Histologic study of normal rat brain tissue after neodymium-yttrium aluminum garnet laser irradiation. I. Cerebral hemisphere.
We report a histologic study of normal rat brain tissue after neodymium-yttrium aluminum garnet laser irradiation. Morphological changes occurred at a maximum depth of 5 mm after 60-W, 1-second exposure, at a 2-mm distance between the optical fiber tip and the brain surface. Polymorphonuclear leukocyte infiltration into the irradiated area was observed 48 hours after irradiation. After 72 hours, macrophages and fibroblasts appeared; their number increased thereafter. At 1 month, tissue defects attributable to neodymium-yttrium aluminum garnet laser irradiation were small. Gliotic changes were rarely seen. We conclude that 60-W irradiation is harmful to young rats but not to adult rats.
D000818:Animals; D001927:Brain Diseases / Q000209:etiology* / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology* / Q000528:radiation effects; D007834:Lasers / Q000009:adverse effects*; D012377:Rodentia