1/15. Histopathology of corneal changes in lecithin-cholesterol acyltransferase deficiency.PURPOSE: Lecithin-cholesterol acyltransferase (LCAT) deficiency is a rare entity. This dyslipoproteinemia may lead to corneal opacity, renal failure, and arteriosclerosis. methods: Presentation of a 66-year-old man with bilateral corneal opacification due to LCAT deficiency caused by a single-nucleotide exchange in codon 123 of gene. An extracapsular cataract extraction combined with full-thickness corneal transplantation was performed. The corneal specimen was analyzed by light and transmission electron microscopy. RESULTS: All stromal layers showed extracellular vacuoles with acid mucopolysaccharide contents measuring up to 2.5 microm. Amyloid deposits measuring up to 12 microm in diameter were detected in the stroma and especially predescemetally. CONCLUSION: To our knowledge, this is the first histologic description of secondary amyloidosis in a full-thickness corneal specimen with LCAT deficiency. The disease is associated with anemia, proteinuria, a lack of plasma high-density lipoprotein, and the presence of target cells. Bilateral corneal opacification is a characteristic of the disease and may allow early detection of homozygous LCAT deficiency by the ophthalmologist.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
2/15. Cornea with Peters' anomaly: perturbed differentiation of corneal cells and abnormal extracellular matrix in the corneal stroma.PURPOSE: We examined histopathologically the anterior ocular segment including the cornea and lens of an eye which had been enucleated in a patient with Peters' anomaly because of untreatable corneal perforation. Special effort was made to differentiate the corneal stromal and endothelial cells, and the stromal extracellular matrix.methods: light microscopy, with hematoxylin and eosin staining, and transmission electron microscopy were employed.RESULTS: Corneal endothelial cells and Descemet's membrane were not detected in the central cornea, where there were immature cells with a fibroblastic configuration. The inner surface of the peripheral cornea was covered with cells containing pigment granules in the cytoplasm. Cell density in the central corneal stroma was relatively high. The diameter of the stromal collagen fibrils was not uniform. A mature collagen fibril-free area was also seen in the central corneal stroma.CONCLUSIONS: Differentiation of neural crest-derived cells in corneal stroma and endothelium might have been perturbed in the cornea of this patient with Peters' anomaly, inducing the defect in the corneal endothelium and the qualitative and quantitative abnormalities of the extracellular matrix.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
3/15. Application of energy-dispersive X-ray microanalysis on the diagnosis of atypical calcific band keratopathy.We describe pathological, ultrastructural, and spectrographic analyses of surgically resected cornea from a man with atypical corneal opacification, and discuss the corneal pathogenesis, and the utility of energy-dispersive X-ray microanalysis (EDXA). The histopathologic features of a case presenting with longstanding bilateral corneal clouding are reported, which was difficult to be diagnosed clinically as calcific band keratopathy. The patient underwent keratoplasty on his right eye. paraffin sections of the host corneal button were subjected to hematoxylin and eosin (H&E). An adjacent section was studied by means of EDXA. Plastic sections were observed under a transmission electron microscope (TEM). H&E staining revealed flattened corneal epithelial cells and disappearing Bowman's membrane accompanied by numerous basophilic granular deposits within the underlying corneal stroma. EDXA demonstrated the elevated peaks of calcium and phosphorus within the area of granular deposits. TEM revealed electron dense material consistent with extracellular calcospherites. Given the patient's past medical and family history, and the serologic test results, the clinical presentation and histological findings were most consistent with calcific band keratopathy associated with preexisting minimal syphilitic keratitis. Extensive histologic studies including EDXA on resected corneal tissue can be helpful for the differential diagnosis and may elucidate the pathogenesis of corneal diseases.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
4/15. Subepithelial fibrosis after myopic epikeratoplasty. Report of a case.A 29-year-old man with a -22.00-diopter myopia in the right eye underwent a planar, nonfreeze myopic epikeratoplasty and postoperatively developed a central subepithelial opacity. The opacity recurred after two superficial keratectomies; finally, another epikeratoplasty was performed. light microscopic examination of the original button showed that the epithelium was thickened, collagenous subepithelial fibrocellular tissue was present, and Bowman's layer was focally disrupted. The stroma was edematous and peripherally scarred with scattered keratocytes. Examination by transmission electron microscopy revealed keratocytes lying anterior and posterior to Bowman's layer. The subepithelial fibrocellular tissue corresponded to an area of a break in Bowman's layer and probably originated from the donor stroma. The break in Bowman's layer may have been caused by the microkeratome cuts, but its origin is not certain.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
