Staphylococcus aureus causes acute inflammatory episodes in the cornea during contact lens wear

The aim of this investigation was to determine the ability of Staphylococcus aureus to cause keratitis during contact lens wear in the rabbit. Rabbits were fitted with hydrogel lenses and wore them on an extended wear schedule for 7 weeks. At the end of each week of wear, one drop of S. aureus was added to the eyes, and the eyes were monitored using slit lamp bio-microscopy, with subsequent microbial and histological studies of the cornea. In the presence of S. aureus, keratitis occurred after 3 weeks of lens wear, a condition that was characterized by diffuse infiltration of the peripheral cornea and limbal redness. In the absence of bacteria, there was no infiltration until week 6. Contact lens wear also prolonged the retention of bacteria in the eye. Extended contact lens wear and S. aureus caused non-ulcerative keratitis in a rabbit model, and disturbances in the ability of the eye to remove bacteria.     

软性角膜接触镜在治疗角膜穿孔中的应用

目的评价软性角膜接触镜在治疗角膜穿孔中的效果。方法9例(9眼)新鲜角膜穿孔伴前房消失,其中角膜溃疡致穿孔7例,角膜穿孔伤2例。所有患眼均配戴软性角膜接触镜治疗。戴镜期间根据不同病例选择用药,接触镜每周消毒1次。结果所有患眼1~2 d内前房恢复,22~40 d角膜溃疡愈合,5例病灶见新生血管长入,1例角膜溃疡前房反复消失,后行穿透性角膜移植,2例角膜穿孔伤口对合整齐。结论软性角膜接触镜在治疗角膜小穿孔中是一种安全有效的辅助治疗方法。     

配戴软性角膜接触镜对CCT和曲率的影响

目的：探讨配戴软性角膜接触镜(soft contact lens,SCL)对角膜中央厚度(central corneal thickness,CCT)、曲率的影响。方法：检测143例286眼配戴SCL患者的CCT、角膜地形图。154例308眼正常人为正常对照。比较连续配戴角膜接触镜不同年限患者和正常人的角膜厚度、角膜曲率的差异。结果：配戴SCL较短者(≤2a)的CCT与对照组相比并没有明显的变化;但戴镜时间超过2a的Ⅱ组和Ⅲ组与对照组及配戴SCL≤2a的Ⅰ组CCT相比时差异均有显著性(P<0.05);配戴SCL对角膜曲率无显著影响。结论：短期配戴SCL后角膜厚度尚无明显的变化,但随着戴镜时间的延长,角膜厚度逐渐变薄。而不论长期或者较短时间配戴SCL角膜曲率并无显著变化,但随着戴镜时间的延长角膜的不规则性有增加的趋势。     

软性角膜接触镜对角膜地形图的影响

目的:探讨软性角膜接触镜对角膜地形图的影响。方法:利用角膜地形图ORBSCANⅡ检查戴软性角膜接触镜患者41例81眼取镜当天及2wk后的角膜中央厚度,角膜中心的屈光度,散光,角膜前、后表面高度和曲率半径的变化。用统计学配对t检验分析结果。结果:角膜中央厚度,角膜屈光度,散光两组数据之间有显著性差异;角膜前、后表面高度和曲率半径两组数据之间无显著性差异。结论:戴软性角膜接触镜会影响角膜形态,角膜中央厚度,角膜屈光度,散光在脱镜2wk的变化有显著性差异。这种改变可能主要与角膜的供氧得到改善,角膜基质水肿减轻有关。     

长期持续配戴软性角膜接触镜对角膜中央厚度的影响

目的 :探讨长期持续配戴软性角膜接触镜者与无角膜接触镜配戴史者中央角膜厚度的差异。方法 :应用超声角膜测厚仪检测无角膜接触镜配戴史者 10 0例 (198眼 )和长期持续配戴软性角膜接触镜者 4 0例 (77眼 )的中央角膜厚度。结果 :无角膜接触镜配戴史者中 ,高度近视眼组与中低度近视眼组的角膜中央厚度平均值 ,差异无统计学意义 (P>0 .0 5 )。长期持续配戴软性角膜接触镜者平均中央角膜厚度为 (0 .5 4 7± 0 .0 30 )mm ,无角膜接触镜配戴史者平均中央角膜厚度为 (0 .5 5 7± 0 .0 4 8)mm ,两组比较差异有显著性 (P <0 .0 5 )。结论 :长期持续配戴软性角膜接触镜者角膜中央厚度明显薄于无角膜接触镜配戴史者     

