PURPOSE: To report 4 cases of Acanthamoeba keratitis related to orthokeratology lens overnight wear. METHODS: Four patients had histories of overnight orthkeratology lens wear of 10 months to 3 years when they presented with corneal ulcers. RESULTS: The organism isolated by corneal scraping was Aanthamoeba. The patients were treated with polyhexamethylene biguanide (PHMB), and chlorhexidine, resulting in a resolution of ocular inflammation. CONCLUSION: The risk of Acanthamoeba keratitis as a potential complication of overnight orthkeratology should be considered.
Acanthamoeba Keratitis* ; Acanthamoeba* ; Chlorhexidine ; Humans ; Inflammation ; Ulcer

Recently, the number of reports of Acanthamoeba keratitis has been increased apparently as a consequence of association with use of contact lenses, contaminated contact lens care system and high concern of ophthalmologist to Acanthamoeba keratitis. But, there were few epidemiologic studies of contamination of contact lens care system by Acanthamoeba and there was no report in Korea. We carried out a survey to demonstrate the contamination of contact lens care system by Acanthamoeba and bacteria and analysed the results according to the types of contact lenses and methods of disinfection. We examined the contact lens care system of 185 asymptomatic contact lens wearer for the contamination of Acanthamoeba and bacteria. The result showed a significant contamination of Acanthamoeba and bacteria. Twenty eight(15%) were contaminated with Acanthamoeba, eighteen(10%) were mixed with bacterial contamination and seventy four(40%) were contaminated with bacteria. There was no significant difference with sex and the result showed a lot of cocontamination with bacteria and amoeba and chemical disinfection showed a high Acanthamoeba contamination rate. Based on data from this and previous studies, the most of contact lens care system of contact lens wearer was contaminated with bacteria, amoeba and other microorganism. So, ophthalmologists should be concerned about Acanthamoeba contamination of contact lens care system.
Acanthamoeba Keratitis ; Acanthamoeba* ; Amoeba ; Bacteria ; Contact Lenses ; Disinfection ; Korea

To evaluate amoebicidal efficacy of various disinfectants, we treated four ocular isolates of Acanthamoeba with three kinds of commercial available contact lens(CL) disinfectants, chlorhexidine, thimerosal, polyhexamethylene biguanide(PHMB) and hexamidine, Acanthamoeba cysts were collected from axenic nonnutrient agar plates from 4-week cultures. Cyst suspension(100microliter) was inoculated on 96-well microplate with concentration of 5x103 cyssts/ml. Each well was treated with three kinds of CL disinfectants(100microliter each, 4, 8, 12, 24hrs) and two-fold diluted chlorhexidine, PHMB and hexamidine(100microliter each, 8 and 48hrs). Only one CL disinfectant containing chlorhexidine(0.005%) and thimerosal(0.001%) showed cysticidal effect. Minimal cysticidal concentration(MCC) of PHMB, chlorhexidine, hexamidine ranged 1.17-3.12microgram/ml, 3.12-12.50microgram/ml, 8.64-52.07microgram/ml respectively with 48hr treatment. In 8hr treatment, MCC of PHMB and chlorhexidine were 4.42-12.50microgram/ml and 9.31-25.0microgram/ml respectively, but hexamidine did not demonstrate cysticidal effect. Therefore for proper sterilzation of contact lens and CL caes, effective disinfectant should be included in the composition of CL cleaning solution. Among the currently used topical amoebicidal agents, PHMB was the most potent cysticidal agent in in vitro study with four ocular stains of Acanthamoeba.
Acanthamoeba Keratitis* ; Acanthamoeba* ; Agar ; Chlorhexidine ; Coloring Agents ; Disinfectants* ; Thimerosal

Acanthamoeba keratitis is uncommon and rarely reported in Korea. It has been reported in world literature as a very severe, progressive necrotizing stromal keratitis due to a non-parasitic free-living amoeba. It is frequently associated with minimal corneal trauma especially from contact lens but sometimes occurs in patients without any past history. We report a case of acanthamoeba keratitis without a specific past history in a 42-year-old man. Light and electron microscopy demonstrated severe stromal keratitis with numerous thick-walled cysts, 10~15 m in diameter, scattered in the superficial and deep stroma. Because this keratitis is most often mistaken for fungal, bacterial or herpetic keratitis, early confirmatory diagnosis by direct smear, biopsy or culture is essentially required for the prevention of visual loss or devastating eyeball loss.
Acanthamoeba Keratitis* ; Acanthamoeba* ; Adult ; Amoeba ; Biopsy ; Diagnosis ; Humans ; Keratitis ; Keratitis, Herpetic ; Korea ; Microscopy, Electron

Acanthamoeba keratitis has been increasing in recent years. Main risk factors are contact lens wear and their cleaning solutions. Most contact lens wearers use multipurpose disinfecting solutions (MPDS) for cleansing and disinfecting microorganisms because of its convenience. We determined amoebicidal effects of MPDS made in Korea and their cytotoxicity on human corneal epithelium cells. Fifteen commercial MPDS (A to O) were tested for their amoebicidal effects on Acanthamoeba castellanii trophozoites and cysts by using a most probable number (MPN) technique. Among them, 7 kinds of MPDS showed little or no amoebicidal effects for 24 hr exposure. Solutions A, B, G, H, L, and O showed positive amoebicidal effects, and solutions M and N killed almost all trophozoites and cysts after 24 hr exposure. However, 50%-N solution showed 56% cytotoxicity on human corneal epithelial cells within 4 hr exposure, and 50%-O solution also showed 62% cytotoxicity on human cells within 4 hr exposure. Solution A did not show any cytotoxicity on human cells. These results revealed that most MPDS made in Korea were ineffective to kill Acanthamoeba. The solutions having amoebicidal activity also showed high levels of cytotoxicity on human corneal epithelial cells. New formulations for improved MPDS that are amoebicidal but safe for host cells are needed to prevent Acanthamoeba keratitis.
Acanthamoeba castellanii* ; Acanthamoeba Keratitis ; Acanthamoeba* ; Epithelial Cells ; Epithelium, Corneal ; Humans ; Korea ; Risk Factors ; Trophozoites

