Overnight orthokeratology-associated microbial keratitis

PURPOSE: This study was designed to report the clinical aspects, microbiologic findings, and treatment outcomes of overnight orthokeratology-associated microbial keratitis. METHODS: Medical records of patients with overnight orthokeratology-associated microbial keratitis at National Taiwan University Hospital from August 2000 to October 2001were reviewed. The clinical and microbiologic characteristics and treatment outcomes were investigated. RESULTS: Nine patients (in total 10 eyes) from aged 8 to 17 (mean, 12.3 +/- 2.9) years were included in this study. Eight patients had a unilateral infection and one had a bilateral infection. The initial best corrected visual acuities ranged from hand motion to 20/20. The lesions were located at the central cornea in nine eyes (90%). Smears and cultures from corneal scrapings were obtained from all patients. Four eyes were culture-positive, which included nonfermentative Gram-negative bacillus, Pseudomonas aeruginosa and Acanthamoeba. Positive smears from another two eyes revealed Gram-negative bacilli and double-walled cyst. All patients were cured using antimicrobial medications with complete re-epithelization and disappearance of corneal infiltrates. Four eyes had a final best corrected visual acuity of 20/30 or worse after a mean follow-up of 9.4 months, including one eye that had visual acuity of hand motion only. Complications included corneal opacity in all eyes, glaucoma in one eye, and cataract in one eye. CONCLUSIONS: Overnight orthokeratology is an important risk factor of microbial keratitis, especially in school children. Acanthamoeba and Gram-negative bacilli, especially Pseudomonas aeruginosa, are the most common pathogens in our series. The risk of microbial keratitis after overnight orthokeratology should not be overlooked.     

Antibiotic susceptibility of bacterial isolates from bacterial keratitis cases in a university hospital in Taiwan

PURPOSE: To analyze in vitro antibiotic susceptibility of bacterial isolates from patients with bacterial keratitis at the National Taiwan University Hospital over the past 12 years. DESIGN: Retrospective cross-sectional study. METHODS: Medical records were reviewed for patients with culture-proven bacterial keratitis at the National Taiwan University Hospital from January 1994 to December 2005. Microbial isolation and in vitro antibiotic susceptibility were analyzed. RESULTS: A total of 272 pathogens were isolated from 254 eyes. Pseudomonas species were the most commonly isolated organisms (46.7%), followed by Staphylococcus species (11%), Propionibacterium species (8.1%), Streptococcus species (7.6%), and nontuberculous Mycobacteria (6.6%). There was no significant change in antibiotic susceptibility in the strains of Staphylococcus, Streptococcus, Pseudomonas, or nontuberculous Mycobacteria during the study period. From 1994 to 2005, 81.8% of the gram-negative organisms were susceptible to the combination of cefazolin and gentamicin, whereas 95.8% were susceptible to ciprofloxacin (P < .001). For all bacterial isolates, 83.7% and 89.7% were susceptible to the combination of cefazolin and gentamicin and the combination of cefazolin and ciprofloxacin, respectively (P < .001). CONCLUSION: There was no increase in drug resistance in strains of Pseudomonas, Staphylococcus, Streptococcus, or nontuberculous Mycobacteria from 1994 to 2005. Ciprofloxacin is a more efficacious choice than the combination of cefazolin and gentamicin for gram-negative bacterial keratitis in Taiwan. The combination of cefazolin and ciprofloxacin is an effective empirical therapeutic regimen for bacterial keratitis.     

