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EyeWorld Asia-Pacific December 2024 Issue

1 EyeWorld Asia-Pacific | December 2024 Vol. 20 No. 4 December 2024 The Asia-Pacific Association of Cataract and Refractive Surgeons PLUS Meeting Round Up: Clearing the Path to Perfect Vision In Trend And In Sight: Breaking Barriers in Clinical & Surgical Challenges Scan the QR Code or visit www.eyeworldap.apacrs.org for more information. Clearing Clinical & Surgical Hurdles

2 EyeWorld Asia-Pacific | December 2024 LEARNING FROM THE MASTERS PROGRAM HIGHLIGHTS Visit www.apacrs2025.org for regular updates. APACRS LIM LECTURE The APACRS LIM Lecture is the highest award of the society. Outstanding ophthalmologists who have made extraordinary contributions to the development of cataract and refractive surgery have been invited to deliver this prestigious lecture at its annual meetings. Join us as Prof Thomas Kohnen delivers the 2025 APACRS LIM Lecture titled Bridging Laser and Lens Extraction – The evolution of phakic IOLs on Friday, 22 August 2025. MASTERCLASSES Covering the most relevant and focused topics and conducted by some of the world’s leading surgeons on Thursday, 21 August 2025! Expect the hottest topics in ophthalmic surgery today, where you will learn to master Biometry, Corneal Endothelial Transplantation, Intrastromal Refractive Surgery Updates, IOL Fixation, MIGS for the Phaco Surgeon, Paediatric Cataract Surgery, Phaco 2025, Phaco Complications, Phakic IOLs, Toric IOLS, Vitrectomy & OCT for the Cataract Surgeon, and What They Don’t Teach You in Residency. SCIENTIFIC SYMPOSIA Exciting symposia covering General Cataract, IIIC Lectures – The Perfect Save!, Managing Challenging Cases, Navigating Cataract Complications, Presbyopia... Seeing It All, Refractive Surgery Updates, Today’s Innovation Tomorrow’s Impact, What Would You Do? and What’s New In IOLs? COMBINED SYMPOSIUM OF CATARACT & REFRACTIVE SOCIETIES (CSCRS) – Masters Don’t Always Agree! This combined symposium of the three leading cataract and refractive societies (APACRS, ASCRS, and ESCRS) will look at areas of contention in our constant pursuit of precise and perfect outcomes. There are many ways to achieving optimal outcomes and this symposium will address the most topical controversies in our field covering immediate sequential cataract surgery versus delayed cataract surgery, presbyopia correction in the eye versus on the eye, correcting low astigmatism through corneal incision versus using toric IOL. Join us at this thought-provoking session on Friday, 22 August 2025! APACRS FILM FESTIVAL The APACRS Film Festival entertains and educates, creatively displaying new innovations and breakthroughs in anterior segment ophthalmic surgery. Don’t miss this exciting session on the evening of Friday, 22 August 2025. WISDOM FROM THE GURUS – Top Cataract Surgery Tips Some of the most renowned cataract surgeons each offer practical cataract surgery tips that surgeons can use immediately on their next visit to the operating theatre. Join us to learn top practical tips from experts on Saturday, 23 August 2025. The 37th APACRS Annual Meeting will be held in Ahmedabad, a prominent cultural and industrial hub in India that offers colourful landscapes, unique culinary delights and the famous garba dance. Co-hosted with Ahmedabad Ophthalmological Society (AOS) and the All Gujarat Ophthalmological Society (AGOS) and supported by Intraocular Implant & Refractive Society of India (IIRSI), the 37th APACRS annual meeting promises to deliver a great learning experience in 2025. The hunger for more knowledge and quality education in our delegates means that we always strive to present an up-to date yet relevant and practical scientific meeting.

3 EyeWorld Asia-Pacific | December 2024 CONTENT CATARACT 19 On- And Off-Label Indications For Small Aperture Technology 23 Floaters Getting In The Way Of Postop Patient Happiness? 27 Cataract Surgery In Patients With Keratoconus NEWS & OPINION 49 Role Of Artificial Intelligence In Myopia Control CORNEA 41 Cataract Surgery In Eyes With Endothelial Damage GLAUCOMA 46 Knocking Down XEN Obstacles EDITORIAL 4Clearing Clinical & Surgical Hurdles REFRACTIVE SURGERY 35 The Impact Of HOAs On Refractive Options And Outcomes 31 Angle Kappa And Its Influence On Multifocal IOL Outcomes 6Light Adjustable Lens (LAL) vs. IOL Formulae 10 Phaco vs. Femto 14 SMILE vs. LASIK FEATURE 6Pathways To Precision And Perfection The Combined Symposium of the Cataract & Refractive Societies (CSCRS) explores three areas of contention along the constant pursuit of precise and perfect surgical outcomes, at the 36th APACRS 24th CSCRS Joint Meeting in Chengdu, China.

