共焦显微镜观察慢性角膜水肿患者角膜各层形态特点

目的：应用活体共焦显微镜(IVCM)观察慢性角膜水肿患者角膜各层形态特点。

方法：使用IVCM观察不同病因的慢性角膜水肿的患者21例21眼,并与5例拟行白内障手术患者的正常角膜进行对照。

结果：IVCM观察到所有慢性角膜水肿患者角膜上皮层均可见大泡,表现为黑色、圆形、边缘清晰。18眼(86%)上皮细胞出现高反射的无细胞结构的片状区域和瘢痕。12眼(57%)患者中央区角膜上皮下未发现神经纤维,9眼(43%)患者中央区角膜上皮下神经平均密度显著降低。所有患者Bowman膜(BZ)表现为明显的异常,除了瘢痕外,BZ呈分支的、细的、黑线状。13眼(62%)患者前基质表现为细颗粒或粗颗粒,且反光不同。所有患者角膜基质细胞密度降低。所有患者角膜内皮表现为正常六边形结构消失,细胞边界不清。对照组角膜正常未见上述改变。

结论：IVCM可以用来观察慢性角膜水肿角膜各层微观结构上的变化,包括上皮瘢痕形成、上皮下神经纤维及基质细胞的减少。随着角膜内皮移植术的日益普及,本研究支持IVCM在定量评估术前、术后角膜水肿的作用。     

共焦显微镜在角膜溃疡病原学诊断中的临床应用

目的:评价共焦显微镜(confocal microscope,CM)在角膜溃疡病原学诊断中的临床应用。方法:利用共焦显微镜对临床拟诊为角膜溃疡的36例患者进行检查,并对结果进行分析比较。结果:患者36例中,有16例(16眼)观察到角膜基质内有菌丝,显示菌丝图像为相对暗的背景中的明亮的线状形态。有2例(2眼)观察到了阿巴包囊,表现为位于浅基质层中白色闪光的圆形小体。结论:作为一种无创伤性的快速诊断工具,共焦显微镜在角膜溃疡病原学诊断的临床应用中有着重要的作用和显著的优点,并在对该病的病理特点的研究中也有着巨大的潜力。     

Sodium hyaluronate eye drop. A scanning and transmission electron microscopy study of the corneal surface

The association with time (0-60 min) of an eye drop preparation containing sodium hyaluronate with the corneal epithelial cell surface was examined using both cryofixation and osmium tetroxide vapor fixation and scanning (SEM) and transmission electron microscopy (TEM). In phosphate-buffered saline (PBS)-treated control eyes of adult mice, 37 postnatal days (PND) old, a variably thick, but well-defined preocular mucus coat was seen, while 5-PND-old animals treated with PBS lacked morphologically detectable mucus at the corneal surface. In mice of both ages, the eye drop preparation was detectable at the corneal surface at time 0 and 5, 15, 30 and 60 min after its application. For these time periods, in both the adult and the pup, the eye drop preparation containing sodium hyaluronate appeared to be composed of electron-dense filamentous material (TEM) which associated with corneal surface cell microvilli. SEM revealed that the eye drop preparation was globular in composition and that its distribution became patchy over the cornea with time for both the adult and the pup.     

Effects of acetylcysteine on rabbit conjunctival and corneal surfaces. A scanning electron microscopy study

Conjunctival and corneal epithelial surfaces of normal rabbit eyes with their associated mucus were studied by scanning electron microscopy before and after treatment with the mucolytic agent N-acetylcysteine (AC). Four groups received topically one 50-microliters drop of either (Group A) 0.1 MAC, (Group B) 0.1 M AC every 5 min for 1 hr, (Group C) 0.1 M AC every 5 min for 2 hr, or (Group D) three drops of 20% AC over 15 min. The effects of the instillation of AC on mucus removal and cellular lesions increased in the order (A) less than (B) less than (C) less than (D). Treatment A had no effect on cornea and conjunctiva. Treatment B cleaned away mucosal debris without alteration of either conjunctival or corneal epithelium. Treatment C had a similar effect on the mucus but was associated with focal necrosis, and treatment D produced widespread necrosis, desquamation of epithelial cells, and inflammation.     

Fuchs' corneal dystrophy. A clinicopathologic study of the variation in corneal edema

Corneal buttons from six patients with Fuchs' dystrophy had varying degrees of clinical edema measured in most cases by preoperative optical or ultrasonic pachymetry. These were sectioned in the operating room so that histologic correlations could be made. Histologically, marked thickening of Descemet's membrane and abnormal corneal endothelium corresponded to areas of severe clinical edema and were usually located in the central and paracentral regions. Descemet's membrane displayed multiple prominent guttata of varying size and shape, either facing the anterior chamber, or buried within multilaminar Descemet's membrane. In some corneas, aggregates of 10 nm fibrils were seen at the edges of guttata, corresponding to areas that stained for oxytalan fibrils. The endothelium was attenuated underlying the guttata. Clinical edema was not present unless accompanied by marked thickening of Descemet's membrane with multiple guttata and attenuation of corneal endothelium. The peripheral cornea was relatively clear clinically and showed minimal histologic changes.     

