Focus On

577-nm wavelength system delivers safety


577 nm Wavelength System Delivers Safety

By Samantha Stahl, Assistant Editor

While the original diode lasers had revolutionary capabilities when they debuted, the systems were somewhat problematic for patient comfort. The high wavelengths caused pain when near-infrared light would pass through blood and was absorbed by the RPE.

The Pascal Streamline 577 from Topcon Medical is a solid-state, yellow- wavelength system. Focused on increasing safety and comfort for the patient, the system gives surgeons full control over the laser parameters.


Steve Charles, MD, of Memphis, explains that the device's “Streamline” name came about when physicians realized the need for a system that addressed ergonomic issues.

“We all know that we pay for office space by the foot. In Asia, which has very small clinic rooms, you simply can't get larger lasers into the room.” The compact design saves precious office real estate without sacrificing patient comfort, he says. While working on larger patients with some lasers can be a struggle, he finds that “patients of all sizes fit nicely into this system.”

The Streamline system uses the 577 nm "true yellow" wavelength.

Of course, the most important component of the system is the true yellow wavelength. Because the yellow light is not absorbed to any great extent in the xanthophyll pigment, it is safer to use near the macula. Recently, Dr. Charles notes, there has been a major paradigm shift concerning the role of laser applications. While intravitreal injections have become the standard of care for macular degeneration, the 577's main purpose has turned to microaneurysms in diabetic retinopathy, central serous retinopathy with focal leaks and the rare case of extrafoveal choroidal neovascular membrane. “It's a different application now, but a crucial one,” he says.

He also notes that some surgeons have reduced use of grid photocoagulation because of the potential to decrease patient's reading speeds. Instead, he says, “it's now all about focal treatment of micro aneurysms, which is better than many monthly injections. If you treat it once with a laser, maybe you're done.”

Another welcome benefit: the Streamline 577 will be priced comparatively to the standard 532 nm Pascal laser, according to Topcon.


For PRP cases, Dr. Charles initially started all treatments at the suggested 30% to 40% decreased power—for 532 PRP, he typically starts at 375 mW, whereas for 577 PRP he starts at 225 mW. For two PRP cases, he ended up at higher power, about 450 mW and 30 ms, but both cases presented media opacity. He then followed with two subsequent cases that seemed to follow the lower-power-is-better trend flawlessly. He used a 5x5 pattern, 275 mW, 20 ms and .75 spacing. The first patient was a 2,500-spot PRP and the second patient was a 2,476-spot PRP. Both completed the treatment in one session. “Both patients said they felt no pain and neither had experienced laser before that day,” Dr. Charles said. “We looked at post-treatment burns with the headset and observed about 95% efficacy with the burn ‘takes.'”

Topcon also recently launched an upgrade called endpoint management. According to the manufacturer, the upgrade includes landmark treatment options, used to give reference marks as feedback on proper dosage and location and positioning of ordinarily subvisible laser applications.

There are also options for printed summaries of each procedure and an on-board video teaching system with an integrated video camera and monitor. The laser ensures that physicians and patients alike can have an optimal surgical experience. RP

For more information, visit