Refractive surgery has come a long way over the last few decades, and it’s growing in both depth and breadth of options. It’s one of the most popular and common surgeries in the world, and is set to only grow as more patients demand good vision.
Until recently, lenticule extraction surgery was dominated by one name and one name alone: Zeiss. Their VisuMax FS (Carl Zeiss Medited AG, Jena, Germany) has dominated the market to the tune of essentially 100% market share until just 2020. In that year, SmartSight (SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany) and CLEAR (Ziemer Ophthalmic Systems AG, Port, Switzerland) received CE approval, opening the path to their use in European markets.
We can reasonably speculate that these devices will soon reach U.S. and other shores, so they’re worth looking into. How do they compare to Zeiss’s devices (that’s fun to say) and what can ophthalmologists expect from them? That’s what we’re here to find out, so let’s dive in — but first, a bit of background.
The Current Status of Laser Refractive Surgery
Many of our physician readers will be aware of the general state of laser refractive surgery, but let’s point out some refreshing stats. First, a study in the long-long ago of 2008 demonstrated that the huge, adverb-needing majority of LASIK patients were satisfied with their surgical outcome, at 98.8%. Another whopping 99.5% of patients met a spectacle-free visual acuity of 20/40.
So, if the goal of laser refractive surgery is good vision and good outcomes, the industry has been there already. Now we’re into the refining stage of the process. Lenticule extraction can counteract some of the drawbacks of LASIK by reducing the occurrence of dry eye disease (DED), a larger functional optical zone, and no flap.
It’ll be important to continue to refine and customize refractive surgery, especially as the number of myopia patients is expected to rise to 5 billion people by 2050.2 High myopia will similarly rise to nearly a billion people. That’s a big deal.
Presbyopia has also been big news (and big business) lately and will continue to trend that direction. Nobody is getting younger, and nearly everyone is looking at screens more — so patients are more aware than ever of their vision problems.
Competition is natural in any healthy industry, so the entrance of new devices for the lenticule extraction market is normal. Zeiss just had a massive head start on their competition, but here it comes.
Betting on the dark horses?
One of our favorite doctors, Dr. Jodhbir Mehta, co-authored a study1 that examined the differences between the two new entrants into the lenticule extraction business, which we’ll do our best to summarize here. If you’d like to read the full text, check here for details.
For now, let’s start with CLEAR. The procedure itself is an optional software upgrade on the FEMTO LDV Z8 platform (Ziemer Ophthalmic Systems). The platform itself is multifunctional, and can be used for cataract surgery, corneal transplantation, LASIK flap creation and presbyopic surgery — just for example. It uses a low-energy, high-frequency concept, ensuring decreased stromal gas formation and highly focused laser pulses that overlap. The platform also offers a number of centration options, including recentering the treatment area after docking — something not currently possible with VisuMax.
Additionally, the Z8 features inbuilt intraoperative OCT, which may be used following lenticule creation and useful in potentially complicated cases.
While a group of Chinese scientists noted that CLEAR took longer than SMILE, CLEAR offered OCT scanning and offsetting before performing the laser procedure. This may explain the additional time spent. The group noted that both anterior and posterior lenticule surfaces were smoother using CLEAR than SMILE. Keep in mind, however, this was a study on enucleated porcine eyes, so, y’know … take a grain of salt with this bacon.
For now, expect more studies to compare CLEAR and SMILE. We’re still very early in the comparative process.
The same story is true with SmartSight, which relies on the SCHWIND ATOS FS, which is notable because of its lightweight and more portable nature. The ATOS offers eye tracking, pupil recognition, and cyclotorsion compensation for precise centering. This can be notably helpful in correcting astigmatism.
ATOS’s laser and SmartSight uses lower energy than SMILE but higher than that of CLEAR. So does that make for a happy middle ground? We’ll have to wait and see.
Both SmartSight and CLEAR do not use any side cysts, and so do not have a minimal thickness as does SMILE.
Lenticule Extraction Heats Up
Lenticule extraction surgery is already gaining popularity, and we’re fairly sure it will only gain steam. Want to know more about lenticule extraction and just how it works? Be sure to check out Media MICE’s interview with three top lenticule extraction docs on March 2, 2022 for a deep dive into the current status and future of the procedure.
References
- Fuest M, Mehta JS. Advances in refractive corneal lenticule extraction. Taiwan J Ophthalmol. 2021;11(2): 113–121.
- Holden BA, Fricke TR, Wilson DA, et al. Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology. 2016;123(5):1036-1042.
