多点与单点模式激光术后视网膜组织变化的实验观察

目的　比较５３２ｎｍ激光多点模式与单点模式术后视网膜组织形态学变化。方法　健康成年无眼疾青紫蓝兔３２只随机分为多点模式组与单点模式组，两组按光凝后观察时间１ｄ、７ｄ、１４ｄ及２８ｄ再分为４个亚组，每亚组４只。左眼为空白对照组，右眼为实验组，分别于建立模型后相应时间点获取兔眼标本，在光镜和电镜下观察光凝区视网膜组织病理学变化。结果　单点模式组和多点模式组光凝后１ｄ、７ｄ光斑区略隆起，视锥、视杆细胞和外核层细胞可见凝固坏死，视网膜色素上皮层轻度隆起，线性结构破坏，视网膜神经感觉层（ｒｅｔｉｎａｌｎｅｕｒｏｅｐｉｔｈｅｌｉａｌｌａｙｅｒ，ＲＮＬ）水肿增厚，与空白对照组比较差异均有统计学意义（均为Ｐ＜０．０５）。光凝后１４ｄ、２８ｄ两组ＲＮＬ水肿均基本恢复，光斑中央区ＲＮＬ变薄、凹陷。单点模式组光凝后１４ｄ、２８ｄ和多点模式组光凝后２８ｄＲＮＬ厚度与空白对照组比较差异均有统计学意义（均为Ｐ＜０．０５），而多点模式组光凝后１４ｄＲＮＬ厚度与空白对照组比较差异无统计学意义（Ｐ＞０．０５）。单点模式组和多点模式组光凝后１ｄ、７ｄ、１４ｄ、２８ｄＲＮＬ厚度比较差异均有统计学意义（均为Ｐ＜０．０５）。单点模式组光凝后２８ｄ视网膜色素上皮细胞和纤维组织增生，有些光斑处甚至可见有新生血管长入。结论　多点模式对视网膜的损伤较单点模式小，可以达到和单点模式相同的治疗效果，并且激光副作用较小。

Retinal tissue changes after multi-point and single-point mode laser photocoagulation

Objective To compare the retinal morphological changes after 532 nm laser multi-mode and single-point photocoagulation. Methods Thirty-two healthy adult Chinchilla rabbits without oculopathy were randomly divided into multi-point mode group and single-point mode group. According to the observation time after photocoagulation,two groups were further divided into I day,7 days,14 days and 28 days sub-groups , and four rabbits in each group. The left eye was the control group and the right eye was the experimental group. The eyeballs were enucleated at different time points after photocoagulation in rabbit to observe the retinal histopathological changes under the light and electron microscopy. Results Spot area was slightly uplift in single-point mode group and multi-point mode group at I day and 7 days after photocoagulation . the cone rod cells and outer nuclear layer cells were necrosis ,the retinal pigment epithelial layer was slightly uplift , linear structure damaged , retinal neuroepithelial layer ( RNL) was edema and thicken, compared with the blank control group , there was significant difference ( all P < 0. 05) . RNL edema recovered at 14 days and 28 days , central district RNL spot was thin and depressed. Compared with blank control group, RNL thickness in single-point mode group at 14 days ,28 days and multi-point mode group at 28 days had obvious statistical differences ( all P < 0. 05 ) . but there was no significant difference in RNL thickness at 14 days between multi-point mode group and blank control group (P > 0. 05 ) . There were statistical differences in RNL thickness at I day, 7 days , 14 days and 28 days between single-point mode group and multi-point mode group ( all P < 0. 05 ) . At 28 days , retinal pigment epithelial cells and fibrous tissue hyperplasia were seen. even neovascularization at some spots were seen in single-point mode group. Conclusion Compared with single-point mode , multi-point mode have little retinal damage , can reach the same therapeutic effects with less side effects.