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Sample records for acute corneal hydrops

  1. Mechanisms for acute corneal hydrops and perforation.

    PubMed

    McMonnies, Charles W

    2014-07-01

    Acute corneal hydrops (ACH) and perforation in corneal thinning diseases are the consequences of exposure to distending intraocular pressure (IOP) forces that are in excess of corneal resistance to them. Apart from thinning, resistance to these forces may be reduced by disease-related tissue changes, such as corneal scarring, which could lower resistance to IOP. Eye rubbing trauma has sometimes been found to be associated with ACH and perforation. This association is not surprising given that the combination of rubbing-related mechanical tissue trauma and the associated increased distending stress of higher IOP seem likely to increase the risk of complications. Many cases of ACH and perforation are described as spontaneous, but this classification may be the consequence of not considering the multiple potential mechanisms for IOP elevation such as coughing, sneezing, nose blowing, and sneeze suppression in addition to those related to eye rubbing/wiping/massaging/touching as well as changes in body orientation, strenuous exercise, and wearing swimming goggles for example. Classification of ACH or perforation as spontaneous may lead patients to assume that nothing can be done to avoid these complications. Patients with corneal thinning diseases who are counseled regarding the potential precipitating mechanisms for IOP elevation will have the opportunity of reducing exposure to them and the risk of the associated complications. In addition, when ACH or perforation occur, faster resolution of edema and wound healing may depend on reducing potentially exacerbating exposures to mechanisms for IOP elevation. PMID:25390550

  2. Acute Corneal Hydrops 3 Years after Intra-corneal Ring Segments and Corneal Collagen Cross-linking

    PubMed Central

    Antonios, Rafic; Dirani, Ali; Fadlallah, Ali; Chelala, Elias; Hamadeh, Adib; Jarade, Elias

    2016-01-01

    This case report describes a 15-year-old male with allergic conjunctivitis and keratoconus, who underwent uneventful intra-corneal ring segment (ICRS) implantation and corneal collagen cross-linking (CXL) in the right eye. During the follow-up periods, the patient was noted to have several episodes of allergic conjunctivitis that were treated accordingly. At the 2 years postoperatively, he presented with another episode of allergic conjunctivitis and progression of keratoconus was suspected on topography. However, the patient was lost to follow-up, until he presented with acute hydrops at 3 years postoperatively. There are no reported cases of acute corneal hydrops in cross-linked corneas. We suspect the young age, allergic conjunctivitis and eye rubbing may be a risk factors associated with possible progression of keratoconus after CXL. Prolonged follow-up and aggressive control of the allergy might be necessary in similar cases. PMID:26957859

  3. Acute Corneal Hydrops in Children with Primary Infantile Glaucoma: A Report of 31 Cases over 23 Years at the LVPEI

    PubMed Central

    Mandal, Anil K.

    2016-01-01

    Purpose Relatively little data exist regarding the outcomes of children with primary infantile glaucoma presenting with acute corneal hydrops. The aim of our study was to determine the surgical outcome of children of infantile glaucoma who presented with acute corneal hydrops. Methods In total, 38 eyes of 31 consecutive children of infantile glaucoma presented with acute corneal hydrops who underwent primary combined trabeculotomy-trabeculectomy (CTT) by a single surgeon from January 1990 to December 2012 at the LV Prasad Eye Institute (LVPEI), a tertiary eye care centre in Southern India were enrolled in this retrospective study. Primary outcome measures were intraocular pressure (IOP) control (IOP ≤ 16 mmHg under anaesthesia or IOP ≤ 21 mmHg without anaesthesia) and clearance of corneal edema. Secondary outcome measures were visual acuity (VA), corneal diameter, bleb appearance, intraoperative and postoperative complications. Results Mean age at presentation was 6.4 months (range, 2–11 months) and seven eyes (23%) had bilateral affliction. At presentation, all eyes (100%) had moderate to severe degree of corneal edema with a mean preoperative IOP of 25.6 ±5.1 mmHg. Postoperatively, the IOP reduced to 12.0 ± 3.8 mmHg (difference = -13.6, 95% CI = -15.7 to -11.5, t = -13.18, p<0.0001), and the percentage reduction in IOP was 53.05%. Preoperatively 83% of the eyes were on antiglaucoma medication, and postoperatively 2 eyes (5.3%) required 1 antiglaucoma medication for control of IOP. Preoperatively, corneal edema was present in all eyes and postoperatively it cleared in all of them. Significant myopic astigmatism was present in 28 eyes (74%), the commonest being compound myopic astigmatism (75%) followed by simple myopic astigmatism (21%). Normal VA (best-corrected VA; BCVA ≥ 20/60) was achieved in 44.4% of the eyes and 22.2% eyes had low vision (BCVA, <20/60 to 20/400). Complete success (IOP control and clearance of corneal oedema) was obtained in 94

  4. Infectious keratitis with corneal perforation associated with corneal hydrops and contact lens wear in keratoconus.

    PubMed Central

    Donnenfeld, E D; Schrier, A; Perry, H D; Ingraham, H J; Lasonde, R; Epstein, A; Farber, B

    1996-01-01

    BACKGROUND: Corneal perforation is an uncommon complication associated with keratoconus. The first cases of infectious keratitis and corneal perforation associated with corneal hydrops and contact lens wear are reported in two keratoconus patients. METHODS: A retrospective chart review and histopathological examination were carried out. RESULTS: Both patients progressed to corneal perforation and emergency penetrating keratoplasty. One patient cultured Fusarium and the second patient Serratia marcesens. Both patients wore contact lenses against medical advice. CONCLUSIONS: The tear in Descement's membrane, stromal oedema, and epithelial bedewing associated with corneal hydrops results in loss of the epithelial-endothelial barrier of the cornea, creating a conduit for infectious organisms through the cornea. Acute hydrops associated with epithelial keratitis, stromal swelling, and a Descement's membrane tear may be a significant risk factor for infectious keratitis and corneal perforation. Contact lenses should not be worn during an active corneal hydrops owing to the increased risk for severe infectious keratitis and corneal perforation. Images PMID:8695560

  5. Corneal hydrops induced by diabetic ketoacidosis: A case report

    PubMed Central

    Feng, Meiyan; Wang, Chao

    2016-01-01

    To the best of our knowledge, there have been no reports of corneal hydrops associated with diabetic ketoacidosis. The present study first reports a case of a 20-year-old male patient with diabetic ketoacidosis-induced corneal hydrops. The patient exhibited mild hydrops in their left eyelid, which was accompanied by mixed hyperemia, and hazy turbid in a white color was observed in the cornea. To alleviate the corneal hydrops, 5% glucose was administered dropwise to the left eye for 2 h to alleviate the inflammation. Finally, the patient was discharged from the hospital with a satisfactory outcome. PMID:27602094

  6. "Christmas eye". Acute corneal erosion.

    PubMed

    Colvin, C S

    1979-12-15

    The term "Christmas eye" is one I have coined to describe a type of acute corneal erosion which seems to occur only between late November and mid January, in country areas of New South Wales. Since 1970, I have seen 20 cases, all monocular, in people from an area bounded by Wellington, Mudgee, Grenfell, Cowra and Young. Twelve patients were adult males, three were adult females, and there were five children (one female, four male). The incidence varies; six cases presented in 1976, and none in 1978.

  7. Changes in cochlear function during acute endolymphatic hydrops development in guinea pigs.

    PubMed

    Brown, Daniel J; Chihara, Yasuhiro; Curthoys, Ian S; Wang, Yuan; Bos, Marieke

    2013-02-01

    Previous studies have injected artificial endolymph into scala media in anaesthetized guinea pigs as an acute model of endolymphatic hydrops. Here, we have injected artificial endolymph into scala media in guinea pigs at rates of 40-80 nl/min, whilst monitoring Compound Action Potential (CAP) thresholds, the Summating Potential (SP)/CAP ratio, Cochlear Microphonic (CM) distortion, low-frequency modulated Distortion Product Otoacoustic Emissions (DPOAEs), and the Endocochlear Potential (EP). We found that abrupt recovery of CAP thresholds, SP/CAP ratio, and CM and DPOAE asymmetric distortion could occur several times during a single injection of less than 3 μl, suggesting that endolymph pressure could periodically decrease while the injection was ongoing. Larger volumes are thought to produce a rupture of the membranous labyrinth, however, our results suggest that multiple injections, each larger than 3 μl and within 40 min of each other, cause multiple pressure-related changes, which are difficult to be explained on the basis of a simple labyrinth rupture. We have also examined the morphological changes of the temporal bones ex vivo using X-ray micro-tomography. Both the functional changes and the micro-CT images suggest ruptures of the membranous labyrinth may not always be responsible for abrupt changes in inner ear function. Our results provide a new insight into the changes in cochlear function occurring during acute hydrops development, which compares well to the clinical findings observed in Ménière's Disease. We suggest that hydrops development may be a continual process, yet cause discontinuous functional changes due to mechanisms other than a simple rupture of the membranous labyrinth. PMID:23270618

  8. Lipopolysaccharide induced acute red eye and corneal ulcers.

    PubMed

    Schultz, C L; Morck, D W; McKay, S G; Olson, M E; Buret, A

    1997-01-01

    Using a new animal model, the aims of this study were to assess the role played by purified lipopolysaccharide (LPS) and neutrophils in the pathogenesis of acute red-eye reactions (ARE) and corneal ulcers. In addition, IL-1 alpha was assessed for its implications in the formation of corneal ulcers. Following corneal abrasion, eyes of rabbits underwent single or double exposures to various doses of LPS from Pseudomonas aeruginosa or Serratia marcescens. This protocol induced ARE symptoms, and their severity depended on the dosage, number of LPS exposures, and type of LPS used (LPS from S. marcescens showing highest virulence). Corneal ulcers were induced by delivering a high dose of Serratia LPS (100 micrograms) followed by a low dose (10 micrograms). Histopathological examination revealed that both ARE and corneal ulceration were associated with prominent neutrophil infiltration. In addition, many lymphocytes and other monocytic cells infiltrated ulcerated ocular tissue. Tear fluids obtained from ulcerated eyes contained high concentrations of a protein recognized by anti-rabbit IL-1 alpha antibodies as demonstrated by immunoblotting studies. The results indicate that LPS can induce ARE and corneal ulceration in the absence of any live bacteria. Moreover, the findings implicate the accumulation of neutrophils and IL-1 alpha-related proteins in the pathogenesis of ARE and corneal ulcers.

  9. Endolymph movement visualized with light sheet fluorescence microscopy in an acute hydrops model.

    PubMed

    Brown, Daniel J; Pastras, Christopher J; Curthoys, Ian S; Southwell, Cassandra S; Van Roon, Lieke

    2016-09-01

    There are a variety of techniques available to investigate endolymph dynamics, primarily seeking to understand the cause of endolymphatic hydrops. Here we have taken the novel approach of injecting, via a glass micropipette, fluorescein isothiocyanate-dextran (FITC-dex) and artificial endolymph into scala media of anaesthetized guinea pigs, with subsequent imaging of the inner ear using Light Sheet Fluorescence Microscopy (LSFM) as a means to obtain highly resolved 3D visualization of fluid movements. Our results demonstrate endolymph movement into the utricle, semicircular canals and endolymphatic duct and sac when more than 2.5 μl of fluid had been injected into scala media, with no apparent movement of fluid into the perilymphatic compartments. There was no movement of endolymph into these compartments when less than 2.5 μl was injected. The remarkable uptake of the FITC-dex into the endolymphatic duct, including an absorption into the periductal channels surrounding the endolymphatic duct, highlights the functional role this structure plays in endolymph volume regulation. PMID:27377233

  10. [Hydrops of the gallbladder and hepatitis associated with scarlet fever].

    PubMed

    Rocco, Roberto; Benedetti, Laura; Escudero, Gabriela; Jordán, Federico

    2010-03-01

    Hydrops of the gallbladder is a rare pediatric disease. It consists of acute distension of the gallbladder without associated congenital anomalies, biliary calculi or acute local inflammation. Although the etiology is unknown, it appears frequently associated with systemic illnesses. Hepatitis is a rare complication of scarlet fever in the pediatric population. We report a four years old girl with gallbladder hydrops and hepatitis associated to scarlet fever. To the best of our knowledge this is the first case report in the medical literature describing an association of these three conditions

  11. Observation on ultrastructure and histopathology of cornea following femtosecond laser-assisted deep lamellar keratoplasty for acute corneal alkaline burns

    PubMed Central

    Li, Wen-Jing; Hu, Yu-Kun; Song, Hui; Gao, Xiao-Wei; Zhao, Xu-Dong; Dong, Jing; Guo, Yun-Lin; Cai, Yan

    2016-01-01

    AIM To demonstrate the changes in ultrastructure and histopathology of the cornea in acute corneal alkaline burns after femtosecond laser-assisted deep lamellar keratoplasty. METHODS The New Zealand white rabbits treated with alkaline corneal burn were randomized into two groups, Group A (16 eyes) with femtosecond laser-assisted deep lamellar keratoplasty 24h after burn and Group B (16 eyes) without keratoplasty as controls. All eyes were evaluated with transmission electron microscopy (TEM) at 1, 2, 3, and 4wk follow-up, then all corneas were tested by hematoxylin and eosin staining histology. RESULTS The corneal grafts in Group A were transparent, while those in Group B showed corneal stromal edema and loosely arranged collagen fibers. One week after treatment, TEM revealed the intercellular desmosomes in the epithelial layers and intact non-dissolving nuclei in Group A. At week 4, the center of the corneas in Group A was transparent with regularly arranged collagen fibers and fibroblasts in the stroma. In Group B, squamous cells were observed on the corneal surface and some epithelial cells were detached. CONCLUSION Femtosecond laser-assisted deep lamellar keratoplasty can suppress inflammatory responses, prevent toxic substance-induced injury to the corneal endothelium and inner tissues with quicker recovery and better visual outcomes. PMID:27162716

  12. Establishment and Characterization of an Air-Liquid Canine Corneal Organ Culture Model To Study Acute Herpes Keratitis

    PubMed Central

    Harman, Rebecca M.; Bussche, Leen; Ledbetter, Eric C.

    2014-01-01

    ABSTRACT Despite the clinical importance of herpes simplex virus (HSV)-induced ocular disease, the underlying pathophysiology of the disease remains poorly understood, in part due to the lack of adequate virus–natural-host models in which to study the cellular and viral factors involved in acute corneal infection. We developed an air-liquid canine corneal organ culture model and evaluated its susceptibility to canine herpesvirus type 1 (CHV-1) in order to study ocular herpes in a physiologically relevant natural host model. Canine corneas were maintained in culture at an air-liquid interface for up to 25 days, and no degenerative changes were observed in the corneal epithelium during cultivation using histology for morphometric analyses, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assays, and transmission electron microscopy (TEM). Next, canine corneas were inoculated with CHV-1 for 48 h, and at that time point postinfection, viral plaques could be visualized in the corneal epithelium and viral DNA copies were detected in both the infected corneas and culture supernatants. In addition, we found that canine corneas produced proinflammatory cytokines in response to CHV-1 infection similarly to what has been described for HSV-1. This emphasizes the value of our model as a virus–natural-host model to study ocular herpesvirus infections. IMPORTANCE This study is the first to describe the establishment of an air-liquid canine corneal organ culture model as a useful model to study ocular herpesvirus infections. The advantages of this physiologically relevant model include the fact that (i) it provides a system in which ocular herpes can be studied in a virus–natural-host setting and (ii) it reduces the number of experimental animals needed. In addition, this long-term explant culture model may also facilitate research in other fields where noninfectious and infectious ocular diseases of dogs and humans are being studied. PMID

  13. Fetal hydrops and anemia as signs of Down syndrome.

    PubMed

    Sükür, Yavuz Emre; Gözüküçük, Murat; Bayramov, Vugar; Koç, Acar

    2011-11-01

    Before the 20th week of gestation, the most common cause of nonimmune hydrops fetalis is chromosomal abnormalities. Herein, we report a case of fetal hydrops, anemia, and intrauterine growth retardation that presented at 27 weeks of gestation with a negative chromosomal abnormality screening. Cordocentesis and karyotype analysis revealed fetal pancytopenia and Down syndrome. Down syndrome rarely presents with fetal hydrops and anemia. Therefore, when hydrops and anemia are diagnosed, especially in the second trimester of gestation, the possibility of Down syndrome should be kept in mind. In addition, if the pregnancy results in a live birth, the baby should be examined for transient abnormal myelopoiesis.

  14. Corneal dystrophies

    PubMed Central

    Klintworth, Gordon K

    2009-01-01

    The term corneal dystrophy embraces a heterogenous group of bilateral genetically determined non-inflammatory corneal diseases that are restricted to the cornea. The designation is imprecise but remains in vogue because of its clinical value. Clinically, the corneal dystrophies can be divided into three groups based on the sole or predominant anatomical location of the abnormalities. Some affect primarily the corneal epithelium and its basement membrane or Bowman layer and the superficial corneal stroma (anterior corneal dystrophies), the corneal stroma (stromal corneal dystrophies), or Descemet membrane and the corneal endothelium (posterior corneal dystrophies). Most corneal dystrophies have no systemic manifestations and present with variable shaped corneal opacities in a clear or cloudy cornea and they affect visual acuity to different degrees. Corneal dystrophies may have a simple autosomal dominant, autosomal recessive or X-linked recessive Mendelian mode of inheritance. Different corneal dystrophies are caused by mutations in the CHST6, KRT3, KRT12, PIP5K3, SLC4A11, TACSTD2, TGFBI, and UBIAD1 genes. Knowledge about the responsible genetic mutations responsible for these disorders has led to a better understanding of their basic defect and to molecular tests for their precise diagnosis. Genes for other corneal dystrophies have been mapped to specific chromosomal loci, but have not yet been identified. As clinical manifestations widely vary with the different entities, corneal dystrophies should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, particularly in both corneas, and especially in the presence of a positive family history or in the offspring of consanguineous parents. Main differential diagnoses include various causes of monoclonal gammopathy, lecithin-cholesterol-acyltransferase deficiency, Fabry disease, cystinosis, tyrosine transaminase deficiency, systemic lysosomal storage diseases (mucopolysaccharidoses

  15. Histomorphometric and proteomic analysis of the acute rabbit corneal tissue response following in vitro exposure to 1540-nm laser light

    NASA Astrophysics Data System (ADS)

    Eurell, Thomas E.; Johnson, Thomas E.; Roach, William P.

    2003-06-01

    In vitro exposures of explant rabbit corneas to single pulse 1540 nm infrared laser light operating at a pulse width of 0.8 milliseconds resulted in coagulative necrosis of both the corneal epithelium and stroma. Histomorphometric data correlated with increasing tissue radiant exposures. Histologic alterations in the corneal stroma were typical of matrix remodeling within the beam path and reactive to antibodies against matrix metalloproteinase-2. A two-dimensional electrophoretic analysis, using a mini-gel format, was developed to determine if specific corneal protein changes within tissue sections could be detected. Frozen sections taken through the center of the laser lesion were evaluated for proteomic data using tissue isoelectric focusing in the first dimension and polyacrylamide gel electrophoresis in the second dimension. Histomorphometric data describing the extent of the laser lesions were compared to the isoelectric points, molecular weights and relative densities of individual corneal proteins. Increasing radiant exposures of corneal tissues were associated with characteristic histomorphometric and proteomic changes.

  16. Diagnosis and management of cochlear hydrops.

    PubMed

    Glasscock, M E; Miller, G W

    1977-02-01

    In an early case of cochlear hydrops, the symptoms of a mild pressure sensation or fullness in the involved ear may be mistaken for a blocked eustachian tube. More severe cases demonstrate a true sensori-neutral hearing loss that fluctuates. Tinnitis is usually present during the attack and will often subside when the hearing returns to normal. The neurotologic evaluation is negative and attempts to establish an etiology are seldom fruitful. The treatment is usually medical, and empirically, these individuals are treated with diuretics, low salt diet, and vasodilators. It is felt by most investigators that cochlear hydrops is an early form of Ménière's disease, and over a long period of time these individuals may develop vertigo as a complaint. The purpose of this paper is to discuss this interesting form of Ménière's disease in detail concerning etiology, physiology, diagnosis, and treatment. A small series of patients who have undergone the subarachnoid endolymphatic sac procedure will be reported according to the guidelines set forth by the Committee on Hearing and Equilibrium of the American Academy of Ophthalmology and Otolaryngology. Based on the result in these patients, it would appear that this procedure should be considered in those individuals who are refractory to medical management. There is convincing evidence that the shunt does stabilize the hearing in many instances. PMID:839917

  17. A corneal scarring model.

    PubMed

    Gibson, Daniel J; Schultz, Gregory S

    2013-01-01

    Corneal opacification (i.e., haze) following a non-denaturing acute injury to the cornea is a process which takes about 5 days to manifest itself, indicating that it is the consequence of cellular and molecular biological processes. In order to obtain a better understanding of the haze development process, and to test candidate anti-haze therapies, we use a corneal scarring model whereby we create an excimer laser wound in the center of rabbit corneas. The primary data generated by this model are (1) changes in corneal thickness with time; (2) wound closure rates, or re-epithelialization; (3) changes in the location and density of corneal sub-epithelial haze; and (4) molecular and histological changes leading up to, during, and following the formation of haze. While the use of excimer lasers to generate consistent wounds in rabbit corneas is not a novel protocol for the study of corneal haze, the photographic technique presented here for the more objective recording and quantification of corneal haze is. At present, a qualitative, semiquantitative, grading system is employed whereby the amount of iris detail discernible through the scar is assigned a value between 0 and 4. Such a system makes direct comparisons amongst reported anti-haze trials nearly impossible. Furthermore, the additional "geographic" detail provided by the image provides a new layer of information about the formation of haze and the ability to troubleshoot dosing regimens. Altogether, with the information present herein, we believe that the study of corneal haze formation and the ability to compare and contrast candidate therapies are both greatly improved.

  18. Familial Hemophagocytic Lymphohistiocytosis Presenting as Hydrops Fetalis.

    PubMed

    Iwatani, Sota; Uemura, Kazuya; Mizobuchi, Masami; Yoshimoto, Seiji; Kawasaki, Keiichiro; Kosaka, Yoshiyuki; Hori, Masayuki; Yasumi, Takahiro; Nakao, Hideto

    2015-04-01

    Background Familial hemophagocytic lymphohistiocytosis (FLH) is an autosomal recessive disorder of immune regulation that leads to a hyperinflammatory syndrome. Fetal onset FHL is extremely rare and is considered to be the most severe form of FHL. Case We report a preterm case of FHL that presented as hydrops fetalis. The infant was treated with a chemotherapy regimen based on the HLH-2004 protocol from the third day of life. However, he had persistent cytopenia and died on the 18th day of life due to bacteremia. The detection of defective perforin expression in the patient's natural killer cells and mutations in the PRF1 gene resulted in a molecular diagnosis of FHL. Conclusion We suggest that early diagnosis and the development of an appropriate immunosuppressive strategy that can induce and maintain remission until hematopoietic stem cell transplantation can be performed are required to improve the outcomes of fetal onset FHL. PMID:26199792

  19. Familial Hemophagocytic Lymphohistiocytosis Presenting as Hydrops Fetalis.

    PubMed

    Iwatani, Sota; Uemura, Kazuya; Mizobuchi, Masami; Yoshimoto, Seiji; Kawasaki, Keiichiro; Kosaka, Yoshiyuki; Hori, Masayuki; Yasumi, Takahiro; Nakao, Hideto

    2015-04-01

    Background Familial hemophagocytic lymphohistiocytosis (FLH) is an autosomal recessive disorder of immune regulation that leads to a hyperinflammatory syndrome. Fetal onset FHL is extremely rare and is considered to be the most severe form of FHL. Case We report a preterm case of FHL that presented as hydrops fetalis. The infant was treated with a chemotherapy regimen based on the HLH-2004 protocol from the third day of life. However, he had persistent cytopenia and died on the 18th day of life due to bacteremia. The detection of defective perforin expression in the patient's natural killer cells and mutations in the PRF1 gene resulted in a molecular diagnosis of FHL. Conclusion We suggest that early diagnosis and the development of an appropriate immunosuppressive strategy that can induce and maintain remission until hematopoietic stem cell transplantation can be performed are required to improve the outcomes of fetal onset FHL.

  20. Corneal Laceration

    MedlinePlus

    ... 30, 2016 Toddlers Most at Risk of Chemical Burns to Eyes Aug 26, 2016 Corneal Collagen Cross-linking Approved to Treat Keratoconus in ... Public & Patients: Contact Us About the Academy Jobs at the ...

  1. Corneal injury

    MedlinePlus

    ... as sand or dust Ultraviolet injuries: Caused by sunlight, sun lamps, snow or water reflections, or arc- ... a corneal injury if you: Are exposed to sunlight or artificial ultraviolet light for long periods of ...

  2. Corneal holder.

    PubMed

    Slappey, T E

    1975-09-01

    As a result of the widespread use of M-K (McCarey-Kaufman) medium preserved corneas, as well as other methods of preserving corneas in a viable state, I developed a corneal holder to facilitate the lamellar dissection of previously excised whole human corneas. Consisting of a moderately heavy base, cutting pedestal, scleral rim-sealing sleeve, and retaining ring, the corneal holder is economically manufactured, simple to use, and easily sterilized. Its weight and construction allow unassisted dissection of a lamellar graft of any size.

  3. Corneal thickness in glaucoma.

    PubMed

    De Cevallos, E; Dohlman, C H; Reinhart, W J

    1976-02-01

    The central corneal stromal thickness of patients with open angle glaucoma, secondary glaucoma (the majority aphakic), or a history of unilateral acute angle closure glaucoma were measured and compared with the stromal thickness of a group of normal patients. In open angle glaucoma, there was a small but significant increase in the average stromal thickness. This thickness increase was, in all likelihood, due to an abnormal function of the endothelium in this disease since the level of the intraocular pressure did not seem to be a factor. There was no correlation between stromal thickness and duration of the glaucoma or type of anti-glaucomatous medication. Most cases of secondary glaucome, controlled medically or not, had markedly increased corneal thickness, again, most likely, due to endothelial damage rather than to level of intraocular pressure. After an angle closure attack, permanent damage to the cornea was found to be rare. PMID:1247273

  4. [Changes of audio-vestibular parameters in experimental endolymphatic hydrops].

    PubMed

    Zhang, S Z

    1993-01-01

    Endolymphatic hydrops were produced in twenty guinea pigs by obliteration of the endolymphatic sac. Auditory and vestibular functions were investigated before and after the obliteration. Our experimental data showed that: 1) the SPVN (sinusoidal pendular vestibular nystagmus) frequency decreased after the obliteration of the lymphatic sac; 2) the CAP response threshold to filtered clicks and the CAP response threshold to clicks were both elevated after obliteration of the endolymphatic sac; and 3) 2f1-f2 DPO (distortion product otoacoustic emissions) amplitudes, as induced by primary tones of adequate frequency and level rations, decreased as endolymphatic hydrops occurred. PMID:8192928

  5. Nonimmunologic hydrops fetalis. A study of ten cases.

    PubMed

    Moerman, P; Fryns, J P; Goddeeris, P; Lauweryns, J M

    1982-11-01

    Ten cases of hydrops fetalis not associated with serologic incompatibility between mother and infant were studied by autopsy. Classic trisomy 21 was present in two, and in six others the postmortem examination revealed major congenital abnormalities (hydrometrocolpos-polydactyly syndrome, achondrogenesis type 2, congenital adenomatoid malformation of the lung, and aortic valvular dysplasia with left ventricular endocardial fibroelastosis). In two instances, anasarca was associated with a congenital tumor: a sacrococcygeal teratoma and an adrenal neuroblastoma. In six fetuses, prenatal diagnosis of hydrops fetalis or severe congenital malformations was established by ultrasonography. PMID:6897172

  6. Multiple marker screening test: identification of fetal cystic hygroma, hydrops, and sex chromosome aneuploidy.

    PubMed

    Wenstrom, K D; Boots, L R; Cosper, P C

    1996-01-01

    The goal of this study was to determine if the multiple marker screening test (maternal serum alpha-fetoprotein, unconjugated estriol, human chorionic gonadotrophin, and maternal age) detects fetal Turner syndrome or just cystic hygroma/hydrops. Multiple marker screening tests from 4 groups were compared: 1) Turner syndrome with hydrops/ hygroma group (n = 10) = fetuses with cystic hygroma/hydrops and a 45X karyotype, 2) Turner syndrome without hydrops/hygroma (n = 9) = sonographically unremarkable fetal Turner syndrome or Turner mosaic, 3) hydrops group (n = 8) = all cases of fetal cystic hygroma/hydrops excluding Turner syndrome, 4) sex chromosome aneuploidy group (n = 16) = other sonographically normal fetal sex chromosome aneuploidies. Positive screening tests (Down syndrome risk > or = 1:190 or MSAFP > or = 2.5 MOM) were found in 60% (6/10) of the Turner syndrome with hydrops/hygroma group, but only 11% (1/9) of the Turner syndrome without hydrops/hygroma group (P = .04). The incidence of positive screening tests in the Hydrops group was 75% (6/8), while it was only 12.5% (2/16) in the other sex chromosome aneuploidy group. We conclude that the multiple marker screening test identifies fetuses with cystic hygroma/hydrops, and may do so independently of the etiology of the hydrops. PMID:8796763

  7. Before the horse is out of the barn: fetal surgery for hydrops.

    PubMed

    Bullard, K M; Harrison, M R

    1995-12-01

    Hydrops fetalis, a condition characterized by abnormal accumulation of fluid and edema in the fetus, is the final common pathway in a number of pathological conditions. The diagnosis of hydrops is based on ultrasonographic findings of generalized edema along with a serous effusion (ascites, pleural effusion, or pericardial effusion). Polyhydramnios and placentomegaly may also be present. Historically, hydrops fetalis has been described in cases of Rh alloimmunization and severe erythroblastosis (immune hydrops). Hydrops is considered "nonimmune" if there is no evidence of fetal-maternal blood group incompatibility. Over the past few decades, nonimmune hydrops has been recognized more frequently. In a number of series, 80% to 90% of hydropic fetuses were considered nonimmune. Incidence ranges from 1 in 1,500 to 1 in 3,800 births. Etiology is diverse and associated conditions include cardiovascular malformations, chromosomal abnormalities, thoracic lesions, infections, metabolic disorders, fetal anemia and twinning. Overall prognosis is poor, with mortality between 50% and 98%. Advances in obstetric ultrasound and prenatal diagnosis have made it possible to diagnose a number of congenital anomalies early in gestation. In some cases, anatomic anomalies diagnosed in utero progress to nonimmune hydrops and almost certain fetal demise. It is these conditions that can be considered for fetal surgical intervention. This article reviews the pathophysiology and rationale behind surgical correction of two conditions that lead to hydrops: fetal thoracic lesions (congenital cystic adenomatoid malformation, pulmonary sequestration, and fetal pleural effusions) and sacrococcygeal teratoma (SCT). PMID:8822330

  8. [Pediatric corneal surgery and corneal transplantation].

    PubMed

    Bachmann, B; Avgitidou, G; Siebelmann, S; Cursiefen, C

    2015-02-01

    The surgical treatment of congenital corneal diseases or corneal diseases occurring during infancy is demanding even for experienced corneal surgeons. Besides the need for frequent examinations under anesthesia during the postoperative follow-up in young children and infants (e.g. after corneal transplantation), the surgeon frequently encounters intraoperative and postoperative problems, such as low scleral rigidity, positive vitreous pressure and a narrow anterior chamber. Other problems include increased fibrin reaction, an increased risk of rejection in cases of allogenic corneal transplantation and frequent loosening of sutures necessitating replacement or early removal. Lamellar corneal transplantation reduces the risk of graft rejection and the risk of wound leakage. Moreover, posterior lamellar keratoplasty in children offers a faster visual recovery compared to penetrating keratoplasty and thus reduces the risk of amblyopia.

  9. Corneal Foreign Body

    MedlinePlus

    ... Care Guidelines As with corneal abrasions and recurrent erosion of the cornea, self-care includes: Never rubbing ... can be found about corneal abrasions and recurrent erosion of the cornea in their respective diagnoses. When ...

  10. Corneal transplant - series (image)

    MedlinePlus

    Corneal transplantation is recommended for: severe corneal infection, injury, damage, or scarring corneas that no longer allow light to pass through (opaque), often secondary to lens surgery (see cataract surgery), infections, and inherited diseases ...

  11. Pseudomonas corneal ulcer. The causative role of contaminated eye cosmetics.

    PubMed

    Reid, F R; Wood, T O

    1979-09-01

    The clinical significance of contaminated ocular cosmetics is illustrated by the case of a 47-year-old woman in whom a Pseudomonas corneal ulcer developed immediately after she sustained minor corneal trauma with a mascara applicator. Pseudomonas aeruginosa was cultured from the corneal ulcer and the mascara. In addition to the causative role in acute corneal ulcers, contaminated eye cosmetics contribute to chronic external eye infections. Retail eye cosmetics are typically free of contamination when purchased. The inoculation of the cosmetic occurs during normal use. PMID:112953

  12. Congenital neonatal chylothorax with hydrops fetalis treated with octreotide

    PubMed Central

    Dammas, Ali Saed

    2013-01-01

    Congenital idiopathic chylothorax is the most common form of pleural effusion in neonates. It results from collection of lymphatic fluid in the pleural space secondary to leakage from the thoracic duct or one of its main tributaries. Chylothorax complicated by hydrops fetalis in a premature or term infant is an uncommon, serious clinical problem. We report on two cases with congenital chylothorax both treated with octreotide. One of the cases responded well to octreotide treatment, while the other did not. We conclude that octreotide should be considered in the treatment of neonatal chylothorax. PMID:27493357

  13. Morphometric comparison of the acute rabbit corneal response to 1540-nm laser light following in-vitro exposure to millisecond or nanosecond pulse widths

    NASA Astrophysics Data System (ADS)

    Eurell, Thomas E.; Johnson, Thomas E.; Roach, William P.

    2002-06-01

    Significant damage to rabbit corneal tissue was produced by a single pulse, in vitro exposure of 1540 m infrared laser light operating in either millisecond or nanosecond pulse widths. Millisecond pulse widths of infrared laser light produced a marked coagulative necrosis of both the corneal epithelium and stroma. We also noted histologic alterations in the stromal matrix within the beam path that we interpreted as matrix remodeling. To test this interpretation, we used an indirect immunohistochemical procedure to detect Matrix Metalloproteinase-2 (MMP-2) activity. Immunohistochemistry revealed that the MMP-2 reaction was mostly limited to the margins of the beam path. In addition, the MMP-2 reaction was less intense than expected given the significant tissue changes observed in the histologic sections. Exposure of rabbit corneal tissue to the nanosecond pulse widths produced a less severe coagulative necrosis of the tissue when compared to the millisecond exposures. However, a markedly stronger immunohistochemical pattern than would have been predicted from the histologic sections was observed, with approximately half of the beam path filled with MMP-2 reaction product. These data suggest an association between infrared laser pulse width and the degree of extracellular matrix remodeling in rabbit corneal tissue.

  14. Corneal mucus plaques.

    PubMed

    Fraunfelder, F T; Wright, P; Tripathi, R C

    1977-02-01

    Corneal mucus plaques adhered to the anterior corneal surface in 17 of 67 advanced cases of keratoconjunctivitis sicca. The plaques were translucent to opaque and varied in size and shape, from multiple isolated islands to bizarre patterns involving more than half the corneal surface. Ultrastructurally, they consisted of mucus mixed with desquamated degenerating epithelial cells and proteinaceous and lipoidal material. The condition may be symptomatic but can be controlled and prevented in most cases by topical ocular application of 10% acetylcysteine.

  15. Characterization of Corneal Indentation Hysteresis.

    PubMed

    Ko, Match W L; Dongming Wei; Leung, Christopher K S

    2015-01-01

    Corneal indentation is adapted for the design and development of a characterization method for corneal hysteresis behavior - Corneal Indentation Hysteresis (CIH). Fourteen porcine eyes were tested using the corneal indentation method. The CIH measured in enucleated porcine eyes showed indentation rate and intraocular pressure (IOP) dependences. The CIH increased with indentation rate at lower IOP (<; 25 mmHg) and decreased with indentation rate at higher IOP (> 25 mmHg). The CIH was linear proportional to the IOP within an individual eye. The CIH was positively correlated with the IOP, corneal in-plane tensile stress and corneal tangent modulus (E). A new method based on corneal indentation for the measurement of Corneal Indentation Hysteresis in vivo is developed. To our knowledge, this is the first study to introduce the corneal indentation hysteresis and correlate the corneal indentation hysteresis and corneal tangent modulus.

  16. Corneal ulceration following measles in Nigerian children.

    PubMed Central

    Sandford-Smith, J H; Whittle, H C

    1979-01-01

    Acute corneal ulceration in malnourished children is the commonest cause of childhood blindness in Northern Nigeria and usually develops after measles. Other severe diseases in malnourished children rarely precipitate corneal ulceration. A survey in a school for blind children showed that 69% of the children were blind from corneal disease, and a survey of children with corneal scars showed that at least 42% were caused by ulceration after measles. The clinical appearance of the active ulcers was very varied. The serum retinol-binding protein and prealbumin levels in children with corneal ulcers following measles were below normal, but a group of malnourished children without eye complaints following measles were found to have even lower levels. Thus a specific deficiency of vitamin A does not appear to be the primary cause of these ulcers, though it may be a contributory one. A specific measles keratitis and secondary herpes simplex infectious may be local factors contributing to this ulceration, and there is nearly always a background of protein calorie malnutrition. Racial factors may also be of some significance. PMID:508686

  17. Corneal cells for regeneration.

    PubMed

    Kinoshita, S; Nakamura, T

    2005-01-01

    In cases of corneal epithelial stem cell deficiency where ocular surface reconstruction is required, corneal epithelial replacement using a tissue engineering technique shows great potential. Autologous cultivated corneal epithelial stem cell sheets are the safest and most reliable forms of sheet we can use for such treatment; however, they are not useful for treating bilaterally affected ocular surface disorders. In order to treat such cases, we must choose either an allogeneic cultivated corneal epithelial sheet or an autologous cultivated oral mucosal epithelial sheet. If we use the former, the threat of immunological reaction must be dealt with. Therefore, it is imperative that we have a basic understanding of the immunological aspects of ocular surface reconstruction using allogeneic tissues. When using an autologous cultivated oral mucosal epithelial sheet, a basic understanding of ocular surface epithelial biology is required as the sheet is not exactly the same as corneal epithelium. PMID:16080287

  18. Corneal-shaping electrode

    DOEpatents

    Doss, James D.; Hutson, Richard L.

    1982-01-01

    The disclosure relates to a circulating saline electrode for changing corneal shape in eyes. The electrode comprises a tubular nonconductive electrode housing having an annular expanded base which has a surface substantially matched to a subject corneal surface. A tubular conductive electrode connected to a radiofrequency generating source is disposed within the electrode housing and longitudinally aligned therewith. The electrode has a generally hemispherical head having at least one orifice. Saline solution is circulated through the apparatus and over the cornea to cool the corneal surface while radiofrequency electric current emitted from the electrode flows therefrom through the cornea to a second electrode, on the rear of the head. This current heats the deep corneal stroma and thereby effects corneal reshaping as a biological response to the heat.

  19. Current status of corneal xenotransplantation.

    PubMed

    Kim, Mee Kum; Hara, Hidetaka

    2015-11-01

    Corneal allo-transplantation is a well-established technique to treat corneal blindness. However, the limited availability of human donors demands the exploration of alternative treatments such as corneal xenotransplantation (e.g., pigs as donors) and bioengineered corneas. Since the first attempt of corneal xenotransplantation using a donor pig cornea in 1844, great advances have been made in the development of genetically-engineered pigs, effective immunosuppressive protocols and the establishment of guidelines for the conduction of clinical trials. We highlight immunological and physio-anatomical barriers of corneal xenotransplantation, recent progress of corneal xenotransplantation in non-human-primates studies, and regulatory guidelines to conduct clinical trials for corneal xenotransplantation.

  20. Hypertonic saline in the treatment of corneal jellyfish stings.

    PubMed

    Yu Yao, Hsin; Cho, Ta Hsiung; Lu, Ching Hsiang; Lin, Feng Chi; Horng, Chi Ting

    2016-02-01

    A 20-year-old male soldier was hit by the jellyfish. The ophthalmic examination revealed that epithelial keratitis and corneal oedema in the right eye. We prescribed 3% NaCl eyedrops and 0.3% Norfloxacin eyedrops in the treatment of the corneal jellyfish stings. Two weeks later, the cornea in the right eye healed. In this case report, 3% NaCl eyedrops was effective in the treatment of acute phase of jellyfish stings of the cornea. PMID:26883926

  1. [Glaucoma and corneal transplantation].

    PubMed

    Geerling, G; Müller, M; Zierhut, M; Klink, T

    2010-05-01

    Glaucoma and corneal disorders are often associated and are of diagnostic, therapeutic and prognostic relevance for each other. Glaucoma is already present in approximately 15% of eyes prior to keratoplasty, whereas in addition approximately 15% of cases are diagnosed following corneal transplantation. Corneal opacities, surface irregularities and pachymetric deviations from the norm can have a negative impact on tonometry, perimetry and morphological glaucoma diagnosis. Digital and intracameral tonometry as well as flash VEP to determine the visual potential can be helpful in this setting. Increased intraocular pressure (IOP), long-term application of antiglaucomatous medication or the use of antimetabolites in glaucoma surgery can all induce keratopathy. Therefore, intraocular pressure should be regulated prior to corneal transplantation. Risk factors for the evolution of glaucoma following corneal transplantation are the specific indication and surgical technique (e. g. combined corneal and cataract/vitreoretinal surgery), as well as postoperative steroid application and chamber angle synechiae. Unpreserved glaucoma medication without pro-inflammatory effects should be preferred following keratoplasty. In the long term surgery to control IOP is required in approximately 25% of eyes. The wider use of lamellar techniques for corneal transplantation is likely to reduce the incidence of secondary glaucoma.

  2. Corneal blindness and xenotransplantation.

    PubMed

    Lamm, Vladimir; Hara, Hidetaka; Mammen, Alex; Dhaliwal, Deepinder; Cooper, David K C

    2014-01-01

    Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

  3. Corneal blindness and xenotransplantation.

    PubMed

    Lamm, Vladimir; Hara, Hidetaka; Mammen, Alex; Dhaliwal, Deepinder; Cooper, David K C

    2014-01-01

    Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future. PMID:25268248

  4. [Updates in corneal transplantation].

    PubMed

    Rémont, L; Duchesne, B; La, C; Rakic, J M; Hick, S

    2014-09-01

    Corneal transplantation or keratoplasty has rapidly developed over the last 10 years. Penetrating keratoplasty, a well-known operation consisting of full thickness replacement of the cornea, has remained the dominant procedure for a long time. It allows appropriate therapy of most causes of corneal blindness. However, this technique is currently evolving toward slamellar keratoplasties which selectively treat the specific affected layers: deep anterior lamellar keratoplasty replaces the diseased corneal stromal layers; endothelial keratoplasty replace the affected endothelium. This article will present these techniques, and briefly discuss their advantages.

  5. Importance of Corneal Thickness

    MedlinePlus

    ... News About Us Donate In This Section The Importance of Corneal Thickness email Send this article to ... is important because it can mask an accurate reading of eye pressure, causing doctors to treat you ...

  6. Effects of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell counts

    PubMed Central

    Gao, Feng; Lin, Tao; Pan, Yingzhe

    2016-01-01

    Diabetic keratopathy is an ocular complication that occurs with diabetes. In the present study, the effect of diabetic keratopathy on corneal optical density, central corneal thickness, and corneal endothelial cell count was investigated. One hundred and eighty diabetic patients (360 eyes) were enrolled in the study during the period from March, 2012 to March, 2013. The patients were divided into three age groups: <5, 5–10 and >10 years, with 60 patients per group (120 eyes). During the same period, 60 healthy cases (120 eyes) were selected and labeled as the normal control group. The Pentacam was used to measure the corneal optical density, and central corneal thickness. Specular microscopy was used to examine the corneal endothelial cell density. The coefficient of partial correlation was used to control age and correlate the analysis between the corneal optical density, corneal endothelial cell density, and central corneal thickness. The stage of the disease, the medial and intimal corneal optical density and central corneal thickness was analyzed in the diabetes group. The corneal optical density in the diabetes group increased compared with that of the normal control group. The medial and intimal corneal optical density and central corneal thickness were positively correlated with the course of the disease. However, the corneal endothelial cell density was not associated with the course of diabetes. There was a positive association between the medial and intimal corneal optical density and central corneal thickness of the diabetic patients. In conclusion, the results of the present study show that medial and intimal corneal optical density and central corneal thickness were sensitive indicators for early diabetic keratopathy. PMID:27588090

  7. Recurrent fatal hydrops fetalis associated with a nucleotide substitution in the erythrocyte beta-spectrin gene.

    PubMed Central

    Gallagher, P G; Weed, S A; Tse, W T; Benoit, L; Morrow, J S; Marchesi, S L; Mohandas, N; Forget, B G

    1995-01-01

    We studied a kindred in which four third-trimester fetal losses occurred, associated with severe Coombs-negative hemolytic anemia and hydrops fetalis. Postmortem examination of two infants revealed extensive extramedullary erythropoiesis. Studies of erythrocytes and erythrocyte membranes from the parents revealed abnormal erythrocyte membrane mechanical stability as well as structural and functional abnormalities in spectrin, the principal structural protein of the erythrocyte membrane. Genetic studies identified a point mutation of the beta-spectrin gene, S2019P, in a region of beta spectrin that is critical for normal spectrin function. Both parents and two living children were heterozygous for this mutation; three infants dying of hydrops fetalis were homozygous for this mutation. In an in vitro assay using recombinant peptides, the mutant beta-spectrin peptide demonstrated a significant abnormality in its ability to interact with alpha spectrin. This is the first description of a molecular defect of the erythrocyte membrane associated with hydrops fetalis. Images PMID:7883966

  8. Hydrops uteri in a caprine doe pregnant with goat-sheep hybrid fetuses.

    PubMed

    Jones, S L; Fecteau, G

    1995-06-15

    A 5-year-old caprine doe was examined for abdominal enlargement and inability to stand. Hydrops uteri was diagnosed via ultrasonography, and was determined to be the cause of hind limb paresis. The placentomes appeared to be abnormal in shape and number. Uterine fluid electrolyte concentrations were similar to fluid from cows and sheep with hydrops amnion. Two fetuses were dead at the time of induced parturition. Hydrops uteri is rare in goats and, in the goat of this report, was believed to be caused by pregnancy with an unusual goat-sheep hybrid. The placental abnormalities discovered by ultrasonography may have been responsible for the abnormal accumulation of fluid, but a fetal abnormality also was considered to be possible. PMID:7790309

  9. Corneal steepening after epikeratoplasty.

    PubMed

    Nirankari, V S

    1989-12-01

    Four patients had removal of their epikeratoplasty lenticules for unsatisfactory visual results. This was out of a consecutive series of 36 eyes. Three eyes were myopic and one was aphakic. In all four eyes, there was significant corneal steepening with an average increase in myopia of 2.4 diopters and an average increase in keratometry reading of 4.8 diopters. Corneoscopy was done in three cases and showed central corneal steepening. In addition, one patient (Case 1) had significant scarring of the recipient cornea and a decrease in visual acuity to 20/100. The reasons for corneal steepening may be related to midperipheral partial trephination, annular keratectomy, and spreading of the peripheral cornea.

  10. Placental transmission of human parvovirus 4 in newborns with hydrops, Taiwan.

    PubMed

    Chen, Mao-Yuan; Yang, Shiu-Ju; Hung, Chien-Ching

    2011-10-01

    In studying the epidemiology of parvovirus 4 (PARV4) in Taiwan, we detected DNA in plasma of 3 mothers and their newborns with hydrops. In 1 additional case, only the mother had PARV4 DNA. Our findings demonstrate that PARV4 can be transmitted through the placenta.

  11. EPHB4 kinase-inactivating mutations cause autosomal dominant lymphatic-related hydrops fetalis.

    PubMed

    Martin-Almedina, Silvia; Martinez-Corral, Ines; Holdhus, Rita; Vicente, Andres; Fotiou, Elisavet; Lin, Shin; Petersen, Kjell; Simpson, Michael A; Hoischen, Alexander; Gilissen, Christian; Jeffery, Heather; Atton, Giles; Karapouliou, Christina; Brice, Glen; Gordon, Kristiana; Wiseman, John W; Wedin, Marianne; Rockson, Stanley G; Jeffery, Steve; Mortimer, Peter S; Snyder, Michael P; Berland, Siren; Mansour, Sahar; Makinen, Taija; Ostergaard, Pia

    2016-08-01

    Hydrops fetalis describes fluid accumulation in at least 2 fetal compartments, including abdominal cavities, pleura, and pericardium, or in body tissue. The majority of hydrops fetalis cases are nonimmune conditions that present with generalized edema of the fetus, and approximately 15% of these nonimmune cases result from a lymphatic abnormality. Here, we have identified an autosomal dominant, inherited form of lymphatic-related (nonimmune) hydrops fetalis (LRHF). Independent exome sequencing projects on 2 families with a history of in utero and neonatal deaths associated with nonimmune hydrops fetalis uncovered 2 heterozygous missense variants in the gene encoding Eph receptor B4 (EPHB4). Biochemical analysis determined that the mutant EPHB4 proteins are devoid of tyrosine kinase activity, indicating that loss of EPHB4 signaling contributes to LRHF pathogenesis. Further, inactivation of Ephb4 in lymphatic endothelial cells of developing mouse embryos led to defective lymphovenous valve formation and consequent subcutaneous edema. Together, these findings identify EPHB4 as a critical regulator of early lymphatic vascular development and demonstrate that mutations in the gene can cause an autosomal dominant form of LRHF that is associated with a high mortality rate. PMID:27400125

  12. EPHB4 kinase–inactivating mutations cause autosomal dominant lymphatic-related hydrops fetalis

    PubMed Central

    Martin-Almedina, Silvia; Holdhus, Rita; Vicente, Andres; Fotiou, Elisavet; Lin, Shin; Petersen, Kjell; Simpson, Michael A.; Hoischen, Alexander; Atton, Giles; Karapouliou, Christina; Brice, Glen; Gordon, Kristiana; Wiseman, John W.; Wedin, Marianne; Rockson, Stanley G.; Jeffery, Steve; Mortimer, Peter S.; Snyder, Michael P.; Berland, Siren; Mansour, Sahar; Makinen, Taija

    2016-01-01

    Hydrops fetalis describes fluid accumulation in at least 2 fetal compartments, including abdominal cavities, pleura, and pericardium, or in body tissue. The majority of hydrops fetalis cases are nonimmune conditions that present with generalized edema of the fetus, and approximately 15% of these nonimmune cases result from a lymphatic abnormality. Here, we have identified an autosomal dominant, inherited form of lymphatic-related (nonimmune) hydrops fetalis (LRHF). Independent exome sequencing projects on 2 families with a history of in utero and neonatal deaths associated with nonimmune hydrops fetalis uncovered 2 heterozygous missense variants in the gene encoding Eph receptor B4 (EPHB4). Biochemical analysis determined that the mutant EPHB4 proteins are devoid of tyrosine kinase activity, indicating that loss of EPHB4 signaling contributes to LRHF pathogenesis. Further, inactivation of Ephb4 in lymphatic endothelial cells of developing mouse embryos led to defective lymphovenous valve formation and consequent subcutaneous edema. Together, these findings identify EPHB4 as a critical regulator of early lymphatic vascular development and demonstrate that mutations in the gene can cause an autosomal dominant form of LRHF that is associated with a high mortality rate. PMID:27400125

  13. Investigation and management of non-immune fetal hydrops.

    PubMed

    Désilets, Valérie; Audibert, François

    2013-10-01

    Objectif : Décrire les moyens actuels de procéder à l’exploration et à la prise en charge de l’anasarque fœtoplacentaire non immune, en mettant l’accent sur les étiologies traitables ou récurrentes. Issues : Offrir de meilleurs services de counseling et de prise en charge en présence de cas d’anasarque non immune identifiés par diagnostic prénatal. Résultats : La littérature publiée a été récupérée par l’intermédiaire de recherches menées dans PubMed, CINAHL et The Cochrane Library en 2011 au moyen de mots clés (« non-immune hydrops fetalis », « fetal hydrops », « fetal therapy », « fetal metabolism »). Les résultats ont été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs, aux études observationnelles et aux exposés de cas significatifs. D’autres publications ont été repérées à partir des bibliographies de ces articles. Aucune restriction n’a été appliquée en matière de date ou de langue. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu’en mai 2012. La littérature grise (non publiée) a été identifiée par l’intermédiaire de recherches menées dans les sites Web d’organismes s’intéressant à l’évaluation des technologies dans le domaine de la santé et d’organismes connexes, dans des collections de directives cliniques, dans des registres d’essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales. Avantages, désavantages et coûts : La présente directive clinique sensibilise les lecteurs aux causes de l’anasarque fœtoplacentaire non immune, ainsi qu’au diagnostic prénatal et à la prise en charge de celle-ci. Elle offre également une approche standardisée envers l’anasarque fœtoplacentaire non immune, en mettant l’accent sur la recherche de troubles pouvant être pris en charge pendant la période pr

  14. Diabetic corneal neuropathy.

    PubMed Central

    Schultz, R O; Peters, M A; Sobocinski, K; Nassif, K; Schultz, K J

    1983-01-01

    Corneal epithelial lesions can be found in approximately one-half of asymptomatic patients with diabetes mellitus. These lesions are transient and clinically resemble the keratopathy seen in staphylococcal keratoconjunctivitis. Staphylococcal organisms, however, can be isolated in equal percentages from diabetic patients without keratopathy. Diabetic peripheral neuropathy was found to be related to the presence of diabetic keratopathy after adjusting for age with analysis of covariance. The strongest predictor of both keratopathy and corneal fluorescein staining was vibration perception threshold in the toes (P less than 0.01); and the severity of keratopathy was directly related to the degree of diminution of peripheral sensation. Other predictors of keratopathy were: reduced tear breakup time (P less than 0.03), type of diabetes (P less than 0.01), and metabolic status as indicated by c-peptide fasting (P less than 0.01). No significant relationships were found between the presence of keratopathy and tear glucose levels, endothelial cell densities, corneal thickness measurements, the presence of S epidermidis, or with duration of disease. It is our conclusion that asymptomatic epithelial lesions in the nontraumatized diabetic cornea can occur as a manifestation of generalized polyneuropathy and probably represent a specific form of corneal neuropathy. Images FIGURE 1 FIGURE 2 FIGURE 3 PMID:6676964

  15. Corneal Hydration Control in Fuchs' Endothelial Corneal Dystrophy

    PubMed Central

    Wacker, Katrin; McLaren, Jay W.; Kane, Katrina M.; Baratz, Keith H.; Patel, Sanjay V.

    2016-01-01

    Purpose To assess corneal hydration control across a range of severity of Fuchs' endothelial corneal dystrophy (FECD) by measuring the percent recovery per hour (PRPH) of central corneal thickness after swelling the cornea and to determine its association with corneal morphologic parameters. Methods Twenty-three corneas of 23 phakic FECD patients and 8 corneas of 8 healthy control participants devoid of guttae were graded (modified Krachmer scale). Effective endothelial cell density (ECDe) was determined from the area of guttae and local cell density in confocal microscopy images. Steady-state corneal thickness (CTss) and standardized central corneal backscatter were derived from Scheimpflug images. Corneal swelling was induced by wearing a low-oxygen transmissible contact lens for 2 hours in the morning. De-swelling was measured over 5 hours after lens removal or until corneal thickness returned to CTss. Percent recovery per hour was 100 × (1 – e−k), where k was determined from CT(t) = (de−kt) + CTss, and where d was the initial change from CTss. Results After contact lens wear, corneas swelled by 9% (95% CI 9–10). Percent recovery per hour was 49%/h (95% CI 41–57) in controls and 37%/h in advanced FECD (95% CI 29–43, P = 0.028). Low PRPH was associated with disease severity, low ECDe, and increased anterior and posterior corneal backscatter. Anterior backscatter was associated with PRPH in a multivariable model (R2 = 0.44). Conclusions Corneal hydration control is impaired in advanced FECD and is inversely related to anterior corneal backscatter. Anterior corneal backscatter might serve as an indicator of impaired endothelium in FECD. PMID:27661858

  16. A Rare Association of Non-Compaction of the Ventricular Myocardium, and Non-Immune Hydrops Fetalis.

    PubMed

    Nandyal, Raja; Moorthy, Ganga

    2016-01-01

    Hydrops fetalis is a rare manifestation of severe congestive heart failure in a fetus, resulting in pathological fluid accumulation in fetal soft tissues and/or serous cavities. Non-compaction of the ventricular myocardium, frequently referred to as the left ventricular non-compaction (LVNC), is a very rare congenital cardiomyopathy. For LVNC, echocardiography is the diagnostic modality of choice. Various diagnostic criteria exist based on either echocardiography or MRI. Currently, nonimmune hydrops fetalis (NIHF) comprise almost 90% of all hydrops fetalis cases. Among cardiovascular conditions that contribute to NIHF (20%), structural malformations (especially hypoplastic left heart, endocardial cushion defect) and arrhythmias are the most frequent etiological factors. We describe an extremely preterm neonate who presented with features of non-Immune hydrops fetalis (NIHF) associated with LVNC and profound refractory systemic hypotension. PMID:27328555

  17. Nanomedicine Approaches for Corneal Diseases

    PubMed Central

    Chaurasia, Shyam S.; Lim, Rayne R.; Lakshminarayanan, Rajamani; Mohan, Rajiv R.

    2015-01-01

    Corneal diseases are the third leading cause of blindness globally. Topical nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, antibiotics and tissue transplantation are currently used to treat corneal pathological conditions. However, barrier properties of the ocular surface necessitate high concentration of the drugs applied in the eye repeatedly. This often results in poor efficacy and several side-effects. Nanoparticle-based molecular medicine seeks to overcome these limitations by enhancing the permeability and pharmacological properties of the drugs. The promise of nanomedicine approaches for treating corneal defects and restoring vision without side effects in preclinical animal studies has been demonstrated. Numerous polymeric, metallic and hybrid nanoparticles capable of transporting genes into desired corneal cells to intercept pathologic pathways and processes leading to blindness have been identified. This review provides an overview of corneal diseases, nanovector properties and their applications in drug-delivery and corneal disease management. PMID:25941990

  18. Computational Model for Corneal Transplantation

    NASA Astrophysics Data System (ADS)

    Cabrera, Delia

    2003-10-01

    We evaluated the refractive consequences of corneal transplants using a biomechanical model with homogeneous and inhomogeneous Young's modulus distributions within the cornea, taking into account ablation of some stromal tissue. A FEM model was used to simulate corneal transplants in diseased cornea. The diseased cornea was modeled as an axisymmetric structure taking into account a nonlinearly elastic, isotropic formulation. The model simulating the penetrating keratoplasty procedure gives more change in the postoperative corneal curvature when compared to the models simulating the anterior and posterior lamellar graft procedures. When a lenticle shaped tissue was ablated in the graft during the anterior and posterior keratoplasty, the models provided an additional correction of about -3.85 and -4.45 diopters, respectively. Despite the controversy around the corneal thinning disorders treatment with volume removal procedures, results indicate that significant changes in corneal refractive power could be introduced by a corneal transplantation combined with myopic laser ablation.

  19. Fuchs’ corneal dystrophy

    PubMed Central

    Eghrari, Allen O; Gottsch, John D

    2010-01-01

    Fuchs’ corneal dystrophy (FCD) is a progressive, hereditary disease of the cornea first described a century ago by the Austrian ophthalmologist Ernst Fuchs. Patients often present in the fifth to sixth decade of life with blurry morning vision that increases in duration as the disease progresses. Primarily a condition of the posterior cornea, characteristic features include the formation of focal excrescences of Descemet membrane termed ‘guttae’, loss of endothelial cell density and end-stage disease manifested by corneal edema and the formation of epithelial bullae. Recent advances in our understanding of the genetic and pathophysiological mechanisms of the disease, as well as the application of new imaging modalities and less invasive surgical procedures, present new opportunities for improved outcomes among patients with FCD. PMID:20625449

  20. Lamellar corneal transplantation.

    PubMed

    Arenas, Eduardo; Esquenazi, Salomon; Anwar, Mohammad; Terry, Mark

    2012-11-01

    Penetrating keratoplasty (PK) has been the gold standard for the surgical treatment of most corneal pathologies; lamellar keratoplasty that only replaces the diseased corneal layers has recently evolved as an alternative, however. Innovations in surgical technique and instrumentation provide visual outcomes comparable to PK. We review the indications and outcomes of various techniques of anterior lamellar surgery developed to treat stromal disorders. Similarly, we discuss posterior lamellar keratoplasty techniques such as Descemet stripping automated endothelial keratoplasty and Descemet membrane endothelial keratoplasty. Posterior lamellar keratoplasty provides faster visual rehabilitation than PK in cases of Fuchs endothelial dystrophy and pseudophakic bullous keratopathy. In addition, for medically unresponsive infectious keratitis, therapeutic anterior lamellar keratoplasty yields similar graft survival to PK without an increased risk of disease recurrence.

  1. The immunobiology of corneal transplantation.

    PubMed

    Williams, Keryn A; Coster, Douglas J

    2007-10-15

    Corneal allotransplantation is highly successful in the short term, but much less successful in the longer term. Many corneal grafts in recipients with corneal neovascularization or the sequelae of ocular inflammation undergo irreversible rejection, despite topical immunosuppression with glucocorticosteroids. Sensitization to cornea-derived alloantigen proceeds by both direct and indirect routes, but the anatomic location of sensitization remains unclear. Multiple and redundant mechanisms operate in the effector phase of corneal graft rejection, which is largely cell-mediated rather than antibody-mediated. Human leukocyte antigen matching may improve outcomes in high-risk patients but systemic immunosuppression is frequently ineffective and is seldom used.

  2. Impediment of basilar membrane motion reduces overload protection but not threshold sensitivity: evidence from clinical and experimental hydrops.

    PubMed

    Braun, M

    1996-08-01

    The mechanical function of the basilar membrane (BM) in the mammalian cochlea has been newly debated after the discovery of frequency selectivity of single hair cells. Decisive information on this matter can be expected from hydropic ears, since hydrops presumably alters cochlear mechanics by (1) impeding BM motion and (2) uncoupling outer hair cell (OHC) stereocilia from the tectorial membrane (TM). Therefore hearing in Menière's disease (MD) was examined analysing data on epidemiology of MD types and audiogram types, 2f thresholds, over-recruitment, loudness intolerance, and otoacoustic emissions. Further, hearing in experimental hydrops (XH) was examined analysing data on: morphological changes on TM and OHCs in relation to hydrops duration; morphological and electrophysiological changes upon acoustic overstimulation. The results were unequivocal on two points: (1) co-occurrence of hydrops and normal hearing thresholds can appear both in MD and XH, (2) co-occurrence of non-hearing-loss hydrops and loudness hypersensitivity is typical both in MD and XH. The conclusion is that BM motion apparently is no necessary element in the chain of cochlear sound transmission but obviously is an auxiliary element for overload protection through resonant absorption. The results are further indicative of audiometric methods for an early detection of incipient MD. PMID:8844181

  3. Hydropic leiomyoma of the uterus presenting as a giant abdominal mass.

    PubMed

    Horta, Mariana; Cunha, Teresa Margarida; Oliveira, Rita; Magro, Paula

    2015-01-01

    We describe a case of a 35-year-old woman with a pedunculated uterine leiomyoma with diffuse hydropic degeneration presenting as a giant abdominal mass. The patient was admitted in the emergency department because of diffuse abdominal bloating and discomfort. Ultrasonography (US) showed a heterogeneous abdominopelvic mass. Magnetic resonance imaging (MRI) was performed to further characterise and revealed a myometrial pedunculated tumour. Despite its marked T2-signal heterogeneity and volume, there were no other suspicious findings to suggest a malignant nature; therefore, fertility-sparing myomectomy was performed. Leiomyomas frequently undergo degenerative changes altering their imaging appearances. Leiomyomas with uncommon degenerative changes may be difficult to differentiate from malignant myometrial tumours, based solely on imaging. To the best of our knowledge, a diffuse hydropic degeneration imaging appearance has only been described twice in the literature. We describe the imaging appearance of this rare form of leiomyoma drawing attention to its differential diagnosis.

  4. Hepatitis, gallbladder hydrops, splenomegaly, and ascites in a child with scarlet fever.

    PubMed

    Wang, Li Yueh; Young, Ton-Ho

    2012-11-01

    We report a case of scarlet fever associated with hepatitis, gallbladder hydrops, splenomegaly, and ascites in a 15-year-old girl. The girl presented with fever and skin rash. Leukocyte, liver enzyme, and serum C-reactive protein concentrations were elevated. Ultrasonography revealed marked gallbladder wall thickening, diffuse liver parenchymal disease with moderate splenomegaly, and moderate ascites throughout the abdominal and pelvic cavities. Blood cultures for group A β-hemolytic streptococci were negative. Complete recovery was facilitated with antibiotic treatment.

  5. Case of a healthy infant born following antenatal enterovirus myocarditis and hydrops.

    PubMed

    Bonnin, Aurore; Tassin, Mikael; Vauloup-Fellous, Christelle; Letamendia, Emmanuelle; Stos, Bertrand; Bonnet, Damien; Gajdos, Vincent; Mabille, Mylène; Benachi, Alexandra

    2014-11-01

    Fetal hydrops and myocarditis were diagnosed in a woman at 32 weeks of gestation (WG). Transplacental enterovirus infection was suspected because all other causes of myocarditis and hydrops were excluded, it was during an endemic period, and there was a setting of maternal infection (fever a few days before). We opted for in utero treatment because of the risk of resuscitating a neonate with myocarditis and hydrops. We administered dexamethasone 12mg twice for pulmonary maturation and presumed it would partially improve the myocarditis. Fetal arrhythmia was noted at 35 WG and we decided to deliver the infant as postnatal treatment of the heart disorder would be more effective. RT-PCR (ARGENE(®)) showed that the neonate's throat and anal tissues and cord blood sampled on the day of birth contained enterovirus ribonucleic acid and coxsackievirus B5, as did the mother's anal sample. Laboratory tests, heart MRI and probably brain MRI indicated neonatal enterovirus infection. Findings were normal at two-year follow-up. PMID:25242311

  6. Case of a healthy infant born following antenatal enterovirus myocarditis and hydrops.

    PubMed

    Bonnin, Aurore; Tassin, Mikael; Vauloup-Fellous, Christelle; Letamendia, Emmanuelle; Stos, Bertrand; Bonnet, Damien; Gajdos, Vincent; Mabille, Mylène; Benachi, Alexandra

    2014-11-01

    Fetal hydrops and myocarditis were diagnosed in a woman at 32 weeks of gestation (WG). Transplacental enterovirus infection was suspected because all other causes of myocarditis and hydrops were excluded, it was during an endemic period, and there was a setting of maternal infection (fever a few days before). We opted for in utero treatment because of the risk of resuscitating a neonate with myocarditis and hydrops. We administered dexamethasone 12mg twice for pulmonary maturation and presumed it would partially improve the myocarditis. Fetal arrhythmia was noted at 35 WG and we decided to deliver the infant as postnatal treatment of the heart disorder would be more effective. RT-PCR (ARGENE(®)) showed that the neonate's throat and anal tissues and cord blood sampled on the day of birth contained enterovirus ribonucleic acid and coxsackievirus B5, as did the mother's anal sample. Laboratory tests, heart MRI and probably brain MRI indicated neonatal enterovirus infection. Findings were normal at two-year follow-up.

  7. Diagnostic Value of Vestibular Evoked Myogenic Potentials in Endolymphatic Hydrops: A Meta-Analysis

    PubMed Central

    Zhang, Sulin; Leng, Yangming; Liu, Bo; Shi, Hao; Lu, Meixia; Kong, Weijia

    2015-01-01

    In this study, we evaluated the clinical diagnostic value of vestibular evoked myogenic potentials (VEMPs) for endolymphatic hydrops (EH) by systematic review and Meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under summary receiver operating characteristic curves (AUC) were calculated. Subgroup analysis and publication bias assessment were also conducted. The pooled sensitivity and the specificity were 49% (95% CI: 46% to 51%) and 95% (95% CI: 94% to 96%), respectively. The pooled positive likelihood ratio was 18.01 (95% CI: 9.45 to 34.29) and the pooled negative likelihood ratio was 0.54 (95% CI: 0.47 to 0.61). AUC was 0.78 and the pooled diagnostic odds ratio of VEMPs was 39.89 (95% CI: 20.13 to 79.03). In conclusion, our present meta-analysis has demonstrated that VEMPs test alone is not sufficient for Meniere’s disease or delayed endolymphatic hydrops diagnosis, but that it might be an important component of a test battery for diagnosing Meniere’s disease or delayed endolymphatic hydrops. Moreover, VEMPs, due to its high specificity and non-invasive nature, might be used as a screening tool for EH. PMID:26455332

  8. Fetal hydrops, associated with maternal propylthiouracil exposure, reversed by intrauterine therapy.

    PubMed

    Yanai, N; Shveiky, D

    2004-02-01

    Thyroid hormone is essential for fetal neurological development. Among other etiologies, fetal hypothyroidism may be caused by maternal exposure to antithyroid drugs (ATDs). The most common presentation of fetal hypothyroidism is fetal goiter, which can cause dystocia, in addition to airway obstruction in the neonate. Intra-amniotic treatment with levothyroxine normalizes fetal thyroid status and reduces goiter size. We present a case of fetal hypothyroidism diagnosed in a patient who was treated with propylthiouracil (PTU) for Grave's disease. The fetus had marked hydrops fetalis and a large goiter. In addition, anal stenosis, vesicovaginal fistula, bilateral pyelectasia and polydactyly were diagnosed in the neonate. Intra-amniotic treatment with levothyroxine resulted in a regression of the hydrops and a reduction in the goiter size. A euthyroid, non-edematous, non-goitrous neonate was delivered. At the age of 27 months the child's psychomotor development was normal. The present case indicates that hydrops fetalis may be an unusual manifestation of fetal hypothyroidism, caused by intrauterine exposure to maternal antithyroid drugs (ATDs), and that it may be resolved by treatment with intra-amniotic levothyroxine. PMID:14770404

  9. Percutaneous In Utero Thoracoamniotic Shunt Creation for Fetal Thoracic Abnormalities Leading to Non-Immune Hydrops

    PubMed Central

    White, Sarah B.; Tutton, Sean M.; Rilling, William S.; Kuhlmann, Randall S.; Peterson, Erika L.; Wigton, Thomas R.; Ames, Mary B.

