The Favorable Effect of Mesenchymal Stem Cell Treatment on the Antioxidant Protective Mechanism in the Corneal Epithelium and Renewal of Corneal Optical Properties Changed after Alkali Burns

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Cejka, Cestmir; Holan, Vladimir; Trosan, Peter; Zajicova, Alena; Javorkova, Eliska; Cejkova, Jitka

2016-01-01

The aim of this study was to examine whether mesenchymal stem cells (MSCs) and/or corneal limbal epithelial stem cells (LSCs) influence restoration of an antioxidant protective mechanism in the corneal epithelium and renewal of corneal optical properties changed after alkali burns. The injured rabbit corneas (with 0.25 N NaOH) were untreated or treated with nanofiber scaffolds free of stem cells, with nanofiber scaffolds seeded with bone marrow MSCs (BM-MSCs), with adipose tissue MSCs (Ad-MSC...

Research on mouse model of grade II corneal alkali burn

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Jun-Qiang Bai

2016-04-01

Full Text Available AIM: To choose appropriate concentration of sodium hydroxide (NaOH solution to establish a stable and consistent corneal alkali burn mouse model in grade II. METHODS: The mice (n=60 were randomly divided into four groups and 15 mice each group. Corneal alkali burns were induced by placing circle filter paper soaked with NaOH solutions on the right central cornea for 30s. The concentrations of NaOH solutions of groups A, B, C, and D were 0.1 mol/L, 0.15 mol/L , 0.2 mol/L, and 1.0 mol/L respectively. Then these corneas were irrigated with 20 mL physiological saline (0.9% NaCl. On day 7 postburn, slit lamp microscope was used to observe corneal opacity, corneal epithelial sodium fluorescein staining positive rate, incidence of corneal ulcer and corneal neovascularization, meanwhile pictures of the anterior eyes were taken. Cirrus spectral domain optical coherence tomography was used to scan cornea to observe corneal epithelial defect and corneal ulcer. RESULTS: Corneal opacity scores ( were not significantly different between the group A and group B (P=0.097. Incidence of corneal ulcer in group B was significantly higher than that in group A (P=0.035. Incidence of corneal ulcer and perforation rate in group B was lower than that in group C. Group C and D had corneal neovascularization, and incidence of corneal neovascularization in group D was significantly higher than that in group C (P=0.000. CONCLUSION: Using 0.15 mol/L NaOH can establish grade II mouse model of corneal alkali burns.

Expression of S100B during the innate immune of corneal epithelium against fungi invasion

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Jie Zhang

2016-02-01

Full Text Available AIM: To explore the expression of S100B in corneal epithelial cells under Aspergillus stimulation both in vivo and in vitro. METHODS: Immortalized human corneal epithelial cells (HCECs were exposed to inactive Aspergillus fumigatus (A. fumigatus conidia at 0, 4, 8, 12, 16, and 24h respectively. The corneas of Wistar rats were exposed to active A. fumigatus at 0, 12, 24, 48h and the normal rat corneas were used for normal control. The mRNA level of S100B was evaluated by real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR. S100B protein expression in cornea epithelium was detected by immunohistochemical/immunocytochemical staining (IHC/ICC. RESULTS: Histopathology revealed a significant inflammatory cell infiltration in fungal keratitis human and rat cornea. Corneal epithelial cells didn’t express or rarely express S100B at baseline. A. fumigatus significantly induced S100B mRNA expression in cultured corneal epithelial cells in a time depended manner in vitro, the mRNA began to rise significantly at 8h in vitro (P<0.05 and continue to rise as time prolonged (P<0.01. In vivo, S100B mRNA level was low in the normal corneas. However, it was increased in keratitis corneas from 12h after infection (P<0.05 and reached to a peak at 24h (P<0.001. Immunochemistry revealed an obvious staining in fungal keratitis corneas as well as immortalized HCECs compared to the normal ones respectively, indicating an increased expression of S100B protein. CONCLUSION: S100B exists in corneal epithelial cells and is over-expressed under A. fumigatus stimulation. S100B may play an important role in the innate immune response of the corneal epithelium during A. fumigatus infection.

Expression of S100B during the innate immune of corneal epithelium against fungi invasion

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Zhang, Jie; Zhao, Gui-Qiu; Qu, Jing; Che, Cheng-Ye; Lin, Jing; Jiang, Nan; Zhao, Han; Wang, Xue-Jun

2016-01-01

AIM To explore the expression of S100B in corneal epithelial cells under Aspergillus stimulation both in vivo and in vitro. METHODS Immortalized human corneal epithelial cells (HCECs) were exposed to inactive Aspergillus fumigatus (A. fumigatus) conidia at 0, 4, 8, 12, 16, and 24h respectively. The corneas of Wistar rats were exposed to active A. fumigatus at 0, 12, 24, 48h and the normal rat corneas were used for normal control. The mRNA level of S100B was evaluated by real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). S100B protein expression in cornea epithelium was detected by immunohistochemical/immunocytochemical staining (IHC/ICC). RESULTS Histopathology revealed a significant inflammatory cell infiltration in fungal keratitis human and rat cornea. Corneal epithelial cells didn't express or rarely express S100B at baseline. A. fumigatus significantly induced S100B mRNA expression in cultured corneal epithelial cells in a time depended manner in vitro, the mRNA began to rise significantly at 8h in vitro (P<0.05) and continue to rise as time prolonged (P<0.01). In vivo, S100B mRNA level was low in the normal corneas. However, it was increased in keratitis corneas from 12h after infection (P<0.05) and reached to a peak at 24h (P<0.001). Immunochemistry revealed an obvious staining in fungal keratitis corneas as well as immortalized HCECs compared to the normal ones respectively, indicating an increased expression of S100B protein. CONCLUSION S100B exists in corneal epithelial cells and is over-expressed under A. fumigatus stimulation. S100B may play an important role in the innate immune response of the corneal epithelium during A. fumigatus infection. PMID:26949634

Corneal epithelium expresses a variant of P2X(7 receptor in health and disease.

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Courtney Mankus

Full Text Available Improper wound repair of the corneal epithelium can alter refraction of light resulting in impaired vision. We have shown that ATP is released after injury, activates purinergic receptor signaling pathways and plays a major role in wound closure. In many cells or tissues, ATP activates P2X(7 receptors leading to cation fluxes and cytotoxicity. The corneal epithelium is an excellent model to study the expression of both the full-length P2X(7 form (defined as the canonical receptor and its truncated forms. When Ca(2+ mobilization is induced by BzATP, a P2X(7 agonist, it is attenuated in the presence of extracellular Mg(2+ or Zn(2+, negligible in the absence of extracellular Ca(2+, and inhibited by the competitive P2X7 receptor inhibitor, A438079. BzATP enhanced phosphorylation of ERK. Together these responses indicate the presence of a canonical or full-length P2X(7 receptor. In addition BzATP enhanced epithelial cell migration, and transfection with siRNA to the P2X(7 receptor reduced cell migration. Furthermore, sustained activation did not induce dye uptake indicating the presence of truncated or variant forms that lack the ability to form large pores. Reverse transcription-polymerase chain reaction and Northern blot analysis revealed a P2X(7 splice variant. Western blots identified a full-length and truncated form, and the expression pattern changed as cultures progressed from monolayer to stratified. Cross-linking gels demonstrated the presence of homo- and heterotrimers. We examined epithelium from age matched diabetic and non-diabetic corneas patients and detected a 4-fold increase in P2X(7 mRNA from diabetic corneal epithelium compared to non-diabetic controls and an increased trend in expression of P2X(7variant mRNA. Taken together, these data indicate that corneal epithelial cells express full-length and truncated forms of P2X(7, which ultimately allows P2X(7 to function as a multifaceted receptor that can mediate cell proliferation and

Immunohistochemical expression of matrix metalloproteinases in the rabbit corneal epithelium upon UVA and UVB irradiation

Czech Academy of Sciences Publication Activity Database

Ardan, Taras; Čejková, Jitka

2012-01-01

Roč. 114, č. 6 (2012), s. 540-546 ISSN 0065-1281 R&D Projects: GA ČR GPP302/10/P155 Institutional research plan: CEZ:AV0Z50390512 Keywords : cornea * corneal epithelium * eye Subject RIV: FF - HEENT, Dentistry Impact factor: 1.608, year: 2012

Delayed healing of corneal epithelium after phototherapeutic keratectomy for lattice dystrophy.

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Das, Sujata; Langenbucher, Achim; Seitz, Berthold

2005-04-01

To evaluate the time period necessary for complete epithelial healing after phototherapeutic keratectomy (o-PTK) carried out for various superficial corneal opacities. A total of 197 eyes were divided into 9 groups: group 1, Cogan dystrophy including recurrences (n = 15); group 2, Reis Bucklers dystrophy including recurrences (n = 12); group 3, granular dystrophy including recurrences (n = 63); group 4, lattice dystrophy including recurrences (n = 19); group 5, macular dystrophy including recurrences (n = 10); group 6, herpetic scars (n = 5); group 7, corneal scars of nonherpetic origin (including scrofulous, traumatic, central keratoconus, post-pterygium surgery) (n = 31); group 8, Salzmann nodular degeneration (n = 22); and group 9, miscellaneous (such as bullous keratopathy, acute chemical burn, corneal degeneration) (n = 20). After o-PTK, patients were examined daily at the slit lamp using fluorescein and blue light. The time period necessary for complete healing of the epithelial defect was compared among these groups. Delayed healing was considered where the epithelium was not closed after 7 days. One hundred sixty-one eyes (95%) healed within 7 days. Overall, 63%, 80%, and 85% of epithelial defects were closed within 3, 4, and 5 days, respectively. Out of 9 eyes that had delayed healing, 6 eyes (67%) belonged to lattice dystrophy category. Mean time taken for healing in group 4 (8.6 +/- 8.4 days) was significantly longer than those in group 1 (3.0 +/- 1.5 days, P = 0.009), group 2 (3.7 +/- 3.1 days, P = 0.03), group 3 (3.1 +/- 1.5 days, P = 0.001), group 5 (2.7 +/- 0.8 days, P = 0.01), group 7 (3.6 +/- 2.4 days, P = 0.007), group 8 (3.3 +/- 1.3 days, P = 0.009), and group 9 (3.0 +/- 1.9 days, P = 0.011). Eyes with lattice corneal dystrophy suffered from delayed epithelial healing after o-PTK. In addition to adequate counseling, these patients should be followed up closely until complete closure of the epithelium to avoid ulceration, scarring, or even

Caveolin-1 as a novel indicator of wound-healing capacity in aged human corneal epithelium.

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Rhim, Ji Heon; Kim, Jae Hoon; Yeo, Eui-Ju; Kim, Jae Chan; Park, Sang Chul

2010-01-01

Excess caveolin-1 has been reported to play a role in age-dependent hyporesponsiveness to growth factors in vitro. Therefore, we hypothesized that caveolin-1-dependent hyporesponsiveness to growth factors in aged corneal epithelial cells might be responsible for delayed wound healing in vivo. To test this hypothesis, we evaluated corneal wound-healing time by vital staining using fluorescein after laser epithelial keratomileusis (LASEK). We compared wound-healing times in young, middle-aged and elderly patients. We also examined caveolin-1 levels and other aging markers, such as p53 and p21, in the corneal epithelium. Elderly patients generally had higher caveolin-1 levels in the corneal epithelia than young patients. There were, however, variations among individuals with increased caveolin-1 in some young patients and decreased levels in some elderly patients. Wound-healing time after LASEK correlated well with the corneal caveolin-1 status. Therefore, we suggest that caveolin-1 status might be responsible for delayed wound healing in elderly patients after LASEK. Caveolin-1 status might be a regulator for wound-healing capacity and a novel target for in vivo adjustment.

Topical administration of orbital fat-derived stem cells promotes corneal tissue regeneration.

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Lin, Ko-Jo; Loi, Mei-Xue; Lien, Gi-Shih; Cheng, Chieh-Feng; Pao, Hsiang-Yin; Chang, Yun-Chuang; Ji, Andrea Tung-Qian; Ho, Jennifer Hui-Chun

2013-06-14

Topical administration of eye drops is the major route for drug delivery to the cornea. Orbital fat-derived stem cells (OFSCs) possess an in vitro corneal epithelial differentiation capacity. Both the safety and immunomodulatory ability of systemic OFSC transplantation were demonstrated in our previous work. In this study, we investigated the safety, therapeutic effect, and mechanism(s) of topical OFSC administration in an extensive alkali-induced corneal wound. Corneal injury was created by contact of a piece of 0.5 N NaOH-containing filter paper on the corneal surface of a male Balb/c mouse for 30 s. The area of the filter paper covered the central 70% or 100% of the corneal surface. OFSCs (2 × 10(5)) in 5 μl phosphate-buffered saline (PBS) were given by topical administration (T) twice a day or by two intralimbal (IL) injections in the right cornea, while 5 μl of PBS in the left cornea served as the control. Topical OFSCs promoted corneal re-epithelialization of both the limbal-sparing and limbal-involved corneal wounds. In the first three days, topical OFSCs significantly reduced alkali-induced corneal edema and stromal infiltration according to a histopathological examination. Immunohistochemistry and immunofluorescence staining revealed that transplanted cells were easily detectable in the corneal epithelium, limbal epithelium and stroma, but only some of transplanted cells at the limbal epithelium had differentiated into cytokeratin 3-expressing cells. OFSCs did not alter neutrophil (Ly6G) levels in the cornea, but significantly reduced macrophage (CD68) infiltration and inducible nitrous oxide synthetase (iNOS) production during acute corneal injury as quantified by a Western blot analysis. Continuous topical administration of OFSCs for seven days improved corneal transparency, and this was accompanied by diffuse stromal engraftment of transplanted cells and differentiation into p63-expressing cells at the limbal area. The therapeutic effect of the

Topical administration of orbital fat-derived stem cells promotes corneal tissue regeneration

Science.gov (United States)

2013-01-01

Introduction Topical administration of eye drops is the major route for drug delivery to the cornea. Orbital fat-derived stem cells (OFSCs) possess an in vitro corneal epithelial differentiation capacity. Both the safety and immunomodulatory ability of systemic OFSC transplantation were demonstrated in our previous work. In this study, we investigated the safety, therapeutic effect, and mechanism(s) of topical OFSC administration in an extensive alkali-induced corneal wound. Methods Corneal injury was created by contact of a piece of 0.5 N NaOH-containing filter paper on the corneal surface of a male Balb/c mouse for 30 s. The area of the filter paper covered the central 70% or 100% of the corneal surface. OFSCs (2 × 105) in 5 μl phosphate-buffered saline (PBS) were given by topical administration (T) twice a day or by two intralimbal (IL) injections in the right cornea, while 5 μl of PBS in the left cornea served as the control. Results Topical OFSCs promoted corneal re-epithelialization of both the limbal-sparing and limbal-involved corneal wounds. In the first three days, topical OFSCs significantly reduced alkali-induced corneal edema and stromal infiltration according to a histopathological examination. Immunohistochemistry and immunofluorescence staining revealed that transplanted cells were easily detectable in the corneal epithelium, limbal epithelium and stroma, but only some of transplanted cells at the limbal epithelium had differentiated into cytokeratin 3-expressing cells. OFSCs did not alter neutrophil (Ly6G) levels in the cornea, but significantly reduced macrophage (CD68) infiltration and inducible nitrous oxide synthetase (iNOS) production during acute corneal injury as quantified by a Western blot analysis. Continuous topical administration of OFSCs for seven days improved corneal transparency, and this was accompanied by diffuse stromal engraftment of transplanted cells and differentiation into p63-expressing cells at the limbal area. The

Development of a human corneal epithelium model utilizing a collagen vitrigel membrane and the changes of its barrier function induced by exposing eye irritant chemicals.

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Takezawa, Toshiaki; Nishikawa, Kazunori; Wang, Pi-Chao

2011-09-01

The brief TEER (trans-epithelial electrical resistance) assay after exposing chemicals to corneal epithelium in vivo is known as a suitable method for evaluating corneal irritancy and permeability quantitatively and continuously. A collagen vitrigel membrane we previously developed is a thin (about 20 μm thick) and transparent membrane composed of high density collagen fibrils equivalent to connective tissues in vivo, e.g. corneal Bowman's membrane. To develop such a TEER assay system in vitro utilizing a human corneal epithelial model, HCE-T cells (a human corneal epithelial cell line) were cultured on the collagen vitrigel membrane substratum prepared in a Millicell chamber suitable for TEER measurement. Human corneal epithelium model possessing 5-6 cell layers sufficient for TEER assay was successfully reconstructed on the substratum in the Millicell chamber by culturing the cells in monolayer for 2 days and subsequently in air-liquid interface for 7 days. The exposure of chemicals to the model induced the time-dependent relative changes of TEER in response to the characteristic of each chemical within a few minutes. These results suggest that the TEER assay using the human corneal epithelial model is very useful for an ocular irritancy evaluation as an alternative to the Draize eye irritation test. Copyright © 2011 Elsevier Ltd. All rights reserved.

Human corneal epithelial subpopulations

DEFF Research Database (Denmark)

Søndergaard, Chris Bath

2013-01-01

Corneal epithelium is being regenerated throughout life by limbal epithelial stem cells (LESCs) believed to be located in histologically defined stem cell niches in corneal limbus. Defective or dysfunctional LESCs result in limbal stem cell deficiency (LSCD) causing pain and decreased visual acuity...... subpopulations in human corneal epithelium using a combination of laser capture microdissection and RNA sequencing for global transcriptomic profiling. We compared dissociation cultures, using either expansion on γ-irradiated NIH/3T3 feeder cells in serum-rich medium or expansion directly on plastic in serum...

Cytokeratin expression in mouse lacrimal gland germ epithelium.

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Hirayama, Masatoshi; Liu, Ying; Kawakita, Tetsuya; Shimmura, Shigeto; Tsubota, Kazuo

2016-05-01

The lacrimal gland secretes tear fluids that protect the ocular surface epithelium, and its dysfunction leads to dry eye disease (DED). The functional restoration of the lacrimal gland by engraftment of a bioengineered lacrimal gland using lacrimal gland germ epithelial cells has been proposed to cure DED in mice. Here, we investigate the expression profile of cytokeratins in the lacrimal gland germ epithelium to clarify their unique characteristics. We performed quantitative polymerase chain reaction (Q-PCR) and immunohistochemistry (IHC) analysis to clarify the expression profile of cytokeratin in the lacrimal gland germ epithelium. The mRNA expression of keratin (KRT) 5, KRT8, KRT14, KRT15, and KRT18 in the lacrimal gland germ epithelium was increased compared with that in mouse embryonic stem cells and the lacrimal gland germ mesenchyme, as analyzed by Q-PCR. The expression level of KRT15 increased in the transition from stem cells to lacrimal gland germ epithelium, then decreased as the lacrimal gland matured. IHC revealed that the expression set of these cytokeratins in the lacrimal gland germ epithelium was different from that in the adult lacrimal gland. The expression of KRT15 was observed in the lacrimal gland germ epithelium, and it segmentalized into some of the basal cells in the intercanulated duct in mature gland. We determined the expression profile of cytokeratins in the lacrimal gland epithelium, and identified KRT15 as a candidate unique cellular marker for the lacrimal gland germ epithelium. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantitative Assessment of Ultrastructure and Light Scatter in Mouse Corneal Debridement Wounds

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Boote, Craig; Du, Yiqin; Morgan, Sian; Harris, Jonathan; Kamma-Lorger, Christina S.; Hayes, Sally; Lathrop, Kira L.; Roh, Danny S.; Burrow, Michael K.; Hiller, Jennifer; Terrill, Nicholas J.; Funderburgh, James L.; Meek, Keith M.

2012-01-01

Purpose. The mouse has become an important wound healing model with which to study corneal fibrosis, a frequent complication of refractive surgery. The aim of the current study was to quantify changes in stromal ultrastructure and light scatter that characterize fibrosis in mouse corneal debridement wounds. Methods. Epithelial debridement wounds, with and without removal of basement membrane, were produced in C57BL/6 mice. Corneal opacity was measured using optical coherence tomography, and collagen diameter and matrix order were quantified by x-ray scattering. Electron microscopy was used to visualize proteoglycans. Quantitative PCR (Q-PCR) measured mRNA transcript levels for several quiescent and fibrotic markers. Results. Epithelial debridement without basement membrane disruption produced a significant increase in matrix disorder at 8 weeks, but minimal corneal opacity. In contrast, basement membrane penetration led to increases in light scatter, matrix disorder, and collagen diameter, accompanied by the appearance of abnormally large proteoglycans in the subepithelial stroma. This group also demonstrated upregulation of several quiescent and fibrotic markers 2 to 4 weeks after wounding. Conclusions. Fibrotic corneal wound healing in mice involves extensive changes to collagen and proteoglycan ultrastructure, consistent with deposition of opaque scar tissue. Epithelial basement membrane penetration is a deciding factor determining the degree of ultrastructural changes and resulting opacity. PMID:22467580

Safety and Efficacy of Epithelium-On Corneal Collagen Cross-Linking Using a Multifactorial Approach to Achieve Proper Stromal Riboflavin Saturation

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Aleksandar Stojanovic

2012-01-01

Full Text Available Purpose. To evaluate the efficacy and safety of epithelium-on corneal collagen cross-linking (CXL using a multifactorial approach to achieve proper stromal riboflavin saturation. Methods. This non-randomized retrospective study comprised 61 eyes with progressive keratoconus treated with epithelium-on CXL. Chemical epithelial penetration enhancement (benzalkonium chloride-containing local medication and hypotonic riboflavin solution, mechanical disruption of the superficial epithelium, and prolongation of the riboflavin-induction time until verification of stromal saturation were used before the UVA irradiation. Uncorrected and corrected distance visual acuity (UDVA, CDVA, refraction, corneal topography, and aberrometry were evaluated at baseline and at 1, 3, 6, and 12 months postoperative. Results. At 12-month, UDVA and CDVA improved significantly. None of the eyes lost lines of CDVA, while 27.4% of the eyes gained 2 or more lines. Mean spherical equivalent decreased by 0.74 D, and mean cylindrical reduction was 1.15 D. Irregularity index and asymmetry from Scheimpflug-based topography and Max-K at the location of cone from Placido-based topography showed a significant decrease. Higher-order-aberration data demonstrated a slight reduction in odd-order aberrations S 3, 5,7 (=0.04. Postoperative pain without other complications was recorded. Conclusion. Epithelium-on CXL with our novel protocol appeared to be safe and effective in the treatment of progressive keratoconus.

Changes in corneal epithelial layer inflammatory cells in aqueous tear-deficient dry eye.

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Lin, Hui; Li, Wei; Dong, Nuo; Chen, Wensheng; Liu, Jing; Chen, Lelei; Yuan, Hongxia; Geng, Zhixin; Liu, Zuguo

2010-01-01

To investigate the morphology, distribution, and density of inflammatory cells in the corneal epithelium of aqueous tear-deficient dry eye. Thirty-two patients with non-Sjögren's syndrome (NSS) dry eye, 14 patients with Sjögren's syndrome (SS) dry eye, and 33 healthy volunteers were studied. In vivo laser scanning confocal microscopy was used to investigate both Langerhans cell (LCs) and leukocyte distribution and density in the peripheral and central corneal epithelium. LC morphology was also evaluated. Multifactor regression analysis assessed whether there is a correlation between clinical manifestations and inflammatory cell densities. LCs were present in both central (34.9 +/- 5.7 cells/mm(2)) and peripheral (90.7 +/- 8.2 cells/mm(2)) parts of the normal corneal epithelium. Moreover, LC density increased dramatically in the central corneal epithelium in patients with NSS (89.8 +/- 10.8 cells/mm(2)) and SS (127.9 +/- 23.7 cells/mm(2)). The ratio of LCs with obvious processes was much higher in patients with dry eye than in healthy volunteers. LC density also increased in peripheral corneal epithelium in patients with SS, but not in those with NSS. Leukocyte density in normal corneal epithelium was very low, whereas it increased in the central corneal epithelium (4.6 +/- 1.0 cells/mm(2)) in NSS and in both central (49.0 +/- 12.9 cells/mm(2)) and peripheral (84.2 +/- 36.8 cells/mm(2)) corneal epithelium in SS. Densities of LCs and leukocytes showed significant correlation with the severity found in clinical evaluation. The LC and leukocyte changes in the corneal epithelium suggest their involvement in aqueous tear-deficient dry eye pathophysiology. In vivo dynamic assessment of central corneal inflammatory cell density may serve as an indicator of dry eye severity and provide new insight for dry eye treatment.

Corneal Regeneration After Photorefractive Keratectomy: A Review

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Javier Tomás-Juan

2015-07-01

Full Text Available Photorefractive keratectomy (PRK remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain.

Can Riboflavin Penetrate Stroma Without Disrupting Integrity of Corneal Epithelium in Rabbits? Iontophoresis and Ultraperformance Liquid Chromatography With Electrospray Ionization Tandem Mass Spectrometry.

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Novruzlu, Şahin; Türkcü, Ümmühani Özel; Kvrak, İbrahim; Kvrak, Şeyda; Yüksel, Erdem; Deniz, Nuriye Gökçen; Bilgihan, Ayşe; Bilgihan, Kamil

2015-08-01

To examine riboflavin concentrations in corneas and aqueous humor from rabbits with standard and transepithelial methods and iontophoresis without disrupting the integrity of the corneal epithelium before corneal collagen cross-linking. Twenty-four eyes of 12 adult New Zealand rabbits were used. They were assigned to 4 groups, each including 6 eyes. Group 1 was exposed to the standard method and given riboflavin 0.1% after epithelial debridement. Group 2 was exposed to the transepithelial method and given benzalkonium chloride (BAC), ethylenediaminetetraacetic acid (EDTA), trometamol (TRIS), hydroxypropylmethylcellulose (HPMC), and riboflavin 0.2% 3 times at 1.5-minute intervals followed by riboflavin 0.2%. Group 3 was given riboflavin 0.1% by using 1-mA electric current for 10 minutes with the help of iontophoresis without using substances disrupting the integrity of the corneal epithelium. Group 4 received the same treatment as did group 3, except that it was given riboflavin 0.2%. Following these treatments, riboflavin concentrations in aqueous humor and corneas were measured with ultraperformance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). Riboflavin concentrations in the cornea and aqueous humor were higher in group 1 (42.4 ± 5.4 μg/g) than in the other groups. They were significantly higher in group 4 (34.2 ± 6.6 μg/g) than in group 2 (24.4 ± 1.2 μg/g) (P = 0.009) and group 3 (23.6 ± 6.1 μg/g) (P = 0.026). There was not a significant difference in corneal riboflavin concentrations between group 2 and group 3 (P = 0.937). Intrastromal and aqueous riboflavin concentrations after administration of riboflavin 0.2% through iontophoresis without disrupting the integrity of the corneal epithelium were lower than those after the standard method, but higher than those after the transepithelial method. In this study, in which riboflavin concentrations were measured with a very sensitive method

Corneal Regeneration After Photorefractive Keratectomy: A Review.

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Tomás-Juan, Javier; Murueta-Goyena Larrañaga, Ane; Hanneken, Ludger

2015-01-01

Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Cultivated Oral Mucosa Epithelium in Ocular Surface Reconstruction in Aniridia Patients

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Dariusz Dobrowolski

2015-01-01

Full Text Available Purpose. Efficacy of cultivated oral mucosa epithelial transplantation (COMET procedure in corneal epithelium restoration of aniridia patients. Methods. Study subjects were aniridia patients (13 patients; 17 eyes with irregular, vascular conjunctival pannus involving visual axis who underwent autologous transplantation of cultivated epithelium. For the procedure oral mucosa epithelial cells were obtained from buccal mucosa with further enzymatic treatment. Suspension of single cells was seeded on previously prepared denuded amniotic membrane. Cultures were carried on culture dishes inserts in the presence of the inactivated with Mitomycin C monolayer of 3T3 fibroblasts. Cultures were carried for seven days. Stratified oral mucosa epithelium with its amniotic membrane carrier was transplanted on the surgically denuded corneal surface of aniridia patients with total or subtotal limbal stem cell deficiency. Outcome Measures. Corneal surface, epithelial regularity, and visual acuity improvement were evaluated. Results. At the end of the observation period, 76.4% of the eyes had regular transparent epithelium and 23.5% had developed epithelial defects or central corneal haze; in 88.2% of cases visual acuity had increased. VA range was from HM 0.05 before the surgery to HM up to 0.1 after surgery. Conclusion. Application of cultivated oral mucosa epithelium restores regular epithelium on the corneal surface with moderate improvement in quality of vision.

Clinical effects of conjunctival sac flushing using different concentration of povidoneiodine on corneal epithelium before cataract surgeries

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Xue-Lian Gu

2015-10-01

Full Text Available AIM:To determine the most optimal concentration of the safe usage of povidone-iodine(PVP-Iin the flushing to disinfect the conjunctive sac before cataract surgeries, in order to provide a scientific basis for clinical eye surgery work.METHODS:Sixty-two patients with phacoemulsification and intraocular lens implantation in our hospital from October 2012 to October 2014 were randomly divided into 0.25g/L PVP-I group(Ⅰand 5g/L PVP-I group(Ⅱ. Sterilizing effect and the complications postoperative were analyzed.RESULTS:The sterilizing effects of the two groups after flushing conjunctiva sac using different concentrations of PVP-I were both remarkable, but the difference between the two groups was not statistically significant(P>0.05. No endophthalmitis occurred in the two groups. Observing the corneal condition after rinsing, no severe conjunctival hyperemia, corneal edema and other serious complications occurred. There was slightly punctate corneal epithelial shedding in groupⅡ, and the difference was statistically significant(PPCONCLUSION:Using 0.25g/L PVP-I in the conjunctiva sac rinsing before surgeries can inhibit the growth of bacteria in the conjunctival sac, reduce the impact on the corneal epithelium thereby reducing the incidence of postoperative complications and the positive rate of bacterial culture, increasing the comfort degree of patients, bringing a better area for the surgeries.

Recovery of the spermatogenetic epithelium in the mouse after irradiation with 1-MeV fission neutrons

International Nuclear Information System (INIS)

Aardweg, G.J.M.J. van den.

1983-01-01

In this thesis the recovery of the spermatogenetic epithelium in the mouse is studied after damage with 1-MeV fission neutrons. A severe depletion of A-spermatogonia and radiosensitive stem cells occurs after neutron irradiation. Recovery of the epithelium is initiated by surviving radioresistant stem cells giving rise to colonies, which grow into the empty seminiferous tubules. After discussing properties of normal and irradiated spermatogenetic epithelium, the growth and the differentiation of spermatogenetic colonies in the mouse testis after irradiation, as well as response and kinetics of colony-forming spermatogonial stem cells in CBA mice up to 30 weeks after a first neutron dose and recovery of the epithelium after a second irradiation are investigated. These four subjects are dealt with in separate papers. Finally, a discussion and a summary of these studies is presented. (Auth.)

Molecular mechanism of ocular surface damage: application to an in vitro dry eye model on human corneal epithelium.

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Meloni, Marisa; De Servi, Barbara; Marasco, Daniela; Del Prete, Salvatore

2011-01-12

The present study was concerned with the development of a new experimental model of dry eye using human reconstructed in vitro corneal epithelium (HCE). The model is based on the use of adapted culture conditions that induce relevant modifications at the cellular and molecular level thus mimicking dry eye. The HCE model was maintained in a controlled environmental setting (relative humidity eye. The evolution of the dry eye condition was assessed by histology, immunohistochemistry staining, scanning electron microscopy, and gene expression by using TaqMan gene assay technology (mucin-4 [MUC4], matrix metallopeptidase-9 [MMP9], tumor necrosis factor-α [TNF-α], and defensin β-2 [DEFB2). The effects of different commercially available tear substitutes on the induced dry eye condition were tested. This in vitro dry eye HCE model, that was well established within 24 h, has the characteristic features of a dry eye epithelium and could be satisfactorily used for preliminary assessment of the protective activity of some artificial tears. The transcriptional study of selected biomarkers showed an increase in MUC4, MMP9, TNF-α, and hBD-2 (DEFB2) gene expression. By using a dynamic approach, we were able to define a biomarker gene signature of dry eye-induced effects that could be predictive of corneal damage in vivo and to discriminate the efficacy among different commercial artificial tears.

Assessment of corneal epithelial thickness in dry eye patients.

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Cui, Xinhan; Hong, Jiaxu; Wang, Fei; Deng, Sophie X; Yang, Yujing; Zhu, Xiaoyu; Wu, Dan; Zhao, Yujin; Xu, Jianjiang

2014-12-01

To investigate the features of corneal epithelial thickness topography with Fourier-domain optical coherence tomography (OCT) in dry eye patients. In this cross-sectional study, 100 symptomatic dry eye patients and 35 normal subjects were enrolled. All participants answered the ocular surface disease index questionnaire and were subjected to OCT, corneal fluorescein staining, tear breakup time, Schirmer 1 test without anesthetic (S1t), and meibomian morphology. Several epithelium statistics for each eye, including central, superior, inferior, minimum, maximum, minimum - maximum, and map standard deviation, were averaged. Correlations of epithelial thickness with the symptoms of dry eye were calculated. The mean (±SD) central, superior, and inferior corneal epithelial thickness was 53.57 (±3.31) μm, 52.00 (±3.39) μm, and 53.03 (±3.67) μm in normal eyes and 52.71 (±2.83) μm, 50.58 (±3.44) μm, and 52.53 (±3.36) μm in dry eyes, respectively. The superior corneal epithelium was thinner in dry eye patients compared with normal subjects (p = 0.037), whereas central and inferior epithelium were not statistically different. In the dry eye group, patients with higher severity grades had thinner superior (p = 0.017) and minimum (p dry eye corneal epithelium was thinner than normal eyes in the superior region. In more severe dry eye disease patients, the superior and minimum epithelium was much thinner, with a greater range of map standard deviation.

Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model.

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Khoh-Reiter, Su; Jessen, Bart A

2009-07-28

Benzalkonium chloride (BAC) is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D) corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC) and olopatadine (0.01% BAC) was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T) cell cultures, expression levels (mRNA and protein) of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 microL drops twice daily in 1 eye for 1 year) in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC) and untreated eyes. The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC contained in ophthalmic solutions are not likely to cause

Evaluation of the cytotoxic effects of ophthalmic solutions containing benzalkonium chloride on corneal epithelium using an organotypic 3-D model

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Jessen Bart A

2009-07-01

Full Text Available Abstract Background Benzalkonium chloride (BAC is a common preservative used in ophthalmic solutions. The aim of this study was to compare the cytotoxic effects of BAC-containing ophthalmic solutions with a BAC-free ophthalmic solution using an organotypic 3-dimensional (3-D corneal epithelial model and to determine the effects of latanoprost ophthalmic solution and its BAC-containing vehicle on corneal thickness in a monkey model. Methods The cytotoxicity of commercially available BAC-containing ophthalmic formulations of latanoprost (0.02% BAC and olopatadine (0.01% BAC was compared to that of BAC-free travoprost and saline in a corneal organotypic 3-D model using incubation times of 10 and 25 minutes. To compare the extent of differentiation of 3-D corneal cultures to monolayer transformed human corneal epithelial (HCE-T cell cultures, expression levels (mRNA and protein of the corneal markers epidermal growth factor receptor, transglutaminase 1 and involucrin were quantified. Finally, latanoprost ophthalmic solution or its vehicle was administered at suprapharmacologic doses (two 30 μL drops twice daily in 1 eye for 1 year in monkey eyes, and corneal pachymetry was performed at baseline and at weeks 4, 13, 26 and 52. Results In the 3-D corneal epithelial culture assays, there were no significant differences in cytotoxicity between the BAC-containing latanoprost and olopatadine ophthalmic solutions and BAC-free travoprost ophthalmic solution at either the 10- or 25-minute time points. The 3-D cultures expressed higher levels of corneal epithelial markers than the HCE-T monolayers, indicating a greater degree of differentiation. There were no significant differences between the corneal thickness of monkey eyes treated with latanoprost ophthalmic solution or its vehicle (both containing 0.02% BAC and untreated eyes. Conclusion The lack of cytotoxicity demonstrated in 3-D corneal cultures and in monkey studies suggests that the levels of BAC

A minimal model of epithelial tissue dynamics and its application to the corneal epithelium

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Henkes, Silke; Matoz-Fernandez, Daniel; Kostanjevec, Kaja; Coburn, Luke; Sknepnek, Rastko; Collinson, J. Martin; Martens, Kirsten

Epithelial cell sheets are characterized by a complex interplay of active drivers, including cell motility, cell division and extrusion. Here we construct a particle-based minimal model tissue with only division/death dynamics and show that it always corresponds to a liquid state with a single dynamic time scale set by the division rate, and that no glassy phase is possible. Building on this, we construct an in-silico model of the mammalian corneal epithelium as such a tissue confined to a hemisphere bordered by the limbal stem cell zone. With added cell motility dynamics we are able to explain the steady-state spiral migration on the cornea, including the central vortex defect, and quantitatively compare it to eyes obtained from mice that are X-inactivation mosaic for LacZ.

Corneal iron ring after conductive keratoplasty.

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Kymionis, George D; Naoumidi, Tatiana L; Aslanides, Ioannis M; Pallikaris, Ioannis G

2003-08-01

To report formation of corneal iron ring deposits after conductive keratoplasty. Observational case report. Case report. A 54-year-old woman underwent conductive keratoplasty for hyperopia. One year after conductive keratoplasty, iron ring pattern pigmentation was detected at the corneal epithelium of both eyes. This is the first report of the appearance of corneal iron ring deposits following conductive keratoplasty treatment in a patient. It is suggested that alterations in tear film stability, resulting from conductive keratoplasty-induced changes in corneal curvature, constitute the contributory factor for these deposits.

Increase of corneal epithelium cell radioresistance during regeneration

International Nuclear Information System (INIS)

Popova, M.F.; Bulyakova, N.V.; Azarova, V.S.

1985-01-01

A comparative study of the radiosensitivity of the normal and regenerating cornea epithelium of C 57 Bl mice was performed on the cellular level, the duration of the cell cycle being taken into account. Criteria of radiation injuries were the number of chromosome aberrations, mitotic index and duration of mitotic block. The anterior part of the head was irradiated singly with 1.75, 3.5 or 7.0 Gy and also repeatedly 3.5 + 3.5 at a 24-hours interval. The corneas were fixed 2, 4, 6, 12, 24, 48, 72 and 96 hours after irradiation. In all cases of irradiated mice the regenerating epithelium showed a shorter mitotic block and significantly lower cytogenetic injury as compared with the controls. Effects of fractionated irradiation were only shown in the regenerating epithelium. The results obtained indicate that regenerating epithelium cells of the cornea are significantly more radioresistant than normal epithelium due to activation of post-radiation recovery, and also, possibly, due to an increase in the content of endogenous radioprotectors. (author)

Transepithelial Riboflavin Absorption in an Ex Vivo Rabbit Corneal Model.

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Gore, Daniel M; O'Brart, David; French, Paul; Dunsby, Chris; Allan, Bruce D

2015-07-01

To measure depth-specific riboflavin concentrations in corneal stroma using two-photon fluorescence microscopy and compare commercially available transepithelial corneal collagen cross-linking (CXL) protocols. Transepithelial CXL riboflavin preparations--MedioCross TE, Ribocross TE, Paracel plus VibeX Xtra, and iontophoresis with Ricrolin+--were applied to the corneal surface of fresh postmortem rabbit eyes in accordance with manufacturers' recommendations for clinical use. Riboflavin 0.1% (VibeX Rapid) was applied after corneal epithelial debridement as a positive control. After riboflavin application, eyes were snap frozen in liquid nitrogen. Corneal cross sections 35-μm thick were cut on a cryostat, mounted on a slide, and imaged by two-photon fluorescence microscopy. Mean (SD) concentrations were calculated from five globes tested for each protocol. Peak riboflavin concentration of 0.09% (± 0.01) was observed within the most superficial stroma (stromal depth 0-10 μm) in positive controls (epithelium-off). At the same depth, peak stromal riboflavin concentrations for MedioCross TE, Ricrolin+, Paracel/Xtra, and Ribocross TE were 0.054% (± 0.01), 0.031% (0.003), 0.021% (± 0.001), and 0.015% (± 0.004), respectively. At a depth of 300 μm (within the demarcation zone commonly seen after corneal cross-linking), the stromal concentration in epithelium-off positive controls was 0.075% (± 0.006), while at the same depth MedioCross TE and Ricrolin+ achieved 0.018% (± 0.006) and 0.016% (0.002), respectively. None of the remaining transepithelial protocols achieved concentrations above 0.005% at this same 300-μm depth. Overall, MedioCross TE was the best-performing transepithelial formulation. Corneal epithelium is a significant barrier to riboflavin absorption into the stroma. Existing commercial transepithelial CXL protocols achieve relatively low riboflavin concentrations in the anterior corneal stroma when compared to gold standard epithelium-off absorption

Corneal collagen cross-linking and liposomal amphotericin B combination therapy for fungal keratitis in rabbits

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Zhao-Qin Hao

2016-11-01

Full Text Available AIM: To observe the therapeutic effect of corneal collagen cross-linking (CXL in combination with liposomal amphotericin B in fungal corneal ulcers. METHODS: New Zealand rabbits were induced fungal corneal ulcers by scratching and randomly divided into 3 groups, i.e. control, treated with CXL, and combined therapy of CXL with 0.25% liposomal amphotericin B (n=5 each. The corneal lesions were documented with slit-lamp and confocal microscopy on 3, 7, 14, 21 and 28d after treatment. The corneas were examined with transmission electron microscopy (TEM at 4wk. RESULTS: A rabbit corneal ulcer model of Fusarium was successfully established. The corneal epithelium defect areas in the two treatment groups were smaller than that in the control group on 3, 7, 14 and 21d (P<0.05. The corneal epithelium defect areas of the combined group was smaller than that of the CXL group (P<0.05 on 7 and 14d, but there were no statistical differences on 3, 21 and 28d. The corneal epithelium defects of the two treatment groups have been healed by day 21. The corneal epithelium defects of the control group were healed on 28d. The diameters of the corneal collagen fiber bundles (42.960±7.383 nm in the CXL group and 37.040±4.160 nm in the combined group were thicker than that of the control group (24.900±1.868 nm, but there was no difference between the two treatment groups. Some corneal collagen fiber bundles were distorted and with irregular arrangement, a large number of fibroblasts could be seen among them but no inflammatory cells in both treatment groups. CONCLUSION: CXL combined with liposomal amphotericin B have beneficial effects on fungal corneal ulcers. The combined therapy could alleviate corneal inflammattions, accelerate corneal repair, and shorten the course of disease.

Activation of cell division and nucleic acid synthesis in the corneal epithelium of albino rats by repeated stress

International Nuclear Information System (INIS)

Berezhnova, N.I.; Timoshin, S.S.

1985-01-01

Adaption to unfavorable factors is accompanied by activation of nucleic acid and protein synthesis in systems responsible for adaption. The authors investigate the possibility of similar changes taking place in structures not actively participating in adaptation. The corneas of the dead male albin rats were preincubated with tritium-uridine for 1.5 hours. The mitotic index, the index of tritium-thymidine-labeled nuclei and the intensity of thymidine labeling were determined. The results indicate that after a single exposure to hypoxia, hyperthermia, and immobilization, mitotic index in the corneal epithelium decreased and DNA synthesis under these circumstances remained stable

Regeneration of tracheal epithelium using mouse induced pluripotent stem cells.

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Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Yoshie, Susumu; Otsuki, Koshi; Miyake, Masao; Hazama, Akihiro; Wada, Ikuo; Omori, Koichi

2016-01-01

Conclusion The findings demonstrated the potential use of induced pluripotent stem cells for regeneration of tracheal epithelium. Objective Autologous tissue implantation techniques using skin or cartilage are often applied in cases of tracheal defects with laryngeal inflammatory lesions and malignant tumor invasion. However, these techniques are invasive with an unstable clinical outcome. The purpose of this study was to investigate regeneration in a tracheal defect site of nude rats after implantation of ciliated epithelium that was differentiated from induced pluripotent stem cells. Method Embryoid bodies were formed from mouse induced pluripotent stem cells. They were cultured with growth factors for 5 days, and then cultured at the air-liquid interface. The degree of differentiation achieved prior to implantation was determined by histological findings and the results of real-time polymerase chain reaction. Embryoid bodies including ciliated epithelium were embedded into collagen gel that served as an artificial scaffold, and then implanted into nude rats, creating an 'air-liquid interface model'. Histological evaluation was performed 7 days after implantation. Results The ciliated epithelial structure survived on the lumen side of regenerated tissue. It was demonstrated histologically that the structure was composed of ciliated epithelial cells.

Resolvin D1 promotes corneal epithelial wound healing and restoration of mechanical sensation in diabetic mice.

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Zhang, Zhenzhen; Hu, Xiaoli; Qi, Xia; Di, Guohu; Zhang, Yangyang; Wang, Qian; Zhou, Qingjun

2018-01-01

To investigate the effect and mechanism of proresolving lipid mediator resolvin D1 (RvD1) on the corneal epithelium and the restoration of mechanical sensation in diabetic mice. Type 1 diabetes was induced in mice with intraperitoneal streptozocin injections. The healthy and diabetic mice underwent removal of the central corneal epithelium, and then 100 ng/ml RvD1 or its formyl peptide receptor 2 (FPR2) antagonist WRW4 was used to treat the diabetic mice. Regeneration of the corneal epithelium and nerves was observed with sodium fluorescein staining and whole-mount anti-β3-tubulin fluorescence staining. The inflammatory response level was measured with hematoxylin and eosin staining (inflammatory cell infiltration), enzyme-linked immunosorbent assay (tumor necrosis factor alpha and interleukin-1 beta content), myeloperoxidase activity, and fluorescence staining (macrophage content). The reactive oxygen species (ROS) and glutathione (GSH) levels were examined with incubation with fluorescent probes, and oxidative stress-related protein expression levels were evaluated with fluorescence staining and western blotting. Topical application of RvD1 promoted regeneration of the corneal epithelium in diabetic mice, accompanied by the reactivation of signaling and inflammation resolution related to regeneration of the epithelium. Furthermore, RvD1 directly attenuated the accumulation of ROS and nicotinamide adenine dinucleotide phosphate oxidase 2/4 expression, while RvD1 enhanced GSH synthesis and reactivated the Nrf2-ARE signaling pathway that was impaired in the corneal epithelium in the diabetic mice. More interestingly, topical application of RvD1 promoted regeneration of corneal nerves and completely restored impaired mechanical sensitivity of the cornea in diabetic mice. In addition, the promotion of corneal epithelial wound healing by RvD1 in diabetic mice was abolished by its FPR2 antagonist WRW4. Topical application of RvD1 promotes corneal epithelial wound

Generation of tooth-periodontium complex structures using high-odontogenic potential dental epithelium derived from mouse embryonic stem cells.

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Zhang, Yancong; Li, Yongliang; Shi, Ruirui; Zhang, Siqi; Liu, Hao; Zheng, Yunfei; Li, Yan; Cai, Jinglei; Pei, Duanqing; Wei, Shicheng

2017-06-08

A number of studies have shown that tooth-like structures can be regenerated using induced pluripotent stem cells and mouse embryonic stem (mES) cells. However, few studies have reported the regeneration of tooth-periodontium complex structures, which are more suitable for clinical tooth transplantation. We established an optimized approach to induce high-odontogenic potential dental epithelium derived from mES cells by temporally controlling bone morphogenic protein 4 (BMP4) function and regenerated tooth-periodontium complex structures in vivo. First, immunofluorescence and quantitative reverse transcription-polymerase chain reaction were used to identify the watershed of skin and the oral ectoderm. LDN193189 was then used to inhibit the BMP4 receptor around the watershed, followed by the addition of exogenous BMP4 to promote BMP4 function. The generated dental epithelium was confirmed by western blot analysis and immunofluorescence. The generated epithelium was ultimately combined with embryonic day 14.5 mouse mesenchyme and transplanted into the renal capsules of nude mice. After 4 weeks, the tooth-periodontium complex structure was examined by micro-computed tomography (CT) and hematoxylin and eosin (H&E) staining. Our study found that the turning point of oral ectoderm differentiation occurred around day 3 after the embryoid body was transferred to a common culture plate. Ameloblastin-positive dental epithelial cells were detected following the temporal regulation of BMP4. Tooth-periodontium complex structures, which included teeth, a periodontal membrane, and alveolar bone, were formed when this epithelium was combined with mouse dental mesenchyme and transplanted into the renal capsules of nude mice. Micro-CT and H&E staining revealed that the generated tooth-periodontium complex structures shared a similar histological structure with normal mouse teeth. An optimized induction method was established to promote the differentiation of mES cells into dental

Experiment of amnion epithelial cell suspension liquid used for acute rabbit corneal alkali burn

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Yan-Yan Zhang

2017-10-01

Full Text Available AIM: To investigate the effects of amnion epithelial cell(AECsuspension liquid on the biological behavior of the rabbit's corneal epithelium, combined with the in vitro and in vivo experiments. METHODS: The rabbit's corneal epithelium were cultured in the lower chamber of transwell, and AEC suspension liquid was dropwised in the upper chamber. There was only culture medium in the upper chamber of the control group. The proliferation of rabbit's corneal epithelium was observed with CCK-8 automated colorimetry and the expression of PCNA was detected by immunocytochemistry. We used the scratch wound assay to detect the migration of corneal epithelial cell(CEC. The in vivo models were established by placing a 10mm diameter corneal trephine in the center of the cornea, within 1mol/L NaOH for 1min. We divided those into three groups: treatment group of AEC suspension liquid eye drop, AEC suspension liquid subconjunctival injection and the control group without any treatment. Using the slit-lamp biomicroscope and fluorescence staining to observe the cornea per week. After 28d we took the eyeballs with the HE staining. The expression of VEGF was detected by immunohistochemistry. RESULTS: The activity of CEC with AEC treatment was much higher than the control group(PPIn vivo, the inflammation of the corneal and the CNV of the AEC group were all significantly reduced compared with the control group(PPCONCLUSION: AEC suspension liquid can promote the proliferation and migration of the rabbit's corneal epithelium. The potential of AEC suspension liquid as a therapy for acute corneal alkali burn.

A Comparison of Different Corneal Iontophoresis Protocols for Promoting Transepithelial Riboflavin Penetration.

Science.gov (United States)

Gore, Daniel M; O'Brart, David P; French, Paul; Dunsby, Chris; Allan, Bruce D

2015-12-01

To measure corneal riboflavin penetration using different transepithelial iontophoresis protocols. Freshly enucleated rabbit eyes were divided into nine treatment groups of 4 eyes. One group, in which 0.1% wt/vol riboflavin was applied for 30 minutes without iontophoresis after corneal epithelial debridement, acted as a control. The remaining groups were treated with an intact epithelium using different riboflavin formulations and varying iontophoresis current, soak, and rinse times. After riboflavin application, eyes were snap frozen in liquid nitrogen. Corneal cross sections 35 μm thick were then imaged immediately by two-photon fluorescence microscopy, using image processing software to quantify stromal riboflavin concentration at different corneal depths. In the epithelium-on iontophoresis treatment groups, greater stromal riboflavin penetration was achieved with higher-concentration riboflavin solutions, greater iontophoresis dosage, and longer solution contact times. A protocol utilizing 0.25% wt/vol riboflavin with benzalkonium chloride (BAC) 0.01% and two cycles of applied current and subsequent soaking (1 mA 5 minutes, soak 5 minutes; 0.5 mA 5 minutes, soak 5 minutes) achieved similar stromal riboflavin penetration to epithelium-off controls. The best-performing non-BAC-containing protocol produced stromal riboflavin penetration approximately 60% that of epithelium-off controls. Riboflavin solutions containing saline resulted in minimal stromal penetration. Riboflavin loading within the epithelium was equivalent to or higher than that in the subjacent stroma, despite rinsing the ocular surface with balanced salt solution. Modified iontophoresis protocols can significantly improve transepithelial riboflavin penetration in experimental corneal collagen cross-linking.

Melatonin Entrains PER2::LUC Bioluminescence Circadian Rhythm in the Mouse Cornea

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Baba, Kenkichi; Davidson, Alec J.; Tosini, Gianluca

2015-01-01

Purpose Previous studies have reported the presence of a circadian rhythm in PERIOD2::LUCIFERASE (PER2::LUC) bioluminescence in mouse photoreceptors, retina, RPE, and cornea. Melatonin (MLT) modulates many physiological functions in the eye and it is believed to be one of the key circadian signals within the eye. The aim of the present study was to investigate the regulation of the PER2::LUC circadian rhythm in mouse cornea and to determine the role played by MLT. Methods Corneas were obtained from PER2::LUC mice and cultured to measure bioluminescence rhythmicity in isolated tissue using a Lumicycle or CCD camera. To determine the time-dependent resetting of the corneal circadian clocks in response to MLT or IIK7 (a melatonin type 2 receptor, MT2, agonist) was added to the cultured corneas at different times of the day. We also defined the location of the MT2 receptor within different corneal layers using immunohistochemistry. Results A long-lasting bioluminescence rhythm was recorded from cultured PER2::LUC cornea and PER2::LUC signal was localized to the corneal epithelium and endothelium. MLT administration in the early night delayed the cornea rhythm, whereas administration of MLT at late night to early morning advanced the cornea rhythm. Treatment with IIK7 mimicked the MLT phase-shifting effect. Consistent with these results, MT2 immunoreactivity was localized to the corneal epithelium and endothelium. Conclusions Our work demonstrates that MLT entrains the PER2::LUC bioluminescence rhythm in the cornea. Our data indicate that the cornea may represent a model to study the molecular mechanisms by which MLT affects the circadian clock. PMID:26207312

Expression of the type VI intermediate filament proteins CP49 and filensin in the mouse lens epithelium.

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FitzGerald, Paul; Sun, Ning; Shibata, Brad; Hess, John F

2016-01-01

The differentiated lens fiber cell assembles a filamentous cytoskeletal structure referred to as the beaded filament (BF). The BF requires CP49 (bfsp2) and filensin (bfsp1) for assembly, both of which are highly divergent members of the large intermediate filament (IF) family of proteins. Thus far, these two proteins have been reported only in the differentiated lens fiber cell. For this reason, both proteins have been considered robust markers of fiber cell differentiation. We report here that both proteins are also expressed in the mouse lens epithelium, but only after 5 weeks of age. Localization of CP49 was achieved with immunocytochemical probing of wild-type, CP49 knockout, filensin knockout, and vimentin knockout mice, in sections and in the explanted lens epithelium, at the light microscope and electron microscope levels. The relationship between CP49 and other cytoskeletal elements was probed using fluorescent phalloidin, as well as with antibodies to vimentin, GFAP, and α-tubulin. The relationship between CP49 and the aggresome was probed with antibodies to γ-tubulin, ubiquitin, and HDAC6. CP49 and filensin were expressed in the mouse lens epithelium, but only after 5 weeks of age. At the light microscope level, these two proteins colocalize to a large tubular structure, approximately 7 × 1 μm, which was typically present at one to two copies per cell. This structure is found in the anterior and anterolateral lens epithelium, including the zone where mitosis occurs. The structure becomes smaller and largely undetectable closer to the equator where the cell exits the cell cycle and commits to fiber cell differentiation. This structure bears some resemblance to the aggresome and is reactive with antibodies to HDAC6, a marker for the aggresome. However, the structure does not colocalize with antibodies to γ-tubulin or ubiquitin, also markers for the aggresome. The structure also colocalizes with actin but appears to largely exclude vimentin and �

Glycoproteins of mouse vaginal epithelium: differential expression related to estrous cyclicity

DEFF Research Database (Denmark)

Horvat, B; Multhaupt, H A; Damjanov, I

1993-01-01

We used lectin overlay blotting and SDS-PAGE to analyze the estrous cycle-specific expression of mouse vaginal epithelial glycoproteins. Seven lectins chosen for their differential carbohydrate-binding specificity revealed 15 glycoproteins that showed cycle-related expression. Each lectin had...... in proestrus, coincident with the transformation of two superficial layers of vaginal squamous epithelium into mucinous cuboidal cells. Electron microscopic lectin histochemistry revealed the glycoproteins in the mucinous granules of surface cuboidal cells and in the lumen of the vagina. Our results illustrate...... the complexity of glycoconjugate synthesis in mouse vagina and reveal the distinct cycle-specific patterns of individual glycoprotein expression. These cyclic glycoproteins could serve as vaginal biochemical markers for the specific phases of the estrous cycle....

[Alterations in the metabolism of cornmeal epithelium during medium-term storage (author's transl)].

Science.gov (United States)

Schmidt-Martens, F W; Hennighausen, U; Wirz, K; Teping, C

1977-08-08

Freshly prepared bovine corneas were stored in medium TC 199 with penicillin and fetal calf serum at +4 degrees C over a storage period of 168h. Every 24h, the levels of glucose, lactate, and pyruvate in the corneal epithelium were estimated. Also the glucose levels in the corneal epithelium and stroma were compared at the same time intervals. Furthermore, alterations in the enzyme pattern of the epithelial cells during storage were observed.

The SULFs, extracellular sulfatases for heparan sulfate, promote the migration of corneal epithelial cells during wound repair.

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Inna Maltseva

Full Text Available Corneal epithelial wound repair involves the migration of epithelial cells to cover the defect followed by the proliferation of the cells to restore thickness. Heparan sulfate proteoglycans (HSPGs are ubiquitous extracellular molecules that bind to a plethora of growth factors, cytokines, and morphogens and thereby regulate their signaling functions. Ligand binding by HS chains depends on the pattern of four sulfation modifications, one of which is 6-O-sulfation of glucosamine (6OS. SULF1 and SULF2 are highly homologous, extracellular endosulfatases, which post-synthetically edit the sulfation status of HS by removing 6OS from intact chains. The SULFs thereby modulate multiple signaling pathways including the augmentation of Wnt/ß-catenin signaling. We found that wounding of mouse corneal epithelium stimulated SULF1 expression in superficial epithelial cells proximal to the wound edge. Sulf1⁻/⁻, but not Sulf2⁻/⁻, mice, exhibited a marked delay in healing. Furthermore, corneal epithelial cells derived from Sulf1⁻/⁻ mice exhibited a reduced rate of migration in repair of a scratched monolayer compared to wild-type cells. In contrast, human primary corneal epithelial cells expressed SULF2, as did a human corneal epithelial cell line (THCE. Knockdown of SULF2 in THCE cells also slowed migration, which was restored by overexpression of either mouse SULF2 or human SULF1. The interchangeability of the two SULFs establishes their capacity for functional redundancy. Knockdown of SULF2 decreased Wnt/ß-catenin signaling in THCE cells. Extracellular antagonists of Wnt signaling reduced migration of THCE cells. However in SULF2- knockdown cells, these antagonists exerted no further effects on migration, consistent with the SULF functioning as an upstream regulator of Wnt signaling. Further understanding of the mechanistic action of the SULFs in promoting corneal repair may lead to new therapeutic approaches for the treatment of corneal injuries.

Clinical applications of corneal confocal microscopy

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Mitra Tavakoli

2008-06-01

Full Text Available Mitra Tavakoli1, Parwez Hossain2, Rayaz A Malik11Division of Cardiovascular Medicine, University of Manchester and Manchester Royal Infirmary, Manchester, UK; 2University of Southampton, Southampton Eye Unit, Southampton General Hospital, Southampton, UKAbstract: Corneal confocal microscopy is a novel clinical technique for the study of corneal cellular structure. It provides images which are comparable to in-vitro histochemical techniques delineating corneal epithelium, Bowman’s layer, stroma, Descemet’s membrane and the corneal endothelium. Because, corneal confocal microscopy is a non invasive technique for in vivo imaging of the living cornea it has huge clinical potential to investigate numerous corneal diseases. Thus far it has been used in the detection and management of pathologic and infectious conditions, corneal dystrophies and ecstasies, monitoring contact lens induced corneal changes and for pre and post surgical evaluation (PRK, LASIK and LASEK, flap evaluations and Radial Keratotomy, and penetrating keratoplasty. Most recently it has been used as a surrogate for peripheral nerve damage in a variety of peripheral neuropathies and may have potential in acting as a surrogate marker for endothelial abnormalities.Keywords: corneal confocal microscopy, cornea, infective keratitis, corneal dystrophy, neuropathy

Development of organoids from mouse and human endometrium showing endometrial epithelium physiology and long-term expandability.

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Boretto, Matteo; Cox, Benoit; Noben, Manuel; Hendriks, Nikolai; Fassbender, Amelie; Roose, Heleen; Amant, Frédéric; Timmerman, Dirk; Tomassetti, Carla; Vanhie, Arne; Meuleman, Christel; Ferrante, Marc; Vankelecom, Hugo

2017-05-15

The endometrium, which is of crucial importance for reproduction, undergoes dynamic cyclic tissue remodeling. Knowledge of its molecular and cellular regulation is poor, primarily owing to a lack of study models. Here, we have established a novel and promising organoid model from both mouse and human endometrium. Dissociated endometrial tissue, embedded in Matrigel under WNT-activating conditions, swiftly formed organoid structures that showed long-term expansion capacity, and reproduced the molecular and histological phenotype of the tissue's epithelium. The supplemented WNT level determined the type of mouse endometrial organoids obtained: high WNT yielded cystic organoids displaying a more differentiated phenotype than the dense organoids obtained in low WNT. The organoids phenocopied physiological responses of endometrial epithelium to hormones, including increased cell proliferation under estrogen and maturation upon progesterone. Moreover, the human endometrial organoids replicated the menstrual cycle under hormonal treatment at both the morpho-histological and molecular levels. Together, we established an organoid culture system for endometrium, reproducing tissue epithelium physiology and allowing long-term expansion. This novel model provides a powerful tool for studying mechanisms underlying the biology as well as the pathology of this key reproductive organ. © 2017. Published by The Company of Biologists Ltd.

Protective effects of trehalose on the corneal epithelial cells.

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Aragona, Pasquale; Colosi, Pietro; Rania, Laura; Colosi, Francesca; Pisani, Antonina; Puzzolo, Domenico; Micali, Antonio

2014-01-01

Aim of the present work was to evaluate the effects of the trehalose on the corneal epithelium undergoing alcohol delamination. Twelve patients undergoing laser subepithelial keratomileusis (LASEK) were consecutively included in the study. The right eyes were pretreated with 3% trehalose eye drops, whilst left eyes were used as control. Epithelial specimens were processed for cells vitality assessment, apoptosis, and light and transmission electron microscopy; a morphometric analysis was performed in both groups. In both trehalose-untreated eyes (TUE) and trehalose-treated eyes (TTE), the percentage of vital cells was similar and no apoptotic cells were observed. In TUE, the corneal epithelium showed superficial cells with reduced microfolds, wing cells with vesicles and dilated intercellular spaces, and dark basal cells with vesicles and wide clefts. In TTE, superficial and wing cells were better preserved, and basal cells were generally clear with intracytoplasmatic vesicles. The morphometric analysis showed statistically significant differences between the two groups: the TTE epithelial height was higher, the basal cells showed larger area and clearer cytoplasm. The distribution of desmosomes and hemidesmosomes was significantly different between the groups. Trehalose administration better preserved morphological and morphometric features of alcohol-treated corneal epithelium, when compared to controls.

Recovery of Corneal Sensitivity and Increase in Nerve Density and Wound Healing in Diabetic Mice After PEDF Plus DHA Treatment.

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He, Jiucheng; Pham, Thang Luong; Kakazu, Azucena; Bazan, Haydee E P

2017-09-01

Diabetic keratopathy decreases corneal sensation and tear secretion and delays wound healing after injury. In the current study, we tested the effect of treatment with pigment epithelium-derived factor (PEDF) in combination with docosahexaenoic acid (DHA) on corneal nerve regeneration in a mouse model of diabetes with or without corneal injury. The study was performed in streptozotocin-induced diabetic mice (C57BL/6). Ten weeks after streptozotocin injection, diabetic mice showed significant decreases of corneal sensitivity, tear production, and epithelial subbasal nerve density when compared with age-matched normal mice. After diabetic mice were wounded in the right eye and treated in both eyes with PEDF+DHA for 2 weeks, there was a significant increase in corneal epithelial nerve regeneration and substance P-positive nerve density in both wounded and unwounded eyes compared with vehicle-treated corneas. There also was elevated corneal sensitivity and tear production in the treated corneas compared with vehicle. In addition, PEDF+DHA accelerated corneal wound healing, selectively recruited type 2 macrophages, and prevented neutrophil infiltration in diabetic wounded corneas. These results suggest that topical treatment with PEDF+DHA promotes corneal nerve regeneration and wound healing in diabetic mice and could potentially be exploited as a therapeutic option for the treatment of diabetic keratopathy. © 2017 by the American Diabetes Association.

Corneal hydrops induced by Bell’s paralysis in a case of corneal ectasia

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Lokman Aslan

2017-09-01

Full Text Available An 18-year-old male patient presented with suddenly decreased vision, itching, corneal edema and an inability to close the left eye. They had left Bell’s paralysis for two weeks and had used high diopter glasses for five years. The best corrected visual acuity was 0.4 in their right eye and counting fingers in the left eye. Biomicroscopic examination revealed thinning and steepening of the cornea in the right eye and anterior protrusion of the cornea, stromal edema and punctate disruption of the epithelium in the left eye. Topographic image of the right eye was consistent with keratoconus. Six months later, stromal edema gradually regressed and a corneal scar ensued. This case presentation emphasizes that Bell’s palsy may induce disease progression in a patient with preexisting corneal ectasia and results in corneal hydrops. [Arch Clin Exp Surg 2017; 6(3.000: 165-167

Pathophysiology of Corneal Scarring in Persistent Epithelial Defects After PRK and Other Corneal Injuries.

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Wilson, Steven E; Medeiros, Carla S; Santhiago, Marcony R

2018-01-01

To analyze corneal persistent epithelial defects that occurred at 3 to 4 weeks after -4.50 diopter (D) photorefractive keratectomy (PRK) in rabbits and apply this pathophysiology to the treatment of persistent epithelial defects that occur after any corneal manipulations or diseases. Two of 168 corneas that had -4.50 D PRK to study epithelial basement membrane regeneration developed spontaneous persistent epithelial defects that did not heal at 3 weeks after PRK. These were studied with slit-lamp photographs, immunohistochemistry for the myofibroblast marker alpha-smooth muscle actin (α-SMA), and transmission electron microscopy. Myofibroblasts developed at the stromal surface within the persistent epithelial defect and for a short distance peripheral to the leading edge of the epithelium. No normal epithelial basement membrane was detectable within the persistent epithelial defect or for up to 0.3 mm behind the leading edge of the epithelium, although epithelial basement membrane had normally regenerated in other areas of the zone ablated by an excimer laser where the epithelium healed promptly. A persistent epithelial defect in the cornea results in the development of myofibroblasts and disordered extracellular matrix produced by these cells that together cause opacity within, and a short distance beyond, the persistent epithelial defect. Clinicians should treat persistent epithelial defects within 10 days of non-closure of the epithelium to facilitate epithelial healing to prevent long-term stromal scarring (fibrosis). [J Refract Surg. 2018;34(1):59-64.]. Copyright 2018, SLACK Incorporated.

A Mouse Model of Hyperproliferative Human Epithelium Validated by Keratin Profiling Shows an Aberrant Cytoskeletal Response to Injury

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Samal Zhussupbekova

2016-07-01

Full Text Available A validated animal model would assist with research on the immunological consequences of the chronic expression of stress keratins KRT6, KRT16, and KRT17, as observed in human pre-malignant hyperproliferative epithelium. Here we examine keratin gene expression profile in skin from mice expressing the E7 oncoprotein of HPV16 (K14E7 demonstrating persistently hyperproliferative epithelium, in nontransgenic mouse skin, and in hyperproliferative actinic keratosis lesions from human skin. We demonstrate that K14E7 mouse skin overexpresses stress keratins in a similar manner to human actinic keratoses, that overexpression is a consequence of epithelial hyperproliferation induced by E7, and that overexpression further increases in response to injury. As stress keratins modify local immunity and epithelial cell function and differentiation, the K14E7 mouse model should permit study of how continued overexpression of stress keratins impacts on epithelial tumor development and on local innate and adaptive immunity.

Inhibition of Corneal Neovascularization with the Combination of Bevacizumab and Plasmid Pigment Epithelium-Derived Factor-Synthetic Amphiphile INTeraction-18 (p-PEDF-SAINT-18 Vector in a Rat Corneal Experimental Angiogenesis Model

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Ching-Hsein Chen

2013-04-01

Full Text Available Bevacizumab, a 149-kDa protein, is a recombinant humanized monoclonal antibody to VEGF. PEDF, a 50-kDa glycoprotein, has demonstrated anti-vasopermeability properties. In this study, we demonstrated that the combination of bevacizumab and plasmid pigment epithelium-derived factor-synthetic amphiphile INTeraction-18 (p-PEDF-SAINT-18 has a favorable antiangiogenic effect on corneal NV. Four groups (Group A: 0 μg + 0 μg, B: 0.1 μg + 0.1 μg, C: 1 μg + 1 μg, and D: 10 μg + 10 μg of bevacizumab + p-PEDF-SAINT-18 were prepared and implanted into the rat subconjunctival substantia propria 1.5 mm from the limbus on the temporal side. Then, 1 μg of p-bFGF-SAINT-18 was prepared and implanted into the rat corneal stroma 1.5 mm from the limbus on the same side. The inhibition of NV was observed and quantified from days 1 to 60. Biomicroscopic examination, western blot analysis and immunohistochemistry were used to analyze the 18-kDa bFGF, 50-kDa PEDF and VEGF protein expression. No inhibition activity for normal limbal vessels was noted. Subconjunctival injection with the combination of bevacizumab and p-PEDF-SAINT-18 successfully inhibited corneal NV. The bFGF and PEDF genes were successfully expressed as shown by western blot analysis, and a mild immune response to HLA-DR was shown by immunohistochemistry. We concluded that the combination of bevacizumab and p-PEDF-SAINT-18 may have more potent and prolonged antiangiogenic effects, making it possible to reduce the frequency of subconjunctival.Bevacizumab, a 149-kDa protein, is a recombinant humanized monoclonalantibody to VEGF. PEDF, a 50-kDa glycoprotein, has demonstrated anti-vasopermeabilityproperties. In this study, we demonstrated that the combination of bevacizumaband plasmid pigment epithelium-derived factor-synthetic amphiphile INTeraction-18(p-PEDF-SAINT-18 has a favorable antiangiogenic effect on corneal NV. Four groups(Group A: 0 μg + 0 μg, B: 0.1 μg + 0.1 μg, C: 1 μg + 1 μg, and

Healing of corneal epithelial wounds in marine and freshwater fish.

