大鼠慢性高眼压青光眼模型的构建及鉴定

目的:手术建立慢性高眼压青光眼大鼠模型对研究青光眼发病机制、治疗和视神经保护这三方面的研究尤为必要。方法:烧灼3条表浅巩膜静脉,并术中联合应用结膜瓣下浸有0.2g/L的丝裂霉素的凝胶海绵,阻断大鼠的眼部房水外流,建立大鼠慢性高眼压模型,手术后2h;1,3,7,14,28,56d处死5只大鼠,空白对照组亦处死5只大鼠;摘除眼球光镜下进行视网膜形态的观察及视网膜厚度测量,研究眼压、视网膜神经节细胞(retinal ganglion cells,RGC)和视神经损伤的特性。结果:大鼠手术眼与假手术眼、空白对照眼的术后各时间点的眼压比较差异有显著性(P<0.01)。结论:建立大鼠慢性高眼压模型操作简单,重复性好,成模率高,高眼压可稳定维持长时间,慢性高眼压将导致整个视网膜的变薄和萎缩。     

两种慢性高眼压大鼠模型视网膜结构和眼压变化的评估

目的 评估两种慢性高眼压大鼠模型的升眼压效果和视网膜结构的改变.方法 分别通过前房内注射微珠(微珠组)和结扎3支巩膜上静脉(结扎组)的方法制作两种慢性高眼压大鼠模型(每组6只).使用TonoPen眼压计测量大鼠眼压,模型制作当天及其后每周测量大鼠眼压,大鼠右眼为实验眼,左眼为对照眼(假手术眼).采用荧光金上丘逆标的方法标记视网膜神经节细胞并计数;使用免疫荧光标记的方法观察大鼠视网膜结构的改变.结果 造模后1-8周微球组和结扎组大鼠眼压均升高;其中结扎组眼压为(27.20±1.83) mmHg(1 kPa=7.5 mmHg),其对照眼眼压为(19.80±1.35) mmHg(P=0.001,n=6);微珠组眼压为(27.40±1.88) mmHg,其对照眼眼压为(19.40±1.00) mmHg(P=0.000,n=6).造模后8周,巩膜上静脉结扎组视网膜神经节细胞丢失37.9％、39.6％和33.5％(均为P=O.000,n=6),前房内注射微珠组丢失37.3％、39.4％和32.3％(均为P=0.000,n=6),两组视网膜神经节细胞的丢失数量比较差异均无统计学意义(P =0.855、0.949、0.634,n=6).高眼压模型8周后,相较于对照组,微珠组和结扎组视网膜神经节细胞核数量均有明显减少,组织厚度变薄,但两组间差异无统计学意义[对照组厚度(7.32±0.39) μm,结扎组厚度(4.97±0.33)μm,微珠组厚度(5.00 ±0.31) μm].前房内注射微珠组在部分组织切片可发现微珠污染.结论 巩膜上静脉结扎和前房内注射微珠均可以使大鼠眼压稳定增高.巩膜上静脉结扎具有实施方便和价格低的优势,并且没有微珠污染的缺点.     

烙闭大鼠上巩膜静脉对眼压和视网膜影响的研究

目的通过手术烙闭大鼠上巩膜静脉,观察术后大鼠眼压和眼底变化情况。方法SD大鼠40只,烙闭大鼠右眼3支上巩膜静脉,于术后连续观测眼压,并在不同的时间点进行病理组织切片观测视网膜厚度的变化。结果(1)术后即刻眼压平均升高175%;术后1个月时平均眼压是术前的1·85倍,术后2个月时平均眼压是术前的1·81倍,术后3个月时平均眼压是术前的1·69倍。(2)造模后各时间点模型眼视网膜各层与对照眼的视网膜比较呈不同程度变薄。结论上巩膜静脉烙闭法能较稳定地、持续时间较长地升高大鼠眼压。     

