Reactive uveitis, retinal vasculitis and scleritis as ocular end-stage of Acanthamoeba keratitis: a histological study

We analysed histologically two Acanthamoeba keratitis(AK) eyes with anterior and posterior segment inflammation and blindness. Two enucleated eyes of 2 patients(age 45 and 51y) with AK(PCR of epithelial abrasion positive) were analysed. Histological analysis was performed using hematoxylin-eosin, periodic acid-Schiff and G?m?rimethenamine silver staining. We could not observe Acanthamoeba trophozoites or cysts neither in the cornea nor in other ocular tissues. Meanwhile, we found uveitis, retinal vasculitis and scleritis in these eyes, due to the long-standing, recalcitrant AK. So in this stage of AK, systemic immune suppression may be necessary for a longer time period.

Comparison of anterior segment optical coherence tomography findings in acanthamoeba keratitis and herpetic epithelial keratitis

This study is to investigate the characteristic features of Acanthamoeba keratitis（AK） that differentiating it from herpetic epithelial keratitis（HEK） using anterior segment optical coherence tomography（AS-OCT）. Medical records of three eyes of each AK and herpetic keratitis who had AS-OCT examination were reviewed in this study. Slitlamp biomicroscopy and AS-OCT was performed on the initial visit and on every follow-up visits in all patients. In all three AK cases, reflective bands in the corneal stroma that correspond to the area of radial keratoneuritis were observed. The depth of the reflective bands varied in each case. After AK treatment, slit-lamp biomicroscopy confirmed that radial keratoneuritis had resolved and AS-OCT confirmed that reflective bands in the corneal stroma had also disappeared in all patients. Unlike the AS-OCT results found in AK, highly reflective HEK lesions were observed only in the subepithelial area, not in the stroma. AS-OCT seems to be helpful analyzing the specific depth of the lesion which enables to distinguish AK from HEK.

A review of Acanthamoeba keratitis in the Middle East and Iran

Acanthamoeba keratitis, a vision-threatening disease, is caused by a free-living amoeba of genus Acanthamoeba. Amoeba is widely distributed all around the world. Several cases of Acanthamoeba keratitis have been reported from the Middle East and Iran as well. The infection is mainly caused by inappropriate use of contact lens;therefore, it is more common among lens wearers. The number of reported cases worldwide is increasing annually due to the increasing number of contact lens wearers for medical or cosmetic reasons. It is known that early diagnosis and treatment can reduce consequent damages, while the delay in these processes will deteriorate the vision. Nowadays contact lens wearing, surgery and use of corticosteroids are known to predispose to Acanthamoeba keratitis, and it was also believed that trauma was the main cause. Increasing public knowledge about Acanthamoeba infection, inquiring the history of patients, clinical signs and laboratory findings can be helpful to early diagnosis and better treatment. Regardless of the increasing knowledge of diagnosis and treatment, this disease is still a challenge. Considering the long curative time, and insufficient efficacy of available treatments, it seems that the prevention is more important than the treatment. This review aimed to explain Acanthamoeba keratitis in the Middle East and Iran from the aspects of epidemiology, diagnosis, and therapeutic treatment.

Atypical Presentation of Acanthamoeba Keratitis in a Contact Lens Wearer

Acanthamoeba keratitis is a serious infection that can lead to loss of vision. It is highly challenging and often poses a diagnostic dilemma, causing delay in diagnosis and treatment. We report herewith the clinical and histopathology findings of a patient with an atypical presentation of acanthamoeba keratitis in Bahrain. The patient is a 16-year-old Bahraini teenager who was a cosmetic contact lens wearer. She presented with clinical signs and symptoms of microbial keratitis, which was initially misdiagnosed elsewhere as a case of herpetic corneal infection. Her corneal biopsy confirmed the clinical diagnosis as acanthamoeba keratitis. The patient was started on anti amoebic treatment. The infection got eradicated. The cornea healed with a central scar. Eventually, she underwent penetrating keratoplasty. This case report serves to raise awareness of this rare condition. Clinicians should have a high index of suspicion when diagnosing such cases among contact lens wearers. Early diagnosis and treatment are crucial to prevent serious complications.

