共查询到20条相似文献,搜索用时 10 毫秒
1.
2.
Estil S Kravik K Haaskjold E Refsum SB Bjerknes R Wilson G 《Acta ophthalmologica Scandinavica》2002,80(5):517-523
PURPOSE: To determine whether apoptosis contributes to regeneration of the corneal epithelium following erosion and following ultraviolet irradiation. METHODS: Central corneal erosions were made on one eye of 16 rats. One eye of another set of 16 rats was exposed to UVB irradiation. The rats were killed at time intervals varying from 12 hours to 7 days after treatment. Enucleated eyes were fixed in buffered formaldehyde and evaluated by terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate (dUTP) nick-end labelling (TUNEL) and morphology. The total number of cells and the number of TUNEL positive cells were counted in perpendicular sections using light microscopy. RESULTS: Following central erosion the total epithelial cell number was restored by day 3. During the first 5 days, TUNEL positive cells were observed only in small numbers, but an increase occurred by days 6 and 7. After UVB, an increase in TUNEL positive cells was noted for at least 3 days, and by day 7 there was a small increase of TUNEL positive cells. This differed from the results seen in control animals. CONCLUSIONS: The present study indicates that after injury, apoptosis occurs in two distinct phases. There is an initial early phase of apoptosis which subsides at about the time the cell mass is being restored and after damaged cells have been removed. A later phase of apoptosis occurs suggests it has a homeostatic role which contributes to the regulation of the cell population. 相似文献
3.
H Brewitt H Honegger 《Ophthalmologica. Journal international d'ophtalmologie. International journal of ophthalmology. Zeitschrift für Augenheilkunde》1979,178(6):327-336
The morphological changes of the corneal epithelium after burning with hydrochloric acid were examined using a scanning electron microscope. A drop of hydrochloric acid of differing concentrations (1--0.000001 N HCl) was applied under standardized conditions to normal rabbit eyes for a reaction period of 5 or 30 min. The changes in the cell surface, which are dependent on the concentration of the acid, include a loss of microvilli and microplicae, outlining of the cell nucleus, disruption of the intercellular spaces, cell desquamation and even the most severe damage to the cell membrane and cytoplasm of the corneal epithelial cells. 相似文献
4.
A A Khodadoust A M Silverstein D R Kenyon J E Dowling 《American journal of ophthalmology》1968,65(3):339-348
5.
A laser scanning optical microscope was used to study the structure of the rabbit corneal epithelium. From the results obtained, satisfactory images have been taken of unfixed, 0.05% glutaraldehyde-fixed and 4% paraformaldehyde-fixed materials. Continuous optical sections were taken between the superficial layer of the corneal epithelium and the basal layer. It was concluded that this device is useful for investigating the tissue structure of fresh biological materials. 相似文献
6.
目的 观察大鼠穿透性角膜移植术后角膜上皮表面的超微结构变化。方法 成年Wistar大鼠 18只 ,右眼行穿透性角膜移植手术 ,左眼为正常对照。术后 1、3、7d及 2、4及 6周分别摘除眼球行角膜上皮扫描电子显微镜检查 ,观察植片、植床及植片 植床交界处上皮形态及上皮细胞表面微绒毛结构的变化。结果 穿透性角膜移植术后角膜上皮表层细胞出现形态异常 ,植片上皮表面粗糙 ,表层细胞失去平整性 ,卷边、脱落明显增多 ,细胞间出现裂隙 ,术后 4周恢复正常 ;植床上皮出现相似改变 ,术后 1周基本恢复正常 ;植片 植床交界处术后 1周完成上皮覆盖 ,术后 4周表面形态接近正常。术后角膜上皮细胞表面微绒毛密度明显减少 ,术后 4周恢复正常。结论 穿透性角膜移植术后角膜上皮表面形态出现异常 ,术后 4周基本恢复正常 相似文献
7.
8.
9.
10.
11.