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Ubels, J L; Edelhauser, H F

The corneal epithelium of a fish is in direct contact with the aquatic environment and is a barrier to movement of ions and water into and through the cornea. This tissue layer is thus important in maintenance of corneal transparency. When the epithelium is wounded, its protective function is lost and corneal transparency remains compromised until the epithelial barrier is re-established. This study was undertaken to investigate the healing response of the fish cornea to epithelial abrasion. Wounds were stained with fluorescein and photographed during healing. Wound areas were measured by planimetry. The cornea of the sculpin, a marine teleost, becomes edematous after wounding and heals at 2.54 to 3.42 mm2/hr. Nonswelling corneas of the elasmobranchs--dogfish shark and skate--heal at 1.29 mm2/hr, respectively. The wounded eye of the rainbow trout, a freshwater teleost, is stressed by the low osmolality of the environment. Severe corneal edema and cataracts develop following epithelial wounding, and the cornea heals at 0.64 mm2/hr. Although the healing rates in teleosts differ from those in mammals, histology shows that the corneal healing mechanism is essentially the same in fish and mammals.

Protective Effects of Trehalose on the Corneal Epithelial Cells

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Pasquale Aragona

2014-01-01

Full Text Available Purpose. Aim of the present work was to evaluate the effects of the trehalose on the corneal epithelium undergoing alcohol delamination. Methods. Twelve patients undergoing laser subepithelial keratomileusis (LASEK were consecutively included in the study. The right eyes were pretreated with 3% trehalose eye drops, whilst left eyes were used as control. Epithelial specimens were processed for cells vitality assessment, apoptosis, and light and transmission electron microscopy; a morphometric analysis was performed in both groups. Results. In both trehalose-untreated eyes (TUE and trehalose-treated eyes (TTE, the percentage of vital cells was similar and no apoptotic cells were observed. In TUE, the corneal epithelium showed superficial cells with reduced microfolds, wing cells with vesicles and dilated intercellular spaces, and dark basal cells with vesicles and wide clefts. In TTE, superficial and wing cells were better preserved, and basal cells were generally clear with intracytoplasmatic vesicles. The morphometric analysis showed statistically significant differences between the two groups: the TTE epithelial height was higher, the basal cells showed larger area and clearer cytoplasm. The distribution of desmosomes and hemidesmosomes was significantly different between the groups. Conclusions. Trehalose administration better preserved morphological and morphometric features of alcohol-treated corneal epithelium, when compared to controls.

Identification of Lgr5-Independent Spheroid-Generating Progenitors of the Mouse Fetal Intestinal Epithelium

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Roxana C. Mustata

2013-10-01

Full Text Available Immortal spheroids were generated from fetal mouse intestine using the culture system initially developed to culture organoids from adult intestinal epithelium. Spheroid proportion progressively decreases from fetal to postnatal period, with a corresponding increase in production of organoids. Like organoids, spheroids show Wnt-dependent indefinite self-renewing properties but display a poorly differentiated phenotype reminiscent of incompletely caudalized progenitors. The spheroid transcriptome is strikingly different from that of adult intestinal stem cells, with minimal overlap of Wnt target gene expression. The receptor LGR4, but not LGR5, is essential for their growth. Trop2/Tacstd2 and Cnx43/Gja1, two markers highly enriched in spheroids, are expressed throughout the embryonic-day-14 intestinal epithelium. Comparison of in utero and neonatal lineage tracing using Cnx43-CreER and Lgr5-CreERT2 mice identified spheroid-generating cells as developmental progenitors involved in generation of the prenatal intestinal epithelium. Ex vivo, spheroid cells have the potential to differentiate into organoids, qualifying as a fetal type of intestinal stem cell.

CCL20, (gamma)(delta) T cells, and IL-22 in corneal epithelial healing

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After corneal epithelial abrasion, leukocytes and platelets rapidly enter the corneal stroma, and CCR6 (+) IL-17(+) gamma delta T cells migrate into the epithelium. Gamma delta T-cell-deficient (TCRd(-/-)) mice have significantly reduced inflammation and epithelial wound healing. Epithelial CCL20 mR...

Mutations in LOXHD1, a Recessive-Deafness Locus, Cause Dominant Late-Onset Fuchs Corneal Dystrophy

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Riazuddin, S. Amer; Parker, David S.; McGlumphy, Elyse J.; Oh, Edwin C.; Iliff, Benjamin W.; Schmedt, Thore; Jurkunas, Ula; Schleif, Robert; Katsanis, Nicholas; Gottsch, John D.

2012-01-01

Fuchs corneal dystrophy (FCD) is a genetic disorder of the corneal endothelium and is the most common cause of corneal transplantation in the United States. Previously, we mapped a late-onset FCD locus, FCD2, on chromosome 18q. Here, we present next-generation sequencing of all coding exons in the FCD2 critical interval in a multigenerational pedigree in which FCD segregates as an autosomal-dominant trait. We identified a missense change in LOXHD1, a gene causing progressive hearing loss in humans, as the sole variant capable of explaining the phenotype in this pedigree. We observed LOXHD1 mRNA in cultured human corneal endothelial cells, whereas antibody staining of both human and mouse corneas showed staining in the corneal epithelium and endothelium. Corneal sections of the original proband were stained for LOXHD1 and demonstrated a distinct increase in antibody punctate staining in the endothelium and Descemet membrane; punctate staining was absent from both normal corneas and FCD corneas negative for causal LOXHD1 mutations. Subsequent interrogation of a cohort of >200 sporadic affected individuals identified another 15 heterozygous missense mutations that were absent from >800 control chromosomes. Furthermore, in silico analyses predicted that these mutations reside on the surface of the protein and are likely to affect the protein's interface and protein-protein interactions. Finally, expression of the familial LOXHD1 mutant allele as well as two sporadic mutations in cells revealed prominent cytoplasmic aggregates reminiscent of the corneal phenotype. All together, our data implicate rare alleles in LOXHD1 in the pathogenesis of FCD and highlight how different mutations in the same locus can potentially produce diverse phenotypes. PMID:22341973

Effects of artificial tear treatment on corneal epithelial thickness and corneal topography findings in dry eye patients.

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Çakır, B; Doğan, E; Çelik, E; Babashli, T; Uçak, T; Alagöz, G

2018-05-01

To investigate the effects of artificial tear treatment on central corneal epithelial thickness, and central, mid-peripheral and peripheral corneal thicknesses in patients with dry eye disease (DED). Patients with DED underwent ocular examinations, including Schirmer-2 test, slit lamp examination for tear break-up time (BUT), corneal topography (CT) for measuring mean central, mid-peripheral and peripheral corneal thickness values and anterior segment optic coherence tomography (AS-OCT) for obtaining central corneal epithelial thickness. After artificial tear treatment (carboxymethylcellulose and sodium hyaluronate formulations) for one month, patients were examined again at a second visit and the results were compared. Sixty-one eyes of 33 female dry eye patients (mean age: 38.3±5.7 years) were enrolled. The mean follow-up time was 36.4±3.3 days. The mean tear BUT and Schirmer-1 tests revealed significant improvement after treatment (P=0.000, P=0.000, respectively). Central corneal epithelium and mean mid-peripheral corneal thicknesses measured significantly higher after treatment (P=0.001, P=0.02). Changes in central and peripheral corneal thicknesses were not statistically significant. Artificial tear treatment in dry eye patients seems to increase central corneal epithelial and mid-peripheral corneal thicknesses. Measurement of corneal epithelial thickness can be a useful tool for evaluation of treatment response in dry eye patients. Further long-term prospective studies are needed to investigate this item. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Gene expression and functional annotation of the human and mouse choroid plexus epithelium.

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Sarah F Janssen

Full Text Available BACKGROUND: The choroid plexus epithelium (CPE is a lobed neuro-epithelial structure that forms the outer blood-brain barrier. The CPE protrudes into the brain ventricles and produces the cerebrospinal fluid (CSF, which is crucial for brain homeostasis. Malfunction of the CPE is possibly implicated in disorders like Alzheimer disease, hydrocephalus or glaucoma. To study human genetic diseases and potential new therapies, mouse models are widely used. This requires a detailed knowledge of similarities and differences in gene expression and functional annotation between the species. The aim of this study is to analyze and compare gene expression and functional annotation of healthy human and mouse CPE. METHODS: We performed 44k Agilent microarray hybridizations with RNA derived from laser dissected healthy human and mouse CPE cells. We functionally annotated and compared the gene expression data of human and mouse CPE using the knowledge database Ingenuity. We searched for common and species specific gene expression patterns and function between human and mouse CPE. We also made a comparison with previously published CPE human and mouse gene expression data. RESULTS: Overall, the human and mouse CPE transcriptomes are very similar. Their major functionalities included epithelial junctions, transport, energy production, neuro-endocrine signaling, as well as immunological, neurological and hematological functions and disorders. The mouse CPE presented two additional functions not found in the human CPE: carbohydrate metabolism and a more extensive list of (neural developmental functions. We found three genes specifically expressed in the mouse CPE compared to human CPE, being ACE, PON1 and TRIM3 and no human specifically expressed CPE genes compared to mouse CPE. CONCLUSION: Human and mouse CPE transcriptomes are very similar, and display many common functionalities. Nonetheless, we also identified a few genes and pathways which suggest that the CPE

14-3-3{sigma} controls corneal epithelial cell proliferation and differentiation through the Notch signaling pathway

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Xin, Ying [Stem Cell Institute, James Brown Cancer Center, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Lu, Qingxian [Tumor Immunobiology Group, James Brown Cancer Center, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Li, Qiutang, E-mail: q.li@louisville.edu [Stem Cell Institute, James Brown Cancer Center, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States); Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202 (United States)

2010-02-19

14-3-3{sigma} (also called stratifin) is specifically expressed in the stratified squamous epithelium and its function was recently shown to be linked to epidermal stratification and differentiation in the skin. In this study, we investigated its role in corneal epithelium cell proliferation and differentiation. We showed that the 14-3-3{sigma} mutation in repeated epilation (Er) mutant mice results in a dominant negative truncated protein. Primary corneal epithelial cells expressing the dominant negative protein failed to undergo high calcium-induced cell cycle arrest and differentiation. We further demonstrated that blocking endogenous 14-3-3{sigma} activity in corneal epithelial cells by overexpressing dominative negative 14-3-3{sigma} led to reduced Notch activity and Notch1/2 transcription. Significantly, expression of the active Notch intracellular domain overcame the block in epithelial cell differentiation in 14-3-3{sigma} mutant-expressing corneal epithelial cells. We conclude that 14-3-3{sigma} is critical for regulating corneal epithelial proliferation and differentiation by regulating Notch signaling activity.

14-3-3σ controls corneal epithelial cell proliferation and differentiation through the Notch signaling pathway

International Nuclear Information System (INIS)

Xin, Ying; Lu, Qingxian; Li, Qiutang

2010-01-01

14-3-3σ (also called stratifin) is specifically expressed in the stratified squamous epithelium and its function was recently shown to be linked to epidermal stratification and differentiation in the skin. In this study, we investigated its role in corneal epithelium cell proliferation and differentiation. We showed that the 14-3-3σ mutation in repeated epilation (Er) mutant mice results in a dominant negative truncated protein. Primary corneal epithelial cells expressing the dominant negative protein failed to undergo high calcium-induced cell cycle arrest and differentiation. We further demonstrated that blocking endogenous 14-3-3σ activity in corneal epithelial cells by overexpressing dominative negative 14-3-3σ led to reduced Notch activity and Notch1/2 transcription. Significantly, expression of the active Notch intracellular domain overcame the block in epithelial cell differentiation in 14-3-3σ mutant-expressing corneal epithelial cells. We conclude that 14-3-3σ is critical for regulating corneal epithelial proliferation and differentiation by regulating Notch signaling activity.

Corneal Absorption of a New Riboflavin-Nanostructured System for Transepithelial Collagen Cross-Linking

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Bottos, Katia M.; Oliveira, Anselmo G.; Bersanetti, Patrícia A.; Nogueira, Regina F.; Lima-Filho, Acácio A. S.; Cardillo, José A.; Schor, Paulo; Chamon, Wallace

2013-01-01

Corneal collagen cross-linking (CXL) has been described as a promising therapy for keratoconus. According to standard CXL protocol, epithelium should be debrided before treatment to allow penetration of riboflavin into the corneal stroma. However, removal of the epithelium can increase procedure risks. In this study we aim to evaluate stromal penetration of a biocompatible riboflavin-based nanoemulsion system (riboflavin-5-phosphate and riboflavin-base) in rabbit corneas with intact epithelium. Two riboflavin nanoemulsions were developed. Transmittance and absorption coefficient were measured on corneas with intact epithelia after 30, 60, 120, 180, and 240 minutes following exposure to either the nanoemulsions or standard 0.1% or 1% riboflavin-dextran solutions. For the nanoemulsions, the epithelium was removed after measurements to assure that the riboflavin had passed through the hydrophobic epithelium and retained within the stroma. Results were compared to de-epithelialized corneas exposed to 0.1% riboflavin solution and to the same riboflavin nanoemulsions for 30 minutes (standard protocol). Mean transmittance and absorption measured in epithelialized corneas receiving the standard 0.1% riboflavin solution did not reach the levels found on the debrided corneas using the standard technique. Neither increasing the time of exposure nor the concentration of the riboflavin solution from 0.1% to 1% improved riboflavin penetration through the epithelium. When using riboflavin-5-phosphate nanoemulsion for 240 minutes, we found no difference between the mean absorption coefficients to the standard cross-linking protocol (p = 0.54). Riboflavin nanoemulsion was able to penetrate the corneal epithelium, achieving, after 240 minutes, greater stromal concentration when compared to debrided corneas with the standard protocol (p = 0.002). The riboflavin-5-phosphate nanoemulsion diffused better into the stroma than the riboflavin-base nanoemulsion. PMID:23785497

Comparison of Mouse and Human Retinal Pigment Epithelium Gene Expression Profiles: Potential Implications for Age-Related Macular Degeneration

NARCIS (Netherlands)

Bennis, A.; Gorgels, T.G.M.F.; ten Brink, J.B.; van der Spek, P.J.; Bossers, K.; Heine, V.M.; Bergen, A.A.

2015-01-01

Background The human retinal pigment epithelium (RPE) plays an important role in the pathogenesis of age related macular degeneration (AMD). AMD is the leading cause of blindness worldwide. There is currently no effective treatment available. Preclinical studies in AMD mouse models are essential to

Comparison of Mouse and Human Retinal Pigment Epithelium Gene Expression Profiles : Potential Implications for Age-Related Macular Degeneration

NARCIS (Netherlands)

Bennis, Anna; Gorgels, Theo G M F; Ten Brink, Jacoline B; van der Spek, Peter J; Bossers, Koen; Heine, Vivi M; Bergen, Arthur A

2015-01-01

BACKGROUND: The human retinal pigment epithelium (RPE) plays an important role in the pathogenesis of age related macular degeneration (AMD). AMD is the leading cause of blindness worldwide. There is currently no effective treatment available. Preclinical studies in AMD mouse models are essential to

Comparison of Mouse and Human Retinal Pigment Epithelium Gene Expression Profiles: Potential Implications for Age-Related Macular Degeneration

NARCIS (Netherlands)

Bennis, Anna; Gorgels, Theo G. M. F.; ten Brink, Jacoline B.; van der Spek, Peter J.; Bossers, Koen; Heine, Vivi M.; Bergen, Arthur A.

2015-01-01

The human retinal pigment epithelium (RPE) plays an important role in the pathogenesis of age related macular degeneration (AMD). AMD is the leading cause of blindness worldwide. There is currently no effective treatment available. Preclinical studies in AMD mouse models are essential to develop new

Cell flux through S phase in the mouse duodenal epithelium determined by cell sorting and radioautography

International Nuclear Information System (INIS)

Bjerknes, M.; Cheng, H.

1982-01-01

An accumulation of cells in early S phase was observed in normal mouse duodenal epithelium studied with flow cytometry. To determine if this accumulation of cells was the result of a lower rate of DNA synthesis, animals were given a single injection of 3 H-thymidine and the epithelium collected one hour later. The epithelium was processed for flow cytometry. Seven sort windows were established in different portions of the DNA histogram. Cells from each window were sorted onto glass slides that were then processed for radioautography. The number of silver grains over the nuclei of each sorted population was counted. It was found that cells in early S phase had significantly fewer grains over their nuclei than did mid- or late-S phase cells. We conclude that the accumulation of cells in early S phase is due, at least in part, to a lower rate of DNA synthesis in early than in mid or late S phase

Conditional inactivation of p53 in mouse ovarian surface epithelium does not alter MIS driven Smad2-dominant negative epithelium-lined inclusion cysts or teratomas.

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Suzanne M Quartuccio

Full Text Available Epithelial ovarian cancer is the most lethal gynecological malignancy among US women. The etiology of this disease, although poorly understood, may involve the ovarian surface epithelium or the epithelium of the fallopian tube fimbriae as the progenitor cell. Disruptions in the transforming growth factor beta (TGFβ pathway and p53 are frequently found in chemotherapy-resistant serous ovarian tumors. Transgenic mice expressing a dominant negative form of Smad2 (Smad2DN, a downstream transcription factor of the TGFβ signaling pathway, targeted to tissues of the reproductive tract were created on a FVB background. These mice developed epithelium-lined inclusion cysts, a potential precursor lesion to ovarian cancer, which morphologically resembled oviductal epithelium but exhibited protein expression more closely resembling the ovarian surface epithelium. An additional genetic "hit" of p53 deletion was predicted to result in ovarian tumors. Tissue specific deletion of p53 in the ovaries and oviducts alone was attempted through intrabursal or intraoviductal injection of Cre-recombinase expressing adenovirus (AdCreGFP into p53 (flox/flox mice. Ovarian bursal cysts were detected in some mice 6 months after intrabursal injection. No pathological abnormalities were detected in mice with intraoviductal injections, which may be related to decreased infectivity of the oviductal epithelium with adenovirus as compared to the ovarian surface epithelium. Bitransgenic mice, expressing both the Smad2DN transgene and p53 (flox/flox, were then exposed to AdCreGFP in the bursa and oviductal lumen. These mice did not develop any additional phenotypes. Exposure to AdCreGFP is not an effective methodology for conditional deletion of floxed genes in oviductal epithelium and tissue specific promoters should be employed in future mouse models of the disease. In addition, a novel phenotype was observed in mice with high expression of the Smad2DN transgene as validated

Selenium-binding lactoferrin is taken into corneal epithelial cells by a receptor and prevents corneal damage in dry eye model animals.

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Higuchi, Akihiro; Inoue, Hiroyoshi; Kaneko, Yoshio; Oonishi, Erina; Tsubota, Kazuo

2016-11-11

The ocular surface is strongly affected by oxidative stress, which causes many ocular diseases including dry eye. Previously, we showed that selenium compounds, e.g., selenoprotein P and Se-lactoferrin, were candidates for treatment of dry eye. This paper shows the efficacy of Se-lactoferrin for the treatment of dry eye compared with Diquas as a control drug using two dry eye models and incorporation of lactoferrin into corneal epithelial cells via lactoferrin receptors. We show the efficacy of Se-lactoferrin eye drops in the tobacco smoke exposure rat dry eye model and short-term rabbit dry eye model, although Diquas eye drops were only effective in the short-term rabbit dry eye model. These results indicate that Se-lactoferrin was useful in the oxidative stress-causing dry eye model. Se-lactoferrin was taken into corneal epithelium cells via lactoferrin receptors. We identified LRP1 as the lactoferrin receptor in the corneal epithelium involved in lactoferrin uptake. Se-lactoferrin eye drops did not irritate the ocular surface of rabbits. Se-lactoferrin was an excellent candidate for treatment of dry eye, reducing oxidative stress by a novel mechanism.

Choline transport in the isolated rabbit corneal epithelium

International Nuclear Information System (INIS)

Faust, R.L.

1988-01-01

In the present study, isolated epithelial sheets were obtained by performing two sequential anterior keratectomies, three weeks apart, on rabbit corneas. Light microscopy of the isolated sheets revealed a multilayered epithelium with an intact basal cell layer without contamination from other cell types. The accumulation of [ 3 H]choline into the epithelial sheets was studied at substrate concentrations varying from 1 to 100 μMoles with and without the addition of specific metabolic and stereochemical inhibitors. Accumulation of [ 3 H]choline into these sheets was saturable. Kinetic analysis, performed by estimation from double-reciprocal plots, revealed a single component system with a K m of 24.9 μM. The metabolic inhibitors potassium cyanide and ouabain showed no effect on the uptake of [ 3 H]choline; however, the stereochemical inhibitor hemicholinium-3 significantly reduced the accumulation of radiolabel at both high and low substrate concentrations. The results suggest a non-energy dependent yet a highly specific transport system for the accumulation of choline into the rabbit epithelium

System for tracking transplanted limbal epithelial stem cells in the treatment of corneal stem cell deficiency

Science.gov (United States)

Boadi, J.; Sangwal, V.; MacNeil, S.; Matcher, S. J.

2015-03-01

The prevailing hypothesis for the existence and healing of the avascular corneal epithelium is that this layer of cells is continually produced by stem cells in the limbus and transported onto the cornea to mature into corneal epithelium. Limbal Stem Cell Deficiency (LSCD), in which the stem cell population is depleted, can lead to blindness. LSCD can be caused by chemical and thermal burns to the eye. A popular treatment, especially in emerging economies such as India, is the transplantation of limbal stem cells onto damaged limbus with hope of repopulating the region. Hence regenerating the corneal epithelium. In order to gain insights into the success rates of this treatment, new imaging technologies are needed in order to track the transplanted cells. Optical Coherence Tomography (OCT) is well known for its high resolution in vivo images of the retina. A custom OCT system has been built to image the corneal surface, to investigate the fate of transplanted limbal stem cells. We evaluate two methods to label and track transplanted cells: melanin labelling and magneto-labelling. To evaluate melanin labelling, stem cells are loaded with melanin and then transplanted onto a rabbit cornea denuded of its epithelium. The melanin displays strongly enhanced backscatter relative to normal cells. To evaluate magneto-labelling the stem cells are loaded with magnetic nanoparticles (20-30nm in size) and then imaged with a custom-built, magneto-motive OCT system.

Toxicological effects and recovery of the corneal epithelium in Cyprinus carpio communis Linn. exposed to monocrotophos: an scanning electron microscope study.

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Uppal, Ravneet Kaur; Johal, Mohinder Singh; Sharma, Madan Lal

2015-05-01

This study was conducted based on the evidence of fish habitats in North India being affected by organophosphate pesticides draining from agricultural fields into bodies of water, especially during the rainy season. Various tissues of fish such as scales, gills ovaries, kidney, and liver have been studied from the toxicological point of view, but the toxicological effects of aquatic pollutants on fish cornea have not been investigated to date. We conducted comparative toxicological studies on the cornea of Cyprinus carpio communis using two sublethal (0.038 and 0.126 ppm) concentrations of monocrotophos pesticide for 30 days. Corneas from all the groups were evaluated by a scanning electron microscope. The fish exposed to the monocrotophos pesticide developed corneal necrosis due to the formation of crystalloid-like structures, thinning and shrinkage of microridges on the corneal epithelium. After 30 days, fish from the monocrotophos-treated tank were transferred to normal environmental conditions. After 60 days under natural condition, epithelial cells did not fully recover. In conclusion, exposure to monocrotophos induces irreversible changes in the cornea of C. carpio communis. As fish and mammalian visual systems share many similarities, the reported finding may offer useful insights for further toxicological and ophthalmological studies in humans. © 2013 American College of Veterinary Ophthalmologists.

Comparison of transepithelial corneal crosslinking with epithelium-off crosslinking (epithelium-off CXL in adult Pakistani population with progressive keratoconus

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Bushra Akbar

2017-01-01

CONCLUSION: Transepithelial CXL is not recommended to be replaced completely by standard epithelium-off CXL due to continued ectatic progression in 25% of cases. However, thin corneas, unfit for standard epithelium-off CXL, can benefit from transepithelial CXL.

Ontogeny and innervation of taste buds in mouse palatal gustatory epithelium.

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Rashwan, Ahmed; Konishi, Hiroyuki; El-Sharaby, Ashraf; Kiyama, Hiroshi

2016-01-01

We investigated the relationship between mouse taste bud development and innervation of the soft palate. We employed scanning electron microscopy and immunohistochemistry using antibodies against protein gene product 9.5 and peripherin to detect sensory nerves, and cytokeratin 8 and α-gustducin to stain palatal taste buds. At E14, nerve fibers were observed along the medial border of the palatal shelves that tracked toward the epithelium. At E15.5, primordial stages of taste buds in the basal lamina of the soft palate first appeared. At E16, the taste buds became large spherical masses of columnar cells scattered in the soft palate basal lamina. At E17, the morphology and also the location of taste buds changed. At E18-19, some taste buds acquired a more elongated shape with a short neck, extending a variable distance from the soft palate basal lamina toward the surface epithelium. At E18, mature taste buds with taste pores and perigemmal nerve fibers were observed on the surface epithelium of the soft palate. The expression of α-gustducin was demonstrated at postnatal day 1 and the number of pored taste buds increased with age and they became pear-shaped at 8 weeks. The percent of pored fungiform-like papillae at birth was 58.3% of the whole palate; this increased to 83.8% at postnatal day 8 and reached a maximum of 95.7% at 12 weeks. The innervation of the soft palate was classified into three types of plexuses in relation to taste buds: basal nerve plexus, intragemmal and perigemmal nerve fibers. This study reveals that the nerve fibers preceded the development of taste buds in the palate of mice, and therefore the nerve fibers have roles in the initial induction of taste buds in the soft palate. Copyright © 2015 Elsevier B.V. All rights reserved.

The tissue-engineered human cornea as a model to study expression of matrix metalloproteinases during corneal wound healing.

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Couture, Camille; Zaniolo, Karine; Carrier, Patrick; Lake, Jennifer; Patenaude, Julien; Germain, Lucie; Guérin, Sylvain L

2016-02-01

Corneal injuries remain a major cause of consultation in the ophthalmology clinics worldwide. Repair of corneal wounds is a complex mechanism that involves cell death, migration, proliferation, differentiation, and extracellular matrix (ECM) remodeling. In the present study, we used a tissue-engineered, two-layers (epithelium and stroma) human cornea as a biomaterial to study both the cellular and molecular mechanisms of wound healing. Gene profiling on microarrays revealed important alterations in the pattern of genes expressed by tissue-engineered corneas in response to wound healing. Expression of many MMPs-encoding genes was shown by microarray and qPCR analyses to increase in the migrating epithelium of wounded corneas. Many of these enzymes were converted into their enzymatically active form as wound closure proceeded. In addition, expression of MMPs by human corneal epithelial cells (HCECs) was affected both by the stromal fibroblasts and the collagen-enriched ECM they produce. Most of all, results from mass spectrometry analyses provided evidence that a fully stratified epithelium is required for proper synthesis and organization of the ECM on which the epithelial cells adhere. In conclusion, and because of the many characteristics it shares with the native cornea, this human two layers corneal substitute may prove particularly useful to decipher the mechanistic details of corneal wound healing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of topical vitamin E on ethanol-induced corneal epithelial apoptosis.

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Bilgihan, Kamil; Konuk, Onur; Hondur, Ahmet; Akyürek, Nalan; Ozogul, Candan; Hasanreisoglu, Berati

2005-01-01

Ethanol is used to loosen the corneal epithelium before photoablation in laser subepithelial keratomileusis (LASEK). In this study, the apoptotic index of corneal epithelium after ethanol exposure and the effects of topical vitamin E were evaluated. The study was performed on 28 rabbit eyes in four groups. Group 1 comprised the controls. In group 2, 20% ethanol was applied topically for 20 seconds. In group 3, topical vitamin E was applied following 20% ethanol application. In group 4, only topical vitamin E was applied. Apoptosis was evaluated with TUNEL assay and transmission electron microscopy. Epithelial apoptosis was detected in all specimens in group 2. No apoptosis was detected in other groups except for one eye in group 1. The apoptotic index in group 2 was statistically higher than other groups (P < .001).

Spontaneous Healing of Corneal Perforation after Temporary Discontinuation of Erlotinib Treatment

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Naoyuki Morishige

2014-01-01

Full Text Available Purpose: To report a case of corneal perforation associated with oral administration of erlotinib and its spontaneous healing after temporary discontinuation of drug treatment. Case Report: A 65-year-old man with metastatic lung cancer was treated with erlotinib (150 mg/day, a specific tyrosine kinase inhibitor of the epidermal growth factor receptor. He was referred to our corneal service for the treatment of bilateral corneal disorders, diagnosed with mild aqueous-deficient dry eye, and treated by insertion of punctal plugs. His corneal epithelial disorders initially improved, but subsequently worsened, as manifested by the development of bilateral corneal ulceration with corneal perforation in the right eye. The oral administration of erlotinib was interrupted in preparation for tectonic keratoplasty, but 2 days later the corneal perforation of the right eye and the bilateral epithelial defects had healed spontaneously. Treatment with erlotinib was resumed at half the initial dose, and the cornea of both eyes has remained apparently healthy. Discussion: Erlotinib may be secreted into tear fluid and thereby adversely affect the corneal epithelium. The development of corneal epithelial disorders in patients receiving this drug may be reversed by reducing its dose.

Construction of Anterior Hemi-Corneal Equivalents Using Nontransfected Human Corneal Cells and Transplantation in Dog Models.

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Xu, Bin; Song, Zhan; Fan, Tingjun

2017-11-01

Tissue-engineered human anterior hemi-cornea (TE-aHC) is a promising equivalent for treating anterior lamellar keratopathy to surmount the severe shortage of donated corneas. This study was intended to construct a functional TE-aHC with nontransfected human corneal stromal (ntHCS) and epithelial (ntHCEP) cells using acellular porcine corneal stromata (aPCS) as a carrier scaffold, and evaluate its biological functions in a dog model. To construct a TE-aHC, ntHCS cells were injected into an aPCS scaffold and cultured for 3 days; then, ntHCEP cells were inoculated onto the Bowman's membrane of the scaffold and cultured for 5 days under air-liquid interface condition. After its morphology and histological structure were characterized, the constructed TE-aHC was transplanted into dog eyes via lamellar keratoplasty. The corneal transparency, thickness, intraocular pressure, epithelial integrity, and corneal regeneration were monitored in vivo, and the histological structure and histochemical property were examined ex vivo 360 days after surgery, respectively. The results showed that the constructed TE-aHC was highly transparent and composed of a corneal epithelium of 7-8 layer ntHCEP cells and a corneal stroma of regularly aligned collagen fibers and well-preserved glycosaminoglycans with sparsely distributed ntHCS cells, mimicking a normal anterior hemi-cornea (aHC). Moreover, both ntHCEP and ntHCS cells maintained positive expression of their marker and functional proteins. After transplantation into dog eyes, the constructed TE-aHC acted naturally in terms of morphology, structure and inherent property, and functioned well in maintaining corneal clarity, thickness, normal histological structure, and composition in dog models by reconstructing a normal aHC, which could be used as a promising aHC equivalent in corneal regenerative medicine and aHC disorder therapy. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Corneal surface reconstruction - a short review

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Madhavan H N

2009-01-01

patients with persistent epithelial defects, pterygium, symblepharon, and for ocular surface reconstruction. The role of AMT in ocular disorders has been recently re-evaluated by Schwab and coworkers.11 They carefully examined the protocols used in the manufacture of the bio-engineered construct to assess the risks and reviewed 20 published reports of human trials conducted between 1996 and 2005 in a report suggesting that the currently used transplant procedures carry potential health risks not only to individuals but also to "the wider community" because they "rely on the use of materials from animal and human donors". Their review revealed that most protocols used animal-derived products including fetal calf serum (FCS with a potential for transmissible spongiform encephalopathy (TSE infection (of the brain or allergic reactions and further state that the use of commercially available fibrin tissue "adds to the risk of microbial or prion contamination". Since no investigations have been done, the use of AMT can potentially induce "disease transmission through contamination with bacteria, viruses, or other infectious agents", they also stated that with 3T3 cells being commonly used (that come from mice possibilities of "xenozoonosis", or animal-to-human disease transmission are a concern.Several studies have been undertaken using oral mucosal epithelial cells cultivated on amniotic membrane for useful tissue engineering of damaged corneal surface. Higa and Shimazaki have carried out a study of transplantation in cultivated oral mucosal epithelial which has been useful in achieving a stable ocular surface. However, in addition to using epithelial sheets with AM, they developed a technique for generating carrier-free sheets using fibrin sealants. These sheets seem to contain more differentiated epithelium than those obtained with AM while retaining similar levels of colony-forming progenitor cells. In terms of isolation and cultivation of corneal epithelial stem

Effect of Schizandra chinensis lignans on cell division in the corneal epithelium and tongue of albino rats exposed to chronic cold stress

International Nuclear Information System (INIS)

Mel'nik, E.I.; Lupandin, A.V.; Timoshin, S.S.

1985-01-01

The authors study the possibility of correcting cellular manifestations of disadaptation following chronic exposure to cold stress by means of preparations of Sch. chinensis. The model of chronic stress was cooling male albino rats daily for 1.5 h to a temperature of 28-30 C for 28 days. Since differences between levels of proliferation in intact animals and in the rats receiving 1.9% ethanol solution were absent, values obtained in the group of intact animals are presented in a table as the control. The animals underwent euthanasia 48 hours after the final exposure to the cold. The rats received an injection of tritium-thymidine one hour before sacrifice. It is shown that the results confirm those in previous studies of stimulation of DNA synthesis and mitotic activity in the corneal and lingual epithelium of albino rats during chronic exposure to stress

Human stem cell based corneal tissue mimicking structures using laser-assisted 3D bioprinting and functional bioinks.

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Sorkio, Anni; Koch, Lothar; Koivusalo, Laura; Deiwick, Andrea; Miettinen, Susanna; Chichkov, Boris; Skottman, Heli

2018-07-01

There is a high demand for developing methods to produce more native-like 3D corneal structures. In the present study, we produced 3D cornea-mimicking tissues using human stem cells and laser-assisted bioprinting (LaBP). Human embryonic stem cell derived limbal epithelial stem cells (hESC-LESC) were used as a cell source for printing epithelium-mimicking structures, whereas human adipose tissue derived stem cells (hASCs) were used for constructing layered stroma-mimicking structures. The development and optimization of functional bioinks was a crucial step towards successful bioprinting of 3D corneal structures. Recombinant human laminin and human sourced collagen I served as the bases for the functional bioinks. We used two previously established LaBP setups based on laser induced forward transfer, with different laser wavelengths and appropriate absorption layers. We bioprinted three types of corneal structures: stratified corneal epithelium using hESC-LESCs, lamellar corneal stroma using alternating acellular layers of bioink and layers with hASCs, and finally structures with both a stromal and epithelial part. The printed constructs were evaluated for their microstructure, cell viability and proliferation, and key protein expression (Ki67, p63α, p40, CK3, CK15, collagen type I, VWF). The 3D printed stromal constructs were also implanted into porcine corneal organ cultures. Both cell types maintained good viability after printing. Laser-printed hESC-LESCs showed epithelial cell morphology, expression of Ki67 proliferation marker and co-expression of corneal progenitor markers p63α and p40. Importantly, the printed hESC-LESCs formed a stratified epithelium with apical expression of CK3 and basal expression of the progenitor markers. The structure of the 3D bioprinted stroma demonstrated that the hASCs had organized horizontally as in the native corneal stroma and showed positive labeling for collagen I. After 7 days in porcine organ cultures, the 3D bioprinted

Metaherpetic corneal disease in a dog associated with partial limbal stem cell deficiency and neurotrophic keratitis.

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Ledbetter, Eric C; Marfurt, Carl F; Dubielzig, Richard R

2013-07-01

To describe clinical, in vivo confocal microscopic, histopathologic, and immunohistochemical features of a dog with metaherpetic corneal disease that developed subsequent to a protracted episode of canine herpesvirus-1 (CHV-1) dendritic ulcerative keratitis. A 7-year-old, spayed-female, Miniature Schnauzer was treated for bilateral CHV-1 dendritic ulcerative keratitis. Following resolution of ulcerative keratitis, sectoral peripheral superficial corneal gray opacification, vascularization, and pigmentation slowly migrated centripetally to the axial cornea of both eyes. Corneal sensitivity measured with a Cochet-Bonnet esthesiometer was dramatically and persistently reduced. In vivo corneal confocal microscopic examination revealed regions of epithelium with a conjunctival phenotype. In these areas, the surface epithelium was thin, disorganized, and composed of hyper-reflective epithelial cells. Goblet cells and Langerhans cells were frequent, and the subbasal nerve plexus was completely absent or markedly diminished. Histopathologic abnormalities in the globes were restricted to the superficial cornea and included sectoral corneal conjunctivalization, increased anterior stromal spindle cells, and vascularization. Immunohistochemical evaluation of the corneas with anti-neurotublin antibody demonstrated attenuation of the epithelial and subbasal nerve plexuses with marked stromal hyperinnervation and increased numbers of morphologically abnormal neurites. Similar to herpes simplex virus keratitis in humans, CHV-1 ulcerative keratitis may be associated with the development of chronic degenerative corneal disease in dogs. In the described dog, this chronic corneal disease included progressive corneal opacification because of partial limbal stem cell deficiency and neurotrophic keratitis. Long-term monitoring of dogs following resolution of active CHV-1 keratitis may be indicated, particularly when ulcerations persist for an extended period. © 2012 American College of

Effect of Viscous Agents on Corneal Density in Dry Eye Disease.

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Wegener, Alfred R; Meyer, Linda M; Schönfeld, Carl-Ludwig

2015-10-01

To investigate the effect of the viscous agents, hydroxypropyl methylcellulose (HPMC), carbomer, povidone, and a combination of HPMC and povidone on corneal density in patients with dry eye disease. In total, 98 eyes of 49 patients suffering from dry eye and 65 eyes of 33 healthy age-matched individuals were included in this prospective, randomized study. Corneal morphology was documented with Scheimpflug photography and corneal density was analyzed in 5 anatomical layers (epithelium, bowman membrane, stroma, descemet's membrane, and endothelium). Corneal density was evaluated for the active ingredients HPMC, carbomer, povidone, and a combination of HPMC and povidone as the viscous agents contained in the artificial tear formulations used by the dry eye patients. Data were compared to the age-matched healthy control group without medication. Corneal density in dry eye patients was reduced in all 5 anatomical layers compared to controls. Corneal density was highest and very close to control in patients treated with HPMC containing ocular lubricants. Patients treated with lubricants, including carbomer as the viscous agent displayed a significant reduction of corneal density in layers 1 and 2 compared to control. HPMC containing ocular lubricants can help to maintain physiological corneal density and may be beneficial in the treatment of dry eye disease.

Vps35-deficiency impairs SLC4A11 trafficking and promotes corneal dystrophy.

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Wei Liu

Full Text Available Vps35 (vacuolar protein sorting 35 is a major component of retromer that selectively promotes endosome-to-Golgi retrieval of transmembrane proteins. Dysfunction of retromer is a risk factor for the pathogenesis of Parkinson's disease (PD and Alzheimer's disease (AD. However, Vps35/retromer's function in the eye or the contribution of Vps35-deficiency to eye degenerative disorders remains to be explored. Here we provide evidence for a critical role of Vps35 in mouse corneal dystrophy. Vps35 is expressed in mouse and human cornea. Mouse cornea from Vps35 heterozygotes (Vps35+/- show features of dystrophy, such as loss of both endothelial and epithelial cell densities, disorganizations of endothelial, stroma, and epithelial cells, excrescences in the Descemet membrane, and corneal edema. Additionally, corneal epithelial cell proliferation was reduced in Vps35-deficient mice. Intriguingly, cell surface targeting of SLC4A11, a membrane transport protein (OH- /H+ /NH3 /H2O of corneal endothelium, whose mutations have been identified in patients with corneal dystrophy, was impaired in Vps35-deficient cells and cornea. Taken together, these results suggest that SLC4A11 appears to be a Vps35/retromer cargo, and Vps35-regulation of SLC4A11 trafficking may underlie Vps35/retromer regulation of corneal dystrophy.

Estimation of the in vitro eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust by using reconstituted human corneal epithelium tissue cultures

DEFF Research Database (Denmark)

Cao, Yi; Arenholt-Bindslev, Dorthe; Kjærgaard, Søren K

2015-01-01

CONTEXT: Eye irritation is a common complaint in indoor environment, but the causes have still not been identified among the multiple exposures in house environments. To identify the potential environmental factors responsible for eye irritation and study the possible mechanisms, an in vitro model...... AND CONCLUSION: LPS and dust showed in vitro eye irritating and inflammatory potential, and cytokines/chemokines like IL-1β and IL-8 may be involved in the mechanisms of eye irritation. The HCE tissue culture may be used as an in vitro model to study environmental exposure induced eye irritation and inflammation....... for eye irritation is suggested. MATERIALS AND METHODS: In this study, reconstituted human corneal epithelium (HCE) tissue cultures were used to study the eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust. HCE tissue cultures were exposed to a range of concentrations of LPS...

Corneal wound healing is compromised by immunoproteasome deficiency.

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Deborah A Ferrington

Full Text Available Recent studies have revealed roles for immunoproteasome in regulating cell processes essential for maintaining homeostasis and in responding to stress and injury. The current study investigates how the absence of immunoproteasome affects the corneal epithelium under normal and stressed conditions by comparing corneas from wildtype (WT mice and those deficient in two immunoproteasome catalytic subunits (lmp7(-/-/mecl-1(-/-, L7M1. Immunoproteasome expression was confirmed in WT epithelial cells and in cells of the immune system that were present in the cornea. More apoptotic cells were found in both corneal explant cultures and uninjured corneas of L7M1 compared to WT mice. Following mechanical debridement, L7M1 corneas displayed delayed wound healing, including delayed re-epithelialization and re-establishment of the epithelial barrier, as well as altered inflammatory cytokine production compared to WT mice. These results suggest that immunoproteasome plays an important role in corneal homeostasis and wound healing.

Reactivation of Herpes Zoster Keratitis With Corneal Perforation After Zoster Vaccination.

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Jastrzebski, Andre; Brownstein, Seymour; Ziai, Setareh; Saleh, Solin; Lam, Kay; Jackson, W Bruce

2017-06-01

We present a case of reactivated herpes zoster keratouveitis of 6 years duration with corneal perforation requiring penetrating keratoplasty shortly after inoculation with herpes zoster vaccine (Zostavax, Merck, Quebec, Canada). Retrospective case report. A 67-year-old woman with a 5-year history of recurrent unilateral herpes zoster keratouveitis in her right eye presented with another recurrence 2 weeks after Zostavax vaccination. Three months later, she developed descemetocele and 2 months afterward, corneal perforation, which was managed by penetrating keratoplasty. Immunohistopathological examination disclosed positive staining for varicella zoster virus in most of the keratocytes adjacent to the descemetocele and perforation, most vividly in the deeper two-thirds of the stroma where the keratocytes were most dense, but not in corneal epithelium or endothelium. Electron microscopic examination showed universally severely degenerated corneal keratocytes in the corneal stroma adjacent to the perforation with variable numbers of herpes virus capsids present in half of these cells. Only a rare normal-appearing keratocyte was identified in the more peripheral corneal stroma. We present a case of reactivation of herpes keratouveitis shortly after vaccination with Zostavax in a patient with previous herpes zoster ophthalmicus. We demonstrate, for the first time, ultrastructural evidence consistent with inactive virus capsids in diffusely degenerated keratocytes in the extracted corneal tissue.

Efficacy of a new topical cationic emulsion of cyclosporine A on dry eye clinical signs in an experimental mouse model of dry eye.

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Daull, Philippe; Feraille, Laurence; Barabino, Stefano; Cimbolini, Nicolas; Antonelli, Sophie; Mauro, Virgine; Garrigue, Jean-Sébastien

2016-12-01

Dry eye disease (DED) is a complex, multifactorial pathology characterized by corneal epithelium lesions and inflammation. The aim of the present study was to evaluate the efficacy of a cationic emulsion of cyclosporine A (CsA) in a mouse model that mimics severe dry eye. Eight to 12-week-old female C57BL/6N mice with tail patches of scopolamine were housed in controlled environment chambers to induce dry eye. At day three, following dry eye confirmation by corneal fluorescein staining (CFS, score 0-15) and phenol red thread (PRT) lacrimation test, the mice (n = 10/gp) were either treated 3 times a day in both eyes with drug-free cationic emulsion, a 0.1% CsA cationic emulsion, or 1% methylprednisolone (positive control), or non-treated. Aqueous tear production and CFS scores were evaluated at baseline and throughout the treatment period. The lacrimation test confirmed the scopolamine-induced decrease in aqueous production by the lacrimal gland. A reduction of 59% in induced-CFS was observed following topical treatment with 0.1% CsA. The beneficial effect of the cationic emulsion vehicle itself on keratitis was also clearly evidenced by its better performance over 1% methylprednisolone, -36%, vs. -28% on the CFS scores, respectively. This study indicates that the cationic emulsion of CsA (0.1%) was a very effective formulation for the management of corneal epithelium lesions in a severe DED mouse model. In addition, it performed better than a potent glucocorticosteroid (1% methylprednisolone). This cationic emulsion of CsA (0.1%), combining CsA and a tear film oriented therapy (TFOT), i.e. with vehicle properties that mechanically stabilize the tear film, represents a promising new treatment strategy for the management of the signs of dry eye. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Progress in corneal wound healing

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Ljubimov, Alexander V.; Saghizadeh, Mehrnoosh

2015-01-01

Corneal wound healing is a complex process involving cell death, migration, proliferation, differentiation, and extracellular matrix remodeling. Many similarities are observed in the healing processes of corneal epithelial, stromal and endothelial cells, as well as cell-specific differences. Corneal epithelial healing largely depends on limbal stem cells and remodeling of the basement membrane. During stromal healing, keratocytes get transformed to motile and contractile myofibroblasts largely due to activation of transforming growth factor-β system. Endothelial cells heal mostly by migration and spreading, with cell proliferation playing a secondary role. In the last decade, many aspects of wound healing process in different parts of the cornea have been elucidated, and some new therapeutic approaches have emerged. The concept of limbal stem cells received rigorous experimental corroboration, with new markers uncovered and new treatment options including gene and microRNA therapy tested in experimental systems. Transplantation of limbal stem cell-enriched cultures for efficient re-epithelialization in stem cell deficiency and corneal injuries has become reality in clinical setting. Mediators and course of events during stromal healing have been detailed, and new treatment regimens including gene (decorin) and stem cell therapy for excessive healing have been designed. This is a very important advance given the popularity of various refractive surgeries entailing stromal wound healing. Successful surgical ways of replacing the diseased endothelium have been clinically tested, and new approaches to accelerate endothelial healing and suppress endothelial-mesenchymal transformation have been proposed including Rho kinase (ROCK) inhibitor eye drops and gene therapy to activate TGF-β inhibitor SMAD7. Promising new technologies with potential for corneal wound healing manipulation including microRNA, induced pluripotent stem cells to generate corneal epithelium, and

Differentiation/Purification Protocol for Retinal Pigment Epithelium from Mouse Induced Pluripotent Stem Cells as a Research Tool.

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Yuko Iwasaki

Full Text Available To establish a novel protocol for differentiation of retinal pigment epithelium (RPE with high purity from mouse induced pluripotent stem cells (iPSC.Retinal progenitor cells were differentiated from mouse iPSC, and RPE differentiation was then enhanced by activation of the Wnt signaling pathway, inhibition of the fibroblast growth factor signaling pathway, and inhibition of the Rho-associated, coiled-coil containing protein kinase signaling pathway. Expanded pigmented cells were purified by plate adhesion after Accutase® treatment. Enriched cells were cultured until they developed a cobblestone appearance with cuboidal shape. The characteristics of iPS-RPE were confirmed by gene expression, immunocytochemistry, and electron microscopy. Functions and immunologic features of the iPS-RPE were also evaluated.We obtained iPS-RPE at high purity (approximately 98%. The iPS-RPE showed apical-basal polarity and cellular structure characteristic of RPE. Expression levels of several RPE markers were lower than those of freshly isolated mouse RPE but comparable to those of primary cultured RPE. The iPS-RPE could form tight junctions, phagocytose photoreceptor outer segments, express immune antigens, and suppress lymphocyte proliferation.We successfully developed a differentiation/purification protocol to obtain mouse iPS-RPE. The mouse iPS-RPE can serve as an attractive tool for functional and morphological studies of RPE.

Caveolin-1 as a Novel Indicator of Wound-Healing Capacity in Aged Human Corneal Epithelium

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Rhim, Ji Heon; Kim, Jae Hoon; Yeo, Eui-Ju; Kim, Jae Chan; Park, Sang Chul

2010-01-01

Excess caveolin-1 has been reported to play a role in age-dependent hyporesponsiveness to growth factors in vitro. Therefore, we hypothesized that caveolin-1–dependent hyporesponsiveness to growth factors in aged corneal epithelial cells might be responsible for delayed wound healing in vivo. To test this hypothesis, we evaluated corneal wound-healing time by vital staining using fluorescein after laser epithelial keratomileusis (LASEK). We compared wound-healing times in young, middle-aged a...

Effect of the Regenerative Agent Poly(Carboxymethylglucose Sulfate) on Corneal Wound Healing After Corneal Cross-Linking for Keratoconus.

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Kymionis, George D; Liakopoulos, Dimitrios A; Grentzelos, Michael A; Tsoulnaras, Konstantinos I; Detorakis, Efstathios T; Cochener, Béatrice; Tsilimbaris, Miltiadis K

2015-08-01

To evaluate the effect of a regenerative agent (RGTA) [Cacicol20-poly(carboxymethyl glucose sulfate); OTR3, Paris, France] on corneal reepithelialization and pain after corneal cross-linking (CXL) for keratoconus. In this prospective comparative (contralateral) clinical study, patients with bilateral progressive keratoconus underwent CXL treatment. The corneal epithelium during CXL was removed using transepithelial phototherapeutic keratectomy (Cretan protocol). One eye of each patient was randomly instilled with an RGTA (Cacicol20) once a day (study group), whereas the fellow eye was instilled with artificial tears (control group). Patients were examined daily until complete reepithelialization. Postoperative examinations included slit-lamp biomicroscopy to assess the epithelial defect size and subjective evaluation of pain. The study enrolled 18 patients (36 eyes). The mean epithelial defect size for study and control groups was 19.6 ± 4.2 mm versus 21.5 ± 2.8 mm, respectively, at day 1 (P = 0.019) and 6.4 ± 3.4 mm versus 7.9 ± 4.3 mm, respectively, at day 2 (P = 0.014). At day 3 postoperatively, 61.1% of study eyes were fully reepithelialized, compared with 11.1% of control eyes (P = 0.002). RGTA (Cacicol20) instillation seems to result in faster corneal reepithelialization after CXL in this study. However, there was no significant effect in subjective pain/discomfort.

Pax6 downregulation mediates abnormal lineage commitment of the ocular surface epithelium in aqueous-deficient dry eye disease.

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Ying Ting Chen

Full Text Available Keratinizing squamous metaplasia (SQM of the ocular surface is a blinding consequence of systemic autoimmune disease and there is no cure. Ocular SQM is traditionally viewed as an adaptive tissue response during chronic keratoconjunctivitis sicca (KCS that provokes pathological keratinization of the corneal epithelium and fibrosis of the corneal stroma. Recently, we established the autoimmune regulator-knockout (Aire KO mouse as a model of autoimmune KCS and identified an essential role for autoreactive CD4+ T cells in SQM pathogenesis. In subsequent studies, we noted the down-regulation of paired box gene 6 (Pax6 in both human patients with chronic KCS associated with Sjögren's syndrome and Aire KO mice. Pax6 encodes a pleiotropic transcription factor guiding eye morphogenesis during development. While the postnatal function of Pax6 is largely unknown, we hypothesized that its role in maintaining ocular surface homeostasis was disrupted in the inflamed eye and that loss of Pax6 played a functional role in the initiation and progression of SQM. Adoptive transfer of autoreactive T cells from Aire KO mice to immunodeficient recipients confirmed CD4+ T cells as the principal downstream effectors promoting Pax6 downregulation in Aire KO mice. CD4+ T cells required local signaling via Interleukin-1 receptor (IL-1R1 to provoke Pax6 loss, which prompted a switch from corneal-specific cytokeratin, CK12, to epidermal-specific CK10. The functional role of Pax6 loss in SQM pathogenesis was indicated by the reversal of SQM and restoration of ocular surface homeostasis following forced expression of Pax6 in corneal epithelial cells using adenovirus. Thus, tissue-restricted restoration of Pax6 prevented aberrant epidermal-lineage commitment suggesting adjuvant Pax6 gene therapy may represent a novel therapeutic approach to prevent SQM in patients with chronic inflammatory diseases of the ocular surface.

Transcriptome profiling reveals novel expression markers that predispose patients to develop post- photorefractive keratectomy corneal haze

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Nimisha Nimisha

2017-10-01

Full Text Available Photorefractive keratectomy is an excimer laser [1] based ablation surgery of corneal surface used for correcting refractive errors. Corneal haze is the result of an aggressive wound healing response with an incidence rate [2] of 1.44% post PRK, making it an important health burden. Studies thus far have only focused on molecular alterations post haze development. Since the corneal epithelium is an important mediator of the stromal haze response, we studies its role in predisposing subjects to develop aberrant wound healing response. Corneal epithelium samples collected intra-operatively from clinically healthy patients during PRK. This epithelium from 6 eyes that developed haze postoperatively and 10 eyes of age matched controls without haze were compared. Gene expression microarrays were performed for the mRNA samples followed by ontological analysis of underlying molecular pathways. The identified targets were validated in an independent set of post haze epithelial samples from 3 subjects with PRK induced haze. In vitro studies were done on HCE cells for differential dose of TGFβ for inflammatory markers, corneal structure & fibrosis associated genes and regulators of signal transduction. In addition, loss and gain of function studies was performed using PREX1 as a novel, prototype target. Mean age of groups was 25-28 years. A total of 1100 up and 1700 down regulated genes were revealed by microarray. Alterations in Oxidative stress, ECM-Receptor interactions, Wnt signaling pathway and CXC motif containing chemokines contributes to cellular proliferation and wound healing, which is observed in in vitro model. In cornea novel target PREX1, an oxidative stress gene, when over expressed exhibits faster wound closure in HCE cells with and without TGFβ. Loss of function using PREX1 shRNA shows reduced wound closure. Our study shows that novel genes are involved in pathogenesis of post PRK haze. PREX1 over expression results in faster wound

Higher order optical aberrations and visual acuity in a randomized controlled trial comparing transepithelial versus epithelium-off corneal crosslinking for progressive keratoconus

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Godefrooij DA

2017-10-01

Full Text Available Daniel A Godefrooij, Mustapha El Kandoussi, Nienke Soeters, Robert PL Wisse Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands Purpose: The purpose of this study was to compare the effects of transepithelial crosslinking (trans-CXL versus epithelium-off crosslinking (epi-off CXL for progressive keratoconus with respect to the development of higher order aberrations (HOAs and their effects on visual acuity.Materials and methods: A total of 61 patients were randomized and examined preoperatively and 1, 3, 6, and 12 months postoperatively in an academic referral center. Total corneal HOAs were compared between the two treatment groups using mixed linear modeling. Types of HOAs (coma, trefoil, and spherical aberration that differed between groups were entered in a multivariable analysis to test their effect on uncorrected distance visual acuity (UDVA and corrected distance visual acuity (CDVA.Results: The epi-off CXL group had more flattening in maximal keratometry compared to the trans-CXL group (P=0.02. UDVA did not differ significantly between the groups (P=0.59; however, CDVA was significantly more improved in the trans-CXL group (P=0.02. Horizontal trefoil improved more in the epi-off group compared to the trans-CXL group (P=0.04, whereas the other HOAs were virtually unchanged in both groups. Differences in changes in HOAs between the two groups had no effect on either UCVA (P=0.76 or CDVA (P=0.96.Conclusion: Although HOAs are clinically relevant determinants of vision quality in keratoconus patients, the change in total HOAs post treatment did not differ between the trans-CXL and epi-off CXL groups. Only horizontal trefoil differed significantly post treatment between the trans-CXL and epi-off CXL groups. However, this difference did not independently affect either UDVA or CDVA. Trans-CXL provides no benefit over epi-off CXL regarding visual relevant HOAs. Keywords

Myogel supports the ex-vivo amplification of corneal epithelial cells.

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Francis, D; Abberton, K; Thompson, E; Daniell, M

2009-03-01

Limbal stem cell deficiency leads to conjunctivalisation of the cornea and subsequent loss of vision. The recent development of transplantation of ex-vivo amplified corneal epithelium, derived from limbal stem cells, has shown promise in treating this challenging condition. The purpose of this research was to compare a variety of cell sheet carriers for their suitability in creating a confluent corneal epithelium from amplified limbal stem cells. Cadaveric donor limbal cells were cultured using an explant technique, free of 3T3 feeder cells, on a variety of cell sheet carriers, including denuded amniotic membrane, Matrigel, Myogel and stromal extract. Comparisons in rate of growth and degree of differentiation were made, using immunocytochemistry (CK3, CK19 and ABCG2). The most rapid growth was observed on Myogel and denuded amniotic membrane, these two cell carriers also provided the most reliable substrata for achieving confluence. The putative limbal stem cell marker, ABCG2, stained positively on cells grown over Myogel and Matrigel but not for those propagated on denuded amniotic membrane. In the clinical setting amniotic membrane has been demonstrated to provide a suitable carrier for limbal stem cells and the resultant epithelium has been shown to be successful in treating limbal stem cell deficiency. Myogel may provide an alternative cell carrier with a further reduction in risk as it is has the potential to be derived from an autologous muscle biopsy in the clinical setting.

Mechanisms of constitutive and ATP-evoked ATP release in neonatal mouse olfactory epithelium

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Hayoz Sébastien

2012-05-01

Full Text Available Abstract Background ATP is an extracellular signaling molecule with many ascribed functions in sensory systems, including the olfactory epithelium. The mechanism(s by which ATP is released in the olfactory epithelium has not been investigated. Quantitative luciferin-luciferase assays were used to monitor ATP release, and confocal imaging of the fluorescent ATP marker quinacrine was used to monitor ATP release via exocytosis in Swiss Webster mouse neonatal olfactory epithelial slices. Results Under control conditions, constitutive release of ATP occurs via exocytosis, hemichannels and ABC transporters and is inhibited by vesicular fusion inhibitor Clostridium difficile toxin A and hemichannel and ABC transporter inhibitor probenecid. Constitutive ATP release is negatively regulated by the ATP breakdown product ADP through activation of P2Y receptors, likely via the cAMP/PKA pathway. In vivo studies indicate that constitutive ATP may play a role in neuronal homeostasis as inhibition of exocytosis inhibited normal proliferation in the OE. ATP-evoked ATP release is also present in mouse neonatal OE, triggered by several ionotropic P2X purinergic receptor agonists (ATP, αβMeATP and Bz-ATP and a G protein-coupled P2Y receptor agonist (UTP. Calcium imaging of P2X2-transfected HEK293 “biosensor” cells confirmed the presence of evoked ATP release. Following purinergic receptor stimulation, ATP is released via calcium-dependent exocytosis, activated P2X1,7 receptors, activated P2X7 receptors that form a complex with pannexin channels, or ABC transporters. The ATP-evoked ATP release is inhibited by the purinergic receptor inhibitor PPADS, Clostridium difficile toxin A and two inhibitors of pannexin channels: probenecid and carbenoxolone. Conclusions The constitutive release of ATP might be involved in normal cell turn-over or modulation of odorant sensitivity in physiological conditions. Given the growth-promoting effects of ATP, ATP-evoked ATP

Microspectroscopy of spectral biomarkers associated with human corneal stem cells

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Nakamura, Takahiro; Kelly, Jemma G.; Trevisan, J?lio; Cooper, Leanne J.; Bentley, Adam J.; Carmichael, Paul L.; Scott, Andrew D.; Cotte, Marine; Susini, Jean; Martin-Hirsch, Pierre L.; Kinoshita, Shigeru; Fullwood, Nigel J.; Martin, Francis L.

2010-01-01

Purpose Synchrotron-based radiation (SRS) Fourier-transform infrared (FTIR) microspectroscopy potentially provides novel biomarkers of the cell differentiation process. Because such imaging gives a ?biochemical-cell fingerprint? through a cell-sized aperture, we set out to determine whether distinguishing chemical entities associated with putative stem cells (SCs), transit-amplifying (TA) cells, or terminally-differentiated (TD) cells could be identified in human corneal epithelium. Methods D...

Primary Outcomes of Accelerated Epithelium-Off Corneal Cross-Linking in Progressive Keratoconus in Children: A 1-Year Prospective Study

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Sherif A. Eissa

2017-01-01

Full Text Available Purpose. To evaluate corneal transparency following accelerated collagen cross-linking (ACXL in pediatric keratoconus. Design. A prospective interventional case series. Methods. This study included 47 eyes (25 patients, aged 9–14 years, with documented progressive keratoconus. After applying 0.1% riboflavin drops, ACXL was performed. Assessment included corrected distance visual acuity (CDVA, uncorrected visual acuity (UCVA, corneal haze, and corneal densitometry in grayscale units (GSU. Result. The mean baseline and corneal densitometry peaked at 3 months post-ACXL while central and posterior densitometry showed a statistically significant increase (P<0.05 and peaked at 8 months postoperatively. By 12 months, densitometry in all corneal layers (P≥0.99 and concentric zones (P≥0.97 reached near baseline values. Slit-lamp graded haze peaked at 1 month to 1.82 ± 0.65 (P<0.05 and declined to near baseline at 12 months (0.39 ± 0.58. There was a statistically significant increase in the mean UCVA and CDVA at 12 months. Conclusion. Total and anterior corneal densitometry peaked after 3 months, while central and posterior densitometry peaked after 8 months. Maximum haze was at 1 month post-ACXL. All corneal layers, concentric zone densitometry and haze reached near baseline values after 1 year. Scheimpflug densitometry showed weak correlation with CDVA over the 12-month follow-up period (r=−0.193.

Corneal thickness changes during corneal collagen cross-linking with UV-A irradiation and hypo-osmolar riboflavin in thin corneas

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Belquiz Amaral Nassaralla

2013-06-01

Full Text Available PURPOSE: To evaluate the thinnest corneal thickness changes during and after corneal collagen cross-linking treatment with ultraviolet-A irradiation, using hypo-osmolar riboflavin solution in thin corneas. METHODS: Eighteen eyes of 18 patients were included in this study. After epithelium removal, iso-osmolar 0.1% riboflavin solution was instilled to the cornea every 3 minutes for 30 minutes. Hypo-osmolar 0.1% riboflavin solution was then applied every 20 seconds for 5 minutes or until the thinnest corneal thickness reached 400 µm. Ultraviolet-A irradiation was performed for 30 minutes. During irradiation, iso-osmolar 0.1% riboflavin drops were applied every 5 minutes. Ultrasound pachymetry was performed at approximately the thinnest point of the cornea preoperatively, after epithelial removal, after iso-osmolar riboflavin instillation, after hypo-osmolar riboflavin instillation, after ultraviolet-A irradiation, and at 1, 6 and 12 months after treatment. RESULTS: Mean preoperative thinnest corneal thickness was 380 ± 11 µm. After epithelial removal it decreased to 341 ± 11 µm, and after 30 minutes of iso-osmolar 0.1% riboflavin drops, to 330 ± 7.6 µm. After hypo-osmolar 0.1% riboflavin drops, mean thinnest corneal thickness increased to 418 ± 11 µm. After UVA irradiation, it was 384 ± 10 µm. At 1, 6 and 12 months after treatment, it was 372 ± 10 µm, 381 ± 12.7, and 379 ± 15 µm, respectively. No intraoperative, early postoperative, or late postoperative complications were noted. CONCLUSIONS: Hypo-osmolar 0.1% riboflavin solution seems to be effective for swelling thin corneas. The swelling effect is transient and short acting. Corneal thickness should be monitored throughout the procedure. Larger sample sizes and longer follow-up are required in order to make meaningful conclusions regarding safety.

Enhanced detection method for corneal protein identification using shotgun proteomics

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Schlager John J

2009-06-01

Full Text Available Abstract Background The cornea is a specialized transparent connective tissue responsible for the majority of light refraction and image focus for the retina. There are three main layers of the cornea: the epithelium that is exposed and acts as a protective barrier for the eye, the center stroma consisting of parallel collagen fibrils that refract light, and the endothelium that is responsible for hydration of the cornea from the aqueous humor. Normal cornea is an immunologically privileged tissue devoid of blood vessels, but injury can produce a loss of these conditions causing invasion of other processes that degrade the homeostatic properties resulting in a decrease in the amount of light refracted onto the retina. Determining a measure and drift of phenotypic cornea state from normal to an injured or diseased state requires knowledge of the existing protein signature within the tissue. In the study of corneal proteins, proteomics procedures have typically involved the pulverization of the entire cornea prior to analysis. Separation of the epithelium and endothelium from the core stroma and performing separate shotgun proteomics using liquid chromatography/mass spectrometry results in identification of many more proteins than previously employed methods using complete pulverized cornea. Results Rabbit corneas were purchased, the epithelium and endothelium regions were removed, proteins processed and separately analyzed using liquid chromatography/mass spectrometry. Proteins identified from separate layers were compared against results from complete corneal samples. Protein digests were separated using a six hour liquid chromatographic gradient and ion-trap mass spectrometry used for detection of eluted peptide fractions. The SEQUEST database search results were filtered to allow only proteins with match probabilities of equal or better than 10-3 and peptides with a probability of 10-2 or less with at least two unique peptides isolated within

Neural crest contribution to lingual mesenchyme, epithelium and developing taste papillae and taste buds.

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Liu, Hong-Xiang; Komatsu, Yoshihiro; Mishina, Yuji; Mistretta, Charlotte M

2012-08-15

The epithelium of mammalian tongue hosts most of the taste buds that transduce gustatory stimuli into neural signals. In the field of taste biology, taste bud cells have been described as arising from "local epithelium", in distinction from many other receptor organs that are derived from neurogenic ectoderm including neural crest (NC). In fact, contribution of NC to both epithelium and mesenchyme in the developing tongue is not fully understood. In the present study we used two independent, well-characterized mouse lines, Wnt1-Cre and P0-Cre that express Cre recombinase in a NC-specific manner, in combination with two Cre reporter mouse lines, R26R and ZEG, and demonstrate a contribution of NC-derived cells to both tongue mesenchyme and epithelium including taste papillae and taste buds. In tongue mesenchyme, distribution of NC-derived cells is in close association with taste papillae. In tongue epithelium, labeled cells are observed in an initial scattered distribution and progress to a clustered pattern between papillae, and within papillae and early taste buds. This provides evidence for a contribution of NC to lingual epithelium. Together with previous reports for the origin of taste bud cells from local epithelium in postnatal mouse, we propose that NC cells migrate into and reside in the epithelium of the tongue primordium at an early embryonic stage, acquire epithelial cell phenotypes, and undergo cell proliferation and differentiation that is involved in the development of taste papillae and taste buds. Our findings lead to a new concept about derivation of taste bud cells that include a NC origin. Copyright © 2012 Elsevier Inc. All rights reserved.

Preserved and unpreserved 12 anti-allergic ophthalmic solutions and ocular surface toxicity: in vitro assessment in four cultured corneal and conjunctival epithelial cell lines.

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Ayaki, Masahiko; Iwasawa, Atsuo; Yaguchi, Shigeo; Koide, Ryohei

2010-12-01

In the present study, we evaluated the cytotoxicity of anti-allergic ophthalmic solutions in cultured corneal and conjunctival cells, namely SIRC (rabbit corneal epithelium), BCE C/D-1b (bovine corneal epithelial cells), RC-1 (rabbit corneal epithelium), and Chang (human conjunctival cells). The viability of cell cultures was determined following the exposure of cells to 12 commercially available anti-allergic ophthalmic solutions for varying exposure times and at various dilutions using the MTT and neutral red assays. The cell viability score (CVS) was used to compare the toxicity of different drugs. Based on CVS data, the order of cell viability after exposure to the drugs was Zepelin ≥ Tramelas PF ≥ Cumorol PF ≥ Ketotifen PF ≥ Eyevinal = Fumarton ≥ Cumorol > Intal ≥ Rizaben ≥ Tramelas ≥ Patanol Livostin. In conclusion, cell viability was mostly affected by the concentration of benzalkonium chloride rather than the active component and/or the anti-allergic action of the drug. The CVS was useful in comparing the toxicity of different drugs.

