BBI Contributing Editor
SAN DIEGO, California – During the American Society of Cataract and Refractive Surgery (ASCRS) annual meeting here in late April, more than 5,000 refractive surgeons were bombarded with an array of new and pending products designed to improve clinical results and enhance safety. This flood of new devices seems to be unaffected by the current refractive procedure market down-cycle, proving that surgeons have an insatiable appetite for new technologies.
IntraLase (Irvine, California) promoted an all-laser approach to refractive surgery. The Pulsion FS (femtosecond) laser is positioned as an alternative to the mechanical microkeratome. "The Pulsion is a focal laser that focuses down into the stromal layer of the cornea," said Trudy Larkins, director of marketing and communications at IntraLase. "This laser creates a dissection plane, with a tiny 1 to 2 micron spot size. These spots are then stacked along the periphery – up to the surface of the cornea – and cut through the surface, thus creating a flap."
Unlike a microkeratome, the Pulsion FS laser "can virtually be programmed to leave the hinge at any location on the cornea and to cut precisely within 5 microns," Larkins noted. The Pulsion also has "an incomparable safety profile," she said. "There is nothing that goes across the eye, like a metal blade, so you do not end up with any epithelial defects or a partial cut." In short, the Pulsion "eliminates or greatly reduces all of the risk associated with the creation of a corneal flap."
The FDA-approved Pulsion FS laser is being placed only on a per-procedure basis, with pricing based on volume. "Our laser was designed to sit side-by-side with current excimer laser technology," she said. "In the future, our laser may be able to do the full refractive correction by intrastromal ablation only. But we've only started feasibility studies outside the U.S."
Other companies, however, believe the microkeratome remains viable technology. Schwind eye-tech-solutions (Kleinostheim, Germany) has obtained exclusive worldwide distribution rights from View Point Technology for the new Carriazo-Pendular microkeratome, developed by Cesar Carriazo, MD, from Colombia. "The pendular cutting movement of this keratome provides many advantages," said Claudia Lanzinger, international marketing manager at Schwind. "Our motto for this product is 'We get the ball rolling,' referring to the ball-shaped surface of the device, which distributes the pressure mainly to the center of the eye and protects the corneal center."
Easy handling and assembly, constant flap thickness and a mechanically safe and solid construction are three other advantages of the Carriazo-Pendular, which is still under clinical investigation. "The constant flap thickness is due to a steady drive speed," Lanzinger said, adding that the device has controlled vacuum and a "good suction grip due to bigger vacuum chambers in the suction ring." The keratome also offers automatic or manual cut, as well as visual control during flap cutting. "The bayonet connection ensures that the drive can be easily removed in every cutting position," Lanzinger said. In addition, there are no permanent internal and external gears in the cutting head. Moreover, "the Carriazo-Pendular is suited for very small eyes because of the minimum dimensions of the suction ring and motor," she added.
Lumenis (formerly Coherent Medical Group; Santa Clara, California) debuted the Selecta 7000 Glaucoma Laser System ($55,000), a 532 nm Q-switched Nd:YAG laser for performing selective laser trabeculoplasty (SLT) which recently gained FDA approval. "SLT causes a biologic response in the trabecular meshwork, which results in lower intraocular pressure without thermal damage to healthy trabecular tissue," said Peter Falzon, director of ophthalmic marketing.
Although the procedure is similar to argon laser trabeculoplasty (ALT), "it is actually easier to perform because precise focusing onto the trabecular meshwork is not required," Falzon said. "This is a whole new approach in managing open-angle glaucoma. Clinical trials indicate that in a patient group of uncontrolled glaucoma on maximally tolerated medical therapy, 70% responded favorably to SLT. Furthermore, because there is no damage to the structure of the trabecular meshwork, the treatment is potentially repeatable, unlike with ALT."
Asclepion-Meditec (U.S. headquarters, Santa Ana, California) showcased the MEL-70 excimer laser for customized ablation ($450,000) and Phacolase, an erbium laser for cataract, vitreous and glaucoma treatments ($80,000). The MEL-70 laser is being sold worldwide, with U.S. clinical trials scheduled to begin this summer. "This excimer laser combines topographic and wavefront links that are commercially available outside the U.S.," said Bill Kelley, general manager for North America. Phacolase already is undergoing clinical trials in the U.S. and is commercially available elsewhere. "This is a non-thermal alternative to standard phacoemulsification, which relies on ultrasound," he said.
Kelley and others at Asclepion-Meditec predict that the erbium laser will eventually become the laser of choice for phaco. "We're committed to being on the leading edge of using lasers for ophthalmic applications," he said.
Visx (Santa Clara, California) promoted its Star S3 Activetrak excimer laser, priced at about $450,000. "Our laser system now employs a 3-D active eye tracker," said Thomas McKay, senior marketing manager. "No matter which way the patient's eye moves during surgery, the tracker is able to follow the eye and adjust the laserbeam, according to the movement of the eye." The tracker also does not require pupil dilation.
Variable spot scanning is another advantage of the Star S3 Activetrak. "This is a method to scan the laserbeam around the eye and change the shape and size of the beam during the scanning treatment," McKay noted. Scanning correlates with the patient's refractive error. "We can make the beam adjust to those needs."
Visx also has the WaveScan Wavefront System ($75,000), which permits surgeons to precisely measure higher-order refractive aberrations, in addition to sphere, cylinder and axis. "We use highly advanced micro-optic arrays," McKay said. "The optics project light into the eye and analyze the returning wavelength using a Hartmann-Shack sensor containing thousands of tiny lenslets." From the wavefront system, surgeons obtain a WavePrint. "This is a unique 'fingerprint' of the eye, which makes an accurate assessment of the patient's refractive errors for more customized laser vision correction," McKay said. In short, "the use of this diagnostic information combined with the other high-tech advancements of the laser platform represents the future of laser- vision correction."
