Expert Commentary
Different Concepts to Approach the Same Technology
The main commercially available femtosecond devices have different concepts and applications on how the technology should be used. The IntraLase was the first device and set the standards regarding energy delivered and geometry of cuts. The IntraLase had the strategic advantage of being the first, and achieved a significant market penetration, so that it is number one in the marketshare.
The LDV from Ziemer has implemented a different concept. It is a device entirely focused on flap creation (even though intrastromal ring channels and lamellar keratoplasty can be performed), with the lowest pulse energy, fastest pulse rate and negligible, if any, OBL formation. The device is portable and can be used by different lasers centers, optimizing cost. However, the vertical cut is not available and changes in the geometry of the intrastromal cut are very limited. It is touted as being the simplest and cheapest way to replace the microkeratome for a laser.
The Technolas Femtec laser and Carl Zeiss Visumax initially followed the same standards for flap creation set by IntraLase, yet their features offer newer approaches and applications, which help to differentiate them. Both systems have a curved docking interface (more physiologic and less IOP rise during applanation). The customizable features in Technolas are similar to IntraLase; however, the Femtec laser has been used to first perform and popularize intrastromal cutting to induce a biomechanical effect in the IntraCor procedure. The Carl Zeiss Visumax is the largest and most complex (and expensive) of the devices. The technical specifications of the laser beam lies somewhere between IntraLase and LDV, with relatively low pulse energy and fast repetition rate. It has the most customizable software and is focused on the development of 'femtosecond-only' refractive tissue removal with the FLEx and SmILE procedures.
The new Wavelight FS200 from Alcon follows the same successful path of IntraLase in its basic concept, being similar in technical specifications. However, it addresses some of the early issues found in the IntraLase device, promising a faster procedure with the 200-KHz rate and less OBL formation.
Femtosecond laser-assisted cataract surgery devices are expected to be released during 2011. The first generations are expected to be 'cataract only' devices, and it is possible that future versions will have the ability to combine cataract and refractive surgical applications (i.e., flaps, ring channels, and so on). This could consolidate femtosecond laser technology into a versatile workstation for cataract, refractive and corneal surgeries.
What concept will prove to be the best has not yet been determined, but it is possible that a variety of concepts will be successful. For example, the portability, simplicity and low cost of Ziemer LDV may be best for lower volume centers, while more complex and expensive devices may be chosen in the larger corporate and academic centers.
Expert Rev Ophthalmol. 2011;6(1):55-65. © 2011 Expert Reviews Ltd.
Cite this: Comparison of Commercially Available Femtosecond Lasers in Refractive Surgery - Medscape - Feb 01, 2011.