PURPOSE: To evaluate the cysticidal effect of 5 kinds of commercially available contact lens disinfectants against 2 clinical isolates of Acanthamoeba. METHODS: Five kinds of commercially available contact lens disinfectants were soaked with cysts of Acanthamoeba ludgdunesis and castellanii at the concentration of 10(3), 10(4), and 10(5) cells/ml for 1 and 4 or 6 hours. Cysts which were not excysted in 7 days after treatment were recognized to be killed. Morphologic changes were evaluated by electron microscopic observation. RESULTS: Contact lens disinfectants which contain myristamidopropyl dimethylamine (MAPD) showed the best cysticidal effect. These disinfectants demonstrated a cysticidal effect on both Acanthamoeba species of all concentrations in 6-hour treatment. Contact lens disinfectants which contain polyhexamethylene biguanide (PHMB) did not demonstrate cysticidal effect, except for Acanthamoeba castellanii at the concentration of 10(3) cells/ml, in either 4- or 6-hour treatment. Separation of plasma membrane from endocyst and damage of organelles were prominent in cases showing a cysticidal effect. CONCLUSIONS: Contact lens disinfectant which contains MAPD may be helpful in preventing the Acanthamoeba keratitis. A higher concentration of PHMB is required to be effective in preventing Acanthamoeba keratitis.
Acanthamoeba castellanii ; Acanthamoeba Keratitis ; Acanthamoeba* ; Cell Membrane ; Contact Lens Solutions ; Disinfectants ; Organelles

Laboratory diagnostic methods, applied for the diagnosis of Acanthamoeba Keratitis, were evaluated for their usefulness in 16 patients of suspicious Acanthamoeba keratitis. Wet smear, Acridine orange(AO) stain, Gram stain and culture on nonnuturent agar plate were routinely used in all patients, and among them, and used saline of 7 contact lens not ideal for the corneal scraping specimens. AO and Gram stains were very useful in the identification of acanthamoeba, and culture on nonnutrient agar plates was essential to confirm this infection. Light and electron microscopic examinations were also useful in patients with negative results of ordinary diagnostic techniques. Suspicion of Acanthamoeba infection in patients that are recalcitrant to antibiotic treatment or related to contact lens wear, is the mont important step for the diagnosis of Acanthamoeba Keratitis. And also examination of corneal specimens by experienced observer is prerequisite for the accurate diagnosis of Acanthamoeba keratitis.
Acanthamoeba ; Acanthamoeba Keratitis ; Agar ; Clinical Laboratory Techniques* ; Coloring Agents ; Diagnosis ; Humans ; Keratitis*

We experienced a case of chronic keratitis with corneal ulcer and conjunctival injection while wearing contact lens. In spite of broad-spectrum antibiotics therapy, corneal lesion was not improved, and bacterial smear and culture were negative. Specimens from corneal scraping were examined with Giemsa-Wright stain and H and E(Hematoxylin-Eosin) stain. We could find double walled acanthamoebic cysts. The specimens were cultured on 1.5% non-nutrient agar with E, coli suspension, and aeanthamoebic cysts and trophozoites were found with H and E stain. Aeanthamoebic cysts and trophozoites were cultured from the specimens of ulcered cornea. So we report this case.
Acanthamoeba Keratitis* ; Acanthamoeba* ; Agar ; Anti-Bacterial Agents ; Cornea ; Corneal Ulcer ; Keratitis ; Trophozoites ; Ulcer

In 44 out of 218 cases of contact lens related infectious keratitis from 19 hospitals throughout the country, contact lenses or contact lens storge cases were cultured. Microorganism was detected in 40 cases[90.9%]. Two or more organisms were isolated in 31 cases[77.5%]. Pseudomonas was the most common organism isolated from contact lens or contact lens storage medium[31 out of 84, 45.2%], followed by Serratia[15 out of 84, 17.9%], fungi [4], and acanthamoeba[4]. Acanthamoeba was found only in one hospital. Antibiotic sensitivity test for isolated pseudomonas showed that 96%of cases was sensitive to ciprofloxacin and 88%to ceftazidime.
Acanthamoeba ; Ceftazidime ; Ciprofloxacin ; Contact Lenses ; Fungi ; Keratitis* ; Pseudomonas

OBJECTIVEThe objective of this article was to review the current advances in diagnostic methods for Acanthamoeba keratitis (AK).

DATA SOURCESData used in this review were retrieved from PubMed (1970-2013). The terms "Acanthamoeba keratitis" and "diagnosis" were used for the literature search.

STUDY SELECTIONData from published articles regarding AK and diagnosis in clinical trials were identified and reviewed.

RESULTSThe 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.

CONCLUSIONClinically, conjunction of various diagnostic methods to diagnose AK was necessary.