    2015-01-01

    Purpose In a fetus, rare, fetal thoracic abnormalities can cause mediastinal shift and vena cava obstruction resulting in fetal hydrops and intra-uterine fetal demise. This series describes a trans-abdominal, trans-uterine Seldinger based percutaneous approach to create a shunt for treatment of these fetal abnormalities. Material and Methods Five fetuses presented with non-immune fetal hydrops due to fetal thoracic abnormalities causing severe mass effect. Under direct ultrasound guidance, an 18 G needle was used to access the malformation. Through a peel away sheath, a customized pediatric transplant 4.5 French double J ureteral stent was advanced; the leading loop was placed in the fetal thorax and the trailing end left outside the fetal thorax within the amniotic cavity. Results Seven thoracoamniotic shunts were successfully placed in 5 fetuses, with one shunt immediately replaced due to displacement during the procedure and the second not functioning at follow-up requiring insertion of a second shunt. All fetuses had successful decompression of the thoracic malformation, allowing lung re-expansion and resolution of hydrops. Three of 5 mothers had meaningful (> 7 days) prolongation of their pregnancies. All pregnancies were maintained to > 30 weeks, with a range of 30 weeks 1 day to 37 weeks 2 days. There were no maternal complications. Conclusions Seldinger based percutaneous approach to draining fetal thoracic abnormalities is feasible and can allow for prolongation of pregnancy, antenatal lung development and ultimately result in fetal survival. PMID:24702750

  10. Corneal amyloidosis associated with keratoconus.

    PubMed

    Stern, G A; Knapp, A; Hood, C I

    1988-01-01

    Nodular, gray-white, central corneal opacities which extended from the subepithelial zone through the anterior four fifths of the stroma developed in a 50-year-old man with a longstanding history of hard contact lens wear for keratoconus. Results of histopathologic analysis of the corneal button obtained at the time of penetrating keratoplasty disclosed that the opacities were composed of amyloid. Corneal amyloidosis is rarely found in association with keratoconus. Although there were some similarities in the pattern of amyloid deposition to that seen in primary familial amyloidosis of the cornea, the authors believe that their patient is more likely to have had a secondary amyloidosis. Corneal amyloidosis should be considered in keratoconus patients with development of unusual forms of central corneal opacification. PMID:3278260

  11. Induction of endolymphatic hydrops in the guinea pig by perisaccular deposition of sepharose beads carrying and not carrying immune complexes.

    PubMed

    Bouman, H; Klis, S F; de Groot, J C; Huizing, E H; Smoorenburg, G F; Veldman, J E

    1998-03-01

    We tried to induce endolymphatic hydrops in guinea pig cochleas by unilateral, perisaccular deposition of sepharose beads carrying immune complexes. Controls consisted of the deposition of sepharose beads without immune complexes and the contralateral, untreated ear. The effects of the treatment were studied by light microscopy and electrophysiological recordings of the gross cochlear potentials 1, 2, and 6 weeks after treatment. Each condition included six animals. Analysis of variance of the morphometric data concerning the ears treated with deposition of the beads showed a statistically significant difference (P = 0.04) between the degree of hydrops found for the beads with immune complexes and for those without. The difference between the treated ears and the contralateral untreated ears was significant (P = 0.01) for the beads with immune complexes and not significant (P = 0.8) for those without immune complexes while there was no significant effect of post-treatment time interval. Analysis of variance of the electrophysiological data, collected in response to tone bursts at the apex of the cochlea, showed no significant differences between the results for the beads with and without immune complexes. Therefore these results were pooled. One week after treatment the pooled results for the compound action potential showed a small decrease in amplitude, just significant at 2 kHz, but not at 4 and 8 kHz. This decrease disappeared completely after 6 weeks. The pooled results for the negative summating potential (SP) showed a significant increase in magnitude at all frequencies decreasing with post-treatment interval. The cochlear microphonics did not demonstrate any change in amplitude after treatment. The results indicate that deposition of sepharose beads with immune complexes induces endolymphatic hydrops. Also, deposition of the sepharose beads itself may have induced hydrops together with enhancement of the SP. SP enhancement may be related to the development

  12. Corneal seal device

    NASA Technical Reports Server (NTRS)

    Baehr, E. F. (Inventor)

    1977-01-01

    A corneal seal device is provided which, when placed in an incision in the eye, permits the insertion of a surgical tool or instrument through the device into the eye. The device includes a seal chamber which opens into a tube which is adapted to be sutured to the eye and serves as an entry passage for a tool. A sealable aperture in the chamber permits passage of the tool through the chamber into the tube and hence into the eye. The chamber includes inlet ports adapted to be connected to a regulated source of irrigation fluid which provides a safe intraocular pressure.

  13. Corneal structure and transparency

    PubMed Central

    Meek, Keith M.; Knupp, Carlo

    2015-01-01

    The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225

  14. Corneal structure and transparency.

    PubMed

    Meek, Keith M; Knupp, Carlo

    2015-11-01

    The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency. PMID:26145225

  15. Corneal blindness: a global perspective.

    PubMed Central

    Whitcher, J. P.; Srinivasan, M.; Upadhyay, M. P.

    2001-01-01

    Diseases affecting the cornea are a major cause of blindness worldwide, second only to cataract in overall importance. The epidemiology of corneal blindness is complicated and encompasses a wide variety of infectious and inflammatory eye diseses that cause corneal scarring, which ultimately leads to functional blindness. In addition, the prevalence of corneal disease varies from country to country and even from one population to another. While cataract is responsible for nearly 20 million of the 45 million blind people in the world, the next major cause is trachoma which blinds 4.9 million individuals, mainly as a result of corneal scarring and vascularization. Ocular trauma and corneal ulceration are significant causes of corneal blindness that are often underreported but may be responsible for 1.5-2.0 million new cases of monocular blindness every year. Causes of childhood blindness (about 1.5 million worldwide with 5 million visually disabled) include xerophthalmia (350,000 cases annually), ophthalmia neonatorum, and less frequently seen ocular diseases such as herpes simplex virus infections and vernal keratoconjunctivitis. Even though the control of onchocerciasis and leprosy are public health success stories, these diseases are still significant causes of blindness--affecting a quarter of a million individuals each. Traditional eye medicines have also been implicated as a major risk factor in the current epidemic of corneal ulceration in developing countries. Because of the difficulty of treating corneal blindness once it has occurred, public health prevention programmes are the most cost-effective means of decreasing the global burden of corneal blindness. PMID:11285665

  16. Management of advanced corneal ectasias.

    PubMed

    Maharana, Prafulla K; Dubey, Aditi; Jhanji, Vishal; Sharma, Namrata; Das, Sujata; Vajpayee, Rasik B

    2016-01-01

    Corneal ectasias include a group of disorders characterised by progressive thinning, bulging and distortion of the cornea. Keratoconus is the most common disease in this group. Other manifestations include pellucid marginal degeneration, Terrien's marginal degeneration, keratoglobus and ectasias following surgery. Advanced ectasias usually present with loss of vision due to high irregular astigmatism. Management of these disorders is difficult due to the peripheral location of ectasia and associated severe corneal thinning. Newer contact lenses such as scleral lenses are helpful in a selected group of patients. A majority of these cases requires surgical intervention. This review provides an update on the current treatment modalities available for management of advanced corneal ectasias. PMID:26294106

  17. Optimizing rejection readouts in a corneal allograft transplantation model

    PubMed Central

    Hildebrand, Antonia; Böhringer, Daniel; Betancor, Paola Kammrath; Schlunck, Günther; Reinhard, Thomas

    2016-01-01

    Purpose To evaluate the feasibility of anterior segment spectral domain optic coherence tomography (ASOCT) as rejection readout in a keratoplasty mouse model and to compare ASOCT against the current standard (i.e., a clinical score system). Furthermore, to compare both approaches with respect to intra- and inter-individual observer variability and to calculate a critical point that distinguishes between rejection and non-rejection in ASOCT analysis. Methods Allogeneic penetrating keratoplasties (PKs) were performed using C3H/He donor mice and BALB/c recipient mice; syngeneic transplantations served as controls using BALB/c donors and recipients. Corneal graft rejection was determined with a clinical score. ASOCT was used to determine the central thickness of the corneal grafts in the same animals. The rejection status was corroborated with histopathological examination. Results The median survival time (MST) of the corneal allografts in the wild-type BALB/c mice was 12 days. Allogeneic transplantation led to a 100% rejection rate, whereas signs of rejection after syngeneic transplantation appeared in up to 20% of the mice. Central corneal thickness (CCT) determination via customized software revealed a direct correlation with the clinical score. Receiver operating curve (ROC) analysis confirmed CCT as a valid surrogate for rejection. Calculation of the area under the curve (AUC) revealed a value of 0.88 with an optimal cut-off at 267 pixels. Conclusions An increase in the CCT during acute allogeneic corneal graft rejection significantly correlated with the clinical surrogate parameter “corneal opacity.” ASOCT not only generates source data, but also analysis of the ASOCT data shows lower readout variability and fewer interpreter variations than the clinical score commonly used to define the time point of graft rejection in mice. PMID:27777504

  18. [Methods for sealing of corneal perforations].

    PubMed

    Samoilă, O; Totu, Lăcrămioara; Călugăru, M

    2012-01-01

    A variety of corneal pathology can lead to corneal ulcers and perforations. A deep corneal ulcer may need surgical treatment to allow good volume restoration and reepithelisation. Corneal perforation must be sealed and when the perforation is large, the task of repairing the defect can be underwhelming. The elegant solution is the corneal transplant, but this is not always readily available, especially in undeveloped countries. We present here two cases with different solutions to seal the perforated cornea: the first one has a large peripheral defect and it is successfully sealed with scleral patch and the second one is central with small perforation and is successfully sealed with multilayered amniotic membrane. Both cases are followed for over 12 months and demonstrate good corneal restoration (both on clinical examination and corneal topography). Sclera and amniotic membrane can be used to seal corneal defects when corneal transplant is not readily available.

  19. Corneal transplantation and glaucoma.

    PubMed

    Haddadin, Ramez I; Chodosh, James

    2014-01-01

    Glaucoma is the leading cause of irreversible vision loss post-keratoplasty and an important cause of graft failure. With newer techniques, such as lamellar, endothelial, and laser-assisted keratoplasty as well as keratoprosthesis gaining popularity, clinicians will need to consider the incidence, risks, evaluation, and management of glaucoma for each type of keratoplasty when determining which type of transplant may be most appropriate. A comprehensive literature search of glaucoma in the setting of corneal transplantation was performed and serves as the basis for this review. Preexisting glaucoma and aphakia are notable risk factors. Patients that are candidates for deep anterior lamellar keratoplasty may benefit from reduced rates of post-keratoplasty glaucoma. Although glaucoma also complicates eyes with Descemet stripping endothelial keratoplasty, the severity is less and the intraocular pressure is more easily controlled when compared to penetrating keratoplasty. Endothelial keratoplasty creates unique perioperative issues mostly related to management of anterior chamber air bubbles.

  20. Corneal Collagen Cross-Linking

    PubMed Central

    Jankov II, Mirko R.; Jovanovic, Vesna; Nikolic, Ljubisa; Lake, Jonathan C.; Kymionis, Georgos; Coskunseven, Efekan

    2010-01-01

    Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet-A (UVA) is a new technique of corneal tissue strengthening by using riboflavin as a photosensitizer and UVA to increase the formation of intra and interfibrillar covalent bonds by photosensitized oxidation. Keratocyte apoptosis in the anterior segment of the corneal stroma all the way down to a depth of about 300 microns has been described and a demarcation line between the treated and untreated cornea has been clearly shown. It is important to ensure that the cytotoxic threshold for the endothelium has not been exceeded by strictly respecting the minimal corneal thickness. Confocal microscopy studies show that repopulation of keratocytes is already visible 1 month after the treatment, reaching its pre-operative quantity and quality in terms of functional morphology within 6 months after the treatment. The major indication for the use of CXL is to inhibit the progression of corneal ectasias, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photoablation. This treatment has also been used to treat infectious corneal ulcers with apparent favorable results. Combination with other treatments, such as intracorneal ring segment implantation, limited topography-guided photoablation and conductive keratoplasty have been used with different levels of success. PMID:20543933

  1. Drug-induced corneal damage.

    PubMed

    2014-04-01

    Corneal damage can have a variety of causes, including infections, chemical splashes, environmental factors (radiation, trauma, contact lenses, etc.), and systemic diseases (genetic, autoimmune, inflammatory, metabolic, etc.). A wide range of drugs can also damage the cornea. The severity of drug-induced corneal changes can range from simple asymptomatic deposits to irreversible, sight-threatening damage. Several factors can influence the onset of corneal lesions. Some factors, such as the dose, are treatment-related, while others such as contact lenses, are patient-related. A variety of mechanisms may be involved, including corneal dryness, changes in the corneal epithelium, impaired wound healing and deposits. Many drugs can damage the cornea through direct contact, after intraocular injection or instillation, including VEGF inhibitors, anti-inflammatory drugs, local anaesthetics, glaucoma drugs, fluoroquinolones, and preservatives. Some systemically administered drugs can also damage the cornea, notably cancer drugs, amiodarone and isotretinoin. Vulnerable patients should be informed of this risk if they are prescribed a drug with the potential to damage the cornea so that they can identify problems in a timely manner. It may be necessary to discontinue the suspect drug when signs and symptoms of corneal damage occur.

  2. Intrastromal Corneal Ring Implants for Corneal Thinning Disorders

    PubMed Central

    2009-01-01

    Executive Summary Objective 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: Safety Corneal Surface Topographic Effects: Effects on corneal surface remodelling Impact of these changes on subsequent interventions, particularly corneal transplantation (penetrating keratoplasty [PKP]) Visual Acuity Refractive Outcomes Visual Quality (Symptoms): such as contrast vision or decreased visual symptoms (halos, fluctuating vision) Contact lens tolerance Functional visual rehabilitation and quality of life Patient satisfaction: Disease Process: Impact on corneal thinning process Effect on delaying or deferring the need for corneal transplantation Clinical Need: 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

  3. Contributions of tissue-specific pathologies to corneal injuries following exposure to SM vapor.

    PubMed

    McNutt, Patrick M; Tuznik, Kaylie M; Glotfelty, Elliot J; Nelson, Marian R; Lyman, Megan E; Hamilton, Tracey A

    2016-06-01

    Corneal injuries resulting from ocular exposure to sulfur mustard (SM) vapor are the most prevalent chemical warfare injury. Ocular exposures exhibit three distinct, dose-dependent clinical trajectories: complete injury resolution, immediate transition to a chronic injury, or apparent recovery followed by the subsequent development of persistent ocular manifestations. These latter two trajectories include a constellation of corneal symptoms that are collectively known as mustard gas keratopathy (MGK). The etiology of MGK is not understood. Here, we synthesize recent findings from in vivo rabbit SM vapor studies, suggesting that tissue-specific damage during the acute injury can decrement the regenerative capacities of corneal endothelium and limbal stem cells, thereby predisposing the cornea to the chronic or delayed forms of MGK. This hypothesis not only provides a mechanism to explain the acute and MGK injuries but also identifies novel therapeutic modalities to mitigate or eliminate the acute and long-term consequences of ocular exposure to SM vapor.

  4. Contributions of tissue-specific pathologies to corneal injuries following exposure to SM vapor.

    PubMed

    McNutt, Patrick M; Tuznik, Kaylie M; Glotfelty, Elliot J; Nelson, Marian R; Lyman, Megan E; Hamilton, Tracey A

    2016-06-01

    Corneal injuries resulting from ocular exposure to sulfur mustard (SM) vapor are the most prevalent chemical warfare injury. Ocular exposures exhibit three distinct, dose-dependent clinical trajectories: complete injury resolution, immediate transition to a chronic injury, or apparent recovery followed by the subsequent development of persistent ocular manifestations. These latter two trajectories include a constellation of corneal symptoms that are collectively known as mustard gas keratopathy (MGK). The etiology of MGK is not understood. Here, we synthesize recent findings from in vivo rabbit SM vapor studies, suggesting that tissue-specific damage during the acute injury can decrement the regenerative capacities of corneal endothelium and limbal stem cells, thereby predisposing the cornea to the chronic or delayed forms of MGK. This hypothesis not only provides a mechanism to explain the acute and MGK injuries but also identifies novel therapeutic modalities to mitigate or eliminate the acute and long-term consequences of ocular exposure to SM vapor. PMID:27310673

  5. An autophagic vacuolar myopathy-like disorder presenting as nonimmune hydrops in a female fetus.

    PubMed

    Kepron, Charis; Blumenthal, Andrea; Chitayat, David; Cutz, Ernest; Superti-Furga, Andrea; Keating, Sarah

    2009-01-01

    A 37-year-old woman presented for routine obstetrical care at 15 weeks' gestational age and the fetus was found to have hydrops fetalis. Following elective termination of the pregnancy at 18 weeks' gestational age, pathologic examination of the female conceptus revealed findings suggestive of a lysosomal storage disease within the liver and cardiac muscle. Enzyme assays for beta-galactosidase, neuraminidase, alpha-l-iduronidase, beta-glucuronidase, beta-glucosidase, Morquio disease type A enzyme, beta-fucosidase, alpha-mannosidase, and beta-mannosidase were all normal, ruling out many of the common storage diseases. Electron microscopy identified vacuoles within hepatocytes, Kupffer cells, and cardiac myocytes resembling the autophagic vacuoles characteristic of a group of diseases known as the autophagic vacuolar myopathies (AVMs). Because these diseases are exceptionally rare in females, and because such autophagic vacuoles have never before been described in liver, we propose a novel entity of "AVM-like lysosomal storage disease" presenting as nonimmune hydrops in a female fetus.

  6. Substrates for Expansion of Corneal Endothelial Cells towards Bioengineering of Human Corneal Endothelium

    PubMed Central

    Navaratnam, Jesintha; Utheim, Tor P.; Rajasekhar, Vinagolu K.; Shahdadfar, Aboulghassem

    2015-01-01

    Corneal endothelium is a single layer of specialized cells that lines the posterior surface of cornea and maintains corneal hydration and corneal transparency essential for vision. Currently, transplantation is the only therapeutic option for diseases affecting the corneal endothelium. Transplantation of corneal endothelium, called endothelial keratoplasty, is widely used for corneal endothelial diseases. However, corneal transplantation is limited by global donor shortage. Therefore, there is a need to overcome the deficiency of sufficient donor corneal tissue. New approaches are being explored to engineer corneal tissues such that sufficient amount of corneal endothelium becomes available to offset the present shortage of functional cornea. Although human corneal endothelial cells have limited proliferative capacity in vivo, several laboratories have been successful in in vitro expansion of human corneal endothelial cells. Here we provide a comprehensive analysis of different substrates employed for in vitro cultivation of human corneal endothelial cells. Advances and emerging challenges with ex vivo cultured corneal endothelial layer for the ultimate goal of therapeutic replacement of dysfunctional corneal endothelium in humans with functional corneal endothelium are also presented. PMID:26378588

  7. Corneal Biomechanical Findings in Contact Lens Induced Corneal Warpage.

    PubMed

    Alipour, Fateme; Letafatnejad, Mojgan; Beheshtnejad, Amir Hooshang; Mohammadi, Seyed-Farzad; Ghaffary, Seyed Reza; Hassanpoor, Narges; Yaseri, Mehdi

    2016-01-01

    Purpose. To evaluate the difference in biomechanical properties between contact lens induced corneal warpage and normal and keratoconic eyes. Method. Prospective observational case control study, where 94 eyes of 47 warpage suspicious and 46 eyes of 23 keratoconic patients were included. Warpage suspected cases were followed until a definite diagnosis was made (warpage, normal, or keratoconus). Results. 44 eyes of 22 patients had contact lens related corneal warpage. 46 eyes of 23 people were diagnosed as nonwarpage normal eyes. 46 eyes of 23 known keratoconus patients were included for comparison. The mean age of the participants was 23.8 ± 3.8 years, and 66.2% of the subjects were female. The demographic and refractive data were not different between warpage and normal groups but were different in the keratoconus group. The biomechanical properties (corneal hysteresis or CH and corneal resistance factor or CRF) were different with the highest value in the warpage group followed by normal and keratoconus groups. CRF was 10.08 ± 1.75, 9.23 ± 1.22, and 7.38 ± 2.14 and CH was 10.21 ± 1.57, 9.59 ± 1.21, and 8.69 ± 2.34 in the warpage, normal, and keratoconus groups, respectively. Conclusion. Corneal biomechanics may be different in people who develop contact lens induced warpage. PMID:27688908

  8. Corneal Biomechanical Findings in Contact Lens Induced Corneal Warpage

    PubMed Central

    Letafatnejad, Mojgan; Beheshtnejad, Amir Hooshang; Ghaffary, Seyed Reza; Hassanpoor, Narges; Yaseri, Mehdi

    2016-01-01

    Purpose. To evaluate the difference in biomechanical properties between contact lens induced corneal warpage and normal and keratoconic eyes. Method. Prospective observational case control study, where 94 eyes of 47 warpage suspicious and 46 eyes of 23 keratoconic patients were included. Warpage suspected cases were followed until a definite diagnosis was made (warpage, normal, or keratoconus). Results. 44 eyes of 22 patients had contact lens related corneal warpage. 46 eyes of 23 people were diagnosed as nonwarpage normal eyes. 46 eyes of 23 known keratoconus patients were included for comparison. The mean age of the participants was 23.8 ± 3.8 years, and 66.2% of the subjects were female. The demographic and refractive data were not different between warpage and normal groups but were different in the keratoconus group. The biomechanical properties (corneal hysteresis or CH and corneal resistance factor or CRF) were different with the highest value in the warpage group followed by normal and keratoconus groups. CRF was 10.08 ± 1.75, 9.23 ± 1.22, and 7.38 ± 2.14 and CH was 10.21 ± 1.57, 9.59 ± 1.21, and 8.69 ± 2.34 in the warpage, normal, and keratoconus groups, respectively. Conclusion. Corneal biomechanics may be different in people who develop contact lens induced warpage. PMID:27688908

  9. Stromal corneal scar following YAG capsulotomy.

    PubMed

    Bailey, L; Donzis, P B; Kastl, P R

    1988-05-01

    The case of a 70-year-old patient who suffered inadvertant YAG laser burns to the central corneal stroma is presented. Although focal stromal scarring resulted, no endothelial damage or corneal decompensation was noted, and the patient was asymptomatic.

  10. Corneal plaque containing levofloxacin in a dog.

    PubMed

    Park, Young-Woo; Kang, Byung-Jae; Lim, Jae Hyun; Ahn, Jung-Mo; Lim, Hyun Sook

    2015-11-01

    A 13-year-old castrated male Yorkshire terrier developed a corneal ulcer 2 weeks after intracapsular lens extraction (ICLE) in the right eye. The corneal ulcer was treated with levofloxacin eye drops. A plaque with a white luster developed in the central cornea 2 weeks after treatment with levofloxacin eye drops. The corneal plaque was surgically removed under inhalant anesthesia. The corneal plaque displayed antimicrobial activity against Escherichia coli. Furthermore, levofloxacin content in the plaque was confirmed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry (MS). The corneal ulcer completely resolved 2 weeks after the surgical removal of the corneal lesion and replacement of levofloxacin eye drops with tobramycin eye drops. Although the topical use of levofloxacin is unlikely to lead to corneal chemical deposits due to the high water solubility of the drug compared to other topical fluoroquinolones, this patient developed corneal plaque of the antibiotic drop.

  11. Corneal biomechanics: a review.

    PubMed

    Piñero, David P; Alcón, Natividad

    2015-03-01

    Biomechanics is often defined as 'mechanics applied to biology'. Due to the variety and complexity of the behaviour of biological structures and materials, biomechanics is better defined as the development, extension and application of mechanics for a better understanding of physiology and physiopathology and consequently for a better diagnosis and treatment of disease and injury. Different methods for the characterisation of corneal biomechanics are reviewed in detail, including those that are currently commercially available (Ocular Response Analyzer and CorVis ST). The clinical applicability of the parameters provided by these devices are discussed, especially in the fields of glaucoma, detection of ectatic disorders and orthokeratology. Likewise, other methods are also reviewed, such as Brillouin microscopy or dynamic optical coherence tomography and others with potential application to clinical practice but not validated for in vivo measurements, such as ultrasonic elastography. Advantages and disadvantages of all these techniques are described. Finally, the concept of biomechanical modelling is revised as well as the requirements for developing biomechanical models, with special emphasis on finite element modelling. PMID:25470213

  12. 21 CFR 886.1220 - Corneal electrode.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Corneal electrode. 886.1220 Section 886.1220 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1220 Corneal electrode. (a) Identification. A corneal electrode is an AC-powered device, usually part of a special contact lens, intended to be applied...

  13. 21 CFR 886.1220 - Corneal electrode.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Corneal electrode. 886.1220 Section 886.1220 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1220 Corneal electrode. (a) Identification. A corneal electrode is an AC-powered device, usually part of a special contact lens, intended to be applied...

  14. 21 CFR 886.1220 - Corneal electrode.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Corneal electrode. 886.1220 Section 886.1220 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1220 Corneal electrode. (a) Identification. A corneal electrode is an AC-powered device, usually part of a special contact lens, intended to be applied...

  15. 21 CFR 886.1220 - Corneal electrode.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal electrode. 886.1220 Section 886.1220 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1220 Corneal electrode. (a) Identification. A corneal electrode is an AC-powered device, usually part of a special contact lens, intended to be applied...

  16. 21 CFR 886.1220 - Corneal electrode.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Corneal electrode. 886.1220 Section 886.1220 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1220 Corneal electrode. (a) Identification. A corneal electrode is an AC-powered device, usually part of a special contact lens, intended to be applied...

  17. Obtaining corneal tissue for keratoplasty.

    PubMed

    Navarro Martínez-Cantullera, A; Calatayud Pinuaga, M

    2016-10-01

    Cornea transplant is the most common tissue transplant in the world. In Spain, tissue donation activities depend upon transplant coordinator activities and the well-known Spanish model for organ and tissue donation. Tissue donor detection system and tissue donor evaluation is performed mainly by transplant coordinators using the Spanish model on donation. The evaluation of a potential tissue donor from detection until recovery is based on an exhaustive review of the medical and social history, physical examination, family interview to determine will of the deceased, and a laboratory screening test. Corneal acceptance criteria for transplantation have a wider spectrum than other tissues, as donors with active malignancies and infections are accepted for kearatoplasty in most tissue banks. Corneal evaluation during the whole process is performed to ensure the safety of the donor and the recipient, as well as an effective transplant. Last step before processing, corneal recovery, must be performed under standard operating procedures and in a correct environment.

  18. Gene therapy in corneal transplantation.

    PubMed

    Qazi, Yureeda; Hamrah, Pedram

    2013-01-01

    Corneal transplantation is the most commonly performed organ transplantation. Immune privilege of the cornea is widely recognized, partly because of the relatively favorable outcome of corneal grafts. The first-time recipient of corneal allografts in an avascular, low-risk setting can expect a 90% success rate without systemic immunosuppressive agents and histocompatibility matching. However, immunologic rejection remains the major cause of graft failure, particularly in patients with a high risk for rejection. Corticosteroids remain the first-line therapy for the prevention and treatment of immune rejection. However, current pharmacological measures are limited in their side-effect profiles, repeated application, lack of targeted response, and short duration of action. Experimental ocular gene therapy may thus present new horizons in immunomodulation. From efficient viral vectors to sustainable alternative splicing, we discuss the progress of gene therapy in promoting graft survival and postulate further avenues for gene-mediated prevention of allogeneic graft rejection.

  19. [Pay attention to the donor material supply for corneal transplantation].

    PubMed

    Pan, Z Q; Liang, Q F

    2016-09-11

    Corneal transplantation is an important method in the treatment of corneal blindness. It is imperative to improve the treatment effectiveness of corneal disease and reduce the possibility of corneal blindness with the progress of corneal transplantation surgery, the construction and development of eye banks and the rational use of donor materials. This article reviews the component corneal transplantation technology promotion, eye bank construction and preparation of donor slices for component corneal transplantation surgery. (Chin J Ophthalmol, 2016, 52: 641-643). PMID:27647243

  20. Progress in corneal wound healing.

    PubMed

    Ljubimov, Alexander V; Saghizadeh, Mehrnoosh

    2015-11-01

    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 (TGF-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

  1. Animal Models of Corneal Injury

    PubMed Central

    Chan, Matilda F.; Werb, Zena

    2015-01-01

    The cornea is an excellent model system to use for the analysis of wound repair because of its accessibility, lack of vascularization, and simple anatomy. Corneal injuries may involve only the superficial epithelial layer or may penetrate deeper to involve both the epithelial and stromal layers. Here we describe two well-established in vivo corneal wound models: a mechanical wound model that allows for the study of re-epithelialization and a chemical wound model that may be used to study stromal activation in response to injury (Stepp et al., 2014; Carlson et al., 2003). PMID:26191536

  2. Jumping translocation in a newborn boy with dup(4q) and severe hydrops fetalis

    SciTech Connect

    Duval, E.; Enden, A. van den; Vanhaesebrouck, P.; Speleman, F.

    1994-08-15

    We report on the unusual cytogenetic findings in a newborn boy with severe hydrops fetalis. He has a mosaic for 2 unbalanced chromosome rearrangements: a der(18)t(4;18)(q31;q23) and a der(18)t(4;18)(q31;p11). As a result, this patient had a duplication of 4q31-qter in cells, and was possibly monosomic for the distal ends of 18p and 18q, respectively in the 2 cell lines. Sine in both rearrangements the same chromosome 4 segment was translocated to 2 different chromosome regions, we consider the present finding as a peculiar type of jumping translocation. 32 refs., 3 figs., 1 tab.

  3. Treatment of congenital chylothorax with octreotide in a hydropic preterm infant.

    PubMed

    Choo, Yao Mun; Lim, Chin Theam

    2013-05-01

    Congenital chylothorax is rare in preterm infants. While most cases respond to conservative treatment, a few require surgery. Treatment with intravenous octreotide has been reported to have varying success in preterm infants. A fetus was diagnosed with bilateral hydrothoraces at 29 weeks of gestation and repeated thoracocentesis was performed antenatally to allow growth of the lungs. She was delivered electively at 32 weeks by caesarean section. Hydrops fetalis was confirmed and chest tubes were inserted bilaterally soon after birth. Intravenous octreotide was commenced on day 4 of life, titrated to a maximum of 10 μg/kg/hr for a total of 28 days. Hydrothorax resolved at day 30 and total parenteral nutrition was given for a total of 37 days. She was successfully extubated on day 40 of life and discharged on day 80. On review at 6 months of age, she was thriving and developing normally.

  4. Congenital heart block with hydrops fetalis treated with high-dose dexamethasone; a case report.

    PubMed

    Chua, S; Ostman-Smith, I; Sellers, S; Redman, C W

    1991-11-26

    A 32-year-old woman with systemic lupus erythematosus was found to have a fetus with heart block and fetal ascites at 23 weeks gestation. Treatment with high-dose corticosteroids ameliorated the early signs of heart failure, although the fetal heart rate gradually fell from 48 beats/min to 42 beats/min by 34 weeks. Sudden deterioration of the fetal state occurred at 35 weeks, and this only partially responded to digitalisation. Neonatal death occurred on Day 18 from the consequences of severe birth asphyxia. The relationship and pathogenesis of anti-Ro antibodies, congenital heart block and hydrops fetals are discussed, together with the in utero management of this condition. PMID:1765211

  5. Degeneration and Regeneration of Subbasal Corneal Nerves after Infectious Keratitis: A Longitudinal In Vivo Confocal Microscopy Study

    PubMed Central

    Müller, Rodrigo; Abedi, Farshad; Cruzat, Andrea; Witkin, Deborah; Baniasadi, Neda; Cavalcanti, Bernardo M.; Jamali, Arsia; Chodosh, James; Dana, Reza; Pavan-Langston, Deborah; Hamrah, Pedram

    2015-01-01

    Purpose To investigate the longitudinal alterations of subbasal corneal nerves in patients with infectious keratitis (IK) during acute phase, cessation of treatment and recovery phase by in vivo confocal microscopy (IVCM). Design Prospective, longitudinal, case-control, single-center study. Subjects Fifty-six eyes of 56 patients with the diagnosis of bacterial (n=28), fungal (n=15), and Acanthamoeba (n=13) keratitis were included in the study. Thirty eyes of 30 normal volunteers constituted the control group. Methods Corneal sensation and serial IVCM of the central cornea were performed prospectively, by using the Heidelberg Retina Tomograph 3/Rostock Cornea Module (Heidelberg Engineering, Germany). IVCM images were assessed at 3 time points: at the first visit of the patient to the cornea service, at cessation of antimicrobial treatment, and up to six months after the resolution of infection. Main outcome measures Total nerve number and length, main nerve trunks, branching and corneal sensation were assessed during the follow-up period. Results Corneal nerves were significantly reduced during the acute phase in eyes with IK compared with controls across all subgroups, with total nerve length of 5.47 ± 0.69 vs. 20.59 ± 1.06 mm/mm2; p<0.0001. At the cessation of treatment, corneal nerves in patients with IK had regenerated, including total nerve length (8.49 ± 0.94; p=0.02) and nerve branch length (4.80 ± 0.37; p=0.005). During the recovery phase, after resolution of infection, corneal nerves further regenerated, including total nerve length (12.13 ± 1.97; p=0.005), main nerve trunk length (5.80 ± 1.00; p=0.01) and nerve branch length (6.33 ± 0.76; p=0.003) as compared to the acute phase, but were still significantly lower when compared to controls (p<0.05 for all parameters). Corneal degeneration and regeneration correlated with corneal sensation (r=0.47, p=0.0009). Conclusion Patients with IK, suffering from profound loss of corneal nerves during the acute

  6. Glaucoma risks in advanced corneal surgery.

    PubMed

    Maurino, Vincenzo; Aiello, Francesco

    2015-01-01

    Penetrating corneal transplant (PKP) surgery has been performed for centuries as the procedure of choice to restore vision in cases of advanced corneal disease. However, the last two decades have seen the introduction of lamellar corneal surgery (deep anterior lamellar keratoplasty, DALK; Descemet stripping-automated endothelial keratoplasty, DSAEK; and Descemet membrane endothelial keratoplasty, DMEK) which has shown several advantages over PKP and has rapidly gained popularity, given its benefits. Glaucoma after corneal graft surgery is an important cause of visual loss and graft failure. The main risk factors for developing glaucoma after any type of corneal graft are steroid-related intraocular hypertension and pre-existing glaucoma. The incidence of glaucoma after corneal graft surgery varies according to the specific risk factors and the type of corneal graft performed. One major advantage of modern layer selective lamellar keratoplasty is the reduced risk of glaucoma compared with PKP. This reduced glaucoma risk after corneal lamellar graft surgery is mainly due to the less destructive surgical nature of the lamellar procedures and also the reduced use of postoperative steroid treatment. Glaucoma can complicate not only corneal transplantation but has also been observed following other anterior segment procedures from laser refractive surgery to keratoprosthesis. The aim of this chapter is to describe the incidence, etiology, and management of glaucoma after corneal transplant and some common corneal surgical procedures.

  7. Corneal Regeneration After Photorefractive Keratectomy: A Review.

    PubMed

    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.

  8. Corneal Regeneration After Photorefractive Keratectomy: A Review☆

    PubMed Central

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

    2014-01-01

    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. PMID:25444646

  9. Quantitation of corneal inflammation by chemiluminescense.

    PubMed

    Chusid, M J; Shea, M L

    1986-10-01

    Various inflammatory agents, including Pseudomonas aeruginosa, bacterial filtrates, endotoxin, and phorbol myristate acetate were found to induce significant increases in corneal chemiluminescense (CLM). Disruption of polymorphonuclear leukocytes within corneas by sonication, freeze-thawing or cryotherapy, or reduction of corneal infiltration by induction of neutropenia resulted in marked decreases of CLM. Increased corneal CLM was associated with significant increases in corneal thickness and water content. Oxygen-free radical scavengers significantly inhibited CLM of experimentally infected corneas in vitro, as did the anti-inflammatory agents prednisolone acetate, indomethacin, and salicylic acid. In vivo therapy of infected corneas with prednisolone resulted in significant reductions in corneal CLM, thickness, and water content compared with saline-treated eyes. The CLM assay is a simple technique that allows quantitation of corneal inflammation and evaluation of the effect of therapeutic agents on corneal inflammation. PMID:3094481

  10. Effects of topical and systemic administration of Eugenia caryophyllata buds essential oil on corneal anesthesia and analgesia

    PubMed Central

    Khalilzadeh, Emad; Hazrati, Reza; Saiah, Gholamreza Vafaei

    2016-01-01

    Clinical studies suggest that essential oil of Eugenia caryophyllata (Clove) buds (EOEC) is efficacious in the treatment of dental pain. In the present study, we investigated the analgesic and local anesthetic effects of EOEC and its possible mechanisms of action in acute corneal pain in rats. EOEC was extracted by hydro-distillation in a Clevenger type apparatus from clove buds. The acute corneal pain was induced by applying a drop (40 µl) of 5 M NaCl solution on the corneal surface, and the numbers of eye wipes were counted during the first 30 s. The mechanical sensation of the cornea was evaluated by calibrated Von Frey filaments. Systemic administration of EOEC (100 and 200 mg/kg, SC) and morphine (2.5 and 5 mg/kg, IP) produced a significant antinociceptive effect in acute corneal pain. Pretreatment with naloxone or atropine prevented the EOEC-induced analgesia. However, L-arginine and methylene blue did not change the suppressive effect of EOEC on corneal pain response. Topical application of EOEC, eugenol and lidocaine significantly decreased corneal sensitivity. Combination treatments of eugenol (25 µg) with lidocaine (0.5%) and EOEC (50 µg) with lidocaine (0.5%) also significantly suppressed corneal sensitivity. Systemic administration of EOEC produced analgesia in the acute corneal pain through mechanisms that involved both opioidergic and cholinergic systems. In addition, topical instillation of EOEC, eugenol, and lidocaine produced local anesthesia in the rat cornea. Sub-anesthetic doses of EOEC or eugenol produced a significant local anesthetic effect when concurrently used with the sub-anesthetic dose of lidocaine.

  11. Effects of topical and systemic administration of Eugenia caryophyllata buds essential oil on corneal anesthesia and analgesia.

    PubMed

    Khalilzadeh, Emad; Hazrati, Reza; Saiah, Gholamreza Vafaei

    2016-07-01

    Clinical studies suggest that essential oil of Eugenia caryophyllata (Clove) buds (EOEC) is efficacious in the treatment of dental pain. In the present study, we investigated the analgesic and local anesthetic effects of EOEC and its possible mechanisms of action in acute corneal pain in rats. EOEC was extracted by hydro-distillation in a Clevenger type apparatus from clove buds. The acute corneal pain was induced by applying a drop (40 µl) of 5 M NaCl solution on the corneal surface, and the numbers of eye wipes were counted during the first 30 s. The mechanical sensation of the cornea was evaluated by calibrated Von Frey filaments. Systemic administration of EOEC (100 and 200 mg/kg, SC) and morphine (2.5 and 5 mg/kg, IP) produced a significant antinociceptive effect in acute corneal pain. Pretreatment with naloxone or atropine prevented the EOEC-induced analgesia. However, L-arginine and methylene blue did not change the suppressive effect of EOEC on corneal pain response. Topical application of EOEC, eugenol and lidocaine significantly decreased corneal sensitivity. Combination treatments of eugenol (25 µg) with lidocaine (0.5%) and EOEC (50 µg) with lidocaine (0.5%) also significantly suppressed corneal sensitivity. Systemic administration of EOEC produced analgesia in the acute corneal pain through mechanisms that involved both opioidergic and cholinergic systems. In addition, topical instillation of EOEC, eugenol, and lidocaine produced local anesthesia in the rat cornea. Sub-anesthetic doses of EOEC or eugenol produced a significant local anesthetic effect when concurrently used with the sub-anesthetic dose of lidocaine. PMID:27651809

  12. Effects of topical and systemic administration of Eugenia caryophyllata buds essential oil on corneal anesthesia and analgesia

    PubMed Central

    Khalilzadeh, Emad; Hazrati, Reza; Saiah, Gholamreza Vafaei

    2016-01-01

    Clinical studies suggest that essential oil of Eugenia caryophyllata (Clove) buds (EOEC) is efficacious in the treatment of dental pain. In the present study, we investigated the analgesic and local anesthetic effects of EOEC and its possible mechanisms of action in acute corneal pain in rats. EOEC was extracted by hydro-distillation in a Clevenger type apparatus from clove buds. The acute corneal pain was induced by applying a drop (40 µl) of 5 M NaCl solution on the corneal surface, and the numbers of eye wipes were counted during the first 30 s. The mechanical sensation of the cornea was evaluated by calibrated Von Frey filaments. Systemic administration of EOEC (100 and 200 mg/kg, SC) and morphine (2.5 and 5 mg/kg, IP) produced a significant antinociceptive effect in acute corneal pain. Pretreatment with naloxone or atropine prevented the EOEC-induced analgesia. However, L-arginine and methylene blue did not change the suppressive effect of EOEC on corneal pain response. Topical application of EOEC, eugenol and lidocaine significantly decreased corneal sensitivity. Combination treatments of eugenol (25 µg) with lidocaine (0.5%) and EOEC (50 µg) with lidocaine (0.5%) also significantly suppressed corneal sensitivity. Systemic administration of EOEC produced analgesia in the acute corneal pain through mechanisms that involved both opioidergic and cholinergic systems. In addition, topical instillation of EOEC, eugenol, and lidocaine produced local anesthesia in the rat cornea. Sub-anesthetic doses of EOEC or eugenol produced a significant local anesthetic effect when concurrently used with the sub-anesthetic dose of lidocaine. PMID:27651809

  13. Systemic cyclosporine and corneal transplantation.

    PubMed

    Ziaei, Mohammed; Ziaei, Fatemeh; Manzouri, Bita

    2016-02-01

    Corneal transplantation is the most commonly performed tissue transplant boasting over a century of history, science, and tradition. While favorable outcomes have been reported after penetrating keratoplasty, rejection remains a major cause of graft failure. The long-term survival rates of this relatively immunologically privileged tissue are only just comparable to those of vascularized organs. While corticosteroids treatment remains the gold standard for postoperative immunomodulation, other agents have been utilized in an ongoing effort to improve graft survival and patient outcomes. One of the most promising immunomodulatory substances whose immunosuppressive effect has revolutionized solid organ transplantation is cyclosporine (CsA). A calcineurin inhibitor, cyclosporine has been used as an immunosuppressive agent in corneal transplantation since the 1980's. Although some studies have shown beneficial effects of cyclosporine in both low- and high-risk corneal transplant patients the use of cyclosporine in rejection prophylaxis and treatment remain controversial and disputable. We herein present a literature review on the role of systemic cyclosporine in corneal transplantation.

  14. Biomechanics of Corneal Ring Implants

    PubMed Central

    2015-01-01

    Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. Results: For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. Conclusions: The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus. PMID:26312619

  15. Corneal microprojections in coleoid cephalopods.

    PubMed

    Talbot, Christopher; Jordan, Thomas M; Roberts, Nicholas W; Collin, Shaun P; Marshall, N Justin; Temple, Shelby E

    2012-12-01

    The cornea is the first optical element in the path of light entering the eye, playing a role in image formation and protection. Corneas of vertebrate simple camera-type eyes possess microprojections on the outer surface in the form of microridges, microvilli, and microplicae. Corneas of invertebrates, which have simple or compound eyes, or both, may be featureless or may possess microprojections in the form of nipples. It was previously unknown whether cephalopods (invertebrates with camera-type eyes like vertebrates) possess corneal microprojections and, if so, of what form. Using scanning electron microscopy, we examined corneas of a range of cephalopods and discovered nipple-like microprojections in all species. In some species, nipples were like those described on arthropod compound eyes, with a regular hexagonal arrangement and sizes ranging from 75 to 103 nm in diameter. In others, nipples were nodule shaped and irregularly distributed. Although terrestrial invertebrate nipples create an antireflective surface that may play a role in camouflage, no such optical function can be assigned to cephalopod nipples due to refractive index similarities of corneas and water. Their function may be to increase surface-area-to-volume ratio of corneal epithelial cells to increase nutrient, gas, and metabolite exchange, and/or stabilize the corneal mucous layer, as proposed for corneal microprojections of vertebrates.

  16. IL-17 and VEGF are necessary for efficient corneal nerve regeneration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contribution of acute inflammation to sensory nerve regeneration was investigated in the murine cornea using a model of corneal abrasion that removes the stratified epithelium and subbasal nerve plexus. Abrasion induced accumulation of IL-17(+) CCR6(+) yo T cells, neutrophils, and platelets in t...

  17. Localization and Expression of Zonula Occludins-1 in the Rabbit Corneal Epithelium following Exposure to Benzalkonium Chloride

    PubMed Central

    Zhang, Zhenhao; Chen, Lelei; Xie, Hui; Dong, Nuo; Chen, Yongxiong; Liu, Zuguo

    2012-01-01

    Preservatives are a major component of the ophthalmic preparations in multi-dose bottles. The purpose of this study was to investigate the acute effect of benzalkonium chloride (BAC), a common preservative used in ophthalmic preparations, on the localization and expression of zonula occludens (ZO)-1 in the rabbit corneal epithelium in vivo. BAC at 0.005%, 0.01%, or 0.02% was topically applied to one eye each of albino rabbits at 5 min intervals for a total of 3 times. The contralateral untreated eyes served as controls. The following clinical indications were evaluated: Schirmer test, tear break-up time (BUT), fluorescein and rose Bengal staining. The structure of central cornea was examined by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance and permeability to carboxy fluorescein. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of ZO-1, 2, occludin, claudin-1, Ki67 and cell apoptosis in the epithelium. The expression of ZO-1 in the corneal epithelium was also examined by western blot and reverse transcription-polymerase chain reaction analyses. Exposure to BAC resulted in higher rose Bengal staining scores while no significant changes in BUT, Schirmer and corneal florescein scores. It also induced corneal epithelial cell damage, dispersion of ZO-1 and ZO-2 from their normal locus at the superficial layer and disruption of epithelial barrier function. However, the amounts of ZO-1 mRNA and protein in the corneal epithelium were not affected by BAC treatment. Exposure to BAC can quickly impair the corneal epithelium without tear deficiency. BAC disrupts the tight junctions of corneal epithelium between superficial cells in the rabbit corneal epithelium in vivo. PMID:22815857

  18. Turning the tide of corneal blindness.

    PubMed

    Oliva, Matthew S; Schottman, Tim; Gulati, Manoj

    2012-01-01

    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. PMID:22944753

  19. Turning the tide of corneal blindness.

    PubMed

    Oliva, Matthew S; Schottman, Tim; Gulati, Manoj

    2012-01-01

    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.

  20. Prenatal management and perinatal outcome in giant placental chorioangioma complicated with hydrops fetalis, fetal anemia and maternal mirror syndrome

    PubMed Central

    2012-01-01

    Background Giant placental chorioangiomas have been associated with a number of severe fetal complications and high perinatal mortality. Case presentation We report a case of giant chorioangioma with fetal hydrops, additionally complicated by severe anemia, mild cardiomegaly with hyperdinamic heart circulation and maternal mirror syndrome. Intrauterine blood transfusion and amniodrainage was performed at 29 weeks. Worsening of the fetal and maternal condition prompted us to proceed with delivery at 29 + 5 weeks. The newborn died 3 hours later due to pulmonary hypoplasia and hemodynamic failure. Maternal course was favourable, mirror syndrome resolved in the second day and the patient was discharged four days following delivery. Conclusions In the case described here, fetal condition got worse despite of the anemia correction and amniodrainage. Our outcome raises the issue whether additional intrauterine clinical intervention, as intersticial laser, should have been performed to stop further deterioration of the fetal condition when progressive severe hydrops develops. PMID:22840187

  1. Nonimmune fetal hydrops and placentomegaly: Diagnosis of familial Wiedemann-Beckwith syndrome with trisomy 11p15 using FISH

    SciTech Connect

    Drut, R.M.; Drut, R.

    1996-03-15

    We have studied a family in which four members of the same generation were affected with Wiedemann-Beckwith syndrome (WBS). Trisomy 11p15 was demonstrated using molecular probes in interphase nuclei of formalin-fixed paraffin-embedded placenta from a stillborn fetus and in peripheral blood lymphocytes from two liveborn female relatives. Clinical examination showed nonimmune hydrops and placentomegaly in two siblings and multiple phenotypic abnormalities consistent with WBS in the two other relatives. Paternal karyotype of the stillborn infants demonstrated a reciprocal translocation (46,XY,t(10;11) (q26;p15)) explaining the origin of the extra 11p15 material. This study illustrates the advantages of FISH for interphase analysis of chromosome aberrations otherwise not detected even by conventional cytogenetic analysis and documents that nonimmune hydrops associated with placentomegaly may be presenting features in familial WBS. 24 refs., 6 figs.

  2. [Regeneration and fibrosis of corneal tissues].

    PubMed

    Simirskiĭ, V N

    2014-01-01

    In this review, the features of the regeneration of corneal tissue and its disorders leading to the development of fibrosis are considered. The data on the presence of stem (clonogenic) cell pool in the corneal tissues (epithelium, endothelium, stroma) are given; these cells can serve as a source for regeneration of the tissues at injury or various diseases. The main steps of regeneration of corneal tissues and their disorders that lead to outstripping proliferation of myofibroblasts and secretion of extracellular matrix in the wound area and eventually cause the formation of connective tissue scar and corneal opacity are considered. Particular attention is given to the successes of translational medicine in the treatment of corneal tissue fibrosis. The methods of cell therapy aimed at the restoration of stem cell pool of corneal tissues are the most promising. Gene therapy provides more opportunities; one of its main objectives is the suppression of the myofibroblast proliferation responsible for the development of fibrosis.

  3. Regenerative Cell Therapy for Corneal Endothelium.

    PubMed

    Bartakova, Alena; Kunzevitzky, Noelia J; Goldberg, Jeffrey L

    2014-09-01

    Endothelial cell dysfunction as in Fuchs dystrophy or pseudophakic bullous keratopathy, and the limited regenerative capacity of human corneal endothelial cells (HCECs), drive the need for corneal transplant. In response to limited donor corneal availability, significant effort has been directed towards cell therapy as an alternative to surgery. Stimulation of endogenous progenitors, or transplant of stem cell-derived HCECs or in vitro-expanded, donor-derived HCECs could replace traditional surgery with regenerative therapy. Ex vivo expansion of HCECs is technically challenging, and the basis for molecular identification of functional HCECs is not established. Delivery of cells to the inner layer of the human cornea is another challenge: different techniques, from simple injection to artificial corneal scaffolds, are being investigated. Despite remaining questions, corneal endothelial cell therapies, translated to the clinic, represent the future for the treatment of corneal endotheliopathies. PMID:25328857

  4. [Recent studies on corneal epithelial barrier function].

    PubMed

    Liu, F F; Li, W; Liu, Z G; Chen, W S

    2016-08-01

    Corneal epithelium, the outermost layer of eyeball, is the main route for foreign materials to enter the eye. Under physiological conditions, the corneal epithelial superficial cells form a functionally selective permeability barrier. Integral corneal epithelial barrier function not only ensures the enrolling of nutrients which is required for regular metabolism, but also prevents foreign bodies, or disease-causing microorganism invasion. Recently, a large number of clinical and experimental studies have shown that abnormal corneal epithelial barrier function is the pathological basis for many ocular diseases. In addition, some study found that corneal epithelial barrier constitutes a variety of proteins involved in cell proliferation, differentiation, apoptosis, and a series of physiological and pathological processes. This paper reviewed recent studies specifically on the corneal epithelial barrier, highlights of its structure, function and influence factors. (Chin J Ophthalmol, 2016, 52: 631-635). PMID:27562284

  5. Effects of Topically Applied Vitamin D during Corneal Wound Healing

    PubMed Central

    Reins, Rose Y.; Hanlon, Samuel D.; Magadi, Sri; McDermott, Alison M.

    2016-01-01

    Vitamin D is an important regulator of immune function and largely acts to dampen chronic inflammatory events in a variety of tissues. There is also accumulating evidence that vitamin D acts to enhance initial inflammation, beneficial during both infection and wound healing, and then promotes resolution and prevention of chronic, damaging inflammation. The current study examines the effect of topical vitamin D in a mouse of model of corneal epithelial wound healing, where acute inflammation is necessary for efficient wound closure. At 12 and 18 hours post-wounding, vitamin D treatment significantly delayed wound closure by ~17% and increased infiltration of neutrophils into the central cornea. Basal epithelial cell division, corneal nerve density, and levels of VEGF, TGFβ, IL-1β, and TNFα were unchanged. However, vitamin D increased the production of the anti-microbial peptide CRAMP 12 hours after wounding. These data suggest a possible role for vitamin D in modulating corneal wound healing and have important implications for therapeutic use of vitamin D at the ocular surface. PMID:27035345

  6. MR imaging of Ménière's disease after combined intratympanic and intravenous injection of gadolinium using HYDROPS2.

    PubMed

    Naganawa, Shinji; Yamazaki, Masahiro; Kawai, Hisashi; Bokura, Kiminori; Iida, Tatsuo; Sone, Michihiko; Nakashima, Tsutomu

    2014-01-01

    Endolymphatic hydrops (EH) in Ménière's disease is currently evaluated by 3-dimensional (3D)-real inversion recovery (IR) sequence after intratympanic (IT) administration of gadolinium (Gd) or by heavily T2-weighted (hT2W)-3D-fluid-attenuated IR (FLAIR) sequence after intravenous (IV) injection of Gd. Unilateral IT injection is usually performed. We employed a method in which we simultaneously administered contrast into one ear intravenously (IV side) and into the other ear both intravenously and intratympanically (IT + IV side) to evaluate EH in 10 patients with Ménière's disease. We then compared a HYDROPS2 image obtained by subtracting magnetic resonance cisternography from hT2W-3D-FLAIR with an image obtained by 3D-real IR and found that we could evaluate EH in all ears on the HYDROPS2 image but only in the IT + IV side on the 3D-real IR image.

  7. Primary corneal melanocytoma in a Collie.

    PubMed

    Bauer, Bianca; Leis, Marina L; Sayi, Soraya

    2015-09-01

    A 6-year-old female, spayed Collie was referred to the Western College of Veterinary Medicine for a 12-month history of a progressive right corneal mass. A superficial keratectomy was performed and histopathology revealed a corneal melanocytoma with complete excision. There has been no recurrence of the neoplasm to date (12 months). This is the first known report of an isolated corneal melanocytoma in a canine. PMID:25296627

  8. [Corneal manifestations of measles in the unvaccinated adult: two typical cases during an epidemic].

    PubMed

    M'garrech, M; Gendron, G; de Monchy, I; Pogorzalek, N; Rebaudet, S; Vittecoq, D; Labetoulle, M

    2013-03-01

    Measles is a disease due to morbillivirus, which belongs to the paramyxoviridae subfamily. It affects mostly young patients, and evolves through four phases: incubation, invasion, eruption and desquamation. Ophthalmic manifestations may occur during the invasive and eruptive phases. Conjunctivitis is the most common ophthalmologic manifestation and is often asymptomatic. Measles keratitis is the most concerning manifestation, with possible corneal ulcer, bacterial superinfection and corneal perforation. We report two cases of acute keratitis occurring during the eruptive phase of measles in two unvaccinated young adults. The involvement was central and strictly epithelial in both patients. The outcome was favorable with symptomatic treatment.

  9. Recurrent corneal erosion: clinical features.

    PubMed

    Hope-Ross, M W; Chell, P B; Kervick, G N; McDonnell, P J

    1994-01-01

    The clinical features of a group of 30 patients with recalcitrant recurrent corneal erosions (i.e. those who failed to respond to conventional therapy) were evaluated. Associated ocular and facial abnormalities were documented. Meibomian gland dysfunction was present in all patients as manifest by dropout and inspissation of the meibomian glands, reduced tear film break-up time and debris in the tear film. Dropout of meibomian glands was present in 25 (83%) patients and was maximum in the medial half of the lid in 21 (84%) of these 25 patients. Tear film break-up time was reduced in all patients, being instant in 7 (23%), between 1 and 5 seconds in 22 (74%) and between 10 and 15 seconds in 1 (3%) patient. Superficial corneal abnormalities were present in 28 (93%) patients as manifest by maps, dots and fingerprints. Facial abnormalities such as telangiectasia, rhinophyma and acne rosacea were present in 22 (73%) patients. The findings of our study suggest an association between recalcitrant recurrent corneal erosions and meibomian gland dysfunction.

  10. KLF1-null neonates display hydrops fetalis and a deranged erythroid transcriptome

    PubMed Central

    Magor, Graham W.; Tallack, Michael R.; Gillinder, Kevin R.; Bell, Charles C.; McCallum, Naomi; Williams, Bronwyn

    2015-01-01

    We describe a case of severe neonatal anemia with kernicterus caused by compound heterozygosity for null mutations in KLF1, each inherited from asymptomatic parents. One of the mutations is novel. This is the first described case of a KLF1-null human. The phenotype of severe nonspherocytic hemolytic anemia, jaundice, hepatosplenomegaly, and marked erythroblastosis is more severe than that present in congenital dyserythropoietic anemia type IV as a result of dominant mutations in the second zinc-finger of KLF1. There was a very high level of HbF expression into childhood (>70%), consistent with a key role for KLF1 in human hemoglobin switching. We performed RNA-seq on circulating erythroblasts and found that human KLF1 acts like mouse Klf1 to coordinate expression of many genes required to build a red cell including those encoding globins, cytoskeletal components, AHSP, heme synthesis enzymes, cell-cycle regulators, and blood group antigens. We identify novel KLF1 target genes including KIF23 and KIF11 which are required for proper cytokinesis. We also identify new roles for KLF1 in autophagy, global transcriptional control, and RNA splicing. We suggest loss of KLF1 should be considered in otherwise unexplained cases of severe neonatal NSHA or hydrops fetalis. PMID:25724378

  11. Delayed endolymphatic hydrops and its relationship to Meniére's disease.

    PubMed

    Schuknecht, H F; Suzuka, Y; Zimmermann, C

    1990-11-01

    Delayed endolymphatic hydrops (EH) can be characterized as having ipsilateral and contralateral types. They are similar in that both have early and late phases of otologic symptoms and that the early phase is a profound hearing loss in one ear. The late phases differ, however, in that the ipsilateral type develops the symptoms of EH (episodic vertigo) in the deaf ear and the contralateral type develops the symptoms of EH (fluctuating hearing loss and/or episodic vertigo) in the hearing ear. In more than half the cases of both types of delayed EH, the profound hearing losses in the early phase are simply discovered to be present in early childhood without a known time of onset. The temporal bones of two patients with contralateral delayed EH show pathologic changes in the deaf ears that are similar to those known to occur in mumps and measles labyrinthitis, whereas the pathologic changes in the hearing ears are similar to those known to occur in Meniere's disease. These observations support the proposition that Meniere's disease may occur as a delayed sequela of inner ear damage sustained during an attack of subclinical viral labyrinthitis occurring in childhood. PMID:2241008

  12. Right-sided diaphragmatic eventration: a rare cause of non-immune hydrops fetalis.

    PubMed

    Zankl, A; Osterheld, M-C; Vial, Y; Beurret, N; Meuli, R; Meagher-Villemure, K; Roth-Kleiner, M

    2007-01-01

    We report 2 cases of non-immune hydrops fetalis (NIHF) in which autopsy findings revealed an association with right-sided congenital diaphragmatic eventration (CDE). Both patients born at 30 weeks of gestation presented with severe generalized skin oedema, pleural effusions and ascites. They both died shortly after birth of cardiorespiratory insufficiency due to lung hypoplasia and low output heart failure. The right thoracic cavity was filled with the membranous but intact right diaphragm covering the herniated visceral organs including parts of the liver, small bowel and colon surrounded by voluminous ascites. In similar fashion to the situation seen in congenital diaphragmatic hernia (CDH), the displaced visceral organs led to impaired lung growth resulting in important lung hypoplasia and obstructed venous return. Extravascular liquid accumulation was probably further aggravated by hypoproteinaemia secondary to liver dysfunction resulting from the venous congestion and cardiac failure. In summary, CDE is a rare condition resulting from impaired ingrowth of muscle fibres into the diaphragm during the first trimester. Prenatal differentiation of CDE from CDH is a real challenge. The association of CDE and NIHF has not been previously described.

  13. A Case of Thanatophoric Dysplasia Type I with Fetal Hydrops in the First Trimester

    PubMed Central

    Calongos, Giannina; Hori, Masateru; Ogino, Mai; Sawai, Hideaki

    2016-01-01

    During a routine prenatal exam, a 36-year-old female in her third pregnancy was diagnosed with fetal hydrops at 11 weeks of gestation. The pregnancy was monitored with periodic ultrasounds; however, spontaneous resolution was not observed. Amniotic fluid examination at 16 weeks of gestation showed a normal karyotype; however, macrocephaly, a narrow thorax, and shortening of the long bones were observed on ultrasonography. With the strong suspicion of a fetal skeletal disease, specifically thanatophoric dysplasia (TD), and after extensive genetic counseling, termination of the pregnancy was performed per the parents' wishes with mechanical cervical dilation and gemeprost (PGE1) administration. Following delivery, the fetus was found to have macrocephaly, a narrow bell-shaped thorax, and a protuberant abdomen, as well as curved long bones, H-shaped platyspondyly, and curved clavicles on skeletal radiography. As a result, the fetus was diagnosed with TD type I. This case illustrates that although TD is a rare disease, an accurate prenatal diagnosis can be made with the use of ultrasonography. PMID:27006844

  14. A Case of Thanatophoric Dysplasia Type I with Fetal Hydrops in the First Trimester.

    PubMed

    Calongos, Giannina; Hori, Masateru; Ogino, Mai; Sawai, Hideaki

    2016-01-01

    During a routine prenatal exam, a 36-year-old female in her third pregnancy was diagnosed with fetal hydrops at 11 weeks of gestation. The pregnancy was monitored with periodic ultrasounds; however, spontaneous resolution was not observed. Amniotic fluid examination at 16 weeks of gestation showed a normal karyotype; however, macrocephaly, a narrow thorax, and shortening of the long bones were observed on ultrasonography. With the strong suspicion of a fetal skeletal disease, specifically thanatophoric dysplasia (TD), and after extensive genetic counseling, termination of the pregnancy was performed per the parents' wishes with mechanical cervical dilation and gemeprost (PGE1) administration. Following delivery, the fetus was found to have macrocephaly, a narrow bell-shaped thorax, and a protuberant abdomen, as well as curved long bones, H-shaped platyspondyly, and curved clavicles on skeletal radiography. As a result, the fetus was diagnosed with TD type I. This case illustrates that although TD is a rare disease, an accurate prenatal diagnosis can be made with the use of ultrasonography. PMID:27006844

  15. Incidence of virus infection as a cause of Meniere's disease or endolymphatic hydrops assessed by electrocochleography.

    PubMed

    Selmani, Ziane; Marttila, Timo; Pyykkö, Ilmari

    2005-04-01

    Meniere's disease (MD) may follow viral infection such as by neurotropic viruses known to invade the endolymphatic sac (ES) and provoke endolymphatic hydrops (EH). The objective of this study was to investigate whether neurotropic viruses may cause infection of the inner ear and provoke EH. Antiviral immunoglobulin (IgG) assay against herpes simplex 1 (HSV1), herpes simplex 2 (HSV2), adenovirus (ADV), varicella zoster virus (VZV) and cytomegalovirus (CMV) were performed in 109 patients with an advanced stage of MD and compared with those obtained from 26 patients operated on because of vestibular schwannoma (VS), who served as a control group, to evaluate whether there is an association between the IgG levels and the ECoGs summating potential/action potential ratio (SP/AP ratio) in the MD group. In MD patients, the IgG titre against VZV and ADV were significantly higher than in the control (schwannoma) group. However, no correlation was found between the IgG levels against ADV and VZV with the SP/AP ratio. Neurotropic viruses such VZV and ADV may play a role in the pathogenesis of MD, despite the absence of association between the levels of IgG titres and the SP/AP ratio.

  16. [Fetal cardiac rhabdomyoma as a rare cause of hydrops fetalis. A report of a case].

    PubMed

    Gayón Vera, Eduardo; López, Candiani Carlos; Carrera González, José Ernesto

    2009-12-01

    Cardiac tumors are rare entities at any age. The reported incidence in fetal echocardiograms is 0.17%. This case report presents the detection of a cardiac rhabdomyoma in a 27.5 weeks of gestational age (WGA) fetus during a routine sonogram. Treatment with terbutaline, as a cardiac inotropic and chronotropic agent, was started because of fetal bradichardia of 86 beats per minute, as well as fetal lung maturity inductors. At 30 WGA furosemide was added because of fetal hydrops. At 32 WGA a cesarean section was performed. The fetal development at the time of birth was in accordance to the gestational age, the newborn weight was 1,820 g and the Apgar score was 1-0, at one and five minutes after delivery. The newborn died immediately after the interruption of the umbilical circulation, because of a 90% obstruction of the left ventricular cavity caused by the tumor. The present case is an evidence of the utility of a medical treatment in a severely ill fetus, that allowed it to continue with its normal development for four weeks after the diagnosis and opens the possibility for fetal medical therapy in the future for similar cases. PMID:20077883

  17. Piezo2 expression in corneal afferent neurons.

    PubMed

    Bron, Romke; Wood, Rhiannon J; Brock, James A; Ivanusic, Jason J

    2014-09-01

    Recently, a novel class of mechanically sensitive channels has been identified and have been called Piezo channels. In this study, we explored Piezo channel expression in sensory neurons supplying the guinea pig corneal epithelium, which have well-defined modalities in this species. We hypothesized that a proportion of corneal afferent neurons express Piezo2, and that these neurons are neurochemically distinct from corneal polymodal nociceptors or cold-sensing neurons. We used a combination of retrograde tracing to identify corneal afferent neurons and double label in situ hybridization and/or immunohistochemistry to determine their molecular and/or neurochemical profile. We found that Piezo2 expression occurs in ∼26% of trigeminal ganglion neurons and 30% of corneal afferent neurons. Piezo2 corneal afferent neurons are almost exclusively non-calcitonin gene-related peptide (CGRP)-immunoreactive (-IR), medium- to large-sized neurons that are NF200-IR, suggesting they are not corneal polymodal nociceptors. There was no coexpression of Piezo2 and transient receptor potential cation channel subfamily M member 8 (TRPM8) transcripts in any corneal afferent neurons, further suggesting that Piezo2 is not expressed in corneal cold-sensing neurons. We also noted that TRPM8-IR or CGRP-IR corneal afferent neurons are almost entirely small and lack NF200-IR. Piezo2 expression occurs in a neurochemically distinct subpopulation of corneal afferent neurons that are not polymodal nociceptors or cold-sensing neurons, and is likely confined to a subpopulation of pure mechano-nociceptors in the cornea. This provides the first evidence in an in vivo system that Piezo2 is a strong candidate for a channel that transduces noxious mechanical stimuli.

  18. [A comparison of corneal sensitivity between healthy cats and cats with corneal sequestra].

    PubMed

    Wagner, Frank; Meyer-Lindenberg, Andrea; Heider, Hans-Josef; Görig, Christiane; Nolte, Ingo

    2003-01-01

    In order to establish reference values for corneal sensitivity in ophthalmologically healthy persians (n = 40) and domestic short hair cats (n = 60) a prospective study was conducted. Furthermore corneal sensitivity in 48 cats with a corneal sequestrum was measured. Corneal sensitivity was recorded with the help of the aesthesiometer according to Cochet and Bonnet in five different corneal locations (central, nasal, dorsal, temporal, and ventral). The sensitivity for the central corneal region was recorded as amounting to 3.58 +/- 0.56 cm in ophthalmologically healthy domestic short hair cats and to 2.97 +/- 0.58 cm in healthy persian cats. The sensitivity of the central corneal area of a cat with a corneal sequester only amounts to 2.03 +/- 0.53 cm. Between the diseased and the healthy eyes no statistical difference could be demonstrated for any of the measured corneal locations. The sensitivity of the peripheral corneal locations is significantly lower than that of the central corneal region in all three groups examined. PMID:14526473

  19. Matrix metalloproteinase 14 overexpression reduces corneal scarring.

    PubMed

    Galiacy, S D; Fournié, P; Massoudi, D; Ancèle, E; Quintyn, J-C; Erraud, A; Raymond-Letron, I; Rolling, F; Malecaze, F

    2011-05-01

    Once a corneal scar develops, surgical management remains the only option for visual rehabilitation. Corneal transplantation is the definitive treatment for a corneal scar. In addition to the challenges posed by graft rejections and other postoperative complications, the lack of high-quality donor corneas can limit the benefits possible with keratoplasty. The purpose of our study was to evaluate a new therapeutic strategy for treating corneal scarring by targeting collagen deposition. We overexpressed a fibril collagenase (matrix metalloproteinase 14 (MMP14)) to prevent collagen deposition in the scar tissue. We demonstrated that a single and simple direct injection of recombinant adeno-associated virus-based vector expressing murine MMP14 can modulate gene expression of murine stromal keratocytes. This tool opens new possibilities with regard to treatment. In a mouse model of corneal full-thickness incision, we observed that MMP14 overexpression reduced corneal opacity and expression of the major genes involved in corneal scarring, especially type III collagen and α-smooth muscle actin. These results represent proof of concept that gene transfer of MMP14 can reduce scar formation, which could have therapeutic applications after corneal trauma.

  20. Corneal hysteresis and its relevance to glaucoma

    PubMed Central

    Deol, Madhvi; Taylor, David A.; Radcliffe, Nathan M.

    2015-01-01

    Purpose of review Glaucoma is a leading cause of irreversible blindness worldwide. It is estimated that roughly 60.5 million people had glaucoma in 2010 and that this number is increasing. Many patients continue to lose vision despite apparent disease control according to traditional risk factors. The purpose of this review is to discuss the recent findings with regard to corneal hysteresis, a variable that is thought to be associated with the risk and progression of glaucoma. Recent findings Low corneal hysteresis is associated with optic nerve and visual field damage in glaucoma and the risk of structural and functional glaucoma progression. In addition, hysteresis may enhance intraocular pressure (IOP) interpretation: low corneal hysteresis is associated with a larger magnitude of IOP reduction following various glaucoma therapies. Corneal hysteresis is dynamic and may increase in eyes after IOP-lowering interventions are implemented. Summary It is widely accepted that central corneal thickness is a predictive factor for the risk of glaucoma progression. Recent evidence shows that corneal hysteresis also provides valuable information for several aspects of glaucoma management. In fact, corneal hysteresis may be more strongly associated with glaucoma presence, risk of progression, and effectiveness of glaucoma treatments than central corneal thickness. PMID:25611166

  1. [To Protect Corneal Transparency against Diseases].

