角膜激光共聚焦显微镜在单眼感染性角膜炎疾病诊断中的应用

摘要 目的：探讨角膜激光共聚焦显微镜在单眼感染性角膜炎疾病诊断中的应用价值。方法：回顾性研究2020年6月到2021年6月选择在本院诊治的单眼感染性角膜炎疾病患者62例,所有患者都给予角膜激光共聚焦显微镜检查,记录影像学特征并判断诊断价值（以病原学诊断为金标准）。结果：真菌性角膜炎在角膜激光共焦显微镜下的病变区纵横交错的高反射的真菌菌丝或高反光细长颗粒状的孢子,细菌性角膜炎的病变处会聚集活化的树突状细胞及大量的炎症细胞,病毒性角膜炎的基底膜下神经纤维密度、神经主干的分支数减少,棘阿米巴性角膜炎的包囊表现为圆形高反光厚壁结构。角膜激光共聚焦显微镜判断为病毒性角膜炎17例,诊断病毒性角膜炎的敏感性与特异性为94.4 %和100.0 %;角膜激光共聚焦显微镜判断为棘阿米巴性角膜炎4例,诊断棘阿米巴性角膜炎的敏感性与特异性为94.4 %和100.0 %;角膜激光共聚焦显微镜判断为细菌性角膜炎21例,诊断细菌性角膜炎的敏感性与特异性为95.5 %和97.5 %;角膜激光共聚焦显微镜判断为真菌性角膜炎20例,诊断真菌性角膜炎的敏感性与特异性为94.4 %和93.2 %。ROC曲线分析显示角膜激光共聚焦显微镜诊断细菌性角膜炎、真菌性角膜炎、病毒性角膜炎、棘阿米巴性角膜炎的曲线下面积分别为0.525、0.579、0.777、0.731。结论：角膜激光共聚焦显微镜在单眼感染性角膜炎疾病诊断中的应用能较好的区分细菌性角膜炎、真菌性角膜炎、病毒性角膜炎、棘阿米巴性角膜炎,具有良好的诊断敏感性与特异性。     

IL-17 produced by Th17 cells alleviates the severity of fungal keratitis by suppressing CX43 expression in corneal peripheral vascular endothelial cells

Fungal keratitis is a relatively common ocular disease requiring positive medical management combined with surgical intervention. Interleukin-17 (IL-17) was reported to promote the activation and mobilization of neutrophile granulocyte to foci of inflammation. This study investigated the effect of IL-17 production from Th17 cells on the progression of fungal keratitis. A mouse model of fungal keratitis induced by Candida albicans was successfully constructed to detect infiltration of inflammatory cells in corneal tissues by hematoxylin-eosin (HE) staining and immunohistochemistry. Fungal load capacity of mouse cornea was also detected. The regulatory role of IL-17 in fungal keratitis with the involvement of CX43 was investigated with the relevant expression of inflammatory factors detected and activation of vascular endothelial cells assessed. Furthermore, in vivo experiment was also performed to confirm the role of CX43 in keratitis. Mice with fungal keratitis showed increased level of inflammatory cytokines and infiltration of inflammatory cells. Silencing IL-17 in Th17 cells and overexpressing CX43 could inhibit the activation of vascular endothelial cells. Besides, CX43 knockdown in vivo alleviated fungal keratitis in mice. The possible mechanism of the above findings could be IL-17 inhibiting the level of CX43 through the AKT signaling pathway. Taken together, IL-17 could inhibit the occurrence and development of fungal keratitis by suppressing CX43 expression through the AKT signaling pathway. Therefore, this study provides a potential target for the treatment of fungal keratitis.     

