A comparison of intravitreal piperacillin/tazobactam with ceftazidime in experimental Pseudomonas aeruginosa endophthalmitis

In the present study, we aimed at comparing the efficacies of intravitreal piperacillin/tazobactam and ceftazidime applications in the treatment of experimental Pseudomonasaeruginosa endophthalmitis in rabbit eyes. Twenty-four New Zealand white albino rabbits were divided into three groups (n=8 in each), and the right eyes received 0.1 ml intravitreal injections of P. aeruginosa suspension. The left eyes served as uninfected control and were injected with 0.1 ml of saline solution. The right eyes of rabbits in group 1 were treated with intravitreal injection of 250 microg/0.1 ml piperacillin/tazobactam 24 hr after intravitreal inoculation of P. aeruginosa, whereas group 2 eyes received intravitreal 1 mg/0.1 ml ceftazidime. Group 3 eyes received no treatment and served as infected controls. Clinical, microbiological and histopathological evaluations of the eyes in each group were performed on the 1st, 3rd, and 6th day after the inoculation of P. aeruginosa. The mean clinical scores of each group were similar at the first day after P. aeruginosa inoculation (P>0.05). At the 6th day, there was no statistically significant difference in mean clinical scores between group 1 and 2, but mean clinical score of group 3 was significantly higher (P<0.001). Microbiological analysis and histopathological scoring demonstrated no statistically significant difference between group 1 and 2 (for each, P>0.05). Group 3 eyes had a significantly more CFU/ml and higher histopathological score (for each, P<0.001). In conclusion, intravitreal application of 250 microg/0.1 ml piperacillin/tazobactam seems to be effective in the treatment of P. aeruginosa endophthalmitis in rabbits, but is not superior to intravitreal ceftazidime application. Therefore, intravitreal piperacillin/tazobactam may be a useful alternative to ceftazidime for pseudomonal endophthalmitis.     

The efficacy of piperacillin/tazobactam in experimental Pseudomonas aeruginosa endophthalmitis: a histopathological and microbiological evaluation

PURPOSE: To investigate the efficacy of intravitreal piperacillin/tazobactam (250 microg/0.1 ml) in the treatment of experimental Pseudomonas aeruginosa endophthalmitis in rabbits. MATERIALS AND METHODS: Twenty New Zealand White albino rabbits were used in this study. The rabbits were divided into two groups (10 rabbits in each), and the right eyes were treated with 0.1 ml intravitreal injections of P. aeruginosa suspension (ATCC 27853, 2 x 10(4) CFU); the left eyes served as uninfected control and were injected with 0.1 ml of saline solution. The right eyes of rabbits in group 1 (n = 10) received intravitreal injection of 250 microg piperacillin/tazobactam 24 h after intravitreal inoculation of P. aeruginosa. Group 2 eyes (n = 10) received no treatment and served as infected controls. Clinical examination of the eyes in each group was performed on the first, third, and sixth day after the inoculation of P. aeruginosa. After the last ophthalmic examination, 0.1 ml vitreous aspirates were obtained for microbiological analysis, and then the eyes were enucleated for histopathological evaluation. RESULTS: The mean clinical scores of group 1 and group 2 at the first day after P. aeruginosa inoculation were similar (p > 0.05). At the sixth day, the mean clinical score of group 1 was significantly lower when compared with group 2 eyes (p < 0.001). Microbiological analysis revealed that group 2 had a significantly more cfu/ml than group 1 (p < 0.001), and the mean histopathological score of group 2 was significantly higher than group 2 (p = 0.009). CONCLUSIONS: Intravitreal application of 250 microg/0.1 ml piperacillin/tazobactam seems to be effective in the treatment of P. aeruginosa endophthalmitis in rabbits. Intravitreal piperacillin/tazobactam combination may be a new therapy for P. aeruginosa endophthalmitis.     

