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

Aims: Piper sarmentosum or locally known as Kaduk, is a tropical herb plant that was investigated for its phenolic content by previous researchers. The present study aimed at the analysis of crude methanolic extract of P. sarmentosum leaves for phenolic compounds identification and its anti-amoebic properties against pathogenic Acanthamoeba castellanii. Methodology and results: Folin-Ciocalteu assay was used to determine P. sarmentosum leaves methanolic extract (PSLME)’s total phenolic content (TPC). The extract was further characterized by using gas chromatography-mass spectrometry (GC-MS), reverse phase-high performance liquid chromatography (RP-HPLC) and liquid chromatography-mass spectrometry (LC-MS) analyses to determine the chemical constituents in methanolic PSLME extract. The cytotoxicity of the extract was evaluated through the determination of inhibition concentration for half of cell population (IC50) of pathogenic A. castellanii followed by cell morphological analysis using inverted light and scanning electron microscopies. Acridine-orange/Propidium iodide (AOPI) staining was also conducted to determine the integrity of cell membrane for quantitative analysis. The results demonstrated that the TPC from PSLME was 142.72 mg [GAE]/g with a total of 33 phenolic compounds identified. The IC50 value obtained for A. castellanii was low (74.64 μg/mL) which indicates promising anti-acanthamoebic activity. Microscopy analyses showed that the plant extract caused cells encystment, in which exhibited by distinctive morphological changes on the cells shape and organelle, as well as shortening of acanthopodia. The dual staining and its quantitative analysis prove compromised membrane integrity in the treated amoeba. Conclusion, significance and impact of study This finding provides the evidence that PSLME contains active phenolic compounds contributing to the anti-acanthamoebic activity on pathogenic Acanthamoeba species.
Piperaceae ; Acanthamoeba castellanii--pathogenicity

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

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

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

PURPOSE: To compare the amoebicidal effects of nephrite containing contact lens (CL) storage cases with conventional CL storage cases. METHODS: Acanthamoeba lugdunensis were inoculated onto 5% nephrite containing CL storage cases as well as conventional CL storage cases both with and without silicone hydrogel contact lenses (SHCLs). Then the amount of Acanthamoeba proliferation on CL storage cases and the number of adherent Acanthamoeba on SHCLs were determined and compared. The effects of multipurpose solution (MPS) with and without 1% or 5% nephrite solution on Acanthamoeba adhesion were analyzed. RESULTS: Nephrite containing CL storage cases showed more inhibitory effects on Acanthamoeba proliferation (p = 0.02) and significantly reduced the number of adherent Acanthamoeba on SHCLs compared with conventional CL storage cases, regardless of SHCLs generation (p = 0.001, p = 0.001 and p < 0.001, respectively). The number of adherent Acanthamoeba on the first generation of SHCLs was significantly reduced by MPS with 1% and 5% nephrite solutions (p = 0.03 and p = 0.004, respectively), but the numbers for the second and third generation SHCLs were not. CONCLUSIONS: Nephrite could be used as a new additive component for CL storage cases and multipurpose solutions to improve the disinfection effects on Acanthamoeba.
Acanthamoeba ; Contact Lenses ; Disinfection ; Hydrogel ; Silicon ; Silicones

BACKGROUND: This study aimed to evaluate the adhesion of Acanthamoeba trophozoites on cosmetic contact lenses (CLs) with and without CL care multipurpose solution (MPS) treatment. METHODS: Acanthamoeba lugdunensis L3a trophozoites were inoculated onto disks trimmed from CLs: 1-day Acuvue moist, 1-day Acuvue define, Acuvue 2, and Acuvue 2 define. After 18-hour inoculation, the number of adherent trophozoites was counted under phase contrast microscopy. The effects of MPS, Opti-Free Express, soaking CLs for 6 hours, on Acanthamoeba adhesion were analyzed. Scanning electron microscopic examination was performed for assessment of Acanthamoeba attached on the lens surface. RESULTS: Acanthamoeba trophozoites showed greater adhesion to cosmetic CL (P = 0.017 for 1-day CL and P = 0.009 for 2-week CL) although there was no significant difference between the types of cosmetic CL. On all lenses, the number of adherent Acanthamoeba was significantly reduced after treatment with MPS (P < 0.001 for 1-day Acuvue moist, P = 0.046 for 1-day Acuvue define, P < 0.001 for Acuvue 2, and P = 0.015 for Acuvue 2 define), but there was still significant difference between conventional and cosmetic CLs (P = 0.003 for 1-day CL and P < 0.001 for 2-week CL, respectively). More attachment of Acanthamoeba was observed on colored area and the acanthopodia of Acanthamoeba was placed on the rough surface of colored area. CONCLUSION: Acanthamoeba showed a greater affinity for cosmetic CL and mostly attached on colored area. Although MPS that contained myristamidopropyl dimethylamine reduced the adhesion rate, there was a significant difference between conventional and cosmetic CLs.
Acanthamoeba ; Contact Lenses ; Microscopy, Phase-Contrast ; Trophozoites

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

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