川芎嗪对慢性高眼压大鼠视网膜神经节细胞凋亡的影响

目的 研究川芎嗪对慢性高眼压大鼠视网膜神经节细胞(retina ganglion cells,RGC)凋亡的保护作用.方法 健康SD大鼠30只,随机分为正常组、高眼压组和川芎嗪治疗组,每组10只.高眼压组和治疗组分别采用上巩膜静脉烧灼法制作高眼压模型,正常对照组不做处理.造模成功后7d治疗组给予川芎嗪腹腔注射,正常组与高眼压组给予等量的生理盐水腹腔注射.造模3周后取三组大鼠眼球,行视网膜HE染色、TUNEL原位细胞凋亡检测和Bcl-2免疫组织化学检测.结果 造模后高眼压组、川芎嗪治疗组各时间点眼压与正常组比较,差异均有统计学意义(均为P ＜0.05),而两组间各时间点比较,差异均无统计学意义(均为P＞0.05).正常组、高眼压组、川芎嗪治疗组大鼠视网膜RGC层TUNEL阳性细胞数分别为0、9.00±0.89、3.50±1.89,三组间差异有统计学意义(F =86.160,P=0.000);三组间两两比较,差异均有统计学意义(均为P =0.000).三组大鼠RGC层Bcl-2阳性表达光密度值分别为0.373±0.090、0.375±0.146、0.390±0.268,三组差异有统计学意义(F=84.658,P=0.000);三间组两两比较,差异均有显著统计学意义(均为P=0.000).结论 川芎嗪通过上调Bcl-2蛋白的表达可明显抑制慢性高眼压大鼠RGC凋亡,从而发挥RGC保护作用.     

大鼠慢性高眼压模型的建立

目的：建立一种稳定的、眼压中度升高的大鼠慢性高眼压模型。方法：SD大鼠40只，烙闭大鼠右眼3支上巩膜静脉，于术后连续观测眼压，并在不同的时间点进行病理组织切片观测视网膜厚度的变化。结果：①术后即刻眼压平均升高175％，术后1个月时平均眼压是术前的1．85倍，术后2个月时平均眼压是术前1．81倍，术后3个月时平均眼压是术前的1．69倍。②造模后各时间点模型眼视网膜各层与对照眼的视网膜有不同程度变薄。结论：上巩膜静脉烙闭法能建立较稳定的、持续时间较长的大鼠高眼压模型。     

白藜芦醇对青光眼大鼠视神经损伤的保护作用及其机制

目的:分析白藜芦醇对青光眼大鼠视神经的保护作用及对磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(Akt)信号通路及其相关因子的影响。方法:SPF级SD大鼠以烧灼巩膜表面静脉法制作右眼青光眼模型,建模成功后以不同剂量(10、20、40mg/kg腹腔注射)白藜芦醇干预,末次给药后2h检测各组大鼠眼压,进行视网膜铺片观察视网膜神经节细胞(RGC)存活情况,采用实时荧光定量PCR及Western blot法检测视网膜PI3K、Akt、碱性成纤维细胞生长因子(bFGF)、脑源性神经营养因子(BDNF)mRNA及蛋白表达情况。结果:模型组眼压(30.25±4.25mmHg)高于低剂量组(26.30±4.05mmHg)、中剂量组(22.31±3.68mmHg)和高剂量组(18.32±3.21mmHg),模型组RGC标识率(48.25%±4.50%)低于低剂量组(56.32%±5.05%)、中剂量组(66.03%±6.68%)和高剂量组(78.56%±7.82%)(均P<0.05),且低、中、高剂量组眼压呈剂量依赖性下降,RGC标识率呈剂量依赖性升高。模型组p-PI3K/PI3K、p-Akt/Akt蛋白比值及bFGF、BDNF mRNA和蛋白相对表达量低于低剂量组、中剂量组和高剂量组(均P<0.05),且低剂量组、中剂量组、高剂量组呈剂量依赖性升高。结论:白藜芦醇能抑制青光眼大鼠RGC的凋亡,减轻视神经损伤,其机制可能与上调PI3K/Akt信号通路中相关蛋白的磷酸化及视神经保护作用因子基因与蛋白的表达有关。     

灯盏细辛对大鼠慢性高眼压模型视神经损伤保护的实验研究

目的:建立大鼠慢性高眼压模型,观察灯盏细辛(Erigeronbrevicapas hand mass,EBHM)对眼压升高诱导视神经损伤的保护作用。方法:选用健康成年Wistar大鼠90只,分为3组。用波长为532nm的氪离子黄绿激光光凝第1和第2组大鼠双眼小梁网,建立大鼠高眼压模型。在眼压升高后1wk开始用EBHM对第2组大鼠15mg/100g肌肉注射,行视神经保护性治疗。第1组作为光凝对照组,第3组大鼠作为正常对照组。在第9wk同时处死3组大鼠做全视网膜铺片,1%甲苯氨蓝染色,记数平均视网膜神经节细胞(retinalganglion cells,RGCs)密度。结果:所有光凝眼眼压均中等程度升高,光凝前眼压为14.70±3.2mmHg;光凝后第3,6,9wk眼压分别为27.25±4.75,28.75±6.24,25.47±5.60mmHg,与光凝前比较,差别有显著性(P<0.05)。经视网膜铺片甲苯胺蓝染色,视网膜RGCs密度值(个/mm2)为:第1组1654±136,第2组2135±125,第3组2516±196。第2组大鼠视网膜RGCs密度值与第1和第3组大鼠RGCs密度值比较,差别有显著性(P<0.05)。结论:光凝大鼠小梁网成功建立大鼠慢性高眼压模型,光凝眼眼压中等程度升高,RGC密度降低;EBHM能够部分保护大鼠慢性高眼压诱导的视神经损害。     

