Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Keratoconus is the most common form of corneal dystrophy. It consists of a non inflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. In more advanced cases, opacities can be seen at the apex of the cone. Traditional conservative management of keratoconus begins with spectacle correction and contact lenses. Surgery is recommended when a stable contact lens fit fails to provide adequate vision. Keratoplasty was long the only surgical treatment, but recent years have seen the introduction of new surgical options:--Collagen cross-linking stiffens the cornea and can halt disease progression;--Intrastromal corneal rings can reduce astigmatism and improve visual acuity;--Intraocular lenses are valuable additional options for the correction of refractive errors. Currently, keratoplasty is mainly restricted to patients with opacities of the central cornea.
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PMID:[Keratoconus, the most common corneal dystrophy. Can keratoplasty be avoided?]. 2203 7

Keratoconus (KTCN), a non-inflammatory corneal disorder characterized by stromal thinning, represents a major cause of corneal transplantations. Genetic and environmental factors have a role in the etiology of this complex disease. Previously reported linkage analysis revealed that chromosomal region 13q32 is likely to contain causative gene(s) for familial KTCN. Consequently, we have chosen eight positional candidate genes in this region: MBNL1, IPO5, FARP1, RNF113B, STK24, DOCK9, ZIC5 and ZIC2, and sequenced all of them in 51 individuals from Ecuadorian KTCN families and 105 matching controls. The mutation screening identified one mutation and three sequence variants showing 100% segregation under a dominant model with KTCN phenotype in one large Ecuadorian family. These substitutions were found in three different genes: c.2262A>C (p.Gln754His) and c.720+43A>G in DOCK9; c.2377-132A>C in IPO5 and c.1053+29G>C in STK24. PolyPhen analyses predicted that c.2262A>C (Gln754His) is possibly damaging for the protein function and structure. Our results suggest that c.2262A>C (p.Gln754His) mutation in DOCK9 may contribute to the KTCN phenotype in the large KTCN-014 family.
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PMID:Novel mutation and three other sequence variants segregating with phenotype at keratoconus 13q32 susceptibility locus. 2204 97

In a seven-year-old male cynomolgus monkey, erythema of the upper eyelid and forehead and corneal opacity, edema and conical protrusion in the eye were observed. At necropsy, ophthalmological and serological examinations revealed binocular corneal opacity and conical protrusion and a high IgE level, respectively. Thinning of the epithelium and stroma of the cornea were noted histopathologically. At the center of the corneal epithelium, the number of epithelial cells was reduced, their cytoplasm was poorer and the basal cells were flatter than at the periphery. Bowman's membrane was folded with partial loss or breakage. Collagen fibers were compacted or disarranged, and the keratocytes were increased in the stroma, with focal pyknosis or loss of the endothelium and folding of Descemet's membrane. Electron microscopical examination revealed atrophy of the corneal epithelial basal cells. This is the first report of a case of keratoconus in a cynomolgus monkey.
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PMID:Keratoconus in a cynomolgus monkey. 2227 12

Keratoconus is the most common corneal distrophy. It's a noninflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. Many treatment choices include spectacle correction and contact lens wear, collagen cross linking, intracorneal ring segments implantation and finally keratoplasty. Contact lenses are commonly used to reduce astigmatism and increase vision. There are various types of lenses are available. We reviewed soft contact lenses, rigid gas permeable contact lenses, piggyback contact lenses, hybrid contact lenses and scleral-semiscleral contact lenses in keratoconus management. The surgical option is keratoplasty, but even after sutur removal, high astigmatism may stil exists. Therefore, contact lens is an adequate treatment option to correct astigmatism after keratoplasty.
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PMID:Contact lens visual rehabilitation in keratoconus and corneal keratoplasty. 2229 12

This paper documents a rare nonprogressive developmental disorder-bilateral circumscribed posterior keratoconus-in a 60-year-old man referred for a cataract surgery. For the first time ultrasound biomicroscopy was used to visualise the local anterior bulging of the posterior corneal surface with concomitant thinning of the stroma. The amount of localized posterior depression, corneal thickness and the refractive power of both the posterior and anterior corneal curvature were measured using slit-scanning topography analysis (Orbscan).
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PMID:Bilateral circumscribed posterior keratoconus: visualization by ultrasound biomicroscopy and slit-scanning topography analysis. 2249 63

The objective of this case was to report unilateral tilted disc in a boy with ipsilateral keratoconus. The tilted disc syndrome is a non-hereditary bilateral condition. This configuration is accompanied by situs inversus of the retinal vessels, congenital inferonasal conus, thinning of the inferonasal retinal pigment epithelium and choroid, and myopic astigmatism. Unilateral tilted disc syndrome is a rare condition. Keratoconus is a disorder characterised by progressive corneal steepening. The author present a case of unilateral tilted disc in a boy with ipsilateral keratoconus. Pterygium is a common disorder and tilted disc syndrome is a bilateral condition. But unilateral tilted disc in a boy with ipsilateral keratoconus is the first report in literature. Due to these clinical presentation, this report is an exception in literature and reported an unknown clinical coincident.
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PMID:Unilateral tilted disc and ipsilateral keratoconus in the same eye. 2269 92

