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At least 19 recordsLinked to original sources
PubMed2006

Effects of corneal neovascularization on the manifestations of Avellino corneal dystrophy (granular corneal dystrophy type II).

PURPOSE: To evaluate the corneal deposits of Avellino corneal dystrophy (ACD) in patients with corneal neovascularization from pterygium or phthisis bulbi as a way of understanding the pathogenesis of ACD. METHODS: Five patients with ACD with pterygium, 10 patients with ACD (age >50 years) without pterygium, 1 patient with ACD with phthisis bulbi with corneal neovascularization, and 1 patient with ACD with phthisis bulbi without corneal neovascularization were examined. The corneal deposits of all patients were assessed by slit-lamp examination and reviewed with biomicroscopic photographs. The distance between the limbus and the nearest corneal opacities was measured. RESULTS: In eyes with vascularized nasal pterygia, there was a granule-free zone adjacent to the advancing edge of the pterygium so that the distance between the nasal limbus and the most nasally located granule exceeds that of the distance between the limbus and the closest granule elsewhere on the cornea. In patients with ACD with phthisis bulbi, no granular deposits were observed in the cornea with neovascularization, but there were deposits in the cornea without neovascularization. CONCLUSION: Corneal neovascularization prevents the deposition of corneal opacities in patients with ACD.

Adult↗
PubMed2003

A molecular perspective on corneal dystrophies.

Corneal dystrophies refer to a group of corneal diseases and that are genetically determined. These have been traditionally classified with respect to the layer of cornea involved. We now know that this does not reflect the underlying pathobiology. Most of the corneal dystrophies are of Mendelian inheritance with some phenotype diversity and a variable degree of penetrance. The dystrophies involving enzymatic processes tend to be of autosomal recessive inheritance. In some cases, such as keratoconus, the inheritance pattern is not always clear and is considered complex. The age of onset of the disease, as in most inherited eye disorders, is variable and does not reflect the underlying pathogenic defect. Few cases are congenital. Our understanding of corneal dystrophies is undergoing somewhat of a revolution as over 12 chromosomes have been associated with corneal dystrophies with mutations identified in at least 14 genes if one includes anterior segment dysgenesis in this group of conditions. Several dystrophies remain without a gene or a genetic location (locus) and more familial studies are required. The new molecular information is challenging the traditional thinking about these conditions that was usually guided by the histopathological findings. As this new knowledge becomes more refined, the classification of this group of disorders will eventually be revisited to have a molecular basis. The elucidation of the underlying biochemical pathways may allow us to envisage the possibility of modulating these phenotypes in the future.

Corneal Dystrophies, Hereditary↗
PubMed1991

[Current status of linkage studies for gene localization in corneal dystrophies].

Corneal dystrophies with primarily autosomal dominant inheritance have been clearly identified both histologically and histochemically. No information is available to date on the causal enzymatic protein defect of the individual forms of dystrophy. By using linkage analysis to study families with various corneal dystrophies, an attempt is being made with polymorphous markers to find an indirect indication for localization in a chromosome. Numerous factors which exclude linkage can be named for granular, lattice and Schnyder's corneal dystrophy. Our linkage analysis studies of a second family with Schnyder's dystrophy support our indications of linkage with the sites for adenylate kinase (AK1) and the AB0 blood groups on chromosome 9.

Chromosome Aberrations↗
PubMed1989

[Corneal dystrophies].

Corneal dystrophies are rare and have multiple clinical expressions. Some of them are isolated, without any systemic background, and often familial; they evolve slowly with opacification or deformation of the corneal stroma or with recurrent erosions; treatment consists of corneal grafting which generally has a favourable outcome. Other corneal dystrophies are manifestations of a systemic metabolic disorder; they are often associated with other ocular lesions and their prognosis is rather poor.

Corneal Dystrophies, Hereditary↗
PubMed1991

Corneal dystrophies.

