Management of contact lens associated Acanthamoeba keratitis

Four patients with contact lens associated Acanthamoeba keratitis were treated at Wills Eye Hospital between 1987 and 1989. Two patients had used daily wear soft contact lenses and two had worn hard contact lenses. All four patients were treated with topical antibiotics (propamidine and neomycin), oral ketoconazole, and varying amounts of topical steroids. Two of these patients received topical clotrimazole. All four patients eventually required surgery for either control of their infection (three cases) or control of secondary disease (glaucoma and cataract). Medical therapy for Acanthamoeba keratitis remains problematic, and therefore prevention of this disease by avoidance of risk factors remains paramount.     

Clinical management and prognosis in Acanthamoeba keratitis: a retrospective study of 25 cases

PURPOSE: To assess risk factors, clinical characteristics, diagnosis and outcome in patients with Acanthamoeba keratitis. METHODS: We reviewed 23 patients (25 eyes) treated for Acanthamoeba keratitis in the XV-XX Hospital between November 1994 and October 2000. Acanthamoeba were found either in corneal scrapings and/or contact lenses and/or storage solutions. RESULTS: A predisposing factor was found in 22/23 patients: most of them (20/22) were contact lens (CL) wearers, two patients had a recent history of corneal trauma, and 15/23 patients had been treated for presumed herpetic keratitis before examination in our hospital. The average delay between first symptoms and diagnosis was 2 months. All patients were treated with two or three topical antiparasitic eye drops for 2 to 6 months. Five patients received systemic treatment (ketoconazole or itraconazole). Nine eyes received surgical treatment: penetrating keratoplasty in eight cases, conjunctival flap in one case, enucleation in one case. Visual outcome was poor in ten eyes (less than 20/60) because of delayed diagnosis. CONCLUSION: Acanthamoeba keratitis is a serious vision-threatening disease. Early diagnosis and treatment are essential for improving visual outcome. Methods such as confocal microscopy and Acanthamoeba-PCR, allowing earlier diagnosis and treatment, will improve the management of Acanthamoeba keratitis.     

The diagnosis and management of Acanthamoeba keratitis.

PURPOSE: The purpose of this study was to evaluate the immunology, pathogenesis and therapy of Acanthamoeba keratitis. METHODS: The recent development of an animal model of Acanthamoeba keratitis and its impact on the medical treatment and immunology of Acanthamoeba keratitis was reviewed. RESULTS: After initial reports, Acanthamoeba infection of the cornea remained a rare disease until an association with contact lens wear was first recognized. Although the disease is closely associated with contact lens wear, it appeared that the contaminated solutions that were coming into contact with the lenses caused the disease. All types of contact lenses can be associated with development of Acanthamoeba keratitis. Therefore, the contact lens serves as a carrier of Acanthamoeba to the surface of the eye. The typical patient with Acanthamoeba keratitis is a young healthy individual who is either a contact lens wearer or has had significant exposure to water contaminated with Acanthamoeba. There are several risk factors such as corneal trauma, contaminated solution and contact lenses that have been reported to be associated with Acanthamoeba keratitis. In spite of significant improvement in the diagnosis of Acanthamoeba keratitis, progress in developing and utilizing effective antimicrobial agents for treating this disease have been disappointing. A growing body of evidence suggests that the mammalian immune system, if properly activated, is capable of preventing and controlling ocular infections. CONCLUSIONS: In order to develop effective immunotherapeutic modalities, and to better understand the immune effector mechanisms that protect the cornea against Acanthamoeba infection, it is necessary to fully characterize and evaluate the immunobiology of Acanthamoeba keratitis.     

Epidemiological typing of Acanthamoeba strains isolated from keratitis cases in Belgium

From the corneas of nine keratitis patients and from their contact lenses, contact lens boxes and saline solutions, 15 strains of Acanthamoeba have been isolated. An Acanthamoeba strain was isolated from the swimming pool where one of the patients swam, while in the tapwater of the houses of three patients investigated, no Acanthamoeba could be detected. All the Acanthamoeba isolates from the cornea belong to genotype T4, but are different subtypes of T4. The Acanthamoeba detected on the contact lenses (and/or associated paraphernalia) of a patient are of the same subtype as that isolated from the cornea. The only Acanthamoeba strain isolated from a contact lens which was not related to an Acanthamoeba keratitis infection proved to be another genotype. A strain of Hartmannella from a cornea and two vahlkampfiids isolated from contact lenses had no connection with keratitis. This study confirms that, as found elsewhere, only Acanthamoeba genotype T4 of the 12 known Acanthamoeba genotypes is responsible for keratitis in Belgium. Most cases of Acanthamoeba keratitis cases are due to poor hygiene in the treatment (cleaning and storage) of contact lenses.     

