激光照射对豚鼠内耳结构和前庭功能的影响

Influence of He-Ne Laser Irradiation on the Structure of theInner Ear and Vestibulum Function of Guinea Pigs

为了探讨ＨｅＮｅ激光照射鼓膜对内耳结构和前庭功能的影响，用不同功率密度的ＨｅＮｅ激光照射豚鼠鼓膜，观察内耳结构及前庭功能的变化。结果发现ＨｅＮｅ激光每天照射豚鼠鼓膜１０ｍｉｎ～１５ｍｉｎ，连续１０天后，当光纤末端输出功率密度为４２４ｍＷ／ｃｍ２时，Ｃｏｒｔｉ氏器外毛细胞和静纤毛排列紊乱；当光纤末端输出功率密度为５６６ｍＷ／ｃｍ２时，除上述改变外，还有Ｃｏｒｔｉ氏器变形，内毛细胞境界不清，静纤毛部分残缺不齐，部分消失，Ｃｌａｕｄｉｕｓ细胞和边界细胞内出现空泡；当功率密度为３５４ｍＷ／ｃｍ２时，内耳结构无改变。上述功率密度的激光照射豚鼠鼓膜，对前庭功能均无影响。提示临床上用ＨｅＮｅ激光照射鼓膜治疗中耳病变时，其光纤末端输出功率密度应控制在３５４ｍＷ／ｃｍ２以下，每天照射时间不宜超过１５ｍｉｎ，连续照射以１０天为宜，否则可能影响听力。

he purpose of this study is to investigate the influence of He-Ne laser irradiation of tympanic membrane on the structure of inner ear and on the vestibulum function. The impairment of the structure in the inner ear was examined by light and electron microscopy and the vestibulum function was tested after HeNe laser irradiation to the guinea pig tympanic membrane with various power densities. It is demonstrated that after the laser irradiation at 42.4 mW/cm^2 for 10 or 15 minutes once a day for 10 days, the outer hair cells and stereocilia in the Corti's organ are disarranged. When the power density of 56.6 mW/cm^2 was used there were deformation of the Corti's organ, vague appearance of inner hair cells, regional disorder or loss of stereocilia and vacuolization of Claudius cells and border cells, but the vestibulum function was well preserved. When a power density of 35.4 mW/cm^2 was used, the Corti's organ was normal. It is suggested that when the tympanic membrane is irradiated by He-Ne laser, in order to avoid any possible damage to hearing, the output power density from the optic fiber tip should be controlled under 35.4 mW/cm^2, the irradiation time not longer than 15 minutes, and no more than 10 times for a session.