贝伐单抗对小鼠单纯疱疹病毒性角膜炎角膜新生血管和瘢痕形成的抑制作用

背景 单纯疱疹病毒性角膜炎(HSK)可诱导发生角膜新生血管和炎症反应,传统的治疗药物为阿昔洛韦(ACV),研究已证实贝伐单抗具有抑制新生血管的作用,但其是否对HSK发挥治疗作用值得研究. 目的 研究贝伐单抗对小鼠HSK角膜瘢痕和新生血管的抑制作用.方法 利用体外培养并感染的Vero细胞生产单纯疱疹病毒Ⅰ型(HSV-1),以无血清DMEM培养基于冰上对HSV-1进行10倍梯度稀释后制备成HSV-1液.选用SPF级雄性6～8周龄C57 BL/6小鼠200只,用0.6μl滴度为l×l0 7空斑形成单位(PUF)/ml的HSV-1行小鼠角膜基质注射以制备HSK模型,将模型眼分为单纯ACV注射组、ACV+贝伐单抗注射组和生理盐水注射组,按照分组分别于感染后5、8、11和14d选择角膜混浊评分为1分的模型眼结膜下注射50μg ACV、50 μg ACV+5 μl贝伐单抗和5μl生理盐水.此外采用紫外线照射均有轻度新生血管和瘢痕的6只模型小鼠双眼诱导HSK复发,于复发后0、2、4和6d行5μl贝伐单抗(25 mg/ml)右眼结膜下注射,左眼结膜下注射5 μl生理盐水.于造模后5、7、11、14和17d以及复发的0、2、4和6d行小鼠角膜裂隙灯显微镜检查并用角膜知觉测量仪行中央角膜敏感度检测;制备角膜铺片,采用免疫荧光检测法检测角膜中CD31和βⅢTubulin荧光表达以评估角膜新生血管和角膜神经纤维分布;采用Image J软件测定角膜新生血管面积和瘢痕面积. 结果 HSK成模率达80％以上,造模后7d和复发后2d角膜混浊最重,造模后15 d和复发后2d角膜新生血管面积最大.造模后模型眼中央角膜敏感度逐渐降低,于造模后9d下降到最低.ACV+贝伐单抗注射组角膜病变面积小于单纯ACV注射组,ACV+贝伐单抗注射组小鼠中央角膜敏感度为5.50±0.71,明显高于生理盐水注射组的0.50±1.41,差异有统计学意义(Z=-2.397,P=0.029).ACV+贝伐单抗注射组小鼠角膜病变面积增长率为(167.10±52.53)％,低于生理盐水注射组的(312.30±74.18)％,差异有统计学意义(Z=-1.992,P=0.046).实时荧光定量PCR显示造模后7d,模型眼角膜及同侧三叉神经节(TG)中胸苷激酶(TK)和感染细胞蛋白-27(ICP-27) mRNA相对表达量均较高,造模后45 d明显下降,诱导复发后2d TKmRNA和ICP-27 mRNA均再次升高,复发后7d表达量降至最低.造模后45 d同侧TG中均可见LAT mRNA表达量达峰值,诱导复发后2d相对表达量下降,复发后7d相对表达量再次升高,差异均有统计学意义(均P＜0.01).角膜铺片结果显示,造模后生理盐水注射组小鼠较正常对照小鼠角膜新生血管明显增加,角膜神经纤维明显减少,单纯ACV注射组和ACV+贝伐单抗注射组小鼠角膜新生血管少于生理盐水注射组,ACV+贝伐单抗注射组小鼠角膜神经纤维较生理盐水组注射组和单纯ACV注射组均增加.结论 贝伐单抗结膜下注射可抑制HSK模型小鼠角膜新生血管生成和瘢痕形成,与ACV联合应用时二者有协同作用.     