敲低NLRP12对高眼压大鼠RGCs的保护作用及其抑制细胞焦亡的机制

目的探讨敲低NOD样受体家族热蛋白结构域12(NLRP12)对高眼压大鼠视网膜神经节细胞(RGCs)炎症因子水平和视网膜损伤的影响及其机制。方法选取70只SPF级成年雄性SD大鼠, 采用随机数字表法分为对照组、高眼压组、高眼压+小干扰RNA阴性对照(siNC)组、高眼压+siNLRP12组和高眼压+siNLRP12+重组大鼠caspase-1(rrcaspase-1)组, 每组14只。其中对照组仅接受右眼结膜切口处理, 其他各组均采用巩膜外静脉烧灼法建立大鼠右眼高眼压模型;高眼压+siNC组、高眼压+siNLRP12组和高眼压+siNLRP12+rrcaspase-1组建立高眼压模型后分别给予尾静脉注射siNC、siNLRP12和siNLRP12+rrcaspase-1试剂。巩膜外静脉烧灼术后1 d、1周、2周、3周, 测量大鼠右眼眼压;巩膜外静脉烧灼术后3周, 采用苏木精-伊红染色法观察各组大鼠视网膜结构, 计数各组RGCs数量。将RGCs分为对照组、rrcaspase-1组、siNC+rrcaspase-1组、siNLRP12+rrcaspase-1组, 其中rrcaspase-1...     

姜黄素对慢性高眼压大鼠视网膜神经节细胞凋亡的影响及机制

目的：探讨姜黄素对慢性高眼压大鼠视网膜神经节细胞(RGCs)凋亡的影响及机制。

方法：将21只SD大鼠随机分为3组,每组7只,高眼压模型组和姜黄素治疗组大鼠通过烧灼巩膜上静脉法建立慢性高眼压模型,假手术组大鼠仅剪开球结膜,不烧灼巩膜上静脉; 姜黄素治疗组给予4mL/kg姜黄素灌胃,假手术组和高眼压模型组给予4mL/kg纯水灌胃,连续3wk。造模后3wk,采用HE染色观察各组大鼠视网膜组织形态病理变化、RGCs数量及神经节细胞层(GCL)厚度; 采用TUNEL染色观察各组大鼠RGCs和视网膜细胞凋亡情况; 采用实时荧光定量PCR、免疫组织化学染色和Western blot法检测各组大鼠视网膜谷氨酰半胱氨酸连接酶调节亚基(GCLM)与血红素加氧酶-1(HO-1)的表达水平。

结果：与假手术组相比,高眼压模型组和姜黄素治疗组大鼠视网膜组织形态紊乱,RGCs数量减少,GCL变薄,RGCs和视网膜细胞凋亡率均升高,GCLM和HO-1表达量均升高; 与高眼压模型组相比,姜黄素治疗组大鼠视网膜组织形态基本正常,RGCs数量增多,GCL增厚,RGCs和视网膜细胞凋亡率均降低,GCLM和HO-1表达量均升高。