Down-regulation of Pax6 is associated with abnormal differentiation of corneal epithelial cells in severe ocular surface diseases

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Li, W; Chen, Y-T; Hayashida, Y; Blanco, G; Kheirkah, A; He, H; Chen, S-Y; Liu, C-Y; Tseng, SCG

2010-01-01

Pax6 is the universal master control gene for eye morphogenesis. Other than retina and lens, Pax6 also expressed in the ocular surface epithelium from early gestation until the postnatal stage, in which little is known about the function of Pax6. In this study, corneal pannus tissues from patients with ocular surface diseases such as Stevens–Johnson syndrome (SJS), chemical burn, aniridia and recurrent pterygium were investigated. Our results showed that normal ocular surface epithelial cells expressed Pax6. However, corneal pannus epithelial cells from the above patients showed a decline or absence of Pax6 expression, accompanied by a decline or absence of K12 keratin but an increase of K10 keratin and filaggrin expression. Pannus basal epithelial cells maintained nuclear p63 expression and showed activated proliferation, evidenced by positive Ki67 and K16 keratin staining. On 3T3 fibroblast feeder layers, Pax6 immunostaining was negative in clones generated from epithelial cells harvested from corneal pannus from SJS or aniridia, but positive in those from the normal limbal epithelium; whereas western blots showed that some epithelial clones expanded from pannus retained Pax6 expression. Transient transfection of an adenoviral vector carrying EGFP–Pax6 transgenes into these Pax6− clones increased both Pax6 and K12 keratin expression. These results indicate that Pax6 helps to maintain the normal corneal epithelial phenotype postnatally, and that down-regulation of Pax6 is associated with abnormal epidermal differentiation in severe ocular surface diseases. Reintroduction of activation of the Pax6 gene might be useful in treating squamous metaplasia of the ocular surface epithelium. PMID:18027901

Comparative Ultrastructural Studies on the Impact of Moderate and Hyperthermic Environment on the Corneal Structure of two Species of Wild Rodents

International Nuclear Information System (INIS)

Naguib, N.I.; El-Dawi, E.F.

2011-01-01

This study was carried out to investigate the impact of environmental climate (temperature) on the corneal structure of two wild rodents; the nocturnal Norway rats (Rattus norvegicus) and the diurnal golden spiny mouse (Acomys russatus). Both rodents were collected from two extreme climatic environment and their dissected corneas were prepared for light, scanning and transmission electron microscopy. The corneas of both rodents are composed of three main layers; an outer epithelium, stroma, Descemet's membrane, and an inner endothelium. The mean thickness of the epithelium, stroma, Descemet's membrane and inner endothelium of both rodents were measured. The scanning electron microscopy revealed that in R. norvegicus and A. russatus; the outermost cells of the corneal epithelium, are mostly polygonal in shape with nearly regular borders and show dense pattern of microplicae with different scatter electron that exhibits three polymorphic appearances (A, B, C) and two (A, B), respectively. Numerous A-light cells with dense microplicae, many B-dark cells with a moderate density of microplicae and few C-dark cells with a less density of microplicae were observed. Using transmission electron microscope, the epithelial cells of both species possess glycocalyx and the cytokeratin filaments are more extensive in the apical epithelial cells in A. russatus. The stroma in R. norvegicus is formed of outer and inner lamellar zones with spaces in between its wavy bundles. In A. russatus, the stroma is formed of one lamellar zone of flattened bundles of highly wavy and branched collagen fibrils. On the other hand, the surface of the endothelial cells in R. norvegicus is slightly bulging with many blebs whereas it showed flattened and nearly smooth surface in A. russatus. In conclusion, the differences in the number of the superficial epithelial cells and the thickness of the stroma and structure of the endothelium of R. norvegicus (nocturnal) and A. russatus (diurnal) are most

Laser-induced corneal cross-linking upon photorefractive ablation with riboflavin

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Kornilovskiy IM

2016-04-01

Full Text Available Igor M Kornilovskiy,1 Elmar M Kasimov,2 Ayten I Sultanova,2 Alexander A Burtsev1 1Department of Eye Diseases, Federal State Budgetary Institution “National Pirogov Medical Surgical Centre”, Ministry of Health, Moscow, Russia; 2Department of Eye Diseases, Zarifa Aliyeva National Ophthalmology Center, Ministry of Health, Baku, Azerbaijan Aim: To estimate the biomechanical effect of the laser-induced cross-linking resulting from photorefractive ablation of the cornea with riboflavin.Methods: Excimer laser ablation studies were performed ex vivo (32 eyes of 16 rabbits by phototherapeutic keratectomy (PTK and in vivo (24 eyes of 12 rabbits by transepithelial photorefractive keratectomy (TransPRK, with and without riboflavin saturation of the stroma. Then, we performed corneal optical coherence tomography on 36 eyes of 18 patients with varying degrees of myopia at different times after the TransPRK was performed with riboflavin saturation of the stroma.Results: Biomechanical testing of corneal samples saturated with riboflavin revealed cross-linking effect accompanied by the increase in tensile strength and maximum strength. PTK showed increase in tensile strength from 5.1±1.4 to 7.2±1.6 MPa (P=0.001, while TransPRK showed increase in tensile strength from 8.8±0.9 to 12.8±1.3 MPa (P=0.0004. Maximum strength increased from 8.7±2.5 to 12.0±2.8 N (P=0.005 in PTK and from 12.8±1.6 to 18.3±1.2 N (P=0.0004 in TransPRK. Clinical optical coherence tomography studies of the biomicroscopic transparent cornea at different times after TransPRK showed increased density in the surface layers of the stroma and membrane-like structure beneath the epithelium.Conclusion: Photorefractive ablation of the preliminary corneal stroma saturation with riboflavin causes the effect of laser-induced cross-linking, which is attended with an increase in corneal tensile strength, maximum strength, increased density in the surface layers of the stroma, and formation of

Toxic corneal epitheliopathy after intravitreal methotrexate and its treatment with oral folic acid.

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Gorovoy, Ian; Prechanond, Tidarat; Abia, Maravillas; Afshar, Armin R; Stewart, Jay M

2013-08-01

To determine whether oral folic acid can ameliorate an iatrogenic, visually significant corneal epitheliopathy, which commonly occurs with intravitreal injections of methotrexate for the treatment of intraocular lymphoma. We report 2 cases of visually significant corneal epitheliopathy occurring after intravitreal injections of methotrexate for intraocular lymphoma. The first patient did not receive any treatment for the corneal disease, and the second patient with bilateral intraocular lymphoma received 1 mg of oral folic acid daily, a commonly used dosage for patients on systemic methotrexate. In the first patient without treatment, there was a complete regression of the corneal epithelial disease only when the frequency of intravitreal methotrexate was reduced from weekly to monthly as per a commonly used dosage regimen for methotrexate. In the second patient, the corneal disease improved 80% within 1 week of initiating oral folic acid for her eye already experiencing severe epitheliopathy during her weekly dosing regimen of methotrexate and also had significantly decreased epithelial disease in her second eye that started weekly intravitreal methotrexate several weeks after beginning oral folic acid. Currently, oral folic acid supplements are recommended for patients using systemic methotrexate to minimize drug toxicity. We suggest a similar use in patients undergoing intravitreal methotrexate injections to decrease toxic effects on the corneal epithelium.

Epidermal Growth Factor Receptor Transactivation by the Cannabinoid Receptor (CB1) and Transient Receptor Potential Vanilloid 1 (TRPV1) Induces Differential Responses in Corneal Epithelial Cells

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2010-01-01

inflammatory cytokine release in corneal epithelium through MAPK signaling. J. Cell Physiol. 213, 730e739. Zhang, J., Li , H., Wang, J., Dong, Z., Mian ...Kang, S.S., Li , T., Xu, D., Reinach, P.S., Lu, L., 2000. Inhibitory effect of PGE2 on EGF- induced MAP kinase activity and rabbit corneal epithelial

The application of excimer lasers for corneal sculpturing

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King, M.C.

1990-01-01

Of the broad selection of lasers available for surgery, the argon fluoride excimer laser offers a set of attributes that make it uniquely suited for the removal of corneal tissue. With ultraviolet radiation at 193mm, the energy of an individual photon (6.3 electron volts) is sufficient to break bonds in protein molecules without generating molecular vibration (heat). A single laser pulse is capable of removing 0.25 microns of corneal tissue over a well defined area 80 mm 2 in extent. This excision with a lateral precision to a fraction of a micron causes no discernible damage to neighboring cells. The smooth surface left after the tissue is removed promotes a quick and predictable regrowth of the epithelium. The penetration of radiation into the underlying tissue is the order of a micron so there is no potential harm to the lens or retinal tissue. Insignificant mutagenesis or unscheduled DNA synthesis has been detected as a result of tissue irradiation at this wavelength. In the past few years major progress has been made towards developing ophthalmic procedures which utilize the unique properties of this laser. To date there are FDA IDE's (Investigational Device Exemptions) for the following procedures: Photorefractive Keratectomy (PRK) or corneal reshaping for correcting near-sightedness, far-sightedness and astigmatism without the need for eye glasses, contact lenses or conventional refractive surgery (Radial Keratotomy); Partial Excimer Trabeculectomy for relieving the pressure build-up caused by glaucoma; T-Excisons for reducing astigmatism; Myopic Keratomileusis (MKM) for the refractive correction of severe myopia; superficial Keratectomy (corneal smoothing) for treating various corneal scars, dystrophies, recurrent corneal erosion etc. In this paper the fundamentals of beam tissue interaction at 193nm will be discussed

Differential proteiomic analysis of mouse intestinal epithelium irradiated by γ-ray

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Zhang Bo; Su Yongping; Liu Xiaohong; Ai Guoping; Ran Xinze; Wei Yongjiang; Wang Junping; Cheng Tianmin

2003-01-01

Objective: For elucidating the molecular mechanism of reconstruction of intestinal epithelium damaged by ionizing radiation, the proteomes of murine intestinal epithelium from normal and irradiated mice were compared by 2-D electrophoresis. Methods: Histopathologic sections of whole small intestine made from BALB/c mice 3 h and 72 h after total-body irradiation were stained with hematoxylin-eosin. Intestinal epithelial cells were isolated from normal and irradiated mice. The total protein samples prepared by one-step method were used in 2-D electrophoresis, the protein maps were compared and the differential spots were detected with PDQuest analysis software. Twenty-eight different spots were cut off from the gels, digested in gel with trypsin, measured with MALDI-TOF-MS and searched in database. Results: Small intestinal epithelium was damaged as early as 3 h after irradiation, and reconstructed 72 h later. After Coomassie-staining, the 2-DE image analysis by PDQuest software detected 638 ± 39 protein spots in normal mice group, 566 ± 32 spots in 3 hours post irradiation group, and 591 ± 29 spots in 3 days post irradiation group. The 2-DE images showed that proteomes of intestinal epithelium were altered with γ-irradiation. The proteins identified by peptide mass fingerprinting involved in cellular events, including signal transduction, metabolism and oxidative stress responses. Conclusions: Gamma-irradiation can induce the protein expression of intestinal epithelium. The technique of 2-D electrophoresis is a useful tool in the study of molecular mechanism of radiation damage

Corneal Collagen Cross-Linking with Hypoosmolar Riboflavin Solution in Keratoconic Corneas

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Shaofeng Gu

2014-01-01

Full Text Available Purpose. To report the 12-month outcomes of corneal collagen cross-linking (CXL with a hypoosmolar riboflavin and ultraviolet-A (UVA irradiation in thin corneas. Methods. Eight eyes underwent CXL using a hypoosmolar riboflavin solution after epithelial removal. The corrected distance visual acuity (CDVA, manifest refraction, the mean thinnest corneal thickness (MTCT, and the endothelial cell density (ECD were evaluated before and 6 and 12 months after CXL. Results. The MTCT was 413.9 ± 12.4 μm before treatment and reduced to 381.1 ± 7.3 μm after the removal of the epithelium. After CXL, the thickness decreased to 410.3 ± 14.5 μm at the last follow-up. Before treatment, the mean K-value of the apex of the keratoconus corneas was 58.7 ± 3.5 diopters and slightly decreased (57.7 ± 4.9 diopters at 12 months. The mean CDVA was 0.54 ± 0.23 logarithm of the minimal angle of resolution before treatment and increased to 0.51 ± 0.21 logarithm at the last follow-up. The ECD was 2731.4 ± 191.8 cells/mm2 before treatment and was 2733.4 ± 222.6 cells/mm2 at 12 months after treatment. Conclusions. CXL with a hypoosmolar riboflavin in thin corneas seems to be a promising method for keratoconic eyes with the mean thinnest corneal thickness less than 400 μm without epithelium.

Corneal photoablation in vivo with the erbium:YAG laser: first report

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Jean, Benedikt J.; Bende, Thomas; Matallana, Michael; Kriegerowski, Martin

1995-05-01

As an alternative to far-UV lasers for corneal refractive surgery, the Erbium:YAG laser may be used in TEM00 mode. The resulting gaussian beam profile leads to a certain amount of myopic correction per laser pulse. Although animal data suggest that the clinical outcome should be comparable to the UV-lasers, no human data were available until now. We performed Erbium:YAG laser areal ablation in 5 blind human eyes. In TEM00 mode, the laser parameters were: effective diameter of laser spot equals 3.4 mm, fluence equals 380 mJ/cm2, pulse duration equals 250 microsecond(s) , Repetition rate equals 4 Hz, Number of applied laser pulses equals 15. Four patients with no light perception, one with intact light projection on one eye (some of them scheduled for enucleation) were treated under topical anaesthesia. Patient selection and informed consent were agreed to by the University's independent Ethics Committee. Prior to laser irradiation, corneal epithelium was removed. A postoperative silicone cast of the cornea was analyzed with a confocal laser micro-topometer for the ablation profile. The eyes were treated with antibiotic ointment until the epithelium was closed. Clinical appearance and, where possible, profilometry of the ablated area was observed. The ablation profile in cornea was gaussian shaped with a maximal depth of 30 micrometers . During laser treatment, the corneal surface becomes opaque, clearing in a matter of seconds. Epithelial healing and clinical appearance was similar to excimer laser treatment. However, during the first week, the irradiated area shows subepithelial irregularities, resembling small bubbles, disappearing thereafter.

Hyperopic correction: clinical validation with epithelium-on and epithelium-off protocols, using variable fluence and topographically customized collagen corneal crosslinking

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Kanellopoulos AJ

2014-12-01

Full Text Available Anastasios John Kanellopoulos,1,2 George Asimellis1 1LaserViison.gr Clinical and Research Eye Institute, Athens, Greece; 2Department of Ophthalmology, New York University Medical School, New York, NY, USAPurpose: To report novel application of topographically-customized collagen crosslinking aiming to achieve hyperopic refractive changes. Two approaches were evaluated, one based on epithelium-off and one based on epithelium-on (transepithelial. Methods: A peripheral annular-shaped topographically customizable design was employed for high-fluence ultraviolet (UV-A irradiation aiming to achieve hyperopic refractive changes. A total of ten eyes were involved in this study. In group-A (five eyes, a customizable ring pattern was employed to debride the epithelium by excimer laser ablation, while in group-B (also five eyes, the epithelium remained intact. In both groups, specially formulated riboflavin solutions were applied. Visual acuity, cornea clarity, keratometry, topography, and pachymetry with a multitude of modalities, as well as endothelial cell counts were evaluated. Results: One year postoperatively, the following changes have been noted: in group-A, average uncorrected distance visual acuity changed from 20/63 to 20/40. A mean hyperopic refractive increase of +0.75 D was achieved. There was some mild reduction in the epithelial thickness. In group-B, average uncorrected distance visual acuity changed from 20/70 to 20/50. A mean hyperopic refractive increase of +0.85 D was achieved. Epithelial thickness returned to slightly reduced levels (compared to baseline in group-A, whereas to slightly increased levels in group-B. Conclusion: We introduce herein the novel application of a topographically-customizable collagen crosslinking to achieve a hyperopic refractive effect. This novel technique may be applied either with epithelial removal, offering a more stable result or with a non-ablative and non-incisional approach, offering a minimally

Methods Development for the Isolation and Culture of Primary Corneal Endothelial Cells

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2017-02-01

a cell population particularly suitable for low serum propagation, provided that appropriate growth factors are available. A low serum medium...of MGK. 15. SUBJECT TERMS Cornea, chemical warfare agent, corneal endothelial cell, endothelium, growth , isolation, mouse, rabbit, porcine, in...with corneal SM exposure.2 A primary requirement in achieving this goal is to develop methods that enable the isolation of a pure CEC population and

Bilateral congenital corneal keloids and anterior segment mesenchymal dysgenesis in a case of Rubinstein-Taybi syndrome.

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Rao, Srinivas K; Fan, Dorothy S P; Pang, C P; Li, Winnie W Y; Ng, Joan S K; Good, William V; Lam, Dennis S C

2002-01-01

To report the unusual association of bilateral corneal keloids and anterior segment mesenchymal dysgenesis in a child with Rubinstein-Taybi syndrome. Case report of a 2-year-old boy. Excision of the epicorneal mass in the right eye was followed by recurrence of the lesion. Multiple penetrating keratoplasties were unsuccessful in reconstructing the anterior segment because of recurrent corneal epithelial breakdown, suggesting limbal stem cell insufficiency. Histopathology and electron microscopy of the excised mass lesion showed features typical of a corneal keloid: thickened keratinized epithelium, absent Bowman's layer, and fibrovascular hyperplasia, with haphazard orientation of the collagen lamellae. Ultrasound biomicroscopy and intraoperative findings suggested a diagnosis of Peter anomaly, but genetic analysis did not show a PAX6 mutation. The findings in our patient add to the spectrum of ocular changes described in Rubinstein-Taybi syndrome and confirm earlier reports of poor ocular prognosis in corneal keloids and Rubinstein-Taybi syndrome.

Association of a Chromosomal Rearrangement Event with Mouse Posterior Polymorphous Corneal Dystrophy and Alterations in Csrp2bp, Dzank1, and Ovol2 Gene Expression.

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Anna L Shen

Full Text Available We have previously described a mouse model of human posterior polymorphous corneal dystrophy (PPCD and localized the causative mutation to a 6.2 Mbp region of chromosome 2, termed Ppcd1. We now show that the gene rearrangement linked to mouse Ppcd1 is a 3.9 Mbp chromosomal inversion flanked by 81 Kbp and 542 bp deletions. This recombination event leads to deletion of Csrp2bp Exons 8 through 11, Dzank1 Exons 20 and 21, and the pseudogene Znf133. In addition, we identified translocation of novel downstream sequences to positions adjacent to Csrp2bp Exon 7 and Dzank1 Exon 20. Twelve novel fusion transcripts involving Csrp2bp or Dzank1 linked to downstream sequences have been identified. Eight are expressed at detectable levels in PPCD1 but not wildtype eyes. Upregulation of two Csrp2bp fusion transcripts, as well as upregulation of the adjacent gene, Ovol2, was observed. Absence of the PPCD1 phenotype in animals haploinsufficient for Csrp2bp or both Csrp2bp and Dzank1 rules out haploinsufficiency of these genes as a cause of mouse PPCD1. Complementation experiments confirm that PPCD1 embryonic lethality is due to disruption of Csrp2bp expression. The ocular expression pattern of Csrp2bp is consistent with a role for this protein in corneal development and pathogenesis of PPCD1.

Induction of Functional 3D Ciliary Epithelium-Like Structure From Mouse Induced Pluripotent Stem Cells.

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Kinoshita, Hirofumi; Suzuma, Kiyoshi; Kaneko, Jun; Mandai, Michiko; Kitaoka, Takashi; Takahashi, Masayo

2016-01-01

To generate ciliary epithelium (CE) from mouse induced pluripotent stem (iPS) cells. Recently, a protocol for self-organizing optic cup morphogenesis in three-dimensional culture was reported, and it was suggested that ocular tissue derived from neural ectoderm could be differentiated. We demonstrated that a CE-like double-layered structure could be induced in simple culture by using a modified Eiraku differentiation protocol. Differentiation of a CE-like double-layered structure could be promoted by glycogen synthase kinase 3β (GSK-3β) inhibitor. Connexin43 and aquaporin1 were expressed in both thin layers, and induced CE-like cells expressed ciliary marker genes, such as cyclinD2, zic1, tgfb2, aldh1a3, wfdc1, otx1, BMP4, and BMP7. Increases in cytoplasmic and nuclear β-catenin in aggregates of the CE-like double-layered structure were confirmed by Western blot analysis. In addition, tankyrase inhibitor prevented the induction of the CE-like double-layered structure by GSK-3β inhibitor. Dye movement from pigmented cells to nonpigmented cells in the mouse iPS cell-derived CE-like structure was observed in a fluid movement experiment, consistent with the physiological function of CE in vivo. We could differentiate CE from mouse iPS cells in the present study. In the future, we hope that this CE-like complex will become useful as a graft for transplantation therapy in pathologic ocular hypotension due to CE dysfunction, and as a screening tool for the development of drugs for diseases associated with CE function.

Genomic locus modulating corneal thickness in the mouse identifies POU6F2 as a potential risk of developing glaucoma.

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Rebecca King

2018-01-01

Full Text Available Central corneal thickness (CCT is one of the most heritable ocular traits and it is also a phenotypic risk factor for primary open angle glaucoma (POAG. The present study uses the BXD Recombinant Inbred (RI strains to identify novel quantitative trait loci (QTLs modulating CCT in the mouse with the potential of identifying a molecular link between CCT and risk of developing POAG. The BXD RI strain set was used to define mammalian genomic loci modulating CCT, with a total of 818 corneas measured from 61 BXD RI strains (between 60-100 days of age. The mice were anesthetized and the eyes were positioned in front of the lens of the Phoenix Micron IV Image-Guided OCT system or the Bioptigen OCT system. CCT data for each strain was averaged and used to QTLs modulating this phenotype using the bioinformatics tools on GeneNetwork (www.genenetwork.org. The candidate genes and genomic loci identified in the mouse were then directly compared with the summary data from a human POAG genome wide association study (NEIGHBORHOOD to determine if any genomic elements modulating mouse CCT are also risk factors for POAG.This analysis revealed one significant QTL on Chr 13 and a suggestive QTL on Chr 7. The significant locus on Chr 13 (13 to 19 Mb was examined further to define candidate genes modulating this eye phenotype. For the Chr 13 QTL in the mouse, only one gene in the region (Pou6f2 contained nonsynonymous SNPs. Of these five nonsynonymous SNPs in Pou6f2, two resulted in changes in the amino acid proline which could result in altered secondary structure affecting protein function. The 7 Mb region under the mouse Chr 13 peak distributes over 2 chromosomes in the human: Chr 1 and Chr 7. These genomic loci were examined in the NEIGHBORHOOD database to determine if they are potential risk factors for human glaucoma identified using meta-data from human GWAS. The top 50 hits all resided within one gene (POU6F2, with the highest significance level of p = 10-6 for

Corneal regeneration by induced human buccal mucosa cultivated on an amniotic membrane following alkaline injury.

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Man, Rohaina Che; Yong, Then Kong; Hwei, Ng Min; Halim, Wan Haslina Wan Abdul; Zahidin, Aida Zairani Mohd; Ramli, Roszalina; Saim, Aminuddin Bin; Idrus, Ruszymah Binti Hj

2017-01-01

Various clinical disorders and injuries, such as chemical, thermal, or mechanical injuries, may lead to corneal loss that results in blindness. PURPOSE : The aims of this study were to differentiate human buccal mucosa (BMuc) into corneal epithelial-like cells, to fabricate engineered corneal tissue using buccal mucosal epithelial cells, and to reconstruct a damaged corneal epithelium in a nude rat model. BMuc were subjected to 10 d of induction factors to investigate the potential of cells to differentiate into corneal lineages. Corneal stem cell markers β1-integrin, C/EBPδ, ABCG2, p63, and CK3 were upregulated in the gene expression analysis in induced BMuc, whereas CK3 and p63 showed significant protein expression in induced BMuc compared to the uninduced cells. BMuc were then left to reach 80% confluency after differential trypsinization. The cells were harvested and cultivated on a commercially available untreated air-dried amniotic membrane (AM) in a Transwell system in induction medium. The corneal constructs were fabricated and then implanted into damaged rat corneas for up to 8 weeks. A significant improvement was detected in the treatment group at 8 weeks post-implantation, as revealed by slit lamp biomicroscopy analysis. The structure and thickness of the corneal layer were also analyzed using histological staining and time-domain optical coherence tomography scans and were found to resemble a native corneal layer. The protein expression for CK3 and p63 were continuously detected throughout the corneal epithelial layer in the corneal construct. In conclusion, human BMuc can be induced to express a corneal epithelial-like phenotype. The addition of BMuc improves corneal clarity, prevents vascularization, increases corneal thickness and stromal alignment, and appears to have no adverse effect on the host after implantation.

Comparative analysis of human conjunctival and corneal epithelial gene expression with oligonucleotide microarrays.

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Turner, Helen C; Budak, Murat T; Akinci, M A Murat; Wolosin, J Mario

2007-05-01

To determine global mRNA expression levels in corneal and conjunctival epithelia and identify transcripts that exhibit preferential tissue expression. cDNA samples derived from human conjunctival and corneal epithelia were hybridized in three independent experiments to a commercial oligonucleotide array representing more than 22,000 transcripts. The resultant signal intensities and microarray software transcript present/absent calls were used in conjunction with the local pooled error (LPE) statistical method to identify transcripts that are preferentially or exclusively expressed in one of the two tissues at significant levels (expression >1% of the beta-actin level). EASE (Expression Analysis Systematic Explorer software) was used to identify biological systems comparatively overrepresented in either epithelium. Immuno-, and cytohistochemistry was performed to validate or expand on selected results of interest. The analysis identified 332 preferential and 93 exclusive significant corneal epithelial transcripts. The corresponding numbers of conjunctival epithelium transcripts were 592 and 211, respectively. The overrepresented biological processes in the cornea were related to cell adhesion and oxiredox equilibria and cytoprotection activities. In the conjunctiva, the biological processes that were most prominent were related to innate immunity and melanogenesis. Immunohistochemistry for antigen-presenting cells and melanocytes was consistent with these gene signatures. The transcript comparison identified a substantial number of genes that have either not been identified previously or are not known to be highly expressed in these two epithelia, including testican-1, ECM1, formin, CRTAC1, and NQO1 in the cornea and, in the conjunctiva, sPLA(2)-IIA, lipocalin 2, IGFBP3, multiple MCH class II proteins, and the Na-Pi cotransporter type IIb. Comparative gene expression profiling leads to the identification of many biological processes and previously unknown genes that

Mechanisms of allograft rejection of corneal endothelium

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Tagawa, Y.; Silverstein, A.M.; Prendergast, R.A.

1982-01-01

The local intraocular graft-vs.-host (GVH) reaction, involving the destruction of the corneal endothelial cells of the rabbit host by sensitized donor lymphoid cells, has been used to study the mechanism of corneal allograft rejection. Pretreatment of donor cells with a specific mouse monoclonal hybridoma anti-T cell antibody and complement suppresses the destructive reaction, suggesting that a cellular-immune mechanism is primarily involved. Pretreatment of donor cells with mitomycin-C completely abolishes the local GVH reaction, indicating that the effector lymphocytes must undergo mitosis within the eye before they can engage in target cell destruction. Finally, studies of the local GVH reaction in irradiated leukopenic recipients or in preinflamed rabbit eyes suggest that host leukocytes may contribute nonspecifically to enhance the destructive process. These studies show that the local ocular GVH reaction may provide a useful model for the study of the mechanisms involved in the rejection of corneal allografts

Corneal collagen crosslinking for keratoconus. A review

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M. M. Bikbov

2014-10-01

Full Text Available Photochemical crosslinking is widely applied in ophthalmology. Its biochemical effect is due to the release of singlet oxygen that promotes anaerobic photochemical reaction. Keratoconus is one of the most common corneal ectasia affecting 1 in 250 to 250 000 persons. Currently, the rate of iatrogenic ectasia following eximer laser refractive surgery increases due to biomechanical weakening of the cornea. Morphologically and biochemically, ectasia is characterized by corneal layers thinning, contact between the stroma and epithelium resulting from Bowman’s membrane rupture, chromatin fragmentation in keratocyte nuclei, phagocytosis, abnormal staining and arrangement of collagen fibers, enzyme system disorders, and keratocyte apoptosis. In corneal ectasia, altered enzymatic processes result in the synthesis of abnormal collagen. Collagen packing is determined by the activity of various extracellular matrix enzymes which bind amines and aldehydes of collagen fiber amino acids. In the late stage, morphological changes of Descemet’s membrane (i.e., rupture and detachment develop. Abnormal hexagonal-shaped keratocytes and their apoptosis are the signs of endothelial dystrophy. The lack of analogs in domestic ophthalmology encouraged the scientists of Ufa Eye Research Institute to develop a device for corneal collagen crosslinking. The parameters of ultraviolet (i.e., wavelength, exposure time, power to achieve the desired effect were identified. The specifics of some photosensitizers in the course of the procedure were studied. UFalink, a device for UV irradiation of cornea, and photosensitizer Dextralink were developed and adopted. Due to the high risk of endothelial damage, this treatment is contraindicated in severe keratoconus (CCT less than 400 microns. Major effects of corneal collagen crosslinking are the following: Young’s modulus (modulus of elasticity increase by 328.9 % (on average, temperature tolerance increase by 5�

Subepithelial corneal fibrosis partially due to epithelial-mesenchymal transition of ocular surface epithelium

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Kawashima, Motoko; Higa, Kazunari; Satake, Yoshiyuki; Omoto, Masahiro; Tsubota, Kazuo; Shimmura, Shigeto; Shimazaki, Jun

2010-01-01

Purpose To determine whether epithelial-mesenchymal transition is involved in the development of corneal subepithelial fibrosis (pannus). Methods Frozen samples of pannus tissue removed from human corneas with a diagnosis of total limbal stem cell deficiency were characterized by immunostaining for both epithelial and mesenchymal markers. We selected transformation-related protein 63 (p63) and pancytokeratin as epithelial markers and vimentin and α-smooth muscle actin (α-SMA) as mesenchymal markers. Immunostaining for β-catenin and E-cadherin was performed to determine wingless-Int (Wnt)-pathway activation. RT–PCR analysis was also performed on epithelial tissue obtained from pannus samples after dispase digestion. Results Immunohistochemistry revealed strong nuclear expression of p63 and weak intercellular expression of E-cadherin in epithelial basal cells of pannus tissue. Furthermore, translocation of β-catenin from intercellular junctions to the nucleus and cytoplasm was also observed. Double-positive cells for both p63 and α-SMA were observed in the subepithelial stroma of pannus tissue, which was supported by RT–PCR and cytospin analysis. Conclusions Epithelial-mesenchymal transition may be partially involved in the development of subepithelial corneal fibrosis due to total limbal stem cell deficiency. PMID:21179238

Metabolic activation of carbon tetrachloride by the cervico-vaginal epithelium in rodents

International Nuclear Information System (INIS)

Brittebo, E.B.; Brandt, I.

1989-01-01

The metabolism and binding of 14 C-labelled carbon tetrachloride (CCl 4 ) in the genital tract of female adult or juvenile NMRI-mice and Sprague-Dawly rats (mainly in the pro-oestrous/oestrous stage) and an adult New Zealand rabbit were studied. A marked irreversible binding of radioactivity in the squamous cervico-vaginal epithelium of mice given intravenous injections of 14 C-CCl 4 was revealed by autoradiography of solvent-extracted tissue. The localization of binding in the mouse genital tract incubated with 14 C-CCl 4 under air was similar to that observed in vivo. Bound radioactivity was also present in the cylindrical epithelium of the rabbit vagina incubated with 14 C-CCl 4 in vitro. For a comparison, no preferential binding of radiolabelled diethylstilbestrol or ethinylestradiol was observed in the mouse cervico-vaginal epithelium. The level of irreversible binding to PMSG-primed (pregnant mare's serum gonadotrophin) vaginal epithelial 100 x g supernatants of mice and rats incubated with 14 C-CCl 4 under air was low. Addition of the reducing agent dithionite to the incubations increased the binding in the vaginal epithelium 20-fold. In juvenile mice and rats injected with 14 C-CCl 4 , the levels of metabolites in the epithelium were low, whereas PMSG-primed juvenile rats contained a higher level of metabolites. The results show that the cervico-vaginal epithelium can metabolically activate CCl 4 to reactive metabolites and suggest that the metabolism is under endocrine control. (author)

Unilateral congenital corneal keloid with anterior segment mesenchymal dysgenesis and subluxated lens: case report and review of literature.

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Vanathi, M; Sen, Seema; Panda, Anita; Dada, Tanuj; Behera, Geeta; Khokhar, Sudharshan

2007-01-01

To report the unusual association of unilateral congenital corneal keloid with anterior-segment mesenchymal dysgenesis and bilateral subluxated lens. A 20-year old man presented with a mass lesion involving the left cornea. The corneal lesion had been present since birth. On biomicroscopic examination, a well-defined vascularized, grayish-white mass occupying the whole of the left cornea was seen. The right eye showed multiple peripheral corneal opacities with iridocorneal adhesions, a poorly defined supranasal limbus, and a subluxated lens. Excision biopsy of the mass was done for histopathologic examination. Histopathologic examination of the excised corneal mass showed features consistent with that of a corneal keloid: thickened keratinized epithelium, absent Bowman membrane layer, and fibrovascular hyperplasia composed of hyalinized collagen fibers with irregular orientation of the collagen lamellae. During penetrating keratoplasty of the left eye, an anomalous iris pattern with poorly defined angle and a supranasal subluxated lens was also observed. Extraction of the subluxated lens was also done. The graft failed subsequent to a nonhealing persistent epithelial defect. Our case report highlights the rare association of a unilateral congenital corneal keloid with anterior-segment mesenchymal dysgenesis and bilateral subluxated lens.

Polysaccharide hydrogel combined with mesenchymal stem cells promotes the healing of corneal alkali burn in rats.

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Yifeng Ke

Full Text Available Corneal chemical burns are common ophthalmic injuries that may result in permanent visual impairment. Although significant advances have been achieved on the treatment of such cases, the structural and functional restoration of a chemical burn-injured cornea remains challenging. The applications of polysaccharide hydrogel and subconjunctival injection of mesenchymal stem cells (MSCs have been reported to promote the healing of corneal wounds. In this study, polysaccharide was extracted from Hardy Orchid and mesenchymal stem cells (MSCs were derived from Sprague-Dawley rats. Supplementation of the polysaccharide significantly enhanced the migration rate of primarily cultured rat corneal epithelial cells. We examined the therapeutic effects of polysaccharide in conjunction with MSCs application on the healing of corneal alkali burns in rats. Compared with either treatment alone, the combination strategy resulted in significantly better recovery of corneal epithelium and reduction in inflammation, neovascularization and opacity of healed cornea. Polysaccharide and MSCs acted additively to increase the expression of anti-inflammatory cytokine (TGF-β, antiangiogenic cytokine (TSP-1 and decrease those promoting inflammation (TNF-α, chemotaxis (MIP-1α and MCP-1 and angiogenesis (VEGF and MMP-2. This study provided evidence that Hardy Orchid derived polysaccharide and MSCs are safe and effective treatments for corneal alkali burns and that their benefits are additive when used in combination. We concluded that combination therapy with polysaccharide and MSCs is a promising clinical treatment for corneal alkali burns and may be applicable for other types of corneal disorder.

Polysaccharide Hydrogel Combined with Mesenchymal Stem Cells Promotes the Healing of Corneal Alkali Burn in Rats

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Liu, Xun; Yu, Min; Yang, Chunbo; Li, Xiaorong

2015-01-01

Corneal chemical burns are common ophthalmic injuries that may result in permanent visual impairment. Although significant advances have been achieved on the treatment of such cases, the structural and functional restoration of a chemical burn-injured cornea remains challenging. The applications of polysaccharide hydrogel and subconjunctival injection of mesenchymal stem cells (MSCs) have been reported to promote the healing of corneal wounds. In this study, polysaccharide was extracted from Hardy Orchid and mesenchymal stem cells (MSCs) were derived from Sprague-Dawley rats. Supplementation of the polysaccharide significantly enhanced the migration rate of primarily cultured rat corneal epithelial cells. We examined the therapeutic effects of polysaccharide in conjunction with MSCs application on the healing of corneal alkali burns in rats. Compared with either treatment alone, the combination strategy resulted in significantly better recovery of corneal epithelium and reduction in inflammation, neovascularization and opacity of healed cornea. Polysaccharide and MSCs acted additively to increase the expression of anti-inflammatory cytokine (TGF-β), antiangiogenic cytokine (TSP-1) and decrease those promoting inflammation (TNF-α), chemotaxis (MIP-1α and MCP-1) and angiogenesis (VEGF and MMP-2). This study provided evidence that Hardy Orchid derived polysaccharide and MSCs are safe and effective treatments for corneal alkali burns and that their benefits are additive when used in combination. We concluded that combination therapy with polysaccharide and MSCs is a promising clinical treatment for corneal alkali burns and may be applicable for other types of corneal disorder. PMID:25789487

Effects of topical vitamin E on corneal superoxide dismutase, glutathione peroxidase activities and polymorphonuclear leucocyte infiltration after photorefractive keratectomy.

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Bilgihan, Ayse; Bilgihan, Kamil; Yis, Ozgür; Sezer, Cem; Akyol, Gülen; Hasanreisoglu, Berati

2003-04-01

Photorefractive keratectomy (PRK) induces free radical formation and polymorphonuclear (PMN) cell infiltration in the cornea. Vitamin E is a free radical scavenger and protects the cells from reactive oxygen species. We investigated the effects of topical vitamin E on corneal PMN cell infiltration and corneal antioxidant enzyme activities after PRK. We studied four groups, each consisting of seven eyes. Group 1 were control eyes. In group 2 the corneal epithelium was removed by a blunt spatula (epithelial scrape). In group 3, corneal photoablation (59 micro m, 5 dioptres) was performed after epithelial removal (traditional PRK). In group 4 we tested the effects of topical Vitamin E after traditional PRK. Corneal tissues were removed and studied with enzymatic analysis (measurement of corneal superoxide dismutase and glutathione peroxidase activities) and histologically. Stromal PMN leucocyte counts were significantly higher after mechanical epithelial removal and traditional PRK (p < 0.05). Corneal superoxide dismutase and glutathione peroxidase activities decreased significantly after mechanical epithelial removal and traditional PRK (p < 0.05). In group 4, treated with vitamin E, corneal superoxide dismutase activity did not differ significantly from that in the medically non-treated groups, nor did corneal PMN cell infiltration after traditional PRK. The reduction of corneal glutathione peroxidase activity after PRK was reduced significantly after topical vitamin E treatment. Topical vitamin E treatment may be useful for reducing the harmful effects of reactive oxygen radical after epithelial scraping and PRK in that it increases corneal glutathione peroxidase activity.

Corneal Biofilms: From Planktonic to Microcolony Formation in an Experimental Keratitis Infection with Pseudomonas Aeruginosa.

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Saraswathi, Padmanabhan; Beuerman, Roger W

2015-10-01

Microbial biofilms commonly comprise part of the infectious scenario, complicating the therapeutic approach. The purpose of this study was to determine in a mouse model of corneal infection if mature biofilms formed and to visualize the stages of biofilm formation. A bacterial keratitis model was established using Pseudomonas aeruginosa ATCC 9027 (1 × 10(8) CFU/ml) to infect the cornea of C57BL/6 black mouse. Eyes were examined post-infection (PI) on days 1, 2, 3, 5, and 7, and imaged by slit lamp microscopy, and light, confocal, and electron microscopy to identify the stages of biofilm formation and the time of appearance. On PI day 1, Gram staining showed rod-shaped bacteria adherent on the corneal surface. On PI days 2 and 3, bacteria were seen within webs of extracellular polymeric substance (EPS) and glycocalyx secretion, imaged by confocal microscopy. Scanning electron microscopy demonstrated microcolonies of active infectious cells bound with thick fibrous material. Transmission electron microscopy substantiated the formation of classical biofilm architecture with P. aeruginosa densely packed within the extracellular polymeric substances on PI days 5 and 7. Direct visual evidence showed that biofilms routinely developed on the biotic surface of the mouse cornea. The mouse model can be used to develop new approaches to deal therapeutically with biofilms in corneal infections. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Transplantation with cultured stem cells derived from the human amniotic membrane for corneal alkali burns: an experimental study.

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Zeng, Wei; Li, Yanwei; Zeng, Guangwei; Yang, Bo; Zhu, Yu

2014-01-01

Amniotic membranes (AM) have been used in a wide range of clinical applications. We successfully extracted mesenchymal stem cells (MSCs) from human AM, but little is known about the use and efficacy of human amniotic membrane-derived mesenchymal stem cells (hAM-dMSCs) for the treatment of alkali burns. We utilized hAM-dMSCs transplantation, AM grafting, and their combined use in the treatment of alkali burns. An experimental model in rabbits was devised to analyze the use of these techniques with immunocytochemistry and ELISA. The survival and migration of hAM-dMSCs labeled by SPION in the host were assessed with Prussian blue staining. Compared with the control group, the treated groups demonstrated faster reconstruction of the corneal epithelium, and lower levels of corneal opacification and neovascularization within corneal alkali burns. Furthermore, dark blue-stained particles were detected in the limbus corneae at day 28. These results demonstrated the ability of hAM-dMSCs to enhance epithelial healing and reduce corneal opacification and neovascularization in corneal alkali wounds.

In Vivo-Like Culture Conditions in a Bioreactor Facilitate Improved Tissue Quality in Corneal Storage.

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Schmid, Richard; Tarau, Ioana-Sandra; Rossi, Angela; Leonhardt, Stefan; Schwarz, Thomas; Schuerlein, Sebastian; Lotz, Christian; Hansmann, Jan

2018-01-01

The cornea is the most-transplanted tissue worldwide. However, the availability and quality of grafts are limited due to the current methods of corneal storage. In this study, a dynamic bioreactor system is employed to enable the control of intraocular pressure and the culture at the air-liquid interface. Thereby, in vivo-like storage conditions are achieved. Different media combinations for endothelium and epithelium are tested in standard and dynamic conditions to enhance the viability of the tissue. In contrast to culture conditions used in eye banks, the combination of the bioreactor and biochrom medium 1 allows to preserve the corneal endothelium and the epithelium. Assessment of transparency, swelling, and the trans-epithelial-electrical-resistance (TEER) strengthens the impact of the in vivo-like tissue culture. For example, compared to corneas stored under static conditions, significantly lower optical densities and significantly higher TEER values were measured (p-value <0.05). Furthermore, healing of epithelial defects is enabled in the bioreactor, characterized by re-epithelialization and initiated stromal regeneration. Based on the obtained results, an easy-to-use 3D-printed bioreactor composed of only two parts was derived to translate the technology from the laboratory to the eye banks. This optimized bioreactor facilitates noninvasive microscopic monitoring. The improved storage conditions ameliorate the quality of corneal grafts and the storage time in the eye banks to increase availability and reduce re-grafting. © 2017 The Authors. Biotechnology Journal Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Retinal pigment epithelium, age-related macular degeneration and neurotrophic keratouveitis.

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Bianchi, Enrica; Scarinci, Fabio; Ripandelli, Guido; Feher, Janos; Pacella, Elena; Magliulo, Giuseppe; Gabrieli, Corrado Balacco; Plateroti, Rocco; Plateroti, Pasquale; Mignini, Fiorenzo; Artico, Marco

2013-01-01

Age-related macular degeneration (AMD) is the leading cause of impaired vision and blindness in the aging population. The aims of our studies were to identify qualitative and quantitative alterations in mitochondria in human retinal pigment epithelium (RPE) from AMD patients and controls and to test the protective effects of pigment epithelium-derived factor (PEDF), a known neurotrophic and antiangiogenic substance, against neurotrophic keratouveitis. Histopathological alterations were studied by means of morphometry, light and electron microscopy. Unexpectedly, morphometric data showed that the RPE alterations noted in AMD may also develop in normal aging, 10-15 years later than appearing in AMD patients. Reduced tear secretion, corneal ulceration and leukocytic infiltration were found in capsaicin (CAP)-treated rats, but this effect was significantly attenuated by PEDF. These findings suggest that PEDF accelerated the recovery of tear secretion and also prevented neurotrophic keratouveitis and vitreoretinal inflammation. PEDF may have a clinical application in inflammatory and neovascular diseases of the eye.

Ultrastructural analysis of corneal exposure to UV radiation

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Pitts, D.G.; Bergmanson, J.P.G.; Chu, L.W.-F.

1987-01-01

The primate cornea was exposed to 300 nm UVR with five levels of radiant expsure from 0.08 to 0.6 Jcm/sup -2/. All cellular layers of the cornea were damaged at the 0.08 Jcm/sup -2/ exposure, and damage became more severe as the exposure level was increased. The corneal cells showed variable response in that essentially normal cells were found among damaged cells. Eight days post-exposure using the 0.6 Jcm/sup -2/ level, the epithelium had regained its normal thickness and was populated largely by normal appearing cells; however, the stroma showed damaged keratocytes and the loss of keratocytes. The corneal basement membranes (the epithelial basement membrane and the posterior limiting lamina) and the anterior limiting lamina were not damaged at any exposure level except for an isolated area along the epithelial basement membrane in one cornea. Therefore, one is lead to conclude that basement membranes are unaffected by UVR. The endothelium continued to demonstrate the loss of mitochondria, endoplasmic reticulum and some vacuoles at 8 days after exposure. However, the endothelium appeared to have resumed its physiological function as demonstrated by the reduced stromal oedema. This research gives the first complete description of UV-B induced corneal damage and repair of the full, in-depth cornea of the primate using the EM.

Ultrastructural analysis of corneal exposure to UV radiation

International Nuclear Information System (INIS)

Pitts, D.G.; Bergmanson, J.P.G.; Chu, L. W-F.

1987-01-01

The primate cornea was exposed to 300 nm UVR with five levels of radiant expsure from 0.08 to 0.6 Jcm -2 . All cellular layers of the cornea were damaged at the 0.08 Jcm -2 exposure, and damage became more severe as the exposure level was increased. The corneal cells showed variable response in that essentially normal cells were found among damaged cells. Eight days post-exposure using the 0.6 Jcm -2 level, the epithelium had regained its normal thickness and was populated largely by normal appearing cells; however, the stroma showed damaged keratocytes and the loss of keratocytes. The corneal basement membranes (the epithelial basement membrane and the posterior limiting lamina) and the anterior limiting lamina were not damaged at any exposure level except for an isolated area along the epithelial basement membrane in one cornea. Therefore, one is lead to conclude that basement membranes are unaffected by UVR. The endothelium continued to demonstrate the loss of mitochondria, endoplasmic reticulum and some vacuoles at 8 days after exposure. However, the endothelium appeared to have resumed its physiological function as demonstrated by the reduced stromal oedema. This research gives the first complete description of UV-B induced corneal damage and repair of the full, in-depth cornea of the primate using the EM. (author)

In vivo 3D measurement of moxifloxacin and gatifloxacin distributions in the mouse cornea using multiphoton microscopy

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Lee, Seunghun; Lee, Jun Ho; Park, Jin Hyoung; Yoon, Yeoreum; Chung, Wan Kyun; Tchah, Hungwon; Kim, Myoung Joon; Kim, Ki Hean

2016-05-01

Moxifloxacin and gatifloxacin are fourth-generation fluoroquinolone antibiotics used in the clinic to prevent or treat ocular infections. Their pharmacokinetics in the cornea is usually measured from extracted ocular fluids or tissues, and in vivo direct measurement is difficult. In this study multiphoton microscopy (MPM), which is a 3D optical microscopic technique based on multiphoton fluorescence, was applied to the measurement of moxifloxacin and gatifloxacin distribution in the cornea. Intrinsic multiphoton fluorescence properties of moxifloxacin and gatifloxacin were characterized, and their distributions in mouse cornea in vivo were measured by 3D MPM imaging. Both moxifloxacin and gatifloxacin had similar multiphoton spectra, while moxifloxacin had stronger fluorescence than gatifloxacin. MPM imaging of mouse cornea in vivo showed (1) moxifloxacin had good penetration through the superficial corneal epithelium, while gatifloxacin had relatively poor penetration, (2) both ophthalmic solutions had high intracellular distribution. In vivo MPM results were consistent with previous studies. This study demonstrates the feasibility of MPM as a method for in vivo direct measurement of moxifloxacin and gatifloxacin in the cornea.

Reconstruction of limbal stem cell deficient corneal surface with induced human bone marrow mesenchymal stem cells on amniotic membrane.

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Rohaina, Che Man; Then, Kong Yong; Ng, Angela Min Hwei; Wan Abdul Halim, Wan Haslina; Zahidin, Aida Zairani Mohd; Saim, Aminuddin; Idrus, Ruszymah B H

2014-03-01

The cornea can be damaged by a variety of clinical disorders or chemical, mechanical, and thermal injuries. The objectives of this study were to induce bone marrow mesenchymal stem cells (BMSCs) to corneal lineage, to form a tissue engineered corneal substitute (TEC) using BMSCs, and to treat corneal surface defects in a limbal stem cell deficiency model. BMSCs were induced to corneal lineage using limbal medium for 10 days. Induced BMSCs demonstrated upregulation of corneal stem cell markers; β1-integrin, C/EBPδ, ABCG2, and p63, increased protein expression of CK3 and p63 significantly compared with the uninduced ones. For TEC formation, passage 1 BMSCs were trypsinized and seeded on amniotic membrane in a transwell co-culture system and were grown in limbal medium. Limbal stem cell deficiency models were induced by alkaline injury, and the TEC was implanted for 8 weeks. Serial slit lamp evaluation revealed remarkable improvement in corneal regeneration in terms of corneal clarity and reduced vascularization. Histologic and optical coherence tomography analyses demonstrated comparable corneal thickness and achieved stratified epithelium with a compact stromal layer resembling that of normal cornea. CK3 and p63 were expressed in the newly regenerated cornea. In conclusion, BMSCs can be induced into corneal epithelial lineage, and these cells are viable for the formation of TEC, to be used for the reconstruction of the corneal surface in the limbal stem cell deficient model. Copyright © 2014 Mosby, Inc. All rights reserved.

Topical Use of Angiopoietin-like Protein 2 RNAi-loaded Lipid Nanoparticles Suppresses Corneal Neovascularization

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Yukako Taketani

2016-01-01

Full Text Available Corneal neovascularization (CNV is a sight-threatening condition that is encountered in various inflammatory settings including chemical injury. We recently confirmed that angiopoietin-like protein 2 (ANGPTL2 is a potent angiogenic and proinflammatory factor in the cornea, and we have produced a single-stranded proline-modified short hairpin anti-ANGPTL2 RNA interference molecule that is carried in a lipid nanoparticle (ANGPTL2 Li-pshRNA for topical application. In this study, we have further examined the topical delivery and anti-ANGPTL2 activity of this molecule and have found that fluorescence-labeled ANGPTL2 Li-pshRNA eye drops can penetrate all layers of the cornea and that ANGPTL2 mRNA expression was dramatically inhibited in both epithelium and stroma at 12 and 24 hours after administration. We also examined the inhibitory effect of ANGPTL2 Li-pshRNA on CNV in a mouse chemical injury model and found that the area of angiogenesis was significantly decreased in corneas treated with ANGPTL2 Li-pshRNA eye drops compared to controls. Together, these findings indicate that this modified RNA interference agent is clinically viable in a topical formulation for use against CNV.

Prolonging survival of corneal transplantation by selective sphingosine-1-phosphate receptor 1 agonist.

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Min Gao

Full Text Available Corneal transplantation is the most used therapy for eye disorders. Although the cornea is somewhat an immune privileged organ, immune rejection is still the major problem that reduces the success rate. Therefore, effective chemical drugs that regulate immunoreactions are needed to improve the outcome of corneal transplantations. Here, a sphingosine-1-phosphate receptor 1 (S1P1 selective agonist was systematically evaluated in mouse allogeneic corneal transplantation and compared with the commonly used immunosuppressive agents. Compared with CsA and the non-selective sphingosine 1-phosphate (S1P receptor agonist FTY720, the S1P1 selective agonist can prolong the survival corneal transplantation for more than 30 days with a low immune response. More importantly, the optimal dose of the S1P1 selective agonist was much less than non-selective S1P receptor agonist FTY720, which would reduce the dose-dependent toxicity in drug application. Then we analyzed the mechanisms of the selected S1P1 selective agonist on the immunosuppression. The results shown that the S1P1 selective agonist could regulate the distribution of the immune cells with less CD4+ T cells and enhanced Treg cells in the allograft, moreover the expression of anti-inflammatory cytokines TGF-β1 and IL-10 unregulated which can reduce the immunoreactions. These findings suggest that S1P1 selective agonist may be a more appropriate immunosuppressive compound to effectively prolong mouse allogeneic corneal grafts survival.

Normal X-inactivation mosaicism in corneas of heterozygous FlnaDilp2/+ female mice--a model of human Filamin A (FLNA diseases

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Douvaras Panagiotis

2012-02-01

Full Text Available Abstract Background Some abnormalities of mouse corneal epithelial maintenance can be identified by the atypical mosaic patterns they produce in X-chromosome inactivation mosaics and chimeras. Human FLNA/+ females, heterozygous for X-linked, filamin A gene (FLNA mutations, display a range of disorders and X-inactivation mosaicism is sometimes quantitatively unbalanced. FlnaDilp2/+ mice, heterozygous for an X-linked filamin A (Flna nonsense mutation have variable eye, skeletal and other abnormalities, but X-inactivation mosaicism has not been investigated. The aim of this study was to determine whether X-inactivation mosaicism in the corneal epithelia of FlnaDilp2/+ mice was affected in any way that might predict abnormal corneal epithelial maintenance. Results X-chromosome inactivation mosaicism was studied in the corneal epithelium and a control tissue (liver of FlnaDilp2/+ and wild-type (WT female X-inactivation mosaics, hemizygous for the X-linked, LacZ reporter H253 transgene, using β-galactosidase histochemical staining. The corneal epithelia of FlnaDilp2/+ and WT X-inactivation mosaics showed similar radial, striped patterns, implying epithelial cell movement was not disrupted in FlnaDilp2/+ corneas. Corrected stripe numbers declined with age overall (but not significantly for either genotype individually, consistent with previous reports suggesting an age-related reduction in stem cell function. Corrected stripe numbers were not reduced in FlnaDilp2/+ compared with WT X-inactivation mosaics and mosaicism was not significantly more unbalanced in the corneal epithelia or livers of FlnaDilp2/+ than wild-type Flna+/+ X-inactivation mosaics. Conclusions Mosaic analysis identified no major effect of the mouse FlnaDilp2 mutation on corneal epithelial maintenance or the balance of X-inactivation mosaicism in the corneal epithelium or liver.

Resolution of persistent corneal erosion after administration of topical rebamipide

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Kashima T

2012-08-01

Full Text Available Tomoyuki Kashima,1,2 Hideo Akiyama,1 Fumihide Miura,2 Shoji Kishi11Department of Ophthalmology, Gunma University School of Medicine, Maebashi, Japan; 2Department of Ophthalmology, Saku Central Hospital, Saku, JapanAbstract: Rebamipide is an antiulcer agent used to treat gastric ulcer and gastritis. Biological effects of rebamipide include cytoprotection, wound healing, and anti-inflammatory properties that are known to be universal for a variety of tissues in addition to gastrointestinal mucosa. The therapeutic effects of rebamipide eye drops are due to its ability to increase corneal and conjunctival mucin-like substances and improve corneal and conjunctival injury in vivo. In this paper, we report a case of Sjögren's syndrome with complete disappearance of corneal erosion after administration of rebamipide eye drops. This was observed even though corneal erosion had not improved for 6 months after punctal occlusion surgery. The patient was a 33-year-old female, diagnosed with Sjögren's syndrome by a salivary gland biopsy. The corneal and conjunctival surfaces were filled with dense erosions, which did not improve with topical drugs. Punctal plugs were applied several times; however, the plugs were repeatedly shed. All four puncta of both eyelids were surgically occluded, and both corneal and conjunctival erosion was clearly improved. However, the erosion in the inferior cornea of both eyes had not improved for 6 months after surgery. We used the newly approved topical rebamipide for treatment of this patient. The corneal erosion gradually improved and completely disappeared 4 weeks after administration of the drug. Dry eye sensation disappeared at the same time. Both membrane-associated mucin and secreted mucin in the ocular surface are thought to be essential for maintenance of the tear film. Induction of mucin from ocular surface epithelium could be an effective treatment in cases of dry eye caused by mucin deficiency. Through its various

Assessment of Corneal and Tear Film Parameters in Rheumatoid Arthritis Patients Using Anterior Segment Spectral Domain Optical Coherence Tomography.

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El-Fayoumi, Dina; Youssef, Maha Mohamed; Khafagy, Mohamed Mahmoud; Badr El Dine, Nashwa; Gaber, Wafaa

2018-01-01

To study the corneal changes in rheumatoid arthritis (RA) patients in vivo, using spectral domain anterior segment optical coherence tomography (AS-OCT). A case-control study was done on 43 RA patients and 40 controls. The disease activity score (DAS28-ESR) was calculated and all participants had lower tear meniscus, corneal thickness, and epithelial thickness evaluation using AS-OCT. The lower tear meniscus height (LTMH) and the lower tear meniscus area (LTMA) were significantly lower in the RA patients than in controls (p < 0.001). RA patients also had a significantly thinner central corneal thickness (p = 0.02) and their epithelium was found to be thinner in the superotemporal peripheral sector. The LTMH and LTMA are significantly reduced in RA patients, despite the absence of clinical diagnosis of dry eye. RA patients have thinner corneal thickness and epithelial thickness than controls, which did not correlate with either disease duration or activity.

Corneal wound healing promoted by 3 blood derivatives: an in vitro and in vivo comparative study.

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Freire, Vanesa; Andollo, Noelia; Etxebarria, Jaime; Hernáez-Moya, Raquel; Durán, Juan A; Morales, María-Celia

2014-06-01

The aim of this study was to compare the effect on corneal wound healing of 3 differently manufactured blood derivatives [autologous serum (AS), platelet-rich plasma, and serum derived from plasma rich in growth factors (s-PRGF)]. Scratch wound-healing assays were performed on rabbit primary corneal epithelial cultures and human corneal epithelial cells. Additionally, mechanical debridement of rabbit corneal epithelium was performed. Wound-healing progression was assessed by measuring the denuded areas remaining over time after treatment with each of the 3 blood derivatives or a control treatment. In vitro data show statistically significant differences in the healing process with all the derivatives compared with the control, but 2 of them (AS and s-PRGF) induced markedly faster wound healing. In contrast, although the mean time required to complete in vivo reepithelization was similar to that of AS and s-PRGF treatment, only wounds treated with s-PRGF were significantly smaller in size from 2.5 days onward with respect to the control treatment. All 3 blood derivatives studied are promoters of corneal reepithelization. However, the corneal wound-healing progresses differently with each derivative, being faster in vitro under AS and s-PRGF treatment and producing in vivo the greatest decrease in wound size under s-PRGF treatment. These findings highlight that the manufacturing process of the blood derivatives may modulate the efficacy of the final product.

Corneal Laceration

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Effect of syngeneic thymocytes on proliferation of the small intestinal epithelium in mice

International Nuclear Information System (INIS)

Shmakov, A.N.; Aparovich, G.G.; Trufakin, V.A.

1986-01-01

This paper describes the study of the action of syngeneic thymocytes on proliferation of the epithelium of the mouse small intestine. The mice were injected with 3 H-thymidine in the experiments. Under the experimental conditions presented here, syngeneic thymocytes can reduce the number of DNA-synthesizing cells in the intestinal epithelium, causing narrowing of the zone of proliferation and enlargement of the zone of differentiation of the enterocytes

Spontaneous Corneal Hydrops in a Patient with a Corneal Ulcer

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Hatim Batawi

2016-01-01

Full Text Available Purpose: We report the case of a 77-year-old man with no history of keratoconus or other ectatic disorders who presented with corneal hydrops in the setting of a corneal ulcer. The risk factors, pathogenesis and treatment options of corneal hydrops are discussed. Method: This is an observational case report study. Results: A 77-year-old man presented with a 1-day history of severe pain, redness, mucous discharge and photophobia in the right eye. A slit-lamp examination of the right eye showed an area of focal corneal edema and protrusion. Within the area of edema and protrusion, there was an infiltrate with an overlying epithelial defect consistent with an infectious corneal ulcer. The Seidel test showed no leakage, so a clinical diagnosis of corneal hydrops associated with nonperforated corneal ulcer was made. With appropriate antibiotic treatment, the corneal ulcer and hydrops both resolved over a 1-month period. Conclusion: Corneal hydrops can occur in the setting of corneal infections.

Comparison of confocal microscopy and two-photon microscopy in mouse cornea in vivo.

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Lee, Jun Ho; Lee, Seunghun; Gho, Yong Song; Song, In Seok; Tchah, Hungwon; Kim, Myoung Joon; Kim, Ki Hean

2015-03-01

High-resolution imaging of the cornea is important for studying corneal diseases at cellular levels. Confocal microscopy (CM) has been widely used in the clinic, and two-photon microscopy (TPM) has recently been introduced in various pre-clinical studies. We compared the performance of CM and TPM in normal mouse corneas and neovascularized mouse corneas induced by suturing. Balb/C mice and C57BL/6 mice expressing green fluorescent protein (GFP) were used to compare modalities based on intrinsic contrast and extrinsic fluorescence contrast. CM based on reflection (CMR), CM based on fluorescence (CMF), and TPM based on intrinsic/extrinsic fluorescence and second harmonic generation (SHG) were compared by imaging the same sections of mouse corneas sequentially in vivo. In normal mouse corneas, CMR visualized corneal cell morphologies with some background noise, and CMF visualized GFP expressing corneal cells clearly. TPM visualized corneal cells and collagen in the stroma based on fluorescence and SHG, respectively. However, in neovascularized mouse corneas, CMR could not resolve cells deep inside the cornea due to high background noise from the effects of increased structural irregularity induced by suturing. CMF and TPM visualized cells and induced vasculature better than CMR because both collect signals from fluorescent cells only. Both CMF and TPM had signal decays with depth due to the structural irregularity, with CMF having faster signal decay than TPM. CMR, CMF, and TPM showed different degrees of image degradation in neovascularized mouse corneas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Corneal biomechanical properties from air-puff corneal deformation imaging

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Marcos, Susana; Kling, Sabine; Bekesi, Nandor; Dorronsoro, Carlos

2014-02-01

The combination of air-puff systems with real-time corneal imaging (i.e. Optical Coherence Tomography (OCT), or Scheimpflug) is a promising approach to assess the dynamic biomechanical properties of the corneal tissue in vivo. In this study we present an experimental system which, together with finite element modeling, allows measurements of corneal biomechanical properties from corneal deformation imaging, both ex vivo and in vivo. A spectral OCT instrument combined with an air puff from a non-contact tonometer in a non-collinear configuration was used to image the corneal deformation over full corneal cross-sections, as well as to obtain high speed measurements of the temporal deformation of the corneal apex. Quantitative analysis allows direct extraction of several deformation parameters, such as apex indentation across time, maximal indentation depth, temporal symmetry and peak distance at maximal deformation. The potential of the technique is demonstrated and compared to air-puff imaging with Scheimpflug. Measurements ex vivo were performed on 14 freshly enucleated porcine eyes and five human donor eyes. Measurements in vivo were performed on nine human eyes. Corneal deformation was studied as a function of Intraocular Pressure (IOP, 15-45 mmHg), dehydration, changes in corneal rigidity (produced by UV corneal cross-linking, CXL), and different boundary conditions (sclera, ocular muscles). Geometrical deformation parameters were used as input for inverse finite element simulation to retrieve the corneal dynamic elastic and viscoelastic parameters. Temporal and spatial deformation profiles were very sensitive to the IOP. CXL produced a significant reduction of the cornea indentation (1.41x), and a change in the temporal symmetry of the corneal deformation profile (1.65x), indicating a change in the viscoelastic properties with treatment. Combining air-puff with dynamic imaging and finite element modeling allows characterizing the corneal biomechanics in-vivo.

RECURRENT CORNEAL EROSION SYNDROME (a review

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S. V. Trufanov

2015-01-01

Full Text Available Recurrent corneal erosion (RCE syndrome is characterized by episodes of recurrent spontaneous epithelial defects. Main clinical symptoms (pain, redness, photophobia, lacrimation occurred at night. Corneal lesions revealed by slit lamp exam vary depending on the presence of corneal epithelium raise, epithelial microcysts or epithelial erosions, stromal infiltrates and opacities. Microtraumas, anterior corneal dystrophies, and herpesvirus give rise to RCE. Other causes or factors which increase the risk of RCE syndrome include meibomian gland dysfunction, keratoconjunctivitis sicca, diabetes, and post-LASIK conditions. Basal membrane abnormalities and instability of epithelial adhesion to stroma play a key role in RCE pathogenesis. Ultrastructural changes in RCE include abnormalities of basal epithelial cells and epithelial basal membrane, absence or deficiency of semi-desmosomes, loss of anchor fibrils. Increase in matrix metalloproteinases and collagenases which contribute to basal membrane destruction results in recurrent erosions and further development of abnormal basal membrane. The goals of RCE therapy are to reduce pain (in acute stage, to stimulate re-epithelization, and to restore «adhesion complex» of basal membrane. In most cases, RCE responds to simple conservative treatment that includes lubricants, healing agents, and eye patches. RCEs that are resistant to simple treatment, require complex approach. Non-invasive methods include long-term contact lens use, instillations of autologous serum (eye drops, injections of botulinum toxin (induces ptosis, antiviral agent use or oral intake of metalloproteinase inhibitors. Cell membrane stabilizers, i.e., antioxidants, should be included into treatment approaches as well. Antioxidant effect of Emoxipine promotes tissue reparation due to the prevention of cell membrane lipid peroxidation as well as due to its anti-hypoxic, angioprotective, and antiplatelet effects. If conservative therapy

Contributions of ocular surface components to matrix-metalloproteinases (MMP)-2 and MMP-9 in feline tears following corneal epithelial wounding.

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Petznick, Andrea; Madigan, Michele C; Garrett, Qian; Sweeney, Deborah F; Evans, Margaret D M

2013-01-01

This study investigated ocular surface components that contribute to matrix-metalloproteinase (MMP)-2 and MMP-9 found in tears following corneal epithelial wounding. Laboratory short-haired cats underwent corneal epithelial debridement in one randomly chosen eye (n = 18). Eye-flush tears were collected at baseline and during various healing stages. Procedural control eyes (identical experimental protocol as wounded eyes except for wounding, n = 5) served as controls for tear analysis. MMP activity was analyzed in tears using gelatin zymography. MMP staining patterns were evaluated in ocular tissues using immunohistochemistry and used to determine MMP expression sites responsible for tear-derived MMPs. The proMMP-2 and proMMP-9 activity in tears was highest in wounded and procedural control eyes during epithelial migration (8 to 36 hours post-wounding). Wounded eyes showed significantly higher proMMP-9 in tears only during and after epithelial restratification (day 3 to 4 and day 7 to 28 post-wounding, respectively) as compared to procedural controls (pTears from wounded and procedural control eyes showed no statistical differences for pro-MMP-2 and MMP-9 (p>0.05). Immunohistochemistry showed increased MMP-2 and MMP-9 expression in the cornea during epithelial migration and wound closure. The conjunctival epithelium exhibited highest levels of both MMPs during wound closure, while MMP-9 expression was reduced in conjunctival goblet cells during corneal epithelial migration followed by complete absence of the cells during wound closure. The immunostaining for both MMPs was elevated in the lacrimal gland during corneal healing, with little/no change in the meibomian glands. Conjunctival-associated lymphoid tissue (CALT) showed weak MMP-2 and intense MMP-9 staining. Following wounding, migrating corneal epithelium contributed little to the observed MMP levels in tears. The major sources assessed in the present study for tear-derived MMP-2 and MMP-9 following

Corneal Laceration

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[Characterization of stem cells derived from the neonatal auditory sensory epithelium].

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Diensthuber, M; Heller, S

2010-11-01

In contrast to regenerating hair cell-bearing organs of nonmammalian vertebrates the adult mammalian organ of Corti appears to have lost its ability to maintain stem cells. The result is a lack of regenerative ability and irreversible hearing loss following auditory hair cell death. Unexpectedly, the neonatal auditory sensory epithelium has recently been shown to harbor cells with stem cell features. The origin of these cells within the cochlea's sensory epithelium is unknown. We applied a modified neurosphere assay to identify stem cells within distinct subregions of the neonatal mouse auditory sensory epithelium. Sphere cells were characterized by multiple markers and morphologic techniques. Our data reveal that both the greater and the lesser epithelial ridge contribute to the sphere-forming stem cell population derived from the auditory sensory epithelium. These self-renewing sphere cells express a variety of markers for neural and otic progenitor cells and mature inner ear cell types. Stem cells can be isolated from specific regions of the auditory sensory epithelium. The distinct features of these cells imply a potential application in the development of a cell replacement therapy to regenerate the damaged sensory epithelium.

Cloning of radiation-induced new gene RS1 expressed in mouse intestinal epithelium by enhanced RACE

International Nuclear Information System (INIS)

Wang Fengchao; Wang Junping; Su Yongping; Gao Jinsheng; Lou Shufen; Liu Xiaohong; Ren Jiong; Zhang Bo

2003-01-01

Objective: To obtain full-length cDNA of radiation-induced new gene RS1 expressed in mouse intestinal epithelium. Methods: The tissue expression profile of RS1 was analyzed by semi-quantitative RT-PCR to find the target tissue which highly expresses RS1. The total RNA extracted from the corresponding tissue was taken as the template for reverse-transcription. Enhanced RACE PCR was used to clone the full-length cDNA of RS1, including enrichment of the target gene through biotin-labeled probe for magnetic bead purification and nested PCR. Results: About a 2 kb long 3' end was successfully cloned and cloning of the 5' end proceeded well. Conclusion: The result is consistent with our experiment design. The set of combined techniques has been identified with the cloning of full-length cDNA from EST sequence especially when the optimal gene-specific primers are not available or the expression level of target gene is low

Extended latanoprost release from commercial contact lenses: in vitro studies using corneal models.