    PubMed

    Usui, Tomohiko

    2016-03-01

    To protect corneal transparency, we tried to develop a new therapeutic strategy for corneal neovascularization, corneal scar, and TGFBI-related corneal dystrophy using nucleic acid drug. 1. The expression of angiopietin-like protein 2 (Angptl2) markedly increased in the neovascularized corneas compared to the normal cornea, and Angtpl2 was(a potent inducer of inflammatory corneal neovascularization. We have produced a single-stranded proline-modified short hairpin anti-Angptl2 ribonucleric acid interference (RNAi) molecule that is carried in a lipid nanoparticle for topical application. We have found this agent can penetrate all layers of the cornea. Angptl2 mRNA expression and corneal neovascularization were inhibited in a mouse alkari injury model by topical application of this agent. Thus, this modified RNAi agent is a new topical formulation for use against corneal neovascularization and scar. 2. Human umbilical vein endothelial cells (HUVECs) were cultured with human corneal keratocytes under serum-free conditions. We performed microarray gene-expression analysis in the coculture system and selected angiopoietin-like protein 7 (Angptl7). In vivo, intrastromal injections of an anti-Angptl7 RNAi agent into the avascular corneal stroma of mice resulted in the growth of blood vessels. Further, we examined the effects of Angptl7 on corneal nerves using culture rat trigeminal cells and this molecule had neurotrophic property on the cornea. Thus, Angpt17 is a unique molecule, which contain its bilateral character (anti-angiogenic and neurotrophic) in the cornea; an agonistic nucleic acid drug for Angptl7 may be a new therapeutic tool for protecting corneal transparency. 3. We examined local gene editing for TGFBI-related corneal dystrophy using CRISPR-Cas9 mediated homology directed repair (HDR). Cultured corneal keratocytes were obtained from a patient of R124H granular dystrophy. The R124H gene arrangement was corrected by a tranfection of guide RNA and HDR repair

  2. Corneal neovascularization and contemporary antiangiogenic therapeutics.

    PubMed

    Hsu, Chih-Chien; Chang, Hua-Ming; Lin, Tai-Chi; Hung, Kuo-Hsuan; Chien, Ke-Hung; Chen, Szu-Yu; Chen, San-Ni; Chen, Yan-Ting

    2015-06-01

    Corneal neovascularization (NV), the excessive ingrowth of blood vessels from conjunctiva into the cornea, is a common sequela of disease insult that can lead to visual impairment. Clinically, topical steroid, argon laser photocoagulation, and subconjunctival injection of bevacizumab have been used to treat corneal NV. Sometimes, the therapies are ineffective, especially when the vessels are large. Large vessels are difficult to occlude and easily recanalized. Scientists and physicians are now dedicated to overcoming this problem. In this article, we briefly introduce the pathogenesis of corneal NV, and then highlight the existing animal models used in corneal NV research-the alkali-induced model and the suture-induced model. Most of all, we review the potential therapeutic targets (i.e., vascular endothelial growth factor and platelet-derived growth factor) and their corresponding inhibitors, as well as the immunosuppressants that have been discovered in recent years by corneal NV studies.

  3. Interferometric measurements of fine corneal topography

    NASA Astrophysics Data System (ADS)

    Kasprzak, Henryk T.; Kowalik, Waldemar; Jaronski, Jaroslaw W.

    1995-02-01

    The cornea is the most refractive element in the eye. Its refractive power is about 70% of the power of the whole eye. The shape of the cornea is aspheric, and almost always has no rotational symmetry. Even small surface irregularities can cause a perceptible reduction in visual acuity. Standard methods for evaluation of the corneal topography used in clinical practice include keratometry, photokeratoscopy, and computer assisted videokeratography. All of these methods used the principles of geometrical optics, and their accuracy is about 0.25 D. An application of interference phenomenon's to examine the corneal contour map significantly increase the accuracy. Using the interferometric inspection of the corneal shape one can easily observe the fine corneal topography, the fast, dynamic changes of the corneal surface, and the topology of the tear film and its irregularities. The paper presents the Twyman Green interferometer, used in experiments, an example of sequence of interferograms and their 3D presentations.

  4. Corneal autofluorescence in presence of diabetic retinopathy

    NASA Astrophysics Data System (ADS)

    Rovati, Luigi; Docchio, Franco; Azzolini, Claudio; Van Best, Jaap A.

    1998-06-01

    Recently corneal autofluorescence has been proposed as an ocular diagnostic tool for diabetic retinopathy. The method is based on the sensible increase of the natural fluorescence of corneal tissue within specific wavelength in presence of early stage of diabetic retinopathy. The main advantages of this method are that the corneal autofluorescence has been demonstrated to be not age-related and that the cornea is readily accessible to be investigated. In this study 47 insulin-dependent diabetes mellitus and 51 non-insulin- dependent diabetes mellitus patients aged 20 - 90 years have been considered. Patients were selected from the Eye Clinic of S. Raffaele Hospital. The modified Airlie House classification was used to grade the diabetic retinopathy. Corneal autofluorescence has been measured by using both a specifically designed instrument and the Fluorotron Master. Corneal autofluorescence mean value for each diabetic retinopathy measured by using both the instruments correlated with the retinopathy grade.

  5. Riboflavin for corneal cross-linking.

    PubMed

    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. PMID:27458610

  6. Visualization of endolymphatic hydrops with MR imaging in patients with Ménière's disease and related pathologies: current status of its methods and clinical significance.

    PubMed

    Naganawa, Shinji; Nakashima, Tsutomu

    2014-04-01

    Ménière's disease is an inner ear disorder characterized by vertigo attacks, fluctuating low-frequency hearing loss, ear fullness, and tinnitus. Endolymphatic hydrops has long been thought to be the pathological basis for Ménière's disease. Some patients have inner ear symptoms that do not match the diagnostic guidelines for Ménière's disease, and these are also thought to be related to endolymphatic hydrops. The diagnosis of endolymphatic hydrops is usually made based on clinical symptoms with some assistance from otological functional tests. Recently, the objective diagnosis of endolymphatic hydrops by MR imaging has become possible and many research results have been reported regarding the imaging methods, evaluation methods, the correlation between imaging results and functional otological tests and the correlation between imaging findings and clinical symptoms. In this article we summarize the development of current imaging methods, evaluation techniques and clinical reports based on a review of the literature. We also attempt to characterize the current significance and future directions of MR imaging of endolymphatic hydrops.

  7. Endolymphatic Hydrops Detected by 3-Dimensional Fluid-Attenuated Inversion Recovery MRI following Intratympanic Injection of Gadolinium in the Asymptomatic Contralateral Ears of Patients with Unilateral Ménière’s Disease

    PubMed Central

    Liu, Yupeng; Jia, Huan; Shi, Jun; Zheng, Hui; Li, Yuhua; Yang, Jun; Wu, Hao

    2015-01-01

    Background The aim of this study was to identify the incidence of endolymphatic hydrops using 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI) in the contralateral ear in patients with unilateral Ménière’s disease (MD). Material/Methods This was a prospective study. 3D-FLAIR MRI was performed with a 3 Tesla (3 T) unit 24 h after the intratympanic administration of gadolinium (Gd) in 30 unilateral MD patients with an asymptomatic contralateral ear. The incidence of contralateral involvement in unilateral MD patients and the potential correlations between the affected and contralateral ears were analyzed. Results Endolymphatic hydrops was observed in 7 of the 30 (23.3%) asymptomatic ears. The mean PTA of the asymptomatic ears in the contralateral hydrops patients (33.0±6.1 dB) was significantly higher compared with the non-hydrops patients (17.8±5.7 dB). The patients with observed contralateral hydrops exhibited a significantly longer duration of the disease compared with the non-hydrops patients (6.7±6.3 vs. 2.9±3.1 years, respectively). Furthermore, the patients with contralateral hydrops had a worse hearing level in the affected ears compared with the non-hydrops patients (70.3±7.4 vs. 52.5±3.8 dB, respectively). Conclusions Endolymphatic hydrops is closely related to hearing loss but does not necessarily result in Ménière’s symptoms. Patients with a long history of MD and severe hearing loss in the affected ear are more likely to exhibit endolymphatic hydrops in the asymptomatic contralateral ear. Adequate attention should focus on unilateral MD patients with contralateral ear hydrops because of the potential to develop bilateral MD. PMID:25742875

  8. Differential diagnosis of Schnyder corneal dystrophy.

    PubMed

    Weiss, Jayne S; Khemichian, Arbi J

    2011-01-01

    Schnyder corneal dystrophy (SCD) is a rare corneal dystrophy characterized by abnormally increased deposition of cholesterol and phospholipids in the cornea leading to progressive vision loss. SCD is inherited as an autosomal dominant trait with high penetrance and has been mapped to the UBIAD1 gene on chromosome 1p36.3. Although 2/3 of SCD patients also have systemic hypercholesterolemia, the incidence of hypercholesterolemia is also increased in unaffected members of SCD pedigrees. Consequently, SCD is thought to result from a local metabolic defect in the cornea. The corneal findings in SCD are very predictable depending on the age of the individual, with initial central corneal haze and/or crystals, subsequent appearance of arcus lipoides in the third decade and formation of midperipheral haze in the late fourth decade. Because only 50% of affected patients have corneal crystals, the International Committee for Classification of Corneal Dystrophies recently changed the original name of this dystrophy from Schnyder crystalline corneal dystrophy to Schnyder corneal dystrophy. Diagnosis of affected individuals without crystalline deposits is often delayed and these individuals are frequently misdiagnosed. The differential diagnosis of the SCD patient includes other diseases with crystalline deposits such as cystinosis, tyrosinemia, Bietti crystalline dystrophy, hyperuricemia/gout, multiple myeloma, monoclonal gammopathy, infectious crystalline keratopathy, and Dieffenbachia keratitis. Depositions from drugs such as gold in chrysiasis, chlorpromazine, chloroquine, and clofazamine can also result in corneal deposits and are different from SCD. Diseases of systemic lipid metabolism that cause corneal opacification, such as lecithin-cholesterol acyltransferase deficiency, fish eye disease and Tangier disease, should also be considered although these are autosomal recessive disorders. PMID:21540632

  9. Corneal biomechanical properties in thyroid eye disease.

    PubMed

    Karabulut, Gamze Ozturk; Kaynak, Pelin; Altan, Cıgdem; Ozturker, Can; Aksoy, Ebru Funda; Demirok, Ahmet; Yılmaz, Omer Faruk

    2014-06-01

    The purpose of this study is to investigate the effect of thyroid eye disease (TED) on the measurement of corneal biomechanical properties and the relationship between these parameters and disease manifestations. A total of 54 eyes of 27 individuals with TED and 52 eyes of 30 healthy control participants were enrolled. Thyroid ophthalmopathy activity was defined using the VISA (vision, inflammation, strabismus, and appearance/exposure) classification for TED. The intraocular pressure (IOP) measurement with Goldmann applanation tonometer (GAT), axial length (AL), keratometry, and central corneal thickness (CCT) measurements were taken from each patient. Corneal biomechanical properties, including corneal hysteresis (CH) and corneal resistance factor (CRF) and noncontact IOP measurements, Goldmann-correlated IOP (IOPg) and corneal-compensated IOP (IOPcc) were measured with the Ocular Response Analyzer (ORA) using the standard technique. Parameters such as best corrected visual acuity, axial length, central corneal thickness, and corneal curvature were not statistically significant between the two groups (p > 0.05). IOP measured with GAT was higher in participants with TED (p < 0.001). The CH of TED patients was significantly lower than that of the control group. There was no significant difference in the corneal resistance factor between groups. However, IOPg and IOPcc were significantly higher in TED patients. CH and VISA grading of TED patients showed a negative correlation (p = 0.007). In conclusion, TED affects the corneal biomechanical properties by decreasing CH. IOP with GAT and IOPg is found to be increased in these patients. As the severity of TED increases, CH decreases in these patients.

  10. Corneal endothelium: developmental strategies for regeneration

    PubMed Central

    Zavala, J; López Jaime, G R; Rodríguez Barrientos, C A; Valdez-Garcia, J

    2013-01-01

    The main treatment available for restoration of the corneal endothelium is keratoplasty. This procedure is faced with several difficulties, including the shortage of donor tissue, post-surgical complications associated with the use of drugs to prevent immune rejection, and a significant increase in the occurrence of glaucoma. Recently, surgical procedures such as Descemet's stripping endothelial keratoplasty have focused on the transplant of corneal endothelium, yielding better visual results but still facing the need for donor tissue. The emergent strategies in the field of cell biology and tissue cultivation of corneal endothelial cells aim at the production of transplantable endothelial cell sheets. Cell therapy focuses on the culture of corneal endothelial cells retrieved from the donor, in the donor's cornea, followed by transplantation into the recipient. Recently, research has focused on overcoming the challenge of harvesting human corneal endothelial cells and the generation of new biomembranes to be used as cell scaffolds in surgical procedures. The use of corneal endothelial precursors from the peripheral cornea has also demonstrated to be effective and represents a valuable tool for reducing the risk of rejection in allogeneic transplants. Several animal model reports also support the use of adult stem cells as therapy for corneal diseases. Current results represent important progresses in the development of new strategies based on alternative sources of tissue for the treatment of corneal endotheliopathies. Different databases were used to search literature: PubMed, Google Books, MD Consult, Google Scholar, Gene Cards, and NCBI Books. The main search terms used were: ‘cornea AND embryology AND transcription factors', ‘human endothelial keratoplasty AND risk factors', ‘(cornea OR corneal) AND (endothelium OR endothelial) AND cell culture', ‘mesenchymal stem cells AND cell therapy', ‘mesenchymal stem cells AND cornea', and ‘stem cells AND

  11. Infantile lethal variant of Simpson-Golabi-Behmel syndrome associated with hydrops fetalis.

    PubMed

    Terespolsky, D; Farrell, S A; Siegel-Bartelt, J; Weksberg, R

    1995-11-20

    Simpson-Golabi Behmel syndrome (SGBS) is an X-linked disorder characterized by pre- and postnatal macrosomia, minor facial anomalies, and variable visceral, skeletal, and neurological abnormalities. Since its first description by Simpson et al. [1975: BD:OA XI(2):18-24], a wide clinical range of cases has been reported. There is great variability in severity, ranging from a mild form associated with long-term survival to an early lethal form with multiple congenital anomalies and severe mental retardation. In 8 reported families, affected individuals died in infancy. Here we present 4 maternally related, male cousins with a severe variant of SGBS. One of these males was aborted therapeutically at 19 weeks of gestation following the detection of multicystic kidneys on ultrasound. The 3 liveborn males were hydropic at birth with a combination of craniofacial anomalies including macrocephaly; apparently low-set, posteriorly angulated ears; hypertelorism; short, broad nose with anteverted nares; large mouth with thin upper vermilion border; prominent philtrum; high-arched or cleft palate; short neck; redundant skin; hypoplastic nails; skeletal defects involving upper and lower limbs; gastrointestinal and genitourinary anomalies. All 3 patients were hypotonic and neurologically impaired from birth. With the exception of a trilobate left lung in one patient, the cardiorespiratory system was structurally normal. All patients died within the first 8 weeks of life of multiple complications including pneumonia and sepsis. Two SGBS kindreds, with moderate expression of the condition, have been mapped to Xq27. It is not known whether severe, familial cases, such as ours, are genetically distinct from and map to another locus. Final resolution of the genetic basis of the phenotypic variability in SGBS must await cloning and mutation analysis of the SGBS gene(s). PMID:8599356

  12. Hydrops associated with chondrodysplasia of the fetus in a miniature Scottish Highland cow.

    PubMed

    Catalina Cabrera, L; McNabb, Bret R; Woods, Sarah E; Cartoceti, Andrew N; Busch, Rosie C

    2016-03-01

    CASE DESCRIPTION A 2-year-old primiparous miniature Scottish Highland cow with an unknown breeding date was evaluated for suspected hydrops. CLINICAL FINDINGS Transabdominal and transrectal ultrasonographic examination identified a large amount of hypoechoic fluid within an enlarged uterus; the fetus could not be identified. Presence of a severely distended uterus and concerns regarding associated health risks to the cow led to the decision to induce labor. Although fluids were expelled, parturition did not progress further over the following 48 hours. Vaginal examination revealed a partially dilated cervix and an abnormally shaped fetus that was too large to pass vaginally. TREATMENT AND OUTCOME Supportive care was provided to the cow, and a stillborn bull calf was delivered by cesarean section. Grossly evident chondrodystrophic dwarfism with hydrocephalus, compatible with so-called bulldog calf malformations, was confirmed by diagnostic imaging and histopathologic evaluation. The cow recovered from surgery uneventfully and was discharged from the hospital the following day. Genetic analysis of DNA from hair roots collected from the sire and dam confirmed both were carriers of an aggrecan-1 gene mutation (bulldog dwarfism1) previously associated with dwarfism and bulldog calf malformations in Dexter cattle. CLINICAL RELEVANCE To our knowledge, this is the first reported case of bulldog calf malformations associated with an aggrecan-1 gene mutation in miniature Scottish Highland cattle, confirming that at least 1 genetic mutation associated with this condition is found in cattle breeds other than Dexter. The findings highlighted the clinical importance of testing for known genetic diseases in breeding cattle, particularly among miniature breeds. PMID:26885599

  13. Infantile lethal variant of Simpson-Golabi-Behmel syndrome associated with hydrops fetalis

    SciTech Connect

    Terespolsky, D.; Siegel-Bartelt, J.; Weksberg, R.; Farrell, S.A.

    1995-11-20

    Simpson-Golabi Behmel syndrome (SGBS) is an X-linked disorder characterized by pre- and postnatal macrosomia, minor facial anomalies, and variable visceral, skeletal, and neurological abnormalities. Since its first description by Simpson et al., a wide clinical range of cases has been reported. There is great variability in severity, ranging from a mild form associated with long-term survival to an early lethal form with multiple congenital anomalies and severe mental retardation. In 8 reported families, affected individuals died in infancy. Here we present 4 maternally related, male cousins with a severe variant of SGBS. One of these males was aborted therapeutically at 19 weeks of gestation following the detection of multicystic kidneys on ultrasound. The 3 liveborn males were hydropic at birth with a combination of craniofacial anomalies including macrocephaly; apparently low-set, posteriorly angulated ears; hypertelorism; short, broad nose with anteverted nares; large mouth with thin upper vermilion border; prominent philtrum; high-arched or cleft palate; short neck; redundant skin; hypoplastic nails; skeletal defects involving upper and lower limbs; gastrointestinal and genitourinary anomalies. All 3 patients were hypotonic and neurologically impaired from birth. With the exception of a trilobate left lung in one patient, the cardiorespiratory system was structurally normal. All patients died within the first 8 weeks of life of multiple complications including pneumonia and sepsis. Two SGBS kindreds, with moderate expression of the condition, have been mapped to Xq27. It is not known whether severe, familiar cases, such as ours, are genetically distinct from and map to another locus. Final resolution of the genetic basis of the phenotypic variability in SGBS must await cloning and mutation analysis of the SGBS gene(s). 21 refs., 4 figs., 1 tab.

  14. Corneal Regeneration by Deep Anterior Lamellar Keratoplasty (DALK) Using Decellularized Corneal Matrix

    PubMed Central

    Hashimoto, Yoshihide; Funamoto, Seiichi; Sasaki, Shuji; Negishi, Jun; Honda, Takako; Hattori, Shinya; Nam, Kwangwoo; Kimura, Tsuyoshi; Mochizuki, Manabu; Kobayashi, Hisatoshi; Kishida, Akio

    2015-01-01

    The purpose of this study is to demonstrate the feasibility of DALK using a decellularized corneal matrix obtained by HHP methodology. Porcine corneas were hydrostatically pressurized at 980 MPa at 10°C for 10 minutes to destroy the cells, followed by washing with EGM-2 medium to remove the cell debris. The HHP-treated corneas were stained with H-E to assess the efficacy of decellularization. The decellularized corneal matrix of 300 μm thickness and 6.0 mm diameter was transplanted onto a 6.0 mm diameter keratectomy wound. The time course of regeneration on the decellularized corneal matrix was evaluated by haze grading score, fluorescein staining, and immunohistochemistry. H-E staining revealed that no cell nuclei were observed in the decellularized corneal matrix. The decellularized corneal matrices were opaque immediately after transplantation, but became completely transparent after 4 months. Fluorescein staining revealed that initial migration of epithelial cells over the grafts was slow, taking 3 months to completely cover the implant. Histological sections revealed that the implanted decellularized corneal matrix was completely integrated with the receptive rabbit cornea, and keratocytes infiltrated into the decellularized corneal matrix 6 months after transplantation. No inflammatory cells such as macrophages, or neovascularization, were observed during the implantation period. The decellularized corneal matrix improved corneal transparency, and remodelled the graft after being transplanted, demonstrating that the matrix obtained by HHP was a useful graft for corneal tissue regeneration. PMID:26161854

  15. Corneal modeling for analysis of photorefractive keratectomy

    NASA Astrophysics Data System (ADS)

    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

  16. Molecular analysis of patients with {Beta}-glucuronidase deficiency presenting as hydrops fetalis or as early mucopolysaccharidosis VII

    SciTech Connect

    Vervoort, R.; Liebaers, I.; Lissens, W.

    1996-03-01

    Although not all mucopolysaccharidosis type VII (MPS VII) neonates present with hydrops fetalis or with related symptoms, hydrops fetalis is a common form of presentation of this mucopolysaccharidosis. We used reverse-transcription-PCR-SSCP and direct sequencing to screen for mutations in the human {beta}-glucuronidase cDNA of 17 MPS VII patients with severe presentation of the disease. Mutations resulting in an unstable mRNA were detected in genomic DNA with direct sequencing of the PCR-amplified {beta}-glucuronidase exons. We found extensive genetic heterogeneity in MPS VII alleles: in addition to 6 of 12 previously reported mutations (L176F, R216W, R357X, R382C, W507X, and W627C), we detected 14 undescribed mutations in the {beta}-glucuronidase coding region that produce MPS VII alleles (G136R, E150K, S312X, Y320S, Y320C, H351Y, R382H, R374C, R435P, R477W, G572D, Y508C, K606N, and 1900{Delta}GA). The mutations in hydropic fetuses were widely scattered in the {beta}-glucuronidase gene. Analysis of three polymorphic sites of the mutant alleles (1766T/C, 1972C/T, and a new 1091+27C/G polymorphism) allowed exclusion of identity by descent for some recurrent mutations. Three of four mutations introducing a premature translation stop codon were found to affect mRNA abundance and/or structure. Expression studies provided evidence for the causal relationship between each of the mutations found in MPS VII alleles and the enzyme deficiency, in that all mutations identified exhibited markedly reduced enzyme activity expressed in COS7 cells following transfection with the mutant cDNA. 52 refs., 4 figs., 5 tabs.

  17. Molecular analysis of patients with beta-glucuronidase deficiency presenting as hydrops fetalis or as early mucopolysaccharidosis VII.

    PubMed Central

    Vervoort, R.; Islam, M. R.; Sly, W. S.; Zabot, M. T.; Kleijer, W. J.; Chabas, A.; Fensom, A.; Young, E. P.; Liebaers, I.; Lissens, W.

    1996-01-01

    Although not all mucopolysaccharidosis type VII (MPS VII) neonates present with hydrops fetalis or with related symptoms, hydrops fetalis is a common form of presentation of this mucopolysaccharidosis. We used reverse-transcription-PCR-SSCP and direct sequencing to screen for mutations in the human beta-glucuronidase cDNA of 17 MPS VII patients with severe presentation of the disease. Mutations resulting in an unstable mRNA were detected in genomic DNA with direct sequencing of the PCR-amplified beta-glucuronidase exons. We found extensive genetic heterogeneity in MPS VII alleles: in addition to 6 or 12 previously reported mutations (L176F, R216W, R357X, R382C, W507X, and W627C), we detected 14 undescribed mutations in the beta-glucuronidase coding region that produce MPS VII alleles (G136R, E150K, S312X, Y320S, Y320C, H351Y, R382H, R374C, R435P, R477W, G572D, Y508C, K606N and 1900 delta GA). The mutations in hydropic fetuses were widely scattered in the beta-glucuronidase gene. Analysis of three polymorphic sites of the mutant alleles (1766T/C, 1972C/T and a new 1091+27C/G polymorphism) allowed exclusion of identity by descent for some recurrent mutations. Three of four mutations introducing a premature translation stop codon were found to affect mRNA abundance and/or structure. Expression studies provided evidence for the causal relationship between each of the mutations found in MPS VII alleles and the enzyme deficiency, in that all mutations identified exhibited markedly reduced enzyme activity expressed in COS7 cells following transfection with the mutant cDNA. Images Figure 2 Figure 3A Figure 3BC Figure 4 PMID:8644704

  18. Defective pericyte recruitment of villous stromal vessels as the possible etiologic cause of hydropic change in complete hydatidiform mole.

    PubMed

    Kim, Kyu Rae; Sung, Chang Ohk; Kwon, Tae Jeong; Lee, JungBok; Robboy, Stanley J

    2015-01-01

    The pathogenetic mechanism underlying the hydropic change in complete hydatidiform moles (CHMs) is poorly understood. A growing body of data suggests that pericytes play a role in vascular maturation. Since maturation of villous stromal vessels in CHMs is markedly impaired at early stages, we postulated that a defect in pericytes around stromal vessels in chorionic villi might cause vascular immaturity and subsequent hydropic change. To investigate this, we examined several markers of pericytes, namely, α-smooth muscle actin (α-SMA), platelet-derived growth factor receptor-β (PDGFR-β), and desmin, in 61 normally developing placentas and 41 CHMs with gestational ages of 4-12 weeks. The ultrastructure of villous stromal vessels was also examined. Mature blood vessels from normal placentas show patent vascular lumens and formed hematopoietic components in the villous stroma. α-SMA and PDGFR-β expression in the villous stroma gradually increased and extended from the chorionic plate to peripheral villous branches. The labeled cells formed a reticular network in the villous stroma and, after week 7, encircled villous stromal vessels. In comparison, α-SMA and PDGFR-β expression in the villous stroma and stromal vessels of CHMs was significantly lower (p<0.05). Ultrastructurally, endothelial cells in villous stromal vessels in normal placentas were consistently attached by pericytes after week 7 when the vessels formed distinct lumen, whereas the villous stromal vessels in CHMs consisted of linear chains of endothelial cells, often disclosing primitive clefts without hematopoietic cells inside, and neither pericytes nor basal lamina surrounded the endothelial cells at any gestational age studied. This suggests that pericytes recruitment around villous stromal vessels is defective in CHMs and links to the persistent vascular immaturity of the villous stroma in CHMs, which in turns leads to hydropic villi. PMID:25849742

  19. Stromal vascularization prevents corneal ulceration.

    PubMed

    Conn, H; Berman, M; Kenyon, K; Langer, R; Gage, J

    1980-04-01

    Experiments were performed with a model of focal, thermal-induced ulceration to test the clinical impression that vascularization prevents ulceration of the corneal stroma. Slow-release polymers containing a vasoproliferase agent (tumor angiogenesis factor) were placed in corneal pockets 2 mm central to the limbus of albino rabbits. These polymers elicited blood vessel ingrowth up to the implant. Control eyes received empty polymers which caused minimal to no vessel growth. Polymers were removed, and each cornea received a focal, thermal burn placed just central to the polymer site. All control corneas ulcerated: most (79%) developed deep stromal or perforating ulcers. Only 25% of prevascularized corneas developed stromal ulcers, and none was deep or perforating. After thermal burns, vessels in both groups grew at the same linear rate toward the burned area. There was a direct relationship between the distance separating the nearest blood vessel and the burned area at the time of burning and the maximum depth of stromal ulceration. Thus prevention of or less severe stromal ulceration is correlated with the earlier presence of vessels in the burned area.

  20. Corneal Nerves in Health and Disease

    PubMed Central

    Shaheen, Brittany; Bakir, May; Jain, Sandeep

    2013-01-01

    Corneal nerves are responsible for the sensations of touch, pain, and temperature and play an important role in the blink reflex, wound healing, and tear production and secretion. Corneal nerve dysfunction is a frequent feature of diseases that cause opacities and result in corneal blindness. Corneal opacities rank as the second most frequent cause of blindness. Technological advances in in vivo corneal nerve imaging, such as optical coherence tomography and confocal scanning, have generated new knowledge regarding the phenomenological events that occur during reinnervation of the cornea following disease, injury, or surgery. The recent availability of transgenic neurofluorescent murine models has stimulated the search for molecular modulators of corneal nerve regeneration. New evidence suggests that neuro-regenerative and inflammatory pathways in the cornea are intertwined. Evidence-based treatment of neurotrophic corneal diseases includes using neuro-regenerative (blood component-based and neurotrophic factors), neuroprotective, and ensconcing (bandage contact lens and amniotic membrane) strategies and avoiding anti-inflammatory therapies, such as cyclosporine and corticosteroids. PMID:24461367

  1. Corneal laceration caused by river crab

    PubMed Central

    Vinuthinee, Naidu; Azreen-Redzal, Anuar; Juanarita, Jaafar; Zunaina, Embong

    2015-01-01

    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. PMID:25678769

  2. [Corneal neovascularization: epidemiological, physiopathological, and clinical features].

    PubMed

    Benayoun, Y; Casse, G; Forte, R; Dallaudière, B; Adenis, J-P; Robert, P-Y

    2013-09-01

    Corneal neovascularization is defined as the presence of vessels within the normally avascular corneal stroma. This physiopathological process is the consequence of local hyper-expression of pro-angiogenic factors in response to tissue damage. These new vessels (neovessels), initially immature and poorly developed, predispose the cornea to lipid exudation, inflammation, and scarring. Additionally, the influx of vascular cells into the stroma induces a loss of the cornea's immune privilege, resulting in a higher rate of graft rejection. In this literature review, we touch on epidemiological, physiopathological, and clinical aspects of corneal neovascularization, as well as secondary complications.

  3. Technology needs for corneal transplant surgery

    NASA Astrophysics Data System (ADS)

    Vaddavalli, Pravin K.; Yoo, Sonia H.

    2011-03-01

    Corneal transplant surgery has undergone numerous modifications over the years with improvements in technique, instrumentation and eye banking. The main goals of corneal transplantation are achieving excellent optical clarity with long-term graft survival. Penetrating, anterior and posterior lamellar surgery along with femtosecond laser technology have partially met these goals, but outcomes are often unpredictable and surgeon dependent. Technology to predictably separate stroma from Descemet's membrane, techniques to minimize endothelial cell loss, improvements in imaging technology and emerging techniques like laser welding that might replace suturing, eventually making corneal transplantation a refractively predictable procedure are on the wish list of the cornea surgeon.

  4. Polar Value Analysis of Corneal Astigmatism in Intrastromal Corneal Ring Segment Implantation

    PubMed Central

    Rho, Chang Rae; Kim, Min-Ji

    2016-01-01

    Purpose. To evaluate surgically induced astigmatism (SIA) and the average corneal power change in symmetric intrastromal corneal ring segment (ICRS) implantation. Methods. The study included 34 eyes of 34 keratoconus patients who underwent symmetric Intacs SK ICRS implantation. The corneal pocket incision meridian was the preoperative steep meridian. Corneal power data were obtained before and 3 months after Intacs SK ICRS implantation using scanning-slit topography. Polar value analysis was used to evaluate the SIA. Hotelling's trace test was used to compare intraindividual changes. Results. Three months postoperatively, the combined mean polar value for SIA changed significantly (Hotelling's T2 = 0.375; P = 0.006). The SIA was 1.54 D at 99° and the average corneal power decreased significantly by 3.8 D. Conclusion. Intacs SK ICRS placement decreased the average corneal power and corneal astigmatism compared to the preoperative corneal power and astigmatism when the corneal pocket incision was made at the preoperative steep meridian. PMID:27795856

  5. The Relationship between Corvis ST Tonometry Measured Corneal Parameters and Intraocular Pressure, Corneal Thickness and Corneal Curvature

    PubMed Central

    Asaoka, Ryo; Nakakura, Shunsuke; Tabuchi, Hitoshi; Murata, Hiroshi; Nakao, Yoshitaka; Ihara, Noriko; Rimayanti, Ulfah; Aihara, Makoto; Kiuchi, Yoshiaki

    2015-01-01

    The purpose of the study was to investigate the correlation between Corneal Visualization Scheimpflug Technology (Corvis ST tonometry: CST) parameters and various other ocular parameters, including intraocular pressure (IOP) with Goldmann applanation tonometry. IOP with Goldmann applanation tonometry (IOP-G), central corneal thickness (CCT), axial length (AL), corneal curvature, and CST parameters were measured in 94 eyes of 94 normal subjects. The relationship between ten CST parameters against age, gender, IOP-G, AL, CST-determined CCT and average corneal curvature was investigated using linear modeling. In addition, the relationship between IOP-G versus CST-determined CCT, AL, and other CST parameters was also investigated using linear modeling. Linear modeling showed that the CST measurement ‘A time-1’ is dependent on IOP-G, age, AL, and average corneal curvature; ‘A length-1’ depends on age and average corneal curvature; ‘A velocity-1’ depends on IOP-G and AL; ‘A time-2’ depends on IOP-G, age, and AL; ‘A length-2’ depends on CCT; ‘A velocity-2’ depends on IOP-G, age, AL, CCT, and average corneal curvature; ‘peak distance’ depends on gender; ‘maximum deformation amplitude’ depends on IOP-G, age, and AL. In the optimal model for IOP-G, A time-1, A velocity-1, and highest concavity curvature, but not CCT, were selected as the most important explanatory variables. In conclusion, many CST parameters were not significantly related to CCT, but IOP usually was a significant predictor, suggesting that an adjustment should be made to improve their usefulness for clinical investigations. It was also suggested CST parameters were more influential for IOP-G than CCT and average corneal curvature. PMID:26485129

  6. Effects of subconjunctivally injected antineoplastic agents on three models of corneal inflammation.

    PubMed

    Rootman, J; Bussanich, N; Gudauskas, G; Kumi, C

    1985-06-01

    Three models of corneal inflammation--acute toxic keratitis, phlyctenular keratitis and corneal graft rejection--were induced in rabbits and treated with subconjunctival injections of antineoplastic agents (methotrexate, cytosine arabinoside, 5-fluorouracil and 6-mercaptopurine) and Solu-Medrol (methylprednisolone sodium succinate). The inflammations responded to the drugs to various degrees when compared with the response in control animals treated with saline. Cytosine arabinoside effected a slight decrease in the clinical features of acute toxic keratitis, methotrexate was superior in decreasing inflammation and neovascularization in phlyctenular keratitis, and Solu-Medrol appeared to be the most useful in the treatment of graft rejection. When injected repeatedly, 5-fluorouracil tended to have significant toxicity in the presence of inflammation.

  7. Surgical compensation of presbyopia with corneal inlays.

    PubMed

    Konstantopoulos, Aris; Mehta, Jodhbir S

    2015-05-01

    Presbyopia, the physiological change in near vision that develops with ageing, gradually affects individuals older than 40 years and is a growing cause of visual disability due to ageing demographics of the global population. The routine use of computers and 'smartphones', combined with the affluence of the 'baby boomers' generation has set high standards for near vision correction. Corneal inlays are a relatively new treatment modality that is effective at compensating for presbyopia. The dimensions of these devices vary from 2 to 3.8 mm in diameter and 5 to 32 μm in thickness. They are implanted in the anterior corneal stroma of the non-dominant eye, most commonly, in a femtosecond laser created corneal pocket. They improve near vision by increasing the depth of focus, creating a hyper-prolate region of increased central cornea power or providing a refractive add power. This article reviews the literature on the efficacy and safety of corneal inlays.

  8. Surgical compensation of presbyopia with corneal inlays.

    PubMed

    Konstantopoulos, Aris; Mehta, Jodhbir S

    2015-05-01

    Presbyopia, the physiological change in near vision that develops with ageing, gradually affects individuals older than 40 years and is a growing cause of visual disability due to ageing demographics of the global population. The routine use of computers and 'smartphones', combined with the affluence of the 'baby boomers' generation has set high standards for near vision correction. Corneal inlays are a relatively new treatment modality that is effective at compensating for presbyopia. The dimensions of these devices vary from 2 to 3.8 mm in diameter and 5 to 32 μm in thickness. They are implanted in the anterior corneal stroma of the non-dominant eye, most commonly, in a femtosecond laser created corneal pocket. They improve near vision by increasing the depth of focus, creating a hyper-prolate region of increased central cornea power or providing a refractive add power. This article reviews the literature on the efficacy and safety of corneal inlays. PMID:25652889

  9. Clear Corneal Incision in Cataract Surgery

    PubMed Central

    Al Mahmood, Ammar M.; Al-Swailem, Samar A.; Behrens, Ashley

    2014-01-01

    Since the introduction of sutureless clear corneal cataract incisions, the procedure has gained increasing popularity worldwide because it offers several advantages over the traditional sutured scleral tunnels and limbal incisions. Some of these benefits include lack of conjunctival trauma, less discomfort and bleeding, absence of suture-induced astigmatism, and faster visual rehabilitation. However, an increasing incidence of postoperative endophthalmitis after clear corneal cataract surgery has been reported. Different authors have shown a significant increase up to 15-fold in the incidence of endophthalmitis following clear corneal incision compared to scleral tunnels. The aim of this report is to review the advantages and disadvantages of clear corneal incisions in cataract surgery, emphasizing on wound construction recommendations based on published literature. PMID:24669142

  10. Genetics Home Reference: congenital stromal corneal dystrophy

    MedlinePlus

    ... of decorin. This abnormal protein interferes with the organization of collagen fibrils in the cornea. As poorly arranged collagen fibrils accumulate, the cornea becomes cloudy. These corneal changes lead to reduced visual acuity and related eye ...

  11. Corneal ulcer caused by Bipolaris hawaiiensis.

    PubMed

    Anandi, V; Suryawanshi, N B; Koshi, G; Padhye, A A; Ajello, L

    1988-01-01

    Following an injury to the right eye, a corneal ulcer with hypopyon developed in a leprosy patient. Direct examination of the corneal scrapings on three occasions showed septate, branched, dematiaceous hyphal elements. When scrapings were cultured on Sabouraud's glucose and brain heart infusion agars. Bipolaris hawaiiensis was isolated repeatedly. The patient responded successfully to treatment with nystatin ointment, although the central opacity of the cornea remained and visual acuity did not improve.

  12. Corneal Biomechanics Determination in Healthy Myopic Subjects.

    PubMed

    Qiu, Kunliang; Lu, Xuehui; Zhang, Riping; Wang, Geng; Zhang, Mingzhi

    2016-01-01

    Purpose. To determine the corneal biomechanical properties by using the Ocular Response Analyzer™ and to investigate potential factors associated with the corneal biomechanics in healthy myopic subjects. Methods. 135 eyes from 135 healthy myopic subjects were included in this cross-sectional observational study. Cornea hysteresis (CH), corneal resistance factor (CRF), cornea-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure (IOPg) were determined with the Reichert Ocular Response Analyzer (ORA). Univariate and multivariate regression analyses were performed to investigate factors associated with corneal biomechanics. Results. The mean CH and CRF were 9.82 ± 1.34 mmHg and 9.64 ± 1.57 mmHg, respectively. In univariate regression analysis, CH was significantly correlated with axial length, refraction, central corneal thickness (CCT), and IOPg (r = -0.27, 0.23, 0.45, and 0.21, resp.; all with p ≤ 0.015), but not with corneal curvature or age; CRF was significantly correlated with CCT and IOPg (r = 0.52 and 0.70, resp.; all with p < 0.001), but not with axial length/refraction, corneal curvature, or age. In multivariate regression analysis, axial length, IOPcc, and CCT were found to be independently associated with CH, while CCT and IOPg were associated with CRF. Conclusions. Both CH and CRF were positively correlated with CCT. Lower CH but not CRF was associated with increasing degree of myopia. Evaluation of corneal biomechanical properties should take CCT and myopic status into consideration. PMID:27525109

  13. Corneal ulcer caused by Bipolaris hawaiiensis.

    PubMed

    Anandi, V; Suryawanshi, N B; Koshi, G; Padhye, A A; Ajello, L

    1988-01-01

    Following an injury to the right eye, a corneal ulcer with hypopyon developed in a leprosy patient. Direct examination of the corneal scrapings on three occasions showed septate, branched, dematiaceous hyphal elements. When scrapings were cultured on Sabouraud's glucose and brain heart infusion agars. Bipolaris hawaiiensis was isolated repeatedly. The patient responded successfully to treatment with nystatin ointment, although the central opacity of the cornea remained and visual acuity did not improve. PMID:3236148

  14. Corneal Biomechanics Determination in Healthy Myopic Subjects

    PubMed Central

    Qiu, Kunliang; Lu, Xuehui; Zhang, Riping; Wang, Geng

    2016-01-01

    Purpose. To determine the corneal biomechanical properties by using the Ocular Response Analyzer™ and to investigate potential factors associated with the corneal biomechanics in healthy myopic subjects. Methods. 135 eyes from 135 healthy myopic subjects were included in this cross-sectional observational study. Cornea hysteresis (CH), corneal resistance factor (CRF), cornea-compensated intraocular pressure (IOPcc), and Goldmann-correlated intraocular pressure (IOPg) were determined with the Reichert Ocular Response Analyzer (ORA). Univariate and multivariate regression analyses were performed to investigate factors associated with corneal biomechanics. Results. The mean CH and CRF were 9.82 ± 1.34 mmHg and 9.64 ± 1.57 mmHg, respectively. In univariate regression analysis, CH was significantly correlated with axial length, refraction, central corneal thickness (CCT), and IOPg (r = −0.27, 0.23, 0.45, and 0.21, resp.; all with p ≤ 0.015), but not with corneal curvature or age; CRF was significantly correlated with CCT and IOPg (r = 0.52 and 0.70, resp.; all with p < 0.001), but not with axial length/refraction, corneal curvature, or age. In multivariate regression analysis, axial length, IOPcc, and CCT were found to be independently associated with CH, while CCT and IOPg were associated with CRF. Conclusions. Both CH and CRF were positively correlated with CCT. Lower CH but not CRF was associated with increasing degree of myopia. Evaluation of corneal biomechanical properties should take CCT and myopic status into consideration. PMID:27525109

  15. Asphericity analysis using corneal wavefront and topographic meridional fits

    NASA Astrophysics Data System (ADS)

    Arba-Mosquera, Samuel; Merayo-Lloves, Jesús; de Ortueta, Diego

    2010-03-01

    The calculation of corneal asphericity as a 3-D fit renders more accurate results when it is based on the corneal wavefront aberrations rather than on the corneal topography of the principal meridians. A more accurate prediction could be obtained for hyperopic treatments compared to myopic treatments. We evaluate a method to calculate corneal asphericity and asphericity changes after refractive surgery. Sixty eyes of 15 consecutive myopic patients and 15 consecutive hyperopic patients (n=30 each) are retrospectively evaluated. Preoperative and 3-month-postoperative topographic and corneal wavefront analyses are performed using corneal topography. Ablations are performed using a laser with an aberration-free profile. Topographic changes in asphericity and corneal aberrations are evaluated for a 6-mm corneal diameter. The induction of corneal spherical aberrations and asphericity changes correlates with the achieved defocus correction. Preoperatively as well as postoperatively, asphericity calculated from the topography meridians correlates with asphericity calculated from the corneal wavefront in myopic and hyperopic treatments. A stronger correlation between postoperative asphericity and the ideally expected/predicted asphericity is obtained based on aberration-free assumptions calculated from corneal wavefront values rather than from the meridians. In hyperopic treatments, a better correlation can be obtained compared to the correlation in myopic treatments. Corneal asphericity calculated from corneal wavefront aberrations represents a 3-D fit of the corneal surface; asphericity calculated from the main topographic meridians represents a 2-D fit of the principal corneal meridians. Postoperative corneal asphericity can be calculated from corneal wavefront aberrations with higher fidelity than from corneal topography of the principal meridians. Hyperopic treatments show a greater accuracy than myopic treatments.

  16. A Dual Role for Corneal Dendritic Cells in Herpes Simplex Keratitis: Local Suppression of Corneal Damage and Promotion of Systemic Viral Dissemination

    PubMed Central

    Hu, Kai; Harris, Deshea L.; Yamaguchi, Takefumi; von Andrian, Ulrich H.; Hamrah, Pedram

    2015-01-01

    The cornea is the shield to the foreign world and thus, a primary site for peripheral infections. However, transparency and vision are incompatible with inflammation and scarring that may result from infections. Thus, the cornea is required to perform a delicate balance between fighting infections and preserving vision. To date, little is known about the specific role of antigen-presenting cells in viral keratitis. In this study, utilizing an established murine model of primary acute herpes simplex virus (HSV)-1 keratitis, we demonstrate that primary HSV keratitis results in increased conventional dendritic cells (cDCs) and macrophages within 24 hours after infection. Local depletion of cDCs in CD11c-DTR mice by subconjuntival diphtheria toxin injections, led to increased viral proliferation, and influx of inflammatory cells, resulting in increased scarring and clinical keratitis. In addition, while HSV infection resulted in significant corneal nerve destruction, local depletion of cDCs resulted in a much more severe loss of corneal nerves. Further, local cDC depletion resulted in decreased corneal nerve infection, and subsequently decreased and delayed systemic viral transmission in the trigeminal ganglion and draining lymph node, resulting in decreased mortality of mice. In contrast, sham depletion or depletion of macrophages through local injection of clodronate liposomes had neither a significant impact on the cornea, nor an effect on systemic viral transmission. In conclusion, we demonstrate that corneal cDCs may play a primary role in local corneal defense during viral keratitis and preserve vision, at the cost of inducing systemic viral dissemination, leading to increased mortality. PMID:26332302

  17. A Dual Role for Corneal Dendritic Cells in Herpes Simplex Keratitis: Local Suppression of Corneal Damage and Promotion of Systemic Viral Dissemination.

    PubMed

    Hu, Kai; Harris, Deshea L; Yamaguchi, Takefumi; von Andrian, Ulrich H; Hamrah, Pedram

    2015-01-01

    The cornea is the shield to the foreign world and thus, a primary site for peripheral infections. However, transparency and vision are incompatible with inflammation and scarring that may result from infections. Thus, the cornea is required to perform a delicate balance between fighting infections and preserving vision. To date, little is known about the specific role of antigen-presenting cells in viral keratitis. In this study, utilizing an established murine model of primary acute herpes simplex virus (HSV)-1 keratitis, we demonstrate that primary HSV keratitis results in increased conventional dendritic cells (cDCs) and macrophages within 24 hours after infection. Local depletion of cDCs in CD11c-DTR mice by subconjuntival diphtheria toxin injections, led to increased viral proliferation, and influx of inflammatory cells, resulting in increased scarring and clinical keratitis. In addition, while HSV infection resulted in significant corneal nerve destruction, local depletion of cDCs resulted in a much more severe loss of corneal nerves. Further, local cDC depletion resulted in decreased corneal nerve infection, and subsequently decreased and delayed systemic viral transmission in the trigeminal ganglion and draining lymph node, resulting in decreased mortality of mice. In contrast, sham depletion or depletion of macrophages through local injection of clodronate liposomes had neither a significant impact on the cornea, nor an effect on systemic viral transmission. In conclusion, we demonstrate that corneal cDCs may play a primary role in local corneal defense during viral keratitis and preserve vision, at the cost of inducing systemic viral dissemination, leading to increased mortality.

  18. Corneal dystrophy in the dog and cat.

    PubMed

    Cooley, P L; Dice, P F

    1990-05-01

    Two types of epithelial dystrophy have been described in dogs, one each in the Boxer and Shetland Sheepdog breeds, both of which can be associated with corneal erosions. Medical therapy is recommended when erosions or tear film abnormalities are present. Stromal dystrophies documented in dogs appear to be a primary lipid deposition in various layers of the stroma, depending on the breed. Stromal dystrophies seldom lead to loss of vision, but vision loss has been observed in middle aged Airedale Terriers and aged Siberian Huskies. Treatment is usually unnecessary. The dog demonstrates two types of endothelial dystrophy, one of which (posterior polymorphous dystrophy in the American Cocker Spaniel) does not lead to corneal edema. Endothelial dystrophy observed in the Boston Terrier, Chihuahua, and other breeds is associated with progressive corneal edema, which can lead to bullous keratopathy and corneal erosions. Stromal and endothelial dystrophies, both of which are associated with rapid progression of corneal edema, occur rarely in the cat. Treatment of dystrophies with progressive corneal edema is symptomatic and palliative.

  19. [Research progress of corneal epithelial basal cells and basement membrane].

    PubMed

    Qu, J H; Sun, X G

    2016-09-11

    The cylinder cells at the bottom of corneal epithelial cells are basal cells. Their cytoplasm contains keratin intermediate filament which is important in secretion of basement membrane. Corneal epithelial dysfunction due to diabetes or ocular surgery is intimately related with basal cell abnormality. Corneal epithelial basement membrane is a highly specific extracellular matrix which is made up of lamina lucida and lamina densa. It plays an extremely important role in renewal and restoration. Many ocular abnormalities and diseases have been described to relate to the corneal epithelial basement membrane, such as traumatic recurrent corneal erosion, corneal dystrophy and keratoconus. (Chin J Ophthalmol, 2016, 52: 703-707). PMID:27647251

  20. Relative strength of scleral corneal and clear corneal incisions constructed in cadaver eyes.

    PubMed

    Ernest, P H; Lavery, K T; Kiessling, L A

    1994-11-01

    Square scleral corneal, square clear corneal, and rectangular clear corneal incisions were constructed in six cadaver eyes that had no previous intraocular surgery. The 3.2 mm or smaller wounds had sutureless closures. To determine their relative abilities to resist leakage and iris prolapse, eyes were tested at external pressures of up to 525 pounds per square inch (psi) at one of two intraocular pressure (IOP) ranges: 10 to 15 mm Hg or 20 to 25 mm Hg. The square scleral corneal (3.2 mm x 3.2 mm) and square clear corneal wounds (3.2 mm x 3.2 mm, 2.0 mm x 2.0 mm, 1.0 mm x 1.0 mm) withstood external pressure without effect at both IOP ranges, up to the maximum 525 psi. This level of external pressure was far greater than pressures withstood by rectangular clear corneal wounds, especially the wound usually constructed in clinical practice (3.2 mm x 2.0 mm), which leaked and demonstrated iris prolapse at 13 psi at the lower IOP. The square clear corneal wounds that were stable at 525 psi, however, are either clinically impractical (visual axis encroachment from 3.2 mm x 3.2 mm wound) or not technologically feasible until the size of phacoemulsification tips and intraocular lenses can be further reduced. Thus, of the procedures for small incision cataract surgery presently in use, the square scleral corneal incision with 1.5 mm internal corneal lip appears to offer greater stability and safety than the conventional rectangular clear corneal incision (3.2 mm x 2.0 mm).

  1. Cultured corneal epithelia for ocular surface disease.

    PubMed Central

    Schwab, I R

    1999-01-01

    PURPOSE: To evaluate the potential efficacy for autologous and allogeneic expanded corneal epithelial cell transplants derived from harvested limbal corneal epithelial stem cells cultured in vitro for the management of ocular surface disease. METHODS: Human Subjects. Of the 19 human subjects included, 18 (20 procedures) underwent in vitro cultured corneal epithelial cell transplants using various carriers for the epithelial cells to determine the most efficacious approach. Sixteen patients (18 procedures on 17 eyes) received autologous transplants, and 2 patients (1 procedure each) received allogeneic sibling grafts. The presumed corneal epithelial stem cells from 1 patient did not grow in vitro. The carriers for the expanded corneal epithelial cells included corneal stroma, type 1 collagen (Vitrogen), soft contact lenses, collagen shields, and amniotic membrane for the autologous grafts and only amniotic membrane for the allogeneic sibling grafts. Histologic confirmation was reviewed on selected donor grafts. Amniotic membrane as carrier. Further studies were made to determine whether amniotic membrane might be the best carrier for the expanding corneal epithelial cells. Seventeen different combinations of tryspinization, sonication, scraping, and washing were studied to find the simplest, most effective method for removing the amniotic epithelium while still preserving the histologic appearance of the basement membrane of the amnion. Presumed corneal epithelial stem cells were harvested and expanded in vitro and applied to the amniotic membrane to create a composite graft. Thus, the composite graft consisted of the amniotic membrane from which the original epithelium had been removed without significant histologic damage to the basement membrane, and the expanded corneal epithelial stem cells, which had been applied to and had successfully adhered to the denuded amniotic membrane. Animal model. Twelve rabbits had the ocular surface of 1 eye damaged in a standard

  2. Ciliary neurotrophic factor promotes the activation of corneal epithelial stem/progenitor cells and accelerates corneal epithelial wound healing.

    PubMed

    Zhou, Qingjun; Chen, Peng; Di, Guohu; Zhang, Yangyang; Wang, Yao; Qi, Xia; Duan, Haoyun; Xie, Lixin

    2015-05-01

    Ciliary neurotrophic factor (CNTF), a well-known neuroprotective cytokine, has been found to play an important role in neurogenesis and functional regulations of neural stem cells. As one of the most innervated tissue, however, the role of CNTF in cornea epithelium remains unclear. This study was to explore the roles and mechanisms of CNTF in the activation of corneal epithelial stem/progenitor cells and wound healing of both normal and diabetic mouse corneal epithelium. In mice subjecting to mechanical removal of corneal epithelium, the corneal epithelial stem/progenitor cell activation and wound healing were promoted by exogenous CNTF application, while delayed by CNTF neutralizing antibody. In cultured corneal epithelial stem/progenitor cells, CNTF enhanced the colony-forming efficiency, stimulated the mitogenic proliferation, and upregulated the expression levels of corneal epithelial stem/progenitor cell-associated transcription factors. Furthermore, the promotion of CNTF on the corneal epithelial stem/progenitor cell activation and wound healing was mediated by the activation of STAT3. Moreover, in diabetic mice, the content of CNTF in corneal epithelium decreased significantly when compared with that of normal mice, and the supplement of CNTF promoted the diabetic corneal epithelial wound healing, accompanied with the advanced activation of corneal epithelial stem/progenitor cells and the regeneration of corneal nerve fibers. Thus, the capability of expanding corneal epithelial stem/progenitor cells and promoting corneal epithelial wound healing and nerve regeneration indicates the potential application of CNTF in ameliorating limbal stem cell deficiency and treating diabetic keratopathy.

  3. Genetics Home Reference: lattice corneal dystrophy type I

    MedlinePlus

    ... lattice pattern. Affected individuals often have recurrent corneal erosions, which are caused by separation of particular layers of the cornea from one another. Corneal erosions are very painful and can cause sensitivity to ...

  4. Genetics Home Reference: lattice corneal dystrophy type II

    MedlinePlus

    ... In addition, affected individuals can have recurrent corneal erosions, which are caused by separation of particular layers of the cornea from one another. Corneal erosions are very painful and can cause sensitivity to ...

  5. 21 CFR 886.4070 - Powered corneal burr.

    Code of Federal Regulations, 2010 CFR

    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...

  6. 21 CFR 886.4070 - Powered corneal burr.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) 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...

  7. 21 CFR 886.4070 - Powered corneal burr.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) 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...

  8. 21 CFR 886.4070 - Powered corneal burr.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) 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...

  9. 21 CFR 886.4070 - Powered corneal burr.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) 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...

  10. Changes on the corneal thickness and curvature after orthokeratology

    NASA Astrophysics Data System (ADS)

    Mitsui, Iwane; Yamada, Yoshiya

    2004-07-01

    To evaluate the corneal thickness and curvature changes after Orthokeratology contact lens wear, using the ORBSCAN II corneal topography system, corneal thickness and corneal curvature were measured on one hundred and twenty eyes of sixty patients before and after wearing the custom rigid gas permeable contact lenses for Orthokeratology. The contact lenses were specially designed for each eye. The subjects wore the orthokeratology lenses for approximately Four hours with their eyes closed. The corneal thickness of the subjects was increased on fifty-five eyes at not only the peripheral zone but also the center of the cornea. The average increase of central and peripheral corneal thickness was 18 micrometer and 22micrometer, respectively. The mean anterior curvature of corneal surface changed 1.25D. The mean posterior curvature of corneal endothelium side changed 0.75D.

  11. Rare case of massive congenital bilateral chylothorax in a hydropic fetus with true mosaicism 47,XXX/46,XX.

    PubMed

    Cremonini, Giorgio; Poggi, Alice; Capucci, Roberta; Vesce, Fortunato; Patella, Alfredo; Marci, Roberto

    2014-01-01

    Fetal congenital chylothorax is a rare condition that occurs sporadically or can be associated with abnormal karyotype or structural chromosomal anomalies. We report a unique case of fetal congenital bilateral chylothorax associated with mosaicism 47,XXX/46,XX. A female fetus affected by massive bilateral hydrothorax and ascites was diagnosed at 34(+1) weeks of gestation. Previous ultrasonographic exams were completely normal. Immune causes of hydrops were excluded. Elective cesarean section was performed soon after bilateral thoracocentesis. The analysis of drained pleural fluid revealed its lymphatic nature. The fetal karyotyping, performed on chorionic villi at the 11th week, had shown mosaicism 47,XXX/46,XX, later confirmed in the newborn's blood. We hypothesized that chylothorax may be part of the phenotypic spectrum of 47 XXX karyotype and we suggest an ultrasound follow-up of the fetus at closer intervals than the routine timing for this condition, even if it is not usually characterized by severe phenotypic features.

  12. [Corneal ulcer with hypopion in a patient with perforant keratoplasty].

    PubMed

    Nicula, Cristina; Bran, L

    2010-01-01

    After corneal transplantation, the patients' problems are far from being definitively resolved. The transplant pathology requires an attentive follow-up, as there is always a danger of corneal graft failure. We present here the case of young patient who had a corneal transplantation after an eye injury and who has developed a corneal ulcer on the grafted cornea, with subsequent risk of graft failure and consequent loss of the eye.

  13. Influence of corneal hydration on optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Twa, Michael D.; Vantipalli, Srilatha; Singh, Manmohan; Li, Jiasong; Larin, Kirill V.

    2016-03-01

    Corneal biomechanical properties are influenced by several factors, including intraocular pressure, corneal thickness, and viscoelastic responses. Corneal thickness is directly proportional to tissue hydration and can influence corneal stiffness, but there is no consensus on the magnitude or direction of this effect. We evaluated the influence of corneal hydration on dynamic surface deformation responses using optical coherence elastography (OCE). Fresh rabbit eyes (n=10) were prepared by removing the corneal epithelium and dropping with 0.9% saline every 5 minutes for 1 hour, followed by 20% dextran solution every 5 minutes for one hour. Corneal thickness was determined from structural OCT imaging and OCE measurements were performed at baseline and every 20 minutes thereafter. Micron-scale deformations were induced at the apex of the corneal tissue using a spatially-focused (150μm) short-duration (<1ms) air-pulse delivery system. These dynamic tissue responses were measured non-invasively with a phase-stabilized swept source OCT system. The tissue surface deformation response (Relaxation Rate: RR) was quantified as the time constant, over which stimulated tissue recovered from the maximum deformation amplitude. Elastic wave group velocity (GV) was also quantified and correlated with change in corneal thickness due to hydration process. Corneal thickness rapidly increased and remained constant following epithelium removal and changed little thereafter. Likewise, corneal stiffness changed little over the first hour and then decreased sharply after Dextran application (thickness: -46% [-315/682 μm] RR: - 24% [-0.7/2.88 ms-1]; GV: -19% [-0.6/3.2 m/s]). Corneal thickness and corneal stiffness (RR) were well correlated (R2 = .66). Corneal biomechanical properties are highly correlated with tissue hydration over a wide range of corneal thickness and these changes in corneal stiffness are quantifiable using OCE.

  14. Review of past and present techniques of measuring corneal topography.

    PubMed

    Fowler, C W; Dave, T N

    1994-01-01

    Various methods of measuring corneal topography are described. The advantages and disadvantages of the principles used in the measurement of corneal shape by the various techniques are discussed. The corneal surface may be described in a number of ways; some researchers have used conic sections while others have used more complex polynomial expressions. Computer algorithms have also been developed to calculate quantitative measures of corneal topography to augment the information obtained from topographical maps. These descriptors are discussed in this article.

  15. The molecular genetics of the corneal dystrophies--current status.

    PubMed

    Klintworth, Gordon K

    2003-05-01

    The pertinent literature on inherited corneal diseases is reviewed in terms of the chromosomal localization and identification of the responsible genes. Disorders affecting the cornea have been mapped to human chromosome 1 (central crystalline corneal dystrophy, familial subepithelial corneal amyloidosis, early onset Fuchs dystrophy, posterior polymorphous corneal dystrophy), chromosome 4 (Bietti marginal crystalline dystrophy), chromosome 5 (lattice dystrophy types 1 and IIIA, granular corneal dystrophy types 1, 2 and 3, Thiel-Behnke corneal dystrophy), chromosome 9 (lattice dystrophy type II), chromosome 10 (Thiel-Behnke corneal dystrophy), chromosome 12 (Meesmann dystrophy), chromosome 16 (macular corneal dystrophy, fish eye disease, LCAT disease, tyrosinemia type II), chromosome 17 (Meesmann dystrophy, Stocker-Holt dystrophy), chromosome 20 (congenital hereditary endothelial corneal dystrophy types I and II, posterior polymorphous corneal dystrophy), chromosome 21 (autosomal dominant keratoconus) and the X chromosome (cornea verticillata, cornea farinata, deep filiform corneal dystrophy, keratosis follicularis spinulosa decalvans, Lisch corneal dystrophy). Mutations in nine genes (ARSC1, CHST6, COL8A2, GLA, GSN, KRT3, KRT12, M1S1and TGFBI [BIGH3]) account for some of the corneal diseases and three of them are associated with amyloid deposition in the cornea (GSN, M1S1, TGFBI) including most of the lattice corneal dystrophies (LCDs) [LCD types I, IA, II, IIIA, IIIB, IV, V, VI and VII] recognized by their lattice pattern of linear opacities. Genetic studies on inherited diseases affecting the cornea have provided insight into some of these disorders at a basic molecular level and it has become recognized that distinct clinicopathologic phenotypes can result from specific mutations in a particular gene, as well as some different mutations in the same gene. A molecular genetic understanding of inherited corneal diseases is leading to a better appreciation of the

  16. [Representation and mathematical analysis of human corneal surface].

    PubMed

    Tălu, Stefan; Tălu, Mihai; Giovanzana, Stefano

    2011-01-01

    In the description and analysis of human corneal surface are used various mathematical models based on parametric representations, used in biomechanical studies and 3D solid modeling of the cornea. Mathematical models are important into the biomechanics of the cornea to model the corneal behavior. Corneal biomechanics also has the potential to improve outcomes in refractive surgery. The objective of this paper is to present the most representative mathematical models currently used for modeling of human corneal in optics and biomechanics fields.

  17. Corneal Phaeohyphomycosis Caused by Bipolaris hawaiiensis

    PubMed Central

    Chaidaroon, Winai; Supalaset, Sumet; Tananuvat, Napaporn; Vanittanakom, Nongnuch

    2016-01-01

    Purpose To report a rare case of keratitis infected by Bipolaris hawaiiensis. Methods A patient who was diagnosed as fungal keratitis caused by B. hawaiiensis was retrospectively reviewed for history, clinical characteristics, risk factors, laboratory findings, treatments, and outcomes. Results A 63-year-old man with a history of trauma and saw dust in the left eye presented with a corneal ulcer. Eye examination revealed whitish infiltration with a feathery edge and small brownish deposits in the anterior stroma of the left cornea. Numerous septate hyphal fragments were detected in a corneal specimen, and nucleotide sequence analysis identified B. hawaiiensis. Treatment was started with 5% natamycin eyedrops and oral itraconazole. Subsequently, a corneal plaque developed which did not respond to medication and debridement. The patient underwent therapeutic penetrating keratoplasty. Conclusions B. hawaiiensis is a rare cause of corneal phaeohyphomycosis. A brownish pigmented infiltration is an important diagnostic clue, however microbiologic studies are required to obtain a definite diagnosis. Although antifungal medication and debridement are the mainstay of most corneal fungal infection, therapeutic penetrating keratoplasty can prevent morbidity related to this fungal infection. PMID:27721785

  18. Corneal Cross-Linking and Safety Issues

    PubMed Central

    Spoerl, Eberhard; Hoyer, Anne; Pillunat, Lutz E; Raiskup, Frederik

    2011-01-01

    Purpose: To compile the safety aspects of the corneal collagen cross-linking (CXL) by means of the riboflavin/UVA (370 nm) approach. Materials and Methodology: Analysis of the current treatment protocol with respect to safety during CXL. Results: The currently used UVA dose density of 5.4 J/cm2 and the corresponding irradiance of 3 mW/cm2 are below the known damage thresholds of UVA for the corneal endothelium, lens, and retina. Regarding the photochemical damages due to the free radicals the damage threshold for endothelial cells is 0.35 mW/cm2. In a 400μm thick corneal stroma saturated with riboflavin, the irradiance at the endothelial level is about 0.18 mW/cm2, which is a factor of 2 smaller than the damage threshold. Conclusion: As long as the corneal stroma treated has a minimal thickness of 400 microns (as recommended), neither corneal endothelium nor deeper structures such as lens and retina will suffer any damages. The light source should provide a homogenous irradiance avoiding hot spots. PMID:21399770

  19. Corneal and conjunctival sensitivity in rosacea patients

    PubMed Central

    Örnek, Nurgül; Karabulut, Ayşe Anıl; Örnek, Kemal; Onaran, Zafer; Usta, Gülşah

    2015-01-01

    Purpose To assess corneal and conjunctival sensitivity in rosacea patients. Methods A total of 55 patients with rosacea and 37 control subjects participated in the study. Corneal and conjunctival sensitivity was determined by Cochet-Bonnet esthesiometer. Subjective symptoms of ocular dryness were evaluated using Ocular Surface Disease Index (OSDI). Schirmer’s I test (ST), tear breakup time (tBUT) and ocular surface staining with fluorescein were carried out to measure objective signs. Results The mean corneal and conjunctival sensitivity did not differ significantly between rosacea patients and controls (all p > 0.05). Schirmer’s I test and tBUT were significantly reduced (p = 0.004 for OD and p < 0.001 for OS) and grade of ocular surface staining was significantly high (p = 0.018 for OD and p = 0.038 for OS) in rosacea patients. Corneal and conjunctival sensitivity did not show significant correlation with ST, tBUT, ocular surface staining (Oxford Schema), duration of rosacea and OSDI score. Conclusions Corneal and conjunctival sensitivity did not change significantly in rosacea. PMID:26949355

  20. Corneal fungal disease in small animals.

    PubMed

    Andrew, Stacy E

    2003-08-01

    Corneal fungal diseases, including fungal keratitis and stromal abscess, are uncommon in small animals. Ocular infection secondary to systemic mycosis is reported far more frequently. Suspicion of a fungal corneal ulcer should be raised based on a history of underlying trauma, especially with plant material, geographic location, chronic use of topical antibiotics or corticosteroids, or an extremely prolonged course of disease despite appropriate treatment. Clinical signs observed with fungal keratitis may include blepharospasm, epiphora, miosis, corneal opacity, and vascularization. Unfortunately, none of these signs is specific to fungal infection. If fungal keratitis is suspected or confirmed, then aggressive medical therapy should be instituted. Medications used include topical antifungals, parasympatholytics, anticollagenases, and antibacterials as well as systemic anti-inflammatory drugs. Because there are very few fungicidal medications, the course of medical treatment for fungal corneal disease requires a prolonged duration with frequent re-examination and assessment. Surgical treatment is sometimes required to save the eye and vision. Surgeries to be considered include debridement, conjunctival graft placement, and corneal transplantation. PMID:14604093

  1. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  2. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  3. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Corneal radius measuring device. 886.1450 Section 886.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius...

  4. Sparfloxacin-associated corneal epithelial toxicity

    PubMed Central

    Agarwal, Aniruddha Kishandutt; Ram, Jagat; Singh, Ramandeep

    2014-01-01

    Sparfloxacin is a broad-spectrum fluoroquinolone antibiotic commonly used for various bacterial corneal infections. Topical use of fluoroquinolones is considered to be safe leading to their widespread use. Common indications include blepharitis, conjunctivitis and corneal ulcers. However, unsupervised prolonged use is associated with deposition of crystalline material in the epithelial and anterior stromal layers of the cornea. These may be associated with significant visual symptoms including diminution of vision and glare/photophobia. We present a case of a 40-year-old man who was treated with topical 0.3% sparfloxacin unsupervised for a long time. The patient developed significant visual impairment due to diffuse epitheliopathy. Cessation of the drug was slowly followed by reversal of manifestations and normalisation of corneal morphology. PMID:25239984

  5. [Metabolic disorders and corneal changes (author's transl)].

    PubMed

    François, J

    1981-06-01

    The following inborn errors of metabolism may show corneal changes: A. Inborn errors of metabolism affecting the corneal epithelium: (1) familial dysautonomia, (2) tyrosinaemia type II, (3) Fabry's glycolipidosis. B. Inborn errors of metabolism affecting the corneal stroma: I. Localized amyloidosis (lattice dystrophy of the cornea), II. Defects in carbohydrate metabolism: (1) localized mucopolysaccharidosis (macular dystrophy of the cornea), (2) systemic mucopolysaccharides, (3) glycogen storage disease. III. Defects in lipid metabolism: (1) localized from (Schnyder's crystalline dystrophy), (2) systemic forms (hyperlipoproteinaemia, hypolipoproteinaemia, Lecithin-cholesterol acyl transferase deficiency, Wolman's disease, Gaucher's disease). IV. Combined defects in lipid and carbohydrate metabolism (mucolipidoses). V. Other inherited metabolic disorders: (1) aminoacidopathies (cystinosis, Wilson's disease, ochronosis, Chediak-Higashi syndrome), (2) hemochromatosis.

  6. XENOTRANSPLANTATION – THE FUTURE OF CORNEAL TRANSPLANTATION?

    PubMed Central

    Hara, Hidetaka; Cooper, David K.C.

