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Purpose: To establish a phenotype-genotype correlation of various autosomal-dominant corneal dystrophies among French subjects., Design: Retrospective molecular genetic study and clinicopathologic correlation., Participants: Forty-four subjects from 26 unrelated French families were included in this study, and 60 corneal buttons could be examined at the histologic and ultrastructural levels., Methods: Light microscopy and transmission electron microscopy were performed on corneal specimens obtained during keratoplasty. Blood samples were collected for DNA analysis., Main Outcome Measures: After genomic DNA extraction from peripheral blood leukocytes of each family member, exons of the TGFBI gene were amplified by polymerase chain reaction (PCR), and the PCR products were directly sequenced on both strands., Results: Four different mutations were found to be responsible for dystrophy of granular type (R555W, R124L, R124H, and R124L+delT125-delE126), three other different mutations produced a lattice type (R124C, H626R, and A546T), and the last mutation identified was associated with the honeycomb-shaped dystrophy (R555Q). Each subtype of dystrophy showed, histologically and ultrastructurally, specific characteristics that are easily recognizable. However, besides these stereotyped forms, differential histologic diagnosis of atypical forms remains difficult, and these forms could be misdiagnosed., Conclusions: The characteristic biomicroscopic appearance and histopathologic features of each "classic" dystrophy present a significant degree of specificity and generally provide an accurate diagnosis. However, atypical forms in which clinical and histologic data alone could be misleading, are unequivocally diagnosed after DNA analysis.

Objective: This study was designed to describe the clinical, histologic, and ultrastructural features of the corneal dystrophy associated with the R124L mutation of the BIGH3 gene., Design: Retrospective clinical and histologic review of a new genetic mutation., Participants: Thirty-four patients from five unrelated French families with corneal dystrophy caused by the R124L mutation of the BIGH3 gene were studied at the clinical, histologic, and ultrastructural levels. Records of patients carrying this mutation were compared with those from three unrelated patients with corneal dystrophy of Bowman's layer (CDB) type 2 (R555Q mutation) and from three unrelated patients with classic corneal granular dystrophy (R555W mutation)., Intervention: The mutational genetic status of the BIGH3 gene was determined for each patient, and the histologic and ultrastructural data available after corneal graft were analyzed., Main Outcomes Measures: Genomic DNA was extracted from peripheral blood leukocytes. Exons 4 and 12 of the BIGH3 gene were amplified by the polymerase chain reaction (PCR), and the PCR products were directly sequenced., Results: All 34 patients with the R124L mutation displayed the clinical, histologic, and electron microscopic features of the dystrophy previously described as a superficial variant of corneal granular dystrophy. Combining molecular genetics with clinical and histologic findings established a clear distinction between the R555Q and R555W dystrophies., Conclusions: The R124L mutation of the BIGH3 gene is associated with specific clinical and morphologic criteria. This indicates that molecular studies are needed for an adequate classification of corneal dystrophies. All criteria are presently available to segregate the dystrophy caused by the R124L mutation (known as CDB1) from the dystrophy caused by the R555Q mutation (known as CDB2).

Background: GIAK is a surgical technique developed for the correction of myopia. We evaluated the biocompatibility of a gamma-ray crosslinked poly(ethylene oxide) gel in two critical situations., Materials and Methods: In 3 rabbits, a 5 mm inner diameter annular channel of 1 mm width was delaminated at 80% corneal depth and a sterile gamma-ray crosslinked polyethylene oxide gel was injected in the channel. In cornea 1 (control), the annulus was centered on the corneal apex and the channel was fully filled with gel. In cornea 2, the delamination was purposely decentered and the channel was approximately 1 mm from the limbus at its closest point. In cornea 3, the centered channel was purposely partially filled. After a 6 month follow-up, the rabbits were sacrificed for histology., Results: Histopathology showed the oval channel walls to be irregular and a slight thinning of the epithelium located above the implant but no abnormalities in the stromal thickness. No mononuclear, polynuclear cells or other signs of encapsulation or rejection were found around the polymer in any of the animals. In cornea 3, fibroblasts were found on the lateral sides of the hydrogel globules. No limbal neovascularization was observed over the 6 month period in any of the animals., Conclusions: The injected PEO gel followed intimately the delaminated stromal channel and was well tolerated in the cornea. The fibroblastic reaction found in partially filled channels is caused by the normal wound healing process and not by the hydrogel chemical properties.

The authors report the case of a 37 year-old male who presented with type I Hurler-Scheie (H-S) mucopolysaccharidosis revealed by ocular complications including bilateral corneal opacification and glaucoma. These complications are identical to those seen in Scheie's mucopolysaccharidosis. The patient underwent a trabeculectomy and a penetrating keratoplasty in both eyes. The corneal storage material was shown on the histological and ultrastructural examination of the buttons. These ocular complications result from excessive tissular storage of acid mucopolysaccharides due to an enzymatic alpha-L-iduronidase deficiency which was proved in our patient. H-S mucopolysaccharidosis is also characterized by dysmorphia and altered intellectual functions like in Hurler's disease in which the prognosis is however. The characteristics of the disease are discussed as well as the different therapeutical strategies which rely on leucocyte injections, skin fibroblast or bone marrow transplantation.

Previous studies have demonstrated the potential use of microporous, biocompatible materials to improve the long-term stability of keratoprosthesis. To determine the factors that will influence corneal tissue ingrowth into biocompatible, microporous materials, we have compared three types of fluorocarbon polymers--Impra, Gore-Tex, and Proplast--after intrastromal implantation in rabbit corneas. Despite similar physicochemical structures, a great difference was observed in histologic and ultrastructural cross sections after 4- and 8-month follow-ups. For Gore-Tex, we observed extrusion of the implant and infiltration of necrotic and inflammatory cells. All implants of Proplast also led to significant corneal damage resulting in extrusion of the material. Through the use of electron and light microscopy and image analysis, this study demonstrates the presence of cell differentiation and collagen synthesis in the pores of the Impra implant. Apart from biocompatibility, this experiment demonstrates the influence of pore size, porous microorganization, and biomechanical factors on prosthetic corneal material. Only Impra offers satisfactory interface, allowing fibroblastic cells and neocollagen synthesis into its pores, and it can become transparent.

This article reports a case of bilateral corneal pellucid marginal degeneration. The right cornea had an acute hydrops. Both eyes underwent penetrating keratoplasty. A histopathological study of the corneal specimens was performed by light and electron microscopy. The histological changes observed on the right cornea showed breaks on Bowman's layer, edema and disorganization of the stromal collagen, and break of Descemet's membrane. The ultrastructural changes were similar to those observed in acute keratoconus, leading to the belief that these two corneal diseases are closely related.

Corneal dysplasia has been recently reported. Clinically, it is characterized by a progressive epithelial corneal opacity with pearly or greyish white coloration. Its topography may be either next to either far from the limbus. The recurrences are frequent after surgical treatment. Histologically, many aspects are described. Morphological changes affecting the cells and/or the architecture of the modified epithelium, may vary from light dysplasia to true carcinoma in situ. Some peculiar clinical conditions may coexist with corneal dysplasia, which may also be isolated. Three clinical cases are reported, with detailed pathological data. The signification of the use of the term "dysplasia" and the histogenesis are discussed, and the conclusions for treatment are drawn.