Recurrent interface abscess secondary to Acanthamoeba keratitis treated by deep anterior lamellar keratoplasty

Dear Sir,I am Dr. Yan-Long Bi, from the Department of Ophthalmology of the Tongji Hospital affiliated to Tongji University School of Medicine, Shanghai, China. I write to present a case report of recurrent amoebic corneal abscess

Riboflavin-UVA collagen cross-linking for the treatment of acanthamoeba keratitis

In this review,recent studies regarding riboflavin-ultraviolet A(UVA)collagen cross-linking for the treatment of acanthamoeba keratitis(AK)were reviewed.English written studies about acanthamoeba,keratitis,riboflavin and collagen cross-linking were retrieved from PubMed search engine(www.ncbi.nlm.nih.gov/pubmed).Although there were significant numbers of cases reporting the effectiveness of riboflavin-UVA collagen cross-linking in AK,experimental studies(in vivo and in vitro)failed to verify amoebicidal or cysticidal effect of riboflavin-UVA collagen cross-linking.In conclusion,the efficacy of riboflavin-UVA collagen cross-linking for the treatment of AK is still debatable.It is necessary to conduct a prospective case-control study for clear guidance for clinicians.

Review of clinical and basic approaches of fungal keratitis

Fungal keratitis（FK） is a serious disease which can cause blindness. This review has current information about the pathogenesis, limitations of traditional diagnosis and therapeutic strategies, immune recognition and the diagnosis and therapy of FK. The information of this summary was reviewed regularly and updated as what we need in the diagnosis and therapy of FK nowadays.

Infectious keratitis in Vietnam:etiology,organisms,and management at Vietnam National Eye Hospital

AIM:To report the etiologies,risk factors,treatments,and outcomes of infectious keratitis(IK)at a major Vietnamese eye hospital.METHODS:This is a retrospective review of all cases of IK at Vietnam National Eye Hospital(VNEH)in Hanoi,Vietnam.Medical histories,demographics,clinical features,microbiological results,and treatment outcomes were reviewed.RESULTS:IK was diagnosed in 1974 eyes of 1952 patients,with ocular trauma being the greatest risk factor for IK(34.2%),frequently resulting from an agriculturerelated injur y(53.3%).The mean duration between symptom onset and presentation to VNEH was 19.3±14.4 d,and 98.7%of patients had been treated with topical antibiotic and/or antifungal agents prior to evaluation at VNEH.Based on smear results of 1706 samples,the most common organisms identified were bacteria(n=1107,64.9%)and fungi(n=1092,64.0%),with identification of both bacteria and fungi in 614(36.0%)eyes.Fifty-five of 374 bacterial cultures(14.7%)and 426 of 838 fungal cultures(50.8%)were positive,with the most commonly cultured pathogens being Pseudomonas aeruginosa,Streptococcus pneumonia,Fusarium spp.,and Aspergillus spp.Corneal perforation and descemetocele developed in 391(19.8%)and 93(4.7%)eyes,respectively.Medical treatment was successful in resolving IK in 50.4%eyes,while 337(17.1%)eyes underwent penetrating or anterior lamellar keratoplasty.Evisceration was performed in 7.1%of eyes,most commonly in the setting of fungal keratitis.CONCLUSION:Ocular trauma is a major risk factor for IK in Vietnam,which is diagnosed in almost 400 patients each year at VNEH.Given this,and as approximately one quarter of the eyes that develop IK require corneal transplantation or evisceration,greater emphasis should be placed on the development of prevention and treatment programs for IK in Vietnam.

A Preliminary Report of Predisposing Factors and Predominant Microbiological Diagnosis of Corneal Ulcers Seen at the Federal Teaching Hospital Abakaliki, Nigeria