Intravitreal taurolidine against experimental Staphylococcus epidermidis endophthalmitis in rabbits

PURPOSE: Taurolidine is a broad spectrum, non-antibiotic antimicrobial agent, not previously tested against infectious endophthalmitis. The efficacy of intravitreal taurolidine in the treatment of experimental Staphylococcus epidermidis endophthalmitis was evaluated and compared with vancomycin in a rabbit model. METHODS: The right eyes of 34 albino rabbits were infected with an intravitreal inoculum of S. epidermidis (10(5) colony-forming units/0.1 ml). The right eyes of four rabbits (group 7) were not infected and served as uninfected controls. 24 hours after inoculation of bacteria the animals were divided into the following treatment groups: group 1 (7 rabbits) received intravitreal taurolidine at 24 hours and group 2 (7 rabbits) received at 48 hours. Group 3 (7 rabbits) received vancomycin at 24 hours and group 4 (7 rabbits) at 48 hours. Group 5 (3 rabbits) received polyvinylpyrrolidone at 24 hours and group 6 (3 rabbits) at 48 hours. Clinical scoring was performed at 24, 48 and 72 hours. At 72 hours post inoculation, vitreous samples were collected for quantitative microbiological studies and then, the eyes were enucleated for histopathological scorings. RESULTS: The clinical and histopathological examinations revealed significant amelioration of inflammation in eyes treated with taurolidine and vancomycin when compared with polyvinylpyrrolidone. The eyes treated with taurolidine also had significantly lower colony forming units than the eyes treated with polyvinylpyrrolidone and taurolidine rendered many eyes sterile. CONCLUSION: Taurolidine is expected to be a potential agent for treatment of S. epidermidis endophthalmitis.     

The efficacy of intravitreal levofloxacin and intravitreal dexamethasone in experimental Staphylococcus epidermidis endophthalmitis

This study was designed to investigate the efficacy of intravitreal levofloxacin, and intravitreal levofloxacin and dexamethasone combined in Staphylococcus epidermidis endophthalmitis. Albino rabbits (n = 25), infected with an intravitreal inoculum of S. epidermidis (1.0 x 10(5) colony forming units/0.1 ml), were divided into five groups (n = 5). Groups 1 and 2 received treatment 24 h after the inoculation, and groups 3 and 4 48 h after the inoculation. No treatment was given to the control group. Treatment efficacy was assessed by vitreous culture, clinical examination and histopathology. Five days after treatment, groups 1 and 2 had significantly lower clinical scores than the control group (p = 0.004, p = 0.007). The culture results of the treatment groups were sterile. The histopathological scores of the treatment groups were lower than the control group (p = 0.007). Studies on retinal toxicity and dose-response relation are needed to prove the efficacy of levofloxacin in S. epidermidis endophthalmitis.     

Determination of nontoxic concentrations of piperacillin/tazobactam for intravitreal application. An electroretinographic, histopathologic and morphometric analysis

BACKGROUND: To investigate the highest nontoxic intravitreal dose of piperacillin/tazobactam in rabbits. MATERIAL AND METHODS: Forty New Zealand white albino rabbits were used in this study. The rabbits were divided into four equal groups (10 rabbits in each) and the right eyes were treated with 0.1 ml intravitreal injections of 1,000 microg piperacillin/tazobactam in group 1, 500 microg in group 2, 250 microg in group 3, and 100 microg in group 4. The left eyes served as controls and were injected with 0.1 ml of saline solution. Ganzfeld electroretinogram (ERG) was performed on all eyes before and after 4 weeks of intravitreal injections. Then, the rabbits were killed and the eyes were enucleated for histopathological evaluation of the retina. Retinal sections were evaluated by morphometric analyses on cell counts of ganglion cell layer and thickness of the various retinal layers. RESULTS: Baseline ERGs were similar among the groups (p > 0.05). After 4 weeks of injection, there were a reduction of the b-wave amplitude and extension of the b-wave implicit time in photopic and scotopic ERGs in group 1 and group 2 when compared with controls (for each, p < 0.001). Intravitreal injection of 100 and 250 microg piperacillin/tazobactam did not cause any deterioration of the b-wave of ERGs throughout the follow-up period of 4 weeks (for each, p > 0.05). After morphometric analysis of retinal sections in all groups, there were no statistically significant differences in the mean number of surviving ganglion cells, thickness of the whole retina and the inner plexiform layer compared with controls (p > 0.05). CONCLUSION: 250 microg/0.1 ml piperacillin/tazobactam is the highest nontoxic dose to the normal retinas of adult albino rabbits as intravitreal injection. Piperacillin/tazobactam may be a new, potentially important drug in the treatment of endophthalmitis as it has a broad antimicrobial spectrum.     