Acanthamoeba keratitis and contact lens disinfecting solutions

OBJECTIVES: To report cases of culture-proved Acanthamoeba keratitis in Greece over a 10-year period and to evaluate the effectiveness of the commonly used commercial contact lens disinfecting systems in clinical cases of Acanthamoeba keratitis. MATERIAL AND METHODS: During the years 1994-2004, 45 contact lens wearers and 3 non-contact lens wearers presenting with symptoms and signs of keratitis underwent corneal sampling. The scrapings obtained were inoculated directly onto appropriate culture media for bacteria, fungi and Acanthamoeba. All proved positive for Acanthamoeba. The contact lenses and contact lens disinfecting solutions (16 one-step 3% hydrogen peroxide and 3 multipurpose solutions) of 19/45 patients with culture-proven Acanthamoeba keratitis were cultured for bacteria, fungi and Acanthamoeba. RESULTS: Acanthamoeba was isolated from contact lenses and contact lens disinfecting solutions in all 19 cases of Acanthamoeba keratitis studied. CONCLUSIONS: The main risk factor for corneal infection in contact lens wearers is the use of contact lens disinfecting systems ineffective at killing Acanthamoeba cysts and trophozoites, as well as bacteria and fungi. Improvement or development of new contact lens disinfecting systems by manufacturers is needed to prevent Acanthamoeba keratitis.     

Acanthamoeba keratitis: risk factors and outcome.

AIMS/BACKGROUND--This study was initiated to investigate risk factors for and outcome of Acanthamoeba keratitis. METHODS--Results of treatment were studied in 22 patients (23 eyes) presenting to Bristol Eye Hospital between 1985 and February 1995. Details related to the use and disinfection of contact lenses were also obtained. An additional two patients who were seen at Bristol but mainly treated elsewhere were surveyed for contact lens related information only. RESULTS--The incidence of Acanthamoeba keratitis rose substantially in the 1990s: three patients presented before 1990, while the remaining 21 presented between January 1990 and February 1995. Eleven patients have presented since january 1994. All of the patients in this series were contact lens wearers, 16 (67%) using daily wear disposable contact lenses. Contact lens disinfection data were available in 22 patients of whom 11 (50%) were using chlorine disinfectant. Other types of disinfection were much less common. Four patients (18%) had not used any disinfectant. During the course of the series the average diagnostic delay has fallen markedly, although in 77% of patients a diagnosis of a viral keratitis, most commonly herpes simplex, was made on first presentation. All but three of the series were treated with a combination of polyhexamethylene biguanide and propamidine isethionate. Penetrating keratoplasty was performed in 9/23 eyes (39%); in all of these eyes diagnosis was delayed for at least 6 weeks. All but one of the eyes in the series achieved a visual acuity of 6/9 or better after treatment, and 18 eyes (78%) saw 6/6 or better. CONCLUSIONS--Most patients with Acanthamoeba keratitis can now expect a good visual result and cure by medical therapy alone is favoured by early diagnosis.     