    2010-01-01

    Although corneal transplantation is readily available in the USA and certain other regions of the developed world, the need for human donor corneas worldwide far exceeds supply. There is currently renewed interest in the possibility of using corneas from other species, especially pigs, for transplantation into humans (xenotransplantation). The biomechanical properties of human and pig corneas are similar. Studies in animal models of corneal xenotransplantation have documented both humoral and cellular immune responses that play roles in xenograft rejection. The results obtained from the Tx of corneas from wild-type (i.e., genetically-unmodified) pigs into nonhuman primates have been surprisingly good and encouraging. Recent progress in the genetic manipulation of pigs has led to the prospect that the remaining immunological barriers will be overcome. There is every reason for optimism that corneal xenoTx will become a clinical reality within the next few years. PMID:21099407

  7. Sparfloxacin-associated corneal epithelial toxicity.

    PubMed

    Agarwal, Aniruddha Kishandutt; Ram, Jagat; Singh, Ramandeep

    2014-01-01

    Sparfloxacin is a broad-spectrum fluoroquinolone antibiotic commonly used for various bacterial corneal infections. Topical use of fluoroquinolones is considered to be safe leading to their widespread use. Common indications include blepharitis, conjunctivitis and corneal ulcers. However, unsupervised prolonged use is associated with deposition of crystalline material in the epithelial and anterior stromal layers of the cornea. These may be associated with significant visual symptoms including diminution of vision and glare/photophobia. We present a case of a 40-year-old man who was treated with topical 0.3% sparfloxacin unsupervised for a long time. The patient developed significant visual impairment due to diffuse epitheliopathy. Cessation of the drug was slowly followed by reversal of manifestations and normalisation of corneal morphology. PMID:25239984

  8. Human pluripotent stem cell-derived limbal epithelial stem cells on bioengineered matrices for corneal reconstruction.

    PubMed

    Mikhailova, Alexandra; Ilmarinen, Tanja; Ratnayake, Anjula; Petrovski, Goran; Uusitalo, Hannu; Skottman, Heli; Rafat, Mehrdad

    2016-05-01

    Corneal epithelium is renewed by limbal epithelial stem cells (LESCs), a type of tissue-specific stem cells located in the limbal palisades of Vogt at the corneo-scleral junction. Acute trauma or inflammatory disorders of the ocular surface can destroy these stem cells, leading to limbal stem cell deficiency (LSCD) - a painful and vision-threatening condition. Treating these disorders is often challenging and complex, especially in bilateral cases with extensive damage. Human pluripotent stem cells (hPSCs) provide new opportunities for corneal reconstruction using cell-based therapy. Here, we investigated the use of hPSC-derived LESC-like cells on bioengineered collagen matrices in serum-free conditions, aiming for clinical applications to reconstruct the corneal epithelium and partially replace the damaged stroma. Differentiation of hPSCs towards LESC-like cells was directed using small-molecule induction followed by maturation in corneal epithelium culture medium. After four to five weeks of culture, differentiated cells were seeded onto bioengineered matrices fabricated as transparent membranes of uniform thickness, using medical-grade porcine collagen type I and a hybrid cross-linking technology. The bioengineered matrices were fully transparent, with high water content and swelling capacity, and parallel lamellar microstructure. Cell proliferation of hPSC-LESCs was significantly higher on bioengineered matrices than on collagen-coated control wells after two weeks of culture, and LESC markers p63 and cytokeratin 15, along with proliferation marker Ki67 were expressed even after 30 days in culture. Overall, hPSC-LESCs retained their capacity to self-renew and proliferate, but were also able to terminally differentiate upon stimulation, as suggested by protein expression of cytokeratins 3 and 12. We propose the use of bioengineered collagen matrices as carriers for the clinically-relevant hPSC-derived LESC-like cells, as a novel tissue engineering approach for

  9. Transcriptome Analysis of the Human Corneal Endothelium

    PubMed Central

    Frausto, Ricardo F.; Wang, Cynthia; Aldave, Anthony J.

    2014-01-01

    Purpose. To comprehensively characterize human corneal endothelial cell (HCEnC) gene expression and age-dependent differential gene expression and to identify expressed genes mapped to chromosomal loci associated with the corneal endothelial dystrophies posterior polymorphous corneal dystrophy (PPCD)1, Fuchs endothelial corneal dystrophy (FECD)4, and X-linked endothelial dystrophy (XECD). Methods. Total RNA was isolated from ex vivo corneal endothelium obtained from six pediatric and five adult donor corneas. Complementary DNA was hybridized to the Affymetrix GeneChip 1.1ST array. Data analysis was performed using Partek Genomics Suite software, and differentially expressed genes were validated by digital molecular barcoding technology. Results. Transcripts corresponding to 12,596 genes were identified in HCEnC. Nine genes displayed the most significant differential expression between pediatric and adult HCEnC: CAPN6, HIST1H3A, HIST1H4E, and HSPA2 were expressed at higher levels in pediatric HCEnC, while ITGBL1, NALCN, PREX2, TAC1, and TMOD1 were expressed at higher levels in adult HCEnC. Analysis of the PPCD1, FECD4 and XECD loci demonstrated transcription of 53/95 protein-coding genes in the PPCD1 locus, 27/40 in the FECD4 locus, and 35/68 in the XECD locus. Conclusions. An analysis of the HCEnC transcriptome reveals the expression of almost 13,000 genes, with less than 1% mapped to chromosomal loci associated with PPCD1, FECD4, and XECD. At least nine genes demonstrated significant differential expression between pediatric and adult HCEnC, defining specific functional properties distinct to each age group. These data will serve as a resource for vision scientists investigating HCEnC gene expression and can be used to focus the search for the genetic basis of the corneal endothelial dystrophies for which the genetic basis remains unknown. PMID:25377225

  10. Regulation of Corneal Stroma Extracellular Matrix Assembly

    PubMed Central

    Chen, Shoujun; Mienaltowski, Michael J.; Birk, David E.

    2014-01-01

    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. PMID:25819456

  11. Host immune cellular reactions in corneal neovascularization

    PubMed Central

    Abdelfattah, Nizar S.; Amgad, Mohamed; Zayed, Amira A

    2016-01-01

    Corneal neovascularization (CNV) is a global important cause of visual impairment. The immune mechanisms leading to corneal heme- and lymphangiogenesis have been extensively studied over the past years as more attempts were made to develop better prophylactic and therapeutic measures. This article aims to discuss immune cells of particular relevance to CNV, with a focus on macrophages, Th17 cells, dendritic cells and the underlying immunology of common pathologies involving neovascularization of the cornea. Hopefully, a thorough understanding of these topics would propel the efforts to halt the detrimental effects of CNV. PMID:27162740

  12. Reversible Corneal Toxicity of Retained Intracameral Perfluoro-n-octane.

    PubMed

    Alharbi, Saad S; Asiri, Mohammed S

    2016-01-01

    A 58-year-old female presented with intracameral retained perfluoro-n-octane (PFO) following previous retinal reattachment surgery. After 4 years of follow-up without related sequelae, the patient complained of a gradual decrease in vision secondary to corneal edema with whitish corneal precipitate inferiorly corresponding to the area of retained PFO. Three weeks after anterior chamber washout, corneal edema resolved and the patient obtained 20/40 visual acuity. Even though PFO considered to have a relatively good safety profile, early anterior chamber washout may prevent corneal toxicity and avoid later persistent corneal decompensation.

  13. Reversible Corneal Toxicity of Retained Intracameral Perfluoro-n-octane

    PubMed Central

    Alharbi, Saad S.; Asiri, Mohammed S.

    2016-01-01

    A 58-year-old female presented with intracameral retained perfluoro-n-octane (PFO) following previous retinal reattachment surgery. After 4 years of follow-up without related sequelae, the patient complained of a gradual decrease in vision secondary to corneal edema with whitish corneal precipitate inferiorly corresponding to the area of retained PFO. Three weeks after anterior chamber washout, corneal edema resolved and the patient obtained 20/40 visual acuity. Even though PFO considered to have a relatively good safety profile, early anterior chamber washout may prevent corneal toxicity and avoid later persistent corneal decompensation. PMID:27555718

  14. Posterior Corneal Characteristics of Cataract Patients with High Myopia

    PubMed Central

    Jing, Qinghe; Tang, Yating; Qian, Dongjin; Lu, Yi; Jiang, Yongxiang

    2016-01-01

    Purpose To evaluate the characteristics of the posterior corneal surface in patients with high myopia before cataract surgery. Methods We performed a cross-sectional study at the Eye and ENT Hospital of Fudan University, Shanghai, China. Corneal astigmatism and axial length were measured with a rotating Scheimpflug camera (Pentacam) and partial coherence interferometry (IOLMaster) in a high-myopia study group of 167 eyes (axial length ≥ 26 mm) and a control group of 150 eyes (axial length > 20 mm and < 25 mm). Results Total corneal astigmatism and anterior corneal astigmatism values were higher in the high-myopia group than in the control group. There was no significant difference in posterior corneal astigmatism between the high-myopia study group and the control group. In the study group, the mean posterior corneal astigmatism (range 0 – −0.9 diopters) was –0.29 diopters (D) ± 0.17 standard deviations (SD). The steep corneal meridian was aligned vertically (60°–120°) in 87.43% of eyes for the posterior corneal surface, and did not change with increasing age. There was a significant correlation (r = 0.235, p = 0.002) between posterior corneal astigmatism and anterior corneal astigmatism, especially when the anterior corneal surface showed with-the-rule (WTR) astigmatism (r = 0.452, p = 0.000). There was a weak negative correlation between posterior corneal astigmatism and age (r = –0.15, p = 0.053) in the high-myopia group. Compared with total corneal astigmatism values, the anterior corneal measurements alone overestimated WTR astigmatism by a mean of 0.27 ± 0.18 D in 68.75% of eyes, underestimated against-the-rule (ATR) astigmatism by a mean of 0.41 ± 0.28 D in 88.89% of eyes, and underestimated oblique astigmatism by a mean of 0.24 ± 0.13 D in 63.64% of eyes. Conclusions Posterior corneal astigmatism decreased with age and remained as ATR astigmatism in most cases of high myopia. There was a significant correlation between posterior corneal

  15. Air assisted lamellar keratectomy for the corneal haze model.

    PubMed

    Kim, Soohyun; Park, Young Woo; Lee, Euiri; Park, Sang Wan; Park, Sungwon; Kim, Jong Whi; Seong, Je Kyung; Seo, Kangmoon

    2015-01-01

    To standardize the corneal haze model in the resection depth and size for efficient corneal haze development, air assisted lamellar keratectomy was performed. The ex vivo porcine corneas were categorized into four groups depending on the trephined depth: 250 µm (G1), 375 µm (G2), 500 µm(G3) and 750 µm (G4). The stroma was equally ablated at the five measurement sites in all groups. Significant differences were observed between the trephined corneal depths for resection and ablated corneal thickness in G1 (p < 0.001). No significant differences were observed between the trephined corneal depth for resection and the ablated corneal thickness in G2, G3, and G4. The resection percentage was similar in all groups after microscopic imaging of corneal sections. Air assisted lamellar keratectomy (AK) and conventional keratectomy (CK) method were applied to six beagles, after which development of corneal haze was evaluated weekly until postoperative day 28. The occurrence of corneal haze in the AK group was significantly higher than that in the CK group beginning 14 days after surgery. Alpha-smooth muscle actin expression was significantly higher in the AK group (p < 0.001) than the CK group. Air assisted lamellar keratectomy was used to achieve the desired corneal thickness after resection and produce sufficient corneal haze.

  16. Air assisted lamellar keratectomy for the corneal haze model

    PubMed Central

    Kim, Soohyun; Park, Young Woo; Lee, Euiri; Park, Sang Wan; Park, Sungwon; Kim, Jong Whi; Seong, Je Kyung

    2015-01-01

    To standardize the corneal haze model in the resection depth and size for efficient corneal haze development, air assisted lamellar keratectomy was performed. The ex vivo porcine corneas were categorized into four groups depending on the trephined depth: 250 µm (G1), 375 µm (G2), 500 µm (G3) and 750 µm (G4). The stroma was equally ablated at the five measurement sites in all groups. Significant differences were observed between the trephined corneal depths for resection and ablated corneal thickness in G1 (p < 0.001). No significant differences were observed between the trephined corneal depth for resection and the ablated corneal thickness in G2, G3, and G4. The resection percentage was similar in all groups after microscopic imaging of corneal sections. Air assisted lamellar keratectomy (AK) and conventional keratectomy (CK) method were applied to six beagles, after which development of corneal haze was evaluated weekly until postoperative day 28. The occurrence of corneal haze in the AK group was significantly higher than that in the CK group beginning 14 days after surgery. Alpha-smooth muscle actin expression was significantly higher in the AK group (p < 0.001) than the CK group. Air assisted lamellar keratectomy was used to achieve the desired corneal thickness after resection and produce sufficient corneal haze. PMID:25797296

  17. Corneal heat scar caused by photodynamic therapy performed through an implanted corneal inlay.

    PubMed

    Mita, Mariko; Kanamori, Tomomi; Tomita, Minoru

    2013-11-01

    A 60-year-old man had a combination of laser in situ keratomileusis and Kamra corneal inlay implantation to correct presbyopia. Although the outcome was favorable postoperatively, central serous chorioretinopathy was observed in the left eye along with a decrease in the uncorrected (UDVA) and corrected (CDVA) distance visual acuities and the corrected near visual acuity (CNVA). Photodynamic therapy (PDT) was later performed in a university hospital. After PDT, the patient experienced a decline in the visual acuity and came to our clinic a month after the PDT. Degeneration and a scar were observed at the location of the inlay due to the heat and burning. Flattening of the corneal topography was also observed where the corneal scar was located, along with a significant decrease in CDVA in the left eye. Prior to any surgery in which the corneal inlay is an impediment, surgeons should take advantage of the reversibility of the Kamra inlay by explanting the inlay.

  18. [Cross-linking and intrastromal corneal ring segment].

    PubMed

    Renesto, Adimara da Candelaria; Sartori, Marta; Campos, Mauro

    2011-01-01

    Corneal cross-linking is a procedure used for stabilizing the cornea in patients with progressive keratoconus by increasing corneal rigidity, and it is also used in corneal inflammatory melting process. The intrastromal corneal ring segments act by flattening the center of the cornea. Originally designed for the correction of mild myopia, the segments are now being used for reduction of keratoconus in order to improve the uncorrected visual acuity, the best spectacle corrected visual acuity, to allow good tolerance to the use of contact lenses and delay the need for corneal grafting procedures. The present text presents a review of corneal cross-linking and insertion of intrastromal corneal ring segments, emphasizing their indications, results and complications related until now. PMID:21670914

  19. Novel aspects of corneal angiogenic and lymphangiogenic privilege

    PubMed Central

    Ellenberg, David; Azar, Dimitri T.; Hallak, Joelle A.; Tobaigy, Faisal; Han, Kyu Yeon; Jain, Sandeep; Zhou, Zhongjun; Chang, Jin-Hong

    2013-01-01

    In this article, we provide the results of experimental studies demonstrating that corneal avascularity is an active process involving the production of anti-angiogenic factors, which counterbalance the proangiogenic/lymphangiogenic factors that are upregulated during wound healing. We also summarize pertinent published reports regarding corneal neovascularization (NV), corneal lymphangiogenesis and corneal angiogenic/lymphangiogenic privilege. We outline the clinical causes of corneal NV, and discuss the angiogenic proteins (VEGF and bFGF) and angiogenesis regulatory proteins. We also describe the role of matrix metalloproteinases MMP-2, -7, and MT1-MMP, anti-angiogenic factors, and lymphangiogenic regulatory proteins during corneal wound healing. Established and potential new therapies for the treatment of corneal neovascularization are also discussed. PMID:20100589

  20. Normative Values for Corneal Nerve Morphology Assessed Using Corneal Confocal Microscopy: A Multinational Normative Data Set

    PubMed Central

    Tavakoli, Mitra; Ferdousi, Maryam; Petropoulos, Ioannis N.; Morris, Julie; Pritchard, Nicola; Zhivov, Andrey; Ziegler, Dan; Pacaud, Danièle; Romanchuk, Kenneth; Perkins, Bruce A.; Lovblom, Leif E.; Bril, Vera; Singleton, J. Robinson; Smith, Gordon; Boulton, Andrew J.M.; Efron, Nathan

    2015-01-01

    OBJECTIVE Corneal confocal microscopy is a novel diagnostic technique for the detection of nerve damage and repair in a range of peripheral neuropathies, in particular diabetic neuropathy. Normative reference values are required to enable clinical translation and wider use of this technique. We have therefore undertaken a multicenter collaboration to provide worldwide age-adjusted normative values of corneal nerve fiber parameters. RESEARCH DESIGN AND METHODS A total of 1,965 corneal nerve images from 343 healthy volunteers were pooled from six clinical academic centers. All subjects underwent examination with the Heidelberg Retina Tomograph corneal confocal microscope. Images of the central corneal subbasal nerve plexus were acquired by each center using a standard protocol and analyzed by three trained examiners using manual tracing and semiautomated software (CCMetrics). Age trends were established using simple linear regression, and normative corneal nerve fiber density (CNFD), corneal nerve fiber branch density (CNBD), corneal nerve fiber length (CNFL), and corneal nerve fiber tortuosity (CNFT) reference values were calculated using quantile regression analysis. RESULTS There was a significant linear age-dependent decrease in CNFD (−0.164 no./mm2 per year for men, P < 0.01, and −0.161 no./mm2 per year for women, P < 0.01). There was no change with age in CNBD (0.192 no./mm2 per year for men, P = 0.26, and −0.050 no./mm2 per year for women, P = 0.78). CNFL decreased in men (−0.045 mm/mm2 per year, P = 0.07) and women (−0.060 mm/mm2 per year, P = 0.02). CNFT increased with age in men (0.044 per year, P < 0.01) and women (0.046 per year, P < 0.01). Height, weight, and BMI did not influence the 5th percentile normative values for any corneal nerve parameter. CONCLUSIONS This study provides robust worldwide normative reference values for corneal nerve parameters to be used in research and clinical practice in the study of diabetic and other peripheral

  1. Fibrin glue-assisted for the treatment of corneal perforations using glycerin-cryopreserved corneal tissue

    PubMed Central

    Dong, Nuo; Li, Cheng; Chen, Wen-Sheng; Qin, Wen-Juan; Xue, Yu-Hua; Wu, Hu-Ping

    2014-01-01

    AIM To evaluate the outcomes and safety of lamellar keratoplasty (LK) assisted by fibrin glue in corneal perforations. METHODS Six eyes of 6 patients affected by different corneal pathologies (2 posttraumatic corneal scar and 3 bacterial keratitis) underwent LK procedures by using fibrin glue. The mean corneal perforation diameter was 1.35±0.64mm (range, 0.7-2.5mm), and the greatest diameter of the ulcerative stromal defect was 2.47±0.77mm in average (range, 1.5-3.5mm). The donor corneal lamella diameters were 0.20-mm larger and thicker than the recipient to restore a physiologic corneal thickness and shape: mean donor diameter was 8.34±0.28mm (range, 8.2-8.7mm) and mean thickness was 352±40.27mm (range, 220-400mm). Mean follow-up was 7.33±1.97 months (range, 6-11 months). Postoperatively, the graft status, graft clarity, anterior chamber response, the visual prognosis, intraocular pressures, and postoperative complications were recorded. RESULTS All the corneal perforations were successfully healed after the procedure. The best-corrected visual acuity (BCVA) ranged from 20/1 000 to 20/50 in their initial presentation, and from 20/100 to 20/20 in their last visit, showed increase in all the patients. No major complications such as graft dislocation and graft failure were noted. Neovascularization developed in the superficial stroma of donor graft in 1 case. High intraocular pressure developed on day 2 after surgery, while was remained in normal range after application of anti-glaucomatous eyedrops for 1 week in 1 case. CONCLUSION Fibrin glue-assisted sutureless LK is valuable for maintaining the ocular integrity in the treatment of corneal perforations. PMID:24634865

  2. Corneal Higher Order Aberrations in Granular, Lattice and Macular Corneal Dystrophies

    PubMed Central

    Yagi-Yaguchi, Yukari; Yamaguchi, Takefumi; Okuyama, Yumi; Satake, Yoshiyuki; Tsubota, Kazuo; Shimazaki, Jun

    2016-01-01

    Purpose To evaluate the corneal higher-order aberrations (HOAs) in granular, lattice and macular corneal dystrophies. Methods This retrospective study includes consecutive patients who were diagnosed as granular corneal dystrophy type2 (GCD2; 121 eyes), lattice corneal dystrophies type 1, type 3A (LCDI; 20 eyes, LCDIIIA; 32 eyes) and macular corneal dystrophies (MCD; 13 eyes), and 18 healthy control eyes. Corneal HOAs were calculated using anterior segment optical coherence tomography, and the correlations between HOAs and visual acuity were analyzed. Results HOAs of the total cornea within 4 mm diameter were significantly larger in GCD2 (0.17 ± 0.35 μm), in LCDI (0.33 ± 0.27), LCDIIIA (0.61 ± 1.56) and in MCD (0.23 ± 0.18), compared with healthy controls (0.09 ± 0.02μm, all P < 0.01). HOAs of the total cornea within 6 mm diameter were significantly larger in GCD2 (0.32 ± 0.48), in LCDI (0.60 ± 0.46), LCDIIIA (0.83 ± 2.29) and in MCD (0.44 ± 0.24), compared with healthy controls (0.19 ± 0.06, all P < 0.001). In GCD2, there was no significant correlation between logMAR and HOAs (r = 0.113, P = 0.227). In MCD, LCDI and LCDIIIA, logMAR was positively significantly correlated with HOAs (r = 0.620 and P = 0.028, r = 0.587 and P = 0.007, r = 0.614 and P < 0.001, respectively). Conclusions Increased HOAs occur in eyes with corneal dystrophies, especially in eye with LCD and MCD. Larger amount corneal HOAs are associated with poorer visual acuity in patients with LCD and MCD. PMID:27536778

  3. A brief history of corneal transplantation: From ancient to modern.

    PubMed

    Crawford, Alexandra Z; Patel, Dipika V; McGhee, Charles Nj

    2013-09-01

    This review highlights many of the fundamental concepts and events in the development of corneal transplantation - from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD). Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17(th) and 18(th) centuries, true scientific and surgical experimentation in this field did not begin until the 19(th) century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term "keratoplasty". Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838-unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of corticosteroids. Recent

  4. A brief history of corneal transplantation: From ancient to modern

    PubMed Central

    Crawford, Alexandra Z; Patel, Dipika V; McGhee, Charles NJ

    2013-01-01

    This review highlights many of the fundamental concepts and events in the development of corneal transplantation – from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD). Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17th and 18th centuries, true scientific and surgical experimentation in this field did not begin until the 19th century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term “keratoplasty”. Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838—unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of corticosteroids. Recent

  5. A brief history of corneal transplantation: From ancient to modern.

    PubMed

    Crawford, Alexandra Z; Patel, Dipika V; McGhee, Charles Nj

    2013-09-01

    This review highlights many of the fundamental concepts and events in the development of corneal transplantation - from ancient times to modern. Tales of eye, limb, and even heart transplantation appear in ancient and medieval texts; however, in the scientific sense, the original concepts of corneal surgery date back to the Greek physician Galen (130-200 AD). Although proposals to provide improved corneal clarity by surgical interventions, including keratoprostheses, were better developed by the 17(th) and 18(th) centuries, true scientific and surgical experimentation in this field did not begin until the 19(th) century. Indeed, the success of contemporary corneal transplantation is largely the result of a culmination of pivotal ideas, experimentation, and perseverance by inspired individuals over the last 200 years. Franz Reisinger initiated experimental animal corneal transplantation in 1818, coining the term "keratoplasty". Subsequently, Wilhelmus Thorne created the term corneal transplant and 3 years later Samuel Bigger, 1837, reported successful corneal transplantation in a gazelle. The first recorded therapeutic corneal xenograft on a human was reported shortly thereafter in 1838-unsurprisingly this was unsuccessful. Further progress in corneal transplantation was significantly hindered by limited understanding of antiseptic principles, anesthesiology, surgical technique, and immunology. There ensued an extremely prolonged period of debate and experimentation upon the utility of animal compared to human tissue, and lamellar versus penetrating keratoplasty. Indeed, the first successful human corneal transplant was not performed by Eduard Zirm until 1905. Since that first successful corneal transplant, innumerable ophthalmologists have contributed to the development and refinement of corneal transplantation aided by the development of surgical microscopes, refined suture materials, the development of eye banks, and the introduction of corticosteroids. Recent

  6. Quantitative proteomic analysis of mice corneal tissues reveals angiogenesis-related proteins involved in corneal neovascularization.

    PubMed

    Shen, Minqian; Tao, Yimin; Feng, Yifan; Liu, Xing; Yuan, Fei; Zhou, Hu

    2016-07-01

    Corneal neovascularization (CNV) was induced in Balb/c mice by alkali burns in the central area of the cornea with a diameter of 2.5mm. After fourteen days, the cornea from one eye was collected for histological staining for CNV examination, while the cornea from the other eye of the same mouse was harvested for proteomic analysis. The label-free quantitative proteomic approach was applied to analyze five normal corneal tissues (normal group mice n=5) and five corresponding neovascularized corneal tissues (model group mice n=5). A total of 2124 proteins were identified, and 1682 proteins were quantified from these corneal tissues. Among these quantified proteins, 290 proteins were significantly changed between normal and alkali burned corneal tissues. Of these significantly changed proteins, 35 were reported or predicted as angiogenesis-related proteins. Then, these 35 proteins were analyzed using Ingenuity Pathway Analysis Software, resulting in 26 proteins enriched and connected to each other in the protein-protein interaction network, such as Lcn-2, αB-crystallin and Serpinf1 (PEDF). These three significantly changed proteins were selected for further Western blotting validation. Consistent with the quantitative proteomic results, Western blotting showed that Lcn-2 and αB-crystallin were significantly up-regulated in CNV model, while PEDF was down-regulated. This study provided increased understanding of angiogenesis-related proteins involved in corneal vascular development, which will be useful in the ophthalmic clinic of specifically target angiogenesis.

  7. High-frequency ultrasound corneal pachymetry in the assessment of corneal scars for therapeutic planning.

    PubMed

    Reinstein, D Z; Aslanides, I M; Silverman, R H; Asbell, P A; Coleman, D J

    1994-07-01

    We used high-frequency ultrasound B-scanning with digital signal processing for pachymetric analysis of corneal scars to help determine the optimal management strategy. Four patients were selected for this report. By an automated motor system, 12 consecutive, parallel ultrasound B-scans, each 2.5 to 3 mm wide at 0.25 mm intervals, were obtained from the central corneal area of three patients with anterior corneal scarring. In a fourth patient with near complete corneal scarring obscuring the view of the anterior chamber, a set of 15 mm wide B-scans was obtained. Digitized ultrasound signals were used to produce high-resolution images and I-scans enabling a pachymetric precision of +/- 2 microns (SD). Epithelial, scar, and corneal thickness measurements were made along each scan to determine the most significant zone of pathology. Pachymetry of the cornea and the individual layers was used to assess the suitability for either photorefractive or penetrating keratectomy. B-scan imaging of the full anterior segment provided useful information for the preoperative planning of anterior segment reconstruction and the prognostic evaluation of penetrating keratoplasty. This method provides a powerful tool for the corneal surgeon in management planning.

  8. Corneal injuries from liquid detergent pods.

    PubMed

    Gray, Michael E; West, Constance E

    2014-10-01

    Laundry and dishwasher detergent "pods" were introduced to the United States market in 2010 and are sold by several manufacturers. They represent a high percentage of household cleaning product exposure in the United Kingdom. We present a consecutive case series of 10 children seen in a 9-month period with corneal injuries from exposure to liquid detergent pods.

  9. Corneal topography measurements for biometric applications

    NASA Astrophysics Data System (ADS)

    Lewis, Nathan D.

    The term biometrics is used to describe the process of analyzing biological and behavioral traits that are unique to an individual in order to confirm or determine his or her identity. Many biometric modalities are currently being researched and implemented including, fingerprints, hand and facial geometry, iris recognition, vein structure recognition, gait, voice recognition, etc... This project explores the possibility of using corneal topography measurements as a trait for biometric identification. Two new corneal topographers were developed for this study. The first was designed to function as an operator-free device that will allow a user to approach the device and have his or her corneal topography measured. Human subject topography data were collected with this device and compared to measurements made with the commercially available Keratron Piccolo topographer (Optikon, Rome, Italy). A third topographer that departs from the standard Placido disk technology allows for arbitrary pattern illumination through the use of LCD monitors. This topographer was built and tested to be used in future research studies. Topography data was collected from 59 subjects and modeled using Zernike polynomials, which provide for a simple method of compressing topography data and comparing one topographical measurement with a database for biometric identification. The data were analyzed to determine the biometric error rates associated with corneal topography measurements. Reasonably accurate results, between three to eight percent simultaneous false match and false non-match rates, were achieved.

  10. Corneal changes in Tay-Sachs disease.

    PubMed

    Ghosh, M; Hunter, W S; Wedge, C

    1990-06-01

    Tay-Sachs disease is a well-known inherited disease leading to an accumulation of gangliosides in the brain and retina. Our report is based on a case of Tay-Sachs disease in a non-Jewish infant where pathologic changes were noted in corneal endothelium as well as in the retina.

  11. Aspergillus terreus recovered from a corneal scraping.

    PubMed

    Campbell, Suzanne

    2014-01-01

    A 52 year old, healthy male presented to his optometrist complaining of redness and irritation in the right eye. A foreign body was removed from the eye. The patient was started on ophthalmic solutions of vigamox and systane. At 48 hours, the patient reported increased redness, limited vision, and yellow discharge from the eye. The patient was referred to an ophthalmologist for further evaluation. Physical assessment revealed a superlative central infiltrate (extreme, centrally located injury that had permeated the cornea), diffuse corneal haze, and edema with a 3- to 4+ conjunctival injection and a 1 millimeter hypopyon (an effusion of pus into the anterior chamber of the eye). Corneal scrapings were collected for aerobic and anaerobic bacterial and fungal cultures. The patient was then prescribed. vancomycin, tobramycin, and natamycin ophthalmic eyedrops. On day three, fungal culture results indicated possible fungal forms seen. On day 12, results from the fungal culture of the corneal scraping revealed the causative agent to be Aspergillus terreus. Voriconazole eyedrops were added to the treatment regimen and continued for 10 weeks. The physician order for a fungal culture as well as laboratory data providing the final identification of Aspergillus terreus and laboratory comments indicating an elevated minimum inhibitory concentration (MIC) (> 2 microg/mL) to amphotericin B is associated with treatment failure positively impacted the patient outcome. After completion of the treatment regimen, a photo-therapeutic keratectomy (PTK) was performed in an attempt to remove the dense corneal scarring caused by the fungal infection.

  12. Corneal collagen cross-linking: A review

    PubMed Central

    O’Brart, David P.S.

    2014-01-01

    The aim was to review the published literature on corneal collagen cross-linking. The emphasis was on the seminal publications, systemic reviews, meta-analyses and randomized controlled trials. Where such an evidence did not exist, selective large series cohort studies, case controlled studies and case series with follow-up preferably greater than 12 months were included. Riboflavin/Ultraviolet A (UVA) corneal collagen cross-linking appears to be the first treatment modality to halt the progression of keratoconus and other corneal ectatic disorders with improvement in visual, keratometric and topographic parameters documented by most investigators. Its precise mechanism of action at a molecular level is as yet not fully determined. Follow-up is limited to 4–6 years at present but suggests continued stability and improvement in corneal shape with time. Most published data are with epithelium-off techniques. Epithelium-on studies suggest some efficacy but less than with the epithelium-off procedures and long-term data are not currently available. The use of Riboflavin/UVA CXL for the management of infectious and non-infectious keratitis appears very promising. Its use in the management of bullous keratopathy is equivocal. Investigation of other methodologies for CXL are under investigation. PMID:25000866

  13. Autophagy in granular corneal dystrophy type 2.

    PubMed

    Choi, Seung-Il; Kim, Eung Kweon

    2016-03-01

    Autophagy is a lysosomal degradative process that is essential for cellular homeostasis and metabolic stress adaptation. Defective autophagy is involved in the pathogenesis of many diseases including granular corneal dystrophy type 2 (GCD2). GCD2 is an autosomal dominant disorder caused by substitution of histidine for arginine at codon 124 (R124H) in the transforming growth factor β-induced gene (TGFBI) on chromosome 5q31. Transforming growth factor β-induced protein (TGFBIp) is degraded by autophagy, but mutant-TGFBIp accumulates in autophagosomes and/or lysosomes, despite significant activation of basal autophagy, in GCD2 corneal fibroblasts. Furthermore, inhibition of autophagy induces cell death of GCD2 corneal fibroblasts through active caspase-3. As there is currently no pharmacological treatment for GCD2, development of novel therapies is required. A potential strategy for preventing cytoplasmic accumulation of mutant-TGFBIp in GCD2 corneal fibroblasts is to enhance mutant-TGFBIp degradation. This could be achieved by activation of the autophagic pathway. Here, we will consider the role and the potential therapeutic benefits of autophagy in GCD2, with focus on TGFBIp degradation, in light of the recently established role of autophagy in protein degradation.

  14. Peptide Amphiphiles in Corneal Tissue Engineering

    PubMed Central

    Miotto, Martina; Gouveia, Ricardo M.; Connon, Che J.

    2015-01-01

    The increasing interest in effort towards creating alternative therapies have led to exciting breakthroughs in the attempt to bio-fabricate and engineer live tissues. This has been particularly evident in the development of new approaches applied to reconstruct corneal tissue. The need for tissue-engineered corneas is largely a response to the shortage of donor tissue and the lack of suitable alternative biological scaffolds preventing the treatment of millions of blind people worldwide. This review is focused on recent developments in corneal tissue engineering, specifically on the use of self-assembling peptide amphiphiles for this purpose. Recently, peptide amphiphiles have generated great interest as therapeutic molecules, both in vitro and in vivo. Here we introduce this rapidly developing field, and examine innovative applications of peptide amphiphiles to create natural bio-prosthetic corneal tissue in vitro. The advantages of peptide amphiphiles over other biomaterials, namely their wide range of functions and applications, versatility, and transferability are also discussed to better understand how these fascinating molecules can help solve current challenges in corneal regeneration. PMID:26258796

  15. Flow cytometric DNA analysis of corneal epithelium.

    PubMed

    Burns, E R; Roberson, M C; Brown, M F; Shock, J P; Pipkin, J L; Hinson, W G; Anson, J F

    1990-03-01

    We have modified an existing technique in order to perform DNA analysis by flow cytometry (FCM) of corneal epithelium from the mouse, rat, chicken, rabbit, and human. This protocol permitted an investigation of human corneal scrapings from several categories: normal, aphakic bullous keratopathy (ABK), keratoconus (KC), Fuch's dystrophy, edema, epithelial dysplasia, and lipid degeneration. No abnormal characteristic cell-kinetic profile was detected when averaged DNA histograms were compared statistically between the normal and either ABK, KC, edema, or Fuch's dystrophy groups. Abnormal DNA histograms were recorded for cell samples that were taken 1) from three individuals who had epithelial dysplasia and 2) from one individual diagnosed with lipid degeneration. The former condition was characterized by histograms that had a subpopulation of cells with an aneuploid amount of DNA or had higher than normal percentages of cells in the S and G2 + M phases of the cell cycle. Corneal cells from the patient who had lipid degeneration had an abnormally high percentage of cells in the G2 + M phases of the cell cycle. The availability of accurate DNA flow cytometric analysis of corneal epithelium allows further studies on this issue from both experimental and clinical situations.

  16. [Future Innovative Medicine for Corneal Diseases].

    PubMed

    Nishida, Kohji

    2016-03-01

    Japan faces an aging population and a declining birth rate, so medical professionals and the public are seeking next-generation ophthalmological treatments to preserve and restore visual function. Two fields lie at the heart of this future concept of ophthalmological treatments. The first is predictive medicine and early intervention and treatment. This field is based on precision medicine to treat chronic conditions such as keratoconus, glaucoma, and macular degeneration while the condition is latent or soon after it has developed. The second field is regenerative therapy. This field includes cell therapy, regenerative medicine, artificial corneas and retinal implants. Precision medicine is the concept of examining the effects of genomic information and environmental factors on the onset or progression of a condition. Precision medicine involves dividing patients with a given condition into subgroups and then developing an appropriate method of preventing or treating that condition for each group. This may prove useful in treating corneal conditions such as keratoconus and dry eye. To accomplish that goal, however, overarching genomic, imaging, and biomarker studies must be conducted. Markers related to the onset or progression of a condition must also be identified. This paper describes results of preliminary study of 2 types of markers: biomarkers, and genetic markers. These markers have been used in efforts to predict the onset or progression of keratoconus. The development of regenerative medicine requires basic studies of stem cells and microenvironments (niches) in which to sustain those cells. N-cadherin is a cell adhesion molecule, and the current authors are the first to contend that this molecule plays an important role in the corneal epithelial stem cell niche. In addition, the current authors are the first to report that corneal endothelial cells expressing p75 may potentially be corneal endothelial precursor cells. Capitalizing on the results of that

  17. [Future Innovative Medicine for Corneal Diseases].

    PubMed

    Nishida, Kohji

    2016-03-01

    Japan faces an aging population and a declining birth rate, so medical professionals and the public are seeking next-generation ophthalmological treatments to preserve and restore visual function. Two fields lie at the heart of this future concept of ophthalmological treatments. The first is predictive medicine and early intervention and treatment. This field is based on precision medicine to treat chronic conditions such as keratoconus, glaucoma, and macular degeneration while the condition is latent or soon after it has developed. The second field is regenerative therapy. This field includes cell therapy, regenerative medicine, artificial corneas and retinal implants. Precision medicine is the concept of examining the effects of genomic information and environmental factors on the onset or progression of a condition. Precision medicine involves dividing patients with a given condition into subgroups and then developing an appropriate method of preventing or treating that condition for each group. This may prove useful in treating corneal conditions such as keratoconus and dry eye. To accomplish that goal, however, overarching genomic, imaging, and biomarker studies must be conducted. Markers related to the onset or progression of a condition must also be identified. This paper describes results of preliminary study of 2 types of markers: biomarkers, and genetic markers. These markers have been used in efforts to predict the onset or progression of keratoconus. The development of regenerative medicine requires basic studies of stem cells and microenvironments (niches) in which to sustain those cells. N-cadherin is a cell adhesion molecule, and the current authors are the first to contend that this molecule plays an important role in the corneal epithelial stem cell niche. In addition, the current authors are the first to report that corneal endothelial cells expressing p75 may potentially be corneal endothelial precursor cells. Capitalizing on the results of that

  18. Identification of a novel nonsense mutation in the FOXP3 gene in a fetus with hydrops--Expanding the phenotype of IPEX syndrome.

    PubMed

    Reichert, Sara L; McKay, Eileen M; Moldenhauer, Julie S

    2016-01-01

    IPEX Syndrome is a well-characterized, however rare, autoimmune condition primarily affecting males presenting with neonatal onset of severe diarrhea, diabetes, dermatitis, and other autoimmune symptoms. The gene responsible for this condition, FOXP3, is important in the function of T-regulatory cells which maintain tolerance to self-antigens and are implicated in many autoimmune conditions. While females who carry FOXP3 mutations are typically asymptomatic, pregnancy loss of male fetuses in families with a history of IPEX syndrome has been noted. This loss is likely unrelated to the maternal carrier status, and rather related to pathogenic fetal autoimmunity. Fetal presentation of IPEX Syndrome has been recently reported in two families. Of the two reported probands, one had onset of severe intrauterine growth restriction and the second involved monochorionic diamniotic twins affected with fetal hydrops. Loss of male fetuses was noted in both families. We present a third family who suffered the loss of two male fetuses as a result of fetal hydrops of an unknown etiology. Whole Exome Sequencing on fetal remains following the second loss identified a novel nonsense mutation in the FOXP3 gene, which was inherited from the mother and subsequently confirmed in saved cells from the first pregnancy. These two cases further expand the fetal phenotype of IPEX Syndrome. While rare, IPEX syndrome should be another potential differential when considering the onset of unexplained hydrops in a male fetus.

  19. Identification of a novel nonsense mutation in the FOXP3 gene in a fetus with hydrops--Expanding the phenotype of IPEX syndrome.

    PubMed

    Reichert, Sara L; McKay, Eileen M; Moldenhauer, Julie S

    2016-01-01

    IPEX Syndrome is a well-characterized, however rare, autoimmune condition primarily affecting males presenting with neonatal onset of severe diarrhea, diabetes, dermatitis, and other autoimmune symptoms. The gene responsible for this condition, FOXP3, is important in the function of T-regulatory cells which maintain tolerance to self-antigens and are implicated in many autoimmune conditions. While females who carry FOXP3 mutations are typically asymptomatic, pregnancy loss of male fetuses in families with a history of IPEX syndrome has been noted. This loss is likely unrelated to the maternal carrier status, and rather related to pathogenic fetal autoimmunity. Fetal presentation of IPEX Syndrome has been recently reported in two families. Of the two reported probands, one had onset of severe intrauterine growth restriction and the second involved monochorionic diamniotic twins affected with fetal hydrops. Loss of male fetuses was noted in both families. We present a third family who suffered the loss of two male fetuses as a result of fetal hydrops of an unknown etiology. Whole Exome Sequencing on fetal remains following the second loss identified a novel nonsense mutation in the FOXP3 gene, which was inherited from the mother and subsequently confirmed in saved cells from the first pregnancy. These two cases further expand the fetal phenotype of IPEX Syndrome. While rare, IPEX syndrome should be another potential differential when considering the onset of unexplained hydrops in a male fetus. PMID:26395338

  20. Review: corneal epithelial stem cells, their niche and wound healing.

    PubMed

    Castro-Muñozledo, Federico

    2013-01-01

    Stem cells emerged as a concept during the second half of 19(th) century, first as a theoretical entity, but then became one of the most promising research fields in cell biology. This work describes the most important characteristics of adult stem cells, including the experimental criteria used to identify them, and discusses current knowledge that led to the proposal that stem cells existed in different parts of the eye, such as the retina, lens, conjunctiva, corneal stroma, Descemet's membrane, and the subject of this review: the corneal epithelium. Evidence includes results that support the presence of corneal epithelial stem cells at the limbus, as well as the major obstacles to isolating them as pure cell populations. Part of this review describes the variation in the basement membrane composition between the limbus and the central cornea, to show the importance of the corneal stem cell niche, its structure, and the participation of extracellular matrix (ECM) components in regulating corneal stem cell compartment. Results obtained by various laboratories suggest that the extracellular matrix plays a central role in regulating stem cell commitment, corneal differentiation, and participation in corneal wound healing, in addition to other environmental signals such as cytokines and growth factors. The niche could define cell division patterns in corneal stem cell populations, establishing whether stem cells divide asymmetrically or symmetrically. Characterization and understanding of the factors that regulate corneal epithelial stem cells should open up new paths for developing new therapies and strategies for accelerating and improving corneal wound healing. PMID:23901244

  1. Review: Corneal epithelial stem cells, their niche and wound healing

    PubMed Central

    2013-01-01

    Stem cells emerged as a concept during the second half of 19th century, first as a theoretical entity, but then became one of the most promising research fields in cell biology. This work describes the most important characteristics of adult stem cells, including the experimental criteria used to identify them, and discusses current knowledge that led to the proposal that stem cells existed in different parts of the eye, such as the retina, lens, conjunctiva, corneal stroma, Descemet’s membrane, and the subject of this review: the corneal epithelium. Evidence includes results that support the presence of corneal epithelial stem cells at the limbus, as well as the major obstacles to isolating them as pure cell populations. Part of this review describes the variation in the basement membrane composition between the limbus and the central cornea, to show the importance of the corneal stem cell niche, its structure, and the participation of extracellular matrix (ECM) components in regulating corneal stem cell compartment. Results obtained by various laboratories suggest that the extracellular matrix plays a central role in regulating stem cell commitment, corneal differentiation, and participation in corneal wound healing, in addition to other environmental signals such as cytokines and growth factors. The niche could define cell division patterns in corneal stem cell populations, establishing whether stem cells divide asymmetrically or symmetrically. Characterization and understanding of the factors that regulate corneal epithelial stem cells should open up new paths for developing new therapies and strategies for accelerating and improving corneal wound healing. PMID:23901244

  2. Anatomical characterization of central, apical and minimal corneal thickness

    PubMed Central

    Saenz-Frances, Federico; Bermúdez-Vallecilla, Martha Cecilia; Borrego-Sanz, Lara; Jañez, Luis; Martinez-de-la-Casa, José María; Morales-Fernandez, Laura; Santos-Bueso, Enrique; Garcia-Sanchez, Julián; Garcia-Feijoo, Julián

    2014-01-01

    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. PMID:25161940

  3. Acellular porcine corneal matrix as a carrier scaffold for cultivating human corneal epithelial cells and fibroblasts in vitro

    PubMed Central

    Zhang, Ju; Zhang, Can-Wei; Du, Li-Qun; Wu, Xin-Yi

    2016-01-01

    AIM To investigate the feasibility of corneal anterior lamellar reconstruction with human corneal epithelial cells and fibroblasts, and an acellular porcine cornea matrix (APCM) in vitro. METHODS The scaffold was prepared from fresh porcine corneas which were treated with 0.5% sodium dodecyl sulfate (SDS) solution and the complete removal of corneal cells was confirmed by hematoxylin-eosin (HE) staining and 4′, 6-diamidino-2-phenylindole (DAPI) staining. Human corneal fibroblasts and epithelial cells were cultured with leaching liquid extracted from APCM, and then cell proliferative ability was evaluated by MTT assay. To construct a human corneal anterior lamellar replacement, corneal fibroblasts were injected into the APCM and cultured for 3d, followed by culturing corneal epithelial cells on the stroma construction surface for another 10d. The corneal replacement was analyzed by HE staining, and immunofluorescence staining. RESULTS Histological examination indicated that there were no cells in the APCM by HE staining, and DAPI staining did not detect any residual DNA. The leaching liquid from APCM had little influence on the proliferation ability of human corneal fibroblasts and epithelial cells. At 10d, a continuous 3 to 5 layers of human corneal epithelial cells covering the surface of the APCM was observed, and the injected corneal fibroblasts distributed within the scaffold. The phenotype of the construction was similar to normal human corneas, with high expression of cytokeratin 12 in the epithelial cell layer and high expression of vimentin in the stroma. CONCLUSION Corneal anterior lamellar replacement can be reconstructed in vitro by cultivating human corneal epithelial cells and fibroblasts with an acellular porcine cornea matrix. This laid the foundation for the further transplantation in vivo. PMID:26949602

  4. Transplacental transfer of cefuroxime in uncomplicated pregnancies and those complicated by hydrops or changes in amniotic fluid volume.

    PubMed Central

    Holt, D E; Fisk, N M; Spencer, J A; de Louvois, J; Hurley, R; Harvey, D

    1993-01-01

    The transplacental transfer of cefuroxime was determined at antenatal fetal blood sampling in a cross sectional study of 78 patients between 15-35 weeks' gestation, 8-138 minutes after a maternal intravenous dose of 750 mg. Mean serum cefuroxime concentration, measured by high performance liquid chromatography, was 7.4 (95% confidence interval (CI) 6.8 to 8.1) mg/l in control fetuses; concentrations in hydropic fetuses were similar (6.2 mg/l, CI 4.7 to 7.7) but in fetuses with oligohydramnios they were significantly lower, (4.9 mg/l, CI 3.6 to 6.2). Antibiotic concentration did not correlate with gestational age and remained unchanged by transfusion of packed red cells. We conclude that (i) fetal serum concentrations of cefuroxime obtained after a maternal dose of 750 mg are only adequate for prophylaxis against organisms with a minimum inhibitory concentration of < 4 mg/l and (ii) transplacental passage of cefuroxime is significantly reduced in the presence of oligohydramnios. PMID:8439202

  5. Use of electrocochleography for assessing endolymphatic hydrops in patients with Lyme disease and Ménière's disease.

    PubMed

    Selmani, Ziane; Pyykkö, Ilmari; Ishizaki, Hisayoshi; Ashammakhi, Nureddin

    2002-03-01

    From an otological standpoint, Lyme disease can manifest itself as Ménière's disease both clinically and electrophysiologically. The aim of this study was to describe the findings of routine clinical, auditory and vestibular tests in patients with Ménière's and Lyme disease and to use electrocochleography (ECoG) to assess the presence of endolymphatic hydrops (EH) in both diseases. Transtympanic ECoG was performed in 91 patients with Ménière's disease and in 11 patients with confirmed Lyme disease. In both diseases the majority of patients had more than one complaint. There was one case with isolated hearing loss in the Lyme disease group. Typical clinical manifestations of Ménière's disease (vertigo, sensorineural hearing loss and tinnitus) were found in 6/11 patients (54.5%) in the Lyme disease group. The ECoG results indicated that there were 65/91 patients (71.4%) with Ménière's disease and 5 patients (45.5%) with Lyme disease who presented with EH. No statistically significant difference was found between the incidence of different symptoms of Ménière's and Lyme disease. On the basis of these results, patients with Lyme disease should undergo careful examination and investigation, especially in endemic regions. The presence of EH does not exclude the presence of infection with borreliosis as a cause of Ménière's disease-like symptoms.

  6. Interferometer for measuring dynamic corneal topography

    NASA Astrophysics Data System (ADS)

    Micali, Jason Daniel

    The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface where the majority of refraction takes place in the eye. A significant component of vision quality is determined by the shape of the cornea and stability of the tear film. It is desirable to possess an instrument that can measure the corneal shape and tear film surface with the same accuracy and resolution that is currently performed on common optical elements. A dual interferometer system for measuring the dynamic corneal topography is designed, built, and verified. The completed system is validated by testing on human subjects. The system consists of two co-aligned polarization splitting Twyman-Green interferometers designed to measure phase instantaneously. The primary interferometer measures the surface of the tear film while the secondary interferometer simultaneously tracks the absolute position of the cornea. Eye motion, ocular variation, and a dynamic tear film surface will result in a non-null configuration of the surface with respect to the interferometer system. A non-null test results in significant interferometer induced errors that add to the measured phase. New algorithms are developed to recover the absolute surface topography of the tear film and corneal surface from the simultaneous interferometer measurements. The results are high-resolution and high-accuracy surface topography measurements of the in vivo cornea that are captured at standard camera frame rates. This dissertation will cover the development and construction of an interferometer system for measuring the dynamic corneal topography of the human eye. The discussion starts with the completion of an interferometer for measuring the tear film. The tear film interferometer is part of an

  7. [Peripheral corneal melting syndrome in psoriatic arthritis treated with adalimumab].

    PubMed

    Restrepo, Juan Pablo; Medina, Luis Fernando; Molina, María del Pilar

    2015-01-01

    Peripheral corneal melting syndrome is a rare immune condition characterized by marginal corneal thinning and sometimes perforation. It is associated with rheumatic and non-rheumatic diseases. Few cases of peripheral corneal melting have been reported in patients with psoriasis. The pathogenesis is not fully understood but metalloproteinases may play a pathogenic role. Anti-TNF therapy has shown to decrease skin and serum metalloproteinases levels in psoriasis. We report a 61-year-old man with peripheral corneal melting syndrome associated with psoriatic arthritis who received Adalimumab to control skin and ocular inflammation. To our knowledge, this is the first case report of peripheral corneal melting syndrome in psoriatic arthritis treated with Adalimumab showing resolution of skin lesions and complete healing of corneal perforation in three months.

  8. Corneal topography in the study of astigmatic excimer laser ablation

    NASA Astrophysics Data System (ADS)

    McDonnell, Peter J.

    1992-08-01

    Corneal astigmatism, both naturally occurring and iatrogenically induced, is a commonly encountered problem. Examination of corneal topography with instruments that digitize reflected ring images and calculate corneal geometry suggests that corneal astigmatism often deviates from spherocylindrical optics; the observed topography may be highly asymmetrical about the center of the pupil. Currently used incisional procedures are limited in terms of predictability of surgical outcome. The 193 nm excimer laser can be used to alter anterior corneal curvature and flatten the cornea to correct myopia. For correction of astigmatism, a slit-opening in the laser delivery system can be used to selectively flatten the steep meridian. Early results using this procedure for correction of iatrogenically induced high corneal astigmatism are promising. A nationwide multicenter clinical trial is now underway in the United States to evaluate this technique for the correction of naturally occurring astigmatism and compound myopic astigmatism.

  9. Using genipin-crosslinked acellular porcine corneal stroma for cosmetic corneal lens implants.

    PubMed

    Liu, Zhao; Zhou, Qiang; Zhu, Jixiang; Xiao, Jianhui; Wan, Pengxia; Zhou, Chenjing; Huang, Zheqian; Qiang, Na; Zhang, Wei; Wu, Zheng; Quan, Daping; Wang, Zhichong

    2012-10-01

    Acellular porcine corneal stroma (APCS) has been proven to maintain the matrix microenvironment and is therefore an ideal biomaterial for the repair and reconstruction of corneal stroma. This study aims to develop a method to prepare cosmetic corneal lens implants for leukoma using genipin-crosslinked APCS (Gc-APCS). The Gc-APCS was prepared from APCS immersed in 1.0% genipin aqueous solution (pH 5.5) for 4 h at 37 °C, followed by lyophilization at -10 °C. The color of the Gc-APCS gradually deepened to dark-blue. The degree of crosslinking was 45.7 ± 4.6%, measured by the decrease of basic and hydroxy amino acids. The porous structure and ultrastructure of collagenous lamellae were maintained, and the porosity and BET SSA were 72.7 ± 4.6% and 23.01 ± 3.45 m(2)/g, respectively. The Gc-APCS rehydrated to the physiological water content within 5 min and was highly resistant to collagenase digestion. There were no significant differences in the areal modulus and curvature variation between Gc-APCS and nature porcine cornea. The dark-blue pigments were stable to pH, light and implantation in vivo. Gc-APCS extracts had no inhibitory effects on the proliferation of keratocytes. Corneal neovascularization, graft degradation and corneal rejection were not observed within 6 months.

  10. Corneal Biomechanical Assessment Using Corneal Visualization Scheimpflug Technology in Keratoconic and Normal Eyes

    PubMed Central

    Huang, Yi-Fei; Wang, Li-Qiang; Bai, Hua; Wang, Qun; Jiang, Jing-Jing; Wu, Ying; Gao, Min

    2014-01-01

    Purpose. To compare the corneal biomechanical properties of keratoconic patients and age-matched controls using corneal visualization Scheimpflug technology (Corvis ST). Methods. Sixty keratoconic eyes from 47 keratoconus patients and 60 normal eyes from 60 controls were enrolled in this prospective study. Tomography and biomechanical parameters of all eyes were obtained with the Pentacam and Corvis ST, respectively. Intraocular pressure was measured using a Goldmann applanation tonometer. Results. The tomography and biomechanical parameters of the keratoconic corneas were significantly different from those of the normal corneas except for the anterior chamber angle, first applanation length, the highest concavity time, and peak distance. The deformation amplitude was the best predictive parameter (area under the curve: 0.882), with a sensitivity of 81.7%, although there was a significant overlap between keratoconic and normal corneas that ranged from 1.0 to 1.4 mm. In both the keratoconus and control groups, the deformation amplitude was negatively correlated with intraocular pressure, central corneal thickness, and corneal volume at 3 and 5 mm. Conclusions. Corvis ST offers an alternative method for measuring corneal biomechanical properties. The possibility of classifying keratoconus based on deformation amplitude deserves clinical attention. PMID:24800059

  11. Giant papillary conjunctivitis associated with elevated corneal deposits.

    PubMed

    Dunn, J P; Weissman, B A; Mondino, B J; Arnold, A C

    1990-10-01

    A patient presented with central corneal scarring and neovascularization associated with elevated deposits that were shown to be keratin and calcium. Giant papillary conjunctivitis (GPC) was noted at a corresponding location in the palpebral conjunctiva. The lid reaction resolved after the elevated corneal deposits were debrided. A rigid gas-permeable contact lens was then fitted for visual rehabilitation. Either foreign bodies or elevated corneal deposits may cause GPC.

  12. Analysis of correlation between corneal topographical data and visual performance

    NASA Astrophysics Data System (ADS)

    Zhou, Chuanqing; Yu, Lei; Ren, Qiushi

    2007-02-01

    Purpose: To study correlation among corneal asphericity, higher-order aberrations and visual performance for eyes of virgin myopia and postoperative laser in situ keratomileusis (LASIK). Methods: There were 320 candidates 590 eyes for LASIK treatment included in this study. The mean preoperative spherical equivalence was -4.35+/-1.51D (-1.25 to -9.75), with astigmatism less than 2.5 D. Corneal topography maps and contrast sensitivity were measured and analyzed for every eye before and one year after LASIK for the analysis of corneal asphericity and wavefront aberrations. Results: Preoperatively, only 4th and 6th order aberration had significant correlation with corneal asphericity and apical radius of curvature (p<0.001). Postoperatively, all 3th to 6th order aberrations had statistically significant correlation with corneal asphericity (p<0.01), but only 4th and 6th order aberration had significant correlation with apical radius of curvature (p<0.05). The asymmetrical aberration like coma had significant correlation with vertical offset of pupil center (p<0.01). Preoperatively, corneal aberrations had no significant correlation with visual acuity and area under the log contrast sensitivity (AULCSF) (P>0.05). Postoperatively, corneal aberrations still didn't have significant correlation with visual acuity (P>0.05), but had significantly negative correlation with AULCSF (P<0.01). Corneal asphericity had no significant correlation with AULCSF before and after the treatment (P>0.05). Conclusions: Corneal aberrations had different correlation with corneal profile and visual performance for eyes of virgin myopia and postoperative LASIK, which may be due to changed corneal profile and limitation of metrics of corneal aberrations.

  13. Corneal Chromoblastomycosis Caused by Fonsecaea pedrosoi

    PubMed Central

    Chaidaroon, Winai; Tananuvat, Napaporn; Chavengsaksongkram, Pimploy; Vanittanakom, Nongnuch

    2015-01-01

    Purpose To report 2 unusual cases of fungal keratitis due to Fonsecaea pedrosoi. Methods Two patients were diagnosed with Fonsecaea pedrosoi keratitis. Their files were reviewed for predisposing factors, clinical characteristics, microbiological study, treatment, and outcome. Results Two consecutive patients presented with brownish pigmented corneal ulcers in their eyes after sustaining eye trauma from vegetative matter. In both cases, corneal scrapings were collected for microscopic examination and culture. Dematiaceous hyphae were seen on the smears, and dark pigmented colonies grew on the culture media, identified as F. pedrosoi. Both patients were treated and cured with combined topical antifungal agents and oral itraconazole. The first patient required an amniotic membrane patch, while the second received an intracameral amphotericin B injection. Conclusions Pigmented infiltrates can be an important diagnostic clue, but a microscopic evaluation and culture are required to obtain an accurate diagnosis of Fonsecaea keratitis. The prompt diagnosis and combined antifungal treatment can prevent morbidity associated with this fungal infection. PMID:25873892

  14. Corneal cross-linking treatment of keratoconus

    PubMed Central

    Farjadnia, Mahgol; Naderan, Mohammad

    2015-01-01

    Keratoconus as the most common cause of ectasia is one of the leading cause of corneal transplants worldwide. The current available therapies do not modify the underlying pathogenesis of the disease, and none of the available approaches but corneal transplant hinder the ongoing ectasia. Several studies document Crosslink defect between collagen fibrils in the pathogenesis of keratoconus. Collagen cross link is a relatively new approach that with the application of the riboflavin and ultraviolet A, new covalent bands reform. Subjective and objective results following this method seem to be promising. Endothelial damage besides other deep structural injury, which is the major concern of this technique have not yet been reported, when applying the standard method. PMID:26622134

  15. Complications of Corneal Collagen Cross-Linking

    PubMed Central

    Dhawan, Shikha; Rao, Kavita; Natrajan, Sundaram

    2011-01-01

    Cross-linking of corneal collagen (CXL) is a promising approach for the treatment of keratoconus and secondary ectasia. Several long-term and short-term complications of CXL have been studied and documented. The possibility of a secondary infection after the procedure exists because the patient is subjected to epithelial debridement and the application of a soft contact lens. Formation of temporary corneal haze, permanent scars, endothelial damage, treatment failure, sterile infiltrates, and herpes reactivation are the other reported complications of this procedure. Cross-linking is a low-invasive procedure with low complication and failure rate but it may have direct or primary complications due to incorrect technique application or incorrect patient's inclusion and indirect or secondary complications related to therapeutic soft contact lens, patient's poor hygiene, and undiagnosed concomitant ocular surface diseases. PMID:22254130

  16. Corneal epithelial and neuronal interactions: role in wound healing.

    PubMed

    Kowtharapu, Bhavani S; Stahnke, Thomas; Wree, Andreas; Guthoff, Rudolf F; Stachs, Oliver

    2014-08-01

    Impaired corneal innervation and sensitivity are the main causes of corneal neurotrophic keratopathy which simultaneously also leads to poor epithelial wound healing. Restoration of the diminished communication between the corneal epithelium and trigeminal nerve is indispensable for the proper functioning of the epithelium. The present study aims to investigate corneal epithelial and trigeminal neuron interactions to shed light on corneal wound healing during neurotrophic keratopathy. Mouse trigeminal neurons and corneal epithelial cells were cultured according to standard methods. To study the effect of corneal epithelial cells on trigeminal neurons as well as the effect of trigeminal neurons on corneal epithelial cells during wound healing, conditioned media from the cultures of pure trigeminal neurons (CNM) and corneal epithelial cells (CEM) were collected freshly and applied on the other cell type. Neurite outgrowth assay and RT-PCR analysis using primers specific for substance P (SP), Map1a, Map1b were performed on trigeminal neurons in the presence of CEM. We observed an increase in the neurite outgrowth in the presence of CEM and also in co-culture with corneal epithelial cells. Increase in the expression of SP mRNA and a decrease in the expression of Map1b mRNA was observed in the presence of CEM. We also observed the presence of epithelial-to-mesenchymal transition (EMT)-like phenomenon during wound healing using a scratch assay in primary corneal epithelial cultures. This system was further employed to study the effect of CNM on corneal epithelial cells in the context of wound healing to find the effect of trigeminal neurons on epithelial cells. RT-PCR analysis of Pax6 expression in corneal epithelial cell cultures with scratch served as a positive control. Further, we also show the expression of bone morphogenetic protein 7 (BMP7) mRNA in corneal epithelial cells which is decreased gradually along with Pax6 mRNA when cultured together in the presence of

  17. Clinical correlates of common corneal neovascular diseases: a literature review

    PubMed Central

    Abdelfattah, Nizar Saleh; Amgad, Mohamed; Zayed, Amira A; Salem, Hamdy; Elkhanany, Ahmed E; Hussein, Heba; Abd El-Baky, Nawal

    2015-01-01

    A large subset of corneal pathologies involves the formation of new blood and lymph vessels (neovascularization), leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization (CNV) by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis, contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatments available so far. PMID:25709930

  18. Phototherapeutic keratectomy in the treatment of corneal scarring from trachoma.

    PubMed

    Goldstein, M; Loewenstein, A; Rosner, M; Lipshitz, I; Lazar, M

    1994-01-01

    Trachoma is still one of the world's major blinding diseases. Characteristically, trachoma causes deep scarring of the conjunctiva and tarsus that can result in tear deficiency, trichiasis, and entropion. Another common finding is a diffused corneal opacity that is the end stage of peripheral and central corneal infiltrates. The conventional treatment of the corneal opacities is keratoplasty, which has a guarded prognosis because of severe dryness and trichiasis. We report on our experience in treating patients with corneal trachoma with phototherapeutic keratectomy (PTK) with the excimer laser.

  19. Corneal stromal demarcation line after collagen cross-linking in corneal ectatic diseases: a review of the literature

    PubMed Central

    Spadea, Leopoldo; Tonti, Emanuele; Vingolo, Enzo Maria

    2016-01-01

    Collagen cross-linking (CXL) is a relatively new conservative approach for progressive corneal ectasia, which is able to strengthen corneal tissue reforming new covalent bonds. Subjective and objective results following this method seem to be promising. In recent years, newer CXL protocols have been developed to perform more effective and less invasive procedures. The increasing diffusion of CXL in the corneal ectatic disease has increased the need to have actual indices regarding the efficacy of the treatment. Evaluation of demarcation line (DL), a transition zone between the cross-linked anterior corneal stroma and the untreated posterior corneal stroma, is considered a measurement of the depth of CXL treatment into the stroma. Some evidence in the literature emphasize that DL could be a measure of effectiveness of the CXL. On the contrary, some authors believe that the “the deeper, the better” principle is rather a simplistic approach for interpreting the clinical importance of the corneal stromal DL.

  20. Corneal stromal demarcation line after collagen cross-linking in corneal ectatic diseases: a review of the literature

    PubMed Central

    Spadea, Leopoldo; Tonti, Emanuele; Vingolo, Enzo Maria

    2016-01-01

    Collagen cross-linking (CXL) is a relatively new conservative approach for progressive corneal ectasia, which is able to strengthen corneal tissue reforming new covalent bonds. Subjective and objective results following this method seem to be promising. In recent years, newer CXL protocols have been developed to perform more effective and less invasive procedures. The increasing diffusion of CXL in the corneal ectatic disease has increased the need to have actual indices regarding the efficacy of the treatment. Evaluation of demarcation line (DL), a transition zone between the cross-linked anterior corneal stroma and the untreated posterior corneal stroma, is considered a measurement of the depth of CXL treatment into the stroma. Some evidence in the literature emphasize that DL could be a measure of effectiveness of the CXL. On the contrary, some authors believe that the “the deeper, the better” principle is rather a simplistic approach for interpreting the clinical importance of the corneal stromal DL. PMID:27695286

  1. Human excimer laser corneal surgery: preliminary report.

    PubMed Central

    L'Esperance, F A; Taylor, D M; Del Pero, R A; Roberts, A; Gigstad, J; Stokes, M T; Warner, J W; Telfair, W B; Martin, C A; Yoder, P R

    1988-01-01

    The first human trial utilizing the argon fluoride excimer laser at 193 nm to produce a superficial keratectomy in ten human eyes has been described with the histopathological evaluation of four eyes and the longer gross appearance of six eyes at intervals extending to 10 months post-excimer laser treatment. The process of laser superficial keratectomy has proved to be one of the promising areas of surgical intervention for reconstructive or refractive keratoplasty in the future. Intensive investigations need to be undertaken on the corneal wound healing process following laser ablation as well as the nature, and long-term stability of the corneal excisions or induced refractive corrections. It is essential that the optimal laser parameters be established for the various refractive corrections and other corneal surgical techniques, and that pathophysiologic and histopathologic changes that have been induced by the excimer laser-corneal tissue interaction in animals and humans be critically and extensively analyzed. Images FIGURE 1 FIGURE 19 A FIGURE 19 B FIGURE 20 A FIGURE 20 B FIGURE 21 A FIGURE 21 B FIGURE 22 A FIGURE 22 B FIGURE 23 FIGURE 24 FIGURE 25 FIGURE 26 FIGURE 27 FIGURE 28 FIGURE 29 A FIGURE 29 B FIGURE 29 C FIGURE 29 D FIGURE 30 A FIGURE 30 B FIGURE 31 A FIGURE 31 B FIGURE 32 FIGURE 33 FIGURE 34 FIGURE 35 FIGURE 36 FIGURE 37 A FIGURE 37 B FIGURE 37 C FIGURE 38 A FIGURE 38 B FIGURE 39 A FIGURE 39 B FIGURE 39 C FIGURE 40 A FIGURE 40 B PMID:2979049

  2. Corneal proteoglycan changes under vitamin A deficiency

    SciTech Connect

    Twining, S.S.; Wilson, P.M.

    1986-05-01

    The vitamin A-deficient keratinized cornea is very susceptible to ulceration possibly due to altered stromal components. In this study the proteoglycans present in the corneal stroma of vitamin A-deficient, pair-fed and normal rabbits were compared. Rabbits after weaning were placed on a vitamin A deficient diet, the same diet with retinyl palmitate added (pair-fed) or normal rabbit chow. After 5 months, the corneas of the vitamin A-deficient animals became keratinized. The corneal components were then labeled by injection of /sup 3/H-leucine and Na/sup 35/SO/sub 4/ into the anterior chamber of the eyes on 3 successive days. On the 4th day the animals were sacrificed the corneas removed and dissected. The labeled corneal stromas were extracted with 4 M GuHCl and the components separated on a DEAE-Sepharose column. The proteoglycans were eluted with 0.5 M and 1.0 M NaCl. The 1.0 M NaCl fraction (mainly keratin sulfate proteoglycans) was increased 25% in the vitamin A-deficient corneas over that for the pair-fed and normal corneas. These proteoglycans from the deficient corneas gave a different elution pattern on Octyl-Sepharose eluted with a Triton X-100 gradient than those from the pair-fed corneas. The total labeled proteoglycans were similar in the stromas from the 3 types of rabbits. These results indicate the various corneal proteoglycan ratios differ under vitamin A deficiency conditions.