Three-dimensional confocal laser scanning microscopy of the corneal nerve structure

PURPOSE: The aim of this study was the evaluation of a technology for in vivo visualization of distribution and morphology of corneal nerves by means of 3D confocal laser scanning microscopy (3D-CLSM). METHOD: The anterior corneas of four human volunteers were examined by an in-house developed confocal laser scanning microscope based on a commercially available instrument (Heidelberg Retina Tomograph II, Heidelberg Engineering GmbH, Germany). Raw stacks were converted using ImageJ (NIH, USA) for 3D-reconstruction using AMIRA 3.1 (TGS Inc, USA). RESULTS: The spatial arrangement of epithelium, nerves and keratocytes was visualized by in vivo 3D-CLSM. After 3D-reconstruction of volunteers' corneas, volume rendering and selective oblique sections have been done to demonstrate the nerves in the central human cornea. 3D-imaging shows thick nerve bundles rising out of the deeper stroma. The nerves further divide, resulting in fibers that are arranged parallel to Bowman's layer and are partly interconnected. Branches rising up to the superficial cell layer cannot be visualized. Wound healing following refractive surgery can be evaluated. CONCLUSIONS: 3D-CLSM allows in vivo visualization and analysis of the spatial arrangement of the epithelium, nerves and keratocytes of the human cornea. The developed method provides a basis for further studies on the alterations of the cellular arrangement and epithelial innervation in corneal diseases. This may help to clarify gross variations of nerve fiber patterns under various clinical and experimental conditions.     

The network structure of corneal fibroblasts in the rat as revealed by scanning electron microscopy

The overall morphology of corneal fibroblasts in the rat was examined by scanning electron microscopy after removal of stromal connective tissue elements by tryptic digestion and HCl hydrolysis. Fibroblasts thus exposed were flattened and stellate cells with a diameter of about 10 micron and had a number of ramified cytoplasmic processes. The processes of neighboring fibroblasts contacted with each other to form an extensive and continuous network structure parallel to the plane of collagenous lamellae. The cellular network appears to constitute an integrated system which may be involved in the synchronized regulation of the metabolic and physiologic homeostasis for the maintenance of corneal transparency.     

角膜穿通伤的临床分析

本文分析７９例（８０眼）角膜穿通伤的发生率、致伤原因、受伤部位、伤口大小，并发症及治疗情况，并对伤口、眼内容物脱出及外伤性白内障的处理提出讨论。指出角膜穿通伤后及时控制眼内感染，积极预防并发症，争取恢复视功能的重要性。     

The limbal vascular response to corneal injury. An autoradiographic study

Thermal cautery of the peripheral cornea in rats caused proliferation of the limbal vasculature and invasion of the cornea. Tritiated-thymidine was used to identify premitotic activity in a total of 53,192 limbal vascular cells in five categories, viz., arteriolar endothelial cells, venular endothelial cells, arteriolar perivascular cells, venular perivascular cells, and capillary cells. From normal values in the range of 0.29 to 1.37%, the 2 h labeling indices reached a maximum of 13 to 14% in both endothelial and perivascular cells of venules and capillaries. Of particular interest was the finding of 18% labeling in arteriolar perivascular cells, and 7% in arteriolar endothelial cells. The categories showed a staggered onset of DNA synthesis, ranging from 17 h postcautery for capillary cells to 36 h for arteriolar endothelium and both arteriolar and venular perivascular cells. The duration of increased DNA synthesis also varied. Endothelial cells of both arterioles and venules showed narrow labeling peaks (12 to 24 h), while the adjacent perivascular cells and cells of the small vessels labeled for some 60 to 70 h. These results suggest that more than one stimulus to angiogenesis may be involved, or that the various cell types respond differently to the same stimulus.     

Desquamation of the corneal epithelium in the immature mouse: a scanning and transmission microscopy study

The normal immature mouse corneal epithelium as characterized by scanning electron microscopy (SEM) is composed of dark, medium and light cells covered with surface microvilli. Microvilli are more numerous on the light and medium than the dark cells. In transmission electron microscopy (TEM) light cells of SEM are electron dense. The medium and dark cells of SEM on the other hand, have pale cytoplasm with few microvilli. The process of epithelial desquamation in the above cell population was detailed sequentially. The initial step in desquamation of a surface cell is swelling and reduction in number of surface microvilli. This is followed by the appearance of dehiscences or slits in the plasma membrane of surface cells. In TEM these dehiscences are readily visible as small slits in the apical plasma membrane of cells with pale appearing cytoplasm. Next, the desquamating cell pulls away from its lateral cell borders. Finally, the cell detaches from the intermediate cell layer by rupture of desmosomes. This mechanism of desquamation would not appear to contribute to or to insure stability of the mucin component of the precorneal tear film.     

On the evaluation of the corneal epithelial surface by scanning electron microscopy

A comprehensive and objective survey is presented of the use of the scanning electron microscope from 1967 to 1989 to assess the characteristics of the corneal epithelial surface in the rabbit and other vertebrates. The technique shows the corneal surface as a mosaic of cells that are very heterogeneous with respect to character (light, medium, and dark electron reflexes), size (small, medium, and large), and shape (angular or rounded), yet the numerous published micrographs of normal corneas show substantial differences. The reasons for these differences are discussed using examples of 50 to 15,000 x magnification micrographs of rabbit corneas within the context of the basic principles of glutaraldehyde-based fixation of biological tissues for electron microscopy. The qualitative similarities between the scanning electron microscope image and the in vivo reflected light microscope (specular microscopy and CONFOCAL microscopy) image are reviewed and discussed.     

超声乳化人工晶状体植入术后角膜内皮水肿的观察

目的分析超声乳化人工晶状体植入术后角膜内皮水肿的相关因素并探讨其防治原则。方法选取不同硬度白内障314眼,记录术中平均相对超声功率和平均超声乳化时间。对术中的相对能量复合参数(RECP)和术后角膜内皮水肿的发生率进行相关性研究。结果平均相对超声功率和平均超声(乳化)时间随晶状体核硬度的增加而增加。术中RECP与术后角膜内皮水肿的发生率呈显著正相关(r=0.392,P<0.01)。结论术中累积超声能量和时间与术后角膜内皮水肿的发生密切相关。术中应用劈核技术、提高超声乳化效率、保持前房稳定等,是降低角膜内皮水肿发生的关键环节。