影响近视眼角膜中央厚度的相关因素分析

目的:探讨影响近视患者角膜中央厚度的相关因素。方法:对近视眼患者2027例4002眼用超声角膜测厚仪、电脑验光仪、非接触眼压计、A超和角膜地形图分别测量角膜中央厚度、屈光度、眼压和内皮细胞计数等数据,并统计是否有配戴角膜接触镜史。对所得数据结果进行统计学分析。结果:有无配戴角膜接触镜史与角膜中央厚度为负相关(t=-4.475,P=0.000)。角膜中央厚度与眼压呈正相关(r=2.856,P=0.000);与屈光度数为负相关(r=-0.662,P=0.000),与内皮细胞计数无相关(r=0.003,P=0.065),建立多元回归方程:y=-0.626X1-0.662X2+0.003X3+2.856X4+500.606。结论:影响近视眼患者角膜中央厚度的主要因素是:配戴角膜接触镜史、屈光度数和眼压。     

长期配戴角膜接触镜对角膜内皮细胞的影响

目的 评价长期配戴角膜接触镜对角膜内皮细胞的影响。方法 将配戴角膜接触镜超过５年以上的患者根据不同的戴镜种类分成四组,每组又以年龄划分为亚组（２０～６０岁,每十岁一组）,与相应年龄段的无戴镜史的人群比较。使用ＫｏｎａｎＳＰ－８０００角膜内皮细胞显微镜测量和许角膜内皮细胞密度（ＣＤ）,角膜内皮细胞面积变异系数（ＣＶ）和六角形细胞频率（６４Ａ（％））。结果 ＰＭＭＡ镜片、低含水量软性镜片和低Ｄｋ值ＲＧ     

生物羊膜联合治疗性角膜软接触镜治疗角膜溃疡

目的:探讨角膜溃疡患者行生物羊膜联合治疗性角膜软接触镜的治疗效果及可行性。方法:对33例35眼角膜溃疡患者进行削除病变组织,在植床平铺与溃疡面大小相仿生物羊膜(溃疡较深行多层羊膜覆盖填塞),将稍大于溃疡灶的外层生物羊膜与周围正常角膜组织间断缝合,术后第2d配戴治疗性角膜软接触镜,并针对不同病因的角膜溃疡点用治疗性眼药水。结果:所有患者1～2d内恢复前房,1wk左右局部刺激症状明显好转,溃疡平均愈合时间30～45d,5例患者见新生血管长入,角膜不同程度的瘢痕形成,2例角膜溃疡前房反复消失,后行穿通性角膜移植。治疗后视力均有不同程度的提高。结论:此方法能有效修复角膜溃疡组织,为后期角膜移植创造良好的局部条件。     

绷带型角膜接触镜在角膜深层异物取出术后的应用

目的:观察绷带型角膜接触镜在角膜深层异物取出术后的临床疗效.方法:对角膜深层异物取出术后患者46例46眼,随机分成戴镜组和对照组各23例23眼,两组均实施角膜深层异物取出术,比较两组患者术后1、3、7d的眼部疼痛程度及术后7d角膜上皮愈合情况.结果:术后1、3、7d两组患者眼部疼痛程度评分:戴镜组分别为0.44±0.26、0.26±0.14、0.12±0.08分,对照组分别为1.26±0.44、1.02±0.38、0.68±0.26分,两组同一时段的眼部疼痛程度差异有统计学意义(P<0.05);术后7d两组患者角膜上皮缺损情况:戴镜组角膜上皮完全修复21眼(91%),对照组上皮完全修复14眼(61%),差异有统计学意义(P<0.05).结论:配戴绷带型角膜接触镜能有效缓解角膜深层异物取出术后患者的眼部刺激症状,能加速术后角膜创面的修复.     

