激光角膜病竈清除術

目的探討YAG激光對角膜潰瘍中深層病的機械清除的可能性及是否對病原體有破壞作用和是否影響病周圍正常的角膜組織.方法以YAG激光的低中度能量對角膜潰瘍表面壞死組織進行水平及垂直定點爆破式清除,并有針對性的進行了分組間的對照觀察.結果80%以上的病人出現了意想不到的變化,表現為潰瘍愈合、炎癥消退、角膜混濁區縮小,程度不同的視力提高,而兩對照組的治愈率僅為50%及36%、6%,且病程長,易復發,後者的角膜混濁面積大等.結論YAG激光作為一種新的角膜病清除方式具有安全、準確、可靠、高效等優點,并可能對病内的病原體有一定的物理破壞作用.關鍵詞 YAG激光角膜潰瘍病清除     

正常国人全角膜数字模型的建立

目的探讨国人个体角膜数学模型的二次曲线方程模式及初步结果。方法建立角膜顶点为原点的笛卡儿空间三维坐标,绕z轴旋转坐标,建立新的三维空间坐标系,并明确新旧坐标的转换关系;采集ORBSCANⅡ角膜地形图系统测量的角膜顶点、0°、30°、60°、90°、120°、150°、180°、210°、240°、270°、300°、330°子午线上距角膜顶点分别为1．0、1．5、2．0、2．5、3．0、3．5、4．0、4．5mm处点的前、后表面曲率和角膜厚度值d0,代人一套方程组,解出二次曲线公式x^2=a2x^2＋a1x（前表面截痕）、^2=a1（z-d0）^2＋a2（z—d0）（后表面截痕,d0为中央角膜厚度）,确定各切面截痕特性及偏心率Q值;从各子午线的截痕的曲线特征归纳角膜前、后表面曲面空间形态的数学表达式。结果角膜前、后表面各子午线截痕的数学表达式均为椭圆二次曲线轨迹。角膜前、后表面曲面符合椭球二次曲面数学表达式。结论本研究报告了二次曲线公式的人眼角膜前、后表面数学模型新表达式;本小样本正常国人角膜前后表面各子午线截痕均符合椭圆二次曲线的形态特征,角膜前、后表面的曲面空间形态均为椭球面。     

正常个体人眼角膜空间形态数学建模路线研究

目的通过数学方法分析角膜的三维数据,并以数学表达式的方式归纳和反映正常成年个体人眼角膜空间形态特征。方法以Orbscan-Ⅱ角膜地形图系统测量和采集角膜顶点0°、30°、60°、90°、120°、150°、180°、210°、240°、270°、300°、330°子午线上距角膜顶点距离分别为1.0 mm1、.5 mm、2.0 mm、2.5 mm、3.0 mm、3.5 mm、4.0 mm、4.5 mm处的前、后表面曲率,角膜厚度值利用空间三维坐标旋转、曲率公式、曲率半径公式及二次曲线公式等进行数据分析和归纳,推导出角膜前、后表面各子午线截面的曲线数学表达式及前、后表面的曲面的数学表达式。并通过个体角膜实际测得的数据对该数学表达式进行具体推导。且验证角膜前、后表面的曲率分布符合Toric光学面特性。结果正常个体角膜前表面数学表达式:x2/7.76762+y2/7.66182+(z-7.8629)2/7.86292=1;后表面数学表达式:x2/7.52082+y2/6.68952+(z-9.3944)2/8.86442=1。结论正常个体角膜的前、后表面各子午线的截面曲线为椭圆,因此其前、后表面均为椭球面。     

Fluorescent dyes demonstrate the uniform expansion of the growing rabbit cornea

Thiocyanate and triazinyl chloride derivatives of fluorescent dyes have been employed for the covalent labeling of components of the connective tissue of the rabbit cornea. Collagen is the major macromolecular component that becomes dyed. Some of the stromal components that are labeled by these reagents in the first two weeks of life persist over many months, but are progressively dispersed over a greater area consistent with a uniform expansion of the tissue with growth without complete turnover. These dyes may find useful application in the morphologic study of other persistent connective tissue components during development and wound healing.     

