角膜新生血管形成机制

临床上许多角膜病变均能引起角膜新生血管（CNV），CNV破坏角膜正常微环境，不仅严重影响视力，而且是角膜移植失败的主要原因。近年来，随着对CNV的深入研究，大量实验研究表明许多因素参与CNV的形成过程，本文主要就CNV的形成机制作一综述。     

Structure of intracorneal femtosecond laser pulse effects in conical incision profiles

PURPOSE: As the applicative potential of femtosecond lasers is to be extended from LASIK-flap creation into intrastromal ablation uses, the interdependency of influencing factors has to be understood. We therefore evaluated the relationship between focus depth, energy level, spatial distribution and morphology of fs-Laser pulse effects at a given repetition rate in corneal tissue. METHODS: The experimental study included five porcine corneae obtained from slaughterhouse pigs. Using a prototype of a femtosecond laser (FEMTEC; 20/10 Perfect Vision AG, Heidelberg, Germany), a conical circular cut was performed in posterior-anterior direction through the entire corneal profile. The laser energy applied ranged from 4.0 to 8.5 muJ. Histological sections (n = 337) of a thickness of 7 mum were obtained, stained with hematoxylin/eosin, and morphometrically evaluated. RESULTS: The intrastromal femtosecond laser effects were aligned throughout the corneal stroma in a line that followed the dissection line programmed for the laser. The lesions were mostly of roughly elliptic shape with a fine dense lining at the inner wall, without evidence of a collateral damage beyond the disruption cavity. The mean maximal diameter of the intrastromal laser effects was 34.2 +/- 18.6 mum (range: 9-120 mum), and the mean maximal lesion diameter was 60.8 +/- 42.6 mum. In multivariate analysis, the lesion type (single shot cavity, partly confluent lesions, and fully confluent lesions) was significantly associated with the laser energy applied (P = 0.027) and the lesion diameter (P = 0.01). CONCLUSIONS: At higher laser energies, the intrastromal laser lesions were larger and more confluent, suggesting that, with the prototype of femtosecond laser used, a higher laser energy may lead to more confluent intrastromal laser effects. It may facilitate the complete cutting of the corneal tissue with the laser. Neither discernable debris nor stainable collateral damage were detected, suggesting a purely mechanical action of the laser.     

Muscarinic cholinoceptor-stimulated phosphatidyl inositol pathway in corneal epithelial and endothelial cells

Background Muscarinic cholinoceptors are distributed widely in both the central and peripheral nervous system. The presence of muscarinic cholinoceptors in corneal tissue is well established. Previous reports have shown that corneal muscarinic cholinoceptors are of the m2 or m4 subtype. However, recent studies have indicated the presence of the m5 muscarinic cholinoceptor subtype in human corneal epithelium and endothelium. The aim of the study was to confirm the presence of the m5 cholinoceptor subtype in bovine corneal epithelium and endothelium and the activation of phosphatidyl inositol pathway by its stimulation. Methods Muscarinic m5 cholinoceptor sites, phosphatidyl inositol 4,5-biphosphate, inositol 1,4,5-triphosphate and protein kinase C, were studied using immunocytochemistry and immunofluorescence. Activation of protein kinase C after stimulation of the m5 muscarinic cholinoceptor subtype was measured using the HTS protein kinase C assay kit. Results Immunocytochemistry/immunofluorescence revealed the presence of the m5 muscarinic cholinoceptor subtype, phosphatidyl inositol 4,5-biphosphate and protein kinase C in bovine corneal epithelial and endothelial cells. In bovine corneal epithelium and endothelium, protein kinase C activity was stimulated by acetylcholine in a dose-dependent manner (P<0.0001). Conclusions Our findings indicate that acetylcholine-induced stimulation of muscarinic m5 cholinoceptors activates the phosphatidyl inositol pathway in corneal epithelial and endothelial cells, resulting in increased protein kinase C activity. Further work will be needed to clear the physiologic role of this signaling pathway in corneal epithelium and endothelium. The authors have no proprietary interest in any of the products used in the study.     

