In order to investigate the feasibility of the modified chitosan-gelatin crosslinked membrane (MC-Gel) and chitosan-gelatin crosslinked membrane (CS-Gel) to be a potential biomaterial for corneal regeneration, we evaluated their physicochemical properties and intraocular biocompatibility in this study. White light transmission and permeability of these membranes were detected. Results showed that white light transmission of both membranes was above 90% at 500 nm, which was similar to that of human cornea. The glucose, tryptophan and NaCl permeability of MC-Gel membrane and CS-Gel membrane was better than or similar to those of human cornea. The methylthiazol tetrazolium (MTT) assay was used to assess cell viability and proliferation. Also, interlamellar corneal transplantation was carried out to evaluate ophthalmic biocompatibility of MC-Gel membrane and CS-Gel membrane. Results indicated that MC-Gel membranes could support the proliferation of HCEC and displayed good intraocular biocompatibility when implanted into rabbits. No severe inflammatory reaction occurred after transplantation and the implanted MC-Gel membrane degraded completely 16 weeks post-operation. Due to its good physicochemical properties and biocompatibility, MC-Gel membrane could be a promising candidate material for corneal regeneration.
Animals ; Biocompatible Materials ; chemistry ; Cells, Cultured ; Chitosan ; chemistry ; Cornea ; cytology ; Corneal Injuries ; Cross-Linking Reagents ; Epithelium, Corneal ; cytology ; physiology ; surgery ; Gelatin ; chemistry ; Guided Tissue Regeneration ; methods ; Humans ; Membranes, Artificial ; Rabbits ; Regeneration ; Tissue Engineering ; methods ; Tissue Scaffolds

OBJECTIVETo observe the influence of flap-on or flap-off Epipolis laser in situ keratomileusis (epi-LASIK) on the release of transforming growth factor-β1 (TGF-β1) in tear fluid and corneal haze formation.

METHODSThirty patients (60 eyes) with myopia underwent epi-LASIK surgery with epithelial flap repositioning (flap-on) in the right eyes and epithelial flap removal (flap-off) in the left eyes. The level of TGF-β1 in tears was measured preoperatively and on days 1, 3, and 7 postoperatively. Corneal haze was graded at 1, 3 and 6 months after surgery.

RESULTSThe mean preoperative spherical equivalent refraction was -4.98∓2.28 D (-2.50 to -7.25 D) in flap-on group and -5.20∓4.02 D (-1.75 to -7.00 D) in flap-off group, showing no significant difference between the two groups (P=0.80). TGF-β1 levels in the tear fluid were similar in the two groups preoperatively (P=0.11) and at 1, 3, and 7 days postoperatively (P=0.55, 0.45, 0.19, respectively). TGF-β1 levels in tears gradually decreased after the first postoperative day in both groups, but were still higher than the preoperative value till the 7th postoperative day. Corneal haze scores in the two groups were similar at 1 month (P=0.98), 3 months (P=0.52), and 6 months (P=0.72) after the operation.

CONCLUSIONFlap-on and flap-off epi-LASIK surgeries do not differ significantly in postoperative TGF-β1 levels in the tear fluid or in the postoperative haze scores. TGF-β1 may play a role in corneal wound healing.

Adult ; Cornea ; surgery ; Epithelium, Corneal ; pathology ; surgery ; Female ; Humans ; Keratomileusis, Laser In Situ ; methods ; Male ; Postoperative Period ; Surgical Flaps ; Tears ; metabolism ; Transforming Growth Factor beta1 ; metabolism ; Young Adult

We report a case of corneal deposition of pigments from cosmetic contact lenses after intense pulsed-light (IPL) therapy. A 30-year-old female visited our outpatient clinic with ocular pain and epiphora in both eyes; these symptoms developed soon after she had undergone facial IPL treatment. She was wearing cosmetic contact lenses throughout the IPL procedure. At presentation, her uncorrected visual acuity was 2/20 in both eyes, and the slit-lamp examination revealed deposition of the color pigment of the cosmetic contact lens onto the corneal epithelium. We scraped the corneal epithelium along with the deposited pigments using a no. 15 blade; seven days after the procedure, the corneal epithelium had healed without any complications. This case highlights the importance of considering the possibility of ocular complications during IPL treatment, particularly in individuals using contact lenses. To prevent ocular damage, IPL procedures should be performed only after removing the lenses and applying eyeshields.
Adult ; Coloring Agents/*pharmacokinetics ; Contact Lenses/*adverse effects ; Cornea/*metabolism/pathology/*radiation effects ; Cosmetic Techniques/*adverse effects ; Debridement ; Epithelium, Corneal/surgery ; Female ; Humans ; Phototherapy/*adverse effects ; Postoperative Period ; Treatment Outcome ; Visual Acuity