软性角膜接触镜在翼状胬肉切除联合自体角膜缘干细胞移植术后的应用

目的：探讨翼状胬肉切除联合自体角膜缘干细胞移植术后应用软性角膜接触镜的临床效果。

方法：选择单侧翼状胬肉患者90例90眼,按照随机数字表法分为两组：观察组45例45眼翼状胬肉切除联合自体角膜缘干细胞移植术后应用软性角膜接触镜,对照组45例45眼翼状胬肉切除联合自体角膜缘干细胞移植术后不应用软性角膜接触镜。对比两组患者角膜愈合时间,术后1、3、5、7d角膜刺激症状评分,术后 24、48h两组患者疼痛程度(VAS评分),翼状胬肉复发率。

结果：对照组角膜愈合时间(5.38±1.67d)长于观察组(3.10±1.12d); 术后角膜刺激症状评分、VAS评分高于观察组,差异有统计学意义(P<0.05); 两组患者翼状胬肉复发率比较差异无统计学意义(P>0.05)。

结论：翼状胬肉切除联合自体角膜缘干细胞移植术后应用软性角膜接触镜可减少创面愈合时间,减轻术后角膜刺激症状,同时对胬肉复发率无影响。     

Effects of alpha-toxin-deficient Staphylococcus aureus on the production of peripheral corneal ulceration in an animal model

PURPOSE: To examine the role of Staphylococcus aureus alpha-toxin in contact lens-induced peripheral ulceration (CLPU). MATERIALS AND METHODS: Proteolytic enzyme, hyaluronidase, alpha-toxin, and beta-toxin production by S. aureus 8325-4 and its alpha-toxin-deficient mutant (S. aureus DU1090) were examined. Using a rabbit model of CLPU, animals were fitted with hydrogel contact lenses colonized by either S. aureus 8325-4 or the mutant strain. The clinical presentation, bacterial cultures, and histology of the ulceration were examined. RESULTS: Both strains of S. aureus produced similar levels of caseinase, gelatinase, elastase, hyaluronidase, and beta-toxin. S. aureus DU1090 induced weaker haemolysis of rabbit blood cells than S. aureus 8325-4. Ulceration in the S. aureus DU1090 eye was less frequent and less severe than that caused by S. aureus 8325-4. CONCLUSIONS: The enzyme production profile of S. aureus DU1090 was similar to the parent strain. S. aureus strains may produce CLPU-like lesions irrespective of alpha-toxin production, but severe infectious lesions are produced only in the presence of alpha-toxin.     

The effects of fenestrating soft contact lenses on corneal swelling: a re-examination

Previous studies have suggested that central corneal oedema during hydrogel lens wear can be reduced by placing peripheral fenestrations in the lens. In this study, optical pachometry was used to monitor central and peripheral corneal swelling in response to a peripherally fenestrated hydrogel lens. The experiment was conducted in a double-masked, randomized manner on 10 unadapted subjects. Fenestrations did not alter central corneal oedema, but peripheral corneal oedema was reduced by 34% (p > 0.001). Fenestrations may therefore provide a useful strategy for minimizing lens-induced corneal oedema. Clinical trials with fenestrated lenses are now indicated.     