Background: Microbial keratitis often results in poor visual outcome despite treatment. A revision of treatment protocol based on local evidence may be required in order to obtain better treatment outcome. Objectives: To determine the predisposing factors and predominant microbiological diagnosis of corneal ulcers seen at the Federal Teaching Hospital Abakaliki (FETHA), Ebonyi State, Nigeria. Materials and Methods: This is a preliminary report of an on-going longitudinal descriptive study of all consenting corneal ulcer patients managed at the FETHA eye clinic over a 4-month period. Information obtained were socio-demographic data, presenting complaints, duration of symptoms prior to presentation, history of preceding trauma, medications used before presentation, presenting and final visual acuity and microbiological diagnosis. Results: A diagnosis of corneal ulcer was made in 8 out of the 852 outpatients seen over the study period giving a hospital prevalence rate of 0.59%. Five patients (62.50%) were males, five (62.50%) were farmers and 4 patients (50%) were above 60 years of age. The microbial diagnoses were bacterial keratitis 37.5% (Staphylococcus aureus), fungal keratitis 25% (Fusarium spp. and aspergillus) and acanthamoeba (25%). None of the patients ever used contact lenses. There was a history of eye trauma in 50% of the patients. All the eyes presented blind after a period of failed attempts to treat by self or quacks. Mean duration before presentation was two weeks. Treatment improved the visual acuity in 37.5% of patients. Conclusion: Bacteria, fungi and acanthamoeba organisms were the microbiological isolates from the scrapings of corneal ulcer patients seen in the eye clinic of FETHA;with bacterial organisms being the most common. Farming activities, preceding eye trauma, delayed presentation, self-medication and use of traditional eye medications (TEM) were common findings among the patients. A future larger study is recommended to confirm the findings of this study. Eye health education campaigns should be directed at farmers to encourage early presentation to hospitals.

Non-related contact lens coinfection with Acanthamoeba and Fusarium

Rationale: Microbial keratitis caused by coinfection with more than one species of pathogens is a severe condition with an unfavorable prognosis. Patient concerns: An immunocompetent Nepali woman complained of pain in the left eye, redness, watering and decreased vision for 5 months. Interventions: The patient was discarded and accurately diagnosed with coinfection with Fusarium sp. and Acanthamoeba sp. The habit of washing the eyes with tap water from a domestic storage tank was the most likely source of infection since it was found to be contaminated with cysts of Acanthamoeba sp. The woman received eye drops of fluconazole and natamycin(5%), cefazoline(50 mg/m L), atropine, and tablets of itraconazole(100 mg), which were later switched to eye drops of clotrimazole(1%), natamycin(5%) and voriconazole(1%), and tablets of itraconazole. A full thickness penetrating keratoplasty was performed followed by treatment with eye drops of voriconazole(1%), natamet(5%), ofloxacin, atropine and carboxymethylcellulose for one week.Outcomes: After treatment, the condition of the patient significantly improved and was discharged one week after keratoplasty. Lessons: This is the first report of Acanthamoeba keratitis in Nepal and the first report of coinfection with Fusarium in this country and highlights the importance of early diagnosis of microbial keratitis both in single microorganism infections and coinfections, even in no contact lens wearers.

Current advances in diagnostic methods of Acanthamoeba keratitis

Objective The objective of this article was to review the current advances in diagnostic methods for Acanthamoeba keratitis （AK）.Data sources Data used in this review were retrieved from PubMed （1970-2013）.The terms ＂Acanthamoeba keratitis＂ and ＂diagnosis＂ were used for the literature search.Study selection Data from published articles regarding AK and diagnosis in clinical trials were identified and reviewed.Results The diagnostic methods for the eight species implicated in AK were reviewed.Among all diagnostic procedures,corneal scraping and smear examination was an essential diagnostic method.Polymerase chain reaction was the most sensitive and accurate detection method.Culturing of Acanthamoeba was a reliable method for final diagnosis of AK.Confocal microscopy to detect Acanthamoeba was also effective,without any invasive procedure,and was helpful in the early diagnosis of AK.Conclusion Clinically,conjunction of various diagnostic methods to diagnose AK was necessary.