角膜穿孔临床研究分析

目的：研究角膜穿孔(corneal perforation,CP)患者的临床发病特点。

方法：回顾性分析1995-07/2010-07福建医科大学附属第一医院住院确诊的CP患者72例72眼,分析其患者临床特点。

结果：福建地区角膜溃疡穿孔发病率逐年上升,男女发病率比为 17：7 , 48岁为发病集中年龄,产业工人 23例(32%),23例有明确外伤史,菌属鉴定结果：前两位为：真菌感染和棘阿米巴原虫感染。 其中10例有糖皮质激素用药史。

结论：外伤、真菌性、棘阿米巴角膜炎、蚕食性角膜炎等所致CP的原发病因多种多样,福建地区CP多发于中老年的男性,多数外伤为诱因,致病菌属以真菌感染为主。     

The clinical diagnosis of microbial keratitis

PURPOSE: To evaluate the ability of ophthalmologists to predict the laboratory results of presumed microbial keratitis and to explore which findings may influence diagnostic prognostication. DESIGN: Prospective, cross-sectional study. METHODS: Fifteen ophthalmologists completed study forms at the initial presentation of patients with presumed microbial keratitis. After predicting the category of microbial recovery, clinicians submitted corneal scrapings for masked laboratory processing. The relative effects of ocular inflammatory signs on correct microbial diagnosis were explored with Poisson regression. RESULTS: Clinical examiners correctly predicted the presence or absence of microbial recovery in 79 (76%) of 104 ulcerative keratitis cases and successfully distinguished among bacterial, fungal, and amebic keratitis for 54 (73%) of 74 culture-positive infections, although only 31 (42%) were subcategorized properly. The positive predictive value of clinical diagnosis was 65% (95% confidence interval [CI], 43% to 84%) for 20 eyes with Pseudomonas keratitis cases, 48% (95% CI, 32% to 63%) for 38 other bacterial keratitis, 45% (95% CI, 17% to 77%) for 13 fungal keratitis, and 89% (95% CI, 52% to 100%) for nine Acanthamoeba keratitis cases. The recognition of Pseudomonas keratitis significantly improved by the occurrence of a larger infiltrate (P = .02), and correctly predicting Acanthamoeba keratitis was enhanced by observing a ring infiltrate (P < .001). Antimicrobial use before referral significantly attenuated clinical diagnosis (P = .03) and hampered microbial recovery (P = .004). CONCLUSIONS: Established Pseudomonas keratitis and Acanthamoeba keratitis can be suspected before laboratory confirmation, but overlapping inflammatory features and recent empiric antimicrobial treatment limits etiologic recognition of most microbial corneal infections.     

基质环形浸润性棘阿米巴角膜炎的治疗与分期初探

目的探讨有角膜环形基质浸润病变的棘阿米巴角膜炎的临床分期、治疗及预后。方法对17例（17眼）有角膜环形基质浸润病变的棘阿米巴角膜炎或合并真菌感染病例作了回顾性研究，根据角膜环形基质浸润的病程、环宽、浸润深浅、色泽分为早期和晚期，然后分别给予相应的药物和手术治疗。结果早期者8眼，药物治愈5眼，手术成功2眼，手术失败1眼；晚期者9眼，药物治愈2眼，手术成功5眼，手术失败2眼。结论早期诊断、正确分期及应用有效的药物治疗和选择适当的术式是成功治疗有环形基质浸润病变的棘阿米巴角膜炎的关键。     

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.     

Acanthamoeba sclerokeratitis: treatment with systemic immunosuppression

OBJECTIVE: This study describes the clinical features, management, and outcome of 19 patients who had severe Acanthamoeba sclerokeratitis (ASK) unresponsive to conventional management, requiring systemic immunosuppression to control disease. DESIGN: Retrospective, non-comparative, interventional case series. PARTICIPANTS: Records of all patients with Acanthamoeba keratitis treated at Moorfields Eye Hospital between 1989 and 2000 were reviewed. From more than 200 patients, 19 who developed ASK treated with systemic immunosuppression were identified. MAIN OUTCOME MEASURES: Visual acuity, level of pain, and degree of inflammation were recorded after immunosuppressive treatment. RESULTS: ASK requiring immunosuppression occurred in 20 eyes of 19 patients (11 males and 8 females). The mean age (mean +/- standard deviation) at onset was 38.6 +/- 13.2 years. On presentation, best-corrected visual acuity was counting fingers or worse in 11 eyes (55%), 6/18 to 6/60 in 5 eyes (25%), and 6/12 or better in 4 eyes (20%). The mean time between onset of initial symptoms of Acanthamoeba keratitis and commencement of systemic immunosuppression was 4.8 +/- 3.5 months. The mean duration of immunosuppression required to control inflammation was 7.2 +/- 3.9 months. Severe scleritic pain remained uncontrolled in two patients and resulted in enucleation. Best-corrected visual acuity at final follow-up was counting fingers or worse in eight eyes (40%), 6/18 to 6/60 in six eyes (30%), and 20/40 or better in six eyes (30%). The mean follow-up period after resolution of inflammation was 24.3 +/- 20.9 months (range, 0.2-59.7 months). CONCLUSIONS: ASK is an uncommon complication of Acanthamoeba keratitis. The scleritis associated with this infection seems to be an immune-mediated response. After topical amebicidal treatment, systemic immunosuppression may be required to control the pain and tissue destruction associated with ASK.     

