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Importance: The identification of steep corneal curvatures in a significant percentage of patients with posterior polymorphous corneal dystrophy (PPCD) confirms this previously reported association and suggests a role for the ZEB1 protein in keratocyte function., Objective: To determine whether PPCD is characterized by significant corneal steepening., Design, Setting, and Participants: Cross-sectional study at university-based and private ophthalmology practices of 38 individuals (27 affected and 11 unaffected) from 23 families with PPCD., Exposure: Slitlamp examination and corneal topographic imaging were performed for individuals with PPCD and unaffected family members. Saliva or blood samples were obtained from each individual for DNA isolation and ZEB1 sequencing. Corneal ZEB1 expression was measured using immunohistochemistry., Main Outcomes and Measures: Percentage of individuals affected with PPCD and controls with an average keratometric value greater than 48.0 diopters (D) in each eye; the mean keratometric value averaged for both eyes of individuals with PPCD and controls; and the correlation of ZEB1 mutation with keratometric value., Results: ZEB1 coding region mutations were identified in 7 of the 27 affected individuals. Ten of the 38 individuals (26.3%) had average keratometric values greater than 48.0 D OU: 10 of 27 individuals with PPCD (37.0%; 6 of 7 individuals with ZEB1 mutations [85.7%] and 4 of 20 individuals without ZEB1 mutations [20.0%]) and 0 of 11 unaffected individuals (P = .04 for unaffected vs affected individuals; P = .004 for individuals with PPCD with vs without ZEB1 mutation). The mean keratometric value of each eye of affected individuals (48.2 D) was significantly greater than that of each eye of unaffected family members (44.1 D) (P = .03). Affected individuals with ZEB1 mutations demonstrated a mean keratometric value of 53.3 D, which was significantly greater than that of affected individuals without ZEB1 mutations (46.5 D; P = .004). Fluorescence immunohistochemistry demonstrated ZEB1 expression in keratocyte nuclei., Conclusions and Relevance: Abnormally steep corneal curvatures are identified in 37% of all individuals with PPCD and 86% of affected individuals with PPCD secondary to ZEB1 mutations. ZEB1 is present in keratocyte nuclei, suggesting a role for ZEB1 in keratocyte function. Therefore, ZEB1 may play a role in both corneal stromal and endothelial development and function, and PPCD should be considered both an endothelial dystrophy and an ectatic disorder.

Objective: To report a novel mutation in TGFBI (GenBank NM_000358), p.Met619Lys, associated with a variant of combined granular-lattice corneal dystrophy., Methods: Slitlamp examination and DNA collection from the proband and affected and unaffected relatives. All 17 exons of TGFBI were amplified and sequenced in the proband. Exon 14 was amplified and sequenced in the proband's family members and in 100 controls. Histopathologic examination of the excised corneal buttons from the proband and 3 family members was also performed., Results: Affected individuals demonstrated an age-dependent phenotype, with the progression from central subepithelial needlelike deposits in younger individuals to polymorphic anterior stromal opacities in older family members. Screening of TGFBI in the proband demonstrated a novel mutation, p.Met619Lys, which was also present in all affected family members. Histopathologic examination revealed stromal deposits that stained with the Congo red and Masson trichrome stains as well as an antibody to the protein product of TGFBI., Conclusions: We present a unique corneal dystrophy phenotype associated with the novel p.Met619Lys mutation in TGFBI. Clinical Relevance The atypical and variable phenotype and the demonstration of both hyaline and amyloid stromal deposits indicate that neither clinical nor histopathologic features may be relied on to accurately diagnose and classify the corneal dystrophies.

Recurrence of macular corneal dystrophy after keratoplasty is rare. We report light microscopic, immunohistochemical, electron microscopic, and serologic findings in a 78-year-old woman who underwent regrafting 49 years following the first penetrating keratoplasty. Examination of the corneal button revealed deposits of glycosaminoglycans in the graft beneath the Bowman layer, throughout the stroma, and in the endothelium with positive staining for antigenic keratan sulfate. By transmission electron microscopy, intracellular and extracellular deposits of a fibrillogranular material were detected in the stroma, Descemet membrane, and endothelium. The serum level of antigenic keratan sulfate was normal. Our findings indicate that macular corneal dystrophy type II may show late recurrence after penetrating keratoplasty with intense deposition of antigenic keratan sulfate in all corneal layers.

