LASIK术中微型角膜板层刀对角膜厚度的影响

目的　比较 L ASIK手术前后角膜厚度的变化 ,分析微型角膜板层刀对角膜厚度的影响。方法　 48例(96只眼 )的角膜厚度在 L ASIK术前及术后不同时期进行测量 ,比较术后理论值与实测值的差异 ,分析理论值与实测值的差异所在 ,从而判断微型角膜板层刀是否对角膜厚度产生一定的影响。结果　术后 3天、7天的角膜厚度实测值与理论值有显著性差异 (P <0 .0 5 ) ,术后 1月实测值与理论值差异无显著性 (P >0 .0 5 )。结论　 L ASIK术中微型角膜板层刀的切割作用对角膜厚度会产生一定的影响。     

微型角膜刀板层角膜成形联合准分子激光角膜切削术治疗高度近视

为评价微型角膜刀板层角膜成形联合准分子激光角膜切削术（ＭＬＫ－Ｅ或ＬＡＳＬＫ）治疗高度近视的效果和安全性，利用微型角膜刀作一带蒂角膜瓣，在其下用ｓｃｈｗｉｎｄＫｅｒａｔｏｍⅠ型准分子激光机进行ＰＲＫ激光切削，共治疗了３０例４７眼，术前屈光状态＜－１５Ｄ的Ⅰ组共３５眼，屈光度为－１０．２０±２．０４Ｄ，最佳矫正视力为０．９２±０．２６（０．４—１．５）；等球镜≥－１５Ｄ的Ⅱ组共１２眼，屈光度平均为－１７．６４±１．８３Ｄ，最佳矫正视力为０．４２±０．２３（０．１—０．８）。散光最高为４．５Ｄ。结果：术后３个月随访：Ⅰ组：屈光度平均为－０．４８±０．５２Ｄ（－１．７５—＋０．５０Ｄ），裸眼视力３４眼（９７％）达到０．５以上（另１眼裸眼视力等于术前），２５眼（７１．４％）裸眼视力达到术前最佳矫正视力。Ⅱ组：屈光度平均为－１．４４±１．９７Ｄ（－５．５０—＋１．２５Ｄ），８眼（６６．７％）裸眼视力达到术前最佳矫正视力。是一种安全有效的高度近视治疗方法。     

两种显微角膜板层刀制作角膜瓣厚度的对比分析

目的:对Hansatome自动旋转式显微角膜刀及AmadeusⅡ自动平推式显微角膜刀制作准分子激光原位角膜磨镶术(LASIK)角膜瓣厚度进行对比分析。方法:对来我院行LASIK的患者50例100眼,随机分成两组,一组用Hansatome显微角膜刀160μm刀头制作角膜瓣,另一组用AmadeusⅡ显微角膜刀140μm刀头制作角膜瓣。对所有患者进行术前中央角膜厚度测量及术中角膜基质床厚度测量,从而计算角膜瓣厚度。所有的患者均先行右眼手术再行左眼。对两组患者实际切削的角膜瓣厚度进行对比,同时对两种显微角膜板层刀制作角膜瓣厚度左右眼之间进行对比分析。结果:Hansatome组实际角膜瓣厚度67～158(平均98.70±18.04)μm;AmadeusⅡ组实际角膜瓣厚度69～171(平均110.60±16.47)μm,两种角膜刀制作角膜瓣厚度差异有统计学意义(P=0.001)。Hansatome组右眼104.40±18.78μm,左眼93.00±15.61μm,两眼角膜瓣厚度差异有统计学意义(P=0.01);AmadeusⅡ组右眼115.12±18.74μm,左眼105.20±12.29μm,P=0.024,患者左眼角膜瓣均比右眼要薄,差异有统计学意义。结论:在LASIK术中角膜板层刀制作的角膜瓣厚度与预计值有一定的偏差,术中测量角膜瓣厚度有重要的参考价值。     

