The corneal rust ring is made artificaily by anexperimental method on the rabbit and the fate of the rust ring is observed by SEM for the interval of 1 week to 3 months. Because of the shortness of the observation period, the complete natural process of removal of the corneal rust ring can not be fully explained. But several interesting results can be obtained by this experiment. The implanted iron particles are falled off by the natural healng course without articial removal in three weeks. The rust ring can be detected on the corneal epithelium 21 days after implantation and continued until 3 months and moreover, by the SEM examination. Many PMNs and macrophages are present in the vicinity of the rust ring until 35 days and decrease gradually thereafter. The presence of these inflammatory cells reveals that these inflammatory cells reveals that these cells can take part in the process of the removal of the iron rust rings formed on the superficial eornea.
Epithelium, Corneal ; Iron ; Macrophages

PURPOSE: To investigate proliferation rate of the corneal epithelium with rigid gas permeable lens(RGP) or reverse geometry lens(RGL) wearing. METHODS: Twenty-four rabbits were fitted with either a RGP or RGL on right eye, with left eye serving as a control. They were sacrificed at 1, 3, 7, and 14 days after lens fitting. after immunohistochemistry using 5-bromo-2-deotyuridine, BrdU-labeled cells were counted in 10-medium power fields (X200) in each sample using light microscope by 1.0 mm intervals between superior limbus and the center. RESULTS: The number of BrdU-labeled cells was highest in peripheral cornea, and lowest in limbus(p<0.05). The BrdU-labeled cells of limbus increased by 127% but labeled-cells of the center decreased by 24% in RGP group after 1-day fitting. Increase of the labeled cells was observed in the mid-peripheral and central cornea by 12% and 121% each but the decrease of labelled cells was found at the limbus by 16% in RGL fitting group at 1 day. After 14days, Both RGP and RGL group showed decrease of BrdU-labeled cells in limbus by 8% each, and in the center by 32% and 63%, respectively. CONCLUSIONS: Normal rabbit cornea was characterized by different epithelial proliferation rates according to location. However these pattern was significantly altered with both RGL and RGP fitting group. The change was greater in RGL group than in RGP group. This suggested wearing the RGL might be less physiologic than RGP fitting.
Cornea ; Epithelium, Corneal ; Immunohistochemistry ; Rabbits

Cornea ; Epithelium, Corneal ; Iontophoresis ; Riboflavin

The marginal epithelium of corneal ulcer is occasionally edernatous and detached from corneal stroma in chronic corneal ulcer. This leads to retard healing of corneal epithelium because the migration and adhesion of corneal epithelium are prevented. We performed Nd-YAG laser in chronic corneal ulcer, 6 eyes of 6 patients from July 1996 to December 1996. It was used to improve the healing of corneal epithelium. The patiente were treated with Nd-YAG laser using 0.8 to 1. 2mJ per pulse applied to the region of Bowman`s membrane in the margin of corneal ulcer. The mean number of laser spots in one procedure was 22 and the rnean frequency of Nd-YAG laser use in each patient was 2. 3 times. The Nd-YAG laser induced adhesion of corneal epithelium in all patients and improved the healing of corneal epithelium. Therefore, the treatment of Nd-YAG laser can become 8 useful procedure for chronic corneal ulcer accompanied with corneal epithelial detachment.
Corneal Stroma ; Corneal Ulcer* ; Epithelium ; Epithelium, Corneal ; Humans ; Lasers, Solid-State* ; Membranes