Successful Medical Management of Recalcitrant Fusarium solani Keratitis: Molecular Identification and Susceptibility Patterns

Fungal keratitis is a rare but sight-threatening infection of the cornea that may be caused by several fungal pathogens. A delay in diagnosis and inadequate treatment may even lead to loss of the affected eye. Fungal keratitis is often misdiagnosed as bacterial keratitis because isolation and identification of the fungal pathogen is difficult and requires experience, and fungal growth in culture requires time. In this report, a 14-year-old boy with recalcitrant Fusarium solani keratitis, unresponsive to initial therapy, is presented. CLSI M38-A2 in vitro antifungal susceptibility tests demonstrated that only amphotericin B (0.5 μg/ml) had potent activity against F. solani; however, fluconazole (>64 μg/ml), itraconazole (>16 μg/ml), voriconazole (8 μg/ml), and posaconazole (>16 μg/ml) had high minimum inhibitory concentrations. In addition, caspofungin (>16 μg/ml) and anidulafungin (>16 μg/ml) exhibited high minimum effective concentrations. Repeated intrastromal voriconazole injections, topical voriconazole, and caspofungin combined with systemic antifungal agents improved of the corneal lesion with a significant increase in visual acuity. Intrastromal voriconazole injection may be used as an adjunctive treatment method for recalcitrant fungal keratitis with no prominent complications. The intrastromal route could be an effective route of administration of antifungal agents, especially for F. solani keratitis, as in this case. A combination of various antifungal agents administered by different routes prevented loss of the eye.     

Rare Fungal Keratitis Caused by Coprinellus Radians

Mycopathologia - A case of fungal keratitis due to Coprinellus radians is reported. To our knowledge, fungal keratitis caused by this species was rare. Fungal hyphae were detected in corneal...     

张家口地区真菌性角膜炎病原菌的临床分析

目的：分析张家口地区真菌性角膜炎的病原学及流行病学特征,为其临床诊治提供一定的参考依据。方法：回顾性分析2010年12月-2012年6月我院收治的97例真菌性角膜炎患者的临床资料,分析其病原菌的构成、诊断方法及药物敏感性情况。结果：总共鉴定出84株真菌,分属12个属、23个种,其中以镰刀菌属感染最为多见（51．2％）,其次为曲霉属（14．3％）和假丝酵母属（10．7％）;感染者以男性劳动者居多,外伤是最常见的诱因,秋冬季为高发季节;不同菌种对药物的敏感性存在区别,主要致病菌种对两性霉素B和纳他霉素的敏感性均达70％以上,较其它抗真菌药物高。结论：镰刀菌为本地区真菌性角膜炎的主要致病菌,病原体种类和构成与其他北方地区无明显区别。两性霉素B和纳他霉素为大多数菌种的敏感药物,可作为本地区临床预防和治疗的首选药物。     

A new method to predict the epidemiology of fungal keratitis by monitoring the sales distribution of antifungal eye drops in Brazil

Purpose

Fungi are a major cause of keratitis, although few medications are licensed for their treatment. The aim of this study is to observe the variation in commercialisation of antifungal eye drops, and to predict the seasonal distribution of fungal keratitis in Brazil.

Methods

Data from a retrospective study of antifungal eye drops sales from the only pharmaceutical ophthalmologic laboratory, authorized to dispense them in Brazil (Opthalmos) were gathered. These data were correlated with geographic and seasonal distribution of fungal keratitis in Brazil between July 2002 and June 2008.

Results

A total of 26,087 antifungal eye drop units were sold, with a mean of 2.3 per patient. There was significant variation in antifungal sales during the year (p<0.01). A linear regression model displayed a significant association between reduced relative humidity and antifungal drug sales (R2 = 0.17,p<0.01).

Conclusions

Antifungal eye drops sales suggest that there is a seasonal distribution of fungal keratitis. A possible interpretation is that the third quarter of the year (a period when the climate is drier), when agricultural activity is more intense in Brazil, suggests a correlation with a higher incidence of fungal keratitis. A similar model could be applied to other diseases, that are managed with unique, or few, and monitorable medications to predict epidemiological aspects.     

Fungal Keratitis: Epidemiological Profile in Argentina

Purpose of Review

The purpose of this review is to describe the epidemiology and species distribution of fungi-causing keratitis in Argentina during the past 10 years.

Recent Findings

In Argentina, reports of distribution and frequency of fungal keratitis are scarce and little is known about its current epidemiology.In the present study, a review of the published data on fungal keratitis was done according to the global context focusing on the current situation in our country.

Summary

Data presented here were obtained in a reference ophthalmological hospital in the Autonomous city of Buenos Aires from 2007 to 2017 and represents an approach to the current status of fungal keratitis. However, larger national data is required to assess the actual epidemiological situation in Argentina.

