Influence of topical Cyclosporine A and dissolvent on corneal epithelium permeability of fluorescein

The corneal stroma is the major barrier to penetration for the lipophilic Cyclosporine A (CsA) molecule and prevents the use of the common ophthalmic solvents. At present, corn oil, castor oil and olive oil are the three most commonly used vehicles. The aim of this study was to determine the effect that topically applied CsA dissolved in different oils has on corneal epithelial permeability measured by fluorophotometry. Forty healthy volunteers, with absence of ocular or systemic disease and not receiving topical or systemic drugs were enrolled. Measurements were taken before and 45 min after the instillation of 40 microliters of a 2% aqueous solution of sodium fluorescein without preservatives. Basal corneal permeability and the permeability 24 h after the instillation of 2% CsA-olive oil, olive oil alone, 2% CsA-castor oil, castor oil alone, 2% CsA-corn oil and corn oil alone, were calculated. To prepare the topical 2% CsA, a Sandimmun oral solution (Sandoz, Basel, Switzerland) was employed under sterile conditions. We found that epithelial permeability 24 h after the instillation of any CsA formulations or solvents increased more than 6.62 times (p < 0.001). No differences in corneal permeability values were found between any of the CsA formulations and the vehicles. We conclude that oils used to dissolve CsA are mainly responsible for the increased corneal epithelial permeability. No differences were found in the effects of the tested solvents on corneal epithelial permeability.     

Effects of central corneal thickness on the efficacy of topical ocular hypotensive medications

PURPOSE: To determine the effect of central corneal thickness (CCT) on the efficacy of intraocular pressure (IOP)-reducing drugs in patients with ocular hypertension (OHT). METHODS: This retrospective study analyzed research records of 115 OHT patients and 97 ocular normotensive (ONT) volunteers. CCT was measured by slit-lamp pachymetry and IOP by pneumatonometry. The OHT patients were divided into Thick (>540 microm, n=52) and Thin (相似文献   

Influence of artificial tears on corneal epithelium in dry-eye syndrome

The corneal epithelium of patients with dry-eye syndrome is stressed by both tear film insufficiency and the frequent use of eye drops (artificial tears). In order to quantify corneal epithelial damage, the permeability of corneal epithelium to sodium fluorescein was determined in 40 consecutive patients with dry eyes (BST < 10 mm), who did not exhibit visible corneal lesions upon slit-lamp examination. The corneal epithelial permeability of dry-eye patients was shown to be 2.8 times greater than that of individuals without ocular disease. Corneal epithelial permeability of patients using artificial tears containing benzalkonium chloride was increased 3.1 times and that of patients using drops preserved with chlorobutanol only 1.7 times.     

抗过敏滴眼液对体外培养的人角膜上皮细胞的毒性作用

目的 探讨0.1%奥洛他定、0.025%富马酸酮替酚及0.1%吡嘧司特钾对体外培养的人角膜上皮细胞的毒性作用.方法 实验研究.使用无血清角膜细胞培养基(K-SFM)进行人角膜上皮细胞的体外培养;将传2-4代的细胞暴露于0.1%奥洛他定(A组)、0.025%富马酸酮替酚(B组)、0.1%吡嘧司特钾(C组)3种滴眼液,以无血清角膜细胞培养基将滴眼液分别稀释到50.0%、20.0%、4.0%、0.8%的浓度,与细胞共同孵育的时间分别为10、30 min,2、6、12、24 h.滴眼液所致细胞毒性的评估采用光学显微镜和扫描电镜对细胞进行的形态学观察、钙贡绿素和乙锭同型二聚体活性与毒性荧光双染色及四唑氮蓝还原法(MTr Assay).统计学方法使用单因素方差分析、组间两两比较SNK-q检验.结果 (1)形态学改变:于光镜下观察,随着药物浓度的增加、作用时间延长,细胞连接逐渐松解、细胞变圆、脱落.于扫描电镜下观察,3组药物均可减少细胞表面的微绒毛层,细胞膜出现裂孔.滴眼液稀释到20.0%时,A组细胞膜形态的改变较B、C组轻.(2)细胞活性与毒性荧光染色:乙锭同型二聚体阳性提示细胞膜受损、通透性升高.20.0%浓度时A组6、12、24 h的胞膜受损细胞的百分比低于B、C组[A组分别为(29.7±2.6)%、(36.9±3.2)%、(51.2±4.3)%;B组分别为(36.5±3.1)%、(48.5±4.3)%、(75.5±3.8)%;C组分别为(37.1±2.2)%、(52.7±3.4)%、(71.1±5.1)%],差异均有统计学意义(6h时,q_(A-B)=3.27,P=0.031;q_(A-C)=4.31,P=0.023).钙贡绿素阴性提示细胞质内酯酶活性丧失.A、B、C组药物作用于细胞后,随着浓度和作用时间的提高,细胞内酯酶活性逐渐降低,但3组之间差异无统计学意义[作用24 h时A、B、C组无酯酶活性细胞的百分比:50.0%浓度时,3组均为100.0%;20.0%浓度时,分别为(23.2±4.6)%、(29.5±5.2)%、(31.1±5.5)%,F=1.97,P=0.377].(3)MTT分析:除滴眼液稀释到0.8%浓度外,其余随药物浓度升高、作用时间延长,则MTT值降低.滴眼液稀释到20.0%浓度、作用6h时(A、B、C组MTT值为0.429±0.028、0.367±0.038、0.379±0.012)和4.0%浓度、作用24 h时(A、B、C组MTT值为0.457±0.025、0.401±0.008、0.387±0.012),A组MTT值高于B、C组,差异有统计学意义(浓度20.0%、6h时,q_(A-B)=3.01,P=0.044,q_(A-C)=3.77,P=0.038;浓度4.0%、24 h时,q_(A-B)=3.63,P=0.028,q_(A-C)=4.11,P=0.031).其余浓度的各作用时间点3组之间比较,差异无统计学意义.结论 0.1%奥洛他定对体外培养的人角膜上皮细胞的毒性比0.025%富马酸酮替酚和0.1%吡嘧司特钾小,在临床长期使用治疗过敏性角膜、结膜炎时,可能比后两种药物对角膜上皮细胞的毒性低.     