4 EyeWorld Asia-Pacific | December 2024 Graham Barrett Chief Medical Editor EyeWorld Asia-Pacific • China • Korea • India EDITORIAL BOARD Chief Medical Editor Graham Barrett, MD INDIAN EDITION Regional Managing Editor Abhay Vasavada, MD Deputy Regional Editor S. Natarajan, MD KOREAN EDITION Regional Managing Editor Hungwon Tchah, MD Deputy Regional Editor Chul Young Choi, MD APACRS Publisher: EyeWorld Asia-Pacific Edition (ISSN 1793-1835) is published quarterly by the Asia-Pacific Association of Cataract & Refractive Surgeons (APACRS), c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (65) 6322-7469, fax (65) 6327-8630, email ewap@apacrs.org. Printed in Singapore. Editorial Offices: EyeWorld Asia-Pacific Edition: Asia-Pacific Association of Cataract & Refractive Surgeons (APACRS), c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (65) 6322-7469, fax (65) 6327-8630, email ewap@apacrs.org. Advertising Office: EyeWorld Asia-Pacifi c Edition: Asia-Pacific Association of Cataract & Refractive Surgeons (APACRS), c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (1-703) 975-7766, email don@apacrs.org. Copyright 2021, Asia-Pacifi c Association of Cataract & Refractive Surgeons (APACRS), c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (65) 6322-7469, fax (65) 6327-8630, email ewap@apacrs.org. Licensed through the American Society of Cataract & Refractive Surgery (ASCRS), 4000 Legato Road, Suite 700, Fairfax, VA 22033-4003, USA. All rights reserved. No part of this publication may be reproduced without written permission from the publisher. Letters to the editor and other unsolicited material are assumed intended for publication and are subject to editorial review and acceptance. The ideas and opinions expressed in EyeWorld Asia-Pacific do not necessarily reflect those of the editors, publishers or its advertisers. Subscriptions: Requests should be addressed to the APACRS publisher, c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (65) 6322-7469, fax (65) 6327-8630, email ewap@apacrs.org. Back copies: Subject to availability. Contact the APACRS publisher, c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (65) 6322-7469, fax (65) 6327-8630, email ewap@apacrs.org. Requests to reprint, use or republish: Requests to reprint or use material published herein should be made in writing only to the APACRS publisher, c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (65) 6322-7469, fax (65) 6327-8630, email ewap@apacrs.org. Change of address: Notice should be sent to the APACRS publisher, c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, six weeks in advance of effective date. Include old and new addresses and label from a recent issue. The APACRS publisher cannot accept responsibility for undelivered copies. KDN number: PPS1766/07/2013(022955) MCI (P) 038/02/2024 CHINESE EDITION Regional Managing Editor Yao Ke, MD Deputy Regional Editor He Shouzhi, MD Zhao Jialiang, MD Assistant Editors Zhouqi, MD Shentu Xingchao, MD EDITORIAL MEMBERS Chan Wing Kwong, MD Singapore Ronald Yeoh, MD Singapore John Chang, MD Hong Kong SAR Pannet Pangputhipong, MD Thailand YC Lee, MD Malaysia Hiroko Bissen-Miyajima, MD Japan Kimiya Shimizu, MD Japan Sri Ganesh, MD India Chee Soon Phaik, MD Singapore Johan Hutauruk, MD Indonesia PUBLISHING TEAM Chief Publisher Ronald Yeoh, MD Executive Director Kathy Chen kathy.chen@apacrs.org Publishing Consultant Donald R Long don@apacrs.org Production Team Gretel Tan Aileen Bian ewap@apacrs.org EDITORIAL Clearing clinical and surgical hurdles remains a relevant effort for all surgeons who perform cataract surgery. This issue of Eyeworld Asia-Pacific contains several examples of hurdles that need to be overcome: including the management of floaters, the presence of high order aberrations and achieving satisfactory outcomes in patients with keratoconus. I personally regard pre-existing keratoconus in cataract surgery particularly challenging, but with careful planning, cataract surgery can be life changing for these patients. Any discussion needs to recognise the spectrum of the condition which can vary from mild forme fruste corneal changes to patients being totally dependent on rigid gas permeable (RGP) contact lens correction for adequate vision. Naturally, the surgical approach will differ depending on the severity of the condition. It is very important to establish whether the patient has been able to achieve satisfactory vision at some stage with spectacles. In the presence of significant cataract this may require obtaining records from their optometrist prior to the development of cataract. Although there is a trend to consider small aperture IOLs to address corneal irregularity, my experience suggests that this is not Clearing Clinical & Surgical Hurdles

5 EyeWorld Asia-Pacific | December 2024 required in the majority of patients. Even with high levels of astigmatism and asymmetry, as long as the meridian of the steep axis is identifiable and the history suggests adequate vison with spectacle correction, I would recommend considering toric IOLs. Obviously, one cannot expect the same level of prediction accuracy for sphere or astigmatism postoperatively but reducing the amount of astigmatism will facilitate spectacle wear and possibly reduce spectacle dependency for some patients. Custom toric IOLs with high toric cylinder powers are available and I have found these lenses very helpful for patients with keratoconus and high levels of astigmatism beyond the normal range. In order to be successful, it is important to remove RGP lenses for at least 8 weeks prior to biometry. This can be challenging for patients who are totally RGP dependent but can be managed by separating the surgeries, operating on the denser cataract and allowing the patient to continue contact lens wear in the eye with better vision. The operated eye then provides adequate vision for the RGP lens to be removed prior to surgery in the second eye. I would recommend using the True K Toric formula selecting the keratoconus option preferably with the measured PCA option. The K calculator which combines the Ks from multiple devices is very helpful in this context. There is no need to target significant myopia when using a custom keratoconus formula as is the case with standard formulae. This is one scenario where I do consider the patients’ preop refraction (prior to the development of cataract) relevant. It is reassuring if the amount and axis of the spectacle cylinder is similar to the biometry. If the spectacle cylinder is significantly less than the biometry then consider reducing the toric cylinder as the corneal apex may be displaced and the patient may be looking through a different part of the cornea than that measured by biometry or evident on topography. In patients who have no record of adequate vision with spectacles or who prefer to continue with RGP contact lens wear, a toric IOL is not recommended. Fitting a RGP contact lens is more difficult with a toric IOL implanted typically requiring a Bitoric Contact lens. Similarly, if the plan is to continue with RGP contact lens wear I would not implant a toric IOL, I would still target a spherical outcome close to emmetropia or a modest level of myopia. Occasionally, patients present with cataract and advanced keratoconus. An RGP contact lens may not be feasible and significant corneal scarring may impact acuity. For selected patients who understand the complexity of Keratoplasty and the long wait for the final outcome, initial Keratoplasty followed by delayed cataract surgery when the sutures are removed, can provide excellent visual rehabilitation, addressing both the cataract and keratoconus. I hope these thoughts will prove helpful in overcoming some of the obstacles that arise during the management of patients who present with both cataract and keratoconus. Warmest regards, Graham Barrett