Treatment of experimental methicillin-resistant Staphylococcus epidermidis endophthalmitis with intravitreal vancomycin

Endophthalmitis remains a dreaded complication of intraocular surgery and penetrating eye trauma. Subconjunctival, topical, and systemic antibiotics have been largely ineffective in the treatment of endophthalmitis, whereas intravitreal antibiotics have proved efficacious. Methicillin-resistant Staphylococcus epidermidis has become an important pathogen in many infections, including endophthalmitis. Toxicity, clearance, and efficacy of intravitreal vancomycin were evaluated in the treatment of experimental methicillin-resistant S. epidermidis endophthalmitis. No evidence of retinal toxicity was found and therapeutic levels were demonstrated six days after injection. The treated rabbit eyes showed a marked beneficial effect when compared to the untreated eyes. If experience confirms the safety of intravitreal vancomycin in human eyes, vancomycin should be considered the drug of choice for methicillin-resistant S. epidermidis endophthalmitis.     

High dose intramuscular methylprednisolone in experimental Staphylococcus aureus endophthalmitis.

We attempted to determine whether treatment using intramuscular methylprednisolone plus intravitreal vancomycin decreased ocular inflammation and preserved retinal function better in experimental Staphylococcus aureus (S. aureus) endophthalmitis than treatment with intravitreal vancomycin alone. Sixteen rabbits received intravitreal inoculations in both eyes with S. aureus and the rabbits were divided into two groups (group I and group II) of eight rabbits each. Group I rabbits were treated with one injection of intravitreal vancomycin in each eye at either 24, 36, 48 or 72 hours after bacterial inoculation followed by seven consecutive days of high dose intramuscular methylprednisolone (30 mg/kg per day). Group II rabbits were treated with only one intravitreal injection of vancomycin in each eye at equivalent time intervals as in Group I. Clinical evaluations of ocular inflammation were performed by slit-lamp biomicroscopy and indirect ophthalmoscopy. Electroretinography (ERG) was performed eight days after bacterial inoculation to assess retinal function in all eyes. The combination of intramuscular methylprednisolone and intravitreal vancomycin resulted in a degree of ocular inflammation equal to eyes treated with intravitreal vancomycin alone at all treatment intervals. ERG responses were not significantly different in either group. A single intravitreal injection of vancomycin plus daily intramuscular methylprednisolone for seven days were found neither to decrease ocular inflammation nor preserve retinal function better than a single intravitreal injection of vancomycin in our experimental model of S. aureus endophthalmitis.     

Inflammatory response in experimental Staphylococcus and Pseudomonas endophthalmitis.

Staphylococcus epidermidis [2.0 x 10(4) colony-forming units (CFU)/0. 1 ml] and Pseudomonas aeruginosa (2.0 x 10(3) CFU/ml) were inoculated in the vitreous humor of rabbits. In S. epidermidis endophthalmitis, the numbers of microorganisms reached a maximum (4. 1 x 10(7) CFU/ml) at day 2 after inoculation and then declined spontaneously. However, clinical scores were observed to be worst at day 5. In P. aeruginosa endophthalmitis, the numbers of microorganisms reached a maximum (9.3 x 10(6) CFU/ml) 36 h after inoculation. However, culture results were persistently positive until day 15. Electroretinogram (ERG) b-wave amplitudes in S. epidermidis endophthalmitis continued to decrease from day 3 (>24%) until day 5, and then recovered to the preinoculative level of amplitudes at day 7. ERG b-wave amplitudes in P. aeruginosa endophthalmitis continued to decrease after 24 h (>24%). ERG b-wave amplitudes from day 7 to day 15 were flat. The inflammatory response continued under the absence of microorganisms in S. epidermidis endophthalmitis. The time in which a maximum in the number of microorganisms was reached was earlier than that in the clinical examination scores in both S. epidermidis and P. aeruginosa endophthalmitis.     

