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Microsporidia are a rare and commonly misdiagnosed cause of corneal infection, accounting for approximately 0.4% of cases of microbial keratitis in some populations. Ocular microsporidiosis most often presents as either microsporidial keratoconjunctivitis (MKC) or microsporidial stromal keratitis (MSK). Though these two clinical entities exhibit similar symptomology, they are distinguished from one another by the time course for disease progression, findings on slit-lamp examination, and response to medical therapy. This review summarizes the current literature on the etiology and clinical presentation of microsporidial infections of the cornea and highlights ongoing developments in available diagnostic modalities and treatment regimens. [ABSTRACT FROM AUTHOR]

The article presents an update on the research about the role of corneal epithelial, stromal and endothelial stem cells as sources of regenerative cell-based therapy. The alternative sources of the corneal stem cells are also examined, such as oral mucosal epithelium and mesenchymal stem cells. The researchers also identify the barriers to the successful translation of stem cell transplantation to the clinical setting, including the engineering of a biocompatible tissue equivalent.

The article reports on findings of current researches for using adult corneal stem cells for regenerative therapy of the cornea. Studies on the effectiveness of using stem cells from corneal limbal epithelial (LESCs), stromal, and human corneal endothelial (HCE) layers are discussed. Alternative sources of stem cells from cultured conjunctival epithelial cells, dental pulp, and hair follicles are also discussed.

The concept of lamellar keratoplasty (LK) is not new. However, newer forms of lamellar keratoplasty techniques have emerged in the last decade or so revolving around the concept of targeted replacement of diseased corneal layers. These include anterior lamellar keratoplasty (ALK) techniques that aim to selectively replace diseased corneal stroma and endothelial keratoplasty techniques aiming to replaced damaged endotheliumin endothelial disorders. Recent improvements in surgical instruments and introduction of new techniques as well as inherent advantages such as preservation of globe integrity and decreased graft rejection have resulted in the reintroduction of LK as an acceptable alternative to conventional PK. In this review, indications, benefits, limitations, and outcomes of various anterior and posterior lamellar keratoplasty techniques are discussed. [ABSTRACT FROM AUTHOR]

The article describes endophthalmitis, an inflammation of the internal structures of the eye and can be infectious or non-infectious. It focuses on infectious postoperative endophthalmitis, classified further into acute, delayed-onset, and late-onset categories. It describes noninfectious inflammatory endophthalmitis (NIE) as a sterile inflammatory reaction that can clinically mimic the appearance of an infectious endophthalmitis.

Objective: To evaluate the ability of human adiposederived stem cells (h-ASCs) to survive and differentiate in corneal stroma. Methods: Our experiment consisted of 2 phases. First, we cultured h-ASCs in different types of hyaluronic acid (HA)-derived synthetic extracellular matrixes (sECMs) to determine the capability of proliferation and survival of the cells in hydrogels. Second, h-ASCs were grown in plastic flasks, labeled with an intracytoplasmic membrane fluorescent molecule, transferred onto different types of sECMs or the native HA product, and then inserted into the corneal stroma of the rabbits. After 10 weeks, we assessed the viability of the stem cells and the expression of cornea-specific proteins. Results: The in vitro study showed that the HyStem-HP hydrogel had the highest yield of cells (1.1×106/mL) compared with other types of HA-derived sECMs culture media, and the cells grown in the HyStem-HP hydrogel appeared more elongated and fibroblastlike. The in vivo study demonstrated that the labeled h-ASCs could be identified in the stroma with any type of sECM. The HAderived sECMs, particularly the HyStem-HP hydrogel, showed better survival and cell morphologic features compared with pure HA. Immunostaining of keratocan, aldehyde dehydrogenase, and type I collagen revealed that the stem cells had expressed human cornea-specific proteins. Conclusion: Human adipose-derived stem cells can be successfully grown on HA-derived sECMs in vivo and can express human cornea-specific proteins. Clinical Relevance: Human ASCs on an HA-derived scaffold may be used as a source of keratocytes to regenerate extracellular matrix-like material in situations where the cornea stroma has been compromised. [ABSTRACT FROM AUTHOR]