6 EyeWorld Asia-Pacific | December 2024 FEATURE Pathways to Precision and Perfection – Light Adjustable Lens (LAL) vs. IOL Formulae The theme for this year’s Combined Symposium of Cataract & Refractive Societies (CSCRS) session is “Pathways to Precision and Perfection”, and the idea is to provide different perspectives on 3 alternative pathways to perfection. Light Adjustable Lens (LAL) vs. IOL Formulae by David Chang, MD Light Adjustable Lens (LAL) Adoption of the Light Adjustable Lens (LAL; RxSight) and its newer iteration, the LAL Plus, is accelerating in the United States. Through a combination of greater surface convexity and negative spherical aberration, the LAL Plus may provide up to a diopter of extended depth of focus in a slightly myopic eye. Cataract surgery with LAL implantation is performed using standard techniques. Approximately 3-4 weeks later, the patient is refracted and a slit lamp based digital light delivery device (LDD) system is used to deliver UV light in a precisely programmed pattern to induce a predictable change in the shape and refractive power of the optic. Treatment times range between 60-120 seconds. After the newly-adjusted refraction is confirmed several days later, a “lock-in” dose is given with the LDD, at which point no further refractive change will occur. We have many excellent non-adjustable, advanced technology IOLs and hitting the refractive target remains crucial for these eyes. A common question is: do we really need adjustable IOLs given how much better our formulas and biometry have become? I would answer that when we miss the refractive target, the confounding variable is usually the corneal curvature measurement, rather than an inaccurate formula. The very best formulas still yield different results due to corneal variability in patients with dry or abnormal ocular surfaces. Because the biometry/ IOL calculation printout is derived from a single moment in time, our practice routinely repeats the entire biometry/ calculation process twice (IOL Master 700, Zeiss) and I am struck by how frequently the resulting predictions differ due to variable keratometry. For me, the ultimate verdict was when Warren Hill, MD reported in an ASCRS presentation last April that he chose the LAL for both his and his wife’s eyes. Beyond achieving greater precision in hitting emmetropia, there is a second major benefit that comes with using an adjustable IOL. Some patients – perfectionists and engineers for example – agonize preoperatively over what specific refractive target they want. With the LAL, these patients can wait to try out their binocular pseudophakic vision postoperatively, and then confirm or modify their refractive preference based on their daily experience. This, and the fact that they won’t have diffractive ring halos, dramatically relieves the anxiety for this type of patient.For another example, many patients prioritize not having to wear readers, and don’t mind distance glasses. These individuals can customize and determine the optimal amount of myopia in one or both eyes based on their binocular postoperative experience. LAL patients

7 EyeWorld Asia-Pacific | December 2024 FEATURE Pathways to Precision and Perfection – Light Adjustable Lens (LAL) vs. IOL Formulae essentially find the sweet spot where they can meet critical needs at near (e.g. reading their mobile device without glasses) while blurring their distance vision as little as possible. With contact lens fittings, presbyopic patients take advantage of refractive adjustability in one or both eyes all the time. Indeed, in our practice, our optometrists handle much of the postoperative decision-making with the LAL by simulating different outcomes with trial lenses – just as they do with mini-monovision contact lens fittings. So, this isn’t simply a question of whether the LAL outperforms modern biometry/formulae in hitting a refractive target. The problem is that we often don’t know preoperatively what the best target is. Having to choose preoperatively between competing IOL designs and refractive targets that they cannot preview or later easily reverse can be very stressful. It is challenging for preoperative patients to comprehend the difference between being plano or -1.00, the difference between having 0.75 D of astigmatism versus none, and the difference of 1 versus 1.5 diopters of intentional anisometropia. After making these lifelong decisions and finally selecting a refractive objective, we then add the disclaimer that we cannot guarantee their desired refractive outcome. We all know that taking away too much of someone’s preoperative functional myopia is risky. Discovering that they’ve lost their ability to read their phone, read in bed, or apply makeup, is a major source of “buyer’s remorse” for many patients who fancied good distance vision. This is why the ability to change the refractive target or IOL type in the second eye based on the patient’s experience with the first eye is the most important benefit of delayed sequential bilateral cataract surgery (DSBCS). This becomes a moot point with the LAL, and I therefore offer every bilateral LAL patient the option of immediate sequential bilateral cataract surgery (ISBCS). Thanks to adjusting both eyes simultaneously postoperatively, my LAL patients typically make the same total number of trips to the office/surgery center as if they had undergone DSBCS with traditional IOLs. More than 90% of my bilateral LAL patients have chosen the option of ISBCS. Although LALs can be used for anyone, it is particularly well-suited for our most challenging refractive IOL patients. These include post-keratorefractive or refractive lens exchange (RLE) patients, those with inconsistent keratometry (e.g., dry or abnormal ocular surface), uncompromising personalities demanding a specific outcome (e.g., no distance or no reading glasses), and those who’ve never worn eyeglasses thanks to rigid contact lens monovision and expect this to continue. Thanks to greater refractive precision and optimal quality of day and nighttime vision with LALs, we finally have an excellent IOL technology to reliably satisfy most RLE patients. I recently performed bilateral same day RLE on my own wife with LAL Plus. Fortunately, I am still married! I believe that as ophthalmologists gain more experience with the LAL, they will perform more RLE with this platform. The resulting word of mouth will increase interest and demand among presbyopic patients in their 60s who don’t have any cataract. The older published literature pertains to early versions of the LAL used in the first clinical trials. The LAL platform first introduced in several European and Canadian investigational centers could not correct astigmatism, explaining the muted enthusiasm for that first iteration. Because the FDA has not approved low power toric IOLs in the US, the LAL is the only IOL in the US that can correct as little as 0.5 D of astigmatism. Another LAL advance is Active Shield (RxSight), which theoretically eliminates the need for constant UV protection postoperatively. Since this became available 3 years ago, I stopped having my patients wear UV glasses indoors. This has significantly improved the patient’s experience and decreased the urgency to get the LALs locked in as early as possible. I continue to use all the multifocal, extended depth of focus, and monofocal IOL models available to me in the US. However, for a growing subset of patients, some of whom are among the most difficult to satisfy, it has been wonderful to have this game-changing technology as an option.

8 EyeWorld Asia-Pacific | December 2024 by Graham Barrett, MD IOL Formulae With deep respect and affection for David’s ethics as an individual and surgeon, I will offer a consideration and comparison of LALs to IOL Formulae which considers precision and perfection of outcomes, as well as any additional effort, expense and safety involved. Firstly, I should note the LAL project’s inception in 1996— whereas Formulae have progressively evolved and achieved significantly greater prediction accuracy than those available when this project was initially conceived. Let’s focus first on outcomes. At present there are relatively few published studies on the refractive outcomes of patients who have had a light adjustable lens implanted. I have listed the outcomes in terms of the number of eyes achieving within 0.5 D of predicted outcomes. Most studies include normal eyes with no history of previous refractive surgery eyes as displayed in the green columns. Other studies focus on eyes with previous refractive surgery as displayed in the orange columns when available, and the published results are quite variable. The outcomes in normal eyes vary from 80% in the paper published by Villegas to 100% in the paper by Folden and co-authors. The 12-month study by Moshirfar with 89% is similar to the outcomes in the FDA study of 92% within 0.5D of the intended outcome. The outcomes in eyes with a history of previous refractive surgery are even more variable ranging from 55% in the Moshifar study to 100% within 0.5D in the Folden study. A recent study by Ferguson and co-authors which only considered eyes with previous refractive surgery reported 86% within 0.5 D. These results are excellent but it is certainly feasible to achieve similar outcomes with precision biometry and formulae. In my own patients, the percentage of eyes achieving an outcome within 0.5 D is consistently in the 90% range both for sphere and cylinder. Similar results have been published by others for example the study in 545 eyes published by Dr Chung and others in 2021 where 90% had a prediction error with 0.5 D. I am sure David achieves similar outcomes with normal eyes and that is why LAL is often recommended for patients who have had previous refractive surgery. 100 80 60 40 20 0 Haigis SRK/T Holladay II BUII IOL Formulae Outcomes - Normal 90% 86% 85% 83% Comparative prediction accuracy between total keratometry and conventional keratometry cataract surgery with refractive multifocal intraocular lens implantation. Source: Graham Barrett, MD Ho Seok Chung, Jae Lim Chung, Young Jun Kim, Hun Lee, Jae Yong Kim and Hungwon Tchah Sci Rep. 2021; 11: 19234 100 80 60 40 20 0 Moshirfar et al Folden et al Villegas et al Fegurson et al FDA Light Adjustable Lens (LAL) Outcomes 89% 55% 100% 100% 80% 92% 86% Post Refractive Normal Source: Graham Barrett, MD FEATURE Pathways to Precision and Perfection – Light Adjustable Lens (LAL) vs. IOL Formulae

