An in Vitro Experimental Study on the Antimicrobial Activity of Silicone Oil against Anaerobic Bacteria

Purpose: To investigate the in vitro antimicrobial activity of silicone oil against anaerobic agents, specifically Propionibacterium acnes, Peptostreptococcus spp., Peptostreptococcus anaerobius, Bacteroides fragilis, Fuobacterium spp., and Clostridium tertium.

Method: A 0.5 McFarland turbidity of Propionibacterium acnes, Peptostreptococcus spp., Peptostreptococcus anaerobius, Bacteroides fragilis, Fuobacterium spp., and Clostridium tertium was prepared, and 0.1?mL was inoculated into 0.9?mL of silicone oil. Control inoculations were performed in anaerobic blood agar and fluid thioglycollate medium without silicone oil.

Results: Propionibacterium acnes retained their viability on the 3rd day in the presence of silicone oil. In total, 9.7?×?10⁶ colonies were enumerated from 1?mL of silicone oil. After a prolonged incubation of 7 days, the number of colonies observed was 9.2?×?10⁶. The other bacteria disappeared after the 3rd day of incubation in silicone oil.

Conclusions: Propionibacterium acnes, which is the most common chronic postoperative endophthalmitis agent, is thought to be resistant to silicone oil.     

外伤性眼内炎对眼免疫赦免状态的影响

目的研究外伤后眼内炎症对眼免疫赦免状态的影响。方法在Ｗｉｓｔａｒ大鼠和新西兰白兔建立外伤性眼内炎模型。将牛血清白蛋白分别接种于受伤眼和正常眼玻璃体腔。接受附加佐剂的牛血清白蛋白免疫方案１周后,评价其诱导玻璃体腔相关免疫偏离的能力,并观察受伤眼组织病理学改变。结果眼外伤后５～７天发生中度到重度炎症反应。常规免疫组动物均出现抗原特异性迟发型超敏反应（ＤＴＨ）阳性;单纯玻璃体腔抗原接种组动物均显示ＤＴＨ阴性;受伤眼玻璃体腔抗原接种组和受伤眼玻璃体抗原接种后对侧正常眼玻璃体抗原接种组均显示ＤＴＨ阳性。结论外伤性眼内炎导致受伤眼和正常眼免疫偏离诱导的失败。眼相关免疫偏离的消失可能参与了交感性眼炎的发病过程。     

转移性细菌性眼内炎22例临床报告

目的：探讨转移性细菌性眼内炎的临床特点。方法：回顾性分析了我科近年诊治的22例转移性细菌性眼内炎的临床特点。结果：出现眼部症状前有身体其它部位感染17例(77％);早期眼部检查2例虹膜面有脓性结节,3例视网膜可见黄白色脓性栓塞灶(23％);全部病例早期血液化验示白细胞总数和中性分叶核细胞数明显升高,淋巴细胞计数明显降低;细菌培养阳性率为36％。结论：转移性细菌性眼内炎患发病前常有身体其它部位感染史,早期临床表现和实验室检查有一定的特异性,细菌培养是确定诊断的可靠方法,但是培养技术有待进一步提高。     

曲安奈得:用于玻璃体内注射的配制法

目的：具有抗增生、抗水肿、抗炎和血管稳定作用的曲安奈得（TA）混悬液在眼水肿、新生血管和增生性疾病,特别是黄斑疾病的应用正在不断增加.本文描述玻璃体内注射用的TA的配制法并分析赋形剂（苯甲基乙醇）过滤后的实际剂量.方法：从40mg Volon A瓶中,相当于Kenalog40mg,抽取0.625mL结晶混悬液,相当于TA25mg.在无菌条件下,过滤混悬液以去除溶剂苯甲基乙醇,结晶体用9g/L氯化钠洗涤4次,进行TA玻璃体注射.需要密切随访,监测在头2wk内的眼内炎和1～2mo的高眼压.结果：预期25mg TA的浓度在溶剂过滤后测量为23.8mg.在另一个药学实验室,同样过滤后结果是12.8mg,均不是预期的剂量25mg TA.结论：还没有玻璃体内注射TA的标准剂量.手术医生应该知道过滤后玻璃体内注射TA的剂量将比预期的要少.需要在注射后密切随访：在第1wk监测无菌性眼内炎或假性眼内炎,在第2wk要识别感染性眼内炎,它可能出现在无痛和不充血的眼,但必须立即治疗.继发性高眼压可能在注射后1～2mo发生;一般可用抗青光眼药物控制.     

