Keratokonus: Epidemiologie, Risikofaktoren und Diagnostik

Abstract

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.

Study of <b><i>VSX1</i></b> Mutations in Patients with Keratoconus in Southwest Iran Using PCR-Single-Strand Conformation Polymorphism/Heteroduplex Analysis and Sequencing Method

“…In spite of an enormous amount of research conducted to explain the etiology and disease progression, VSX1 is the sole gene indicated as an important genetic factor in determining KC. In this study, 3 sequence variations were detected, all of which have been previously reported [3,4,18,29,30]. We found the H244R mutation in exon 4 of the gene; it was present in 2% of the patients and 2% of the healthy control subjects, which is concordant with the results of other studies [12,23,31,32,33,34,35,36] (table 3).…”

The point mutation and polymorphism in keratoconus candidate gene TGFBI in Chinese population

“…The etiology of the disease was considered to the abnormal collagen synthesis or degradation caused by numerous factors, including genetic, virus, toxins, metabolic and immune variations (Hu and Wei, 2010;Romero-Jimenez et al, 2010). In recent years, the disease was considered as a disease caused by multiple genetic variations, including those controlling the collagen dynamics during development (Edwards et al, 2001;Grunauer-Kloevekorn and Duncker, 2006;Rabinowitz, 2003;Romero-Jimenez et al, 2010). For instance, there were correlationship studies between keratoconus and collagen type VI α1 chain (COL6A1) gene, homeobox VSX1 gene, as well as TGFBI gene (Heon et al, 2002;Hu and Wei, 2010;Stabuc-Silih et al, 2009;Suesskind et al, 2006).…”

Riboflavin–UVA corneal collagen crosslinking as an evolving surgical procedure for progressive ophthalmic tissue diseases

“…The frequency of keratoconus in the general population is approximately 1 in 2000. 1 The condition starts at puberty, progressing in approximately 20% to an extent that penetrating keratoplasty (PKP) becomes necessary. Along with PKP, hard contact lenses are the major treatment modality for keratoconus.…”