贝伐单抗抑制角膜移植术后新生血管及免疫排斥反应的作用

目的 探讨贝伐单抗对同种异体角膜移植术后免疫排斥反应的影响,评价其对角膜植片存活的疗效及作用机制。设计 实验研究。研究对象 近交系F344大鼠15只为供体,近交系Lewis大鼠30只为受体。方法 受体大鼠右眼行穿透性角膜移植术后随机数字法分为3组：对照组（A组）、贝伐单抗组（B组）、地塞米松组（C组）,每组10只。B、C组分别于术后0、3、6、9天结膜下注射40 μl贝伐单抗注射液及20 μl地塞米松磷酸钠注射液;A组不做处理。术后裂隙灯下观察14天,记录排斥指数（RI,为植片水肿、混浊、新生血管长入评分合计）和新生血管侵袭面积（IA）。术后14天,采用免疫荧光法检测角膜植片中CD4+、CD8+免疫细胞的表达。主要指标 角膜新生血管面积,免疫排斥时间,免疫细胞的数量。结果 术后7天IA分别为：A组（22.50±3.67）mm2,B组（14.21±2.79）mm2,C组（15.38±0.84）mm2;A组明显多于B组及C组（P=0.00和0.01）,B组与C组无显著差异（P=0.059）。术后14天IA分别为：A组（27.96±0.50）mm2,B组（18.76±2.73）mm2,C组（23.74±2.14）mm2。A组及C组多于B组（P=0.000）。免疫排斥时间A组8天,B组11天,C组13天。B组及C组角膜植片存活时间均长于A组（P均=0.000）。免疫细胞： CD4+阳性细胞数：A组（13.2±2.94）个,B组（6.14±1.07）个,C组（3.5±1.78）个;CD8+阳性细胞数：A组（14.4±2.44）个,B组（4.5±1.51）个,C组（3.38±1.68）个。术后14天,B组、C组角膜植片中CD4+、CD8+细胞亦明显少于A组（P均=0.000）。结论 结膜下注射贝伐单抗可有效抑制大鼠同种异体穿透性角膜移植术后新生血管的生长,并可能通过此作用延缓移植排斥反应,延长角膜植片存活时间。但贝伐单抗抗移植排斥反应疗效略逊于地塞米松。（眼科,2017, 26： 101-105）     

Avastin两种用药方法抑制大鼠角膜碱烧伤后早期新生血管增生的比较

目的:探讨avastin滴眼液和结膜下注射方法对SD大鼠角膜碱烧伤后早期新生血管增生的影响。方法:制作SD大鼠角膜碱烧伤动物模型,随机分成3组,A组(对照组)、B组(avastin滴眼液组)、C组(avastin结膜下注射组),每组20只。各组分别在烧伤后3,5,7,14d应用裂隙灯显微镜观察角膜新生血管(cornealneovascu-larization,CNV)增生情况,拍照并计算CNV面积变化。同时每组各处死大鼠5只,摘取角膜组织,采用免疫组织化学方法检测VEGFR-2的表达,免疫荧光法检测CD31表达。结果:A组在伤后各时段CNV增生面积均大于B,C组;B,C组伤后各个时段VEGFR-2及CD31的表达均显著低于A组,差异有统计学意义(P<0.01);而B,C两组之间CNV增生面积及伤后各时段VEGFR-2及CD31的表达差异无统计学意义(P>0.01)。结论:角膜碱烧伤后早期应用avastin滴眼液和结膜下注射均能有效地抑制CNV生成。     

贝伐单抗抑制角膜新生血管的实验研究

目的评价贝伐单抗（avastin）局部应用对小鼠角膜新生血管（CNV）的抑制作用。方法通过碱烧伤建立CNV模型,将30只Balb／c小鼠随机分成5组,A组贝伐单抗1mg／mL每日点眼2次;B组贝伐单抗3mg／mL每日点眼2次;C组贝伐单抗5mg／mL每日点眼2次;D组0．1％地塞米松每日点眼2次;E组生理盐水每日点眼2次。分别于术后3、7、14d观察CNV情况并拍照。术后第14天,处死全部小鼠,行CNV内皮细胞荧光标记,计算CNV所占全角膜面积的比例。结果各组CNV面积为A组（37．11±3．17）％、B组（29．75±3．56）％、C组（18．76±2．55）％、D组（20．91±2．75）％,E组（41．65±2．11）％。各组小鼠CNV面积依次为c组〈D组〈B组〈A组〈E组,C组同A、B、E组比较差异均有统计学意义（P〈0．01）,c组与D组比较差异无统计学意义（P=0．694）。结论局部应用贝伐单抗对小鼠角膜化学烧伤后的CNV有抑制作用。     