     

Current Thoughts in Fungal Keratitis: Diagnosis and Treatment

Fungal keratitis remains a challenging and often elusive diagnosis in geographic regions where it is endemic. Marred by delays in diagnosis, the sequelae of corneal fungal infections, though preventable, can be irreversible. Recent studies and advances in the arena have broadened the approach and treatment to mycotic keratitis. This review will discuss current diagnostic modalities of fungal keratitis and will particularly focus on treatment regimens. It will also explore future therapeutic models and critique the potential benefit of each.     

Review and Update on the Epidemiology,Clinical Presentation,Diagnosis, and Treatment of Fungal Keratitis

Current Fungal Infection Reports - Fungal keratitis is a leading cause of ocular morbidity worldwide. Globally, there has been a steady increase in the prevalence of fungal keratitis, yet the...     

应用ROC曲线分析泪液（1-3）-β-D葡聚糖对真菌性角膜炎的诊断价值

目的 探讨真菌性角膜炎患者泪液（1-3）-β-D葡聚糖的阈值,通过受试者工作特征曲线（ROC）评价其对真菌性角膜炎的诊断价值。方法 分别测定100例真菌性角膜炎患者和100例健康志愿者泪液中（1-3）-β-D葡聚糖水平,应用ROC曲线评估泪液（1-3）-β-D葡聚糖诊断真菌性角膜炎的最佳临界值及其灵敏度、特异性。结果 泪液（1-3）-β-D葡聚糖诊断真菌性角膜炎的ROC曲线下面积为0.992,阈值为23.82 pg/mL,灵敏度为97.0%,特异性为98.0%。结论 泪液（1-3）-β-D葡聚糖对真菌性角膜炎的诊断具有较高的灵敏度和特异性,具有一定临床应用价值。     

念珠菌致真菌性角膜炎3例报告

真菌性角膜炎是严重的致菌性眼病，本文报告我院于2011年诊治的3例念珠菌致真菌性角膜炎，这有助于了解在本地区该疾病的致病菌及主要特点。     

Toll-like receptor 2 siRNA suppresses corneal inflammation and attenuates Aspergillus fumigatus keratitis in rats

Toll-like receptors (TLRs) are key components of innate immunity that detect microbial infection and trigger host defense responses. However, they are capable of initiating both protective and damaging immune responses, as exaggerated expression of inflammatory components can have devastating effects on the host. We previously reported that TLR2 in corneal epithelium has an important role in the pathogenesis of fungal keratitis, however, how the corneal inflammation is modulated remains to be elucidated. This study aims to investigate the effect of targeting TLR2 on Aspergillus fumigatus keratitis in rats. The control or TLR2 small interfering RNA (siRNA) was applied sub-conjunctively and topically to the cornea. TLR2 immunostaining was performed to determine the feasibility of TLR2 siRNA delivery. Production of inflammatory cytokines and chemokines were determined by real-time quantitative PCR. Polymorphonuclear leukocyte (PMN) infiltration was assessed by myeloperoxidase activity. It was found that rat corneas treated with TLR2 siRNA showed a significant reduction of TLR2 expression in corneal epithelium. TLR2 siRNA treatment improved the outcome of keratitis, which was characterized by decreased corneal opacity, less corneal perforation, suppressed PMN infiltration, reduced production of inflammatory cytokines and chemokines, and less fungal burden. In conclusion, TLR2 siRNA treatment attenuated A. fumigatus keratitis by suppressing corneal inflammation and preventing fungal invasion, suggesting a novel avenue to control fungal infection and avert damage caused by excessive inflammation.     

Mycotic keratitis caused by Curvularia brachyspora (Boedjin)

Curvularia brachyspora has been identified for the first time as a cause of mycotic keratitis. Mycotic infections of the eye have assumed increasing importance in ophthalmology, resulting in a need for fungal identification and early specific treatment for the successful management of cases. A case of mycotic keratitis caused by C. brachyspora is described against the background of other Curvularia species causing mycoses.     

