Spectroscopy Study of Packed Erythrocytes Irradiated by 532 nm Low Level Laser

Abstract

Background: Low-level laser wavelengths have been used in a variety of medical applications due to their ability to modulate blood rheology and enhance microcirculation. The reaction of human blood to low-level laser irradiation (LLLI) offers valuable information regarding the interaction of laser light with tissues. Objective: The aim of the study was to observe whether in vitro irradiation affects packed red blood cells and whole blood. Methods: Blood samples were each split into two equal aliquots labelled as control (non- irradiated) and irradiated groups. Irradiated sample was exposed to LLLI output powers of 60, 80, and 100 mW at 532 nm wavelength with various irradiation time ranged from 30, 60, 90, 120, and 150 s. Results: Irradiated samples for packed red blood cells (RBCs) before mixing with plasma have a lower absorption range compared to irradiated samples after mixing with plasma.When compared to whole blood, RBCs have a higher absorption range. Blood samples smeared showed variations in the packed RBCs morphology between the control samples. Blood samples smeared showed no changes in the red blood cell morphology between the control and irradiated samples. Conclusion: The results revealed that different irradiation exposure durations resulted in significant differences in light absorption of RBCs and whole blood. The optimum laser dose obtained from the result for RBC packed cell is 100 mW at 150 s while for whole blood is 80 mW at 60s exposure time.