PURPOSE: A corneal epithelial debridement using three different instruments was performed in rabbits, and the rates of corneal epithelium recovery were compared. Additionally, the extent of corneal damage as determined by the scanning electron microscopy was evaluated in each group. METHODS: Nineteen eyes of ten rabbits were classified into three groups according to the instruments used. The corneal epithelial debridement was performed using three different instruments: a Beaver blade (group A), a Bard-Parker blade No.15 (group B) and a dry cotton-tipped ap plicator (group C). After epithelial debridement, each cornea was observed every 24 hours for three days. After completion of the corneal recovery, each cornea was severed along the limbus and observed under the scanning electron microscope. RESULTS: The rate of corneal epithelial healing of the group C (dry cotton-tipped applicator) showed no statistical significance from those of the other groups. However, according to the corneal status observed under scanning electron microscope after debridement, cracks in the corneal surface in portions of group A and B were observed in contrast with no creaks in group C. CONCLUSIONS: Based on these results, corneal epithelial debridement using a cotton-tipped applicator is expected to reduce the occurrence of postoperative corneal complications. Use of a dry cotton-tipped applicator for corneal epithelial debridement in vitreoretinal surgery is suggested.
Cornea ; Debridement ; Electrons ; Epithelium, Corneal ; Eye ; Microscopy, Electron, Scanning ; Rabbits ; Rodentia ; Vitreoretinal Surgery

We report our experience with corneal epithelium, grown in vivo, transplantation in three patients with persistent epithelial defect (PED). The three patients had ocular surface disease unresponsive to standard treatments and were therefore chosen for transplantation. They underwent transplantation of epithelial sheets, grown in vivo, to the most affected eye. In vivo cultivation was carried out in the cornea of a living related donor. After epithelialization was completed, the epithelium grown on an amniotic membrane was harvested gently; it was then transplanted into the patient's eye after debridement of fibrovascular tissue. The cultivated epithelium was completely epithelialized by 2 weeks; it was well-differentiated with well-formed hemidesmosome. On immunohistochemical staining, p63, connexin 43, and Integrin beta4 were expressed in the cells on the epithelial sheet. The PED was covered completely and maintained for 4 weeks in all cases. However, corneal erosion recurred after 5 weeks in two cases. This novel technique demonstrates the corneal epithelial cells can be expanded in vivo successfully on denuded amniotic membrane of a healthy cornea and harvested safely. A corneal epithelial sheet, grown in vivo, can be transplanted to treat eye with a severe ocular surface disease, such as total limbal deficiency.
Adult ; Cell Culture Techniques ; Cells, Cultured ; Corneal Diseases/etiology/pathology/*surgery ; Corneal Transplantation/*methods ; Epithelial Cells/cytology/*transplantation ; Epithelium, Corneal/cytology/*transplantation ; Eye Burns/complications ; Humans ; Limbus Corneae/*pathology ; Male ; Middle Aged ; Stem Cells/*pathology ; Stevens-Johnson Syndrome/complications

To evaluate the efficacy of amniotic membrane in the management of painful bullous keratopathy secondary to the intractable glaucoma and in preventing exposure of drainage devices, we inserted Ahmed valve with amniotic membrane patch graft over the implant itself, and debrided corneal epithelium with amniotic membrane graft over the exposed stroma as a single operation. During the follow-up periods, we monitored vision, intraocular pressure (IOP), presence of ocular pain, and postoperative complications associated with the implants. The mean follow up period was 8.4+/-3.2 months. IOP was well controlled after the intervention. The preoperative mean IOP was measured as 43.9+/-9.0 mmHg and lowered to 16.1+/-1.8 mmHg at the last visit and no complications associated with the implants were noted. Even though the improvement in vision was not prominent, the ocular surface stabilized rapidly and ocular pain associated with bullous keratopathy disappeared soon after surgery. Conclusively the use of amniotic membrane in conjunction with Ahmed valve implantation is an effective way to relieve ocular pain and lessen the chances of complications associated with the implant in patients with intractable glaucoma and bullous keratopathy.
Retrospective Studies ; Middle Aged ; Male ; Humans ; *Glaucoma Drainage Implants ; Glaucoma/complications/surgery ; Female ; Epithelium, Corneal/pathology/surgery ; Corneal Transplantation/*methods ; Corneal Diseases/etiology/pathology/*surgery ; Amnion/*transplantation ; Aged

The purpose of this study is to characterize and compare the ultrastructural changes occurring during the in vivo cultivation of corneal epithelium on amniotic membrane (AM) at several different time points. Corneal burn patients (n=7) with a corneal epithelial defect and severe limbal damage were selected. Initially, AM transplantation with limbal autograft was performed at the acute stage of corneal burn to reconstruct the damaged ocular surface. One to six (mean interval; 3.3+/-1.2) months later, the central part of AM containing an in vivo expanded corneal epithelium was excised and retransplanted in adjacent lesions. The excised epithelium with AM was examined by electron microscopy and immunohistochemical study. By electron microscopy, one and two months after expansion, cultivated epithelium on AM showed an undifferentiated epithelium and an incomplete basement membrane (BM). But, after three months, the cultivated epithelium began to differentiate into a multilayered epithelium with a continuous BM with increased hemidesmosomes. These findings were further confirmed by immunohistochemical study, that cytokeratin K3 was expressed in the cultivated corneal epithelium and newly formed BM was partially positive of collagen IV at three months. At least 3 months may be needed for the proliferation and differentiation of in vivo cultivated corneal epithelium on AM.
Stem Cells/cytology ; Stem Cell Transplantation/*methods ; Middle Aged ; Microscopy, Electron ; Male ; Keratin-3/biosynthesis ; Immunohistochemistry ; Humans ; Epithelium, Corneal/cytology/*metabolism/*pathology/*transplantation ; Corneal Diseases/*therapy ; Burns/*surgery/therapy ; Biological Dressings ; Amnion/*ultrastructure ; Adult

OBJECTIVETo investigate the proliferation and differentiation of cultured corneal stem cells and determine the effect of corneal stem cells cultured on amniotic membranes on the limbal area for treating corneal burns.

