Latina M A, Park C
Wellman Laboratories, Massachusetts General Hospital, Boston 02114, USA.
Exp Eye Res. 1995 Apr;60(4):359-71. doi: 10.1016/s0014-4835(05)80093-4.
The purpose of the present study was to selectively target pigmented trabecular meshwork cells without producing collateral damage to adjacent non-pigmented cells or structures. The ability to selectively target trabecular meshwork cells without coagulation, while preserving the structural integrity of the meshwork, could be a useful approach to study whether the biological response of non-coagulative damage to the trabecular meshwork and trabecular meshwork cells is similar to that seen with coagulative damage to the trabecular meshwork which occurs with argon laser trabeculoplasty. This approach also may be useful to non-invasively deplete trabecular meshwork cells while preserving the structural integrity of the trabecular meshwork in an animal model. A mixed cell culture of pigmented and non-pigmented trabecular meshwork cells were irradiated with Q-switched Nd-YAG and frequency-doubled Nd-YAG lasers, microsound pulsed dye-lasers, and an argon ion laser in order to define a regime where laser absorption would be confined to pigmented trabecular meshwork cells, thereby permitting selective targeting of these cells without producing collateral thermal damage to adjacent non-pigmented cells. Pulse durations ranged from 10 nsec to 0.1 sec. A fluorescent viability/cytotoxicity assay was used to evaluate laser effects and threshold energies, and cells were examined morphologically by light and TEM. Selective targeting of pigmented trabecular meshwork cells was achieved with pulse durations between 10 nsec and 1 microsec and 1 microsec without producing collateral thermal or structural damage to adjacent non-pigmented trabecular meshworks cells when examined by light and transmission electron microscopy. Pulse durations greater than 1 microsec resulted in non-selective killing of non-pigmented trabecular meshwork cells. Threshold radiant exposures were as low as 18 mJ cm-2, and increased at longer wavelengths, longer pulse durations and lower melanin contents within the cells. It is concluded that selective targeting of pigmented trabecular meshwork cells can be achieved using pulsed lasers with low threshold radiant exposures avoiding collateral thermal damage to adjacent non-pigmented trabecular meshwork cells. This approach can be readily applied in vivo.
本研究的目的是选择性地靶向色素性小梁网细胞，同时不 对相邻的非色素性细胞或结构造成附带损伤。在保持小梁网结构完整性的同时，能够选择性地靶向小梁网细胞而不发生凝固，这可能是一种有用的方法，用于研究小梁网和小梁网细胞的非凝固性损伤的生物学反应是否与氩激光小梁成形术对小梁网造成的凝固性损伤相似。这种方法对于在动物模型中在保持小梁网结构完整性的同时非侵入性地清除小梁网细胞也可能是有用的。用调Q钕钇铝石榴石激光、倍频钕钇铝石榴石激光、微声脉冲染料激光和氩离子激光照射色素性和非色素性小梁网细胞的混合细胞培养物，以确定激光吸收局限于色素性小梁网细胞的条件，从而能够选择性地靶向这些细胞，而不会对相邻的非色素性细胞造成附带热损伤。脉冲持续时间范围为10纳秒至0.1秒。使用荧光活力/细胞毒性测定法评估激光效应和阈值能量，并通过光学显微镜和透射电子显微镜对细胞进行形态学检查。当通过光学显微镜和透射电子显微镜检查时，在10纳秒至1微秒和1微秒之间的脉冲持续时间能够实现对色素性小梁网细胞的选择性靶向，而不会对相邻的非色素性小梁网细胞造成附带热损伤或结构损伤。大于1微秒的脉冲持续时间导致非色素性小梁网细胞的非选择性杀伤。阈值辐射暴露低至18 mJ cm-2，并随着波长变长、脉冲持续时间变长和细胞内黑色素含量降低而增加。结论是，使用具有低阈值辐射暴露的脉冲激光可以实现对色素性小梁网细胞的选择性靶向，避免对相邻的非色素性小梁网细胞造成附带热损伤。这种方法可以很容易地应用于体内。