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Saman Mohammadi

Full Text Available In this study, we compared, for the first time, the release of a 432 kDa prostaglandin F2a analogue drug, Latanoprost, from commercially available contact lenses using in vitro models with corneal epithelial cells. Conventional polyHEMA-based and silicone hydrogel soft contact lenses were soaked in drug solution (131 μg = ml solution in phosphate buffered saline. The drug release from the contact lens material and its diffusion through three in vitro models was studied. The three in vitro models consisted of a polyethylene terephthalate (PET membrane without corneal epithelial cells, a PET membrane with a monolayer of human corneal epithelial cells (HCEC, and a PET membrane with stratified HCEC. In the cell-based in vitro corneal epithelium models, a zero order release was obtained with the silicone hydrogel materials (linear for the duration of the experiment whereby, after 48 hours, between 4 to 6 μg of latanoprost (an amount well within the range of the prescribed daily dose for glaucoma patients was released. In the absence of cells, a significantly lower amount of drug, between 0.3 to 0.5 μg, was released, (p <0:001. The difference observed in release from the hydrogel lens materials in the presence and absence of cells emphasizes the importance of using an in vitro corneal model that is more representative of the physiological conditions in the eye to more adequately characterize ophthalmic drug delivery materials. Our results demonstrate how in vitro models with corneal epithelial cells may allow better prediction of in vivo release. It also highlights the potential of drug-soaked silicone hydrogel contact lens materials for drug delivery purposes.

Role of corneal collagen fibrils in corneal disorders and related pathological conditions

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Hong-Yan Zhou

2017-05-01

Full Text Available The cornea is a soft tissue located at the front of the eye with the principal function of transmitting and refracting light rays to precisely sense visual information. Corneal shape, refraction, and stromal stiffness are to a large part determined by corneal fibrils, the arrangements of which define the corneal cells and their functional behaviour. However, the modality and alignment of native corneal collagen lamellae are altered in various corneal pathological states such as infection, injury, keratoconus, corneal scar formation, and keratoprosthesis. Furthermore, corneal recuperation after corneal pathological change is dependent on the balance of corneal collagen degradation and contraction. A thorough understanding of the characteristics of corneal collagen is thus necessary to develop viable therapies using the outcome of strategies using engineered corneas. In this review, we discuss the composition and distribution of corneal collagens as well as their degradation and contraction, and address the current status of corneal tissue engineering and the progress of corneal cross-linking.

Interkinetic nuclear migration in the mouse embryonic ureteric epithelium: Possible implication for congenital anomalies of the kidney and urinary tract.

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Motoya, Tomoyuki; Ogawa, Noriko; Nitta, Tetsuya; Rafiq, Ashiq Mahmood; Jahan, Esrat; Furuya, Motohide; Matsumoto, Akihiro; Udagawa, Jun; Otani, Hiroki

2016-05-01

Interkinetic nuclear migration (INM) is a phenomenon in which progenitor cell nuclei migrate along the apico-basal axis of the pseudostratified epithelium, which is characterized by the presence of apical primary cilia, in synchrony with the cell cycle in a manner of apical mitosis. INM is suggested to regulate not only stem/progenitor cell proliferation/differentiation but also organ size and shape. INM has been reported in epithelia of both ectoderm and endoderm origin. We examined whether INM exists in the mesoderm-derived ureteric epithelium. At embryonic day (E) 11.5, E12.5 and E13.5, C57BL/6J mouse dams were injected with 5-bromo-2'-deoxyuridine (BrdU) and embryos were killed 1, 2, 4, 6, 8, 10 and 12 h later. We immunostained transverse sections of the ureter for BrdU, and measured the position of BrdU (+) nuclei in the ureteric epithelia along the apico-basal axis at each time point. We analyzed the distribution patterns of BrdU (+) nuclei in histograms using the multidimensional scaling. Changes in the nucleus distribution patterns suggested nucleus movement characteristic of INM in the ureteric epithelia, and the mode of INM varied throughout the ureter development. While apical primary cilia are related with INM by providing a centrosome for the apical mitosis, congenital anomalies of the kidney and urinary tract (CAKUT) include syndromes linked to primary ciliary dysfunction affecting epithelial tubular organs such as kidney, ureter, and brain. The present study showed that INM exists in the ureteric epithelium and suggests that INM may be related with the CAKUT etiology via primary ciliary protein function. © 2015 Japanese Teratology Society.

Corneal cell adhesion to contact lens hydrogel materials enhanced via tear film protein deposition.

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Claire M Elkins

Full Text Available Tear film protein deposition on contact lens hydrogels has been well characterized from the perspective of bacterial adhesion and viability. However, the effect of protein deposition on lens interactions with the corneal epithelium remains largely unexplored. The current study employs a live cell rheometer to quantify human corneal epithelial cell adhesion to soft contact lenses fouled with the tear film protein lysozyme. PureVision balafilcon A and AirOptix lotrafilcon B lenses were soaked for five days in either phosphate buffered saline (PBS, borate buffered saline (BBS, or Sensitive Eyes Plus Saline Solution (Sensitive Eyes, either pure or in the presence of lysozyme. Treated contact lenses were then contacted to a live monolayer of corneal epithelial cells for two hours, after which the contact lens was sheared laterally. The apparent cell monolayer relaxation modulus was then used to quantify the extent of cell adhesion to the contact lens surface. For both lens types, lysozyme increased corneal cell adhesion to the contact lens, with the apparent cell monolayer relaxation modulus increasing up to an order of magnitude in the presence of protein. The magnitude of this increase depended on the identity of the soaking solution: lenses soaked in borate-buffered solutions (BBS, Sensitive Eyes exhibited a much greater increase in cell attachment upon protein addition than those soaked in PBS. Significantly, all measurements were conducted while subjecting the cells to moderate surface pressures and shear rates, similar to those experienced by corneal cells in vivo.

The high-risk corneal regraft model: a justification for tissue matching in humans

Czech Academy of Sciences Publication Activity Database

Vitova, A.; Kuffova, L.; Klaska, I.; Holáň, Vladimír; Cornall, R.J.; Forrester, J.V.

2013-01-01

Roč. 26, č. 4 (2013), s. 453-461 ISSN 0934-0874 Institutional support: RVO:68378050 Keywords : accelerated rejection * corneal transplantation * dendritic cell s * regraft * T- cell memory * transgenic mouse Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.120, year: 2013

Amelioration of ultraviolet-induced photokeratitis in mice treated with astaxanthin eye drops.

Science.gov (United States)

Lennikov, Anton; Kitaichi, Nobuyoshi; Fukase, Risa; Murata, Miyuki; Noda, Kousuke; Ando, Ryo; Ohguchi, Takeshi; Kawakita, Tetsuya; Ohno, Shigeaki; Ishida, Susumu

2012-01-01

Ultraviolet (UV) acts as low-dose ionizing radiation. Acute UVB exposure causes photokeratitis and induces apoptosis in corneal cells. Astaxanthin (AST) is a carotenoid, present in seafood, that has potential clinical applications due to its high antioxidant activity. In the present study, we examined whether topical administration of AST has preventive and therapeutic effects on UV-photokeratitis in mice. C57BL/6 mice were administered with AST diluted in polyethylene glycol (PEG) in instillation form (15 μl) to the right eye. Left eyes were given vehicle alone as controls. Immediately after the instillation, the mice, under anesthesia, were irradiated with UVB at a dose of 400 mJ/cm². Eyeballs were collected 24 h after irradiation and stained with H&E and TUNEL. In an in vitro study, mouse corneal epithelial (TKE2) cells were cultured with AST before UV exposure to quantify the UV-derived cytotoxicity. UVB exposure induced cell death and thinning of the corneal epithelium. However, the epithelium was morphologically well preserved after irradiation in AST-treated corneas. Irradiated corneal epithelium was significantly thicker in eyes treated with AST eye drops, compared to those treated with vehicles (peyes than controls after irradiation (peffect increased with the dose of AST. Topical AST administration may be a candidate treatment to limit the damages by UV irradiation with wide clinical applications.

Corneal neurotoxicity due to topical benzalkonium chloride.

Science.gov (United States)

Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

2012-04-06

The aim of this study was to determine and characterize the effect of topical application of benzalkonium chloride (BAK) on corneal nerves in vivo and in vitro. Thy1-YFP+ neurofluorescent mouse eyes were treated topically with vehicle or BAK (0.01% or 0.1%). Wide-field stereofluorescence microscopy was performed to sequentially image the treated corneas in vivo every week for 4 weeks, and changes in stromal nerve fiber density (NFD) and aqueous tear production were determined. Whole-mount immunofluorescence staining of corneas was performed with antibodies to axonopathy marker SMI-32. Western immunoblot analyses were performed on trigeminal ganglion and corneal lysates to determine abundance of proteins associated with neurotoxicity and regeneration. Compartmental culture of trigeminal ganglion neurons was performed in Campenot devices to determine whether BAK affects neurite outgrowth. BAK-treated corneas exhibited significantly reduced NFD and aqueous tear production, and increased inflammatory cell infiltration and fluorescein staining at 1 week (P reduction in neurites occurred after BAK addition to compartmental cultures of dissociated trigeminal ganglion cells. Although both BAK doses (0.0001% and 0.001%) reduced nerve fiber length, the reduction was significantly more with the higher dose (P < 0.001). Topical application of BAK to the eye causes corneal neurotoxicity, inflammation, and reduced aqueous tear production.

Corneal densitometry and its correlation with age, pachymetry, corneal curvature, and refraction.

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Garzón, Nuria; Poyales, Francisco; Illarramendi, Igor; Mendicute, Javier; Jáñez, Óscar; Caro, Pedro; López, Alfredo; Argüeso, Francisco

2017-12-01

To determine normative corneal densitometry values in relation to age, sex, refractive error, corneal thickness, and keratometry, measured using the Oculus Pentacam system. Three hundred and thirty-eight healthy subjects (185 men; 153 women) with no corneal disease underwent an exhaustive ocular examination. Corneal densitometry was expressed in standardized grayscale units (GSU). The mean corneal densitometry over the total area was 16.46 ± 1.85 GSU. The Pearson correlation coefficient for total densitometry was r = 0.542 (p  0.05). This is the first report of normative corneal densitometry values in relation to keratometry, corneal thickness, and spherical equivalent measured with the latest Oculus Pentacam software. Corneal densitometry increases with age, but corneal keratometry and refractive parameters do not affect light scattering in the human cornea.

Olfaction in three genetic and two MPTP-induced Parkinson's disease mouse models.

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Stefan Kurtenbach

Full Text Available Various genetic or toxin-induced mouse models are frequently used for investigation of early PD pathology. Although olfactory impairment is known to precede motor symptoms by years, it is not known whether it is caused by impairments in the brain, the olfactory epithelium, or both. In this study, we investigated the olfactory function in three genetic Parkinson's disease (PD mouse models and mice treated with MPTP intraperitoneally and intranasally. To investigate olfactory function, we performed electro-olfactogram recordings (EOGs and an olfactory behavior test (cookie-finding test. We show that neither a parkin knockout mouse strain, nor intraperitoneal MPTP treated animals display any olfactory impairment in EOG recordings and the applied behavior test. We also found no difference in the responses of the olfactory epithelium to odorants in a mouse strain over-expressing doubly mutated α-synuclein, while this mouse strain was not suitable to test olfaction in a cookie-finding test as it displays a mobility impairment. A transgenic mouse expressing mutated α-synuclein in dopaminergic neurons performed equal to control animals in the cookie-finding test. Further we show that intranasal MPTP application can cause functional damage of the olfactory epithelium.

Systematic assessment of microneedle injection into the mouse cornea.

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Matthaei, Mario; Meng, Huan; Bhutto, Imran; Xu, Qingguo; Boelke, Edwin; Hanes, Justin; Jun, Albert S

2012-06-20

Corneal intrastromal injection is an important mode of gene-vector application to subepithelial layers. In a mouse model, this procedure is substantially complicated by the reduced corneal dimensions. Furthermore, it may be difficult to estimate the corneal area reached by the volume of a single injection. This study aimed to investigate intrastromal injections into the mouse cornea using different microneedles and to quantify the effect of injecting varying volumes. A reproducible injection technique is described. Forty eyes of 20 129 Sv/J mice were tested. India ink was intrastromally injected using 30° beveled 33 G needles, tri-surface 25° beveled 35 G needles, or hand-pulled and 25° beveled glass needles. Each eye received a single injection of a volume of 1 or 2 μL. Corneoscleral buttons were fixed and flat mounted for computer-assisted quantification of the affected corneal area. Histological assessment was performed to investigate the intrastromal location of the injected dye. A mean corneal area of 5.0 ± 1.4 mm(2) (mean ± SD) and 7.7 ± 1.4 mm(2) was covered by intrastromal injections of 1 and 2 μL, respectively. The mean percentage of total corneal area reached ranged from 39% to 53% for 1 μL injections, and from 65% to 81% for 2 μL injections. Injections using the 33 G needles tended to provide the highest distribution area. Perforation rates were 8% for 30° beveled 33 G needles and 44% for tri-surface beveled 35 G needles. No perforation was observed with glass needle; however, intrastromal breakage of needle tips was noted in 25% of these cases. Intracorneal injection using a 30° beveled 33 G needle was safe and effective. The use of tri-surface beveled 35 G needles substantially increased the number of corneal perforations. Glass needles may break inside the corneal stroma. Injections of 1 μL and 2 μL resulted in an overall mean of 49% and 73% respectively of total corneal area involved.

Clinical observation of corneal lamellar debridement combined with sutureless amniotic membrane transplantation for the treatment of superficial fungal keratitis

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Huang Zhang

2014-09-01

Full Text Available AIM:To evaluate the clinical efficacy of corneal lamellar debridement combined with sutureless amniotic membrane transplantation for the treatment of superficial fungal keratitis.METHODS:Totally 22 cases(22 eyeswith superficial fungal keratitis were referred to our hospital from April 2012 to October 2013. The patients with persistent cornea ulcer after treatment of local and systemic antifungal drugs underwent corneal lamellar debridement combined with sutureless amniotic membrane transplantation, and the recipient bed was covered with an amniotic membrane using fibrin sealant during the operation. All patients were still given topical antifungal therapy for 1-2mo after operation. The followed-up time was 3mo or above. We observed the corneal healing and amniotic membrane adhesion by split lamp microscope, and investigated the transformation of amniotic membrane and fungal infection recurrence with confocal microscope. RESULTS: Corneal edema and anterior chamber reaction of 21 patients disappeared gradually, and no amniotic membrane graft dissolved and shed off within 1-2wk postoperatively. Two weeks after operation, the graft integrated into the corneal and the corneal wounds' thickness increased gradually, the corneal epithelium reconstructed and corneas became clear. Four weeks after operation, the corneal scarring developed gradually and fluorescence staining was negative. Nineteen cases' amniotic membranes that adhered with the cornea dissolved 4wk after operation. There were different degrees of corneal nebula or macula remained 3mo postoperatively. All patients' vision improved in varying degrees, except in 1 case with fungal keratitis who had been cured by lamellar keratoplasty.CONCLUSION:Corneal lamellar debridement combined with sutureless amniotic membrane transplantation can effectively remove the foci of inflammation, improve the local efficacy, shorten the operation time, relieve the postoperative reaction, and promote cornea

Subthreshold UV radiation-induced peroxide formation in cultured corneal epithelial cells: the protective effects of lactoferrin

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Shimmura, Shigeto; Suematsu, Makoto; Shimoyama, Masaru; Oguchi, Yoshihisa; Ishimura, Yuzuru

1996-01-01

Acute exposure to suprathreshold ultraviolet B radiation (UV-B) is known to cause photokeratitis resulting from the necrosis and shedding of corneal epithelial cells. However, the corneal effects of low dose UV-B in the environmental range is less clear. In this study, subthreshold UV-B was demonstrated to cause non-necrotic peroxide formation in cultured corneal epithelial cells, which was attenuated by the major tear protein lactoferrin. Intracellular oxidative insults and cell viability of rabbit corneal epithelial cells (RCEC) were assessed by dual-color digital microfluorography using carboxydichlorofluorescin (CDCFH) diacetate bis (acetoxymethyl) ester, a hydroperoxide-sensitive fluoroprobe, and propidium iodode (PI) respectively. The magnitude of UV-induced oxidative insults was calibrated by concentrations of exogenously applied H 2 O 2 which evoke compatible levels of CDCFH oxidation. Exposure of RCEC to low-dose UV-B (2.0 mJ cm -2 at 313 nm, 10.0 mJ cm -2 total UV-B) caused intracellular oxidative changes which were equivalent to those elicited by 240 μM hydrogen peroxide under the conditions of the study. The changes were dose dependent, non-necrotic, and were partially inhibited by lactoferrin ( 1 mg ml -1 ) but not by iron-saturated lactoferrin. Pretreatment with deferoxamine (2 mΜ) or catalase (100 U ml -1 ) also attenuated the UV-induced oxidative stress. The results indicate that UV-B comparable to solar irradiation levels causes significant intracellular peroxide formation in corneal epithelial cells, and that lactoferrin in tears may have a physiological role in protecting the corneal epithelium from solar UV irradiation. (Author)

Development of teeth in chick embryos after mouse neural crest transplantations.

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Mitsiadis, Thimios A; Chéraud, Yvonnick; Sharpe, Paul; Fontaine-Pérus, Josiane

2003-05-27

Teeth were lost in birds 70-80 million years ago. Current thinking holds that it is the avian cranial neural crest-derived mesenchyme that has lost odontogenic capacity, whereas the oral epithelium retains the signaling properties required to induce odontogenesis. To investigate the odontogenic capacity of ectomesenchyme, we have used neural tube transplantations from mice to chick embryos to replace the chick neural crest cell populations with mouse neural crest cells. The mouse/chick chimeras obtained show evidence of tooth formation showing that avian oral epithelium is able to induce a nonavian developmental program in mouse neural crest-derived mesenchymal cells.

Molecular evidence and functional expression of multidrug resistance associated protein (MRP) in rabbit corneal epithelial cells.

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Karla, Pradeep K; Pal, Dananjay; Mitra, Ashim K

2007-01-01

Multidrug resistance associated protein (MRP) is a major family of efflux transporters involved in drug efflux leading to drug resistance. The objective of this study was to explore physical barriers for ocular drug absorption and to verify if the role of efflux transporters. MRP-2 is a major homologue of MRP family and found to express on the apical side of cell membrane. Cultured Rabbit Corneal Epithelial Cells (rCEC) were selected as an in vitro model for corneal epithelium. [14C]-erythromycin which is a proven substrate for MRP-2 was selected as a model drug for functional expression studies. MK-571, a known specific and potent inhibitor for MRP-2 was added to inhibit MRP mediated efflux. Membrane fraction of rCEC was used for western blot analysis. Polarized transport of [14C]-erythromycin was observed in rCEC and transport from B-->A was significantly high than from A-->B. Permeability's increased significantly from A-->B in the presence of MK-571 and ketoconozole. Uptake of [14C]-erythromycin in the presence of MK-571 was significantly higher than control in rCEC. RT-PCR analysis indicated a unique and distinct band at approximately 498 bp corresponding to MRP-2 in rCEC and MDCK11-MRP-2 cells. Immunoprecipitation followed by Western Blot analysis indicated a specific band at approximately 190 kDa in membrane fraction of rCEC and MDCK11-MRP-2 cells. For the first time we have demonstrated high expression of MRP-2 in rabbit corneal epithelium and its functional activity causing drug efflux. RT-PCR, immunoprecipitation followed by Western blot analysis further confirms the result.

Therapeutic effects of zerumbone in an alkali-burned corneal wound healing model.

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Kim, Jong Won; Jeong, Hyuneui; Yang, Myeon-Sik; Lim, Chae Woong; Kim, Bumseok

2017-07-01

Cornea is an avascular transparent tissue. Ocular trauma caused by a corneal alkali burn induces corneal neovascularization (CNV), inflammation, and fibrosis, leading to vision loss. The purpose of this study was to examine the effects of Zerumbone (ZER) on corneal wound healing caused by alkali burns in mice. CNV was induced by alkali-burn injury in BALB/C female mice. Topical ZER (three times per day, 3μl each time, at concentrations of 5, 15, and 30μM) was applied to treat alkali-burned mouse corneas for 14 consecutive days. Histopathologically, ZER treatment suppressed alkali burn-induced CNV and decreased corneal epithelial defects induced by alkali burns. Corneal tissue treated with ZER showed reduced mRNA levels of pro-angiogenic genes, including vascular endothelial growth factor, matrix metalloproteinase-2 and 9, and pro-fibrotic factors such as alpha smooth muscle actin and transforming growth factor-1 and 2. Immunohistochemical analysis demonstrated that the infiltration of F4/80 and/or CCR2 positive cells was significantly decreased in ZER-treated corneas. ZER markedly inhibited the mRNA and protein levels of monocyte chemoattractant protein-1 (MCP-1) in human corneal fibroblasts and murine peritoneal macrophages. Immunoblot analysis revealed that ZER decreased the activation of signal transducer and activator of transcription 3 (STAT3), with consequent reduction of MCP-1 production by these cells. In conclusion, topical administration of ZER accelerated corneal wound healing by inhibition of STAT3 and MCP-1 production. Copyright © 2017. Published by Elsevier B.V.

Novel nuclear localization and potential function of insulin-like growth factor-1 receptor/insulin receptor hybrid in corneal epithelial cells.

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Yu-Chieh Wu

Full Text Available BACKGROUND: Type I insulin-like growth factor receptor (IGF-1R and insulin receptor (INSR are highly homologous molecules, which can heterodimerize to form an IGF-1R/INSR hybrid (Hybrid-R. The presence and biological significance of the Hybrid-R in human corneal epithelium has not yet been established. In addition, while nuclear localization of IGF-1R was recently reported in cancer cells and human corneal epithelial cells, the function and profile of nuclear IGF-1R is unknown. In this study, we characterized the nuclear localization and function of the Hybrid-R and the role of IGF-1/IGF-1R and Hybrid-R signaling in the human corneal epithelium. METHODOLOGY/PRINCIPLE FINDINGS: IGF-1-mediated signaling and cell growth were examined in a human telomerized corneal epithelial (hTCEpi cell line using co-immunoprecipitation, immunoblotting and cell proliferation assays. The presence of Hybrid-R in hTCEpi and primary cultured human corneal epithelial cells was confirmed by immunofluorescence and reciprocal immunoprecipitation of whole cell lysates. We found that IGF-1 stimulated Akt and promoted cell growth through IGF-1R activation, which was independent of the Hybrid-R. The presence of Hybrid-R, but not IGF-1R/IGF-1R, was detected in nuclear extracts. Knockdown of INSR by small interfering RNA resulted in depletion of the INSR/INSR and preferential formation of Hybrid-R. Chromatin-immunoprecipitation sequencing assay with anti-IGF-1R or anti-INSR was subsequently performed to identify potential genomic targets responsible for critical homeostatic regulatory pathways. CONCLUSION/SIGNIFICANCE: In contrast to previous reports on nuclear localized IGF-1R, this is the first report identifying the nuclear localization of Hybrid-R in an epithelial cell line. The identification of a nuclear Hybrid-R and novel genomic targets suggests that IGF-1R traffics to the nucleus as an IGF-1R/INSR heterotetrameric complex to regulate corneal epithelial homeostatic

Establishment of a new immortalized human corneal epithelial cell line (iHCE-NY1) for use in evaluating eye irritancy by in vitro test methods.

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Yamamoto, Naoki; Kato, Yoshinao; Sato, Atsushi; Hiramatsu, Noriko; Yamashita, Hiromi; Ohkuma, Mahito; Miyachi, Ei-Ichi; Horiguchi, Masayuki; Hirano, Koji; Kojima, Hajime

2016-08-01

In vitro test methods that use human corneal epithelial cells to evaluate the eye irritation potency of chemical substances do not use human corneal epithelium because it has been difficult to maintain more than four passages. In this study, we make a new cell line comprising immortalized human corneal epithelial cells (iHCE-NY1). The IC50 of iHCE-NY1 cells is slightly higher than that of Statens Seruminstitut Rabbit Cornea (SIRC) cells, which are currently used in some in vitro test methods. CDKN1A in iHCE-NY1 cells was used as a marker of gene expression to indicate cell cycle activity. This enabled us to evaluate cell recovery characteristics at concentrations lower than the IC50 of cytotoxic tests.

Removal of the basement membrane enhances corneal wound healing.

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Pal-Ghosh, Sonali; Pajoohesh-Ganji, Ahdeah; Tadvalkar, Gauri; Stepp, Mary Ann

2011-12-01

Recurrent corneal erosions are painful and put patients' vision at risk. Treatment typically begins with debridement of the area around the erosion site followed by more aggressive treatments. An in vivo mouse model has been developed that reproducibly induces recurrent epithelial erosions in wild-type mice spontaneously within two weeks after a single 1.5 mm corneal debridement wound created using a dulled-blade. This study was conducted to determine whether 1) inhibiting MMP9 function during healing after dulled-blade wounding impacts erosion development and 2) wounds made with a rotating-burr heal without erosions. Oral or topical inhibition of MMPs after dulled-blade wounding does not improve healing. Wounds made by rotating-burr heal with significantly fewer erosions than dulled-blade wounds. The localization of MMP9, β4 integrin and basement membrane proteins (LN332 and type VII collagen), immune cell influx, and reinnervation of the corneal nerves were compared after both wound types. Rotating-burr wounds remove the anterior basement membrane centrally but not at the periphery near the wound margin, induce more apoptosis of corneal stromal cells, and damage more stromal nerve fibers. Despite the fact that rotating-burr wounds do more damage to the cornea, fewer immune cells are recruited and significantly more wounds resolve completely. Copyright © 2011 Elsevier Ltd. All rights reserved.

Progress of research on corneal collagen cross-linking for corneal melting

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Ke-Ren Xiao

2016-06-01

Full Text Available Corneal collagen cross-linking(CXLcould increase the mechanical strength, biological stability and halt ectasia progression due to covalent bond formed by photochemical reaction between ultraviolet-A and emulsion of riboflavin between collagen fibers in corneal stroma. Corneal melting is an autoimmune related noninfectious corneal ulcer. The mechanism of corneal melting, major treatment, the basic fundamental of ultraviolet-A riboflavin induced CXL and the clinical researches status and experiment in CXL were summarized in the study.

Response of mouse tongue epithelium to single doses of bleomycin and radiation

International Nuclear Information System (INIS)

Dorr, W.; Hirler, E.; Honig, M.

1993-01-01

Both bleomycin (BLM) and local X-irradiation (25 kV) induce denudation in the tongue epithelium of the C3H-Neuherberg mouse in a dose-dependent manner. In the present study the effect of BLM alone and of combined single doses of drug and radiation were studied using the incidence of epithelial denudation as the end-point. In 'time-line' experiments, 8 mg/kg BLM were given before or after graded doses of X-rays. BLM treatment required a reduction of the radiation dose (ED 50 ) from 15 Gy to 5-7 Gy, independent of sequence or time interval. In contrast, the time course of the response was clearly dependent on the treatment interval. Latency decreased when the drug was injected less than 2 h before irradiation with minimum latency observed at 30 min. Isobologram analysis of experiments with varying combinations of X-rays and BLM demonstrated that small drug doses were relatively more effective than larger doses, suggesting an upward concavity of the BLM dose-effective curve in vivo, i.e. a 'negative shoulder' of the curve in the low dose region. In contrast to the response to X-rays alone, which has a constant latent time to ulcer of 10 days, the latency in combined treatment was clearly shortened with increasing drug dose and at high doses eventually approximated the epithelial turnover time of 5 days. The data suggest that BLM both as a single agent and in combination with X-rays reduced the probability of abortive divisions and through this effect shortened the latent time to epithelial denudation. (author)

Intraocular pressure, corneal thickness, and corneal hysteresis in Steinert's myotonic dystrophy

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Carlos Alexandre de A. Garcia Filho

2011-06-01

Full Text Available PURPOSE: Low intraocular pressure (IOP measured by Goldmann applanation tonometry (GAT is one of the ocular manifestations of Steinert's myotonic dystrophy. The goal of this study was to evaluate the corneal-compensated IOP as well as corneal properties (central corneal thickness and corneal hysteresis in patients with myotonic dystrophy. METHODS: A total of 12 eyes of 6 patients with Steinert's myotonic dystrophy (dystrophy group and 12 eyes of 6 age-, race-, and gender-matched healthy volunteers (control group were included in the study. GAT, Dynamic Contour Tonometry (DCT-Pascal and Ocular Response Analyzer (ORA were used to assess the IOP. Central corneal thickness was obtained by ultrasound pachymetry, and corneal hysteresis was analyzed using the ORA device. In light of the multiplicity of tests performed, the significance level was set at 0.01 rather than 0.05. RESULTS: The mean (standard deviation [SD] GAT, DCT, and corneal-compensated ORA IOP in the dystrophy group were 5.4 (1.4 mmHg, 9.7 (1.5 mmHg, and 10.1 (2.6 mmHg, respectively. The mean (SD GAT, DCT, and corneal-compensated ORA IOP in the control group was 12.6 (2.9 mmHg, 15.5 (2.7 mmHg, and 15.8 (3.4 mmHg, respectively. There were significant differences in IOP values between dystrophy and control groups obtained by GAT (mean, -7.2 mmHg; 99% confidence interval [CI], -10.5 to -3.9 mmHg; P<0.001, DCT (mean, -5.9 mmHg; 99% CI, -8.9 to -2.8 mmHg; P<0.001, and corneal-compensated ORA measurements (mean, -5.7 mmHg; 99% CI, -10.4 to -1.0 mmHg; P=0.003. The mean (SD central corneal thickness was similar in the dystrophy (542 [31] µm and control (537 [11] µm groups (P=0.65. The mean (SD corneal hysteresis in the dystrophy and control groups were 11.2 (1.5 mmHg and 9.7 (1.2 mmHg, respectively (P=0.04. CONCLUSIONS: Patients with Steinert's myotonic dystrophy showed lower Goldmann and corneal-compensated IOP in comparison with healthy individuals. Since central corneal thickness and

Communication between corneal epithelial cells and trigeminal neurons is facilitated by purinergic (P2) and glutamatergic receptors.

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Oswald, Duane J; Lee, Albert; Trinidad, Monique; Chi, Cheryl; Ren, Ruiyi; Rich, Celeste B; Trinkaus-Randall, Vickery

2012-01-01

Previously, we demonstrated that nucleotides released upon mechanical injury to corneal epithelium activate purinergic (P2) receptors resulting in mobilization of a Ca(2+) wave. However, the tissue is extensively innervated and communication between epithelium and neurons is critical and not well understood. Therefore, we developed a co-culture of primary trigeminal neurons and human corneal limbal epithelial cells. We demonstrated that trigeminal neurons expressed a repertoire of P2Yand P2X receptor transcripts and responded to P2 agonists in a concentration-dependent manner. Mechanical injuries to epithelia in the co-cultures elicited a Ca(2+) wave that mobilized to neurons and was attenuated by Apyrase, an ectonucleotidase. To elucidate the role of factors released from each cell type, epithelial and neuronal cells were cultured, injured, and the wound media from one cell type was collected and added to the other cell type. Epithelial wound media generated a rapid Ca(2+) mobilization in neuronal cells that was abrogated in the presence of Apyrase, while neuronal wound media elicited a complex response in epithelial cells. The rapid Ca(2+) mobilization was detected, which was abrogated with Apyrase, but it was followed by Ca(2+) waves that occurred in cell clusters. When neuronal wound media was preincubated with a cocktail of N-methyl-D-aspartate (NMDA) receptor inhibitors, the secondary response in epithelia was diminished. Glutamate was detected in the neuronal wound media and epithelial expression of NMDA receptor subunit transcripts was demonstrated. Our results indicate that corneal epithelia and neurons communicate via purinergic and NMDA receptors that mediate the wound response in a highly orchestrated manner.

Communication between corneal epithelial cells and trigeminal neurons is facilitated by purinergic (P2 and glutamatergic receptors.

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Duane J Oswald

Full Text Available Previously, we demonstrated that nucleotides released upon mechanical injury to corneal epithelium activate purinergic (P2 receptors resulting in mobilization of a Ca(2+ wave. However, the tissue is extensively innervated and communication between epithelium and neurons is critical and not well understood. Therefore, we developed a co-culture of primary trigeminal neurons and human corneal limbal epithelial cells. We demonstrated that trigeminal neurons expressed a repertoire of P2Yand P2X receptor transcripts and responded to P2 agonists in a concentration-dependent manner. Mechanical injuries to epithelia in the co-cultures elicited a Ca(2+ wave that mobilized to neurons and was attenuated by Apyrase, an ectonucleotidase. To elucidate the role of factors released from each cell type, epithelial and neuronal cells were cultured, injured, and the wound media from one cell type was collected and added to the other cell type. Epithelial wound media generated a rapid Ca(2+ mobilization in neuronal cells that was abrogated in the presence of Apyrase, while neuronal wound media elicited a complex response in epithelial cells. The rapid Ca(2+ mobilization was detected, which was abrogated with Apyrase, but it was followed by Ca(2+ waves that occurred in cell clusters. When neuronal wound media was preincubated with a cocktail of N-methyl-D-aspartate (NMDA receptor inhibitors, the secondary response in epithelia was diminished. Glutamate was detected in the neuronal wound media and epithelial expression of NMDA receptor subunit transcripts was demonstrated. Our results indicate that corneal epithelia and neurons communicate via purinergic and NMDA receptors that mediate the wound response in a highly orchestrated manner.

Integrin Beta 1 Suppresses Multilayering of a Simple Epithelium

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Chen, Jichao; Krasnow, Mark A.

2012-01-01

Epithelia are classified as either simple, a single cell layer thick, or stratified (multilayered). Stratified epithelia arise from simple epithelia during development, and transcription factor p63 functions as a key positive regulator of epidermal stratification. Here we show that deletion of integrin beta 1 (Itgb1) in the developing mouse airway epithelium abrogates airway branching and converts this monolayer epithelium into a multilayer epithelium with more than 10 extra layers. Mutant lung epithelial cells change mitotic spindle orientation to seed outer layers, and cells in different layers become molecularly and functionally distinct, hallmarks of normal stratification. However, mutant lung epithelial cells do not activate p63 and do not switch to the stratified keratin profile of epidermal cells. These data, together with previous data implicating Itgb1 in regulation of epidermal stratification, suggest that the simple-versus-stratified developmental decision may involve not only stratification inducers like p63 but suppressors like Itgb1 that prevent simple epithelia from inappropriately activating key steps in the stratification program. PMID:23285215

Intrastromal corneal ring implants for corneal thinning disorders: an evidence-based analysis.

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2009-01-01

The purpose of this project was to determine the role of corneal implants in the management of corneal thinning disease conditions. An evidence-based review was conducted to determine the safety, effectiveness and durability of corneal implants for the management of corneal thinning disorders. The evolving directions of research in this area were also reviewed. SUBJECT OF THE EVIDENCE-BASED ANALYSIS: The primary treatment objectives for corneal implants are to normalize corneal surface topography, improve contact lens tolerability, and restore visual acuity in order to delay or defer the need for corneal transplant. Implant placement is a minimally invasive procedure that is purported to be safe and effective. The procedure is also claimed to be adjustable, reversible, and both eyes can be treated at the same time. Further, implants do not limit the performance of subsequent surgical approaches or interfere with corneal transplant. The evidence for these claims is the focus of this review. The specific research questions for the evidence review were as follows: SafetyCorneal Surface Topographic Effects:Effects on corneal surface remodellingImpact of these changes on subsequent interventions, particularly corneal transplantation (penetrating keratoplasty [PKP])Visual AcuityRefractive OutcomesVISUAL QUALITY (SYMPTOMS): such as contrast vision or decreased visual symptoms (halos, fluctuating vision)Contact lens toleranceFunctional visual rehabilitation and quality of lifePatient satisfaction:Disease Process:Impact on corneal thinning processEffect on delaying or deferring the need for corneal transplantation TARGET POPULATION AND CONDITION Corneal ectasia (thinning) comprises a range of disorders involving either primary disease conditions such as keratoconus and pellucid marginal corneal degeneration or secondary iatrogenic conditions such as corneal thinning occurring after LASIK refractive surgery. The condition occurs when the normally round dome-shaped cornea

Intraoperative corneal thickness measurements during corneal collagen cross-linking with isotonic riboflavin solution without dextran in corneal ectasia.

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Cınar, Yasin; Cingü, Abdullah Kürşat; Sahin, Alparslan; Türkcü, Fatih Mehmet; Yüksel, Harun; Caca, Ihsan

2014-03-01

Abstract Objective: To monitor the changes in corneal thickness during the corneal collagen cross-linking procedure by using isotonic riboflavin solution without dextran in ectatic corneal diseases. The corneal thickness measurements were obtained before epithelial removal, after epithelial removal, following the instillation of isotonic riboflavin solution without dextran for 30 min, and after 10 min of ultraviolet A irradiation. Eleven eyes of eleven patients with progressive keratoconus (n = 10) and iatrogenic corneal ectasia (n = 1) were included in this study. The mean thinnest pachymetric measurements were 391.82 ± 30.34 µm (320-434 µm) after de-epithelialization of the cornea, 435 ± 21.17 µm (402-472 µm) following 30 min instillation of isotonic riboflavin solution without dextran and 431.73 ± 20.64 µm (387-461 µm) following 10 min of ultraviolet A irradiation to the cornea. Performing corneal cross-linking procedure with isotonic riboflavin solution without dextran might not induce corneal thinning but a little swelling throughout the procedure.

Treatment with solubilized Silk-Derived Protein (SDP enhances rabbit corneal epithelial wound healing.

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Waleed Abdel-Naby

Full Text Available There is a significant clinical need to improve current therapeutic approaches to treat ocular surface injuries and disease, which affect hundreds of millions of people annually worldwide. The work presented here demonstrates that the presence of Silk-Derived Protein (SDP on the healing rabbit corneal surface, administered in an eye drop formulation, corresponds with an enhanced epithelial wound healing profile. Rabbit corneas were denuded of their epithelial surface, and then treated for 72-hours with either PBS or PBS containing 5 or 20 mg/mL SDP in solution four times per day. Post-injury treatment with SDP formulations was found to accelerate the acute healing phase of the injured rabbit corneal epithelium. In addition, the use of SDP corresponded with an enhanced tissue healing profile through the formation of a multi-layered epithelial surface with increased tight junction formation. Additional biological effects were also revealed that included increased epithelial proliferation, and increased focal adhesion formation with a corresponding reduction in the presence of MMP-9 enzyme. These in vivo findings demonstrate for the first time that the presence of SDP on the injured ocular surface may aid to improve various steps of rabbit corneal wound healing, and provides evidence that SDP may have applicability as an ingredient in therapeutic ophthalmic formulations.

Cell therapy of congenital corneal diseases with umbilical mesenchymal stem cells: lumican null mice.

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Hongshan Liu

Full Text Available BACKGROUND: Keratoplasty is the most effective treatment for corneal blindness, but suboptimal medical conditions and lack of qualified medical personnel and donated cornea often prevent the performance of corneal transplantation in developing countries. Our study aims to develop alternative treatment regimens for congenital corneal diseases of genetic mutation. METHODOLOGY/PRINCIPAL FINDINGS: Human mesenchymal stem cells isolated from neonatal umbilical cords were transplanted to treat thin and cloudy corneas of lumican null mice. Transplantation of umbilical mesenchymal stem cells significantly improved corneal transparency and increased stromal thickness of lumican null mice, but human umbilical hematopoietic stem cells failed to do the same. Further studies revealed that collagen lamellae were re-organized in corneal stroma of lumican null mice after mesenchymal stem cell transplantation. Transplanted umbilical mesenchymal stem cells survived in the mouse corneal stroma for more than 3 months with little or no graft rejection. In addition, these cells assumed a keratocyte phenotype, e.g., dendritic morphology, quiescence, expression of keratocyte unique keratan sulfated keratocan and lumican, and CD34. Moreover, umbilical mesenchymal stem cell transplantation improved host keratocyte functions, which was verified by enhanced expression of keratocan and aldehyde dehydrogenase class 3A1 in lumican null mice. CONCLUSIONS/SIGNIFICANCE: Umbilical mesenchymal stem cell transplantation is a promising treatment for congenital corneal diseases involving keratocyte dysfunction. Unlike donated corneas, umbilical mesenchymal stem cells are easily isolated, expanded, stored, and can be quickly recovered from liquid nitrogen when a patient is in urgent need.

Estimation of the in vitro eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust by using reconstituted human corneal epithelium tissue cultures.

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Cao, Yi; Bindslev, Dorthe A; Kjærgaard, Søren K

2015-01-01

Eye irritation is a common complaint in indoor environment, but the causes have still not been identified among the multiple exposures in house environments. To identify the potential environmental factors responsible for eye irritation and study the possible mechanisms, an in vitro model for eye irritation is suggested. In this study, reconstituted human corneal epithelium (HCE) tissue cultures were used to study the eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust. HCE tissue cultures were exposed to a range of concentrations of LPS for 6 h and dust for 24 h, respectively. After exposure, viability and secretion of interleukins (IL) IL-1β, IL-8, and tumor necrosis factor (TNFα) were examined. Histology was used to indicate the morphological changes after dust exposure. Both LPS and dust affected HCE viability. There was an increased level of IL-8 after LPS exposure, while the concentrations of IL-1β and TNFα remained unaffected. Dust exposure resulted in an elevation of both IL-1β and IL-8, but not TNFα. Histology study showed increased vacuolization and reduced thickness after 24 h exposure to 5 mg/mL dust. LPS and dust showed in vitro eye irritating and inflammatory potential, and cytokines/chemokines like IL-1β and IL-8 may be involved in the mechanisms of eye irritation. The HCE tissue culture may be used as an in vitro model to study environmental exposure induced eye irritation and inflammation.

Hormonal regulation of Na+/K+-dependent ATPase activity and pump function in corneal endothelial cells.

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Hatou, Shin

2011-10-01

Na- and K-dependent ATPase (Na,K-ATPase) in the basolateral membrane of corneal endothelial cells plays an important role in the pump function of the corneal endothelium. We investigated the role of dexamethasone in the regulation of Na,K-ATPase activity and pump function in these cells. Mouse corneal endothelial cells were exposed to dexamethasone or insulin. ATPase activity was evaluated by spectrophotometric measurement, and pump function was measured using an Ussing chamber. Western blotting and immunocytochemistry were performed to measure the expression of the Na,K-ATPase α1-subunit. Dexamethasone increased Na,K-ATPase activity and the pump function of endothelial cells. Western blot analysis indicated that dexamethasone increased the expression of the Na,K-ATPase α1-subunit but decreased the ratio of active to inactive Na,K-ATPase α1-subunit. Insulin increased Na,K-ATPase activity and pump function of cultured corneal endothelial cells. These effects were transient and blocked by protein kinase C inhibitors and inhibitors of protein phosphatases 1 (PP1) and 2A (PP2A). Western blot analysis indicated that insulin decreased the amount of inactive Na,K-ATPase α1-subunit, but the expression of total Na,K-ATPase α1-subunit was unchanged. Immunocytochemistry showed that insulin increased cell surface expression of the Na,K-ATPase α1-subunit. Our results suggest that dexamethasone and insulin stimulate Na,K-ATPase activity in mouse corneal endothelial cells. The effect of dexamethasone activation in these cells was mediated by Na,K-ATPase synthesis and an increased enzymatic activity because of dephosphorylation of Na,K-ATPase α1-subunits. The effect of insulin is mediated by the protein kinase C, PP1, and/or PP2A pathways.

TRPV4 Regulates Tight Junctions and Affects Differentiation in a Cell Culture Model of the Corneal Epithelium.

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Martínez-Rendón, Jacqueline; Sánchez-Guzmán, Erika; Rueda, Angélica; González, James; Gulias-Cañizo, Rosario; Aquino-Jarquín, Guillermo; Castro-Muñozledo, Federico; García-Villegas, Refugio

2017-07-01

TRPV4 (transient receptor potential vanilloid 4) is a cation channel activated by hypotonicity, moderate heat, or shear stress. We describe the expression of TRPV4 during the differentiation of a corneal epithelial cell model, RCE1(5T5) cells. TRPV4 is a late differentiation feature that is concentrated in the apical membrane of the outmost cell layer of the stratified epithelia. Ca 2+ imaging experiments showed that TRPV4 activation with GSK1016790A produced an influx of calcium that was blunted by the specific TRPV4 blocker RN-1734. We analyzed the involvement of TRPV4 in RCE1(5T5) epithelial differentiation by measuring the development of transepithelial electrical resistance (TER) as an indicator of the tight junction (TJ) assembly. We showed that TRPV4 activity was necessary to establish the TJ. In differentiated epithelia, activation of TRPV4 increases the TER and the accumulation of claudin-4 in cell-cell contacts. Epidermal Growth Factor (EGF) up-regulates the TER of corneal epithelial cultures, and we show here that TRPV4 activation mimicked this EGF effect. Conversely, TRPV4 inhibition or knock down by specific shRNA prevented the increase in TER. Moreover, TRPP2, an EGF-activated channel that forms heteromeric complexes with TRPV4, is also concentrated in the outmost cell layer of differentiated RCE1(5T5) sheets. This suggests that the EGF regulation of the TJ may involve a heterotetrameric TRPV4-TRPP2 channel. These results demonstrated TRPV4 activity was necessary for the correct establishment of TJ in corneal epithelia and as well as the regulation of both the barrier function of TJ and its ability to respond to EGF. J. Cell. Physiol. 232: 1794-1807, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Systematic assessment of microneedle injection into the mouse cornea

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Matthaei Mario

2012-06-01

Full Text Available Abstract Background Corneal intrastromal injection is an important mode of gene-vector application to subepithelial layers. In a mouse model, this procedure is substantially complicated by the reduced corneal dimensions. Furthermore, it may be difficult to estimate the corneal area reached by the volume of a single injection. This study aimed to investigate intrastromal injections into the mouse cornea using different microneedles and to quantify the effect of injecting varying volumes. A reproducible injection technique is described. Methods Forty eyes of 20 129 Sv/J mice were tested. India ink was intrastromally injected using 30° beveled 33 G needles, tri-surface 25° beveled 35 G needles, or hand-pulled and 25° beveled glass needles. Each eye received a single injection of a volume of 1 or 2 μL. Corneoscleral buttons were fixed and flat mounted for computer-assisted quantification of the affected corneal area. Histological assessment was performed to investigate the intrastromal location of the injected dye. Results A mean corneal area of 5.0 ±1.4 mm2 (mean ± SD and 7.7 ±1.4 mm2 was covered by intrastromal injections of 1 and 2 μL, respectively. The mean percentage of total corneal area reached ranged from 39% to 53% for 1 μL injections, and from 65% to 81% for 2 μL injections. Injections using the 33 G needles tended to provide the highest distribution area. Perforation rates were 8% for 30° beveled 33 G needles and 44% for tri-surface beveled 35 G needles. No perforation was observed with glass needle; however, intrastromal breakage of needle tips was noted in 25% of these cases. Conclusions Intracorneal injection using a 30° beveled 33 G needle was safe and effective. The use of tri-surface beveled 35 G needles substantially increased the number of corneal perforations. Glass needles may break inside the corneal stroma. Injections of 1 μL and 2 μL resulted in an overall mean of 49% and 73% respectively

Elevated IGFBP3 levels in diabetic tears: a negative regulator of IGF-1 signaling in the corneal epithelium.

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Wu, Yu-Chieh; Buckner, Benjamin R; Zhu, Meifang; Cavanagh, H Dwight; Robertson, Danielle M

2012-04-01

To determine the ratio of IGFBP3:IGF-1 in normal and diabetic human tears, and in telomerase-immortalized human corneal epithelial cells (hTCEpi) cultured under elevated glucose conditions and to correlate these changes with total and phosphorylated levels of IGF-1R. Tear samples were collected noninvasively from diabetic subjects and non-diabetic controls; corneal sensitivity was assessed using a Cochet-Bonnet Aesthesiometer. Conditioned media were collected following culture of hTCEpi cells in normal (5 mM) and elevated (25 mM) glucose conditions; mannitol was used as an osmotic control. IGFBP3, IGF-1, and phosphorylated IGF-1R levels were assessed by ELISA. IGFBP3 and IGF-1R mRNA were assessed by real-time polymerase chain reaction (PCR). Total and phosphorylated IGF-1R expression in whole cell lysates was assessed by western blot. There was a 2.8-fold increase in IGFBP3 in diabetic tears compared to non-diabetic controls (P=0.006); IGF-1 levels were not significantly altered. No difference in corneal sensitivity was detected between groups. The concentration of IGFBP3 in tears was independent of IGF-1. Consistent with human tear measurements in vivo, IGFBP3 secretion was increased 2.2 fold (Ptears compared to normal controls blocked phosphorylation of the IGF-1R by IGF-1 (Ptears may attenuate IGF-1R signaling in the diabetic cornea. A long-term increase in IGFBP3 may contribute to epithelial compromise and the pathogenesis of ocular surface complications reported in diabetes. Copyright © 2012 Elsevier Inc. All rights reserved.

Epithelium

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The term "epithelium" refers to layers of cells that line hollow organs and glands. It is also those cells that make ... Kierszenbaum AL, Tres LL. Epithelium. In: Kierszenbaum AL, Tres LL, ... to Pathology . 4th ed. Philadelphia, PA: Elsevier Saunders; ...

The effects of dexamethasone on the Na,K-ATPase activity and pump function of corneal endothelial cells.

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Hatou, Shin; Yamada, Masakazu; Mochizuki, Hiroshi; Shiraishi, Atsushi; Joko, Takeshi; Nishida, Teruo

2009-05-01

The Na(+)- and K(+)-dependent ATPase (Na,K-ATPase) expressed in the basolateral membrane of corneal endothelial cells plays an important role in the pump function of the corneal endothelium. We investigated the possible role of dexamethasone in the regulation of Na,K-ATPase activity and pump function in corneal endothelial cells. Confluent monolayers of mouse corneal endothelial cells were exposed to dexamethasone. ATPase activity of the cells was evaluated by spectrophotometric measurement of phosphate released from ATP with the use of ammonium molybdate, with Na,K-ATPase activity being defined as the portion of total ATPase activity sensitive to ouabain. Pump function of the cells was measured with the use of an Ussing chamber, with the pump function attributable to Na,K-ATPase activity being defined as the portion of the total short-circuit current sensitive to ouabain. Western blot analysis was examined to measure the expression of the Na,K-ATPase alpha(1)-subunit. Dexamethasone (1 or 10 microM) increased the Na,K-ATPase activity and pump function of the cultured cells. These effects of dexamethasone were blocked by cycloheximide, a protein synthesis inhibitor. Western blot analysis also indicated that dexamethasone increased the expression of the Na,K-ATPase alpha(1)-subunit, whereas it decreased the expression of the phospho-Na,K-ATPase alpha(1)-subunit. Our results suggest that dexamethasone stimulates Na,K-ATPase activity in mouse corneal endothelial cells. The effect of dexamethasone activation in these cells is mediated by Na,K-ATPase synthesis and increase in an enzymatic activity by dephosphorylation of Na,K-ATPase alpha(1)-subunits.

Confocal microscopy evaluation of stromal fluorescence intensity after standard and accelerated iontophoresis-assisted corneal cross-linking.

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Lanzini, Manuela; Curcio, Claudia; Spoerl, Eberhard; Calienno, Roberta; Mastropasqua, Alessandra; Colasante, Martina; Mastropasqua, Rodolfo; Nubile, Mario; Mastropasqua, Leonardo

2017-02-01

The aim of this study is to determine modifications in stromal fluorescence intensity after different corneal cross-linking (CXL) procedures and to correlate stromal fluorescence to corneal biomechanical resistance. For confocal microscopy study, 15 human cadaver corneas were examined. Three served as control (group 1), three were just soaked with iontophoresis procedure (group 2), three were treated with standard epi-off technique (group 3), and six underwent iontophoresis imbibition. Three of later six were irradiated for 30 min with 3 mW/cm 2 UVA (group 4) and three for 9 min at 10 mW/cm 2 UVA (group 5). Confocal microscopy was performed to quantify the fluorescence intensity in the cornea at different stromal depths. For biomechanical study, 30 human cadaver corneas were randomly divided into five groups and treated as previously described. Static stress-strain measurements of the corneas were performed. Iontophoresis imbibition followed by 10mW/cm 2 irradiation proved to increase stromal fluorescence into the corneal stroma and significant differences were revealed between group 3 and 5 both at 100 (p = 0.0171) and 250 µm (p = 0.0024), respectively. Biomechanical analysis showed an improvement of corneal resistance in group 5. Iontophoresis imbibition followed by accelerated irradiation increased the stromal fluorescence and is related to an improvement of biomechanical resistance. This approach may represent a new strategy to achieve greater concentrations of riboflavin without removing corneal epithelium and improve clinical results while reducing the side effects of CXL.

Neuropilin 1 Receptor Is Up-Regulated in Dysplastic Epithelium and Oral Squamous Cell Carcinoma.

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Shahrabi-Farahani, Shokoufeh; Gallottini, Marina; Martins, Fabiana; Li, Erik; Mudge, Dayna R; Nakayama, Hironao; Hida, Kyoko; Panigrahy, Dipak; D'Amore, Patricia A; Bielenberg, Diane R

2016-04-01

Neuropilins are receptors for disparate ligands, including proangiogenic factors such as vascular endothelial growth factor and inhibitory class 3 semaphorin (SEMA3) family members. Differentiated cells in skin epithelium and cutaneous squamous cell carcinoma highly express the neuropilin-1 (NRP1) receptor. We examined the expression of NRP1 in human and mouse oral mucosa. NRP1 was significantly up-regulated in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC). NRP1 receptor localized to the outer suprabasal epithelial layers in normal tongue, an expression pattern similar to the normal skin epidermis. However, dysplastic tongue epithelium and OSCC up-regulated NRP1 in basal and proliferating epithelial layers, a profile unseen in cutaneous squamous cell carcinoma. NRP1 up-regulation is observed in a mouse carcinogen-induced OSCC model and in human tongue OSCC biopsies. Human OSCC cell lines express NRP1 protein in vitro and in mouse tongue xenografts. Sites of capillary infiltration into orthotopic OSCC tumors correlate with high NRP1 expression. HSC3 xenografts, which express the highest NRP1 levels of the cell lines examined, showed massive intratumoral lymphangiogenesis. SEMA3A inhibited OSCC cell migration, suggesting that the NRP1 receptor was bioactive in OSCC. In conclusion, NRP1 is regulated in the oral epithelium and is selectively up-regulated during epithelial dysplasia. NRP1 may function as a reservoir to sequester proangiogenic ligands within the neoplastic compartment, thereby recruiting neovessels toward tumor cells. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

The Role of Limbal Epithelial Stem Cells in Regulating Corneal (Lymphangiogenic Privilege and the Micromilieu of the Limbal Niche following UV Exposure

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M. Notara

2018-01-01

Full Text Available The cornea is a clear structure, void of blood, and lymphatic vessels, functioning as our window to the world. Limbal epithelial stem cells, occupying the area between avascular cornea and vascularized conjunctiva, have been implicated in tissue border maintenance, preventing conjunctivalisation and propagation of blood and lymphatic vessels into the cornea. Defects in limbal epithelial stem cells are linked to corneal neovascularisation, including lymphangiogenesis, chronic inflammation, conjunctivalisation, epithelial abnormalities including the presence of goblet cells, breaks in Bowman’s membrane, persistent epithelial defects and ulceration, ocular surface squamous neoplasia, lipid keratopathy, pain, discomfort, and compromised vision. It has been postulated that pterygium is an example of focal limbal deficiency. Previous reports showing changes occurring in limbal epithelium during pterygium pathogenesis suggest that there is a link to stem cell damage. In this light, pterygium can serve as a model disease of UV-induced stem cell damage also characterised by corneal blood and lymphangiogenesis. This review focuses on the role of corneal and limbal epithelial cells and the stem cell niche in maintaining corneal avascularity and corneal immune privilege and how this may be deregulated following UV exposure. We present an overview of the PUBMED literature in the field as well as recent work from our laboratories.

Equine corneal stromal abscesses

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Henriksen, M. D. L.; Andersen, P. H.; Plummer, C. E.

2013-01-01

The last 30 years have seen many changes in the understanding of the pathogenesis and treatment of equine corneal stromal abscesses (SAs). Stromal abscesses were previously considered an eye problem related to corneal bacterial infection, equine recurrent uveitis, corneal microtrauma and corneal....... Medical and surgical treatments are now directed towards elimination of fungal and bacterial infections, reduction and replacement of diseased corneal stroma, and suppression of iridocyclitis. If the abscess and anterior uveitis do not respond satisfactorily to medical therapy, full thickness or split...

NK cells modulate the inflammatory response to corneal epithelial abrasion and thereby support wound healing

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Natural killer cells are lymphocytes of the innate immune system that have crucial cytotoxic and regulatory roles in adaptive immunity and inflammation. Herein, we consider a role for these cells in corneal wound healing. After a 2-mm central epithelial abrasion of the mouse cornea, a subset of clas...

Therapeutic Effects of Topical Netrin-4 Inhibits Corneal Neovascularization in Alkali-Burn Rats

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Han, Yun; Shao, Yi; Liu, Tingting; Qu, Yang-Luowa; Li, Wei; Liu, Zuguo

2015-01-01

Netrins are secreted molecules involved in axon guidance and angiogenesis. However, the role of netrins in the vasculature remains unclear. Netrin-4 and netrin-1 have been found to be either pro- or antiangiogenic factors. Previously, we found that netrin-1 acts as an anti-angiogenic factor in rats by inhibiting alkali burn-induced corneal neovascularization. Here, we further investigate the effects of netrin-4, another member of the same netrin family, on neovascularization in vitro and in vivo. We found that netrin-4 functions similarly as netrin-1 in angiogenesis. In vitro angiogenesis assay shows that netrin-4 affected human umbilical vein endothelial cell (HUVEC) tube formation, viability and proliferation, apoptosis, migration, and invasion in a dose-dependent manner. Netrin-4 was topically applied in vivo to alkali-burned rat corneas on day 0 (immediately after injury) and/or day 10 post-injury. Netrin-4 subsequently suppressed and reversed corneal neovascularization. Netrin-4 inhibited corneal epithelial and stromal cell apoptosis, inhibited vascular endothelial growth factor (VEGF), but promoted pigment epithelium-derived factor (PEDF) expression, decreased NK-KB p65 expression, and inhibits neutrophil and macrophage infiltration. These results indicate that netrin-4 shed new light on its potential roles in treatmenting for angiogenic diseases that affect the ocular surface, as well as other tissues. PMID:25853509

Dynamic corneal deformation response and integrated corneal tomography

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Marcella Q Salomão

2018-01-01

Full Text Available Measuring corneal biomechanical properties is still challenging. There are several clinical applications for biomechanical measurements, including the detection of mild or early forms of ectatic corneal diseases. This article reviews clinical applications for biomechanical measurements provided by the Corvis ST dynamic non contact tonometer

Expression of hypoxia-inducible factor-1α and erythropoietin at corneal neovascularization in rats

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Ji-Min Wang

2014-12-01

Full Text Available AIM: To describe the expression of hypoxia-inducible factor-1α(HIF-1αand erythropoietin(EPOin rats' corneal and evaluate its potential effect on corneal neovascularization(CNVgrowth. METHODS: The young SD rats(3mowas chosen and randomly divided into 2 groups, which were experimental group and normal control group. CNV model was established by alkali burn, and the length and area of CNV was observed everyday after operation by slit lamp. After that, the expression of HIF-1α and EPO was measured by SABC and RT-PCR methods at 1, 3, 5, 7, and 14d after alkali burn. The data was analyzed by SPSS 20.0. RESULTS: The area of CNV was increasing at 1, 3, 5, 7, and 14d after alkali burn, and the peak point appear at 7d. The growth speed was decreased after 14d. SABC method told us that no HIF-1α and very tiny amount EPO was detected at normal rats' corneal. The expression of the two factors increased at 1d after alkali burn in corneal epithelium and endoderm. The results of RT-PCR showed that a few amounts of HIF-1α and EPO mRNA were detected at normal group. The expression of the two factors was increased at 3d after alkali burn, and the peak value was found at 7d, however, it was decreased at 14d. Statistical difference was found at different time(PCONCLUSION: HIF-1α and EPO is closely related to CNV.

Collagen VII deficient mice show morphologic and histologic corneal changes that phenotypically mimic human dystrophic epidermolysis bullosa of the eye.

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Chen, Vicki M; Shelke, Rajani; Nyström, Alexander; Laver, Nora; Sampson, James F; Zhiyi, Cao; Bhat, Najma; Panjwani, Noorjahan

2018-06-16

Absence of collagen VII causes blistering of the skin, eyes and many other tissues. This disease is termed dystrophic epidermolysis bullosa (DEB). Corneal fibrosis occurs in up to 41% and vision loss in up to 64% of patients. Standard treatments are supportive and there is no cure. The immune-histologic and morphologic changes in the corneas of the mouse model for this disease have not been described in the literature. Our purpose is to characterize the eyes of these mice to determine if this is an appropriate model for study of human therapeutics. Western blot analysis (WB) and immunohistochemistry (IHC) were performed to assess the relative collagen VII protein levels and its location within the cornea. Additional IHC for inflammatory and fibrotic biomarkers alpha-smooth muscle actin (α-SMA), transforming growth factor-beta (TGF-β), connective tissue growth factor (CTGF), proteinase 3, tenascin C and collagen III were performed. Clinical photographs documenting opacification of the corneas of animals of differing ages were assessed and scored independently by 2 examiners. Histology was then used to investigate morphologic changes. IHC and WB confirmed that these mice are deficient in collagen VII production at the level of the basement membrane when compared with wild-types. IHC showed anomalous deposition of collagen III throughout the stroma. Of the 5 biomarkers tested, TGF-β showed the strongest and most consistently staining. Photographs documented corneal opacities only in mice older than 10 weeks, opacities were not seen in younger animals. Histology showed multiple abnormalities, including epithelial hyperplasia, ulceration, fibrosis, edema, dysplasia, neovascularization and bullae formation. The collagen VII hypomorphic mouse shows reduced collagen VII production at the level of the corneal basement membrane. Corneal changes are similar to pathology seen in humans with this disease. The presence of anomalous stromal collagen III and TGF-β appear to be

Ocular dimensions, corneal thickness, and corneal curvature in quarter horses with hereditary equine regional dermal asthenia.

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Badial, Peres R; Cisneros-Àlvarez, Luis Emiliano; Brandão, Cláudia Valéria S; Ranzani, José Joaquim T; Tomaz, Mayana A R V; Machado, Vania M; Borges, Alexandre S

2015-09-01

The aim of this study was to compare ocular dimensions, corneal curvature, and corneal thickness between horses affected with hereditary equine regional dermal asthenia (HERDA) and unaffected horses. Five HERDA-affected quarter horses and five healthy control quarter horses were used. Schirmer's tear test, tonometry, and corneal diameter measurements were performed in both eyes of all horses prior to ophthalmologic examinations. Ultrasonic pachymetry was performed to measure the central, temporal, nasal, dorsal, and ventral corneal thicknesses in all horses. B-mode ultrasound scanning was performed on both eyes of each horse to determine the dimensions of the ocular structures and to calculate the corneal curvature. Each corneal region examined in this study was thinner in the affected group compared with the healthy control group. However, significant differences in corneal thickness were only observed for the central and dorsal regions. HERDA-affected horses exhibited significant increases in corneal curvature and corneal diameter compared with unaffected animals. The ophthalmologic examinations revealed mild corneal opacity in one eye of one affected horse and in both eyes of three affected horses. No significant between-group differences were observed for Schirmer's tear test, intraocular pressure, or ocular dimensions. Hereditary equine regional dermal asthenia-affected horses exhibit decreased corneal thickness in several regions of the cornea, increased corneal curvature, increased corneal diameter, and mild corneal opacity. Additional research is required to determine whether the increased corneal curvature significantly impacts the visual accuracy of horses with HERDA. © 2014 American College of Veterinary Ophthalmologists.

Efficacy of Tectonic Corneal Patch Graft for Progressive Peripheral Corneal Thinning

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Cafer Tanrıverdio

2014-12-01

Full Text Available Objectives: To report the results of tectonic corneal patch graft (TCPG in patients with progressive peripheral corneal thinning (PCT. Materials and Methods: In this study, we included 8 patients who underwent TCPG for PCT or perforated corneal ulceration at Ankara Training and Research Hospital. Results: We performed TCPG in 7 patients for PCT and in 1 patient for perforated corneal ulceration. Mean age was 57.2±16.7 (38- 82 years. Postoperative follow-up time ranged from 6 to 24 months (mean 13.9±6.7. Possible etiologies leading to progressive PCT were trachoma, infectious corneal ulcer, and rheumatoid arthritis-severe dry eye in 2 patients each. Other 2 patients had a progressive PCT following ocular surgery. One of the patients with infectious corneal ulcer also had a trauma caused by a scissor. Amnion membrane transplantation was performed in 3 patients prior to TCPG. While the anatomic success was achieved in all 8 patients, best-corrected visual acuity (BCVA was 0.1 or better in 4 patients (50%. Postoperative BCVA was better than preoperative BCVA in 6 patients (75%. Local peripheral anterior synechiae developed in two eyes. Conclusion: TCPG is a useful therapeutic option in selected cases of corneal thinning and perforations because it effectively restores the integrity of the globe and allows acceptable visual results. (Turk J Ophthalmol 2014; 44: 440-4

Construction of a human corneal stromal equivalent with non-transfected human corneal stromal cells and acellular porcine corneal stromata.

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Diao, Jin-Mei; Pang, Xin; Qiu, Yue; Miao, Ying; Yu, Miao-Miao; Fan, Ting-Jun

2015-03-01

A tissue-engineered human corneal stroma (TE-HCS) has been developed as a promising equivalent to the native corneal stroma for replacement therapy. However, there is still a crucial need to improve the current approaches to render the TE-HCS equivalent more favorable for clinical applications. At the present study, we constructed a TE-HCS by incubating non-transfected human corneal stromal (HCS) cells in an acellular porcine corneal stromata (aPCS) scaffold in 20% fetal bovine serum supplemented DMEM/F12 (1:1) medium at 37 °C with 5% CO2in vitro. After 3 days of incubation, the constructed TE-HCS had a suitable tensile strength for transplantation, and a transparency that is comparable to native cornea. The TE-HCS had a normal histological structure which contained regularly aligned collagen fibers and differentiated HCS cells with positive expression of marker and functional proteins, mimicking a native HCS. After transplantation into rabbit models, the TE-HCS reconstructed normal corneal stroma in vivo and function well in maintaining corneal clarity and thickness, indicating that the completely biological TE-HCS could be used as a HCS equivalent. The constructed TE-HCS has promising potentials in regenerative medicine and treatment of diseases caused by corneal stromal disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Corneal Crosslinking With Rose Bengal and Green Light: Efficacy and Safety Evaluation.

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Zhu, Hong; Alt, Clemens; Webb, Robert H; Melki, Samir; Kochevar, Irene E

2016-09-01

To evaluate crosslinking of cornea in vivo using green light activation of Rose Bengal (RGX) and assess potential damaging effects of the green light on retina and iris. Corneas of Dutch belted rabbits were de-epithelialized, then stained with Rose Bengal and exposed to green light, or not further treated. Corneal stiffness was measured by uniaxial tensiometry. Re-epithelialization was assessed by fluorescein fluorescence. Keratocytes were counted on hematoxylin and eosin (H&E)-stained sections, and iris cell damage was assessed by lactate dehydrogenase staining. Thermal effects on the blood-retinal barrier (BRB) were assessed by fluorescein angiography and those on photoreceptors, retinal pigment epithelium (RPE), and choriocapillaris by light microscopy and transmission electron microscopy. RGX (10-min irradiation; 150 J/cm) increased corneal stiffness 1.9-fold on day 1 (1.25 ± 0.21 vs. 2.38 ± 0.59 N/mm; P = 0.036) and 2.8-fold compared with controls on day 28 (1.70 ± 0.74 vs. 4.95 ± 1.86 N/mm; P = 0.003). Keratocytes decreased only in the anterior stroma on day 1 (24.0 ± 3.0 vs. 3.67 ± 4.73, P = 0.003) and recovered by day 28 (37.7 ± 8.9 vs. 34.5 ± 2.4, P = 0.51). Iris cells were not thermally damaged. No evidence of BRB breakdown was detected on days 1 or 28. Retina from RGX-treated eyes seemed normal with RPE cells showing intact nuclei shielded apically by melanosomes, morphologically intact photoreceptor outer segments, normal outer nuclear layer thickness, and choriocapillaris containing intact erythrocytes. The substantial corneal stiffening produced by RGX together with the lack of significant effects on keratocytes and no evidence for retina or iris damage suggest that RGX-initiated corneal crosslinking may be a safe, rapid, and effective treatment.

Corneal Laceration

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Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration ... Laceration Treatment What Is Corneal Laceration? Leer en Español: ¿Qué es una laceración de la córnea? Written ...

Keratocyte apoptosis and corneal antioxidant enzyme activities after refractive corneal surgery.

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Bilgihan, K; Bilgihan, A; Adiguzel, U; Sezer, C; Yis, O; Akyol, G; Hasanreisoglu, B

2002-01-01

Refractive corneal surgery induces keratocyte apoptosis and generates reactive oxygen radicals (ROS) in the cornea. The purpose of the present study is to evaluate the correlation between keratocyte apoptosis and corneal antioxidant enzyme activities after different refractive surgical procedures in rabbits. Rabbits were divided into six groups. All groups were compared with the control group (Group 1), after epithelial scraping (Group 2), epithelial scrape and photorefractive keratectomy (PRK) (traditional PRK: Group 3), transepithelial PRK (Group 4), creation of a corneal flap with microkeratome (Group 5) and laser-assisted in situ keratomileusis (LASIK, Group 6). Terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labelling assay (to detect DNA fragmentation in situ) and light microscopy were used to detect apoptosis in rabbit eyes. Glutathione peroxidase (Gpx) and superoxide dismutase (SOD) activities of the corneal tissues were measured with spectrophotometric methods. Corneal Gpx and SOD activities decreased significantly in all groups when compared with the control group (P<0.05) and groups 2, 3 and 6 showed a significantly higher amount of keratocyte apoptosis (P<0.05). Not only a negative correlation was observed between corneal SOD activity and keratocyte apoptosis (cc: -0.3648) but Gpx activity also showed negative correlation with keratocyte apoptosis (cc: -0.3587). The present study illustrates the negative correlation between keratocyte apoptosis and corneal antioxidant enzyme activities. This finding suggests that ROS may be partly responsible for keratocyte apoptosis after refractive surgery.