9 EyeWorld Asia-Pacific | December 2024 About The Physicians David Chang, MD | Altos Eye Physicians, California Graham Barrett, MD | Australia Relevant Disclosures Chang: RxSight, Perfect Lens, J&J Vision, Alcon, and Carl Zeiss Barrett: Alcon, Haag Streit, Rayner, Zeiss and Bausch & Lomb But even in these more challenging cases, as published by Dr Liangpin Li and coauthors in 2023, 80% or more of eyes can be predicted within 0.5 D following Lasik using modern formulae. These results are not dissimilar to the LAL studies and are compatible with my own experience. Using the measured posterior cornea option in the True K formulae equivalent to the True K TK, further improves the prediction accuracy in eyes with a history of previous refractive surgery. 100 80 60 40 20 0 Shammas Haigis-L M-Masket Masket True K NH True K IOL Formulae Outcomes - Post Refractive 56% 46% 38% 26% 82% 74% Comparative analysis of IOL power calculations in postoperative refractive surgery patients: A theoretical surgical model for FS-LASIK and SMILE procedures. Source: Graham Barrett, MD Liangpin Li, Liyun Yuan, Kun Yang, Yanan Wu, Xia Hua, Yan Wang and Xiaoyong Yuan BMC Opthalmology volume 23, Article number: 416 (2023) The outcomes achievable with the different pathways are therefore similar but the additional effort required with the adjustable IOL is far greater. The LAL requires patients to wear protective sunglasses for several weeks and at least 3 additional visits for adjustment and final lock-in with a light delivery device. Not least repeated refraction, which is inherently variable compared to the precision of biometry, is required with additional personnel – this is truly disruptive technology! Optimum results with biometry do require more than a single instrument, optimising the ocular surface measuring the posterior cornea and occasionally repeating measurements. The effort required to implement these simple measures is straightforward and within reach of all practices. The additional expense to incorporate the light adjustable lens far exceeds that required for accurate biometry. Biometers and topographers are an essential part of any practice that performs cataract surgery but implanting the adjustable IOL requires the additional purchase of a light delivery device and the cost of the additional time and effort is also costly. The additional costs for a patient are also considerable and estimated to be in the range of US$5,000 per eye. I do recognise that many patients are willing to pay and the ability for surgeons to charge patients more as a premium option may be one of the reasons this lens is more popular in the USA than other countries. Finally, in regard to safety there are potential complications related to the use of UV light at 650 nm. 49% of patients experience a red tint to their vision or erythropsia and a small percentage (1.8%) have experienced a Tritan anomaly in their colour perception. Postoperatively, the minimum pupil diameter required for complete lock-in is greater than 6.5 mm and this is not always achievable. There are anecdotal reports of unexpected outcomes after LAL implantation and lock-in. Failure to wear protective glasses can be problematic as in this case report in Ophthalmology of a patient who failed to wear protective glasses and required explantation of the light adjustable IOL. Undiagnosed previous herpetic keratitis can be reactivated and there are a number of medications susceptible to photosensitization that must be avoided. So use of the light adjustable IOL does entail some risk compared to the use of formulae. To summarise the comparison of which pathway you should choose for perfection, comparing the light adjustable lenses vs formulae. I would regard the outcomes as equivalent but consideration of LAL is reasonable in post refractive eyes. The additional effort required for using an adjustable light IOL is considerable and the logistics are problematic compared to formulae. Routine use of a light adjustable IOL is definitely considered cost effective in some health delivery systems. And there are certain safety considerations and precautions required. I would like to conclude with an ancient Chinese proverb. It is far better to “Measure twice and cut once” in woodwork and I would suggest the same applies in cataract surgery. I would consider accurate biometry and formulae a preferable pathway to precision and perfection. FEATURE Pathways to Precision and Perfection – Light Adjustable Lens (LAL) vs. IOL Formulae