Keratitis Due to the Wood Saprobic Ascomycete, Auerswaldia lignicola (Family Botryosphaeriaceae), in a Carpenter in India

Keratitis due to Auerswaldia lignicola in a 32-year-old Indian male carpenter is described. At presentation, the patient reported persistent pain and tearing (left eye) in spite of topical antimicrobial therapy for more than 3 weeks. Clinically, mycotic keratitis was suspected, and direct microscopy of corneal scrapings stained by lactophenol cotton blue and Gram stains revealed broad septate hyphae. Intensive topical antifungal therapy was then given for 15 days. The keratitis continued to progress, necessitating therapeutic penetrating keratoplasty. Following the keratoplasty, there was rapid reduction in inflammation and gradual quietening of the eye. Brown–black fungal colonies resembling Lasiodiplodia theobromae were isolated from corneal scrape and corneal button (post-surgery) material on Sabouraud glucose–neopeptone agar; however, sporulation did not occur, so the morphological identification could not be confirmed. Sequence analysis of the 18S rRNA region of extracted fungal genomic DNA yielded an identification of A. lignicola Ariyawansa, J.K. Liu & K.D. Hyde; the sequence data have been deposited in GenBank (A. lignicola strain DK/V4, accession number KC866317.1). Medical management of keratitis due to such rarely reported fungal species may be difficult, necessitating surgical procedures.     

Epidemio-Clinico-Microbiological Study of Mycotic Keratitis in North-West Region of Rajasthan

Aim and Objectives

Mycotic keratitis, with its diverse clinical presentation and difficulties in treatment, makes it a challenging task for clinicians and an important object of study. The aim of present study was to determine the frequency of occurrence and epidemiological association with identification of fungal isolates from mycotic keratitis cases.

Materials and Methods

This was a prospective and observational study conducted in Mycology Laboratory, Department of Microbiology, S.P. Medical College, Bikaner, on corneal scrapings and swabs of a total of 480 patients attending the Ophthalmology OPD, P.B.M. Hospital, Bikaner, during July 2005 to June 2012.

Results

Out of 480 suspected cases, 180 were found to be positive for fungus by smear/culture examination. Increased incidence was seen in the months of May to September with Aspergillus fumigatus being the most common isolate.

Conclusion

Mycotic keratitis, though an age-old disease, still presented with challenging aspects of diagnosis and treatment. The study showed fungal keratitis is prevalent in rural parts of north-west Rajasthan, mainly found in males (age group 21–40 years) with low socio-economic status (farm or factory workers). The most common cause of fungal keratitis was found to be species of Aspergillus.

     

两种手术方式治疗真菌性角膜炎的临床观察

目的 观察深板层角膜移植术（deep lamellar keratoplasty,DLKP）和穿透性角膜移植术（penetrating keratoplasty,PKP）治疗真菌性角膜炎的临床疗效.方法 回顾44例（44眼）临床确诊为真菌性角膜炎的患者,根据共焦激光显微镜检查是否累及角膜内皮分别行DLKP 28例（28眼）或PKP 16例（16眼）.术后随访6～24个月,观察术后真菌复发情况以及拆线后两周视力和角膜地形图散光.结果 术后角膜病理切片检查均检出真菌.术后DLKP组有1例、PKP组有3例出现排斥反应,经抗排斥治疗后均好转.拆线后两周最佳矫正视力DLKP组为0.59×0.04,PKP组为0.41 ×0.05,两组间相比较差异具有统计学意义（t =2.577,P =0.01）;角膜地形图散光DLKP组为（2.0 ×0.17） D;PKP组为（2.9×0.30）D,两组间相比较差异具有统计学意义（t =0.088,P=0.016）.结论 激光共焦显微镜检查对于手术方式的选择提供了良好的客观依据.两种手术方式治疗真菌性角膜炎均有良好的疗效,DLKP术后视觉疗效优于PKP.     