Delayed-onset mycobacterial keratitis after LASIK

PURPOSE: To describe the time course, diagnosis, clinical features, and treatment of seven patients with Mycobacterium szulgai keratitis that developed from 7 to 24 weeks after laser in situ keratomileusis (LASIK). METHODS: Seven of 30 eyes of 18 patients were identified with keratitis after LASIK. The first two patients presented 12 to 14 weeks after LASIK; nontuberculous mycobacteria were identified 1 month after the flaps were cultured. Patient recall identified three additional cases by culture and two cases by clinical features alone. Pulsed-field gel electrophoresis (PFGE) was used to type the isolates, and treatment was modified based on susceptibilities. RESULTS: M. szulgai was identified in five patients for whom cultures were performed, but response to empiric therapy based on cultures proved unsatisfactory. The keratitis resolved in all patients with treatment including clarithromycin based on susceptibilities. Medical therapy was sufficient, although one patient required flap amputation. Six of seven patients recovered best-corrected visual acuity (BCVA), while one patient lost one line of BCVA. Two patients lost one line of postoperative uncorrected visual acuity (UCVA), two patients gained one line of UCVA, and three patients recovered postoperative UCVA. PFGE analysis revealed that the M. szulgai strains were identical, and the infection source was contaminated ice used to chill syringes for saline lavage. CONCLUSIONS: Nontuberculous mycobacterial keratitis after LASIK is a diagnostic and management challenge, but outcomes can be preserved with treatment based on susceptibilities. This cluster underscores the importance of adherence to sterile protocol during LASIK.     

Infectious keratitis after penetrating keratoplasty]

PURPOSE: To investigate the prevalence of microbial keratitis, predisposing risk factors, the spectrum of pathogens and the prognosis for graft survival and visual outcome in patients who developed microbial keratitis following penetrating keratoplasty (PK). MATERIAL: and methods: We reviewed 16 cases (15 patients) of microbial keratitis after PK. In all cases, corneal scrapings were obtained and microbiologically analyzed. Efficacy of treatment was evaluated by anatomical (clarity of graft) and visual recovery. RESULTS: Principal indications for PK were pseudophakic bullous keratopathy (50%) and microbial keratitis in the previous graft (25%). Sixty-three per cent of infections occurred within 1 year of PK. Principal predisposing risk factors were suture-related problems (44%) and microbial keratitis in the previous graft (25%). All of the scrapings were positive according to the microbiological evaluation with gram-positive cocci (64%), gram-positive rods (12%), fungi (18%), and Acanthamoeba (6%). We found 1 case of polymicrobial infection. Best visual and anatomical results were observed in nonadvanced cases and/or these treated early. After medical and surgical treatments, 8 patients (50%) had a clear graft and 10 patients (63%) had visual acuity less than 20/200. CONCLUSION: Postoperative control of risk factors and early recognition of infectious complications may decrease the incidence of severe microbial keratitis after PK.     