S M Crispin 《Cornea》1988,7(2):149-161
Crystalline stromal dystrophy a condition resembling human Schnyder's crystalline stromal dystrophy, is described in both the Cavalier King Charles Spaniel and Rough Collie breeds of dog. Both clinical cases and controls were normolipoproteinaemic; neither showed evidence of arcus lipoides corneae. Lipid histochemistry indicated the presence of cholesterol, cholesterol ester, and phospholipid in the superficial stroma. Free fatty acids were also detected in some samples, but triglycerides were not detected in any samples. Electron microscopy showed lamellated and nonlamellated vacuoles both within and outside abnormal fibroblasts. Acicular and rhomboidal clefts, some with a characteristic notch, were observed mainly in extracellular locations, although they were also associated with dying fibroblasts. The epithelium, basal lamina, Descemet's membrane, and endothelium were unaffected, apart from an irregularity of the basal lamina in some specimens. 相似文献
12.
准分子激光原位角膜磨镶术术后角膜上皮内生4例分析 总被引:2,自引:0,他引:2
LASIK术后发生角膜上皮内生虽然少见,但处理不及时或不当将会严重损害视力,现将我院遇见的4例患者作简要介绍。 相似文献
13.
体外重建角膜上皮组织的实验研究 总被引:4,自引:1,他引:3
利用体外培养重建同基因角膜上皮组织的新方法,为角膜化学伤后重建角膜表面提供理想的角膜上皮移植片。方法以同种或异种脱水保存的浅层角膜基质片作为载体,通过体外培养自体缘上皮细胞,并使其在体外形成复层角膜上皮组织。 相似文献
14.
15.
PURPOSE: The anterior surface of the cornea of mammals, including humans, has numerous folds in the anterior epithelial cell membranes in the form of microvilli and microplicae. The role of these surface irregularities may be to increase cell-surface area and therefore aid in intra- and extracellular movement of nutritional and waste products across the cell membranes in addition to stabilizing the corneal tear film. The aim of this study was to investigate and compare the nature of these corneal-surface features in various vertebrate classes residing in different environments. METHODS: The anterior corneal surfaces of various vertebrates were investigated by using field emission scanning electron microscopy. Cell areas were analyzed by using image-analysis software. RESULTS: Representative species were examined from all the vertebrate classes, with the exception of the Cephalaspidomorphi. The mean epithelial cell density of aquatic vertebrates (17,602 +/- 9,604 cells/mm2) is greater (p = 0.000018) than that of aerial and terrestrial vertebrate species, including amphibians (3,755 +/- 2,067 cells/ mm2). Similarly, the mean epithelial cell density for the marine vertebrates (22,553 +/- 8,878 cells/mm2) is greater (p = 0.0015) than that of the freshwater and estuarine species (10,529 +/- 5,341 cells/mm2). The anterior corneal surfaces of all species examined were found to show a variety of cell-surface structures. Microvilli are predominant in reptiles, birds, and mammals; microridges appear to be characteristic of the Osteichthyes; and microholes were observed only in the Chondrichthyes. CONCLUSION: The function of these morphologic variations in surface structure appear to be correlated with the range of ecologic environments (marine, aerial, and terrestrial) occupied by each species, corneal phylogeny, and the demands placed on the cornea to ensure clear vision. 相似文献
16.
实验性角膜新生血管形成的形态学研究 总被引:2,自引:2,他引:2
采用氢氧化钠灼伤角膜方法,诱导20只兔眼角膜新生血管形成,并对其发生、发展过程进行裂隙灯显微镜、光镜和透射电镜观察。结果发现,伤后8小时,角膜缘组织已有中性粒细胞浸润等明显急性炎症变化;渗出于血管外的中性粒细胞胞质内吞噬溶酶体异常丰富。在伤后2天,角膜缘才出现新生血管芽,角膜新生血管周围可见中性粒细胞浸润及其崩解产物。提示白细胞,特别是中性粒细胞,参与角膜新生血管形成过程,并可能起介导作用。 相似文献
17.