硅胶治疗碱性角膜烧伤的实验研究

目的 探讨硅胶对实验性角膜碱烧伤早期的治疗作用及疗效机制。方法：新西兰兔23只，单眼角膜中度碱烧伤，选择结膜囊内硅胶粉填充法（A组）和眼表局部硅胶粉隔吸法（B组）。C组为对照组，角膜碱烧伤后仅予生理盐水冲洗。第3，5周末摘取角膜行病理检查，烧伤后第7天摘取角膜行扫描电镜检查。结果 A组于第2周角膜溃疡形成，第2周末溃疡穿孔；B组无1例形成溃疡，第7周角膜透明或半透明。对照组多形核白细胞（PMN）大量浸润，角膜细胞显著增多，胶原纤维杂乱排列，新生血管丰富。B组PMN浸润明显减少，胶原排列轻度紊乱，血管少而疏，瘢痕组织少。电镜下见A组角膜烧伤区表面及细胞间明显的硅胶颗粒残留，B组未见硅胶颗粒。结论 在角膜碱烧伤早期应用硅胶治疗可获良效，但应避免硅胶粉直接与眼表接触。     

Avastin对大鼠角膜新生血管的抑制及超微结构的影响

目的:探讨Avastin对角膜新生血管形成及角膜内血管内皮生长因子(VEGF)的影响及其超微结构的影响。方法:Wistar大鼠96只随机分3组,采用碱烧伤的方法制备大鼠角膜新生血管模型;正常不烧伤组4只。烧伤后隔日球结膜下注射0.1mL生理盐水组32只,烧伤后隔日球结膜下注射Avastin0.1mL组32只,烧伤后隔日球结膜下注射地塞米松0.1mL组32只。碱烧伤术后在裂隙灯显微镜下观察大鼠角膜混浊度;宏观测量新生血管长度;组织病理切片HE染色作微血管计数;透射电镜观察超微结构的改变;免疫组化检测角膜VEGF的蛋白表达情况;CD34标记新生血管,显微镜下微血管计数方法研究角膜新生血管形成及抑制情况。结果:治疗组在3,7,10,14d较对照组角膜混浊程度轻(P<0.05);14d形成的新生血管数量较对照组少(P<0.05)。实验组新生血管微血管数量减少,VEGF蛋白表达下降,具有统计学差异。VEGF主要表达在角膜受损区的感染细胞胞质内,其出现时间与位置与角膜新生血管一致。Avastin和地塞米松均可有效抑制角膜新生血管,减少角膜内VEGF表达,两者无统计学差异,结膜下注射Avastin和地塞米松后,大鼠角膜超微结构无除烧伤后其它显著改变。结论:Avastin和地塞米松可抑制角膜新生血管,减少角膜内VEGF表达,对角膜的超微结构均无显著毒性。     