Objective: To investigate the origin and distribution of granular deposits in the corneas of 3 patients with granular dystrophy, 1 of whom had previously received a lamellar keratoplasty in which the granular dystrophy had recurred., Method: Corneal tissue from 2 patients with primary granular dystrophy (patients 1 and 2) and from a patient with recurrent granular dystrophy (patient 3) was examined. Corneal graft tissue was fixed in (1) 3% glutaraldehyde in sodium cacodylate buffer, (2) 2.5.% glutaraldehyde in sodium acetate buffer containing cuprolinic blue, and (3) 4% paraformaldehyde in phosphate-buffered saline., Results: In patient 1 (aged 48 years), electron-dense granular structures were observed in epithelium, Bowman layer, and throughout the stroma. Bowman layer was absent in several places. Patient 2 (aged 78 years) showed similar features except with more deposits in the stroma. In patient 3 (aged 48 years), granular structures were heavily deposited in the epithelium; there were also some deposits in the posterior (host) stroma, some of which were associated with partially degenerated keratocytes. Bowman layer appeared normal. In all 3 patients, the intracellular or extracellular granular structures were surrounded by fine fibrillar material and abnormal proteoglycans. Electron-lucent spaces within the corneal stroma contained large quantities of abnormal proteoglycan filaments that were attached in part to collagen fibrils., Conclusions: Results from patient 3 support an epithelial origin for the deposits, presumably from keratoepithelin, aggregated with other proteins. The role of keratocytes is less clear, although the presence of deposits in the stroma of all 3 patients, some associated with keratocytes, suggests that these cells might produce granular material in addition to abnormal proteoglycans.

Objective: To characterize the relation of the beta ig-h3 protein to the diagnostic corneal deposits in the hereditary corneal dystrophies recently shown to have mutations in the beta ig-h3 gene on chromosome 5q31., Methods: Corneas with lattice, granular, mixed granular-lattice ("Avellino"), and 2 types of Reis-Bücklers dystrophy were diagnosed by the histochemical and ultrastructural characteristics of their abnormal aggregates. Dystrophic and normal corneas were compared for immunolocalization of beta ig-h3 protein., Results: In normal corneas, immunoreactivity for beta ig-h3 protein was strongest in the Bowman layer, and next strong along stromal interlamellar junctions and attachment sites of collagen to the Descemet membrane. Antibody binding was intense on all dystrophic aggregates, mimicking somewhat the normal protein distribution. Mixed granular-lattice dystrophy had the most variation in beta ig-h3-immunopositive forms. The aggregates in both the "rod-shaped" Reis-Bücklers type and the "curly fiber" Thiel-Behnke type were strongly stained for beta ig-h3 protein, consistent with mutations on the beta ig-h3 gene., Conclusions: The marked immunopositivity for beta ig-h3 protein in the abnormal deposits in these dystrophies indicates that beta ig-h3 protein is a major component. The variety and quantity of immunopositive forms suggests that they consist primarily of the mutant protein, self-polymerizing and/or incorrectly binding to other corneal components. Variability of forms may relate to both the specific mutation and regional interactions of this protein.

We report an unusual case of posterior polymorphous dystrophy in which corneal failure began within a few weeks of birth. Histopathologic findings included the presence of abnormal corneal endothelial cells with many microvilli on the surface. Descemet membrane was severely attenuated, and there was a thick posterior collagenous layer consisting of numerous fibroblast-like cells in a fibrillar extracellular matrix; ultrastructural immunocytochemistry showed this to contain tenascin, fibronectin, and collagen type I. Few histopathologic data on this disease at such an early age have been available, and to our knowledge, the composition of Descemet membrane has not been examined before. The microvilli-covered cells are shown to be present from the outset of the disease, not just in long-standing cases as in previous reports; changes in Descemet membrane may influence disease evolution.

The pathogenesis of posterior polymorphous dystrophy was analyzed by immunohistologic methods. Sections of corneal buttons from two patients undergoing transplantation owing to posterior polymorphous dystrophy were stained with 2B4.14.1, a monoclonal antibody that reacts with human corneal endothelium, and with a cocktail of antihuman cytokeratin monoclonal antibodies that do not react with normal corneal endothelium. Single-stained sections revealed a variegated, intermittent staining pattern of antibody reactive and nonreactive cells. Double-stained sections revealed some cells that stained with only one of the antibodies and many cells that stained with both antibodies. The presence of cells staining positively for both 2B4.14.1 antigen and cytokeratins supports the hypothesis that the cytokeratin-expressing epithelial-like cells found in corneas with posterior polymorphous dystrophy arise via a metaplastic process in which the phenotype of endothelial cells becomes progressively abnormal.