超声乳化白内障吸除术后角膜前后表面高阶像差的变化

目的 探讨利用Pentacam观察超声乳化白内障吸除术前后角膜前后表面高阶像差的变化.方法 前瞻性系列病例研究.对45例(51只眼)年龄相关性白内障患者行3.2 mm透明角膜切口的超声乳化白内障吸除联合折叠型人工晶状体植入术,分别于术前1 d,术后7 d、1个月及3个月利用Pentacam测量角膜前后表面的高阶像差(包括总的高阶像差、球差、彗差、三叶草以及3～6阶像差),将角膜前、后表面高阶像差按直径范围不同(3 mm直径和6 mm直径)分为两组,用具有一个重复测量的两因素设计定量资料方差分析方法对两组数据分别进行统计学分析.结果 角膜前表面总的高阶像差术前1 d为(0.289±0.171)μm,至术后3个月时轻度增加为(0.312±0.158)μm(3 mm直径);术前1 d为(0.980 ±0.215)μm,至术后3个月时轻度增加为(1.054±0.308)μm(6mm直径),但手术前后变化无统计学差异(F=1.55,P=0.22),且两组总的高阶像差随时间的变化趋势相同(F=0.95,P=0.42);其余各项高阶像差手术前后的变化与总的高阶像差的变化相似.角膜后表面总的高阶像差术前1 d为(0.548±0.220)μm,至术后3个月时明显增加为(0.661±0.275)μm(3 mm直径);术前1 d为(1.780±0.453)μm,至术后3个月时明显增加为(1.945±0.532)μm(6mm直径),手术前后变化差异有统计学意义(F=15.83,P=0.00),且两组总的高阶像差随时间的变化趋势不同(F=12.46,P=0.00);其余各项高阶像差手术前后的变化与总的高阶像差的变化相似.结论 超声乳化白内障吸除术后角膜前表面高阶像差的变化不影响术后患者的视觉质量.但是,手术前后角膜后表面高阶像差发生了显著的变化,可能影响术后患者的视觉质量.     

干眼病患者角膜表面规则性及人工泪液对角膜表面规则性的影响

目的　评价干眼病患者的角膜表面规则性及人工泪液对其角膜表面规则性的影响。方法　应用TMS 1角膜地形图仪检测正常人 33例 ( 6 4只眼 )及干眼病患者 2 2例 ( 42只眼 )的角膜表面规则指数 (surfaceregularityindex ,SRI)、表面不对称指数 (surfaceasymmetryindex ,SAI)及角膜预测视力(potentialvisualacuity ,PVA) ,并对干眼病患者应用人工泪液前后角膜表面规则性及PVA的变化进行观察。结果　干眼病患者的SRI、SAI及PVA值分别为 0 .31± 0 .2 2、0 .30± 0 .16及 2 0 /17.89± 2 0 /3.0 4;而正常人分别为 1.2 8± 0 .73、1.0 5± 1.17及 2 0 /33.45± 2 0 /13.99。干眼病患者的SRI和SAI值较正常人明显升高 ,PVA值则明显降低 ,各组间比较差异有非常显著性 (P <0 .0 0 1)。干眼病患者的平均散光度( 2 .10± 1.96 )D明显较正常人 ( 1.13± 0 .5 3)D高 (P =0 .0 2 )。在干眼病患者中 ,SRI与SAI与角膜荧光素染色程度呈正相关 (SRI:P =0 .0 0 5 ;SAI:P =0 .0 16 ) ,而平均PVA与平均实际矫正视力比较差异无显著性。干眼病患者角膜地形图中对称蝴蝶结形所占的比例较正常人明显降低 ,而不规则形者所占比例则明显升高。干眼病患者在滴用人工泪液后 ,SRI、SAI和平均散光度均明显降低 (P值分别为<0 .0 0 1,<0 .0 0     

单纯疱疹病毒1功能性基因在角膜内潜伏感染的实验研究

目的 研究角膜中是否有单纯疱疹病毒１型功能性基因的潜伏。方法 在新西兰白兔角膜上制作典型的单纯疱疹病毒１型引发的角膜炎模型,然后将进入稳定期的病变角膜移植到健康兔眼上,术后２周取下植片。每下植片标本均分为三部分,一部分角膜片先行ＨＳＶ－１抗原检测,另一部分采用多聚酶链反应技术检测ＨＳＶ－１潜伏相关转录、胸苷激酶和ＤＮＡ聚合酶基因,第三部分经器官培养３周后,再与兔原代肾细胞一起培养１周,再检测培养后     