10 EyeWorld Asia-Pacific | December 2024 Phaco vs. Femto by Nic J. Reus, MD, PhD, FEBOS-CR Phaco A surgeon uses a keratome, capsulorhexis foreceps, and a phacoemulsification handpiece to perform a conventional cataract surgery (CCS). It relies heavily on the surgeon’s skill and precision as it involves several manual steps, including corneal incisions, capsulorhexis, hydrodissection, lens fragmentation, lens emulsification, and intraocular lens (IOL) implantation. Despite its manual nature, CCS is renowned for its reliability and efficiency, yielding excellent visual outcomes with low complication rates. However, the manual aspects of the procedure can lead to variations in results, particularly among less experienced surgeons. Femtosecond laser-assisted cataract surgery (FLACS) represents a more recent advancement, utilizing laser technology to automate several key steps, such as incisions, capsulotomies, and lens fragmentation. Despite this innovation, hydrodissection, lens emulsification, and IOL implantation remain manual processes. The primary advantage of FLACS is its precision, facilitating uniform capsulotomies, and reducing the use of energy during lens fragmentation. Nevertheless, the clinical significance of this increased precision is debated, as CCS typically achieves excellent outcomes for most patients. Surgically-Induced Astigmatism Various studies have investigated the clinical outcomes of CCS versus FLACS. A meta-analysis by Kolb et al. (2020) found no significant difference in surgically-induced astigmatism between the two techniques, indicating that both methods yield similar outcomes in corneal astigmatism post-surgery, an important consideration for patients seeking precise refractive results. Capsulorhexis and Capsulotomy A notable distinction between the two techniques is the quality of capsulorhexis in CCS compared to the capsulotomy in FLACS. The laser technology in FLACS creates a perfectly round and centered opening, while the manual creation of capsulorhexis by the surgeon in CCS often results in more variability. However, the clinical relevance of this distinction remains debatable. Even manual capsulorhexis creation has been shown to yield an accurate postoperative axial position, tilt, and centration of the IOL (Findl, 2017). Only eyes with a severely malformed capsulorhexis, typically associated with inexperienced surgeons, show a slightly decentered IOL. Refractive Outcomes Another major concern for patients undergoing cataract surgery is the refractive outcome. According to the meta-analysis by Kolb et al. (2020), there is no significant difference in the spherical equivalent (SE) between CCS and FLACS, suggesting that both techniques deliver comparable results in correcting vision. Endothelial Cell Loss One significant advantage of FLACS is the reduced energy required during lens fragmentation. Using less phaco energy may help minimize corneal endothelial cell damage, which is critical for maintaining corneal clarity after surgery. However, meta-analyses, including one by Wang et al. (2023), indicate that endothelial cell loss is comparable between CCS and FLACS. This suggests that while FLACS uses less energy, it may not necessarily provide better corneal protection than CCS. FEATURE Pathways to Precision and Perfection – Phaco vs. Femto

11 EyeWorld Asia-Pacific | December 2024 The top section illustrates the steps involved in conventional cataract surgery (CCS). The bottom section shows the steps in femtosecond laserassisted cataract surgery (FLACS), where incisions, capsulotomy, and lens fragmentation are performed using a laser. All remaining steps in FLACS are identical to those in CCS. Source: Nic Reus, MD The Cost Debate: Is FLACS Worth the Investment? A substantial difference between CCS and FLACS is the associated cost. FLACS is significantly more expensive, both in terms of equipment and the time required to perform the surgery. According to a study by Day et al. (2020), the cost of FLACS is nearly double that of conventional phaco. Additionally, the operating time for FLACS is slightly longer because the laser procedure must be performed separately from the manual steps involved in the actual cataract removal. References 1. Day AC, Burr JM, Bennett K, et al. (2020): Femtosecond laser–assisted cataract surgery compared with phacoemulsification cataract surgery: randomized noninferiority trial with 1-year outcomes. J Cataract Refract Surg 46: 1360–1367. 2. Findl O, Hirnschall N, Draschl P & Wiesinger J (2017): Effect of manual capsulorhexis size and position on intraocular lens tilt, centration, and axial position. J Cataract Refract Surg 43: 902–908. 3. Kolb CM, Shajari M, Mathys L, Herrmann E, Petermann K, Mayer WJ, Priglinger S & Kohnen T (2020): Comparison of femtosecond laser–assisted cataract surgery and conventional cataract surgery: a meta-analysis and systematic review. J Cataract Refract Surg 46: 1075–1085. 4. Wang H, Chen X, Xu J & Yao K (2023): Comparison of femtosecond laser-assisted cataract surgery and conventional phacoemulsification on corneal impact: A metaanalysis and systematic review. PLOS ONE 18: e0284181. However, FLACS may be a worthwhile investment for practices that charge patients an additional fee for the laser component, or those that perform a high volume of premium IOL surgeries. Economically speaking, CCS remains more cost-effective, especially in settings where resources are limited or where patients cannot afford the additional fees. Conclusion: Which is Better? The decision between CCS and FLACS ultimately hinges on a balance of precision, cost, and clinical outcomes. FLACS offers enhanced precision with laser-created capsulotomies and reduced phaco energy, which may benefit certain patient groups. However, these advantages do not translate into significant clinical improvements for most cases. Conventional phacoemulsification remains the gold standard for cataract surgery due to its lower cost, shorter operating time, and comparable visual outcomes. For both surgeons and patients, the choice between these two methods should be guided by individual circumstances. FLACS might be preferable for very complex cases, for surgeons with a high complication rate, or for patients seeking the latest in technological advancements. However, for most patients, CCS will deliver excellent results at a lower cost. In conclusion, while FLACS is an impressive technological advancement, conventional phaco remains a reliable, efficient, and cost-effective choice for the majority of cataract surgeries. FEATURE Pathways to Precision and Perfection – Phaco vs. Femto

12 EyeWorld Asia-Pacific | December 2024 by Ke Yao, MD, Xinyi Chen, MD FLACS is making steady progress in China Cataract surgery is one of the most frequently-performed ophthalmic surgeries worldwide, with conventional phacoemulsification surgery (CPS) becoming mainstream for decades. However, with advancements in technology, Femtosecond laser-assisted cataract surgery (FLACS), approved by the FDA in 2010, has rapidly gained traction, especially in China. FLACS was approved by the CFDA for clinical using in China in 2013, and there are more than 350 clinics to practice this new procedure and more than 400,000 cases of FLACS in China. In our eye hospital, 6500 FLACS cases were performed in 2023, accounting for 25% of the whole 26,000 cataract surgeries. FLACS uses femtosecond lasers to perform corneal incisions, anterior capsulotomy, and lens fragmentation, astigmatism correction, offering several advantages over traditional techniques. There is currently a large amount of literature discussing the clinical progress of FLACS, its benefits compared to CPS, and potential future directions. A study that our team conducted in 2016, with a followup period of 6 months found that there was not much difference between the two in terms of macular, corneal, and intraocular inflammation, indicating both FLACS and CPS achieved similar safety and efficacy outcomes.1 1542 eyes which underwent FLACS were involved in this prospective, multicenter registry study in 19 cataract surgery clinics in China to evaluate the efficacy and safety of FLACS. The completion rate of a circular anterior capsulotomy, lens fragmentation and corneal incision were 98.6%, 99.5% and 97.6%, respectively.2 Compared to conventional CPS, FLACS demonstrates multiple clinical advantages, including faster postoperative visual recovery, reduced corneal endothelial cell loss (ECL), lower surgical energy dissipation, less intraoperative complications and so on. 1. Faster Visual Recovery: Numerous clinical studies have shown that patients undergoing FLACS experience quicker visual recovery.3 Patients with hard nuclear cataracts in the FLACS group especially achieved a stable CDVA at 1 month postoperatively, while patients in the CPS group achieved this in 3 months.4 This rapid recovery is attributed to the precision and reduced tissue trauma of FLACS.2 2. Reduced Corneal Endothelial Cell Loss: One of the significant benefits of FLACS is its ability to minimize corneal endothelial cell loss, especially in cases of hard nuclear cataracts. Studies have reported that ECL in the FLACS group was approximately 7.85% three month postoperatively, while the CPS group showed a much higher rate of 19.96% after a similar postoperative period. This underscores the protective effect of femtosecond laser pre-fragmentation on the corneal endothelium.4 At the same time, individualized FLACS settings can also maximize the protective effect. Studies have shown that Grade 3 nucleus cataracts are suitable for the sextant pattern pre-fragmentation, while Grade 4 or 5 are suitable for quadrant.5 3. Lower Surgical Energy Consumption: FLACS reduces the amount of energy required during surgery because the laser pre-fragments the lens. Consequently, less ultrasound energy is needed during phacoemulsification, resulting in less intraoperative trauma to ocular tissues and shorter operative times. 4. Less intraoperative Complications: FLACS is associated with a lower rate of intraoperative complications compared to CPS. This advantage is more pronounced in complex cataracts, especially white cataracts6,7. FLACS decreased the incidence of anterior capsular tears and irregularity and decentration of capsulorhexis in white cataract from 12.1%(8/66) to 0%(0/66).7 Despite its advantages, FLACS is not without challenges. The high cost of femtosecond laser equipment is a significant barrier to its widespread adoption. But with the improvement of living standards, the impact of this issue Source: Ke Yao, MD FEATURE Pathways to Precision and Perfection – Phaco vs. Femto