人羊膜作为载体体外培养兔角膜上皮细胞移植治疗碱烧伤动物的实验研究

目的观察培养生长于人羊膜的兔角膜上皮细胞使其扩增并移植治疗角膜碱烧伤的效果。为培养角膜上皮细胞移植技术及应用于临床实践提供最佳的理论和实验依据。方法新西兰白兔30只（30眼）,随机分为3组（n=10）,右眼制成碱烧伤模型。A组：角膜上皮细胞羊膜移植组;B组单纯羊膜移植组;C组为对照组（碱烧伤后不作任何移植）。术后观察角膜透明度、角膜新生血管及上皮修复情况,裂隙灯显微镜照相记录。3组均于术后1周、2周、1个月及3个月时各取1眼角膜标本行病理组织检查。结果A组除1眼移植片在第7天脱落外,所有移植片在术后3d水肿消退,角膜逐渐透明。B组移植片持续水肿,眼前段炎性反应稍重,但较碱烧伤对照组轻。C组角结膜高度水肿浑浊,烧伤后观察3个月未发现角膜恢复透明现象。病理组织检查显示：A组角膜及周边上皮细胞为多层结构,角膜新生血管消失,基质的炎性细胞浸润减退;B组覆盖上皮细胞表现为完整上皮细胞型,C组角膜浑浊,新生血管及肉芽组织形成。结论人羊膜作载体体外培养兔角膜上皮细胞移植重建角膜基底膜和角膜上皮结构治疗兔碱烧伤后的角结膜损伤是一种合理有效的方法。     

贝伐单抗联合曲安奈德治疗穿透性角膜移植术后新生血管

目的：观察球结膜下注射贝伐单抗和曲安奈德治疗穿透性角膜移植术后新生血管的临床疗效。
　　方法：对19例20眼因眼外伤行穿透性角膜移植术后3mo,新生血管增生达到Ⅲ度以上患眼随机分为四组。 A组：对照组;B组：贝伐单抗2.5mg(0.1mL);C组：贝伐单抗及曲安奈德各0.1mL;D 组：曲安奈德0.1mL;每月1次,共两次球结膜下注射药物。
　　结果：平均随访3a,B组和C组视力保持稳定或稍有增进,新生血管和免疫反应明显减退(P<0.01),患者眼痛、畏光流泪症状减轻。
　　结论：贝伐单抗联合曲安奈德在治疗穿透性角膜移植术后新生血管的过程中能够有效减退新生血管,并减轻排斥反应,对保持植片的透明性有积极的治疗作用。     

角膜新生血管对角膜损伤神经再生影响的研究

目的 探讨角膜新生血管对大鼠角膜损伤神经再生的影响。设计 实验研究。研究对象 SD大鼠。方法 采用随机数字表法将18只SD大鼠分为3组,每组6只。A组行缝线铲针角膜基质层间切开及缝线诱导新生血管术,术后0、3、7天给予结膜下注射贝伐单抗;B组行缝线铲针角膜基质层间切开及缝线诱导新生血管术;C组0、3、7天行结膜下注射贝伐单抗操作。分别在术后1天、1周、2周、4周,采用裂隙灯照相法观察记录角膜新生血管面积;角膜共聚焦显微镜记录神经长度。采用Cochet-Bonnet知觉仪测量缝线区的角膜知觉,采用Schirmer试验泪液线测量右眼的泪液分泌量。术后4周角膜全层铺片免疫荧光染色,记录上皮下神经密度。主要指标 角膜新生血管面积比、神经长度、上皮下神经密度、角膜知觉、泪液分泌量。结果 A、B组术后1、2周有角膜新生血管生长,术后4周消退闭锁,C组无角膜新生血管生长。A组术后1、2周新生血管面积比为（10.86±1.57）%和（1.87±0.69）%,分别小于B组的（25.42±2.65）%和（6.48±1.10）%（P均=0.000）。术后1天A、B组神经长度分别为（151.02±4.74）μm、（149.69±4.32）μm（P=0.306）;术后1、2、4周,A组神经长度均长于B组,分别为（193.84±2.25）μm与（155.73±2.98）μm、（217.15±2.08）μm与（166.21±2.41）μm、（220.70±1.41）μm与（203.76±1.74）μm（P均=0.000）。术后A、B组神经长度均有减少并有恢复趋势,C组无明显变化。术后4周A组损伤区上皮下神经密度（22.60%±2.02%）明显高于B组（9.41%±2.01%）（P=0.000）。A、B组上皮下神经短小稀疏、密度低,C组形态正常。A、B组术后1、2、4周时角膜知觉及泪液分泌量均无统计学差异（P均＞0.05）。A、B组均有下降并恢复趋势,C组无明显变化。结论 角膜新生血管可能抑制角膜损伤神经再生,抑制角膜新生血管有利于神经再生。（眼科, 2017, 26： 106-111）     