  3. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    PubMed Central

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

    2012-01-01

    Purpose. 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. Methods. 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. Results. BAK-treated corneas exhibited significantly reduced NFD and aqueous tear production, and increased inflammatory cell infiltration and fluorescein staining at 1 week (P < 0.05). These changes were most significant after 0.1% BAK treatment. The extent of inflammatory cell infiltration in the cornea showed a significant negative correlation with NFD. Sequential in vivo imaging of corneas showed two forms of BAK-induced neurotoxicity: reversible neurotoxicity characterized by axonopathy and recovery, and irreversible neurotoxicity characterized by nerve degeneration and regeneration. Increased abundance of beta III tubulin in corneal lysates confirmed regeneration. A dose-related significant 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). Conclusion. Topical application of BAK to the eye causes corneal neurotoxicity, inflammation, and reduced aqueous

  4. Corneal Infection Therapy with Topical Bacteriophage Administration

    PubMed Central

    Fadlallah, Ali; Chelala, Elias; Legeais, Jean-Marc

    2015-01-01

    Staphylococcus aureus is a major pathogen in bacterial keratitis, a vision-threatening disease. Although the incidence of S. aureus keratitis varies worldwide, the increasing trend of resistance to certain antibiotics makes this condition an important, global, healthcare concern. We report the case of a 65-year-old woman with nosocomial left-eye corneal abscess and interstitial keratitis.The patient then undergo topical Phage therapy with successful results. PMID:26862360

  5. Release of platelet activating factor (PAF) and eicosanoids in UVC-irradiated corneal stromal cells.

    PubMed

    Sheng, Y; Birkle, D L

    1995-05-01

    Ultraviolet (UV) irradiation provokes acute inflammation of the eye, and can be used to model processes that occur in response to damage to the anterior segment. This study characterized ultraviolet-C (UVC, 254 nm) irradiation-induced PAF synthesis, and arachidonic acid (20:4) and eicosanoid release in rabbit corneal stromal cells maintained in vitro. PAF was measured by radioimmunoassay (RIA) after exposing cultured corneal stromal cells to UVC irradiation (20 min, 2, 5, 10 mW/cm2). 14C-20:4-labeled stromal cells were also stimulated with UVC and radiolabeled phospholipids, neutral lipids and eicosanoids were measured. Synthesis of cell-associated and secreted PAF from corneal stromal cells was increased by UV irradiation. UV irradiation (254 nm, 5mW/cm2) enhanced 20:4 release from triacylglycerols, phosphatidylinositol, phosphatidylserine and phosphatidylethanolamine, and increased levels of 20:4-diacylglycerol and unesterified 20:4. The released 20:4 entered both the cyclooxygenase and lipoxygenase pathways after UVC irradiation. The PAF antagonist, BN52021 (10 microM) reduced UVC irradiation-induced stimulation of prostaglandin production, but failed to inhibit UVC-induced 20:4 release and synthesis of lipoxygenase products. Furthermore, exogenous PAF (1 microM) stimulated prostaglandin production, but did not increase the synthesis of lipoxygenase products from radiolabeled 20:4. The effects of PAF on prostaglandin synthesis were inhibited by BN52021. These findings indicate that responses to injury in cultured corneal stromal cells include PAF synthesis, release of 20:4 from glycerolipids, accumulation of diacylglycerol and synthesis of eicosanoids. The data further suggest that during UVC irradiation in vitro, PAF is not a primary or initial mediator of 20:4 release and synthesis of lipoxygenase products, but may mediate UVC-induced prostaglandin synthesis. PMID:7648859

  6. Decreased central corneal thickness in ankylosing spondylitis.

    PubMed

    Ortak, Huseyin; Inanır, Ahmet; Demir, Selim; Uysal, Alper; Şahin, Şafak; Sağcan, Mustafa; Önder, Yalçın; Alim, Sait; Demir, Ayşe Kevser

    2014-04-01

    Central corneal thickness and dry eye tests were evaluated in a study population consisting of 68 ankylosing spondylitis patients diagnosed according to the modified New York criteria, and 61 age-matched controls without ankylosing spondylitis. A full ophthalmological evaluation was performed on each subject. All subjects were screened for age, gender, HLA-B27, tear break-up time test, Schirmer test, and duration of disease. Central corneal thickness was measured under topical anesthesia with an ultrasonic pachymeter. The mean central corneal thickness was 537.3 ± 30.6 μm, range 462-600 μm, in ankylosing spondylitis patients, whereas it was 551.7 ± 25.2 μm, range 510-620 μm, in controls (p = 0.005). The Schirmer test result was 7.3 ± 5.9 mm for the ankylosing spondylitis patients and 11.7 ± 5.8 mm for the control group (p = 0.002). Tear break-up time was 7.3 ± 3.2 s for the ankylosing spondylitis patients and 14.0 ± 4.5 s for the control group (p < 0.001). The possibility of a thinner cornea should be taken into consideration in ankylosing spondylitis. In addition, attention must be given to lower dry eye tests in surgical interventions such as photorefractive keratectomy and laser in situ keratomileusis in ankylosing spondylitis patients.

  7. Lymphatic endothelial lineage assemblage during corneal lymphangiogenesis

    PubMed Central

    Connor, Alicia L.; Kelley, Philip M.; Tempero, Richard M.

    2015-01-01

    Post natal inflammatory lymphangiogenesis presumably requires precise regulatory processes to properly assemble proliferating lymphatic endothelial cells (LECs). The specific mechanisms that regulate the assembly of LECs during new lymphatic vessel synthesis are unclear. Dynamic endothelial shuffling and rearrangement has been proposed as a mechanism of blood vessel growth. We developed genetic lineage tracing strategies using an inductive transgenic technology to track the fate of entire tandem dimer tomato positive (tdT) lymphatic vessels or small, in some cases clonal, populations of LECs. We coupled this platform with a suture induced mouse model of corneal lymphangiogenesis and used different analytic microscopy techniques including serial live imaging to study the spatial properties of proliferating tdT+ LEC progenies. LEC precursors and their progeny expanded from the corneal limbal lymphatic vessel and were assembled contiguously to comprise a subunit within a new lymphatic vessel. VE-cadherin blockade induced morphologic abnormalities in newly synthesized lymphatic vessels, but did not disrupt the tdT+ lymphatic endothelial lineage assembly. Analysis of this static and dynamic data based largely on direct in vivo observations supports a model of lymphatic endothelial lineage assemblage during corneal inflammatory lymphangiogenesis. PMID:26658452

  8. Lymphatic endothelial lineage assemblage during corneal lymphangiogenesis.

    PubMed

    Connor, Alicia L; Kelley, Philip M; Tempero, Richard M

    2016-03-01

    Postnatal inflammatory lymphangiogenesis presumably requires precise regulatory processes to properly assemble proliferating lymphatic endothelial cells (LECs). The specific mechanisms that regulate the assembly of LECs during new lymphatic vessel synthesis are unclear. Dynamic endothelial shuffling and rearrangement has been proposed as a mechanism of blood vessel growth. We developed genetic lineage-tracing strategies using an inductive transgenic technology to track the fate of entire tandem dimer tomato-positive (tdT) lymphatic vessels or small, in some cases clonal, populations of LECs. We coupled this platform with a suture-induced mouse model of corneal lymphangiogenesis and used different analytic microscopy techniques including serial live imaging to study the spatial properties of proliferating tdT(+) LEC progenies. LEC precursors and their progeny expanded from the corneal limbal lymphatic vessel and were assembled contiguously to comprise a subunit within a new lymphatic vessel. VE-cadherin blockade induced morphologic abnormalities in newly synthesized lymphatic vessels, but did not disrupt the tdT(+) lymphatic endothelial lineage assembly. Analysis of this static and dynamic data based largely on direct in vivo observations supports a model of lymphatic endothelial lineage assemblage during corneal inflammatory lymphangiogenesis. PMID:26658452

  9. Enhancement of Corneal Visibility in Optical Coherence Tomography Images with Corneal Opacification

    PubMed Central

    Chung, Cheuk Wang; Ang, Marcus; Farook, Mohamed; Strouthidis, Nicholas G.; Mehta, Joddhbir S.; Mari, Jean Martial; Girard, Michaël J. A.

    2016-01-01

    Purpose To establish and to rank the performance of a corneal adaptive compensation (CAC) algorithm in enhancing corneal images with scars acquired from three commercially available anterior segment optical coherence tomography (ASOCT) devices. Methods Horizontal B-scans of the cornea were acquired from 10 patients using three ASOCT devices (Spectralis, RTVue, and Cirrus). We compared ASOCT image quality (with and without CAC) by computing the intralayer contrast (a measure of shadow removal), the interlayer contrast (a measure of tissue boundary visibility), and the tissue/background contrast (a measure of overall corneal visibility). All six groups (Spectralis, RTVue, Cirrus, Spectralis+CAC, RTVue+CAC, and Cirrus+CAC) were ranked according to a global performance index that averaged all contrast quantities. Results CAC provided mean intralayer contrasts improvement for all devices (all P < 0.05). Mean tissue/boundary contrasts were also improved for Spectralis and Cirrus (both P < 0.001). Mean interlayer contrasts were increased for Spectralis (P = 0.011) only. When comparing global performance indices, all CAC groups outperformed their corresponding baseline groups significantly. RTVue performed best without CAC, but Spectralis+CAC was ranked first. Conclusions ASOCT images of corneal scars may be enhanced by CAC through shadow removal, improved tissue boundary visibility, and enhanced corneal visibility against the image background. RTVue produces the finest baseline images but the best image quality can be achieved by applying CAC to Spectralis images. Translational Relevance CAC could enhance visibility of corneal images with scars acquired from commercially available ASOCT devices and could aid preoperative planning of patients for ophthalmic procedures.

  10. Enhancement of Corneal Visibility in Optical Coherence Tomography Images with Corneal Opacification

    PubMed Central

    Chung, Cheuk Wang; Ang, Marcus; Farook, Mohamed; Strouthidis, Nicholas G.; Mehta, Joddhbir S.; Mari, Jean Martial; Girard, Michaël J. A.

    2016-01-01

    Purpose To establish and to rank the performance of a corneal adaptive compensation (CAC) algorithm in enhancing corneal images with scars acquired from three commercially available anterior segment optical coherence tomography (ASOCT) devices. Methods Horizontal B-scans of the cornea were acquired from 10 patients using three ASOCT devices (Spectralis, RTVue, and Cirrus). We compared ASOCT image quality (with and without CAC) by computing the intralayer contrast (a measure of shadow removal), the interlayer contrast (a measure of tissue boundary visibility), and the tissue/background contrast (a measure of overall corneal visibility). All six groups (Spectralis, RTVue, Cirrus, Spectralis+CAC, RTVue+CAC, and Cirrus+CAC) were ranked according to a global performance index that averaged all contrast quantities. Results CAC provided mean intralayer contrasts improvement for all devices (all P < 0.05). Mean tissue/boundary contrasts were also improved for Spectralis and Cirrus (both P < 0.001). Mean interlayer contrasts were increased for Spectralis (P = 0.011) only. When comparing global performance indices, all CAC groups outperformed their corresponding baseline groups significantly. RTVue performed best without CAC, but Spectralis+CAC was ranked first. Conclusions ASOCT images of corneal scars may be enhanced by CAC through shadow removal, improved tissue boundary visibility, and enhanced corneal visibility against the image background. RTVue produces the finest baseline images but the best image quality can be achieved by applying CAC to Spectralis images. Translational Relevance CAC could enhance visibility of corneal images with scars acquired from commercially available ASOCT devices and could aid preoperative planning of patients for ophthalmic procedures. PMID:27642539

  11. NADPH oxidase 2 plays a role in experimental corneal neovascularization.

    PubMed

    Chan, Elsa C; van Wijngaarden, Peter; Chan, Elsie; Ngo, Darleen; Wang, Jiang-Hui; Peshavariya, Hitesh M; Dusting, Gregory J; Liu, Guei-Sheung

    2016-05-01

    Corneal neovascularization, the growth of new blood vessels in the cornea, is a leading cause of vision impairment after corneal injury. Neovascularization typically occurs in response to corneal injury such as that caused by infection, physical trauma, chemical burns or in the setting of corneal transplant rejection. The NADPH oxidase enzyme complex is involved in cell signalling for wound-healing angiogenesis, but its role in corneal neovascularization has not been studied. We have now analysed the role of the Nox2 isoform of NADPH oxidase in corneal neovascularization in mice following chemical injury. C57BL/6 mice aged 8-14 weeks were cauterized with an applicator coated with 75% silver nitrate and 25% potassium nitrate for 8 s. Neovascularization extending radially from limbal vessels was observed in corneal whole-mounts from cauterized wild type mice and CD31+ vessels were identified in cauterized corneal sections at day 7. In contrast, in Nox2 knockout (Nox2 KO) mice vascular endothelial growth factor-A (Vegf-A), Flt1 mRNA expression, and the extent of corneal neovascularization were all markedly reduced compared with their wild type controls. The accumulation of Iba-1+ microglia and macrophages in the cornea was significantly less in Nox2 KO than in wild type mice. In conclusion, we have demonstrated that Nox2 is implicated in the inflammatory and neovascular response to corneal chemical injury in mice and clearly VEGF is a mediator of this effect. This work raises the possibility that therapies targeting Nox2 may have potential for suppressing corneal neovascularization and inflammation in humans. PMID:26814205

  12. Corneal injury from 1318-nm single laser pulses

    NASA Astrophysics Data System (ADS)

    Roach, William P.; Ketzenberger, Bryan K.; Burton, Margaret B.; Johnson, Thomas E.

    2002-06-01

    Threshold, median effective dose, and the mechanism of laser-tissue interaction are not well defined at the 1318-nm wavelength for human corneal exposures. The goals of this research effort are to identify at-risk groups, characterize the lesions imposed, and establish the ED50 for single pulse 1318-nm laser exposures on the cornea. A Neodymium: Yttrium Aluminum Garnet (Nd:YAG) laser was used to deliver 1318-nm wavelength pulses to the corneas of ten female Dutch Belted rabbits (Oryctolagus cuniculus). Single pulses of 0.5-ms duration and radiant beam energy ranging from 116 to 2250 joules/per square centimeter (J/cm2) were used. Exposure sites were clinically evaluated acutely, one hour and twenty-four hours post-exposure for the presence of a lesion. Results from the twenty-four hour evaluation were used to determine the ED50. Grossly, the lesions appeared as small, circular, well-demarcated, white, opaque lesions. Histologically, the lesions appeared as conical shaped coagulative necrosis with the base of the lesion at the epithelial surface of the cornea and extending to the apex at the endothelial border of the cornea. The ED50 for 1318-nm exposures to the rabbit cornea was determined to be 383 J/cm2 for a 0.1-mm spot size as measured at 1/e2.

  13. [Animal experiment studies on the problem of treating corneal lesions].

    PubMed

    Niedermeier, S

    1987-01-01

    From the clinical point of view an ointment containing retinol, thiamine hydrochloride and calcium pantothenate (Regepithel) seems to be of benefit in the treatment of various corneal diseases. The influence of Regepithel on healing time after superficial corneal injuries in rabbits is demonstrated on the basis of comparative histological findings. PMID:3573651

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

    PubMed

    Wu, Ying; Tian, Lei; Huang, Yi-Fei

    2016-01-01

    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 (V in/out), highest concavity- (HC-) radius, peak distance (PD), and DA showed a normal distribution. Univariate linear regression showed a statistically significant correlation between V in, V out, DA, PD, and HC-radius and IOP, CCT, and corneal volume, respectively. Multivariate analysis showed that IOP and CCT were negatively correlated with V in, DA, and PD, while there was a positive correlation between V out 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. PMID:27493965

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

    PubMed Central

    Wu, Ying

    2016-01-01

    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. PMID:27493965

  16. Alterations of Tear Mediators in Patients with Keratoconus after Corneal Crosslinking Associate with Corneal Changes

    PubMed Central

    Kolozsvári, Bence Lajos; Berta, András; Petrovski, Goran; Miháltz, Kata; Gogolák, Péter; Rajnavölgyi, Éva; Hassan, Ziad; Széles, Péter; Fodor, Mariann

    2013-01-01

    Keratoconus (KC) is the most common primary corneal ectatic disease which has considerable importance in public health. Corneal collagen crosslinking (CXL) is a procedure to mitigate progression of KC and reduce demand for corneal transplantation. Although studies have proven the efficacy of CXL regarding corneal shape, none have investigated the effects of CXL on tear biomarkers which are useful tools to understand molecular mechanisms behind CXL. Our purpose was to determine the effect of CXL on tear mediators in patients with KC and analyze associations with corneal changes. Tear samples were collected pre-CXL from 26 eyes of 23 patients and during a 12-month follow-up. The mediators’ concentration was measured by Cytometric Bead Array technology. Corneal topography parameters measured by Scheimpflug Camera included: Thinnest-corneal-thickness (ThCT), keratometry values (K1, K2), Radii-Minimum (Rmin), Keratoconus-Index (KI), Center-KI (CKI), Index-of-Height Asymmetry (IHA) and Index-of-Surface Variance (ISV). At baseline, KI was correlated negatively with chemokine (C-C motif) ligand 5 (CCL5) (p=0.015) and matrix metalloproteinase (MMP)-13 (p=0.007). At day 4, interleukin (IL)-6 and IL-8 increased, while IL-13, IL-17A, interferon (IFN)-γ, CCL5, MMP-13, epidermal growth factor (EGF), nerve growth factor (NGF) and plasminogen activator inhibitor (PAI-1) decreased significantly compared to pre-CXL concentrations (p≤0.02). At 6 months tissue plasminogen activator (t-PA) increased (p=0.02), while at 12 months Rmin increased (p≤0.004), and IL-6 and CXCL8 (p=0.005 and p=0.047) as well as K1, ISV and KI decreased. After 6 months CKI and ISV showed significant associations with IL-17A; CKI with IL-13 and ThCT with IL-13 (p≤0.02), while at 12 months there were reverse associations between ThCT and IL-6, IL-13, INFγ, CCL5 and PAI-1 (p≤0.02). Alterations of mediators in tear fluid after CXL associate with topographic changes highlight the fact that many

  17. [Corneal higher order aberrations and their changes with aging].

    PubMed

    Cermáková, S; Skorkovská, S

    2010-12-01

    Cornea is the most important refractive medium of the eye and affects its total aberration state. This paper deals with corneal higher order aberrations in healthy humans and evaluates their changes with aging and corneal curvature. The influence of the corneal anterior and posterior surfaces on aberrations of the whole cornea was also investigated. The examination was performed with a Scheimpflug camera which enables to examine the anterior and posterior corneal surface separately. The results show that higher order aberrations of the whole cornea are influenced mainly by the anterior surface aberrations. The main corneal higher order aberration is the Z (4,0) spherical aberration which has a positive value and increases with age. Also, 3rd order aberration values are of importance, especially coma which also increases with age. As a consequence, the root-mean-square of the 3rd and 4th order aberrations in elderly people has a higher value.

  18. Distributed scanning volumetric SDOCT for motion corrected corneal biometry

    PubMed Central

    McNabb, Ryan P.; LaRocca, Francesco; Farsiu, Sina; Kuo, Anthony N.; Izatt, Joseph A.

    2012-01-01

    We present a method, termed distributed scanning OCT (DSOCT), which reduces the effects of patient motion on corneal biometry utilizing current-generation clinically available spectral domain optical coherence tomography (SDOCT) systems. We first performed a pilot study of the power spectrum of normal patient axial eye motion based on repeated (M-mode) SDOCT. Using DSOCT to reduce the effects of patient motion, we conducted a preliminary patient study comparing the measured anterior and posterior corneal curvatures and the calculated corneal power to both corneal topography and Scheimpflug photography in normal subjects. The repeatability for the measured radius of curvature of both anterior and posterior surfaces as well as calculated corneal refractive power using DSOCT was comparable to those of both topography and Scheimpflug photography. PMID:23024900

  19. [Clinical picture of pure corneal ulcers of different localizations].

    PubMed

    Tarasova, L N; Kudriashova, Iu I

    1999-01-01

    Pure corneal ulcers can be localized at the periphery and in the center. Peripheral ulcers are bilateral in 66% and multifocal in 48% cases. They are combined with local vasculitis of perilimbic vessels of the conjunctiva. In 84% cases the disease occurred in patients with connective tissue and articular diseases. Clinical picture of the peripheral corneal ulcer differs from Mourene's phagodenic ulcer. Central corneal ulcers are bilateral in 40% patients, are associated with primary and secondary "dry eye" syndrome in Sjogren's disease, rheumatoid arthritis, systemic vasculitis, Behçet's disease, and in 18% patients with cicatricial deformation of the conjunctiva after Stevens-Johnson's syndrome, trachoma, and chemical burns of the eyes. Pure corneal ulcers run a chronic relapsing course, complicated in one-fourth of patients by corneal perforation and secondary infections.

  20. Understanding Neuropathic Corneal Pain--Gaps and Current Therapeutic Approaches.

    PubMed

    Goyal, Sunali; Hamrah, Pedram

    2016-01-01

    The richly innervated corneal tissue is one of the most powerful pain generators in the body. Corneal neuropathic pain results from dysfunctional nerves causing perceptions such as burning, stinging, eye-ache, and pain. Various inflammatory diseases, neurological diseases, and surgical interventions can be the underlying cause of corneal neuropathic pain. Recent efforts have been made by the scientific community to elucidate the pathophysiology and neurobiology of pain resulting from initially protective physiological reflexes, to a more persistent chronic state. The goal of this clinical review is to briefly summarize the pathophysiology of neuropathic corneal pain, describe how to systematically approach the diagnosis of these patients, and finally summarizing our experience with current therapeutic approaches for the treatment of corneal neuropathic pain.

  1. Corneal collagen crosslinking for corneal ectasia of post-LASIK: one-year results

    PubMed Central

    Li, Gang; Fan, Zheng-Jun; Peng, Xiu-Jun

    2012-01-01

    AIM To evaluate the efficacy and safety of corneal collagen crosslinking (CXL) to prevent the progression of post-laser in situ keratomileusis (LASIK) corneal ectasia. METHODS In a prospective, nonrandomized, single-centre study, CXL was performed in 20 eyes of 11 patients who had LASIK for myopic astigmatism and subsequently developed keratectasia.The procedure included instillation of 0.1% riboflavin-20% dextrane solution 30 minutes before UVA irradiation and every 5 minutes for an additional 30 minutes during irradiation. The eyes were evaluated preoperatively and at 1-, 3-, 6-, and 12-month intervals. The complete ophthalmologic examination comprised uncorrected visual acuity, best spectacle-corrected visual acuity, endothelial cell count, ultrasound pachymetry, corneal topography, and in vivo confocal microscopy. RESULTS CXL appeared to stabilise or partially reverse the progression of post-LASIK corneal ectasia without apparent complication in our cohort. UCVA and BCVA improvements were statistically significant(P<0.05) beyond 12 months after surgery (improvement of 0.07 and 0.13 logMAR at 1 year, respectively). Mean baseline flattest meridian keratometry and mean steepest meridian keratometry reduction (improvement of 2.00 and 1.50 diopters(D), respectively) were statistically significant (P<0.05) at 12 months postoperatively. At 1 year after CXL, mean endothelial cell count did not deteriorate. Mean thinnest cornea pachymetry increased significantly. CONCLUSION The results of the study showed a long-term stability of post-LASIK corneal ectasia after crosslinking without relevant side effects. It seems to be a safe and promising procedure to stop the progression of post-LASIK keratectasia, thereby avoiding or delaying keratoplasty. PMID:22762048

  2. A nanoparticle formulation reduces the corneal toxicity of indomethacin eye drops and enhances its corneal permeability.

    PubMed

    Nagai, Noriaki; Ito, Yoshimasa; Okamoto, Norio; Shimomura, Yoshikazu

    2014-05-01

    Indomethacin (IMC) has been shown to reduce post-operative inflammation and to decrease intraocular irritation after cataract extraction and in cystoid macular edema; however, the clinical use of its most commonly used eye drops is limited due to topical side-effects that include burning sensation, irritation and epithelial keratitis. It is known that decreasing direct cell stimulation and reducing the amount applied via increasing bioavailability are useful for improving these issues. In this study, we designed ophthalmic formulations containing 0.5% IMC nanoparticles using zirconia beads and Bead Smash 12 (IMCnano eye drops; particle size 76 ± 59 nm, mean ± S.D.), and investigated the corneal toxicity of these IMCnano eye drops. IMCnano eye drops are tolerated better by a human cornea epithelial cell line (HCE-T) than commercially available NDSAIDs preparations (IMC, pranoprofen, diclofenac, bromfenac and nepafenac eye drops), and corneal wound healing in rat eyes with debrided corneal epithelium instilled with IMCnano eye drops is significantly better than that of eyes instilled with commercially available IMC eye drops. In addition, the accumulation of IMC in HCE-T cells treated with the IMCnano eye drops for 30 min was 19.9% that of the accumulation from commercially available IMC eye drops. On the other hand, the corneal penetration of IMC from IMCnano eye drops was significantly greater than in the case of the commercially available IMC eye drops in both in vivo and in vitro studies using rabbit corneas. Taken together, we hypothesize that a nanoparticle formulation reduces the corneal toxicity of IMC eye drops, probably because the accumulation of IMC from IMCnano eye drops in the eye is lower than that from commercially available IMC eye drops. In addition, the nanoparticle formulation may allow a decrease in the amount of IMC used due to the increase in bioavailability, resulting in reduced drug toxicity. These findings provide significant information

  3. Riboflavin concentration in corneal stroma after intracameral injection

    PubMed Central

    Li, Na; Peng, Xiu-Jun; Fan, Zheng-Jun; Pang, Xu; Xia, Yu; Wu, Teng-Fei

    2015-01-01

    AIM To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo. METHODS The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions (BSS) were injected into the anterior chamber (10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5 mm in diameter from each group were dissected at 30min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography (HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for 30min on the corneal surface (8 without epithelium and 8 with intact epithelium). RESULTS The mean riboflavin concentrations were 11.19, 18.97, 25.08, 20.18, and 1.13 µg/g for 0.5%, 1%, 2%, de-epithelialzed samples, and the transepithelial groups, respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking (CXL) could be achieved by intracameral 1% riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30min. CONCLUSION Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL. PMID:26085993

  4. In Vivo Confocal Microscopic Observation of Lamellar Corneal Transplantation in the Rabbit Using Xenogenic Acellular Corneal Scaffolds as a Substitute

    PubMed Central

    Feng, Yun; Wang, Wei

    2015-01-01

    Background: The limiting factor to corneal transplantation is the availability of donors. Research has suggested that xenogenic acellular corneal scaffolds (XACS) may be a possible alternative to transplantation. This study aimed to investigate the viability of performing lamellar corneal transplantation (LCT) in rabbits using canine XACS. Methods: Fresh dog corneas were decellularized by serial digestion, and LCT was performed on rabbit eyes using xenogeneic decellularized corneal matrix. Cellular and morphological changes were observed by slit-lamp, light, and scanning electron microscopy at 7, 30 and 90 days postoperatively. Immunocytochemical staining for specific markers such as keratin 3, vimentin and MUC5AC, was used to identify cells in the graft. Results: Decellularized xenogenic corneal matrix remained transparent for about 1-month after LCT. The recipient cells were able to survive and proliferate into the grafts. Three months after transplantation, grafts had merged with host tissue, and graft epithelialization and vascularization had occurred. Corneal nerve fibers were able to grow into the graft in rabbits transplanted with XACS. Conclusions: Xenogenic acellular corneal scaffolds can maintain the transparency of corneal grafts about 1-month and permit growth of cells and nerve fibers, and is, therefore, a potential substitute or carrier for a replacement cornea. PMID:25836615

  5. Tear Film Interferometry and Corneal Surface Roughness

    PubMed Central

    King-Smith, P. Ewen; Kimball, Samuel H.; Nichols, Jason J.

    2014-01-01

    Purpose. Previous studies of optical interference from the whole thickness of the precorneal tear film showed much lower contrast than from the pre–contact lens tear film. It is hypothesized that the recorded low contrast is related to roughness of the corneal surface compared with the smooth contact lens surface. This hypothesis is tested, and characteristics of this roughness are studied. Methods. Reflectance spectra were recorded from 20 healthy individuals using a silicon-based sensor used in previous studies (wavelength range, 562–1030 nm) and an indium-gallium-arsenide (InGaAs) sensor responding at longer wavelengths (912–1712 nm). Interference from the whole thickness of the precorneal tear film caused oscillations in the reflectance spectra. Results. Spectral oscillations recorded with the InGaAs sensor were found to decay as a Gaussian function of wave number (1/wavelength). This is consistent with a rough corneal surface, whose distribution of surface height is also a Gaussian function. Contrast of spectral oscillations for the InGaAs sensor was, on average, approximately four times greater than that for the silicon sensor. Conclusions. For the Gaussian roughness model based on InGaAs spectra, the corneal surface was characterized by a surface height SD of 0.129 μm. Spectral oscillations recorded with a silicon-based camera can have higher contrast than expected from this Gaussian roughness model, indicating some reflectance from a smoother or more compact surface. The results also indicate that InGaAs cameras could provide whole-thickness interference images of higher contrast than silicon-based cameras. PMID:24692127

  6. Fractal dimension based corneal fungal infection diagnosis

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Madhusudhanan; Perkins, A. Louise; Beuerman, Roger W.; Iyengar, S. Sitharama

    2006-08-01

    We present a fractal measure based pattern classification algorithm for automatic feature extraction and identification of fungus associated with an infection of the cornea of the eye. A white-light confocal microscope image of suspected fungus exhibited locally linear and branching structures. The pixel intensity variation across the width of a fungal element was gaussian. Linear features were extracted using a set of 2D directional matched gaussian-filters. Portions of fungus profiles that were not in the same focal plane appeared relatively blurred. We use gaussian filters of standard deviation slightly larger than the width of a fungus to reduce discontinuities. Cell nuclei of cornea and nerves also exhibited locally linear structure. Cell nuclei were excluded by their relatively shorter lengths. Nerves in the cornea exhibited less branching compared with the fungus. Fractal dimensions of the locally linear features were computed using a box-counting method. A set of corneal images with fungal infection was used to generate class-conditional fractal measure distributions of fungus and nerves. The a priori class-conditional densities were built using an adaptive-mixtures method to reflect the true nature of the feature distributions and improve the classification accuracy. A maximum-likelihood classifier was used to classify the linear features extracted from test corneal images as 'normal' or 'with fungal infiltrates', using the a priori fractal measure distributions. We demonstrate the algorithm on the corneal images with culture-positive fungal infiltrates. The algorithm is fully automatic and will help diagnose fungal keratitis by generating a diagnostic mask of locations of the fungal infiltrates.

  7. [First experience of intrastromal ring segments insertion for correction of posttraumatic cicatricial corneal astigmatism].

    PubMed

    Neroev, V V; Gundorova, R A; Beliaev, D S; Petukhova, A B; Oganesian, O G; Penkina, A V

    2013-01-01

    The potential of MAGELLAN MAPPER corneal topographer in evaluation of corneal refraction in the early postoperative period after surgical debrigement of scleral and corneal penetrating wounds is shown. The accuracy of corneal topography is satisfactory and its results reproducible what makes the method suitable for evaluation of corneal refraction and follow-up in patients with penetrating wounds and scarring of sclera and cornea. The possibility of posttraumatic cicatricial astigmatism correction by insertion of Keraring intrastromal corneal ring segments (ICRS) using femtosecond surgical laser FEMTO LDV were studied. Results of cicatricial corneal astigmatism correction in early posttraumatic period are encouraging.

  8. Clinical utility of the KAMRA corneal inlay.

    PubMed

    Naroo, Shehzad Anjam; Bilkhu, Paramdeep Singh

    2016-01-01

    The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye), with a large proportion of patients achieving Jaeger (J) 2 to J1 (~0.00 logMAR to ~0.10 logMAR) at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better). The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient's visual function.

  9. Clinical utility of the KAMRA corneal inlay

    PubMed Central

    Naroo, Shehzad Anjam; Bilkhu, Paramdeep Singh

    2016-01-01

    The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye), with a large proportion of patients achieving Jaeger (J) 2 to J1 (~0.00 logMAR to ~0.10 logMAR) at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better). The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient’s visual function. PMID:27274194

  10. Iatrogenic corneal perforation in Terrien Marginal Degeneration.

    PubMed

    M R, Kursiah

    2013-04-01

    This case report is about a rare disease with unusual presentation. Failure to recognise atypical presentation may lead to error in managing the patient and cause disastrous complications. Here we highlight a case of Terrien Marginal Degeneration in both eyes with atypical presentation; namely pseudopterygium. A 22 year old man was referred to our centre for iatrogenic right eye corneal perforation after having an atypical pterygium removed at another hospital. On arrival, his vision was 1/60 in both eyes with bilateral cornea Terrien Marginal Degeneration. His right eye anterior chamber was deep with a conjunctival flap covering the perforation site which was located from the 2.30 - 3.30 clock position nasally with no aqueous leak. However after a day his right eye anterior chamber became flat and there was fast aqueous leak from the perforation site. An emergency C shaped peripheral corneal lamellar keratoplasty was performed to seal the perforation. Post operatively his right eye improved to 6/24.

  11. Clinical utility of the KAMRA corneal inlay.

    PubMed

    Naroo, Shehzad Anjam; Bilkhu, Paramdeep Singh

    2016-01-01

    The treatment of presbyopia has been the focus of much scientific and clinical research over recent years, not least due to an increasingly aging population but also the desire for spectacle independence. Many lens and nonlens-based approaches have been investigated, and with advances in biomaterials and improved surgical methods, removable corneal inlays have been developed. One such development is the KAMRA™ inlay where a small entrance pupil is exploited to create a pinhole-type effect that increases the depth of focus and enables improvement in near visual acuity. Short- and long-term clinical studies have all reported significant improvement in near and intermediate vision compared to preoperative measures following monocular implantation (nondominant eye), with a large proportion of patients achieving Jaeger (J) 2 to J1 (~0.00 logMAR to ~0.10 logMAR) at the final follow-up. Although distance acuity is reduced slightly in the treated eye, binocular visual acuity and function remain very good (mean 0.10 logMAR or better). The safety of the inlay is well established and easily removable, and although some patients have developed corneal changes, these are clinically insignificant and the incidence appears to reduce markedly with advancements in KAMRA design, implantation technique, and femtosecond laser technology. This review aims to summarize the currently published peer-reviewed studies on the safety and efficacy of the KAMRA inlay and discusses the surgical and clinical outcomes with respect to the patient's visual function. PMID:27274194

  12. Scanning electron microscopy of rabbit corneal scars.

    PubMed

    Cintron, C; Szamier, R B; Hassinger, L C; Kublin, C L

    1982-07-01

    Central full-thickness perforating excision wounds were made in rabbit corneas and were examined by light and scanning electron microscopy at various times after wounding to study the three-dimensional morphologic changes in the tissue during healing and remodeling. Formation of a fibrin clot soon after wounding seals the hole and functions as a substrate for the healing epithelium. Changes in the histologic appearance of the fibrin lot immediately below the new epithelium are followed by migration of adjacent stromal cells under the epithelium, parallel to the basal surface of this tissue. Further healing is characterized by the organization of stromal fibroblasts into several layers parallel to the corneal surface and the deposition of collagen as a matted meshwork of fibrils tangential to the cell surface. Although remodeling of the collagenous matrix of corneal scar is evident and the scar eventually appears less opaque, the lamellae of the scar are narrower and shorter than normal. Evidence from this and other studies suggests that the orientation of the fibroblasts in healing tissues is determined by the organization of the newly formed epithelium. Furthermore, our observations are consistent with the hypothesis that collagen fibrils are deposited parallel to the flat surface of the fibroblasts during scar formation. Subsequent reorganization of this collagenous matrix approaches the normal lamellar appearance, but the matrix fails to regenerate even after 2 years.

  13. Corneal astigmatism measuring module for slit lamps

    NASA Astrophysics Data System (ADS)

    Ventura, L.; Riul, C.; Sousa, S. J. F.; DeGroote, J. G. S.; Rosa Filho, A. B.; Oliveira, G. C. D.

    2006-06-01

    We have developed an automatic keratometer module for slit lamps that provides automatic measurements of the radii of the corneal curvature. The system projects 72 light spots displayed in a precise circle at the examined cornea. The displacement and deformation of the reflected image of these light spots are analysed providing the keratometry. Measurements in the range of 26.8-75 D can be obtained and a self-calibration system has been specially designed in order to keep the system calibrated. Infrared LEDs indicate automatically which eye is being examined. Volunteer patients (492) have been submitted to the system and the results show that our system has a high correlation factor with the commercially available manual keratometers and the keratometry measurements from a topographer. Our developed system is 95% in agreement with the corneal topographer (Humphrey—Atlas 995 CZM) and the manual keratometer (Topcon OM-4). The system's nominal precision is 0.05 mm for the radii of curvature and 1° for the associated axis. This research has been supported by Fundação de Apoio à Pesquisa do Estado de São Paulo (FAPESP).

  14. Topographic corneal changes after collagen cross-linking in patients with corneal keratoconus

    PubMed Central

    Razmjoo, Hasan; Nasrollahi, Alireza Peyman Kobra; Salam, Hasan; Karbasi, Najmeh; Najarzadegan, Mohammad Reza

    2013-01-01

    Background: Corneal collagen cross-linking with riboflavin, also known as collagen cross-linking (CXL), involves the application of riboflavin solution to the eye that is activated by illumination with ultraviolet A (UVA) light. We survey here the topographic corneal changes one year after CXL in patients with corneal keratoconus. Materials and Methods: This prospective randomized clinical trial study comprised 66 patients with progression of keratoconus during one year who were enrolled at Feiz University Referral Eye Center in Isfahan. Before and after the operation, patients were examined with slit lamp and funduscopic examinations and measurement of uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA) was done with a logarithm of minimal angle of resolution (logMAR) scale. Corneal topographic and pachymetry values were derived from Orbscan II. The paired t-test test was used for statistical analyses with SPSS software version 20 (SPSS Inc., Chicago, IL, USA). Results: All 66 patients completed postoperative follow-up at 12 months. The mean age of the patients was 22.4 ± 5.4 years (range: 18-29 years). Thirty-six (54.55%) subjects were men and 30 (45.45%) were women. The mean preoperative sphere was −2.66 ± 2.14 diopter (D), the mean cylinder was −3.97 ± 2.29, and the mean spherical equivalent (SE) was −4.64 ± 2.56. Postoperatively, the mean sphere was −2.22 ± 2.57 D, the mean cylinder was −3.60 ± 2.40 D, and SE was −4.02 ± 2.93 D (P = 0.037). SE also demonstrated a mean difference of 0.62 ± 0.37 D significantly (P = 0.006). The mean diameter of preoperative posterior best-fit sphere (BFS) was 6.33 ± 0.35mm (range: 5.51-7.73 mm) before operation, and it improved to 6.28 ± 0.34mm (range: 4.36-6.13 mm) after operation; the difference was significant (P = 0.039). Conclusion: Our study showed a significant improvement in topographic corneal changes and refractive results in patients with corneal ectasia after CXL

  15. Hypercalcemia Leads to Delayed Corneal Wound Healing in Ovariectomized Rats.

    PubMed

    Nagai, Noriaki; Ogata, Fumihiko; Kawasaki, Naohito; Ito, Yoshimasa; Funakami, Yoshinori; Okamoto, Norio; Shimomura, Yoshikazu

    2015-01-01

    Hypercalcemia is often observed in postmenopausal women as well as in patients with primary hyperparathyroidism or malignant tumors. In this study, we investigated the relationship between calcium ion (Ca(2+)) levels in lacrimal fluid and the rate of corneal wound healing in hypercalcemia using ovariectomized (OVX) rat debrided corneal epithelium. We also determined the effects of Ca(2+) levels on cell adhesion, proliferation and viability in a human cornea epithelial cell line (HCE-T). The calcium content in bones of OVX rats decreased after ovariectomy. Moreover, the Ca(2+) content in the blood of OVX rats was increased 1 month after ovariectomy, and decreased. The Ca(2+) content in the lacrimal fluid of OVX rats was also increased after ovariectomy, and then decreased similarly as in blood. Corneal wound healing in OVX rats was delayed in comparison with Sham rats (control rats), and a close relationship was observed between the Ca(2+) levels in lacrimal fluid and the rate of corneal wound healing in Sham and OVX rats (y=-0.7863x+8.785, R=0.78, n=25). In addition, an enhancement in Ca(2+) levels caused a decrease in the viability in HCE-T cells. It is possible that enhanced Ca(2+) levels in lacrimal fluid may cause a decrease in the viability of corneal epithelial cells, resulting in a delay in corneal wound healing. These findings provide significant information that can be used to design further studies aimed at reducing corneal damage of patients with hypercalcemia.

  16. Growing Three-Dimensional Corneal Tissue in a Bioreactor

    NASA Technical Reports Server (NTRS)

    Spaulding, Glen F.; Goodwin, Thomas J.; Aten, Laurie; Prewett, Tacey; Fitzgerald, Wendy S.; OConnor, Kim; Caldwell, Delmar; Francis, Karen M.

    2003-01-01

    Spheroids of corneal tissue about 5 mm in diameter have been grown in a bioreactor from an in vitro culture of primary rabbit corneal cells to illustrate the production of optic cells from aggregates and tissue. In comparison with corneal tissues previously grown in vitro by other techniques, this tissue approximates intact corneal tissue more closely in both size and structure. This novel three-dimensional tissue can be used to model cell structures and functions in normal and abnormal corneas. Efforts continue to refine the present in vitro method into one for producing human corneal tissue to overcome the chronic shortage of donors for corneal transplants: The method would be used to prepare corneal tissues, either from in vitro cultures of a patient s own cells or from a well-defined culture from another human donor known to be healthy. As explained in several articles in prior issues of NASA Tech Briefs, generally cylindrical horizontal rotating bioreactors have been developed to provide nutrient-solution environments conducive to the 30 NASA Tech Briefs, October 2003 growth of delicate animal cells, with gentle, low-shear flow conditions that keep the cells in suspension without damaging them. The horizontal rotating bioreactor used in this method, denoted by the acronym "HARV," was described in "High-Aspect-Ratio Rotating Cell-Culture Vessel" (MSC-21662), NASA Tech Briefs, Vol. 16, No. 5 (May, 1992), page 150.

  17. Impact of Hydration Media on Ex Vivo Corneal Elasticity Measurements

    PubMed Central

    Dias, Janice; Ziebarth, Noël M.

    2014-01-01

    Objectives To determine the effect of hydration media on ex vivo corneal elasticity. Methods Experiments were conducted on forty porcine eyes retrieved from an abattoir (10 eyes each for PBS, BSS, Optisol, 15% Dextran). The epithelium was removed and the cornea was excised with an intact scleral rim and placed in 20% Dextran overnight to restore its physiological thickness. For each hydration media, corneas were evenly divided into two groups: one with an intact scleral rim and the other without. Corneas were mounted onto a custom chamber and immersed in a hydration medium for elasticity testing. While in each medium, corneal elasticity measurements were performed for 2 hours: at 5-minute intervals for the first 30 minutes and then 15-minute intervals for the remaining 90 minutes. Elasticity testing was performed using nanoindentation with spherical indenters and Young’s modulus was calculated using the Hertz model. Thickness measurements were taken before and after elasticity testing. Results The percentage change in corneal thickness and elasticity was calculated for each hydration media group. BSS, PBS, and Optisol showed an increase in thickness and Young’s moduli for corneas with and without an intact scleral rim. 15% Dextran exhibited a dehydrating effect on corneal thickness and provided stable maintenance of corneal elasticity for both groups. Conclusions Hydration media affects the stability of corneal thickness and elasticity measurements over time. 15% Dextran was most effective in maintaining corneal hydration and elasticity, followed by Optisol. PMID:25603443

  18. Cell-based approach for treatment of corneal endothelial dysfunction.

    PubMed

    Okumura, Naoki; Kinoshita, Shigeru; Koizumi, Noriko

    2014-11-01

    Decompensation of the corneal endothelium causes severe visual impairments that lead to blindness. Although corneal transplantation is a well-known effective therapy for corneal endothelial dysfunction, many patients are not afforded that therapeutic opportunity owing to the worldwide shortage of donor corneas. Thus, a tissue engineering-based therapy for treating corneal endothelial dysfunction is highly anticipated. Obstacles associated with the development of tissue engineering therapy include in vitro culture of corneal endothelial cells (CECs) and the techniques used to transplant those cells. Limited proliferation ability, cellular senescence, and fibroblastic transformation during culture are all problems associated with the cultivation of CECs. In addition, transplantation of cultured CECs is technically difficult because the corneal endothelium is composed of a fragile monolayer sheet of cells located at the posterior cornea. In this review article, we present our recent findings using a novel cell culture protocol and show that modulation of CEC adhesion properties through a Rho-kinase inhibitor enables transplantation of CECs in the form of a cell suspension without the use of a carrier. Finally, we provide an update on the clinical application status of a cell-based therapy for treating corneal endothelial dysfunction.

  19. Impact of facial conformation on canine health: corneal ulceration.

    PubMed

    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 <0.5) were twenty times more likely to be affected than non-brachycephalic 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.

  20. Impact of Facial Conformation on Canine Health: Corneal Ulceration

    PubMed Central

    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 <0.5) were twenty times more likely to be affected than non-brachycephalic 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

  1. Evaluating alternative stem cell hypotheses for adult corneal epithelial maintenance

    PubMed Central

    West, John D; Dorà, Natalie J; Collinson, J Martin

    2015-01-01

    In this review we evaluate evidence for three different hypotheses that explain how the corneal epithelium is maintained. The limbal epithelial stem cell (LESC) hypothesis is most widely accepted. This proposes that stem cells in the basal layer of the limbal epithelium, at the periphery of the cornea, maintain themselves and also produce transient (or transit) amplifying cells (TACs). TACs then move centripetally to the centre of the cornea in the basal layer of the corneal epithelium and also replenish cells in the overlying suprabasal layers. The LESCs maintain the corneal epithelium during normal homeostasis and become more active to repair significant wounds. Second, the corneal epithelial stem cell (CESC) hypothesis postulates that, during normal homeostasis, stem cells distributed throughout the basal corneal epithelium, maintain the tissue. According to this hypothesis, LESCs are present in the limbus but are only active during wound healing. We also consider a third possibility, that the corneal epithelium is maintained during normal homeostasis by proliferation of basal corneal epithelial cells without any input from stem cells. After reviewing the published evidence, we conclude that the LESC and CESC hypotheses are consistent with more of the evidence than the third hypothesis, so we do not consider this further. The LESC and CESC hypotheses each have difficulty accounting for one main type of evidence so we evaluate the two key lines of evidence that discriminate between them. Finally, we discuss how lineage-tracing experiments have begun to resolve the debate in favour of the LESC hypothesis. Nevertheless, it also seems likely that some basal corneal epithelial cells can act as long-term progenitors if limbal stem cell function is compromised. Thus, this aspect of the CESC hypothesis may have a lasting impact on our understanding of corneal epithelial maintenance, even if it is eventually shown that stem cells are restricted to the limbus as proposed

  2. Pseudomonas-induced corneal ulcers associated with contaminated eye mascaras.

    PubMed

    Wilson, L A; Ahearn, D G

    1977-07-01

    Seven Pseudomonas-induced corneal ulcers were associated with the use of four brands of mascara contaminated with P. aeruginosa. In laboratory studies, preservative systems of three of the four brands were inadequate in comparison with a control mascara of known antimicrobial activity. If the corneal epithelium is scratched during the application of mascara, particularly if the applicator is old, the cornea should be treated immediately and the mascara cultured to detect Pseudomonas. The high incidence of recurrent corneal ulceration in cases of Pseudomonas-induced keratitis indicates that initial chemotherapy should be intensive and maintained until the lesion stabilizes.

  3. Eye observation and corneal protection during endonasal surgery.

    PubMed

    Cuddihy, P J; Whittet, H

    2005-07-01

    Traumatic orbital complications of endonasal surgery, although rare, are a cause of significant morbidity. Although a variety of methods of monitoring eye function during surgery have been described, the best method remains direct perioperative observation of the eye. However, the eye must also be protected during surgery otherwise corneal drying will occur and corneal abrasion may result. This article describes and illustrates the use of Geliperm, a sterile, transparent, pliant hydrogel dressing, as a corneal protector allowing continuous observation of the eye during endonasal surgery.

  4. Pseudomonas-induced corneal ulcers associated with contaminated eye mascaras.

    PubMed

    Wilson, L A; Ahearn, D G

    1977-07-01

    Seven Pseudomonas-induced corneal ulcers were associated with the use of four brands of mascara contaminated with P. aeruginosa. In laboratory studies, preservative systems of three of the four brands were inadequate in comparison with a control mascara of known antimicrobial activity. If the corneal epithelium is scratched during the application of mascara, particularly if the applicator is old, the cornea should be treated immediately and the mascara cultured to detect Pseudomonas. The high incidence of recurrent corneal ulceration in cases of Pseudomonas-induced keratitis indicates that initial chemotherapy should be intensive and maintained until the lesion stabilizes. PMID:409295

  5. Development and clinical application of excimer laser corneal shaping

    NASA Astrophysics Data System (ADS)

    Homolka, Peter; Biowski, R.; Husinsky, Wolfgang; Blaas, C.; Simader, Ch.; Baumgartner, I. Gosch; Kaminski, Stefan; Grabner, G.

    1998-06-01

    Excimer Laser Corneal Shaping using an 193 nm Excimer Laser (ArF) provides a possibility for the fabrication of corneal transplants of various forms for various clinical applications such as (epi-)keratoplasty. Another area of application envisioned is the production of 'living contact lenses' for epikeratophakia. A device for lathing and perforating corneal donor tissue with a scanning laser beam is presented. A new ablation algorithm (Optimized Scanning Laser Ablation) was recently developed and increased the quality of lenticules and donor buttons considerably.

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

    PubMed Central

    Du, Jun; Zheng, Guang-Ying; Wen, Cheng-Lin; Zhang, Xiao-Fang; Zhu, Yu

    2016-01-01

    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. PMID:27366685

  7. Secondary Endolymphatic Hydrops (SEH)

    MedlinePlus

    ... content Facebook Twitter LinkedIn Pinterest About Contact FAQ Vestibular Disorders Association Login Donate Now Subscribe To V-newS Main menu About Vestibular Disorders Educational Resources Finding Help & Support Resources for ...

  8. Corneal Graft Rejection Ten Years after Penetrating Keratoplasty in the Cornea Donor Study

    PubMed Central

    Dunn, Steven P.; Gal, Robin L.; Kollman, Craig; Raghinaru, Dan; Dontchev, Mariya; Blanton, Christopher L.; Holland, Edward J; Lass, Jonathan H.; Kenyon, Kenneth R.; Mannis, Mark J; Mian, Shahzad I.; Rapuano, Christopher J.; Stark, Walter J.; Beck, Roy W.

    2015-01-01

    Purpose To assess the effect of donor and recipient factors on corneal allograft rejection and evaluate whether a rejection event was associated with graft failure. Methods 1,090 subjects undergoing penetrating keratoplasty for a moderate risk condition (principally Fuchs’ dystrophy or pseudophakic corneal edema) were followed for up to 12 years. Associations of baseline recipient and donor factors with the occurrence of a rejection event were assessed in univariate and multivariate proportional hazards models. Results Among 651 eyes with a surviving graft at 5 years, the 10-year graft failure (± 99% CI) rates were 12% ± 4% among eyes with no rejection events in the first 5 years, 17% ± 12% in eyes with at least one probable, but no definite rejection event, and 22% ± 20% in eyes with at least one definite rejection event. The only baseline factor significantly associated with a higher risk of definite graft rejection was a preoperative history of glaucoma, particularly when prior glaucoma surgery had been performed and glaucoma medications were being used at time of transplant (10-year incidence 35% ± 23% compared with 14% ± 4% in eyes with no history of glaucoma/intraocular pressure treatment, p=0.008). Conclusion Those patients who experienced a definite rejection event frequently went on to graft failure raising important questions as to how we might change acute and long-term corneal graft management. Multivariate analysis indicated that the prior use of glaucoma medications and glaucoma filtering surgery was a significant risk factor related to a definite rejection event. PMID:25119961

  9. Corneal Transplant Improves Vision and Daily Life for Some Children

    MedlinePlus

    ... 01, 2011 Rare, but Effective: Corneal Transplant Improves Vision, Life for Some Children SAN FRANCISCO— Teens, children, ... Transplants were considered successful if they significantly improved vision and the new corneas remained healthy over 10 ...

  10. The management of lens damage in perforating corneal lacerations.

    PubMed Central

    Muga, R.; Maul, E.

    1978-01-01

    Lens damage is present in 30% of perforating injuries of the anterior segment of the eye. There is no consensus on whether the cataractous lens should be removed at the initial repair of the corneal laceration or later, when the eye has recovered from injury. Twenty-seven consecutive cases with a perforating corneal injury and lens damage were alternatively treated either with simultaneous corneal suturing and cataract removal or with corneal suturing and delayed cataract removal several weeks later. The difference in the frequency of complications between the 2 groups was significant. The 1-step procedure was technically easier to perform, the period of postoperative irritation was shorter, complications due to the presence of an injured lens were prevented, and visual rehabilitation occurred earlier. PMID:568933

  11. Keratoprostheses for corneal blindness: a review of contemporary devices

    PubMed Central

    Avadhanam, Venkata S; Smith, Helen E; Liu, Christopher

    2015-01-01

    According to the World Health Organization, globally 4.9 million are blind due to corneal pathology. Corneal transplantation is successful and curative of the blindness for a majority of these cases. However, it is less successful in a number of diseases that produce corneal neovascularization, dry ocular surface and recurrent inflammation, or infections. A keratoprosthesis or KPro is the only alternative to restore vision when corneal graft is a doomed failure. Although a number of KPros have been proposed, only two devices, Boston type-1 KPro and osteo-odonto-KPro, have came to the fore. The former is totally synthetic and the latter is semi-biological in constitution. These two KPros have different surgical techniques and indications. Keratoprosthetic surgery is complex and should only be undertaken in specialized centers, where expertise, multidisciplinary teams, and resources are available. In this article, we briefly discuss some of the prominent historical KPros and contemporary devices. PMID:25945031

  12. Severe unilateral corneal melting after uneventful phacoemulsification cataract surgery.

    PubMed

    Praidou, Anna; Brazitikos, Periklis; Dastiridou, Anna; Androudi, Sofia

    2013-01-01

    We present a rare case of severe unilateral corneal melt after uneventful phacoemulsification. A 38-year-old woman presented one week after uneventful phacoemulsification cataract surgery complaining of pain and blurred vision in her operated eye. Our differential diagnosis included peripheral ulcerative keratitis, Mooren's ulcer and herpetic keratitis. The patient was started on oral acyclovir and topical steroids. An extensive blood work-up was done to rule out autoimmune diseases. Purified protein derivative test demonstrated 15 mm of erythema. Because the clinical picture was progressing, the patient was started on triple anti-tuberculosis therapy. Despite treatment, the patient was complaining of excruciating eye pain that was relieved only with intramuscular prednisone injections. The corneal melt healed after approximately three months without any other intervention, leaving a 90 per cent thickness loss in its central area. Idiopathic corneal melt after uneventful phacoemulsification is a rare complication, which must be managed in a multidirectional treatment approach to prevent devastating corneal perforation.

  13. Corneal Neovascularization: An Anti-VEGF Therapy Review

    PubMed Central

    Chang, Jin-Hong; Garg, Nitin K.; Lunde, Elisa; Han, Kyu-Yeon; Jain, Sandeep; Azar, Dimitri T.

    2013-01-01

    Corneal neovascularization is a serious condition that can lead to a profound decline in vision. The abnormal vessels block light, cause corneal scarring, compromise visual acuity, and may lead to inflammation and edema. Corneal neovascularization occurs when the balance between angiogenic and antiangiogenic factors is tipped toward angiogenic molecules. Vascular endothelial growth factor (VEGF), one of the most important mediators of angiogenesis, is upregulated during neovascularization. In fact, anti-VEGF agents have efficacy in the treatment of neovascular age-related macular degeneration, diabetic retinopathy, macular edema, neovascular glaucoma, and other neovascular diseases. These same agents have great potential for the treatment of corneal neovascularization. We review some of the most promising anti-VEGF therapies, including bevacizumab, VEGF trap, siRNA, and tyrosine kinase inhibitors. PMID:22898649

  14. Corneal Gene Therapy: Basic Science and Translational Perspective

    PubMed Central

    Mohan, Rajiv R.; Rodier, Jason T.; Sharma, Ajay

    2013-01-01

    Corneal blindness is the third leading cause of blindness worldwide. Gene therapy is an emerging technology for corneal blindness due to the accessibility and immune-privileged nature of the cornea, ease of vector administration and visual monitoring, and ability to perform frequent noninvasive corneal assessment. Vision restoration by gene therapy is contingent upon vector and mode of therapeutic gene introduction into targeted cells/tissues. Numerous efficacious vectors, delivery techniques, and approaches have evolved in last decade for developing gene-based interventions for corneal diseases. Maximizing the potential benefits of gene therapy requires efficient and sustained therapeutic gene expression in target cells, low toxicity, and a high safety profile. This review describes the basic science associated with many gene therapy vectors and the present progress of gene therapy carried out for various ocular surface disorders and diseases. PMID:23838017

  15. Corneal depositions in tyrosinaemia type I during treatment with Nitisinone.

    PubMed

    Wisse, Robert P L; Wittebol-Post, Dienke; Visser, Gepke; van der Lelij, Allegonda

    2012-11-30

    We present a 17-year-old boy, diagnosed with tyrosinaemia type I at an age of 7 months, with new complaints of severe intermittent photophobia and burning eyes. His tyrosinaemia type I is treated with nitisinone and a protein-restricted diet. Dietary compliance is low since he entered puberty. His ocular complaints are attributable to subepithelial corneal deposits, resembling the common corneal phenotype of tyrosinaemia type II. Serum tyrosine levels were markedly elevated. Tyrosinaemia is a metabolic disease of tyrosine metabolism, subdivided into two types. Corneal deposits and photophobia are cardinal features of untreated tyrosinaemia type II, but not of type I. Novel treatment strategies (with nitisinone) for type I tyrosinaemia lead to a phenotype comparable with type II, including these corneal deposits. At follow-up visits his ocular complaints unfortunately remained unchanged, though he states his dietary compliance improved through the years.

  16. Transverse chromatic aberration after corneal refractive surgery

    NASA Astrophysics Data System (ADS)

    Anera, R. G.; Jiménez, J. R.; Jiménez del Barco, L.; Hita, E.

    2005-05-01

    An expression has been deduced theoretically from a schematic-eye model, for the transverse or lateral chromatic aberration (TCA) after refractive surgery. The aim was to investigate analytically how chromatic aberration varies after the emmetropization process. These changes in the TCA have been characterized from changes in corneal asphericity. The results indicate that TCA after refractive surgery diminishes as the degree of myopia increases, a trend contrary to that occurring with monochromatic aberrations, such as spherical or coma. These results can explain the fact that the real deterioration of the visual function under photopic conditions detected in those operated on for myopia is less than expected when only monochromatic aberrations are taken into account.

  17. Corneal toxic changes after cataract extraction.

    PubMed

    Zabel, R W; Mintsioulis, G; MacDonald, I M; Valberg, J; Tuft, S J

    1989-12-01

    Over an 18-month period 10 patients (12 eyes) presented with severe corneal toxic changes after cataract extraction. Defined stages in the keratopathy included punctate epithelial keratopathy, pseudodendrite, central epithelial ulcer and central stromal ulcer. Periods of up to 13 months were required for resolution of the defects. Axial scarring and nonhealing epithelial defects resulted in a final visual acuity of counting fingers and hand movement in two patients. We believe that exposure during the postoperative period to benzalkonium chloride contained in ophthalmic medications represents the most likely cause of the toxic changes and that no single ophthalmic medication can be held responsible. The past ocular histories of the patients included chronic open-angle glaucoma, dry eye syndrome and anterior membrane dystrophy. Prior exposure to benzalkonium-containing antiglaucoma medications, tear film deficiencies or abnormalities of epithelial adhesion may have predisposed the corneas in these patients to the development of benzalkonium-related toxic changes.

  18. Crystalline corneal opacities in the Siberian Husky.

    PubMed

    MacMillan, A D; Waring, G O; Spangler, W L; Roth, A M

    1979-10-15

    Bilaterally symmetric opacities were detected in the corneal stroma of 78 (14%) of 560 Siberian Huskies, aged 7 months to 12 years, examined in ophthalmology screening clinics. The opacities were round or horizontally oval and consisted of a diffuse gray homogeneous haze in the anterior stroma or an array of fine polychromatic crystals in the posterior stroma, or both. The corneas were not inflamed. The frequency of occurrence and density of the opacities increased with age. Several affected dogs were closely related, but a specific inheritance pattern could not be established. Light and electron microscopy disclosed clusters of extracellular, thin, needle-shaped, crystalline clefts. Histochemical stains on frozen sections identified neutral fats, phospholipids, and cholesterol as components of the crystals.

  19. Brillouin Optical Microscopy for Corneal Biomechanics

    PubMed Central

    Scarcelli, Giuliano; Pineda, Roberto

    2012-01-01

    Purpose. The mechanical properties of corneal tissue are linked to prevalent ocular diseases and therapeutic procedures. Brillouin microscopy is a novel optical technology that enables three-dimensional mechanical imaging. In this study, the feasibility of this noncontact technique was tested for in situ quantitative assessment of the biomechanical properties of the cornea. Methods. Brillouin light-scattering involves a spectral shift proportional to the longitudinal modulus of elasticity of the tissue. A 532-nm single-frequency laser and a custom-developed ultrahigh-resolution spectrometer were used to measure the Brillouin frequency. Confocal scanning was used to perform Brillouin elasticity imaging of the corneas of whole bovine eyes. The longitudinal modulus of the bovine corneas was compared before and after riboflavin corneal collagen photo-cross-linking. The Brillouin measurements were then compared with conventional stress–strain mechanical test results. Results. High-resolution Brillouin images of the cornea were obtained, revealing a striking depth-dependent variation of the elastic modulus across the cornea. Along the central axis, the Brillouin frequency shift varied gradually from 8.2 GHz in the epithelium to 7.5 GHz near the endothelium. The coefficients of the down slope were measured to be approximately 1.09, 0.32, and 2.94 GHz/mm in the anterior, posterior, and innermost stroma, respectively. On riboflavin collagen cross-linking, marked changes in the axial Brillouin profiles (P < 0.001) were noted before and after cross-linking. Conclusions. Brillouin imaging can assess the biomechanical properties of cornea in situ with high spatial resolution. This novel technique has the potential for use in clinical diagnostics and treatment monitoring. PMID:22159012

  20. Practical aspects of a corneal topography system.

    PubMed

    McCarey, B E; Zurawski, C A; O'Shea, D S

    1992-10-01

    We used the EyeSys Corneal Topography System to examine several issues relating to corneal topography systems and the interpretation of their results. Interferometry measurements of EyeSys calibration spheres indicated that they deviated from suggested values by 0.05 +/- 0.13 D (mean +/- 1 standard deviation). The EyeSys unit reliably determined the calibration spheres to be spherical with differences between the flat and steep axis of 0.10 +/- 0.09 D. The data for the 3 mm chord circle was the least reliable. The spherical equivalent values for the calibration spheres were constantly greater than the 0.25 D reproducibility suggested by the manufacturer. Furthermore, the precision of the outputted values (0.01 D) is beyond the capability of the instrument. This gives the impression that the topography unit cannot consistently reproduce measurements of the calibration objects or chrome plated steel spheres. Image centralization and focus were found to be critical in obtaining accurate results. A target off center by more than 0.25 mm resulted in unreliable data; increasing the focal distance by greater than 1 mm beyond the focal point resulted in a sharp decrease in accuracy (a decrease in the focal distance was even more critical). When measuring aspheric contact lenses, it was found that the keratometer and EyeSys unit provided a close approximation of the surface characteristics of the lenses. A realistic view of the limitations of the topography system being used is critical for proper interpretation of the data.

  1. Tear Mediators in Corneal Ectatic Disorders

    PubMed Central

    Pásztor, Dorottya; Kolozsvári, Bence Lajos; Csutak, Adrienne; Berta, András; Hassan, Ziad; Ujhelyi, Bernadett; Gogolák, Péter; Fodor, Mariann

    2016-01-01

    Purpose To compare the concentrations of 11 tear mediators in order to reveal the biochemical difference between pellucid marginal degeneration (PMD) and keratoconus (KC). Methods We have designed a cross-sectional study in which patients with corneal ectasia based on slit-lamp biomicroscopy and Pentacam HR (keratometry values (K1, K2, Kmax), astigmatism, minimal radius of curvature (Rmin), corneal thickness (Apex and Min), indices (surface variation, vertical asymmetry, keratoconus, central keratoconus, height asymmetry and decentration)) were enrolled. Eyes of keratoconic patients were similar to the PMD patients in age and severity (K2, Kmax and Rmin). Non-stimulated tear samples were collected from nine eyes of seven PMD patients, 55 eyes of 55 KC patients and 24 eyes of 24 healthy controls. The mediators’ (interleukin -6, -10, chemokine ligand 5, -8, -10, matrix metalloproteinase (MMP) -9, -13, tissue inhibitor of metalloproteinases (TIMP)-1, tissue plasminogen activator, plasminogen activator inhibitor, nerve growth factor) concentrations were measured using Cytometric Bead Array. Results MMP-9 was the only mediator which presented relevant variances between the two patient groups (p = 0.005). The ratios of MMP-9 and TIMP-1 were 2.45, 0.40 and 0.23 in PMD, KC and the controls, respectively. Conclusion As far as we are aware, this is the first study that aims to reveal the biochemical differences between PMD and KC. Further studies of biomarkers to investigate the precise role of these mediators need to be defined, and it is important to confirm the observed changes in a larger study to gain further insights into the molecular alterations in PMD. PMID:27074131

  2. Corneal autofluorescence in choroidal melanoma or in choroidal naevus

    PubMed Central

    Muskens, R; Van Best, J A; Bleeker, J; Keunen, J

    2001-01-01

    AIMS—To investigate whether corneal autofluorescence is different in patients with choroidal melanoma or choroidal naevus.
METHODS—Corneal autofluorescence was determined by fluorophotometry in both eyes of 32 patients with a unilateral choroidal melanoma, 32 patients with a unilateral choroidal naevus, and 32 age matched healthy controls. The corneal autofluorescence ratio between affected and contralateral eyes of patients or between randomly selected eyes of healthy controls was calculated.
RESULTS—Mean corneal autofluorescence ratio of patients with a choroidal melanoma was significantly higher than that of healthy controls (mean ratio: 1.09 (SD 0.15) and 1.00 (0.09), respectively, ANOVA p=0.014), and than that of patients with choroidal naevus (mean ratio 0.96 (0.09), p<0.001). Mean ratios of patients with choroidal naevus and healthy controls were not significantly different (p=0.27).
CONCLUSIONS—Corneal autofluorescence ratio of patients with a unilateral choroidal melanoma is increased. This is probably due to an increased flow of glucose through the impaired blood-aqueous barrier in the affected eye, resulting in additional glycation of corneal proteins and hence in increased autofluorescence. The corneal autofluorescence is not increased in patients with a choroidal naevus, because the blood-aqueous barrier is not impaired in the affected eye in these patients. Measurement of corneal autofluorescence is simple, fast, and non-invasive, and might be helpful to distinguish between patients with choroidal melanoma and those with choroidal naevus.

 PMID:11371483

  3. [The use of iontophoresis in corneal crosslinking technique].

    PubMed

    Stanca, Horia T; Tabacaru, Bogdana

    2013-01-01

    Iontophoresis is a method of facilitating the penetration of a drug through an intact tissue in the presence of an low intensity electrical current. In corneal crosslinking technique, iontophoresis is used for transepitelial impregnation of cornea with riboflavin. Compared to passive technique of corneal impregnation, iontophoresis shortens the time needed for impregnation, the time of exposure to UVA radiation and does not require de-epithelialisation.

  4. Optical Coherence Tomography of Clear Corneal Incisions for Cataract Surgery

    PubMed Central

    Schallhorn, Julie M.; Tang, Maolong; Li, Yan; Song, Jonathan C.; Huang, David

    2008-01-01

    Purpose To study the architecture of clear corneal incisions for phacoemulsification cataract surgery using optical coherence tomography (OCT). Setting University-based cornea practice. Methods A prospective study of twenty eyes of twenty patients one month after cataract surgery performed by two experienced surgeons. Temporal clear corneal single-plane incisions were made with 3-mm metal keratomes; five of the twenty eyes received sutures for wound closure. Each eye was scanned before and 1 month after surgery with a prototype high-speed anterior segment OCT system (Carl Zeiss Meditec Inc.). The OCT scans were repeated 3 times during the same visit. The length of the corneal incision, thickness of the cornea, and position of the incision (distance from the external wound edge to the scleral spur) were measured using a computer caliper. The angle of the incision relative to the corneal surface was then calculated. Results The mean corneal incision length was 1.81±0.27mm, the mean corneal thickness at the incision was 747±67µm, and the mean distance between the incision and the scleral spur was 1.46±0.24mm. The average angle of the incision was 26.8±5.5°. The measurements were repeatable to within 0.072mm (pooled standard deviation) for the incision length, 11µm for the corneal thickness, and 0.042mm for the position of the incision. There was no statistically significant difference in any of the parameters between eyes with sutures and those without. Conclusions OCT provides an excellent way to evaluate corneal incisions in cataract surgery postoperatively. Measurements of wound dimensions using OCT are highly repeatable. PMID:18721720

  5. The IC3D Classification of the Corneal Dystrophies

    PubMed Central

    Weiss, Jayne S.; Møller, H. U.; Lisch, Walter; Kinoshita, Shigeru; Aldave, Anthony J.; Belin, Michael W.; Kivelä, Tero; Busin, Massimo; Munier, Francis L.; Seitz, Berthold; Sutphin, John; Bredrup, Cecilie; Mannis, Mark J.; Rapuano, Christopher J.; Van Rij, Gabriel; Kim, Eung Kweon; Klintworth, Gordon K.

