PURPOSE: This study was carried out to clarify the histological characteristics of the interface of the corneal stroma and Descemet's membrane of the human eye. METHODS: Nighteen donor eyes without corneal pathology were examined by scanning and transmission electron microscopy. The Descemet's membrane including the corneal endothelium was cheked for scanning electron microscopy. The junctional characteristics of the posterior corneal stroma and Descemet's membrane was examined by transmission electron microscopy. RESULTS: The scanning electron microscopy showed that collagen sheet faced each other at the right angle near the Descemet's membrane and penetrated the Descemet's membrane with the irregular arrangement. The transmission electron microscopy showed that the electron-dense collagen filaments extended to the posterior stroma from Descemet's membrane. The arrangement of electron-dense collagen filaments paralleled with the arrangement of the collagen fibrils of the posterior stroma. CONCLUSIONS: The interface of the corneal stroma and Descemet's membrane was composed of two-typed extracellular materials without the intercellular specificatons.
Collagen ; Corneal Stroma* ; Descemet Membrane* ; Endothelium, Corneal ; Humans ; Microscopy, Electron ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Pathology ; Tissue Donors

No abstract available.
Adult ; Cataract Extraction/*adverse effects ; Corneal Edema/diagnosis/*etiology ; Corneal Stroma/*pathology ; Epithelium, Corneal/*pathology ; Female ; Hallermann's Syndrome/*complications/diagnosis ; Humans ; Lens Implantation, Intraocular

OBJECTIVE: To explore the relationship between corneal thickness and postmortem interval (PMI) in rabbit. METHODS: The rabbit model was established by air embolism. The rabbit cornea was sampled at 6-hour-interval from 0 to 72 h postmortem. After routine HE staining, the whole cornea image was collected by the optical microscope. Three markers were observed including corneal epithelial thickness (x1), corneal stromal thickness (x2) and whole corneal thickness (x3) using Motic Images Plus 2.0 image analysis software and the data were statistically analyzed to establish the regression function with PMI (y). RESULTS: Within 72 h postmortem, rabbit corneal stromal thickness and whole corneal thickness increased at 12h postmortem and reached the peak at 54h postmortem. The two markers showed positive correlation with PMI. The regression functions of the two markers were y = -0.070 2 x2(2) +11.398 x2 + 1634 (R2 = 0.712 2, P < 0.05) and y = -0.074 9 x3(2) +12.036 x3 + 1819.4 (R = 0.675 0, P < 0.05), respectively. CONCLUSION The two markers of corneal stromal thickness and the whole corneal thickness showed the strong linear correlation with PMI. The correlation of the corneal stromal thickness is better than the whole corneal thickness. The two markers can be used to estimate PMI.
Animals ; Autopsy ; Cornea/pathology* ; Corneal Opacity/pathology* ; Corneal Stroma/pathology* ; Female ; Forensic Medicine/methods* ; Image Processing, Computer-Assisted ; Male ; Microscopy, Confocal ; Postmortem Changes ; Rabbits ; Time Factors

OBJECTIVETo screen the transforming growth factor, beta-induced (TGFBI) gene mutation in three Chinese families with autosomal dominant corneal dystrophy.

METHODSAnalysis of the TGFBI gene mutations was performed by direct sequencing of the whole coding regions and exon-intron boundaries of the TGFBI gene in all affected members from the three families.

RESULTSThree kinds of TGFBI gene mutations, R124C and H626R were detected in the patients of the two lattice conneal dystrophy families, and R124H was detected in the Avellino corneal dystrophy family.

CONCLUSIONTGFBI gene mutations are the underlying molecular mechanism of the pathogenesis for corneal dystrophy. The R124 and H626 are the hot spots of TGFBI gene mutation in this disease.

