经房角镜光凝小梁网法建立慢性高眼压大鼠模型及其与经角膜缘光凝法的比较

Establishment of chronic ocular hypertension rat model by transgoniscope laser photocoagulation to trabecular meshwork and its comparison with translimbal laser photocoagulation

背景慢性高眼压动物模型的建立是青光眼发病机制研究的基础，以往激光光凝建立慢性高眼压动物模型的方法存在模型眼压波动大，需要重复光凝和并发症多的问题，造模方法的改良对于顺利开展相关的实验研究具有重要意义。目的用经房角镜光凝小梁网法建立大鼠慢性高眼模型，并与以往的经角膜缘光凝法进行比较。方法选取8～12周龄清洁级Fischer344大鼠36只，将动物分为正常对照组、经角膜缘光凝组和经房角镜光凝组，每组12只，经角膜缘光凝组采用532nmYAG激光经角膜缘光凝大鼠右眼小梁网建立慢性高眼压模型，激光能量为440—500mW，激射光斑40～60个；经房角镜光凝组激光能量为800～850mw，激射光斑100～120个。光凝后用Tonolab眼压计测量并观察各组大鼠眼压变化；于光凝后第3周每组处死5只大鼠，分离视网膜，采用免疫荧光技术检测并比较各组大鼠视网膜中Tuj一1阳性的视网膜神经节细胞（RGCs）数目。实验动物的使用及喂养遵循ARVO声明。结果造模后3周各组大鼠一般情况可，眼表无明显损伤。经角膜缘光凝组和房角镜光凝组慢性高眼压模型的成模率分别为75％和100％。正常对照组、经角膜缘光凝组和经房角镜光凝组大鼠模型眼造模后3周的平均眼压分别为（11．0±1．3）、（23．4±12．6）和（25．3±4。9）mmHg（1mmHg=0．133kPa），峰服压分别为（12．3±1．0）、（50．5±7．3）和（44．3±12．3）mmHg，组问总体比较差异均有统计学意义（F=25．496、80．762，均P〈0．001），其中经角膜缘光凝组和经房角镜光凝组大鼠模型眼平均眼压均明显高于正常对照组，差异均有统计学意义（均P〈0．001），而2个组间平均眼压和峰眼压差异均无统计学意义（P=1．000、0．195）。正常对照组、经角膜缘光凝组和经房角镜光凝组大鼠视网膜中Tuj-1阳性RGCs数目分别为（2048．2±148．5）、（645．2±177．1）及（1223．7±148．6）／mm2，总体比较差异有统计学意义（F=98．767，P〈0．001），其中经角膜缘光凝组和经房角镜光凝组大鼠视网膜中Tuj-1阳性RGCs数目均明显少于正常对照组，且经角膜缘光凝组大鼠视网膜中Tuj-1阳性RGCs数目明显少于经房角镜光凝组，差异均有统计学意义（均P〈0．01）。结论经房角镜光凝小梁网能够诱导大鼠慢性高眼压并导致RGCs损害，但眼压升高模式及RGCs损害程度与经角膜缘光凝法有所不同，经房角镜光凝法建立慢性高眼压模型成模率更高。

Background The establishment of chronic ocular hypertension is a basis for the research of glaucoma. Previous laser photocoagulation method to establish ocular hypertension model showed obvious fluctuation of intraocular pressure （IOP） and complications and need repeatedly photocoagulation. Improvement of modeling method is of important significance for glaucoma. Objective This study was to establish chronic ocular hypertension rat models by transgoniscope laser pbotocoagulation to trabecular meshwork and to compare this method with previous translimbal laser photocoagulation. Methods Thirty-six 8 to 12-week-old clean grade Fischer344 rats were collected and divided into normal control group, translimbal laser photocoagulation group and transgoniscope laser photocoagulation group, 12 rats for each group. Five hundred and thirty-two nm YAG laser was used to photocoagulate trabecular meshwork translimbally in the right eyes of rats in the translimbal laser photocoagulation group,with the laser power 440-500 mW and spots 40-60,and the photocoagulation was perfored transgoniscopely in the right eyes of rats in the transgoniscope laser photocoagulation group,with the laser power 800-850 mW and spots 100-120. IOP was measured by using Tonolab tonometer in all the rats after modeling. The rats were sacrificed 3 weeks after modeling and retinas were isolated, the Tuj-1 positive retinal ganglion cells （RGCs） were counted by immunofluorescence technology. The use and care of the animals followed the Statement of ARVO. Results The successful rate of establishement of models was 75% in the translimbal laser photocoagulation group and 100% in the transgoniscope laser photocoagulation group. The mean IOP was （ 11.01±. 3） , （23.4±12.6） and （25.3± 4.9） mmHg,and the peak IOP was （ 12.3 ± 1.0 ）, （ 50. 5 ± 7.3 ） and （ 44.3 ± 12.3 ） mmHg in the normal control group, transgoniscope laser photocoagulation group and translimbal laser photocoagulation group, respectively, with significant differences among the groups （F= 25. 496,80. 762 ,both at P〈0. O01 ） ,and the mean IOP was significantly higher in the transgoniscope laser photocoagulation group and translimbal laser photocoagulation group than that in the normal control group （ all at P〈0. 001） ,and no significant differences in the mean and peak IOP between transgoniscope laser photocoagulation group and translimbal laser photocoagulation group （P = 5. 000, P = 0. 195 ）. The numbers of Tuj-1 positive RGCs in the retinas were （2 048.2~ 148.5 ）, （ 645.2 -e 177.1 ） and （ 1 223.7 ~ 148.6 ）/mm2 in the normal control group, transgoniscope laser photocoagulation group and translimbal laser photocoagulation group, showing a significant difference among the groups （ F= 98. 767 ,P〈0.00L ）. The number of Tuj-1 positive RGCs was considerably reduced in the transgoniscope laser photocoagulation group and translimbal laser photocoagulation group compared with the normal control group and the number of Tuj-1 postive RGCs was low in the translimbal laser photocoagulation group compared with the transgoniscope laser photocoagulation group （ all at P〈0. 001）. Conclusions Transgoniscope laser photocoagulation targeting trabecular meshwork can induce chronic ocular hypertension and RGCs losing. However,its pattern is different from translimba] laser photocoagulation. Transgoniscope laser photocoagulation has a higher successful rate of chronic ocular hypertention than that of translimbal laser photocoagulation.