Comparison of polyhexamethylene biguanide and chlorhexidine as monotherapy agents in the treatment of Acanthamoeba keratitis

PURPOSE: To compare the therapeutic outcomes of polyhexamethylene biguanide (PHMB) and chlorhexidine for Acanthamoeba keratitis. DESIGN: Prospective, double-masked, randomized comparative study. METHODS: Fifty-six eyes of 55 patients with Acanthamoeba keratitis were randomized to receiving PHMB 0.02% or chlorhexidine 0.02%. Diagnosis was made based on positive culture results (cornea or contact lens case) or on clinical grounds. The primary outcome measure was treatment failure defined as failure to induce a favorable clinical response within two weeks. Secondary outcomes were: 1) recovery of visual acuity (VA), 2) the degree of corneal scarring posttreatment, or 3) the need for penetrating keratoplasty. RESULTS: Fifty-one eyes completed the study. Twenty-three eyes received PHMB and 28 received chlorhexidine. Ninety-eight percent were contact lens wearers. Eighteen (78%) PHMB patients were treatment successes compared with 24 (85.7%) chlorhexidine patients (P = .71). Diagnosis was confirmed by positive corneal culture results in 26 cases (51%). Diagnosis was made within 28 days in 29 cases (56.9%), between one and two months in 13 cases (25.5%), and after more than two months in eight cases (15.7%). Improvement in VA was seen in 13 eyes (56.5%) receiving PHMB vs 20 eyes (71.4%) receiving chlorhexidine. Mild one-quadrant corneal scarring was seen in 43.5% of eyes receiving PHMB and 71.4% of eyes receiving chlorhexidine, whereas moderate corneal scarring in two or three quadrants was seen in 21.7% of eyes receiving PHMB and in 10.7% of eyes receiving chlorhexidine. Five eyes worsened while receiving PHMB vs four eyes worsening while receiving chlorhexidine. Penetrating keratoplasty was required in three eyes from PHMB group and in two eyes from chlorhexidine group. CONCLUSIONS: Outcomes were similar when using PHMB and chlorhexidine as monotherapy agents in treating Acanthamoeba keratitis.     

Nontuberculous (atypical) mycobacterial keratitis after LASIK: current status and clinical implications

PURPOSE: Corneal infection with unfamiliar organisms such as nontuberculous (atypical) mycobacteria after laser in situ keratomileusis (LASIK) can be a significant clinical problem, and mismanagement of such corneal infection in an otherwise healthy, young individual can lead to significant medicolegal issues for the refractive surgeon. Because nontuberculous (atypical) mycobacterial keratitis is the most common infection after LASIK, the refractive surgeon should be aware of all aspects of this dreaded infection to be better prepared to manage such cases. METHODS: Literature search. RESULTS/CONCLUSIONS: This article provides a comprehensive compilation of all reported cases of nontuberculous (atypical) mycobacterial keratitis in the English literature and provides some useful recommendations for the clinical management of such corneal infection after LASIK.     

Results of a trial of combined propamidine isethionate and neomycin therapy for Acanthamoeba keratitis. Brolene Study Group.

PURPOSE: To characterize patients with Acanthamoeba keratitis and to evaluate the safety and efficacy of propamidine isethionate 0.1% ophthalmic solution (Brolene) when administered concomitantly with neomycin-polymyxin B-gramicidin ophthalmic solution (Neotricin) in the treatment of Acanthamoeba keratitis. DESIGN: Prospective, noncomparative case series. METHODS: The authors report the clinical characteristics and outcomes of patients who entered this multicentered, open-label, clinical trial. Eighty-three patients with Acanthamoeba keratitis representing 87 infected eyes entered the trial. RESULTS: Sixty (69%) of the 87 eyes enrolled had data analyzed for treatment efficacy and safety. Of these 60 eyes, 50 (83%) experienced treatment success. Thirty (60%) patients successfully treated adhered to treatment protocol guidelines. Patients who broke protocol had disease exacerbation during the maintenance therapy phase. The only eyes lost/enucleated were 7 of 17 in which penetrating keratoplasty was performed before eradication of the infectious agent. CONCLUSION: Propamidine isethionate and neomycin are an effective treatment for Acanthamoeba keratitis. Penetrating keratoplasty should be performed only for visual rehabilitation and not to "debulk" an active infection. The authors advocate treating patients with topical medications, mainly Brolene, until all organisms are eradicated. There should be no signs of infection for at least 3 months in the patients not receiving antiamebic medications before penetrating keratoplasty is performed.     