Corneal dystrophies are inherited (usually autosomal dominant) disorders involving virtually every layer of the cornea. They result in opacities of various sizes and shapes that primarily affect the central cornea relatively early in life. Diagnosis is most often based on clinical appearance and careful biomicroscopic examination to assess the corneal layer(s) that are affected. Because most dystrophies are slowly progressive, visual acuity is often minimally affected for much of an individual's lifetime. Dystrophies are not associated with any prior corneal inflammations or systemic disease. This paper is a discussion of the most commonly encountered dystrophies affecting the epithelium, Bowman's membrane, stroma, and endothelium. The optometric management of many of these dystrophies may, at times, present a challenge to the clinician. Treatment may range anywhere from a simple therapeutic contact lens to referral for penetrating keratoplasty.

Contact Lenses↗
PubMed1990

Proteoglycan biosynthesis by human corneas from patients with types 1 and 2 macular corneal dystrophy.

Corneal buttons were obtained from patients with types 1 and 2 macular corneal dystrophy (MCD) and from control patients with Fuchs' dystrophy or keratoconus. Buttons were incubated for 20 h in the presence of [3H]glucosamine or [2-3H]mannose. Radiolabeled proteoglycans and lactosaminoglycan-glycoproteins (L-GPs) were purified using chromatography on Q-Sepharose, Superose 6, and octyl-Sepharose. They were identified using chondroitinase ABC, keratanase or endo-beta-galactosidase digestion, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis or Superose 6 chromatography. This study confirms previous reports that type 1 MCD corneas synthesize a normal dermatan sulfate-proteoglycan (DS-PG) and an abnormal keratan sulfate-proteoglycan (KS-PG). The data indicate that typ 1 MCD corneas synthesize L-GP instead of KS-PG. This L-GP has a core protein of similar hydrophobicity (elution from octyl-Sepharose) and nearly similar mass (42 kDa) as the core protein of the KS-PG. It has identical glycoconjugates as those of the KS-PG except that they lack sulfate. Thus, type 1 MCD fails to synthesize keratan sulfate as a result of a defect in a sulfotransferase specific for sulfating lactosaminoglycans. Further, proteoglycans synthesized by a cornea from a patient with type 2 MCD were studied. This cornea synthesized a normal ratio of KS-PG to DS-PG although net synthesis of proteoglycans was approximately 30% below normal. The KS-PG appeared normal whereas the DS-PG had dermatan sulfate chains that were approximately 40% shorter than normal.

Cells, Cultured↗
PubMed1989

Linkage analysis in granular corneal dystrophy (Groenouw I), Schnyder's crystalline corneal dystrophy, and Reis-Bücklers' corneal dystrophy.

Tight linkage was excluded for 8 markers in 37 blood relatives from 3 families, 29 of whom had granular corneal dystrophy (Groenouw I). Inconclusive results were obtained for linkage with four marker loci. The highest positive LOD score was 0.57 for linkage between glutamic pyruvic transaminase and granular corneal dystrophy. Tight linkage was excluded for glyoxalase-1 in eight individuals from one family with Schnyder's crystalline corneal dystrophy. Results were inconclusive for another six markers. Positive LOD scores were obtained for linkage with adenylate-kinase 1 and the ABO blood group, with values of 1.16 and 0.67, respectively. Among six blood relatives with Reis-Bücklers' corneal dystrophy, the highest positive LOD score was 1.17 for linkage with mitochondrial malic enzyme. For another six markers informative for linkage analysis, the results were inconsistent.

Blood Group Antigens↗
PubMed2005

Electrolysis for corneal opacities in a young patient with superficial variant of granular corneal dystrophy (Reis-Bücklers corneal dystrophy).

PURPOSE: To report the efficacy of electrolysis as a treatment of corneal opacities in a young patient with the superficial variant of granular corneal dystrophy. DESIGN: Interventional case report. METHODS: An 11-year-old boy presented with subepithelial opacities in both eyes. His visual acuity was 0.2 in the left eye; he received corneal electrolysis under topical anesthesia. RESULTS: The electrolysis, which required only 5 minutes, resulted in the disappearance of the subepithelial opacities. His visual acuity improved to 0.4 on the next day and was 1.0 eight months later. The corneal curvature and thickness were not altered by the electrolysis. CONCLUSIONS: Corneal electrolysis proved to be an effective treatment for subepithelial opacities, and we recommend electrolysis as an effective and simple treatment for young patients with SGCD.