METHODSThe proliferation and differentiation of corneal stem cells in vitro had been examined using colony-forming efficiency and immunohistochemistry. The stem cells had been cultured on amniotic membranes and transplanted to the limbal area for treating corneal burns.

RESULTSCorneal stem cells had a high proliferation capacity in primary and first passage, cytokeratin 3 was not expressed in primary culture but partly in first passage. The stem cells could proliferate to form cell layer on an amniotic membrane. When transplanted, stem cells could survive on limbus. After transplantation, ocular inflammation resolved, the cornea re-epithelialized, the stromal opacity reduced, the superficial neovascularity was lessened and the conjunctival fornix re-established.

CONCLUSIONSOcular surface conditions could be improved by allograft of corneal stem cells cultured on amniotic membranes.

Alkalies ; Amnion ; transplantation ; Animals ; Burns, Chemical ; surgery ; Cell Culture Techniques ; methods ; Cell Differentiation ; Cell Division ; Cell Transplantation ; methods ; Cells, Cultured ; Epithelium, Corneal ; chemistry ; cytology ; Eye Burns ; chemically induced ; surgery ; Graft Survival ; Humans ; Keratins ; analysis ; Limbus Corneae ; chemistry ; cytology ; Rabbits ; Stem Cells ; chemistry ; cytology ; Treatment Outcome

The purpose of this study is to demonstrate a method of how to remove epithelium grown beneath the hinge area after laser in situ keratomileusis (LASIK) without affecting the refractive part of the lenticule. In three cases, an incision was made at the base of the hinge by RK diamond knife to free the lenticule from the stroma. The lenticule was lifted from the nasal edge. The epithelium grown along the interface beneath the hinge area was removed with a Bard-Parker No. 15 knife. The lenticular flap was repositioned with interrupted sutures using 10-0 nylon. No further epithelial ingrowth was observed. The central cornea remained clear leaving a peripheral ring-shaped opacity without affecting the preoperative naked visual acuity. In conclusion, epithelial ingrowth along the interface after LASIK can be removed safely without affecting the refractive part by the incision of the hinge area with a RK diamond knife, removal of the epithelium, and suturing of the lenticule to the stromal bed.
Adult ; Epithelium, Corneal/surgery* ; Epithelium, Corneal/pathology* ; Female ; Human ; Keratectomy, Photorefractive, Excimer Laser/adverse effects* ; Male ; Reoperation ; Suture Techniques ; Treatment Outcome ; Visual Acuity/physiology

The effect of hyaluronic acid(HA) on corneal reepithelization following excimer laser keraectomy was evaluated in rats. An argon fluoride excimer laser(193nm) was used to perform laser keratectomy in each eye of 44 rats (4mm in diameter and 38micrometer in depth). The animals were divided into two guoups: the control group(dropping with PBS) and the HA treated group (dropping with 10mg/ml HA). The healing rate of the epithelial defectarea as well as morphologic changes were observed and the healing response of the cornea was analyzed immunohistochemically to determine the dirsribution of fibronectin. The results were as follows: 1. The reduction of epithelial defect area after 15 hours following laser keratectomy was significantly accelerated in HA treated group compared with the control group(P<0.005). The mean epithelial healing rate was 0.38+/-0.05mm2/hr in the HA treated group and 0.32+/-0.05mm2/hr in the control group. 2. Histologically, remarkable epithelial thickening and less polymorphonuclear leukocyte infiltration under leading epithelium in the HA treated group were observed, which were limited in anterior stroma. 3. Under the transmission electrom microscope, after 72 hours, the intercellular spaces of wing cell layer were bridged by desmosoes more tightly, and remarkable hemidesmosomes were shown in Ha treated group compared with the control group. 4. Fibronectin immunoreactivity observed was under the leading epithelium by using immunohistochemistry at 15 hours following keratectomy in both groups. The results indicate that hyaluronic acid stimulates epithelial wound healing following excimer laser keratectomy by enhancing cell migration and promoting the tight ntercellular junction. The expression of fibronectin was not influenced by HA.
Animals ; Argon ; Cell Movement ; Cornea ; Corneal Surgery, Laser ; Epithelium ; Extracellular Space ; Fibronectins ; Fluorides ; Hemidesmosomes ; Hyaluronic Acid* ; Immunohistochemistry ; Lasers, Excimer* ; Neutrophils ; Rats* ; Wound Healing