PURPOSE: To compare preoperative and postoperative thickness and to investigate the difference in the thickness change of corneal epithelium and stroma after cataract surgery through scleral tunnel incision. METHODS: Forty eyes of forty patients who were 40 years old or older and underwent small-incision superior scleral tunnel cataract surgery with phacoemulsification were included. Using the RTVue instrument (Optovue Inc., Fremont, CA, USA), corneal epithelial (ET) and stromal thicknesses (ST) of all subjects were measured preoperatively and at 3 days, 1 week, and 1 month postoperatively. Thicknesses were classified into 3 zones according to the distance from the vertex: central zone (within 2 mm), paracentral zone (2-5 mm diameter) and midperipheral zone (5-6 mm diameter). RESULTS: Mean central ST was 486.68 ± 25.15 µm, 535.16 ± 48.13 µm, 515.98 ± 44.07 µm, and 502.28 ± 34.87 µm preoperatively, and at 3 days, 1 week, and 1 month postoperatively, respectively (p < 0.001 for all). ST showed significant thickening in all three zones from 3 days to 1 month postoperatively (p < 0.001 for all). Mean central, paracentral, and midperipheral ET was 52.13 ± 3.41 µm, 50.42 ± 2.97 µm, 49.12 ± 3.05 µm at preoperatively and 51.03 ± 3.63 µm, 48.96 ± 3.62 µm, 47.67 ± 3.81 µm at 1 month postoperatively, respectively (p = 0.061, 0.006, 0.001, respectively), while there were no signficant changes in all three zones at 3 and 7 days postoperatively. Changes in ET and ST were prominent at the superotemporal incision site. CONCLUSIONS: After scleral tunnel cataract surgery, corneal edema was observed in the stroma immediately after surgery. There was no significant change at early times after surgery in the epithelium, and there was a decrease in the peripheral cornea at 1 month postoperatively. The change in ET was considered a compensatory change due to stromal edema and appeared between 1 week to 1 month postoperatively.
Cataract* ; Cornea ; Corneal Edema ; Corneal Stroma ; Edema ; Epithelium ; Epithelium, Corneal ; Humans ; Phacoemulsification

Limbal epithelium plays a great role in reconstruction of damaged corneal epithelium and early limbal transplantation showed better results in limbal injury.However, there is no consensus about the appropriate time for limbal transplantation.We, therefore, investigated the results of autologous limbal transplantation (ALT)immediately following limbal epithelial injury in rabbits.We classified the rabbits in three groups whether the application of ALT and therapeutic contact lens were done or not.Injury of limbal and corneal epithelium was made by application of n-heptanol and tarsorrhaphy was done in all groups.ALT from the healthy fellow eye was done in Group 1 and Group 2 but not in Group 3, control group.Therapeutic soft contact lens was applied to Group 2 after ALT.We evaluated epithelial defect, haze, and neovascularization of corneas at 3 days, 1 week, and 2 weeks after operation.We also examined tissue specimen of corneas after two weeks of operation.Epithelial defect was almost healed within 2 weeks after operation in Group 1 and Group 2, but Group 3 showed persistent epithelial defect. Corneal neovascularization and haze were the most severe in Group 3, but was not so severe in Group 1 and Group 2, and there was no significant difference between the two groups.On histopathologic examination, Group 1 and Group 2 showed almost normal corneal epithelium though a few inflammatory cells and goblet cells were observed in some cases but control group showed severe inflammaton and many new vessels and goblet cells.In conclusion, ALT immediately following severe limbal injury is effective in reconstructing corneal epithelium.
Consensus ; Contact Lenses, Hydrophilic ; Cornea ; Corneal Neovascularization ; Epithelium ; Epithelium, Corneal ; Goblet Cells ; Heptanol ; Rabbits*

PURPOSE: Although a confocal microscopy has been largely used, there has been no domestic report concerning the normal structure of rabbit and human cornea by confocal microscope. In this study, we investigated confocal microscopic morphology of normal cornea of rabbit and human. MEHTODS: Using confocal microscope (ConfoScan 2.0, Fortune Technology, Italy), cross-sectioned corneal images of the corneal epithelium, Bowman's layer, stromal layer (anterior, middle, and posterior keratocyte), Descemet 's membrane, and endothelium were examined in vivo. RESULTS: In normal rabbit corneas, the superficial epithelium was polygonal and Bowman's layer was wrinkled. The stromal keratocyte nuclei was elliptical anteriorly and was with less cellularity posteriorly. The endothelium of rabbit was uniform, hexagonal in shape and had highly reflective cell borders. In human corneas, the superficial epithelium had highly reflective nuclei and regular wing cell or subepithelial nerve plexus was visible. Bowman's layer was fold-like structure. The shape of anterior and middle keratocyte nuclei were polygonal, but posterior keratocyte was oval shape. Also the nerve plexus of middle stromal layer was visible and the nucleus of endothelial cell was reflective hexagonal shape. CONCLUSIONS: The normal corneal morphological findings were studied by confocal microscopy. These data might provide the useful informations for the diagnosis of corneal disease.
Cornea ; Corneal Diseases ; Diagnosis ; Endothelial Cells ; Endothelium ; Epithelium ; Epithelium, Corneal ; Humans* ; Membranes ; Microscopy, Confocal