Mathematical model of the rotation of cornea

The aim of our study is to informatise the procedure, ie, design the computer system and software necessary to automatically define the parameters of our problem. To achieve this, we have used an image analyser which permits us to acquire and digitalise a photograph of the lesioned cornea. Digitalisation of the image allows us to determine the co-ordinates (x, y) of the points which lie on the lesion periphery as well as the co-ordinates of the corneal centre, ie, geometric centre of the cornea. One calculates the centre of trephination and the optimal diameter of trephination as a function of a point situated on the lesion edge.     

Long-term stability of the posterior cornea after laser in situ keratomileusis

PURPOSE: To study long-term changes in posterior corneal elevation after laser in situ keratomileusis (LASIK) using Scheimpflug topography (Pentacam, Oculus, Inc.) in eyes 1 year after LASIK. SETTING: Department of Ophthalmology, Albany Medical Center, and a private practice, Albany, New York, USA. METHODS: One hundred two myopic eyes of 52 consecutive patients presenting for their 1-year follow-up were prospectively evaluated using the Pentacam to determine elevation changes to the posterior corneal surface between preoperative and 1-year postoperative measurements. Changes in posterior elevation were performed by comparing the best-fit sphere preoperatively and postoperatively with a fixed reference sphere determined by the central 9.0 mm preoperative cornea. Statistical and graphical analyses were performed. RESULTS: One hundred two post-LASIK eyes (mean correction -4.33 diopters; mean ablation depth 68.70 microm; mean estimated residual bed thickness 327 microm) had a mean posterior displacement of -0.47 microm +/- 3.48 (SD) (range -10.0 to +7 microm). The mean follow-up period was 13.6 months (range 8.8 to 19.3 months). CONCLUSIONS: In this population, no patient had significant forward protrusion of the posterior corneal surface a mean of 14 months after LASIK. The posterior cornea in post-LASIK myopic eyes was very stable. Contrary to results in previous studies, progressive changes to the posterior corneal surface did not routinely occur after LASIK performed within established parameters.     

Ex-vivo expansion of cornea stem cells. Experimental principles and initial clinical results

The ocular surface epithelium is composed of conjunctiva, limbus and cornea. These three compartments and an stable preocular tear film are crucial factors determining ocular surface health. Stem cells of the corneal epithelium are exclusively located at the limbus. Limbal stem cells are the ultimate source of regeneration of the entire corneal epithelium and in a variety of ocular surface diseases limbal stem cell deficiency has been observed to be a characteristic feature. Therefore renewal of the limbal stem cell population using different surgical techniques has been described as the only possible therapeutic strategy. Recent advancements in cell biology have enabled the development of new models of tissue engineering as a tool for tissue replacement. The aim of this review is to summarize recently reported clinical and experimental studies showing new developments in tissue engineering for the reconstitution of the ocular surface epithelium.     

国产化人工角膜植入兔眼的稳定性评估

目的 评价国产化人工角膜在兔眼角膜中的中长期稳定性.方法 实验研究.采用长耳大白兔10只,均选右眼作为国产化Moroz改良型永久性人工角膜植入眼,左眼为对照眼.手术分两期完成,一期手术用第三眼睑(软骨组织与人耳软骨有类似效果)加固角膜前层,联合自体结膜遮盖植入人工角膜支架;3个月后进行二期手术,植人人工角膜镜柱.全部手术完成后观察6个月以上.术后抗生素滴眼预防感染,定期观察,照相记录.最终行眼组织病理学检查.并与左眼进行对照.结果 除1只兔在二期术中因麻醉意外死亡外,9只兔均顺利完成手术和术后观察,术后各观察时间点人工角膜均在位,眼表血管化良好,未发生角膜组织融解、房水渗漏、高眼压、感染等严重并发症.组织病理学检查显示:加固的软骨组织均在位,人工角膜支架与周围组织紧密结合,有较活跃的纤维组织增生包绕,角膜炎症反应很轻.对侧眼无异常.结论 国产化人工角膜具有良好的生物相容性和中长期在位稳定性,用耳软骨加固和自体结膜遮盖有助于提高人工角膜稳定性.     

