Friday, February 15, 2008
ATul Jain, M.D.
Contributing Editor
Nd:YAG (neodymium-doped yttrium aluminium garnet = type of crystal used) solid state laser systems, AKA—photodisruptive lasers, have been commonly used in ophthalmology for several years, mainly for performing YAG capsulotomies and laser iridotomies. There are several major manufacturers of photodisruptive Nd:YAG lasers for ophthalmic applications (Carl Zeiss Meditec, Lumenis, and Nidek), each with different systems which will be discussed here.
CARL ZEISS MEDITEC
The new Zeiss system is known as the Visulas Yag III. It is a foot pedal operated system that comes coupled to its own slit lamp. The Visulas system uses a 4 point aiming beam system that allows for more precise focus by allowing compensation for astigmatism. The Visulas is controlled by a touch screen control system that rests next to the slit lamp that allows for single, double, and triple pulse laser application in addition to an adjustable focal point for the laser. A Visulas Yag III Combi system is also available that integrates the YAG system with a green laser photocoagulation system on one slit lamp. The photocoagulation system can also be removed and attached to a diagnostic slit lamp as well.
OPTO GLOBAL ADVANT
The Q-switched Advant YAG Laser from Opto Global has a state-of-the-art integrated design with a large display and all controls at reach of the physician's fingertips. There is a five-position magnification changer for improved functionality of the slit lamp in diagnosis and treatment. With a dual spot aiming system and a 2.5Hz firing rate, the Advant should provide more consistant cutting and more stable energy delivery over the long haul. The system also has a 500um posterior and anterior offset for added safety and flexibility.
LUMENIS AURA PT
The latest and greatest YAG system from Lumenis is the Aura PT system. This is a very compact system that allows it to be placed easily on a table. It is joystick operated and the control panel is integrated into the body of the slit lamp (CSO SL 950) below the oculars and above the joystick. The Aura PT has a 2 point aiming beam. The system allows for single, double, and triple laser pulse application in addition to an adjustable focal point for the laser.
NIDEK YC-1800
The newest YAG from Nidek is named the YC-1800 and it is similar in size and operability to the Lumenis Aura PT with a few notable differences, the main one being that the controls can be adjusted with the same hand while it also controls the joystick. This system also allows for single, double, and triple laser pulse application with an adjustable focal point for the laser. The YC-1800 can be coupled to a Nidek green laser photocoagulator (GYC-1000) so that both photodisruption and photocoagulation are possible from the same slit lamp setup to save space. The combination system can be purchased together or the photocoagulator later as an attachment.
Thus, in conclusion, the most popular YAG systems are very similar with subtle differences, mainly in ergonomics and aiming beam profiles. The Zeiss and Nidek systems offer a discount if the combination packages are purchased, which is helpful if one is in the market for both a photodisruptive and photocoagulation system [though note, only a green photocoagulation laser (532 nm) is available in the combinations, if other wavelengths are needed, an entirely separate system is required].