Cell Surface Glycosaminoglycans As Receptors for Adhesion of Candida Spp. To Corneal Cells

The most common causal agents of fungal keratitis are yeasts of the Candida genus. Adhesion constitutes the first stage of pathogenesis. Previous studies have shown that glycosaminoglycans from the corneal cell surface play an essential role in bacterial keratitis, although little is known about their role in fungal infections. The objective of this work is to analyze the role that glycosaminoglycans (GAGs) play in the adhesion of fungi of the Candida genus to corneal epithelial cells. The participation of GAGs in the adhesion of fungi was studied through the specific inhibition of the synthesis of these molecules by enzymatic digestion using specific lyases and the silencing of various genes involved in heparan sulfate sulfation. The results seem to indicate that glycosaminoglycans act to some extent as receptors for this fungus, although there are differences between fungal species. Treatment with inhibitors partially reduced the adherence of fungal species. Digestion of cell surface heparan sulfate further reduced the adherence of Candida albicans and Candida glabrata compared to chondroitin sulfate, indicating that the binding is preferentially mediated by heparan sulfate. Degradation of both heparan sulfate and chondroitin sulfate produced similar effects on the adherence of Candida parapsilosis. However, adhesion of C. albicans hyphae is not dependent on GAGs, suggesting the expression of other adhesins and the recognition of other receptors present in corneal cells. Our results open the door to new strategies for stopping the adhesion of pathogenic fungi, and their subsequent invasion of the cornea; thus, reducing the probability of the keratitis development.     

Fungal Eye Infections: New Hosts,Novel Emerging Pathogens but No New Treatments?

Purpose of Review

We sought to explore the current incidence and associated risk factors associated with fungal eye infections. We also reviewed new diagnostic strategies and recent clinical studies exploring the use of topical and oral antifungal agents.

Recent Findings

Incidence and associated risks continue to vary with geographic region, and access to timely healthcare. Nosocomial fungal endophthalmitis can result from minor surgical procedures to the eye. Molecular methods offer increasing diagnostic utility. Clinical treatment studies have mainly focussed on the treatment of fungal keratitis and have been conducted in South Asia. Topical natamycin remains superior to topical reconstituted voriconazole and remains the preferred therapy including for Fusarium eye infections. Neither adjunctive oral ketoconazole nor oral voriconazole has been shown to have added clear benefit to topical treatment.

Summary

Larger international studies with more heterogenous populations are required for future clinical studies which should include patients with contact lens fungal keratitis and those with fungal endophthalmitis. Basic science studies exploring the immunology of fungal eye infections and drug levels to understand the differences in clinical outcomes are encouraged.

     

束状刺盘孢角膜炎的实验研究

目的初步研究束状刺盘孢感染兔角膜的临床表现和组织病理学特征。方法选择15只新西兰白兔,应用基质内直接注射法建立模型。肉眼观察角膜变化,并在接种后第5 d、14 d、21 d处死家兔,对角膜行HE染色和PAS染色,观察其组织病理学改变。结果兔束状刺盘孢角膜炎动物模型成功建立,肉眼可以见到典型的真菌性角膜炎的表现。组织病理学检查,在感染早期即可看到大量真菌病原体生长,菌丝垂直于角膜基质,后期出现新生血管和瘢痕。结论角膜基质内直接注射法复制真菌性角膜炎动物模型成功率高、稳定。兔束状刺盘孢角膜炎有典型的真菌性角膜炎的表现,组织学中菌丝垂直于角膜基质生长。     

Lasiodiplodia theobromae Keratitis: A Case Report and Review of Literature

A case report and review of literature is reported of a rare case of fungal keratitis from eastern India. A 32-year-old woman with a history of vegetative trauma presented with keratitis in left eye. Microbiological examination of corneal scraping showed refractile hyphae with aseptate branching filaments and black pigmented colonies on multiple solid agar medium. Organism was identified from culture using D1/D2 region of LSU (Large Sub Unit: 28S rDNA)-based molecular technique. PCR amplified a band with a sequence that was 100?% homologous with Lasiodiplodia theobromae. The organism was susceptible to amphotericin B and voriconazole and demonstrated resistance to itraconazole and fluconazole. A therapeutic keratoplasty was performed following non-responsiveness to initial topical voriconazole (2?%) therapy. Recurrence in graft was controlled with topical voriconazole and intracameral amphotericin B. However, the graft failed at the end of 3?months. L. theobromae is a rare cause of fungal keratitis. Management of these cases is difficult, often involving surgical procedures.