Effects of intravitreal moxifloxacin and dexamethasone in experimental Staphylococcus aureus endophthalmitis

PURPOSE: To evaluate the effects of intravitreal moxifloxacin and moxifloxacin and dexamethasone combination in an experimental rabbit model of Staphylococcus aureus endophthalmitis. METHODS: The right eyes of 24 rabbits weighing 2 to 3 kg were used. Ten thousand colony-forming units (CFU) of S. aureus in 0.1 ml saline solution were inoculated into the vitreous cavity. The eyes were randomly assigned to one of the four groups equally. Twenty-four hours after the inoculation of S. aureus, group 1 received 50 microg moxifloxacin, group 2 received 50 microg moxifloxacin plus 400 microg dexamethasone, and group 3 received 1 mg vancomycin intravitreally. No treatment was given to group 4. Clinical examination scores were recorded. Vitreous aspirates were obtained for microbiological analysis just before sacrifice, and the eyes were enucleated for histopathologic examination. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: In all treatment groups, mean number of CFU and histopathologic score were significantly lower compared with control group (p<0.05), and the difference between treatment groups was not statistically significant (p>0.05). The clinical score was not significantly different between groups (p>0.05). CONCLUSIONS: Intravitreal injection of 50 microg moxifloxacin was effective in the treatment of S. aureus endophthalmitis. Bacteriological, histopathologic, and clinical outcomes after treatment using moxifloxacin, moxifloxacin and dexamethasone combination, and vancomycin were comparable. Intravitreal moxifloxacin may be an option in the treatment of S. aureus endophthalmitis.     

玻璃体腔注射阿霉素和万古霉素治疗眼球穿孔伤并发症的实验研究

目的观察玻璃体腔注射阿霉素和万古霉素对感染性眼内炎及外伤性增生性玻璃体视网膜病变（PVR）的抑制效果。方法40只新西兰白兔随机分为4组,每组10只。右眼建立外伤性出血性眼球穿孔伤模型,左眼为空白对照眼。4个组中生理盐水组,玻璃体腔注射生理盐水0．1mL;阿霉素组,注射阿霉素2．5μg（0．1mL）;万古霉素组,注射万古霉素1．0mg（0．1mL）;联合用药,注射阿霉素2．5μg（0．1mL）及万古霉素1．0mg（0．1mL）。以裂隙灯显微镜观察眼前段炎症情况,炎症持续超过2周者行玻璃体微生物学培养;直接检眼镜观察外伤性PVR情况。结果联合用药组PVR程度低于生理盐水组（P=0．023）及万古霉素组（P=0．034）;生理盐水组、阿霉素组各发生细菌性眼内炎2例（20．0％）;万古霉素组、联合用药组未见细菌性眼内炎发生。结论在外伤性出血性眼球穿孔伤动物模型中,玻璃体腔注射阿霉素可能降低外伤性PVR程度;而玻璃体腔注射万古霉素可能降低感染性眼内炎症发生率。     

Endophthalmitis caused by staphylococcus epidermidis: in vitro antibiotic susceptibilities and clinical outcomes.

BACKGROUND AND OBJECTIVE: To investigate the antibiotic sensitivities and clinical outcomes of eyes with endophthalmitis caused by methicillin-sensitive versus methicillin-resistant Staphylococcus epidermidis (MSSE/MRSE). PATIENTS AND METHODS: A retrospective, consecutive case series of all patients with endophthalmitis caused by S. epidermidis from January 1, 1996, through July 1, 2004, was conducted. The antibiotic sensitivities and clinical outcomes were obtained from the corresponding medical records. RESULTS: The study included 86 eyes of 86 patients with S. epidermidis endophthalmitis (34 MSSE and 52 MRSE). Endophthalmitis categories included cataract surgery (58), glaucoma surgery (12), trauma (7), vitrectomy (4), penetrating keratoplasty (4), and corneal suture ulcer (1). In vitro testing revealed that all MSSE and MRSE isolates were sensitive to vancomycin, 67% of MSSE isolates and 67% of MRSE isolates were sensitive to gatifloxacin, and 73% of MSSE isolates and 67% of MRSE isolates were sensitive to moxifloxacin (overall 68% sensitive). All eyes were treated with intravitreal vancomycin and either ceftazidime or amikacin. Visual acuity improved to a median of 20/80 at 3 months and 20/60 at 1 year. I CONCLUSIONS: In the current study, all MSSE and MRSE isolates were sensitive to vancomycin and 68% were sensitive to the fourth-generation fluoroquinolones. There were no significant differences in visual acuity outcomes of endophthalmitis caused by MSSE versus MRSE isolates.     