Asian Continental Ancestry Group ; genetics ; Corneal Dystrophies, Hereditary ; genetics ; pathology ; Corneal Stroma ; pathology ; DNA Mutational Analysis ; Family Health ; Female ; Humans ; Male ; Mutation ; Pedigree ; Transforming Growth Factors ; genetics

To determine if the residual corneal stromal bed of 250 micrometer is enough to prevent iatrogenic keratectasia in laser in situ keratomileusis (LASIK), we studied 958 patients who underwent LASIK from April 2000 to October 2003 retrospectively. The estimated probabilities of the residual stromal bed, that was less than 250 micrometer, were calculated using the published flap thickness data of Moria C&B microkeratome. Then we calculated the ratio of the real incidence of keratectasia to the expected the percentage of the patients with less than 250 micrometer residual stromal bed in our study. Using the LASIK flap thickness data of Miranda, Kezirian and Nagy, the expected probabilities that the residual stroma would be less than 250 micrometer were 8.8%, 4.3% and 1.5% of the 1,916 eyes respectively, while keratectasia developed in both eyes (0.1%) of 1 patient in our study. The estimated ratio of the keratectatic eyes to eyes with less than 250 micrometer stromal bed were 1.2-6.9%. Compared to the number of eyes with residual stromal thickness less than 250 micrometer, the incidence of keratectasia was relatively low. The residual stromal bed thickness of more than 250 micrometer may possibly be safe, but further observations for long period are necessary.
Postoperative Complications/*prevention & control ; Middle Aged ; Keratomileusis, Laser In Situ/*adverse effects ; Iatrogenic Disease/*prevention & control ; Humans ; Dilatation, Pathologic ; Corneal Stroma/*pathology ; Corneal Diseases/etiology/*prevention & control ; Adult

PURPOSE: To compare corneal flaps created in rabbits with a 60 kHz femtosecond (FS) laser using different levels of raster energy and to measure early inflammation, corneal stromal cell death, and late postoperative adhesion strength. METHODS: Sixty rabbits were divided into three groups of 20 each. A flap 110 micrometer thick and 9.0 mm in diameter was made in one eye of each rabbit at raster energies of 0.7 microJ, 1.1 microJ, and 2.4 microJ. Histopathological evaluation for inflammation and apoptosis using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed at 4 and 24 hours after flap creation. The adhesion strength of the flaps was measured with a tension meter at 1 and 3 months. RESULTS: Twenty four hours after flap creation, the 2.4 microJ group had more inflammatory and CD11b-positive cells than the 0.7 and 1.1 microJ groups. The number of TUNEL-positive cells increased with raster energy at 4 and 24 hours. The grams of force (gf) needed to detach the flaps at 3 months was significantly higher in 2.4 microJ group (170 gf) than in 0.7 microJ group (97.5 gf) and 1.1 microJ group (100 gf, p = 0.03). CONCLUSIONS: Using raster energy lower than 1.1 microJ to make a flap with a 60 kHz FS laser decreases inflammatory cell infiltration and corneal stromal cell death in the central cornea but may result in a weaker flap than using higher raster energy (2.4 microJ).
Animals ; Cell Death ; Corneal Stroma/*pathology/*surgery ; Keratitis/*pathology/*prevention & control ; Laser Therapy/*methods ; Male ; Models, Animal ; Rabbits ; *Surgical Flaps ; Tissue Adhesions/pathology/surgery

PURPOSE: To compare corneal flaps created in rabbits with a 60 kHz femtosecond (FS) laser using different levels of raster energy and to measure early inflammation, corneal stromal cell death, and late postoperative adhesion strength. METHODS: Sixty rabbits were divided into three groups of 20 each. A flap 110 micrometer thick and 9.0 mm in diameter was made in one eye of each rabbit at raster energies of 0.7 microJ, 1.1 microJ, and 2.4 microJ. Histopathological evaluation for inflammation and apoptosis using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed at 4 and 24 hours after flap creation. The adhesion strength of the flaps was measured with a tension meter at 1 and 3 months. RESULTS: Twenty four hours after flap creation, the 2.4 microJ group had more inflammatory and CD11b-positive cells than the 0.7 and 1.1 microJ groups. The number of TUNEL-positive cells increased with raster energy at 4 and 24 hours. The grams of force (gf) needed to detach the flaps at 3 months was significantly higher in 2.4 microJ group (170 gf) than in 0.7 microJ group (97.5 gf) and 1.1 microJ group (100 gf, p = 0.03). CONCLUSIONS: Using raster energy lower than 1.1 microJ to make a flap with a 60 kHz FS laser decreases inflammatory cell infiltration and corneal stromal cell death in the central cornea but may result in a weaker flap than using higher raster energy (2.4 microJ).
Animals ; Cell Death ; Corneal Stroma/*pathology/*surgery ; Keratitis/*pathology/*prevention & control ; Laser Therapy/*methods ; Male ; Models, Animal ; Rabbits ; *Surgical Flaps ; Tissue Adhesions/pathology/surgery

