title: Spatially correlated microthermography maps threshold temperature in laser-induced damage.
abstract: We measured threshold temperatures for cell death resulting from short (0.1-1.0 s) 514-nm laser exposures using an in vitro retinal model. Real-time thermal imaging at sub-cellular resolution provides temperature information that is spatially correlated with cells at the boundary of cell death, as indicate by post-exposure fluorescence images. Our measurements indicate markedly similar temperatures, not only around individual boundaries (single exposure), but among all exposures of the same duration in a laser irradiance-independent fashion. Two different methods yield similar threshold temperatures with low variance. Considering the experimental uncertainties associated with the thermal camera, an average peak temperature of 53 ± 2 °C is found for laser exposures of 0.1, 0.25, and 1.0 s. Additionally, we find a linear relationship between laser exposure duration and time-averaged integrated temperature. The mean thermal profiles for cells at the boundary of death were assessed using the Arrhenius rate law using parameter sets (frequency factor and energy of activation) found in three different articles.
authors: TASC, Inc., Biomedical Sciences and Technology Department, San Antonio, Texas 78235, USA.
authors: Michael L
authors: ML
authors: Denton
authors: Gary D
authors: GD
authors: Noojin
authors: Michael S
authors: MS
authors: Foltz
authors: Clifton D
authors: CD
authors: Clark
authors: Larry E
authors: LE
authors: Estlack
authors: Benjamin A
authors: BA
authors: Rockwell
authors: Robert J
authors: RJ
authors: Thomas
mesh_terms: D016923:Cell Death / Q000528:radiation effects; D002460:Cell Line; D003627:Data Interpretation, Statistical; D006801:Humans; D007834:Lasers / Q000009:adverse effects*; D008954:Models, Biological; D055096:Optical Devices; D055620:Optical Phenomena; D012160:Retina / Q000293:injuries* / Q000528:radiation effects*; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000293:injuries / Q000528:radiation effects; D013696:Temperature; D013817:Thermography / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data