13 EyeWorld Asia-Pacific | December 2024 Source: Ke Yao, MD will become less important. Moreover, FLACS requires specialized equipment maintenance and learning curve for surgeons, which may diminish its advantages.8 Besides, FLACS resulted in higher risk of postoperative fluorescein staining and dry eye symptoms,9 caused more SIA than manually created corneal incisions, which could have resulted from inaccurate or uncertain corneal incision positioning of the femtosecond machine.10 With ongoing technological advancements, the future of FLACS is promising. Continued optimization and individualization of surgical parameters could further reduce complication rates and shorten operative times, improving vision restoration. The integration of FLACS with other emerging technologies, such as optical coherence tomography (OCT) and artificial intelligence (AI) could enhance surgical precision, automate processes, and improve safety. Numerous studies have systematically evaluated FLACS. Femtosecond laser-assisted cataract surgery has demonstrated substantial clinical advantages over conventional phacoemulsification surgery in recent years. FLACS offers improved precision, reduced complication rates, and faster postoperative recovery, especially in complex cases like hard nuclear cataracts and high myopia.11-13 While cost and technical challenges remain, FLACS is likely to become a dominant cataract surgery method in the future, especially for refractive cataract surgery.14 References 1. Yu, Y., et al., Comparative outcomes of femtosecond laser-assisted cataract surgery and manual phacoemusification: a six-month follow-up. Clin Exp Ophthalmol, 2016. 44(6): p. 472-80. 2. Zhang, X., et al., Performance of femtosecond laser-assisted cataract surgery in Chinese patients with cataract: a prospective, multicenter, registry study. BMC Ophthalmol, 2019. 19(1): p. 77. 3. Zhong, Y., et al., Femtosecond laser-assisted cataract surgery versus conventional phacoemulsification: comparison of internal aberrations and visual quality. Graefes Arch Clin Exp Ophthalmol, 2022. 260(3): p. 901-911. 4. Chen, X., et al., Clinical outcomes of femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery for hard nuclear cataracts. J Cataract Refract Surg, 2017. 43(4): p. 486-491. 5. Lyu, D., et al., Comparison of Perioperative Parameters in Femtosecond Laser-Assisted Cataract Surgery Using 3 Nuclear Fragmentation Patterns. Am J Ophthalmol, 2020. 213: p. 283-292. 6. Zhu, Y., et al., Parameters of Capsulorrhexis and Intraocular Lens Decentration After Femtosecond and Manual Capsulotomies in High Myopic Patients With Cataracts. Front Med (Lausanne), 2021. 8: p. 640269. 7. Zhu, Y., et al., Lens capsule-related complications of femtosecond laser-assisted capsulotomy versus manual capsulorhexis for white cataracts. J Cataract Refract Surg, 2019. 45(3): p. 337-342. 8. Zhang, X., et al., Incidence and analysis of intraoperative complications in femtosecond laser-assisted cataract surgery: a large-scale cohort study to establish the learning curve. Br J Ophthalmol, 2024. 9. Yu, Y., et al., Evaluation of dry eye after femtosecond laser-assisted cataract surgery. J Cataract Refract Surg, 2015. 41(12): p. 2614-23. 10. Zhu, S., et al., Morphologic features and surgically induced astigmatism of femtosecond laser versus manual clear corneal incisions. J Cataract Refract Surg, 2017. 43(11): p. 1430-1435. 11. Wang, H., et al., Comparison of femtosecond laser-assisted cataract surgery and conventional phacoemulsification on corneal impact: A meta-analysis and systematic review. PLoS One, 2023. 18(4): p. e0284181. 12. Xu, J., et al., Safety of femtosecond laser-assisted cataract surgery versus conventional phacoemulsification for cataract: A meta-analysis and systematic review. Adv Ophthalmol Pract Res, 2022. 2(1): p. 100027. 13. Chen, X., et al., Comparing the Curative Effects between Femtosecond Laser-Assisted Cataract Surgery and Conventional Phacoemulsification Surgery: A Meta-Analysis. PLoS One, 2016. 11(3): p. e0152088. 14. Chen, X., et al., Cataract: Advances in surgery and whether surgery remains the only treatment in future. Adv Ophthalmol Pract Res, 2021. 1(1): p. 100008. About the Physicians Nic Reus, MD, PhD, FEBOS-CR | Breda, The Netherlands, Molengracht 21, 4811 CK | nreus@amphia.nl Ke Yao, MD | Chief & Professor, Zhejiang University Eye Hospital Eye Center, Second Affiliated Hospital Zhejiang University School of Medicine | xlren@zju.edu.cn Relevant Disclosures Reus: Alcon, Johnson & Johnson, and Zeiss Yao: None FEATURE Pathways to Precision and Perfection – Phaco vs. Femto

