Biomedicine How Lasers Can Heal Surgeons' Incisions Lasers and a century-old dye could supplant needles and thread. by Lauren Gravitz February 11, 2009 Sponsored by After removing a small ellipse of tissue from an anesthetized rabbit, surgeon Ying Wang sews the deeper layers of the wound shut with traditional sutures; the laser that the team uses does not penetrate this deep tissue and so cannot bind it together. Wang has closed the right half of the epidermal wound with cosmetic stitches. She then drips Rose Bengal dye onto the left half. Wang and surgeon Min Yao position a metal frame that directs a green surgical laser over the incision. The frame keeps the instrument steady and at a measured distance from the skin. They shine the light onto the cut to activate the dye, leaving it on for three minutes. A lens in the metal stand modifies the shape of the laser’s focal point so that it’s ideal for healing a long, thin surgical incision. Activated by the light, the Rose Bengal stain causes collagen fibers in the skin to link, sealing the wound. Once the laser is removed, the left half of the incision remains closed without sutures; it requires no further care and will leave behind almost no scar. The stitches on the right half, however, must remain in place for up to two weeks and will result in small but visible cross-hatch scars.