Mitochondria play a role of energy production and produce intracellular reactive oxygen species (ROS), especially superoxide anion (O2(-)) as a byproduct of energy metabolism at the same time. O2(-) is converted from oxygen and is overproduced by excessive electron leakage from the mitochondrial respiratory chain. It is well known that mitochondrial complexes I and III in the electron transport system are the major endogenous ROS sources. We have previously demonstrated that mutations in complex II can result in excessive ROS (specifically in SDHC: G71E in Caenorhabditis elegans, I71E in Drosophila and V69E in mouse). Moreover, this results in premature death in C. elegans and Drosophila as well as tumorigenesis in mouse embryonic fibroblast cells. In humans, it has been reported that mutations in SDHB, SDHC or SDHD, which are the subunits of mitochondrial complex II, often result in inherited head and neck paragangliomas (PGLs). Recently, we established Tet-mev-1 conditional transgenic mice using our uniquely developed Tet-On/Off system, which can induce the mutated SDHC gene to be equally and competitively expressed compared to the endogenous wild-type SDHC gene. These mice experienced mitochondrial respiratory chain dysfunction that resulted in oxidative stress. The mitochondrial oxidative stress caused excessive apoptosis in several tissues leading to low-birth-weight infants and growth retardation during neonatal developmental phase in Tet-mev-1 mice. Tet-mev-1 mice also displayed precocious age-dependent corneal physiological changes, delayed corneal epithelialization, decreased corneal endothelial cells, thickened Descemet's membrane and thinning of parenchyma with corneal pathological dysfunctions such as keratitis, Fuchs' corneal dystrophy (FCD) and probably keratoconus after the normal development and growth phase. Here, we review the relationships between mitochondrial oxidative stress and phenomena in mev-1 animal models with mitochondrial complex II SDHC mutations. This article is part of a Special Issue entitled: Respiratory complex II: Role in cellular physiology and disease.
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PMID:Model animals for the study of oxidative stress from complex II. 2314 69

We report a rare case of bilateral keratoconus in association with achondroplasia. A 26-year-old male, with a known case of achondroplasia, complained of bilateral gradual deterioration in vision for the past few years. Slit lamp biomicroscopy showed bilateral central corneal protrusion and stromal thinning at the apex consistent with keratoconus. a trial of hard contact lens fitting failed to improve VA in the left eye (LE). Right eye (RE) improved to 20/25. The patient underwent penetrating keratoplasty (PKP) in his LE. Twenty-seven months postoperatively, uncorrected visual acuity (UCVA) was 20/30. Ophthalmologists should be aware that patients with achondroplasia who complain of poor vision should be suspected of having keratoconus once other more common conditions are ruled out.
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PMID:Achondroplasia associated with bilateral keratoconus. 2325 98

Severe loss of vision manifests from the corneal protrusion, thinning and distortion that characterises keratoconus, which in its most severe form is still treated primarily by lamellar or penetrating keratoplasty. Unfortunately, alternative therapeutic options targeting the underlying pathobiology remain limited, attributable to an incomplete understanding of the biological mechanisms instigating stromal deterioration and other disease processes. We postulate that underlying abnormalities in stromal repair and reactive species-linked activities and the interaction between these phenomena are implicated in the development of keratoconus. This revised interpretation of the pathophysiology may, with further investigation, advance our knowledge and the clinical management of this prevalent ectatic disorder.
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PMID:A new perspective on the pathobiology of keratoconus: interplay of stromal wound healing and reactive species-associated processes. 2333 6

Keratoconus is a progressive and non-inflammatory thinning of the cornea, which may result in severe visual impairment due to irregular curvature and scarring. It can occur in isolation but is often seen in association with other systemic or ocular disorders. There is a well-recognised genetic component to keratoconus, as evidenced by family and twin studies; however, the aetiology of the disease is complex with both genetic and environmental factors playing a role. Over the last decade significant progress has been made in identifying genetic risk factors for keratoconus. Multiple approaches have been taken including candidate gene studies and genome-wide studies. VSX1 remains as the best characterised keratoconus gene but only accounts for rare cases. Other candidate genes with a role to play include SOD1, other corneal dystrophy genes such as ZEB1 and TGFBI and collagen genes. Family-based studies have recently led to the identification of the MIR184 gene for keratoconus with cataract and to the DOCK9 gene in a family with isolated keratoconus. Numerous other linkages have been reported and new sequencing technologies are set to rapidly expand the number of identified keratoconus genes in these regions. Similarly, recent genome-wide association studies in case-controlled cohorts have identified common variations in and around HGF, RAB3GAP1 and LOX as candidate risk factors for keratoconus. These gene identifications are beginning to reveal the molecular aetiology of keratoconus but despite this recent progress, there remain numerous genetic risk factors to be identified for this relatively common yet complex disease.
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PMID:Insights into keratoconus from a genetic perspective. 2338 89


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