Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model
Characterization of retinal damage in the episcleral vein cauterization rat glaucoma model
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DOI：
10.1016/j.exer.2005.06.013
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发表时间：
2006-02-01
影响因子：
3.4
通讯作者：
Mittag, T
中科院分区：
文献类型：
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作者：
Danias, J;Shen, F;Mittag, T
在大鼠中使用巩膜外静脉烧灼（EVC）来产生具有高眼内压（IOP）的青光眼模型。然而，这种青光眼模型中的长期视网膜损伤尚未准确量化。本文报道了EVC引起的大鼠眼压升高对视网膜神经节细胞（retinal ganglion cell，RGC）损伤的部位和数量，Wistar（N = 5）和Brown-Norway（B-N）（N = 7）大鼠的一只眼被EVC升高眼压，每月监测一次，直到术后5个月对侧眼的眼压达到10P。动物再饲养3.5 - 4.5个月。没有EVC的B-N大鼠（N = 7）作为该品系的对照。在基线和即将实施安乐死前记录暗视闪光ERG。对侧眼的视网膜平片中所有逆行标记的RGC的自动计数进行测定和比较。绘制RGC密度图，测定RGC大小分布，眼压升高组眼的振荡电位在安乐死时降低，此时眼压已恢复正常。正常B-N大鼠组对侧眼RGC计数相似。在实验组中，RGC的平均数量在对照眼和实验眼之间没有显著差异，但5只Wistar实验眼和7只B-N实验眼中的2只实验眼的RGC比对侧对照眼至少减少30%。B-N实验眼的视网膜总面积高于对侧眼。实验眼的累积IOP暴露与RGC损失适度相关，而振荡电位似乎与RGC损失呈负相关。在广泛（> 30%RGC损失）但未完全损伤的视网膜中，较小的细胞比较大的细胞保存得更好。上述结果表明，在通过EVC长时间升高IOP后，Wistar和B-N品系的RGC损失是可变的。尽管IOP水平和ERG异常相当，但这种变异性表明可以保护IOP应激的RGC的未知因素。这些因子的鉴定和增强可以证明对青光眼治疗有用。(c)2005爱思唯尔有限公司保留所有权利。
Episcleral vein cauterization (EVC) is used in rats to generate a glaucoma model with high intraocular pressure (IOP). The long-term retinal damage in this glaucoma model, however, has not been accurately quantified. We report the location and amount of retinal ganglion cell (RGC) damage caused by (EVC) induced IOP elevation in two rat strains.IOP was raised in one eye of Wistar (N=5) and Brown-Norway(B-N)(N=7) rats by EVC and monitored monthly until 10P in contralateral eyes equalized at 5 months post-surgery. Animals were maintained for 3.5-4.5 additional months. B-N rats (N=7) that had no EVC served as controls for this strain. Scotopic flash ERGs were recorded at baseline and just prior to euthanasia. Automated counts of all retrogradely labeled RGCs in retinal flat-mounts were determined and compared between contralateral eyes. RGC density maps were constructed and RGC size distribution was determined.Oscillatory potentials in the group of eyes which had elevated IOP were decreased at the time of euthanasia, when IOP had returned to normal. The group of normal B-N rats had similar RGC counts between contralateral eyes. In the experimental group the mean number of RGCs was not significantly different between control and experimental eyes, but I of 5 Wistar and 2 of 7 B-N experimental eyes had at least 30% fewer RGCs than contralateral control eyes. Total retinal area in B-N experimental eyes was higher compared to contralateral eyes. Cumulative IOP exposure of the experimental eyes was modestly correlated with RGC loss while oscillatory potentials appeared to be inversely related to RGC loss. In retinas with extensive (> 30% RGC loss) but not complete damage, smaller cells were preserved better than larger ones.The above results indicate that RGC loss in both Wistar and B-N strains is variable after a prolonged elevation of IOP via EVC. Such variability despite equivalent IOP levels and ERG abnormalities, suggests unknown factors that can protect IOP-stressed RGCs. Identification and enhancement of such factors could prove useful for glaucoma therapy. (c) 2005 Elsevier Ltd. All rights reserved.