Vitamin A supply of the cornea

Results are presented indicating that epithelial cells from the bovine cornea accumulate [³H]retinol from the retinol-binding protein (RBP). The uptake process is saturable with characteristics similar to those of small intestinal cells. It therefore seems likely that vitamin A is delivered to the corneal cells by RBP. Different routes for the passage of RBP to the cornea were investigated. Tear fluid from a monkey did not contain even trace amounts of RBP. Aqueous humor from monkeys contained a significant quantity of prealbumin but only small amounts of RBP. In contrast, both RBP and prealbumin could be demonstrated in considerable amounts within the monkey cornea. Experiments in rabbits with radioactively labeled serum albumin as a model substance suggested that the scleral blood vessels in the limbus region are the likely source for most of the vitamin A required by the cornea.     

Effect of itraconazole on the cornea in a murine suture model and penetrating keratoplasty model

AIM: To investigate the anti-(lymph)angiogenic and/or anti-inflammatory effect of itraconazole in a corneal suture model and penetrating keratoplasty (PK) model. METHODS: Graft survival, corneal neovascularization, and corneal lymphangiogenesis were compared among itraconazole, amphotericin B, dexamethasone, phosphate buffered saline (PBS) and surgery-only groups following subconjunctival injection in mice that underwent PK and corneal suture. Immunohistochemical staining and analysis were performed in each group. Real-time polymerase chain reaction (RT-PCR) was performed to quantify the expression of inflammatory cytokines (TNF-alpha, IL-6) and vascular endothelial growth factor (VEGF)-A, VEGF-C, VEGFR-2, and VEGFR-3. RESULTS: In the suture model, the itraconazole group showed less angiogenesis, less lymphangiogenesis, and less inflammatory infiltration than the PBS group (all P<0.05). The itraconazole group showed reduced expression of VEGF-A, VEGFR-2, TNF-alpha, IL-6 than the PBS group (all P<0.05). In PK model, the two-month graft survival rate was 28.57% in itraconazole group, 62.50% in dexamethasone group, 12.50% in PBS group, 0 in amphotericin B group and 0 in surgery-only group. Graft survival in the itraconazole group was higher than that in the amphotericin, PBS and surgery-only group (P=0.057, 0.096, 0.012, respectively). The itraconazole group showed less total angiogenesis and lymphangiogenesis than PBS group (all P<0.05). CONCLUSION: Itraconazole decrease neovascularization, lymphangiogenesis, and inflammation in both a corneal suture model and PK model. Itraconazole has anti-(lymph)-angiogenic and anti-inflammatory effects in addition to its intrinsic antifungal effect and is therefore an alternative treatment option in cases where steroids cannot be used.     

环孢素A纳米粒滴眼液抗大鼠角膜移植术后排斥反应的实验研究

目的 探讨环孢素A纳米粒滴眼液对大鼠同种异体角膜移植术后角膜排斥反应的抑制作用。设计 实验研究。研究对象 Lewis大鼠50只,F344大鼠25只。方法 Lewis大鼠作为穿透性角膜移植受体分5组各10只,A组为阴性对照组,给予环孢素A纳米粒滴眼液基质点眼,B组为普通环孢素滴眼液组,C、D、E组分别为0.5%、1%、2%环孢素A纳米粒滴眼液组。F344大鼠为供体。术后各组滴用相应的滴眼剂,每日3次。术后14天内每日、14天后每2日拍摄角膜照片,观察至术后28天。术后14天取大鼠角膜组织行组织病理学检查。主要指标 角膜植片存活时间、角膜排斥反应指数（RI）、角膜组织病理改变。结果 A、B、C、D、E组角膜植片存活时间分别为8.1±1.37天、12.5±4.72天、12.11±4.46天、13.11±4.65天和13.56±3.88天（F=2.916,P=0.032）。普通环孢素滴眼液组,0.5%、1%、2%环孢素A纳米粒滴眼液组与基质组相比,差异具有统计学意义（P均<0.05）。普通环孢素滴眼液组与0.5%、1%、2%环孢素A纳米粒滴眼液组相比,差异无统计学意义（P均>0.05）。A、B、C、D、E组RI分别为7.3±0.67、5.5±1.35、6.11±1.45、5.22±1.48和4.77±1.20,（F=5.782,P=0.001）。普通环孢素滴眼液组、0.5%、1%、2%环孢素A纳米粒滴眼液组与基质组相比,RI有统计学意义（P均<0.05。普通环孢素滴眼液组与0.5%、1%、2%环孢素A纳米粒滴眼液组比较,差异无统计学意义（P均>0.05）。2%环孢素A纳米粒滴眼液组与0.5%环孢素A纳米粒滴眼液组比较差异具有统计学意义（P=0.03）。 结论 环孢素A纳米粒滴眼液与普通环孢素滴眼液具有相似的抑制角膜移植术后排斥反应的作用,2%环孢素A纳米粒滴眼液组效果优于0.5%浓度组。（眼科,2012,21：55-59）     

