Corneal fibroblasts may play an important role in the defense system of the cornea by recognizing the presence of LPS and subsequently expressing adhesion molecules and chemokines that promote leukocyte infiltration.

PURPOSE. The detection of bacterial lipopolysaccharide (LPS) by human cells is facilitated by LPS-binding protein (LBP) and soluble (s)CD14. The effects of these proteins on chemokine release and adhesion molecule expression in cultured human corneal fibroblasts were examined. METHODS. The release of chemokines into culture supernatants and the expression of the intercellular adhesion molecule (ICAM)-1 on the cell surface were determined by enzymelinked immunosorbent assays. The intracellular abundance of chemokine and ICAM-1 mRNAs was quantitated by reverse transcription and real-time polymerase chain reaction analyses. The phosphorylation and degradation of IB-␣ and the subcellular localization of NF-B were examined by immunoblot and immunofluorescence analyses, respectively. RESULTS. Neither sCD14 nor LBP alone affected the expression of chemokines or ICAM-1 in cultured human corneal fibroblasts. However, sCD14 or LBP enhanced the LPS-induced upregulation of ICAM-1 and the chemokines interleukin-8 and monocyte chemoattractant protein (MCP)-1 in these cells at the protein and mRNA levels. B acterial corneal ulcer is a major cause of loss of vision in developed and developing countries. This condition results from the destruction of collagen fibrils in the corneal stroma by collagenolytic enzymes produced as a consequence of bacterial infection.1 Pathologic examination has revealed the presence of many infiltrating leukocytes, including neutrophils and macrophages, in or surrounding corneal ulcers. 1 We have shown that the interaction of resident corneal fibroblasts with infiltrating leukocytes very likely promotes collagen degradation.2 Whereas corneal fibroblasts alone in culture degrades collagen fibrils to a small extent, neutrophils alone do not. However, the addition of either neutrophils or neutrophilconditioned medium to corneal fibroblasts results in a marked increase in the amount of collagen degraded by the fibroblasts. We have also demonstrated an interaction between bacteria and corneal fibroblasts in culture, in that elastase produced by Pseudomonas aeruginosa both degrades collagen directly and activates the collagen-degrading matrix metalloproteinases produced by corneal fibroblasts.3 In addition, we found that corneal fibroblasts are able to detect the presence of lipopolysaccharide (LPS), a component of the cell membrane of Gramnegative bacteria, and that they upregulate the expression of the chemokines interleukin (IL)-8 and monocyte chemoattractant protein (MCP)-1 and that of intercellular adhesion molecule (ICAM)-1 in response.4 Such a response in vivo would be expected to trigger the local infiltration of leukocytes. Corneal fibroblasts may thus function as sentinel and effector cells in the defense of the cornea against bacterial infection.LPS is an amphipathic molecule with a large hydrophobic component and a small hydrophilic domain. 5 The lipophilic portion of LPS, known as lipid A, is the active component. 6 In an aqueous environment, LPS exists as polymeric aggregates, with the hydro...

Overnight orthokeratology improved uncorrected visual acuity and reduced refractive error but increased corneal irregularity and impaired contrast sensitivity. However, these changes in visual function and corneal shape were reversed after discontinuation of orthokeratology lens wear.

Eyedrops containing FGLM-amide and SSSR were effective for the prevention of SPK after cataract surgery in diabetic patients.

The BCL index was increased after cataract surgery and in eyes affected by bullous keratopathy, conditions associated with corneal epithelial oedema. This quantitative measure obtained by confocal microscopy may prove useful in the clinical evaluation of corneal epithelial oedema.