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

PURPOSE: To analyze healing changes of corneal wounds of different corneal incision sizes with or without stromal hydration in cataract surgery using anterior segment optical coherence tomography. METHODS: Cataract surgeries were performed by a single surgeon and 2.2- and 2.8-mm corneal incisions were made using a diamond blade (ME-759; Meyco, Biel-Bienne, Swiss). Patients were divided into four groups according to incision size (2.2 and 2.8 mm), and with/without stromal hydration. Fifteen eyes were assigned to each group and incision wounds were measured using anterior segment optical coherence tomography at 2 hours, 1 day, 1 week, 1 month, and 3 months postoperatively. Corneal thickness, incision length and incision angle were measured and existence of epithelial, endothelial gaping and Descemet's membrane detachment was evaluated. RESULTS: Incision thickness was greater in the group with stromal hydration than in the group without on operation day (p < 0.05). Stromal hydration exerted greater influence in the 2.2-mm incision group than in the 2.8-mm incision group. Corneal thickness decreased more rapidly in the stromal hydration group than in the group with no hydration (p = 0.022). Endothelial gaping was greater in the 2.2-mm incision group than in the 2.8-mm incision group 1 day, 1 month, and 3 months after surgery (p = 0.035, p = 0.009, and p = 0.008, respectively). No other statistical significance was observed between the two groups (2.2 and 2.8 mm) during follow-up regarding corneal thickness, epithelial gaping and Descemet's membrane detachment. CONCLUSIONS: Corneal wounds with a smaller incision could be more vulnerable to external stimuli such as stromal hydration and are less stable than those with a larger incision.
Aged ; Anterior Eye Segment ; Cataract Extraction/*methods ; Corneal Stroma/pathology/*surgery ; Female ; Humans ; Male ; Middle Aged ; Surgical Wound Dehiscence/diagnosis/*prevention & control ; Tomography, Optical Coherence/*methods ; *Wound Healing

PURPOSE: To report the clinical outcomes of deep anterior lamellar keratoplasty (DALK) when sterile gamma-irradiated acellular corneal tissues (VisionGraft) are used in combination with amniotic membrane transplantation (AMT) for intractable ocular surface diseases. METHODS: The medical records of fifteen patients who had DALK with AMT were retrospectively reviewed. Indications for surgery included ocular burn, bacterial keratitis, herpes simplex virus keratitis, corneal opacity with Stevens-Johnson syndrome, Mooren's ulcer, idiopathic myxoid degeneration of corneal stroma, and recurrent band keratopathy. DALK was performed using partial-thickness acellular corneal tissue and a temporary amniotic membrane patch was added at the end of the operation. RESULTS: All cases that underwent DALK with AMT became epithelialized within 2 postoperative weeks. Twelve patients showed favorable outcomes without graft rejection, corneal opacification, or neovascularization. The other three grafts developed corneal opacification and neovascularization, and required additional penetrating keratoplasty (PK). Unlike the results of previous PKs, there were no graft rejections and the graft clarity was well-maintained in these three cases for at least 8 months after PK. CONCLUSIONS: DALK using sterile acellular corneal tissues in combination with AMT may be a good therapeutic strategy for treating intractable ocular surface diseases because of lowered immune rejection, fibroblast activation, and facilitation of epithelialization. Furthermore, DALK can help stabilize the ocular surface, prolong graft survival, and may allow better outcomes when combined with subsequent PK.
Adult ; Aged ; Amnion/*transplantation ; Corneal Diseases/pathology/*surgery ; Corneal Stroma/radiation effects/*transplantation ; Female ; Graft Survival ; Humans ; Keratoplasty, Penetrating/*methods ; Male ; Middle Aged ; Retrospective Studies ; Visual Acuity ; Young Adult