结论：姜黄素在慢性高眼压大鼠模型中可通过上调抗氧化基因GCLM与HO-1的表达抑制RGCs凋亡。     

银杏叶提取物对大鼠持续性高眼压下的视网膜神经节细胞活性的保护作用

目的:探讨银杏叶提取物(extractof Ginkgo bilobaleaves,EGb)对大鼠持续性高眼压损伤下的视网膜神经节细胞(retinalganglioncells,RGC)活性的保护作用。方法:健康SD大鼠20只,采用烧烙法,烙闭大鼠左眼2条浅层巩膜静脉,制作大鼠持续性高眼压模型,从中选出眼压稳定在实验要求(眼压>26mmHg)的大鼠12只随机分为A组(对照组)和B组(EGb治疗组)。治疗组予EGb每日150mg/kg灌胃治疗,对照组为空白对照,不做任何处理。1mo后处死大鼠摘取眼球,制作眼球标本,常规石蜡切片,AgNOR染色观察RGC细胞核内的银染颗粒。采用计算机图象分析系统对RGC细胞核内的银染颗粒进行定量分析。结果:A组大鼠模型眼RGC细胞核内银染颗粒为1.33±0.07个/细胞,B组为1.83±0.09个/细胞,B组模型眼较A组模型眼RGC细胞核内银染颗粒多,其差异有显著性意义(P<0.05)。两组模型眼较正常眼的RGC细胞核内银染颗粒明显减少,其差异有显著性意义(P<0.05)。结论:大鼠持续性高眼压可导致RGC细胞核内银染颗粒减少,而EGb对RGC活性有部分保护作用。     

A new method of duplication of the chronic intraocular hypertension model: underwater electrocoagulation

To study the experimental method of inducing the chronic intraocular hypertension in rat eyes. · METHODS: Twenty Wistar rats were randomly divided into ocular hypertension and sham control groups. Intraocular pressure (IOP) was raised by electrocoagulating at least 3 episcleral and limbal veins on the right eye of each rat in ocular hypertension group and its contralateral eye was used as control. At 1, 2, 3, 4 and 8 week after the electrocoagulation of the veins, IOP were measured. · RESULTS: The treatment of electrocoagulation caused a significant IOP increase of the right eyes over the baseline, over the contralateral eyes, and over the sham control eyes (repeated measures ANOVA, P <0.001). At 1 week, IOP was 30.12±5.18mmHg, and maintained the high IOP up to 8 weeks. · CONCLUSION: The chronic intraocular hypertension model could be successfully created by electrocoagulating three or more episcleral and limbal veins.     

Mouse model of sustained elevation in intraocular pressure produced by episcleral vein occlusion

We have developed an inducible mouse model of glaucoma based on episcleral vein cauterization (EVC). Intraocular pressure (IOP) elevation in adult mice was produced by cauterizing three episcleral veins. Serial IOP measurements were done by induction-impact tonometry. IOP was significantly elevated by 104+/-20% in 20 out of 23 mice (87%) within the first day after EVC, and remained elevated for 4 weeks, with mean IOP 94% higher in EVC-treated vs. contralateral control eyes. Aqueous outflow blockade was verified from the IOP response to pulsed fluid infusions into the anterior chamber. Retinal ganglion cell (RGC) loss, determined by retrograde labelling using Fluoro-Gold applied to the superior colliculous, was approximately 20% at 2 weeks after EVC. We conclude that episcleral vein occlusion in mice produces significant and sustained elevation in IOP associated with increased outflow resistance and RGC loss, and thus may be useful to model glaucoma in genetically modified and drug-treated mice.     

Ocular hypotensive effects of topically administered agmatine in a chronic ocular hypertensive rat model

Agmatine, a primary polyamine and potential neuromodulator, exhibits a high affinity to the α₂-adrenergic receptor as well as imidazoline receptors. As α₂-adrenergic receptor agonists display positive ocular hypotensive effects, we assessed whether agmatine effectively lowers intraocular pressure (IOP) using a chronic ocular hypertensive rat model. We raised IOP in unilateral eyes of Sprague-Dawley rats by cauterizing three episcleral veins per eye. Four weeks later, we topically administered 10⁻³ M agmatine solution 4 times a day for 6 consecutive weeks. After confirming the recovery of IOP to pretreatment level at 13 weeks after cauterization, the retinal ganglion cells (RGCs) were retrogradely labeled and counted. Eyes subjected to episcleral vein cauterization (EVC) demonstrated significant increases in IOP (48.39% increase over baseline IOP), and the elevated IOP was well maintained until 12 weeks. Topically administered agmatine powerfully lowered IOP to 30.29% of its pretreatment level, and the associated washout period was about two weeks. EVC was associated with a 55.44% loss of RGCs in the control group, but agmatine appeared to attenuate this RGC loss to 18.65%. Overall, topically administered agmatine appeared to effectively lower IOP and rescue RGCs in a chronic ocular hypertensive rat model. Although the mechanism underlying these effects is not yet established, it is possible that agmatine offers a powerful new ocular hypotensive agent for eyes with chronic ocular hypertension and/or glaucoma.     