板层角膜移植术治疗真菌性角膜炎的临床疗效分析

目的：探讨板层角膜移植术治疗药物难以控制的中、浅层真菌性角膜炎的手术适应证及时机,并对其临床效果进行分析。方法：对临床确诊为真菌性角膜炎（病灶均位于角膜中浅层）且经抗真菌药物治疗无效的患者68例（68只眼）行板层角膜移植术,观察术后角膜真菌复发率、角膜植片透明率及角膜植片免疫排斥反应等情况,并对术中取下的病变角膜组织行真菌培养、菌属鉴定及组织病理学检查。结果：68例患者中,64例治愈,成功率为94％;随访观察6－36个月,植片全部透明,矫正视力为0．2－1．0;4例复发,复发率为6％。59例角膜组织标本真菌培养阳性,其中镰刀菌属41例,曲霉菌属8例,念珠菌属4例,青霉菌属2例,其他丝状菌属4例。61例病理切片行高碘酸－Schiff染色可见菌丝,57例菌丝均未超出病变角膜切片的深度和边缘,仅4例复发者可见菌丝达角膜组织切片全层,其中曲霉菌属3例,镰刀菌属1例。结论：板层角膜移植术是一种对经抗真菌药物治疗无效及溃疡直径较大或偏中心的中、浅层真菌性角膜炎患者具有治疗和复明作用的有效术式。     

Immunoelectron microscopic localization of the opioid growth factor receptor (OGFr) and OGF in the cornea

This study was conducted to determine the cellular and subcellular location(s) of the opioid growth factor receptor (OGFr), and the opioid growth factor (OGF), [Met(5)]-enkephalin, in the corneal epithelium. Laser scanning confocal microscopy analysis revealed that both OGFr and OGF were colocalized in the paranuclear cytoplasm and cell nuclei in basal, as well as suprabasal, cells of adult rat corneal epithelium. Using a postembedding immunogold procedure for immunoelectron microscopy that included embedding in Unicryl, both single- and double-face labeling studies were performed. Immunogold labeling of OGFr was detected on the outer nuclear envelope, in the paranuclear cytoplasm proximal to the nuclear envelope, perpendicular to the nuclear envelope in a putative nuclear pore complex, and within the nucleus adjacent to heterochromatin. Immunoreactivity for OGF was noted in locations similar to that for OGFr. In addition, aggregates of staining for OGF were found throughout the cytoplasm, including subjacent to the plasma membrane. Double labeling experiments revealed that complexes of OGF-OGFr were colocalized on the outer nuclear envelope, in the paranuclear cytoplasm, extending across the nuclear pore complex, and in the nucleus. Anti-OGFr IgG by itself, but not anti-OGF IgG alone, was associated with the outer nuclear envelope, and uncomplexed OGF immunoreactivity was detected in the cytoplasm in dual labeling experiments. These results based on complementary approaches of confocal microscopy and immunoelectron microscopy, suggest that: (i) OGFr resides on the outer nuclear envelope, (ii) OGF interacts with OGFr at the outer nuclear envelope, (iii) the colocalized receptor and peptide translocates between the cytoplasm and the nucleus at the nuclear pore, and (iv) signal transduction for modulation of cell proliferation necessitates a peptide-receptor complex that interfaces with chromatin in the nucleus.     

角膜氯离子通道的研究进展

氯离子参与生物体多种功能,如细胞免疫应答、细胞迁移、增生、分化和凋亡.这种功能的多样性是因为体内存在不同基因编码、不同种类的氯离子通道之故.有研究表明,氯通道的功能改变或缺失与多种角膜疾病有关,因此,角膜氯通道的研究也越来越受到重视.该文综述了近年来有关角膜氯通道在角膜各层细胞功能中的作用、特点等方面的研究进展,以期进一步探讨角膜疾病与离子通道功能异常之间的关系.     

消毒蜂蜜治疗碱性角膜烧伤的动物实验研究

目的 探讨消毒蜂蜜对兔实验性碱烧伤后角膜修复的疗效及其机制。方法 制作兔角膜碱烧伤模型，烧伤后实验组用20％消毒蜂蜜滴眼，对照组用生理盐水滴眼，以计算机图像分析系统定量分析角膜上皮愈合的面积。结果 图像分析测得角膜上皮愈合面积，在第3、5、7、9和14d实验组与对照组比较差异均有显著意义（P〈0．05）。结论 消毒蜂蜜可以促进角膜上皮的愈合。