on technology & technique
Solid State Revisited
The world's first totally solid-state laser cavity extends laser life and shortens refire time dramatically.
By Christopher Kent, Senior Associate Editor
Ah, the disadvantages of modern technology. While every surgeon is concerned about a laser's accuracy, other factors -- such as waiting for a laser to regenerate between pulses, dealing with a gradual loss of consistency over time, and having to replace the laser periodically -- can become a major source of irritation.
The Super Q Convertible YAG laser
system from Laserex.
Recently, Laserex (the world's leading manufacturer of YAG laser systems, often labeled and sold by other companies) created a new, more advanced version of its portable
Nd: YAG laser. The new model, called the Laserex Super Q Convertible YAG laser system, includes a feature that alleviates much of the aforementioned irritation: a new, solid-state shutter (the mechanism that allows the pulses of light to emerge from the laser cavity).
Although so-called "solid-state" YAG lasers have been available for years, the shutter mechanism has traditionally been a dye acetate Q switch -- which is not solid state. The dye acetate switch consists of an opaque film that briefly becomes clear when an electrical charge is applied to it. This technology relies on chemicals coating the film and it's susceptible to excessive humidity and heat, so it eventually breaks down, eroding the reliability and consistency of the laser. And when the shutter goes, the entire laser cavity has to be replaced.
Instead, Laserex's Super Q system uses a special proprietary shutter that functions much like the film-based shutter, but "opens" and "shuts" more quickly, and doesn't wear out nearly as fast as the older style of switch. Laserex calls this "Super-Q Technology."
Advantages of the Solid-State Shutter
Because of the new Q-switch, the Super-Q YAG laser's sealed, solid-state laser cavity is the first totally solid-state laser cavity ever made available. This proprietary design has numerous advantages over previous lasers:
- It delivers more than 300,000 shots. (Most YAG lasers only deliver about 100,000 shots.) This translates into years of additional life for the instrument. Although the initial cost of the laser is slightly higher than the cost of some other lasers, the extended lifetime makes the cost per use much lower.
- The solid-state switch regeneration time is the world's fastest: 2.3 hertz (vs. 2 hertz or less on contemporary systems). This means treatments go faster, and rapid repeat firing doesn't cause technical difficulties.
- The Super-Q produces more consistent energy delivery than the old style switch. That means you need fewer shots to get the job done, and the cutting action on the membrane is far more efficient.
- The complete laser system comes with a limited parts and labor warranty good for 2 years, and the Super-Q laser cavity has a 3-year limited parts warranty or 300,000 shots (whichever comes first) -- the best warranty available.
- The new design enhances optical breakdown plasma formation, which lets you treat using lower energy levels.
- It delivers the highest output available: 0.3 to 12.0 mJ in a single shot, and up to 45 mJ maximum in triple pulse mode.
- It has multi-burst capability (one, two or three impulses), making it easier to perform primary
Other Design Advantages
The Super-Q also offers these useful features:
Portability. The laser is small and lightweight:
- The system fits into two protective suitcases that can easily be moved by one person.
- According to Laserex, assembling the laser is simple enough that anyone on your staff can install it within minutes.
- Portability allows the use of the laser at multiple offices without the purchase of extra lasers. (This can be a good investment for offices that may expand in the future.)
Laserex also offers a freestanding version available with optional motorized tables.
The Super-Q laser comes with motorized table options designed to let wheelchair-bound patients reach the chin holder without
High resolution European optics. According to the company, the optics are made by
CSO, an Italian optical company (Leica uses the same optics in its microscopes); they allow enhanced focusing, flat field and increased working distance. A dual diode aiming system helps ensure precise focusing. This system uses the smallest focusing spot available, reducing glare and enhancing treatment flexibility.
Variable defocusing YAG offset. This feature helps to minimize IOL lens pitting by letting you alter the position of the plasma formation spark relative to the red aiming beam focal plane.
The spark position is continuously adjustable up to 250 microns behind the focal plane. Or, you can position it coincident with the focusing beams for peripheral
iridotomies, dusting anterior lens precipitates or cutting anterior membranes. (The target tissue always remains in focus.)
Small footprint. The laser doesn't require a lot of space in the laser room.
Optional "Total Access" wheelchair-accessible table. The laser can sit on a variety of adjustable tables (optional with the laser) designed for different size offices with different needs. Two of the designs are motorized to allow total wheelchair access (one with wheels, one without). This design also allows the wheelchair patient to reach the chin holder without difficulty.
Help if you need it. In the event of a problem, Laserex has knowledgeable people available by phone to assist you, as well as an overnight repair service.
Comments From the Field
Siepser, M.D., an anterior segment surgeon in private practice in Plymouth Meeting, Pa., uses a Laserex unit at Wills Eye Hospital. "One of the things that's bothered me about most available lasers is that they have very slow recycle times," he says. "You fire, you wait. You fire, you wait. In contrast, the Super-Q laser has a very fast repetition rate. Patients are treated in just minutes. I've gotten used to hearing, 'Doctor -- you're done already?'
"Another key piece of any YAG laser is the slit lamp. This slit lamp has variable beam size, variable illumination, 180° rotation, filters, red-free illumination and an immediate override that can provide high illumination. This is a well designed, fully-functional slit lamp, not just a device added to a laser."
Effect of Super Q switching versus older style
dye acetate Q
switching on laser
lifespan. (Data on file at Laserex.)
Dr. Siepser also says the Super Q laser is easy to use. "The controls are very intuitive. Anyone who can operate a calculator can run this machine.
"I've had a lot of experience with this product," he adds. "I've taken it to third world countries. It's tough, and it really performs. And it doesn't break down much -- it's not a maintenance headache.
"I definitely give the Super Q laser a thumbs up."
For Further Information
To find out more, contact your local Laserex representative at
(800) 824-7444, visit www.laserexsystems.com, or send an e-mail to
Ophthamology Management, Issue: September 2003