Child↗
PubMed2000

Lisch corneal dystrophy is genetically distinct from Meesmann corneal dystrophy and maps to xp22.3.

PURPOSE: There is an ongoing discussion whether Lisch corneal dystrophy (band-shaped and whorled microcystic dystrophy of the corneal epithelium) represents a disorder that is different from Meesmann corneal dystrophy. The purpose of this study was to evaluate at the molecular level if Lisch and Meesmann corneal dystrophies are genetically distinct. METHODS: We examined at the slit lamp a total of 48 members of a family with an aggregation of Lisch corneal dystrophy. Genomic DNA was extracted from leukocytes of the peripheral blood of seven affected and six unaffected members of this family. Mutational hotspots in the cornea-specific keratin genes K3 and K12 were scanned for mutations by single-strand conformation analysis. To test for linkage to the keratin K3 or K12 loci or for X-chromosomal inheritance, six (K3) and four (K12) microsatellite markers each flanking the keratin loci as well as 22 microsatellite markers covering the X-chromosome were typed. Linkage was analyzed using the MLINK and FASTMAP procedures. RESULTS: A total of 19 trait carriers were identified in six generations of the family. No hereditary transmission from father to son was observed. Linkage was excluded for the keratin K3 and K12 genes. Furthermore, single-strand conformation analysis detected no mutations in these genes. Multipoint linkage analysis revealed linkage with a maximum likelihood of the odds (LOD) score of 2.93 at Xp22.3. Linkage was excluded for Xp22.2 to Xqter. CONCLUSIONS: Lisch corneal dystrophy is genetically different from Meesmann corneal dystrophy. Evidence was found for linkage of the gene for Lisch corneal dystrophy to Xp22.3.

Adolescent↗
PubMed2004

Anterior basement membrane corneal dystrophy and pseudo-unilateral lattice corneal dystrophy in a patient with recurrent corneal erosions.

PURPOSE: To report the utility of genetic testing in the diagnosis and management of patients with suspected corneal dystrophies. DESIGN: Case report. METHODS: A 58-year-old man with a history of recurrent corneal erosions was diagnosed with bilateral anterior basement membrane dystrophy and unilateral lattice corneal dystrophy. All 17 exons of the TGFBI gene were screened for mutations previously associated with lattice corneal dystrophy as well as novel coding region changes. RESULTS: No mutations were found in the 17 exons of the TGFBI gene. A nucleotide change in exon 6 (651C>G) did not result in a change in the encoded amino acid (Leu217Leu). CONCLUSIONS: In cases of suspected TGFBI corneal dystrophies, genetic testing is a useful tool to confirm the clinical diagnosis. In this case of suspected unilateral lattice corneal dystrophy, screening of the TGFBI gene ruled out the diagnosis, raising the possibility that the corneal changes were related to the coexistent anterior basement membrane dystrophy.

Basement Membrane↗
PubMed2004

Analysis of human transforming growth factor beta-induced gene mutation in corneal dystrophy.

BACKGROUND: Corneal dystrophy is a group of inherited blinding diseases of the cornea. This study was to identify the mutations of the keratoepithelin (KE) gene for proper diagnosis of corneal dystrophy. METHODS: Three families with corneal dystrophy were analysed. Thirteen individuals at risk for corneal dystrophy in family A, the proband and her son in family B, and the proband in family C were examined after their blood samples were obtained. Mutation screening of human transforming growth factor beta-induced gene (BIGH3 gene) was performed. RESULTS: Five individuals in family A were found by clinical evaluation to be affected with granular corneal dystrophy and carried the BIGH3 mutation W555R. However, both probands in families B and C, also diagnosed with granular corneal dystrophy, harboured the BIGH3 mutation R124H. CONCLUSION: Molecular genetic analysis can improve accurate diagnosis of corneal dystrophy.

Adolescent↗
PubMed1984

Lack of evidence for protein AA reactivity in amyloid deposits of lattice corneal dystrophy and amyloid corneal degeneration.