Role of protein kinase C in regulation of Na+- and K +-dependent ATPase activity and pump function in corneal endothelial cells.

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Hatou, Shin; Yamada, Masakazu; Mochizuki, Hiroshi; Nishida, Teruo

2009-05-01

Na+- and K+-dependent ATPase (Na,K-ATPase) plays an important role in the pump function of the corneal endothelium. We investigated the possible role of protein kinase C (PKC) in regulation of Na,K-ATPase activity and pump function in corneal endothelial cells. Confluent monolayers of mouse corneal endothelial cells were exposed to phorbol 12,13-dibutyrate (PDBu) to induce activation of PKC. ATPase activity of the cells was evaluated by using ammonium molybdate in spectrophotometric measurement of phosphate released from ATP, with Na,K-ATPase activity being defined as the portion of total ATPase activity sensitive to ouabain. Pump function of the cells was measured with a Ussing chamber, with the pump function attributable to Na,K-ATPase activity being defined as the portion of the total short-circuit current sensitive to ouabain. PDBu (10(-7) M) increased the Na,K-ATPase activity and pump function of the cultured cells. These effects of PDBu were potentiated by the cyclooxygenase inhibitor indomethacin and the cytochrome P(450) inhibitor resorufin and were blocked by okadaic acid, an inhibitor of protein phosphatases 1 and 2A. Our results suggest that PKC bidirectionally regulates Na,K-ATPase activity in mouse corneal endothelial cells: it inhibits Na,K-ATPase activity in a cyclooxygenase- and cytochrome P(450)-dependent manner, whereas it stimulates such activity by activating protein phosphatases 1 or 2A.

Binding of the aliphatic halides 1,2-dibromoethane and chloroform in the rodent vaginal epithelium

International Nuclear Information System (INIS)

Brittebo, E.B.; Brandt, I.; Kowalski, B.

1987-01-01

Whole-body and light microscopic autoradiography were used to study the binding of 1,2-dibromo( 14 C)ethane ( 14 C-DBE) and 14 C-chloroform ( 14 C-CF) in the mouse and rat vaginal epithelium in vitro and in vivo. In pregnant mice, mice pretreated with pregnant mare's serum gonadotropin (PMSG) or ovariectomized mice primed with medroxyprogesterone, a high level of bound 14 C-DBE metabolites were present in the epithelium, while in ovariectomized oestradiol-primed mice or intact oestradiol-primed mice, the binding was low. Similar results were obtained with 14 C-CF, although the level of binding generally was lower than that observed after 14 C-DBE-exposure. No binding of 14 C-DBE-metabolites was observed in the juvenile rat vaginal epithelium, whereas a high binding was present in the PMSG-primed adult rat vaginal epithelium. Collectively, these data show that 14 C-DBE and 14 C-CF are transformed in situ to metabolites that are irreversibly bound to the vaginal epithelium. The results also suggest that the activating enzyme is under endocrine control and has a low activity in the juvenile and oestradiol-primed adult animal. (author)

Corneal protection with high-molecular-weight hyaluronan against in vitro and in vivo sodium lauryl sulfate-induced toxic effects.

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Pauloin, Thierry; Dutot, Mélody; Liang, Hong; Chavinier, Emilie; Warnet, Jean-Michel; Rat, Patrice

2009-10-01

The aim of this study was to investigate high-molecular-weight hyaluronan (HA-HMW) corneal protection against sodium lauryl sulfate (SLS)-induced toxic effects with in vitro and in vivo experimental approaches. In vitro experiments consisted of a human corneal epithelial cell line incubated with HA-HMW, rinsed, and incubated with SLS. Cell viability, oxidative stress, chromatin condensation, caspase-3, -8, -9, and P2X7 cell death receptor activation, interleukin-6, and interleukin-8 production were investigated. In vivo experiments consisted of 36 New Zealand white rabbits treated for 3 days, 3 times per day, with HA-HMW or phosphate-buffered salt solution. At day 4, eyes were treated with SLS. Clinical observation and in vivo confocal microscopy using the Rostock Cornea Module of the Heidelberg Retina Tomograph-II were performed to evaluate and to compare SLS-induced toxicity between eyes treated with HA-HMW and eyes treated with phosphate-buffered salt solution. In vitro data indicate that exposure of human corneal epithelial cells to HA-HMW significantly decreased SLS-induced oxidative stress, apoptosis, and inflammation cytokine production. In vivo data indicate that SLS cornea injuries, characterized by damaged corneal epithelium, damaged anterior stroma, and inflammatory infiltrations, were attenuated with HA-HMW treatment. A good correlation was seen between in vitro and in vivo findings showing that HA-HMW decreases SLS-induced toxic effects and protects cornea.

The junctional epithelium originates from the odontogenic epithelium of an erupted tooth.

Science.gov (United States)

Yajima-Himuro, Sara; Oshima, Masamitsu; Yamamoto, Gou; Ogawa, Miho; Furuya, Madoka; Tanaka, Junichi; Nishii, Kousuke; Mishima, Kenji; Tachikawa, Tetsuhiko; Tsuji, Takashi; Yamamoto, Matsuo

2014-05-02

The junctional epithelium (JE) is an epithelial component that is directly attached to the tooth surface and has a protective function against periodontal diseases. In this study, we determined the origin of the JE using a bioengineered tooth technique. We transplanted the bioengineered tooth germ into the alveolar bone with an epithelial component that expressed green fluorescence protein. The reduced enamel epithelium from the bioengineered tooth fused with the oral epithelium, and the JE was apparently formed around the bioengineered tooth 50 days after transplantation. Importantly, the JE exhibited green fluorescence for at least 140 days after transplantation, suggesting that the JE was not replaced by oral epithelium. Therefore, our results demonstrated that the origin of the JE was the odontogenic epithelium, and odontogenic epithelium-derived JE was maintained for a relatively long period.

Early Detection of Ovarian Cancer by Tumor Epithelium-Targeted Molecular Ultrasound

Science.gov (United States)

2014-10-01

successful pregnancy outcome. *PIF Proprietary G-12 IL-33-responsive group 2 innate lymphoid cells are present in mouse uterine tissue and may play roles in... innate lymphoid cells (ILC2s) that are responsive to IL-33 drive helminth immunity, type 2 immune responses, and tissue pathology and homeostasis in...16 (IL-16) secreted by immune cells . Inflammation of the ovary and tubal epithelium due to frequent ovulation leads to the development of oxidative

Corneal tissue welding with infrared laser irradiation after clear corneal incision.

Science.gov (United States)

Rasier, Rfat; Ozeren, Mediha; Artunay, Ozgür; Bahçecioğlu, Halil; Seçkin, Ismail; Kalaycoğlu, Hamit; Kurt, Adnan; Sennaroğlu, Alphan; Gülsoy, Murat

2010-09-01

The aim of this study was to investigate the potential of infrared lasers for corneal welding to seal corneal cuts done in an experimental animal model. Full-thickness corneal cuts on freshly enucleated bovine eyes were irradiated with infrared (809-nm diode, 980-nm diode, 1070-nm YLF, and 1980-nm Tm:YAP) lasers to get immediate laser welding. An 809-nm laser was used with the topical application of indocyanine green to enhance the photothermal interaction at the weld site. In total, 60 bovine eyes were used in this study; 40 eyes were used in the first part of the study for the determination of optimal welding parameters (15 eyes were excluded because of macroscopic carbonization, opacification, or corneal shrinkage; 2 eyes were used for control), and 20 eyes were used for further investigation of more promising lasers (YLF and Tm:YAP). Laser wavelength, irradiating power, exposure time, and spot size were the dose parameters, and optimal dose for immediate closure with minimal thermal damage was estimated through histological examination of welded samples. In the first part of the study, results showed that none of the applications was satisfactory. Full-thickness success rates were 28% (2 of 7) for 809-nm and for 980-nm diode lasers and 67% (2 of 3) for 1070-nm YLF and (4 of 6) for 1980-nm Tm:YAP lasers. In the second part of the study, YLF and Tm:YAP lasers were investigated with bigger sample size. Results were not conclusive but promising again. Five corneal incisions were full-thickness welded out of 10 corneas with 1070-nm laser, and 4 corneal incisions were partially welded out of 10 corneas with 1980-nm laser in the second part of the study. Results showed that noteworthy corneal welding could be obtained with 1070-nm YLF laser and 1980-nm Tm:YAP laser wavelengths. Furthermore, in vitro and in vivo studies will shed light on the potential usage of corneal laser welding technique.

Epithelium-on photorefractive intrastromal cross-linking (PiXL for reduction of low myopia

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Lim WK

2017-06-01

Full Text Available Wee Kiak Lim,1,2 Zhi Da Soh,1 Harold Kah Yen Choi,1 Julian Thiam Siew Theng1,3 1Eagle Eye Centre, Mount Alvernia Hospital, 2Department of Ophthalmology, Tan Tock Seng Hospital, 3Department of Ophthalmology, Khoo Teck Puat Hospital, Singapore Purpose: To report the 9–12-month outcomes of a novel procedure for reduction of low myopia through epithelium-on photorefractive intrastromal cross-linking (PiXL with customized control of topographic distribution of ultraviolet (UV-fluence. Method: Myopic patients with normal (non-ectatic corneas underwent the PiXL procedure for reduction of low myopia. PiXL treatments were delivered through selective application of UVA light based on the refractive error of each patient. Clinical evaluation included safety (corrected distance visual acuity, endothelial cell count, central corneal thickness, anterior ocular health and efficacy (uncorrected distance visual acuity, manifest refraction, K-mean examinations. In addition, a patient satisfaction survey was conducted at 9 months post-procedure to evaluate patients’ subjective experience with the procedure. Results: Fourteen myopic eyes (mean manifest refraction spherical equivalent –1.62±0.6D; range –0.75 to –2.65D of 8 subjects (mean age 30 years old; range 24–51 years old were enrolled in the study. At 12 months post-procedure, a mean manifest refraction spherical equivalent reduction of 0.72±0.43D (P<0.001 was observed, with a corresponding gain in uncorrected visual acuity of 0.25 logMAR and mean K-mean flattening of 0.47±0.46D. All patients achieved best corrected visual acuity of 20/20 or better from 1 month onward. There were no cases of ocular infection or secondary changes to the crystalline lens and retina due to UV exposure, while transient corneal haze subsided gradually. Conclusion: The epithelium-on PiXL procedure was safe and effective in reducing myopic refractive error in this study with up to 12 months follow-up. Early results of

Neurotrophic corneal and conjunctival xerosis

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Svetlana Gennadyevna Zhurova

2014-03-01

Full Text Available Purpose: to develop a method of surgical treatment of patients with corneal ulcers of xerotic etiology and evaluate its efficacy in different time periods after operation. Materials and methods: 68 patients (86 eyes with severe dry eye syndrome complicated by xerotic corneal ulcers were examined. In all patients, the ulcer defect was covered with conjunctiva and amniotic membrane. The operation was combined with an outer tarsorrhaphy and temporary blepharorraphy. Results: All 86 eyes (100% achieved total closure of the ulcer defect, sealing of any perforation and maintaining of corneal transparency beyond the ulcer defect. Conclusion: Surgical closure of corneal ulcers with conjunctiva is an effective method of treatment of xerotic corneal ulcers. It could be recommended in patients with corneal perforation and tendency of descemetocele formation.

Iontophoresis Transcorneal Delivery Technique for Transepithelial Corneal Collagen Crosslinking With Riboflavin in a Rabbit Model.

Science.gov (United States)

Cassagne, Myriam; Laurent, Camille; Rodrigues, Magda; Galinier, Anne; Spoerl, Eberhard; Galiacy, Stéphane D; Soler, Vincent; Fournié, Pierre; Malecaze, François

2016-02-01

We compared an iontophoresis riboflavin delivery technique for transepithelial corneal collagen crosslinking (I-CXL) with a conventional CXL (C-CXL). We designed three experimental sets using 152 New Zealand rabbits to study riboflavin application by iontophoresis using charged riboflavin solution (Ricrolin+) with a 1-mA current for 5 minutes. The first set was to compare riboflavin concentration measured by HPLC in corneas after iontophoresis or conventional riboflavin application. The second set was to analyze autofluorescence and stromal collagen modification immediately and 14 days after I-CXL or C-CXL, by using nonlinear two-photon microscopy (TP) and second harmonic generation (SHG). In the third set, physical modifications after I-CXL and C-CXL were evaluated by stress-strain measurements and by studying corneal resistance against collagenase digestion. Based on HPLC analysis, we found that iontophoresis allowed riboflavin diffusion with 2-fold less riboflavin concentration than conventional application (936.2 ± 312.5 and 1708 ± 908.3 ng/mL, respectively, P riboflavin delivery in crosslinking treatments, preserving the epithelium.

A new 3D reconstituted human corneal epithelium model as an alternative method for the eye irritation test.

Science.gov (United States)

Jung, Kyoung-Mi; Lee, Su-Hyon; Ryu, Yang-Hwan; Jang, Won-Hee; Jung, Haeng-Sun; Han, Ju-Hee; Seok, Seung-Hyeok; Park, Jae-Hak; Son, Youngsook; Park, Young-Ho; Lim, Kyung-Min

2011-02-01

Many efforts are being made to develop new alternative in vitro test methods for the eye irritation test. Here we report a new reconstructed human corneal epithelial model (MCTT HCE model) prepared from primary-cultured human limbal epithelial cells as a new alternative in vitro eye irritation test method. In histological and immunohistochemical observation, MCTT HCE model displayed a morphology and biomarker expressions similar to intact human cornea. Moreover, the barrier function was well preserved as measured by high transepithelial electrical resistance, effective time-50 for Triton X-100, and corneal thickness. To employ the model as a new alternative method for eye irritation test, protocol refinement was performed and optimum assay condition was determined including treatment time, treatment volume, post-incubation time and rinsing method. Using the refined protocol, 25 reference chemicals with known eye irritation potentials were tested. With the viability cut-off value at 50%, chemicals were classified to irritant or non-irritant. When compared with GHS classification, the MCTT HCE model showed the accuracy of 88%, sensitivity of 100% and specificity of 77%. These results suggest that the MCTT HCE model might be useful as a new alternative eye irritation test method. Copyright © 2010 Elsevier Ltd. All rights reserved.

Intravital two-photon microscopy of immune cell dynamics in corneal lymphatic vessels.

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Philipp Steven

Full Text Available BACKGROUND: The role of lymphatic vessels in tissue and organ transplantation as well as in tumor growth and metastasis has drawn great attention in recent years. METHODOLOGY/PRINCIPAL FINDINGS: We now developed a novel method using non-invasive two-photon microscopy to simultaneously visualize and track specifically stained lymphatic vessels and autofluorescent adjacent tissues such as collagen fibrils, blood vessels and immune cells in the mouse model of corneal neovascularization in vivo. The mouse cornea serves as an ideal tissue for this technique due to its easy accessibility and its inducible and modifiable state of pathological hem- and lymphvascularization. Neovascularization was induced by suture placement in corneas of Balb/C mice. Two weeks after treatment, lymphatic vessels were stained intravital by intrastromal injection of a fluorescently labeled LYVE-1 antibody and the corneas were evaluated in vivo by two-photon microscopy (TPM. Intravital TPM was performed at 710 nm and 826 nm excitation wavelengths to detect immunofluorescence and tissue autofluorescence using a custom made animal holder. Corneas were then harvested, fixed and analyzed by histology. Time lapse imaging demonstrated the first in vivo evidence of immune cell migration into lymphatic vessels and luminal transport of individual cells. Cells immigrated within 1-5.5 min into the vessel lumen. Mean velocities of intrastromal corneal immune cells were around 9 µm/min and therefore comparable to those of T-cells and macrophages in other mucosal surfaces. CONCLUSIONS: To our knowledge we here demonstrate for the first time the intravital real-time transmigration of immune cells into lymphatic vessels. Overall this study demonstrates the valuable use of intravital autofluorescence two-photon microscopy in the model of suture-induced corneal vascularizations to study interactions of immune and subsequently tumor cells with lymphatic vessels under close as possible

Corneal markers of diabetic neuropathy.

Science.gov (United States)

Pritchard, Nicola; Edwards, Katie; Shahidi, Ayda M; Sampson, Geoff P; Russell, Anthony W; Malik, Rayaz A; Efron, Nathan

2011-01-01

Diabetic neuropathy is a significant clinical problem that currently has no effective therapy, and in advanced cases, leads to foot ulceration and lower limb amputation. The accurate detection, characterization and quantification of this condition are important in order to define at-risk patients, anticipate deterioration, monitor progression, and assess new therapies. This review evaluates novel corneal methods of assessing diabetic neuropathy. Two new noninvasive corneal markers have emerged, and in cross-sectional studies have demonstrated their ability to stratify the severity of this disease. Corneal confocal microscopy allows quantification of corneal nerve parameters and noncontact corneal esthesiometry, the functional correlate of corneal structure, assesses the sensitivity of the cornea. Both these techniques are quick to perform, produce little or no discomfort for the patient, and are suitable for clinical settings. Each has advantages and disadvantages over traditional techniques for assessing diabetic neuropathy. Application of these new corneal markers for longitudinal evaluation of diabetic neuropathy has the potential to reduce dependence on more invasive, costly, and time-consuming assessments, such as skin biopsy.

Topical thrombin-related corneal calcification.

Science.gov (United States)

Kiratli, Hayyam; Irkeç, Murat; Alaçal, Sibel; Söylemezoğlu, Figen

2006-09-01

To report a highly unusual case of corneal calcification after brief intraoperative use of topical thrombin. A 44-year-old man underwent sclerouvectomy for ciliochoroidal leiomyoma, during which 35 UNIH/mL lyophilized bovine thrombin mixed with 9 mL of diluent containing 1500 mmol/mL calcium chloride was used. From the first postoperative day, corneal and anterior lenticular capsule calcifications developed, and corneal involvement slightly enlarged thereafter. A year later, 2 corneal punch biopsies confirmed calcification mainly in the Bowman layer. Topical treatment with 1.5% ethylenediaminetetraacetic acid significantly restored corneal clarity. Six months later, a standard extracapsular cataract extraction with intraocular lens placement improved visual acuity to 20/60. This case suggests that topical thrombin drops with elevated calcium concentrations may cause acute corneal calcification in Bowman layer and on the anterior lens capsule.

Plasma polymer-coated contact lenses for the culture and transfer of corneal epithelial cells in the treatment of limbal stem cell deficiency.

Science.gov (United States)

Brown, Karl David; Low, Suet; Mariappan, Indumathi; Abberton, Keren Maree; Short, Robert; Zhang, Hong; Maddileti, Savitri; Sangwan, Virender; Steele, David; Daniell, Mark

2014-02-01

Extensive damage to the limbal region of the cornea leads to a severe form of corneal blindness termed as limbal stem cell deficiency (LSCD). Whereas most cases of corneal opacity can be treated with full thickness corneal transplants, LSCD requires stem cell transplantation for successful ocular surface reconstruction. Current treatments for LSCD using limbal stem cell transplantation involve the use of murine NIH 3T3 cells and human amniotic membranes as culture substrates, which pose the threat of transmission of animal-derived pathogens and donor tissue-derived cryptic infections. In this study, we aimed to produce surface modified therapeutic contact lenses for the culture and delivery of corneal epithelial cells for the treatment of LSCD. This approach avoids the possibility of suture-related complications and is completely synthetic. We used plasma polymerization to deposit acid functional groups onto the lenses at various concentrations. Each surface was tested for its suitability to promote corneal epithelial cell adhesion, proliferation, retention of stem cells, and differentiation and found that acid-based chemistries promoted better cell adhesion and proliferation. We also found that the lenses coated with a higher percentage of acid functional groups resulted in a higher number of cells transferred onto the corneal wound bed in rabbit models of LSCD. Immunohistochemistry of the recipient cornea confirmed the presence of autologous, transplanted 5-bromo-2'-deoxyuridine (BrdU)-labeled cells. Hematoxylin staining has also revealed the presence of a stratified epithelium at 26 days post-transplantation. This study provides the first evidence for in vivo transfer and survival of cells transplanted from a contact lens to the wounded corneal surface. It also proposes the possibility of using plasma polymer-coated contact lenses with high acid functional groups as substrates for the culture and transfer of limbal cells in the treatment of LSCD.

Corneal Transplantation

DEFF Research Database (Denmark)

Hjortdal, Jesper Østergaard

with less risk of rejection episodes. Besides covering updated chapters on penetrating keratoplasty, and anterior and posterior lamellar procedures, this textbook also gives a thorough overview of the history of corneal transplantation and a detailed presentation of the microstructural components...... and to assist fellows and corneal surgeons in their advice and selection of patients for the best surgical procedure considering benefi ts and risks....

Recovery of the sub-basal nerve plexus and superficial nerve terminals after corneal epithelial injury in mice.

Science.gov (United States)

Downie, Laura E; Naranjo Golborne, Cecilia; Chen, Merry; Ho, Ngoc; Hoac, Cam; Liyanapathirana, Dasun; Luo, Carol; Wu, Ruo Bing; Chinnery, Holly R

2018-06-01

Our aim was to compare regeneration of the sub-basal nerve plexus (SBNP) and superficial nerve terminals (SNT) following corneal epithelial injury. We also sought to compare agreement when quantifying nerve parameters using different image analysis techniques. Anesthetized, female C57BL/6 mice received central 1-mm corneal epithelial abrasions. Four-weeks post-injury, eyes were enucleated and processed for PGP9.5 to visualize the corneal nerves using wholemount immunofluorescence staining and confocal microscopy. The percentage area of the SBNP and SNT were quantified using: ImageJ automated thresholds, ImageJ manual thresholds and manual tracings in NeuronJ. Nerve sum length was quantified using NeuronJ and Imaris. Agreement between methods was considered with Bland-Altman analyses. Four-weeks post-injury, the sum length of nerve fibers in the SBNP, but not the SNT, was reduced compared with naïve eyes. In the periphery, but not central cornea, of both naïve and injured eyes, nerve fiber lengths in the SBNP and SNT were strongly correlated. For quantifying SBNP nerve axon area, all image analysis methods were highly correlated. In the SNT, there was poor correlation between manual methods and auto-thresholding, with a trend towards underestimating nerve fiber area using auto-thresholding when higher proportions of nerve fibers were present. In conclusion, four weeks after superficial corneal injury, there is differential recovery of epithelial nerve axons; SBNP sum length is reduced, however the sum length of SNTs is similar to naïve eyes. Care should be taken when selecting image analysis methods to compare nerve parameters in different depths of the corneal epithelium due to differences in background autofluorescence. Copyright © 2018 Elsevier Ltd. All rights reserved.

Applications of corneal topography and tomography: a review.

Science.gov (United States)

Fan, Rachel; Chan, Tommy Cy; Prakash, Gaurav; Jhanji, Vishal

2018-03-01

Corneal imaging is essential for diagnosing and management of a wide variety of ocular diseases. Corneal topography is used to characterize the shape of the cornea, specifically, the anterior surface of the cornea. Most corneal topographical systems are based on Placido disc that analyse rings that are reflected off the corneal surface. The posterior corneal surface cannot be characterized using Placido disc technology. Imaging of the posterior corneal surface is useful for diagnosis of corneal ectasia. Unlike corneal topographers, tomographers generate a three-dimensional recreation of the anterior segment and provide information about the corneal thickness. Scheimpflug imaging is one of the most commonly used techniques for corneal tomography. The cross-sectional images generated by a rotating Scheimpflug camera are used to locate the anterior and posterior corneal surfaces. The clinical uses of corneal topography include, diagnosis of corneal ectasia, assessment of corneal astigmatism, and refractive surgery planning. This review will discuss the applications of corneal topography and tomography in clinical practice. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

CON4EI: SkinEthic™ Human Corneal Epithelium Eye Irritation Test (SkinEthic™ HCE EIT) for hazard identification and labelling of eye irritating chemicals.

Science.gov (United States)

Van Rompay, A R; Alépée, N; Nardelli, L; Hollanders, K; Leblanc, V; Drzewiecka, A; Gruszka, K; Guest, R; Kandarova, H; Willoughby, J A; Verstraelen, S; Adriaens, E

2018-06-01

Assessment of ocular irritancy is an international regulatory requirement and a necessary step in the safety evaluation of industrial and consumer products. Although a number of in vitro ocular irritation assays exist, none are capable of fully categorizing chemicals as a stand-alone assay. Therefore, the CEFIC-LRI-AIMT6-VITO CON4EI (CONsortium for in vitro Eye Irritation testing strategy) project was developed with the goal of assessing the reliability of eight in vitro/alternative test methods as well as establishing an optimal tiered-testing strategy. One of the in vitro assays selected was the validated SkinEthic™ Human Corneal Epithelium Eye Irritation Test method (SkinEthic™ HCE EIT). The SkinEthic™ HCE EIT has already demonstrated its capacity to correctly identify chemicals (both substances and mixtures) not requiring classification and labelling for eye irritation or serious eye damage (No Category). The goal of this study was to evaluate the performance of the SkinEthic™ HCE EIT test method in terms of the important in vivo drivers of classification. For the performance with respect to the drivers all in vivo Cat 1 and No Cat chemicals were 100% correctly identified. For Cat 2 chemicals the liquids and the solids had a sensitivity of 100% and 85.7%, respectively. For the SkinEthic™ HCE EIT test method, 100% concordance in predictions (No Cat versus No prediction can be made) between the two participating laboratories was obtained. The accuracy of the SkinEthic™ HCE EIT was 97.5% with 100% sensitivity and 96.9% specificity. The SkinEthic™ HCE EIT confirms its excellent results of the validation studies. Copyright © 2017. Published by Elsevier Ltd.

A histological study of rabbit corneas after transepithelial corneal crosslinking using partial epithelial photoablation or ethanol treatment.

Science.gov (United States)

Ozmen, Mehmet Cuneyt; Hondur, Ahmet; Yilmaz, Guldal; Bilgihan, Kamil; Hasanreisoglu, Berati

2014-01-01

To evaluate the histological changes after transepithelial corneal crosslinking (CXL) using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study. Right eyes of twenty-four rabbits were studied. Four eyes received total epithelial debridement (group I). Four eyes received partial thickness epithelial ablation with excimer laser (group II). Twelve eyes were treated with different durations (30s and 60s) and concentrations (18% to 48%) of ethanol (group III). Riboflavin was applied for 30min intervals along with topical proparacaine drops with benzalkonium chloride, and 370 nm irradiation was performed for 30min, while riboflavin was instilled every 3min. Four eyes (group IV) received 48% ethanol for 30s without riboflavin and irradiation. Eyes were collected after 24h and examined histologically. All eyes in group I showed keratocyte loss in the superficial 300 µ of corneal storma. In group II, 1-4 layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60s revealed no keratocyte loss. CXL after treatment with 48% and higher ethanol concentrations yielded keratocyte loss in the superficial 200 µ to 300 µ of cornea. Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24% concentration and up to 60s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thickness excimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.

A histological study of rabbit corneas after transepithelial corneal crosslinking using partial epithelial photoablation or ethanol treatment

Directory of Open Access Journals (Sweden)

Mehmet Cuneyt Ozmen

2014-12-01

Full Text Available AIM: To evaluate the histological changes after transepithelial corneal crosslinking (CXL using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study.METHODS: Right eyes of twenty-four rabbits were studied. Four eyes received total epithelial debridement (group I. Four eyes received partial thickness epithelial ablation with excimer laser (group II. Twelve eyes were treated with different durations (30s and 60s and concentrations (18% to 48% of ethanol (group III. Riboflavin was applied for 30min intervals along with topical proparacaine drops with benzalkonium chloride, and 370 nm irradiation was performed for 30min, while riboflavin was instilled every 3min. Four eyes (group IV received 48% ethanol for 30s without riboflavin and irradiation. Eyes were collected after 24h and examined histologically.RESULTS: All eyes in group I showed keratocyte loss in the superficial 300 µ of corneal storma. In group II, 1-4 layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60s revealed no keratocyte loss. CXL after treatment with 48% and higher ethanol concentrations yielded keratocyte loss in the superficial 200 µ to 300 µ of cornea.CONCLUSION: Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24% concentration and up to 60s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thickness excimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.

Loss of the Wnt receptor frizzled 7 in the mouse gastric epithelium is deleterious and triggers rapid repopulation in vivo

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Dustin J. Flanagan

2017-08-01

Full Text Available The gastric epithelium consists of tubular glandular units, each containing several differentiated cell types, and populations of stem cells, which enable the stomach to secrete the acid, mucus and various digestive enzymes required for its function. Very little is known about which cell signalling pathways are required for homeostasis of the gastric epithelium. Many diseases, such as cancer, arise as a result of deregulation of signalling pathways that regulate homeostasis of the diseased organ. Therefore, it is important to understand the biology of how normal conditions are maintained in a tissue to help inform the mechanisms driving disease in that same tissue, and to identify potential points of therapeutic intervention. Wnt signalling regulates several cell functions, including proliferation, differentiation and migration, and plays a crucial role during homeostasis of several tissues, including the intestinal epithelium. Wnt3a is required in the culture medium of gastric organoids, suggesting it is also important for the homeostasis of the gastric epithelium, but this has not been investigated in vivo. Here, we show that the Wnt receptor frizzled 7 (Fzd7, which is required for the homeostasis of the intestine, is expressed in the gastric epithelium and is required for gastric organoid growth. Gastric-specific loss of Fzd7 in the adult gastric epithelium of mice is deleterious and triggers rapid epithelial repopulation, which we believe is the first observation of this novel function for this tissue. Taken together, these data provide functional evidence of a crucial role for Wnt signalling, via the Fzd7 receptor, during homeostasis of the gastric epithelium.

Topical Drug Formulations for Prolonged Corneal Anesthesia

Science.gov (United States)

Wang, Liqiang; Shankarappa, Sahadev A.; Tong, Rong; Ciolino, Joseph B.; Tsui, Jonathan H.; Chiang, Homer H.; Kohane, Daniel S.

2013-01-01

Purpose Ocular local anesthetics (OLA’s) currently used in routine clinical practice for corneal anesthesia are short acting and their ability to delay corneal healing makes them unsuitable for long-term use. In this study, we examined the effect on the duration of corneal anesthesia of the site-1 sodium channel blocker tetrodotoxin (TTX), applied with either proparacaine or the chemical permeation enhancer OTAB. The effect of test solutions on corneal healing was also studied. Methods Solutions of TTX, proparacaine, and OTAB, singly or in combination were applied topically to the rat cornea. The blink response, an indirect measure of corneal sensitivity, was recorded using a Cochet-Bonnet esthesiometer, and the duration of corneal anesthesia calculated. The effect of test compounds on the rate of corneal epithelialization was studied in vivo following corneal debridement. Results Combination of TTX and proparacaine resulted in corneal anesthesia that was 8–10 times longer in duration than that from either drug administered alone, while OTAB did not prolong anesthesia. The rate of corneal healing was moderately delayed following co-administration of TTX and proparacaine. Conclusion Co-administration of TTX and proparacaine significantly prolonged corneal anesthesia but in view of delayed corneal re-epithelialization, caution is suggested in use of the combination. PMID:23615270

Evaluation of intraocular pressure according to corneal thickness before and after excimer laser corneal ablation for myopia.

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Hamed-Azzam, Shirin; Briscoe, Daniel; Tomkins, Oren; Shehedeh-Mashor, Raneen; Garzozi, Hanna

2013-08-01

Intraocular pressure is affected by corneal thickness and biomechanics. Following ablative corneal refractive surgery, corneal structural changes occur. The purpose of the study is to determine the relationship between the mean central corneal thickness (CCT) and the change in intraocular pressure measurements following various corneal ablation techniques, using different measurement methods. Two hundred myopic eyes undergoing laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) were enrolled into a prospective, non-randomized study. Corneal parameters examined included full ocular examination, measurement of CCT, corneal topography, corneal curvature and ocular refractivity. Intraocular pressure measurements were obtained using three different instruments-non-contact tonometer, Goldmann applanation tonometer and TonoPen XL (TonoPen-Central and TonoPen-Peripheral). All measurements were performed pre-operatively and 4 months post-operatively. Post-operative intraocular pressure was significantly lower than pre-operative values, with all instruments (p value tonometer and non-contact tonometer (p value < 0.001, ANOVA). Intraocular pressure readings are significantly reduced following corneal ablation surgery. We determined in our myopic patient cohort that the TonoPen XL intraocular pressure measurement method is the least affected following PRK and LASIK as compared to other techniques.

Trifluoperazine: corneal endothelial phototoxicity

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Hull, D.S.; Csukas, S.; Green, K.

1983-01-01

Trifluoperazine is used for the treatment of psychiatric disorders. Perfusion of corneal endothelial cells with trifluoperazine-HC1 concurrent with exposure to long wavelength ultraviolet light resulted in a corneal swelling rate greater than that found in perfused corneas not exposed to ultraviolet light. Exposure of endothelial cells to 25 W incandescent light during perfusion with trifluoperazine-HC1 did not result in a higher corneal swelling rate compared to those perfused in the dark. The increased corneal swelling rate could be produced by pre-exposure of the trifluoperazine-HC1 perfusing solution to ultraviolet light suggesting the production of toxic photoproducts during exposure of trifluoperazine-HC1 to ultraviolet light. Perfusion of corneal endothelial cells with non-ultraviolet illuminated trifluoperazine-HC1 had no effect on endothelial cell membranes or ultrastructure. This is in contrast to cells perfused with trifluoperazine-HC1 that had been exposed to ultraviolet light in which there was an alteration of mitochondria and a loss of cytoplasmic homogeneity. The data imply that the trifluoperazine-HC1 photoproduct had an adverse effect on cellular transport mechanisms. The study also further demonstrates the value of the corneal endothelial cell model for identifying the physiological and anatomical changes occuring in photo-induced toxic reactions. (author)

Corneal surface temperature change as the mode of stimulation of the non-contact corneal aesthesiometer.

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Murphy, P J; Morgan, P B; Patel, S; Marshall, J

1999-05-01

The non-contact corneal aesthesiometer (NCCA) assesses corneal sensitivity by using a controlled pulse of air, directed at the corneal surface. The purpose of this paper was to investigate whether corneal surface temperature change was a component in the mode of stimulation. Thermocouple experiment: A simple model corneal surface was developed that was composed of a moistened circle of filter paper placed on a thermocouple and mounted on a glass slide. The temperature change produced by different stimulus pressures was measured for five different ambient temperatures. Thermal camera experiment: Using a thermal camera, the corneal surface temperature change was measured in nine young, healthy subjects after exposure to different stimulus air pulses. Pulse duration was set at 0.9 s but was varied in pressure from 0.5 to 3.5 millibars. Thermocouple experiment: An immediate drop in temperature was detected by the thermocouple as soon as the air flow was incident on the filter paper. A greater temperature change was produced by increasing the pressure of the incident air flow. A relationship was found and a calibration curve plotted. Thermal camera experiment: For each subject, a drop in surface temperature was detected at each stimulus pressure. Furthermore, as the stimulus pressure increased, the induced reduction in temperature also increased. A relationship was found and a calibration curve plotted. The NCCA air-pulse stimulus was capable of producing a localized temperature change on the corneal surface. The principal mode of corneal nerve stimulation, by the NCCA air pulse, was the rate of temperature change of the corneal surface.

CONTACT LENS RELATED CORNEAL ULCER

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AGARWAL P

2010-01-01

Full Text Available A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are:overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. The presenting symptoms of contact lens related corneal ulcers include eye discomfort, foreign body sensation and lacrimation. More serious symptoms are redness (especially circum-corneal injection, severe pain, photophobia, eye discharge and blurring of vision. The diagnosis is established by a thorough slit lamp microscopic examination with fluorescein staining and corneal scraping for Gram stain and culture of the infective organism. Delay in diagnosing and treatment can cause permanent blindness, therefore an early referral to ophthalmologist and commencing of antimicrobial therapy can prevent visual loss.

Reconstituted human corneal epithelium: a new alternative to the Draize eye test for the assessment of the eye irritation potential of chemicals and cosmetic products.

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Doucet, O; Lanvin, M; Thillou, C; Linossier, C; Pupat, C; Merlin, B; Zastrow, L

2006-06-01

The aim of this study was to evaluate the interest of a new three-dimensional epithelial model cultivated from human corneal cells to replace animal testing in the assessment of eye tolerance. To this end, 65 formulated cosmetic products and 36 chemicals were tested by means of this in vitro model using a simplified toxicokinetic approach. The chemicals were selected from the ECETOC data bank and the EC/HO International validation study list. Very satisfactory results were obtained in terms of concordance with the Draize test data for the formulated cosmetic products. Moreover, the response of the corneal model appeared predictive of human ocular response clinically observed by ophthalmologists. The in vitro scores for the chemicals tested strongly correlated with their respective scores in vivo. For all the compounds tested, the response of the corneal model to irritants was similar regardless of their chemical structure, suggesting a good robustness of the prediction model proposed. We concluded that this new three-dimensional epithelial model, developed from human corneal cells, could be promising for the prediction of eye irritation induced by chemicals and complex formulated products, and that these two types of materials should be tested using a similar protocol. A simple shortening of the exposure period was required for the chemicals assumed to be more aggressively irritant to the epithelial tissues than the cosmetic formulae.

Functional promiscuity in a mammalian chemosensory system: extensive expression of vomeronasal receptors in the main olfactory epithelium of mouse lemurs

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Philipp eHohenbrink

2014-09-01

Full Text Available The vomeronasal organ (VNO is functional in most terrestrial mammals, though progressively reduced in the primate lineage, and is used for intraspecific communication and predator recognition. Vomeronasal receptor (VR genes comprise two families of chemosensory genes (V1R and V2R that have been considered to be specific for the VNO. However, recently a large number of VRs were reported to be expressed in the main olfactory epithelium (MOE of mice, but there is little knowledge of the expression of these genes outside of rodents. To explore the function of VR genes in mammalian evolution, we analyzed and compared the expression of 64 V1R and 2 V2R genes in the VNO and the MOE of the grey mouse lemur (Microcebus murinus, the primate with the largest known VR repertoire. We furthermore compared expression patterns in adults of both sexes and seasons, and in an infant. A large proportion (83% – 97% of the VR loci was expressed in the VNO of all individuals. The repertoire in the infant was as rich as in adults, indicating reliance on olfactory communication from early postnatal development onwards. In concordance with mice, we also detected extensive expression of VRs in the MOE, with proportions of expressed loci in individuals ranging from 29% to 45%. TRPC2, which encodes a channel protein crucial for signal transduction via VRs, was co-expressed in the MOE in all individuals indicating likely functionality of expressed VR genes in the MOE. In summary, the large VR repertoire in mouse lemurs seems to be highly functional. Given the differences in the neural pathways of MOE and VNO signals, which project to higher cortical brain centers or the limbic system, respectively, this raises the intriguing possibility that the evolution of MOE-expression of VRs enabled mouse lemurs to adaptively diversify the processing of VR-encoded olfactory information.

Correlations between corneal and total wavefront aberrations

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Mrochen, Michael; Jankov, Mirko; Bueeler, Michael; Seiler, Theo

2002-06-01

Purpose: Corneal topography data expressed as corneal aberrations are frequently used to report corneal laser surgery results. However, the optical image quality at the retina depends on all optical elements of the eye such as the human lens. Thus, the aim of this study was to investigate the correlations between the corneal and total wavefront aberrations and to discuss the importance of corneal aberrations for representing corneal laser surgery results. Methods: Thirty three eyes of 22 myopic subjects were measured with a corneal topography system and a Tschernig-type wavefront analyzer after the pupils were dilated to at least 6 mm in diameter. All measurements were centered with respect to the line of sight. Corneal and total wavefront aberrations were calculated up to the 6th Zernike order in the same reference plane. Results: Statistically significant correlations (p the corneal and total wavefront aberrations were found for the astigmatism (C3,C5) and all 3rd Zernike order coefficients such as coma (C7,C8). No statistically significant correlations were found for all 4th to 6th order Zernike coefficients except for the 5th order horizontal coma C18 (p equals 0.003). On average, all Zernike coefficients for the corneal aberrations were found to be larger compared to Zernike coefficients for the total wavefront aberrations. Conclusions: Corneal aberrations are only of limited use for representing the optical quality of the human eye after corneal laser surgery. This is due to the lack of correlation between corneal and total wavefront aberrations in most of the higher order aberrations. Besides this, the data present in this study yield towards an aberration balancing between corneal aberrations and the optical elements within the eye that reduces the aberration from the cornea by a certain degree. Consequently, ideal customized ablations have to take both, corneal and total wavefront aberrations, into consideration.

Loss of the Wnt receptor frizzled 7 in the mouse gastric epithelium is deleterious and triggers rapid repopulation in vivo.

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Flanagan, Dustin J; Barker, Nick; Nowell, Cameron; Clevers, Hans; Ernst, Matthias; Phesse, Toby J; Vincan, Elizabeth

2017-08-01

The gastric epithelium consists of tubular glandular units, each containing several differentiated cell types, and populations of stem cells, which enable the stomach to secrete the acid, mucus and various digestive enzymes required for its function. Very little is known about which cell signalling pathways are required for homeostasis of the gastric epithelium. Many diseases, such as cancer, arise as a result of deregulation of signalling pathways that regulate homeostasis of the diseased organ. Therefore, it is important to understand the biology of how normal conditions are maintained in a tissue to help inform the mechanisms driving disease in that same tissue, and to identify potential points of therapeutic intervention. Wnt signalling regulates several cell functions, including proliferation, differentiation and migration, and plays a crucial role during homeostasis of several tissues, including the intestinal epithelium. Wnt3a is required in the culture medium of gastric organoids, suggesting it is also important for the homeostasis of the gastric epithelium, but this has not been investigated in vivo Here, we show that the Wnt receptor frizzled 7 (Fzd7), which is required for the homeostasis of the intestine, is expressed in the gastric epithelium and is required for gastric organoid growth. Gastric-specific loss of Fzd7 in the adult gastric epithelium of mice is deleterious and triggers rapid epithelial repopulation, which we believe is the first observation of this novel function for this tissue. Taken together, these data provide functional evidence of a crucial role for Wnt signalling, via the Fzd7 receptor, during homeostasis of the gastric epithelium. © 2017. Published by The Company of Biologists Ltd.

Alcohol-assisted versus Mechanical Epithelium Removal in Photorefractive Keratectomy

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Mohammad Ghoreishi,

2010-01-01

Full Text Available Purpose: To compare the outcomes and complications of alcohol-assisted versus mechanical corneal epithelial debridement for photorefractive keratectomy (PRK. Methods: This randomized controlled trial included 1,250 eyes of 625 patients undergoing PRK for correction of myopia and myopic astigmatism. Each patient was randomly assigned to alcohol-assisted or mechanical epithelial removal. Results: A total of 658 eyes underwent alcohol-assisted epithelial removal while the epithelium was removed mechanically in 592 eyes. Mean spherical equivalent was ‑4.37}2.3 D in the alcohol group and ‑3.8}1.3 D in the mechanical group (P = 0.78. There was no significant difference in postoperative pain between the study groups (P = 0.22. Uncorrected visual acuity ≥ 20/20 and ≥ 20/40 was achieved in 90.9% versus 93.4% (P = 0.08, and 98.9% versus 99.5% (P = 0.36 of eyes in the alcohol and mechanical groups, respectively. Final refractive error within 1D of emmetropia was achieved in 90% versus 92.2% of eyes in the alcohol and mechanical groups, respectively (P = 0.23. Alcohol-assisted debridement required less time than mechanical debridement (96±18 vs. 118±26 seconds, P=0.035. There was no significant difference between the two groups in terms of early and late postoperative complications. Conclusion: Alcohol-assisted and mechanical epithelium removal are comparable in terms of efficacy and side effects. The method of epithelial debridement in PRK may be left to the surgeon′s choice.

Expression of olfactory signaling genes in the eye.

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Alexey Pronin

Full Text Available To advance our understanding how the outer eye interacts with its environment, we asked which cellular receptors are expressed in the cornea, focusing on G protein-coupled receptors.Total RNA from the mouse cornea was subjected to next-generation sequencing using the Illumina platform. The data was analyzed with TopHat and CuffLinks software packages. Expression of a representative group of genes detected by RNA-seq was further analyzed by RT-PCR and in situ hybridization using RNAscope technology and fluorescent microscopy.We generated more than 46 million pair-end reads from mouse corneal RNA. Bioinformatics analysis revealed that the mouse corneal transcriptome reconstructed from these reads represents over 10,000 gene transcripts. We identified 194 GPCR transcripts, of which 96 were putative olfactory receptors. RT-PCR analysis confirmed the presence of several olfactory receptors and related genes, including olfactory marker protein and the G protein associated with olfaction, Gαolf. In situ hybridization showed that mRNA for olfactory marker protein, Gαolf and possibly some olfactory receptors were found in the corneal epithelial cells. In addition to the corneal epithelium, Gαolf was present in the ganglionic and inner nuclear layers of the retina. One of the olfactory receptors, Olfr558, was present primarily in vessels of the eye co-stained with antibodies against alpha-smooth muscle actin, indicating expression in arterioles.Several species of mRNA encoding putative olfactory receptors and related genes are expressed in the mouse cornea and other parts of the eye indicating they may play a role in sensing chemicals in the ocular environment.

A new nanosecond UV laser at 355 nm: early results of corneal flap cutting in a rabbit model.

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Trost, Andrea; Schrödl, Falk; Strohmaier, Clemens; Bogner, Barbara; Runge, Christian; Kaser-Eichberger, Alexandra; Krefft, Karolina; Vogel, Alfred; Linz, Norbert; Freidank, Sebastian; Hilpert, Andrea; Zimmermann, Inge; Grabner, Günther; Reitsamer, Herbert A

2013-12-03

A new 355 nm UV laser was used for corneal flap cutting in an animal model and tested for clinical and morphologic alterations. Corneal flaps were created (Chinchilla Bastards; n = 25) with an UV nanosecond laser at 355 nm (150 kHz, pulse duration 850 ps, spot-size 1 μm, spot spacing 6 × 6 μm, side cut Δz 1 μm; cutting depth 130 μm) and pulse energies of 2.2 or 2.5 μJ, respectively. Following slit-lamp examination, animals were killed at 6, 12, and 24 hours after treatment. Corneas were prepared for histology (hematoxylin and eosin [HE], TUNEL-assay) and evaluated statistically, followed by ultrastructural investigations. Laser treatment was tolerated well, flap lift was easier at 2.5 μJ compared with 2.2 μJ. Standard HE at 24 hours revealed intact epithelium in the horizontal cut, with similar increase in corneal thickness at both energies. Irrespective of energy levels, TUNEL assay revealed comparable numbers of apoptotic cells in the horizontal and vertical cut at 6, 12, and 24 hours, becoming detectable in the horizontal cut as an acellular stromal band at 24 hours. Ultrastructural analysis revealed regular morphology in the epi- and endothelium, while in the stroma, disorganized collagen lamellae were detectable representing the horizontal cut, again irrespective of energy levels applied. This new UV laser revealed no epi- nor endothelial damage at energies feasible for corneal flap cutting. Observed corneal swelling was lower compared with existing UV laser studies, albeit total energy applied here was much higher. Observed loss of stromal keratinocytes is comparable with available laser systems. Therefore, this new laser is suitable for refractive surgery, awaiting its test in a chronic environment.

Administration of Menadione, Vitamin K3, Ameliorates Off-Target Effects on Corneal Epithelial Wound Healing Due to Receptor Tyrosine Kinase Inhibition.

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Rush, Jamie S; Bingaman, David P; Chaney, Paul G; Wax, Martin B; Ceresa, Brian P

2016-11-01

The antiangiogenic receptor tyrosine kinase inhibitor (RTKi), 3-[(4-bromo-2,6-difluorophenyl)methoxy]-5-[[[[4-(1-pyrrolidinyl) butyl] amino] carbonyl]amino]-4-isothiazolecarboxamide hydrochloride, targets VEGFR2 (half maximal inhibitory concentration [IC50] = 11 nM); however, off-target inhibition of epidermal growth factor receptor (EGFR) occurs at higher concentrations. (IC50 = 5.8 μM). This study was designed to determine the effect of topical RTKi treatment on EGF-mediated corneal epithelial wound healing and to develop new strategies to minimize off-target EGFR inhibition. In vitro corneal epithelial wound healing was measured in response to EGF using a transformed human cell line (hTCEpi cells). In vivo corneal wound healing was assessed using a murine model. In these complementary assays, wound healing was measured in the presence of varying RTKi concentrations. Immunoblot analysis was used to examine EGFR and VEGFR2 phosphorylation and the kinetics of EGFR degradation. An Alamar Blue assay measured VEGFR2-mediated cell biology. Receptor tyrosine kinase inhibitor exposure caused dose-dependent inhibition of EGFR-mediated corneal epithelial wound healing in vitro and in vivo. Nanomolar concentrations of menadione, a vitamin K3 analog, when coadministered with the RTKi, slowed EGFR degradation and ameliorated the inhibitory effects on epithelial wound healing both in vitro and in vivo. Menadione did not alter the RTKi's IC50 against VEGFR2 phosphorylation or its inhibition of VEGF-induced retinal endothelial cell proliferation. An antiangiogenic RTKi exhibited off-target effects on the corneal epithelium that can be minimized by menadione without deleteriously affecting its on-target VEGFR2 blockade. These data indicate that menadione has potential as a topical supplement for individuals suffering from perturbations in corneal epithelial homeostasis, especially as an untoward side effect of kinase inhibitors.

Corneal Toxicity Following Exposure to Asclepias Tuberosa.

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Mikkelsen, Lauge Hjorth; Hamoudi, Hassan; Gül, Cigdem Altuntas; Heegaard, Steffen

2017-01-01

To present a case of corneal toxicity following exposure to milky plant latex from Asclepias tuberosa. A 70-year-old female presented with blurred vision and pain in her left eye after handling an Ascepias tuberosa . Clinical examination revealed a corneal stromal oedema with small epithelial defects. The corneal endothelium was intact and folds in Descemets membrane were observed. The oedema was treated with chloramphenicol, dexamethasone and scopolamine. The corneal oedema had appeared after corneal exposure to the plant, Asclepias tuberosa , whose latex contains cardenolides that inhibit the Na + / K + -ATPase in the corneal endothelium. The oedema resolved after 96 hours. After nine months the best corrected visual acuity was 20/20. Corneal toxicity has previously been reported for plants of the Asclepias family. This is a rare case describing severe corneal toxicity caused by exposure to latex from Asclepias tuberosa . Handling of plants of the Asclepias family should be kept as a differential diagnosis in cases of acute corneal toxicity.

The Effect of Riboflavin/UVA Collagen Cross-linking Therapy on the Structure and Hydrodynamic Behaviour of the Ungulate and Rabbit Corneal Stroma

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Hayes, Sally; Kamma-Lorger, Christina S.; Boote, Craig; Young, Robert D.; Quantock, Andrew J.; Rost, Anika; Khatib, Yasmeen; Harris, Jonathan; Yagi, Naoto; Terrill, Nicholas; Meek, Keith M.

2013-01-01

Purpose To examine the effect of riboflavin/UVA corneal crosslinking on stromal ultrastructure and hydrodynamic behaviour. Methods One hundred and seventeen enucleated ungulate eyes (112 pig and 5 sheep) and 3 pairs of rabbit eyes, with corneal epithelium removed, were divided into four treatment groups: Group 1 (28 pig, 2 sheep and 3 rabbits) were untreated; Group 2 (24 pig) were exposed to UVA light (3.04 mW/cm2) for 30 minutes and Group 3 (29 pig) and Group 4 (31 pig, 3 sheep and 3 rabbits) had riboflavin eye drops applied to the corneal surface every 5 minutes for 35 minutes. Five minutes after the initial riboflavin instillation, the corneas in Group 4 experienced a 30 minute exposure to UVA light (3.04 mW/cm2). X-ray scattering was used to obtain measurements of collagen interfibrillar spacing, spatial order, fibril diameter, D-periodicity and intermolecular spacing throughout the whole tissue thickness and as a function of tissue depth in the treated and untreated corneas. The effect of each treatment on the hydrodynamic behaviour of the cornea (its ability to swell in saline solution) and its resistance to enzymatic digestion were assessed using in vitro laboratory techniques. Results Corneal thickness decreased significantly following riboflavin application (priboflavin/UVA therapy occur predominantly at the collagen fibril surface and in the protein network surrounding the collagen. PMID:23349690

Distrofia corneal de Schnyder

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Michel Guerra Almaguer

Full Text Available La principal entidad hereditaria con depósitos de lípidos en el estroma corneal es la distrofia cristalina central, conocida como distrofia de Schnyder, quien la describió en Suiza en 1927. Se caracteriza por depósitos blanco-amarillentos en el estroma corneal central y superficial. Se presenta un paciente de 28 años, del sexo masculino y piel negra, con antecedente de salud anterior. Acudió a consulta y refirió una disminución de la visión y cambio de coloración progresiva de ambos ojos, de años de evolución. En la exploración oftalmológica de ambos ojos se apreciaron lesiones blanquecinas anulares a nivel del estroma corneal, con ligera turbidez corneal central. Los estudios refractivos realizados constataron un astigmatismo hipermetrópico simple. El resto del examen oftalmológico fue negativo. Para el diagnóstico de certeza se empleó el microscopio confocal. Se concluye que el caso presenta una distrofia corneal estromal de tipo cristalina, de Schnyder.

Anterior corneal profile with variable asphericity.

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Rosales, Marco A; Juárez-Aubry, Montserrat; López-Olazagasti, Estela; Ibarra, Jorge; Tepichín, Eduardo

2009-12-10

We present a corneal profile in which the eccentricity, e(Q=-e(2)), has a nonlinear continuous variation from the center outwards. This nonlinear variation is intended to fit and reproduce our current experimental data in which the anterior corneal surface of the human eye exhibits different values of e at different diameters. According to our clinical data, the variation is similar to an exponential decay. We propose a linear combination of two exponential functions to describe the variation of e. We then calculate the corneal sagittal height by substituting e in the first-order aspherical surface equation to obtain the corneal profile. This corneal profile will be used as a reference to analyze the resultant profiles of the customized corneal ablation in refractive surgery.

Corneal ring infiltration in contact lens wearers

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Seyed Ali Tabatabaei

2017-01-01

Full Text Available To report a case of atypical sterile ring infiltrates during wearing soft silicone hydrogel contact lens due to poor lens care. A 29-year-old woman presented with complaints of pain, redness, and morning discharge. She was wearing soft silicone hydrogel contact lens previously; her current symptoms began 1 week before presentation. On examination, best-corrected visual acuity was 20/40 in that eye. Slit-lamp examination revealed dense, ring-shaped infiltrate involving both the superficial and deep stromal layers with lucid interval to the limbus, edema of the epithelium, epithelial defect, and vascularization of the superior limbus. Cornea-specific in vivo laser confocal microscopy (Heidelberg Retina Tomograph 2 Rostock Cornea Module, HRT 2-RCM, Heidelberg Engineering GmbH, Dossenheim, Germany revealed Langerhans cells and no sign of Acanthamoeba or fungal features, using lid scraping and anti-inflammatory drops; her vision completely recovered. We reported an atypical case of a sterile corneal ring infiltrate associated with soft contact lens wearing; smear, culture, and confocal microscopy confirmed a sterile inflammatory reaction.

Ethanol impedes embryo transport and impairs oviduct epithelium

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Xu, Tonghui; Yang, Qiuhong; Liu, Ruoxi; Wang, Wenfu; Wang, Shuanglian; Liu, Chuanyong; Li, Jingxin

2016-01-01

Most studies have demonstrated that alcohol consumption is associated with decreased fertility. The aim of this study was to investigate the effects of alcohol on pre-implantation embryo transport and/or early embryo development in the oviduct. We reported here that ethanol concentration-dependently suppressed the spontaneous motility of isolated human oviduct strips (EC50 50 ± 6 mM), which was largely attenuated in the present of L-NAME, a classical nitric oxide synthase(NOS) competitive inhibitor. Notably, either acute or chronic alcohol intake delayed egg transport and retarded early development of the embryo in the mouse oviduct, which was largely rescued by co-administration of L-NAME in a acute alcohol intake group but not in chronic alcohol intake group. It is worth mentioning that the oviductal epithelium destruction was verified by scanning electron microscope (SEM) observations in chronic alcohol intake group. In conclusion, alcohol intake delayed egg transport and retarded early development of the embryo in the oviduct by suppressing the spontaneous motility of oviduct and/or impairing oviductal epithelium. These findings suggested that alcohol abuse increases the incident of ectopic pregnancy.

Ethanol impedes embryo transport and impairs oviduct epithelium.

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Xu, Tonghui; Yang, Qiuhong; Liu, Ruoxi; Wang, Wenfu; Wang, Shuanglian; Liu, Chuanyong; Li, Jingxin

2016-05-16

Most studies have demonstrated that alcohol consumption is associated with decreased fertility. The aim of this study was to investigate the effects of alcohol on pre-implantation embryo transport and/or early embryo development in the oviduct. We reported here that ethanol concentration-dependently suppressed the spontaneous motility of isolated human oviduct strips (EC50 50±6mM), which was largely attenuated in the present of L-NAME, a classical nitric oxide synthase(NOS) competitive inhibitor. Notably, either acute or chronic alcohol intake delayed egg transport and retarded early development of the embryo in the mouse oviduct, which was largely rescued by co-administration of L-NAME in a acute alcohol intake group but not in chronic alcohol intake group. It is worth mentioning that the oviductal epithelium destruction was verified by scanning electron microscope (SEM) observations in chronic alcohol intake group. In conclusion, alcohol intake delayed egg transport and retarded early development of the embryo in the oviduct by suppressing the spontaneous motility of oviduct and/or impairing oviductal epithelium. These findings suggested that alcohol abuse increases the incident of ectopic pregnancy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

History of corneal transplantation in Australia.

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Coster, Douglas J

2015-04-01

Corneal transplantation is a triumph of modern ophthalmology. The possibility of corneal transplantation was first raised in 1797 but a century passed before Zirm achieved the first successful penetrating graft in 1905. Gibson reported the first corneal graft in Australia from Brisbane in 1940 and English established the first eye bank there a few years later. Corneal transplantation evolved steadily over the twentieth century. In the second half of the century, developments in microsurgery, including surgical materials such as monofilament nylon and strong topical steroid drops, accounted for improvements in outcomes. In 2013, approximately 1500 corneal transplants were done in Australia. Eye banking has evolved to cope with the rising demands for donor corneas. Australian corneal surgeons collaborated to establish and support the Australian Corneal Graft Registry in 1985. It follows the outcomes of their surgery and has become an important international resource for surgeons seeking further improvement with the procedure. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

Nerve growth factor regulates neurolymphatic remodeling during corneal inflammation and resolution.

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Darci M Fink

Full Text Available The cellular and physiologic mechanisms that regulate the resolution of inflammation remain poorly defined despite their widespread importance in improving inflammatory disease outcomes. We studied the resolution of two cardinal signs of inflammation-pain and swelling-by investigating molecular mechanisms that regulate neural and lymphatic vessel remodeling during the resolution of corneal inflammation. A mouse model of corneal inflammation and wound recovery was developed to study this process in vivo. Administration of nerve growth factor (NGF increased pain sensation and inhibited neural remodeling and lymphatic vessel regression processes during wound recovery. A complementary in vivo approach, the corneal micropocket assay, revealed that NGF-laden pellets stimulated lymphangiogenesis and increased protein levels of VEGF-C. Adult human dermal lymphatic endothelial cells did not express canonical NGF receptors TrkA and p75NTR or activate downstream MAPK- or Akt-pathway effectors in the presence of NGF, although NGF treatment increased their migratory and tubulogenesis capacities in vitro. Blockade of the VEGF-R2/R3 signaling pathway ablated NGF-mediated lymphangiogenesis in vivo. These findings suggest a hierarchical relationship with NGF functioning upstream of the VEGF family members, particularly VEGF-C, to stimulate lymphangiogenesis. Taken together, these studies show that NGF stimulates lymphangiogenesis and that NGF may act as a pathogenic factor that negatively regulates the normal neural and lymphatic vascular remodeling events that accompany wound recovery.

Rate of riboflavin diffusion from intrastromal channels before corneal crosslinking.

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McQuaid, Rebecca; Mrochen, Michael; Vohnsen, Brian

2016-03-01

To determine the diffusion of riboflavin from intrastromal channels through the effective diffusion coefficients compared with traditional axial diffusion with epithelium on or off. Advanced Optical Imaging Laboratory, University College Dublin, and Wellington Eye Clinic, Sandyford, Dublin, Ireland. Experimental study. The rate of diffusion in whole-mounted porcine eyes was monitored for a 30 minutes using an optical setup with a charge-coupled device camera and a bandpass filter (central wavelength 550 nm and 40 nm bandpass) to image the fluorescence under ultraviolet illumination (365 nm wavelength). For comparison, an isotropic corneal stroma with an annular channel was modeled numerically for different diffusion constants and boundary conditions. Numerical and experimental results were compared, allowing determination of the effective diffusion coefficient for each case. Experimental results for 6 different riboflavin solutions were in all cases found to be higher than for the common crosslinking (CXL) riboflavin protocol, where the diffusion constant is D0 = 6.5 × 10(-5) mm(2)/sec. For the intrastromal channel, 2 isotonic solutions containing riboflavin 0.1% correlated with a diffusion constant of 5D0 = 32.5 × 10(-5) mm(2)/sec. Hypotonic solutions and transepithelium had a higher diffusion coefficient approaching 10D0 = 65.0 × 10(-5) mm(2)/sec, which is an order-of-magnitude increase compared with the typical diffusion coefficient found in standard CXL. In this study, riboflavin had a faster stromal diffusion when injected into a corneal channel than when applied as drops to the anterior corneal surface. Further numerical modeling might allow optimization of the channel structure for any specific choice of riboflavin. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Glaucoma after corneal replacement.

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Baltaziak, Monika; Chew, Hall F; Podbielski, Dominik W; Ahmed, Iqbal Ike K

Glaucoma is a well-known complication after corneal transplantation surgery. Traditional corneal transplantation surgery, specifically penetrating keratoplasty, has been slowly replaced by the advent of new corneal transplantation procedures: primarily lamellar keratoplasties. There has also been an emergence of keratoprosthesis implants for eyes that are high risk of failure with penetrating keratoplasty. Consequently, there are different rates of glaucoma, pathogenesis, and potential treatment in the form of medical, laser, or surgical therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Turning the tide of corneal blindness

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Matthew S Oliva

2012-01-01

Full Text Available Corneal diseases represent the second leading cause of blindness in most developing world countries. Worldwide, major investments in public health infrastructure and primary eye care services have built a strong foundation for preventing future corneal blindness. However, there are an estimated 4.9 million bilaterally corneal blind persons worldwide who could potentially have their sight restored through corneal transplantation. Traditionally, barriers to increased corneal transplantation have been daunting, with limited tissue availability and lack of trained corneal surgeons making widespread keratoplasty services cost prohibitive and logistically unfeasible. The ascendancy of cataract surgical rates and more robust eye care infrastructure of several Asian and African countries now provide a solid base from which to dramatically expand corneal transplantation rates. India emerges as a clear global priority as it has the world′s largest corneal blind population and strong infrastructural readiness to rapidly scale its keratoplasty numbers. Technological modernization of the eye bank infrastructure must follow suit. Two key factors are the development of professional eye bank managers and the establishment of Hospital Cornea Recovery Programs. Recent adaptation of these modern eye banking models in India have led to corresponding high growth rates in the procurement of transplantable tissues, improved utilization rates, operating efficiency realization, and increased financial sustainability. The widespread adaptation of lamellar keratoplasty techniques also holds promise to improve corneal transplant success rates. The global ophthalmic community is now poised to scale up widespread access to corneal transplantation to meet the needs of the millions who are currently blind.

Analysis of the horizontal corneal diameter, central corneal thickness, and axial length in premature infants

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Ozdemir Ozdemir

2014-08-01

Full Text Available Purpose: To determine the horizontal corneal diameter, central corneal thickness, and axial length in premature infants. Methods: Infants with a birth weight of less than 2,500 g or with a gestation period of less than 36 weeks were included in the study. Infants with retinopathy of prematurity (ROP were allocated to Group 1 (n=138, while those without ROP were allocated to Group 2 (n=236. All infants underwent a complete ophthalmologic examination, including corneal diameter measurements, pachymetry, biometry, and fundoscopy. Between-group comparisons of horizontal corneal diameter, central corneal thickness, and axial lengths were performed. Independent sample t-tests were used for statistical analysis. Results: Data was obtained from 374 eyes of 187 infants (102 female, 85 male. The mean gestational age at birth was 30.7 ± 2.7 weeks (range 25-36 weeks, the mean birth weight was 1,514 ± 533.3 g (range 750-1,970 g, and the mean postmenstrual age at examination was 40.0 ± 4.8 weeks. The mean gestational age and the mean birth weight of Group 1 were statistically lower than Group 2 (p0.05. Conclusions: The presence of ROP in premature infants does not alter the horizontal corneal diameter, central corneal thickness, or axial length.

Corneal Toxicity Following Exposure to Asclepias Tuberosa

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Mikkelsen, Lauge Hjorth; Hamoudi, Hassan; Gül, Cigdem Altuntas

2017-01-01

PURPOSE: To present a case of corneal toxicity following exposure to milky plant latex from Asclepias tuberosa. METHODS: A 70-year-old female presented with blurred vision and pain in her left eye after handling an Ascepias tuberosa. Clinical examination revealed a corneal stromal oedema with small...... epithelial defects. The corneal endothelium was intact and folds in Descemets membrane were observed. The oedema was treated with chloramphenicol, dexamethasone and scopolamine. RESULTS: The corneal oedema had appeared after corneal exposure to the plant, Asclepias tuberosa, whose latex contains cardenolides...... that inhibit the Na+/ K+-ATPase in the corneal endothelium. The oedema resolved after 96 hours. After nine months the best corrected visual acuity was 20/20. CONCLUSION: Corneal toxicity has previously been reported for plants of the Asclepias family. This is a rare case describing severe corneal toxicity...

Intestinal subepithelial myofibroblasts support in vitro and in vivo growth of human small intestinal epithelium.

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Nicholas Lahar

Full Text Available The intestinal crypt-niche interaction is thought to be essential to the function, maintenance, and proliferation of progenitor stem cells found at the bases of intestinal crypts. These stem cells are constantly renewing the intestinal epithelium by sending differentiated cells from the base of the crypts of Lieberkühn to the villus tips where they slough off into the intestinal lumen. The intestinal niche consists of various cell types, extracellular matrix, and growth factors and surrounds the intestinal progenitor cells. There have recently been advances in the understanding of the interactions that regulate the behavior of the intestinal epithelium and there is great interest in methods for isolating and expanding viable intestinal epithelium. However, there is no method to maintain primary human small intestinal epithelium in culture over a prolonged period of time. Similarly no method has been published that describes isolation and support of human intestinal epithelium in an in vivo model. We describe a technique to isolate and maintain human small intestinal epithelium in vitro from surgical specimens. We also describe a novel method to maintain human intestinal epithelium subcutaneously in a mouse model for a prolonged period of time. Our methods require various growth factors and the intimate interaction between intestinal sub-epithelial myofibroblasts (ISEMFs and the intestinal epithelial cells to support the epithelial in vitro and in vivo growth. Absence of these myofibroblasts precluded successful maintenance of epithelial cell formation and proliferation beyond just a few days, even in the presence of supportive growth factors. We believe that the methods described here can be used to explore the molecular basis of human intestinal stem cell support, maintenance, and growth.

Establishment of primary cultures for mouse ameloblasts as a model of their lifetime

International Nuclear Information System (INIS)

Suzawa, Tetsuo; Itoh, Nao; Takahashi, Naoyuki; Katagiri, Takenobu; Morimura, Naoko; Kobayashi, Yasuna; Yamamoto, Toshinori; Kamijo, Ryutaro

2006-01-01

To understand how the properties of ameloblasts are spatiotemporally regulated during amelogenesis, two primary cultures of ameloblasts in different stages of differentiation were established from mouse enamel epithelium. Mouse primary ameloblasts (MPAs) prepared from immature enamel epithelium (MPA-I) could proliferate, whereas those from mature enamel epithelium (MPA-M) could not. MPA-M but not MPA-I caused apoptosis during culture. The mRNA expression of amelogenin, a marker of immature ameloblasts, was down-regulated, and that of enamel matrix serine proteiase-1, a marker of mature ameloblasts, was induced in MPA-I during culture. Using green fluorescence protein as a reporter, a visualized reporter system was established to analyze the promoter activity of the amelogenin gene. The region between -1102 bp and -261 bp was required for the reporter expression in MPA-I. These results suggest that MPAs are valuable in vitro models for investigation of ameloblast biology, and that the visualized system is useful for promoter analysis in MPAs

Corneal collagen crosslinking and pigment dispersion syndrome.

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LaHood, Benjamin R; Moore, Sacha

2017-03-01

We describe the case of a keratoconus patient with pigment dispersion syndrome (PDS) who was treated for progressive corneal ectasia with corneal collagen crosslinking (CXL). Pigment dispersion syndrome has been shown to have associated morphologic changes of the corneal endothelium. Corneal CXL has the potential to cause toxicity to the corneal endothelium, and adjacent pigment might increase the likelihood of damage. In this case, the presence of PDS had no detrimental effect on the outcome of treatment, and no complications were observed at 12 months follow-up, indicating that it may be safe to perform corneal CXL in the setting of PDS. This is an important observation as the number of indications for corneal CXL grows. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Area and depth of surfactant-induced corneal injury predicts extent of subsequent ocular responses.