角膜胶原交联联合RGPCL治疗圆锥角膜的临床研究

目的：观察角膜胶原交联(CXL)联合RGPCL治疗圆锥角膜的临床效果。

方法：选取2015-01/2017-01在我院行去上皮加速CXL治疗的进展期圆锥角膜患者51例51眼,根据治疗方式分为A组(30眼,行CXL后配戴框架眼镜)和B组(21眼,行CXL后配戴RGPCL)。分别于治疗前和治疗后12mo观察两组患者最佳矫正视力(BCVA)、等效球镜度(SE)及角膜前后表面形态。

结果：治疗前,两组患者BCVA、SE及角膜形态各参数\〖角膜前表面最小曲率和最大曲率(K1和K2)、平均角膜曲率(Km)、角膜最大曲率(Kmax)、角膜顶点厚度、角膜最薄点厚度\〗均无明显差异(P>0.05)。治疗后12mo,B组患者BCVA优于A组(0.11±0.03 vs 0.26±0.16),角膜顶点厚度低于A组(431.8±14.41μm vs 461.38±32.68μm)(均P<0.05),其余各参数两组之间均无明显差异(P>0.05)。

结论：CXL治疗圆锥角膜可延缓或控制圆锥角膜的进展,联合配戴RGPCL可有效改善矫正视力。     

绷带型角膜接触镜在上睑下垂术后早期的应用价值

目的　探讨上睑下垂术后早期应用绷带型角膜接触镜的临床效果。方法　将先天性上睑下垂矫正术后眼睑闭合不全患者２１例（３２眼）随机分为Ａ组（戴镜组）和Ｂ组（传统组）。２组均按常规方法行额肌肌瓣悬吊术,术后Ａ组均连续配戴绷带型角膜接触镜,每１４ｄ更换１次;Ｂ组均根据传统的方法滴滴眼液和涂眼膏,术前及术后３ｄ、７ｄ、１个月、３个月观察角膜荧光素染色、泪膜破裂时间、泪液分泌试验、患者主觉症状等以评价治疗效果。结果　Ａ组和Ｂ组术后各时间段泪液分泌量均无明显改变,但两组在术后早期均出现了角膜上皮染色,染色点较术前增加,术后３ｄ角膜荧光染色评分明显增加,但两组间差异无统计学意义（Ｐ＝０．６９８）;术后７ｄ、１个月荧光染色评分仍继续增加,且两组间差异有统计学意义（Ｐ＝０．０３２、０．０１０）;术后３个月角膜染色基本消失,两组间差异无统计学意义（Ｐ＝０．５５７）。泪膜破裂时间术前无明显差异,术后３ｄ两组均较术前减少,术后７ｄ、１个月Ａ组较前逐渐变长,Ｂ组变化不明显,两组间差异有统计学意义（Ｐ＝０．０４、０．０２、０．０１）,术后３个月两组均有所恢复,组间差异无统计学意义（Ｐ＝０．７４３）。主觉症状评分术前两组间差异无统计学意义（Ｐ＝０．８３６）,术后３ｄ患者主觉症状明显增加,但Ａ组症状明显较Ｂ组减轻,两组差异有统计学意义（Ｐ＝０．０３５）;术后７ｄ、１个月两组主觉症状均有所减轻,但两组差异仍有统计学意义（Ｐ＝０．０３１、０．０１７）;术后３个月两组主觉症状逐渐消失,组间差异无统计学意义（Ｐ＝０．６９２）。结论　上睑下垂矫正术后早期配戴硅水凝胶角膜接触镜,不仅可使患者早期用眼,而且可促进患者泪膜稳定,减轻眼部不适感,降低发生暴露性角膜炎的风险。     

硬性透气性角膜接触镜与软性角膜接触镜对中低度近视患者角膜形态的影响

目的　探讨屈光不正患者长期配戴软性角膜接触镜（soft contact lens,SCL）和硬性透气性角膜接触镜（rigid gas permeable contact lense,RGPCL）对角膜形态参数的影响。方法　收集视光学中心验配角膜接触镜的屈光不正患者60例(120眼),按照患者配戴SCL或RGPCL分为SCL组和RGPCL组（两组均为30例60眼）,在戴镜前及戴镜后1 a、2 a测量2组患者中央角膜厚度、内皮细胞密度、六角形细胞比例及变异系数,并对2组数据进行对比。结果　SCL组:戴镜后2 a,中央角膜厚度(509±31)μm较戴镜前(549±26)μm明显下降（P<0.05）;角膜内皮细胞密度为(2819.3±169.2）个·mm^-2,较戴镜前密度(3182.6±162.3）个·mm^-2减少;六角形细胞比例（51.52±4.69）%较戴镜前（61.45±4.58）%降低（P<0.05）;内皮细胞变异系数（39.14±3.15）较戴镜前（33.47±2.83）增加（P<0.05）。RGPCL组戴镜前后中央角膜厚度、角膜内皮细胞密度、六角形细胞比例及内皮细胞变异系数比较,差异均无统计学意义（均为P>0.05）。结论　与配戴SCL相比,配戴RGPCL对屈光不正患者的角膜形态和功能影响不明显,更适合长期配戴。     