角膜接触镜相关感染性角膜炎20例临床特征

目的：观察角膜接触镜相关感染性角膜炎的临床特征及治疗转归,以期对临床诊疗提供参考。方法：回顾性观察2009年7月到2019年6月因配戴角膜接触镜发生感染性角膜炎而住院的患者,收集并分析患者的高危护理行为、症状体征、角膜感染灶的特点、病原学检查结果、治疗经过以及病情转归。结果：共20例患者（23眼）纳入本研究,女12例,男8例,平均年龄21.4岁。连续数日配戴及自来水清洗镜片占高危护理行为的72%（8/11）。最常见的临床症状是眼异物感、疼痛、眼红及视力下降。溃疡位于视轴区及视轴旁区15眼（65%）,位于周边区8眼（35%）。病原学检查阳性率为35%（8/23）,4眼为棘阿米巴感染,其中2眼合并表皮葡萄球菌感染;3眼为铜绿假单胞杆菌感染;1眼为表皮葡萄球菌感染。16眼（70%）药物治愈,7眼（30%）手术联合药物治愈。治疗效果佳为8眼（35%）,效果良好为9眼（39%）,效果差为6眼（26%）。结论：连续数日配戴及自来水清洗镜片是引发接触镜感染的重要危险因素;溃疡好发于视轴及视轴旁区;棘阿米巴原虫及铜绿假单胞杆菌是感染最常见的病原体。经过及时合理的药物及手术治疗,多数可获得满意疗效。     

Clinical Presentation in Contact Lens-Associated Infectious Keratitis: A Study of Twenty Cases

Objective: To observe the clinical presentation and outcomes of corneal contact lens-related infectious keratitis, in order to provide a reference for clinical diagnosis and treatment. Methods: Patients who were hospitalized from July 2009 to June 2019 due to contact lens-related infectious keratitis were retrospectively reviewed. The risk factors of lens care, symptoms and signs, characteristics of corneal infection focus, results of etiological examination, treatment process and prognosis of the patients were collected and analyzed. Results: A total of 20 patients (23 eyes) were included in the study, 12 females and 8 males, with an average age of 21.4. Seventy-two percent of high-risk lens care (8/11) were wearing lenses for several days and washing the lenses in tap water. The most common clinical symptoms were foreign body sensation, pain, redness and vision loss. The ulcer in 15 eyes was located in the optic axis and paraoptic areas, and 8 eyes in the peripheral area. The positive rate of etiological examination was 35% (8/23).Acanthamoeba infection was found in 4 eyes, including 2 eyes combined with staphylococcus epidermidis infection, 3 eyes with pseudomonas aeruginosa infection and 1 eye with staphylococcus epidermidis infection. Sixteen eyes were successfully treated with drugs, and 7 eyes were successfully treated by surgery combined with drugs. Treatment outcomes were excellent in 8 eyes (35%), good in 9 eyes (39%), and poor in 6 eyes (26%). Conclusions: Wearing lenses for several days and washing them in tap water are the important risk factors of contact lens infection. Ulcers mainly occur in the optic axis and paraoptic areas. Acanthamoeba and pseudomonas aeruginosa are the most common pathogens. After timely and reasonable drug and surgical treatment, most of the patients can obtain satisfactory results.     

Medical and surgical treatment of Acanthamoeba keratitis

We examined seven patients with Acanthamoeba keratitis. All patients had a history of soft contact lens use. Predisposing factors included use of homemade saline, hydrogen peroxide disinfection, a history of improper lens care, and swimming with contact lenses. Currently recommended medical therapy, including topical propamidine isethionate and dibromopropamidine isethionate, miconazole, Neosporin, corticosteroids, and systemic ketoconazole, was used in all patients. Five patients have undergone penetrating keratoplasty for progressive primary Acanthamoeba keratitis (four patients) or recurrent infection (one patient) after maximal medical therapy. Two patients who began medical therapy less than three weeks after the onset of symptoms have done well. Early diagnosis of Acanthamoeba keratitis appears critical for successful medical therapy. Penetrating keratoplasty continues to have a central role in the management of more advanced cases that are unresponsive, or only transiently responsive, to medical therapy.     

Diagnosis and management of Acanthamoeba keratitis

PURPOSE OF REVIEW: This paper reviews the literature generated on Acanthamoeba keratitis since 1998. RECENT FINDINGS: Acanthamoeba infections may be on the rise. Contact lenses are the biggest risk factor for their development. Silicone hydrogel lenses are increasingly prescribed and may be 'more sticky' to Acanthamoeba organisms. Orthokeratology for the treatment of myopia has been associated with many new cases of Acanthamoeba keratitis. Daily disposable contact lenses are the safest form of soft contact lens. Patients continue to be misdiagnosed as having herpetic keratitis. Impression cytology and confocal microscopy are newer diagnostic modalities. Topical polyhexamethylene biguanide, chlorhexidine and propamidine are the mainstay of medical therapy. Amniotic membrane may be used for cases of persistent epithelial defect and to control inflammation. Penetrating keratoplasty in a medically treated eye affords a good chance of positive outcome. SUMMARY: Acanthamoeba keratitis continues to be a difficult infection to diagnose and manage. The frequency of these infections may be on the rise, most commonly associated with frequent replacement soft contact lenses. The best chance for a good outcome is based on early diagnosis, so it is important for ophthalmologists consider it in patients, especially in the contact lens wearer with suspected herpes simplex keratitis.     

