FOCUS ON …
CZM's Visulas Trion
LESLIE GOLDBERG, ASSOCIATE EDITOR
The Visulas Trion from Carl Zeiss Meditec (Dublin, CA) is designed to provide eye doctors of various disciplines and backgrounds optimum flexibility for a broad spectrum of retinal therapies.
Faisal Jehan, MD, a vitreoretinal specialist for Kaiser Permanente in Fontana, CA, and his colleagues had been using the Zeiss Visulas Trion for almost a month as a demo and were so impressed with its features and performance that they purchased it for their clinic.
"The Visulas has a number of features I've found to be useful and user-friendly," says Dr. Jehan. "The laser settings are controlled via a convenient touch-screen console that's movable and easy to use. Another nice feature is the table for the slit lamp. Ergonomically, it's comfortable for the both the patient and the physician using the laser. Switching between the slit lamp and indirect laser is also simple and quick. The optics of both the slit lamp and indirect are excellent."
RED, YELLOW, AND GREEN WAVELENGTHS
Dr. Jehan says that the most versatile feature of the Visulas is that it is a multi-wavelength laser with red, yellow, and green wavelengths. "Green has been the standard wavelength on most lasers available in the past several years and I certainly use it most," says Dr. Jehan. "This may just be out of habit, as I find myself switching to the yellow wavelength more as I perform more laser procedures on the Visulas. If you consider the absorption curve of the significant pigments within the eye, green, red, and yellow wavelengths, all are absorbed by melanin in the RPE well, which make all 3 ideal for photocoagulating retinal tissue."
Dr. Jehan says that the availability of the different wavelengths allows him to be more versatile in his laser procedure performances, translating into more effective treatment for his patients. Dr. Jehan has started to shift to using the yellow wavelength more frequently for 2 reasons.
"First, since xanthophyll absorbs yellow wavelengths least, in theory, yellow will be gentler on the macula, where xanthophyll is in its highest concentration. Having that element of safety is important, at least in helping to reassure us that there may be less potential for light toxicity," he says.
"Second, yellow light scatters less through nuclear opacities, which I've found to be very useful when using the Visulas. I find that lower laser setting can be used when performing panretinal photocoagulation when cataracts are present, and even with some denser cataracts I'm able to complete a more thorough treatment."
Dr. Jehan says that on occasion he is unable to perform adequate panretinal photocoagulation with the green wavelength because of the problem of scatter through lens opacities, which makes cataract surgery necessary. "If we are able to better treat the retina with the yellow wavelength prior to cataract surgery, we may be able to stabilize patients further, which in turn may lead to better outcomes," states Dr. Jehan.
He has also found the red wavelength to be useful for performing laser through areas of vitreous hemorrhage that green often won't penetrate. "Red wavelengths pass through hemorrhage with little absorption, and clinically this translates into better burns when treating through areas of blood in the vitreous," says Dr. Jehan. "I've been able to treat more diabetic retinopathy at the slit lamp and retinal tears with the indirect laser through hemorrhage than I feel I could have with the green wavelength."
Dr. Jehan says that one disadvantage of the red is that it gives a deeper burn and may cause more discomfort. He says that in cases where he can treat the retina through vitreous hemorrhage, the disease process may stabilize enough to prevent surgery altogether. "This is another example of avoiding the greater risks associated with surgery, which in turn may lead to better outcomes," says Dr. Jehan.
"Having 3 different wavelengths gives the Visulas more versatility than most other lasers that use only a single wavelength. Although green can be used effectively in most cases, I've found that it's advantageous to have yellow to treat through denser cataracts, and red to help treat through vitreous hemorrhage," concludes Dr. Jehan. RP
For more information on the Visulas Trion, please visit the CZM Web site at www.meditec.zeiss.com.