PURPOSE: To evaluate the inflammatory response following the insertion of corneal epithelium into rabbit corneal stroma. METHODS: Newzealand white rabbits were underwent corneal flap procedure using Hansatome and corneal epithelium was inserted. We divided the rabbits into three groups: Group A: flap only, Group B: flap with central epithelium insertion, Group C: flap with peripheral epithelium insertion. Eyes are enucleated, 4, 24, 48, 72 hours, 1 week, 1 month. Immunohistochemical stain fro CD4, CD8, and CD11b were used to test frozen section. RESULTS: Cd4 was expressed weakly at 24 hours in group A, B, C. around limbus and peripheral cornea. CD8 was expressed at 24 hours in group a, b, c especially strongly at group 3. In group B, C, CD8 was persistently expressed at 72 housr. CD11b was expressed at 24 hours in all groups. But in group C. CD11b was expressed strongly and persists at 72 hours and 1 week. CONCLUSION: Macrophage and Cytotoxic T cell maybe play an important role in corneal stromal wound healing after iatrogenic corneal epithelial insertion and further evaluation will be needed.
Cornea ; Corneal Stroma* ; Epithelium ; Epithelium, Corneal ; Frozen Sections ; Macrophages ; Rabbits ; Wound Healing

PURPOSE: To evaluate the clinical effects of early topical steroid treatment on corneal epithelium healing and postoperative corneal haziness after trans-epithelial photorefractive keratectomy (Trans PRK). METHODS: A total of 400 eyes from 200 patients who received Trans PRK with the Schwind Amaris laser platform (SCHWIND eye-tech solutions, Kleinostheim, Germany) were included in the present study. In 200 eyes (100 patients, early treated group) topical steroid was used from operation day but in the other 200 eyes (100 patients, late treated group) topical steroid was not used until therapeutic contact lenses were removed. The epithelial healing time, corneal haziness and visual acuity at postoperative 3, and 6 months were compared between the 2 groups. RESULTS: The therapeutic contact lenses could be removed at postoperative 3.50 +/- 1.46 days and 3.14 +/- 0.50 days in the early treated group and late treated group, respectively (p < 0.01). Breakdown of the epithelium after removal of therapeutic contact lenses occurred in 8 eyes, which were all in the early treated group. The difference of the visual acuity at postoperative 3 and 6 months between the 2 groups was not statistically significant. However, at postoperative 6 months, the corneal opacity developed in 12 eyes (6%) in the late treated group and 2 eyes (1%) in the early treated group (p = 0.01). CONCLUSIONS: Early treatment with topical steroid can delay corneal epithelial healing, especially the attachment of epithelium to stroma. However, the treatment can reduce the prevalence of corneal opacity after Trans PRK.
Composite Resins ; Contact Lenses ; Corneal Opacity ; Epithelium ; Epithelium, Corneal ; Eye ; Humans ; Photorefractive Keratectomy ; Prevalence ; Visual Acuity

PURPOSE: To evaluate the inflammatory response following the insertion of corneal epithelium into rabbit corneal stroma using confocal microscope. METHODS: Newzealand white rabbits were underwent corneal flap procedure using Microkeratome (Hansatome, Chiron, USA) and corneal epithelium was inserted. We divided the rabbits into three groups: Group A: flap only, Group B: flap with central epithelium insertion, Group C: flap with peripheral epithelium insertion. We examined the rabbit corneas at the time point of 4, 24, 72hours, 7days, and 1 month after surgery using confocal microscope and CD 11b immunohistochemical stain. RESULTS: At the early stage, the inflammatory cells were more frequently observed in the group C than in the group A and B, and at postoperative 72hours only in the group C. In stromal and total corneal thickness, there was a tendency of increase to the postoperative 24 hours and decrease in all groups, but the group C was more stronger tendency than other groups (P<0.05). There is no significant difference of the flap thickness among three groups (P>0.05). In immunohistochemical staining (CD11b), polynucleated cells and mast cells were more visible in group B and C than in group A. CONCLUSIONS: The postoperative inflammatory reaction of the LASIK flap may be related with corneal epithelial cells, and we think that more attention should be needed with the management of microkeratome.
Cornea ; Corneal Stroma ; Epithelial Cells* ; Epithelium ; Epithelium, Corneal ; Keratomileusis, Laser In Situ* ; Mast Cells ; Microscopy, Confocal ; Rabbits