Acanthamoeba keratitis during orthokeratology

PURPOSE: To report an infectious complication of overnight rigid gas-permeable contact lenses. METHODS: Case report and medical literature review. RESULTS: A 16-year-old girl developed laboratory-confirmed acanthamoebic keratitis during orthokeratology for myopic reduction. Recent case reports suggest that Acanthamoeba is a cause of microbial keratitis associated with gas-permeable contact lenses among teenagers and young adults undergoing orthokeratology. CONCLUSIONS: Acanthamoeba keratitis is an emerging complication of orthokeratology in young myopes.     

Acanthamoeba keratitis. A growing problem in soft and hard contact lens wearers

Eleven contact lens-wearing patients presented with Acanthamoeba keratitis. Eight cases were culture- and/or stain-positive for Acanthamoeba and three were presumed to have Acanthamoeba keratitis based on history and clinical findings. Six wore daily wear soft contact lenses, two wore extended-wear soft contact lenses, one wore a polymethylmethacrylate hard contact lens, one wore a gas-permeable hard contact lens, and one wore a Saturn lens (combined hard and soft lens). Four patients used distilled water and salt tablet saline, three used tap water and salt tablet saline, two used tap water rinse, two used well water rinse or storage, and one used intravenous (IV) saline. It is apparent that all contact lens wearers are at some risk for Acanthamoeba keratitis developing if proper contact lens care is not maintained. Of great concern is the inability of most current chemical sterilization methods to kill the organism if the lens becomes contaminated. Heat disinfection will kill Acanthamoeba trophozoites and cysts but the lens must not be placed into contaminated solutions afterward. Prevention is very important because medical and surgical treatment failures are frequent. Eye care practitioners who fit contact lenses are advised to use heat disinfection for low-water content stock soft contact lenses, and to use hydrogen peroxide without a catalyst for a minimum of 6 hours for all other stock lens fitting sets, to specifically inquire about contact lens care habits used by their patients, and to discourage the use of homemade saline solutions.     

Rules and regulations concerning contact lens-related infection

Contact lens-related infectious keratitis is a potentially sight-threatening complication. Bacterial keratitis, mostly due to Gram-negative bacteria, is associated with poor lens hygiene, overnight wear, and contaminated lens care solutions. Contamination of the lens storage case may cause fungal keratitis. Acanthamoeba infection is related to the use of tap water or swimming while wearing soft lenses. Viruses are of less concern among contact lens wearers. Possible transmission of Creutzfeldt-Jakob disease by multi-patient trial lenses must be taken in account. To minimize these risk factors, regulations are applied at various levels: CE marking of contact lenses and care products as they are medical devices; contact lens fitting only by health care professionals; distribution of contact lenses by opticians and lens care solutions by opticians and pharmacists; hygienic management of trial lenses following official recommendations. Contact lens-related keratitis must be reported to health care Authorities.     

Perioperative treatment and prognostic factors for penetrating keratoplasty in Acanthamoeba keratitis unresponsive to medical treatment

Background

The purpose of this research is to evaluate the prognostic factors for graft survival after penetrating keratoplasty (PK) for medically unresponsive Acanthamoeba keratitis.

Methods

In this retrospective, interventional case series, 22 affected eyes underwent therapeutic penetrating keratoplasty for medically unresponsive Acanthamoeba keratitis at Shandong Eye Institute during a 10-year period (1996-2006). Diagnosis of Acanthamoeba keratitis was made prior to surgery for 15 eyes, while a delayed diagnosis was made for the other seven eyes. Appropriate anti-microbial agents were administered based on the suspected etiological agents. Intravenous hydrocortisone was given only once in two patients. Systemic and topical use of steroids was avoided within 2 to 3 weeks after operation. The six patients who were misdiagnosed had intravenous hydrocortisone for 3 days postoperatively, and routine administration of systemic and topical steroids until Acanthamoeba was detected. Patients were followed up for 6 to 24 months (mean, 10 months) after PK.

