Levels of Collagen Degradation Products (Telopeptides) in the Tear Film of Patients with Keratoconus

Abalain, Jean-Hervé; Dossou, H; Colin, Joseph; Floch, H.H.

doi:10.1097/00003226-200007000-00014

Cited by 40 publications

(23 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[129][130][131] One study found higher concentrations of C-terminal telopeptide (type I collagen degradation products) in tears of patients with keratoconus than in controls. 132 This behavior is due to the increase of activity and number of enzymes that remodel the ECM; the most prominent changes in keratoconic cornea were observed in collagenase MMP-13, and in particular, in cathepsin K and human trypsin-2, which were strongly expressed in keratoconus, suggesting a role in intra-and extracellular pathological collagen destruction, respectively. 23 A similar report documented 1.9 times more proteolytic activity and gelatinases/collagenases expression (MMP-1, MMP-3, MMP-7, and MMP-13, as well as IL-4, IL-6, and TNF-α that increase the production and activity of the former).…”

Section: Enzymatic Imbalancementioning

confidence: 99%

Keratoconus: an inflammatory disorder?

Galvis

Sherwin

Tello

et al. 2015

Eye

293

199

View full text Add to dashboard Cite

Keratoconus has been classically defined as a progressive, non-inflammatory condition, which produces a thinning and steepening of the cornea. Its pathophysiological mechanisms have been investigated for a long time. Both genetic and environmental factors have been associated with the disease. Recent studies have shown a significant role of proteolytic enzymes, cytokines, and free radicals; therefore, although keratoconus does not meet all the classic criteria for an inflammatory disease, the lack of inflammation has been questioned. The majority of studies in the tears of patients with keratoconus have found increased levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase (MMP)-9. Eye rubbing, a proven risk factor for keratoconus, has been also shown recently to increase the tear levels of MMP-13, IL-6, and TNF-α. In the tear fluid of patients with ocular rosacea, IL-1α and MMP-9 have been reported to be significantly elevated, and cases of inferior corneal thinning, resembling keratoconus, have been reported. We performed a literature review of published biochemical changes in keratoconus that would support that this could be, at least in part, an inflammatory condition.

show abstract

Section: Enzymatic Imbalancementioning

confidence: 99%

Keratoconus: an inflammatory disorder?

Galvis

Sherwin

Tello

et al. 2015

Eye

293

199

View full text Add to dashboard Cite

show abstract

“…Factors determining or affecting the progression or stabilization of KC have not been well understood [3,4]. During tissue degradation - a hallmark of the disease - the expression of inflammatory mediators such as proinflammatory cytokines, cell adhesion molecules and matrix metalloproteinases (MMPs), as well as other enzymes and growth factors, has also been described [4,5,6,7,8,9,10,11,12,13]. Recent studies have suggested a role of the inflammatory events in the pathogenesis of KC [4,14].…”

Section: Introductionmentioning

confidence: 99%

Association between Mediators in the Tear Fluid and the Severity of Keratoconus

Kolozsvári¹,

Petrovski²,

Gogolák

et al. 2013

Ophthalmic Res

View full text Add to dashboard Cite

Purpose: To study the association between different types of mediators in the tear fluid and topographic indices characterizing the severity of keratoconus (KC). Methods: In this study, nonstimulated tear fluid samples were collected from 14 eyes of 11 patients with KC. The following indices were measured by corneal topography: maximum K value, average K value, Klyce/Maeda keratoconus index (KCI), Smolek/Klyce keratoconus severity index, opposite sector index, center/surround index, keratoconus prediction index and standard deviation of corneal power. The concentrations of interleukin (IL)-6, IL-13, CXCL8 (IL-8), chemokine (C-C motif) ligand 5 (CCL5, regulated and normal T cell expressed and secreted), matrix metalloproteinase-9 (MMP-9), MMP-13, tissue inhibitor of metalloproteinase-1, nerve growth factor (NGF) and epidermal growth factor were measured by cytometric bead array technology. Release of mediators was calculated from their concentrations and the volume of tears collected over 2 min. Results: Significant positive associations were found between CCL5, MMP-13 and NGF and several topographic indices. Significant negative correlations were found between IL-6 and KCI. Age-dependent associations were observed between IL-13, CXCL8, CCL5 and MMP-13 and the topographic data. Conclusion: Several correlations were observed between the mediators and the topographic indices, suggesting possible roles in the pathophysiology of KC. Our data indicate that some mediators have different effects on the severity of disease in an age-dependent manner.

show abstract

“…The corneal thinning in KC seems to result from a loss of structural components such as collagen. This loss results more from increased proteolytic activity than from decreased synthesis of these elements [1,26]. Especially the membrane-type 1 matrix metalloprotease and matrix metalloprotease 2 are upregulated in KC [4].…”

Section: Discussionmentioning

confidence: 99%