局部麻醉对兔眼心反射和眼角膜愈合的影响(英文)

目的:在兔模型中利用局部麻醉来研究两种麻醉剂的眼心反射发生率及其预防,同时我们还研究了局部麻醉对角膜愈合的影响。方法:健康的成年新西兰白兔(雌雄皆有)48只,分成两组(A组和B组),分别用氯胺酮(A组,24例)、异丙酚(B组,24例)麻醉。在此双盲研究中,通过用或不用局部麻醉(40g/L利多卡因,5g/L盐酸丙美卡因,5g/L布比卡因)对眼睛的不同干预,记录各组眼心反射发生率。应用每种局部麻醉后,通过对眼睛的临床检查,组织病理学,胶原染色以及投射电子显微等方法对术后1d长达7d角膜毒性和愈合进行评估。结果:在氯胺酮的麻醉下未出现眼心反射,而在异丙酚的麻醉下,心率显著下降(P<0.01)。因此,局部麻醉可以成功地防止眼心反射的发生并且不影响角膜愈合。结论:局部麻醉没有任何局部副作用,可以被推荐用来预防眼心反射。     

Influence of topical anesthetics on oculocardiac reflex and corneal healing in rabbits

AIM: To investigate the incidence of oculocardiac reflex (OCR) with two anesthetic regimens and its prevention using topical anesthetics in a rabbit model, and to explore the effect of topical anesthetics on corneal healing. · METHODS: Forty-eight clinically healthy adult New Zealand white rabbits of either sex were divided into two groups (Group A and B) and anesthetized with either ketamine (Group A, n =24) or propofol (Group B, n =24). he incidence of OCR was recorded in each group with a variety of ocular manipulation with or without the use of topical anesthetics (40g/L lignocaine, 5g/L proparacain, 5g/L bupivacaine). Corneal toxicity and healing following the use of each topical anesthetic was assessed one day after surgery and up to 7 days postoperatively by clinical examination of the eye, histopathology and collagen staining and transmission electron microscopy. · RESULTS: No incidence of OCR was recorded with ocular manipulation under ketamine anesthesia, whereas significant reduction in heart rate (P <0.01) was recorded under propofol anesthesia. Topical anesthetics could successfully prevent the OCR without affecting the corneal healing. · CONCLUSION: Topical anesthetics may be recommended for prevention of OCR without any local adverse effect.     

Effect of the vehicle on the topical itraconazole efficacy for treating corneal ulcers caused by Aspergillus fumigatus

Background:  The clinical behaviour of mycotic keratitis is aggressive, and the options for treating it are limited. This poses a need to explore new options for efficacious, low-cost treatment. Recent evidence suggests that topical itraconazole may be useful for treating this entity and that it may be possible to improve its efficacy using a suitable vehicle.
Methods:  We included 12 New Zealand white (NZW) rabbits (24 eyes). The rabbits were infected with pathogenic strains of Aspergillus fumigatus and subsequently randomized to receive every 2 h for 5 weeks two different preparations of topical itraconazole 1%. In group 1 (12 eyes), ricinus oil and in group 2 (12 eyes), Systane were used as vehicle. Rabbits were evaluated every week by a masked ophthalmologist to determine the treatment response.
Results:  The size of the ulcers was similar in the two groups at the baseline: group 1: 12.7 ± 2.7 mm (median 12.8, range 9.8–15.5 mm); and group 2: 12.3 ± 3.1 mm (median 12.1, range 9.8–20.8; P  = 0.67). Although both groups responded well to the treatment, the response was better in the group 2, especially in weeks 2 and 3: week 1: 12.7 ± 2.7 vs. 9.3 ± 4.61 mm ( P  = 0.1); week 2: 9.4 ± 3.4 vs. 4.1 ± 2.9 mm ( P  = 0.004); week 3: 5.0 ± 3.4 vs. 1.7 ± 1.0 mm ( P  = 0.004); week 4: 1.9 ± 1.9 vs. 1.0 ± 1.2 mm ( P  = 0.1); and week 5: 0.68 ± 1.2 vs. 0.0 ± 0.0 mm ( P  = 0.3).
Conclusion:  Topical itraconazole may be useful for treating corneal ulcers caused by Aspergillus fumigatus , and its efficacy seems to be related with the vehicle solubility.     