飞秒激光和角膜板层刀行LASIK术后视觉质量及角膜瓣的比较

目的:对比分析飞秒激光和角膜板层刀行准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)术后患者的视觉质量及角膜瓣变化。方法:选取2009-03/2012-03将接受飞秒激光35例70眼患者和接受角膜板层刀的患者45例90眼进行对比研究,两组术后视觉质量和角膜瓣进行对比。结果:视觉质量比较:两组患者所行的手术均有显著的可预测性、有效性及安全性,且术后像差和对比敏感度及视力差异不显著,组间差异无统计学意义(P>0.05);角膜瓣比较:两组患者在水平方向的角膜瓣厚度组间差异无统计学意义(P>0.05)。结论:飞秒激光和角膜板层刀行LASIK术后具有良好的视觉效果,且角膜瓣厚度差异不显著,值得临床推广使用。     

LASIK术中角膜板层刀片的使用次数对角膜瓣质量的影响的实验研究

目的:研究离体猪LASIK术中角膜板层刀片使用次数对角膜瓣厚度、均匀性和切削面的光滑程度的影响。方法:新鲜离体猪眼球36只,刀片使用1～6次分成Ⅰ～Ⅵ组,再将Ⅰ和Ⅱ,Ⅲ和Ⅳ,Ⅴ和Ⅵ合并为A,B,C组。测量6组猪眼球的角膜中央厚度、K值及眼压。在猪眼球上模拟角膜瓣的制作过程并计算角膜瓣中央厚度。从6组中各选取3只角膜瓣制成病理切片标本,在光学显微镜下观察角膜瓣厚度的均匀性。从Ⅰ,Ⅳ,Ⅵ组中各选取1只角膜瓣制成标本,在扫描电镜下观察角膜瓣切削面的光滑程度。结果:术前6组角膜瓣的平均角膜中央厚度、K值和眼压无差异。术后角膜瓣的平均厚度分别为152.7±14.6,143.8±9.3,128.3±12.7,114.2±9.6,99.7±5.7和70.0±12.7μm;除Ⅱ组与Ⅰ组无差异外,Ⅲ～Ⅵ组与Ⅰ组角膜瓣厚度均有差异。角膜瓣厚度与刀片使用次数呈负相关性。A,B,C3组角膜瓣的平均厚度分别为150.8±15.4,121.2±13.0和88.3±15.1μm,组间差异明显。随着刀片使用次数增多,角膜瓣厚度均匀性下降,角膜瓣切削面的光滑程度下降。结论:随着刀片使用次数的增多,角膜瓣厚度变薄,角膜瓣厚度的均匀性和角膜瓣切削面的光滑程度均下降。     

自动板层角膜刀行板层角膜移植的超微结构观察

目的：研究自动板层角膜刀行同种异体板层角膜移植后角膜超微结构变化情况。方法：将34只大耳白兔随机分为三组进行实验。A组用自动板层角膜刀,B组用手工角膜刀,C组为正常对照组。结果：自动板层角膜刀行板层角膜移植术后,角膜修复过程较手工角膜刀缩短,角膜透明也得到了提高。结论：自动板层角膜刀可应用于板层角膜移植。     

旋转式角膜板层刀在893眼LASIK中的应用

目的：评价旋转式角膜板层刀在准分子激光原位角膜磨镶术（ｅｘｃｉｍｅｒ ｌａｓｅｒ ｉｎ ｓｉｔｕ ｋｅｒａｔｏｍｉｌｅｕｓｉｓ,ＬＡＳＩＫ）中的应用效果。方法：应用Ｍｏｒｉａ旋转式角膜板层刀对４７１例（８９３眼）近视－０．７５￣－１８．０Ｄ的患者进行ＬＡＳＩＫ治疗。结果：术后１周８９３眼中有８７６眼（９８．１％）,视力达到了术前最好矫正视力,角膜瓣蒂位置;留在鼻上方有５９２眼（６６．２９％）,鼻侧     