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Jester, J V; Petroll, W M; Bean, J; Parker, R D; Carr, G J; Cavanagh, H D; Maurer, J K

1998-12-01

To correlate area and depth of initial corneal injury induced by surfactants of differing type and irritant properties with corneal responses and outcome in the same animals over time by using in vivo confocal microscopy (CM). Six groups of six adult rabbits were treated with anionic, cationic, and nonionic surfactants that caused different levels of ocular irritation. Test materials included slight irritants: 5% sodium lauryl sulfate (SLS), polyoxyethylene glycol monoalkyl ether (POE), and 5% 3-isotridecyloxypropyl-bis(polyoxyethylene) ammonium chloride (ITDOP); mild irritants: 5% 3-decyloxypropyl-bis(polyoxyethylene) amine (DOP) and sodium linear alkylbenzene sulfonate (LAS); and a moderate irritant: a proprietary detergent (DTRGT). Ten microliters surfactant were directly applied to the cornea of one eye of each rabbit. Ten untreated rabbits served as control subjects. Area and depth of initial injury was determined by using in vivo CM to measure epithelial thickness, epithelial cell size, corneal thickness, and depth of stromal injury in four corneal regions at 3 hours and at day 1. Area and depth of corneal responses to injury were evaluated at various times from days 3 through 35 by macroscopic grading and quantitative confocal microscopy through-focusing (CMTF). In vivo CM revealed corneal injury with slight irritants to be restricted to the epithelium, whereas the mild and moderate irritants caused complete epithelial cell loss with increasing anterior stromal damage: DOP < LAS < DTRGT. With the slight ocular irritants there was little or no change in corneal thickness or the CMTF intensity profiles. Three hours after treatment, mild and moderate ocular irritants caused a significant increase in corneal thickness, which peaked at day 1 with DOP (483.3+/-80.1 microm) and LAS (572.3+/-60.0 microm) and day 3 with DTRGT (601.4+/-68.7 microm); returning to normal (similar to control values) by day 7 with DOP and day 35 with LAS and DTRGT. The CMTF intensity

Corneal melanosis successfully treated using topical mitomycin-C and alcohol corneal epitheliectomy: a 3-year follow-up case report

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Mehmet Balcı

2015-08-01

Full Text Available ABSTRACTWe report a case of primary acquired corneal melanosis without atypia associated with corneal haze in a patient with a history of limbal malignant melanoma and the effect of mitomycin-C. A 75-year-old woman with a history of limbal malignant melanoma presented with loss of vision in right eye. Corneal examination showed a patchy melanotic pigmentation with a central haze. Topical mitomycin-C improved visual acuity and corneal haze. However, the pigmented lesions persisted, and they were removed with alcohol corneal epitheliectomy. Histopathological examination demonstrated primary acquired melanosis without atypia. The lesions were successfully removed, and there were no recurrences during the follow-up period of 36 months. The association of conjunctival and corneal melanosis without atypia is a rare condition. In addition, co-existence of central corneal haze and melanosis may decrease visual acuity. Topical mitomycin-C and alcohol corneal epitheliectomy can be useful treatments in this condition.

Cadherins in the retinal pigment epithelium (RPE revisited: P-cadherin is the highly dominant cadherin expressed in human and mouse RPE in vivo.

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Xue Yang

Full Text Available The retinal pigment epithelium (RPE supports the health and function of retinal photoreceptors and is essential for normal vision. RPE cells are post-mitotic, terminally differentiated, and polarized epithelial cells. In pathological conditions, however, they lose their epithelial integrity, become dysfunctional, even dedifferentiate, and ultimately die. The integrity of epithelial cells is maintained, in part, by adherens junctions, which are composed of cadherin homodimers and p120-, β-, and α-catenins linking to actin filaments. While E-cadherin is the major cadherin for forming the epithelial phenotype in most epithelial cell types, it has been reported that cadherin expression in RPE cells is different from other epithelial cells based on results with cultured RPE cells. In this study, we revisited the expression of cadherins in the RPE to clarify their relative contribution by measuring the absolute quantity of cDNAs produced from mRNAs of three classical cadherins (E-, N-, and P-cadherins in the RPE in vivo. We found that P-cadherin (CDH3 is highly dominant in both mouse and human RPE in situ. The degree of dominance of P-cadherin is surprisingly large, with mouse Cdh3 and human CDH3 accounting for 82-85% and 92-93% of the total of the three cadherin mRNAs, respectively. We confirmed the expression of P-cadherin protein at the cell-cell border of mouse RPE in situ by immunofluorescence. Furthermore, we found that oxidative stress induces dissociation of P-cadherin and β-catenin from the cell membrane and subsequent translocation of β-catenin into the nucleus, resulting in activation of the canonical Wnt/β-catenin pathway. This is the first report of absolute comparison of the expression of three cadherins in the RPE, and the results suggest that the physiological role of P-cadherin in the RPE needs to be reevaluated.

Healed corneal ulcer with keloid formation.

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Alkatan, Hind M; Al-Arfaj, Khalid M; Hantera, Mohammed; Al-Kharashi, Soliman

2012-04-01

We are reporting a 34-year-old Arabic white female patient who presented with a white mass covering her left cornea following multiple ocular surgeries and healed corneal ulcer. The lesion obscured further view of the iris, pupil and lens. The patient underwent penetrating keratoplasty and the histopathologic study of the left corneal button showed epithelial hyperplasia, absent Bowman's layer and subepithelial fibrovascular proliferation. The histopathologic appearance was suggestive of a corneal keloid which was supported by further ultrastructural study. The corneal graft remained clear 6 months after surgery and the patient was satisfied with the visual outcome. Penetrating keratoplasty may be an effective surgical option for corneal keloids in young adult patients.

Current status of accelerated corneal cross-linking

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Michael Mrochen

2013-01-01

Full Text Available Corneal cross-linking with riboflavin is a technique to stabilize or reduce corneal ectasia, in diseases such as keratoconus and post-laser-assisted in situ keratomileusis (LASIK ectasia. There is an interest by patient as well as clinicians to reduce the overall treatment time. Especially, the introduction of corneal cross-linking in combination with corneal laser surgery demands a shorter treatment time to assure a sufficient patient flow. The principles and techniques of accelerated corneal cross-linking is discussed.

Evaluation of subbasal nerve morphology and corneal sensation after accelerated corneal collagen cross-linking treatment on keratoconus.

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Ozgurhan, Engin Bilge; Celik, Ugur; Bozkurt, Ercument; Demirok, Ahmet

2015-05-01

The aim of this study was to report on the evaluation of corneal nerve fiber density and corneal sensation after accelerated corneal collagen cross-linking on keratoconus patients. The study was performed on 30 keratoconus eyes (30 participants: 16 M, 14 F; 17-32 years old) treated with accelerated collagen cross-linking for disease stabilization. Mean outcome measures were corneal sensation evaluation by Cochet-Bonnet esthesiometry and subbasal nerve fiber density assessment by corneal in vivo confocal microscopy. All corneal measurements were performed using scanning slit confocal microscopy (ConfoScan 4, Nidek Technologies, Padova, Italy). The accelerated corneal collagen cross-linking procedure was performed on 30 eyes of 30 patients (19 right, 63.3%; 11 left, 27.7%). The mean age was 23.93 ± 4. The preoperative mean keratometry, apex keratometry and pachymetry values were 47.19 ± 2.82 D, 56.79 ± 5.39 and 426.1 ± 25.6 μm, respectively. Preoperative mean corneal sensation was 56.3 ± 5.4 mm (with a range from 40 to 60 mm), it was significantly decreased at 1st and 3rd month visit and increased to preoperative values after 6th month visit. Preoperative mean of subbasal nerve fiber density measurements was 22.8 ± 9.7 nerve fiber/mm(2) (with a range of 5-45 mm), it was not still at the preoperative values at 6th month (p = 0.0001), however reached to the preoperative values at 12th month (p = 0.914). Subbasal nerve fibers could reach the preoperative values at the 12th month after accelerated corneal collagen cross-linking treatment although the corneal sensation was improved at 6th month. These findings imply that the subjective healing process is faster than the objective evaluation of the keratoconus patients' cornea treated with accelerated corneal collagen cross-linking.

Corneal Reinnervation and Sensation Recovery in Patients With Herpes Zoster Ophthalmicus: An In Vivo and Ex Vivo Study of Corneal Nerves.

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Cruzat, Andrea; Hamrah, Pedram; Cavalcanti, Bernardo M; Zheng, Lixin; Colby, Kathryn; Pavan-Langston, Deborah

2016-05-01

To study corneal reinnervation and sensation recovery in Herpes zoster ophthalmicus (HZO). Two patients with HZO were studied over time with serial corneal esthesiometry and laser in vivo confocal microscopy (IVCM). A Boston keratoprosthesis type 1 was implanted, and the explanted corneal tissues were examined by immunofluorescence histochemistry for βIII-tubulin to stain for corneal nerves. The initial central corneal IVCM performed in each patient showed a complete lack of the subbasal nerve plexus, which was in accordance with severe loss of sensation (0 of 6 cm) measured by esthesiometry. When IVCM was repeated 2 years later before undergoing surgery, case 1 showed a persistent lack of central subbasal nerves and sensation (0 of 6). In contrast, case 2 showed regeneration of the central subbasal nerves (4786 μm/mm) with partial recovery of corneal sensation (2.5 of 6 cm). Immunostaining of the explanted corneal button in case 1 showed no corneal nerves, whereas case 2 showed central and peripheral corneal nerves. Eight months after surgery, IVCM was again repeated in the donor tissue around the Boston keratoprosthesis in both patients to study innervation of the corneal transplant. Case 1 showed no nerves, whereas case 2 showed new nerves growing from the periphery into the corneal graft. We demonstrate that regaining corneal innervation and corneal function are possible in patients with HZO as shown by corneal sensation, IVCM, and ex vivo immunostaining, indicating zoster neural damage is not always permanent and it may recover over an extended period of time.

Solvent/Detergent Virally Inactivated Serum Eye Drops Restore Healthy Ocular Epithelium in a Rabbit Model of Dry-Eye Syndrome.

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Tseng, Ching-Li; Chen, Zhi-Yu; Renn, Ting-Yi; Hsiao, Shun-Hung; Burnouf, Thierry

2016-01-01

Application of autologous serum eye drops (SEDs) is a recognized means to treat severe dry-eye syndrome (DES). Due to the inconvenience and difficulty of preparing SEDs from some patients, producing SEDs from allogeneic blood donations is gaining popularity. A major safety concern associated with allogeneic blood is virus transmission. We therefore herein evaluated the possibility of applying a solvent/detergent (S/D) treatment to inactivate viruses and studied the impacts of such treatment of SEDs to resolve DES in a rabbit model. Sera prepared from the blood of five rabbits were pooled and divided into two sub-pools. One was untreated (SEDs), while the other was virally-inactivated with 1% Tri-n-butyl phosphate/1% Triton X-45 at 31°C for 1 h (S/D-SEDs). DES was induced in rabbits using 0.1% benzalkonium chloride (BAC). Rabbits were divided into five groups of two rabbits each. One group was untreated (control), three were treated twice daily for 3 weeks using PBS, SEDs, or S/D-SEDs, and the last received an additional 0.1% BAC (as the negative control). The DES condition was determined by measuring aqueous tear secretion (Schirmer's test), corneal fluorescein staining, a corneal histologic examination, TUNEL stain apoptosis, and corneal inflammatory marker (tumor necrosis factor-α, interleukin (IL)-1β, IL-8, and IL-6) expressions. We first confirmed that SEDs and S/D-SEDs had similar protein profiles and transforming growth factor (TGF)-β contents. Animal experiments showed that tear secretion did not significantly differ between the SED and S/D-SED groups but was significantly higher than in the PBS group. Eye fluorescein staining revealed dramatic improvements in epithelial defects in groups treated with SEDs or S/D-SEDs, and hematoxylin/eosin staining revealed microscopic epithelial layers similar to those of the untreated controls. Inflammatory markers and TUNEL studies showed that healthy epithelium had been restored in groups treated with SEDs or S

Characterization of corneal pannus removed from patients with total limbal stem cell deficiency.

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Espana, Edgar M; Di Pascuale, Mario A; He, Hua; Kawakita, Tetsuya; Raju, Vadrevu K; Liu, Chia-Yang; Tseng, Scheffer C G

2004-09-01

To determine the epithelial lineage of origin in corneal pannus tissue surgically removed from patients with total limbal stem cell (SC) deficiency. The lineage of origin of the entire conjunctivalized pannus removed from eight corneas with a diagnosis of total limbal SC deficiency was characterized by anti-keratin (K)-3 and anti-K19 monoclonal antibodies. The protein and mRNA of epithelial outgrowth from segments of five such pannus specimens were analyzed by Western blot and reverse transcription-polymerase chain reaction, respectively. Cross sections of all eight specimens showed a stratified epithelium with goblet cells expressing mucin (MUC)-5AC, and a stroma showing blood vessels and inflammatory cell infiltrates. Immunostaining showed full-thickness expression of K19 in the entire pannus of all eight specimens. Expression of K3 was negative in seven patients, but was sporadically positive in a patient with Stevens-Johnson syndrome. In culture, all five pannus specimens generated a compact, small epithelial cell outgrowth, and except for one, reached confluence in 2 to 3 weeks. The K3/K12 pair was expressed by extracts of cell outgrowth from the control limbal epithelial explant, but not in all five pannus specimens. A 60-kDa band of DeltaNp63 was expressed in the control specimen and in all five pannus specimens. Cell outgrowth expressed K3 transcript in three, but none showed K12 transcript. The resultant epithelial phenotype of the pannus tissue was not corneal, as evidenced by the negative staining to cornea-specific K12 mRNA and protein, but was conjunctival, as evidenced by the presence of goblet cells, the weak expression of K3, and the strong expression of K19. The abundant expression of DeltaNp63 in such conjunctiva-derived epithelium in eyes with total limbal SC deficiency raises doubts as to its validity as a limbal SC marker. Copyright Association for Research in Vision and Ophthalmology

Tumor suppressor function of Syk in human MCF10A in vitro and normal mouse mammary epithelium in vivo.

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You Me Sung

2009-10-01

Full Text Available The normal function of Syk in epithelium of the developing or adult breast is not known, however, Syk suppresses tumor growth, invasion, and metastasis in breast cancer cells. Here, we demonstrate that in the mouse mammary gland, loss of one Syk allele profoundly increases proliferation and ductal branching and invasion of epithelial cells through the mammary fat pad during puberty. Mammary carcinomas develop by one year. Syk also suppresses proliferation and invasion in vitro. siRNA or shRNA knockdown of Syk in MCF10A breast epithelial cells dramatically increased proliferation, anchorage independent growth, cellular motility, and invasion, with formation of functional, extracellular matrix-degrading invadopodia. Morphological and gene microarray analysis following Syk knockdown revealed a loss of luminal and differentiated epithelial features with epithelial to mesenchymal transition and a gain in invadopodial cell surface markers CD44, CD49F, and MMP14. These results support the role of Syk in limiting proliferation and invasion of epithelial cells during normal morphogenesis, and emphasize the critical role of Syk as a tumor suppressor for breast cancer. The question of breast cancer risk following systemic anti-Syk therapy is raised since only partial loss of Syk was sufficient to induce mammary carcinomas.

Partial Denervation of Subbasal Axons Persists Following Debridement Wounds to the Mouse Cornea

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Pajoohesh-Ganji, Ahdeah; Pal-Ghosh, Sonali; Tadvalkar, Gauri; Kyne, Briana M.; Saban, Daniel R.; Stepp, Mary Ann

2015-01-01

Although sensory reinnervation occurs after injury in the PNS, poor reinnervation in the elderly and those with diabetes often leads to pathology. Here we quantify subbasal axon density in the central and peripheral mouse cornea over time after three different types of injury. The mouse cornea is highly innervated with a dense array of subbasal nerves that form a spiral called the vortex at the corneal center or apex; these nerves are readily detected within flat mounted corneas. After anesthesia, corneal epithelial cells were removed using either a dulled blade or a rotating burr within an area demarcated centrally with a 1.5 mm trephine. A third wound type, superficial trephination, involved demarcating the area with the 1.5 mm trephine but not removing cells. By 7d after superficial trephination, subbasal axon density returns to control levels; by 28d the vortex reforms. Although axon density is similar to control 14d after dulled blade and rotating burr wounding, defects in axon morphology at the corneal apex remain. After 14d, axons retract from the center leaving the subbasal axon density reduced by 37.2% and 36.8% at 28d after dulled blade and rotating burr wounding, respectively, compared to control. Assessment of inflammation using flow cytometry shows that persistent inflammation is not a factor in the incomplete reinnervation. Expression of mRNAs encoding 22 regeneration associated genes (RAGs) involved in axon targeting assessed by QPCR reveals that netrin-1 and ephrin signaling are altered after wounding. Subpopulations of corneal epithelial basal cells at the corneal apex stop expressing ki67 as early as 7d after injury and by 14d and 28d after wounding, many of these basal cells undergo apoptosis and die. While subbasal axons are restored to their normal density and morphology after superficial trephination, subbasal axon recovery is partial after debridement wounds. The increase in corneal epithelial basal cell apoptosis at the apex observed at 14d

Corneal laceration caused by river crab

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Vinuthinee N

2015-01-01

Full Text Available Naidu Vinuthinee,1,2 Anuar Azreen-Redzal,1 Jaafar Juanarita,1 Embong Zunaina2 1Department of Ophthalmology, Hospital Sultanah Bahiyah, Alor Setar, 2Department of Ophthalmology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Malaysia Abstract: A 5-year-old boy presented with right eye pain associated with tearing and photophobia of 1-day duration. He gave a history of playing with a river crab when suddenly the crab clamped his fingers. He attempted to fling the crab off, but the crab flew and hit his right eye. Ocular examination revealed a right eye corneal ulcer with clumps of fibrin located beneath the corneal ulcer and 1.6 mm level of hypopyon. At presentation, the Seidel test was negative, with a deep anterior chamber. Culture from the corneal scrapping specimen grew Citrobacter diversus and Proteus vulgaris, and the boy was treated with topical gentamicin and ceftazidime eyedrops. Fibrin clumps beneath the corneal ulcer subsequently dislodged, and revealed a full-thickness corneal laceration wound with a positive Seidel test and shallow anterior chamber. The patient underwent emergency corneal toileting and suturing. Postoperatively, he was treated with oral ciprofloxacin 250 mg 12-hourly for 1 week, topical gentamicin, ceftazidime, and dexamethasone eyedrops for 4 weeks. Right eye vision improved to 6/9 and 6/6 with pinhole at the 2-week follow-up following corneal suture removal. Keywords: corneal ulcer, pediatric trauma, ocular injury

Visual outcome after corneal transplantation for corneal perforation and iris prolapse in 37 horses

DEFF Research Database (Denmark)

Henriksen, Michala de Linde; Plummer, C. E.; Mangan, B.

2012-01-01

We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation.......We wanted to investigate the visual outcome of horses presented with iris prolapse and treated with corneal transplantation....

Effect of chitosan-N-acetylcysteine conjugate in a mouse model of botulinum toxin B-induced dry eye.

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Hongyok, Teeravee; Chae, Jemin J; Shin, Young Joo; Na, Daero; Li, Li; Chuck, Roy S

2009-04-01

To evaluate the effect of a thiolated polymer lubricant, chitosan-N-acetylcysteine conjugate (C-NAC), in a mouse model of dry eye. Eye drops containing 0.5% C-NAC, 0.3% C-NAC, a vehicle (control group), artificial tears, or fluorometholone were applied in a masked fashion in a mouse model of induced dry eye from 3 days to 4 weeks after botulinum toxin B injection. Corneal fluorescein staining was periodically recorded. Real-time reverse transcriptase-polymerase chain reaction and immunofluorescence staining were performed at the end of the study to evaluate inflammatory cytokine expressions. Mice treated with C-NAC, 0.5%, and fluorometholone showed a downward trend that was not statistically significant in corneal staining compared with the other groups. Chitosan-NAC formulations, fluorometholone, and artificial tears significantly decreased IL-1beta (interleukin 1beta), IL-10, IL-12alpha, and tumor necrosis factor alpha expression in ocular surface tissues. The botulinum toxin B-induced dry eye mouse model is potentially useful in evaluating new dry eye treatment. Evaluation of important molecular biomarkers suggests that C-NAC may impart some protective ocular surface properties. However, clinical data did not indicate statistically significant improvement of tear production and corneal staining in any of the groups tested. Topically applied C-NAC might protect the ocular surface in dry eye syndrome, as evidenced by decreased inflammatory cytokine expression.

Explore the full thick layer of corneal transplantation in the treatment of pseudomonas aeruginosa corneal ulcer infection

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Xin Wang

2015-02-01

Full Text Available AIM: To explore the feasibility, safety and effect of the full-thickness lamellar keratoplasty for the treatment of pseudomonas aeruginosa corneal ulcer. METHODS: Based on a retrospective non-controlled study, 25 patients were given the full-thickness lamellar keratoplasty for clinical diagnosis of pseudomonas aeruginosa infection and corneal ulcer medication conventional anti-gram-negative bacteria. Routine follow-up were carried out at postoperative 1wk; 1, 3, 6, 12, 18mo to observe the situation of corneal epithelial healing, recurrent infection, immune rejection, graft transparency and best corrected visual acuity, etc. At the 6 and 12mo postoperative, corneal endothelial cell density was reexamined.RESULTS: No patients because of Descemet's membrane rupture underwent penetrating keratoplasty surgery: One only in cases of bacterial infection after 1mo, once again did not cultivate a culture of bacteria pseudomonas aeruginosa, and the remaining 24 cases average follow-up 14±6mo, corneal graft were transparent, the cure rate was 96%. At the sixth month after surgery, there were 16 cases of eye surgery best corrected visual acuity ≥4.5, of which 3 cases ≥4.8. At the sixth month after surgery, the average corneal endothelial cell density 2 425±278/mm2; At 12mo postoperatively, it was 2 257± 326/mm2.CONCLUSION: Full-thickness lamellar keratoplasty is an effective method of pseudomonas aeruginosa infection in the treatment of corneal ulcers, corneal drying material glycerol can be achieved by visual effects.

Contact Lens Related Corneal Ulcer

OpenAIRE

Loh, KY; Agarwal, P

2010-01-01

A corneal ulcer caused by infection is one of the major causes of blindness worldwide. One of the recent health concerns is the increasing incidence of corneal ulcers associated with contact lens user especially if the users fail to follow specific instruction in using their contact lenses. Risk factors associated with increased risk of contact lens related corneal ulcers are: overnight wear, long duration of continuous wear, lower socio-economic classes, smoking, dry eye and poor hygiene. Th...

Riboflavin for corneal cross-linking.

Science.gov (United States)

O'Brart, D P S

2016-06-01

Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet A (UVA) radiation is the first therapeutic modality that appears to arrest the progression of keratoconus and other corneal ectasias. Riboflavin is central to the process, acting as a photosensitizer for the production of oxygen singlets and riboflavin triplets. These free radicals drive the CXL process within the proteins of the corneal stroma, altering its biomechanical properties. Riboflavin also absorbs the majority of the UVA radiation, which is potentially cytotoxic and mutagenic, within the anterior stroma, preventing damage to internal ocular structures, such as the corneal endothelium, lens and retina. Clinical studies report cessation of ectatic progression in over 90% of cases and the majority document significant improvements in visual, keratometric and topographic parameters. Clinical follow-up is limited to 5-10 years, but suggests sustained stability and enhancement in corneal shape. Sight-threatening complications are rare. The optimal stromal riboflavin dosage for CXL is as yet undetermined. Copyright 2016 Prous Science, S.A.U. or its licensors. All rights reserved.

Chlorpromazine-induced corneal endothelial phototoxicity

International Nuclear Information System (INIS)

Hull, D.S.; Csukas, S.; Green, K.

1982-01-01

Chlorpromazine, which has been used extensively for the treatment of psychiatric disorders, is known to accumulate in the posterior corneal stroma, lens, and uveal tract. Because it is a phototoxic compound, the potential exists for it to cause cellular damage after light exposure. Specular microscopic perfusion of corneal endothelial cells in darkness with 0.5 mM chlorpromazine HCl resulted in a swelling rate of 18 +/- 2 micrometer/hr, whereas corneas exposed to long-wavelength ultraviolet light for 3 min in the presence of 0.5 mM chlorpromazine swelled at 37 +/- 9 micrometer/hr (p less than 0.01). Preirradiation of 0.5 mM chlorpromazine solution with ultraviolet light for 30 min and subsequent corneal perfusion with the solution resulted in a corneal swelling rate of 45 +/- 19 micrometer/hr. Cornea endothelial cells perfused with 0.5 mM chlorpromazine that was preirradiated with ultraviolet light showed marked swelling on scanning electron microscopic examination, whereas those perfused with nonirradiated chlorpromazine were flat and showed a normal mosaic pattern. Combining either 500 U/ml catalase or 290 U/ml superoxide dismutase with chlorpromazine did not alter photoinduction of corneal swelling. The data suggest that corneal endothelial chlorpromazine phototoxicity is secondary to cytotoxic products resulting from the photodynamically induced decomposition of chlorpromazine and is not caused by hydrogen peroxide or superoxide anion generated during the phototoxic reaction

The corneal epithelium: clinical relevance of cytokine-mediated responses to maintenance of corneal health O epitélio da córnea: relevância clínica das respostas mediadas por citocinas para manter a saúde da córnea

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PS Reinach

2008-12-01

Full Text Available We review the growth factor receptor-mediated cell signaling events that induce the responses required for the maintenance of corneal epithelial health. Our focus is to show how such responses contribute to sustaining corneal transparency and deturgescence, so basic to the pathogenesis of corneal diseases. Furthermore, we point out how alterations of receptor-mediated control of these responses account for losses in corneal transparency. In particular, the roles of growth factors in the mediation of normal corneal function, including epithelial cell proliferation, prevention of compromise of the barrier function of the cornea, and maintenance of normal renewal processes are discussed in relation to clinical entities involving the cornea.Revimos os eventos de sinalização celular mediados por receptores de fatores de crescimento, usados para manter a saúde do epitélio da córnea. O objetivo é mostrar como essas respostas contribuem para manter a transparência e a deturgescência da córnea, críticos na patogênese das doenças da córnea. Mais ainda, enfatizamos como alterações no controle mediado por receptor dessas respostas contribuem na transparência da córnea. Especificamente, o papel dos fatores de crescimento na mediação do controle funcional normal da córnea, incluindo proliferação epitelial, prevenção da quebra da função de barreira, manutenção do processo de renovação são discutidos em relação às entidades clínicas envolvidas na córnea.

Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

OpenAIRE

Sarkar, Joy; Chaudhary, Shweta; Namavari, Abed; Ozturk, Okan; Chang, Jin-Hong; Yco, Lisette; Sonawane, Snehal; Khanolkar, Vishakha; Hallak, Joelle; Jain, Sandeep

2012-01-01

Topical application of benzalkonium chloride (BAK) to the eye causes dose-related corneal neurotoxicity. Corneal inflammation and reduction in aqueous tear production accompany neurotoxicity. Cessation of BAK treatment leads to recovery of corneal nerve density.

Role of insulin in regulation of Na+-/K+-dependent ATPase activity and pump function in corneal endothelial cells.

Science.gov (United States)

Hatou, Shin; Yamada, Masakazu; Akune, Yoko; Mochizuki, Hiroshi; Shiraishi, Atsushi; Joko, Takeshi; Nishida, Teruo; Tsubota, Kazuo

2010-08-01

The Na(+)-/K(+)-dependent ATPase (Na,K-ATPase) expressed in the basolateral membrane of corneal endothelial cells plays an important role in the pump function of the corneal endothelium. The role of insulin in the regulation of Na,K-ATPase activity and pump function in corneal endothelial cells was investigated. Confluent monolayers of mouse corneal endothelial cells were exposed to insulin. ATPase activity was evaluated by spectrophotometric measurement of phosphate released from ATP with the use of ammonium molybdate; Na,K-ATPase activity was defined as the portion of total ATPase activity sensitive to ouabain. Pump function was measured with the use of a Ussing chamber; pump function attributable to Na,K-ATPase activity was defined as the portion of the total short-circuit current sensitive to ouabain. Western blot analysis and immunocytochemistry were performed to measure the expression of the Na,K-ATPase alpha(1)-subunit. Insulin increased the Na,K-ATPase activity and pump function of cultured corneal endothelial cells. These effects were blocked by protein kinase C (PKC) inhibitors and protein phosphatases 1 and 2A inhibitor. Western blot analysis indicated that insulin decreased the ratio of the inactive Na,K-ATPase alpha(1)-subunit. Immunocytochemistry indicated that insulin increased the cell surface expression of the Na,K-ATPase alpha(1)-subunit. These results suggest that insulin increases the Na,K-ATPase activity and pump function of cultured corneal endothelial cells. The effect of insulin is mediated by PKC and presumably results in the activation of PP1, 2A, or both, which are essential for activating Na,K-ATPase by alpha(1)-subunit dephosphorylation.

Long-term outcomes of wedge resection at the limbus for high irregular corneal astigmatism after repaired corneal laceration

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Jun Du

2016-06-01

Full Text Available AIM: To evaluate the clinical value of wedge resection at corneal limbus in patients with traumatic corneal scarring and high irregular astigmatism. METHODS: Patients with traumatic corneal astigmatism received wedge resection at least 6mo after suture removal from corneal wound. The uncorrected distance visual acuities (UCVA and best corrected distance visual acuities (BCVA, pre- and post-operation astigmatism, spherical equivalent (SE, safety and complications were evaluated. RESULTS: Ten eyes (10 patients were enrolled in this study. Mean follow-up time after wedge resection was 37.8±15.4mo (range, 20-61mo. The mean UCVA improved from +1.07±0.55 logMAR to +0.43±0.22 logMAR (P=0.000 and the mean BCVA from +0.50±0.30 logMAR to +0.15±0.17 logMAR (P=0.000. The mean astigmatism power measured by retinoscopy was -2.03±2.27 D postoperatively and -2.83±4.52 D preoperatively (P=0.310. The mean SE was -0.74±1.61 D postoperatively and -0.64±1.89 D preoperatively (P=0.601. Two cases developed mild pannus near the sutures. No corneal perforation, infectious keratitis or wound gape occurred. CONCLUSION: Corneal-scleral limbal wedge resection with compression suture is a safe, effective treatment for poor patients with high irregular corneal astigmatism after corneal-scleral penetrating injury. Retinoscopy can prove particularly useful for high irregular corneal astigmatism when other measurements are not amenable.

A dimensionless ordered pull-through model of the mammalian lens epithelium evidences scaling across species and explains the age-dependent changes in cell density in the human lens

Science.gov (United States)

Wu, Jun Jie; Wu, Weiju; Tholozan, Frederique M.; Saunter, Christopher D.; Girkin, John M.; Quinlan, Roy A.

2015-01-01

We present a mathematical (ordered pull-through; OPT) model of the cell-density profile for the mammalian lens epithelium together with new experimental data. The model is based upon dimensionless parameters, an important criterion for inter-species comparisons where lens sizes can vary greatly (e.g. bovine (approx. 18 mm); mouse (approx. 2 mm)) and confirms that mammalian lenses scale with size. The validated model includes two parameters: β/α, which is the ratio of the proliferation rate in the peripheral and in the central region of the lens; and γGZ, a dimensionless pull-through parameter that accounts for the cell transition and exit from the epithelium into the lens body. Best-fit values were determined for mouse, rat, rabbit, bovine and human lens epithelia. The OPT model accounts for the peak in cell density at the periphery of the lens epithelium, a region where cell proliferation is concentrated and reaches a maximum coincident with the germinative zone. The β/α ratio correlates with the measured FGF-2 gradient, a morphogen critical to lens cell survival, proliferation and differentiation. As proliferation declines with age, the OPT model predicted age-dependent changes in cell-density profiles, which we observed in mouse and human lenses. PMID:26236824

Conditional ablation of the choroideremia gene causes age-related changes in mouse retinal pigment epithelium.

Science.gov (United States)

Wavre-Shapton, Silène T; Tolmachova, Tanya; Lopes da Silva, Mafalda; da Silva, Mafalda Lopes; Futter, Clare E; Seabra, Miguel C

2013-01-01

The retinal pigment epithelium (RPE) is a pigmented monolayer of cells lying between the photoreceptors and a layer of fenestrated capillaries, the choriocapillaris. Choroideremia (CHM) is an X-linked progressive degeneration of these three layers caused by the loss of function of Rab Escort protein-1 (REP1). REP1 is involved in the prenylation of Rab proteins, key regulators of membrane trafficking. To study the pathological consequences of chronic disruption of membrane traffic in the RPE we used a cell type-specific knock-out mouse model of the disease, where the Chm/Rep1 gene is deleted only in pigmented cells (Chm(Flox), Tyr-Cre+). Transmission electron microscopy (TEM) was used to quantitate the melanosome distribution in the RPE and immunofluorescent staining of rhodopsin was used to quantitate phagocytosed rod outer segments in retinal sections. The ultrastructure of the RPE and Bruch's membrane at different ages was characterised by TEM to analyse age-related changes occurring as a result of defects in membrane traffic pathways. Chm/Rep1 gene knockout in RPE cells resulted in reduced numbers of melanosomes in the apical processes and delayed phagosome degradation. In addition, the RPE accumulated pathological changes at 5-6 months of age similar to those observed in 2-year old controls. These included the intracellular accumulation of lipofuscin-containing deposits, disorganised basal infoldings and the extracellular accumulation of basal laminar and basal linear deposits. The phenotype of the Chm(Flox), Tyr-Cre+ mice suggests that loss of the Chm/Rep1 gene causes premature accumulation of features of aging in the RPE. Furthermore, the striking similarities between the present observations and some of the phenotypes reported in age-related macular degeneration (AMD) suggest that membrane traffic defects may contribute to the pathogenesis of AMD.

Conditional ablation of the choroideremia gene causes age-related changes in mouse retinal pigment epithelium.

Directory of Open Access Journals (Sweden)

Silène T Wavre-Shapton

Full Text Available The retinal pigment epithelium (RPE is a pigmented monolayer of cells lying between the photoreceptors and a layer of fenestrated capillaries, the choriocapillaris. Choroideremia (CHM is an X-linked progressive degeneration of these three layers caused by the loss of function of Rab Escort protein-1 (REP1. REP1 is involved in the prenylation of Rab proteins, key regulators of membrane trafficking. To study the pathological consequences of chronic disruption of membrane traffic in the RPE we used a cell type-specific knock-out mouse model of the disease, where the Chm/Rep1 gene is deleted only in pigmented cells (Chm(Flox, Tyr-Cre+. Transmission electron microscopy (TEM was used to quantitate the melanosome distribution in the RPE and immunofluorescent staining of rhodopsin was used to quantitate phagocytosed rod outer segments in retinal sections. The ultrastructure of the RPE and Bruch's membrane at different ages was characterised by TEM to analyse age-related changes occurring as a result of defects in membrane traffic pathways. Chm/Rep1 gene knockout in RPE cells resulted in reduced numbers of melanosomes in the apical processes and delayed phagosome degradation. In addition, the RPE accumulated pathological changes at 5-6 months of age similar to those observed in 2-year old controls. These included the intracellular accumulation of lipofuscin-containing deposits, disorganised basal infoldings and the extracellular accumulation of basal laminar and basal linear deposits. The phenotype of the Chm(Flox, Tyr-Cre+ mice suggests that loss of the Chm/Rep1 gene causes premature accumulation of features of aging in the RPE. Furthermore, the striking similarities between the present observations and some of the phenotypes reported in age-related macular degeneration (AMD suggest that membrane traffic defects may contribute to the pathogenesis of AMD.

Induction of corneal collagen cross-linking in experimental corneal alkali burns in rabbits

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Marcello Colombo-Barboza

2014-10-01

Full Text Available Objective: To evaluate the effect of riboflavin-ultraviolet-A-induced cross-linking (CXL following corneal alkali burns in rabbits. Methods: The right corneas and limbi of ten rabbits were burned using a 1N solution of NaOH and the animals were then divided into two groups: a control group submitted to clinical treatment alone and an experimental group that was treated 1 h after injury with CXL, followed by the same clinical treatment as administered to the controls. Clinical parameters were evaluated post-injury at 1, 7, 15, and 30 days by two independent observers. Following this evaluation, the corneas were excised and examined histologically. Results: There were no statistically significant differences in clinical parameters, such as hyperemia, corneal edema, ciliary injection, limbal ischemia, secretion, corneal neovascularization, symblepharon, or blepharospasm, at any of the time-points evaluated. However, the size of the epithelial defect was significantly smaller in the CXL group (p<0.05 (day 15: p=0.008 and day 30: p=0.008 and the extent of the corneal injury (opacity lesion was also smaller (day 30: p=0.021. Histopathology showed the presence of collagen bridges linking the collagen fibers in only the CXL group. Conclusions: These results suggest that the use of CXL may improve the prognosis of acute corneal alkali burns.

Partial denervation of sub-basal axons persists following debridement wounds to the mouse cornea.

Science.gov (United States)

Pajoohesh-Ganji, Ahdeah; Pal-Ghosh, Sonali; Tadvalkar, Gauri; Kyne, Briana M; Saban, Daniel R; Stepp, Mary Ann

2015-11-01

Although sensory reinnervation occurs after injury in the peripheral nervous system, poor reinnervation in the elderly and those with diabetes often leads to pathology. Here we quantify sub-basal axon density in the central and peripheral mouse cornea over time after three different types of injury. The mouse cornea is highly innervated with a dense array of sub-basal nerves that form a spiral called the vortex at the corneal center or apex; these nerves are readily detected within flat mounted corneas. After anesthesia, corneal epithelial cells were removed using either a dulled blade or a rotating burr within an area demarcated centrally with a 1.5 mm trephine. A third wound type, superficial trephination, involved demarcating the area with the 1.5 mm trephine but not removing cells. By 7 days after superficial trephination, sub-basal axon density returns to control levels; by 28 days the vortex reforms. Although axon density is similar to control 14 days after dulled blade and rotating burr wounding, defects in axon morphology at the corneal apex remain. After 14 days, axons retract from the center leaving the sub-basal axon density reduced by 37.2 and 36.8% at 28 days after dulled blade and rotating burr wounding, respectively, compared with control. Assessment of inflammation using flow cytometry shows that persistent inflammation is not a factor in the incomplete reinnervation. Expression of mRNAs encoding 22 regeneration-associated genes involved in axon targeting assessed by QPCR reveals that netrin-1 and ephrin signaling are altered after wounding. Subpopulations of corneal epithelial basal cells at the corneal apex stop expressing ki67 as early as 7 days after injury and by 14 and 28 days after wounding, many of these basal cells undergo apoptosis and die. Although sub-basal axons are restored to their normal density and morphology after superficial trephination, sub-basal axon recovery is partial after debridement wounds. The increase in corneal

Corneal Toxicity Following Exposure to Asclepias Tuberosa

OpenAIRE

Mikkelsen, Lauge Hjorth; Hamoudi, Hassan; G?l, Cigdem Altuntas; Heegaard, Steffen

2017-01-01

PURPOSE: To present a case of corneal toxicity following exposure to milky plant latex from Asclepias tuberosa.METHODS: A 70-year-old female presented with blurred vision and pain in her left eye after handling an Ascepias tuberosa. Clinical examination revealed a corneal stromal oedema with small epithelial defects. The corneal endothelium was intact and folds in Descemets membrane were observed. The oedema was treated with chloramphenicol, dexamethasone and scopolamine.RESULTS: The corneal ...

A short-term study of corneal collagen cross-linking with hypo-osmolar riboflavin solution in keratoconic corneas

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Shao-Feng Gu

2015-02-01

Full Text Available AIM: To report the 3mo outcomes of collagen cross-linking (CXL with a hypo-osmolar riboflavin in thin corneas with the thinnest thickness less than 400 μm without epithelium. METHODS: Eight eyes in 6 patients with age 26.2±4.8y were included in the study. All patients underwent CXL using a hypo-osmolar riboflavin solution after its de-epithelization. Best corrected visual acuity, manifest refraction, the thinnest corneal thickness, and endothelial cell density were evaluated before and 3mo after the procedure. RESULTS: The mean thinnest thickness of the cornea was 408.5±29.0 μm before treatment and reduced to 369.8±24.8 μm after the removal of epithelium. With the application of the hypo-osmolar riboflavin solution, the thickness increased to 445.0±26.5 μm before CXL and recover to 412.5±22.7 μm at 3mo after treatment, P=0.659. Before surgery, the mean K-value of the apex of the keratoconus corneas was 57.6±4.0 diopters, and slightly decreased (54.7±4.9 diopters after surgery (P=0.085. Mean best-corrected visual acuity was 0.55±0.23 logarithm of the minimal angle of resolution, and increased to 0.53±0.26 logarithm after surgery (P=0.879. The endothelial cell density was 2706.4±201.6 cells/mm2 before treatment, and slightly decreased (2641.2±218.2 cells/mm2 at last fellow up (P=0.002. CONCLUSION: Corneal collagen cross-linking with a hypo-osmolar riboflavin in thin corneas seems to be a promising treatment. Further study should be done to evaluate the safety and efficiency of CXL in thin corneas for the long-term.

Corneal modeling for analysis of photorefractive keratectomy

Science.gov (United States)

Della Vecchia, Michael A.; Lamkin-Kennard, Kathleen

1997-05-01

Procedurally, excimer photorefractive keratectomy is based on the refractive correction of composite spherical and cylindrical ophthalmic errors of the entire eye. These refractive errors are inputted for correction at the corneal plane and for the properly controlled duration and location of laser energy. Topography is usually taken to correspondingly monitor spherical and cylindrical corneorefractive errors. While a corneal topographer provides surface morphologic information, the keratorefractive photoablation is based on the patient's spherical and cylindrical spectacle correction. Topography is at present not directly part of the procedural deterministic parameters. Examination of how corneal curvature at each of the keratometric reference loci affect the shape of the resultant corneal photoablated surface may enhance the accuracy of the desired correction. The objective of this study was to develop a methodology to utilize corneal topography for construction of models depicting pre- and post-operative keratomorphology for analysis of photorefractive keratectomy. Multiple types of models were developed then recreated in optical design software for examination of focal lengths and other optical characteristics. The corneal models were developed using data extracted from the TMS I corneal modeling system (Computed Anatomy, New York, NY). The TMS I does not allow for manipulation of data or differentiation of pre- and post-operative surfaces within its platform, thus models needed to be created for analysis. The data were imported into Matlab where 3D models, surface meshes, and contour plots were created. The data used to generate the models were pre- and post-operative curvatures, heights from the corneal apes, and x-y positions at 6400 locations on the corneal surface. Outlying non-contributory points were eliminated through statistical operations. Pre- and post- operative models were analyzed to obtain the resultant changes in the corneal surfaces during PRK

Preparation of arginine–glycine–aspartic acid-modified biopolymeric nanoparticles containing epigalloccatechin-3-gallate for targeting vascular endothelial cells to inhibit corneal neovascularization

Science.gov (United States)

Chang, Che-Yi; Wang, Ming-Chen; Miyagawa, Takuya; Chen, Zhi-Yu; Lin, Feng-Huei; Chen, Ko-Hua; Liu, Guei-Sheung; Tseng, Ching-Li

2017-01-01

Neovascularization (NV) of the cornea can disrupt visual function, causing ocular diseases, including blindness. Therefore, treatment of corneal NV has a high public health impact. Epigalloccatechin-3-gallate (EGCG), presenting antiangiogenesis effects, was chosen as an inhibitor to treat human vascular endothelial cells for corneal NV treatment. An arginine–glycine–aspartic acid (RGD) peptide–hyaluronic acid (HA)-conjugated complex coating on the gelatin/EGCG self-assembly nanoparticles (GEH-RGD NPs) was synthesized for targeting the αvβ3 integrin on human umbilical vein endothelial cells (HUVECs) in this study, and a corneal NV mouse model was used to evaluate the therapeutic effect of this nanomedicine used as eyedrops. HA-RGD conjugation via COOH and amine groups was confirmed by 1H-nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The average diameter of GEH-RGD NPs was 168.87±22.5 nm with positive charge (19.7±2 mV), with an EGCG-loading efficiency up to 95%. Images of GEH-RGD NPs acquired from transmission electron microscopy showed a spherical shape and shell structure of about 200 nm. A slow-release pattern was observed in the nanoformulation at about 30% after 30 hours. Surface plasmon resonance confirmed that GEH-RGD NPs specifically bound to the integrin αvβ3. In vitro cell-viability assay showed that GEH-RGD efficiently inhibited HUVEC proliferation at low EGCG concentrations (20 μg/mL) when compared with EGCG or non-RGD-modified NPs. Furthermore, GEH-RGD NPs significantly inhibited HUVEC migration down to 58%, lasting for 24 hours. In the corneal NV mouse model, fewer and thinner vessels were observed in the alkali-burned cornea after treatment with GEH-RGD NP eyedrops. Overall, this study indicates that GEH-RGD NPs were successfully developed and synthesized as an inhibitor of vascular endothelial cells with specific targeting capacity. Moreover, they can be used in eyedrops to inhibit angiogenesis in corneal NV

Development of teeth in chick embryos after mouse neural crest transplantations

OpenAIRE

Mitsiadis, Thimios A.; Chéraud, Yvonnick; Sharpe, Paul; Fontaine-Pérus, Josiane

2003-01-01

Teeth were lost in birds 70–80 million years ago. Current thinking holds that it is the avian cranial neural crest-derived mesenchyme that has lost odontogenic capacity, whereas the oral epithelium retains the signaling properties required to induce odontogenesis. To investigate the odontogenic capacity of ectomesenchyme, we have used neural tube transplantations from mice to chick embryos to replace the chick neural crest cell populations with mouse neural crest cells. The mouse/chick ...

Late onset corneal ectasia after LASIK surgery.

Science.gov (United States)

Said, Ashraf; Hamade, Issam H; Tabbara, Khalid F

2011-07-01

To report late onset corneal ectasia following myopic LASIK. A retrospective cohort case series. Nineteen patients with late onset corneal ectasia following LASIK procedure were examined at The Eye Center, Riyadh, Saudi Arabia. Patients underwent LASIK for myopia with spherical equivalent ranging from -1.4 to -13.75 diopters. Age and gender, history of systemic or local diseases, and time of onset of corneal ectasia were recorded. Eye examination and corneal topographical analyses were done before and after LASIK surgery. Nineteen patients (29 eyes) with late onset corneal ectasia were identified from 1998 to 2008 in 13 male and six female patients. The mean follow-up period was 108 ± 23 months (range 72-144 months). No patient had pre-operative identifiable risk factors for corneal ectasia and the mean time of onset was 57 ± 24 months (range 24-120 months after LASIK). The pre-operative values included mean central pachymetry 553 ± 25 μm, mean keratometry reading of 42.9 ± 1.5 diopters, average oblique cylinder of 1.4 ± 1.2 diopters, posterior surface elevation of 26 ± 2.1 diopters, corneal flap thickness of 160 μm, mean spherical equivalent of -5.6 ± 3.6 diopters, and calculated residual corneal stromal bed thickness was 288 ± 35 μm. Three (5 eyes) patients developed ectasia after pregnancy. Three (4 eyes) patients developed corneal ectasia following severe adenoviral keratoconjunctivitis and had positive PCR for adenovirus type 8. Corneal ectasia may develop many years after LASIK surgery and symptoms could go undetected for some time. Pregnancy and adenoviral keratoconjunctivitis occurred post-operatively in six patients.

Designing Hydrogel Adhesives for Corneal Wound Repair

Science.gov (United States)

Grinstaff, Mark W.

2013-01-01

Today, corneal wounds are repaired using nylon sutures. Yet there are a number of complications associated with suturing the cornea, and thus there is interest in an adhesive to replace or supplement sutures in the repair of corneal wounds. We are designing and evaluating corneal adhesives prepared from dendrimers – single molecular weight, highly branched polymers. We have explored two strategies to form these ocular adhesives. The first involves a photocrosslinking reaction and the second uses a peptide ligation reactions to couple the individual dendrimers together to from the adhesive. These adhesives were successfully used to repair corneal perforations, close the flap produced in a LASIK procedure, and secure a corneal transplant. PMID:17889330

Molecular mechanisms of water transport in the eye

DEFF Research Database (Denmark)

Hamann, Steffen

2002-01-01

The four major sites for ocular water transport, the corneal epithelium and endothelium, the ciliary epithelium, and the retinal pigment epithelium, are reviewed. The cornea has an inherent tendency to swell, which is counteracted by its two surface cell layers, the corneal epithelium...... and endothelium. The bilayered ciliary epithelium secretes the aqueous humor into the posterior chamber, and the retinal pigment epithelium transports water from the retinal to the choroidal site. For each epithelium, ion transport mechanisms are associated with fluid transport, but the exact molecular coupling...... sites between ion and water transport remain undefined. In the retinal pigment epithelium, a H+-lactate cotransporter transports water. This protein could be the site of coupling between salt and water in this epithelium. The distribution of aquaporins does not suggest a role for these proteins...

Granular corneal dystrophy Groenouw type I (GrI) and Reis-Bücklers' corneal dystrophy (R-B). One entity?

Science.gov (United States)

Møller, H U

1989-12-01

This paper maintains that Reis-Bücklers' corneal dystrophy and granular corneal dystrophy Groenouw type I are one and the same disease. Included are some of the technically best photographs of Reis-Bücklers' dystrophy found in the literature, and these are compared with photographs from patients with granular corneal dystrophy examined by the author. It is argued that most of the histological and ultrastructural findings on Reis Bücklers' dystrophy described in the literature are either congruent with what is found in granular corneal dystrophy or unspecific.

Using corneal confocal microscopy to track changes in the corneal layers of dry eye patients after autologous serum treatment.

Science.gov (United States)

Mahelkova, Gabriela; Jirsova, Katerina; Seidler Stangova, Petra; Palos, Michalis; Vesela, Viera; Fales, Ivan; Jiraskova, Nada; Dotrelova, Dagmar

2017-05-01

In vivo corneal confocal microscopy allows the examination of each layer of the cornea in detail and the identification of pathological changes at the cellular level. The purpose of this study was to identify the possible effects of a three-month treatment with autologous serum eye-drops in different corneal layers of patients with severe dry eye disease using corneal confocal microscopy. Twenty-six patients with dry eye disease were included in the study. Corneal fluorescein staining was performed. The corneas of the right eyes were examined using in vivo corneal confocal microscopy before and after a three-month treatment with autologous serum drops. The densities of superficial and basal epithelial cells, Langerhans cells, the keratocytes and activated keratocytes, the density of endothelial cells and the status of the sub-basal nerve plexus fibres were evaluated. A significant decrease in corneal fluorescein staining was found after the three-month autologous serum treatment (p = 0.0006). The basal epithelial cell density decreased significantly (p = 0.001), while the density of superficial epithelial cells did not change significantly (p = 0.473) nor did the number of Langerhans cells or activated keratocytes (p = 0.223; p = 0.307, respectively). There were no differences in the other corneal cell layers or in the status of the nerve fibres. The results demonstrate the ability of corneal confocal microscopy to evaluate an improvement in the basal epithelial cell layer of the cornea after autologous serum treatment in patients with dry eye disease. More studies with longer follow-up periods are needed to elucidate the suitability of corneal confocal microscopy to follow the effect of autologous serum treatment on nerve fibres or other corneal layers in dry eye disease patients. © 2016 Optometry Australia.

Increased Regenerative Capacity of the Olfactory Epithelium in Niemann–Pick Disease Type C1

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Anja Meyer

2017-04-01

Full Text Available Niemann–Pick disease type C1 (NPC1 is a fatal neurovisceral lysosomal lipid storage disorder. The mutation of the NPC1 protein affects the homeostasis and transport of cholesterol and glycosphingolipids from late endosomes/lysosomes to the endoplasmic reticulum resulting in progressive neurodegeneration. Since olfactory impairment is one of the earliest symptoms in many neurodegenerative disorders, we focused on alterations of the olfactory epithelium in an NPC1 mouse model. Previous findings revealed severe morphological and immunohistochemical alterations in the olfactory system of NPC1−/− mutant mice compared with healthy controls (NPC1+/+. Based on immunohistochemical evaluation of the olfactory epithelium, we analyzed the impact of neurodegeneration in the olfactory epithelium of NPC1−/− mice and observed considerable loss of mature olfactory receptor neurons as well as an increased number of proliferating and apoptotic cells. Additionally, after administration of two different therapy approaches using either a combination of miglustat, 2-hydroxypropyl-β-cyclodextrin (HPβCD and allopregnanolone or a monotherapy with HPβCD, we recorded a remarkable reduction of morphological damages in NPC1−/− mice and an up to four-fold increase of proliferating cells within the olfactory epithelium. Numbers of mature olfactory receptor neurons doubled after both therapy approaches. Interestingly, we also observed therapy-induced alterations in treated NPC1+/+ controls. Thus, olfactory testing may provide useful information to monitor pharmacologic treatment approaches in human NPC1.

Anatomical characterization of central, apical and minimal corneal thickness

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Federico Saenz-Frances

2014-08-01

Full Text Available AIM: To anatomically locate the points of minimum corneal thickness and central corneal thickness (pupil center in relation to the corneal apex.METHODS: Observational, cross-sectional study, 299 healthy volunteers. Thickness at the corneal apex (AT, minimum corneal thickness (MT and corneal thickness at the pupil center (PT were determined using the pentacam. Distances from the corneal apex to MT (MD and PT (PD were calculated and their quadrant position (taking the corneal apex as the reference determined:point of minimum thickness (MC and point of central thickness (PC depending on the quadrant position. Two multivariate linear regression models were constructed to examine the influence of age, gender, power of the flattest and steepest corneal axes, position of the flattest axis, corneal volume (determined using the Pentacam and PT on MD and PD. The effects of these variables on MC and PC were also determined in two multinomial regression models.RESULTS: MT was located at a mean distance of 0.909 mm from the apex (79.4% in the inferior-temporal quadrant. PT was located at a mean distance of 0.156 mm from the apex. The linear regression model for MD indicated it was significantly influenced by corneal volume (B=-0.024; 95%CI:-0.043 to -0.004. No significant relations were identified in the linear regression model for PD or the multinomial logistic regressions for MC and PC.CONCLUSION: MT was typically located at the inferior-temporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.

Preliminary study of the correlation between refractive error and corneal refractive power, corneal asphericity in myopic eye

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Qi-Chao Han

2014-05-01

Full Text Available AIM: To investigate the correlation between myopic refractive error and relative factors, including the corneal refractive power, posterior refractive power, axial length, corneal asphericity coefficient Q value, central cornea thickness(CCTand intraocular pressure(IOP. METHODS:According to the degree of myopia measured by subjective refraction, 138 myopia patients were divided into three subgroups: mild group(-1.00D--3.00D, moderate group(-3.25D--6.00D, high group(>6.00D. The Pentacam anterior segment tomographer(Germany, Oculus Companywas used to measure the corneal refractive power, posterior refractive power, and corneal asphericity in the right eye. IOP, CCT and axial length were measured by a non-contact tonometer and A-scan ultrasonic, respectively. The data was analyzed with a Pearson correlation analysis and one-way ANOVA. RESULTS: The myopic refractive error was negatively correlated with the axial length(r=-0.682, Pr=0.009, P=0.925. The axial length was negatively correlated with corneal refractive power(r=-0.554, Pr=0.674, Pr=-0.375, P=0.01. There was no significantly correlation between the myopic refractive error and CCT, IOP(r=-0.138, P=0.141; r=-0.121, P=0.157. CONCLUSION:The corneal refractive power plays the role of emmetropization during the development of myopia. There is clinic significance for the correlation between Q value and refractive error, IOP to guide the corneal refractive surgery.

Ocular surface changes in limbal stem cell deficiency caused by chemical injury: a histologic study of excised pannus from recipients of cultured corneal epithelium.

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Fatima, A; Iftekhar, G; Sangwan, V S; Vemuganti, G K

2008-09-01

To report histopathologic changes of the ocular surface pannus in patients with severe limbal stem cell deficiency (LSCD). Corneal and conjunctival pannus tissues from 29 patients undergoing ocular reconstruction with cultured limbal cell transplantation were included. The medical records of these patients were reviewed for demographics, aetiologic diagnosis, type of injury, interval between the initial insult and excision of pannus, and medical history involving human amniotic membrane (HAM) or limbal transplantation. The paraffin-embedded tissues were reviewed for epithelial changes, type-degree of fibrosis, degenerative changes, vascular changes, conjunctivalization of corneal surface, and evidence of residual HAM. We attempted a clinicopathologic correlation to understand the pathogenesis of pannus formation in LSCD. The 29 tissues were from 29 eyes of patients with primary aetiology of chemical burn in 89.6% (undetermined in 10.4%) of cases. The pannus showed epithelial hyperplasia in 62%, active fibrosis in 66%, severe inflammation in 21%, giant cell reaction in 28%, and stromal calcification in 14% cases. Goblet cells were seen over the cornea in 64% cases; their absence was associated with squamous metaplasia of the conjunctiva and with long duration of insult. Evidence of residual HAM was noted in 42% cases. The commonest cause of severe LSCD is alkali-induced injury. Goblet cells over the cornea were seen in 60% of cases. HAM used for ocular surface reconstruction could persist for long periods within the corneal pannus, thus raising the need for further studies with long-term follow-up.

A genetically engineered ovarian cancer mouse model based on fallopian tube transformation mimics human high-grade serous carcinoma development.

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Sherman-Baust, Cheryl A; Kuhn, Elisabetta; Valle, Blanca L; Shih, Ie-Ming; Kurman, Robert J; Wang, Tian-Li; Amano, Tomokazu; Ko, Minoru S H; Miyoshi, Ichiro; Araki, Yoshihiko; Lehrmann, Elin; Zhang, Yongqing; Becker, Kevin G; Morin, Patrice J

2014-07-01

Recent evidence suggests that ovarian high-grade serous carcinoma (HGSC) originates from the epithelium of the fallopian tube. However, most mouse models are based on the previous prevailing view that ovarian cancer develops from the transformation of the ovarian surface epithelium. Here, we report the extensive histological and molecular characterization of the mogp-TAg transgenic mouse, which expresses the SV40 large T-antigen (TAg) under the control of the mouse müllerian-specific Ovgp-1 promoter. Histological analysis of the fallopian tubes of mogp-TAg mice identified a variety of neoplastic lesions analogous to those described as precursors to ovarian HGSC. We identified areas of normal-appearing p53-positive epithelium that are similar to 'p53 signatures' in the human fallopian tube. More advanced proliferative lesions with nuclear atypia and epithelial stratification were also identified that were morphologically and immunohistochemically reminiscent of human serous tubal intraepithelial carcinoma (STIC), a potential precursor of ovarian HGSC. Beside these non-invasive precursor lesions, we also identified invasive adenocarcinoma in the ovaries of 56% of the mice. Microarray analysis revealed several genes differentially expressed between the fallopian tube of mogp-TAg and wild-type (WT) C57BL/6. One of these genes, Top2a, which encodes topoisomerase IIα, was shown by immunohistochemistry to be concurrently expressed with elevated p53 and was specifically elevated in mouse STICs but not in the surrounding tissues. TOP2A protein was also found elevated in human STICs, low-grade and high-grade serous carcinoma. The mouse model reported here displays a progression from normal tubal epithelium to invasive HGSC in the ovary, and therefore closely simulates the current emerging model of human ovarian HGSC pathogenesis. This mouse therefore has the potential to be a very useful new model for elucidating the mechanisms of serous ovarian tumourigenesis, as well as

Application of Novel Drugs for Corneal Cell Regeneration

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Sang Beom Han

2018-01-01

Full Text Available Corneal transplantation has been the only treatment method for corneal blindness, which is the major cause of reversible blindness. However, despite the advancement of surgical techniques for corneal transplantation, demand for the surgery can never be met due to a global shortage of donor cornea. The development of bioengineering and pharmaceutical technology provided us with novel drugs and biomaterials that can be used for innovative treatment methods for corneal diseases. In this review, the authors will discuss the efficacy and safety of pharmacologic therapies, such as Rho-kinase (ROCK inhibitors, blood-derived products, growth factors, and regenerating agent on corneal cell regeneration. The promising results of these agents suggest that these can be viable options for corneal reconstruction and visual rehabilitation.

Conjunctival-limbal autograft in total unilateral limbal stem cell deficiency

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Petra Schollmayer

2017-09-01

Full Text Available Background: Corneal epithelium is renewed by stem cells (SC that reside at the corneal limbus. Reduced number of SC or their abnormal function lead to the ocular surface disease called limbal stem cell deficiency (LSCD, characterized by corneal conjunctivalization, vascularization, persistent epithelial defects, chronic inflammation, and loss of vision. In a case of total unilateral LSCD, autologous transplantation of limbal epithelial stem cells (LESC from the healthy eye is needed. We describe the surgical technique of choice for autologous limbal transplantation, called conjunctival limbal autograft (CLAU that we combined with amniotic membrane (AM use. We present the results of CLAU in three patients with total unilateral LSCD due to chemical injury.Methods: Autologous limbal transplantation CLAU begins with the removal of fibrovascular pannus from the diseased corneal surface and the harvesting of two conjunctival-limbal grafts from the healthy eye. The grafts are then transplanted on to the limbal area of the recipient eye. AM is used as a patch to cover the denuded cornea and limbal grafts, as well as a barrier preventing the conjunctival epithelium from encroaching on to the temporal and nasal side of the corneal surface. In the donor eye, AM is used to cover the donor sites. CLAU with the use of AM was performed in 3 patients with unilateral LSCD due to chemical eye injury. In one patient limbal transplantation was combined with symblepharon lysis for entropium repair. In all cases AM was removed 3–6 days postoperatively to assess the growth of new epithelium from the limbal grafts. In all patients the ocular surface was covered with another AM until the cornea was completely epithelized and the new epithelium stable. In one patient the corneal regrafting and cataract removal was performed subsequently.Results: CLAU was successful in 2 patients and partially successful in 1 patient during the follow up. In all cases the growth of new

Glycosaminoglycans are involved in pathogen adherence to corneal epithelial cells differently for Gram-positive and Gram-negative bacteria

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Beatriz García

2016-11-01

Full Text Available The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies.

Corneal topography with an aberrometry-topography system.

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Mülhaupt, Michael; Dietzko, Sven; Wolffsohn, James; Bandlitz, Stefan

2018-05-07

To investigate the agreement between the central corneal radii and corneal eccentricity measurements generated by the new Wave Analyzer 700 Medica (WAV) compared to the Keratograph 4 (KER) and to test the repeatability of the instruments. 20 subjects (10 male, mean age 29.1 years, range 21-50 years) were recruited from the students and staff of the Cologne School of Optometry. Central corneal radii for the flat (r c/fl ) and steep (r c/st ) meridian as well as corneal eccentricity for the nasal (e nas ), temporal (e temp ), inferior (e inf ) and superior (e sup ) directions were measured using WAV and KER by one examiner in a randomized order. Central radii of the flat (r c/fl ) and steep (r c/st ) meridian measured with both instruments were statically significantly correlated (r = 0.945 and r = 0.951; p  0.05). Limits of agreement (LoA) indicate a better repeatability for the KER compared to WAV. Corneal topography measurements captured with the WAV were strongly correlated with the KER. However, due to the differences in measured corneal radii and eccentricities, the devices cannot be used interchangeably. For corneal topography the KER demonstrated better repeatability. Copyright © 2018 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Rechazo y retrasplante corneal Corneal rejection and re-transplantation

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Miguel O Mokey Castellanos

2007-06-01

Full Text Available Se efectuó una investigación observacional análítica retrospectiva, sobre los transplantes corneales efectuados en el Servicio de Oftalmología del Hospital "Hermanos Ameijeiras. Rechazaron 76 pacientes, que se compararon con un control de 89 pacientes, que en un período similar no tuvieron rechazo. El queratocono fue la afección corneal que predominó. El primer lugar en los rechazos correspondió a queratoherpes (43,5 %. El menor índice de rechazo fue para el queratocono (8,8 %. Se analizó la multiplicidad de rechazos; y fue frecuente que se presentara un solo rechazo, aunque sí hubo congruencia entre el número de rechazos y la necesidad de retrasplantes. Se encontró que los resultados de la conducta médica o quirúrgica se relacionaban con la causa. Se calcula un índice de supervivencia (Kaplan-Meier, que concluye que en los primeros dos años existe menos posibilidad de aparición de rechazoAn retrospective observational analytical research was conducted on corneal transplants performed at Ophthalmological Service in “Hermanos Ameijeiras” hospital . Seventy six patients had graft rejection and were compared to a control group of 89 patients that did not present rejection in the same period of time. Keratoconus was the prevailing corneal problem. The highest rejection rate corresponded to keratoherpes (43,5% whereas the lowest rate was for keratoconus (8,8%. Multiplicity of rejections was analyzed and it was found that mostly one graft rejection occured, but number of rejections was associated with the need of re-transplantation. It was found that the results of medical or surgical performance were related to the cause of graft rejection. A survival index (Kaplan-Meier was estimated, which showed that occurence of graf rejection is less probable in the first two years

Distinct functions and regulation of epithelial progesterone receptor in the mouse cervix, vagina, and uterus.

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Mehta, Fabiola F; Son, Jieun; Hewitt, Sylvia C; Jang, Eunjung; Lydon, John P; Korach, Kenneth S; Chung, Sang-Hyuk

2016-04-05

While the function of progesterone receptor (PR) has been studied in the mouse vagina and uterus, its regulation and function in the cervix has not been described. We selectively deleted epithelial PR in the female reproductive tracts using the Cre/LoxP recombination system. We found that epithelial PR was required for induction of apoptosis and suppression of cell proliferation by progesterone (P4) in the cervical and vaginal epithelium. We also found that epithelial PR was dispensable for P4 to suppress apoptosis and proliferation in the uterine epithelium. PR is encoded by the Pgr gene, which is regulated by estrogen receptor α (ERα) in the female reproductive tracts. Using knock-in mouse models expressing ERα mutants, we determined that the DNA-binding domain (DBD) and AF2 domain of ERα were required for upregulation of Pgr in the cervix and vagina as well as the uterine stroma. The ERα AF1 domain was required for upregulation of Pgr in the vaginal stroma and epithelium and cervical epithelium, but not in the uterine and cervical stroma. ERα DBD, AF1, and AF2 were required for suppression of Pgr in the uterine epithelium, which was mediated by stromal ERα. Epithelial ERα was responsible for upregulation of epithelial Pgr in the cervix and vagina. Our results indicate that regulation and functions of epithelial PR are different in the cervix, vagina, and uterus.

Faster DNA Repair of Ultraviolet-Induced Cyclobutane Pyrimidine Dimers and Lower Sensitivity to Apoptosis in Human Corneal Epithelial Cells than in Epidermal Keratinocytes.

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Justin D Mallet

Full Text Available Absorption of UV rays by DNA generates the formation of mutagenic cyclobutane pyrimidine dimers (CPD and pyrimidine (6-4 pyrimidone photoproducts (6-4PP. These damages are the major cause of skin cancer because in turn, they can lead to signature UV mutations. The eye is exposed to UV light, but the cornea is orders of magnitude less prone to UV-induced cancer. In an attempt to shed light on this paradox, we compared cells of the corneal epithelium and the epidermis for UVB-induced DNA damage frequency, repair and cell death sensitivity. We found similar CPD levels but a 4-time faster UVB-induced CPD, but not 6-4PP, repair and lower UV-induced apoptosis sensitivity in corneal epithelial cells than epidermal. We then investigated levels of DDB2, a UV-induced DNA damage recognition protein mostly impacting CPD repair, XPC, essential for the repair of both CPD and 6-4PP and p53 a protein upstream of the genotoxic stress response. We found more DDB2, XPC and p53 in corneal epithelial cells than in epidermal cells. According to our results analyzing the protein stability of DDB2 and XPC, the higher level of DDB2 and XPC in corneal epithelial cells is most likely due to an increased stability of the protein. Taken together, our results show that corneal epithelial cells have a better efficiency to repair UV-induced mutagenic CPD. On the other hand, they are less prone to UV-induced apoptosis, which could be related to the fact that since the repair is more efficient in the HCEC, the need to eliminate highly damaged cells by apoptosis is reduced.

Granular corneal dystrophy

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Castillo Pérez, Alexeide de la C; Vilches Lescaille, Daysi; Noriega, Justo Luis; Martínez Balido, Daneel; León Balbón, Bárbaro Ramón; León Bernal, Danysleidi

2015-01-01

Las distrofias corneales constituyen un conjunto de enfermedades que presentan, en su mayoría, una baja incidencia y se caracterizan por acúmulo de material hialino o amiloide que disminuyen la transparencia corneal. La distrofia granular es una enfermedad autosómica dominante que presenta opacidades grises en el estroma superficial central de la córnea y se hacen visibles en la primera y segunda décadas de la vida, lo que provoca disminución de la visión más significativa cerca de los 40 año...

Progenitor Epithelium

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Marty-Santos, Leilani

2015-01-01

Insulin-producing β cells within the vertebrate fetal pancreas acquire their fate in a step-wise manner. Whereas the intrinsic factors dictating the transcriptional or epigenetic status of pancreatic lineages have been intensely examined, less is known about cell–cell interactions that might constitute a niche for the developing β cell lineage. It is becoming increasingly clear that understanding and recapitulating these steps may instruct in vitro differentiation of embryonic stem cells and/or therapeutic regeneration. Indeed, directed differentiation techniques have improved since transitioning from 2D to 3D cultures, suggesting that the 3D microenvironment in which β cells are born is critical. However, to date, it remains unknown whether the changing architecture of the pancreatic epithelium impacts the fate of cells therein. An emerging challenge in the field is to elucidate how progenitors are allocated during key events, such as the stratification and subsequent resolution of the pre-pancreatic epithelium, as well as the formation of lumens and branches. Here, we assess the progenitor epithelium and examine how it might influence the emergence of pancreatic multipotent progenitors (MPCs), which give rise to β cells and other pancreatic lineages. PMID:26216134

Prevalence and causes of corneal blindness.

