The comparative effects of the argon, Nd: YAG, and argon-pumped dye lasers on human platelets and erythrocytes in vitro.

The effects of three lasers, Argon, Nd:YAG, and Argon-pumped Dye, on three types of platelet preparations were evaluated. Either EDTA or buffered citrate served as anticoagulants. Platelets separated from plasma and suspended in buffer showed no decrease in counts following lasering, but morphologic damage was evident with transmission electron microscopy (TEM). In platelet-rich plasma, a fall in counts was noted for the Argon and the YAG (at high energy only) but was absent when the Dye laser was employed. Morphologic damage (TEM), however, was noted with all three lasers. When whole blood preparations were used, more marked changes in both RBCs and platelets were seen in samples collected in EDTA compared with citrated samples. Morphologic damage (TEM) to platelets and RBCs occurred with all three lasers. An artifactual increase in "platelet counts," the appearance of spherocytes, and an increase in plasma Hb indicated RBC injury. Both platelets and erythrocytes were sensitive to variations in power (wattage) despite constant total energy delivery.