不同能量半导体激光对大鼠脉络膜新生血管形成的影响

Influence of different power on diode laser-induced choroidal neovascularization model in rats

目的观察不同能量的半导体激光对诱导棕色挪威(BN)大鼠脉络膜新生血管(CNV)形成的影响。方法雄性BN大鼠42只随机分组,将其中的36只根据激射激光的功率不同平均分为3个实验组,其余6只作为正常对照组。采用810nm半导体激光光凝大鼠双眼视网膜,光斑直径75μm,曝光时间0.1s,激光功率分别为120、140和160mW,于光凝后1、7、14、21、28、56d进行荧光素眼底血管造影(FFA)和吲哚菁绿血管造影(ICGA)检查,随后于每个时间点每组各处死2只大鼠,摘除眼球在光学显微镜下检查CNV形成情况。结果不同能量半导体激光光凝BN大鼠视网膜后7dCNV开始形成,21d达高峰,此时根据FFA和ICGA计算的3组CNV的成模率分别为51.3%、91.8%、88.3%及51.3%、92.7%、93.7%,56d时CNV有所减少。光凝后7d可见光凝斑周围炎性细胞增多,CNV形成;14d光凝斑增厚,色素细胞增生、移行;21d时140mW及160mW组多数光凝斑增厚,可见明显CNV;随后炎性细胞减少,胶原纤维增多,56d时仍可见CNV结构。结论功率分别为120、140、160mW的810nm半导体激光均能成功诱导BN大鼠形成CNV,140mW组成模率高且受干扰因素少,是建立BN大鼠CNV模型比较理想的参数。

Objective Choroidal neovaseularization（CNV） is the main cause of blindness in over 50-years-old population. To establish an available CNV animal model is helpful for us to understand the pathogenesis and management of CNV. Purpose of present study was to observe the role of coagulation with different power of diode laser in laser-induced ehoroidal neovascularization model of Brown Norway （BN） rats. Methods Coagulation of 810 nm diode laser（8 - 10 spots for each eye） was performed in 36 male BN rats with the spot diameter 75 μm,shutter time 0. 1 s,power 120 mW,140 mW and 160 mW,respeetively,while 6 normal BN rats were used as contrast. CNV was evaluated by fundus examination, fundus fluorescein angiography （FFA） ,indocyanine green angiography（ICGA） and light microscope on day 1,7,14,21,28 and 56 after photoeoagulation. Results CNV formed on the 7th day after photocoagulation in 120 roW,140 mW and 160 mW groups and reached the peak on the 21st day according to FFA and ICGA manifestation. Incidence of CNV in 120 roW,140 mW and 160 mW group was 51.3% ,91.8% ,88.3% on FFA findings and 51.3% ,92. 7% ,93.7% on ICGA findings, respectively. In 7 days after photoeoagulation, inflammatory cells increased and CNV formed at the lesion. Photocoagulation plaque became thicker with pigment cells proliferating and migrating on 14 days. After that time,inflammatory cells decreased and more collagen fibers emerged. The CNV reminded till the 56th day after photocoagulation. Conclusion CNV model of BN rats can be successfully created using the different power of diode laser （from 120 through 160 mW）. CNV rate under the laser coagulation with 140 mW is higher, indicating that the power of 140 mW may be a suitable parameter for diode laser-induced choroidal neovaseularization model of BN rats.