制作慢性高眼压动物模型的一种新方法--水下电凝巩膜表面静脉法

目的研究慢性高眼压动物模型的制作方法.方法选择20只健康Wistar大鼠,雌雄不限,随机分为高眼压组(10只)和sham对照(假手术)组(10只).高眼压组采用电凝鼠巩膜表面至少三组静脉及角膜缘周围血管,减少房水静脉回流升高眼压,而sham对照组只剪开球结膜,未进行巩膜表面静脉以及角膜缘周围血管电凝.分别于术后1,2,3,4及8wk测大鼠双眼压,结果进行统计学分析.结果高眼压组右眼术后眼压明显升高.术后1wk眼压(30.35±4.98)mmHg(1kPa=7.5mmHg),术后1～8wk间眼压基本稳定.术后各时间点高眼压组右眼眼压与术前、左眼及sham对照组右、左眼间比较,差异有统计学意义(P＜0.001).结论采用电凝鼠巩膜表面至少三组静脉及角膜缘周围血管,减少房水静脉回流能成功复制慢性高眼压动物模型.     

Neuroprotective and intraocular pressure-lowering effects of (-)Delta9-tetrahydrocannabinol in a rat model of glaucoma

In glaucoma, retinal ganglion cell (RGC) death is induced by many risk factors, including ocular hypertension. It has been proposed that glutamate-mediated oxidative stress may also contribute to this RGC death. Cannabinoids are known to possess therapeutic properties including ocular hypotension and antioxidation. In this study, we test the hypothesis that (-)Delta(9)-tetrahydrocannabinol (THC) lowers intraocular pressure (IOP) and prevents RGC death in a rat model of glaucoma. Arat model of experimental glaucoma with chronic, moderately elevated IOP was produced unilaterally by cauterization of episcleral vessels. Rats received weekly injections of THC at a level of 5 mg/kg or vehicle for 20 weeks. IOP of both eyes was measured weekly on anesthetized animals immediately before THC treatment. RGCs were labeled in a retrograde fashion and counted in whole-mounted retinas. IOP was elevated in all operated eyes 1 day after the operation and remained elevated in the vehicle-treated rats throughout 20 weeks. In THC-treated rats, IOP elevation in operated eyes was diminished 2 weeks after operation and remained reduced. IOP in the contralateral control eyes was not affected by THC. In the operated eyes of vehicle-treated animals, there was a loss of approximately 50 and 40% of the RGCs in the peripheral and central retina, respectively. The RGC loss in the operated eyes of the THC-treated animals was reduced to 10-20%. These results demonstrate that THC is a neuroprotectant that preserves RGCs in an experimental model of glaucoma, possibly through a reduction in IOP.     

慢性高眼压模型鼠视网膜神经节细胞及视神经中9位丝氨酸磷酸化糖原合酶激酶3β的表达变化

目的 观察慢性高眼压模型鼠视网膜神经节细胞(retina ganglion cells,RGCs)和视神经中9位丝氨酸磷酸化糖原合酶激酶3β[p-GSK3β(ser9)]的表达变化,探讨GSK3β是否在慢性高眼压RGCs及视神经退行性病变中发挥作用.方法 取健康SD大鼠30只,随机分为3组:模型对照组、慢性高眼压模型2周组、慢性高眼压模型4周组,每组10只.取大鼠右眼,采用巩膜上静脉结扎并烧灼法建立大鼠慢性高眼压模型.分别于造模后2周和4周取5只大鼠眼球行冰冻切片,尼氏染色观察RGCs数目,免疫荧光染色观察RGCs和视神经中p-GSK3β(ser9)的变化;各组取另外5只大鼠眼视网膜,Western blot检测p-GSK3β(ser9)及总-GSK3β的表达.结果 造模前3组大鼠右眼眼压差异无统计学意义(P=0.89);造模后3组间眼压差异有统计学意义(P＜0.01),慢性高眼压模型2周组和4周组眼压与模型对照组比较明显升高,分别升高了59.13％和26.93％,差异均有统计学意义(均为P＜O.01).视网膜尼氏染色RGCs计数发现模型对照组RGCs数为(149±12)个,慢性高眼压模型2周组和4周组RGCs数较模型对照组明显减少,分别为(120±10)个和(86±7)个,差异均有统计学意义(均为P＜0.05);且4周组比2周组进一步减少(P＜0.01).慢性高眼压模型2周组和4周组视网膜中p-GSK3β(ser9)阳性着色,同模型对照组相比,其RGCs层及视神经中p-GSK3β(ser9)染色荧光减弱;4周组较模型对照组减弱更明显.与模型对照组相比,慢性高眼压模型2周组和4周组视网膜中总-GSK3β的表达差异无统计学意义(F=0.24,P=0.79);而3组间p-GSK3β(ser9)表达差异有统计学意义(P＜0.01),与模型对照组相比,慢性高眼压模型2周组和4周组视网膜中p-GSK3β(ser9)分别减少了19.89％和36.46％(均为P ＜0.05).慢性高眼压模型4周组比2周组视网膜中p-GSK3β(ser9)表达持续减少,差异具有统计学意义(P＜0.05).结论 慢性高眼压模型鼠RGCs数目减少,RGCs和视神经中p-GSK3β(ser9)表达减少,推测p-GSK3β(ser9)表达变化可能参与了慢性高眼压模型鼠RGCs及视神经退行性病变.     