干扰素抑制角膜新生血管的实验研究

目的 :探讨局部应用干扰素对角膜新生血管是否具有抑制作用 ,为临床治疗角膜新生血管提供依据。方法 :2 5只大耳白兔皆以双眼碱烧伤制备角膜新生血管模型 ,随机分成实验和对照二组 :实验组分成A、B、C三组 ,B、C组给予不同深度α IFN隔日结膜下注射 ,A组给予α IFN点眼。碱烧伤后第 14天各组免以墨汁灌注法显示角膜新生务管 ,进行血管图像分析 ,统计学处理 ,扫描电镜下比较两组间新生血管形态差异。结果 :结膜下注射α IFN实验和对照血管图像分析 ,统计学处理后F >F0 .0 1,P <0 . 0 1;结膜下注射α IFN使角膜新生血管形成受到抑制破坏。结论 :结膜下注射α IFN具有抑制角膜新生血管作用 ,且剂量大者抑制作用显著。但α IFN局部点眼对角膜新生血管无抑制作用。     

Inhibition of experimental corneal neovascularization by using subconjunctival injection of bevacizumab (Avastin)

PURPOSE: To evaluate the effect of subconjunctival bevacizumab (Avastin) administration on corneal neovascularization (NV) in rabbits. METHODS: NV was induced by placing a suture at the corneal periphery of the right eye of 20 rabbits. Immediately after suturing and again 1 week later, rabbits were divided into 2 groups and administered a subconjunctival injection of normal saline (control) or bevacizumab (Avastin; 5 mg/0.2 mL), respectively. On day 14, digital photographs of the cornea were taken and analyzed to determine the area of the cornea covered by NV. In addition, immunohistochemical analysis was used to determine CD31 and vascular endothelial growth factor (VEGF) expression in corneal tissue. RESULTS: Analysis of digital photographs showed that there was less corneal NV in bevacizumab-treated eyes than in controls (P < 0.001, Mann-Whitney U test). In addition, there was less staining for VEGF and CD31 in corneas from bevacizumab-treated eyes than in control eyes. Subconjunctival bevacizumab injections were not associated with any complications during observation. CONCLUSIONS: Subconjunctival bevacizumab administration decreased suture-induced corneal neovascularization in rabbits.     

Effect of subconjunctival bevacizumab (Avastin) on experimental corneal neovascularization in guinea pigs

PURPOSE: To evaluate the effect of subconjunctival bevacizumab (Avastin) on experimental corneal neovascularization in guinea pigs. METHODS: Forty eyes of 40 guinea pigs were chemically cauterized with 75% silver nitrate and 25% potassium nitrate sticks. Fifteen eyes (group 1) received 2 subconjunctival injections of bevacizumab (0.1 mL, 1.25 mg) simultaneously with cauterization and 3 days later. Fifteen eyes (group 2) received 2 subconjunctival injections of bevacizumab (0.1 mL, 1.25 mg) 3 and 5 days after cauterization. Ten eyes (group 3, control group) received 2 subconjunctival injections of 0.1 mL of balanced salt solution 3 and 5 days after cauterization. After we determined the burn and neovascularization scores for all groups, the animals were killed on the 10th day. The percentages of neovascularization on the surface of the cornea were measured in terms of pixels on digital photographs. The average number of vessels at maximally vascularized areas was determined for each specimen. RESULTS: Neovascularization score was 1.1 +/- 0.3 in group 1, 2.46 +/- 1.3 in group 2, and 3.5 +/- 0.5 in the control group. The difference was statistically significant (P < 0.001). The area of neovascularization at the cornea surface was 15.6% +/- 10.1% in group 1, 19.74% +/- 11.2% in group 2, and 23.5% +/- 7.4% in the control group (P = 0.194). The average number of neovascular vessels at group 1 was significantly reduced in comparison with group 2 and the control group (P < 0.001). CONCLUSIONS: Subconjunctival injection of bevacizumab decreases the extent of chemically induced corneal neovascularization in guinea pigs. The antineovascular effect of bevacizumab is higher if the injection is performed simultaneously with the chemical cauterization.     

