Eyeworld

EW NEWS & OPINION 14 August 2015 by Lauren Lipuma EyeWorld Staff Writer Laser vitreolysis of floaters is a safe and effective alternative to vitrectomy W hen a patient comes into the office com- plaining of floaters, ophthalmologists usually offer only 2 options—learn to live with them or undergo a vitrectomy. A little-known third option exists, however, that treats floaters in a safe, effective, and noninvasive way: vaporizing them with the Nd:YAG laser. YAG laser vitreolysis was pio- neered more than 30 years ago but never took hold as a treatment for floaters, and few doctors perform it today. But now, with new technolo- gies optimized for the procedure and a growing awareness of it among anterior segment surgeons, YAG vit- reolysis could become the standard of care for floater management. How does it work? Vitreolysis was pioneered in the 1980s by European ophthalmolo- gists Franz Fankhauser, MD, and Daniele Aron-Rosa, MD. John Karickhoff, MD, Falls Church, Va., was one of the first surgeons to perform vitreolysis in the U.S. Dr. Karickhoff wrote the only textbook on vitreolysis and developed several surgical contact lenses to assist with floater visualization. The procedure is simple—a Q-switched Nd:YAG laser, optimized for use in the posterior segment, vaporizes the floater material. In- stead of projecting a parallel beam of light, the laser emits a beam that converges to a focal point 8 microns in diameter. With the help of a sur- gical contact lens, the physician uses the laser to locate the floater and focus the beam on it. When the laser is fired, the tem- perature of the floater at the focal point rises to 4000 degrees Celsius, creating plasma that fills the conver- gence angle and converting a small amount of solid floater material to gas. Over the course of 1 or 2 treat- ment sessions of several hundred laser shots, floaters can be rendered small enough that they no longer disturb the patient's vision. A new use for the YAG laser: vaporizing floaters Overall, floater vitreolysis has been shown to be incredibly safe and effective, with only minor instances of rise in intraocular pressure. Dr. Karickhoff reports on his website that he sees success in 95% of cases with a complication rate of 0.1%. Why do so few physicians perform this procedure? Floater vitreolysis is a noninvasive procedure that involves equipment YAG vitreolysis: How it works To accurately treat floaters, the slit lamp illumination beam (visible light), slit lamp observation beams (green beams), HeNe aiming beams (red beams), and the infrared treatment beam must share the same axis. When the laser is fired, the floater material becomes ionized, creating plasma that fills the cone angle. The same floater before, during, and after YAG vitreolysis treatment. The laser has rendered the floater virtually undetectable. Source: Karl Brasse, MD The laser's infrared treatment beam (blue) converges at an angle of 16 degrees to a focal point 8 microns in diameter. The treatment beam diverges past the focal point, so it does not harm the retina. Plasma formation creates a shock wave that vaporizes the floater tissue, creating gas bubbles that float upward. The gas bubbles reflect most of the light and shock wave back toward the lens, preventing the laser's energy from reaching the retina.

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