4 Cover Story REFRACTIVE Laser QUEST FOR PERFECTION LASIK banks on mature technology and reduced complication rates to stay ahead of the competition by Dermot McGrath aser-assisted in situ how many patients fall under the terminally complication rates in recent years. keratomileusis (LASIK) has dissatisfied category over the long term, the “There has definitely been an been assessed and improved by fact that the FDA in the US received just improvement over the past few years which I still believe many more than a decade of clinical 140 “negative reports relating to LASIK” I would attribute to improved technology, “patients disappear studiesL and technological innovation since for the time period 1998-2006 suggests to with better preoperative diagnostics and from their surgeon’s the procedure was first introduced. As some observers that LASIK complication also much better patient screening in terms practices after the one one of the most popular elective surgical and/or dissatisfaction rates are probably of anterior and posterior surface, corneal year of ‘free’ follow- procedures in the world, with one of the under-reported. thickness, and even family history to help up care that most highest safety profiles, LASIK remains the A 2008 study on LASIK complications prevent complications such as post-LASIK provide. Consequently, primary dynamo driving today’s global carried out at Wills Eye Institute (J ectasia,” said Francesco Carones MD, refractive surgery market. Cataract Refract Surg. 2008 Jan;34(1):32- Co-founder and medical director of the I do believe we have However, given the huge volume of 9.), for instance, found that only 29 per Carones Ophthalmology Centre in been underestimating procedures performed since its inception, cent of patients referred for problems Milan, Italy. refractive surgery with an estimated 17 million procedures after LASIK were referred by their LASIK In Dr Carones’ view, the introduction complications in the US alone, it is hardly surprising that surgeon, and a majority (54 per cent) were of the femtosecond laser has played a LASIK complication rates have attained a referred by another eye doctor, while 17 per fundamental role in reducing flap-related higher visibility than many other refractive cent sought a second opinion themselves by complications and corneal ectasia. Christopher J Rapuano MD surgery procedures. searching the Internet or asking friends “The thinner flaps and predictable Even allowing for high overall patient for referrals. thickness of flap creation with the satisfaction rates for LASIK of around 95.4 Christopher J Rapuano MD, lead author femtosecond laser has undoubtedly per cent – based on Dr Kerry Solomon et of the Wills study on LASIK complications contributed to the reduction in post-LASIK al’s 2008 meta-analysis of 19 studies from and director of the Cornea Service and ectasia. I started using the femtosecond 13 countries encompassing 2,198 patients co-director of the Refractive Surgery laser in 2006 and I have had absolutely who underwent LASIK between 1995 and Department at Wills Eye Institute, told no ectasia cases since making the switch “The thinner flaps 2003 (Ophthalmology. 2009 Apr;116(4):691- EuroTimes that many patients clearly felt from the mechanical microkeratome. and predictable 701) – the remaining 4.6 per cent equates uncomfortable “complaining” to their own Intraoperative pachymetry has also helped thickness of flap to a sizeable and frequently vocal minority surgeons, so often sought a second opinion, in this regard, even though the benefit is creation with the of dissatisfied patients. even soon after surgery. probably as much psychological as practical femtosecond laser The type of complications that determine “I still believe many patients disappear since we have usually found very little has undoubtedly which patients end up in the disgruntled from their surgeon’s practices after the deviation from the intended flap thickness minority are familiar to all refractive one year of ‘free’ follow-up care that most anyway,” Dr Carones told EuroTimes. contributed to the surgeons. Corneal ectasia, dry eye provide. Consequently, I do believe we have Michael Knorz MD, medical director reduction in post- syndrome, epithelial ingrowth, buttonholes, been underestimating refractive surgery of the FreeVis LASIK Centre in LASIK ectasia free caps, night vision problems, haloes, complications. Having said that, I have Mannheim, Germany, also highlighted the glare, regression, decentred ablation, light not been seeing as many patients with improvement in excimer laser technology Francesco Carones MD sensitivity, inflammation, infection, make complaints after refractive surgery over with much better ablation algorithms now up a representative but far from exhaustive the past few years as before. That may be available compared to first-generation list of the more common complications because we surgeons are getting better at laser devices. associated with the procedure. it, or perhaps that fewer refractive cases “Modern lasers now more or less all use While many of these complications