A 48-year-old woman suffering from keratoconus of both eyes sought medical attention at the ophthalmology clinic with her left eye having been painful for prior 3 weeks, as well as increased sensitivity to light, foreign body sensation, stinging and watering eye. Her left eye was diagnosed with the dry eye syndrome, in addition to being treated with gas permable contact lens. Physical examination revealed corneal punctate epithelial erosions that stained positively with fluorescein in the left eye. The patient was ultimately diagnosed with dry eye disease of the left eye caused by gas permable contact lens usage.
Keratoconus (KC) is a corneal disease associated with structural abnormalities in the corneal epithelium, Bowman's layer and stroma and altered concentration of tear components. KC corneas show a different pattern of collagen lamellae than their normal counterparts. Also, a reduction of several collagen types in KC epithelium and stroma was observed. Altered expression and/or activity of lysyl oxidase, a critical enzyme of the biogenesis of connective tissue detected in KC corneas, may weaken covalent bonds between collagen and elastin fibrils, what may lead to biomechanical deterioration of the cornea. Increased activity of matrix metalloproteinases observed in KC may induce the degradation of the extracellular matrix causing damage to the cornea. Oxidative and nitrative stress play an important role in KC pathogenesis and KC corneas are characterized by the disturbed lipid peroxidation and nitric oxide pathways. Malfunctioning of these pathways may lead to accumulation of their toxic by-products inducing several detrimental effects, along with apoptosis of the corneal cells, which may result from the loss of β-actin or increased levels of cytokines, including interleukin-1 and -6. Change in the expression of genes associated with wound healing, including the nerve growth factor and the visual system homeobox 1, may contribute to increased susceptibility of KC corneas to injury. Consequently, biochemical changes may play an important role in KC pathophysiology and, therefore, can be considered in prevention, diagnosis, prognosis and in the therapy of this disease as well.
Sieciowanie kolagenu rogówki jest techniką stosowaną w okulistyce, której mechanizm polega na wytworzeniu nowych wiązań pomiędzy włóknami kolagenu, co prowadzi do stabilizacji i usztywnienia struktury rogówki. Najczęstszym wskazaniem do wykonywania zabiegów sieciowania kolagenu rogówki jest zapobieganie progresji zmian ektatycznych rogówki, tzn. stożka rogówki, zwyrodnienia brzeżnego przezroczystego oraz ektazji po zabiegach fotokeratorefrakcyjnych. Doniesienia naukowe wskazują także na skuteczność sieciowania kolagenu rogówki w leczeniu bakteryjnych zakażeń rogówki oraz keratopatii pęcherzowej. Technika ta jest skuteczna w stabilizacji ektazji, a leczenie często prowadzi do zwiększenia ostrości widzenia, zmniejszenia maksymalnej wartości keratometrii oraz poprawy obrazu topografii rogówki. Ponadto dzięki zastosowaniu sieciowania kolagenu rogówki możemy uniknąć konieczności wykonania bardziej inwazyjnych zabiegów chirurgicznych, takich jak przeszczep rogówki, lub odroczyć je w czasie.
EN
Corneal collagen cross-linking, a technique used in ophthalmology, involves the creation of new bonds between collagen fibers, thus leading to stabilization and corneal stiffening. The most common indication for corneal collagen cross-linking procedures is to prevent the progression of corneal ectasia,\ i.e., keratoconus, pellucid marginal degeneration, and ectasia after corneal refractive surgery. Clinical data also indicate that it is effective in the treatment of bacterial corneal infections and bullous keratopathy. Corneal collagen cross-linking was shown to inhibit the progression of corneal ectasia, and the treatment commonly leads to the improvement in visual acuity, decreases the maximum keratometry values, and improves the corneal topography image. In addition, it is possible to avoid or postpone the need for more complex and invasive surgery.
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