Amyloid fibrils occurring in primary and myeloma-associated (AL), secondary (AA), and certain neuropathic hereditary forms of systemic amyloidosis can be distinguished biochemically or immunohistologically as being composed of immunoglobulin light chain, protein AA, or prealbumin respectively. All types of systemic and several localized forms of amyloidosis contain amyloid P component (protein AP). We studied formalin-fixed tissue from eight cases of lattice corneal dystrophy by the immunoperoxidase method using antisera to proteins AA and AP, to normal serum prealbumin and prealbumin isolated from a case of hereditary amyloidosis, and to light-chain determinants; additional cases were examined by indirect immunofluorescence of fresh-frozen material. We found weak (1:10 dilution) staining with anti-AP, but no reactivity with other antisera. Congo red staining was resistant to pretreatment of sections with potassium permanganate, a characteristic of non-AA amyloid. Two-dimensional gels of solubilized proteins from frozen tissue from two cases of lattice corneal dystrophy resembled those obtained from normal human cornea. Western blots of two cases of polymorphous amyloid degeneration and solubilized protein from normal cornea did not react with radioactive iodine-labeled anti-AA or anti-AP with purified protein AP and unfixed protein AA amyloid tissue as controls. We were unable to corroborate the presence of protein AA in the amyloid deposits of lattice corneal dystrophy. Although staining with antiserum to protein AP was demonstrable, the molecular configuration of this protein in stromal deposits remains to be defined.

Amyloid↗
PubMed1989

Granular corneal dystrophy Groenouw type I (GrI) and Reis-Bücklers' corneal dystrophy (R-B). One entity?

This paper maintains that Reis-Bücklers' corneal dystrophy and granular corneal dystrophy Groenouw type I are one and the same disease. Included are some of the technically best photographs of Reis-Bücklers' dystrophy found in the literature, and these are compared with photographs from patients with granular corneal dystrophy examined by the author. It is argued that most of the histological and ultrastructural findings on Reis Bücklers' dystrophy described in the literature are either congruent with what is found in granular corneal dystrophy or unspecific.

Corneal Dystrophies, Hereditary↗
PubMed1983

Abnormalities of proteoglycans and glycoproteins synthesized by corneal organ cultures derived from patients with macular corneal dystrophy.

Macular corneal dystrophy has long been suspected of being a localized storage disease of glycosaminoglycans, but the nature of the storage product and the basic defect remain to be established. To learn more about this disease, the proteoglycans and glycoproteins synthesized by corneal organ cultures from five patients with macular corneal dystrophy and six individuals with surgically enucleated eyes and normal corneas were analyzed. This was done after incubating the corneas in Eagle's minimal essential medium supplemented by fetal or newborn bovine serum and 3H-glucosamine and 35S-sulfate for 24 hours and then extracting the tissues with 4 M guanidine hydrochloride. A consistent finding in organ cultures with macular corneal dystrophy was the diminished synthesis of keratan sulfate proteoglycan, and this was accompanied by the production of a glycoprotein of lower molecular weight with oligosaccharide side chains. A comparable amount of incorporated radioactivity was extracted with 4 M guanidine hydrochloride from corneas with macular dystrophy and corneas of controls. Despite this, corneas with macular dystrophy still contained abundant intra- and extracellular material with the histochemical attributes of nonextracted pathologic corneas, and this correlated with concentrations of nonextracted isotope as shown by autoradiography. Transmission electron microscopy of the guanidine hydrochloride-extracted corneas with macular dystrophy disclosed fibrillogranular material with a similar ultrastructure to the storage substance within nonextracted corneas to be located at sites of disrupted cells. Further work is needed to establish the basic defect in macular corneal dystrophy. Although it is possible that organ cultures of corneas with macular dystrophy synthesize the storage material, which characterizes the disorder, the abnormal product of the organ cultures of the dystrophic corneas may reflect an altered metabolic state of dystrophic corneal fibroblasts, caused by the excessive intracellular accumulation of the storage product that typifies macular corneal dystrophy.

Adolescent↗