Epithelial damage thresholds for multiple-pulse exposures to 80 ns pulses of CO2 laser radiation.
Epithelial damage thresholds for multiple-pulse exposures to 80 ns pulses of CO2 laser radiation.
复制标题
多脉冲暴露于 80 ns CO2 激光辐射脉冲的上皮损伤阈值。
DOI：
10.1097/00004032-200101000-00008
复制
发表时间：
2001
期刊：
影响因子：
2.2
通讯作者：
Bargeron,CB
中科院分区：
文献类型：
--
作者：
McCally,RL;Bargeron,CB
角膜上皮损伤阈值暴露于80 ns脉冲的10.6 [mu] m的红外辐射产生的CO2-TEA激光进行了研究。在10和16 Hz的脉冲重复频率下，对1、2、8、32、128和1，024个脉冲的序列确定了持续时间。阈值损伤通过形式为EDth= CN-[alpha]的经验幂律相关，其中EDth是每个脉冲的阈值辐射暴露，N是脉冲的数量。对于两个脉冲重复频率，常数C和[alpha]是相似的。对于组合数据集，C= 2，955 J m-2 pulse-1（295.5 mJ cm-2 pulse-1），[alpha]= 0.178。对于单个80 ns脉冲曝光，常数C的该值在所测量的损伤阈值的5%内。温度计算表明，由不同阈值暴露引起的前撕裂面下方10 [mu] m处光束轴上的最大温升恒定在平均值的+/-10%范围内。这一结果与临界温度损伤模型是一致的。对冷却角膜的损伤阈值测量表明，损伤机制确实具有很大的热分量。
Corneal epithelial damage thresholds for exposures to 80 ns pulses of 10.6 [mu] m infrared radiation produced by a CO2-TEA laser were investigated. Thresholds were determined for sequences of 1, 2, 8, 32, 128, and 1,024 pulses at pulse repetition frequencies of 10 and 16 Hz. Threshold damage is correlated by an empirical power law of the form EDth= CN-[alpha], in which EDth is the threshold radiant exposure per pulse, and N is the number of pulses. The constants C and [alpha] are similar for the two pulse repetition frequencies. For the combined data set, C= 2,955 J m-2 pulse-1 (295.5 mJ cm-2 pulse-1) and [alpha]= 0.178. This value of the constant C is within 5% of the measured damage threshold for a single 80 ns pulse exposure. Temperature calculations reveal that the maximum temperature increase on the beam axis, 10 [mu] m beneath the anterior tear surface, resulting from the different threshold exposures is constant to within+/-10% of the mean values. This result is consistent with a critical temperature damage model. Damage threshold measurements on cooled corneas indicate that the damage mechanism indeed has a substantial thermal component.