SMILE和FS-LASIK术治疗高度近视的疗效及对角膜和泪膜稳定性的影响

目的：探讨飞秒激光小切口角膜基质透镜取出术(SMILE)和飞秒激光制瓣的准分子激光角膜原位磨镶术(FS-LASIK)矫正高度近视的临床效果和对角膜、泪膜稳定性的影响。

方法：选取2016-08/2017-02我院收治的高度近视患者120例240眼作为研究对象,按照手术方式分为SMILE组(67例134眼)和FS-LASIK组(53例106眼)。SMILE组患者行SMILE术治疗,FS-LASIK组患者行FS-LASIK术治疗,比较两组患者术后视力和屈光度情况,分析手术对角膜和泪膜稳定性的影响。

结果：术后1、3mo,两组患者UCVA、BCVA和屈光度比较,差异均无统计学意义(P>0.05)。术前、术后1mo,两组患者BUT和SⅠt比较,差异均无统计学意义(P>0.05); 术后3mo,两组患者BUT和SⅠt比较,差异均有统计学意义(P<0.001),且SMILE组明显优于FS-LASIK组。术前和术后 1、3mo,两组患者角膜最薄点高度和角膜后表面高度比较,差异均无统计学意义(P>0.05)。

结论：SMILE和FS-LASIK术治疗高度近视均安全有效,有很好的可预测性和稳定性,但SMILE术后泪膜稳定性优于FS-LASIK术,两种术式在角膜生物力学稳定性方面无明显差异。     

猪角膜脱细胞基质的制备及生物相容性的实验研究

目的探讨猪角膜脱细胞基质（CACM）的制备方法，评价其组织学特性和生物相容性。方法应用1％TritonX-100去垢剂振洗，经冷冻干燥处理得到猪CACM，通过苏木精-伊红染色、扫描电镜观察行组织学检测。将猪CACM植入兔角膜板层间观察10周，取材做组织切片，评价其生物组织相容性。结果组织学检测证实角膜细胞完全脱净，胶原纤维排列疏松，板层结构同正常角膜；扫描电镜CACM表面未见细胞结构，纵切面上胶原板层间出现清晰的空穴状裂隙；CACM植入兔角膜层间后，观察期内未见明显排异反应。结论TdtonX．100可以有效地脱净角膜细胞，保存胶原排列的结构特征，经过冷冻干燥可形成多孔隙且胶原排列疏松的板层结构，适合作为载体材料，猪CACM与兔角膜生物相容性好。     

Normogenesis of the cornea and its modification by cyclophosphamide in the animal experiment

Animal experiments serving as models have hitherto been indispensable in order to explain pathogenetic processes in the development of malformations. The results presented here are contribution to studies on the normogenesis of the cornea in defined animal material (albino mice of Agnes Bluhm Jena-Halle stock). A single application of cyclophosphamide during embryogenesis caused inhibition malformations. Of these, different degrees of corneal hypoplasia and Peters' malformation are discussed in detail.