棘阿米巴角膜炎的诊断和治疗探讨

目的 探讨棘阿米巴角膜炎的临床与实验室诊断方法 ,寻找有效滴眼液用以治疗。方法 观察分析 2 5例棘阿米巴角膜炎感染各阶段的临床表现 ,通过角膜细胞学检查、阿米巴分离培养、角膜活检及组织病理学检查确诊 ,检测药物对棘阿米巴的抗原虫作用及临床疗效。结果 感染自角膜上皮层开始 ,进行性侵入基质致盲。细胞学检查见包囊和 /或滋养体 (88 9% )。棘阿米巴培养阳性率 5 7 9%。洗必泰、甲硝唑滴眼液治疗棘阿米巴角膜炎有良效。抗原虫治疗2 4例 (2 5眼 ) ,治愈 2 1眼 ,无复发。结论 棘阿米巴角膜炎并非罕见 ,常因被误诊、误治导致视力丧失。重要的是早期诊断与抗原虫治疗。

18S rDNA的PCR扩增技术在棘阿米巴角膜炎临床诊断中的应用

目的:探讨利用聚合酶链反应(polymerase chain reaction,PCR)技术扩增棘阿米巴18S rDNA在角膜炎早期临床诊断应用中的可行性。方法:以18S rDNA为模板,利用特异性引物JDP1-JDP2配合PCR技术来检测临床标本中的棘阿米巴原虫。结果:在临床拟诊为棘阿米巴角膜炎的16例(16眼)中,通过PCR检测法有12眼证实为棘阿米巴原虫感染,同时100g/L KOH角膜刮片后镜检有5例发现了棘阿米巴包囊。两种诊断方法用Fisher确切概率法统计,P<0.05。结论:18S rDNA PCR技术对正确诊断早期棘阿米巴角膜炎有重要的临床应用价值。

棘阿米巴角膜炎的实验诊断

[目的 ]寻找棘阿米巴角膜炎快速诊断和棘阿米巴快速鉴定的方法。 [方法 ]10 %氢氧化钾 (KOH)湿封片镜检、棘阿米巴培养、倒置显微镜观察、病理切片H .E .染色和SPA染色检查。 [结果 ]角膜刮片及手术切除的角膜材料 ,经 10 %氢氧化钾湿封片镜检 ,前者检出 7例棘阿米巴角膜炎病例 ,后者确诊 5例 ;手术切除的角膜材料经培养 ,分离出 6株棘阿米巴 ;应用倒置显微镜直接观察 ,检出棘阿米巴的包囊、滋养体和棘刺。 [结论 ]应用 10 %KOH湿封片镜检可对棘阿米巴角膜炎作出快速诊断 ;通过倒置显微镜直接观察也可对棘阿米巴角膜炎在 2 0h内作出诊断 ;倒置显微镜可直接观察和鉴定棘阿米巴 ,方法简便、无污染、快速及实用。

家兔棘阿米巴角膜炎动物模型的建立

目的:建立棘阿米巴角膜炎的动物模型。方法:在6 只新西兰家兔角膜基质层内注射地塞米松3 d 后,再注入棘阿米巴原虫悬液。结果:6 只家兔均发生角膜炎。经家兔角膜刮片用10% 氢氧化钾封片镜检、角膜组织原虫培养和病理切片染色检查证实,成功地建立了家兔棘阿米巴角膜炎动物模型。结论:通过角膜基质内注射建立的家兔棘阿米巴角膜炎动物模型。

角膜表面镜片术建立兔棘阿米巴角膜炎模型

目的建立一种理想的模拟临床人角膜棘阿米巴感染的动物模型,并对其角膜组织损伤的临床表现和组织病理学改变进行观察。方法20只新西兰大白兔利用角膜表面镜片术建立棘阿米巴角膜炎的动物模型,在角膜植片内皮面作"#"形划痕,用10-0尼龙缝线将其固定于受体角膜上,将棘阿米巴滋养体混悬液注入植片与植床间,建立棘阿米巴角膜炎模型,右眼为实验眼,左眼为对照眼;并在接种后第1天、第3天、第5天、第7天、第9天、第14天、第28天行裂隙灯显微镜检查及临床评分、角膜刮片湿封片镜检、角膜组织病理检查及培养。结果应用角膜表面镜片术成功建立兔眼棘阿米巴性角膜炎的动物模型,并经角膜刮片及培养、组织病理切片染色检查证实。实验眼角膜出现水肿,基质环形浸润,角膜新生血管等表现,对照眼均未见感染;实验眼病理组织切片上可见基质层内的棘阿米巴滋养体或包囊,伴有中性粒细胞、单核巨噬细胞、嗜酸性粒细胞等浸润。结论应用角膜表面镜片术建立的兔棘阿米巴角膜炎动物模型模拟了临床人角膜棘阿米巴感染过程,为研究棘阿米巴角膜炎的发病机制及临床治疗奠定了可靠的实验基础。

