Acanthamoeba species are vision-threatening agents by causing cornea infections known as Acanthamoeba keratitis. A 5 year-old kid with the complaints of erythema, eyelid edema, inflammation, limitation of eye movements in the right eye, and having no history of wearing contact lenses or trauma, was diagnosed of Acanthamoeba conjunctivitis through laboratory examinations in the Ophthalmology clinic. The visual sharpness of the patient improved after the treatment. A 44 year-old female patient suffering from pain, stinging, irritation, and inability to see in the left eye with the history of wearing contact lenses or trauma was diagnosed of Acanthamoeba keratitis through laboratory examinations. The agent was isolated and identified as "A. castellani" in the Genotype "T2". Examination of the left eye on the 15th day of treatment indicated that all complaints disappeared except for the cataract originated visual loss. However, the first diagnosis of Acanthamoeba keratitis appeared in the literature on a case with no history of wearing contact lenses and trauma it is found to be attention grabbing. We think that Acanthamoeba should not be ignored among microbial agents that cause eye infection with or without trauma and contact lens usage history.

conjunctivitis is a commonly encountered condition in ophthalmology clinics throughout the world. In the management of suspected cases of conjunctivitis, alarming signs for more serious intraocular conditions, such as severe pain, decreased vision, and painful pupillary reaction, must be considered. Additionally, a thorough medical and ophthalmic history should be obtained and a thorough physical examination should be done in patients with atypical findings and chronic course. Concurrent physical exam findings with relevant history may reveal the presence of a systemic condition with involvement of the conjunctiva. Viral conjunctivitis remains to be the most common overall cause of conjunctivitis. Bacterial conjunctivitis is encountered less frequently and it is the second most common cause of infectious conjunctivitis. Allergic conjunctivitis is encountered in nearly half of the population and the findings include itching, mucoid discharge, chemosis, and eyelid edema. Long-term usage of eye drops with preservatives in a patient with conjunctival irritation and discharge points to the toxic conjunctivitis as the underlying etiology. Effective management of conjunctivitis includes timely diagnosis, appropriate differentiation of the various etiologies, and appropriate treatment.

AbstractIntroduction: Chlorine is an effective disinfection agent to kill pathogenic microorganisms in the municipal water treatment system. However, despite treatment, studies have shown that Acanthamoeba is isolated from different water sources in Iran. In this study, the effect of standard concentrations of chlorine used in urban water treatment systems was evaluated on the survival of Acanthamoeba castellanii and its ultrastructure. Materials and methods: Acanthamoeba trophozoites and cysts were exposed to different concentrations (1-10 ppm) of calcium hypochlorite at different times (30 minutes, 1 and 2 hours). Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were used to study the ultrastructural changes of amoebic trophozoite.Results: This study showed that conventional chlorine concentrations could not completely eliminate A. castellanii trophozoites and cysts. Cysts were more resistant to different chlorine concentrations and compared to trophozoites, fewer cysts were killed at the same chlorine concentration and exposure time. Alteration of the cell membrane permeability, decrease in the number of pseudopodia, increase in mitochondria, vacuolation of the cytoplasm, and changes in the endoplasmic reticulum were the main ultrastructural changes in the chlorine-treated amoeba.Conclusion: This study showed that standard chlorine concentrations used as a disinfectant could not eliminate the trophozoites and cysts of A. castellanii. Due to the pathogenicity of the amoeba and its role as the reservoir and transmission of microbial agents, revising the guidelines for using disinfectants such as chlorine in the treatment of urban water systems is highlighted by this study.

Acanthamoeba keratitis (AK) is a serious, potentially sight-threatening corneal infection caused by a pathogenic free-living amoeba. Contact lens wear is the major risk factor in its etiology. This article will review previous studies on the parasitology, epidemiology, pathogenesis, clinical presentations, diagnosis and therapeutic options. This article review previous studies up to 2004 indexed in Medline with the key words: "Acanthamoeba" and "keratitis", Articles with original, clinical, evidence-based and remarkable findings were selected. Data from about 30 articles were extracted. The first cases of AK were reported more than 30 years ago. Its incidence has gradually increased due to the widespread use of contact lenses. Different approaches have been developed to improve diagnosis. Various medications including aromatic diamidines, cationic antiseptics, aminoglycosides, and imidazole derivatives have been proposed for treatment of AK. The medical treatment protocol at Labbafmejad Center, is also introduced. Finally, different surgical modalities which should be considered in case of medically non-responsive AK are discussed. These include epithelial debridement, cryotherapy, lamellar keratectomy and finally penetrating keratoplasty. Although treatment of AK is difficult and time-consuming, early diagnosis and initiation of proper management has a vital role in final visual prognosis and globe integrity.