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.

A 30-year-old man developed a lamellar keratitis around the flap, both inside and outside the flap margin after LASIK. With an impression of peripheral diffuse lamellar keratitis (DLK), topical and systemic steroid were started which led to a dramatic improvement in signs and symptoms. Although, diffuse lamellar keratitis is most often seen in the flap interface, it may be seen outside the flap margin, within the untouched cornea.

Peripheral ulcerative keratitis (PUK) is a rare but serious ocular condition that is an important clinical entity due to its ophthalmological and systemic implications. It is characterized by progressive peripheral corneal stromal thinning with an associated epithelial defect and can be associated with an underlying local or systemic pro-inflammatory condition, or present in an idiopathic form (Mooren ulcer). Associated conditions include autoimmune diseases, systemic and ocular infections, dermatologic diseases, and ocular surgery. Cell-mediated and autoantibody-mediated immune responses have been implicated in the pathogenesis of PUK, destroying peripheral corneal tissue via matrix metalloproteinases. Clinically, patients with PUK present with painful vision loss, a peripheral corneal ulcer, and often adjacent scleritis, episcleritis, iritis, or conjunctivitis. Diagnostic evaluation should be focused on identifying the underlying etiology and ruling out conditions that may mimic PUK, including marginal keratitis and Terrien marginal degeneration. Treatment should be focused on reducing local disease burden with topical lubrication, while simultaneously addressing the underlying cause with antimicrobials or anti-inflammatory when appropriate. Existing and emerging biologic immunomodulatory therapies have proven useful in PUK due to autoimmune conditions. Surgical treatment is generally reserved for cases of severe thinning or corneal perforation.

A 45-year-old female presented with bilateral ocular pain and redness. The best-corrected visual acuity (BCVA) at presentation was 20/30 OD and 20/100 OS. Slit lamp examination revealed 2×2 mm epithelial defects with mid-stromal infiltrate and dark brown corneal plaques on both eyes. The plaque surface was dry and raised with brownish pigmentation. The margins of the stromal infiltrate had feathery edges. Corneal scraping was performed bilaterally. The Sabouraud’, s dextrose agar culture of each eye grew woolly, gray to black colonies by the seventh day. A Curvularia sp. was identified....

Purpose: To study the clinico‑ microbiological profile and outcomes of infectious keratitis (IK) at a tertiary eye care center in North India. Methods: This is a retrospective, hospital‑ based, cross‑ sectional study. One thousand seven hundred and eighty‑ six corneal microbiological reports were identified from January 2017 to December 2018, out of which 625 patients of IK fulfilled the inclusion criteria. They underwent microbiological examination which included corneal scrapings, culture, and antibiotic sensitivity. Demographic features, signs and symptoms, risk factors such as associated trauma, previous ocular surgery, and use of corticosteroids were also recorded. Results: Of the 625 patients, 68. 2% were male and 31. 8% were female. The age group affected most was the sixth decade; 21. 9% (137 cases). Trauma was the most common associated risk factor in 151 cases (24. 2%) followed by previous ocular surgery in 111 (17. 8%). Out of the 625 corneal scrapings, 393 (62. 9%) were culture-positive. Bacterial culture accounted for 60. 6% (238/393) and fungal cultures were 143 (36. 4%). More than 50% of the bacterial keratitis cases and more than 60% of the fungal cases had a favorable outcome. Staphylococcus sp. and Fusarium sp. were the most common bacteria and fungus isolated, respectively. Only one‑ third of the cases required surgical intervention, and the remaining two‑ thirds were managed medically. Conclusions: In the current study, cultures were positive in 63% of cases, and the majority of cases had bacterial growth. Surgical intervention was needed in one‑ third of the cases. Management of corneal infections is incomplete without a good microbiological workup. Ophthalmologists should be encouraged to learn and practice basic staining procedures, and this should start early in the training years.

Purpose: To investigate confocal scan features of corneal subbasal nerve plexus and epithelial dendritic cells in herpes simplex keratitis (HSK) as compared to Acanthamoeba keratitis (AK).Methods: Confocal scan records of patients with clinical and confocal microscopic features compatible with HSK and AK as well as confocal scan records of normal participants were reviewed. The density and morphologic parameters of epithelial dendritic cells (EDCs) and changes in subbasal nerve plexus (SNP) were evaluated and compared among the groups.Results: A total of 52 eyes of 52 patients were enrolled: 12 eyes (23.08%) of 12 patient with clinical and confocal scan features of HSK, 20 eyes of 20 patients (38.46%) with clinical and confocal scan results compatible with AK, and 20 eyes (38.46%) of 20 normal subjects. Mean density, numbers, and area of EDCs were significantly increased in both HSK and AK groups compared to the controls (P<0.001). Main nerve trunk number, nerve branches, total nerve numbers, nerve diameter and subbasal nerve density were statistically lower in HSK and AK groups as compared to the controls (P<0.001). Nerve tortuosity was significantly decreased in HSK and AK groups in comparison to the normal eyes (P=0.013). No statistically significant difference was observed between the HSK and AK groups in abovementioned parameters.Conclusion: Using confocal scan, this study showed significant changes in mean density and morphometric parameters of SNP and EDCs in HSK and AK. The findings can indicate a strong interaction between immune response and corneal innervation in these two corneal diseases.

Background: Amoebic keratitis introduced as a painful corneal infection which sometimes lead to poor vision and blindness. The main goal of this study was to report amoebic keratitis during ten years from 1997-2007 in patients who was suspected to have amoebic keratitis and referred to Parasitology laboratory, School of Public Health, Tehran University of Medical Sciences, Iran. Other aim was to assess the major risk factor for developing this sight-threatening disease. Comparison of lens culture and corneal scrapes culture also was performed.Methods: During 1997-2007, 142 patients referred to Dept. of Medical Parasitology, School of Public Health, Tehran University of Medical Sciences, Iran. Details of each patient such as age, sex, history of contact lens wear, type of contact lens, clinical symptoms were recorded in questioners. Keratitis was diagnosed on the basis of culture of lenses and/or corneal scrapes on non-nutrient agar overlaid with Escherichia coli and direct microscopy of lenses and/or corneal scrapes.Results: Among 142 patients, 49 (34.5%) had amoebic keratitis. 73.46% of these patients were from Tehran but there were a few cases from other cities. The commonest age was between 15-25 yr (75.5%) and more female (37:12) were identified then male. It is worth to mention that 44 patients (89.79%) were contact lens wearers who among them 41 patients (93.18%) wore soft contact lens and only three patients suffer from amoebic keratitis because of wearing hard contact lens. Other finding of this study demonstrated that the most common sign of the patients was severe pain combined with photophobia.Conclusion: This study indicates that Acanthamoeba keratitis continue to rise in Iran. This is due to increase frequency of lens wearers as well as consideration of ophthalmologist to Acanthamoeba as an agent of keratitis and improvement of laboratory methods. Another finding of this research was the confirmation of soft contact lens as a major risk factor. It is recommended to educate contact lens wearers for regular disinfection. Besides, culture of corneal scrapes was negative in most of cases, so lens culture were performed which had a much better result.