【摘要】 为了研究ＹＡＧ激光和ＣＯ２激光行鼓膜造孔对听力的影响，我们用不同功率密度的激光照射豚鼠鼓膜不同时间后观察中耳和耳蜗显微和超微结构的变化。结果发现光关节末端输出功率密度１５８Ｗ／ｍｍ２的ＣＯ２激光照射豚鼠鼓膜２秒，相同功率密度的ＹＡＧ激光照射１０秒可引起鼓膜穿孔、听骨链和耳蜗凝固或点状炭化；显微镜观察见凝固和炭化处柯蒂氏器官均明显破坏或变形，其内部分有炭化灶和／或炭化颗粒。激光输出功率密度愈大，损伤听骨和耳蜗的照射时间愈短。中耳腔内注水可明显避免或减轻ＣＯ２激光对听骨和耳蜗的损伤，但对ＹＡＧ激光无效。提示临床上用ＣＯ２激光造孔治疗渗出性中耳炎时，如中耳腔内积液较少，应先通过鼓膜注入０３ｍｌ生理盐水或地塞米松，然后可用输出功率７Ｗ（密度８９１Ｗ／ｍｍ２）的ＣＯ２激光照射鼓膜，照射时间应控制在６秒；如中耳腔渗液较少，直接用ＣＯ２激光照射鼓膜时，应控制在３２Ｗ（４０Ｗ／ｍｍ２）以下，照射时间以１秒为宜。如用ＹＡＧ激光行鼓膜造孔，光纤末端输出功率应控制在６Ｗ（密度７６４Ｗ／ｍｍ２）以下，光纤末端应与鼓膜准接触，照射时间应控制在２秒，否则可引起耳蜗和听骨的损伤。更多还原

【Abstract】 To study the hole influence in the tympanie membrane perforated by YAG laser and CO 2 laser on hearing the change of the structure in the middle ear and cochlea by light and eleotron microsoopy is viewed after the laser with various pouser densities irradiates the quinea pig’s tympanic membrane for various time.It is demonstrated that the tympanic membrane irradiated for I seconds by CO 2 laser whose output power density of light links end is 1.58W/mm 2 and 10 seconds by YAG laser of same density may result in its perforative hole and coagulation or carbonization point in the ear bones and cochlea;It is discovered by light microscopy that the coagulative or carbonizative stucture in the cortis organ is obviously damaged and changed.The carbonizative substances are contained in it.The larger is the output power of laser,the shorter is the irradiative time of impairment ear bone and cochlea.The water injected in the middle ear cavity may obviously avoid or alleviate the impairment of CO 2 laser but it is inefficiency for YAG laser.It is suggested that while the hole in the tympanic membrane perforated by CO 2 laser sreats the secretony otitis media 0.3ml water or dexamethesone is injected into the middle ear carity if the effusion is less,then the tympanic membrane is irradiated by CO 2 laser whose power is 7W (8.91W/mm 2).Irradiative time should be controlled in 6 seconds;while the membrane is directly irradiated by CO 2 laser the power should be controlled in 3.2W(4.07W/mm 2) and the time is 1 second if it is less.If the hole is perforated by YAG laser the output power in light fiber end should be controlled in 6W(7.64W/mm 2),the time is 2 seconds and the end should come into contact with the tympanic membrane.othewise the impairment in the ear bone and cochlea may occur.更多还原