旋转式角膜板层刀角膜瓣制作不良的试验研究

目的探索使用旋转式角膜板层刀术中角膜瓣并发症产生的原因。方法离体新鲜羊眼90只,均分为9组,应用Moria-2旋转式角膜板层刀模拟以下情况制作角膜瓣,观察角膜瓣情况:①走刀时负压管受阻。②未达到负压值时走刀。③走刀时眼球摇摆不定。④刀刃钝。⑤刀刃有小缺损。⑥刀片未安装到位。⑦刀片卡住不能摆动。⑧刀头未锁。⑨角膜表面及刀头干燥。结果第1组出现2例游离瓣、3例薄瓣。第2组出现1例游离瓣、3例薄瓣、4例瓣起始部稍薄。第3组有4例用较大力量将负压环摇脱,均产生游离不全瓣。第4组出现2例上皮瓣、3例超薄瓣且游离、1例前弹力层岛样残留、4例薄瓣。第5组角膜床均有与刀刃缺损对应的脊样隆起。第6及第7组均未对角膜产生切割作用。第8组出现2例小瓣、5例小游离瓣、3例不规则小游离瓣。第9组出现1例典型纽孔瓣、1例不完整纽孔瓣、2例瓣角膜床中央部隆起瓣、2例断瓣、1例碎瓣、3例不规则游离瓣。结论使用好角膜板层刀,对预防术中角膜瓣并发症的产生至关重要。     

KN-5000LASIK微型角膜刀研究

目的 评价国产ＫＮ－ ５０００ 微型角膜刀在临床角膜瓣技术中的作用,评价治疗高度近视的临床效果,探讨其预测性、安全性和稳定性。方法 选用连续病例２４ 例４４ 眼, 随机分为实验组（Ａ 组） 和对照组（Ｂ组） 。Ａ 组１１ 例２１ 眼,术前平均球镜当量１３２１ ±４７３Ｄ,最大散光度２２５Ｄ。Ｂ 组１３ 例２４ 眼,术前平均球镜当量１１４０ ±２６３Ｄ,最大散光度２７５Ｄ。术中分别用ＫＮ－ ５０００ 微型角膜刀和Ｍｏｒｉａ 微型角膜刀制作角膜瓣。结果 术中制瓣安全简捷,制瓣良好率Ａ 组２１ ／２１ ,Ｂ 组２３／２４ ,２ 组无明显差异,无术中并发症发生。临床病例随访显示：２ 组术后３ｍｏ 裸眼视力大于等于０５ 的比率分别是６１９ ％ 和６５２ ％ ,术后屈光度按球镜当量计算实验组为－ ０６７ ±１８４Ｄ,对照组－ ０７６ ±１７５Ｄ。术后屈光度在－ １Ｄ 之内比率实验组为４２９ ％ ,对照组为４７８ ％ ,这２ 组差异经检验无意义。结论 ＫＮ－ ５０００ 微型角膜刀制作角膜瓣稳定性、预测性良好。进一步临床应用有待继续进行     

自控角膜板层切开联合准分子激光角膜基质内切削成形…

近年来刚刚发展起来的利用自控角膜板层切削成形术与准分子激光角膜切削术联合运用，即Ｌａｓｉｋ术，对近视，尤其是高度近视的矫治能力，矫治范围及可预测性，稳定性优于其它角膜屈光手术。本对此术式发展的经过，优缺点及其目前使用的手术方法进行了综述。     

Pathologic evidence of retinoblastoma seeds supported by field emission scanning electron microscopy and Raman spectroscopy

Purpose:The aim of this study was to examine the pathology of retinoblastoma (RB) seeds with supportive evidence by field emission scanning electron microscopy and Raman spectroscopy.Methods:This study was a laboratory-based observational study. Enucleated eyeballs received in the ocular pathology department of a tertiary eye care center in northeast India were included in the cohort after obtaining written informed consent during the surgery. The study was carried out for 6 years (2015–2020). Most of the eyeballs were Group-E RBs. Standard eyeballs sectioning were done by bread loaf techniques. Gross documentations included RB seeds seen in the smallest calotte done with utmost care. Seeds were documented also in permanent sections. Scanning electron microscopy and Raman spectroscopy were carried out in an index case.Results:Out of the total 59 cases, 35 RB cases had different seedings. The mean age at enucleation was 2.9 years. RB seeds were seen in vitreous (n = 19), subretinal plus vitreous (n = 7), anterior chamber (n = 1), over crystalline lens (n = 3), retinal surface (n = 1), retinal pigment epithelium (RPE; n = 2), subretinal (n = 1), calcified seeds (n = 2). Other characteristics were dusts (n = 7), clouds (n = 11), spheres (n = 4), and unspecified type (n = 13). Histopathological high-risk factors showed significant choroidal (n = 22) and optic nerve (n = 15) involvement. Few cases had extraocular spread. Undifferentiated tumor (n = 24) was seen with higher evidence of necrosis (n = 23). Raman spectra differentiated the seeds from the normal tissue on the basis of lipid and protein content.Conclusion:This study highlights the different types of RB seeds with high-risk factors. The morphology of those seeds showed the difference between vitreous and subretinal seeds under advanced microscopic observations.     