Bilateral acanthamoeba keratitis

PURPOSE: To determine the prevalence and characteristics of binocular involvement among patients with Acanthamoeba keratitis. DESIGN: Retrospective case series. METHODS: Risk factors and outcomes of bilateral infection were explored among consecutive cases of Acanthamoeba keratitis diagnosed at a single institution from 1997 through mid 2007. RESULTS: Fifty eyes were confirmed to have Acanthamoeba keratitis by microbiologic or histopathologic testing; two-thirds occurred during a regional outbreak beginning in 2004. Five (11%) of 45 patients had infection of both eyes, including three with concurrent involvement and two with successive disease of the contralateral cornea. Three binocularly infected patients used soft contact lenses, and two wore rigid gas-permeable lenses. Nine of 10 eyes achieved visual acuity of 20/30 or better after antiamebic therapy. CONCLUSIONS: Bilateral Acanthamoeba keratitis is an infectious complication of contact lens wear. With laboratory confirmation, vision often can be restored with medical therapy.     

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.     

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.     

The effect of propolis in experimental Acanthamoeba keratitis

PURPOSE: To examine the effect of propolis in a rat model of Acanthamoeba keratitis and to determine its in vitro cytotoxicity in cultured corneal epithelial cells. METHODS: Eighteen Wistar albino rats were used. Cultured corneal epithelial cells obtained from two healthy rats for in vitro cytotoxicity of propolis. Corneal stromal inoculation was performed in 16 rats with amoebic culture containing 1 x 10(6) amoeba/mL. Rats with Acanthamoeba keratitis 5 days later after the inoculation were divided randomly into four groups, and eight eyes of each group were treated with study drugs. The propolis, chlorhexidine (CHX), propolis plus CHX and control eyes were treated with topical propolis, 0.002% CHX, propolis plus 0.002% CHX and lubricant eye drops, respectively. The study drugs were instilled every one hour for 10 days. All eyes were examined and keratitis graded by slit-lamp biomicroscopy on days 2, 5 and 10 during the administration of the study drugs. After the completion of keratitis grading, all the 16 rats were humanely killed and their corneas were excised and used for Acanthamoeba culture to evaluate presence of Acanthamoeba growth after treatment 14 days later. RESULTS: Concentrations of propolis higher than 7.81 mg/mL cause damage to corneal epithelial cells in the experiment of in vitro cytotoxicity of propolis on corneal epithelial cells. The keratitis grade on day 2 in the CHX eyes was significantly lower than that in the control eyes (P < 0.05). The keratitis grades on days 5 and 10 in the propolis, CHX and propolis plus CHX eyes were significantly lower compared with those on days 5 and 10 in the control eyes (P < 0.05). In the propolis eyes, the keratitis grade on day 5 was significantly lower than that on day 2 (P < 0.05), and it was significantly lower on day 10 compared with that on day 5 (P < 0.05). In the CHX and propolis plus CHX eyes, the keratitis grade on day 10 was significantly lower compared with that on days 2 and 5 (P < 0.05). In the control eyes, there was no significant difference in the keratitis grades on days 2, 5 and 10 (P > 0.05). The culture positivity at Acanthamoeba growth after treatment experiment in the propolis, CHX and propolis plus CHX eyes was significantly lower than that in the control eyes (P < 0.05). CONCLUSIONS: We suggest that propolis had amoebicidal properties in this rat model of Acanthamoeba keratitis. Further investigations to evaluate the antimicrobial activity of the individual fractions of the resin could yield more information about its mechanism of action in treating this disease.     