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Wang, Haijing; Zhang, Yaoguang; Li, Zhijian; Wang, Tiebin; Liu, Ping

2014-04-01

The study aimed to assess the prevalence and causes of corneal blindness in a rural northern Chinese population. Cross-sectional study. The cluster random sampling method was used to select the sample. This population-based study included 11 787 participants of all ages in rural Heilongjiang Province, China. These participants underwent a detailed interview and eye examination that included the measurement of visual acuity, slit-lamp biomicroscopy and direct ophthalmoscopy. An eye was considered to have corneal blindness if the visual acuity was blindness and low vision. Among the 10 384 people enrolled in the study, the prevalence of corneal blindness is 0.3% (95% confidence interval 0.2-0.4%). The leading cause was keratitis in childhood (40.0%), followed by ocular trauma (33.3%) and keratitis in adulthood (20.0%). Age and illiteracy were found to be associated with an increased prevalence of corneal blindness. Blindness because of corneal diseases in rural areas of Northern China is a significant public health problem that needs to be given more attention. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

Two cases of corneal perforation after oral administration of nonsteroidal anti-inflammatory drugs: oral NSAID-induced corneal damage.

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Masuda, Ikuya; Matsuo, Toshihiko; Okamoto, Kazuo; Matsushita, Kyoko; Ohtsuki, Hiroshi

2010-01-01

To report 2 cases of corneal perforation associated with the use of oral nonsteroidal anti-inflammatory drugs (NSAIDs). In a 62-year-old woman and a 79-year-old woman, corneal perforation occurred after 7 days and 5 months of oral NSAIDs administration, respectively. After NSAIDs were discontinued, the cornea epithelialized and the anterior chamber formed within 14 and 10 days, respectively. It is well known that topical NSAIDs cause corneal perforation. Observations in the present cases suggest that the oral administration of NSAIDs may also cause corneal damage, and hence, medical professionals should consider the risk of damage to the cornea when administering these drugs orally.

Applanation optical coherence elastography: noncontact measurement of intraocular pressure, corneal biomechanical properties, and corneal geometry with a single instrument

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Singh, Manmohan; Han, Zhaolong; Nair, Achuth; Schill, Alexander; Twa, Michael D.; Larin, Kirill V.

2017-02-01

Current clinical tools provide critical information about ocular health such as intraocular pressure (IOP). However, they lack the ability to quantify tissue material properties, which are potent markers for ocular tissue health and integrity. We describe a single instrument to measure the eye-globe IOP, quantify corneal biomechanical properties, and measure corneal geometry with a technique termed applanation optical coherence elastography (Appl-OCE). An ultrafast OCT system enabled visualization of corneal dynamics during noncontact applanation tonometry and direct measurement of micro air-pulse induced elastic wave propagation. Our preliminary results show that the proposed Appl-OCE system can be used to quantify IOP, corneal biomechanical properties, and corneal geometry, which builds a solid foundation for a unique device that can provide a more complete picture of ocular health.

Risk factors for corneal ectasia after LASIK.

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Tabbara, Khalid F; Kotb, Amgad A

2006-09-01

To establish a grading system that helps identify high-risk individuals who may experience corneal ectasia after LASIK. Retrospective, comparative, interventional case series. One hundred forty-eight consecutive patients (148 eyes) were included in this study. Thirty-seven patients who underwent LASIK at other refractive centers experienced corneal ectasia in 1 eye after LASIK. One hundred eleven eyes of 111 patients who underwent successful LASIK during the same period were age and gender matched and served as controls. All patients underwent preoperative and postoperative topographic analysis of the cornea. The follow-up period in both groups of patients ranged from 2 to 5 years, with a mean follow-up of 3.6 years. All patients underwent LASIK for myopia (spherical equivalent, -4.00 to -8.00 diopters). Corneal keratometry, oblique cylinder, pachymetry, posterior surface elevation, difference between the inferior and superior corneal diopteric power, and posterior best sphere fit (BSF) over anterior BSF were given a grade of 1 to 3 each. An ectasia grading system was established, and the cumulative risk score was assessed. Patients who had a grade of 7 or less showed no evidence of corneal ectasia, whereas 16 (59%) of 27 patients who had a grade of 8 to 12 had corneal ectasia. Twenty-one (100%) of 21 patients with a grade of more than 12 had corneal ectasia after LASIK (P<0.0001). A risk score may help in the prediction of patients who are at risk of experiencing corneal ectasia after LASIK. A prospective clinical study is needed to assess the validity of these risk factors.

Inhibition of Inflammation-Associated Olfactory Loss by Etanercept in an Inducible Olfactory Inflammation Mouse Model.

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Jung, Yong Gi; Lane, Andrew P

2016-06-01

To determine the effect of a soluble human tumor necrosis factor alpha (TNF-α) receptor blocker (etanercept) on an inducible olfactory inflammation (IOI) mouse model. An in vivo study using a transgenic mouse model. Research laboratory. To study the impact of chronic inflammation on the olfactory system, a transgenic mouse model of chronic rhinosinusitis-associated olfactory loss was utilized (IOI mouse), expressing TNF-α in a temporally controlled fashion within the olfactory epithelium. In one group of mice (n = 4), etanercept was injected intraperitoneally (100 μg/dose, 3 times/week) concurrent with a 2-week period of TNF-α expression. A second group of mice (n = 2) underwent induction of TNF-α expression for 8 weeks, with etanercept treatment administered during the final 2 weeks of inflammation. Olfactory function was assayed by elecro-olfactogram (EOG), and olfactory tissue was processed for histology and immunohistochemical staining. Each group was compared with an equal-number control group. Compared with nontreated IOI mice, etanercept-treated IOI mice showed significantly improved EOG responses after 2 weeks (P loss of olfactory epithelium and no EOG response in nontreated IOI mice. However, in etanercept-treated mice, regeneration of olfactory epithelium was observed. Concomitant administration of etanercept in IOI mice results in interruption of TNF-α-induced olfactory loss and induction of neuroepithelial regeneration. This demonstrates that etanercept has potential utility as a tool for elucidating the role of TNF-α in other olfactory inflammation models. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Customized toric intraocular lens implantation for correction of extreme corneal astigmatism due to corneal scarring

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R Bassily

2010-03-01

Full Text Available R Bassily, J LuckOphthalmology Department, Royal United Hospital, Combe Park, Bath, UKAbstract: A 76-year-old woman presented with decreased visual function due to cataract formation. Twenty-five years prior she developed right sided corneal ulceration that left her with 10.8 diopters (D of irregular astigmatism at 71.8° (steep axis. Her uncorrected visual acuity was 6/24 and could only ever wear a balanced lens due to the high cylindrical error. Cataract surgery was planned with a custom designed toric intraocular lens (IOL with +16.0 D sphere inserted via a wound at the steep axis of corneal astigmatism. Postoperative refraction was -0.75/+1.50 × 177° with a visual acuity of 6/9 that has remained unchanged at six-week follow-up with no IOL rotation. This case demonstrates the value of high power toric IOLs for the correction of pathological corneal astigmatism.Keywords: intraocular lens, corneal ulceration, visual acuity, scarring

Growth of intestinal epithelium in organ culture is dependent on EGF signalling

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Abud, Helen E.; Watson, Nadine; Heath, Joan K.

2005-01-01

Differentiation of endoderm into intestinal epithelium is initiated at E13.5 of mouse development when there are significant changes in morphology resulting in the conversion of undifferentiated stratified epithelium into a mature epithelial monolayer. Here we demonstrate that monolayer formation is associated with the selective apoptosis of superficial cells lining the lumen while cell proliferation is progressively restricted to cells adjacent to the basement membrane. We describe an innovative embryonic gut culture system that maintains the three-dimensional architecture of gut and in which these processes are recapitulated in vitro. Explants taken from specific regions of the gut and placed into organ culture develop and express molecular markers (Cdx1, Cdx2 and A33 antigen) in the same spatial and temporal pattern observed in vivo indicating that regional specification is maintained. Inhibition of the epidermal growth factor receptor (EGFR) tyrosine kinase using the specific inhibitor AG1478 significantly reduced the proliferation and survival of cells within the epithelial cell layer of cultured gut explants. This demonstrates an essential role for the EGF signalling pathway during the early stages of intestinal development

Pharmacologic strategies in the prevention and treatment of corneal transplant rejection.

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Tabbara, Khalid F

2008-06-01

Corneal transplantation remains one of the most successful organ transplantation procedures in humans. The unique structure of the cornea, with its absence of blood vessels and corneal lymphatic, allows the survival of corneal allograft. Recent advances in sutures, storage media, microsurgical instrumentation, and new pharmacological strategies have greatly improved the success of corneal transplantation and the prevention of corneal allograft rejection. Our strategies in the management and prevention of corneal graft rejection can modify and improve the survival of corneal allografts. Preoperative evaluation, understanding the risk factors, and management of ocular surface disorders may greatly improve the survival of the corneal transplant. Early recognition of corneal allograft rejection and aggressive treatment may improve the survival of the corneal graft. Furthermore, patients who undergo corneal transplantation should be maintained under close ophthalmic surveillance and patients should be informed to report immediately whenever symptoms of corneal graft rejection occur. The mainstay of therapy is topical corticosteroids. In severe cases, periocular, intravenous, and oral corticosteroids therapy can be rendered. New therapeutic modalities such as cyclosporine, tacrolimus, daclizumab, mycophenolate mofetil, leflunomide, rapamycin, and others may prove to be of help in the prevention and treatment of corneal graft rejection. Early recognition of corneal graft rejection and prompt treatment are mandatory for the successful survival of the corneal allograft.

Study on the establishment of corneal alkali chemical injury on rats

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Nan Hu

2013-06-01

Full Text Available AIM:To investigate the appropriate methods to establish corneal alkali chemical injury on rats. METHODS:The rats(n=87were randomly divided into three groups. Corneal alkali injury was induced by placing 1mol/L NaOH soaked filter paper on the limbus of right cornea for 20 seconds(group A, n=34or 40 seconds(group B, n=23, and on the central axis of the right cornea for 40 seconds(group C, n=30respectively. Corneal transparency, corneal ulceration, and corneal neovascularization were observed and recorded under slit- lamp biomicroscope on day 7 post-operation. RESULTS: Incidence of corneal ulceration, corneal perforation and positive rate of corneal fluorescein staining in limbal corneal injury groups(group A and Bwere significantly higher than that of central corneal injury group(group C(P<0.05. Incidence of corneal ulceration and corneal perforation in group B was significantly higher than group A(P<0.05. Corneal neovascularization was observed in all three groups. CONCLUSION: Corneal alkali burns induced by 3mm diameter central cornea injury are fit for the study of corneal neovascularization, while those induced by limbus injury for 20 seconds are fit for the study on limbal stem cells deficiency.

Punctiform and Polychromatophilic Dominant Pre-Descemet Corneal Dystrophy.

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Lagrou, Lisa; Midgley, Julian; Romanchuk, Kenneth Gerald

2016-04-01

To describe the slit-lamp appearance and corneal confocal microscopy of autosomal dominant punctiform and polychromatophilic pre-Descemet corneal dystrophy in 3 members of the same family. Slit-lamp examination of a 9-year-old boy showed bilateral polychromatophilic corneal opacities in a pre-Descemet membrane location evenly deposited limbus to limbus, both horizontally and vertically, with an intervening clear cornea. The corneal endothelium was normal on corneal confocal microscopy, with hyperreflective opacities of various sizes located pre-Descemet membrane. Slit-lamp examination of the patient's father and brother revealed identical crystalline deposition in the pre-Descemet corneal stroma. The remainders of the eye examinations were otherwise normal in all 3 individuals, and all were asymptomatic. The general physical examination and laboratory investigations of the patient were all normal, as were the laboratory investigations of the other 2 family members. There was no progression in the corneal findings over 6 months of follow-up. These patients likely illustrate a rare autosomal dominant pre-Descemet crystalline keratopathy that has been reported only once previously.

Recovery of Corneal Endothelial Cells from Periphery after Injury.

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Sang Ouk Choi

Full Text Available Wound healing of the endothelium occurs through cell enlargement and migration. However, the peripheral corneal endothelium may act as a cell resource for the recovery of corneal endothelium in endothelial injury.To investigate the recovery process of corneal endothelial cells (CECs from corneal endothelial injury.Three patients with unilateral chemical eye injuries, and 15 rabbit eyes with corneal endothelial chemical injuries were studied. Slit lamp examination, specular microscopy, and ultrasound pachymetry were performed immediately after chemical injury and 1, 3, 6, and 9 months later. The anterior chambers of eyes from New Zealand white rabbits were injected with 0.1 mL of 0.05 N NaOH for 10 min (NaOH group. Corneal edema was evaluated at day 1, 7, and 14. Vital staining was performed using alizarin red and trypan blue.Specular microscopy did not reveal any corneal endothelial cells immediately after injury. Corneal edema subsided from the periphery to the center, CEC density increased, and central corneal thickness decreased over time. In the animal study, corneal edema was greater in the NaOH group compared to the control at both day 1 and day 7. At day 1, no CECs were detected at the center and periphery of the corneas in the NaOH group. Two weeks after injury, small, hexagonal CECs were detected in peripheral cornea, while CECs in mid-periphery were large and non-hexagonal.CECs migrated from the periphery to the center of the cornea after endothelial injury. The peripheral corneal endothelium may act as a cell resource for the recovery of corneal endothelium.

Evaluation of corneal symmetry after UV corneal crosslinking for keratoconus

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Mofty H

2017-11-01

Full Text Available Hanan Mofty,1,2 Khaled Alzahrani,2 Fiona Carley,3 Sophie Harper,3 Arun Brahma,3 Leon Au,3 Debbie Morley,3 M Chantal Hillarby2 1Optometry Department, College of Applied Medical Science, King Saud University, Riyadh, Kingdom of Saudi Arabia; 2Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, 3Manchester Royal Eye Hospital, Manchester, UK Purpose: The purpose of this study was to assess UV corneal crosslinking (CXL treatment outcomes for keratoconus by evaluating the corneal regularity in patients through follow-up using the Oculus Pentacam.Patients and methods: A total of 18 eyes from CXL patients with keratoconus were studied before and after CXL treatment, and six eyes from six patients who were not treated with CXL served as controls. Treated patients had Pentacam images taken before CXL treatment and regularly 3 months post treatment up to the 12th month. Controls were imaged during their first appointment and after 12 months. Symmetry and asphericity were evaluated and correlated with both best-corrected visual acuity (BCVA and maximum K-readings.Results: In the CXL-treated group, there was a significant improvement in the index of symmetrical variation (ISV and keratoconus index (KI at 3 months and in the index of height asymmetry (IHA and minimum radius of curvature (Rmin at 9 months post treatment. On the contrary, the untreated group’s indices showed some significant worsening in ISV, KI, central keratoconus index (CKI, and Rmin. A novel finding in our study was a slight positive shift of anterior asphericity in the 6 mm, 7 mm, and 8 mm 3 months after treatment, which had a correlation with BCVA (R2=0.390, p=0.053 and a strong correlation with maximum K-reading (R2=0.690, p=0.005. However, the untreated group had no significant changes after 1 year.Conclusion: The corneal asymmetrical shape is associated with the spherical aberration alteration

Corneal Collagen Crosslinking Combined with Phototherapeutic Keratectomy and Photorefractive Keratectomy for Corneal Ectasia after Laser in situ Keratomileusis.

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Zhu, Wei; Han, Yunfei; Cui, Changxia; Xu, Wenwen; Wang, Xuan; Dou, Xiaoxiao; Xu, Linlin; Xu, Yanyun; Mu, Guoying

2018-01-01

The aim of this study was to analyze the effects of corneal crosslinking (CXL) combined with phototherapeutic keratectomy (PTK) and photorefractive keratectomy (PRK) in halting the progression and improving the visual function of corneal ectasia after laser in situ keratomileusis (LASIK). PTK-PRK-CXL was performed on 14 eyes of 14 patients who developed corneal ectasia after LASIK. The visual acuity, spherical refraction and cylinder, corneal topography indices, thinnest corneal thickness (TCT), and endothelial cell count were evaluated at baseline and at 1, 3, 6, and 12 months postoperatively. The mean uncorrected visual acuity improved significantly from 0.64 ± 0.36 logMAR preoperatively to 0.19 ± 0.12 logMAR at 12 months of follow-up (p 0.05) beyond 6 months after treatment. PTK-PRK-CXL is a promising procedure to halt the progression of post-LASIK keratectasia with significant visual quality improvement. © 2018 S. Karger AG, Basel.

Different Use of Cell Surface Glycosaminoglycans As Adherence Receptors to Corneal Cells by Gram Positive and Gram Negative Pathogens

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García, Beatriz; Merayo-Lloves, Jesús; Rodríguez, David; Alcalde, Ignacio; García-Suárez, Olivia; Alfonso, José F.; Baamonde, Begoña; Fernández-Vega, Andrés; Vazquez, Fernando; Quirós, Luis M.

2016-01-01

The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive, and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies. PMID:27965938

Corneal Laceration

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The leaves of Diospyros kaki exert beneficial effects on a benzalkonium chloride-induced murine dry eye model.

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Kim, Kyung-A; Hyun, Lee Chung; Jung, Sang Hoon; Yang, Sung Jae

2016-01-01

In this study, the beneficial effects of the oral administration of ethanol extract of Diospyros kaki (EEDK) were tested on a mouse dry eye model induced by benzalkonium chloride (BAC). A solution of 0.2% BAC was administered topically to mouse eyes for 14 days, twice daily, to induce dry eye. Various concentrations of EEDK were administrated daily by oral gavage for 14 days after BAC treatment. Preservative-free eye drops were instilled in the positive-control group. The tear secretion volume (Schirmer's test), tear break-up time (BUT), and fluorescein score were measured on the ocular surface. BAC-induced corneal damage was tested with hematoxylin-eosin staining. Moreover, apoptotic cell death in the corneal epithelial layer was investigated with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. The protein expression level of interleukin-1alpha (IL-1α), IL-1β, IL-6, tumor necrosis factor- alpha (TNF-α), and monocyte chemotactic protein-1 (MCP-1) was determined with western blot analysis. Furthermore, squamous metaplasia in the corneal epithelial layer was detected with immunofluorescent staining for cytokeratine-10. The cellular proliferation in the cornea was examined with immunohistochemical staining for Ki-67. EEDK treatment resulted in prolonged BUT, decreased fluorescein score, increased tear volume, and smoother epithelial cells compared with BAC treatment alone in the cornea. Moreover, EEDK treatment inhibited the inflammatory response and corneal epithelial cell death in a BAC-induced murine dry eye model, and changes in squamous cells were inhibited. Proliferative activity in the corneal epithelium cells was improved with EEDK. EEDK could be a potential therapeutic agent in the clinical treatment of dry eye.

Targeted decorin gene therapy delivered with adeno-associated virus effectively retards corneal neovascularization in vivo.

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Rajiv R Mohan

Full Text Available Decorin, small leucine-rich proteoglycan, has been shown to modulate angiogenesis in nonocular tissues. This study tested a hypothesis that tissue-selective targeted decorin gene therapy delivered to the rabbit stroma with adeno-associated virus serotype 5 (AAV5 impedes corneal neovascularization (CNV in vivo without significant side effects. An established rabbit CNV model was used. Targeted decorin gene therapy in the rabbit stroma was delivered with a single topical AAV5 titer (100 µl; 5×10(12 vg/ml application onto the stroma for two minutes after removing corneal epithelium. The levels of CNV were examined with stereomicroscopy, H&E staining, lectin, collagen type IV, CD31 immunocytochemistry and CD31 immunoblotting. Real-time PCR quantified mRNA expression of pro- and anti-angiogenic genes. Corneal health in live animals was monitored with clinical, slit-lamp and optical coherence tomography biomicroscopic examinations. Selective decorin delivery into stroma showed significant 52% (p<0.05, 66% (p<0.001, and 63% (p<0.01 reduction at early (day 5, mid (day 10, and late (day 14 stages of CNV in decorin-delivered rabbit corneas compared to control (no decorin delivered corneas in morphometric analysis. The H&E staining, lectin, collagen type IV, CD31 immunostaining (57-65, p<0.5, and CD31 immunoblotting (62-67%, p<0.05 supported morphometric findings. Quantitative PCR studies demonstrated decorin gene therapy down-regulated expression of VEGF, MCP1 and angiopoietin (pro-angiogenic and up-regulated PEDF (anti-angiogenic genes. The clinical, biomicroscopy and transmission electron microscopy studies revealed that AAV5-mediated decorin gene therapy is safe for the cornea. Tissue-targeted AAV5-mediated decorin gene therapy decreases CNV with no major side effects, and could potentially be used for treating patients.

A Proinflammatory Function of Toll-Like Receptor 2 in the Retinal Pigment Epithelium as a Novel Target for Reducing Choroidal Neovascularization in Age-Related Macular Degeneration.

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Feng, Lili; Ju, Meihua; Lee, Kei Ying V; Mackey, Ashley; Evangelista, Mariasilvia; Iwata, Daiju; Adamson, Peter; Lashkari, Kameran; Foxton, Richard; Shima, David; Ng, Yin Shan

2017-10-01

Current treatments for choroidal neovascularization, a major cause of blindness for patients with age-related macular degeneration, treat symptoms but not the underlying causes of the disease. Inflammation has been strongly implicated in the pathogenesis of choroidal neovascularization. We examined the inflammatory role of Toll-like receptor 2 (TLR2) in age-related macular degeneration. TLR2 was robustly expressed by the retinal pigment epithelium in mouse and human eyes, both normal and with macular degeneration/choroidal neovascularization. Nuclear localization of NF-κB, a major downstream target of TLR2 signaling, was detected in the retinal pigment epithelium of human eyes, particularly in eyes with advanced stages of age-related macular degeneration. TLR2 antagonism effectively suppressed initiation and growth of spontaneous choroidal neovascularization in a mouse model, and the combination of anti-TLR2 and antivascular endothelial growth factor receptor 2 yielded an additive therapeutic effect on both area and number of spontaneous choroidal neovascularization lesions. Finally, in primary human fetal retinal pigment epithelium cells, ligand binding to TLR2 induced robust expression of proinflammatory cytokines, and end products of lipid oxidation had a synergistic effect on TLR2 activation. Our data illustrate a functional role for TLR2 in the pathogenesis of choroidal neovascularization, likely by promoting inflammation of the retinal pigment epithelium, and validate TLR2 as a novel therapeutic target for reducing choroidal neovascularization. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Effect of human milk as a treatment for dry eye syndrome in a mouse model.

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Diego, Jose L; Bidikov, Luke; Pedler, Michelle G; Kennedy, Jeffrey B; Quiroz-Mercado, Hugo; Gregory, Darren G; Petrash, J Mark; McCourt, Emily A

Dry eye syndrome (DES) affects millions of people worldwide. Homeopathic remedies to treat a wide variety of ocular diseases have previously been documented in the literature, but little systematic work has been performed to validate the remedies' efficacy using accepted laboratory models of disease. The purpose of this study was to evaluate the efficacy of human milk and nopal cactus (prickly pear), two widely used homeopathic remedies, as agents to reduce pathological markers of DES. The previously described benzalkonium chloride (BAK) dry eye mouse model was used to study the efficacy of human milk and nopal cactus (prickly pear). BAK (0.2%) was applied to the mouse ocular surface twice daily to induce dry eye pathology. Fluorescein staining was used to verify that the animals had characteristic signs of DES. After induction of DES, the animals were treated with human milk (whole and fat-reduced), nopal, nopal extract derivatives, or cyclosporine four times daily for 7 days. Punctate staining and preservation of corneal epithelial thickness, measured histologically at the end of treatment, were used as indices of therapeutic efficacy. Treatment with BAK reduced the mean corneal epithelial thickness from 36.77±0.64 μm in the control mice to 21.29±3.2 μm. Reduction in corneal epithelial thickness was largely prevented by administration of whole milk (33.2±2.5 μm) or fat-reduced milk (36.1±1.58 μm), outcomes that were similar to treatment with cyclosporine (38.52±2.47 μm), a standard in current dry eye therapy. In contrast, crude or filtered nopal extracts were ineffective at preventing BAK-induced loss of corneal epithelial thickness (24.76±1.78 μm and 27.99±2.75 μm, respectively), as were solvents used in the extraction of nopal materials (26.53±1.46 μm for ethyl acetate, 21.59±5.87 μm for methanol). Epithelial damage, as reflected in the punctate scores, decreased over 4 days of treatment with whole and fat-reduced milk but continued to

Using corneal topography design personalized cataract surgery programs

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Jin-Ou Huang

2014-08-01

Full Text Available AIM:To investigate how to design personalized cataract surgery programs to achieve surgical correction of preoperative corneal astigmatism with surgical astigmatism under the guidance of corneal topography, improve postoperative visual quality and reduce the cost of treatment. METHODS: Totally 202 cases(226 eyescataract patients were divided into randomized treatment group and individualized treatment group. According to the method and location of the incision, randomized treatment group were divided into 8 groups. Surgical astigmatism after different incision were calculated with the use of preoperative and postoperative corneal astigmatism through vector analysis method. Individualized treatment groups were designed personably for surgical method with reference of every surgically induced astigmatism, the surgical method chooses the type of surgical incision based on close link between preoperative corneal astigmatism and surgically induced astigmatism, and the incision was located in the steep meridian. The postoperative corneal astigmatism of individualized treatment group was observed. RESULTS: Postoperative corneal astigmatism of individualized treatment group were lower than that of 3.0mm clear corneal tunnel incision in the randomized treatment group, there were statistically significance difference, while with 3.0mm sclera tunnel incision group there were no statistically significance difference. After 55.8% of patients with the use of individualized surgical plan could undergo the operation of extracapsular cataract extraction with relatively low cost and rigid intraocular lens implantation, the per capita cost of treatment could be reduced. CONCLUSION: Personalized cataract surgery programs are designed to achieve surgical correction of preoperative corneal astigmatism under the use of corneal topography, improve postoperative visual quality and reduce the cost of treatment.

Crystalline Subtype of Pre-Descemetic Corneal Dystrophy

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Rosa Dolz-Marco

2014-01-01

Full Text Available Purpose: To report corneal findings in a familial case of the crystalline subtype of pre- Descemetic corneal dystrophy. Case Report: A 19-year-old girl and her 44-year-old mother were found to have asymptomatic, bilateral, punctiform and multi-colored crystalline opacities across the whole posterior layer of the corneas. Endothelial specular microscopy revealed the presence of white round flecks located at different levels anterior to the endothelium. No systemic abnormalities or medications could be related to account for these findings. Conclusion: To the best of our knowledge, this is the third familial report of this rare corneal disorder. Differential diagnosis may include Schnyder corneal dystrophy, cystinosis, Bietti΄s dystrophy and monoclonal gammopathy.

Crystalline Subtype of Pre-Descemetic Corneal Dystrophy

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Dolz-Marco, Rosa; Gallego-Pinazo, Roberto; Pinazo-Durán, María Dolores; Díaz-Llopis, Manuel

2014-01-01

Purpose To report corneal findings in a familial case of the crystalline subtype of pre-Descemetic corneal dystrophy. Case Report A 19-year-old girl and her 44-year-old mother were found to have asymptomatic, bilateral, punctiform and multi-colored crystalline opacities across the whole posterior layer of the corneas. Endothelial specular microscopy revealed the presence of white round flecks located at different levels anterior to the endothelium. No systemic abnormalities or medications could be related to account for these findings. Conclusion To the best of our knowledge, this is the third familial report of this rare corneal disorder. Differential diagnosis may include Schnyder corneal dystrophy, cystinosis, Bietti´s dystrophy and monoclonal gammopathy. PMID:25279130

The Structure of Urethral Epithelium in Merinos Lambs

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Vasile RUS

2018-05-01

Full Text Available The aim of this study was to investigate by histological techniques the structure of urethral epithelium in lambs. In this study, we harvested several fragments (prostatic, membranous and cavernous from urethra from 5 merino’s lambs of 3 months old. The first anatomical segment, the prostatic urethra, is lined by a urinary epithelium. The intermediary layer of this epithelium is formed of 5-6 rows of oval cells. The second segment of urethra has the same type of epithelium but the intermediary layer is formed of 6-7 rows of oval cells. In the last anatomical segment, the penile urethra, the epithelium is the same, but the intermediary layer has 3-4 rows of oval cells. In lambs, the urethra is lined by urinary epithelium. The urethral epithelium does not have the same thickness in all segments. The thinner epithelium it is in the cavernous urethra, the ticker is the membranous urethra.

An in vitro model of murine middle ear epithelium.

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Mulay, Apoorva; Akram, Khondoker M; Williams, Debbie; Armes, Hannah; Russell, Catherine; Hood, Derek; Armstrong, Stuart; Stewart, James P; Brown, Steve D M; Bingle, Lynne; Bingle, Colin D

2016-11-01

Otitis media (OM), or middle ear inflammation, is the most common paediatric disease and leads to significant morbidity. Although understanding of underlying disease mechanisms is hampered by complex pathophysiology it is clear that epithelial abnormalities underpin the disease. There is currently a lack of a well-characterised in vitro model of the middle ear (ME) epithelium that replicates the complex cellular composition of the middle ear. Here, we report the development of a novel in vitro model of mouse middle ear epithelial cells (mMECs) at an air-liquid interface (ALI) that recapitulates the characteristics of the native murine ME epithelium. We demonstrate that mMECs undergo differentiation into the varied cell populations seen within the native middle ear. Proteomic analysis confirmed that the cultures secrete a multitude of innate defence proteins from their apical surface. We showed that the mMECs supported the growth of the otopathogen, nontypeable Haemophilus influenzae (NTHi), suggesting that the model can be successfully utilised to study host-pathogen interactions in the middle ear. Overall, our mMEC culture system can help to better understand the cell biology of the middle ear and improve our understanding of the pathophysiology of OM. The model also has the potential to serve as a platform for validation of treatments designed to reverse aspects of epithelial remodelling that underpin OM development. © 2016. Published by The Company of Biologists Ltd.

An in vitro model of murine middle ear epithelium

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Apoorva Mulay

2016-11-01

Full Text Available Otitis media (OM, or middle ear inflammation, is the most common paediatric disease and leads to significant morbidity. Although understanding of underlying disease mechanisms is hampered by complex pathophysiology it is clear that epithelial abnormalities underpin the disease. There is currently a lack of a well-characterised in vitro model of the middle ear (ME epithelium that replicates the complex cellular composition of the middle ear. Here, we report the development of a novel in vitro model of mouse middle ear epithelial cells (mMECs at an air–liquid interface (ALI that recapitulates the characteristics of the native murine ME epithelium. We demonstrate that mMECs undergo differentiation into the varied cell populations seen within the native middle ear. Proteomic analysis confirmed that the cultures secrete a multitude of innate defence proteins from their apical surface. We showed that the mMECs supported the growth of the otopathogen, nontypeable Haemophilus influenzae (NTHi, suggesting that the model can be successfully utilised to study host–pathogen interactions in the middle ear. Overall, our mMEC culture system can help to better understand the cell biology of the middle ear and improve our understanding of the pathophysiology of OM. The model also has the potential to serve as a platform for validation of treatments designed to reverse aspects of epithelial remodelling that underpin OM development.

Efeito do colírio de 5-fluorouracil sobre o epitélio corneano íntegro de coelhos Effects of 5-fluorouracil eye drops on intact rabbit corneal epithelium

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Lucieni Cristina Barbarini Ferraz

2003-08-01

Full Text Available OBJETIVO: Observar os efeitos da aplicação tópica de 5-fluorouracil (5-FU sobre o epitélio corneano íntegro. MÉTODOS: Foram utilizados 10 coelhos albinos (14 olhos, divididos em: grupo controle (GC, 4 olhos nos quais não se administraram drogas, grupo 1 (G1, 5 olhos que receberam 5-fluorouracil na concentração 1,25% e grupo 2 (G2, 5 olhos que receberam 5-fluorouracil na concentração de 2,5%. A droga foi instilada 4 vezes por dia, durante 7 dias, quando os animais foram sacrificados, os olhos removidos, separando-se a córnea que foi preparada de modo convencional para estudo em microscópico eletrônico de varredura. RESULTADOS: GC: observaram-se células de formato hexagonal, claras, escuras e intermediárias, compondo o epitélio corneano de coelhos. Presença de numerosas microplicas, principalmente nas células claras. Cada célula possui cerca de 1 a 3 criptas. Nos animais do G1, observou-se maior número de células escuras, regiões com diminuição no número de criptas; alterações da superfície celular, protusão na região do núcleo e descamação de células epiteliais. Os do G2 tiveram aumento de microprojeções na superfície celular, modificações nas junções intercelulares até separação de células adjacentes; diminuição do número e variabilidade no tamanho das criptas. As alterações mais freqüentes ocorreram nas células da periferia da córnea. CONCLUSÃO: O 5-fluorouracil teve efeitos deletérios no epitélio íntegro corneano de coelhos. As alterações observadas foram mais importantes nos animais que receberam a droga mais concentrada (G2 e mais freqüentes na periferia da córnea.PURPOSE: To assess the influence of the antiproliferative agent (5-FU on the intact rabbit corneal epithelium. METHODS: 10 rabbits (14 eyes,were divided into: control group (CG, 4 eyes without drug administration; G1, 5 eyes underwent treatment with topical 12.5 mg/ml 5-fluorouracil and G2, 5 eyes received 5-fluorouracil

Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium.

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Dooley, Ruth

2012-02-01

BACKGROUND: Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. RESULTS: Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. CONCLUSION: Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium

LENUS (Irish Health Repository)

Dooley, Ruth

2011-08-22

Abstract Background Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. Results Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. Conclusion Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

Purinergic receptor antagonists inhibit odorant-mediated CREB phosphorylation in sustentacular cells of mouse olfactory epithelium

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Hatt Hanns

2011-08-01

Full Text Available Abstract Background Extracellular nucleotides have long been known to play neuromodulatory roles and to be involved in intercellular signalling. In the olfactory system, ATP is released by olfactory neurons, and exogenous ATP can evoke an increase in intracellular calcium concentration in sustentacular cells, the nonneuronal supporting cells of the olfactory epithelium. Here we investigate the hypothesis that olfactory neurons communicate with sustentacular cells via extracellular ATP and purinergic receptor activation. Results Here we show that exposure of mice to a mixture of odorants induced a significant increase in the levels of the transcription factor CREB phosphorylated at Ser-133 in the nuclei of both olfactory sensory neurons and sustentacular cells. This activation was dependent on adenylyl cyclase III-mediated olfactory signaling and on activation of P2Y purinergic receptors on sustentacular cells. Purinergic receptor antagonists inhibited odorant-dependent CREB phosphorylation specifically in the nuclei of the sustentacular cells. Conclusion Our results point to a possible role for extracellular nucleotides in mediating intercellular communication between the neurons and sustentacular cells of the olfactory epithelium in response to odorant exposure. Maintenance of extracellular ionic gradients and metabolism of noxious chemicals by sustentacular cells may therefore be regulated in an odorant-dependent manner by olfactory sensory neurons.

Topical Ranibizumab as a Treatment of Corneal Neovascularization

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Ferrari, Giulio; Dastjerdi, Mohammad H.; Okanobo, Andre; Cheng, Sheng-Fu; Amparo, Francisco; Nallasamy, Nambi; Dana, Reza

2014-01-01

Purpose To examine the effect of topical ranibizumab on clinically stable corneal neovascularization (NV). Methods This was a prospective, open-label, monocentric, uncontrolled, non-comparative study. Ten eyes of 9 patients with corneal NV received topical ranibizumab (1%) 4 times a day for 3 weeks with a follow-up of 16 weeks. The main corneal neovascularization outcome measures were: neovascular area (NA), the area occupied by the corneal neovessels; vessel caliber (VC), the mean diameter of the corneal neovessels; and invasion area (IA), the fraction of the total cornea area covered by the vessels. This study was conducted at the Massachusetts Eye and Ear Infirmary, Boston, MA, USA. Results Statistically significant decreases in NA (55.3%, P<0.001), which lasted through 16 weeks, and VC (59%, P<0.001), which continued to improve up to week 16, were observed after treatment. No significant decrease was observed in IA (12.3%, P=0.49). There was no statistically significant change in visual acuity or intraocular pressure. No adverse events ascribed to the treatment were noted. Conclusions Topical application of ranibizumab is effective in reducing the severity of corneal NV in the context of established corneal NV, mostly through decrease in VC rather than IA. PMID:23407316

Corneal changes with accommodation using dual Scheimpflug photography.

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Sisó-Fuertes, Irene; Domínguez-Vicent, Alberto; del Águila-Carrasco, Antonio; Ferrer-Blasco, Teresa; Montés-Micó, Robert

2015-05-01

To assess whether corneal parameters and aberrations are affected by accommodation. Optics Department, University of Valencia, Valencia, Spain. Prospective cross-sectional study. The Galilei G4 dual Scheimpflug device was used to obtain data on the anterior and posterior axial curvatures, total corneal power (TCP), and corneal pachymetry from 3 corneal zones (central: 0.0 up to 4.0 mm; paracentral or mid: 4.0 up to 7.0 mm; peripheral: 7.0 up to 10.0 mm) in young emmetropic eyes in the unaccommodated and 4 accommodated states (from -1.0 to -4.0 diopters [D] in 1.0 D steps). The 2nd-, 3rd-, and 4th-order aberrations as well as the root mean square (RMS) were also determined for the entire cornea at the same accommodative demands. The study evaluated 7 subjects (12 eyes). No significant changes in any measured parameter were found during accommodation for any corneal zone (P > .05). Statistically significant differences were found in the various corneal zones when it was assumed they were constant with accommodation (P the high standard deviation values. Different parameters in various zones of the cornea as well as corneal aberrations were stable during accommodation. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Corneal Biomechanics in Ectatic Diseases: Refractive Surgery Implications

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Ambrósio, Jr, Renato; Correia, Fernando Faria; Lopes, Bernardo; Salomão, Marcella Q.; Luz, Allan; Dawson, Daniel G.; Elsheikh, Ahmed; Vinciguerra, Riccardo; Vinciguerra, Paolo; Roberts, Cynthia J.

2017-01-01

Background: Ectasia development occurs due to a chronic corneal biomechanical decompensation or weakness, resulting in stromal thinning and corneal protrusion. This leads to corneal steepening, increase in astigmatism, and irregularity. In corneal refractive surgery, the detection of mild forms of ectasia pre-operatively is essential to avoid post-operative progressive ectasia, which also depends on the impact of the procedure on the cornea. Method: The advent of 3D tomography is proven as a significant advancement to further characterize corneal shape beyond front surface topography, which is still relevant. While screening tests for ectasia had been limited to corneal shape (geometry) assessment, clinical biomechanical assessment has been possible since the introduction of the Ocular Response Analyzer (Reichert Ophthalmic Instruments, Buffalo, USA) in 2005 and the Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) in 2010. Direct clinical biomechanical evaluation is recognized as paramount, especially in detection of mild ectatic cases and characterization of the susceptibility for ectasia progression for any cornea. Conclusions: The purpose of this review is to describe the current state of clinical evaluation of corneal biomechanics, focusing on the most recent advances of commercially available instruments and also on future developments, such as Brillouin microscopy. PMID:28932334

Corneal biomechanical properties in healthy children measured by corneal visualization scheimpflug technology.

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He, Miao; Ding, Hui; He, Hong; Zhang, Chi; Liu, Liangping; Zhong, Xingwu

2017-05-17

The aim of this study was to evaluate corneal biomechanical properties in a population of healthy children in China using corneal visualization Scheimpflug technology (CST). All children underwent complete bi-ocular examinations. CST provided intraocular pressure (IOP) and corneal biomechanical parameters, including time, velocity, length and deformation amplitude at first applanation (A1T, A1V, A1L, A1DA), at second applanation (A2T, A2V, A2L, A2DA), highest concavity time (HCT), maximum deformation amplitude (MDA), peak distance (PD), and radius of curvature (RoC). Pearson correlation analysis was used to assess the impacts of demographic factors, central corneal thickness (CCT), spherical equivalent (SE), and IOP on corneal biomechanics. One hundred eight subjects (32 girls and 76 boys) with the mean age of 10.80 ± 4.13 years (range 4 to18 years) were included in the final analyses. The right and left eyes were highly symmetrical in SE (p = 0.082), IOP (p = 0.235), or CCT (p = 0.210). Mean A1T of the right eyes was 7.424 ± 0.340 ms; the left eyes 7.451 ± 0.365 ms. MDA was 0.993 ± 0.102 mm in the right eyes and 0.982 ± 0.100 mm in the left eyes. Mean HCT of the right eyes was 16.675 ± 0.502 ms; the left eyes 16.735 ± 0.555 ms. All CST parameters of both eye were remarkably symmetrical with the exception of A2L (p = 0.006), A1DA (p = 0.025). The majority of CST parameters of both eyes were significantly correlated with CCT and IOP (p children eyes. Several CST biomechanical parameters in children are modified by CCT and IOP.

Corneal Laceration

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Full Text Available ... by something sharp flying into the eye. It can also be caused by something striking the eye ... If the corneal laceration is deep enough it can cause a full thickness laceration. This is when ...

In Vivo Corneal Biomechanical Properties with Corneal Visualization Scheimpflug Technology in Chinese Population

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Ying Wu

2016-01-01

Full Text Available Purpose. To determine the repeatability of recalculated corneal visualization Scheimpflug technology (CorVis ST parameters and to study the variation of biomechanical properties and their association with demographic and ocular characteristics. Methods. A total of 783 healthy subjects were included in this study. Comprehensive ophthalmological examinations were conducted. The repeatability of the recalculated biomechanical parameters with 90 subjects was assessed by the coefficient of variation (CV and intraclass correlation coefficient (ICC. Univariate and multivariate linear regression models were used to identify demographic and ocular factors. Results. The repeatability of the central corneal thickness (CCT, deformation amplitude (DA, and first/second applanation time (A1/A2-time exhibited excellent repeatability (CV% ≤ 3.312% and ICC ≥ 0.929 for all measurements. The velocity in/out (Vin/out, highest concavity- (HC- radius, peak distance (PD, and DA showed a normal distribution. Univariate linear regression showed a statistically significant correlation between Vin, Vout, DA, PD, and HC-radius and IOP, CCT, and corneal volume, respectively. Multivariate analysis showed that IOP and CCT were negatively correlated with Vin, DA, and PD, while there was a positive correlation between Vout and HC-radius. Conclusion. The ICCs of the recalculated parameters, CCT, DA, A1-time, and A2-time, exhibited excellent repeatability. IOP, CCT, and corneal volume significantly influenced the biomechanical properties of the eye.

Alloimmunity and Tolerance in Corneal Transplantation.

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Amouzegar, Afsaneh; Chauhan, Sunil K; Dana, Reza

2016-05-15

Corneal transplantation is one of the most prevalent and successful forms of solid tissue transplantation. Despite favorable outcomes, immune-mediated graft rejection remains the major cause of corneal allograft failure. Although low-risk graft recipients with uninflamed graft beds enjoy a success rate ∼90%, the rejection rates in inflamed graft beds or high-risk recipients often exceed 50%, despite maximal immune suppression. In this review, we discuss the critical facets of corneal alloimmunity, including immune and angiogenic privilege, mechanisms of allosensitization, cellular and molecular mediators of graft rejection, and allotolerance induction. Copyright © 2016 by The American Association of Immunologists, Inc.

Corneal thickness: measurement and implications.

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Ehlers, Niels; Hjortdal, Jesper

2004-03-01

The thickness of the cornea was reported in more than 100-year-old textbooks on physiological optics (Helmholtz, Gullstrand). Physiological interest was revived in the 1950s by David Maurice, and over the next 50 years, this 'simple' biological parameter has been studied extensively. Several techniques for its measurement have been described and physiological and clinical significance have been studied. In this review, the different methods and techniques of measurement are briefly presented (optical, ultrasound). While the corneal thickness of many animals are the same over a considerable part of the surface, in the human cornea anterior and posterior curvature are not concentric giving rise to a problem of definition. Based on this the precision and accuracy of determining the central corneal thickness are discussed. Changes in corneal thickness reflects changes in function of the boundary layers, in particular the endothelial barrier. The absolute value of thickness is of importance for the estimation of IOP but also in diagnosis of corneal and systemic disorders. Finally it is discussed to what extent the thickness is a biometric parameter of significance, e.g. in the progression of myopia or in the development of retinal detachment.

Generation of Femtosecond Laser-Cut Decellularized Corneal Lenticule Using Hypotonic Trypsin-EDTA Solution for Corneal Tissue Engineering

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Man-Il Huh

2018-01-01

Full Text Available Purpose. To establish an optimized and standardized protocol for the development of optimal scaffold for bioengineering corneal substitutes, we used femtosecond laser to process human corneal tissue into stromal lenticules and studied to find the most efficient decellularization method among various reagents with different tonicities. Methods. The decellularization efficacy of several agents (0.1%, 0.25%, and 0.5% of Triton X-100, SDS, and trypsin-EDTA (TE, resp. with different tonicities was evaluated. Of all protocols, the decellularization methods, which efficiently removed nuclear materials examined as detected by immunofluorescent staining, were quantitatively tested for sample DNA and glycosaminoglycan (GAG contents, recellularization efficacy, and biocompatibilities. Results. 0.5% SDS in hypertonic and isotonic buffer, 0.25% TE in hypotonic buffer, and 0.5% TE in all tonicities completely decellularized the corneal lenticules. Of the protocols, decellularization with hypotonic 0.25 and 0.5% TE showed the lowest DNA contents, while the GAG content was the highest. Furthermore, the recellularization efficacy of the hypotonic TE method was better than that of the SDS-based method. Hypotonic TE-treated decellularized corneal lenticules (DCLs were sufficiently transparent and biocompatible. Conclusion. We generated an ideal protocol for DCLs using a novel method. Furthermore, it is possible to create a scaffold using a bioengineered corneal substitute.

Triptolide Suppresses Alkali Burn-Induced Corneal Angiogenesis Along with a Downregulation of VEGFA and VEGFC Expression.

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Wang, Geng; Li, Na; Lv, Xiaohong; Ahmed, Naila; Li, Xinlei; Liu, Huidong; Ma, Jing; Zhang, Yafang

2017-07-01

Triptolide (TPL) is an active compound extracted from a Chinese herbal medicine tripterygium wilfordii Hook. f. (Celastraceae), which has been used as an anti-inflammatory drug for years. It also inhibits the growth and proliferation of different types of cancer cells. The inhibitory effect of TPL on angiogenesis after chemical-induced corneal inflammation was studied in vivo. The effects of TPL on the proliferation, apoptosis, migration, and tube formation of rat aortic endothelial cells (RAECs) were studied in vitro. Cell proliferation and apoptosis were measured by MTT assay and flow cytometry, respectively. Migration was analyzed using the scratch wound healing assay and transwell assay. Tube formation assay was used to examine angiogenesis. Real-time PCR and Western blot were used to determine the expression of vascular endothelial growth factor A (VEGFA) and VEGFC. To study the in vivo effects of TPL, the mouse model of alkali burn-induced corneal angiogenesis was used. The angiogenesis was analyzed by determining the density of the newly generated blood vessels in corneas. We found that TPL induced apoptosis and inhibited the proliferation of RAECs in a dose-dependent manner. TPL inhibited migration and tube formation of RAECs and decreased the expression of VEGFA and VEGFC in vitro. Furthermore, TPL suppressed alkali burn-induced corneal angiogenesis and inhibited the expression of VEGFA and VEGFC in corneas in vivo. In conclusion, topical TPL as a pharmacological agent has the ability to reduce angiogenesis in cornea and may have clinical indications for the treatment of corneal angiogenesis diseases which have to be further explored. Anat Rec, 300:1348-1355, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Effects of organophosphorus flame retardant TDCPP on normal human corneal epithelial cells: Implications for human health.

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Xiang, Ping; Liu, Rong-Yan; Li, Chao; Gao, Peng; Cui, Xin-Yi; Ma, Lena Q

2017-11-01

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is one of the most detected organophosphorus flame retardants (OPFRs) in the environment, especially in indoor dust. Continuous daily exposure to TDCPP-containing dust may adversely impact human cornea. However, its detrimental effects on human corneal epithelium are largely unknown. In this study, we investigated the cell apoptosis in normal human corneal epithelial cells (HCECs) after TDCPP exposure and elucidated the underlying molecular mechanisms. Our data indicated a dose-dependent decrease of cell viability after TDCPP exposure with LC 50 at 202 μg/mL. A concentration-dependent apoptotic sign was observed in HCECs after exposing to ≥2 μg/mL TDCPP. Endoplasmic reticulum stress induction was evidenced by up-regulation of its biomarker genes (ATF-4, CHOP, BiP, and XBP1). Furthermore, alternation of Bcl-2/Bax expression, mitochondrial membrane potential loss, cellular ATP content decrease, and caspase-3 and -9 activity increase were observed after exposing to 2 or 20 μg/mL TDCPP. Taken together, the data implicated the involvement of endoplasmic reticulum stress in TDCPP-induced HCEC apoptosis, probably mediated by mitochondrial apoptotic pathway. Our findings showed TDCPP exposure induced toxicity to human cornea. Due to TDCPP's presence at high levels in indoor dust, further study is warranted to evaluate its health risk on human corneas. Published by Elsevier Ltd.

Treatment Results of Corneal Collagen Cross-Linking Combined with Riboflavin and 440 Nm Blue Light for Bacterial Corneal Ulcer in Rabbits.

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Wei, Shufang; Zhang, Cuiying; Zhang, Shaoru; Xu, Yanyun; Mu, Guoying

2017-10-01

To study the treatment effect of corneal collagen cross-linking (CXL) combined with 440 nm blue light and riboflavin on bacterial corneal ulcer using animal experiments. A total of 21 New Zealand white rabbits that developed Staphylococcus aureus corneal ulcer were randomly divided into three groups. Seven rabbits were used as blank control groups; seven rabbits were treated with CXL combined with riboflavin and 440 nm blue light; and seven rabbits were treated with CXL combined with riboflavin and 370 nm ultraviolet A light. Necrotic tissues or secretions from the ulcer surface, eye secretions, conjunctival hyperemia, hypopyon, corneal infiltration, and pathological changes of the cornea were all observed. The 1st, 3th, and 7th day after CXL treatment, a statistically significant difference was found among the inflammation scores of the three groups. The scores of 440 and 370 groups decreased gradually, significantly lower than that of the control group. Bacterial cultures of 440 and 370 groups turned to be negative while that of the control group remained positive. After 1 day of CXL treatment, pathology pictures of the three groups all showed loss of corneal epithelia with many inflammatory cells in deep stroma. After 7 days of CXL treatment, abscess formed in almost all corneal area in the control group, while in 440 and 370 groups, multilayer healing of corneal epithelia, neovascularization, and many inflammatory cells within ulcers and proliferation of a small amount of fibroblast were seen. CXL combined with riboflavin and 440 nm blue light is effective in treating S. aureus corneal ulcer.

Radiation effects of electromagnetic pulses on mouse blood-testis barrier

International Nuclear Information System (INIS)

Hou Wugang; Zhao Jie; Zhang Yuanqiang

2005-01-01

Radiation effects caused by 100 kV/m and 400 kV/m electromagnetic pulse (EMP) irradiations on mouse blood-testis barrier were studied by means of routine HE staining, Lanthanum traced electron microscope and injection of caudal vein with Evans Blue. The EMP irradiation of different dose rates damaged Sertoli's cell and blood-testis barrier of mouse testis in different levels. Severe injuries were observed with the 400 kV/m irradiation group, with apoptosis and necrosis in a large quantity of the spermatogenic cells, shape and structural changes of the Sertoli's cells, and serious injuries to the blood-testis barrier, one day after the irradiation. The basal compartment separated from the adluminal compartment in most of the VIII stage seminiferous epithelium, and a great number of apoptosis and necrosis spermatogenic cells were released into the cavities. Injuries of blood-testis barrier could be observed 21 days after the 400 kV/m irradiation. The injuries of 100 kV/m irradiation groups were less severe than the 400 kV/m groups, in which the damages to the Sertoli's cells, the seminiferous epithelium and blood-testis barrier recovered to some extent 14 days after the irradiation. The authors conclude that EMP irradiation can damage mouse blood-tests barrier. The injuries, and the time for recovery, are related to EMP power intensity. (authors)

Human tears reveal insights into corneal neovascularization.

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Zakaria, Nadia; Van Grasdorff, Sigi; Wouters, Kristien; Rozema, Jos; Koppen, Carina; Lion, Eva; Cools, Nathalie; Berneman, Zwi; Tassignon, Marie-José

2012-01-01

Corneal neovascularization results from the encroachment of blood vessels from the surrounding conjunctiva onto the normally avascular cornea. The aim of this study is to identify factors in human tears that are involved in development and/or maintenance of corneal neovascularization in humans. This could allow development of diagnostic tools for monitoring corneal neovascularization and combination monoclonal antibody therapies for its treatment. In an observational case-control study we enrolled a total of 12 patients with corneal neovascularization and 10 healthy volunteers. Basal tears along with reflex tears from the inferior fornix, superior fornix and using a corneal bath were collected along with blood serum samples. From all patients, ocular surface photographs were taken. Concentrations of the pro-angiogenic cytokines interleukin (IL)-6, IL-8, Vascular Endothelial Growth Factor (VEGF), Monocyte Chemoattractant Protein 1 (MCP-1) and Fas Ligand (FasL) were determined in blood and tear samples using a flow cytometric multiplex assay. Our results show that the concentration of pro-angiogenic cytokines in human tears are significantly higher compared to their concentrations in serum, with highest levels found in basal tears. Interestingly, we could detect a significantly higher concentration of IL- 6, IL-8 and VEGF in localized corneal tears of patients with neovascularized corneas when compared to the control group. This is the first study of its kind demonstrating a significant difference of defined factors in tears from patients with neovascularized corneas as compared to healthy controls. These results provide the basis for future research using animal models to further substantiate the role of these cytokines in the establishment and maintenance of corneal neovascularization.

Generation of Corneal Keratocytes from Human Embryonic Stem Cells.

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Hertsenberg, Andrew J; Funderburgh, James L

2016-01-01

Human Embryonic Stem Cells (hESC) offer an important resource as a limitless supply of any differentiated cell type of the human body. Keratocytes, cells from the corneal stroma, may have the potential for restoration of vision in cell therapy and biomedical engineering applications, but these specialized cells are not readily expanded in vitro. Here we describe a two-part method to produce keratocytes from the H1 hESC cell line. The hESC cells, maintained and expanded in feeder-free culture medium are first differentiated to neural crest cells using the stromal-derived inducing activity (SDIA) of the PA6 mouse embryonic fibroblast cell line. The resulting neural crest cells are selected by their expression of cell-surface CD271 and subsequently cultured as 3D pellets in a defined differentiation medium to induce a keratocyte phenotype.

Clinical Validation of Point-Source Corneal Topography in Keratoplasty

NARCIS (Netherlands)

Vrijling, A C L; Braaf, B.; Snellenburg, J.J.; de Lange, F.; Zaal, M.J.W.; van der Heijde, G.L.; Sicam, V.A.D.P.

2011-01-01

Purpose. To validate the clinical performance of point-source corneal topography (PCT) in postpenetrating keratoplasty (PKP) eyes and to compare it with conventional Placido-based topography. Methods. Corneal elevation maps of the anterior corneal surface were obtained from 20 post-PKP corneas using

Corneal donations in South Africa: A 15-year review.

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York, Nicholas J; Tinley, Christopher

2017-07-28

Corneal pathology is one of the leading causes of preventable blindness in South Africa (SA). A corneal transplant can restore or significantly improve vision in most cases. However, in SA there is a gross shortage of corneal tissue available to ophthalmologists. Little has been published describing the magnitude of the problem. To describe trends in the number of corneal donors per year in SA, the number of corneal transplants performed each year, the origin of donors, the allocation of corneas to the public or private sector, and the demographics of donors. This was a retrospective review of all corneal donations to SA eye banks over the 15-year period 1 January 2002 - 31 December 2016. There was a progressive year-on-year decline in corneal donors over the study period, from 565 per year in 2002 to 89 in 2016. As a direct result, there has been an 85.5% decrease in the number of corneal transplants performed per year using locally donated corneas, from 1 049 in 2002 to 152 in 2016. Of the donors, 48.8% originated from mortuaries, 39.0% from private hospitals and 12.2% from government hospitals; donors from mortuaries showed the most significant decline over the 15-year period, decreasing by 94.8%. Of donated corneas, 79.3% were allocated to the private sector and 21.7% to the public sector. Males comprised 69.1% of donors, while 77.2% were white, 14.0% coloured, 6.3% black and 2.5% Indian/Asian. Donor age demonstrated a bimodal peak at 25 and 55 years. The number of corneal donations in SA has declined markedly, causing the burden of corneal disease requiring transplantation to rise steadily. Population groups with a low donor rate may have cultural and other objections to corneal donation, which should be a major focus of future research and initiatives aimed at reversing the current trends.

Effect of Cycloplegia on Corneal Biometrics and Refractive State.

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Bagheri, Abbas; Feizi, Mohadeseh; Shafii, Aliakbar; Faramarzi, Amir; Tavakoli, Mehdi; Yazdani, Shahin

2018-01-01

To determine changes in refractive state and corneal parameters after cycloplegia with cyclopentolate hydrochloride 1% using a dual Scheimpflug imaging system. In this prospective cross-sectional study patients aged 10 to 40 years who were referred for optometric evaluation enrolled and underwent autorefraction and corneal imaging with the Galilei dual Scheimpflug system before and 30 minutes after twice instillation of medication. Changes in refraction and astigmatism were investigated. Corneal biometrics including anterior and posterior corneal curvatures, total corneal power and corneal pachymetry were compared before and after cycloplegia. Two hundred and twelve eyes of 106 subjects with mean age of 28 ± 5 years including 201 myopic and 11 hyperopic eyes were evaluated. Mean spherical equivalent refractive error before cycloplegia was -3.4 ± 2.6 D. A mean hyperopic shift of 0.4 ± 0.5 D occurred after cycloplegia ( P biometrics should be considered before cataract and refractive surgeries.

Surgically induced astigmatism after phacoemulsification by temporal clear corneal and superior clear corneal approach: a comparison

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Nikose AS

2018-01-01

Full Text Available Archana Sunil Nikose, Dhrubojyoti Saha, Pradnya Mukesh Laddha, Mayuri Patil Department of Ophthalmology, N.K.P. Salve Institute and LMH, Nagpur, Maharashtra, India Introduction: Cataract surgery has undergone various advances since it was evolved from ancient couching to the modern phacoemulsification cataract surgery. Surgically induced astigmatism (SIA remains one of the most common complications. The introduction of sutureless clear corneal incision has gained increasing popularity worldwide because it offers several advantages over the traditional sutured limbal incision and scleral tunnel. A clear corneal incision has the benefit of being bloodless and having an easy approach, but SIA is still a concern.Purpose: In this study, we evaluated the SIA in clear corneal incisions with temporal approach and superior approach phacoemulsification. Comparisons between the two incisions were done using keratometric readings of preoperative and postoperative refractive status.Methodology: It was a hospital-based prospective interventional comparative randomized control trial of 261 patients conducted in a rural-based tertiary care center from September 2012 to August 2014. The visual acuity and detailed anterior segment and posterior segment examinations were done and the cataract was graded according to Lens Opacification Classification System II. Patients were divided for phacoemulsification into two groups, group A and group B, who underwent temporal and superior clear corneal approach, respectively. The patients were followed up on day 1, 7, 30, and 90 postoperatively. The parameters recorded were uncorrected visual acuity, best-corrected visual acuity, slit lamp examination, and keratometry. The mean difference of SIA between 30th and 90th day was statistically evaluated using paired t-test, and all the analyses were performed using SPSS 18.0 (SPSS Inc. software.Results: The mean postoperative SIA in group A was 0.998 D on the 30th day, which

Tissue kinetics in mouse tongue mucosa during daily fractionated radiotherapy

International Nuclear Information System (INIS)

Doerr, W.; Emmendoerfer, H.; Weber-Frisch, M.

1996-01-01

The purpose of the present investigation was to quantify cell flux between the distinct layers of the epithelial lining of the ventral surface of mouse tongue during daily fractionated radiotherapy. In tongue epithelium of untreated mice, the minimum residence time of cells in the germinal layer is 2-3 days. Migration through the functional layers requires an additional 2-3 days before labelled cells are observed in the most superficial layer of nucleated cells. A plateau in LI is observed for several days post-labelling in control epithelium, indicating an equilibrium between loss and proliferation of labelled cells. During fractionated radiotherapy, the minimum time from division to occurrence of labelled cells in the stratum lucidum is less than 2 days, and hence significantly shorter than in control epithelium. In contrast to untreated epithelium, no plateau in the germinal layer LI is seen, indicating that frequently both labelled daughters from dividing labelled cells are being lost from this compartment. In conclusion, the present data support a recently described model of radiation-induced accelerated repopulation in squamous epithelia, which postulates that the majority of damaged cells undergoes abortive divisions resulting in two differentiating daughters. (Author)

Challenges and opportunities for tissue-engineering polarized epithelium.

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Paz, Ana C; Soleas, John; Poon, James C H; Trieu, Dennis; Waddell, Thomas K; McGuigan, Alison P

2014-02-01

The epithelium is one of the most important tissue types in the body and the specific organization of the epithelial cells in these tissues is important for achieving appropriate function. Since many tissues contain an epithelial component, engineering functional epithelium and understanding the factors that control epithelial maturation and organization are important for generating whole artificial organ replacements. Furthermore, disruption of the cellular organization leads to tissue malfunction and disease; therefore, engineered epithelium could provide a valuable in vitro model to study disease phenotypes. Despite the importance of epithelial tissues, a surprisingly limited amount of effort has been focused on organizing epithelial cells into artificial polarized epithelium with an appropriate structure that resembles that seen in vivo. In this review, we provide an overview of epithelial tissue organization and highlight the importance of cell polarization to achieve appropriate epithelium function. We next describe the in vitro models that exist to create polarized epithelium and summarize attempts to engineer artificial epithelium for clinical use. Finally, we highlight the opportunities that exist to translate strategies from tissue engineering other tissues to generate polarized epithelium with a functional structure.

Depósitos corneales de ciprofloxacino Corneal deposits of ciprofloxacin

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Taimi Cárdenas Díaz

2010-01-01

Full Text Available Las fluoroquinolonas son ampliamente utilizadas para el tratamiento de infecciones oculares bacterianas, ya que tienen actividad tanto para grampositivos, como para gramnegativos. Son fármacos seguros, pero se han descrito depósitos blancos cristalinianos en pacientes con administración frecuente y prolongada;en la mayoría de los casos, ellos resuelven de forma lenta al interrumpir el tratamiento. Si esto no ocurre, los depósitos se deben desbridar. Se ilustran 3 casos operados de catarata que llevaron tratamiento con ciprofloxacino en el posoperatorio, en los cuales se presentaron depósitos corneales y aunque disminuyó la agudeza visual, esta se recuperó después de la queratectomía.Fluoroquinolones are broadly used for the treatment of bacterial ocular infections, since they can act upon both grampositive and gramnegative bacteria. They are safe drugs, but white corneal deposits have been described in patients who frequently take this drug for a long period of time. In most of the cases, the deposits disappear slowly after the treatment is interrupted. If this does not happen, the deposits should be eliminated. Three cases operated on from cataract were presented, who had been taken ciprofloxacin in the postoperative stage and had corneal deposits. Although their visual acuity decreased, it recovered after keratectomy.

Transepithelial SCFA fluxes link intracellular and extracellular pH regulation of mouse colonocytes.

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Chu, S; Montrose, M H

1997-10-01

We have studied pH regulation in both intracellular and extracellular compartments of mouse colonic crypts, using distal colonic mucosa with intact epithelial architecture. In this work, we question how transepithelial SCFA gradients affect intracellular pH (pHi) and examine interactions between extracellular pH (pHo) and pHi regulation in crypts of distal colonic epithelium from mouse. We studied pH regulation in three adjacent compartments of distal colonic epithelium (crypt lumen, crypt epithelial cell cytosol, and lamina propria) with SNARF-1 (a pH sensitive fluorescent dye), digital imaging microscopy (for pHi), and confocal microscopy (for pHo). Combining results from the three compartments allows us to find how pHi and pHo are regulated and related under the influence of physiological transepithelial SCFA gradients, and develop a better understanding of pH regulation mechanisms in colonic crypts. Results suggest a complex interdependency between SCFA fluxes and pHo values, which can directly affect how strongly SCFAs acidify colonocytes.

Trans-Corneal Subretinal Injection in Mice and Its Effect on the Function and Morphology of the Retina.

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Yan Qi

Full Text Available To introduce a practical method of subretinal injection in mice and evaluate injection-induced retinal detachment (RD and damage using a dynamic imaging system, electrophysiology, and histology.After full dilation of a 2-month-old C57BL/6J mouse pupil, the cornea near the limbus was punctured with a 30 ½-gague disposable beveled needle. A 33 ½-gauge blunt needle was inserted through the corneal perforation into the anterior chamber, avoiding the lens before going deeper into the vitreous cavity, and penetrating the inner retina to reach the subretinal space. The mice were divided into four groups: in group 1, about 80-100% of the retina was filled with subretinally injected solution; in group 2, approximately 50-70% of the retina was filled with injected solution; in group 3, the procedures were stopped before solution injection; and non-injected eyes were used as the negative control in group 4. An optical coherence tomography (OCT imaging system was used to monitor retinal reattachment during the first three days following the injections. Histological and functional changes were examined by light microscopy and electroretinography (ERG at five weeks post-injection.After a short-term training, a 70% success rate with 50% or more coverage (i.e., retinal blebs occupied 50% or more retinal area and filled with the injected solution with minimal injection-related damages can be achieved. Bleb formation was associated with retinal detachment (RD between the neuroretina and the retinal pigment epithelium (RPE layer. Partial RD could be observed at post-injection day 1, and by day 2 most of the retina had reattached. At 5 weeks post-injection, compared to uninjected control group 4, the b-wave amplitudes of ERG decreased 22% in group 1, 16% in group 2, and 7% in group 3; the b-wave amplitudes were statistically different between the uninjected group and the groups with either 50-70% or 80-100% coverage. The subretinal injection-induced RD reattached

Plasma rich in growth factors (PRGF-Endoret) stimulates corneal wound healing and reduces haze formation after PRK surgery.

Science.gov (United States)

Anitua, E; Muruzabal, F; Alcalde, I; Merayo-Lloves, J; Orive, G

2013-10-01

This study evaluated the efficacy of Plasma rich in growth factors (PRGF-Endoret) on the corneal wound healing process after Photorefractive keratectomy (PRK). To address this, blood from three healthy donors was collected, centrifuged and, the whole plasma column (WP) and the plasma fraction with the highest platelet concentration (F3) were collected. The effects of F3 and WP on the proliferation and migration of human corneal epithelial cells (HCE) were analyzed. PRK was performed on C57BL/6 mice. Animals were divided in three treatment groups: Control, F3, and WP. Corneal wound healing and haze formation were evaluated macroscopically. Eyes were collected at 1, 2, 3, and 7 days after surgery, and were processed for histological studies. Immunofluorescence was used to assess cellular proliferation, apoptosis and myofibroblast transformation in the mouse cornea. Results showed a significant increased on proliferation and wound healing after F3 and WP treatment when compared with control group. In vivo studies showed significant reduction on haze formation in mice treated with both PRGF-Endoret formulations (F3 and WP). Histological studies showed an increase of epithelial cell proliferation in corneas of control group, promoting an epithelial hyperplasia. The number of SMA-positive cells (corresponding to myofibroblast differentiation) was significantly lower in the PRGF-Endoret group than in the control group, correlating with the higher transparence results observed macroscopically in both PRGF-Endoret groups. According to this, it can be concluded that PRGF-Endoret accelerates corneal tissue regeneration after PRK, reducing haze formation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of two different incision phacoemulsification on corneal astigmatism

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Lu Huo

2014-12-01

Full Text Available AIM:To compare the effect of different incision in corneal astigmatism after phacoemulsification. METHODS: Totally 88 cases(122 eyeswith pure cataract were randomly divided into two groups. Forty cases(60 eyeswere clarity corneal incision in group A, and 48 cases(62 eyeswere sclera tunnel incision in group B. Mean corneal astigmatism, surgically induced astigmatism(SIA, uncorrected visual acuity(UCVAand best correct vision acuity(BCVAwere observed in pre- and post-operation at 1d; 1wk; 1mo.RESULTS: The mean astigmatism had statistically significant difference between two groups at 1d; 1wk; 1mo after operation(PPP>0.05. UCVA≥0.5 and BCVA≥0.8 had statistically significant difference at 1d; 1wk(PP>0.05.CONCLUSION: Phacoemulsification with scleral tunnel incision remove combined intraocular lens(IOLimplantation has small changes to corneal astigmatism. By selecting personalized corneal incision according to the corneal topography might be more beneficial.

Integrins beta 5, beta 3 and alpha v are apically distributed in endometrial epithelium.

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Aplin, J D; Spanswick, C; Behzad, F; Kimber, S J; Vićovac, L

1996-07-01

Several adhesion molecules have been shown to occur at the surface of endometrial cells. One of these is the integrin alpha v subunit which associates with various beta chains including beta 5. We demonstrate the presence of integrin beta 5 polypeptide in human endometrial epithelial cells throughout the menstrual cycle using immunocytochemistry with monospecific antibodies, and at the mRNA level by thermal amplification from endometrial cDNA. Integrin beta 5 is also found in a population of bone marrow-derived cells. A notable feature of the distribution of the beta 5 subunit in the glandular and luminal epithelium is its apical localization, which may suggest an involvement in implantation. However, no evidence was found for regulated expression of epithelial beta 5. In mouse, the beta 5 subunit is found at both the apical and basal surface of epithelial cells and expression is essentially oestrous cycle-independent. Comparisons are made in both species with the distribution of the alpha v and beta 3 subunits which also localize to the apical epithelium.