Effects of intravitreal corticosteroid in the treatment of Staphylococcus aureus-induced experimental endophthalmitis

PURPOSE: To investigate whether intravitreal injection of dexamethasone in addition to antibiotics can minimize intraocular tissue injury caused by Staphylococcus aureus endophthalmitis. METHODS: Albino rabbits were infected with an intravitreal injection of 1000 colony-forming units of S. aureus. The rabbits were randomized to receive no treatment (control group; n = 2), intravitreal vancomycin and amikacin (n = 5), or a combination of intravitreal vancomycin, amikacin, and dexamethasone (n = 5) 20 hours following inoculation of bacteria. All rabbits except for the control group also received intravenous imipenem every 8 hours for 4 days. The eyes were evaluated by clinical examination, electroretinogram (ERG), and histologic studies. RESULTS: Eyes treated with intravitreal dexamethasone demonstrated less inflammation on clinical examination compared with eyes that received antibiotics alone. The ERG responses of eyes that received both intravitreal antibiotics and steroid were significantly better at 45 hours, 7 and 14 days following inoculation (P < 0.05) compared to eyes that received antibiotics alone. Histologic studies 14 days following infection demonstrated less tissue destruction for eyes treated with dexamethasone. CONCLUSION: Compared to intravitreal antibiotics alone, intravitreal corticosteroids may improve visual outcome of S. aureus endophthalmitis by reducing inflammation and preserving electrophysiologic retinal function.     

头孢哌酮/舒巴坦玻璃体腔注射治疗兔铜绿假单胞菌性眼内炎

目的评价头孢哌酮/舒巴坦治疗铜绿假单胞菌眼内炎的疗效。方法青紫蓝兔18只,随机分为3组,右眼注菌后6h分别注入100g/L头孢哌酮/舒巴坦、22.5g/L头孢他啶和生理盐水各0.1mL,观察24h。另取青紫蓝兔12只,随机分为2组。早期注药组注菌后6h注入100g/L头孢哌酮/舒巴坦0.1mL,晚期注药组注菌后20h注入100g/L头孢哌酮/舒巴坦0.1mL,观察1周。结果头孢哌酮/舒巴坦组、头孢他啶组与生理盐水组比较除角膜评分外（P〉0.05）,结膜、前房、玻璃体、视网膜、B型超声检查及组织病理学评分结果差异均有统计学意义（P〈0.05）;头孢哌酮/舒巴坦组与头孢他啶组相比,除虹膜炎症反应评分差异有统计学意义外（P〈0.05）,其他评分差异均无统计学意义（P〉0.05）,但从具体评分来看头孢哌酮/舒巴坦组优于头孢他啶组。早期注药组与晚期注药组相比,1周后结膜、前房、虹膜、玻璃体、视网膜、B型超声检查及组织病理学评分差异均有统计学意义（P〈0.05）。结论 100g/L头孢哌酮/舒巴坦0.1mL玻璃体腔注射治疗早期铜绿假单胞菌眼内炎有效。     

Intravitreal trovafloxacin against experimental Staphylococcus epidermidis endophthalmitis

This study was designed to test the effects of intravitreal trovafloxacin on an experimental rabbit model of Staphylococcus epidermidis endophthalmitis. Out of 26 rabbits, 22 were given intravitreal S. epidermidis (100,000 CFU). At 24 h, group 1 (8 rabbits) and, at 48 h, group 2 (8 rabbits) received 100 microg intravitreal trovafloxacin. Group 3 (6 rabbits) was used as inoculated but untreated controls. Four rabbits (group 4) were used as uninfected controls. Clinical scores were calculated at 24, 48 and 72 h. Microbiological and histopathological scorings were made. Microbiological analysis showed that trovafloxacin administered at 24 or 48 h significantly reduced the number of bacteria compared to the untreated group. We conclude that trovafloxacin applied at 24 or 48 h is effective against S. epidermidis endophthalmitis in this experimental rabbit model.     

