Eyeworld

EW REFRACTIVE 38 August 2018 Device focus by Michelle Stephenson EyeWorld Contributing Writer bing, the risk of ectasia is virtually null with these three techniques," Dr. Gatinel said. Future Dr. Slade thinks that surgeons will be performing more SMILE proce- dures in 10 years. "However, I do not see LASIK going away; it's too good of a procedure. I think we will be doing more lens-based surgery. IOLs are getting better, so I think that's becoming more of an option. Maybe someday, we will be doing one-third SMILE, one-third LASIK, one-third lens-based procedures, and a few PRKs," he said. Dr. Cummings said that it will be difficult for any procedure to beat the popularity of LASIK. "Centration is exquisite and highly controllable, precision is in the 0.25 µm order, and customization is possible with topography-guided and wave- front-guided LASIK. In the next 12 months, customization will be possi- ble with ray tracing-guided ablation profiles. There is the fast recovery, too. SMILE will advance, however, and as the technology improves with increased precision and greater ability to customize, it will grow in popularity. I don't think that it will surpass LASIK in 10 years unless there are significant advances on the technology front," he said. Dr. Gatinel agreed. "LASIK has maintained its supremacy over PRK for the past 20 years, and it has still prevailed over SMILE during the past decade. If there are no significant advances in SMILE in the next 10 years, I would not doubt that we will still have LASIK as our predominant corneal refractive technique," he said. EW Editors' note: Drs. Cummings has financial interests with Alcon (Fort Worth, Texas). Dr. Gatinel has finan- cial interests with Alcon, Nidek (Gama- gori, Japan), PhysIOL (Liege, Belgium), and Carl Zeiss Meditec (Jena, Germa- ny). Dr. Slade has financial interests with Alcon and Carl Zeiss Meditec. Contact information Cummings: abc@wellingtoneyeclinic.com Gatinel: gatinel@gmail.com Slade: sgs@visiontexas.com it has been more than 3 years since the primary LASIK procedure, he rec- ommends enhancement using PRK. Dr. Gatinel recommends LASIK for a –2 D correction, a –6 D cor- rection, and hyperopia correction. "As far as enhancement, lifting the LASIK flap can be performed even 20 years after the initial procedure. It warrants time/refraction evolution customization. Enhancement can be indicated not only in the case of refractive regression, but also when the visual needs are changing, such as presbyopia. The fact that en- hancements are easy and safe gives LASIK a great advantage over PRK (pain and regression) and SMILE, which can be enhanced with PRK but with an increased risk of haze," he explained. Safety Dr. Slade said that all three proce- dures are safe, but he prefers LASIK and SMILE to avoid the open cornea that is required with PRK. "Both SMILE and LASIK avoid the wound healing. As far as which is safer between LASIK and SMILE, safety is something that you can give an opinion on, but to prove safety, you must do thousands of eyes to be statistically significant," he added. Dr. Cummings said that PRK and SMILE provide the least chance of flap dislocation, while LASIK has the least chance of haze. "Overall, all three are very safe," he noted. Dr. Gatinel said that safety in refractive surgery depends mostly on the quality of the indication and patients' education. "All proce- dures are safe, as long as they are performed adequately on a patient who is a good candidate and who will comply with the postoperative guidelines and regimen," he said. He added that the main risk factor for PRK is regression of the re- fractive effect (epithelial regression), sometimes accompanied by haze. "The main risk in LASIK is persisting dry eye over the first year, which can cause discomfort and visual quality reduction. To me, the main risk in SMILE is incomplete lenticule ex- traction, which can cause definitive irregular astigmatism. With proper patient selection and education on the dangers of postoperative eye rub- at day 1. "PRK came in third place on both vision and comfort," he said. Dr. Cummings agreed, noting that LASIK has the fastest visual re- covery, followed by SMILE, with PRK bringing up the rear. Most expertise Dr. Slade noted that there is a learning curve with SMILE. "We all know how to do LASIK at this point. SMILE is a new technique, and it has a little bit of a learning curve, but it's not bad," he said. Dr. Cummings said that the procedure that requires the most ex- pertise depends on which platform you use and how you customize the procedures. "In purely technical terms for the operational aspects of the surgery, PRK is simplest, then LASIK, and finally SMILE is the most challenging," he said. Dr. Gatinel agreed. "PRK is the easiest technique to perform, and the transepithelial option makes it virtually surgeon-independent. SMILE is the most demanding tech- nique because it requires a manual dissection of two interfaces and an intact lenticule extraction," he said. Correction of –2 D, –6 D, and hyperopia The surgeons were asked their pref- erence for a patient who has a thick enough cornea to undergo all three procedures and requires a correction of –2 D. Dr. Slade recommended LASIK for this patient. "I would do LASIK. We'll do SMILE down to –3 or so, but typically do LASIK," he said. His preferred enhancement method for LASIK is to lift the flap and perform LASIK. For SMILE, it's PRK on top of the SMILE. "We haven't had to do many SMILE enhancements because it's pretty accurate," he said. Dr. Cummings said that LASIK provides the fastest recovery and the best results for a correction of –2 D and –6 D. For correcting hyperopia, he also recommends LASIK. "I use IOLs if the patient is older or the re- fraction is more than +5 D," he said. His preferred method of enhance- ment is LASIK with LASIK flap lift within 3 years. PRK is the enhance- ment technique of choice for PRK. If Three surgeons share experiences with these ways of correcting refractive error S MILE, PRK, and LASIK are FDA-approved methods to correct refractive error. EyeWorld asked three surgeons from around the world how and when they are per- forming these procedures. Stephen Slade, MD, Hous- ton, and Arthur Cummings, MMed(Ophth), Dublin, Ireland, perform all three procedures. "I was an investigator for the SMILE studies, so I have been performing SMILE for several years," Dr. Slade said. "Additionally, I perform LASIK and PRK." He noted that he performs LASIK more often than the other two procedures. "SMILE is not FDA approved to treat astigmatism, so many patients with astigmatism are still being treated with LASIK," Dr. Slade explained. He thinks there is a significant advantage to being able to offer all three. "You don't have to offer ev- erything, but we've found it's a real advantage to be able to offer SMILE. We do have people who come in asking for SMILE. We're not market- ing it, we're not advertising it, but people find out about it," he said. Dr. Cummings primarily performs LASIK and PRK, but has also done some SMILE procedures. "LASIK provides the best visual results in my hands with the least downtime," he said. Damien Gatinel, MD, PhD, Paris, France, performs only PRK and LASIK. "I perform LASIK most often because it has the broadest range of indications and provides the fastest recovery with minimal discomfort. PRK is indicated when LASIK is not suitable, such as for patients with thin or irregular corneas," he said. Fastest recovery According to Dr. Slade, in the FDA trial for SMILE, which treated one eye with SMILE and the fellow eye with LASIK, LASIK provided eyes better vision at day 1, but the SMILE eyes were a little more comfortable User feedback on SMILE, PRK, and LASIK

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