No abstract available.

No abstract available.

PURPOSE: To evaluate the morphological characteristics of the transitional zone between the corneal endothelium and the trabecular meshwork by flat preparation and electron microscopy. METHODS: The materials comprised 12 eyes examined by the flat preparation and 7 eyes by the electron microscopy. The specimens were derived from the transitional tissue between the corneal endothelium and the trabecular meshwork. The specimens in the flat preparation were stained with hematoxylin-eosin and examined by light microscopy. The specimens for scanning electronic microscopy (SEM) and in transmission electronic microscopy (TEM) were examined through routine processes. RESULTS: In the specimens examined by the flat preparation, unlike peripheral corneal endothelial cells, the endothelial cell nuclei in the transitional zone were overlapped and morphologically oval. On SEM, unlike typical hexagonality and tight interdigitation of corneal endothelial cells, the endothelial cells in the transitional zone were partially successive, spaced intercellularly, and morphologically irregular. On TEM, the endothelial cells in the transitional zone were partially successive. CONCLUSIONS: The loss of cell-cell contact of endothelial cells in the transitional zone may lead to the potential proliferation capacity of endothelial cells in the transitional zone under specific conditions. Therefore, further studies on the proliferation capacity of endothelial cells in the transitional zone are needed together with more research on cell biology.
Endothelial Cells ; Endothelium, Corneal* ; Microscopy ; Microscopy, Electron ; Trabecular Meshwork

PURPOSE: To investigate the morphological characteristics of keratocytes and the interconnection of keratocytes with adjacent keratocytes using the flat preparation method and scanning electron microscopy with a frontal section of the human corneal stroma. METHODS: The thin, corneal collagen lamellae were carefully dissected from the cornea (n=7), which had been stained by the flat preparation method. The remaining tissue was fixed in 3% glutaraldehyde and observed by transmission electron microscopy following the frontal section. RESULTS: The flat preparation revealed the corneal fibroblasts between the lamellae of the collagen fibers and showed that the ramifying cellular processes of the keratocytes were in contact with the cytoplasmic processes or cell bodies of neighboring fibroblasts. Two types of discrete subpopulations of keratocytes were identified: a smaller, cellular type of keratocyte with spindle-shaped nucleus with heterochromatin, and a larger, cellular type with a large indented nucleus with relatively scanty cytoplasm. Collagen fibers ran parallel to each other toward the fenestration of the cytoplasmic wall of the keratocyte. CONCLUSIONS: These flat preparation method results showed that the keratocytes within the corneal stroma are interconnected with the adjacent keratocytes, which indicates the presence of a functional communicating network through the keratocyte circuits within the stroma. A smaller, cellular type of keratocyte with spindle-shaped nucleus was morphologically differentiated from a larger, cellular type with a large, indented nucleus by flat preparation and transmission electron microscopy.
Middle Aged ; Microscopy, Electron, Transmission ; Microscopy, Electron, Scanning ; Intercellular Junctions/*ultrastructure ; Infant ; Humans ; Corneal Stroma/*cytology/pathology ; Child, Preschool ; Child ; Cell Size ; Aged ; Adult ; Adolescent

Four human eyes during embryonic period were examined, with particular emphasis on the developmental characteristics of the eye based on Streeter age group. These eyes should be classified in the age group 13,14,17 and 22, respectively. The morphological characteristics were included from optic vesicle to the formation of primary lens fiber and conjuntival fornix.
Humans*

Four human eyes during embryonic period were examined, with particular emphasis on the developmental characteristics of the eye based on Streeter age group. These eyes should be classified in the age group 13,14,17 and 22, respectively. The morphological characteristics were included from optic vesicle to the formation of primary lens fiber and conjuntival fornix.
Humans*

This study was performed to elucidate the structural changes of the attachment complex in the cultured cornea. The three normal corneal tissues were used in this study. The ultrastructural changes of the attachment complex were observed by electron microscopy in one corneal tissue which was not cultured and cultured for 6 days and two corneal tissues which were cultured 10 days and 20 days, respectively. The cornea cultured for 6 days showed changes in the electron density of the hemidesmosome. The basal lamina was focally detached from the cytoplasmic wall of the basal epithelial cells in the cornea cultured for 10 days. The anchoring fibrils within the nuded corneal stroma, which was cultured for 20 days, were markedly decreased in number. These findings suggest that the normal basal epithelial cell, hemidesmosomes and basal lamina might be the essential factors to maintain the networks of normal anchoring fibrils in corneal stroma.
Basement Membrane ; Cornea ; Corneal Stroma ; Cytoplasm ; Epithelial Cells ; Hemidesmosomes ; Microscopy, Electron

Type VII collagen is one of the major structural components of the corneal epithelial adhesion complex. Using the immunogold technique combined with indirect immunofluorescence analysis, the fine structural distribution of type VII collagen was studied in the corneas obtained from 5 enucleated hyman eyes (age range, 1-77 years) including one pathologic cornea from graft rejection. The findings on normal cornea corroborated the results from previous studies. In pathologic cornea from graft rejection, type VII collagen antibodies generated linear and irregular patchy fluorescence staining along the epithelial-stromal interface and immunogold binding to type VII collagen mainly occurred within the undulating lamina densa, more densealy distributed anchoring plaques and anchoring fibrils. The distribution of type VII collagen in pathologic human cornea from graft rejection is similar to normal human cornea. But, in pathologic cornea, type VII collagen is more densely distributed in superficial stroma and forms more extended anchoring network, which may be derived from the increased secretion of the type VII collagen due to the activated basal epithelial cell during healing process.
Antibodies ; Collagen Type VII* ; Cornea* ; Epithelial Cells ; Fluorescence ; Fluorescent Antibody Technique, Indirect ; Graft Rejection ; Humans ; Immunohistochemistry

The cultured cells were derived from rabbit corneal stroma by explant technique following microdissection and serial passage. The ultrastructural features of fourteenth-passage keratocytes were examined with both scanning and transmission electron microscope. The cells can be divided into activated, intermediate and old cell according to the differences in electron density and surface microvillous pattern. The morphologic characteristics of the cultured keratocytes partially resemble those shown in corneal keratocytes in vivo.
Cells, Cultured ; Corneal Keratocytes* ; Corneal Stroma ; Microdissection ; Serial Passage

Autologous pieces of rabbit conjuntival stroma were implanted into the vitreous cavity of the fellow eye. The eyes were observed at intervals of several days and were enucleated at different times for histologic examination with flat preparation method. The conjuntival stromal cells were transformed into fibroblasts during the first 72 postoperative hours. The cells composing the proliferations included fibroblast and occasional cuboidal to ovoid cells with eosinophilic cytoplasm containing occasional pigment granules. This study showed that vitreous cavity acted as a media for "in vivo" culture of the autologous tissue and also provided a scaffold for intraocular proliferation of the autologous conjuntival stroma.
Cytoplasm ; Eosinophils ; Fibroblasts ; Stromal Cells