Predisposing factors and etiologic diagnosis of ulcerative keratitis

PURPOSE: To determine the predisposing factors, demographic characteristics, and etiology of ulcerative keratitis in a referral center in Bangkok, Thailand. METHODS: The medical records of admitted patients with positive-culture ulcerative keratitis were retrospectively reviewed for demographic data, predisposing factors, and microbial culture results. Predisposing factors were compared between bacterial and fungal keratitis. RESULTS: From January 2001 to December 2004, there were 127 positive-culture ulcerative keratitis cases. The most frequent microbiological diagnosis was bacterial keratitis (76 eyes, 60%), followed by fungal (48 eyes, 38%) and Acanthamoeba keratitis (3 eyes, 2%). The most common organisms isolated were Pseudomonas spp. for bacteria and Fusarium spp. for fungus. Compared with bacterial keratitis, fungal keratitis was more likely to be associated with ocular trauma (odds ratio = 11.20; 95% confidence interval, 3.62-34.66) but less likely to be associated with contact lens wear (odds ratio = 0.02; 95% confidence interval, 0.01-0.08). CONCLUSIONS: In our study, Pseudomonas and Fusarium species are the most common causes of bacterial and fungal keratitis, respectively. Fungal keratitis was more likely than bacterial keratitis to be associated with ocular trauma, whereas fungal keratitis was less likely to be associated with contact lens wear.     

Epidemic and sporadic cases of nontuberculous mycobacterial keratitis associated with laser in situ keratomileusis

PURPOSE: To report national case-finding results for nontuberculous mycobacterial keratitis and describe its association with laser in situ keratomileusis (LASIK). DESIGN: Enhanced passive disease reporting. METHODS: In April 2001, we investigated a California cluster of Mycobacterium chelonae keratitis associated with hyperopic LASIK using a contact lens mask. To identify other possibly related cases, the American Academy of Ophthalmology e-mailed its members asking them to report recent cases of nontuberculous mycobacterial keratitis to the Centers for Disease Control and Prevention. RESULTS: Forty-three additional cases of keratitis were reported (onsets between August 2000 and June 2001). Of these, 31 occurred as part of two unrelated LASIK-associated outbreaks. The 12 other reported cases occurred in sporadic fashion. Of the latter cases, 4 were associated with LASIK surgery. None of the reported cases were related to the M. chelonae cluster in California. CONCLUSIONS: Laser in situ keratomileusis-associated keratitis with nontuberculous mycobacteria may be more common than previously known.     

Six-year review of Acanthamoeba keratitis in New South Wales, Australia: 1997-2002

AIM: To assess the incidence and risk factors for Acanthamoeba keratitis (AK), the diagnostic interval, and the efficacy and outcome of current treatment among the population of New South Wales, Australia. METHODS: A retrospective review was carried out of all cases of AK treated at the Sydney Eye Hospital between January 1997 and December 2002. RESULTS: Twenty patients were identified with a mean follow up of 24.8 +/- 21.5 months. Acanthamoeba keratitis constitutes 4.7% of severe infective keratitis treated at Sydney Eye Hospital. The mean interval from first presentation to diagnosis was 26.6 +/- 35.1 days overall; 17.2 +/- 33.1 days for those presenting directly to our unit (69% being diagnosed within 72 h of presentation), and 44.1 +/- 34.0 days for those first presenting elsewhere. Of those with a diagnostic delay >1 month, 57% had been mistakenly diagnosed with Herpes simplex keratitis. Sixteen (80%) wore contact lenses, and eight (40%) had additional risk factors including poor lens hygiene. Complications occurred in 16 (80%), with seven (35%) requiring surgical intervention. Visual acuity improved in 18 (90%), worsened in two patients (10%), and 75% achieved 6/12 or better at last follow up. CONCLUSIONS: Acanthamoeba keratitis is a rare infection, and contact lens wear remains the commonest association, with poor hygiene constituting significant additional risk. The visual outcome has improved with the availability of effective amoebicidal agents, but patients with a diagnostic delay and non-contact lens wearers are at increased risk of recurrent disease. A high index of clinical suspicion remains the most effective strategy in implementing early treatment, and enabling a favourable outcome.