We describe a family with an unusual autosomal dominant anterior corneal dystrophy. The onset was characterized by frequent, recurrent corneal erosions in the first decade. This subsided during adolescence and was followed by progressive decreased vision. Slit-lamp examination revealed bilateral subepithelial opacities and haze, involving the entire cornea, but most dense centrally. Histopathological study revealed a subepithelial band of eosinophilic, periodic acid-Schiff-positive, alcian blue-positive, hyaluronidase-sensitive material anterior to Bowman's layer. Electron microscopy demonstrated subepithelial deposition of fine fibrillar material consistent with glycosaminoglycan. Immunohistochemical analysis indicated that the accumulated material contained a combination of chondroitin 4-sulfate and dermatan sulfate. This unique condition clinically resembled Grayson-Wilbrandt dystrophy, but differed histochemically. To our knowledge, this anterior corneal dystrophy has not previously been reported, and it is best described by the name "subepithelial mucinous corneal dystrophy."

Keratoplasty specimens from eight patients with granular corneal dystrophy (GCD) and age-matched control subjects were examined by combinations of immunohistological stains, transmission electron microscopy (TEM), and sodium dodecyl sulfate gel electrophoresis. Fresh frozen sections from corneas with GCD stained positively with antibodies to microfibrillar protein by immunofluorescence. Routine TEM disclosed that the granules had central electron-dense areas partially surrounded by 9- to 10-nm tubular microfibrils. Material eluted from corneas with GCD showed denser peptide bands at 65 and 110 kilo than in normal corneas. Stains were negative for elastin, amyloid, neutral lipids, cholesterol, and glycosaminoglycan. Luxol fast blue MBSN stain was strongly positive in the granules in all cases examined. Immunofluorescent stains were negative with antibodies to plasma fibronectin (cold insoluble globulin), laminin, collagens I to V, basement membrane proteoglycan, tropoelastin, and keratin. In two corneas with GCD an increased lipid content was found in every phospholipid class, although cholesterol content was unchanged. Alterations in the fatty acid profiles of phospholipids were also observed.

The distribution of chemical elements in the normal human cornea was studied by energy dispersive x-ray analysis and scanning electron microscopy of routinely prepared paraffin sections. Calcium, phosphorus, and sulfur were consistently present in quantities above background and varied in concentration regionally. Analysis of fresh-frozen tissue, an approximation of the in vivo state, gave a similar elemental profile to paraffin sections, except for the loss of diffusable electrolytes in the latter. After fixation, S was the most abundant element and was highest in Descemet's membrane. Corneas with granular, lattice, macular, and Fuchs' endothelial dystrophies, band keratopathy, and spheroidal degeneration were also examined. Characteristic patterns of abnormal S and Ca distribution were found in each of the dystrophies. The relative proportions of Ca, P, and S gave diagnostic profiles for distinguishing band keratopathy and spheroidal degeneration.

We analyzed lectin binding patterns of amyloid glycoconjugates in patients with lattice dystrophy of the cornea. Results of paraffin and frozen sections differed in some instances. With paraffin sections, three lectins--wheat germ agglutinin (WGA), Ricinus communis agglutinin I (RCA-I), and concanavalin A (Con A)--stained the abnormal deposits. In frozen sections, the abnormal deposits were stained by five lectins--WGA, RCA-I, Con A, peanut agglutinin (PNA), and soybean agglutinin (SBA). In paraffin sections, PNA and SBA did not stain amyloid deposits. In both paraffin and frozen sections, some lectin-positive deposits corresponded to the Congo red-positive material, whereas others were present surrounding and encroaching on the Congo red-reactive material. This study demonstrates that WGA-, RCA-I-, Con A-, PNA-, and SBA-positive abnormal deposits are present in corneas with lattice dystrophy. Since lectins bind to specific sugar residues, we conclude that the abnormal deposits consist, at least in part, of glycoconjugates and that these glycoconjugates contain oligosaccharides with N-acetylglucosamine/sialic acid, mannose/glucose and terminal beta-galactose residues and chains with terminal beta-galactose-N-acetylgalactosamine disaccharides.

Fourteen members of four families with fleck systrophy of the corneal stroma were examined and studied. Corneal and lens changes were noted in all patients. Corneal sensation was normal. Corneal biopsies were performed on two patients and a corneal button of a patient with fleck dystrophy and keratoconus was studied. Light and electron microscopy and histochemical studies showed this dystrophy to consist of abnormal keratocytes with variable numbers of membrane-limited intracytoplasmic vacuoles containing a granular to fibrogranular material that stains positively for mucopolysaccharide. This appears to be the first reported incidence of a dominantly inherited disorder of mucopolysaccharides affecting the eyes.