Comparison of post-cataract surgery endophthalmitis rates using syringing or regurgitation on pressure over the lacrimal sac as a preoperative screening tool for nasolacrimal duct obstruction: An impact assessment of protocol alteration due to the COVID-19 pandemic

Purpose:To compare the post-cataract endophthalmitis (PCE) rates among eyes undergoing syringing or regurgitation on pressure over the lacrimal sac (ROPLAS) test prior to cataract surgery.Methods:We performed a single-center, retrospective, comparative analysis of eyes developing PCE who underwent syringing prior to cataract surgery (group A) in the pre-COVID-19 era between November 1 2019 and January 31, 2020 and the eyes that underwent ROPLAS test prior to cataract surgery (group B) in the COVID-19 era between November 1, 2020 and January 31, 2021.Results:A total of 87,144 eyes underwent cataract surgery during the two time periods of the study. Syringing was performed in 48,071 eyes, whereas ROPLAS was performed in 39,073 eyes. In group A, 19 eyes (0.039%) developed PCE, whereas 20 eyes (0.051%) developed PCE in group B (P = 0.517). Between the two groups, the grade of anterior chamber cellular reaction (P = 0.675), hypopyon (P = 0.738), and vitreous haze (P = 0.664) were comparable. Gram-positive organisms were detected in 4 eyes in group A and 6 eyes in group B; 2 eyes in group A had gram-negative bacilli. The presenting visual acuity (Group A: LogMAR 1.42 and Group B: LogMAR 1.30) and final visual acuity (Group A: LogMAR 0.52 and Group B: LogMAR 0.5) were comparable between the two groups. (P = 0.544 and 0.384, respectively).Conclusion:The rates of PCE were comparable among the eyes undergoing either syringing test or ROPLAS prior to cataract surgery.     

Povidone-iodine concentration and dosing in cataract surgery

Iodine has been recognized as an effective bactericide since the 1800s, and povidone-iodine (PI) solution has been applied to the ocular surface and periocular skin since the 1980s to prevent endophthalmitis in cataract surgery. In vitro, PI solution kills bacteria quickly at dilute concentrations (0.05%–1.0%). In many instances, PI kills bacteria more quickly at these dilute concentrations than more conventional (5%–10%) concentrations. This is due to greater availability of diatomic free iodine in dilute solution, the bactericidal component of PI. The toxicity of PI, both in vitro and clinically, has been shown to be related to concentration. Current American Academy of Ophthalmology and the European Society of Cataract and Refractive Surgeons recommendations regarding PI use suggest using 5% PI before surgery. An alternative dosing strategy uses dilute PI repetitively throughout cataract surgery (0.25% every 30 seconds). We review the povidone-iodine literature with attention to basic science and use of dilute PI.     

Incidence of Endophthalmitis after Intravitreal Injections: Risk Factors,Microbiology Profile,and Clinical Outcomes

Purpose: To report the incidence and characteristics of endophthalmitis after intravitreal injections (IVI) of antivascular endothelial growth factor agents and triamcinolone acetonide.

Methods: Patients’ medical records were retrospectively reviewed from January 2009 to June 2016, and the incidence, risk factors, clinical and microbiological characteristics of post-IVI endophthalmitis were evaluated.

Results: The total number of intravitreal injections given, which included ranibizumab, bevacizumab, and triamcinolone acetonide, was 20,566, of which 27 cases developed endophthalmitis, giving an overall incidence of 0.131%. Significant reduction (p < 0.003) in incidence of endophthalmitis was observed in patients who received prefilled compounded bevacizumab injections (0.050%) compared to multiple bevacizumab injections from a single vial (0.235%). In the triamcinolone acetonide group, the incidence was 0.26%. Staphylococcus species were isolated from 18 cases (67%), and all strains were sensitive to vancomycin.

Conclusions: Adherence to strict aseptic protocols and use of prefilled compounded bevacizumab injections reduces the rate of post-IVI endophthalmitis.     

Conjunctival and corneal findings in bleb‐associated endophthalmitis: an in vivo confocal microscopy study

Purpose: To report the conjunctival and corneal findings in delayed onset glaucoma filtering bleb‐associated endophthalmitis (BAE), by using in vivo confocal microscopy (IVCM). Methods: This was an observational case series. Four eyes of four glaucomatous patients who previously underwent mytomicin C augmented filtering surgery and affected with delayed onset BAE, underwent IVCM of conjunctival bleb and cornea at diagnosis, after 2 and 8 weeks of therapy. The inflammatory status of the conjunctival epithelium and sub‐epithelium was microscopically investigated. Corneal epithelial cells, stromal and endothelial morphology were also evaluated. A group of eight patients with functioning conjunctival filtering bleb was used as control. Results: At diagnosis, a diffuse inflammatory cell infiltration within the conjunctival epithelium presenting evident microcysts was found; conversely, there were no such alterations in the sub‐epithelium. An evident stromal oedema, keratocytes activation and diffuse endothelial inflammatory precipitates were the major corneal hallmarks. After 2 weeks of therapy, besides a remarkable improvement of epithelial inflammation and an evident reduction in endothelial precipitates, dendritic cells appeared within conjunctival sub‐epithelium and corneal epithelium showed aspects of cellular disruption. After 8 weeks, the conjunctival and corneal features consistently improved, except for the endothelium which still presented high‐reflective residual precipitates. Conclusions: In vivo confocal microscopy proved valuable in the analysis of conjunctival bleb and cornea in patients affected with delayed onset BAE, permitting an evaluation of the course of the disease, the response to therapy and the modulation of dose regimen.