进口角膜保护剂与国产角膜保护黏弹剂对眼科手术患者角膜上皮的保护作用和安全性的对比分析

目的 对比分析进口角膜保护剂与国产角膜保护黏弹剂对眼科手术患者角膜上皮的保护作用和安全性.方法 选取2021年1月至7月在山东第一医科大学附属眼科医院拟行单眼白内障手术或眼底手术的患者52例(52眼)为研究对象.采用随机数字法将患者分为试验组和对照组,每组各26眼.试验组使用国产角膜保护黏弹剂,对照组使用波兰产角膜保护...     

Ultrastructural observations on the fetal corneal epithelium

The maturing changes in the central corneal epithelium of 18 fetuses were observed by transmission electron microscopy, revealing that the corneal epithelium comprised 5-6 layers of cells after the 8th month of gestation, when the basal cells were short columnar in shape with oval, regular nuclei, and the cytoplasmic organelles included mitochondria. Golgi complexes, rough endoplasmic reticulum, membrane coating granules, glycogen granules etc. In the middle layers were polygonal cells with flat nuclei and few cytoplasmic organelles. The free surfaces of the superficial flat cells were covered with microvilli of different heights and in random arrangement. The study confirmed that ultrastructurally the fetal corneal epithelium after the 8th month achieved the mature form of the adult cornea.     

Ultrastructure of conjunctival epithelium replacing corneal epithelium

After corneas of mice had been totally denuded of their epithelium by the application of n-heptanol, the new epithelium which grew over the corneas was studied by electron microscopy at intervals up to 7 months. The purpose was to compare the basal attachment of the new cells, derived from conjunctiva, with that of true corneal epithelial cells growing on the same type of substratum, and studied previously. Goblet cells appeared after 2 weeks amid the squamous type of epithelial cells which had resurfaced the cornea in about 1 week. Goblet cells increased up to at least 6 weeks, but had decreased by 3 months. They persisted, however, for the entire 7 months of the study. Goblet cells had only a small area of contact with the basal lamina, and they had few desmosomes or hemidesmosomes. Basal cells of the squamous type had complex features of their basal attachment quite different from those of normal or repairing corneal epithelial cells studied previously. Flat cytoplasmic extensions of squamous cells underlay most of the goblet cell basal pole which therefore had only a small area on the basal lamina. Numerous filaments inserted into desmosomes and hemidesmosomes of squamous cells, and prominent bundles of these filaments lay just above the basal plasma membrane. They were orientated parallel to the radial axis of the cornea. Closely spaced corrugations of the basal plasma membrane were also orientated in this axis, as well as rows of hemidesmosomes. Even after a period of 7 months, the morphological features of conjunctival cells did not come to resemble those of normal corneal epithelium. The radial arrangement of fibers, hemidesmosome rows, and corrugations is interpreted as a reflection of the continued centripetal migration of the epithelium.     

Image analysis of the corneal epithelium

The method for quantifying corneal epithelial images has been examined. When pictures were developed, the images were stored in the memory of the image processing system by video camera. The distribution of the density of the images was analyzed. The density of each pixel of an image was assigned one of 256 grades, from completely black to completely bright. The average (AV), the standard deviation (SD), the coefficient of variation (CV), the skewness (SK) and the sharpness (S) of the density were calculated. Normal epithelium could be differentiated from abnormal by subjectively observing the shapes of the cells, the sizes of the cells and the irregularity of the cell pattern. But there were no statistical differences between the two groups with regard to the AV, SD, CV, SK and S of normal (n = 4) and abnormal (n = 8) corneal epithelial images. Simple analysis of density distribution could not be used as a parameter for the evaluation of the cells.     

Angiogenic activity of the corneal epithelium

A homogenate of corneal epithelial cells was tested to determine if it could induce vascularization in the cornea. Both fresh and cultured cells were used as sources of the homogenate which was evaluated in vivo using a self-contained system to perfuse it constantly into the corneal stroma. A vigorous growth of vessels resulted when the concentration of the homogenate exceeded a threshold of 20 micrograms per ml total protein. This capacity was not destroyed when the homogenate was heated. As a preliminary refinement of this response white blood cells were eliminated from the model with whole body X-irradiation. Vascularization occurred in leukopenic animals but was less than that observed in normal animals. It is concluded that the epithelial homogenate is able to provoke corneal vascularization in the absence of leukocytes.