J P Bergmanson 《Journal of the American Optometric Association》1987,58(10):812-818
Complications from contact lens wear are seldom examined histopathologically. Understanding of the epithelial reactions in response to contact lens wear would help early diagnosis and direct treatment action. Therefore, this study examines the histopathology of abrasion, epithelial edema, epithelial thinning and superficial punctate staining. Important factors in the etiology of these conditions are various definable lens and tear characteristics as well as mechanical effects from the lens. Observations on corneal innervation that have not been previously reported are used to help explain the reduced corneal sensitivity in the contact lens wearer. It is concluded that the breakdown of the epithelial surface prevents the epithelium from fulfilling its fluid and microorganism barrier functions. In addition, disturbance of the normal epithelial structure interferes with its ability to withstand further trauma and to convey the injury to the brain via the neural pathways. 相似文献
18.
目的观察翼状胬肉单纯切除联合巩膜暴露术后应用还原型谷胱甘肽滴眼液的临床反应以及角膜上皮缺损区的愈合过程,评价该药物对角膜上皮修复的促进作用。方法对60例(60眼)翼状胬肉患者进行胬肉单纯切除联合巩膜暴露术,术后在给予每位患者完全相同的抗菌、抗炎治疗的基础上随机将其分为两组:实验组30例(眼),加用还原型谷胱甘肽滴眼液滴眼2周;对照组30例(眼),不加还原型谷胱甘肽滴眼液,即空白对照组。实验组和对照组在年龄、性别、胬肉大小方面差异无统计学意义(P〉0.05)。随访期间观察术后的症状指标,如疼痛、畏光、流泪、异物感、混合性充血并予评分,同时记录角膜上皮的愈合情况及速度。结果实验组术后的症状指标总体评分在术后第3、第5、第7天与对照组比较,差异有统计学意义(P〈0.05)(其分值分别为7.19±2.16/8.23±3.54、4.87±2.55/6.26±2.39和3.15±2.28/5.03±2.57)。角膜上皮修复的客观体征:实验组患者角膜上皮的完全修复时间为(4.53±1.32)d,对照组为(6.01±2.27)d,差异有统计学意义(P〈0.05)。结论翼状胬肉单纯切除联合巩膜暴露术后使用还原型谷胱甘肽滴眼液,能够减轻术后早期疼痛、畏光、流泪、充血、异物感等眼表刺激症状,并有效缩短角膜上皮缺损的愈合时间,有助于术后角膜上皮机械性损伤的修复。 相似文献
19.
目的:探讨软性角膜接触镜治疗糖尿病性视网膜病变患者行玻璃体切割术后角膜上皮缺损的疗效及眼部舒适度的影响。
方法:选取因糖尿病性视网膜病变于我院接受玻璃体切割手术并于术后出现角膜上皮缺损的患者20例20眼,随机分为两组:观察组10例10眼使用软性角膜接触镜联合成纤维细胞生长因子滴眼液、玻璃酸钠滴眼液点眼; 对照组10例10眼仅使用成纤维细胞生长因子滴眼液、玻璃酸钠滴眼液点眼。比较两组患者角膜上皮愈合的时间,同时对两组患者术后眼部舒适度进行比较评分。
结果:观察组患者角膜上皮愈合时间为4.1±1.20d,对照组患者角膜上皮愈合时间为14.2±6.07d,两组比较有统计学意义(P<0.05)。接受治疗后,观察组患者不舒适感明显减轻,对照组改观不明显,组间相比有统计学意义(P<0.05)。术后3mo,两组患者的眼部舒适度基本恢复到术前,组间比较无统计学意义(P>0.05)。
结论:软性角膜接触镜可以减轻角膜上皮缺损对患者造成的不适,缩短缺损修复的时间。 相似文献
20.
Chemical burns were produced using a 4 N NaOH solution in 21 rabbit corneas. The ultrastructural findings were examined under an electron microscope five minutes and 1, 2, 4, 8, 15, and 30 days after the burn. A morphologic disturbance of the basement membrane and its complexes was detected from the first day of the experiment. These findings suggest that the basement membrane plays an important role in the pathogenesis of corneal recurrent erosions and ulcer formation after chemical burns. 相似文献