万古霉素在正常兔眼和细菌性眼内炎兔眼内的药代动力学研究

背景万古霉素近年来常被作为金黄色葡萄球菌性眼内炎治疗的首选药物,万古霉素在眼内药代动力学的研究报道较少。目的观察万古霉素在正常兔眼和细菌性眼内炎兔眼房水、玻璃体及血清中质量浓度的变化,并进行药代动力学参数比较。方法选取健康成年兔72只,采用随机数字表法分为正常组和眼内炎组,每组36只。眼内炎组兔右眼玻璃体腔内接种2000CFU／ml金黄色葡萄球菌建立眼内炎模型,注射后72h待出现典型的眼内炎表现时,兔眼玻璃体腔内注射10g／L万古霉素注射液0．1ml,分别于注射后0．5、2、4、6、12、24、48、72、84h经兔耳缘静脉采血2ml,之后以空气栓塞法处死动物,摘除眼球,收集房水和玻璃体,利用高效液相色谱仪紫外（HPLC—UV）法检测万古霉素在血液、房水和玻璃体内的质量浓度。3p97药代动力学软件拟合药代动力学参数。结果HPLC法的准确度和精确度符合生物样品的检测要求。玻璃体腔内注射万古霉素后,其在正常兔眼内的代谢呈二室模型,拟合曲线的高峰质量浓度Cmax分别为50．16mg／L和751．42mg／L,t1/2为51．04h和53．21h;其在金黄色葡萄球菌性眼内炎兔眼中代谢呈一室模型,高峰质量浓度Cmax分别为24．94mg／L和687．66mg／L,t1/2分别为11．42h和12．91h,2组动物血药质量浓度均较低,差异无统计学意义（P〉0．05）。正常组和眼内炎组玻璃体腔内注射万古霉素后随时间延长,玻璃体中万古霉素的质量浓度逐渐下降,而房水中出现先升高后下降的趋势。与正常组相应时间点比较,眼内炎组玻璃体和房水中万古霉素的质量浓度均明显下降,差异均有统计学意义（P〈0．05,P〈0．01）。结论HPLC能满足万古霉素药代动力学分析的需要;万古霉素在正常兔眼内的质量浓度较高,清除缓慢,而在细菌性眼内炎兔眼中质量浓度较低、清除较快。     

白内障术后眼内炎的治疗分析

目的：探讨白内障术后眼内炎的治疗方案及效果。方法：对我院2006-01/2010-12白内障摘除术＋人工晶状体植入术的21973例28722眼患者的资料（超声乳化20937例27521眼,囊外摘除术1036例1201眼）进行回顾性分析。结果：在全部术眼中,感染性眼内炎11眼,感染率为0.04%,9眼发生于超声乳化术后,2眼发生于白内障囊外摘除术后。共有5眼病原菌培养阳性,其中表皮葡萄球菌2眼,金黄色葡萄球菌,浅绿色气球菌,真菌各1眼。感染发生于白内障术后2wk以内者占73%（8/11）,房水混浊或前房积脓者行前房灌洗＋玻璃体腔注射万古霉素;前房积脓合并明显玻璃体混浊或经前房灌洗＋玻璃体腔注射万古霉素治疗观察1～2d感染加重者行前房灌洗＋玻璃体切割术。治疗后11眼均保住眼球。结论：白内障术后眼内炎经常发生于白内障术后2wk以内,经及时有效的治疗可控制感染发展,保留部分有用视力;前房灌洗＋玻璃体腔注射万古霉素必要时联合玻璃体切割术是有效的治疗方法。     

Real-life comparison of three intravitreal antibiotic drug regimens in endophthalmitis