14 EyeWorld Asia-Pacific | December 2024 SMILE vs. LASIK LASIK is a revolutionary procedure that is safe, effective, and the most successful and widely-studied elective procedure in the world.1-5 In its relatively short history, LASIK has changed the lives of millions of people worldwide by precisely correcting their refractive errors. Despite its rich clinical history and high patient satisfaction rates,6,7 LASIK has several key limitations, particularly relating to corneal biomechanics,8,9 the risk for post-LASIK ectasia,10 side effects such as dry eye, and the potential need for an enhancement. Newer procedures such as SMILE aim to address some of LASIK’s shortcomings and inject surgical volume into the slow market growth seen recently with LASIK. The Evolution Of Refractive Surgery With any surgical specialty—and particularly corneal refractive surgery—two of the driving forces pushing the field forward are safety and efficacy. Procedures such as radial keratotomy (RK) and PRK propelled the field forward in its early days, followed by LASIK and eventually SMILE. Each procedure advanced the precision and outcomes of corneal refractive surgery, with LASIK particularly making a massive impact when it gained FDA approval in 1996. Three years after FDA approval, about 27% of LASIK patients achieved 20/20 vision at 1-month postoperative.11 By 2000, 1-month postoperative outcomes improved to 60% with second-generation hardware (Table 1).12 Although groundbreaking for the era, especially compared to RK, these outcomes seem almost primitive by today’s standards. Refinements to both technique and technologies continued to drive improvements in postoperative outcomes. With fourth-generation hardware and the maturation of femtosecond LASIK techniques, outcomes have improved by William F. Wiley, MD SMILE: Continuing the Evolution of Corneal Refractive Surgery dramatically. By 2018, 94% of LASIK patients were achieving 20/20 uncorrected distance visual acuity at 1-month postoperative,13 moving the needle significantly in terms of efficacy and bringing us closer to modern LASIK results. As good as LASIK has been, shortcomings in some safety aspects, including the potential of flap dislocation,8,9 the potential risk for post-LASIK ectasia,10 side effects such as dry eye, and the potential need for an enhancement, however, may be contributing to a slowing corneal refractive surgery market. The What-Ifs Of Refractive Surgery Postoperative outcomes with SMILE have improved at a faster rate than LASIK. Six years after FDA approval, most of our patients were already achieving 20/20 uncorrected visual acuity at 1 and 6 months (95% and 98%, respectively; Figure 1). FEATURE Pathways to Precision and Perfection – SMILE vs. LASIK Table 1. One-Month Results of LASIK With First- and Second-Generation Excimer Lasers First-Generation Laser* UCVA 20/20 20/25 20/40 POSTOP MONTH 1 27% 54% 87% 3 31% 53% 93% 6 24% 44% 100% Second-Generation Laser** UCVA 20/20 20/25 20/40 POSTOP MONTH 1 60% 79% 90% * N=93 to 41, single surgeon ** N=480, multicenter, multi surgeon The procedure addresses some of the limitations of LASIK.

15 EyeWorld Asia-Pacific | December 2024 There is, however, more to refractive surgery than uncorrected visual acuity. SMILE achieves the precision of LASIK but also addresses some of its most significant what-ifs. It therefore is becoming the pinnacle of corneal refractive surgery. No. 1: What if a patient has an increased risk of dry eye? The severing of corneal nerves during LASIK flap formation often leads to dry eye symptoms.14 This side-effect can be particularly problematic for patients with a predisposition to dry eyes and those who work in environments where dry eye could be exacerbated. SMILE, on the other hand, avoids the creation of a flap and transects fewer corneal nerves.15 This translates to a lower risk of dry eye. No. 2: What if there are flap-related trauma or biomechanical concerns? Without having a flap, SMILE eliminates the short- and long-term concern of traumatic flap dislocation. Furthermore, there may be biomechanical advantages to eliminating the flap. SMILE preserves more of the anterior corneal structure and maintains greater corneal strength compared to LASIK.16 The added biomechanical stability may be theoretically beneficial in terms of reducing the risk of post–refractive surgery ectasia. No. 3: What if the expected target is not achieved? SMILE is performed in a closed system. The treatment produces a stable outcome over a wide range of refractive errors with a low regression rate.17 As a result, there is a lower enhancement rate compared to LASIK. No. 4: What if a patient needs an enhancement years after surgery? One underappreciated aspect of SMILE is its flexibility for enhancements. LASIK is a fantastic procedure for many patients, but if an enhancement is required years after surgery, it may become complicated. Lifting the original flap carries a risk of epithelial ingrowth,18 whereas performing PRK over the LASIK flap can be unpredictable because of the altered healing process associated with epithelial hyperplasia.19 FEATURE Pathways to Precision and Perfection – SMILE vs. LASIK Figure 1. SMILE results with first- and second-generation software at 1 and 6 months. 160 EYES (PLANO TARGET) 6 MONTHS POSTOP 100 80 60 40 20 0 1 1 0 20/12.5 20/32 20/20 20/50 20/80 20/16 20/40 20/25 20/63 20/100 CUMULATIVE SNELLEN VA (20/X OR BETTER) CUMULATIVE % OF EYES 55 98 97 99 100 99 100 100100 100100 100100 100100 100100 213 EYES (PLANO TARGET) 3 MONTHS POSTOP POSTOP UDVA PREOP CDVA 100 80 60 40 20 0 0 0 3 20/12.5 20/32 20/20 20/50 20/80 20/16 20/40 20/25 20/63 20/100 CUMULATIVE SNELLEN VA (20/X OR BETTER) CUMULATIVE % OF EYES 37 95 97 99 100 100100 100100 100100 100100 100100 100100 *WILEY, HURA, BAFNA, DECOURCY ASCRS 2022