Results

Of these patients, none wore contact lenses. The possible causes for infection included trauma with plant matter or dust (13 cases), poultry-feeding (six cases), and occupational exposure to oil (one case). Eighteen grafts were clear at the end of the follow-up. Six eyes (28%) had amoebic recurrence at 2 to 3 weeks after PK, of which five were misdiagnosed prior to surgery and received postoperative corticosteroids treatment. Four of the six eyes that developed a recurrence were regrafted, while the other two remained clear for the ensuing follow-up period.

Conclusions

PK may be performed in eyes with active Acanthamoeba keratitis. To improve the prognosis, surgeons should pay attention to antiamebal therapy and avoid prescribing corticosteroids in the early postoperative period.     

Acanthamoeba keratitis related to cosmetic contact lenses

We report a rare case of Acanthamoeba keratitis related to cosmetic contact lenses in both eyes. A 17-year-old girl with a history of wearing cosmetic contact lenses presented with keratitis. She purchased cosmetic contact lenses via the Internet, and followed a contact lens care system irregularly, occasionally using tap water. Cell culture was performed on samples collected from a corneal scraping, the contact lenses and the storage cases. The isolated organism was Acanthamoeba. The patient was treated with polyhexamethylene biguanide and chlorhexidine for 3 months, and recovered with normal visual acuity. Poor hygiene and insufficient disinfection may be major risk factors for Acanthameoba keratitis in cosmetic contact lens wearers. The cosmetic contact lens user should receive professional advice before accessing the lenses, and this must be communicated to the public.     

Trends in contact lens-associated microbial keratitis in Southern India

OBJECTIVE: To review the microbiologic profile, clinical course, treatment, and outcome in patients with contact lens-associated microbial keratitis in the setting of a tertiary eye care center in a developing country in the Tropics. DESIGN: Retrospective noncomparative case series selected from an ongoing prospective series. PARTICIPANTS: Twenty-eight subjects examined in the contact lens clinic of L. V. Prasad Eye Institute, Hyderabad, south India, between February 1991 and September 2000, who presented with corneal stromal infiltrate on slit-lamp examination, were included in the study. INTERVENTION: All patients underwent standard diagnostic microbiologic evaluation and smear and culture-guided topical antimicrobial therapy. Penetrating keratoplasty was performed in some patients. MAIN OUTCOME MEASURES: Culture results and clinical response to antimicrobial therapy. RESULTS: Twenty eight (0.11%) of 23,889 contact lens-wearing patients presented with laboratory-proven infectious keratitis; this constituted 0.56% of 4967 corneal ulcer patients seen during the same period. Most (15/28) of the patients wore soft contact lenses on a daily basis. Rigid gas-permeable lenses were worn by six patients, therapeutic bandage contact lenses by four, and Silsoft lenses by four. Laboratory results showed bacterial infections in 25 patients (89.2%); Pseudomonas was the most common organism (13/25; 52%). Acanthamoeba, herpes simplex virus, and Aspergillus niger were isolated in one case each. Laboratory-based medical therapy led to the healing of ulcers in 24 (85.7%) of 28 patients, whereas 4 patients required penetrating keratoplasty. Most of the organisms were sensitive to antibiotics. CONCLUSIONS: Contact lens-associated microbial keratitis is rare in southern India. Soft contact lens wear is the most common risk factor; Pseudomonas keratitis is the predominant causative agent. Fungal, viral, and Acanthamoeba keratitis are rare. The offending bacteria are usually sensitive to antibiotics, and the treatment outcome with medical therapy is good.     

Acanthamoeba keratitis; report of the first Norwegian cases.

