New generation intraocular lenses (IOLs) are changing the game for patients seeking more spectacle independence, with reduced visual disturbances. Insight speaks to two surgeons with early access to a new Bausch + Lomb LuxSmart platform now available in Australia.
Whether they are motivated to prolong an active lifestyle or wish to no longer wear glasses for most tasks, patients are increasingly demanding more from their cataract surgeon beyond what’s possible with a monofocal intraocular lens (IOL).
For this reason, Adelaide ophthalmologist Dr Paul Athanasiov has made it a priority to embrace IOL innovations, a trend currently being spearheaded by the resurgence of lenses offering extended range of vision, sometimes referred to as enhanced depth of focus (EDOF) IOLs.
“Even though there are excellent lenses around, they all have slightly different good and bad points – and if you don’t try something else, you don’t know what you’re missing out on,” he says.
“When I was approached by Bausch + Lomb (B+L) to begin implanting its newest IOL platform, I was interested because I’d seen it had performed well in Europe and could be used on most patients. I wanted to try something different and the early results have been impressive. You can base a decision on whether you’re going to continue with a lens after the first 10 implants – then refine your approach from there – and now I’ve performed more than 150 surgeries with this lens.”
The lens Athanasiov is referring to is B+L’s new LuxSmart Preloaded, a premium hydrophobic IOL of which he was the first to implant in Australia. A toric version will follow soon.
The premium IOL was a feature at the RANZCO Congress in Brisbane in October 2022, offering a range of vision required to cover the major needs of cataract patients in their daily activities. Essentially, surgeons report the lens provides distance and intermediate continuous vision with some spectacle dependence for near tasks. Some patients can reportedly read unaided in many cases, especially with mini monovision .
Importantly, LuxSmart offers a potentially similar dysphotopsia profile as a monofocal – an issue that traditionally held back premium posterior chamber IOLs (PC-IOLs). In Clinical Ophthalmology, Campos et al reported the LuxSmart achieved higher performance for uncorrected intermediate and near vision compared with a conventional monofocal IOL, without increasing the risk of photic phenomena, concluding the LuxSmart “may be an attractive and safe option for patients who desire spectacle independence for distance and intermediate vision”.
B+L has achieved this with a lens that is based only on refractive profiles (Pure Refractive Optics Technology – PRO Technology), meaning there are no diffractive areas.
For Athanasiov, it’s been fascinating to see the PC-IOL landscape change dramatically in recent years. In his practice, Eye Surgeons SA, which recently joined Vision Eye Institute, so-called EDOFs were infrequently considered, but are now being offered in up to 90% of patients with private health insurance or seeking a lens exchange.
“Since using the LuxSmart, I’m very confident in saying that we’re going to hit excellent vision for distance. As with any EDOF, you might not get as much near as you were hoping – and that can be pupil dependent, how far away the patient is holding things and the surgeon’s ability to nail the refractive aim – but I feel it’s a more of an ‘everybody lens’,” he explains.
“When talking about intermediate vision, it frustrates me that we sometimes downplay the ability to see things up close. I will measure intermediate vision on a formal chart and if they can read N5 – which they usually can – that’s highly functional; you can essentially do everything you need to out in the real world without glasses, whether it’s seeing the car dashboard or a price tag. It is intermediate, it’s not 30 or 40 cm, but it has a near vision-like effect on your daily life.”
Intermediate vision performance
To demonstrate the LuxSmart’s performance, B+L has been focusing on through-focus modulation transfer function (MTFa), an objective metric to assess the optical quality of IOLs. Via this method, maximum optical quality and depth of focus is determined by the height and width of the MTFa curve.
In the Journal of Refractive Surgery, Azor et al estimated visual acuity and the range of vision of four new ‘extended range of vision’ lenses using the through-focus area under the MTFa curve. They said the LuxSmart and Vivity performed similarly in the intermediate range (-1.00 to -2.00 D) with a 3 mm pupil, with both IOLs showing better performance than the other lenses for that range that also featured in the study.