16 EyeWorld Asia-Pacific | December 2024 References 1. Kremer FB, Pronesti G, Solat J, et al. Prospective LASIK trial for myopia and myopic astigmatism: 1-year results. Ann Ophthalmol. 2001;33(4):315-322. 2. Yuen KH, Chan WK, Kho J, et al. A 10-year prospective audit of LASIK outcomes for myopia in 37,932 eyes at a single institution in Asia. Ophthalmology. 2010;117(6):12361244. 3. Stulting RD, Carr JD, Thompson KP, et al. Complications of laser in situ keratomileusis for the correction of myopia. Ophthalmology. 1999;106(1):13-20. 4. Melki SA, Azar DT. LASIK complications: etiology, management, and prevention. Surv Ophthalmol. 2001;46(2):95-116. 5. Donnenfeld ED. The best for LASIK. Paper presented at the: AAO Subspecialty Days; November 10-11, 2017; New Orleans. 6. Pasquali TA, Smadja D, Savetsky MJ, et al. Long-term follow-up after laser vision correction in physicians: Quality of life and patient satisfaction. J Cataract Refract Surg. 2014;40(3):395-402. 7. Solomon KD, Fernández de Castro LE, Sandoval HP, et al. LASIK world literature review. Ophthalmology. 2009;116(4):691-701. 8. Hashemi H, Roberts CJ, Elsheikh, et al. Corneal biomechanics after SMILE, femtosecond-assisted LASIK, and photorefractive keratectomy: a matched comparison study. Transl Visc Sci Technol. 2023;12(3):12. 9. Guo H, Hosseini-Moghaddam SM, Hodge W. Corneal biomechanical properties after SMILE versus FLEX, LASIK, LASEK, or PRK: a systematic review and meta-analysis. BMC Ophthalmol. 2019;19(1):167. 10. Wolle MA, Randleman JB, Woodward MA. Complications of refractive surgery: ectasia after refractive surgery. Int Ophthalmol Clin. 2016;56(2):129-141. 11. Ahn CS, Clinch TE, Moshirfar M, Weiss JR, Hutchinson CB. Initial results of photorefractive keratectomy and laser in situ keratomileusis performed by a single surgeon. J Cataract Refract Surg. 1999;25(8):1048-1055. 12. Wiley WM, Wiley RG. 10,000 LASIK Eyes Treated NIDEK. Paper presented at the: Carribbean Eye Meeting. March 2001; Cancun, Mexico. 13. Wiley WM, Moarefi A. Long-term outcomes of visual improvement after small-incision lenticule extraction for myopic correction. Paper presented at the: ASCRS/ASOA Annual Meeting; April 13-17, 2018; Washington, DC. 14. Tamimi A, Sheikhzadeh F, Ezabadi SG, et al. Post-LASIK dry eye disease: a comprehensive review of management and current treatment options. Front Med (Lausanne). 2023;10:1057685. 15. Li M, Niu L, Qin B, et al. Confocal comparison of corneal reinnervation after small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FSLASIK). PLoS One. 2013;9;8(12):e81435. 16. Wang D, Liu M, Chen Y, et al. Differences in the corneal biomechanical changes after SMILE and LASIK. J Refract Surg. 2014;30(10)702-707. 17. Charters L. SMILE offers low enhancement rate after nomogram adjustment. Ophthalmology Times. 2021;46(5). 18. Jeng Ting DS, Srinivasan S, Danjoux JP. Epithelial ingrowth following laser in situ keratomileusis (LASIK): prevalence, risk factors, management and visual outcomes. BMJ Open Ophthalmol. 2018;3(1):e000133. 19. Lohmann CP, Güell JL. Regression after LASIK for the treatment of myopia: the role of the corneal epithelium. Semin Ophthalmol. 1998;13(2):79-82. 20. Moshifar M, Parsons MT, Chartrand NA, et al. Photorefractive keratectomy enhancement (PRK) after small-incision lenticule extraction (SMILE). Clin Ophthalmol. 2022;16:3033-3042. 21. Siedlecki J, Luft N, Mayer WJ, et al. CIRCLE enhancement after myopic SMILE. J Refract Surg. 2018;34(5):304-309. 22. Decourcey M. Analysis of refractive outcomes in SMILE converted to LASIK (“cap to flap”) enhancements. Paper presented at the: 2023 American Society of Cataract and Refractive Surgeons annual meeting; May 5-8, 2023; San Diego. 23. Sedky AN, Wahba SS, Roshdy MM, Ayaad NR. Cap-preserving SMILE enhancement surgery. BMC Ophthalmol. 2018;18(1):49. 24. Brar S, Ganesh S, Bhargav S. Comparison of intraoperative time taken for docking, dissection, and overall workflow for SMILE procedure with VisuMax 800 versus the VisuMax 500 for femtosecond laser. J Refract Surg. 2023;39(9):648. FEATURE Pathways to Precision and Perfection – SMILE vs. LASIK SMILE enhancements, however, are much more flexible. PRK,20 thin-flap LASIK, and thick-flap LASIK are all options. Alternatively, the SMILE cap can be converted into a LASIK flap.21 My colleagues and I have demonstrated that converting a SMILE cap to a LASIK flap, the CIRCLE procedure, yields superior short- and long-term outcomes compared to flap lifts or PRK.22 Lastly, a cap-preserving enhancement procedure, or re-SMILE, is a promising development.23 Patient, Surgeon Experience Is A Key Differentiator In today’s experience economy, the patient experience matters just as much as the surgical results. Patients want a quick recovery and minimal disruptions to their daily lives, and SMILE delivers both. Because there is no flap, patients can resume normal activities like driving, returning to work, contact sports, swimming, and even wearing makeup much sooner than after LASIK. A small incision compared to a LASIK flap also means a faster healing process and less discomfort. From a surgeon’s perspective, SMILE also offers a more streamlined workflow. LASIK requires two laser steps: creating the flap with a femtosecond laser and reshaping the cornea with an excimer laser. In contrast, SMILE requires one step with the VisuMax femtosecond laser (Carl Zeiss Meditec). The entire lenticule creation process takes less than 10 seconds, and recent advancements in laser technology—like the VisuMax 800—reduce treatment times even further. In a recent study of 60 patients treated bilaterally comparing the overall workflow of the VisuMax 800 to the VisuMax 500, the overall surgical time improved from 9.52 ±1.72 minutes with the VisuMax 500 to 6.96 ±1.67 minutes with the VisuMax 800.24 Times for docking and lenticule dissection also improved from 194.11 ±47.59 to 133.63 ±38.88 seconds and 115.40 ± -45.03 to 99.06 ±20.19 seconds, respectively. There was no difference in uncorrected distance visual acuity between groups and no suction break in either group. Although this was conducted by experienced VisuMax users with fine-tuned surgical techniques, I think the VisuMax 800 will allow even less experienced surgeons to achieve premier results in a quicker time frame and with a shorter learning curve. Market Growth And Patient Demand More than 10 million SMILE procedures have been performed worldwide, and the market is growing. The reasons behind this are clear: excellent efficacy and advantages over LASIK such as no flap complications, fewer enhancements, reduced risk of dry eye, and better biomechanical stability. While LASIK continues to be an excellent choice for many patients, SMILE represents another evolution in corneal refractive surgery with further horizons to explore. Editors’ note: The procedure addresses some of the limitations of LASIK.

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