利用光学相干断层扫描血管造影分析PM2.5对小鼠角膜上皮和角膜全层厚度的影响

Effect of PM2.5 on thickness of corneal epithelium and cornea in mice analyzed by optical coherence tomography angiography

目的利用光学相干断层扫描血管造影(OCTA)分析PM2.5对小鼠角膜上皮和角膜全层厚度的影响。方法随机选取健康BALB/c小鼠(18~21 g,6~8周龄,雄性)共32只,采取随机数字表法分为实验组、对照组两组,每组16只,体重、周龄匹配。实验组采用5 mg/ml的PM2.5混悬液滴眼,对照组采用PBS滴眼,均为双眼,每天4次。采用系统软件将角膜划分为17个区域,并利用光学相干断层扫描血管造影术分别在干预前,干预后第1、4、7、10及14天对两组小鼠角膜上皮和角膜全层厚度进行测量。结果制作模型前、干预第1天,实验组与对照组小鼠角膜上皮和角膜全层厚度比较差异无统计学意义(P>0.05),第4天起,与对照组比较,实验组小鼠角膜上皮下部的IT5、I5、IN5、IT6、I6及IN6区域增厚(P<0.05),但角膜全层厚度无明显改变(P>0.05)。第7天起,与对照组比较,实验组小鼠角膜上皮所有区域均增厚(P<0.05),角膜全层中央和下部C2、IT5、I5、IN5、IT6、I6及IN6区域厚度延长(P<0.05)。第10和14天,与对照组比较,实验组小鼠角膜上皮和角膜全层各个区域及平均厚度均增厚(P<0.05)。结论 PM2.5能引起小鼠角膜上皮和角膜全层厚度改变,且随着干预时间增加,角膜上皮下部各区最先增厚,其他区域随后增厚。角膜全层厚度随后也变厚,且为中央和下方各区最先增厚,随后其他区域增厚。角膜全层增厚速度慢于角膜上皮增厚速度。

Objective To investigate the effect of PM2.5 on the thickness of corneal epithelium and cornea in mice by optical coherence tomography angiography(OCTA).Methods BALB/c male mice(18-21 g,6-8 weeks of age)were divided into experimental group and control group(n=16).Animals in experimental group received 5 mg/ml PM2.5 eye drops 4 times per day for both eyes while mice in control group experienced dPBS eye drops.Cornea was divided into 17 regions systemically.Thickness of corneal epithelium and corneal were measured using optical coherence tomography angiography at baseline,1 day(D1),4 days(D4),7 days(D7),10 days(D10),14 days(D14)after intervention.Results No significant difference in thickness of corneal epithelium and corneal was founded between experimental group and control group(P>0.05)at baseline and D1.Thickness of corneal epithelium in regions including IT5,I5,IN5,IT6,I6 and IN6 were increased significantly at D4(P<0.05),while no dramatic difference in thickness of the whole cornea were founded in experimental group(P>0.05)compared with control group.Thickness of corneal epithelium in all areas was increased greatly(P<0.05),and thickness of corneal in C2,IT5,I5,IN5,IT6,I6 and IN6 was enhanced obviously(P<0.05)at D7 in experimental group when compared with control group.At D10 and D14,the average thickness of corneal epithelium and cornea was strengthened(P<0.05)compared with that in control group.Conclusions PM2.5 causes increase of thickness in corneal epithelium and cornea in mice.