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Every year a city in the US hosts the American Society for Cataract and Refractive Surgery (ASCRS) conference. Every year new technologies are assessed. Every year has a different buzz word. Usually the buzz is created by overwhelming and compelling clinical data that shows a step change towards a particular technique through an evidence base. This year was different.
Using a laser to treat a cataract or 'laser cataract refractive surgery' (LCRS) is not exactly a new concept. What changed in 2011 was a procession of the world's best known and credible surgeons aligning themselves to the technology with unequivocal support - despite scant data. Perhaps only a few thousand eyes have been treated using LCRS. Not vastly more than this time last year and only a tiny fraction of the estimated 18 million worldwide annual cataract procedures. Out of the five companies that have publicly declared their intention to offer LCRS technology, only two have FDA approval to be operative in the US and only one could be described as 'in commercial use'. Just. There is very limited published data on the step change of patient safety or accuracy of result. Sample sizes of the various ASCRS presentations were generally small and the clinical conclusions somewhat guarded. Yet despite all this, the vast potential to unlock a new era in safety and efficacy was so believed, it was almost palpable. Why?
Think about three elements of cataract surgery.
? A surgeon needs to manually place a diamond knife into tissue to create incisions. If the knife waivers from side to side a bit, the incision is wider than necessary. Now instead imagine a micron accurate laser that always creates a self-sealing wound of the perfect architecture. Infection risk and astigmatism management now look very different
? A surgeon needs to try to manually create a perfectly centred circle in the anterior capsule and place the IOL in the optimal effective position to create the optimal power effect. Now instead imagine a micron accurate laser that always creates a perfect circle in the anterior capsule, which is always perfectly centred and therefore always an optimal lens power opportunity for the patient. Visual results now start to look very different
? A surgeon needs to fragment the lens before removing it, avoid rupturing the posterior capsule and especially avoiding vitreous loss. This step has the greatest learning curve and variability. Vitreous loss can occur in as many as 5 per cent of treatments. Now instead imagine a micron accurate laser where the posterior capsule always remains intact and the phaco energy required to remove the lens was lower and safer. Safety and patient recovery now start to look very different.
The end result? Image-guided cataract surgery with more accurate effective lens placement, better postoperative adjustment by the patient, better vision and all with a safer profile. In short a procedure that is more predictable, safe and reproducible where 'laser precision replaces the most imprecise and manual steps of cataract surgery'. That's the promise anyway. What is certain is cataract procedures have about 10 times the complication rate of standard laser refractive surgery and have visual results only half as good. The intention of LCRS is to close that gap. How much by? Who knows, but practically every authority on this field believes enough to create a new standard of care. The mass of data heading toward peer-reviewed publication will soon tell us.
Pinhole principle
Presbyopia was the other principal area of note within ASCRS this year. It will remain so until someone unlocks that massive group who just wear ready-readers. In-lays are gaining ground. The Kamra in-lay, produced by AcuFocus, works on a pinhole principle increasing depth of focus and was the most prevalent in terms of papers presented. Evidence for 'concurrent' Kamra, meaning correcting hyperopia or myopia with an excimer laser and placing an in-lay to correct presbyopia at the time, was also robust. Dr Tomita, Japan, showed impressive results from over 1,000 consecutive eyes fitted with Kamra with an average of five-line improvement in uncorrected near acuity. Another study showed the detrimental effects to distance vision were minimal in the 'in-lay eye', so already a significant improvement over monovision. Four-year data from Dr Grabner in Salzberg found about 80 per cent of patients could still read J3 unaided with a stable effect. The Vue+ lens, produced by ReVision optics works on a different principle by creating central plus power by increasing curvature over the centre of the pupil. Impressive data and impressively robust data capture was presented. All too often the refractive industry doesn't adapt measurement to fit the same success criteria as the patient. Reading J3 sounds fine, but a patient struggling through J3 on a chart with a bright light behind and walking out to buy a pair of plus ones is unlikely to tell you the same story of treatment success. Data on the Vue+ in-lay showed some impressive stats through a validated real-life questionnaire.
In-lays look exciting as a concept and are producing excellent results. What seems clear is that controlled and careful delivery is key. Rush techniques like this, you'll fail. If you plan well and select the patients properly, in-lays are a useful tool in the armoury and look set to continue to gain ground.
In summary, ASCRS in 2011 was the usual mass of quality information but without doubt, LCRS was the take home message by quite some way. However, we should not get ahead of ourselves. The data needs to match the promise, and the level promise from LCRS has set quite an expectation. The small matter of how this is all going to be paid for remains unclear. Will the increased efficiency or clinical benefits create a case for the NHS? How will the private hospital chains react to this technology? How the refractive industry is reacting to LCRS makes me think of a child aged five that has just been bought a fantastic toy aimed at a child aged seven. The child knows it's better, shinier and newer than anything else she has. She just hasn't quite worked out how to fully use it yet. I think she soon will. And there will plenty more to choose from in the next few years. ?
? Mark Korolkiewicz is clinical services director of Ultralase