Die Struktur der Extrazellul�rmatrix bei Keratokonus

Stachs, Oliver; Bochert, A; Gerber, Thomas; Koczan, Dirk; Thiessen, H. J.; Guthoff, Rudolf

doi:10.1007/s00347-003-0902-3

Cited by 22 publications

(9 citation statements)

References 24 publications

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“…Collagen type IV α1/α2 chains have been reported in KC patients [34], while COL4A1 has been shown to be down-regulated in KC corneas [35]. The chromosomal loci of COL4A1 and COL4A2 are close to 13q32 [32], with the COL4A1 gene consisting of 52 exons and COL4A2 gene of 48 exons [28].…”

Section: Resultsmentioning

confidence: 99%

The Proteins of Keratoconus: a Literature Review Exploring Their Contribution to the Pathophysiology of the Disease

Loukovitis¹,

Kozeis

Gatzioufas³

et al. 2019

Adv Ther

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IntroductionKeratoconus (KC) is a complex, genetically heterogeneous multifactorial degenerative disorder characterized by corneal ectasia and thinning. Its incidence is approximately 1/2000–1/50,000 in the general population. KC is associated with moderate to high myopia and irregular astigmatism, resulting in severe visual impairment. KC structural abnormalities primarily relate to the weakening of the corneal collagen. Their understanding is crucial and could contribute to effective management of the disease, such as with the aid of corneal cross-linking (CXL). The present article critically reviews the proteins involved in the pathophysiology of KC, with particular emphasis on the characteristics of collagen that pertain to CXL.MethodsPubMed, MEDLINE, Google Scholar and GeneCards databases were screened for relevant articles published in English between January 2006 and June 2018. Keyword combinations of the words “keratoconus,” “risk factor(s),” “genetics,” “genes,” “genetic association(s),” “proteins”, “collagen” and “cornea’’ were used. In total, 272 articles were retrieved, reviewed and selected, with greater weight placed on more recently published evidence. Based on the reviewed literature, an attempt was made to tabulate the up- and down-regulation of genes involved in KC and their protein products and to delineate the mechanisms involved in CXL.ResultsA total of 117 proteins and protein classes have been implicated in the pathogenesis and pathophysiology of KC. These have been tabulated in seven distinct tables according to their gene coding, their biochemistry and their metabolic control.ConclusionThe pathogenesis and pathophysiology of KC remain enigmatic. Emerging evidence has improved our understanding of the molecular characteristics of KC and could further improve the success rate of CXL therapies.

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Section: Resultsmentioning

confidence: 99%

The Proteins of Keratoconus: a Literature Review Exploring Their Contribution to the Pathophysiology of the Disease

Loukovitis¹,

Kozeis

Gatzioufas³

et al. 2019

Adv Ther

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“…Assuming a corneal thickness of 500 mm, the anterior 200 mm had an area portion of 0.4 and a remainder of 0.6; therefore, the stress of the whole cornea can be calculated by s Z 0.4 Â s 200 C 0.6 Â s po (s 200 Z stress in the anterior 200 mm; s po Z stress in the posterior cornea). Stachs et al 19 found an irregular structure of keratocytes only in the anterior stroma of keratoconic cornea by confocal laser-scanning microscopy, which is of great importance because this part is mainly responsible for corneal rigidity. New electron microscopic and X-ray scattering measurements have found a lack of obliquely oriented anterior-to-posterior lamellae crossing or interweaving the stress-bearing lamellae in the anterior stroma of keratoconic corneas.…”

Section: Discussionmentioning

confidence: 99%

Biomechanical evidence of the distribution of cross-links in corneastreated with riboflavin and ultraviolet A light

Kohlhaas

Spoerl²,

Schilde³

et al. 2006

Journal of Cataract and Refractive Surgery

407

278

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Treatment of the cornea with riboflavin and UVA significantly stiffened the cornea only in the anterior 200 microm. This depth-dependent stiffening effect may be explained by the absorption behavior for UVA in the riboflavin-treated cornea. Sixty-five percent to 70% of UVA irradiation was absorbed within the anterior 200 microm and only 20% in the next 200 microm. Therefore, deeper structures and even the endothelium are not affected.

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“…Die Bildung des kornealen Apex ist verbunden mit einer Verlagerung der Achsen der Kollagen-Fibrillen und einer Drehung der orthogonalen Matrix [52]. Dadurch kommt es zu einer Veränderung des Quervernetzungsgrades der Hornhaut mit daraus folgender reduzierter mechanischer Stabilität [70]. Ursächlich ist vermutlich eine veränderte interfibrilläre Matrix, die im Bereich der kornealen Lamellenbildung zu einer veränderten Lamellenstruktur führt und die durch eine Deregulation der Kollagene und Proteoglykane erklärt werden kann.…”

Section: Struktur Der Kollageneunclassified

“…Zwei unabhängige Studien beschreiben ein Auftreten eines Mitralklappenprolaps in Zusammenhang mit einem Keratokonus in 44 -58 %. Diese beiden Studien legen die Verbindung eines Keratokonus mit einer Fehlexpression eines Kollagens nahe [7,70]. In einer größeren Studie konnte dieser Zusammenhang jedoch nicht belegt werden [74].…”

Section: Mitralklappenerkrankungenunclassified

Keratokonus: Epidemiologie, Risikofaktoren und Diagnostik

Grünauer-Kloevekorn

Duncker

2006

Klin Monatsbl Augenheilkd

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Keratoconus is a bilateral, non-inflammatory and progredient corneal ectasia with an incidence of approximately 1 per 2,000 in the general population. Within the second decade of life the cornea develops a conical shape, due to thinning of the corneal stroma with subsequent irregular astigmatism and myopia leading to marked impairment of vision. The most common presentation of the keratoconus is as a sporadic disorder, but it has long been recognized that a significant minority of patients exhibit a family history as an autosomal dominant mode of inheritance. Most investigators suggest complete penetrance of predisposing factors with variable phenotypic expression. In some patients heterozygous mutations in the VSX1 gene are described as the underlying gene defect. An association with Down syndrome, monosomia X (Turner syndrome), Leber's congenital amaurosis, mitral valve prolaps, collagenosis, retinitis pigmentosa and Marfan syndrome is described. The role of corneal cells in the pathogenesis of keratoconus is supported by the published reports of recurrence of keratoconus in eyes after penetrating keratoplasty due to graft repopulation by the recipient cells. Placido-based computeed videokeratographic corneal curvature mapping systems, linked with pachymetry, are useful for identifying overt and subclinical cases of keratoconus. Different indices may quantify the clinical features of keratoconus and may improve the classification. We compared videokeratometric data (Fourier series harmonic analysis and wavefront analysis) in eyes with keratoconus to answer the question of which parameters are useful for early diagnosis of keratoconus.

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Die Struktur der Extrazellul�rmatrix bei Keratokonus

Abstract: The changes point on deregulation of the matrix arrangement. The interest in the cause of the disease is focused on the interfibrillar arrangement, the interaction between collagen and proteoglucanes.

Cited by 22 publications

References 24 publications

The Proteins of Keratoconus: a Literature Review Exploring Their Contribution to the Pathophysiology of the Disease

The Proteins of Keratoconus: a Literature Review Exploring Their Contribution to the Pathophysiology of the Disease

Biomechanical evidence of the distribution of cross-links in corneastreated with riboflavin and ultraviolet A light

Keratokonus: Epidemiologie, Risikofaktoren und Diagnostik

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