Avastin不同给药途径对兔角膜新生血管及超微结构的影响

目的研究阿瓦斯汀不同给药途径对兔角膜新生血管及超微结构的影响。方法健康新西兰大白兔50只,随机选取48只兔左眼制作碱烧伤角膜新生血管动物模型,造模成功后随机分为局部滴眼组(A组)、结膜下注射组(B组)、角膜基质注射组(C组)和模型对照组(D组),每组12只,未造模2只兔双眼为空白对照,于碱烧伤后第1天、第4天、第11天、第18天、第32天观察兔眼结膜充血、角膜混浊、新生血管生长情况,并进行眼前节照相,同时计算各实验兔眼角膜新生血管面积;第11天、第18天、第32天每组各处死4只兔,即刻抽取左眼房水检测血管内皮生长因子(vascular endothelial growth factor,VEGF)含量,取新生血管生长最旺盛的角膜组织分别固定,待做电镜、免疫组织化学等检测。结果角膜新生血管在碱烧伤后11d内生长迅速,第18天时有所消退,第32天时趋于相对稳定,A组、B组、C组角膜新生血管面积与D组在各个时间点之间比较,差异均有统计学意义(均为P<0.05)。碱烧伤后各时间点房水中VEGF浓度均高于正常水平,碱烧伤后11d内房水中VEGF浓度逐渐升高,至第18天时达到高峰,第32天时有所下降并趋于较稳定的水平。CD31在正常兔眼角膜组织中未见表达,A组、B组、C组阳性细胞数明显少于D组,差异均有统计学意义(均为P<0.05)。A组、B组、D组角膜超微结构在第11天、第18天、第32天时除碱烧伤损伤外无明显其他改变,在第18天、第32天时C组角膜超微结构损伤重于A组、B组、D组。结论局部滴眼、结膜下注射、角膜基质注射三种给药途径均对角膜新生血管有较好的抑制作用。局部滴眼与结膜下注射给药途径简单安全、效果稳定,未见对角膜超微结构产生明显影响;角膜基质注射虽短期效果显著,但对角膜超微结构产生了较明显的影响。     

结膜下注射Avastin抑制角膜新生血管的实验研究

目的:观察结膜下注射Avastin对实验性兔眼角膜新生血管(neovascularization,NV)的抑制作用,初步探讨作用机制。方法:应用5mm直径的加样器(末端附有棉片)吸入1mol/LNaOH接触新西兰兔右眼(20眼)中央角膜区烧灼30s,制作碱烧伤兔眼角膜NV模型。将实验兔随机分成2组,10眼(A组)碱烧伤后立即结膜下注射Avastin 2.5mg;其余10眼为对照组(B组),结膜下注射等量生理盐水。烧灼后次日每天裂隙灯观察角膜NV、角膜水肿情况,分别于3,7,14,21,28d裂隙灯照相并计算NV面积及NV抑制率。伤后7,28d各组随即处死5只实验兔,取角膜组织做石蜡切片行组织病理学检查及VEGF免疫组织化学检测。结果:两组兔眼伤后第1d角膜缘血管网明显扩张充血,3d时血管开始侵入角膜,7～14d时NV达到高峰,14～21d后NV稳定并逐渐回退。两组角膜NV长度、NV面积及角膜水肿程度存在差异(P<0.05);A组各时间点角膜NV抑制率为44.2%～55%。A组角膜上皮及实质层水肿较轻,NV较少,后弹力层基本完整,VEGF表达明显弱于B组。结论:结膜下注射Avastin对碱烧伤诱导的兔眼角膜NV形成及生长具有明显的抑制作用,可能通过下调VEGF表达发挥作用。     