Objective To evaluate the efficacy of a chemically modified and cross-linked derivative of hyaluronan (CMHA-SX) for treatment of corneal epithelial abrasion and standardized alkali burn injuries. Animals Twelve female New Zealand white rabbits in two groups were used. Procedures Bilateral 6-mm diameter corneal epithelial abrasions were made in each of six rabbits in one group and 6-mm standardized alkali burn injuries were made in the second group. A 1% CMHA-SX formulation was applied topically four times per day in right eye of each rabbit for 1 week, and phosphate buffered saline (PBS) was placed in left (control) eye of each rabbit. The wound size was determined by staining with 1% fluorescein and photographed at the slit lamp with a digital camera at 0, 1, 2, 3 days postoperatively in the first group and 0, 1, 2, 3, 7, 12 days in the second group. Rabbit corneas were collected for histological examination on day 7 in the first group and day 12 in the second group. Results Closure of corneal wound in the abrasion model was complete in the CMHA-SX treated eye by 48 h. The wound closure rate and thickness of the central corneal epithelium in the CMHA-SX treated group was greater than in control eyes for both the abrasion and alkali burn injuries. Moreover, the CMHA-SX treated cornea exhibited better epithelial and stromal organization than the untreated control cornea. Conclusions Chemically modified and cross-linked derivative of hyaluronan improved corneal wound healing and could be useful for treating noninfectious corneal injuries. [ABSTRACT FROM AUTHOR]

An essential step of laser in situ keratomileusis surgery is corneal flap creation, Femtosecond (FS)-assisted or mechanical microkeratome. Each type has rare intraoperative and postoperative complication rates. Several recent studies have identified risk factors and guidelines to help manage these complications. Fortunately, studies have shown no loss of best-corrected visual acuity (BCVA) after the management of intraoperative and postoperative complications in IntraLase FS and mechanical microkeratome. Refractive surgeons need to be aware of the types of complications that can occur, how to avoid them and how to manage them to ensure the best possible outcomes. [ABSTRACT FROM AUTHOR]

Keratoconus is a non-inflammatory, progressive thinning process of the cornea. It is a relatively common disorder of unknown etiology that can involve each layer of the cornea and often leads to high myopia and astigmatism. Computerassisted corneal topography devices are valuable diagnostic tools for the diagnosis of subclinical keratoconus and for tracking the progression of the disease. The traditional conservative management of keratoconus begins with spectacle correction and contact lenses. Several newer, more invasive, treatments are currently available, especially for contact lens-intolerant patients. Intrastromal corneal ring segments can be used to reshape the abnormal cornea to improve the topographic abnormalities and visual acuity. Phakic intraocular lenses such as iris-fixated, angle-supported, posterior chamber implantable collamer and toric lenses are additional valuable options for the correction of refractive error. Corneal cross-linking is a relatively new method of stiffening the cornea to halt the progression of the disease. The future management of keratoconus will most likely incorporate multiple treatment modalities, both simultaneous and sequential, for the prevention and treatment of this disease. [ABSTRACT FROM AUTHOR]

Purpose: To describe a case of necrotizing scleritis due to Pseudomonas aeruginosa resistant to fourth-generation fluoroquinolones. Methods: Case report. A 50-year-old woman with no history of trauma or surgery presented with pain and redness of the left eye. Results: The patient did not respond to empiric treatment and developed scleral edema with a nummular area of avascular sclera nasally. Histopathologic examination revealed necrotizing scleritis and cultures grew P. aeruginosa resistant to fourth-generation fluoroquinolones. Conclusions: A high index of suspicion for an infectious etiology must be maintained in cases not responding to conventional noninfectious scleritis therapy and in cases with unusual presentations. Resistance to commonly used empiric antibiotics may further complicate the diagnosis and management of infectious scleritis. [ABSTRACT FROM AUTHOR]