    2010-01-01

    Background The recent availability of genetic analyses has demonstrated the shortcomings of the current phenotypic method of corneal dystrophy classification. Abnormalities in different genes can cause a single phenotype, whereas different defects in a single gene can cause different phenotypes. Some disorders termed corneal dystrophies do not appear to have a genetic basis. Purpose The purpose of this study was to develop a new classification system for corneal dystrophies, integrating up-to-date information on phenotypic description, pathologic examination, and genetic analysis. Methods The International Committee for Classification of Corneal Dystrophies (IC3D) was created to devise a current and accurate nomenclature. Results This anatomic classification continues to organize dystrophies according to the level chiefly affected. Each dystrophy has a template summarizing genetic, clinical, and pathologic information. A category number from 1 through 4 is assigned, reflecting the level of evidence supporting the existence of a given dystrophy. The most defined dystrophies belong to category 1 (a well-defined corneal dystrophy in which a gene has been mapped and identified and specific mutations are known) and the least defined belong to category 4 (a suspected dystrophy where the clinical and genetic evidence is not yet convincing). The nomenclature may be updated over time as new information regarding the dystrophies becomes available. Conclusions The IC3D Classification of Corneal Dystrophies is a new classification system that incorporates many aspects of the traditional definitions of corneal dystrophies with new genetic, clinical, and pathologic information. Standardized templates provide key information that includes a level of evidence for there being a corneal dystrophy. The system is user-friendly and upgradeable and can be retrieved on the website www.corneasociety.org/ic3d. PMID:19337156

  6. Retrospective review of corneal ulcers in Ipoh Hospital.

    PubMed

    Kursiah, M R; Sharif, F Mohd; Balaravi, P

    2008-12-01

    This study was a retrospective study on corneal ulcer of one year period in Hospital Ipoh. A total of 28 cases were studied. Among the risk factors identified were foreign body on cornea, trauma, contact lens, vernal keratoconjunctivitis and surgical complication. The nature of this disease which was severe and slow healing caused prolonged hospital admission. Identification of causative microorganism by corneal scraping help in the treatment and management of this condition. PMID:19803298

  7. Corneal Ulcer Caused by the New Fungal Species Sarcopodium oculorum

    PubMed Central

    Guarro, Josep; Höfling-Lima, Ana Luisa; Gené, Josepa; De Freitas, Denise; Godoy, Patricio; Zorat-Yu, Maria Luisa; Zaror, Luis; Fischman, Olga

    2002-01-01

    We describe a case of keratitis caused by a new species of the hyphomycetous genus Sarcopodium, S. oculorum. The corneal ulcer developed after 5 months of treatment with corticosteroids in a Brazilian boy diagnosed with allergic conjunctivitis. Fungal hyphae and conidia were detected in corneal scrapings, and repeated cultures were positive for this fungus. The infection was resolved with natamycin and ketoconazole. Eleven antifungals were tested against this fungus, and all except flucytosine and fluconazole showed in vitro activity. PMID:12149384

  8. Corneal lesion as the initial manifestation of tyrosinemia type II.

    PubMed

    Tsai, Chun-Pin; Lin, Pei-Yu; Lee, Ni-Chung; Niu, Dau-Ming; Lee, Shui-Mei; Hsu, Wen-Ming

    2006-06-01

    Tyrosinemia type II (Richner-Hanhart syndrome) is a rare autosomal recessive disease with deficiency of tyrosine aminotransferase and subsequently increasing level of serum tyrosine. We report the case of a 2-year-old girl who was referred due to bilateral corneal lesions. Slit-lamp examination showed small granular white deposits arranged in a dendritic pattern in the superficial central cornea of both eyes. Physical examination revealed painful, non-pruritic, hyperkeratotic plaques on the soles, palms and fingertips. Mental evaluation demonstrated developmental delay for her age. Blood examination revealed serum tyrosine level to be 1868 microM (normal range, 30-110 microM), which decreased to 838 microM with 2-month diet on tyrosine and phenylalanine restriction. The corneal and skin lesions resolved completely. However, the corneal deposits recurred a month later as her mother failed to strictly control the diet because the little girl was losing weight and activity. With specific formula and adjusted diet regimen, the corneal lesions decreased again. Corneal pseudodendritic deposits may be the initial manifestation in patients with tyrosinemia type II. Early diagnosis and intervention with diet control are crucial for preventing permanent visual and developmental deficits. Corneal deposits can be one of the parameters in monitoring the efficacy of diet control.

  9. The oxidant role of 4-hydroxynonenal in corneal epithelium.

    PubMed

    Chen, Longlong; Zong, Rongrong; Zhou, Jing; Ge, Lianping; Zhou, Tong; Ma, Jian-xing; Liu, Zuguo; Zhou, Yueping

    2015-01-01

    4-Hydroxynonenal (4-HNE or HNE) is a main endogenous product of cellular lipid peroxidation in tissues and is reported to play pathogenic roles in eye diseases. Here we investigated the association between 4-HNE and oxidative stress in the corneal epithelium. 4-HNE suppressed the cell viability of human corneal epithelial cells (HCE) in a concentration dependent manner. 4-HNE significantly increased the level of 3-Nitrotyrosine (3-NT), a marker of oxidative stress, in HCE cells and corneal epithelium of rats by immunofluorescent staining and Western blot analysis. To its underlying mechanistic on ROS system, 4-HNE elevated the ROS generation enzyme NADPH oxidase 4 (NOX4) and induced the activation of NF-E2-related factor-2 (NRF2) and its downstream effectors: NAD(P)H dehydrogenase (quinone 1) (NQO1) and glutathione S-transferase P (GSTP). Furthermore, N-acetylcysteine (NAC), an antioxidant and ROS scavenger, antagonized the inhibitory and oxidant effects of 4-HNE on the corneal epithelial cells. In conclusion, 4-HNE plays an oxidant role in the corneal epithelium and this work provides a new strategy for the pathogenesis and treatment of corneal diseases.

  10. In vitro biology of corneal epithelium and endothelium.

    PubMed Central

    Yanoff, M

    1975-01-01

    Four main areas are explored: (1) the proper culture medium for corneal tissue; (2) the effect of serum on in vitro tissue growth; (3) the in vitro interrelationships between corneal epithelium and endothelium; and (4) the biology of cultures of whole corneas (organ cultures). Modified Eagle's minimal essential medium (MEM) proved to be an excellent culture fluid. Corneal tissue could be grown in MEM without serum or clot, thus providing a defined culture medium. The in vitro biology of outgrowths of multilayered corneal epithelium and monolayered corneal endothelium are discussed. Contact inhibition between epithelium and endothelium is demonstrated in whole corneal (organ) cultures. Images FIGURE 5 A FIGURE 5 B FIGURE 10 A FIGURE 10 B FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 2 A FIGURE 2 B FIGURE 3 A FIGURE 3 B FIGURE 4 A FIGURE 4 B FIGURE 6 A FIGURE 6 B FIGURE 7 A FIGURE 7 B FIGURE 8 A FIGURE 8 B FIGURE 9 A FIGURE 9 B FIGURE 11 A FIGURE 11 B FIGURE 12 A FIGURE 12 B FIGURE 12 C FIGURE 13 FIGURE 14 A FIGURE 14 B FIGURE 15 A FIGURE 15 B FIGURE 16 A FIGURE 16 B FIGURE 17 A FIGURE 17 B FIGURE 17 C FIGURE 18 A FIGURE 18 B PMID:1246815

  11. Corneal haze in course of Fuchs' endothelial dystrophy.

    PubMed

    Pescosolido, N; Komaiha, C; Dapoto, L; Lenarduzzi, F; Nebbioso, M

    2012-07-01

    This article describes the observations obtained with confocal microscopy (CM) on the corneal structure in course of corneal edema in a patient with Fuchs endothelial corneal dystrophy (FD). The patient was a 40 year old male, suffering from second stage FD, in course of corneal edema and bullous keratopathy. The tissue structure was analyzed with CM confoscan CS4 (Nidek Technologies(®), Birmingham, UK) using the 40x mode. The CM has shown the presence of gaps due to corneal edema and a diffuse stromal hyper reflectivity related to the alteration of the extracellular matrix. It has also showed the presence of binucleate cells, assimilable to keratocytes, in cytokinesis which presented a typical fusiform aspect with two highly reflective nuclei awaiting cell division. The total number of cells was much lower than that of healthy control subjects of similar age, sex and race. The CM in this case suggests a significantly lower number of cells, presumably keratocytes, compared to normal range, but mostly it shows the presence of cells undergoing cytokinesis, which witnesses the active processes of collagenogenesis and possible vasculogenesis that represent early stages of loss of the normal corneal transparency. PMID:23007820

  12. Does severity of dermatochalasis in aging affect corneal biomechanical properties?

    PubMed Central

    Atalay, Kurşat; Gurez, Ceren; Kirgiz, Ahmet; Serefoglu Cabuk, Kubra

    2016-01-01

    Purpose The aim of this study was to investigate the possibility of a relationship between corneal biomechanical properties and different grades of dermatochalasis. Patients and methods Patients were assigned to four groups according to the severity of their dermatochalasis: normal (Group 1), mild (Group 2), moderate (Group 3), and severe (Group 4). An Ocular Response Analyzer device was used to measure corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc). Results We found no significant differences in the mean values of the CH, CRF, and IOPcc of all groups (P=0.75, P=0.93, and P=0.11, respectively). However, CH and IOPcc were negatively correlated in Group 1, Group 2, and Group 3 patients (P=0.013, r=−0.49; P=0.015, r=−0.52; and P=0.011, r=−0.47, respectively), but this correlation was not apparent in the Group 4 patients (P=0.57, r=0.12). CRF and IOPcc were correlated, but only in Group 4 (P=0.001, r=0.66). Conclusion Severe dermatochalasis was associated with altered corneal biomechanical properties. Some of the important visual consequences of dermatochalasis and related diseases (such as floppy eyelid syndrome) can be understood by considering corneal biomechanical alterations. PMID:27274214

  13. A Case of Solitary Nonvascularized Corneal Epithelial Dysplasia

    PubMed Central

    Morii, Tomoya; Sumioka, Takayoshi; Izutani-Kitano, Ai; Takada, Yukihisa; Okada, Yuka; Kao, Winston W.-Y.; Saika, Shizuya

    2016-01-01

    Background. Epithelial dysplasia is categorized as conjunctival/corneal intraepithelial neoplasia which is a precancerous lesion. The lesion is usually developed at the limbal region and grows towards central cornea in association with neovascularization into the lesion. Here, we report a case of isolated nonvascularized corneal epithelial dysplasia surrounded by normal corneal epithelium with immune histochemical finding of ocular surface tissues cytokeratins, for example, keratin 13 and keratin 12. Case Presentation. A 76-year-old man consulted us for visual disturbance with localized opacification of the corneal epithelium in his left eye. His visual acuity was 20/20 and 20/200 in his right and left eye, respectively. Slit lamp examination showed a whitish plaque-like lesion at the center of his left corneal epithelium. No vascular invasion to the lesion was found. The lesion was surgically removed and subjected to histopathological examination and diagnosed as epithelial dysplasia. Amyloidosis was excluded by direct fast scarlet 4BS (DFS) staining. Immunohistochemistry showed that the dysplastic epithelial cells express keratin 13 and vimentin, but not keratin 12, indicating that the neoplastic epithelial cells lacked corneal-type epithelium differentiation. Conclusions. The lesion was diagnosed as nonvascularized epithelial dysplasia of ocular surface. Etiology of the lesion is not known. PMID:27042371

  14. Mast Cells Participate in Corneal Development in Mice

    PubMed Central

    Liu, Jun; Fu, Ting; Song, Fang; Xue, Yunxia; Xia, Chaoyong; Liu, Peng; Wang, Hanqing; Zhong, Jiajun; Li, Quanrong; Chen, Jiansu; Li, Yangqiu; Cai, Dongqing; Li, Zhijie

    2015-01-01

    The development of the cornea, a highly specialized transparent tissue located at the anterior of the eye, is coordinated by a variety of molecules and cells. Here, we report that mast cells (MCs), recently found to be involved in morphogenesis, played a potentially important role in corneal development in mice. We show that two different waves of MC migration occurred during corneal development. In the first wave, MCs migrated to the corneal stroma and became distributed throughout the cornea. This wave occurred by embryonic day 12.5, with MCs disappearing from the cornea at the time of eyelid opening. In the second wave, MCs migrated to the corneal limbus and became distributed around limbal blood vessels. The number of MCs in this region gradually increased after birth and peaked at the time of eyelid opening in mice, remaining stable after postnatal day 21. We also show that integrin α4β7 and CXCR2 were important for the migration of MC precursors to the corneal limbus and that c-Kit-dependent MCs appeared to be involved in the formation of limbal blood vessels and corneal nerve fibers. These data clearly revealed that MCs participate in the development of the murine cornea. PMID:26627131

  15. Congenital Corneal Anesthesia and Neurotrophic Keratitis: Diagnosis and Management

    PubMed Central

    Mantelli, Flavio; Nardella, Chiara; Tiberi, Eloisa; Sacchetti, Marta; Bruscolini, Alice; Lambiase, Alessandro

    2015-01-01

    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. PMID:26451380

  16. Azithromycin (AZM) treatment increases survival of high risk corneal allotransplants

    PubMed Central

    Medina, Carlos A.; Rowe, Alexander M.; Yun, Hongmin; Knickelbein, Jared E.; Lathrop, Kira L.; Hendricks, Robert L.

    2012-01-01

    Purpose To test the therapeutic efficacy of AZM, a macrolide antibiotic for prolonging murine “high risk” corneal allograft survival. Methods Fully MHC mismatched corneas were transplanted from C57BL/6 donors to BALB/c recipients with suture-induced vascularized “high risk” corneal beds. Recipient mice were either not treated or treated with topical AZM, oral AZM, or both. Evaluation of graft vascularization and clarity was performed in masked fashion. Lymph nodes were excised and analyzed for CD4, FoxP3, and CD44 by flow cytometry; and for T cell priming by proliferation and cytokine production in mixed lymphocyte cultures. Corneal whole mounts were evaluated by confocal microscopy. Results The incidence of graft rejection in the control group (81.8%) was significantly reduced by AZM treatment (18.2% topical, 21.7% oral, 33.3% topical + oral), although corneal vascularization was not affected by treatment. The frequency of corneas that retained complete clarity following transplantation was higher in the AZM treated groups. Reduced graft rejection in the AZM treated groups was not associated with a reduced allospecific T cell response or increased frequency of T regulatory cells. Conclusions AZM is effective in prolonging survival of “high risk” corneal allografts by an as yet undefined mechanism that does not appear to involve modulation of corneal neovascularization or allo-specific T cell priming. PMID:23407315

  17. Corneal organ cultures in tyrosinemia release chemotactic factors.

    PubMed

    Lohr, K M; Hyndiuk, R A; Hatchell, D L; Kurth, C E

    1985-05-01

    Corneal inflammation with subsequent scarring and blindness occurs in the inherited human metabolic disease tyrosinemia type II, yet putative inflammatory mediators in this disorder and in the avascular cornea in general are poorly defined. In a Tyr-fed rat model of tyrosinemia type II, intracellular crystals, presumably Tyr, are hypothesized to be responsible for the increased lysosomal activity observed in corneal epithelial lesions. Because polymorphonuclear leukocytes (PMNs) are seen only at the site of these lesions, we used this model to study humoral mediators released from Tyr-fed rat corneal organ cultures. Only Tyr-fed rats developed stromal edema and linear granular opacities in gray edematous corneal epithelium, compatible with a noninfectious keratitis. Electron micrographs confirmed epithelial edema and showed focal epithelial necrosis with PMN invasion of the stroma. Only Tyr-fed rat corneal culture supernatants contained chemotactic activity that was heat labile and moderately trypsin sensitive. Four peaks with varying amounts of chemotactic activity were found on Sephadex G-75 chromatography. Although the identity of these peaks of activity has not yet been established, we suggest that they may be responsible for the PMN infiltration observed in this model of corneal inflammation.

  18. Inhibition of corneal inflammation following keratoplasty by birch leaf extract.

    PubMed

    Wacker, Katrin; Gründemann, Carsten; Kern, Yvonne; Bredow, Laura; Huber, Roman; Reinhard, Thomas; Schwartzkopff, Johannes

    2012-04-01

    The objective of this study was to determine the effect of birch leaf (Betula pendula) extract (BPE) on corneal inflammation following keratoplasty in the rat model. T cells were stimulated in vitro in the presence of BPE. Proliferation, activation phenotype and the number of apoptotic/necrotic cells in cell culture were analyzed by flow cytometry. Corneal transplantation was performed between Fisher and Lewis rats. Recipient rats were either treated with cyclosporine A at a low dosage (Low-dose CsA=LDCsA) or received LDCsA in combination with BPE (2×1ml/day). Clinical signs for corneal inflammation and rejection time points were determined. Infiltrating leukocytes were analyzed histologically. BPE specifically inhibited T cell proliferation in vitro by inducing apoptosis. The phenotype was not affected. In vivo, BPE significantly delayed the onset of corneal opacification (p<0.05). The amount of infiltrating CD45(+) leukocytes and CD4(+) T cells (p<0.001) was significantly reduced by BPE, whereas infiltration of CD163(+) macrophages was not significantly different between the two groups. BPE selectively induces apoptosis of activated T cells. Accordingly, BPE treatment significantly reduces infiltrating T cells and subsequent corneal opacification following keratoplasty. Our findings suggest BPE as a promising anti-inflammatory drug to treat corneal inflammation.

  19. Corneal toxicity induced by vesicating agents and effective treatment options.

    PubMed

    Goswami, Dinesh G; Tewari-Singh, Neera; Agarwal, Rajesh

    2016-06-01

    The vesicating agents sulfur mustard (SM) and lewisite (LEW) are potent chemical warfare agents that primarily cause damage to the ocular, skin, and respiratory systems. However, ocular tissue is the most sensitive organ, and vesicant exposure results in a biphasic injury response, including photophobia, corneal lesions, corneal edema, ulceration, and neovascularization, and may cause loss of vision. There are several reports on ocular injury from exposure to SM, which has been frequently used in warfare. However, there are very few reports on ocular injury by LEW, which indicate that injury symptoms appear instantly after exposure and faster than SM. In spite of extensive research efforts, effective therapies for vesicant-induced ocular injuries, mainly to the most affected corneal tissue, are not available. Hence, we have established primary human corneal epithelial cells and rabbit corneal organ culture models with the SM analog nitrogen mustard, which have helped to test the efficacy of potential therapeutic agents. These agents will then be further evaluated against in vivo SM- and LEW-induced corneal injury models, which will assist in the development of potential broad-spectrum therapies against vesicant-induced ocular injuries. PMID:27327041

  20. Tissue Engineering of the Corneal Endothelium: A Review of Carrier Materials

    PubMed Central

    Teichmann, Juliane; Valtink, Monika; Nitschke, Mirko; Gramm, Stefan; Funk, Richard H.W.; Engelmann, Katrin; Werner, Carsten

    2013-01-01

    Functional impairment of the human corneal endothelium can lead to corneal blindness. In order to meet the high demand for transplants with an appropriate human corneal endothelial cell density as a prerequisite for corneal function, several tissue engineering techniques have been developed to generate transplantable endothelial cell sheets. These approaches range from the use of natural membranes, biological polymers and biosynthetic material compositions, to completely synthetic materials as matrices for corneal endothelial cell sheet generation. This review gives an overview about currently used materials for the generation of transplantable corneal endothelial cell sheets with a special focus on thermo-responsive polymer coatings. PMID:24956190

  1. Müllerian adenosarcoma of the uterus with low-grade sarcomatous overgrowth characterized by prominent hydropic change resulting in mimicry of a smooth muscle tumor.

    PubMed

    Wu, Roseann I; Schorge, John O; Dal Cin, Paola; Cin, Paola D; Young, Robert H; Oliva, Esther

    2014-11-01

    A 28-y-old woman was found to have a large subserosal uterine mass that was excised and interpreted as a "clear cell leiomyoma." Five years later, the tumor recurred as serosal-based ileal and uterine masses; they were treated by partial ileal resection and hysterectomy. All 3 masses were predominantly characterized by conspicuous edema separating bland cells growing in cords and clusters, with scant to moderately conspicuous clear cytoplasm. The edema was indistinguishable from the hydropic change commonly seen in benign smooth muscle tumors and the cords similar to those often present in them. However, the mass from the hysterectomy specimen had a small, grossly recognizable cystic region, which on microscopic examination was a typical low-grade müllerian adenosarcoma. The stroma of the latter ranged from cellular endometrial-type to edematous and hypocellular similar to that dominating the other specimens. The cellular and edematous regions focally had cords and tubules of sex cord-like type confirmed by inhibin and calretinin positivity. Smooth muscle differentiation was also seen as a "starburst" pattern. This case of adenosarcoma is unusual due to its (1) serosal location, (2) overgrowth of stroma, which differed from typical adenosarcoma with sarcomatous overgrowth by its low-grade nature, (3) hydropic change associated with cords and nests of cells with clear cytoplasm, which prompted the initial specimen to be considered an epithelioid leiomyoma, and (4) prominent smooth muscle metaplasia mostly with a "starburst" morphology. All these features have only rarely been documented in prior müllerian adenosarcomas.

  2. Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia.

    PubMed

    Hou, Jie; Wang, Yan; Lei, Yulin; Zheng, Xiuyun; Zhang, Ying

    2016-01-01

    Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2-5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperative Q-value changes (ΔQ) was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69 ± 4.2, 5.19 ± 3.8, and 6.23 ± 3.9 μm at the center, paracenter, and mid-periphery, resp., P < 0.01). A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r = 0.438, 0.580, and 0.504, resp., P < 0.01). Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia. PMID:27672447

  3. Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

    PubMed Central

    Zheng, Xiuyun

    2016-01-01

    Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperative Q-value changes (ΔQ) was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69 ± 4.2, 5.19 ± 3.8, and 6.23 ± 3.9 μm at the center, paracenter, and mid-periphery, resp., P < 0.01). A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r = 0.438, 0.580, and 0.504, resp., P < 0.01). Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia.

  4. Corneal Epithelial Remodeling and Its Effect on Corneal Asphericity after Transepithelial Photorefractive Keratectomy for Myopia

    PubMed Central

    Zheng, Xiuyun

    2016-01-01

    Purpose. To evaluate the changes in epithelial thickness profile following transepithelial photorefractive keratectomy (T-PRK) for myopia and to investigate the effect of epithelial remodeling on corneal asphericity. Methods. Forty-four patients (44 right eyes) who underwent T-PRK were retrospectively evaluated. Epithelial thickness was measured using spectral-domain optical coherence tomography at different corneal zones (central, 2 mm; paracentral, 2–5 mm; and mid-peripheral, 5-6 mm) preoperatively and at 1 week and 1, 3, and 6 months postoperatively. The correlation between the changes in corneal epithelial thickness (ΔCET) and postoperative Q-value changes (ΔQ) was analyzed 6 months postoperatively. Results. Epithelial thickness at 6 months showed a negative meniscus-like lenticular pattern with less central thickening, which increased progressively toward the mid-periphery (3.69 ± 4.2, 5.19 ± 3.8, and 6.23 ± 3.9 μm at the center, paracenter, and mid-periphery, resp., P < 0.01). A significant positive relationship was observed between epithelial thickening and ΔQ 6 months postoperatively (r = 0.438, 0.580, and 0.504, resp., P < 0.01). Conclusions. Significant epithelial thickening was observed after T-PRK and showed a lenticular change with more thickening mid-peripherally, resulting in increased oblateness postoperatively. Epithelial remodeling may modify the epithelial thickness profile after surface ablation refractive surgery for myopia. PMID:27672447

  5. Precision and Agreement of Corneal Power Measurements Obtained Using a New Corneal Topographer OphthaTOP

    PubMed Central

    Huang, Jinhai; Savini, Giacomo; Chen, Hao; Bao, Fangjun; Li, Yuanguang; Chen, Haisi; Lu, Weicong; Yu, Ye; Wang, Qinmei

    2015-01-01

    Purpose To evaluate repeatability and reproducibility of anterior corneal power measurements obtained with a new corneal topographer OphthaTOP (Hummel AG, Germany) and agreement with measurements by a rotating Scheimpflug camera (Pentacam HR, Oculus, Germany) and an automated keratometer (IOLMaster, Carl Zeiss Meditec, Germany). Methods The right eyes of 79 healthy subjects were prospectively measured three times with all three devices. Another examiner performed three additional scans with the OphthaTOP in the same session. Within one week, the first examiner repeated the measurements using the OphthaTOP. The flat simulated keratometry (Kf), steep K (Ks), mean K (Km), J0, and J45 were noted. Repeatability and reproducibility of measurements were assessed by within-subject standard deviation (Sw), repeatability (2.77 Sw), coefficient of variation (CoV), and intraclass correlation coefficient (ICC). Agreement between devices was assessed using 95% limits of agreement (LoA). Results Intraobserver repeatability and interobserver and intersession reproducibility of all measured parameters showed a 2.77 Sw of 0.29 diopter or less, a CoV of less than 0.24%, and an ICC of more than 0.906. Statistically significant differences (P<0.001) were found between the parameters analyzed by the three devices, except J0 and J45. The mean differences between OphthaTOP and the other two devices were small, and the 95% LoA was narrow for all results. Conclusions The OphthaTOP showed excellent intraobserver repeatability and interobserver and intersession reproducibility of corneal power measurements. Good agreements with the other two devices in these parameters were found in healthy eyes. PMID:25559203

  6. The corneal epithelial basement membrane: structure, function, and disease.

    PubMed

    Torricelli, André A M; Singh, Vivek; Santhiago, Marcony R; Wilson, Steven E

    2013-09-01

    The corneal epithelial basement membrane (BM) is positioned between basal epithelial cells and the stroma. This highly specialized extracellular matrix functions not only to anchor epithelial cells to the stroma and provide scaffolding during embryonic development but also during migration, differentiation, and maintenance of the differentiated epithelial phenotype. Basement membranes are composed of a diverse assemblage of extracellular molecules, some of which are likely specific to the tissue where they function; but in general they are composed of four primary components--collagens, laminins, heparan sulfate proteoglycans, and nidogens--in addition to other components such as thrombospondin-1, matrilin-2, and matrilin-4 and even fibronectin in some BM. Many studies have focused on characterizing BM due to their potential roles in normal tissue function and disease, and these structures have been well characterized in many tissues. Comparatively few studies, however, have focused on the function of the epithelial BM in corneal physiology. Since the normal corneal stroma is avascular and has relatively low keratocyte density, it is expected that the corneal BM would be different from the BM in other tissues. One function that appears critical in homeostasis and wound healing is the barrier function to penetration of cytokines from the epithelium to stroma (such as transforming growth factor β-1), and possibly from stroma to epithelium (such as keratinocyte growth factor). The corneal epithelial BM is also involved in many inherited and acquired corneal diseases. This review examines this structure in detail and discusses the importance of corneal epithelial BM in homeostasis, wound healing, and disease.

  7. LIM Homeobox Domain 2 Is Required for Corneal Epithelial Homeostasis

    PubMed Central

    Sartaj, Rachel; Chee, Ru‐ik; Yang, Jing; Wan, Pengxia; Liu, Aihong; Guaiquil, Victor; Fuchs, Elaine

    2016-01-01

    Abstract The cornea requires constant epithelial renewal to maintain clarity for appropriate vision. A subset of stem cells residing at the limbus is primarily responsible for maintaining corneal epithelium homeostasis. Trauma and disease may lead to stem cell deficiency and therapeutic targeting to replenish the stemness capacity has been stalled by the lack of reliable corneal epithelial stem cell markers. Here we identified the location of Lhx2 in mice (mLhx2) cornea and conjunctival tissue using an Lhx2eGFP reporter model and in human tissues (hLHX2). Lhx2 localized to the basal cells of central cornea, the conjunctiva and the entire limbal epithelium in humans and mice. To ascribe a functional role we generated Lhx2 conditional knockout (cKO) mice and the phenotypic effects in corneas were analyzed by slit lamp microscopy, in cell‐based assays and in a model of corneal epithelium debridement. Immunodetection on corneal sections were used to visualize conjunctivalization, a sign of limbal barrier failure. Lhx2cKO mice produced reduced body hair and spontaneous epithelial defects in the cornea that included neovascularization, perforation with formation of scar tissue and opacification. Cell based assays showed that Lhx2cKO derived corneal epithelial cells have a significantly lower capacity to form colonies over time and delayed wound‐healing recovery when compared to wildtype cells. Repeated corneal epithelial wounding resulted in decreased re‐epithelialization and multiple cornea lesions in Lhx2cKO mice compared to normal recovery seen in wildtype mice. We conclude that Lhx2 is required for maintenance of the corneal epithelial cell compartment and the limbal barrier. Stem Cells 2016;34:493–503 PMID:26661907

  8. Tectonic deep anterior lamellar keratoplasty in impending corneal perforation using cryopreserved cornea.

    PubMed

    Jang, Ji Hye; Chang, Sung Dong

    2011-04-01

    We report a case of tectonic corneal transplantation for impending corneal perforation to preserve anatomic integrity using cryopreserved donor tissue. An 82-year-old woman exhibiting impending corneal perforation suffered from moderate ocular pain in the left eye for one week. After abnormal tissues around the impending perforation area were carefully peeled away using a Crescent blade and Vannas scissors, the patient received tectonic deep anterior lamellar keratoplasty using a cryopreserved cornea stored in Optisol GS® solution at -70℃ for four weeks. At six months after surgery, the cornea remained transparent and restored the normal corneal thickness. There were no complications such as corneal haze or scars, graft rejection, recurrent corneal ulcer, and postoperative rise of intraocular pressure. Cryopreserved donor lamellar tissue is an effective substitute in emergency tectonic lamellar keratoplasty, such as impending corneal perforation and severe necrotic corneal keratitis.

  9. Collagen Cross-Linking Using Riboflavin and Ultraviolet-A for Corneal Thinning Disorders

    PubMed Central

    Pron, G; Ieraci, L; Kaulback, K

    2011-01-01

    Executive Summary Objective The main objectives for this evidence-based analysis were to determine the safety and effectiveness of photochemical corneal collagen cross-linking with riboflavin (vitamin B2) and ultraviolet-A radiation, referred to as CXL, for the management of corneal thinning disease conditions. The comparative safety and effectiveness of corneal cross-linking with other minimally invasive treatments such as intrastromal corneal rings was also reviewed. The Medical Advisory Secretariat (MAS) evidence-based analysis was performed to support public financing decisions. Subject of the Evidence-Based Analysis The primary treatment objective for corneal cross-linking is to increase the strength of the corneal stroma, thereby stabilizing the underlying disease process. At the present time, it is the only procedure that treats the underlying disease condition. The proposed advantages for corneal cross-linking are that the procedure is minimally invasive, safe and effective, and it can potentially delay or defer the need for a corneal transplant. In addition, corneal cross-linking does not adversely affect subsequent surgical approaches, if they are necessary, or interfere with corneal transplants. The evidence for these claims for corneal cross-linking in the management of corneal thinning disorders such as keratoconus will be the focus of this review. The specific research questions for the evidence review were as follows: Technical: How technically demanding is corneal cross-linking and what are the operative risks? Safety: What is known about the broader safety profile of corneal cross-linking? Effectiveness - Corneal Surface Topographic Affects: What are the corneal surface remodeling effects of corneal cross-linking? Do these changes interfere with subsequent interventions, particularly corneal transplant known as penetrating keratoplasty (PKP)? Effectiveness -Visual Acuity: What impacts does the remodeling have on visual acuity? Are these impacts

  10. Fluorouracil as a treatment for corneal papilloma in a Malayan tapir.

    PubMed

    Karpinski, Lorraine G; Miller, Christine L

    2002-09-01

    A 26-year-old, wild caught, male Malayan tapir at the Miami Metrozoo with bilateral corneal papillomas was serially immobilized and given subconjunctival injections of fluorouracil. Over the course of 17 weeks five bilateral injections of 25 mg fluorouracil were given. This treatment caused regression of the corneal lesions as evidenced by decreased lesion diameter, decreased corneal vascularity, increased corneal clarity, and improved visual function. No adverse drug effects were observed.

  11. Pulsed vs continuous light accelerated corneal collagen crosslinking: in vivo qualitative investigation by confocal microscopy and corneal OCT

    PubMed Central

    Mazzotta, C; Traversi, C; Caragiuli, S; Rechichi, M

    2014-01-01

    Purpose To assess qualitative corneal changes and penetration of pulsed and continuous light accelerated crosslinking by in vivo confocal microscopy and corneal OCT. Methods A total of 20 patients affected from progressive keratoconus were enrolled in the study. Ten eyes of 10 patients underwent an epithelium-off pulsed-light accelerated corneal collagen crosslinking (PL-ACXL) by the KXL UV-A source (Avedro Inc.) with 8 min (1 s on/1 s off) of UV-A exposure at 30 mW/cm2 and energy dose of 7.2 J/cm2; 10 eyes of 10 patients underwent an epithelium-off continuous-light accelerated corneal collagen crosslinking (CL-ACXL) at 30 mW/cm2 for 4 min. Riboflavin 0.1% dextran-free plus hydroxyl-propyl-methylcellulose solution (VibeX Rapid, Avedro Inc.) was used for a 10-min corneal soaking. Treated eyes were examined by in vivo scanning laser confocal analysis and spectral anterior segment OCT at 1, 3, and 6 months. Results Epithelial stratification and nerves regeneration improved in time, being complete at month 6 in both groups without endothelial damage. Keratocyte apoptosis in PL-ACXL was estimated at a mean depth of ∼200 μm, whereas an uneven demarcation line was detectable by confocal microscopy at a mean depth of 160 μm in CL-ACXL. Conclusion In vivo confocal microscopy and corneal OCT allowed a precise qualitative analysis of the cornea after epithelium-off PL-ACXL and CL-ACXL treatments. Apoptotic effect was higher in pulsed than in continuous light treatments, exceeding 200 μm in corneal stroma. According to different morphological data, the clinical efficacy of ACXL needs to be determined in a long-term follow-up and large cohort of patients. PMID:25060847

  12. Unilateral Herpes Zoster Ophthalmicus Results in Bilateral Corneal Nerve Alteration

    PubMed Central

    Hamrah, Pedram; Cruzat, Andrea; Dastjerdi, Mohammad H.; Prüss, Harald; Zheng, Lixin; Shahatit, Bashar M.; Bayhan, Hasan A.; Dana, Reza; Pavan-Langston, Deborah

    2013-01-01

    Purpose Herpes zoster ophthalmicus (HZO), thought to be a unilateral disease, results in loss of corneal sensation, leading to neurotrophic keratopathy. This study aimed to analyze bilateral corneal nerve changes in patients with HZO by in vivo confocal microscopy (IVCM) and their correlation with corneal sensation as a measure of nerve function. Design Prospective, cross-sectional, controlled, single-center study. Participants Twenty-seven eyes with the diagnosis of HZO and their contralateral clinically unaffected eyes were studied and compared with normal controls (n = 15). Methods In vivo confocal microscopy (Confoscan 4; Nidek Technologies, Gamagori, Japan) and corneal esthesiometry (Cochet-Bonnet; Luneau Ophthalmologie, Chartres, France) of the central cornea were performed bilaterally in all patients and controls. Patients were grouped into normal (>5.5 cm), mild (>2.5–5.5 cm), and severe (<2.5 cm) loss of sensation. Main Outcome Measures Changes in corneal nerve density, total nerve number, main nerve trunks, branching, and tortuosity were evaluated after IVCM and were correlated to corneal sensation, disease duration, and number of recurrences. Results Eyes with herpes zoster ophthalmicus had a significant (P<0.001) decrease in total nerve length (595.8±358.1 vs. 2258.4±989.0 μm/frame), total number of nerves (5.4±2.8 vs. 13.1±3.8), number of main nerve trunks (2.3±1.1 vs. 4.7±1.2), and number of nerve branches (3.2±2.3 vs. 8.4±3.7) as compared with controls. In the contralateral clinically unaffected eyes, total nerve length (1053.1±441.4 μm/frame), total number of nerves (8.3±2.9), and main nerve trunks (3.1±1.0) also were decreased significantly as compared with controls (P<0.01). Reduced nerve density, total nerve count, main trunks, and tortuosity was correlated significantly with corneal sensation across all subgroups (P<0.001). Conclusions Patients with unilateral HZO demonstrated a profound and significant bilateral loss of the

  13. Sutureless Corneal Transplantation Apparatus And Method

    DOEpatents

    Rowsey, J. James

    1996-12-17

    An eye with a cornea repaired without sutures comprising a donor material in the shape of a partial sphere having a generally central extent, the central extent being of the size and shape of the central portion of a cornea of an eye, the central extent having a periphery of a fixed diameter with an exterior surface in a convex configuration and an interior surface in a concave configuration and with an essentially common thickness throughout, the central extent having a plurality of corneal flaps extending radially from the periphery of the central extent, the flaps having exterior surfaces as a continuation of the exterior surface of the central extent; and a recipient eye in the shape of a partial sphere having a circular aperture in the cornea at its central portion, the central aperture being of a size and shape essentially that of the periphery of the central extent of the donor material, the aperture being of a common thickness at the periphery of the aperture, the central portion having pockets and with the central extent of the donor material located within the aperture of the recipient eye and with the flaps of the central extent being imbricated into the pockets of the recipient eye.

  14. ODE/PDE analysis of corneal curvature.

    PubMed

    Płociniczak, Lukasz; Griffiths, Graham W; Schiesser, William E

    2014-10-01

    The starting point for this paper is a nonlinear, two-point boundary value ordinary differential equation (BVODE) that defines corneal curvature according to a static force balance. A numerical solution to the BVODE is computed by first converting the BVODE to a parabolic partial differential equation (PDE) by adding an initial value (t, pseudo-time) derivative to the BVODE. A numerical solution to the PDE is then computed by the method of lines (MOL) with the calculation proceeding to a sufficiently large value of t such that the derivative in t reduces to essentially zero. The PDE solution at this point is also the solution for the BVODE. This procedure is implemented in R (an open source scientific programming system) and the programming is discussed in some detail. A series approximation to the solution is derived from which an estimate for the rate of convergence is obtained. This is compared to a fitted exponential model. Also, two linear approximations are derived, one of which leads to a closed form solution. Both provide solutions very close to that obtained from the full nonlinear model. An estimate for the cornea radius of curvature is also derived. The paper concludes with a discussion of the features of the solution to the ODE/PDE system.

  15. Induced corneal astigmatism with hydrophilic contact lenses.

    PubMed

    Morgan, J F

    1975-04-01

    Changes in keratometer readings were measured in 87 patients, wearing hydrophilic contact lenses for three to more than eighteen months. Twenty-four eyes in the group had an increase of +0.75 or more in the keratometer readings, which invariably involved the vertical reading and was often associated with a distortion of the mire reflex. The change was high as +2.75 diopters. If greater than +1.00 diopter, it was associated with decreased visual acuity with forward correction and with the hydrophilic contact lenses. All but one of the patients who showedchanges of greater than +0.75 diopters over their baseline keratometer readings, were wearing their lenses on an average of 14-16 hours a day. The keratometer readings reverted to the baseline levels with a loss of the distrotion, if the patient reduced the wearing time to less than 12 hours daily. We believe that a maximum average daily wearing time of 12 hours is the safety limit required to minimize the development of induced corneal astigmatism.

  16. Oxidized alginate hydrogels as niche environments for corneal epithelial cells

    PubMed Central

    Wright, Bernice; De Bank, Paul A; Luetchford, Kim A; Acosta, Fernando R; Connon, Che J

    2014-01-01

    Chemical and biochemical modification of hydrogels is one strategy to create physiological constructs that maintain cell function. The aim of this study was to apply oxidised alginate hydrogels as a basis for development of a biomimetic niche for limbal epithelial stem cells that may be applied to treating corneal dysfunction. The stem phenotype of bovine limbal epithelial cells (LEC) and the viability of corneal epithelial cells (CEC) were examined in oxidised alginate gels containing collagen IV over a 3-day culture period. Oxidation increased cell viability (P ≤ 0.05) and this improved further with addition of collagen IV (P ≤ 0.01). Oxidised gels presented larger internal pores (diameter: 0.2–0.8 µm) than unmodified gels (pore diameter: 0.05–0.1 µm) and were significantly less stiff (P ≤ 0.001), indicating that an increase in pore size and a decrease in stiffness contributed to improved cell viability. The diffusion of collagen IV from oxidised alginate gels was similar to that of unmodified gels suggesting that oxidation may not affect the retention of extracellular matrix proteins in alginate gels. These data demonstrate that oxidised alginate gels containing corneal extracellular matrix proteins can influence corneal epithelial cell function in a manner that may impact beneficially on corneal wound healing therapy. © 2013 The Authors. Journal of Biomedical Materials Research Part A Published byWiley Periodicals, Inc. Part A: 102A: 3393–3400, 2014. PMID:24142706

  17. Corneal biomechanical properties in children with diabetes mellitus.

    PubMed

    Kara, Necip; Yildirim, Yusuf; Univar, Tolga; Kontbay, Tugba

    2012-08-01

    Purpose. To compare the biomechanical properties of corneas in eyes of children with diabetes mellitus and in eyes of children without diabetes mellitus.
Methods. In this prospective, comparative, and cross-sectional study, 46 patients with diabetes mellitus (study group) and 50 healthy individuals (control group) were enrolled. The corneal hysteresis (CH) and corneal resistance factor (CRF) were measured in children with and without diabetes using the Ocular Response Analyzer. Differences in the corneal biomechanical properties were determined using an independent-samples t test. Correlations between ocular and diabetic parameters were also evaluated.
Results. Mean CH was 12.3±1.3 (SD) mmHg and 12.5±1.5 mmHg and the mean CRF was 12.4±1.7 mmHg and 11.9±1.5 mmHg in the diabetic and control groups, respectively (p>0.05). Corneal hysteresis and CRF were not correlated with fasting glucose level, HbA1c, age, or duration of diabetes.
Conclusions. The findings indicate that diabetes mellitus does not affect corneal biomechanical parameters such as CH and CRF in children. In addition, CH and CRF are not affected by fasting glucose level, HbA1c, age, or duration of diabetes. PMID:22890598

  18. Corneal topography from spectral optical coherence tomography (sOCT)

    PubMed Central

    Ortiz, Sergio; Siedlecki, Damian; Pérez-Merino, Pablo; Chia, Noelia; de Castro, Alberto; Szkulmowski, Maciej; Wojtkowski, Maciej; Marcos, Susana

    2011-01-01

    We present a method to obtain accurate corneal topography from a spectral optical coherence tomography (sOCT) system. The method includes calibration of the device, compensation of the fan (or field) distortion introduced by the scanning architecture, and image processing analysis for volumetric data extraction, segmentation and fitting. We present examples of three-dimensional (3-D) surface topography measurements on spherical and aspheric lenses, as well as on 10 human corneas in vivo. Results of sOCT surface topography (with and without fan-distortion correction) were compared with non-contact profilometry (taken as reference) on a spherical lens, and with non-contact profilometry and state-of-the art commercial corneal topography instruments on aspheric lenses and on subjects. Corneal elevation maps from all instruments were fitted by quadric surfaces (as well as by tenth-order Zernike polynomials) using custom routines. We found that the discrepancy in the estimated radius of curvature from nominal values in artificial corneas decreased from 4.6% (without fan distortion correction) to 1.6% (after fan distortion correction), and the difference in the asphericity decreased from 130% to 5%. In human corneas, the estimated corneal radius of curvature was not statistically significantly different across instruments. However, a Bland-Altman analysis showed consistent differences in the estimated asphericity and corneal shape between sOCT topographies without fan distortion correction and the rest of the measurements. PMID:22162814

  19. A new multiple noncontinuous puncture (pointage) technique for corneal tattooing

    PubMed Central

    Park, Jin Hyoung; Um, Taewoong; Kim, Myoung Joon; Tchah, Hungwon; Kim, Jae Yong

    2015-01-01

    AIM To assess the safety and cosmetic efficacy of a new multiple noncontinuous transepithelial puncture technique for tattooing a decompensated cornea. METHODS It was a non-comparative clinical case series study. The study examines 33 eyes in 33 patients with total corneal opacity due to corneal decompensation, which developed following intraocular surgery. Corneal tattooing was performed using the multiple noncontinuous transepithelial puncture technique (i.e. pointage). The safety of this new surgical strategy was assessed by occurrence of adverse events for the follow-up period. The cosmetic efficacy was determined by the patient's cosmetic satisfaction and independent observer's opinion about patient appearance. RESULTS Seven women and 26 men were included in the study. The mean age was 46.4±17.5y (range: 7-67). In total, 30 of 33 patients (91%) reported cosmetic satisfaction within the follow-up period. Only 3 patients (9%) required additional tattooing due to cosmetic unsatisfaction. Cosmetic outcomes were analyzed and classified as excellent or good in 13 (39%) and 17 (52%) patients, respectively. No serious adverse events developed, except delayed epithelial healing in 3 cases. CONCLUSION The cosmetic outcomes of the multiple noncontinuous transepithelial puncture technique for corneal tattooing were good. The safety of this method is higher than conventional procedures. This new procedure also provides improved cost-effectiveness and safety over current corneal tattooing techniques. PMID:26558203

  20. Hydrogen prevents corneal endothelial damage in phacoemulsification cataract surgery.

    PubMed

    Igarashi, Tsutomu; Ohsawa, Ikuroh; Kobayashi, Maika; Igarashi, Toru; Suzuki, Hisaharu; Iketani, Masumi; Takahashi, Hiroshi

    2016-01-01

    In phacoemulsification, ultrasound induces hydroxyl radical (·OH) formation, damaging corneal endothelium. Whether H2 can prevent such oxidative damage in phacoemulsification was examined by in vitro and in vivo studies. H2 was dissolved in a commercial irrigating solution. The effects of H2 against ·OH generation were first confirmed in vitro by electron-spin resonance (ESR) and hydroxyphenyl fluorescein (HPF). ESR showed a significantly decreased signal magnitude, and fluorescence intensity by oxidized HPF was significantly less in the H2-dissolved solution. The effects of H2 in phacoemulsification were evaluated in rabbits, comparing H2-dissolved and control solutions. Five hours after the procedure, the whole cornea was excised and subjected to image analysis for corneal edema, real-time semiquantitative PCR (qPCR) for heme oxygenase (HO)-1, catalase (CAT), superoxide dismutase 1 (SOD1), and SOD2 mRNA, and immunohistochemistry. Corneal edema was significantly less and the increases in anti-oxidative HO-1, CAT and SOD2 mRNA expressions were significantly suppressed in the H2 group. In addition, corneal endothelial cell expressions of two oxidative stress markers, 4-HNE and 8-OHdG, were significantly lower in the H2 group. In conclusion, H2 dissolved in the ocular irrigating solution protected corneal endothelial cells from phacoemulsification-induced oxidative stress and damage. PMID:27498755

  1. Trefoil peptides promote restitution of wounded corneal epithelial cells.

    PubMed

    Göke, M N; Cook, J R; Kunert, K S; Fini, M E; Gipson, I K; Podolsky, D K

    2001-04-01

    The ocular surface shares many characteristics with mucosal surfaces. In both, healing is regulated by peptide growth factors, cytokines, and extracellular matrix proteins. However, these factors are not sufficient to ensure most rapid healing. Trefoil peptides are abundantly expressed epithelial cell products which exert protective effects and are key regulators of gastrointestinal epithelial restitution, the critical early phase of cell migration after mucosal injury. To assess the role of trefoil peptides in corneal epithelial wound healing, the effects of intestinal trefoil factor (ITF/TFF3) and spasmolytic polypeptide (SP/TFF2) on migration and proliferation of corneal epithelial cells were analyzed. Both ITF and SP enhanced restitution of primary rabbit corneal epithelial cells in vitro. While the restitution-enhancing effects of TGF-alpha and TGF-beta were both inhibited by neutralizing anti-TGF-beta-antibodies, trefoil peptide stimulation of restitution was not. Neither trefoil peptide significantly affected proliferation of primary corneal epithelial cells. ITF but not SP or pS2 mRNA was present in rabbit corneal and conjunctival tissues. In summary, the data indicate an unanticipated role of trefoil peptides in healing of ocular surface and demand rating their functional actions beyond the gastrointestinal tract.

  2. Determination of the corneal thickness profile by optical pachometry.

    PubMed

    Edmund, C

    1987-04-01

    A clinical method of measuring central-peripheral corresponding values of corneal thickness and measurement positions in the horizontal meridian is described. Employing a fitting procedure it is demonstrated that the relative increase in the corneal thickness from apex to limbus is proportional to the square of the chord distance. The proportionality factor is defined as the coefficient of thickness variation (TV). Tm is defined as the minimal corneal thickness. In relation to the visual axis the chord distance xm denote the temporal or nasal position of Tm. TV, Tm and xm are characteristic constants of a particular eye. Measuring the corneal thickness and the chord distance in mm pooled values of 80 eyes demonstrates (means +/- SD) Tm to be 0.575 +/- 0.027, and TV to be 0.0088 +/- 0.0020. With the normal interval in parenthes these results imply an enlargement of corneal thickness 0.9% (0.4-1.3%) 1 mm and 22% (12-32%) 5 mm from the visual axis. With respect to the position of Tm 21 eyes (26%) showed a median temporal displacement at 0.4 mm, 4 eyes (5%) showed a median nasal displacement at 0.3 mm and 55 eyes (69%) showed no significant displacement. This corresponds to the usual angle kappa value, which clinically expresses the often slight nasal decentration of the visual axis relative to the optic axis.

  3. Hydrogen prevents corneal endothelial damage in phacoemulsification cataract surgery

    PubMed Central

    Igarashi, Tsutomu; Ohsawa, Ikuroh; Kobayashi, Maika; Igarashi, Toru; Suzuki, Hisaharu; Iketani, Masumi; Takahashi, Hiroshi

    2016-01-01

    In phacoemulsification, ultrasound induces hydroxyl radical (·OH) formation, damaging corneal endothelium. Whether H2 can prevent such oxidative damage in phacoemulsification was examined by in vitro and in vivo studies. H2 was dissolved in a commercial irrigating solution. The effects of H2 against ·OH generation were first confirmed in vitro by electron-spin resonance (ESR) and hydroxyphenyl fluorescein (HPF). ESR showed a significantly decreased signal magnitude, and fluorescence intensity by oxidized HPF was significantly less in the H2-dissolved solution. The effects of H2 in phacoemulsification were evaluated in rabbits, comparing H2-dissolved and control solutions. Five hours after the procedure, the whole cornea was excised and subjected to image analysis for corneal edema, real-time semiquantitative PCR (qPCR) for heme oxygenase (HO)-1, catalase (CAT), superoxide dismutase 1 (SOD1), and SOD2 mRNA, and immunohistochemistry. Corneal edema was significantly less and the increases in anti-oxidative HO-1, CAT and SOD2 mRNA expressions were significantly suppressed in the H2 group. In addition, corneal endothelial cell expressions of two oxidative stress markers, 4-HNE and 8-OHdG, were significantly lower in the H2 group. In conclusion, H2 dissolved in the ocular irrigating solution protected corneal endothelial cells from phacoemulsification-induced oxidative stress and damage. PMID:27498755

  4. Oxidized alginate hydrogels as niche environments for corneal epithelial cells.

    PubMed

    Wright, Bernice; De Bank, Paul A; Luetchford, Kim A; Acosta, Fernando R; Connon, Che J

    2014-10-01

    Chemical and biochemical modification of hydrogels is one strategy to create physiological constructs that maintain cell function. The aim of this study was to apply oxidised alginate hydrogels as a basis for development of a biomimetic niche for limbal epithelial stem cells that may be applied to treating corneal dysfunction. The stem phenotype of bovine limbal epithelial cells (LEC) and the viability of corneal epithelial cells (CEC) were examined in oxidised alginate gels containing collagen IV over a 3-day culture period. Oxidation increased cell viability (P ≤ 0.05) and this improved further with addition of collagen IV (P ≤ 0.01). Oxidised gels presented larger internal pores (diameter: 0.2-0.8 µm) than unmodified gels (pore diameter: 0.05-0.1 µm) and were significantly less stiff (P ≤ 0.001), indicating that an increase in pore size and a decrease in stiffness contributed to improved cell viability. The diffusion of collagen IV from oxidised alginate gels was similar to that of unmodified gels suggesting that oxidation may not affect the retention of extracellular matrix proteins in alginate gels. These data demonstrate that oxidised alginate gels containing corneal extracellular matrix proteins can influence corneal epithelial cell function in a manner that may impact beneficially on corneal wound healing therapy.

  5. Corneal Transplant Infection due to Alternaria alternata: A Case Report

    PubMed Central

    Konidaris, Vasileios; Mersinoglou, Andreana; Vyzantiadis, Timoleon-Achilleas; Papadopoulou, Domniki; Boboridis, Kostas G.; Ekonomidis, Panagiotis

    2013-01-01

    Purpose. To report a case of Alternaria alternata keratitis in a patient with a corneal transplant in her right eye due to bullous pseudophakic keratopathy. Methods. A 66-year-old female underwent a full-thickness keratoplasty in her right eye due to bullous pseudophakic keratopathy. Three weeks after keratoplasty, epithelial edema and a stromal opacity with an infiltrate and development of peripheral corneal opacities appeared. The diagnosis of Alternaria alternata keratitis was made. Results. The patient underwent a second keratoplasty, due to the corneal melting as a result of the fungal infection. She was also given combined antifungal treatment locally and systematically. Conclusion. Corneal transplantation alone would not have been sufficient to keep the fungus in the anterior portion of the eye. Combined antifungal treatment, locally and systematically, was important in attempting to prevent the further spread of the fungus to the interior of the eye. To our knowledge, the case presented here is only the second one in the literature concerning a keratomycosis due to Alternaria alternata corneal transplant infection. PMID:23573439

  6. Construction of a Corneal Stromal Equivalent with SMILE-Derived Lenticules and Fibrin Glue.

    PubMed

    Yin, Houfa; Qiu, Peijin; Wu, Fang; Zhang, Wei; Teng, Wenqi; Qin, Zhenwei; Li, Chao; Zhou, Jiaojie; Fang, Zhi; Tang, Qiaomei; Fu, Qiuli; Ma, Jian; Yang, Yabo

    2016-01-01

    The scarcity of corneal tissue to treat deep corneal defects and corneal perforations remains a challenge. Currently, small incision lenticule extraction (SMILE)-derived lenticules appear to be a promising alternative for the treatment of these conditions. However, the thickness and toughness of a single piece of lenticule are limited. To overcome these limitations, we constructed a corneal stromal equivalent with SMILE-derived lenticules and fibrin glue. In vitro cell culture revealed that the corneal stromal equivalent could provide a suitable scaffold for the survival and proliferation of corneal epithelial cells, which formed a continuous pluristratified epithelium with the expression of characteristic markers. Finally, anterior lamellar keratoplasty in rabbits demonstrated that the corneal stromal equivalent with decellularized lenticules and fibrin glue could repair the anterior region of the stroma, leading to re-epithelialization and recovery of both transparency and ultrastructural organization. Corneal neovascularization, graft degradation, and corneal rejection were not observed within 3 months. Taken together, the corneal stromal equivalent with SMILE-derived lenticules and fibrin glue appears to be a safe and effective alternative for the repair of damage to the anterior cornea, which may provide new avenues in the treatment of deep corneal defects or corneal perforations. PMID:27651001

  7. The Epidemiology of Cosmetic Treatments for Corneal Opacities in a Korean Population

    PubMed Central

    Chang, Ki Cheol; Han, Young Keun; Wee, Won Ryang; Lee, Jin Hak

    2010-01-01

    Purpose To describe etiologies and clinical characteristics of corneal opacities leading patients to seek cosmetic treatments. Methods The medical records of 401 patients who presented for cosmetic improvement in corneal opacities between May 2004 and July 2007 were retrospectively reviewed. The following parameters were analyzed: age, gender, cause of corneal opacity, time course of the corneal disease, associated diseases, prior and current cosmetic treatments, visual acuity, location and depth of the corneal opacity, and the presence of either corneal neovascularization or band keratopathy. A single practitioner examined all patients. Results The most common causes of corneal opacity were ocular trauma (203 eyes, 50.6%), retinal disease (62 eyes, 15.5%), measles (38 eyes, 9.5%), and congenital etiologies (22 eyes, 5.5%). Prior treatments included iris colored contact lenses (125 eyes, 31.1%) and corneal tattooing (34 eyes, 8.46%). A total of 321 of 401 eyes underwent cosmetic treatment for corneal opacities. The most common treatment performed after the primary visit was corneal tattooing (261 eyes, 64.92%). Conclusions This is the first study to investigate the causes and clinical characteristics of patients presenting for cosmetic treatment of corneal opacities rather than for functional improvement. Various cosmetic interventions are available for patients with corneal opacities, and these should be individualized for the needs of each patient. PMID:20532140

  8. Novel Therapy to Treat Corneal Epithelial Defects: A Hypothesis with Growth Hormone

    PubMed Central

    Wirostko, Barbara; Rafii, MaryJane; Sullivan, David A.; Morelli, Julia; Ding, Juan

    2015-01-01

    Impaired corneal wound healing that occurs with ocular surface disease, trauma, systemic disease, or surgical intervention can lead to persistent corneal epithelial defects (PCED), which result in corneal scarring, ulceration, opacification, corneal neovascularization, and, ultimately, visual compromise and vision loss. The current standard of care can include lubricants, ointments, bandage lenses, amniotic membranes, autologous serum eye drops, and corneal transplants. Various inherent problems exist with application and administration of these treatments, which often may not result in a completely healed surface. A topically applicable compound capable of promoting corneal epithelial cell proliferation and/or migration would be ideal to accelerate healing. We hypothesize that human growth hormone (HGH) is such a compound. In a recent study, HGH was shown to activate signal transducer and activators of transcription-5 (STAT5) signaling and promote corneal wound healing by enhancing corneal epithelial migration in a co-culture system of corneal epithelial cells and fibroblasts. These effects require an intact communication between corneal epithelia and fibroblasts. Further, HGH promotes corneal wound healing in a rabbit debridement model, thus demonstrating the effectiveness of HGH in vivo as well. In conclusion, HGH may represent an exciting and effective topical therapeutic to promote corneal wound healing. PMID:26045234

  9. Corneal neurotization from the supratrochlear nerve with sural nerve grafts: a minimally invasive approach.

    PubMed

    Bains, Robert D; Elbaz, Uri; Zuker, Ronald M; Ali, Asim; Borschel, Gregory H

    2015-02-01

    Corneal anesthesia is a debilitating condition which can ultimately lead to blindness from repetitive corneal injury and scarring. We have developed a minimally invasive technique for corneal re-innervation that we have used with excellent results in ten eyes. This article and accompanying video describes the relevant anatomy and demonstrates the technique in detail.

  10. Novel Therapy to Treat Corneal Epithelial Defects: A Hypothesis with Growth Hormone.

    PubMed

    Wirostko, Barbara; Rafii, MaryJane; Sullivan, David A; Morelli, Julia; Ding, Juan

    2015-07-01

    Impaired corneal wound healing that occurs with ocular surface disease, trauma, systemic disease, or surgical intervention can lead to persistent corneal epithelial defects (PCED), which result in corneal scarring, ulceration, opacification, corneal neovascularization, and, ultimately, visual compromise and vision loss. The current standard of care can include lubricants, ointments, bandage lenses, amniotic membranes, autologous serum eye drops, and corneal transplants. Various inherent problems exist with application and administration of these treatments, which often may not result in a completely healed surface. A topically applicable compound capable of promoting corneal epithelial cell proliferation and/or migration would be ideal to accelerate healing. We hypothesize that human growth hormone (HGH) is such a compound. In a recent study, HGH was shown to activate signal transducer and activators of transcription-5 (STAT5) signaling and promote corneal wound healing by enhancing corneal epithelial migration in a co-culture system of corneal epithelial cells and fibroblasts. These effects require an intact communication between corneal epithelia and fibroblasts. Further, HGH promotes corneal wound healing in a rabbit debridement model, thus demonstrating the effectiveness of HGH in vivo as well. In conclusion, HGH may represent an exciting and effective topical therapeutic to promote corneal wound healing.

  11. Construction of a Corneal Stromal Equivalent with SMILE-Derived Lenticules and Fibrin Glue

    PubMed Central

    Yin, Houfa; Qiu, Peijin; Wu, Fang; Zhang, Wei; Teng, Wenqi; Qin, Zhenwei; Li, Chao; Zhou, Jiaojie; Fang, Zhi; Tang, Qiaomei; Fu, Qiuli; Ma, Jian; Yang, Yabo

    2016-01-01

    The scarcity of corneal tissue to treat deep corneal defects and corneal perforations remains a challenge. Currently, small incision lenticule extraction (SMILE)-derived lenticules appear to be a promising alternative for the treatment of these conditions. However, the thickness and toughness of a single piece of lenticule are limited. To overcome these limitations, we constructed a corneal stromal equivalent with SMILE-derived lenticules and fibrin glue. In vitro cell culture revealed that the corneal stromal equivalent could provide a suitable scaffold for the survival and proliferation of corneal epithelial cells, which formed a continuous pluristratified epithelium with the expression of characteristic markers. Finally, anterior lamellar keratoplasty in rabbits demonstrated that the corneal stromal equivalent with decellularized lenticules and fibrin glue could repair the anterior region of the stroma, leading to re-epithelialization and recovery of both transparency and ultrastructural organization. Corneal neovascularization, graft degradation, and corneal rejection were not observed within 3 months. Taken together, the corneal stromal equivalent with SMILE-derived lenticules and fibrin glue appears to be a safe and effective alternative for the repair of damage to the anterior cornea, which may provide new avenues in the treatment of deep corneal defects or corneal perforations. PMID:27651001

  12. Review of developments in corneal transplantation in the regions of Brazil - Evaluation of corneal transplants in Brazil

    PubMed Central

    Almeida, Hirlana Gomes; Hida, Richard Yudi; Kara-Junior, Newton

    2016-01-01

    The aim of this study was to identify inequalities in corneal donation and transplantation among the regions of Brazil. A transversal and retrospective study was specifically conducted using data from the Brazilian Transplant Registry collected by the Brazilian Association of Organ Transplantation between January 2002 and December 2014. The collected data were processed using descriptive statistical methods, and p<0.05 was the rate of rejection of the null hypothesis. From 2002 to 2014, there was an increase in the absolute number of corneal transplants, the annual rate of transplants per million people and the percentage of needed transplants performed in each of the five regions of Brazil. Family refusal and medical contraindication were the most frequent reasons for a lack of corneal donation. Although remarkable progress has been made in the last decade in each of the five Brazilian regions, health professionals’ lack of preparation to approach families with donation requests at the death of a family member appears to be the main obstacle to increasing the number of corneal donations. Thus, the present study suggests the implementation of public policies to make corneal transplants more effective, particularly given that there are considerable disparities in the effectiveness with which regional needs are met and in health professionals’ ability to perform transplants among the Brazilian regions, with higher rates in the South, Southeast and Midwest regions and lower rates in the North and Northeast regions. PMID:27652836

  13. PEP-1-FK506BP inhibits alkali burn-induced corneal inflammation on the rat model of corneal alkali injury

    PubMed Central

    Kim, Dae Won; Lee, Sung Ho; Shin, Min Jea; Kim, Kibom; Ku, Sae Kwang; Youn, Jong Kyu; Cho, Su Bin; Park, Jung Hwan; Lee, Chi Hern; Son, Ora; Sohn, Eun Jeong; Cho, Sung-Woo; Park, Jong Hoon; Kim, Hyun Ah; Han, Kyu Hyung; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2015-01-01

    FK506 binding protein 12 (FK506BP) is a small peptide with a single FK506BP domain that is involved in suppression of immune response and reactive oxygen species. FK506BP has emerged as a potential drug target for several inflammatory diseases. Here, we examined the protective effects of directly applied cell permeable FK506BP (PEP-1-FK506BP) on corneal alkali burn injury (CAI). In the cornea, there was a significant decrease in the number of cells expressing pro-inflammation, apoptotic, and angiogenic factors such as TNF-α, COX-2, and VEGF. Both corneal opacity and corneal neovascularization (CNV) were significantly decreased in the PEP-1-FK506BP treated group. Our results showed that PEP-1-FK506BP can significantly inhibit alkali burn-induced corneal inflammation in rats, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors and inflammatory cytokines. These results suggest that PEP-1-FK506BP may be a potential therapeutic agent for CAI. [BMB Reports 2015; 48(11): 618-623] PMID:25817214

  14. Review of developments in corneal transplantation in the regions of Brazil - Evaluation of corneal transplants in Brazil

    PubMed Central

    Almeida, Hirlana Gomes; Hida, Richard Yudi; Kara-Junior, Newton

    2016-01-01

    The aim of this study was to identify inequalities in corneal donation and transplantation among the regions of Brazil. A transversal and retrospective study was specifically conducted using data from the Brazilian Transplant Registry collected by the Brazilian Association of Organ Transplantation between January 2002 and December 2014. The collected data were processed using descriptive statistical methods, and p<0.05 was the rate of rejection of the null hypothesis. From 2002 to 2014, there was an increase in the absolute number of corneal transplants, the annual rate of transplants per million people and the percentage of needed transplants performed in each of the five regions of Brazil. Family refusal and medical contraindication were the most frequent reasons for a lack of corneal donation. Although remarkable progress has been made in the last decade in each of the five Brazilian regions, health professionals’ lack of preparation to approach families with donation requests at the death of a family member appears to be the main obstacle to increasing the number of corneal donations. Thus, the present study suggests the implementation of public policies to make corneal transplants more effective, particularly given that there are considerable disparities in the effectiveness with which regional needs are met and in health professionals’ ability to perform transplants among the Brazilian regions, with higher rates in the South, Southeast and Midwest regions and lower rates in the North and Northeast regions.

  15. Review of developments in corneal transplantation in the regions of Brazil - Evaluation of corneal transplants in Brazil.

    PubMed

    Almeida, Hirlana Gomes; Hida, Richard Yudi; Kara, Newton

    2016-09-01

    The aim of this study was to identify inequalities in corneal donation and transplantation among the regions of Brazil. A transversal and retrospective study was specifically conducted using data from the Brazilian Transplant Registry collected by the Brazilian Association of Organ Transplantation between January 2002 and December 2014. The collected data were processed using descriptive statistical methods, and p<0.05 was the rate of rejection of the null hypothesis. From 2002 to 2014, there was an increase in the absolute number of corneal transplants, the annual rate of transplants per million people and the percentage of needed transplants performed in each of the five regions of Brazil. Family refusal and medical contraindication were the most frequent reasons for a lack of corneal donation. Although remarkable progress has been made in the last decade in each of the five Brazilian regions, health professionals' lack of preparation to approach families with donation requests at the death of a family member appears to be the main obstacle to increasing the number of corneal donations. Thus, the present study suggests the implementation of public policies to make corneal transplants more effective, particularly given that there are considerable disparities in the effectiveness with which regional needs are met and in health professionals' ability to perform transplants among the Brazilian regions, with higher rates in the South, Southeast and Midwest regions and lower rates in the North and Northeast regions.

  16. Review of developments in corneal transplantation in the regions of Brazil - Evaluation of corneal transplants in Brazil.

    PubMed

    Almeida, Hirlana Gomes; Hida, Richard Yudi; Kara, Newton

    2016-09-01

    The aim of this study was to identify inequalities in corneal donation and transplantation among the regions of Brazil. A transversal and retrospective study was specifically conducted using data from the Brazilian Transplant Registry collected by the Brazilian Association of Organ Transplantation between January 2002 and December 2014. The collected data were processed using descriptive statistical methods, and p<0.05 was the rate of rejection of the null hypothesis. From 2002 to 2014, there was an increase in the absolute number of corneal transplants, the annual rate of transplants per million people and the percentage of needed transplants performed in each of the five regions of Brazil. Family refusal and medical contraindication were the most frequent reasons for a lack of corneal donation. Although remarkable progress has been made in the last decade in each of the five Brazilian regions, health professionals' lack of preparation to approach families with donation requests at the death of a family member appears to be the main obstacle to increasing the number of corneal donations. Thus, the present study suggests the implementation of public policies to make corneal transplants more effective, particularly given that there are considerable disparities in the effectiveness with which regional needs are met and in health professionals' ability to perform transplants among the Brazilian regions, with higher rates in the South, Southeast and Midwest regions and lower rates in the North and Northeast regions. PMID:27652836

  17. Creutzfeldt-Jakob disease via dural and corneal transplants.

    PubMed

    Lang, C J; Heckmann, J G; Neundörfer, B

    1998-10-01

    A review of all published cases of iatrogenic Creutzfeldt-Jakob disease (CJD) via dural (N=71) and corneal (N=4) transplants is given. All but three of the dural cases were obviously due to a commercial product recalled in 1996. Two of the corneal grafts were taken from patients who had died of sporadic CJD. These cases differed from CJD due to human growth hormone injections and the new variant. Instead. they were akin to sporadic cases, but memory loss, disorders of higher cerebral functions and extrapyramidal signs were fewer, while cerebellar abnormalities were more frequent. Progressive dysarthria and gait disorder/gait ataxia were prominent signs during the early stages, myocloni the most salient feature later. A nonperiodic EEG did not contradict the diagnosis. Using current diagnostic criteria the disease was underdiagnosed ante mortem. Utmost care is needed in selecting, harvesting and handling dural and corneal grafts to avoid inadvertent transmission of CJD.

  18. Angiotensin I converting enzyme activity in rabbit corneal endothelial cells.

    PubMed

    Neels, H M; Vanden Berghe, D A; Neetens, A J; Delgadillo, R A; Scharpe, S L

    1983-01-01

    Angiotensin I converting enzyme (ACE) was studied in Vero cells, rabbit corneal fibroblasts, and rabbit corneal endothelial cells. The enzyme activity was determined by means of an assay employing hippuryl-glycyl-glycine as a substrate. The hippuric acid end product was separated from the substrate by reversed phase liquid chromatography and measured spectrophotometrically at 228 nm. The enzyme was further characterized by a captopril inhibition study. Significant ACE activity was found in rabbit corneal endothelial cells but not in other types of cells tested. This is the first report of the presence of this enzyme in a specific ocular cell type and suggests that angiotensin II may play a role in normal ocular physiology.

  19. Corneal Tissue Engineering: Recent Advances and Future Perspectives

    PubMed Central

    Ghezzi, Chiara E.; Rnjak-Kovacina, Jelena

    2015-01-01

    To address the growing need for corneal transplants two main approaches are being pursued: allogenic and synthetic materials. Allogenic tissue from human donors is currently the preferred choice; however, there is a worldwide shortage in donated corneal tissue. In addition, tissue rejection often limits the long-term success of this approach. Alternatively, synthetic homologs to donor corneal grafts are primarily considered temporary replacements until suitable donor tissue becomes available, as they result in a high incidence of graft failure. Tissue engineered cornea analogs would provide effective cornea tissue substitutes and alternatives to address the need to reduce animal testing of commercial products. Recent progress toward these needs is reviewed here, along with future perspectives. PMID:25434371

  20. Corneal fibropapillomatosis in green sea turtles (Chelonia mydas) in Australia.

    PubMed

    Flint, M; Limpus, C J; Patterson-Kane, J C; Murray, P J; Mills, P C

    2010-05-01

    Chelonid corneal fibropapillomatosis has not previously been recorded in Australian waters. During 2008, 724 green sea turtles (Chelonia mydas) were examined in Queensland, Australia at two sites, Moreton Bay (n=155) and Shoalwater Bay (n=569), during annual monitoring. In the same calendar year, 63 turtles were submitted from various sites in southern Queensland for post-mortem examination at the University of Queensland. Four of the 787 animals (0.5%) were found to have corneal fibropapillomas of varying size, with similar gross and microscopical features to those reported in other parts of the world. Two animals with corneal fibropapillomas also had cutaneous fibropapillomas. Clinical assessment indicated that these lesions had detrimental effects on the vision of the turtles and therefore their potential ability to source food, avoid predators and interact with conspecifics. Importantly, these findings represent an emergence of this manifestation of fibropapillomatosis in green sea turtle populations in the southern Pacific Ocean.

  1. [Cytological changes in patients with diabetes mellitus and corneal ulcer].

    PubMed

    Raica, D; Turlea, M; Ciocmăreanu, M; Haidar, A; Demian, C; Jinga, F

    1999-01-01

    There were studied 11 diabetic patients, insulin dependents, from 4 were with juvenile diabetes mellitus. These were hospitalized in the Dept. Ophthalm. of the City Hospital of Arad, during 1996-1998, admitted with the diagnosis of corneal ulcer. There were made samples of the gathered secretion from the level of conjunctiva and of the grataj material, gathered at the level of the edges of the corneal ulcer. All samples were stained with the BPT-Drăgan method. There are described cytologic alterations, insisting on details that indicate the severity of the corneal disease. There are taken into consideration cytologic aspects in relationship with the clinical outcome of the disease, pointing out the cellular alterations which announce a nonfavourable prognosis. Cytologic results can improve the diagnosis and they are involved in therapeutic schedule. PMID:10641114

  2. [The corneal wound healing and the extracellular matrix].

