wolfe titled Measuring in microns – OCT in cataract surgery. Illustrating the use of the CSO MS 39 AS-OCT and its 3.5 micron resolution. He noted the important addition of epithelial mapping. Using cases, he illustrated other features enabling differential diagnosis that were not necessarily previously possible with other instruments. He noted the importance of ray tracing in calculating IOL power; because it is based on Snell’s law, there are no confounding factors like formulae and topography.
BACK AND LIVE IN 2022
AUSCRS concluded with a virtual happy hour, wine discussion and a networking function in the virtual world, as reviewed in the December 2021 edition of mivision.
As a meeting of largely Australian and New Zealand surgeons, I dare say there was a more pragmatic, balanced and down-to-earth approach to the talks and topics at AUSCRS 2021. That said, the flavour and breadth brought to these meetings, from dynamic overseas keynote speakers, was missed.
If all goes to plan, we will be able to return to the full-Monty in Noosa, from 3–6 August 2022, with all the bells and whistles, professional and industry interaction, support staff sessions and, of course, the much-missed banquet and entertainment that AUSCRS is famous for.