Endothelial cell density determined by specular microscopy and scanning electron microscopy.

Human eyes were photographed with a specular microscope and later examined wit a scanning electron microscope. Corneas from patients undergoing corneal transplantation in whom we were able to obtain preoperative specular micrographs were similarly analyzed. An attempt was made to correlate the counts obtained with both microscopic techniques by determining the amount of shrinkage the cornea undergoes while being processed for SEM. All specimens were counted with a planimeter. We found that the specular microscope adequately analyzes the endothelial cell density in the central and paracentral cornea of a normal eye, but because of its small sampling area specular microscopic counts are subject to significant error when dealing with nonhomogeneous populations such as postoperative cases. We found the peripheral corneal endothelial density to be less than the central endothelial density. Furthermore, we found that we could maximize the accuracy of counting by using a variable frame in a nonhomogeneous population, counting a minimum of four photographs per specimen, analyzing different areas, and analyzing larger areas.     

激光共聚焦显微镜观察春季角结膜炎患者的角膜形态变化

目的 探讨应用活体激光共聚焦显微镜观察春季角结膜炎(VKC)患者的角膜形态变化.方法 观察型系列病例研究.选择2008年10月至2009年8月在复旦大学附属眼耳鼻喉科医院眼科就诊的26例双眼VKC患者,其中眼睑型13例、角膜缘型5例、混合型8例;另选择26名年龄、性别匹配的正常志愿者作为对照.使用活体激光共聚焦显微镜对患者右眼角膜进行检查,分别取中央角膜和上方周边部角膜为检查点,对所得图像进行记录和分析.利用内置细胞计数软件计算角膜各层组织的细胞密度,ImageJ软件分析神经密度、直径、分支数量及弯曲度.使用独立t检验比较VKC患者与正常人群角膜各层细胞密度的差异以及VKC患者周边与中央角膜细胞密度的差异;Fisher精确卡方检验比较VKC患者和对照组角膜上皮内郎格罕细胞浸润情况差异;方差分析比较VKC 3种亚型之间和不同病程之间各层细胞密度的差异;独立t检验和卡方检验分析VKC患者与正常人群之间的神经差异.结果 VKC患者的角膜形态学变化包括角膜上皮最表层的高亮多角形细胞缺失、上皮内和上皮下大量郎格罕细胞浸润及浅基质层内大量基质细胞活化.共焦显微镜下,角膜出现新生血管翳的患者表现为角膜上皮结膜化,基质内可见新生血管;合并圆锥角膜的患者,深基质内可见大量粗大的斜形或纵形暗纹.正常对照组的中央和周边部角膜上皮细胞密度分别为(6033.1±998.7)个/mm2和(6098.4±298.3)个/mm2,VKC患者分别为(5972.2±1148.2)个/mm2和(6178.5±318.9)个/mm2,差异无统计学意义(t=1.191,1.011;P=0.238,0.318);但VKC患者周边部上皮细胞密度显著高于中央部(t=2.249,P=0.03).正常对照组的中央和周边浅基质细胞密度分别(1001.4±125.3)个/mm2和(924.6±201.4)个/mm2,VKC患者分别为(1184.5±115.3)个/mm2和(1101.4±151.1)个/mm2,均显著高于正常对照(t=6.617,3.439;均P=0.001).正常对照与VKC患者中央角膜深基质层细胞密度分别为(537.7±42.6)个/mm2和(548.7±79.8)个/mm2,内皮细胞层细胞密度分别为(2985.7±401.2)个/mm2和(3021.5±383.3)个/mm2,两者比较均无明显差异(t=0.174,1.112;P=0.864,0.282).61.5%(16例)VKC患者的角膜上皮内发现郎格罕细胞浸润,显著高于正常人群(2例,7.7%)(x2=12.49,P=0.001).3种不同亚型VKC患者中,角膜缘型和混合型患者上皮内郎格罕细胞浸润情况较为严重.与正常对照组相比,VKC患者的上皮下神经密度和直径下降、弯曲度增加.结论 VKC主要累及角膜上皮层、上皮下神经及浅基质层.共焦显微镜对于VKC的分型诊断有一定辅助价值.