5/15. iris melanocytes on the posterior corneal surface in congenital glaucoma. A clinicopathological case report.The histological and ultrastructural pathology of two corneas that were removed from an infant with congenital glaucoma prior to keratoplasty is described. Clinically, the glaucoma was suspected to be due to an inapparent congenital viral infection, although there was no serological proof. Macroscopic and light microscopic examination of the posterior corneal surface revealed an irregular network of heavily pigmented cells that were overlying an incomplete endothelium and a grossly thickened Descemet's membrane. By scanning and transmission electron microscopy, these melanin-laden cells exhibited the features of iris stromal melanocytes. No evidence of viral infection could be found. The possible mechanisms leading to this unusual morphology are considered and will be discussed in relation to current theories on the etiology of congenital glaucoma.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
6/15. Granular corneal dystrophy Groenouw type I. A report of a probable homozygous patient.A case of severe granular corneal dystrophy is described. The patient, who is most probably homozygous for the dominantly inherited dystrophy gene, is the product of a first cousin marriage with both parents mildly affected by the same dystrophy. The case report describes an early onset and a severe course with two grafts in each eye before the age of 17. Pictures of the clinical appearance, histology and transmission electronmicroscopy are shown.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
7/15. Ocular abnormalities in mucolipidosis IV.Systemic findings in a 23-year-old white man with mucolipidosis type IV included early delayed psychomotor development, mental retardation, and mild facial dysplasia. There was urinary excretion of chondroitin sulfate. Ophthalmologic examination showed corneal haze, pigmentary retinopathy, and severe optic atrophy. light microscopy showed massively engorged superficial and intermediate epithelial cells of both the cornea and the conjunctiva. By transmission electron microscopy these contained fine granular material consistent with acid mucopolysaccharide and concentric lamellar bodies presumably representing phospholipids. This storage phenomenon was also found in macrophages, plasma cells, ciliary epithelial cells, schwann cells, retinal ganglion cells, and vascular endothelial cells. light microscopy also disclosed early cataract formation, marked outer retinal degeneration, and optic atrophy.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
8/15. Scanning electron microscopy of congenital corneal leukomas (Peters' anomaly).Specimens of three corneas in two patients with Peter's anomaly were obtained at the time of penetrating keratoplasty and studied by scanning and transmission electron microscopy. In one patient, the anomaly was monocular, and the endothelial surface showed a central defect in Descemet's layer with isolated rounded defects in the midperiphery. Fine collagenous material covered the posterior surface. The other two specimens were obtained from a patient with rubella syndrome without cataracts. The cornea showed malformation of Descemet's membrane with fibroblastic overgrowth on the endothelial layer. Epithelial-like cells and leukocytes were also found. The congenital central leukoma we believe was caused by adhesion of the pupillary membrane in our first patient, and possibly was inflammatory in our second patient.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
9/15. Intrastromal noninflammatory bacterial colonization of a corneal graft.Progressive branching, needlelike stromal opacities were observed within a corneal transplant. Analysis of the corneal button by light microscopy and transmission electron microscopy disclosed a localized epithelial ingrowth into the stroma at a suture tract accompanied by intrastromal pockets of gram-positive cocci extending across the cornea. No inflammatory reaction was found in the areas of bacterial colonization. To our knowledge, noninflammatory bacterial colonization of the stroma of a corneal transplant has not been previously described.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
10/15. Posterior polymorphous dystrophy of the cornea (Schlichting). An unusual clinical variant.Three members of a family with dominant inherited endothelial dystrophy of the cornea are described. The father showed only subclinical disease with subtle endothelial blisters like those found in Schlichting's dystrophy. His daughter and grandson, however, both suffered from a peculiar, prominent, ring-shaped clouding of the cornea which progressed to severe edema, necessitating keratoplasty. light, transmission, and scanning electron microscopy revealed an epithelial transformation of the endothelium. While the anterior banded part of Descemet's membrane was well-formed in the central cornea, it was missing in the periphery. This corresponded with the ring-shaped opacity and indicated a very early transformation of the endothelium in this area. We believe that this pedigree represents an unusual clinical variant of posterior polymorphous dystrophy of the cornea.- - - - - - - - - - ranking = 1keywords = transmission (Clic here for more details about this article) |
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