Purpose:Real-life comparison of three intravitreal drug regimens used in cases of endophthalmitis at a tertiary care center in India.Methods:In this prospective, comparative study, patients of bacterial endophthalmitis were grouped according to intravitreal antibiotic drug regimens into Group 1 (ceftazidime and vancomycin), Group 2 (piperacillin + tazobactam and vancomycin), and Group 3 (imipenem and vancomycin). Forty-eight hours after injection nonresponding/worsening patients underwent vitrectomy. Vitreous samples were subjected to microbiological and pharmacokinetic tests.Results:A total of 64 patients were included and divided into Group 1: 29, Group 2: 20, and Group 3: 15 cases. Also, 75% of patients were post-surgical endophthalmitis, whereas 25% were post-traumatic. Improvement in vision (V_90-0) and vision at 3 months (V₉₀) were comparable between the three groups. Visual recovery was poorer in post-traumatic cases. In post-surgical cases, visual recovery was poorer in those presenting beyond 72 h of onset of symptoms (P = 0.0002). Polymerase chain reaction (PCR) positivity (66%) was higher than BACTEC™ (33%) and culture (14%). Antibiotic resistance was comparable amongst the three groups. Most patients (62/64) further underwent vitrectomy. Ceftazidime and vancomycin achieved vitreous concentrations more than the minimum inhibitory concentration (MIC) at 48 h after the first injection.Conclusion:The choice of antibiotics did not affect the rate of vitrectomy and final vision in a real-life scenario. Ceftazidime and vancomycin can still be used as first-line intravitreal antibiotics owing to their comparable microbial sensitivity profile and adequate ocular bioavailability.     

The effects of caspofungin and voriconazole in experimental Candida endophthalmitis

PURPOSE: To evaluate the efficacy of newly developed antifungal agents caspofungin and voriconazole in Candida albicans endophthalmitis in rabbit eyes. METHODS: Thirty New Zealand white rabbits were divided into four treatment groups and one control group. One eye of each rabbit was infected by inoculation of 1 x 10(4) CFU/ml of C. albicans. Seventy-two hours after the inoculation, caspofungin 100 microg/0.1 ml in group 1 (n = 6), voriconazole 50 microg/0.1 ml in group 2 (n = 6), amphotericin B 10 microg/0.1 ml in group 3 (n = 6), itraconazole 10 microg/0.1 ml in group 4 (n = 6), and 0.1 ml NaCl 0.9% in control group (n = 6) were injected into the vitreous cavity. Clinical and histopathologic examination scores and microbiological analysis of vitreous aspirates were compared. RESULTS: There was statistically significant difference in the clinical scores, histopathologic scores, and mean CFU/ml between the treatment and control groups (p < 0.05). In caspofungin and voriconazole groups, histopathologic scores and mean CFU were lower than other treatment groups and control group. CONCLUSIONS: Intravitreal injection of caspofungin and voriconazole was effective against C. albicans endophthalmitis in this experimental rabbit model.     

Acute endophthalmitis following intravitreal bevacizumab (Avastin) injection

PURPOSE: To report two cases of acute endophthalmitis following intravitreal bevacizumab injection. METHODS: Two patients with exudative age-related macular degeneration were treated sequentially with an intravitreal injection of bevacizumab and developed signs of severe but painless infectious endophthalmitis 2 days later. Vitreous samples were obtained, followed by the injection of vancomycin 1 mg/0.1 ml and ceftazidime 2.25 mg/0.1 ml. Pulsed-field gel electrophoresis (PFGE) was used to determine whether the isolated microorganisms were the same. RESULTS: Coagulase-negative staphylococci were identified and isolated from the vitreous specimen of both patients. PFGE revealed different patterns of banding, excluding that interpatient contamination occured. CONCLUSIONS: Infectious endophthalmitis is a potential complication of intravitreal bevacizumab injection.     

Intraocular kinetics of ceftazidime (Modacin).

The concentration of ceftazidime was determined in the aqueous humor and the vitreous body of normal, vitrectomized and aphakic/vitrectomized eyes and in the serum of albino rabbits 1 h after intravenous injection of 100 mg/kg ceftazidime. The intravitreal ceftazidime concentration was low (0.1-0.2 microgram/ml) in normal eyes 1 h after intravenous injection, and high (8.7 +/- 8.5 micrograms/ml) in vitrectomized and aphakic/vitrectomized eyes when injected immediately after surgery. The ceftazidime concentration was also determined in the aqueous humor and the vitreous body of normal eyes and in the serum of albino rabbits 3, 6, 12, 24 and 48 h after intravitreal injection of 200 micrograms. The intravitreal ceftazidime concentration after intravitreal injection decreased exponentially for 12 h (half-life about 7.4 h). It decreased more slowly thereafter and remained at 13.0 micrograms/ml (mean) even 48 h after injection. This concentration exceeded the minimum inhibitory concentrations against common gram-positive and gram-negative organisms causing endophthalmitis.