    PubMed

    Varkoly, Gréta; Bencze, János; Hortobágyi, Tibor; Módis, László

    2016-06-19

    The cornea is the first refractive element of the eye. The transparency of the cornea results from the regularly arranged collagen fibrils, forming lamellar structure and the leucin rich proteoglycans, which make interactions between the fibrils. The adult cornea consists mainly of fibril-forming collagens. The cornea has less amount of fibril associated and non-fibrillar collagens. The main proteoglycans of the cornea are keratan-sulfate proteoglycans and it also contains dermatan-sulfate proteoglycans. Disorders of the proteoglycan synthesis lead to the disruption of the unique pattern and result in thicker collagen fibrils. The abnormal structure of the extracellular matrix can generate corneal disorders and the loss of corneal transparency. Furthermore, proteoglycans and collagens have an important role in wound healing. In injury the keratocytes produce higher amounts of collagens and proteoglycans mediated by growth factors. Depending on the ratio of the cells and growth factors the extracellular matrix returns to normal or corneal scar tissue develops. PMID:27287839

  3. Bietti's tapetoretinal degeneration with marginal corneal dystrophy crystalline retinopathy.

    PubMed Central

    Welch, R B

    1977-01-01

    In 1937 Bietti reported a tapetoretinal degeneration with associated corneal deposits at the limbus. The hallmark of the disease was the crystalline characteristics of the retinal spots as well as those at the corneal limbus. Bagolini and Ioli-Spade in 1968 presented a 30 year follow-up on Bietti's cases and presented six additional cases. The present report delas with this entity in Orientals, a Chinese woman and a Japanese man. Corneal and conjunctival biopsy from the female patient revelaed a lipid deposition in both fibroblasts and epithelium. The term "crystalline retinopathy" has been added to the description of this entity since it defines the most characteristic feature of the syndrome. Images FIGURE 7 A FIGURE 7 B FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 2 A FIGURE 2 B FIGURE 2 C FIGURE 3 FIGURE 4 A FIGURE 4 B FIGURE 5 FIGURE 6 A FIGURE 6 B FIGURE 6 C FIGURE 8 PMID:306693

  4. Results of lamellar crescentic resection for pellucid marginal corneal degeneration.

    PubMed

    Cameron, J A

    1992-03-15

    Five eyes in four patients with pellucid marginal corneal degeneration were treated by lamellar crescentic resection of the thinned area inferiorly. Normal-thickness stroma was then reapposed to normal-thickness stroma with multiple interrupted 10-0 polypropylene sutures. If excessive central corneal steepening along a vertical meridian was present three months after surgery, selected sutures were cut and removed depending on the slit-lamp appearance, keratometry reading, and photokeratograph pattern. Improvement of visual acuity to 20/40 or better was obtained in four of the five eyes with a follow-up of 27 to 40 months (mean, 31.8 months). Early loosening of sutures resulted in a recurrence of corneal thinning and astigmatism in one eye. Pannus developed inferiorly in all five eyes.

  5. Inhibition of corneal epithelial cell migration by cadmium and mercury

    SciTech Connect

    Ubels, J.L.; Osgood, T.B. Medical Coll. of Wisconsin, Milwaukee )

    1991-02-01

    In a previous comparative study of corneal healing in fish, the authors observed that corneal epithelial healing occurs very rapidly in vivo in the marine teleost Myoxocephalus octodecimspinosus (longhorn sculpin) with a 6-mm diameter wound on the mammalian cornea. This rapid healing which permits prompt restoration of the epithelial barrier is apparently an adaptation to the large ionic and osmotic gradients between the environment and the intraocular fluids of the fish. These observations suggested that epithelial healing in the sculpin cornea might be useful model in aquatic biomedical toxicology if an in vitro method for measurement of healing rates could be developed. In this report the authors demonstrate that sculpin eyes maintained in short-term organ culture have a rapid corneal epithelial healing response and that this model can be used to demonstrate the toxic effects of heavy metals on epithelial cell migration.

  6. Hydration dependent biomechanical properties of the corneal stroma.

    PubMed

    Hatami-Marbini, Hamed; Etebu, Ebitimi

    2013-11-01

    The cornea is responsible for about seventy percent of refractive power of the eye and transmits more than ninety percent of the incident light. The refractive power and transparency of the cornea are largely contingent upon active maintenance of its precise curvature and highly regular microstructure. The biomechanical properties of the cornea are mainly derived from the stromal layer. Over past decades, many computational models have been proposed to predict the corneal behavior in normal and/or diseased state. The predictions of these numerical methods strongly depend on accurate description of corneal mechanical properties. The present study used unconfined compression technique to characterize the dependence of corneal material parameters on thickness variations due to hydration/dehydration. A series of unconfined compression tests was performed on porcine corneal buttons and stress relaxation response of the samples was obtained. A transversely isotropic biphasic model was used to analyze experimental measurements at each ramp-and-hold step. The in-plane Young's modulus, out-of-plane (transverse) Young's modulus, and permeability coefficient of the samples were determined as a function of average thickness. The average thickness variation due to swelling (or dehydration) was between 0.69 mm and 1.27 mm. It was found that corneal material parameters depend strongly on the tissue thickness (hydration). In particular, the in-plane elastic modulus increased with decreasing the thickness (p < 0.05) and the permeability coefficient decreased with decreasing the thickness (p < 0.05). Furthermore, it was observed that although the out-of-plane modulus was almost constant as the average thickness varied between 1.07 mm and 1.27 mm, it increased with tissue thickness outside this range (p < 0.05). The findings of this study provide important information on biomechanical properties of corneal stroma and are useful in computational simulations of the cornea.

  7. Thiol redox and immune regulation in corneal transplantation.

    PubMed

    Yamada, Jun

    2005-11-01

    Penetrating keratoplasty (PKP) is the most common type of clinical grafting performed in humans. Although PKP has emerged as the most successful form of transplantation, PKP in "high-risk" eyes shows high incidence of allograft rejection. The incidence of epithelial rejection after limbal transplantation (LT) is extremely higher and swifter than PKP rejection, and even intensive systemic immunosuppressive therapy is often of no avail. Because failure of corneal grafts is an important cause of blindness, developing new strategies for suppressing graft rejection is a worthy goal for research. Corneal allograft rejection is mainly mediated by the TH1-type immune response, which leads to a delayed-type hypersensitivity reaction. Because the TH2-type immune response regulates the TH1-type immune response, we have successfully elicited allograft survival after both PKP and LT by inducing systemic TH2-type immune responses. Because intracellular thiol redox status of antigen-presenting cells (APC) reportedly regulates TH1/TH2 balance via distinctive cytokine production by APC, we also investigated the effect of modulating macrophage intracellular thiol redox status on corneal allograft survival. These strategies are quite effective in major histocompatibility complex (MHC) matching in mice, although it is believed that MHC matching has no effect on corneal allograft survival according to many rodent studies. Recently, many laboratories are reconsidering HLA matching for allograft survival in human corneal transplantation. It may be possible that MHC matching improves corneal allograft survival in the context of TH1 suppression. We propose that the suppression of the TH1-type immune response and MHC matching together may promote allograft survival in humans.

  8. Measurement of corneal tangent modulus using ultrasound indentation.

    PubMed

    Wang, Li-Ke; Huang, Yan-Ping; Tian, Lei; Kee, Chea-Su; Zheng, Yong-Ping

    2016-09-01

    Biomechanical properties are potential information for the diagnosis of corneal pathologies. An ultrasound indentation probe consisting of a load cell and a miniature ultrasound transducer as indenter was developed to detect the force-indentation relationship of the cornea. The key idea was to utilize the ultrasound transducer to compress the cornea and to ultrasonically measure the corneal deformation with the eyeball overall displacement compensated. Twelve corneal silicone phantoms were fabricated with different stiffness for the validation of measurement with reference to an extension test. In addition, fifteen fresh porcine eyes were measured by the developed system in vitro. The tangent moduli of the corneal phantoms calculated using the ultrasound indentation data agreed well with the results from the tensile test of the corresponding phantom strips (R(2)=0.96). The mean tangent moduli of the porcine corneas measured by the proposed method were 0.089±0.026MPa at intraocular pressure (IOP) of 15mmHg and 0.220±0.053MPa at IOP of 30mmHg, respectively. The coefficient of variation (CV) and intraclass correlation coefficient (ICC) of tangent modulus were 14.4% and 0.765 at 15mmHg, and 8.6% and 0.870 at 30mmHg, respectively. The preliminary study showed that ultrasound indentation could be applied to the measurement of corneal tangent modulus with good repeatability and improved measurement accuracy compared to conventional surface displacement-based measurement method. The ultrasound indentation can be a potential tool for the corneal biomechanical properties measurement in vivo.

  9. The theory and art of corneal cross-linking.

    PubMed

    McQuaid, Rebecca; Cummings, Arthur B; Mrochen, Michael

    2013-08-01

    Before the discovery of corneal cross-linking (CXL), patients with keratoconus would have had to undergo corneal transplantation, or wear rigid gas permeable lenses (RGPs) that would temporarily flatten the cone, thereby improving the vision. The RGP contact lens (CL) would not however alter the corneal stability and if the keratoconus was progressive, the continued steepening of the cone would occur under the RGP CL. To date, the Siena Eye has been the largest study to investigate long term effects of standard CXL. Three hundred and sixty-three eyes were treated and monitored over 4 years, producing reliable long-term results proving long-term stability of the cornea by halting the progression of keratoconus, and proving the safety of the procedure. Traditionally, CXL requires epithelial removal prior to corneal soakage of a dextran-based 0.1% riboflavin solution, followed by exposure of ultraviolet-A (UV-A) light for 30 min with an intensity of 3 mW/cm2. A series of in vitro investigations on human and porcine corneas examined the best treatment parameters for standard CXL, such as riboflavin concentration, intensity, wavelength of UV-A light, and duration of treatment. Photochemically, CXL is achieved by the generation of chemical bonds within the corneal stroma through localized photopolymerization, strengthening the cornea whilst minimizing exposure to the surrounding structures of the eye. In vitro studies have shown that CXL has an effect on the biomechanical properties of the cornea, with an increased corneal rigidity of approximately 70%. This is a result of the creation of new chemical bonds within the stroma. PMID:23925326

  10. Central Corneal Thickness in Patients with Atopic Keratoconjunctivitis

    PubMed Central

    Ondas, Osman; Keles, Sadullah

    2014-01-01

    Background The aim of this study was to evaluate central corneal thickness in patients with atopic keratoconjunctivitis. Material/Methods The study was conducted in the Atatürk University School of Medicine between April 2011 and June 2013. The study group included 60 eyes of 30 patients with atopic keratoconjunctivitis. Sixty eyes of 30 healthy individuals without any ophthalmic or systemic pathology were used as a control group. The central corneal thickness was measured with ultrasonic pachymetry. Results In each group, all subjects included in the study had a best corrected visual acuity (BCVA) of 20/25 or better. In the study group past medical histories revealed eczema in 19 patients, asthma in 16, and atopic dermatitis in 15. During clinical examination cicatricial conjunctivitis was noted in 5 patients, giant papillae in 4, symblepharon in 2, and entropion in 2. The mean central corneal thickness was 523.45±18.03 μm in the study group (mean age: 37.05±5.7 years) and 540.30±38.91 μm in the control group (mean age: 36.55±7.1 years), and the difference was statistically significant (p<0.001). Conclusions Evaluation of corneal thickness is important in situations such as corneal refractive surgery and contact lens use, and is an essential parameter in a wide range of ocular disorders, including glaucoma and keratoconus. Therefore, ophthalmologists should be aware of the low central corneal thickness in patients with atopic keratoconjunctivitis. PMID:25240805

  11. The theory and art of corneal cross-linking.

    PubMed

    McQuaid, Rebecca; Cummings, Arthur B; Mrochen, Michael

    2013-08-01

    Before the discovery of corneal cross-linking (CXL), patients with keratoconus would have had to undergo corneal transplantation, or wear rigid gas permeable lenses (RGPs) that would temporarily flatten the cone, thereby improving the vision. The RGP contact lens (CL) would not however alter the corneal stability and if the keratoconus was progressive, the continued steepening of the cone would occur under the RGP CL. To date, the Siena Eye has been the largest study to investigate long term effects of standard CXL. Three hundred and sixty-three eyes were treated and monitored over 4 years, producing reliable long-term results proving long-term stability of the cornea by halting the progression of keratoconus, and proving the safety of the procedure. Traditionally, CXL requires epithelial removal prior to corneal soakage of a dextran-based 0.1% riboflavin solution, followed by exposure of ultraviolet-A (UV-A) light for 30 min with an intensity of 3 mW/cm2. A series of in vitro investigations on human and porcine corneas examined the best treatment parameters for standard CXL, such as riboflavin concentration, intensity, wavelength of UV-A light, and duration of treatment. Photochemically, CXL is achieved by the generation of chemical bonds within the corneal stroma through localized photopolymerization, strengthening the cornea whilst minimizing exposure to the surrounding structures of the eye. In vitro studies have shown that CXL has an effect on the biomechanical properties of the cornea, with an increased corneal rigidity of approximately 70%. This is a result of the creation of new chemical bonds within the stroma.

  12. Noncontact depth-resolved micro-scale corneal elastography

    NASA Astrophysics Data System (ADS)

    Wang, Shang; Larin, Kirill V.

    2015-03-01

    Noninvasive high-resolution depth-resolved measurement of corneal biomechanics is of great clinical significance for improving the diagnosis and optimizing the treatment of various degenerated ocular diseases. Here, we report a micro-scale optical coherence elastography (OCE) method that enables noncontact assessment of the depthwise elasticity distribution in the cornea. The OCE system combines a focused air-puff device with phase-sensitive optical coherence tomography (OCT). Low-pressure short-duration air stream is used to load the cornea with the localized displacement at micron level. The phase-resolved OCT detection with nano-scale sensitivity probes the induced corneal deformation at various locations within a scanning line, providing the ultra-fast imaging of the corneal lamb wave propagation. With spectral analysis, the amplitude spectra and the phase spectra are available for the estimation of the frequency range of the lamb wave and the quantification of the wave propagation, respectively. Curved propagation paths following the top and bottom corneal boundaries are selected inside the cornea for measuring the phase velocity of the lamb wave at the major frequency components over the whole depths. Our pilot experiments on ex vivo rabbit eyes indicate the distinct stiffness of different layers in the cornea, including the epithelium, the anterior stroma, the posterior stroma, and the innermost region, which demonstrates the feasibility of this micro-scale OCE method for noncontact depth-resolved corneal elastography. Also, the quantification of the lamb wave dispersion in the cornea could lead to the measurement of the elastic modulus, suggesting the potential of this method for quantitative monitoring of the corneal biomechanics.

  13. The theory and art of corneal cross-linking

    PubMed Central

    McQuaid, Rebecca; Cummings, Arthur B; Mrochen, Michael

    2013-01-01

    Before the discovery of corneal cross-linking (CXL), patients with keratoconus would have had to undergo corneal transplantation, or wear rigid gas permeable lenses (RGPs) that would temporarily flatten the cone, thereby improving the vision. The RGP contact lens (CL) would not however alter the corneal stability and if the keratoconus was progressive, the continued steepening of the cone would occur under the RGP CL. To date, the Siena Eye has been the largest study to investigate long term effects of standard CXL. Three hundred and sixty-three eyes were treated and monitored over 4 years, producing reliable long-term results proving long-term stability of the cornea by halting the progression of keratoconus, and proving the safety of the procedure. Traditionally, CXL requires epithelial removal prior to corneal soakage of a dextran-based 0.1% riboflavin solution, followed by exposure of ultraviolet-A (UV-A) light for 30 min with an intensity of 3 mW/cm2. A series of in vitro investigations on human and porcine corneas examined the best treatment parameters for standard CXL, such as riboflavin concentration, intensity, wavelength of UV-A light, and duration of treatment. Photochemically, CXL is achieved by the generation of chemical bonds within the corneal stroma through localized photopolymerization, strengthening the cornea whilst minimizing exposure to the surrounding structures of the eye. In vitro studies have shown that CXL has an effect on the biomechanical properties of the cornea, with an increased corneal rigidity of approximately 70%. This is a result of the creation of new chemical bonds within the stroma. PMID:23925326

  14. Corneal Pachymetry Mapping with High-speed Optical Coherence Tomography

    PubMed Central

    Li, Yan; Shekhar, Raj; Huang, David

    2006-01-01

    Objective To map corneal thickness before and after LASIK with optical coherence tomography (OCT). Design Cross-sectional observational study. Participants Forty-two eyes of 21 normal subjects undergoing LASIK. Methods A high-speed (2000 axial scans/second) 1.3-μm-wavelength corneal and anterior segment OCT prototype was used for corneal scanning. The scan pattern consisted of 10-mm radial lines on 8 meridians centered on the vertex reflection. The entire scan pattern of 1024 a-scans was acquired in 0.5 seconds. We developed automated computer processing for 3-dimensional corneal reconstruction and measurement. Corneal thickness was measured normal to the anterior surface and presented as color pachymetry maps and zonal statistics. The maps were divided into a central zone (<2 mm) and 3 annular areas (pericentral, 2–5 mm; transitional, 5–7 mm; peripheral, 7–10 mm), which were further divided into quadrantal zones. The average, minimum, and maximum corneal thicknesses were computed for zones within the 7-mm diameter. Optical coherence tomography and ultrasound pachymetry were measured 3 times at the preoperative and 3-month postoperative visits. Reproducibility was assessed by the pooled standard deviations (SDs) of the repeated measurements. Main Outcome Measures Optical coherence tomography pachymetric map and zonal statistic, and ultrasound pachymetry. Results Before LASIK, central corneal thicknesses (CCTs) were 546.9±29.4 μm (mean ± SD) for OCT and 553.3±33.0 μm for ultrasound. After LASIK, CCTs were 513.7±44.5 μm for OCT and 498±46.6 μm for ultrasound. Optical coherence tomography and ultrasound CCT were highly correlated (Pearson correlation r = 0.97 before LASIK and 0.98 afterwards). Optical coherence tomography CCT was slightly less than ultrasound CCT before surgery (mean difference, −6.4 μm; 95% limits of agreement, −23.2 to 10.4 μm) but slightly greater after LASIK (15.7 μm; −1.6 to 33 μm). These differences were statistically

  15. Reduction of corneal sensitivity after retinal detachment surgery.

    PubMed Central

    Gibson, R A

    1981-01-01

    Corneal sensitivity measurements were performed on both eyes of 57 patients after they were subjected to unilateral retinal detachment surgery, the unoperated eyes acting as controls. A marked decrease in corneal sensitivity was found in eyes that were treated with encircling bands, but no significant change of sensitivity could be detected in eyes in which localised radial or circumferential silicone sponge explants alone had been employed. It would appear that encirclement procedures lower the sensitivity of the cornea, and this may continue as a long-term effect. PMID:7295628

  16. Noninvasive spectroscopic diagnosis of superficial ocular lesions and corneal infections

    SciTech Connect

    Mourant, J.R.; Bigio, I.J.; Johnson, T.; Shimada, T.; Gritz, D.C.; Storey-Held, K.

    1994-02-01

    The potential of a rapid noninvasive diagnostic system to detect tissue abnormalities on the surface of the eye has been investigated. The optical scatter signal from lesions and normal areas on the conjunctival sclera of the human eye were measured in vivo. It is possible to distinguish nonpigmented pingueculas from other lesions. The ability of the system to detect malignancies could not be tested because none of the measured and biopsied lesions were malignant. Optical scatter and fluorescence spectra of bacterial and fungal suspensions, and corneal irritations were also collected. Both scattering and fluorescence show potential for diagnosing corneal infections.

  17. Non-Invasive Evaluation of Corneal Abnormalities Using Static and Dynamic Light Scattering

    NASA Technical Reports Server (NTRS)

    Ansari, Rafat R.; Misra, Anup K.; Leung, Alfred B.; King, James F.; Datiles, Manuel B., III

    2002-01-01

    A preliminary study of corneal abnormalities in intact bovine eyes is presented. Twenty-one eyes were treated with chemicals, cotton swabs, and radial and photo-refractive surgeries. Dynamic and static light scattering was performed as a function of the penetration depth into the corneal tissue. Topographical maps of corneal refractive power from untreated and treated corneas were also obtained using videokeratoscopy and results compared. The ultimate aim is to develop the technique of dynamic light scattering (DLS) for clinical applications in early evaluation of corneal complications after laser-assisted in situ keratomileusis (LASIK) surgeries and other corneal abnormalities.

  18. Corneal topography matching by iterative registration.

    PubMed

    Wang, Junjie; Elsheikh, Ahmed; Davey, Pinakin G; Wang, Weizhuo; Bao, Fangjun; Mottershead, John E

    2014-11-01

    Videokeratography is used for the measurement of corneal topography in overlapping portions (or maps) which must later be joined together to form the overall topography of the cornea. The separate portions are measured from different viewpoints and therefore must be brought together by registration of measurement points in the regions of overlap. The central map is generally the most accurate, but all maps are measured with uncertainty that increases towards the periphery. It becomes the reference (or static) map, and the peripheral (or dynamic) maps must then be transformed by rotation and translation so that the overlapping portions are matched. The process known as registration, of determining the necessary transformation, is a well-understood procedure in image analysis and has been applied in several areas of science and engineering. In this article, direct search optimisation using the Nelder-Mead algorithm and several variants of the iterative closest/corresponding point routine are explained and applied to simulated and real clinical data. The measurement points on the static and dynamic maps are generally different so that it becomes necessary to interpolate, which is done using a truncated series of Zernike polynomials. The point-to-plane iterative closest/corresponding point variant has the advantage of releasing certain optimisation constraints that lead to persistent registration and alignment errors when other approaches are used. The point-to-plane iterative closest/corresponding point routine is found to be robust to measurement noise, insensitive to starting values of the transformation parameters and produces high-quality results when using real clinical data.

  19. Tear film MMP accumulation and corneal disease

    PubMed Central

    Smith, V; Rishmawi, H; Hussein, H; Easty, D

    2001-01-01

    BACKGROUND/AIMS—Matrix metalloproteinases (MMPs) accumulate in the tears of patients with active peripheral ulcerative keratitis (PUK) but it is unknown whether these enzymes have a central role in disease progression. The aims of the present investigation were to determine the source of these enzymes and to ascertain whether their accumulation in tears is a phenomenon specific to PUK or a general feature of other anterior segment diseases.
METHODS—The experimental samples were obtained from the culture media of conjunctival and corneal epithelial cells, from fractionated blood plasma and leucocytes of healthy subjects and patients with rheumatoid arthritis, and from the tears of healthy subjects and patients with a variety of anterior segment diseases. The MMPs of all samples were visualised by zymography and tear samples were assayed using nitrophenol acetate and an MMP-9 susceptible quenched fluorescent peptide as substrate.
RESULTS—The major MMPs that accumulate in the tears of patients with rheumatoid arthritis with active ocular disease are MMP-9 and a species of Mr 116 000. By comparing the zymographic activity profiles of the gelatinases present in the samples obtained, it was deduced that the main source of these MMPs was granulocytes. Their accumulation in tears was not unique to patients with PUK; detectable amounts of the enzymes also occurred in the tears of patients with keratoconus with associated atopic disease, patients undergoing treatment for herpetic eye disease, and patients with systemic and non-systemic dry eye disease.
CONCLUSION—The MMPs that accumulate in tears are mainly derived from granulocytes. This may be effected by autoimmune diseases that involve ocular tissue or by ocular diseases that induce an inflammatory response.

 PMID:11159476

  20. Electrophilic PPARγ ligands inhibit corneal fibroblast to myofibroblast differentiation in vitro: a potentially novel therapy for corneal scarring.

    PubMed

    Kuriyan, A E; Lehmann, G M; Kulkarni, A A; Woeller, C F; Feldon, S E; Hindman, H B; Sime, P J; Huxlin, K R; Phipps, R P

    2012-01-01

    A critical component of corneal scarring is the TGFβ-induced differentiation of corneal keratocytes into myofibroblasts. Inhibitors of this differentiation are potentially therapeutic for corneal scarring. In this study, we tested the relative effectiveness and mechanisms of action of two electrophilic peroxisome proliferator-activated receptor gamma (PPARγ) ligands: cyano-3,12-dioxolean-1,9-dien-28-oic acid-methyl ester (CDDO-Me) and 15-deoxy-Δ(-12,14)-prostaglandin J(2) (15d-PGJ(2)) for inhibiting TGFβ-induced myofibroblast differentiation in vitro. TGFβ was used to induce myofibroblast differentiation in cultured, primary human corneal fibroblasts. CDDO-Me and 15d-PGJ(2) were added to cultures to test their ability to inhibit this process. Myofibroblast differentiation was assessed by measuring the expression of myofibroblast-specific proteins (αSMA, collagen I, and fibronectin) and mRNA (αSMA and collagen III). The role of PPARγ in the inhibition of myofibroblast differentiation by these agents was tested in genetically and pharmacologically manipulated cells. Finally, we assayed the importance of electrophilicity in the actions of these agents on TGFβ-induced αSMA expression via Western blotting and immunofluorescence. Both electrophilic PPARγ ligands (CDDO-Me and 15d-PGJ(2)) potently inhibited TGFβ-induced myofibroblast differentiation, but PPARγ was only partially required for inhibition of myofibroblast differentiation by either agent. Electrophilic PPARγ ligands were able to inhibit myofibroblast differentiation more potently than non-electrophilic PPARγ ligands, suggesting an important role of electrophilicity in this process. CDDO-Me and 15d-PGJ(2) are strong inhibitors of TGFβ-induced corneal fibroblast to myofibroblast differentiation in vitro, suggesting this class of agents as potential novel therapies for corneal scarring warranting further study in pre-clinical animal models.

  1. Corneal limbal microenvironment can induce transdifferentiation of hair follicle stem cells into corneal epithelial-like cells.

    PubMed

    Blazejewska, Ewa Anna; Schlötzer-Schrehardt, Ursula; Zenkel, Matthias; Bachmann, Björn; Chankiewitz, Erik; Jacobi, Christina; Kruse, Friedrich E

    2009-03-01

    The aim of this study was to investigate the transdifferentiation potential of murine vibrissa hair follicle (HF) stem cells into corneal epithelial-like cells through modulation by corneal- or limbus-specific microenvironmental factors. Adult epithelial stem cells were isolated from the HF bulge region by mechanical dissection or fluorescence-activated cell sorting using antibodies to alpha6 integrin, enriched by clonal expansion, and subcultivated on various extracellular matrices (type IV collagen, laminin-1, laminin-5, fibronectin) and in different conditioned media derived from central and peripheral corneal fibroblasts, limbal stromal fibroblasts, and 3T3 fibroblasts. Cellular phenotype and differentiation were evaluated by light and electron microscopy, real-time reverse transcription-polymerase chain reaction, immunocytochemistry, and Western blotting, using antibodies against putative stem cell markers (K15, alpha6 integrin) and differentiation markers characteristic for corneal epithelium (K12, Pax6) or epidermis (K10). Using laminin-5, a major component of the corneo-limbal basement membrane zone, and conditioned medium from limbal stromal fibroblasts, clonally enriched HF stem and progenitor cells adhered rapidly and formed regularly arranged stratified cell sheets. Conditioned medium derived from limbal fibroblasts markedly upregulated expression of cornea-specific K12 and Pax6 on the mRNA and protein level, whereas expression of the epidermal keratinocyte marker K10 was strongly downregulated. These findings suggest that adult HF epithelial stem cells are capable of differentiating into corneal epithelial-like cells in vitro when exposed to a limbus-specific microenvironment. Therefore, the HF may be an easily accessible alternative therapeutic source of autologous adult stem cells for replacement of the corneal epithelium and restoration of visual function in patients with ocular surface disorders. PMID:19074417

  2. High-Risk Corneal Graft Rejection in the Setting of Previous Corneal Herpes Simplex Virus (HSV)-1 Infection

    PubMed Central

    Kuffova, Lucia; Knickelbein, Jared E.; Yu, Tian; Medina, Carlos; Amescua, Guillermo; Rowe, Alexander M.; Hendricks, Robert L.; Forrester, John V.

    2016-01-01

    Purpose The “high-risk phenotype” of corneal graft recipients is considered to be related to preexisting vascularization such as that associated with herpes simplex virus-1 (HSV-1) keratitis (HSK). The purpose of this study was to investigate the immunologic mechanisms underlying accelerated corneal graft rejection using a mouse model of HSK. Methods Herpes simplex virus type 1 keratitis was induced in BALB/c mice. Syngeneic and allogeneic (C57BL/6 mice) corneal grafts were performed in mice with HSK at different times after infection. Some grafts were performed on HSV-infected CD4 T cell–deficient BALB/c mice. Clinical, histologic, immunologic, and virus detection studies were performed on samples of cornea, draining lymph node (LN), and trigeminal ganglion (TG) cells. Results Corneal grafts in mice with HSK rejected with higher frequency and more rapid tempo compared with grafts in uninfected mice. In corneas with HSK and vascularization at the time of grafting, both syngeneic and allogeneic corneal grafts failed with similar frequency and tempo. However, in the absence of preexisting inflammation and vascularization, syngeneic grafts were accepted when the grafts were performed at a late time point after HSV infection (42 days), whereas allografts were rejected at this time. In contrast, syngeneic grafts in nonvascularized HSV-infected recipients failed if they were performed within 10 days of HSV infection, an effect that was dependent on CD4 T cells, as demonstrated using CD4 deficient mice. Importantly, a variably sustained but strongly positive anti-HSV T-cell response was detected in allografted HSK recipients with a similar but lesser response in syngeneic hosts. Conclusions A previous HSV-1 corneal infection predisposes donor grafts to a high risk of failure by both innate and adaptive immune mechanisms in which an anti-HSV CD4 T-cell response plays a prominent role. PMID:27050878

  3. Changes in corneal collagen induced by holmium:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Timberlake, George T.; Reinke, Martin H.; Miller, Alvin

    1996-05-01

    Holmium:YAG laser thermokeratoplasty corrects hyperopia (farsightedness) by producing small areas of corneal collagen shrinkage that cause the central cornea to bulge outward, increasing optical power. Collagen shrinkage is probably caused by laser-heated corneal water, but details of the shrinkage mechanism are not known. We investigated the shrinkage mechanism by measuring changes in corneal ultrastructure, surface shrinkage, water content, and strength following Ho:YAG laser exposures. Morphological changes in collagen were documented by measurements from electron micrographs. Corneal adhesive strength was determined by measuring tearing force in a plane parallel to the corneal surface. Laser-induced water loss was measured by weighing corneal samples before and after exposure. Corneal surface shrinkage was assessed by photographing the movement of particles on the cornea. Lasered collagen fibrils increased in diameter, lost their orderly arrangement, and appeared `frayed.' The corneal surface contracted toward lasered areas with a maximal shift of approximately 190 micrometers , more than could be explained by a model based on collagen fibril changes. Water loss plays a minor role in corneal shrinkage since corneal samples lost about only about 1.4% of their weight after massive laser exposure. Despite marked changes in collagen structure, corneal adhesive force was unchanged.

  4. Morselized Amniotic Membrane Tissue for Refractory Corneal Epithelial Defects in Cicatricial Ocular Surface Diseases

    PubMed Central

    Cheng, Anny M. S.; Chua, Lorraine; Casas, Victoria; Tseng, Scheffer C. G.

    2016-01-01

    Purpose To evaluate the clinical efficacy of morselized amniotic membrane and umbilical cord tissue (MAU) in treating refractory corneal epithelial defect in ocular cicatricial diseases. Methods Retrospective review of four patients with ocular cicatricial diseases treated with topical MAU for corneal epithelial defects refractory to conventional treatments including topical lubricants, autologous serum, bandage contact lens, and tarsorraphy. Their symptoms, corneal staining, conjunctival inflammation, and visual acuity were compared before and after treatment. Results After topical application of MAU twice daily, two patients demonstrated rapid corneal epithelialization with prompt visual acuity improvement at the first day. All patients showed corneal epithelialization in 7.3 ± 2.6 days accompanied by a significant relief of symptoms, reduction of ocular surface inflammation, and improvement of visual acuity. Conclusion This pilot study suggests topical MAU can be developed into a novel treatment for treating refractory corneal epithelial defects. Translational Relevance Topical MAU can be an effective novel treatment for refractory corneal epithelial defects. PMID:27226933

  5. Corneal Viscoelastic Properties from Finite-Element Analysis of In Vivo Air-Puff Deformation

    PubMed Central

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

    2014-01-01

    Biomechanical properties are an excellent health marker of biological tissues, however they are challenging to be measured in-vivo. Non-invasive approaches to assess tissue biomechanics have been suggested, but there is a clear need for more accurate techniques for diagnosis, surgical guidance and treatment evaluation. Recently air-puff systems have been developed to study the dynamic tissue response, nevertheless the experimental geometrical observations lack from an analysis that addresses specifically the inherent dynamic properties. In this study a viscoelastic finite element model was built that predicts the experimental corneal deformation response to an air-puff for different conditions. A sensitivity analysis reveals significant contributions to corneal deformation of intraocular pressure and corneal thickness, besides corneal biomechanical properties. The results show the capability of dynamic imaging to reveal inherent biomechanical properties in vivo. Estimates of corneal biomechanical parameters will contribute to the basic understanding of corneal structure, shape and integrity and increase the predictability of corneal surgery. PMID:25121496

  6. Cystitis - acute

    MedlinePlus

    Uncomplicated urinary tract infection; UTI - acute; Acute bladder infection; Acute bacterial cystitis ... International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2010 ...

  7. Neuropathologic Characterization of Pontocerebellar Hypoplasia Type 6 Associated With Cardiomyopathy and Hydrops Fetalis and Severe Multisystem Respiratory Chain Deficiency due to Novel RARS2 Mutations.

    PubMed

    Lax, Nichola Z; Alston, Charlotte L; Schon, Katherine; Park, Soo-Mi; Krishnakumar, Deepa; He, Langping; Falkous, Gavin; Ogilvy-Stuart, Amanda; Lees, Christoph; King, Rosalind H; Hargreaves, Iain P; Brown, Garry K; McFarland, Robert; Dean, Andrew F; Taylor, Robert W

    2015-07-01

    Autosomal recessive mutations in the RARS2 gene encoding the mitochondrial arginyl-transfer RNA synthetase cause infantile-onset myoencephalopathy pontocerebellar hypoplasia type 6 (PCH6). We describe 2 sisters with novel compound heterozygous RARS2 mutations who presented perinatally with neurologic features typical of PCH6 but with additional features including cardiomyopathy, hydrops, and pulmonary hypoplasia and who died at 1 day and 14 days of age. Magnetic resonance imaging findings included marked cerebellar hypoplasia, gyral immaturity, punctate lesions in cerebral white matter, and unfused deep cerebral grey matter. Enzyme histochemistry of postmortem tissues revealed a near-global cytochrome c oxidase-deficiency; assessment of respiratory chain enzyme activities confirmed severe deficiencies involving complexes I, III, and IV. Molecular genetic studies revealed 2 RARS2 gene mutations: a c.1A>G, p.? variant predicted to abolish the initiator methionine, and a deep intronic c.613-3927C>T variant causing skipping of exons 6-8 in the mature RARS2 transcript. Neuropathologic investigation included low brain weights, small brainstem and cerebellum, deep cerebral white matter pathology, pontine nucleus neuron loss (in 1 sibling), and peripheral nerve pathology. Mitochondrial respiratory chain immunohistochemistry in brain tissues confirmed an absence of complexes I and IV immunoreactivity with sparing of mitochondrial numbers. These cases expand the clinical spectrum of RARS2 mutations, including antenatal features and widespread mitochondrial respiratory chain deficiencies in postmortem brain tissues.

  8. Neuropathologic Characterization of Pontocerebellar Hypoplasia Type 6 Associated With Cardiomyopathy and Hydrops Fetalis and Severe Multisystem Respiratory Chain Deficiency due to Novel RARS2 Mutations.

    PubMed

    Lax, Nichola Z; Alston, Charlotte L; Schon, Katherine; Park, Soo-Mi; Krishnakumar, Deepa; He, Langping; Falkous, Gavin; Ogilvy-Stuart, Amanda; Lees, Christoph; King, Rosalind H; Hargreaves, Iain P; Brown, Garry K; McFarland, Robert; Dean, Andrew F; Taylor, Robert W

    2015-07-01

    Autosomal recessive mutations in the RARS2 gene encoding the mitochondrial arginyl-transfer RNA synthetase cause infantile-onset myoencephalopathy pontocerebellar hypoplasia type 6 (PCH6). We describe 2 sisters with novel compound heterozygous RARS2 mutations who presented perinatally with neurologic features typical of PCH6 but with additional features including cardiomyopathy, hydrops, and pulmonary hypoplasia and who died at 1 day and 14 days of age. Magnetic resonance imaging findings included marked cerebellar hypoplasia, gyral immaturity, punctate lesions in cerebral white matter, and unfused deep cerebral grey matter. Enzyme histochemistry of postmortem tissues revealed a near-global cytochrome c oxidase-deficiency; assessment of respiratory chain enzyme activities confirmed severe deficiencies involving complexes I, III, and IV. Molecular genetic studies revealed 2 RARS2 gene mutations: a c.1A>G, p.? variant predicted to abolish the initiator methionine, and a deep intronic c.613-3927C>T variant causing skipping of exons 6-8 in the mature RARS2 transcript. Neuropathologic investigation included low brain weights, small brainstem and cerebellum, deep cerebral white matter pathology, pontine nucleus neuron loss (in 1 sibling), and peripheral nerve pathology. Mitochondrial respiratory chain immunohistochemistry in brain tissues confirmed an absence of complexes I and IV immunoreactivity with sparing of mitochondrial numbers. These cases expand the clinical spectrum of RARS2 mutations, including antenatal features and widespread mitochondrial respiratory chain deficiencies in postmortem brain tissues. PMID:26083569

  9. Evaluation of the usefulness of three-dimensional optical coherence tomography in a guinea pig model of endolymphatic hydrops induced by surgical obliteration of the endolymphatic duct

    NASA Astrophysics Data System (ADS)

    Cho, Nam Hyun; Lee, Jang Woo; Cho, Jin-ho; Kim, Jeehyun; Jang, Jeong Hun; Jung, Woonggyu

    2015-03-01

    Optical coherence tomography (OCT) has advanced significantly over the past two decades and is currently used extensively to monitor the internal structures of organs, particularly in ophthalmology and dermatology. We used ethylenediamine tetra-acetic acid (EDTA) to decalcify the bony walls of the cochlea and investigated the inner structures by deep penetration of light into the cochlear tissue using OCT on a guinea pig model of endolymphatic hydrops (EH), induced by surgical obliteration of the endolymphatic duct. The structural and functional changes associated with EH were identified using OCT and auditory brainstem response tests, respectively. We also evaluated structural alterations in the cochlea using three-dimensional reconstruction of the OCT images, which clearly showed physical changes in the cochlear structures. Furthermore, we found significant anatomical variations in the EH model and conducted graphical analysis by strial atrophy for comparison. The physical changes included damage to and flattening of the organ of Corti-evidence of Reissner's membrane distention-and thinning of the lateral wall. These results indicate that observation of EDTA-decalcified cochlea using OCT is significant in examination of gradual changes in the cochlear structures that are otherwise not depicted by hematoxylin and eosin staining.

  10. Non-mulberry Silk Fibroin Biomaterial for Corneal Regeneration

    PubMed Central

    Hazra, Sarbani; Nandi, Sudip; Naskar, Deboki; Guha, Rajdeep; Chowdhury, Sushovan; Pradhan, Nirparaj; Kundu, Subhas C.; Konar, Aditya

    2016-01-01

    Purpose: Successful repair of a damaged corneal surface is a great challenge and may require the use of a scaffold that supports cell growth and differentiation. Amniotic membrane is currently used for this purpose, in spite of its limitations. A thin transparent silk fibroin film from non-mulberry Antheraea mylitta (Am) has been developed which offers to be a promising alternative. The silk scaffolds provide sufficient rigidity for easy handling, the scaffolds support the sprouting, migration, attachment and growth of epithelial cells and keratocytes from rat corneal explants; the cells form a cell sheet, preserve their phenotypes, express cytokeratin3 and vimentin respectively. The films also support growth of limbal stem cell evidenced by expression of ABCG2. The cell growth on the silk film and the amniotic membrane is comparable. The implanted film within the rabbit cornea remains transparent, stable. The clinical examination as well as histology shows absence of any inflammatory response or neovascularization. The corneal surface integrity is maintained; tear formation, intraocular pressure and electroretinography of implanted eyes show no adverse changes. The silk fibroin film from non-mulberry silk worms may be a worthy candidate for use as a corneal scaffold. PMID:26908015

  11. Personalised lamellar keratoplasty and keratopigmentation in Asian corneal leucoma patients

    PubMed Central

    Liu, Xin; Shen, Jun-Hui; Zhou, Qi; Liu, Zhen-Xing; Tang, Shen-Fei; Chen, Ran-Ran; Sui, Gui-Qin; Bi, Yan-Long

    2015-01-01

    Objective: To describe a personalised lamellar keratoplasty (LK) associated with the keratopigmentation (KTP) technique for corneal leucoma among Asian patients. Methods: This report was a non-randomised, retrospective clinical study performed in 32 consecutive eyes of 32 patients to improve cosmetic appearance. Twenty-two patients underwent LK combined with KTP, either by intralamellar or superficial route. Ten patients underwent the single personalised keratopigmentation method. The subjective and objective cosmetic results, ocular irritation, colour fading, neovascularisation formation and incidence of immune rejection were evaluated until three years after surgery. Results: No complications occurred, and the corneal leucoma was successfully stained with India ink in all 32 patients. Most of the patients showed good cosmetic appearance. Pain, conjunctival congestion, corneal edema and foreign body sensation disappeared gradually within two to three weeks after surgery in all patients. Graft swelling, non-healing, or detaching was not observed during follow-up. However, two patients had slight opacity three years after LK. Colour fading was observed in one patient who underwent intralamellar corneal staining 10 months after surgery. Re-staining was performed. Conclusion: KTP combined with personalised LK is an effective personalised technique that presents long-standing colour staining and good cosmetic efficacy. PMID:26309607

  12. Variations in the corneal surface temperature with contact lens wear.

    PubMed

    Ooi, E H; Ng, E Y K; Purslow, C; Acharya, R

    2007-05-01

    This paper presents the two-dimensional simulation of heat propagation in the human eye model during contact lens wear with finite element analysis. Three types of contact lens are studied: Lotrafilcon A, Balafilcon A, and Etafilcon A. The models are solved for both steady and transient solutions. The corneal surface temperature during contact lens wear is found to decrease (average, 0.52 +/- 0.05 degrees C compared with a bare cornea for all lens types). A contact lens with a higher water content has a lower steady state temperature than a contact lens with a lower water content does. Various initial temperatures for the contact lens are found to affect the first 400 s of the temperature variation. When the initial temperature is lower than the corneal temperature, a reduction in temperature is observed during contact lens insertion while the opposite is observed when the initial temperature is higher than the corneal temperature. The increase in evaporation rate when a contact lens is worn increases the cooling effect on the ocular surface. This is suggested to be the cause of lower corneal surface temperature when wearing a contact lens.

  13. Pasteurella multocida corneal ulcer following a baseball injury.

    PubMed

    Robinson, J D; Kosoko, O; Mason, R P; Cowan, C L

    1989-05-01

    Pasteurella multocida is an ubiquitous organism that can be isolated from a variety of animals and birds. It is an infrequent ocular pathogen but can cause infection as a result of injury or animal exposure. This article reports a case of P multocida corneal ulcer following a baseball injury.

  14. An environmental Sporothrix as a cause of corneal ulcer

    PubMed Central

    Morrison, Annie S.; Lockhart, Shawn R.; Bromley, Jennifer G.; Kim, Joung Y.; Burd, Eileen M.

    2013-01-01

    In this case we introduce Sporothrix pallida, a non-pathogenic environmental Sporothrix species as a cause of infectious keratitis in a corneal transplant recipient. Human infections caused by S. schenckii are well-known but human infection with Sporothrix pallida has not been previously reported. PMID:24432225

  15. [In vitro evaluation of corneal damages after instillation of eye drops using rat debrided corneal epithelium: changes of corneal damage due to benzalkonium chloride by addition of thickening agents].

    PubMed

    Nagai, Noriaki; Ito, Yoshimasa; Okamoto, Norio; Shimomura, Yoshikazu

    2012-01-01

    Benzalkonium chloride (BAC) is known to cause corneal epithelial damage. In this study we investigated the effect of a BAC solution containing a thickening agent, which enhanced residence time in the eyes, on corneal wound healing using in vivo rat model debrided corneal epithelium. 0.5% or 1.0% methylcellulose (MC), carboxymethylcellulose (CMC) and hydroxypropyl-methylcellulose (HPMC) were used as the thickening agent. The levels of corneal wound healing of rat eyes injected with saline were alone approximately 45.0% at 12 h and 93.6% at 24 h after corneal epithelial abrasion, and healing was almost complete at 36 h. The healing rate in the rat eye treated just with MC, CMC and HPMC was higher than that in those injected with saline. In contrast to the treatment result using only this thickening agent, the healing rate in the eye treated with BAC was lower than that in those injected with saline: the corneal wounds in the BAC-treated eye showed approximately 20% healing at 12 h after abrasion. The injection of 0.02% BAC solution containing MC, CMC and HPMC more significantly delayed the healing than did the injection of 0.02% BAC alone. The results show that the in vivo evaluation method for corneal damage using rat debrided corneal epithelium reflects a toxic change depending upon residence time. These findings provide valuable safety and efficacy information for use in the design of eye drops.

  16. The corneal fibrosis response to epithelial-stromal injury.

    PubMed

    Torricelli, Andre A M; Santhanam, Abirami; Wu, Jiahui; Singh, Vivek; Wilson, Steven E

    2016-01-01

    The corneal wound healing response, including the development of stromal opacity in some eyes, is a process that often leads to scarring that occurs after injury, surgery or infection to the cornea. Immediately after epithelial and stromal injury, a complex sequence of processes contributes to wound repair and regeneration of normal corneal structure and function. In some corneas, however, often depending on the type and extent of injury, the response may also lead to the development of mature vimentin+ α-smooth muscle actin+ desmin+ myofibroblasts. Myofibroblasts are specialized fibroblastic cells generated in the cornea from keratocyte-derived or bone marrow-derived precursor cells. The disorganized extracellular matrix components secreted by myofibroblasts, in addition to decreased expression of corneal crystallins in these cells, are central biological processes that result in corneal stromal fibrosis associated with opacity or "haze". Several factors are associated with myofibroblast generation and haze development after PRK surgery in rabbits, a reproducible model of scarring, including the amount of tissue ablated, which may relate to the extent of keratocyte apoptosis in the early response to injury, irregularity of stromal surface after surgery, and changes in corneal stromal proteoglycans, but normal regeneration of the epithelial basement membrane (EBM) appears to be a critical factor determining whether a cornea heals with relative transparency or vision-limiting stromal opacity. Structural and functional abnormalities of the regenerated EBM facilitate prolonged entry of epithelium-derived growth factors such as transforming growth factor β (TGF-β) and platelet-derived growth factor (PDGF) into the stroma that both drive development of mature myofibroblasts from precursor cells and lead to persistence of the cells in the anterior stroma. A major discovery that has contributed to our understanding of haze development is that keratocytes and corneal

  17. Lacosamide diminishes dryness-induced hyperexcitability of corneal cold sensitive nerve terminals.

    PubMed

    Kovács, Illés; Dienes, Lóránt; Perényi, Kristóf; Quirce, Susana; Luna, Carolina; Mizerska, Kamila; Acosta, M Carmen; Belmonte, Carlos; Gallar, Juana

    2016-09-15

    Lacosamide is an anti-epileptic drug that is also used for the treatment of painful diabetic neuropathy acting through voltage-gated sodium channels. The aim of this work was to evaluate the effects of acute application of lacosamide on the electrical activity of corneal cold nerve terminals in lacrimo-deficient guinea pigs. Four weeks after unilateral surgical removal of the main lachrimal gland in guinea pigs, corneas were excised and superfused in vitro at 34°C for extracellular electrophysiological recording of nerve terminal impulse activity of cold thermosensitive nerve terminals. The characteristics of the spontaneous and the stimulus-evoked (cooling ramps from 34°C to 15°C) activity before and in presence of lacosamide 100µM and lidocaine 100µM were compared. Cold nerve terminals (n=34) recorded from dry eye corneas showed significantly enhanced spontaneous activity (8.0±1.1 vs. 5.2±0.7imp/s; P<0.05) and cold response (21.2±1.7 vs. 16.8±1.3imp/s; P<0.05) as well as reduced cold threshold (1.5±0.1 vs. 2.8±0.2 Δ°C; P<0.05) to cooling ramps compared to terminals (n=58) from control animals. Both lacosamide and lidocaine decreased spontaneous activity and peak response to cooling ramps significantly (P<0.05). Temperature threshold was increased by the addition of lidocaine (P<0.05) but not lacosamide (P>0.05) to the irrigation fluid. In summary, the application of lacosamide results in a significant decrease of the augmented spontaneous activity and responsiveness to cold of corneal sensory nerves from tear-deficient animals. Based on these promising results we speculate that lacosamide might be used to reduce the hyperexcitability of corneal cold receptors caused by prolonged ocular surface dryness due to hyposecretory or evaporative dry eye disease. PMID:27263827

  18. Corneal cross-linking in 9 horses with ulcerative keratitis

    PubMed Central

    2013-01-01

    Background Corneal ulcers are one of the most common eye problems in the horse and can cause varying degrees of visual impairment. Secondary infection and protease activity causing melting of the corneal stroma are always concerns in patients with corneal ulcers. Corneal collagen cross-linking (CXL), induced by illumination of the corneal stroma with ultraviolet light (UVA) after instillation of riboflavin (vitamin B2) eye drops, introduces crosslinks which stabilize melting corneas, and has been used to successfully treat infectious ulcerative keratitis in human patients. Therefore we decided to study if CXL can be performed in sedated, standing horses with ulcerative keratitis with or without stromal melting. Results Nine horses, aged 1 month to 16 years (median 5 years) were treated with a combination of CXL and medical therapy. Two horses were diagnosed with mycotic, 5 with bacterial and 2 with aseptic ulcerative keratitis. A modified Dresden-protocol for CXL could readily be performed in all 9 horses after sedation. Stromal melting, diagnosed in 4 horses, stopped within 24 h. Eight of nine eyes became fluorescein negative in 13.5 days (median time; range 4–26 days) days after CXL. One horse developed a bacterial conjunctivitis the day after CXL, which was successfully treated with topical antibiotics. One horse with fungal ulcerative keratitis and severe uveitis was enucleated 4 days after treatment due to panophthalmitis. Conclusions CXL can be performed in standing, sedated horses. We did not observe any deleterious effects attributed to riboflavin or UVA irradiation per se during the follow-up, neither in horses with infectious nor aseptic ulcerative keratitis. These data support that CXL can be performed in the standing horse, but further studies are required to compare CXL to conventional medical treatment in equine keratitis and to optimize the CXL protocol in this species. PMID:23803176

  19. Corneal collagen crosslinking in keratoconus and other eye disease

    PubMed Central

    Alhayek, Adel; Lu, Pei-Rong

    2015-01-01

    Keratoconus is a condition characterized by biomechanical instability of the cornea, presenting in a progressive, asymmetric and bilateral way. Corneal collagen crosslinking (CXL) with riboflavin and Ultraviolet-A (UVA) is a new technique of corneal tissue strengthening that combines the use of riboflavin as a photo sensitizer and UVA irradiation. Studies showed that CXL was effective in halting the progression of keratoconus over a period of up to four years. The published studies also revealed a reduction of max K readings by more than 2 D, while the postoperative spherical equivalent (SEQ) was reduced by an average of more than 1 D and refractive cylinder decreased by about 1 D. The major indication for the use of CXL is to inhibit the progression of corneal ecstasies, such as keratoconus and pellucid marginal degeneration. CXL may also be effective in the treatment and prophylaxis of iatrogenic keratectasia, resulting from excessively aggressive photo ablation. This treatment has been used to treat infectious corneal ulcers with apparent favorable results. Most recent studies demonstrate the beneficial impact of CXL for iatrogenic ecstasies, pellucid marginal degeneration, infectious keratitis, bullous keratopathy and ulcerative keratitis. Several long-term and short-term complications of CXL have been studied and documented. The possibility of a secondary infection after the procedure exists because the patient is subject to epithelial debridement and the application of a soft contact lens. Formation of temporary corneal haze, permanent scars, endothelial damage, treatment failure, sterile infiltrates, bullous keratopathy and herpes reactivation are the other reported complications of this procedure. PMID:25938065

  20. Proteoglycans on normal and migrating human corneal endothelium.

    PubMed

    Davies, Y; Lewis, D; Fullwood, N J; Nieduszynski, I A; Marcyniuk, B; Albon, J; Tullo, A

    1999-03-01

    Proteoglycans are of fundamental importance to the normal functioning of the cornea. They consist of a core protein to which one or more glycosaminoglycan chains are attached. Cell surface proteoglycans are known to mediate many aspects of cell behaviour including cell adhesion, control of extracellular matrix deposition, cell proliferation, cell migration, leukocyte adhesion and modulation of growth factor activity. This paper describes the first investigation into the distribution and function of the three main classes of proteoglycans on human corneal endothelium. Immuno-gold labelling techniques were used at the light, scanning and transmission electron microscope level to localise heparan sulphate, chondroitin sulphate and keratan sulphate proteoglycans on human corneal endothelium. Human corneas were freeze-wounded and kept in organ culture for 3 days in order to study the distribution of proteoglycans on migrating corneal endothelium. An Optimas image analysis system was used to quantify the change in proteoglycan labelling during cell migration. Labelling for chondroitin sulphate and heparan sulphate was at very low levels on normal corneal endothelium while keratan sulphate labelling was at high levels. The wound healing experiments showed that migrating cells had increased labelling for heparan sulphate and chondroitin sulphate with greatly decreased labelling for keratan sulphate. Statistical analysis showed these changes were highly significant (P<0.001). Transmission electron microscopy revealed that chondroitin sulphate and keratan sulphate were present throughout Descemet's membrane while heparan sulphate was concentrated at the interface of Descemet's membrane and the migrating corneal endothelial cells. The pattern of occurrence of chondroitin sulphate, heparan sulphate and keratan sulphate on the human endothelium in normal and wounded cornea suggests that these proteoglycans are linked to the process of cell migration.

  1. Experimental study on the mechanical strain of corneal collagen.

    PubMed

    Avetisov, S E; Bubnova, I A; Novikov, I A; Antonov, A A; Siplivyi, V I

    2013-06-21

    Currently, investigations of biomechanical properties of the fibrous tunic are becoming even more topical, especially for diagnosis of corneal ectatic disease, as well as correct interpretation of intraocular pressure (IOP) parameters, particularly in patients with prior surgery on cornea. The study principle is based on the ability of substances to change optical anisotropy depending on mechanical strain applied to them. An experimental set-up was constructed which allows assessment of polarization degree of light which is emitted during luminescence of strained collagen. The study was performed on 18 corneoscleral discs of chinchilla rabbit eyes at 15 and 50mm Hg pressure, among them in 6 cases before and after making radial incisions, and in 6 cases before and after conducting the mechanical cornea abrasions that were asymmetrical by depth until reaching the local zone of iatrogenic keratectasia. Corneal collagen mechanical strain mappings were formed on 3 experimental models (intact cornea, cornea post radial keratotomy and keratectasia) under intra-chamber pressure of 15 and 50mm Hg. Corneal collagen mechanical strain is evenly allocated in the intact cornea. After radial keratotomy the main mechanical loading was concentrated over the middle part of corneal periphery, particularly in the bottom of keratotomic incisions. The increased intra-chamber pressure made the strain rise in those models. Upon cornea abrasion the main straining is distributed within the thinning zone, and the increase of intra-chamber pressure only increases the load over residual stroma. A new principle of corneal biomechanical properties investigation based on assessment of degree of light polarization emitted during luminescence of strained collagen, has been proposed and experimentally tested. PMID:23680349

  2. Intrastromal Delivery of Bevacizumab Using Microneedles to Treat Corneal Neovascularization

    PubMed Central

    Kim, Yoo C.; Grossniklaus, Hans E.; Edelhauser, Henry F.; Prausnitz, Mark R.

    2014-01-01

    Purpose. This study tested the hypothesis that highly targeted intrastromal delivery of bevacizumab using coated microneedles allows dramatic dose sparing compared with subconjunctival and topical delivery for treatment of corneal neovascularization. Methods. Stainless steel microneedles 400 μm in length were coated with bevacizumab. A silk suture was placed in the cornea approximately 1 mm from the limbus to induce corneal neovascularization in the eyes of New Zealand white rabbits that were divided into different groups: untreated, microneedle delivery, topical eye drop, and subconjunctival injection of bevacizumab. All drug treatments were initiated 4 days after suture placement and area of neovascularization was measured daily by digital photography for 18 days. Results. Eyes treated once with 4.4 μg bevacizumab using microneedles reduced neovascularization compared with untreated eyes by 44% (day 18). Eyes treated once with 2500 μg bevacizumab using subconjunctival injection gave similar results to microneedle-treated eyes. Eyes treated once with 4.4 μg subconjunctival bevacizumab showed no significant effect compared with untreated eyes. Eyes treated with 52,500 μg bevacizumab by eye drops three times per day for 14 days reduced the neovascularization area compared with untreated eyes by 6% (day 18), which was significantly less effective than the single microneedle treatment. Visual exam and histological analysis showed no observable effect of microneedle treatment on corneal transparency or microanatomical structure. Conclusions. This study shows that microneedles can target drug delivery to corneal stroma in a minimally invasive way and demonstrates effective suppression of corneal neovascularization after suture-induced injury using a much lower dose compared with conventional methods. PMID:25212779

  3. The lectin KM+ induces corneal epithelial wound healing in rabbits.

    PubMed

    Chahud, Fernando; Ramalho, Leandra N Z; Ramalho, Fernando S; Haddad, Antonio; Roque-Barreira, Maria C

    2009-04-01

    Neutrophil influx is essential for corneal regeneration (Gan et al. 1999). KM+, a lectin from Artocarpus integrifolia, induces neutrophil migration (Santos-de-Oliveira et al. 1994). This study aims at investigating a possible effect of KM+ on corneal regeneration in rabbits. A 6.0-mm diameter area of debridement was created on the cornea of both eyes by mechanical scraping. The experimental eyes received drops of KM+ (2.5 microg/ml) every 2 h. The control eyes received buffer. The epithelial wounded areas of the lectin-treated and untreated eyes were stained with fluorescein, photographed and measured. The animals were killed 12 h (group 1, n = 5), 24 h (group 2, n = 10) and 48 h (group 3, n = 5) after the scraping. The corneas were analysed histologically (haematoxylin and eosin and immunostaining for proliferation cell nuclear antigen, p63, vascular endothelial growth factor, c-Met and laminin). No significant differences were found at the epithelial gap between treated and control eyes in the group 1. However, the number of neutrophils in the wounded area was significantly higher in treated eyes in this group. Three control and seven treated eyes were healed completely and only rare neutrophils persisted in the corneal stroma in group 2. No morphological distinction was observed between treated and control eyes in group 3. In treated corneas of group 2, there was an increase in immunostaining of factors involved in corneal healing compared to controls. Thus, topical application of KM+ may facilitate corneal epithelial wound healing in rabbits by means of a mechanism that involves increased influx of neutrophils into the wounded area induced by the lectin.

  4. Measuring Corneal Haze by Using Scheimpflug Photography and Confocal Microscopy

    PubMed Central

    McLaren, Jay W.; Wacker, Katrin; Kane, Katrina M.; Patel, Sanjay V.

    2016-01-01

    Purpose We compared corneal backscatter estimated from a Scheimpflug camera with backscatter estimated from a clinical confocal microscope across a wide range of corneal haze. Methods A total of 59 corneas from 35 patients with a range of severity of Fuchs' endothelial corneal dystrophy and 15 corneas from 9 normal participants were examined using a Scheimpflug camera (Pentacam) and a confocal microscope (ConfoScan 4). The mean image brightness from the anterior 120 μm, midcornea, and posterior 60 μm of the cornea across the central 2 mm recorded by the Scheimpflug camera and analogous regions from the confocal microscope were measured and standardized. Differences between instruments and correlations between backscatter and disease severity were determined by using generalized estimating equation models. Results Backscatter measured by the two instruments in the anterior and midcornea were correlated (r = 0.67 and 0.43, respectively, P < 0.001), although in the posterior cornea they were not correlated (r = 0.13, P = 0.66). Measured with the Scheimpflug camera, mean backscatter from the anterior and midcornea were greater, whereas backscatter from the posterior cornea was lower (P < 0.001) than that measured by the confocal microscope. Backscatter from the anterior cornea was correlated with disease severity for both instruments (Scheimpflug, r = 0.55, P < 0.001; confocal, r = 0.49, P = 0.003). Conclusions The Scheimpflug camera and confocal microscope should not be used interchangeably to measure corneal haze. The ability to detect changes in backscatter with disease severity is superior with the Scheimpflug camera. However, the confocal microscope provides higher resolution of corneal structure. PMID:26803798

  5. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing

    PubMed Central

    Veréb, Zoltán; Póliska, Szilárd; Albert, Réka; Olstad, Ole Kristoffer; Boratkó, Anita; Csortos, Csilla; Moe, Morten C.; Facskó, Andrea; Petrovski, Goran

    2016-01-01

    Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases. PMID:27195722

  6. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing.

    PubMed

    Veréb, Zoltán; Póliska, Szilárd; Albert, Réka; Olstad, Ole Kristoffer; Boratkó, Anita; Csortos, Csilla; Moe, Morten C; Facskó, Andrea; Petrovski, Goran

    2016-01-01

    Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases. PMID:27195722

  7. Tissue engineering of feline corneal endothelium using a devitalized human cornea as carrier.

    PubMed

    Proulx, Stéphanie; Audet, Caroline; Uwamaliya, Jeanne d'Arc; Deschambeault, Alexandre; Carrier, Patrick; Giasson, Claude J; Brunette, Isabelle; Germain, Lucie

    2009-07-01

    The difficulties in obtaining good quality tissue for the replacement of corneas of patients suffering from endothelial dysfunctions have prompted us to evaluate the feasibility of producing a tissue-engineered (TE) corneal endothelium using devitalized human stromal carriers. Thus, corneal substitutes were produced by seeding cultured feline corneal endothelial cells on top of previously frozen human corneal stromas. After two weeks of culture to allow attachment and spreading of the seeded cells, the TE corneal endothelium was stained with alizarin red for endothelial cell count and fixed for histology, immunofluorescence labeling, scanning and transmission electron microscopy. Histology and Hoechst staining showed that there were no remaining cells in the devitalized stroma. After seeding, histology and transmission electron microscopy showed that the TE corneal endothelium formed a monolayer of tightly packed cells that were well adhered to Descemet's membrane. Scanning electron microscopy corroborated that the cells covered the entire posterior corneal surface and had an endothelial morphology. Alizarin staining showed that mean cell counts were 2272 +/- 344 cells/mm(2), indicating that the cell density was appropriate for grafting. The TE feline corneal endothelium also expressed the function-related proteins Na(+)/HCO(3)(-), ZO-1, and Na(+)/K(+)-ATPase alpha1, and could easily be marked with a fluorescent tracker. This study demonstrates the feasibility of reconstructing a highly cellular and healthy corneal endothelium on devitalized human corneal stromas. PMID:19125643

  8. Secondary Acute Anterior Uveitis with Hyphema in a Purpose-bred Kitten

    PubMed Central

    Sorrell, Melanie S; Taylor, Karen H; Fish, Richard E

    2008-01-01

    The sudden onset of unilateral blepharospasm and hyphema, without evidence of corneal damage, initiated a thorough diagnostic work-up of an 11-wk-old purpose-bred intact male domestic shorthair kitten. Secondary acute anterior uveitis and hyphema were most likely due to trauma within the primary enclosure. PMID:18702452

  9. Multipurpose Care Solution–Induced Corneal Surface Disruption and Pseudomonas aeruginosa Internalization in the Rabbit Corneal Epithelium

    PubMed Central

    Posch, Leila C.; Zhu, Meifang; Robertson, Danielle M.

    2014-01-01

    Purpose. To evaluate the effects of a chemically preserved multipurpose contact lens care solution (MPS) on the corneal epithelial surface and Pseudomonas aeruginosa (PA) internalization in the rabbit corneal epithelium. Methods. Rabbits were fit in one eye with a silicone hydrogel lens (balafilcon A) soaked overnight in a borate-buffered MPS (BioTrue). The contralateral eye was fit with a lens removed directly from the blister pack containing borate-buffered saline (control). Lenses were worn for 2 hours. Upon lens removal, corneas were challenged ex vivo with invasive PA strain 6487 and assessed for PA internalization. Ultrastructural changes were assessed using scanning electron (SEM) and transmission electron microscopy (TEM). Results. Scanning electron microscopy showed frank loss of surface epithelium in MPS-exposed eyes, while control eyes exhibited occasional loss of surface membranes but retention of intact junctional borders. Transmission electron microscopy data supported and extended SEM findings, demonstrating the presence of epithelial edema in MPS-treated eyes. There was a 12-fold increase in PA uptake into the corneal epithelium following wear of the MPS-treated lens compared to control (P = 0.008). Conclusions. These data demonstrate that corneal exposure to MPS during lens wear damages the surface epithelium and are consistent with our previous clinical data showing an increase in bacterial binding to exfoliated epithelial cells following MPS use with resultant increased risk for lens-mediated infection. These findings also demonstrate that the PA invasion assay may provide a highly sensitive quantitative metric for assessing the physiological impact of lens-solution biocompatibility on the corneal epithelium. PMID:24876286

  10. Modeling of Corneal and Retinal Pharmacokinetics after Periocular Drug Administration

    PubMed Central

    Amrite, Aniruddha C.; Edelhauser, Henry F.; Kompella, Uday B.

    2012-01-01

    Purpose To develop pharmacokinetics models to describe the disposition of small lipophilic molecules in the cornea and retina after periocular (subconjunctival or posterior subconjunctival) administration. Methods Compartmental pharmacokinetics analysis was performed on the corneal and retinal data obtained after periocular administration of 3 mg of celecoxib (a selective COX-2 inhibitor) to Brown Norway (BN) rats. Berkeley Madonna, a differential and difference equation–based modeling software, was used for the pharmacokinetics modeling. The data were fit to different compartment models with first-order input and disposition, and the best fit was selected on the basis of coefficient of regression and Akaike information criteria (AIC). The models were validated by using the celecoxib data from a prior study in Sprague-Dawley (SD) rats. The corneal model was also fit to the corneal data for prednisolone at a dose of 2.61 mg in albino rabbits, and the model was validated at two other doses of prednisolone (0.261 and 26.1 mg) in these rabbits. Model simulations were performed with the finalized model to understand the effect of formulation on corneal and retinal pharmacokinetics after periocular administration. Results Celecoxib kinetics in the BN rat cornea can be described by a two-compartment (periocular space and cornea, with a dissolution step for periocular formulation) model, with parallel elimination from the cornea and the periocular space. The inclusion of a distribution compartment or a dissolution step for celecoxib suspension did not lead to an overall improvement in the corneal data fit compared with the two-compartment model. The more important parameter for enhanced fit and explaining the apparent lack of an increase phase in the corneal levels is the inclusion of the initial leak-back of the dose from the periocular space into the precorneal area. The predicted celecoxib concentrations from this model also showed very good correlation (r = 0

  11. Brittle Cornea Syndrome: Case Report with Novel Mutation in the PRDM5 Gene and Review of the Literature.

    PubMed

    Avgitidou, Georgia; Siebelmann, Sebastian; Bachmann, Bjoern; Kohlhase, Juergen; Heindl, Ludwig M; Cursiefen, Claus

    2015-01-01

    A 3-year-old boy presented with acute corneal hydrops on the left eye and spontaneous corneal rupture on the right eye. A diagnosis of brittle cornea syndrome was confirmed by molecular analysis. A novel mutation, the homozygous variant c.17T>G, p.V6G, was found in the gene for PR-domain-containing protein 5 (PRDM5) in exon 1. Brittle cornea syndrome is a rare connective tissue disease with typical ocular, auditory, musculoskeletal, and cutaneous disorders. Almost all patients suffer from declined vision due to corneal scarring, thinning, and rupture. The most common ophthalmologic findings include keratoconus, progressive central corneal thinning, high myopia, irregular astigmatism, retinal detachment, and high risk for spontaneous corneal or scleral rupture. In addition to describing the case with a novel mutation here we review the current literature on brittle cornea syndrome pathogenesis, clinical findings, and therapy.

  12. Minocycline Inhibits Alkali Burn-Induced Corneal Neovascularization in Mice

    PubMed Central

    Xiao, Ou; Xie, Zhao-lian; Lin, Bin-wu; Yin, Xiao-fang; Pi, Rong-biao; Zhou, Shi-you

    2012-01-01

    The purpose of this study was to investigate the effects of minocycline on alkali burn-induced corneal neovascularization (CNV). A total of 105 mice treated with alkali burns were randomly divided into three groups to receive intraperitoneal injections of either phosphate buffered saline (PBS) or minocycline twice a day (60 mg/kg or 30 mg/kg) for 14 consecutive days. The area of CNV and corneal epithelial defects was measured on day 4, 7, 10, and14 after alkali burns. On day 14, a histopathological examination was performed to assess morphological change and the infiltration of polymorphonuclear neutrophils (PMNs). The mRNA expression levels of vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), basic fibroblast growth factor (bFGF), matrix metalloproteinases (MMPs), interleukin-1α, 1β, 6 (IL-1α, IL-1β, IL-6) were analyzed using real-time quantitative polymerase chain reaction. The expression of MMP-2 and MMP-9 proteins was determined by gelatin zymography. In addition, enzyme-linked immunosorbent assay was used to analyze the protein levels of VEGFR1, VEGFR2, IL-1β and IL-6. Minocycline at a dose of 60 mg/kg or 30 mg/kg significantly enhanced the recovery of the corneal epithelial defects more than PBS did. There were significant decreases of corneal neovascularization in the group of high-dosage minocycline compared with the control group at all checkpoints. On day 14, the infiltrated PMNs was reduced, and the mRNA expression of VEGFR1, VEGFR2, bFGF, IL-1β, IL-6, MMP-2, MMP-9, -13 as well as the protein expression of VEGFR2, MMP-2, -9, IL-1β, IL-6 in the corneas were down-regulated with the use of 60 mg/kg minocycline twice a day. Our results showed that the intraperitoneal injection of minocycline (60 mg/kg b.i.d.) can significantly inhibit alkali burn-induced corneal neovascularization in mice, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors, inflammatory cytokines and MMPs. PMID

  13. Hevin Plays a Pivotal Role in Corneal Wound Healing

    PubMed Central

    Chaurasia, Shyam S.; Perera, Promoda R.; Poh, Rebekah; Lim, Rayne R.; Wong, Tina T.; Mehta, Jodhbir S.