Reinstatement of "germinal epithelium" of the ovary

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Nishida Naoyo

2006-08-01

Full Text Available Abstract Background The existing dogma that the former term ovarian "germinal epithelium" resulted from a mistaken belief that it could give rise to new germ cells is now strongly challenged. Discussion Two years ago, a research group of the University of Tennessee led by Antonin Bukovsky successfully demonstrated the oogenic process from the human ovarian covering epithelium now commonly called the ovarian surface epithelium. They showed the new oocyte with zona pellucida and granulosa cells, both originated from the surface epithelium arising from mesenchymal cells in the tunica albuginea, and stressed that the human ovary could form primary follicles throughout the reproductive period. This gives a big impact not only to the field of reproductive medicine, but also to the oncologic area. The surface epithelium is regarded as the major source of ovarian cancers, and most of the neoplasms exhibit the histology resembling müllerian epithelia. Since the differentiating capability of the surface epithelium has now expanded, the histologic range of the neoplasms in this category may extend to include both germ cell tumors and sex cord-stromal cell tumors. Summary Since the oogenic capability of ovarian surface cells has been proven, it is now believed that the oocytes can originate from them. The term "germinal epithelium", hence, might reasonably be reinstated.

The cytotoxic effect of oxybuprocaine on human corneal epithelial cells by inducing cell cycle arrest and mitochondria-dependent apoptosis.

Science.gov (United States)

Fan, W-Y; Wang, D-P; Wen, Q; Fan, T-J

2017-08-01

Oxybuprocaine (OBPC) is a widely used topical anesthetic in eye clinic, and prolonged and repeated usage of OBPC might be cytotoxic to the cornea, especially to the outmost corneal epithelium. In this study, we characterized the cytotoxic effect of OBPC on human corneal epithelial (HCEP) cells and investigated its possible cellular and molecular mechanisms using an in vitro model of non-transfected HCEP cells. Our results showed that OBPC at concentrations ranging from 0.025% to 0.4% had a dose- and time-dependent cytotoxicity to HCEP cells. Moreover, OBPC arrested the cells at S phase and induced apoptosis of these cells by inducing plasma membrane permeability, phosphatidylserine externalization, DNA fragmentation, and apoptotic body formation. Furthermore, OBPC could trigger the activation of caspase-2, -3, and -9, downregulate the expression of Bcl-xL, upregulate the expression of Bax along with the cytoplasmic amount of mitochondria-released apoptosis-inducing factor, and disrupt mitochondrial transmembrane potential. Our results suggest that OBPC has a dose- and time-dependent cytotoxicity to HCEP cells by inducing cell cycle arrest and cell apoptosis via a death receptor-mediated mitochondria-dependent proapoptotic pathway, and this novel finding provides new insights into the acute cytotoxicity and its toxic mechanisms of OBPC on HCEP cells.

[Effect of topical application of a recombinant adenovirus carrying promyelocytic leukemia gene in a psoriasis-like mouse model].

Science.gov (United States)

Wang, Qiongyu; Zhang, Aijun; Ma, Huiqun; Wang, Shijie; Ma, Yunyun; Zou, Xingwei; Li, Ruilian

2013-03-01

To investigate the effects of topical treatment with adenovirus-mediated promyelocytic leukemia gene (PML) gene in a psoriasis-like mouse model. The effect of adenovirus-mediated PML gene on the granular layer of mouse tail scale epidermis and epithelial mitosis were observed on longitudinal histological sections prepared from the tail skin and vaginal epithelium of the mice. Adenovirus-mediated PML gene significantly inhibited mitosis of mouse vaginal epithelial cells and promoted the formation of granular layer in mouse tail scale epidermis. The therapeutic effect of PML gene in the psoriasis-like mouse model may be associated with increased granular cells and suppressed epidemic cell proliferation.

Differences in activities of antioxidant superoxide dismutase, glutathione peroxidase and prooxidant xanthine oxidoreductase/xanthine oxidase in the normal corneal epithelium of various mammalia

Czech Academy of Sciences Publication Activity Database

Andonova, Janetta; Pláteník, J.; Vejražka, M.; Štípek, S.; Ardan, Taras; Čejka, Čestmír; Midelfart, A.; Čejková, Jitka

2007-01-01

Roč. 56, č. 1 (2007), s. 105-112 ISSN 0862-8408 R&D Projects: GA ČR GA304/06/1379 Institutional research plan: CEZ:AV0Z50390512 Keywords : Mammalia * Cornea * Epithelium Subject RIV: FF - HEENT, Dentistry Impact factor: 1.505, year: 2007

Effects of genipin corneal crosslinking in rabbit corneas.

Science.gov (United States)

Avila, Marcel Y; Narvaez, Mauricio; Castañeda, Juan P

2016-07-01

To evaluate the effect of genipin, a natural crosslinking agent, in rabbit eyes. Department of Ophthalmology, Universidad Nacional de Colombia Centro de Tecnologia Oftalmica, Bogotá, Colombia. Experimental study. Ex vivo rabbit eyes (16; 8 rabbits) were treated with genipin 1.00%, 0.50%, and 0.25% for 5 minutes with a vacuum device to increase corneal permeability. Penetration was evaluated using Scheimpflug pachymetry (Pentacam). In the in vivo model (20 rabbits; 1 eye treated, 1 eye with vehicle), corneas were crosslinked with genipin as described. Corneal curvature, corneal pachymetry, and intraocular pressure (IOP) assessments as well as slitlamp examinations were performed 0, 7, 30, and 60 days after treatment. In the ex vivo model, Scheimpflug pachymetry showed deep penetration in the rabbit corneas with an increase in corneal density and a dose-dependent relationship. Corneal flattening was observed in treated eyes (mean 4.4 diopters ± 0.5 [SD]) compared with the control eyes. Pachymetry and IOP were stable in all evaluations. No eye showed toxicity in the anterior chamber or in the lens. Corneal crosslinking induced by genipin produced significant flattening of the cornea with no toxicity in rabbit eyes. This crosslinking could be useful in the treatment of corneal ectasia and in the modification of corneal curvature. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Airbag induced corneal ectasia.

Science.gov (United States)

Mearza, Ali A; Koufaki, Fedra N; Aslanides, Ioannis M

2008-02-01

To report a case of airbag induced corneal ectasia. Case report. A patient 3 years post-LASIK developed bilateral corneal ectasia worse in the right eye following airbag deployment in a road traffic accident. At last follow up, best corrected vision was 20/40 with -4.00/-4.00 x 25 in the right eye and 20/25 with -1.25/-0.50 x 135 in the left eye. This is a rare presentation of trauma induced ectasia in a patient post-LASIK. It is possible that reduction in biomechanical integrity of the cornea from prior refractive surgery contributed to this presentation.

Expression of p75NGFR, a Proliferative and Basal Cell Marker, in the Buccal Mucosa Epithelium during Re-epithelialization

International Nuclear Information System (INIS)

Ishii, Akihiro; Muramatsu, Takashi; Lee, Jong-Min; Higa, Kazunari; Shinozaki, Naoshi; Jung, Han-Sung; Shibahara, Takahiko

2014-01-01

We investigated the expression of p75 NGFR , a proliferative and basal cell marker, in the mouse buccal mucosa epithelium during wound healing in order to elucidate the role of epithelial stem cells. Epithelial defects were generated in the epithelium of the buccal mucosa of 6-week-old mice using CO 2 laser irradiation. BrdU was immediately administered to mice following laser irradiation. They were then sacrificed after 1, 3, 7, and 14 days. Paraffin sections were prepared and the irradiated areas were analyzed using immunohistochemistry with anti-p75 NGFR , BrdU, PCNA, and CK14 antibodies. During re-epithelialization, PCNA (–)/p75 NGFR (+) cells extended to the wound, which then closed, whereas PCNA (+)/p75 NGFR (+) cells were not observed at the edge of the wound. In addition, p75 NGFR (–)/CK14 (+), which reflected the presence of post-mitotic differentiating cells, was observed in the supra-basal layers of the extended epithelium. BrdU (+)/p75 NGFR (+), which reflected the presence of epithelial stem cells, was detected sparsely in buccal basal epithelial cells after healing, and disappeared after 7 days. These results suggest that p75 NGFR (+) keratinocytes are localized in the basal layer, which contains oral epithelial stem cells, and retain the ability to proliferate in order to regenerate the buccal mucosal epithelium

Transport across the choroid plexus epithelium

DEFF Research Database (Denmark)

Praetorius, Jeppe; Damkier, Helle Hasager

2017-01-01

The choroid plexus epithelium is a secretory epithelium par excellence. However, this is perhaps not the most prominent reason for the massive interest in this modest-sized tissue residing inside the brain ventricles. Most likely, the dominant reason for extensive studies of the choroid plexus...... is the identification of this epithelium as the source of the majority of intraventricular cerebrospinal fluid. This finding has direct relevance for studies of diseases and conditions with deranged central fluid volume or ionic balance. While the concept is supported by the vast majority of the literature......, the implication of the choroid plexus in secretion of the cerebrospinal fluid was recently challenged once again. Three newer and promising areas of current choroid plexus-related investigations are as follows: 1) the choroid plexus epithelium as the source of mediators necessary for central nervous system...

Changes in corneal endothelial cell density and the cumulative risk of corneal decompensation after Ahmed glaucoma valve implantation.

Science.gov (United States)

Kim, Kyoung Nam; Lee, Sung Bok; Lee, Yeon Hee; Lee, Jong Joo; Lim, Hyung Bin; Kim, Chang-Sik

2016-07-01

To evaluate changes in the corneal endothelial cell density (ECD) and corneal decompensation following Ahmed glaucoma valve (AGV) implantation. This study was retrospective and observational case series. Patients with refractory glaucoma who underwent AGV implantation and were followed >5 years were consecutively enrolled. We reviewed the medical records, including the results of central corneal specular microscopy. Of the 127 enrolled patients, the annual change in ECD (%) was determined using linear regression for 72 eyes evaluated at least four times using serial specular microscopic examination and compared with 31 control eyes (fellow glaucomatous eyes under medical treatment). The main outcome measures were cumulative risk of corneal decompensation and differences in the ECD loss rates between subjects and controls. The mean follow-up after AGV implantation was 43.1 months. There were no cases of postoperative tube-corneal touch. The cumulative risk of corneal decompensation was 3.3%, 5 years after AGV implantation. There was a more rapid loss of ECD in the 72 subject eyes compared with the 31 controls (-7.0% and -0.1%/year, respectively; p<0.001). However, the rate of loss decreased over time and statistical significance compared with control eyes disappeared after 2 years postoperatively: -10.7% from baseline to 1 year (p<0.01), -7.0% from 1 year to 2 years (p=0.037), -4.2% from 2 years to 3 years (p=0.230) and -2.7% from 3 years to the final follow-up (p=0.111). In case of uncomplicated AGV implantation, the cumulative risk of corneal decompensation was 3.3%, 5 years after the operation. The ECD loss was statistically greater in eyes with AGV than in control eyes without AGV, but the difference was significant only up to 2 years post surgery. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Corneal manifestations in systemic diseases

OpenAIRE

Zarranz-Ventura, J.; Nova, E. De; Moreno-Montañés, J.

2008-01-01

Un gran número de enfermedades sistémicas presentan manifestaciones corneales dentro de su espectro de enfermedad. El estudio detallado de todos los cuadros que asocian patología corneal resulta inabarcable, por ello se presentan las enfermedades más prevalentes o características. Este estudio contempla las enfermedades pulmonares y conectivopatías (colagenosis, enfermedades reumatológicas y enfermedades inflamatorias idiopáticas), las enfermedades dermatológicas, cardiovasculares, hematológi...

Acute corneal hydrops in keratoconus

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Prafulla K Maharana

2013-01-01

Full Text Available Acute corneal hydrops is a condition characterized by stromal edema due to leakage of aqueous through a tear in descemet membrane. The patient presents with sudden onset decrease in vision, photophobia, and pain. Corneal thinning and ectasias combined with trivial trauma to the eye mostly by eye rubbing is considered as the underlying cause. With conservative approach self-resolution takes around 2 to 3 months. Surgical intervention is required in cases of non-resolution of corneal edema to avoid complications and for early visual rehabilitation. Intracameral injection of air or gas such as perflouropropane is the most common surgical procedure done. Recent investigative modality such as anterior segment optical coherence tomography is an extremely useful tool for diagnosis, surgical planning, and postoperative follow up. Resolution of hydrops may improve the contact lens tolerance and visual acuity but most cases require keratoplasty for visual rehabilitation.

Management of corneal bee sting

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Razmjoo H

2011-12-01

Full Text Available Hassan Razmjoo1,2, Mohammad-Ali Abtahi1,2,4, Peyman Roomizadeh1,3, Zahra Mohammadi1,2, Seyed-Hossein Abtahi1,3,41Medical School, Isfahan University of Medical Sciences (IUMS; 2Ophthalmology Ward, Feiz Hospital, IUMS; 3Isfahan Medical Students Research Center (IMSRC, IUMS; 4Isfahan Ophthalmology Research Center (IORC, Feiz Hospital, IUMS, Isfahan, IranAbstract: Corneal bee sting is an uncommon environmental eye injury that can result in various ocular complications with an etiology of penetrating, immunologic, and toxic effects of the stinger and its injected venom. In this study we present our experience in the management of a middle-aged male with a right-sided deep corneal bee sting. On arrival, the patient was complaining of severe pain, blurry vision with acuity of 160/200, and tearing, which he had experienced soon after the injury. Firstly, we administered conventional drugs for eye injuries, including topical antibiotic, corticosteroid, and cycloplegic agents. After 2 days, corneal stromal infiltration and edema developed around the site of the sting, and visual acuity decreased to 100/200. These conditions led us to remove the stinger surgically. Within 25 days of follow-up, the corneal infiltration decreased gradually, and visual acuity improved to 180/200. We suggest a two-stage management approach for cases of corneal sting. For the first stage, if the stinger is readily accessible or primary dramatic reactions, including infiltration, especially on the visual axis, exist, manual or surgical removal would be indicated. Otherwise, we recommend conventional treatments for eye injuries. Given this situation, patients should be closely monitored for detection of any worsening. If the condition does not resolve or even deteriorates, for the second stage, surgical removal of the stinger under local or generalized anesthesia is indicated.Keywords: bee sting, stinger, cornea, removal, management, surgery

Impact of Facial Conformation on Canine Health: Corneal Ulceration

Science.gov (United States)

Packer, Rowena M. A.; Hendricks, Anke; Burn, Charlotte C.

2015-01-01

Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled) skull shape, the presence of a nasal fold (wrinkle), and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not), or if a previous diagnosis of corneal ulcer(s) was documented in the dogs’ histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%), small breed dogs (mean± SE weight: 11.4±1.1 kg), with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio dogs. A 10% increase in relative eyelid aperture width more than tripled the ulcer risk. Exposed eye-white was associated with a nearly three times increased risk. The results demonstrate that artificially selecting for these facial characteristics greatly heightens the risk of corneal ulcers, and such selection should thus be discouraged to improve canine welfare. PMID:25969983

Study on phototherapeutic keratotomy for bacterial corneal lesions in rabbit

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Xin Zhou

2018-05-01

Full Text Available AIM: To study the effect of phototherapeutic keratectomy(PTKon rabbit bacterial corneal ulcer model and explore the clinical potential of this method. METHODS: Totally 48 eyes from all the 24 New Zealand rabbits were inoculated with Staphylococcus aureus and bacterial corneal ulcer model was established successfully. At 1d after inoculation, 48 eyes were given levofloxacin eye drops when corneal ulcer was confirmed. Then slit lamp inspection and optical coherence tomography(OCTwere performed to measure the central corneal ulcer depth. All the rabbits right eyes were treated with PTK, as an observation group, left eyes were not treated as a control group. The eye section were observed by slit lamp and central thickness of corneal ulcer was measured by OCT at 3 and 7d after this operation. Rabbits were sacrificed and the cornea was removed for pathological section 7d later. RESULTS: The corneal ulcers in both groups had a tendency to heal, showing a decrease in ulcer area and smoothness of the surface. There was no significant difference in the depth of corneal ulcer between the observation group and the control group before PTK(t=0.706, P=0.484. The difference between the two groups of eyes at 3 and 7d after PTK was obviously(PCONCLUSION: PTK can effectively cure rabbit Staphylococcus aureus corneal ulcer and promote ulcer wound healing, which may be used for clinical treatment of patients with bacterial corneal lesions.

Crosslinking and corneal cryotherapy in acanthamoeba keratitis -- a histological study.

Science.gov (United States)

Hager, Tobias; Hasenfus, A; Stachon, T; Seitz, B; Szentmáry, N

2016-01-01

Acanthamoeba keratitis is rare, but difficult to treat. Penetrating keratoplasty is performed in therapy-resistant cases. Nevertheless, subsequent recurrences occur in 40 % of the cases. In addition to triple-topical therapy (polyhexamid, propamidinisoethionat, neomycin), treatment alternatives are corneal cryotherapy and/or crosslinking (CXL). The aim of our present histological study was to analyze the persistence of acanthamoebatrophozoites and cysts, the persistence of bacteria, and activation of keratocytes in corneas of acanthamoeba keratitis patients following corneal cryotherapy and/or CXL. We analyzed histologically corneal buttons (from penetrating keratoplasties) of nine patients with acanthamoeba keratitis, following corneal cryotherapy (two patients) or a combination of crosslinking and corneal cryotherapy (seven patients), using haematoxilin–eosin, periodic acid Schiff (PAS), Gram and alpha-smooth muscle actin (alpha-SMA) stainings. Acanthamoeba trophozoites persisted in three corneas after cryotherapy and CXL. Cysts persisted in one of two corneas following corneal cryotherapy and in six of seven corneas after a combination of CXL and cryotherapy. One cornea showed positive Gram staining, but there were no alpha-SMA positive keratocytes in any of the corneas. Crosslinking and corneal cryotherapy have only limited impact on killing of acanthamoeba trophozoites, cysts, or bacteria. Corneal cryotherapy and CXL did not stimulate myofibroblastic transformation of keratocytes.

Corneal topography

DEFF Research Database (Denmark)

Andersen, J.; Koch-Jensen, P.; Østerby, Ole

1993-01-01

The central corneal zone is depicted on keratoscope photographs using a small target aperture and a large object distance. Information on the peripheral area is included by employing a hemispherical target with a dense circular and radial pattern. On a 16 mm (R = 8 mm) reference steel sphere the ...

Prevalence and associated factors of corneal blindness in Ningxia in northwest China

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Xun-Lun Sheng

2014-06-01

Full Text Available AIM:To describe the prevalence and demographic characteristics of corneal blindness in an urban and rural region of Ningxia, located in the northwest part of China.METHODS:A stratified, randomized sampling procedure was employed in the study, including urban and rural area of all age group. Visual acuity, anterior segment and ocular fundus were checked. Related factor of corneal disease, including age, gender, education status, ethnic group, location and occupation, were identified according to uniform customized protocol. An eye was defined to be corneal blindness if the visual acuity was <20/400 due to a corneal disease.RESULTS:Three thousand individuals (1290 from urban area and 1710 from rural area participated in the investigation, with a response rate of 80.380%. The prevalence of corneal blindness was 0.023% in both eyes and 0.733% in at least one eye. The blindness in at least one eye with varied causes was present in 106 participants (3.533% and in bilateral eyes in 34 participants (1.133%. The corneal diseases accounted for 20.754% of blindness in at least one eye and 20.588% of bilateral blindness. The prevalence of corneal disease was higher in older and Han ethnic group, especially those who occupied in agriculture and outdoor work. People with corneal blindness were more likely to be older and lower education. Rural population were more likely to suffer from bilateral corneal blindness than the urban population in ≥59-year group (χ2=6.716, P=0.019. Infectious, trauma and immune corneal disease were the three leading causes of corneal disease. Trauma corneal disease was more likely leading to blindness in one eye. However, infectious and immune corneal diseases make more contribution to the bilateral corneal blindness.CONCLUSION: Corneal blindness is a significant burden of in Ningxia population, encompassing a variety of corneal infections and trauma; the majority of those were avoidable. Health promotion strategies and good

Citologia de impressão no diagnóstico de infecção corneana por Acanthamoeba: relato de caso Diagnosis of Acanthamoeba corneal infection by impression cytology: case report

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Jeison de Nadai Barros

2007-03-01

cytology samples were obtained from each patient and were stained by PAS, hematoxylin and Papanicolaou. Routine microbiological investigation and culture were also performed using corneal scraping. Positive culture and impression cytology for Acanthamoeba sp was observed in all patients while smears with Giemsa stain were positive in two. Impression cytology Acanthamoeba sp cysts were observed among sheets of corneal epithelial cells and as isolated cells. Cysts were also found in the superficial epithelium in one of these patients after treatment while corneal scraping did not reveal any cyst. Histopathology revealed cysts in the epithelium and stroma in a transplanted cornea in one of these patients. The first description of impression cytology as a diagnostic method for Acanthamoeba keratitis occurred recently. In this study corneal impression cytology detected Acanthamoeba sp cysts successfully in these patients with only superficial involvement. Impression cytology as a non invasive technique can be used to facilitate early recognition of Acanthamoeba infection playing a useful role in the follow-up of the disease.

Telomere shortening impairs regeneration of the olfactory epithelium in response to injury but not under homeostatic conditions.

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Masami Watabe-Rudolph

Full Text Available Atrophy of the olfactory epithelium (OE associated with impaired olfaction and dry nose represents one of the most common phenotypes of human aging. Impairment in regeneration of a functional olfactory epithelium can also occur in response to injury due to infection or nasal surgery. These complications occur more frequently in aged patients. Although age is the most unifying risk factor for atrophic changes and functional decline of the olfactory epithelium, little is known about molecular mechanisms that could influence maintenance and repair of the olfactory epithelium. Here, we analyzed the influence of telomere shortening (a basic mechanism of cellular aging on homeostasis and regenerative reserve in response to chemical induced injury of the OE in late generation telomere knockout mice (G3 mTerc(-/- with short telomeres compared to wild type mice (mTerc(+/+ with long telomeres. The study revealed no significant influence of telomere shortening on homeostatic maintenance of the OE during mouse aging. In contrast, the regenerative response to chemical induced injury of the OE was significantly impaired in G3 mTerc(-/- mice compared to mTerc(+/+ mice. Seven days after chemical induced damage, G3 mTerc(-/- mice exhibited significantly enlarged areas of persisting atrophy compared to mTerc(+/+ mice (p = 0.031. Telomere dysfunction was associated with impairments in cell proliferation in the regenerating epithelium. Deletion of the cell cycle inhibitor, Cdkn1a (p21 rescued defects in OE regeneration in telomere dysfunctional mice. Together, these data indicate that telomere shortening impairs the regenerative capacity of the OE by impairing cell cycle progression in a p21-dependent manner. These findings could be relevant for the impairment in OE function in elderly people.

Corneal Biomechanical Properties after FS-LASIK with Residual Bed Thickness Less Than 50% of the Original Corneal Thickness

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Haixia Zhang

2018-01-01

Full Text Available Background. The changes in corneal biomechanical properties after LASIK remain an unknown but important topic for surgical design and prognostic evaluation. This study aims to observe the postoperative corneal biomechanical properties one month after LASIK with amount of corneal cutting (ACC greater than 50% of the central corneal thickness (CCT. Methods. FS-LASIK was performed in 10 left rabbit eyes with ACC being 60% (L60 and 65% (L65 of the CCT, while the right eyes (R were the control. After 4 weeks, rabbits were executed and corneal strip samples were prepared for uniaxial tensile tests. Results. At the same strain, the stresses of L65 and L60 were larger than those of R. The elastic moduli of L60 and L65 were larger than those of R when the stress was 0.02 MPa, while they began to be less than those of R when stress exceeds the low-stress region. After 10 s relaxation, the stress of specimens L65, L60, and R increased in turn. Conclusion. The elastic moduli of the cornea after FS-LASIK with ACC greater than 50% of the CCT do not become less under normal rabbit IOP. The limit stress grows with the rise of ACC when relaxation becomes stable.

Loss of TRPV4 Function Suppresses Inflammatory Fibrosis Induced by Alkali-Burning Mouse Corneas.

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Yuka Okada

Full Text Available In humans suffering from pulmonary disease and a mouse model, transient receptor potential vanilloid 4 (TRPV4 channel activation contributes to fibrosis. As a corneal alkali burn induces the same response, we determined if such an effect is also attributable to TRPV4 activation in mice. Accordingly, we determined if the alkali burn wound healing responses in wild-type (WT mice are different than those in their TRPV4-null (KO counterpart. Stromal opacification due to fibrosis in KO (n = 128 mice was markedly reduced after 20 days relative to that in WT (n = 157 mice. Immunohistochemistry revealed that increases in polymorphonuclear leukocytes and macrophage infiltration declined in KO mice. Semi-quantitative real time RT-PCR of ocular KO fibroblast cultures identified increases in proinflammatory and monocyte chemoattractant protein-1 chemoattractant gene expression after injury. Biomarker gene expression of fibrosis, collagen1a1 and α-smooth muscle actin were attenuated along with macrophage release of interleukin-6 whereas transforming growth factor β, release was unchanged. Tail vein reciprocal bone marrow transplantation between WT and KO chimera mouse models mice showed that reduced scarring and inflammation in KO mice are due to loss of TRPV4 expression on both corneal resident immune cells, fibroblasts and infiltrating polymorphonuclear leukocytes and macrophages. Intraperitoneal TRPV4 receptor antagonist injection of HC-067047 (10 mg/kg, daily into WT mice reproduced the KO-phenotype. Taken together, alkali-induced TRPV4 activation contributes to inducing fibrosis and inflammation since corneal transparency recovery was markedly improved in KO mice.

Loss of TRPV4 Function Suppresses Inflammatory Fibrosis Induced by Alkali-Burning Mouse Corneas.

Science.gov (United States)

Okada, Yuka; Shirai, Kumi; Miyajima, Masayasu; Reinach, Peter S; Yamanaka, Osamu; Sumioka, Takayoshi; Kokado, Masahide; Tomoyose, Katsuo; Saika, Shizuya

2016-01-01

In humans suffering from pulmonary disease and a mouse model, transient receptor potential vanilloid 4 (TRPV4) channel activation contributes to fibrosis. As a corneal alkali burn induces the same response, we determined if such an effect is also attributable to TRPV4 activation in mice. Accordingly, we determined if the alkali burn wound healing responses in wild-type (WT) mice are different than those in their TRPV4-null (KO) counterpart. Stromal opacification due to fibrosis in KO (n = 128) mice was markedly reduced after 20 days relative to that in WT (n = 157) mice. Immunohistochemistry revealed that increases in polymorphonuclear leukocytes and macrophage infiltration declined in KO mice. Semi-quantitative real time RT-PCR of ocular KO fibroblast cultures identified increases in proinflammatory and monocyte chemoattractant protein-1 chemoattractant gene expression after injury. Biomarker gene expression of fibrosis, collagen1a1 and α-smooth muscle actin were attenuated along with macrophage release of interleukin-6 whereas transforming growth factor β, release was unchanged. Tail vein reciprocal bone marrow transplantation between WT and KO chimera mouse models mice showed that reduced scarring and inflammation in KO mice are due to loss of TRPV4 expression on both corneal resident immune cells, fibroblasts and infiltrating polymorphonuclear leukocytes and macrophages. Intraperitoneal TRPV4 receptor antagonist injection of HC-067047 (10 mg/kg, daily) into WT mice reproduced the KO-phenotype. Taken together, alkali-induced TRPV4 activation contributes to inducing fibrosis and inflammation since corneal transparency recovery was markedly improved in KO mice.

Temporary corneal stem cell dysfunction after radiation therapy

International Nuclear Information System (INIS)

Hiroshi, Fujishima; Kazuo, Tsubota

1996-01-01

Radiation therapy can cause corneal and conjuctival abnormalities that sometimes require surgical treatment. Corneal stem cell dysfunction is described, which recovered after the cessation of radiation. Methods - A 44-year-old man developed a corneal epithelial abnormality associated with conjuctival and corneal inflammation following radiation therapy for maxillary cancer. Examination of brush cytology samples showed goblet cells in the upper and lower parts of the cornea, which showed increased fluorescein permeability, and intraepithelial lymphocytes. Impression cytology showed goblet cells in the same part of the cornea. Specular microscopy revealed spindle type epithelial cells. Patient follow up included artificial tears and an antibiotic ophthalmic ointment. The corneal abnormalities resolved after 4 months with improved visual acuity without any surgical intervention, but the disappearance of the palisades of Vogt did not recover at 1 year after radiation. Radiation therapy in this patient caused temporary stem cell dysfunction which resulted in conjunctivalisation in a part of the cornea. Although limbal stem cell function did not fully recover, this rare case suggested that medical options should be considered before surgery. (Author)

Effects of Silicone Hydrogel Contact Lens Application on Corneal High-order Aberration and Visual Guality in Patients with Corneal Opacities

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Sevda Aydın Kurna

2012-03-01

Full Text Available Pur po se: Evaluation of the corneal high-order aberrations and visual quality changes after application of silicone hydrogel contact lenses in patients with corneal opacities due to various etiologies. Ma te ri al and Met hod: Fifteen eyes of 13 patients with corneal opacities were included in the study. During the ophthalmologic examination before and after contact lens application, visual acuity was measured with Snellen acuity chart and contrast sensitivity - with Bailey-Lowie Charts in letters. Aberrations were measured with corneal aberrometer (NIDEK Magellan Mapper under a naturally dilated pupil. Spherical aberration, coma, trefoil, irregular astigmatism and total high-order root mean square (RMS values were recorded. Measurements were repeated with balafilcon A lenses (PureVision 2 HD, B&L on all patients. Re sults: Patient age varied between 23 and 50 years. Two eyes had subepithelial infiltrates due to adenoviral keratitis, 1 had nebulae due to previous infections or trauma, and 2 had Salzmann’s nodular degeneration. We observed a mean increase of 1 line in visual acuity and 5 letters in contrast sensitivity with contact lenses versus glasses in the patients. Mean RMS values of spherical aberration, irregular astigmatism and total high-order aberrations decreased significantly with contact lenses. Dis cus si on: Silicone hydrogel soft contact lenses may improve visual quality by decreasing the corneal aberrations in patients with corneal opacities. (Turk J Ophthalmol 2012; 42: 97-102

Slit-lamp photography and videography with high magnifications

Science.gov (United States)

Yuan, Jin; Jiang, Hong; Mao, Xinjie; Ke, Bilian; Yan, Wentao; Liu, Che; Cintrón-Colón, Hector R; Perez, Victor L; Wang, Jianhua

2015-01-01

Purpose To demonstrate the use of the slit-lamp photography and videography with extremely high magnifications for visualizing structures of the anterior segment of the eye. Methods A Canon 60D digital camera with Movie Crop Function was adapted into a Nikon FS-2 slit-lamp to capture still images and video clips of the structures of the anterior segment of the eye. Images obtained using the slit-lamp were tested for spatial resolution. The cornea of human eyes was imaged with the slit-lamp and the structures were compared with the pictures captured using the ultra-high resolution optical coherence tomography (UHR-OCT). The central thickness of the corneal epithelium and total cornea was obtained using the slit-lamp and the results were compared with the thickness obtained using UHR-OCT. Results High-quality ocular images and higher spatial resolutions were obtained by using the slit-lamp with extremely high magnifications and Movie Crop Function, rather than the traditional slit-lamp. The structures and characteristics of the cornea, such as the normal epithelium, abnormal epithelium of corneal intraepithelial neoplasia, LASIK interface, and contact lenses, were clearly visualized using this device. These features were confirmed by comparing the obtained images with those acquired using UHR-OCT. Moreover, the tear film debris on the ocular surface and the corneal nerve in the anterior corneal stroma were also visualized. The thicknesses of the corneal epithelium and total cornea were similar to that measured using UHR-OCT (P photography and videography with extremely high magnifications allows better visualization of the anterior segment structures of the eye, especially of the epithelium, when compared with the traditional slit-lamp. PMID:26020484

New Insights on the Morphology of Adult Mouse Penis1

Science.gov (United States)

Rodriguez, Esequiel; Weiss, Dana A.; Yang, Jennifer H.; Menshenina, Julia; Ferretti, Max; Cunha, Tristan J.; Barcellos, Dale; Chan, Lok Yun; Risbridger, Gail; Cunha, Gerald R.; Baskin, Laurence S.

2011-01-01

ABSTRACT The adult mouse penis represents the end point of masculine sex differentiation of the embryonic genital tubercle and contains bone, cartilage, the urethra, erectile bodies, several types of epithelium, and many individual cell types arrayed into specific anatomical structures. Using contemporary high-resolution imaging techniques, we sought to provide new insights to the current description of adult mouse penile morphology to enable understanding of penile abnormalities, including hypospadias. Examination of serial transverse and longitudinal sections, scanning electron microscopy, and three-dimensional (3D) reconstruction provided a new appreciation of the individual structures in the adult mouse penis and their 3D interrelationships. In so doing, we discovered novel paired erectile bodies, the male urogenital mating protuberance (MUMP), and more accurately described the urethral meatus. These morphological observations were quantified by morphometric analysis and now provide accurate morphological end points of sex differentiation of mouse penis that will be the foundation of future studies to identify normal and abnormal penile development. PMID:21918128

Altered corneal biomechanical properties in children with osteogenesis imperfecta.

Science.gov (United States)

Lagrou, Lisa M; Gilbert, Jesse; Hannibal, Mark; Caird, Michelle S; Thomas, Inas; Moroi, Sayoko E; Bohnsack, Brenda L

2018-04-07

To evaluate biomechanical corneal properties in children with osteogenesis imperfecta (OI). A prospective, observational, case-control study was conducted on children 6-19 years of age diagnosed with OI. Patients with OI and healthy control subjects underwent complete ophthalmic examinations. Additional tests included Ocular Response Analyzer (ORA) and ultrasonic pachymetry. Primary outcomes were central corneal thickness (CCT), corneal hysteresis (CH), and corneal resistance factor (CRF). Intraocular pressure (IOP) was measured directly by either iCare or Goldmann applanation and indirectly by the ORA (Goldmann-correlated and corneal-compensated IOP). Statistically significant differences between OI and control groups were determined using independent samples t test. A total of 10 of 18 OI cases (mean age, 13 ± 4.37 years; 8 males) and 30 controls (mean age, 12.76 ± 2.62 years; 16 males) were able to complete the corneal biomechanics and pachymetry testing. Children with OI had decreased CH (8.5 ± 1.0 mm Hg vs 11.6 ± 1.2 mm Hg [P < 0.001]), CRF (9.0 ± 1.9 mm Hg vs 11.5 ± 1.5 [P < 0.001]) and CCT (449.8 ± 30.8 μm vs 568 ± 47.6 μm [P < 0.001]) compared to controls. The corneal-compensated IOP was significantly higher in OI cases (18.8 ± 3.1 mm Hg) than in controls (15.0 ± 1.6 mm Hg, P < 0.004), but there was no significant difference in Goldmann-correlated IOP (16.3 ± 4.2 mm Hg vs 15.8 ± 2.2 mm Hg). Collagen defects in OI alter corneal structure and biomechanics. Children with OI have decreased CH, CRF, and CCT, resulting in IOPs that are likely higher than measured by tonometry. These corneal alterations are present at a young age in OI. Affected individuals should be routinely screened for glaucoma and corneal pathologies. Copyright © 2018 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Highly concentrated collagen solutions leading to transparent scaffolds of controlled three-dimensional organizations for corneal epithelial cell colonization.

Science.gov (United States)

Tidu, Aurélien; Ghoubay-Benallaoua, Djida; Teulon, Claire; Asnacios, Sophie; Grieve, Kate; Portier, François; Schanne-Klein, Marie-Claire; Borderie, Vincent; Mosser, Gervaise

2018-05-29

This study aimed at controlling both the organization and the transparency of dense collagen scaffolds making use of the lyotropic mesogen properties of collagen. Cholesteric or plywood-like liquid crystal phases were achieved using mixtures of acetic and hydrochloric acids as solvents. The critical pH at which the switch between the two phases occurred was around pH = 3. The use of the two acids led to fibrillated collagen I scaffolds, whose visual aspect ranged from opaque to transparent. Rheological investigations showed that viscoelastic properties of the plywood-like solutions were optimized for molding due to faster recovery. They also confirmed the correlation between the elastic modulus and the diameter of collagen fibrils obtained after fibrillogenesis under ammonia vapor. Human corneal epithelial cells, grown from donor limbal explants, were cultured both on transparent plywood-like matrices and on human amniotic membranes for 14 days. The development of corneal epithelium and the preservation of epithelial stem cells were checked by optical microscopy, colony formation assay, immuno-fluorescence and quantitative polymerase chain reaction. A higher level of amplification of limbal stem cells was obtained with collagen matrices compared with amniotic membranes, showing the high biocompatibility of our scaffolds. We therefore suggest that collagen solutions presenting both plywood-like organization and transparency might be of interest for biomedical applications in ophthalmology.

Regulation of corneal stroma extracellular matrix assembly.

Science.gov (United States)

Chen, Shoujun; Mienaltowski, Michael J; Birk, David E

2015-04-01

The transparent cornea is the major refractive element of the eye. A finely controlled assembly of the stromal extracellular matrix is critical to corneal function, as well as in establishing the appropriate mechanical stability required to maintain corneal shape and curvature. In the stroma, homogeneous, small diameter collagen fibrils, regularly packed with a highly ordered hierarchical organization, are essential for function. This review focuses on corneal stroma assembly and the regulation of collagen fibrillogenesis. Corneal collagen fibrillogenesis involves multiple molecules interacting in sequential steps, as well as interactions between keratocytes and stroma matrix components. The stroma has the highest collagen V:I ratio in the body. Collagen V regulates the nucleation of protofibril assembly, thus controlling the number of fibrils and assembly of smaller diameter fibrils in the stroma. The corneal stroma is also enriched in small leucine-rich proteoglycans (SLRPs) that cooperate in a temporal and spatial manner to regulate linear and lateral collagen fibril growth. In addition, the fibril-associated collagens (FACITs) such as collagen XII and collagen XIV have roles in the regulation of fibril packing and inter-lamellar interactions. A communicating keratocyte network contributes to the overall and long-range regulation of stromal extracellular matrix assembly, by creating micro-domains where the sequential steps in stromal matrix assembly are controlled. Keratocytes control the synthesis of extracellular matrix components, which interact with the keratocytes dynamically to coordinate the regulatory steps into a cohesive process. Mutations or deficiencies in stromal regulatory molecules result in altered interactions and deficiencies in both transparency and refraction, leading to corneal stroma pathobiology such as stromal dystrophies, cornea plana and keratoconus. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dextran Preserves Native Corneal Structure During Decellularization.

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Lynch, Amy P; Wilson, Samantha L; Ahearne, Mark

2016-06-01

Corneal decellularization has become an increasingly popular technique for generating scaffolds for corneal regeneration. Most decellularization procedures result in tissue swelling, thus limiting their application. Here, the use of a polysaccharide, dextran, to reduce swelling and conserve the native corneal structure during decellularization was investigated. Corneas were treated with 1% Triton X-100, 0.5% sodium dodecyl sulfate, and nucleases under constant rotation followed by extensive washing. To reduce swelling, decellularization solutions were supplemented with 5% dextran either throughout the whole decellularization process or during the washing cycles only. Quantitative analysis of DNA content showed a 96% reduction after decellularization regardless of the addition of dextran. Dextran resulted in a significant reduction in swelling from 3.85 ± 0.43 nm without to 1.94 ± 0.29-2.01 ± 0.37 nm (p dextran must be present throughout the decellularization protocol to preserve the native corneal architecture, anisotropy analysis demonstrated comparable results (0.22 ± 0.03) to the native cornea (0.24 ± 0.02), p > 0.05. Dextran can counteract the detrimental effects of decellularizing agents on the biomechanical properties of the tissue resulting in similar compressive moduli (mean before decellularization: 5.40 ± 1.18 kPa; mean after decellularization with dextran: 5.64 ± 1.34 kPa, p > 0.05). Cells remained viable in the presence of decellularized scaffolds. The findings of this study indicate that dextran not only prevents significant corneal swelling during decellularization but also enhances the maintenance of the native corneal ultrastructure.

Comparison of the Keratometric Corneal Astigmatic Power after Phacoemulsification: Clear Temporal Corneal Incision versus Superior Scleral Tunnel Incision

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Yongqi He

2009-01-01

Full Text Available Objective. This is prospective randomized control trial to compare the mean keratometric corneal astigmatism diopter power (not surgical induced astigmatism among preop and one-month and three-month postop phacoemulcification of either a clear temporal corneal incision or a superior scleral tunnel Incision, using only keratometric astigmatic power reading to evaluate the difference between the two cataract surgery incisions. Methods. 120 patients (134 eyes underwent phacoemulcification were randomly assigned to two groups: Group A, the clear temporal corneal incision group, and Group B, the superior scleral tunnel incision group. SPSS11.5 Software was used for statistical analysis to compare the postsurgical changes of cornea astigmatism on keratometry. Results. The changes of corneal astigmatic diopter in Groups A and B after 3 month postop from keratometric reading were 1.04 + 0.76 and 0.94 + 0.27, respectively (=.84>.05, which showed no statistic significance difference. Conclusion. The incision through either temporal clear cornea or superior scleral tunnel in phacoemulcification shows no statistic difference in astigmatism change on keratometry 3-month postop.

Biological and genetic properties of the p53 null preneoplastic mammary epithelium

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Medina, Daniel; Kittrell, Frances S.; Shepard, Anne; Stephens, L. Clifton; Jiang, Cheng; Lu, Junxuan; Allred, D. Craig; McCarthy, Maureen; Ullrich, Robert L.

2002-01-01

The absence of the tumor suppressor gene p53 confers an increased tumorigenic risk for mammary epithelial cells. In this report, we describe the biological and genetic properties of the p53 null preneoplastic mouse mammary epithelium in a p53 wild-type environment. Mammary epithelium from p53 null mice was transplanted serially into the cleared mammary fat pads of p53 wild-type BALB/c female to develop stable outgrowth lines. The outgrowth lines were transplanted for 10 generations. The outgrowths were ductal in morphology and progressed through ductal hyperplasia and ductal carcinoma in situ before invasive cancer. The preneoplastic outgrowth lines were immortal and exhibited activated telomerase activity. They are estrogen and progesterone receptor-positive, and aneuploid, and had various levels of tumorigenic potential. The biological and genetic properties of these lines are distinct from those found in most hyperplastic alveolar outgrowth lines, the form of mammary preneoplasia occurring in most traditional models of murine mammary tumorigenesis. These results indicate that the preneoplastic cell populations found in this genetically engineered model are similar in biological properties to a subset of precurser lesions found in human breast cancer and provide a unique model to identify secondary events critical for tumorigenicity and invasiveness.

Aquaporins 6-12 in the human eye

DEFF Research Database (Denmark)

Tran, Thuy Linh; Bek, Toke; Holm, Lars

2012-01-01

Purpose: Aquaporins (AQPs) are widely expressed and have diverse distribution patterns in the eye. AQPs 0-5 have been localized at the cellular level in human eyes. We investigated the presence of the more recently discovered AQPs 6-12 in the human eye. Methods: RT-PCR was performed on fresh tissue...... from two human eyes divided into the cornea, corneal limbus, ciliary body and iris, lens, choroid, optic nerve, retina and sclera. Each structure was examined to detect the mRNA of AQPs 6-12. Twenty-one human eyes were examined using immunohistochemical and immunofluorescence techniques to determine...... was detected in the corneal epithelium, corneal endothelium, trabecular meshwork endothelium, ciliary epithelia, lens epithelium, the inner and outer limiting membrane of the retina, the retinal pigment epithelium and the capillary endothelium of all parts of the eye. AQP9 immunolabelling was detected...

Analysis of corneal topography in patients with pure microphthalmia in Eastern China.

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Hu, Pei-Hong; Gao, Gui-Ping; Yu, Yao; Pei, Chong-Gang; Zhou, Qiong; Huang, Xin; Zhang, Ying; Shao, Yi

2015-12-01

To determine the typical corneal changes in pure microphthalmia using a corneal topography system and identify characteristics that may assist in early diagnosis. Patients with pure microphthalmia and healthy control subjects underwent corneal topography analysis (Orbscan IIZ® Corneal Topography System; Bausch and Lomb, Bridgewater, NJ, USA) to determine degree of corneal astigmatism (mean A), simulation of corneal astigmatism (sim A), mean keratometry (mean K), simulated keratometry (sim K), irregularities in the 3 - and 5-mm zone, and mean thickness of nine distinct corneal regions. Patients with pure microphthalmia (n = 12) had significantly higher mean K, sim K, mean A, sim A, 3.0 mm irregularity and 5.0 mm irregularity, and exhibited significantly more false keratoconus than controls (n = 12). There was a significant between-group difference in the morphology of the anterior corneal surface and the central curvature of the cornea. Changes in corneal morphology observed in this study could be useful in borderline situations to confirm the diagnosis of pure microphthalmia. © The Author(s) 2015.

Congenital Corneal Anesthesia and Neurotrophic Keratitis: Diagnosis and Management

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Flavio Mantelli

2015-01-01

Full Text Available Neurotrophic keratitis (NK is a rare degenerative disease of the cornea caused by an impairment of corneal sensory innervation, characterized by decreased or absent corneal sensitivity resulting in epithelial keratopathy, ulceration, and perforation. The aetiopathogenesis of corneal sensory innervation impairment in children recognizes the same range of causes as adults, although they are much less frequent in the pediatric population. Some extremely rare congenital diseases could be considered in the aetiopathogenesis of NK in children. Congenital corneal anesthesia is an extremely rare condition that carries considerable diagnostic and therapeutic problems. Typically the onset is up to 3 years of age and the cornea may be affected in isolation or the sensory deficit may exist as a component of a congenital syndrome, or it may be associated with systemic somatic anomalies. Accurate diagnosis and recognition of risk factors is important for lessening long-term sequelae of this condition. Treatment should include frequent topical lubrication and bandage corneal or scleral contact lenses. Surgery may be needed in refractory cases. The purpose of this review is to summarize and update data available on congenital causes and treatment of corneal hypo/anesthesia and, in turn, on congenital NK.

Analysis of corneal esthesia in patients undergoing photorefractive keratectomy

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Elmar Torres Neto

2015-12-01

Full Text Available ABSTRACT Purpose: To quantitatively analyze corneal esthesia in patients undergoing photorefractive keratectomy (PRK surgery. Methods: Forty-five patients selected for PRK in one eye underwent corneal esthesia using a Cochet-Bonnet esthesiometer preoperatively and 30 and 90 days postoperatively. Patients with a refractive diopter error of 4 or greater received intraoperative 0.02% mitomycin C for 20 s. Results: Twenty-four (53.3% of the 45 eyes received intraoperative 0.02% mitomycin. Decreased sensitivity was observed on postoperative day 30. By postoperative day 90, corneal esthesia had normalized but remained 14.9% lower than preoperative levels. In the mitomycin group, no recovery of corneal esthesia to normal sensitivity levels was observed. The mean esthesiometer level was 39.2 mm on postoperative day 90 (P<0.001. Conclusions: The results of the present study demonstrate recovery of corneal esthesia to normal levels at 90 days postoperatively in patients who did not receive mitomycin C. In patients administered mitomycin C, a 23.59% reduction in the corneal touch threshold was observed compared with preoperative levels indicating a failure of recovery to normal levels.

Corneal conjunctivalization management with high Dk RGP contact lenses.

Science.gov (United States)

Martin, Raul

2009-06-01

To describe the management of corneal conjunctivalization with a high Dk RGP contact lens (CL) fitting. A high Dk RGP CL (Menicon Z-alpha Dk=189, Japan) was fitted, after temporary suspension of CL wear (6 months and 3 weeks), in two patients (a 36-year-old female and a 38-year-old male) who had corneal conjunctivalization secondary to low Dk soft CL wear. Both patients had worn their soft CLs 12-14 h per day without symptoms for the previous 18-20 years. After 9-15 months of high Dk RGP wear, all signs of corneal conjunctivalization had disappeared (corneal vascularization, late fluorescein stain, etc.) and patients wore their RGP CL comfortably. Corneal conjunctivalization was resolved with non-invasive procedures (temporary discontinuation, preservative-free artificial tears and high Dk RGP CL fitting) and thus other treatments (topical or surgical treatments such as limbus transplantation, amniotic membrane transplant or others) were not necessary. Short temporary suspension of CL wear (3 weeks), preservative-free artificial tears and refitting with high oxygen permeability RGP CL may be an alternative for the management of corneal conjunctivalization secondary to CL wear.

Bioactive self-assembled peptide nanofibers for corneal stroma regeneration.

Science.gov (United States)

Uzunalli, G; Soran, Z; Erkal, T S; Dagdas, Y S; Dinc, E; Hondur, A M; Bilgihan, K; Aydin, B; Guler, M O; Tekinay, A B

2014-03-01

Defects in the corneal stroma caused by trauma or diseases such as macular corneal dystrophy and keratoconus can be detrimental for vision. Development of therapeutic methods to enhance corneal regeneration is essential for treatment of these defects. This paper describes a bioactive peptide nanofiber scaffold system for corneal tissue regeneration. These nanofibers are formed by self-assembling peptide amphiphile molecules containing laminin and fibronectin inspired sequences. Human corneal keratocyte cells cultured on laminin-mimetic peptide nanofibers retained their characteristic morphology, and their proliferation was enhanced compared with cells cultured on fibronectin-mimetic nanofibers. When these nanofibers were used for damaged rabbit corneas, laminin-mimetic peptide nanofibers increased keratocyte migration and supported stroma regeneration. These results suggest that laminin-mimetic peptide nanofibers provide a promising injectable, synthetic scaffold system for cornea stroma regeneration. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Penetrating and Intrastromal Corneal Arcuate Incisions in Rabbit and Human Cadaver Eyes: Manual Diamond Blade and Femtosecond Laser-Created Incisions.

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Gray, Brad; Binder, Perry S; Huang, Ling C; Hill, Jim; Salvador-Silva, Mercedes; Gwon, Arlene

2016-07-01

To compare morphologic differences between freehand diamond or femtosecond laser-assisted penetrating and intrastromal arcuate incisions. Freehand diamond blade, corneal arcuate incisions (180° apart, 60° arc lengths) and 150 kHz femtosecond laser (80% scheimpflug pachymetry depth corneal thickness) arcuate incisions were performed in rabbits. Intrastromal arcuate incisions (100 μm above Descemet's membrane, 100 μm below epithelium) were performed in rabbit corneas (energy 1.2 μJ, spot line separation 3 × 3 μm, 90° side cut angle). Eyes were examined by slit lamp and light microscopy up to 47 days post-procedure. Freehand diamond blade penetrating incisions, and femtosecond laser penetrating and intrastromal arcuate incisions (energy 1.8 μJ, spot line separation 2 × 2 μm) were performed in cadaver eyes. Optical coherence tomography was performed immediately after surgery and the corneas were fixed for light scanning and transmission electron microscopy. The rabbit model showed anterior stromal inflammation with epithelial hyperplasia in penetrating blade and laser penetrating wounds. The laser intrastromal and penetrating incisions showed localized constriction of the stromal layers of the cornea near the wound. In cadaver eyes, penetrating wound morphology was similar between blade and laser whereas intrastromal wounds did not affect the cornea above or below incisions. Penetrating femtosecond laser arcuate incisions have more predictable and controlled outcomes shown by less post-operative scarring than incisions performed with a diamond blade. Intrastromal incisions do not affect uncut corneal layers as demonstrated by histopathology. The femtosecond laser has significant advantages in its ability to make intrastromal incisions which are not achievable by traditional freehand or mechanical diamond blades.

An autocrine ATP release mechanism regulates basal ciliary activity in airway epithelium.

Science.gov (United States)

Droguett, Karla; Rios, Mariana; Carreño, Daniela V; Navarrete, Camilo; Fuentes, Christian; Villalón, Manuel; Barrera, Nelson P

2017-07-15

Extracellular ATP, in association with [Ca 2+ ] i regulation, is required to maintain basal ciliary beat frequency. Increasing extracellular ATP levels increases ciliary beating in airway epithelial cells, maintaining a sustained response by inducing the release of additional ATP. Extracellular ATP levels in the millimolar range, previously associated with pathophysiological conditions of the airway epithelium, produce a transient arrest of ciliary activity. The regulation of ciliary beat frequency is dependent on ATP release by hemichannels (connexin/pannexin) and P2X receptor activation, the blockage of which may even stop ciliary movement. The force exerted by cilia, measured by atomic force microscopy, is reduced following extracellular ATP hydrolysis. This result complements the current understanding of the ciliary beating regulatory mechanism, with special relevance to inflammatory diseases of the airway epithelium that affect mucociliary clearance. Extracellular nucleotides, including ATP, are locally released by the airway epithelium and stimulate ciliary activity in a [Ca 2+ ] i -dependent manner after mechanical stimulation of ciliated cells. However, it is unclear whether the ATP released is involved in regulating basal ciliary activity and mediating changes in ciliary activity in response to chemical stimulation. In the present study, we evaluated ciliary beat frequency (CBF) and ciliary beating forces in primary cultures from mouse tracheal epithelium, using videomicroscopy and atomic force microscopy (AFM), respectively. Extracellular ATP levels and [Ca 2+ ] i were measured by luminometric and fluorimetric assays, respectively. Uptake of ethidium bromide was measured to evaluate hemichannel functionality. We show that hydrolysis of constitutive extracellular ATP levels with apyrase (50 U ml -1 ) reduced basal CBF by 45% and ciliary force by 67%. The apyrase effect on CBF was potentiated by carbenoxolone, a hemichannel inhibitor, and oxidized ATP, an

Pirfenidone nanoparticles improve corneal wound healing and prevent scarring following alkali burn.

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Sushovan Chowdhury

Full Text Available To evaluate the effects of pirfenidone nanoparticles on corneal re-epithelialization and scarring, major clinical challenges after alkali burn.Effect of pirfenidone on collagen I and α-smooth muscle actin (α-SMA synthesis by TGFβ induced primary corneal fibroblast cells was evaluated by immunoblotting and immunocytochemistry. Pirfenidone loaded poly (lactide-co-glycolide (PLGA nanoparticles were prepared, characterized and their cellular entry was examined in primary corneal fibroblast cells by fluorescence microscopy. Alkali burn was induced in one eye of Sprague Dawley rats followed by daily topical treatment with free pirfenidone, pirfenidone nanoparticles or vehicle. Corneal re-epithelialization was assessed daily by flourescein dye test; absence of stained area indicated complete re-epithelialization and the time for complete re-epithelialization was determined. Corneal haze was assessed daily for 7 days under slit lamp microscope and graded using a standard method. After 7 days, collagen I deposition in the superficial layer of cornea was examined by immunohistochemistry.Pirfenidone prevented (P<0.05 increase in TGF β induced collagen I and α-SMA synthesis by corneal fibroblasts in a dose dependent manner. Pirfenidone could be loaded successfully within PLGA nanoparticles, which entered the corneal fibroblasts within 5 minutes. Pirfenidone nanoparticles but not free pirfenidone significantly (P<0.05 reduced collagen I level, corneal haze and the time for corneal re-epithelialization following alkali burn.Pirfenidone decreases collagen synthesis and prevents myofibroblast formation. Pirfenidone nanoparticles improve corneal wound healing and prevent fibrosis. Pirfenidone nanoparticles are of potential value in treating corneal chemical burns and other corneal fibrotic diseases.

Corneal iron ring after hyperopic photorefractive keratectomy.

Science.gov (United States)

Bilgihan, K; Akata, F; Gürelik, G; Adigüzel, U; Akpinar, M; Hasanreisoğlu, B

1999-05-01

To report the incidence and course of corneal iron deposition after hyperopic photorefractive keratectomy (PRK). Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey. Between January 1995 and December 1997, 62 eyes had PRK to correct hyperopia. Nine eyes developed corneal iron ring 5 to 8 months (mean 6.25 months +/- 1.3 [SD]) after PRK for hyperopia. The rings persisted during the mean follow-up of 19 +/- 11.09 months. The ring-shaped iron deposition after PRK for hyperopia must be differentiated from the Fleischer ring. Our results suggest that the slitlamp findings of peripheral corneal iron deposition in hyperopic PRK patients correlate with achieved correction.

[The status quo and expectation of corneal research in China].

Science.gov (United States)

Shi, Weiyun; Xie, Lixin

2014-09-01

In China, corneal disease is currently the second leading cause of blindness. Severe donor shortage, insufficient technique supports and promotion, and the lack of corneal disease specialists due to poor systematic training are all urgent problems to be resolved. The last 5 years have witnessed a considerable progress in basic and clinical researches of corneal disease. Investigations on the pathogenesis and treatment of fungal keratitis have won an international reputation. Results from the study of corneal reconstruction with tissue-engineered and acellular matrix corneas have been tested in clinical trials with good preliminary performance. Moreover, the clinical researches of corneal refractive surgery have kept pace with the latest international progresses. However, Descemet's membrane endothelial keratoplasty needs further promotion, and the development and application of keratoprosthesis remains a blank. Although keratoprosthesis and corneal collagen cross-linking have been widely applied in Europe with satisfactory clinical efficacy, they are still under assessment by China Food and Drug Administration for approval of use.

Induction of Heat Shock Protein 70 Ameliorates Ultraviolet-Induced Photokeratitis in Mice

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Yukihiro Horie

2013-01-01

Full Text Available Acute ultraviolet (UV B exposure causes photokeratitis and induces apoptosis in corneal cells. Geranylgeranylacetone (GGA is an acyclic polyisoprenoid that induces expression of heat shock protein (HSP70, a soluble intracellular chaperone protein expressed in various tissues, protecting cells against stress conditions. We examined whether induction of HSP70 has therapeutic effects on UV-photokeratitis in mice. C57 BL/6 mice were divided into four groups, GGA-treated (500 mg/kg/mouse and UVB-exposed (400 mJ/cm2, GGA-untreated UVB-exposed (400 mJ/cm2, GGA-treated (500 mg/kg/mouse but not exposed and naive controls. Eyeballs were collected 24 h after irradiation, and corneas were stained with hematoxylin and eosin (H&E and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL. HSP70, reactive oxygen species (ROS production, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB and protein kinase B (Akt expression were also evaluated. Irradiated corneal epithelium was significantly thicker in the eyes of mice treated with GGA compared with those given the vehicle alone (p < 0.01. Significantly fewer TUNEL-positive cells were observed in the eyes of GGA-treated mice than controls after irradiation (p < 0.01. Corneal HSP70 levels were significantly elevated in corneas of mice treated with GGA (p < 0.05. ROS signal was not affected by GGA. NF-κB activation was reduced but phospho-(Ser/Ther Akt substrate expression was increased in corneas after irradiation when treated with GGA. GGA-treatment induced HSP70 expression and ameliorated UV-induced corneal damage through the reduced NF-κB activation and possibly increased Akt phosphorilation.

Corynebacterium macginleyi isolated from a corneal ulcer

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Kathryn Ruoff

2010-02-01

Full Text Available We report the isolation of Corynebacterium macginleyi from the corneal ulcer culture of a patient, later enrolled in the Steroids for Corneal Ulcer Trial (SCUT. To our knowledge this is the first published report from North America of the recovery of C. macginleyi from a serious ocular infection.

21 CFR 886.4070 - Powered corneal burr.

Science.gov (United States)

2010-04-01

...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4070 Powered corneal burr. (a) Identification. A powered corneal burr is an AC-powered or battery-powered device that is a motor and drilling tool intended to remove rust rings from the cornea of the eye. (b) Classification. Class I (general controls). When...

Genetic Ablation of Type III Adenylyl Cyclase Exerts Region-Specific Effects on Cilia Architecture in the Mouse Nose.

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Rosemary C Challis

Full Text Available We recently reported that olfactory sensory neurons in the dorsal zone of the mouse olfactory epithelium exhibit drastic location-dependent differences in cilia length. Furthermore, genetic ablation of type III adenylyl cyclase (ACIII, a key olfactory signaling protein and ubiquitous marker for primary cilia, disrupts the cilia length pattern and results in considerably shorter cilia, independent of odor-induced activity. Given the significant impact of ACIII on cilia length in the dorsal zone, we sought to further investigate the relationship between cilia length and ACIII level in various regions throughout the mouse olfactory epithelium. We employed whole-mount immunohistochemical staining to examine olfactory cilia morphology in phosphodiesterase (PDE 1C-/-;PDE4A-/- (simplified as PDEs-/- hereafter and ACIII-/- mice in which ACIII levels are reduced and ablated, respectively. As expected, PDEs-/- animals exhibit dramatically shorter cilia in the dorsal zone (i.e., where the cilia pattern is found, similar to our previous observation in ACIII-/- mice. Remarkably, in a region not included in our previous study, ACIII-/- animals (but not PDEs-/- mice have dramatically elongated, comet-shaped cilia, as opposed to characteristic star-shaped olfactory cilia. Here, we reveal that genetic ablation of ACIII has drastic, location-dependent effects on cilia architecture in the mouse nose. These results add a new dimension to our current understanding of olfactory cilia structure and regional organization of the olfactory epithelium. Together, these findings have significant implications for both cilia and sensory biology.

Comparative analysis of corneal morphological changes after transversal and torsional phacoemulsification through 2.2 mm corneal incision.

Science.gov (United States)

Assaf, Ahmed; Roshdy, Maged Maher

2013-01-01

This paper compares and evaluates the corneal morphological changes occurring after cataract surgery through a 2.2 mm corneal incision. We use two platforms for comparison and evaluation, transversal and torsional phacoemulsification. This study includes 139 consecutive cataractous eyes (nuclear color 2-4, according to the Lens Opacities Classification System III [LOCSIII]) of 82 patients undergoing cataract surgery through a 2.2 mm corneal incision. Two different phacoemulsification platforms were used and assigned randomly: we used the WhiteStar Signature(®) system with the Ellips™ FX transversal continuous ultrasound (US) mode for group I (mean age: 65.33 ± 6.97 years), and we used the Infiniti(®) system with the OZil(®) Intelligent Phaco (IP) torsional US mode for group II (mean age: 64.02 ± 7.55 years). The corneal endothelium and pachymetry were evaluated preoperatively and at 1 month postoperatively. Incision size changes were also evaluated. All surgeries were uneventful. Before intraocular lens implantation, the mean incision size was 2.24 ± 0.06 mm in both groups (P = 0.75). In terms of corneal endothelial cell density, neither preoperative (I vs II: 2304.1 ± 122.5 cell/mm(2) vs 2315.6 ± 83.1 cell/mm(2), P = 0.80) nor postoperative (I vs II: 2264.1 ± 124.3 cell/mm(2) vs 2270.3 ± 89.9 cell/mm(2), P = 0.98) differences between the groups were statistically significant. The mean endothelial cell density loss was 1.7% ± 1.6% and 2.0% ± 1.4% in groups I and II, respectively. Furthermore, no significant differences between groups I and II were found preoperatively (P = 0.40) and postoperatively (P = 0.68) in central pachymetry. With surgery, the mean increase in central pachymetry was 28.1 ± 23.6 μm and 24.0 ± 24.0 μm in groups I and II, respectively (P = 0.1). Ellips™ FX transversal and OZil(®) IP torsional phacoemulsification modes are safe for performing cataract surgery, inducing minimal corneal thickness and endothelial changes.

The Correlation Analysis between Corneal Biomechanical Properties and the Surgically Induced Corneal High-Order Aberrations after Small Incision Lenticule Extraction and Femtosecond Laser In Situ Keratomileusis

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Wenjing Wu

2015-01-01

Full Text Available Background. To investigate the correlation between corneal biomechanics and the surgically induced corneal high-order aberrations (HOAs after small incision lenticule extraction (SMILE and femtosecond laser in situ keratomileusis (FS-LASIK. Methods. A total of 150 right myopic eyes that underwent SMILE or FS-LASIK surgery were included in this retrospective study, 75 eyes in each group. The corneal hysteresis (CH and the corneal resistance factor (CRF with the corneal HOAs of the anterior, posterior, and total cornea were assessed preoperatively and three months postoperatively. Multivariate linear regression was applied to determine the correlations. Results. The preoperative CRF was significantly correlated with the induced 3rd–6th-order HOAs and spherical aberration of the anterior surface and the total cornea after SMILE and FS-LASIK surgeries (P<0.05, postoperatively. The CRF was significantly correlated with the induced vertical coma of the anterior and posterior surfaces and the total cornea after SMILE surgery (P<0.05. There was a significant correlation between the CRF and the induced posterior corneal horizontal coma after FS-LASIK surgery (P=0.013. Conclusions. The corneal biomechanics affect the surgically induced corneal HOAs after SMILE and FS-LASIK surgery, which may be meaningful for screening the patients preoperatively and optimizing the visual qualities postoperatively.

Corneal graft reversal: Histopathologic report of two cases

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Qahtani, Abdullah A.; Alkatan, Hind M.

2014-01-01

Graft reversal is a rare cause for failed PKP. In this case report we are presenting 2 graft failure cases in which the corneal grafts were reversed unintentionally. The onset of signs of graft failure, however was variable. We have included their clinical course and the histopathologic findings of the removed corneal grafts. A total of 6 cases including ours have been reported so far. The aim of this report is to attract the attention of corneal surgeons to an additional rare cause for faile...

Contact lens rehabilitation following repaired corneal perforations

Science.gov (United States)

Titiyal, Jeewan S; Sinha, Rajesh; Sharma, Namrata; Sreenivas, V; Vajpayee, Rasik B

2006-01-01

Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60%) required aphakic contact lenses. The best corrected visual acuity (BCVA) of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25%) eyes with spectacle correction and 37 (92.5%) eyes with the use of contact lens (p < 0.001). The best-corrected visual acuity with spectacles was 0.20 ± 0.13 while the same with contact lens was 0.58 ± 0.26. All the patients showed an improvement of ≥ 2 lines over spectacles in the snellen's acuity chart with contact lens. Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries. PMID:16536877

Indications for Corneal Transplantation at a Tertiary Referral Center in Tehran

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Mohammad Zare

2010-01-01

Full Text Available Purpose: To report the indications and techniques of corneal transplantation at a tertiary referral center in Tehran over a 3-year period. Methods: Records of patients who had undergone any kind of corneal transplantation at Labbafinejad Medical Center, Tehran, Iran from March 2004 to March 2007 were reviewed to determine the indications and types of corneal transplantation. Results: During this period, 776 eyes of 756 patients (including 504 male subjects with mean age of 41.3±21.3 years underwent corneal transplantation. The most common indication was keratoconus (n=317, 40.8% followed by bullous keratopathy (n=90, 11.6%, non-herpetic corneal scars (n=62, 8.0%, infectious corneal ulcers (n=61, 7.9%, previously failed grafts (n=61, 7.9%, endothelial and stromal corneal dystrophies (n=28, 3.6%, and trachoma keratopathy (n=26, 3.3%. Other indications including Terrien′s marginal degeneration, post-LASIK keratectasia, trauma, chemical burns, and peripheral ulcerative keratitis constituted the rest of cases. Techniques of corneal transplantation included penetrating keratoplasty (n=607, 78.2%, deep anterior lamellar keratoplasty (n=108, 13.9%, conventional lamellar keratoplasty (n=44, 5.7%, automated lamellar therapeutic keratoplasty (n=8, 1.0%, and Descemet stripping endothelial keratoplasty (n=6, 0.8% in descending order. The remaining cases were endothelial keratoplasty and sclerokeratoplasty. Conclusion: In this study, keratoconus was the most common indication for penetrating keratoplasty which was the most prevalent technique of corneal transplantation. However, deep anterior lamellar keratoplasty is emerging as a growing alternative for corneal pathologies not involving the endothelium.

Gene expression underlying enhanced, steroid-dependent auditory sensitivity of hair cell epithelium in a vocal fish.

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Fergus, Daniel J; Feng, Ni Y; Bass, Andrew H

2015-10-14

Successful animal communication depends on a receiver's ability to detect a sender's signal. Exemplars of adaptive sender-receiver coupling include acoustic communication, often important in the context of seasonal reproduction. During the reproductive summer season, both male and female midshipman fish (Porichthys notatus) exhibit similar increases in the steroid-dependent frequency sensitivity of the saccule, the main auditory division of the inner ear. This form of auditory plasticity enhances detection of the higher frequency components of the multi-harmonic, long-duration advertisement calls produced repetitively by males during summer nights of peak vocal and spawning activity. The molecular basis of this seasonal auditory plasticity has not been fully resolved. Here, we utilize an unbiased transcriptomic RNA sequencing approach to identify differentially expressed transcripts within the saccule's hair cell epithelium of reproductive summer and non-reproductive winter fish. We assembled 74,027 unique transcripts from our saccular epithelial sequence reads. Of these, 6.4 % and 3.0 % were upregulated in the reproductive and non-reproductive saccular epithelium, respectively. Gene ontology (GO) term enrichment analyses of the differentially expressed transcripts showed that the reproductive saccular epithelium was transcriptionally, translationally, and metabolically more active than the non-reproductive epithelium. Furthermore, the expression of a specific suite of candidate genes, including ion channels and components of steroid-signaling pathways, was upregulated in the reproductive compared to the non-reproductive saccular epithelium. We found reported auditory functions for 14 candidate genes upregulated in the reproductive midshipman saccular epithelium, 8 of which are enriched in mouse hair cells, validating their hair cell-specific functions across vertebrates. We identified a suite of differentially expressed genes belonging to neurotransmission and

Preparation of arginine–glycine–aspartic acid-modified biopolymeric nanoparticles containing epigalloccatechin-3-gallate for targeting vascular endothelial cells to inhibit corneal neovascularization