“The MTFa peak position of the LuxSmart IOL showed pupil dependence, with a myopic shift of approximately -1.00 D for the 2 mm pupil, thus benefiting near vision along with the pupil constriction (miosis) experienced by patients in this viewing condition,” the study authors reported.
“The range of MTFa values of 20 or greater (expected visual acuity = 0.0 logMAR) remained wide for the 2 mm and 3 mm pupil. This effect seems to indicate that the central part of the lens, with the combination of fourth and sixth orders of spherical aberration (SA) of opposite signs, still has a noticeable effect when the pupil widens to 3 mm. As the pupil enlarges further, the aberration neutral periphery of the lens takes part, which may explain the shorter focus extension for a 4.5 mm pupil.”
Further, several studies have demonstrated LuxSmart achieves a “useful range of vision” of 2.3 D for a 2 mm pupil size, 1.7 D for 3 mm and of 0.8 D for 4.5 mm.
In terms of dysphotopsic phenomena, when patients consent to surgery with LuxSmart, Athanasiov is careful to advise they may encounter haloes at night.
“But I haven’t had anybody with LuxSmart who’s seen those yet. It doesn’t mean they won’t occur, but I’ve been specifically telling them in advance and asking afterward, and zero out of the more than 150 surgeries I have performed haven’t reported this.”
Additionally, B+L has designed LuxSmart so that it is only available in a preloaded system. The company says this potentially means less risk of IOL damage and mishandling, while producing faster and more predictable delivery with less wound stretching.
For Athanasiov this will provide some convenience for his ophthalmic nurses who are already well-trained in IOL loading, but he expects the pre-loaded system to have benefit in states like Victoria – where nurses don’t always load IOLs – as well as regional parts of Australia where there is variability in the skills of nursing staff.
Demands for PC-IOLs
Ask any surgeon why there is increased demand for PC-IOLs, and they will explain there are myriad reasons. Some believe new IOL technology is driving greater awareness, while others say patients are becoming more engaged in their care. Or perhaps both factors are feeding one another.
In his experience, Athanasiov puts it down to word-of-mouth referrals with patients wanting some spectacle independence much like their friend, neighbour or clubmate at lawn bowls.
Another factor could be increased demands on the vision system for near and intermediate tasks. Research cited by B+L shows the use of digital devices by Australian seniors in the near and intermediate visual range has increased in recent years, with senior internet use also increasing from 68% to 93% from 2017 to 2020.
In Europe – where the world’s first LuxSmart was implanted by Czech ophthalmologist Dr Pavel Stodulka in 2020 – people over 55 years spend at least six hours daily on activities such as games and computer use, reading, TV, socialising, exercise, recreation, and travel.
“It was a great honour from B+L to trust me and the Gemini Eye Clinic team to perform the first LuxSmart implantation,” he explains. “It’s very rewarding to be able to push the bar higher in eye surgery especially with such a great device.”
After implanting the lens in a significant number of patients, Stodulka has been impressed by the LuxSmart’s ability to achieve stable intraocular position thanks to its four-point fixation haptic design and material.
“This is very important for every premium IOL with complex optic design,” he says.
“In terms of the visual performance, after assessing patients post-operatively, the lens provides high quality distance vision, and at the same time, a lot of patients can read unaided especially with mini-monovision, which I really like.”
During surgery, Stodulka says the surgeon needs to show some patience for complete lens unfolding, but he recommends pushing both IOL optic edges apart by bi-manual cannulas to speed up the process.
“The lens centres reliably and the fully pre-loaded system makes the life of the surgeon easy,” he says.
“For Australian surgeons who will begin implanting the LuxSmart IOL soon, my advice would be not start on myopes and patients with dry eye. I would aim for -0.5 D or -0.75 D of monovision to increase the depth of focus. And stick to the old rule: under-promise, over-deliver.”
Reference
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Australian Communications and Media Authority. Communications and media in Australia; The digital lives of older Australians May 2021.
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