前房注射卡波姆建立大鼠高眼压模型的观察

目的前房注射卡波姆建立大鼠高眼压模型,观察卡波姆升眼压效果及对大鼠眼前节和视网膜的影响。方法随机选取30只SD大鼠,注射前3 d早晚测量基线眼压。右眼定为实验眼,左眼定为对照眼,右眼放出房水后将30μL的5 g·L^-1卡波姆混悬液注入前房,每日早10时、晚22时在大鼠清醒状态下测量眼压。每周进行双眼眼前节照相并对比。4周末处死26只大鼠(另4只持续观察眼压变化至注射后9周)并取双眼眼球行HE染色,观察实验眼与对照眼视网膜形态,对比视网膜厚度及房角形态。结果注射前,实验眼白天和夜间眼压分别为(11.10±0.90)mmHg(1 kPa=7.5 mmHg)和(11.92±1.07)mmHg,对照眼分别为(11.22±1.07)mmHg和(11.76±1.08)mmHg;实验眼与对照眼相比,白天、夜间眼压差异均无统计学意义(均为P>0.05);白天与夜间眼压相比,实验眼、对照眼差异均有统计学意义(均为P<0.05)。卡波姆在前房中呈现出弥散型和沉积型两种存在方式,弥散型和沉积型大鼠1周内眼压分别为(17.83±3.54)mmHg和(13.00±1.55)mmHg,两者相比差异具有统计学意义(P<0.05)。注射后第1天至第19天,实验眼与对照眼白天眼压相比差异均具有统计学意义(均为P<0.05);注射后第1天至第27天,实验眼与对照眼夜间眼压相比差异均具有统计学意义(均为P<0.05)。实验眼视网膜形态发生改变,注射后4周视网膜厚度为(254.70±21.80)μm,与对照眼的(346.73±24.63)μm相比,差异有统计学意义(P=0.00)。实验眼前房充满卡波姆及虹膜的混合成分,紧贴角膜内皮并延伸至房角,堵塞小梁网结构,正常虹膜形态消失;对照眼房角形态正常。结论前房注射卡波姆建立大鼠高眼压模型,可维持高眼压4周以上,昼夜眼压差异较为明显,夜间眼压较白天更高,4周后视网膜出现高眼压损伤后的表现。

Observation of ocular hypertension model in rats induced by anterior chamber injection of carbomer suspension

Objective　To establish a rat model of elevated intraocular pressure （IOP） by injecting Carbomer suspension into the anterior chamber and observe the effect of carbomer on hypertension and the changes in anterior segment and retina.Methods　Thirty Sprague Dawley （SD） rats were randomly selected and baseline IOP was measured 3 days before injection.The right eye was served as the experimental eye and the left as the control.After the aqueous humor was discharged，30 μL 5 g·L^-1 Carbomer suspension was injected into the anterior chamber.The IOP was measured at 10 a.m.and 22 p.m.in the awake state of rats.Photography of the anterior segment was taken every week.After 4 weeks，26 rats were sacrificed and the eyeballs were enucleated for hematoxylin-eosin （HE） staining （Four of the 30 rats were observed to 9 weeks after Carbomer suspension injection）.Comparison of the retinal thickness and anterior chamber angle was performed between experimental group and the control group under light microscope.Results　Before injection，the IOP of the experimental eyes was （11.10±0.90）mmHg （1 kPa=7.5 mmHg） during daytime and （11.92±1.07）mmHg at night，while the control eyes was （11.22±1.07）mmHg and （11.76±1.08）mmHg，respectively.There was no significant difference in the IOP between the experimental eye and the control eye during the day and at night （all P>0.05），but it showed significant differences between daytime and night in experimental eyes and control eyes（all P<0.05）.There were two kinds of Carbomer forms （diffuse and sedimentary form） in the anterior chamber.The 1-week mean IOP of diffuse and sedimentary form were （17.83±3.54）mmHg and （13.00±1.55）mmHg.There were significant differences in the mean IOP of daytime between the experimental eyes and the control eyes from the first day to the 19th day after injection （all P<0.05）.There were significant differences in the mean night IOP between the experimental eyes and the control eyes from the 1st day to the 27th day after injection （all P<0.05）.The morphology of retina was damaged.After 4 weeks of injection，the retinal thickness of the experimental eye was （254.70±21.80）μm，which was significantly different from that of the control group ［（346.73±24.63）μm］ （P=0.00）.The anterior chamber of the experimental eyes was filled with a mixture of Carbomer and iris，which was close to the corneal endothelium and extended to the angle of the chamber，blocked the trabecular meshwork structure，leading to the disappearance of normal iris shape.The anterior chamber angle of the control eye was normal.Conclusion　Carbomer-induced increased IOP maintains for more than 4 weeks.Elevated IOP is significantly different between daytime and night.The IOP at night is higher than that during the daytime.After 4 weeks，the pressure-induced morphological damage of retina is observed in the HE staining.