不同色素兔光化学法诱导视网膜静脉阻塞模型的对比

目的观察并比较光化学法诱导不同色素兔视网膜静脉阻塞（RVO）模型的各自特点与差异。方法普通级有色素兔和日本大耳白兔各10只。经兔耳缘静脉注入孟加拉红（40mg／kg）后，应用倍频532激光光凝兔双眼视网膜静脉主干，制作视网膜静脉阻塞模型。所有实验兔分别于术前和光凝后15min，1、3、7、14、21、28d行眼底彩照和荧光素眼底血管造影（FFA）检查，并于光凝后1d，2组各选取2只模型兔处死，摘除眼球行病理组织切片检查，观察比较不同色素兔眼底的损伤是否存在差异；其余于光凝后28d处死，摘除眼球行光学显微镜检查。结果2组实验兔光凝后均立刻出现视网膜血流阻断现象。光凝后1d，日本大耳白兔出现显著的视网膜水肿和少量视网膜下出血，普通有色素兔则表现为视网膜下火焰状出血和较为明显的视网膜水肿。2组FFA均显示视网膜两侧动静脉主干血流被阻断。2组实验兔在1～3周时，光凝点部位血管均出现不同程度的再通，视网膜出血水肿逐渐吸收。4周时血管基本再通，FFA示普通有色素兔光凝部位血管周围出现小范围的无灌注区、色素紊乱以及血管形态的异常。病理切片显示，光凝术后1d，日本大耳白兔脉络膜中可见血栓形成，而普通有色素兔则无此现象。2组实验兔均可观察到外层视网膜水肿。光凝后28d，2组实验兔均可观察到视网膜神经节细胞核密度减少。结论通过光化学诱导法，普通有色素兔及13本大耳白兔均可成功建立RVO模型。但不同色素兔使用相同激光能量制作RVO模型，眼底损伤部位存在差异。在眼底彩照和FFA检查上，2组有显著区别，且日本大耳白兔显影较差。

Comparison of experimentally induced retinal vein occlusion between pigmented rabbits and conventional albino rabbits

Objective To compare the differences of experimentally induced retinal vein occlusion （RVO） between pigmented rabbits（PR）and conventional albino rabbits（CAR）. Methods PR （n = 10） and CAR （n = 10） were included in the study. RVO was created by using an double-frequency laser（532 nm） following intravenous injection of Rose Bengal. A laser was applied to all major veins at the optic disc margin to mimic central RVO. Fundus photograph and fluorescence fundus angiography （FFA） were performed before photocoagulation and 15 min, 1 d, 3 d, 7 d, 14 d and 28 d after photocoagulation. Two rabbits was sacrificed in each group 1 d after photocoagulation for light microscopy observation, and the rest were killed 28 d after photoeoagnlation for light microscopy observation. Results Immediately following laser application, blood flow ceased or extremely slowed in the retinal veins in all cases. At 1 day after photoeoagulation, CAR showed significant retinal edema and mild hemorrhages, while P1R showed flame-shaped retinal hemorrhages; On FFA, no retinal blood flow was observed in most eyes （neither arteries nor veins） for both groups. Between week 1 and 3, reopening of laser sites and partial or complete revascularization of both retinal arteries and veins occurred ; and most cases showed a progressive appearance of less hemorrhages and intraretinal edema. On week 4, there were small range capillary nonperfusion and pigmentary changes around the blood vessels which received photocoagulation before, however, the vascular pattern was abnormal. Histopathologieal examinations indicated that thrombus formed in choroidal vessels in CAR 1 d after photocoagulation, but PR didn＇t show the same phenomenon. There was outer retinal edema 1 d after photocoagulation and retinal ganglion cell nucleus density decreased 28 d after photocoagulation in both groups. Conclusions RVO models were successfully established in both groups. Rose Bengal photochemical method on ocular fundus of different pigmented rabbits have different photosensitive reaction and histological damages. On Fundus photograph and FFA, the imaging of CAR is significant different from that of PR.