激光共焦显微镜在阿米巴性角膜炎诊断中的应用

目的探讨激光共焦显微镜HRT3-RCM在阿米巴性角膜炎诊断中的应用价值。方法对临床拟诊阿米巴性角膜炎患者9例(10眼)行HRT3-RCM检查,同时进行角膜刮片细胞学检查及阿米巴原虫培养。结果9例患者中,HRT3-RCM显示7例角膜组织内阿米巴包囊为阳性,其中3例查到阿米巴滋养体,2例在角膜组织内查见真菌菌丝。包囊表现为圆形,双壁,高密度影像,直径15～20μm;滋养体表现为不规则高密度影像,其中心或偏中心可见致密的核,直径25～40μm。角膜刮片见阿米巴包囊7例,阿米巴培养阳性6例。结论HRT3-RCM是利用激光作为光源的新一代共焦显微镜,分辨率更高,是一种快速无创的检查方法,可作为阿米巴性角膜炎早期病原学诊断以及治疗随访观察的重要辅助检查手段。

棘阿米巴角膜炎的实验室检查和原虫的鉴定

目的应用简便的方法对棘阿米巴角膜炎进行诊断，并对棘阿米巴原虫进行鉴定。方法角膜刮片或培养的原虫材料经１０％氢氧化钾液湿封片镜检；角膜材料经原虫培养；应用倒置显微镜对棘阿米巴属进行观察和鉴定；角膜病理切片经ＨＥ和ＰＡＳ染色。结果１０％ＫＯＨ湿封片镜检，５例角膜刮片中有２例及培养阳性的原虫材料均呈现棘阿米巴原虫的包囊。同一病例，４例中有３例培养出棘阿米巴原虫。在倒置显微镜下可见棘阿米巴原虫的包囊和滋养体以及滋养体上的棘状伪足。病理切片经ＨＥ和ＰＡＳ染色均显示原虫的包囊。结论１０％ＫＯＨ湿封片可对棘阿米巴角膜炎作初步诊断，最后诊断需经原虫培养获得，应用倒置显微镜可对棘阿米巴原虫进行观察和鉴定。角膜病理切片上看到原虫可进一步印证原虫培养的结果。

感染性角膜炎466例共焦显微镜检查结果临床分析

目的:探讨共焦显微镜在感染性角膜炎的病原学诊断上的意义。方法:回顾性病例系列研究。对2010-01/2013-12共466例467眼感染性角膜炎共焦显微镜的检查结果进行回顾性分析,总结其共焦显微镜图像特点及各类型角膜炎的临床特征。结果:患者466例平均54.4±13.0岁,男264例(56.7%),女202例(43.3%),诊断为真菌性角膜炎190例(40.8%),病毒性角膜炎148例(31.8%),细菌性角膜炎125例(26.8%),棘阿米巴角膜炎3例(0.6%),真菌性角膜炎可见大量真菌菌丝,棘阿米巴角膜炎可见典型阿米巴包囊。结论:共焦显微镜是一种早期辅助诊断感染性角膜炎的有效方法,尤其对真菌及棘阿米巴角膜炎的早期诊断具有特异性,有利于感染性角膜炎的早期诊断及指导治疗。

棘阿米巴性角膜炎6例检测与临床诊疗分析

目的分析6例确诊为棘阿米巴性角膜炎的实验室检查与临床诊疗。方法回顾性分析2011-2013年我院6例棘阿米巴性角膜炎的显微镜检查、病理检查及角膜共聚焦检查和临床诊疗经过。结果 6例检及棘阿米巴包囊或滋养体而确诊,经过0.02%氯已定加抗真菌药物治疗后,4例治愈。无效者分别再行角膜移植和眼内容物摘除。结论结合多种实验室检查方法查找病原体是诊断棘阿米巴性角膜炎的有效手段。早期诊断对预后及有效治疗有重要意义。