Subconjunctival bevacizumab for corneal neovascularization

Objective To report the efficacy of subconjunctival bevacizumab injection in patients with corneal neovascularization (NV). Methods This retrospective interventional case study included two eyes of two patients with corneal NV due to aqueous-deficient dry eye with filamentary keratitis in the first case, and corneal graft failure in the second case. Patients received a subconjunctival injection of 2.5 mg (0.1 ml) bevacizumab. Morphologic changes were investigated by slit-lamp biomicroscopy and corneal photography. Results Corneal NV was dramatically regressed a week after injection in the first case. In the second case, minor vessels were regressed while the major one did not. No infection or inflammation was observed. No relapse was seen within the follow-up of two to three months. Conclusion Subconjunctival injection of bevacizumab may offer an additional strategy for the treatment of corneal NV.     

Bevacizumab inhibits corneal neovascularization in an alkali burn induced model of corneal angiogenesis

BACKGROUND: New and uncontrolled blood vessel development in the cornea is a pivotal process in the pathogenesis of several corneal diseases. These corneal diseases may finally cause blindness and managing them therapeutically is problematic. The data supporting a causal role for vascular endothelial growth factor in corneal neovascularization are extensive. This study aimed to evaluate the effect of subconjunctival bevacizumab (Avastin) on experimental corneal neovascularization in rabbits. METHODS: Chemical cauterization of the cornea was performed by touching central cornea with a 5-mm-diameter NaOH-soaked cotton applicator for 10 s in 20 eyes of 20 White New Zealand rabbits. The rabbits were then divided randomly into two equal groups. Bevacizumab (2.5 mg) was administered to 10 eyes (group 1) by a subconjunctival injection immediately after chemical cauterization of corneal surface. As a control, 10 eyes (group 2) received an injection of distilled water. Rabbits were examined daily for detection of the first signs of neovascularization. Three weeks later, the extent of corneal neovascularization was evaluated by direct examination and photograph analyses. Total corneal neovascularization area, degree of circumference involved and longest neovascular pedicle length were assessed. RESULTS: Bevacizumab significantly decreased the total neovascularization area (P < 0.009), the circumference involved (P < 0.011) and the longest neovascular pedicle length (P < 0.023). CONCLUSION: Local injection of bevacizumab has a significant effect on inhibition of alkali burn-induced corneal neovascularization. This shows the potential value of bevacizumab in the treatment of corneal neovascularization.     

The Effect of Bevacizumab on Corneal Neovascularization in Rabbits

Purpose

To determine the efficacy of topical application and subconjunctival injection of bevacizumab in the treatment of corneal neovascularization.

Methods

Corneal neovascularization was induced with a silk suture of the corneal stroma in 12 rabbits (24 eyes). One week after suturing, four rabbits were treated with topical bevacizumab at 5 mg/mL (group A) and another four rabbits were treated with topical bevacizumab 10 mg/mL (group B) in the right eyes twice a day for two weeks. A subconjunctival injection of bevacizumab 1.25 mg/mL was done in the right eyes of four rabbits (group C). All of the left eyes (12 eyes) were used as controls. The area of corneal neovascularization was measured after one and two weeks, and the concentration of vascular endothelial growth factor (VEGF) in corneal tissue was measured after two weeks.

Results

The neovascularized area was smaller in all treated groups than in the control group (p<0.001). Upon analysis of the neovascularized area, there was no significant difference between groups A and B. However, the mean neovascularized area of group B was significantly smaller than that of group C after two weeks of treatment (p=0.043). The histologic examination revealed fewer new corneal vessels in all treated groups than the control group. The concentration of VEGF was significantly lower in all treated groups compared to the control group (p<0.01), but no difference was shown between treated groups.

Conclusions

Topical and subconjunctival bevacizumab application may be useful in the treatment of corneal neovascularization and further study is necessary.     

