Eye-tracking FS laser will enable lenticule extraction in high astigmatism
Lenticule extraction is a promising method in corneal refractive surgery, offering visual outcomes similar to TransPRK or LASIK. Yet lenticule extraction remains mostly limited to myopia and low astigmatism, largely because current femtosecond lasers lack refinements that excimer lasers added long ago, notably eye tracking.
Schwind eye-tech-solutions is changing that. At this year’s ESCRS Congress in Paris, Schwind is introducing the first femtosecond laser for lenticule extraction with eye tracking. Market launch is planned for early 2020.
In development for almost four years, the system’s innovations should improve vision and surgical experience, advancing lenticule extraction and making it available for many more patients. “We will not settle for the current status of lenticule extraction,” says Rolf Schwind, CEO of the Kleinostheim, Germany-based manufacturer of high technology refractive and therapeutic corneal lasers.
“With an eye tracking-guided docking procedure we offer an objective focusing function to optimally align the patient’s eye to the laser. An objectively determinable treatment offset enables the surgeon to make further fine adjustments. This ensures high precision and optimal postoperative visual acuity,” Mr Schwind explains. Eye tracking also allows cyclotorsion control, which is important for correcting higher astigmatism, he adds.
LESS STRESS IN THE LASER SUITE
The new laser helps make lenticule extraction operations easier for both surgeons and patients, Mr Schwind says. “The technique offers better options for positioning the eye and improved ergonomics for the surgeon.” A small footprint conserves space in tight operating theatres and allows the system to be positioned more easily for optimal access in surgery. An innovative interface reduces corneal applanation and the suction needed for laser docking, optimising treatment precision and patient comfort.
Eye tracking also helps surgeons recover cases should the system lose suction in surgery. Theo Seiler MD, PhD, Zurich, Switzerland, reported successfully redocking the Schwind system and completing surgery in one of the first cases he operated in Bangalore, India.
Dr Seiler believes eye tracking will expanding lenticule extraction indications. “The whole area of myopic astigmatism is now open.”
ENHANCED LENTICULE DISSECTION
Schwind’s new femtosecond laser addresses another common challenge – dissecting the lenticule. Software features including sophisticated laser pulse characteristics and positioning algorithms reduce adhesions between the lenticule and surrounding stroma. This makes for an easier, smoother lenticule dissection and extraction, said Rohit Shetty MD, who performed the first human trials with the new laser in Bangalore.
Studies show a smoother lenticule dissection reduces post-op inflammation, which speeds visual recovery and may improve visual outcomes. Results from the first patients treated with the Schwind femtosecond laser are consistent with these literature findings.
“Our first study with 34 myopic patient eyes showed positive results one month after treatment,” Mr Schwind says. After lenticule extraction to correct spherical equivalent errors ranging from -2.0 to -8.0 dioptres, uncorrected distance visual acuity of treated eyes was equal to or better than pre-op corrected distance visual acuity. The quality of the incision and the roughness of the lenticule were evaluated by the surgeon as consistently good.
“It is noteworthy that the visual recovery was very fast: nearly 90% of eyes achieved visual acuity of 20/20 one day after surgery. Also, in terms of predictability and safety, the first clinical results have confirmed our expectations. Further studies are under way,” Mr Schwind adds.
Mr Schwind believes that the improvements he is making in his femtosecond laser platform will attract more surgeons to lenticule extraction. “In addition to TransPRK and LASIK, lenticule extraction will be an important further option in refractive surgery.”
Adding a femtosecond laser also helps diversify and strengthen the firm’s product portfolio, positioning it for another year of market growth, Mr Schwind adds. After that, the sky is the limit.
“Our new technology and platform provide versatile possibilities for integrating additional features and applications in the future. We already have specific ideas ready to be implemented in a short time and would mean a new disruptive model for refractive corneal surgery,” Mr Schwind concluded.