Two patients with therapy resistant keratitis are described. There were no predisposing diseases. Both patients had been using rigid contact lenses for more than 10 years and both cleaned their lenses in cold tap water. The patients presented with keratitis of several weeks duration resistant to antibacterial and antiviral treatment and not responding to high doses of corticosteroids. Ultimately, after the possibility of a protozoan aetiology had been considered, culture of corneal scrapings from both patients yielded growth of Acanthamoeba trophozoites. Acanthamoeba keratitis is very rare in northern European countries and has never before been diagnosed in Norway. The present cases show that Acanthamoeba should be added to the list of possible pathogenic agents even in northern low temperature areas.     

Successful medical treatment of Acanthamoeba keratitis

Purpose: To describe the outcome of a series ofAcanthamoeba keratitis treated with a similar regimen. Methods: All cases diagnosed with Acanthamoeba keratitisin a referral centre from June 1994 through June 1997 wereincluded. Diagnosis of Acanthamoeba keratitis was based inclinical presentation and laboratory results. Positive laboratoryidentification of Acanthamoeba from corneal scraping or contactlens was required, unless the patient had very characteristicsymptoms (severe pain) and signs of the infection, includingperineural infiltrates. Initial intensive treatment includedtopical polyhexamethylene biguanide (PHMB) 0.02%, propamidineisothionate 0.1% and broad-spectrum antibiotics. The treatmentwas gradually tapered. After documented response toanti-acanthamoeba therapy, topical steroids were introduced; theywere discontinued before cessation of the anti-Acanthamoebaregimen. Results: Six males and four females, with a meanage of 30.0 ± 7.4 years were included in this study. Allcases weared contact lenses. On presentation all cases had severepain, and epitheliopathy was associated with stromal infiltratein most (seven of ten) cases. Four patients had anterior uveitis.Perineural infiltrates were present in three cases and ringinfiltrate in one patient. Anti-amoebic treatment was started12.7 ± 7.2 days after beginning of symptoms. The clinicalresponse to therapy was very satisfactory in all patients. Withintwo to three weeks all patients had remarkable lessening of painand photophobia, and improvement of clinical signs. At two tothree months, visual acuity had improved in all patients. Twopatients required penetrating keratoplasty for visualrehabilitation. Conclusion: The use of PHMB and propamidinecured all cases of Acanthamoeba keratitis. Cautious introductionof steroids was associated with expedited resolution ofinflammation and provided symptomatic relief.     

Acanthamoeba keratitis associated with disposable contact lenses

Two patients developed Acanthamoeba keratitis associated with the use of disposable extended-wear hydrogel contact lenses. Both patients removed, irrigated, and reinserted the contact lenses without disinfecting them. One patient wore the lenses on a daily basis, rinsed the lenses in tap water, stored them overnight, and discarded them weekly. Both infections were treated successfully. In a third patient, Acanthamoeba species was cultured from two pairs of disposable lenses that had been stored in cases rinsed with well water. Potential benefits from disposable contact lens wear are negated when patients do not comply with a continuous wearing schedule.     

Acanthamoeba keratitis cluster: an increase in Acanthamoeba keratitis in Australia

Background:  This study was undertaken in response to an increase in the number of patients treated for Acanthamoeba keratitis at a tertiary referral hospital in Brisbane, Australia. Incidence and patient characteristics were investigated over a 4-year period.
Methods:  A retrospective consecutive case series study was performed on patients with Acanthamoeba keratitis presenting to the Princess Alexandra Hospital between January 2003 and March 2007.
Results:  Nine cases of Acanthamoeba keratitis were identified over 12 months from March 2006 to March 2007 compared with four cases over the previous 37 months from January 2003 to February 2006. This was an increase from 0.07 cases per 1000 outpatient visits to 0.42 per 1000 ( P  = 0.003). Of the 13 cases, 11 patients used soft contact lenses of which two used monthly extended overnight wear silicone hydrogel lenses. Of the five patients who specified the type of contact lens solution they had used, three reported using AMO Complete Moistureplus Multipurpose solution, one reported using the AMO Complete Comfortplus Multipurpose solution and one was unsure which type of AMO Complete solution they were using.
Conclusions:  There has been a significant increase in incidence of cases of Acanthamoeba keratitis presenting to our institution. The type of contact lens solution and the use of silicon hydrogel lenses combined with extended overnight wear may play a role; however, the significance is unclear given the small numbers for analysis. Further study of incidence and patient characteristics is warranted to identify risk factors and causes for the rising incidence.