Wavefront and custom ablation refractive technology also created a buzz at the Nidek (Fremont, California) exhibit booth. Recently FDA-approved, Nidek's OPD-Scan is the first diagnostic instrument to combine corneal topography, auto-refraction and wavefront analysis. "The OPD-Scan takes these measurements at the same time and on the same axis, all in 0.4 seconds," says Bonny Walsh, Nidek's OPD-Scan specialist. Unlike wavefront systems using the Hartmann-Shack sensor, OPD-Scan uses dynamic retinoscopy to measure aberrations through 1,440 data points. These points create refractive power maps to help doctors evaluate their patients. "Because the OPD-Scan gathers so much data, doctors have a new level of diagnostic analysis to help determine the best option for the patient," Walsh said. "This is why we say the OPD-Scan has 'Wavefront PlusTM,' because it really goes beyond the wavefront-only devices that are just now coming to market."
Nidek also displayed the latest enhancements to its EC-5000 excimer laser platform, which will be submitted for supplemental premarket approval by the FDA. Among the many new features is an active eye tracker and custom segmental ablation capability.
The 250 Hz eye tracker does not require pupil dilation and uses four independent tracking points to maintain alignment, even if an instrument being used in the visual field blocks two points. And the custom segmental ablation system allows the Nidek EC-5000 system to place from one to six 1 mm "spots" on the cornea as needed to achieve a true custom ablation for patients.
In addition, Nidek displayed a wide range of other ophthalmic lasers and diagnostic devices, including a prototype laser for Transpupillary thermotherapy (TTT).
Bausch & Lomb (Claremont, California) is conducting a three-site feasibility study in the U.S. on its Zyoptix system for personalized laser vision correction. "Obviously, our definition of custom ablation is different from our competitors," said Randy Mansfield, director of refractive marketing for the Americas. "Our definition is not just wavefront-driven ablation." Besides using a Hartmann-Shack abberometer (Zywave), the Zyoptics platform incorporates an advanced corneal mapping system, the Orbscan II. This is a multi-dimensional diagnostic system that maps both the anterior and posterior surface of the cornea, plus serves as a screening device for pachymetry. In essence, the system "not only provides topography, but also elevation data," he said.
Zylink software is used to transfer data from the Orbscan to the ZyWave, then to the laser (Bausch & Lomb's Technolas 217A excimer laser). "Eventually, the systems will be hard-linked," Mansfield said. "It will become a much more customized procedure for each individual patient." Preliminary results from global data "show the potential for better outcomes," he said. The Technolas 217A also uses a combination 2 mm and 1 mm spot size.
Overall, the Zyoptix system has the potential to diagnose night vision disturbances and minimize post-surgical glare and halos. This new system removes 15% to 20% less tissue compared to the software currently used with the Technolas 217 laser.
As part of its overall custom ablation strategy, LaserSight Technologies (Winter Park, Florida) debuted AstraMax, a precision diagnostic device. "This is the next generation of corneal topography," said Bill Kern, senior vice president of corporate development. "Unlike a conventional topographer, AstraMax provides complete anterior corneal topography, limbus to limbus." Posterior corneal measurement, scotopic pupil size, and pachymetry can also be derived. "All of these readings come in one single exposure," he said.
A patented, multi-camera technology renders "faster and more accurate measurements compared to conventional topographers," Kern added. "Every point on the cornea is looked at by a minimum of two of the three cameras." Moreover, instead of using a circular or placedo grid, a checkered polar grid is used, thus allowing for viewing of torsional distortion.
AstraMax should be available for commercial use in the fall ($50,000). "Wavefront alone will not provide the best subjective patient results," Kern said. For instance, "large pupils have been the cause of many reported postoperative complications, such as glare, halos and loss of contrast sensitivity."
Alcon Laboratories (Fort Worth, Texas) displayed LadarWave, a custom cornea abberometer ($50,000). "In its current status, we're only approved to measure higher-order aberrations; however, we are conducting FDA clinical trials with LadarWave to perform customized ablations," said Bill Barton, vice president and general manager.
The LadarVision 4000 excimer laser (average price $450,000) was also on hand. "This product is unique in the U.S. market in that it provides a combination of a flying small-spot Gaussian beam (a shape similar to a bell curve) and an eyetracker," Barton said. The radar tracker samples eye movement 4,000 times a second and has a 100-Hz bandwidth, "so it can make adjustments 100 times per second," he noted. The LadarVision "also has the widest range of treatment approvals of all lasers in the market today."
Q-Vis (Perth, Australia) was the only company at ASCRS to display a solid-state refractive laser, according to CEO John Roper. "The Q-Vis Quantum uses innovative Crystalogic technology, which makes toxic gases obsolete and therefore eliminates the inherent problems with excimer technology," he said. "Maintenance costs and downtime are reduced, and warm-up time and gas storage problems are eliminated."
Quantum's unique 213-nm wavelength "may improve patient comfort and enable refractive surgeons to achieve more predictable patient results," Roper said. Laboratory studies have demonstrated that attenuation through balanced salt solution was significantly less for a 213-nm wavelength compared to a 193-nm excimer laser wavelength. "This offers the potential for wet field surgery with less stringent monitoring of hydration," he noted. In addition, the Quantum's advanced variable-sized, flying-spot scanning technology provides a flexible range of treatment options and is capable of customized ablations.
Quantum was recently approved for sale in Australia and the company is actively pursuing regulatory approval in Europe. U.S. clinical trials are also under way, with FDA marketing approval expected in 2002. "The Q-Vis Quantum is expected to be priced in the mid-range, with service and support an integral feature of our operation," Roper said.