巩膜上静脉烙闭法建立大鼠高眼压模型对视网膜微观结构的影响

目的　观察巩膜上静脉烙闭法建立的大鼠高眼压模型对视网膜微观结构的影响，为青光眼视神经损伤及保护机制提供研究基础。方法　选取不同体质量SD大鼠40只，分为A组（150~200 g）、B组（>200~250 g）、C组（>250~300 g）、D组（>300~350 g），每组各10只，分别测量3 d白天及夜间基线眼压。随机选取SD大鼠（雌雄随机，250~300 g）40只，术前测量3 d基线眼压，以右眼为实验眼，烙闭实验眼3~4支巩膜上静脉，以左眼为对照眼，于术后即刻、1~7 d、14 d、21 d、28 d分别测量实验眼和对照眼眼压。于术前及术后28 d分别用光学相干断层扫描(optical coherence tomography，OCT)仪测量视网膜厚度。于术后28 d处死大鼠，行石蜡包埋、苏木精伊红（hematoxylin eosin，HE）染色，计数视网膜神经节细胞（retinal ganglion cells，RGCs）并测量视网膜厚度。结果　不同体质量大鼠昼夜眼压比较差异均有统计学意义（均为P<0.001）。A组大鼠眼压较其他3组眼压低（均为P<0.05）。巩膜上静脉烙闭术后即刻实验眼眼压达到峰值，较对照眼高122%（P<0.001），之后缓慢下降，到术后14 d、21 d实验眼眼压较对照眼分别升高约41%、20%（均为P<0.001），到术后28 d实验眼与对照眼眼压差异无统计学意义（P>0.05）。OCT提示内层视网膜变薄（均为P<0.001）。HE染色切片结果提示RGCs数量减少，内、中、外层视网膜均变薄（均为P<0.05），且以内层变化最明显（P<0.001）。结论　大鼠基线眼压昼夜存在差异，白天眼压较夜间眼压低，低体质量（150~200 g）大鼠眼压偏低。烙闭大鼠巩膜上静脉能维持3周的眼压升高，且能使视网膜变薄、RGCs数量减少，故巩膜上静脉烙闭法是建立大鼠高眼压模型的有效方法。     

A rat model of glaucoma induced by episcleral vein ligation

To establish a reliable animal model of glaucoma, we examined if episcleral vein ligation in rat eyes can induce intraocular pressure (IOP) elevation and concomitant characteristic morphological features of glaucoma. IOP elevation was detected on the next day (30.1+/-4.4 mmHg: operated eyes; 21.0+/-1.8 mmHg: control eyes) and persisted at least 7 months after the procedure (24.5+/-2.3 mmHg: operated eyes; 19.7+/-1.9 mmHg: control eyes). These results suggest that episcleral vein ligation can induce very mild IOP elevation immediately after the operation, which can last over several months. Furthermore, it appears there was little variability in the patterns of IOP elevation among the individual eyes treated with episcleral vein ligation. Morphological changes were detected selectively in the retinal ganglion cell (RGC) layer and optic disc excavation was evident in the late stage of chronic IOP elevation. RGCs were selectively lost by apoptotic death. The number of RGCs was reduced by 18% at 12 weeks and eventually by 35% at 8 months postoperatively. Müller cells downregulated the expression of p27Kip1 and appeared to be partially in a reactive state even at the advanced stages of glaucoma. The expression of basic fibroblast growth factor and ciliary neurotrophic factor, which are neurotrophic factors implicated in the control of cell survivals and neuroprotection, significantly declined at the advanced stages. Taken altogether, these observations indicate that the episcleral vein ligation model based on the simple ligation procedure reproducibly provides a reliable glaucoma model and contributes to give insights into the underlying molecular and cellular bases of human glaucoma and to devise the new medication upon the disease.