Detection of virulence factors in Serratia strains isolated from contact lens‐associated corneal ulcers

Purpose: This paper reports on the microbiological findings pertaining to three Serratia isolates from soft contact lens‐related corneal ulcers, which represent a complication of contact lens wear reported with increasing frequency. Methods: Bacterial identification and antibiotic susceptibility testing were performed using the Vitek system. Serratia’s ability to form biofilm, produce gelatinase, elastase and alkaline protease, and invade human corneal epithelial (HCE) cells was investigated. The isolates’ susceptibility to the following disinfectants was tested: (a) ReNu MultiPlus^®, containing polyaminopropyl biguanide 0.0001%; (b) Opti‐Free Express^®, containing polyquaternium‐1 0.001% and myristamidopropyldimethylamine 0.0005%; (c) Opti‐Free Replenish^®, containing polyquaternium‐1 0.001% and myristamidopropyldimethylamine 0.0005%, and (d) Oxysept Comfort^®, a one‐step 3% hydrogen peroxide‐catalase system. Results: Two Serratia marcescens and one Serratia liquefaciens were identified. All the strains were susceptible to aminoglycosides and fluoroquinolones. No isolate formed biofilm or significantly invaded HCE cells; all produced alkaline protease and gelatinase, but not elastase. Opti‐Free Express^® and Opti‐Free Replenish^® were active against S. liquefaciens, but failed to kill the S. marcescens isolates within the minimum recommended time (6 hours). ReNu MultiPlus^® needed 6 hours to kill one strain of S. marcescens, which is 2 hours more than recommended. Conversely, Oxysept Comfort^® was always effective within the minimum recommended time (6 hours). Conclusions: The ability to produce alkaline protease and gelatinase may play a major role in the pathogenesis of contact lens‐related Serratia keratitis. Several types of contact lens solutions may be ineffective in eradicating Serratia from contaminated contact lens cases within the minimum recommended time. Only exposure to Oxysept Comfort^® was always effective against Serratia in this study.     

新鲜羊膜移植联合治疗性软性角膜接触镜在治疗翼状胬肉中的应用

目的：探讨新鲜羊膜移植联合治疗性软性角膜接触镜在治疗翼状胬肉中的临床效果,并总结其临床价值。

方法：回顾性分析2010-01/2011-06在我院行翼状胬肉切除联合新鲜羊膜移植术患者200例220眼,其中100例110眼联合配戴治疗性软性角膜接触镜(试验组),其余患者作为对照组(100例110眼),并对两组患者术后的临床效果进行比较分析。

结果：对照组术后角膜上皮修复时间为2～7(平均3.8)d,术后随访观察6～18mo,有9眼复发,复发率为8.2%; 试验组术后角膜上皮修复时间为1～5(平均2.5)d,随访观察6～18mo,其中有5眼复发,复发率为4.5%,两组疗效比较,差异有统计学意义(P<0.05)。同时,我们也发现配戴角膜接触镜后术后早期刺激症状明显减轻。

结论：翼状胬肉切除联合羊膜移植并配戴治疗性软性角膜接触镜的术后临床效果明显优于翼状胬肉切除联合新鲜羊膜移植术。配戴治疗性软性角膜接触镜可缩短术后角膜上皮的修复时间,可有效降低翼状胬肉术后的复发率,并且可以在一定程度上缓解术后因角膜上皮缺损而导致的畏光、流泪、异物感及眼痛等术后刺激症状。