Abstract：

Objective To explore the morphological characteristics on cornea in patients with vernal keratoconjunctivitis(VKC)by the application of in vivo laser scanning confocal microscopy(LSCM).Methods The experimental design was retrospective observation case series(case control study).Twenty-six patients, each diagnosed as bilateral VKC, were enrolled in the study, among which 13 were tarsal form, 5 were bulbar form and the rest were mixed form. Nine patients had the clinical course less than one year, eight subjects longer than three years, and the rest between them. Another twenty-six healthy volunteers with matching age and gender were selected as normal control. All participants had their right eyes examined with the in vivo confocal microscopy ( HRT Ⅱ/RCM). Central cornea and superior peripheral cornea were chosen as the examination points. The images were recorded automatically and cellular density of each layer was analyzed by installed software. Software Image J was utilized to analyze the density, diameter, branch number and tortuosity of subbasal nerve fiber in VKC patients. Independent t test was performed to assess the differences on cellular density between VKC patients and normal control, as well as those between central and peripheral cornea in VKC patients. Fisher chi-square test was used to compare the infiltration rate of Langerhans cells in corneal epithelium between VKC patients and controls. ANOVA was applied to assess the differences in cellular density among three subtypes, as well as among different duration of VKC. Independent t-test and chi-square test were applied to analyze the parameters of subbasal nerve fiber. Results The morphological changes in cornea included the absence of superficial hyperreflective polygonal epithelial cells, infiltration of Langerhans cells in and(or) underneath corneal epithelium and activation of keratocytes in anterior stroma. Corneal epithelium conjunctivalization and stromal neovascularization could be identified in patients with corneal neovascular epithelium. Longitudinal or oblique dark striae could be found in the posterior stroma in patients with complicated keratoconus. The density of epithelial cells at central and peripheral cornea in healthy controls were (6033. 1 ± 998. 7) cells/mm2 and (6098. 4 ± 298. 3 ) cells/mm2, while that in VKC patients were (5972.2 ± 1148.2) cells/mm2 and (6178.5 ± 318.9) cells/mm2 respectively, the differences being no statistical significant between them (t = 1. 191 , 1. 011; P =0.238, 0. 318). However, it's found in VKC patients that cellular density at peripheral cornea was significantly higher than that at central area( t = 2. 249, P = 0. 03). The density of anterior stromal cells at central and peripheral cornea in healthy controls was (1001. 4 ± 125. 3) cells/mm2 and (924. 6 ± 201.4) cells/mm2, while that in VKC patients was (1184. 5 ± 115. 3 ) cells/mm2 and (1101.4 ± 151. 1) cells/mm2, the difference bearing no statistical significance(t =6. 617,3.439;P =0. 001). The density of posterior stromal cells in normal subjects and VKC patients was (537. 7 ± 42. 6) cells/mm2 and (548. 7 ± 79. 8) cells/mm2, that of endothelial cells was (2985. 7 ± 401. 2 ) cells/mm2 and (3021. 5 ± 383. 3) cells/mm2, respectively, neither difference had statistical significance (t = 0. 174, 1. 112; P = 0. 864, 0. 282 ) . Langerhans cell infiltration could be identified in 61.5% (16 cases) VKC patients, which was significantly higher than normal control (2 cases, 7. 7% ) (x2 = 12. 49, P = 0. 001 ). Furthermore, much intense Langerhans cells infiltration was found in bulbar form and mix form than tarsal form. (t = 6. 617, P = 0. 001). The density and diameter of subbasal nerve fiber in VKC patients decreased significantly than those in normal subjects, whereas the tortuosity increased significantly. Conclusions The morphological changes of cornea in VKC patients mainly involve corneal epithelium, subbasal nerve fiber and anterior stroma. In vivo LSCM is helpful in discriminating the subtypes of VKC.     

Improved procedure for surface analysis of explanted intraocular lenses by combined light microscopy and scanning electron microscopy

An improved surface characterization procedure for evaluating explanted intraocular lens (IOL) biocompatibility was developed. The technique combines aqueous hematoxylin-eosin staining for characterizing adherent cells and tissue with subsequent scanning electron microscopy of the same IOL.     

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.