are are being done because of the economic either aspheric ablations or wavefront- known to resolve spontaneously or after situation, or both,” he said. guided ablations. Surgeons also increasingly treatment in the first six months or so after understand that optical zones should not be surgery, a small percentage of patients, for Technology advances Whatever small in order to save tissue, but sufficiently whom re-treatment or enhancement is not about the economic context, the general large to provide better quality of vision. an option, may face enduring or lifelong consensus from refractive surgeons is that This has definitely improved the optical problems associated with their LASIK advances in laser technology allied to more quality of the outcomes,” he said. surgery. rigorous patient selection have definitely Prof Knorz also emphasised the hard Although there are no reliable figures for contributed to a reduction in LASIK lesson that has been learnt over the years EUROTIMES | Volume 17 | Issue 7/8 5 Courtesy of Amar Agarwal MS, FRCS, FRCOphth Epithelial ingrowth Flap tear in trying to push the limits of excimer laser leading to incomplete or irregular flap as LASIK were among the unhappiest ablation for high myopes or hyperopes. well,” he said. of all patients. “In terms of patient selection, we have Other potential intraoperative issues Despite ongoing problems with dry learned a lot about the poor optics created related to the femtosecond laser have also eye, the situation has probably improved In terms of patient by the correction of higher refractive errors been reported, including opaque bubble somewhat since 2008, believes Dr Rapuano. “selection, we have and subsequently have stopped treating layer, anterior chamber bubbles and “I think surgeons are much more aware learned a lot about these patients with LASIK,” he said. vertical gas breakthrough. these days that dry eye syndrome is an the poor optics created Allon Barsam MA, FRCOphth, a Epithelial ingrowth is yet another issue and we are screening out patients by the correction of cornea and refractive surgeon at the L&D complication that may still occur with better. We are also doing a better job higher refractive errors University Hospital and the Western femtosecond use, added Dr Agarwal, telling patients before surgery about the and subsequently have Eye Hospital in London, UK, agrees that although its incidence is less than with possibility of dry eye. Additionally, I think better patient selection has made a critical mechanical microkeratomes. we are being more aggressive both pre-op stopped treating these difference in reducing LASIK-induced “The best solution for this is to lift the and post-op in treating these patients with patients with LASIK complications such as corneal ectasia. flap, clean it and apply fibrin glue at the cyclosporine, plugs and so forth,” he said. “We now have much better imaging edge of the flap which will prevent any While surface ablation procedures have Michael Knorz MD technology for improved detection of further ingrowth occurring. Another been touted as less likely to induce dry ectasia and forme fruste keratoconus, and effective option is to perform YAG laser as eye than LASIK, Dr Carones said that he are much more proficient at interpreting suggested by Jorge Alio. This low-energy has not noticed any significant difference the topographical data that we obtain procedure uses the YAG laser to spare between PRK and LASIK. and screening out suspect cases,” he said. patients more invasive surgery and avoid “I think the dry eye problem is more Characterising patient factors such as the risks of further complications from a related to the excimer laser than the flap. We now have much young age, residual stromal bed, corneal flap lift,” he said. This issue has taken on such a proportion “ better imaging thickness and so forth have also improved because of the high volume of LASIK technology for outcomes and helped to reduce the risk of Dry eye still an issue The perennial especially in the United States and Europe, postoperative complications, he added. issue of dry eye syndrome is another so everybody attributed the responsibility improved detection complication that has the potential to of the dry eye to LASIK. But if we look of ectasia and forme Flap-complications diminishing cause problems after LASIK, irrespective of at those countries where PRK has been fruste keratoconus, As well as reducing the risk of ectasia, whether the flap has been created by blade performed on a routine basis as a primary and are much the traditional roll-call of flap-related or laser, said Howard M Neff MD, director procedure in a lot of public hospitals we more proficient at complications such as free caps, of refractive surgery, Henry Ford Health know that dry eye may occur as well,” interpreting the buttonholes, partial flaps, flap striae and System, Michigan, US. he said. topographical data decentred flaps, have all but disappeared “I think dry eye remains one of the that we obtain with the introduction of the femtosecond major complications of LASIK.