环孢素A不同给药方式抑制兔眼穿透角膜移植术后免疫排斥反应的研究

背景环孢素A（CsA）是治疗角膜移植免疫排斥反应的主要药物,但合适的药物剂型和给药途径对提高药物利用度有重要意义。目的探讨CsA缓释微球结膜下给药、前房给药及CsA滴眼液局部点眼途径抑制兔眼穿透角膜移植术（PKP）后的排斥反应。方法健康清洁级成年新西兰白兔60只60只眼作为受体,健康清洁级青紫蓝兔30只60只眼作为供体。将受体兔按随机数字表法随机分为空白对照组、结膜下给药组、结膜下对照组、前房给药组、前房对照组和CsA滴眼液组,每组10只实验兔。所有实验兔行PKP。术毕结膜下给药组和前房给药组兔眼以相应的给药途径注射12g／LCsA缓释微球悬液0．1ml,结膜下对照组和前房对照组采取相应的给药途径注射空白微球悬液0．1ml,CsA滴眼液组每日应用质量分数1％（10g／L）CsA滴眼液点眼,空白对照组PKP术后不给予CsA药物。术后裂隙灯显微镜下定期观察各组术眼角膜植片的透明度、水肿情况、新生血管生长情况等,并计算术眼的排斥反应指数（RI）。分别于术前,术后3d,术后1、2、3周和术后1、2、3个月用Tono—pen眼压计测量眼压;分别于术后1个月、3个月获取各组植片行常规组织病理学检查。结果术后各组兔眼眼压较术前均明显下降,手术前后兔眼眼压的总体比较差异有统计学意义（F目目：29．210,P=0．000）;同一时间点各组兔眼眼压比较差异无统计学意义（F捆=0．254,P=0．938）。空白对照组、结膜下对照组及前房对照组于术后2～3周出现不同程度的角膜植片混浊和新生血管,术后4周时植片混浊加重,R1分别为8．60±1．52、8．60±0．55和8．80±0．84;结膜下给药组、前房给药组及CsA滴眼液组于术后3周时出现角膜新生血管,但未发现植片混浊,R1分别为4．40＋0．89、3．20±0．84和3．00±0．71,均明显低于空白对照组、结膜下对照组和前房对照组,差异均有统计学意义（P〈0．05）。其中前房给药组兔眼术后前房有轻度炎症反应,随时间延长逐渐减轻,至术后3个月时}肖失。组织病理学检查可见,空白对照组、结膜下对照组、前房对照组术眼角膜植片均明显增厚,有大量炎性细胞浸润和新生血管长人;而结膜下给药组、前房给药组和CsA滴眼液组植片的炎性细胞浸润明显减轻,新生血管减少。结论CsA缓释微球经不同途径给药均可抑制兔眼角膜移植术后的排斥反应,其中经前房给药途径的整体疗效较经结膜下给药途径更佳。     

Topical and subconjunctival bevacizumab for corneal neovascularization in an experimental rat model

Aims: To evaluate and compare the inhibitory effects of topical and subconjunctival bevacizumab on corneal neovascularization in a rat model. Methods: Twenty corneas of 20 rats were chemically cauterized with silver nitrate sticks. Animals were randomized into four groups: a control group that received only topical artificial tear drops twice daily, a subconjunctival injection group that received 1.25 mg (0.05 ml) of bevacizumab on the 1st, 4th, and 7th day, and two topical bevacizumab groups that received instillation of 4 or 12.5 mg/ml bevacizumab twice daily. Digital photographs of the cornea were taken and analyzed using an image analysis software program. On the 10th day, corneas were excised and examined histologically. Results: The mean percentage of the vascularized corneal area (%) in the control group was 63.32 ± 13.10 (mean ± SD), compared with 30.22 ± 15.73 in the subconjunctival injection group, 26.76 ± 10.23 in the 4-mg/ml topical group, and 25.52 ± 12.45 in the 12.5-mg/ml group. The differences between the control and each treatment group were significant (all p < 0.01). Further, histological examination revealed that each treatment group had fewer vessels than the control group (all p < 0.01). Conclusions: Both subconjunctival injection and topical use of bevacizumab are effective and safe in controlling corneal neovascularization.