    2013-01-01

    Background Hevin is a matricellular protein involved in tissue repair and remodeling via interaction with the surrounding extracellular matrix (ECM) proteins. In this study, we examined the functional role of hevin using a corneal stromal wound healing model achieved by an excimer laser-induced irregular phototherapeutic keratectomy (IrrPTK) in hevin-null (hevin-/-) mice. We also investigated the effects of exogenous supplementation of recombinant human hevin (rhHevin) to rescue the stromal cellular components damaged by the excimer laser. Methodology/Principal Findings Wild type (WT) and hevin-/- mice were divided into three groups at 4 time points- 1, 2, 3 and 4 weeks. Group I served as naïve without any treatment. Group II received epithelial debridement and underwent IrrPTK using excimer laser. Group III received topical application of rhHevin after IrrPTK surgery for 3 days. Eyes were analyzed for corneal haze and matrix remodeling components using slit lamp biomicroscopy, in vivo confocal microscopy, light microscopy (LM), transmission electron microscopy (TEM), immunohistochemistry (IHC) and western blotting (WB). IHC showed upregulation of hevin in IrrPTK-injured WT mice. Hevin-/- mice developed corneal haze as early as 1-2 weeks post IrrPTK-treatment compared to the WT group, which peaked at 3-4 weeks. They also exhibited accumulation of inflammatory cells, fibrotic components of ECM proteins and vascularized corneas as seen by IHC and WB. LM and TEM showed activated keratocytes (myofibroblasts), inflammatory debris and vascular tissues in the stroma. Exogenous application of rhHevin for 3 days reinstated inflammatory index of the corneal stroma similar to WT mice. Conclusions/Significance Hevin is transiently expressed in the IrrPTK-injured corneas and loss of hevin predisposes them to aberrant wound healing. Hevin-/- mice develop early corneal haze characterized by severe chronic inflammation and stromal fibrosis that can be rescued with exogenous

  14. Enhancement of corneal permeation of riboflavin-5'-phosphate through vitamin E TPGS: a promising approach in corneal trans-epithelial cross linking treatment.

    PubMed

    Ostacolo, Carmine; Caruso, Ciro; Tronino, Diana; Troisi, Salvatore; Laneri, Sonia; Pacente, Luigi; Del Prete, Antonio; Sacchi, Antonia

    2013-01-20

    Corneal accumulation of riboflavin-5'-phosphate (riboflavin) is an essential step in the so called corneal cross-linking (CXL), an elective therapy for the treatment of progressive keratoconus, corneal ectasia and irregular astigmatism. CXL is usually performed after surgical debridement of corneal epithelium, since it impedes the stromal penetration of riboflavin in a relatively short time. d-Alpha-tocopheryl poly(ethylene glycol) 1000 succinate (VE-TPGS) is an effective permeation enhancer used to increase adsorption of drugs trough different biological barriers. Moreover, belonging to the group of tocopherol pro-drugs, VE-TPGS exerts a protective effect on biological membrane against free-radical damage. The aim of this work is the evaluation of VE-TPGS effects on riboflavin corneal permeability, and the assessment of its protective effect against free-radicals generated during CXL procedures. Different solutions containing riboflavin (0.125% w/w), dextran (20.0% w/w) and increasing concentration of VE-TPGS were tested. Corneal permeation was evaluated in vitro by the use of modified Franz-cell type diffusion cells and freshly excised porcine corneas as barrier. The effect of VE-TPGS on riboflavin corneal penetration was compared with a standard commercial solution of riboflavin in dextran at different times. Accumulation experiments were conducted both on epithelized and non-epithelized corneas. Moreover, epithelized porcine corneas, treated with the tested solutions, were subjected to an in vitro CXL procedure versus non-epithelized corneas, treated with a commercial solution of riboflavin. Differences were measured by means of corneal rigidity using Young's modulus. The photo-protective effect of tested solutions on corneal epithelium was, finally, evaluated. CXL treatment was applied, in vitro, on human explanted corneas and resulting morphology of corneal epithelium was investigated by scanning electron microscopy. PMID:23046664

  15. Thermosensitive chitosan-based hydrogels for sustained release of ferulic acid on corneal wound healing.

    PubMed

    Tsai, Ching-Yao; Woung, Lin-Chung; Yen, Jiin-Cherng; Tseng, Po-Chen; Chiou, Shih-Hwa; Sung, Yen-Jen; Liu, Kuan-Ting; Cheng, Yung-Hsin

    2016-01-01

    Oxidative damage to cornea can be induced by alkaline chemical burn which may cause vision loss or blindness. Recent studies showed that exogenous application of natural antioxidants may be a potential treatment for corneal wound healing. However, low ocular bioavailability and short residence time are the limiting factors of topically administered antioxidants. Ferulic acid (FA) is a natural phenolic compound and an excellent antioxidant. The study was aimed to investigate the effects of FA in corneal epithelial cells (CECs) under oxidative stress and evaluate the feasibility of use the thermosensitive chitosan-based hydrogel containing FA for corneal wound healing. The results demonstrated that post-treatment of FA on CECs could decrease the inflammation-level and apoptosis. In the rabbit corneal alkali burn model, post-treatment FA-loaded hydrogel may promote the corneal wound healing. The results of study suggest that FA-loaded hydrogel may have the potential applications in treating corneal alkali burn. PMID:26453882

  16. In-vivo human corneal nerve imaging using Fourier-domain OCT

    NASA Astrophysics Data System (ADS)

    Shin, Jun Geun; Lee, Byeong Ha; Eom, Tae Joong; Hwang, Ho Sik

    2015-03-01

    We have imaged human corneal nerve bundles by using real-time Fourier-domain OCT (FD-OCT). Corneal nerves contribute to the maintenance of healthy ocular surface owing to their trophic influences on the corneal epithelium. The FD-OCT system was based on a swept laser of a 50 kHz sweeping rate and 1.31 μm center wavelength. At the area including sclera, limbus, and cornea, we could successfully get the in-vivo tomograms of the corneal nerve bundles. The scan range was 5 x 5mm. In this study, the A-scan images in each B-scan were realigned to have a flat air-surface boundary in the final B-scan image. With this effort, we could align corneal nerve bundle in a same depth and get the 3D image showing the branched and threadlike corneal nerve bundles.

  17. [Emphasizing the prevention and treatment of immune rejection after corneal transplantation].

    PubMed

    Shi, Wei-yun; Xie, Li-xin

    2006-01-01

    Corneal transplantation is a major therapeutic method to recover the sight from corneal blindness, however, the immune rejection is still the major impact factor for graft failure. With the improvement of the medical care in our country, corneal transplantation has been increased continually. Therefore, reducing the complications and increasing the long-term transparency rate of the graft is an important mission for ophthalmologists. The key core of the corneal transplantation is to pay more attention to the follow-up and prevent the immune rejection. Three respects, including the current status and problems of corneal transplantation in China, the update immune rejection theory and the means of reducing the immune rejection of the corneal graft, and the methods to reduce the risk of blindness due to immune rejection, will be focused in this paper.

  18. Isolation of bovine corneal keratan sulfate and its growth factor and morphogen binding.

    PubMed

    Weyers, Amanda; Yang, Bo; Solakyildirim, Kemal; Yee, Vienna; Li, Lingyun; Zhang, Fuming; Linhardt, Robert J

    2013-05-01

    Keratan sulfate (KS) is an important glycosaminoglycan that is found in cartilage, reproductive tissues, and neural tissues. Corneal KS glycosaminoglycan is found N-linked to lumican, keratocan and mimecan proteoglycans, and has been widely studied by investigators interested in corneal development and diseases. Recently, the availability of corneal KS has become severely limited, owing to restrictions on the shipment of bovine central nervous system byproducts across international borders in an effort to prevent additional cases of mad cow disease. We report a simple method for the purification of multi-milligram quantities of bovine corneal KS, and characterize its structural properties. We also examined its protein-binding properties, and discovered that corneal KS bound with high affinity to fibroblast growth factor-2 and sonic hedgehog, a growth factor and a morphogen involved in corneal development and healing. PMID:23402351

  19. Thermosensitive chitosan-based hydrogels for sustained release of ferulic acid on corneal wound healing.

    PubMed

    Tsai, Ching-Yao; Woung, Lin-Chung; Yen, Jiin-Cherng; Tseng, Po-Chen; Chiou, Shih-Hwa; Sung, Yen-Jen; Liu, Kuan-Ting; Cheng, Yung-Hsin

    2016-01-01

    Oxidative damage to cornea can be induced by alkaline chemical burn which may cause vision loss or blindness. Recent studies showed that exogenous application of natural antioxidants may be a potential treatment for corneal wound healing. However, low ocular bioavailability and short residence time are the limiting factors of topically administered antioxidants. Ferulic acid (FA) is a natural phenolic compound and an excellent antioxidant. The study was aimed to investigate the effects of FA in corneal epithelial cells (CECs) under oxidative stress and evaluate the feasibility of use the thermosensitive chitosan-based hydrogel containing FA for corneal wound healing. The results demonstrated that post-treatment of FA on CECs could decrease the inflammation-level and apoptosis. In the rabbit corneal alkali burn model, post-treatment FA-loaded hydrogel may promote the corneal wound healing. The results of study suggest that FA-loaded hydrogel may have the potential applications in treating corneal alkali burn.

  20. Stem cell-based therapy of corneal epithelial and endothelial diseases.

    PubMed

    Yuan, Songtao; Fan, Guoping

    2015-05-01

    Corneal dysfunction is the second leading cause of blindness. Approximately 10 million patients worldwide are affected by some form of corneal disease. More than 50,000 cornea transplants are performed every year, but this procedure is limited by cornea donation availability. Recently, new cell replacement procedures have been developed to treat a variety of corneal diseases. This review will focus on the recent advances in the use of limbal epithelial stem cells (LESCs) to treat corneal epithelial cell deficiency and improvements in replacing dysfunctional corneal endothelial cells (CECs) with exogenous CECs. Several protocols have been developed to differentiate pluripotent stem cells into LESC- or CEC-like cells, potentially yielding an unlimited source for the cell replacement therapy of corneal diseases. PMID:26022766

  1. Assessing the phase retardation in corneal tissues using a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Calhoun, William; Weiblinger, Richard; Beylin, Alexander; Ilev, Ilko K.

    2013-08-01

    We developed and validated a versatile test method for precise quantification of phase retardation in corneal tissues using a femtosecond laser. It is based on an experimental system for direct measurement of corneal phase rotation due to corneal birefringence effects using a dual-polarizer, computer-controlled, femtosecond laser design. It also includes a comprehensive analytical model using Jones matrices. The test method presented is used for quantification of phase retardation in corneal tissues by employing the experimental data obtained from corneal phase rotation measurements and using analytical model assessments. The experimental and theoretical results obtained, and thus, the system's high accuracy and repeatability potential for assessing the corneal phase retardation are validated using control phase retardation evaluation.

  2. A potential therapeutic strategy for inhibition of corneal neovascularization with new anti-VEGF agents.

    PubMed

    Hosseini, Hamid; Nejabat, Mahmood

    2007-01-01

    The factors triggering corneal neovascularization involve various growth factors. The data supporting a causal role for vascular endothelial growth factor (VEGF) in corneal neovascularization are extensive. One possible strategy for treating corneal neovascularization is to inhibit VEGF activity by competitively binding VEGF with a specific neutralizing anti-VEGF antibody. The vireo-retinal service in the recent years enjoyed a high level of success in managing choroidal neovascularization using anti-VEGF strategies. Efficacy and tolerability have been demonstrated for drugs targeting VEGF. We herein hypothesize that topical application of new anti-VEGF agents such as pegaptanib, ranibizumab and bevacizumab are potentially useful for inhibiting corneal neovascularization and restoration of corneal clarity. Further investigations are needed to place these medical treatments alongside corneal neovascularization therapeutics. PMID:17107753

  3. Anterior segment surgery early after corneal wound repair.

    PubMed Central

    Maul, E; Muga, R

    1977-01-01

    Penetrating wounds of the cornea require immediate repair, generally within 24 hours. Tight closure of the wound and a reformed anterior chamber are the primary goals of surgery. However, there is no guarantee that further surgery will not be required for maintaining the healthy function of the anterior segment. At the second operation the effect of the procedure on the previously repaired wound is of prime importance, since in many cases the operation needs to be done before corneal healing is completed. In our series the lens, which was either partially or completely cataractous at the initial operation, became intumescent at different times afterwards, and an immediate removal was necessary. No change in the preoperative wound sealing or transparency of the cornea could be detected after lens surgery performed between 24 hours and 21 days from the initial corneal repair. PMID:603786

  4. Antibody-based immunosuppressive agents for corneal transplantation.

    PubMed

    Thiel, M A; Kaufmann, C; Coster, D J; Williams, K A

    2009-10-01

    The progress in antibody engineering over the last 20 years has created the tools for the development of novel antibody-based drugs and constructs, such as small antibody fragments, suitable for topical administration. In rheumatology, oncology, transplantation medicine and ophthalmology, therapeutic antibody constructs, and antibody fragments have been responsible for the clinical progress seen over the last decade. Although antibody-based therapies have become a well-established immunosuppressive option in solid organ transplantation, there are only very few reports with regard to corneal transplantation. The following review explains some of the important aspects of engineered antibody-based therapeutic agents and summarises the current use of such immunosuppressive therapies in transplantation medicine and corneal transplantation.

  5. Corneal transplantation in the United Kingdom and Republic of Ireland.

    PubMed Central

    Vail, A; Gore, S M; Bradley, B A; Easty, D L; Rogers, C A

    1993-01-01

    The Corneal Transplant Follow up Study has registered 4560 corneal grafts performed in the United Kingdom and Republic of Ireland from July 1987 to June 1991. Rates of reported grafts doubled during that time. This increase was greater for surgeons and regions reporting fewer grafts, but was consistent across patient factors. Eleven of 428 consultants were responsible for over 25% of grafts, and their patients' characteristics differed significantly from others. Overall, reasons for grafting were visual only (77%), visual and other (16%), and non-visual (7%). Most frequent diagnoses were endothelial failure (38%), inflammation (26%), and keratoconus (20%). Age ranged from 2 months to 97 years, and differed markedly with diagnosis. Eighteen per cent of transplants were regrafts, and 40% were vascularised preoperatively. PMID:8218035

  6. [Keratoconus, the most common corneal dystrophy. Can keratoplasty be avoided?].

    PubMed

    Arne, Jean Louis; Fournié, Pierre

    2011-01-01

    Keratoconus is the most common form of corneal dystrophy. It consists of a non inflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. In more advanced cases, opacities can be seen at the apex of the cone. Traditional conservative management of keratoconus begins with spectacle correction and contact lenses. Surgery is recommended when a stable contact lens fit fails to provide adequate vision. Keratoplasty was long the only surgical treatment, but recent years have seen the introduction of new surgical options:--Collagen cross-linking stiffens the cornea and can halt disease progression;--Intrastromal corneal rings can reduce astigmatism and improve visual acuity;--Intraocular lenses are valuable additional options for the correction of refractive errors. Currently, keratoplasty is mainly restricted to patients with opacities of the central cornea. PMID:22039707

  7. Molecular underpinnings of corneal angiogenesis: advances over the past decade.

    PubMed

    Abdelfattah, Nizar Saleh; Amgad, Mohamed; Zayed, Amira A; Hussein, Heba; Abd El-Baky, Nawal

    2016-01-01

    The cornea is maintained in an avascular state by maintaining an environment whereby anti-angiogenic factors take the upper hand over factors promoting angiogenesis. Many of the common pathologies affecting the cornea involve the disruption of such equilibrium and the shift towards new vessel formation, leading to corneal opacity and eventually-vision loss. Therefore it is of paramount importance that the molecular underpinnings of corneal neovascularization (CNV) be clearly understood, in order to develop better targeted treatments. This article is a review of the literature on the recent discoveries regarding pro-angiogenic factors of the cornea (such as vascular endothelial growth factors, fibroblast growth factor and matrix metalloproteinases) and anti-angiogenic factors of the cornea (such as endostatins and neostatins). Further, we review the molecular underpinnings of lymphangiogenesis, a process now known to be almost separate from (yet related to) hemangiogenesis. PMID:27275438

  8. Jaw, blink and corneal reflex latencies in multiple sclerosis.

    PubMed Central

    Sanders, E A; Ongerboer de Visser, B W; Barendswaard, E C; Arts, R J

    1985-01-01

    Jaw, blink and corneal reflexes, which all involve the trigeminal system, were recorded in 54 patients with multiple sclerosis; thirty-seven of these patients were classified as having definite multiple sclerosis and 17 as indefinite multiple sclerosis, according to Schumacher's criteria. The jaw reflex was abnormal less frequently than either of the other two reflexes, but in four cases it was the only abnormal reflex found. Testing a combination of two or three trigeminal reflexes did not yield a higher incidence of abnormalities than testing the blink or corneal reflex alone. Nine patients showed abnormal reflexes which were unexpected on the basis of clinical symptoms. The combined recordings demonstrate at least one abnormal reflex in 74% of the patients. The various types of reflex abnormalities reflect major damage to different parts of the trigeminal system and may therefore make an important contribution to the diagnosis of multiple sclerosis. PMID:4087004

  9. Molecular underpinnings of corneal angiogenesis: advances over the past decade

    PubMed Central

    Abdelfattah, Nizar Saleh; Amgad, Mohamed; Zayed, Amira A.; Hussein, Heba; Abd El-Baky, Nawal

    2016-01-01

    The cornea is maintained in an avascular state by maintaining an environment whereby anti-angiogenic factors take the upper hand over factors promoting angiogenesis. Many of the common pathologies affecting the cornea involve the disruption of such equilibrium and the shift towards new vessel formation, leading to corneal opacity and eventually-vision loss. Therefore it is of paramount importance that the molecular underpinnings of corneal neovascularization (CNV) be clearly understood, in order to develop better targeted treatments. This article is a review of the literature on the recent discoveries regarding pro-angiogenic factors of the cornea (such as vascular endothelial growth factors, fibroblast growth factor and matrix metalloproteinases) and anti-angiogenic factors of the cornea (such as endostatins and neostatins). Further, we review the molecular underpinnings of lymphangiogenesis, a process now known to be almost separate from (yet related to) hemangiogenesis. PMID:27275438

  10. Self inflicted corneal abrasions due to delusional parasitosis

    PubMed Central

    Meraj, Adeel; Din, Amad U; Larsen, Lynn; Liskow, Barry I

    2011-01-01

    The authors report a case of self inflicted bilateral corneal abrasions and skin damage due to ophthalmic and cutaneous delusional parasitosis. A male in his 50s presented with a 10 year history of believing that parasites were colonizing his skin and biting into his skin and eyes. The patient had received extensive medical evaluations that found no evidence that symptoms were due to a medical cause. He was persistent in his belief and had induced bilateral corneal abrasions and skin damage by using heat lamps and hair dryers in an attempt to disinfect his body. The patient was treated with olanzapine along with treatment for his skin and eyes. His delusional belief system persisted but no further damage to his eyes and skin was noted on initial follow-up. PMID:22689836

  11. Triple Subconjunctival Bevacizumab Injection for Early Corneal Recurrent Pterygium: One-Year Follow-Up

    PubMed Central

    Nava-Castañeda, Angel; Ulloa-Orozco, Isabel; Garnica-Hayashi, Lilia; Hernandez-Orgaz, Joaquín; Jimenez-Martinez, Maria Carmen

    2015-01-01

    Abstract Purpose: The aim of the study was to evaluate the effect of 3 subconjunctival bevacizumab injections in patients with an early corneal pterygium recurrence. Methods: This study was a nonrandomized single center trial. Patients with an early corneal pterygium recurrence were selected. All patients received 3 subconjunctival bevacizumab (2.5 mg/0.1 mL) injections (basal, 2 and 4 weeks) in the recurrence area of the pterygium. The corneal and corneal-conjunctival neovascularization areas and the corneal opacification area of each pterygium were determined using digital slit lamp pictures. Results: Thirty-eight patients were enrolled into the study; all patients were injected within 3 months of the diagnosed pterygium recurrence. Interestingly, the bevacizumab injections had a significant effect (P<0.05) on the reduction of corneal, corneal-conjunctival area of neovascularization determined as pixels and on the corneal opacification area determined as mm2 when comparing the basal values, to the values obtained after 15 days, 1 month, 3 months, 6 months, and 12 months after injections. Conclusions: The vascularized area in all recurrent pterygia and the corneal opacification area with this triple regimen of subconjunctival bevacizumab injections were reduced, which remained until the end of the study. These results suggest that bevacizumab subconjunctival injections could be useful to treat recurrent pterygium. PMID:25369364

  12. Corneal ulcer with Scopulariopsis brevicaulis and Staphylococcus aureus--a rare case report.

    PubMed

    Mondal, Kanchan Kumar; Chattopadhyay, Chitrita; Ray, Biswarup; Das, Debabrata; Biswas, Supreeti; Banerjee, Parthajit

    2012-04-01

    Scopulariopsis brevicaulis is a saprophytic fungus, found in soil. It causes human nail infection. Corneal ulcer with this organism is unusual. Here a case of a 36-year-old farmer is reported who developed a paracentral corneal ulcer in the right eye. The ulcer was caused by mixed infection with Staphylococcus aureus and Scopulariopsis brevicaulis. It was treated with topical natamycin 5% and moxifloxacin 0.5% drops. This is a unique case of corneal ulcer with mixed infection of Staphylococcus aureus and Scopulariopsis brevicaulis without any history of trauma, which was treated successfully, resulting in a minimal corneal opacity.

  13. Mitomycin C: a promising agent for the treatment of canine corneal scarring

    PubMed Central

    Gupta, Rangan; Yarnall, Benjamin W.; Giuliano, Elizabeth A.; Kanwar, Jagat R.; Buss, Dylan G.; Mohan, Rajiv R.

    2012-01-01

    Objective To evaluate the safety and efficacy of mitomycin C (MMC) in prevention of canine corneal scarring. Methods With an in vitro approach using healthy canine corneas, cultures of primary canine corneal fibroblasts or myofibroblasts were generated. Primary canine corneal fibroblasts were obtained by growing corneal buttons in minimal essential medium supplemented with 10% fetal bovine serum. Canine corneal myofibroblasts were produced by growing cultures in serum-free medium containing transforming growth factor β1 (1 ng/mL). Trypan blue assay and phase-contrast microscopy were used to evaluate the toxicity of three doses of MMC (0.002%, 0.02% and 0.04%). Real-time PCR, immunoblot, and immunocytochemistry techniques were used to determine MMC efficacy to inhibit markers of canine corneal scarring. Results A single 2-min treatment of 0.02% or less MMC did not alter canine corneal fibroblast or keratocyte phenotype, viability, or growth. The 0.02% dose substantially reduced myofibroblast formation (up to 67%; P < 0.001), as measured by the change in RNA and protein expression of fibrosis biomarkers (α-smooth muscle actin and F-actin). Conclusion This in vitro study suggests that a single 2-min 0.02% MMC treatment to the canine corneal keratocytes is safe and may be useful in decreasing canine corneal fibrous metaplasia. In vivo studies are warranted. PMID:21929607

  14. Corneal stem cells and tissue engineering: Current advances and future perspectives.

    PubMed

    de Araujo, Aline Lütz; Gomes, José Álvaro Pereira

    2015-06-26

    Major advances are currently being made in regenerative medicine for cornea. Stem cell-based therapies represent a novel strategy that may substitute conventional corneal transplantation, albeit there are many challenges ahead given the singularities of each cellular layer of the cornea. This review recapitulates the current data on corneal epithelial stem cells, corneal stromal stem cells and corneal endothelial cell progenitors. Corneal limbal autografts containing epithelial stem cells have been transplanted in humans for more than 20 years with great successful rates, and researchers now focus on ex vivo cultures and other cell lineages to transplant to the ocular surface. A small population of cells in the corneal endothelium was recently reported to have self-renewal capacity, although they do not proliferate in vivo. Two main obstacles have hindered endothelial cell transplantation to date: culture protocols and cell delivery methods to the posterior cornea in vivo. Human corneal stromal stem cells have been identified shortly after the recognition of precursors of endothelial cells. Stromal stem cells may have the potential to provide a direct cell-based therapeutic approach when injected to corneal scars. Furthermore, they exhibit the ability to deposit organized connective tissue in vitro and may be useful in corneal stroma engineering in the future. Recent advances and future perspectives in the field are discussed.

  15. Spontaneous Healing of Corneal Perforation after Temporary Discontinuation of Erlotinib Treatment

    PubMed Central

    Morishige, Naoyuki; Hatabe, Nanami; Morita, Yukiko; Yamada, Naoyuki; Kimura, Kazuhiro; Sonoda, Koh-Hei

    2014-01-01

    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. PMID:24575032

  16. Derivation of Corneal Keratocyte-Like Cells from Human Induced Pluripotent Stem Cells

    PubMed Central

    Naylor, Richard W.; McGhee, Charles N. J.; Cowan, Chad A.; Davidson, Alan J.; Holm, Teresa M.; Sherwin, Trevor

    2016-01-01

    Corneal diseases such as keratoconus represent a relatively common disorder in the human population. However, treatment is restricted to corneal transplantation, which only occurs in the most advanced cases. Cell based therapies may offer an alternative approach given that the eye is amenable to such treatments and corneal diseases like keratoconus have been associated specifically with the death of corneal keratocytes. The ability to generate corneal keratocytes in vitro may enable a cell-based therapy to treat patients with keratoconus. Human induced pluripotent stem cells (hiPSCs) offer an abundant supply of cells from which any cell in the body can be derived. In the present study, hiPSCs were successfully differentiated into neural crest cells (NCCs), the embryonic precursor to keratocytes, and then cultured on cadaveric corneal tissue to promote keratocyte differentiation. The hiPSC-derived NCCs were found to migrate into the corneal stroma where they acquired a keratocyte-like morphology and an expression profile similar to corneal keratocytes in vivo. These results indicate that hiPSCs can be used to generate corneal keratocytes in vitro and lay the foundation for using these cells in cornea cell-based therapies. PMID:27792791

  17. Perforating corneal injury in rat and pentadecapeptide BPC 157.

    PubMed

    Masnec, Sanja; Kokot, Antonio; Zlatar, Mirna; Kalauz, Miro; Kunjko, Kristian; Radic, Bozo; Klicek, Robert; Drmic, Domagoj; Lazic, Ratimir; Brcic, Luka; Radic, Radivoje; Ivekovic, Renata; Seiwerth, Sven; Sikiric, Predrag

    2015-07-01

    Based on its healing effects in various tissues, we hypothesized that the stable gastric pentadecapeptide BPC 157 heals corneal ulcerations in rats and effects corneal transparency. We made a penetrant linear 2-mm incision in the paralimbal region of the left cornea at the 5 o'clock position with a 20-gauge MVR incision knife at 45° under an operating microscope. Medication was BPC 157 (2 pg/mL, 2 ng/mL, and 2 μg/mL distilled water, two eye drops/left rat eye) immediately after injury induction and then every 8 h up to 120 h; controls received an equal volume of distilled water. In contrast to the poor healing response in controls, BPC 157 significantly accelerated the healing process in 2 μg and 2 ng BPC 157-treated eyes, starting 24 h after the injury, and the fluorescein and Seidel tests became negative. The epithelial defects were completely healed at 72 h (2 μg BPC 157-treated group) and at 96 h (2 ng BPC 157-treated group) after injury. Aqueous cells were absent at 96 h and 120 h after injury in the 2 μg and 2 ng BPC 157-treated groups, respectively. In conclusion, BPC 157 effects the rapid regaining of corneal transparency. Whereas controls developed new vessels that grew from the limbus to the penetrated area, BPC 157-treated rats generally had no new vessels, and those that did form in the limbus did not make contact with the penetrated area. Thus, BPC 157 eye drops successfully close perforating corneal incisions in rats. PMID:25912999

  18. Peripheral Optics with Bifocal Soft and Corneal Reshaping Contact Lenses

    PubMed Central

    Ticak, Anita; Walline, Jeffrey J.

    2012-01-01

    Purpose To determine whether bifocal soft contact lenses with a distance center design provide myopic defocus to the peripheral retina similar to corneal reshaping contact lenses. Methods Myopic subjects underwent five cycloplegic autorefraction readings centrally and at 10, 20, and 30 degrees temporally, nasally, superiorly, inferiorly while wearing a Proclear Multifocal “D” contact lens with a +2.00 D add (CooperVision, Fairport, NY) and after wearing a Corneal Refractive Therapy (Paragon Vision Sciences, Mesa, AZ) contact lens for two weeks Results Fourteen subjects completed the study. Nine (64%) were female, and 12 (86%) were Caucasian. The average (± standard deviation) spherical equivalent non-cycloplegic manifest refraction for the right eye was −2.84 ± 1.29 D. The average logMAR best-corrected, binocular high contrast visual acuity was −0.17 ± 0.15 while wearing the bifocal soft contact lens, and −0.09 ± 0.16 following corneal reshaping contact lens wear (ANOVA, p = 0.27). The orthokeratology contact lens yielded a more myopic peripheral optical profile than the soft bifocal contact lens at 20 and 30 degrees eccentricity (except inferior at 20 degrees); the two modalities were similar at 10 degrees eccentricity. Conclusions Our data suggest that the two modalities are dissimilar despite the statistical similarities. The corneal reshaping contact lens shows an increase in relative peripheral myopic refraction, a pattern achieved by other studies, but the bifocal lens does not exhibit such a pattern. The low statistical power of the study could be a reason for a lack of providing statistical difference in other positions of gaze, but the graphical representation of the data shows a marked difference in peripheral optical profile between the two modalities. More sophisticated methods of measuring the peripheral optical profile may be necessary to accurately compare the two modalities and to determine the true optical effect of the bifocal soft

  19. Extremely varied phenotypes in granular corneal dystrophy type 2 heterozygotes

    PubMed Central

    Han, Kyung Eun; Choi, Seung-il; Chung, Woo Suk; Jung, Se Hwan; Katsanis, Nicholas; Kim, Tae-im

    2012-01-01

    Purpose To investigate the phenotypic variability of patients bearing the heterozygous R124H mutation in the TGFBI (transforming growth factor-beta-induced) gene that causes granular corneal dystrophy type 2 (GCD2). Methods We describe the phenotypic range of GCD2 heterozygotes for the common R124H mutation in TGFBI; seven with an extremely mild phenotype and six with an extremely severe phenotype. Detailed slit-lamp photographs of these patients were generated. All patients had no history of ocular surgery and were diagnosed as being heterozygous for GCD2 by DNA analysis from peripheral blood. Expression levels of transforming growth factor-beta-induced protein (TGFBIp) were compared among cultured corneal fibroblasts from ten normal donors. Results We report profound differences in the severity of the phenotype across our case series. Two patients with a mild phenotype were diagnosed as unaffected at presentation; however follow-up examinations revealed granular deposits. Importantly, we also observed familial clustering of phenotypic variance; five patients from two families with a mild phenotype showed a similarly mild phenotype within family members. Similarly, six patients from two families with severe phenotypes showed corneal deposits with similar patterns and severity within each distinct family, but distinct patterns between families. TGFBIp expressions from different donor derived cultured corneal fibroblasts were different between one another. Conclusions GCD2 heterozygotes have extremely varied phenotypes between individual patients. However phenotypes were broadly consistent within families, suggesting that the observed variable expressivity might be regulated by other genetic factors that could influence the abundance of TGFBIp or the function of the pathway. From a clinical perspective, our data also highlighted that genetic analysis and meticulous slit-lamp examination in both eyes at multiple time intervals is necessary. PMID:22815629

  20. Perforating corneal injury in rat and pentadecapeptide BPC 157.

    PubMed

    Masnec, Sanja; Kokot, Antonio; Zlatar, Mirna; Kalauz, Miro; Kunjko, Kristian; Radic, Bozo; Klicek, Robert; Drmic, Domagoj; Lazic, Ratimir; Brcic, Luka; Radic, Radivoje; Ivekovic, Renata; Seiwerth, Sven; Sikiric, Predrag

    2015-07-01

    Based on its healing effects in various tissues, we hypothesized that the stable gastric pentadecapeptide BPC 157 heals corneal ulcerations in rats and effects corneal transparency. We made a penetrant linear 2-mm incision in the paralimbal region of the left cornea at the 5 o'clock position with a 20-gauge MVR incision knife at 45° under an operating microscope. Medication was BPC 157 (2 pg/mL, 2 ng/mL, and 2 μg/mL distilled water, two eye drops/left rat eye) immediately after injury induction and then every 8 h up to 120 h; controls received an equal volume of distilled water. In contrast to the poor healing response in controls, BPC 157 significantly accelerated the healing process in 2 μg and 2 ng BPC 157-treated eyes, starting 24 h after the injury, and the fluorescein and Seidel tests became negative. The epithelial defects were completely healed at 72 h (2 μg BPC 157-treated group) and at 96 h (2 ng BPC 157-treated group) after injury. Aqueous cells were absent at 96 h and 120 h after injury in the 2 μg and 2 ng BPC 157-treated groups, respectively. In conclusion, BPC 157 effects the rapid regaining of corneal transparency. Whereas controls developed new vessels that grew from the limbus to the penetrated area, BPC 157-treated rats generally had no new vessels, and those that did form in the limbus did not make contact with the penetrated area. Thus, BPC 157 eye drops successfully close perforating corneal incisions in rats.

  1. High-risk corneal allografts: A therapeutic challenge

    PubMed Central

    Yu, Tian; Rajendran, Vijayalakshmi; Griffith, May; Forrester, John V; Kuffová, Lucia

    2016-01-01

    Corneal transplantation is the most common surgical procedure amongst solid organ transplants with a high survival rate of 86% at 1-year post-grafting. This high success rate has been attributed to the immune privilege of the eye. However, mechanisms originally thought to promote immune privilege, such as the lack of antigen presenting cells and vessels in the cornea, are challenged by recent studies. Nevertheless, the immunological and physiological features of the cornea promoting a relatively weak alloimmune response is likely responsible for the high survival rate in “low-risk” settings. Furthermore, although corneal graft survival in “low-risk” recipients is favourable, the prognosis in “high-risk” recipients for corneal graft is poor. In “high-risk” grafts, the process of indirect allorecognition is accelerated by the enhanced innate and adaptive immune responses due to pre-existing inflammation and neovascularization of the host bed. This leads to the irreversible rejection of the allograft and ultimately graft failure. Many therapeutic measures are being tested in pre-clinical and clinical studies to counter the immunological challenge of “high-risk” recipients. Despite the prevailing dogma, recent data suggest that tissue matching together with use of systemic immunosuppression may increase the likelihood of graft acceptance in “high-risk” recipients. However, immunosuppressive drugs are accompanied with intolerance/side effects and toxicity, and therefore, novel cell-based therapies are in development which target host immune cells and restore immune homeostasis without significant side effect of treatment. In addition, developments in regenerative medicine may be able to solve both important short comings of allotransplantation: (1) graft rejection and ultimate graft failure; and (2) the lack of suitable donor corneas. The advances in technology and research indicate that wider therapeutic choices for patients may be available to

  2. Mutation hot spots in 5q31-linked corneal dystrophies.

    PubMed Central

    Korvatska, E; Munier, F L; Djemaï, A; Wang, M X; Frueh, B; Chiou, A G; Uffer, S; Ballestrazzi, E; Braunstein, R E; Forster, R K; Culbertson, W W; Boman, H; Zografos, L; Schorderet, D F

    1998-01-01

    Mutations in the BIGH3 gene on chromosome 5q31 cause four distinct autosomal dominant diseases of the human cornea: granular (Groenouw type I), Reis-Bücklers, lattice type I, and Avellino corneal dystrophies. All four diseases are characterized by both progressive accumulation of corneal deposits and eventual loss of vision. We have identified a specific recurrent missense mutation for each type of dystrophy, in 10 independently ascertained families. Genotype analysis with microsatellite markers surrounding the BIGH3 locus was performed in these 10 families and in 5 families reported previously. The affected haplotype could be determined in 10 of the 15 families and was different in each family. These data indicate that R555W, R124C, and R124H mutations occurred independently in several ethnic groups and that these mutations do not reflect a putative founder effect. Furthermore, this study confirms the specific importance of the R124 and R555 amino acids in the pathogenesis of autosomal dominant corneal dystrophies linked to 5q. PMID:9463327

  3. Novel Lutein Loaded Lipid Nanoparticles on Porcine Corneal Distribution

    PubMed Central

    Liu, Chi-Hsien; Chiu, Hao-Che; Wu, Wei-Chi; Sahoo, Soubhagya Laxmi; Hsu, Ching-Yun

    2014-01-01

    Topical delivery has the advantages including being user friendly and cost effective. Development of topical delivery carriers for lutein is becoming an important issue for the ocular drug delivery. Quantification of the partition coefficient of drug in the ocular tissue is the first step for the evaluation of delivery efficacy. The objectives of this study were to evaluate the effects of lipid nanoparticles and cyclodextrin (CD) on the corneal lutein accumulation and to measure the partition coefficients in the porcine cornea. Lipid nanoparticles combined with 2% HPβCD could enhance lutein accumulation up to 209.2 ± 18 (μg/g) which is 4.9-fold higher than that of the nanoparticles. CD combined nanoparticles have 68% of drug loading efficiency and lower cytotoxicity in the bovine cornea cells. From the confocal images, this improvement is due to the increased partitioning of lutein to the corneal epithelium by CD in the lipid nanoparticles. The novel lipid nanoparticles could not only improve the stability and entrapment efficacy of lutein but also enhance the lutein accumulation and partition in the cornea. Additionally the corneal accumulation of lutein was further enhanced by increasing the lutein payload in the vehicles. PMID:25101172

  4. 3D map of the human corneal endothelial cell.

    PubMed

    He, Zhiguo; Forest, Fabien; Gain, Philippe; Rageade, Damien; Bernard, Aurélien; Acquart, Sophie; Peoc'h, Michel; Defoe, Dennis M; Thuret, Gilles

    2016-01-01

    Corneal endothelial cells (CECs) are terminally differentiated cells, specialized in regulating corneal hydration and transparency. They are highly polarized flat cells that separate the cornea from the aqueous humor. Their apical surface, in contact with aqueous humor is hexagonal, whereas their basal surface is irregular. We characterized the structure of human CECs in 3D using confocal microscopy of immunostained whole corneas in which cells and their interrelationships remain intact. Hexagonality of the apical surface was maintained by the interaction between tight junctions and a submembraneous network of actomyosin, braced like a drum. Lateral membranes, which support enzymatic pumps, presented complex expansions resembling interdigitated foot processes at the basal surface. Using computer-aided design and drafting software, we obtained a first simplified 3D model of CECs. By comparing their expression with those in epithelial, stromal and trabecular corneal cells, we selected 9 structural or functional proteins for which 3D patterns were specific to CECs. This first 3D map aids our understanding of the morphologic and functional specificity of CECs and could be used as a reference for characterizing future cell therapy products destined to treat endothelial dysfunctions. PMID:27381832

  5. Heat treatment enhances healing process of experimental pseudomonas corneal ulcer.

    PubMed

    Nanbu, Patricia Naomi; Wakabayashi, Taketoshi; Yamashita, Ryoko; Hayashi, Hideo; Hisano, Setsuji; Oshika, Tetsuro

    2004-01-01

    We investigated the effects of hyperthermia on the healing process of experimental Pseudomonas corneal ulceration (PCU). Hartley guinea pigs were used to develop animal models of PCU. As a heat source, disposable chemical pocket warmers were applied. The healing process of PCU was compared between the heat-treated corneas and the control corneas. The severity of infection and the degree of angiogenesis were classified by a clinical scoring system. The animals were euthanized 14 days after infection and the corneas were submitted for histopathological examination. The expression of vascular endothelial growth factor (VEGF) was examined immunohistochemically. Comparative reverse transcription polymerase chain reaction was performed to measure the expression level of VEGF in the cornea. Hyperthermia significantly promoted corneal epithelization and neovascularization in the PCU model. Heat treatment significantly decreased the number of viable Pseudomonas organisms present in PCU. On immunohistochemistry, the heated cornea demonstrated more intense staining for VEGF. Comparative reverse transcription polymerase chain reaction showed upregulation of the expression level of VEGF mRNA in the heat-treated cornea. Hyperthermia accelerated the healing process of PCU with increased corneal neovascularization. Angiogenesis may play an important role in the PCU healing process, which is enhanced by the heat treatment. PMID:15292660

  6. Theoretical and numerical analysis of the corneal air puff test

    NASA Astrophysics Data System (ADS)

    Simonini, Irene; Angelillo, Maurizio; Pandolfi, Anna

    2016-08-01

    Ocular analyzers are used in the current clinical practice to estimate, by means of a rapid air jet, the intraocular pressure and other eye's parameters. In this study, we model the biomechanical response of the human cornea to the dynamic test with two approaches. In the first approach, the corneal system undergoing the air puff test is regarded as a harmonic oscillator. In the second approach, we use patient-specific geometries and the finite element method to simulate the dynamic test on surgically treated corneas. In spite of the different levels of approximation, the qualitative response of the two models is very similar, and the most meaningful results of both models are not significantly affected by the inclusion of viscosity of the corneal material in the dynamic analysis. Finite element calculations reproduce the observed snap-through of the corneal shell, including two applanate configurations, and compare well with in vivo images provided by ocular analyzers, suggesting that the mechanical response of the cornea to the air puff test is actually driven only by the elasticity of the stromal tissue. These observations agree with the dynamic characteristics of the test, since the frequency of the air puff impulse is several orders of magnitude larger than the reciprocal of any reasonable relaxation time for the material, downplaying the role of viscosity during the fast snap-through phase.

  7. [Corneal metabolism with contact lenses in competitive sports].

    PubMed

    Schnell, D; Khaireddin, R

    2013-06-01

    The corneal metabolism during the use of contact lenses plays an important role for permanent corneal health, especially in competitive sports. Thus, it is important to understand the steps of corneal metabolism in general and during highly competitive sports activity in particular. The aim of this review is to summarize the current knowledge on physiological and biochemical effects of contact lens wear. Of the energy requirements of the cornea 75 % is supplied by aerobic processes; therefore, the eye needs the highest possible amount of oxygen and sufficient glucose which can be obtained from external air and to a lesser degree from within the anterior chamber. If the oxygen supply is too low this results in hypoxic edema. Fitting athletes with contact lenses must still be viewed with caution as the visual needs of athletes are usually much more demanding than those of the general public. An indiscriminate choice of lens design can adversely affect athletic performance and may even create a hazardous situation. An intelligent choice of contact lens can provide some subtle advantages that may improve athletic performance and provide the decisive margin for victory.

  8. Protective effects of matrix metalloproteinase-12 following corneal injury.

    PubMed

    Chan, Matilda F; Li, Jing; Bertrand, Anthony; Casbon, Amy-Jo; Lin, Jeffrey H; Maltseva, Inna; Werb, Zena

    2013-09-01

    Corneal scarring due to injury is a leading cause of blindness worldwide and results from dysregulated inflammation and angiogenesis during wound healing. Here we demonstrate that the extracellular matrix metalloproteinase MMP12 (macrophage metalloelastase) is an important regulator of these repair processes. Chemical injury resulted in higher expression of the fibrotic markers α-smooth muscle actin and type I collagen, and increased levels of angiogenesis in corneas of Mmp12(-/-) mice compared with corneas of wild-type mice. In vivo, we observed altered immune cell dynamics in Mmp12(-/-) corneas by confocal imaging. We determined that the altered dynamics were the result of an altered inflammatory response, with delayed neutrophil infiltration during the first day and excessive macrophage infiltration 6 days later, mediated by altered expression levels of chemokines CXCL1 and CCL2, respectively. Corneal repair returned to normal upon inhibition of these chemokines. Taken together, these data show that MMP12 has a protective effect on corneal fibrosis during wound repair through regulation of immune cell infiltration and angiogenesis.

  9. In Vitro Expansion of Corneal Endothelial Cells on Biomimetic Substrates

    PubMed Central

    Palchesko, Rachelle N.; Lathrop, Kira L.; Funderburgh, James L.; Feinberg, Adam W.

    2015-01-01

    Corneal endothelial (CE) cells do not divide in vivo, leading to edema, corneal clouding and vision loss when the density drops below a critical level. The endothelium can be replaced by transplanting allogeneic tissue; however, access to donated tissue is limited worldwide resulting in critical need for new sources of corneal grafts. In vitro expansion of CE cells is a potential solution, but is challenging due to limited proliferation and loss of phenotype in vitro via endothelial to mesenchymal transformation (EMT) and senescence. We hypothesized that a bioengineered substrate recapitulating chemo-mechanical properties of Descemet's membrane would improve the in vitro expansion of CE cells while maintaining phenotype. Results show that bovine CE cells cultured on a polydimethylsiloxane surface with elastic modulus of 50 kPa and collagen IV coating achieved >3000-fold expansion. Cells grew in higher-density monolayers with polygonal morphology and ZO-1 localization at cell-cell junctions in contrast to control cells on polystyrene that lost these phenotypic markers coupled with increased α-smooth muscle actin expression and fibronectin fibril assembly. In total, these results demonstrate that a biomimetic substrate presenting native basement membrane ECM proteins and mechanical environment may be a key element in bioengineering functional CE layers for potential therapeutic applications. PMID:25609008

  10. Neutrophil extracellular traps involvement in corneal fungal infection

    PubMed Central

    Zhao, Yingying; Zhang, Fan; Wan, Ting; Fan, Fangli; Xie, Xin; Lin, Zhenyun

    2016-01-01

    Purpose Neutrophils release neutrophil extracellular traps (NETs) when defending against invading microorganisms. We investigated the existence of NETs in fungal keratitis. Methods Fourteen patients with unilateral fungal keratitis were included. Detailed information about each patient was recorded, including (1) patient history (onset of symptoms and previous therapy), (2) ocular examination findings by slit-lamp biomicroscopy, (3) laboratory findings from direct smear examination and culture of corneal scrapings, (4) NET formation, and (5) treatment strategy and prognosis. Immunofluorescence staining was used to evaluate the existence of NETs on corneal scrapings. The relationship between the quantification of NETs and the clinical character of the fungal keratitis was identified. Results NETs were identified in all 14 patients. Patients with a higher grade of NET formation and fewer fungal hyphae always showed a good treatment response and a short course of infection. NETs were consistently found mixed with fungal hyphae in the corneal scrapings from infected patients. No statistical significance was found between the grade of NETs formed and the course of infection before presentation, and no relationship between the quantification of NETs and the size of the ulcer was found. Conclusions The results suggest that NETs are involved in fungal keratitis. The number of NETs in infected corneas may provide a tool for evaluating the prognosis for fungal keratitis. PMID:27559290

  11. Cross-linking and the molecular packing of corneal collagen

    NASA Technical Reports Server (NTRS)

    Yamauchi, M.; Chandler, G. S.; Tanzawa, H.; Katz, E. P.

    1996-01-01

    We have quantitatively characterized, for the first time, the cross-linking in bovine cornea collagen as a function of age. The major iminium reducible cross-links were dehydro-hydroxylysinonorleucine (deH-HLNL) and dehydro-histidinohydroxymerodesmosine (deH-HHMD). The former rapidly diminished after birth; however, the latter persisted in mature animals at a level of 0.3 - 0.4 moles/mole of collagen. A nonreducible cross-link, histidinohydroxylysinonorleucine (HHL), previously found only in skin, was also found to be a major mature cross-link in cornea. The presence of HHL indicates that cornea fibrils have a molecular packing similar to skin collagen. However, like deH-HHMD, the HHL content in corneal fibrils only reaches a maximum value with time about half that of skin. These data suggest that the corneal fibrils are comprised of discrete filaments that are internally stabilized by HHL and deH-HHMD cross-links. This pattern of intermolecular cross-linking would facilitate the special collagen swelling property required for corneal transparency.

  12. Transparent, resilient human amniotic membrane laminates for corneal transplantation.

    PubMed

    Hariya, Takehiro; Tanaka, Yuji; Yokokura, Shunji; Nakazawa, Toru

    2016-09-01

    This study evaluated a new technique to toughen and optically clarify human amniotic membrane (AM) tissue, which is naturally thin and clouded, and determined the suitability of the altered tissue for corneal transplantation. The technique created a tissue laminate by repeatedly depositing wet layers of AM and dehydrating them, followed by chemical cross-linking to tighten integration at the layer interfaces and within the layers, thereby improving the physical properties of the laminates by increasing light transmittance and mechanical strength. Interestingly, this improvement only occurred in laminates with at least 4 layers. Cross-linking also improved the resistance of the laminates to collagenase degradation, such as occurs in corneal melting. This study also confirmed that the AM tissue was biocompatible by inserting AM monolayers into the corneal stroma of rabbits, and by performing lamellar keratoplasty in rabbits with cross-linked AM laminates. The laminates were sufficiently thick and resilient to need only one set of sutures, whereas in previously described multi-layer AM transplantation technique, each layer required separate sutures. The current findings are a promising advance in the engineering of novel biomaterials and the alteration of existing tissues for medical use. PMID:27267629

  13. New Trends in Quantitative Assessment of the Corneal Barrier Function

    PubMed Central

    Guimerà, Anton; Illa, Xavi; Traver, Estefania; Herrero, Carmen; Maldonado, Miguel J.; Villa, Rosa

    2014-01-01

    The cornea is a very particular tissue due to its transparency and its barrier function as it has to resist against the daily insults of the external environment. In addition, maintenance of this barrier function is of crucial importance to ensure a correct corneal homeostasis. Here, the corneal epithelial permeability has been assessed in vivo by means of non-invasive tetrapolar impedance measurements, taking advantage of the huge impact of the ion fluxes in the passive electrical properties of living tissues. This has been possible by using a flexible sensor based in SU-8 photoresist. In this work, a further analysis focused on the validation of the presented sensor is performed by monitoring the healing process of corneas that were previously wounded. The obtained impedance measurements have been compared with the damaged area observed in corneal fluorescein staining images. The successful results confirm the feasibility of this novel method, as it represents a more sensitive in vivo and non-invasive test to assess low alterations of the epithelial permeability. Then, it could be used as an excellent complement to the fluorescein staining image evaluation. PMID:24841249

  14. In vitro expansion of corneal endothelial cells on biomimetic substrates.

    PubMed

    Palchesko, Rachelle N; Lathrop, Kira L; Funderburgh, James L; Feinberg, Adam W

    2015-01-01

    Corneal endothelial (CE) cells do not divide in vivo, leading to edema, corneal clouding and vision loss when the density drops below a critical level. The endothelium can be replaced by transplanting allogeneic tissue; however, access to donated tissue is limited worldwide resulting in critical need for new sources of corneal grafts. In vitro expansion of CE cells is a potential solution, but is challenging due to limited proliferation and loss of phenotype in vitro via endothelial to mesenchymal transformation (EMT) and senescence. We hypothesized that a bioengineered substrate recapitulating chemo-mechanical properties of Descemet's membrane would improve the in vitro expansion of CE cells while maintaining phenotype. Results show that bovine CE cells cultured on a polydimethylsiloxane surface with elastic modulus of 50 kPa and collagen IV coating achieved >3000-fold expansion. Cells grew in higher-density monolayers with polygonal morphology and ZO-1 localization at cell-cell junctions in contrast to control cells on polystyrene that lost these phenotypic markers coupled with increased α-smooth muscle actin expression and fibronectin fibril assembly. In total, these results demonstrate that a biomimetic substrate presenting native basement membrane ECM proteins and mechanical environment may be a key element in bioengineering functional CE layers for potential therapeutic applications. PMID:25609008

  15. Decay accelerating factor is essential for successful corneal engraftment

    PubMed Central

    Esposito, Andrew; Suedekum, Brandon; Liu, Jinbo; An, Fengqi; Lass, Jonathan; Strainic, Michael G; Lin, Feng; Heeger, Peter; Medof, M. Edward

    2012-01-01

    In contrast to immune restrictions that pertain for solid organ transplants, the tolerogenic milieu of the eye permits successful corneal transplantation without systemic immunosuppression, even across a fully MHC disparate barrier. Here we show that recipient and donor expression of decay accelerating factor (DAF or CD55), a cell surface C3/C5 convertase regulator recently shown to modulate T cell responses, is essential to sustain successful corneal engraftment. Whereas wild type (WT) corneas transplanted into multiple minor histocompatibility antigen (mH), or HY disparate WT recipients were accepted, DAF’s absence on either the donor cornea or in the recipient bed induced rapid rejection. Donor or recipient DAF deficiency led to expansion of donor-reactive IFN-γ producing CD4+ and CD8+ T cells, as well as inhibition of antigen induced IL-10 and TGF-β, together demonstrating that DAF deficiency precludes immune tolerance. In addition to demonstrating a requisite role for DAF in conferring ocular immune privilege, these results raise the possibility that augmenting DAF levels on corneal endothelium and/or the recipient bed could have therapeutic value for transplants that clinically are at high risk for rejection. PMID:20055803

  16. Shaping Corneal Transplants with a Scanning Laser System

    NASA Astrophysics Data System (ADS)

    Homolka, Peter; Biowski, Robert; Gosch-Baumgartner, Isabella; Husinsky, Wolfgang; Grabner, Günter

    1997-03-01

    We present an improved commercially available Laser device for shaping corneal grafts with an ArF excimer laser. In this system the laser beam is steady and scanning is realized by moving the cornea under the beam using three stepper motors. The Excimer Laser Corneal Shaping System (ELCS-S2) is used to prepare donor buttons for penetrating keratoplasty as well as refractive lenticules of corneal tissue for correcting both hyperopia and myopia with epikeratophakia. Whereas the former is already a routinely used technique, the latter -- like lenticules used for correcting astigmatism -- is still a topic of research. We developed a new algorithm to calculate the ablation parameters based on more sophisticated optimizations of mechanical parameters like beam size and ablation radii and a more accurate mathematical model. Before implementation the algorithm was tested and optimized using a simulation on alpha-generation workstations. We could reduce surface roughness by a factor >10. This is of crucial importance if the optical center of the cornea is effected.

  17. 3D map of the human corneal endothelial cell

    PubMed Central

    He, Zhiguo; Forest, Fabien; Gain, Philippe; Rageade, Damien; Bernard, Aurélien; Acquart, Sophie; Peoc’h, Michel; Defoe, Dennis M.; Thuret, Gilles

    2016-01-01

    Corneal endothelial cells (CECs) are terminally differentiated cells, specialized in regulating corneal hydration and transparency. They are highly polarized flat cells that separate the cornea from the aqueous humor. Their apical surface, in contact with aqueous humor is hexagonal, whereas their basal surface is irregular. We characterized the structure of human CECs in 3D using confocal microscopy of immunostained whole corneas in which cells and their interrelationships remain intact. Hexagonality of the apical surface was maintained by the interaction between tight junctions and a submembraneous network of actomyosin, braced like a drum. Lateral membranes, which support enzymatic pumps, presented complex expansions resembling interdigitated foot processes at the basal surface. Using computer-aided design and drafting software, we obtained a first simplified 3D model of CECs. By comparing their expression with those in epithelial, stromal and trabecular corneal cells, we selected 9 structural or functional proteins for which 3D patterns were specific to CECs. This first 3D map aids our understanding of the morphologic and functional specificity of CECs and could be used as a reference for characterizing future cell therapy products destined to treat endothelial dysfunctions. PMID:27381832

  18. Optimization model for UV-Riboflavin corneal cross-linking

    NASA Astrophysics Data System (ADS)

    Schumacher, S.; Wernli, J.; Scherrer, S.; Bueehler, M.; Seiler, T.; Mrochen, M.

    2011-03-01

    Nowadays UV-cross-linking is an established method for the treatment of keraectasia. Currently a standardized protocol is used for the cross-linking treatment. We will now present a theoretical model which predicts the number of induced crosslinks in the corneal tissue, in dependence of the Riboflavin concentration, the radiation intensity, the pre-treatment time and the treatment time. The model is developed by merging the difussion equation, the equation for the light distribution in dependence on the absorbers in the tissue and a rate equation for the polymerization process. A higher concentration of Riboflavin solution as well as a higher irradiation intensity will increase the number of induced crosslinks. However, performed stress-strain experiments which support the model showed that higher Riboflavin concentrations (> 0.125%) do not result in a further increase in stability of the corneal tissue. This is caused by the inhomogeneous distribution of induced crosslinks throughout the cornea due to the uneven absorption of the UV-light. The new model offers the possibility to optimize the treatment individually for every patient depending on their corneal thickness in terms of efficiency, saftey and treatment time.

  19. Effect of Stratification on Surface Properties of Corneal Epithelial Cells

    PubMed Central

    Yáñez-Soto, Bernardo; Leonard, Brian C.; Raghunathan, Vijay Krishna; Abbott, Nicholas L.; Murphy, Christopher J.

    2015-01-01

    Purpose The purpose of this study was to determine the influence of mucin expression in an immortalized human corneal epithelial cell line (hTCEpi) on the surface properties of cells, such as wettability, contact angle, and surface heterogeneity. Methods hTCEpi cells were cultured to confluence in serum-free medium. The medium was then replaced by stratification medium to induce mucin biosynthesis. The mucin expression profile was analyzed using quantitative PCR and Western blotting. Contact angles were measured using a two-immiscible liquid method, and contact angle hysteresis was evaluated by tilting the apparatus and recording advancing and receding contact angles. The spatial distribution of mucins was evaluated with fluorescently labeled lectin. Results hTCEpi cells expressed the three main ocular mucins (MUC1, MUC4, and MUC16) with a maximum between days 1 and 3 of the stratification process. Upon stratification, cells caused a very significant increase in contact angle hysteresis, suggesting the development of spatially discrete and heterogeneously distributed surface features, defined by topography and/or chemical functionality. Although atomic force microscopy measurements showed no formation of appreciable topographic features on the surface of the cells, we observed a significant increase in surface chemical heterogeneity. Conclusions The surface chemical heterogeneity of the corneal epithelium may influence the dynamic behavior of tear film by “pinning” the contact line between the cellular surface and aqueous tear film. Engineering the surface properties of corneal epithelium could potentially lead to novel treatments in dry eye disease. PMID:26747762

  20. Data acquisition time constraints in elevation mapping corneal topography

    NASA Astrophysics Data System (ADS)

    Baron, William S.; Baron, Sandra F.

    1997-05-01

    Elevation mapping corneal topography instruments provide an array of x, y, z data points describing the corneal surface. An advantage of elevation mapping instruments is their ability to calculate the 3D data array strictly from the instrument's geometry and calibration data; no assumptions about the corneal surface itself are needed. However, uncompensated eye movements can affect accuracy. Longitudinal eye movements occur along the z axis, due to pulmonary and cardiac pulsations. Eye rotations due to saccades and drifts are normal occurrences, as are translational body movements. An analysis of eye and body movements at the cornea's surface indicates a nearly linear relationship between data acquisition times of less than 33 msec, and the possible change in elevation at a point referenced to an instrument axis. The proportionality constant is expected to vary by a factor of about six over the range of clinical patients, since eye and body movements are exaggerated in juvenile patients, geriatric patients, and patients with poor vision. The analysis estimates an elevation change due to rotation and longitudinal translation of the eye of up to +/- 285 micrometers in 33 msec within the clinical population. This analysis indicates that when a topographer's acquisition time is greater than 100 microsecond(s) ec (during which an apparent elevation change of up to 1.0 micrometers may occur) testing on static objects may not provide a realistic measure of an instrument's clinical performance.

  1. Acute Bronchitis

    MedlinePlus

    ... tightness. There are two main types of bronchitis: acute and chronic. Most cases of acute bronchitis get better within several days. But your ... that cause colds and the flu often cause acute bronchitis. These viruses spread through the air when ...

  2. Oxidative Stress to the Cornea, Changes in Corneal Optical Properties, and Advances in Treatment of Corneal Oxidative Injuries

    PubMed Central

    Cejka, Cestmir; Cejkova, Jitka

    2015-01-01

    Oxidative stress is involved in many ocular diseases and injuries. The imbalance between oxidants and antioxidants in favour of oxidants (oxidative stress) leads to the damage and may be highly involved in ocular aging processes. The anterior eye segment and mainly the cornea are directly exposed to noxae of external environment, such as air pollution, radiation, cigarette smoke, vapors or gases from household cleaning products, chemical burns from splashes of industrial chemicals, and danger from potential oxidative damage evoked by them. Oxidative stress may initiate or develop ocular injury resulting in decreased visual acuity or even vision loss. The role of oxidative stress in the pathogenesis of ocular diseases with particular attention to oxidative stress in the cornea and changes in corneal optical properties are discussed. Advances in the treatment of corneal oxidative injuries or diseases are shown. PMID:25861412

  3. Oxidative stress to the cornea, changes in corneal optical properties, and advances in treatment of corneal oxidative injuries.

    PubMed

    Cejka, Cestmir; Cejkova, Jitka

    2015-01-01

    Oxidative stress is involved in many ocular diseases and injuries. The imbalance between oxidants and antioxidants in favour of oxidants (oxidative stress) leads to the damage and may be highly involved in ocular aging processes. The anterior eye segment and mainly the cornea are directly exposed to noxae of external environment, such as air pollution, radiation, cigarette smoke, vapors or gases from household cleaning products, chemical burns from splashes of industrial chemicals, and danger from potential oxidative damage evoked by them. Oxidative stress may initiate or develop ocular injury resulting in decreased visual acuity or even vision loss. The role of oxidative stress in the pathogenesis of ocular diseases with particular attention to oxidative stress in the cornea and changes in corneal optical properties are discussed. Advances in the treatment of corneal oxidative injuries or diseases are shown. PMID:25861412

  4. Differing Roles for TCF4 and COL8A2 in Central Corneal Thickness and Fuchs Endothelial Corneal Dystrophy

    PubMed Central

    Igo, Robert P.; Kopplin, Laura J.; Joseph, Peronne; Truitt, Barbara; Fondran, Jeremy; Bardenstein, David; Aldave, Anthony J.; Croasdale, Christopher R.; Price, Marianne O.; Rosenwasser, Miriam

    2012-01-01

    Fuchs endothelial corneal dystrophy (FECD) is the most common late-onset, vision-threatening corneal dystrophy in the United States, affecting about 4% of the population. Advanced FECD involves a thickening of the cornea from stromal edema and changes in Descemet membrane. To understand the relationship between FECD and central corneal thickness (CCT), we characterized common genetic variation in COL8A2 and TCF4, genes previously implicated in CCT and/or FECD. Other genes previously associated with FECD (PITX2, ZEB1, SLC4A11), and genes only known to affect CCT (COL5A1, FOXO1, AVGR8, ZNF469) were also interrogated. FECD probands, relatives and controls were recruited from 32 clinical sites; a total of 532 cases and 204 controls were genotyped and tested for association of FECD case/control status, a 7-step FECD severity scale and CCT, adjusting for age and sex. Association of FECD grade with TCF4 was highly significant (OR  = 6.01 at rs613872; p = 4.8×10−25), and remained significant when adjusted for changes in CCT (OR  = 4.84; p = 2.2×10−16). Association of CCT with TCF4 was also significant (p = 6.1×10−7), but was abolished with adjustment for FECD grade (p = 0.92). After adjusting for FECD grade, markers in other genes examined were modestly associated (p ∼ 0.001) with FECD and/or CCT. Thus, common variants in TCF4 appear to influence FECD directly, and CCT secondarily via FECD. Additionally, changes in corneal thickness due to the effect of other loci may modify disease severity, age-at-onset, or other biomechanical characteristics. PMID:23110055

  5. Estimation of Intraocular Lens Power Calculation after Myopic Corneal Refractive Surgery: Using Corneal Height in Anterior Segment Optical Coherence Tomography

    PubMed Central

    Kim, Dong Hyun; Wee, Won Ryang

    2015-01-01

    Purpose To investigate the feasibility of estimating effective lens position (ELP) and calculating intraocular lens power using corneal height (CH), as measured using anterior segment optical coherence tomography (AS-OCT), in patients who have undergone corneal refractive surgery. Methods This study included 23 patients (30 eyes) who have undergone myopic corneal refractive surgery and subsequent successful cataract surgery. The CH was measured with AS-OCT, and the measured ELP (ELPm) was calculated. Intraocular lens power, which could achieve actual emmetropia (Preal), was determined with medical records. Estimated ELP (ELPest) was back-calculated using Preal, axial length, and keratometric value through the SRK/T formula. After searching the best-fit regression formula between ELPm and ELPest, converted ELP and intraocular lens power (ELPconv, Pconv) were obtained and then compared to ELPest and Preal, respectively. The proportion of eyes within a defined error was investigated. Results Mean CH, ELPest, and ELPm were 3.71 ± 0.23, 7.74 ± 1.09, 5.78 ± 0.26 mm, respectively. The ELPm and ELPest were linearly correlated (ELPest = 1.841 × ELPm - 2.018, p = 0.023, R = 0.410) and ELPconv and Pconv agreed well with ELPest and Preal, respectively. Eyes within ±0.5, ±1.0, ±1.5, and ±2.0 diopters of the calculated Pconv, were 23.3%, 66.6%, 83.3%, and 100.0%, respectively. Conclusions Intraocular lens power calculation using CH measured with AS-OCT shows comparable accuracy to several conventional methods in eyes following corneal refractive surgery. PMID:26028949

  6. Donor Age and Corneal Endothelial Cell Loss 5 Years after Successful Corneal Transplantation: Specular Microscopy Ancillary Study Results

    PubMed Central

    2010-01-01

    Objective To determine whether endothelial cell loss 5 years after successful corneal transplantation is related to the age of the donor. Design Multicenter, prospective, double-masked clinical trial. Participants Three hundred forty-seven subjects participating in the Cornea Donor Study who had not experienced graft failure 5 years after corneal transplantation for a moderate-risk condition (principally Fuchs’ dystrophy or pseudophakic corneal edema). Testing Specular microscopic images of donor corneas obtained before surgery and postoperatively at 6 months, 12 months, and then annually through 5 years were submitted to a central reading center to measure endothelial cell density (ECD). Main Outcome Measure Endothelial cell density at 5 years. Results At 5 years, there was a substantial decrease in ECD from baseline for all donor ages. Subjects who received a cornea from a donor 12 to 65 years old experienced a median cell loss of 69% in the study eye, resulting in a 5-year median ECD of 824 cells/mm2 (interquartile range, 613–1342), whereas subjects who received a cornea from a donor 66 to 75 years old experienced a cell loss of 75%, resulting in a median 5-year ECD of 654 cells/mm2 (interquartile range, 538–986) (P [adjusted for baseline ECD] = 0.04). Statistically, there was a weak negative association between ECD and donor age analyzed as a continuous variable (r [adjusted for baseline ECD] = −0.19; 95% confidence interval, −0.29 to −0.08). Conclusions Endothelial cell loss is substantial in the 5 years after corneal transplantation. There is a slight association between cell loss and donor age. This finding emphasizes the importance of longer-term follow-up of this cohort to determine if this relationship affects graft survival. PMID:18387408

  7. Entropy of corneal nerve fibers distribution observed by laser scanning confocal microscopy: A noninvasive quantitative method to characterize the corneal innervation in Sjogren's syndrome patients.

    PubMed

    Bianciardi, Giorgio; Latronico, Maria Eugenia; Traversi, Claudio

    2015-12-01

    Sjogren's syndrome (SS) is a progressive autoimmune condition mainly affecting the salivary and lacrimal glands with an incidence of primary SS between 1/100 and 1/1,000. SS implies an alteration in the epithelium and subepithelium innervation, with consequent reduction of corneal sensitivity. It is necessary to have noninvasive quantitative methods to characterize the status of the corneal nerve fibers of the patients in order to choose and follow the best therapy. Entropy (information dimension) of the nerve corneal fibers distribution observed by confocal microscopy was evaluated in patients with primary SS (n = 30, 6 males, 24 females, 21-81 years), diagnosed by biopsy of salivary gland and blood tests and in sex- age-matched healthy subjects (n = 12). Corneal nerve fiber density, Langerhans cell count, and cell density in the nerve plexus images were also evaluated. In selected patients salivary gland atrophy degree was also evaluated. Nerve corneal distribution observed by confocal microscopy is fractal. Entropy of the corneal nerve distribution statistically distinguishes between SS patients and healthy subjects: patients present a lower value of information dimension of the corneal nerve fibers distribution than healthy individuals (P < 0.001). Percentage of grouped cases classified by entropy according to the subjects (selected patients vs. healthy) showed a 100% sensitivity and 96% specificity, P < 0.0001 with a low value of coefficient of variation among the individuals (6-7 times lower than the other morphometric indexes). Entropy correlated with the severity of the disease (salivary gland atrophy degree, P < 0.01). Evaluation of entropy of the corneal nerve distribution observed by a laser confocal microscopy appears to quantitatively and noninvasively characterize an aspect of the SS patients in relation to the recognition of an impairment of their ocular surface, giving us for the first time a method to objectively and precisely

  8. Assessment of Corneal Epithelial Thickness in Dry Eye Patients

    PubMed Central

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

    2014-01-01

    Purpose To investigate the features of corneal epithelial thickness topography with Fourier-domain optical coherence tomography (OCT) in dry eye patients. Methods 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. Results 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 < 0.001) epithelial thickness, more wide range (p = 0.032), and greater deviation (p = 0.003). The average central epithelial thickness had no correlation with tear breakup time, S1t, or the severity of meibomian glands, whereas average superior epithelial thickness positively correlated with S1t (r = 0.238, p = 0.017). Conclusions Fourier-domain OCT demonstrated that the thickness map of the 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. PMID:25279779

  9. Riboflavin-Ultraviolet A Corneal Cross-linking for Keratoconus

    PubMed Central

    El-Raggal, Tamer M.

    2009-01-01

    Purpose: To evaluate the safety, efficacy of riboflavin-ultraviolet A irradiation (UVA) corneal cross-linking and present refractive changes induced by the treatment in cases of keratoconus. Materials and Methods: The study includes 15 eyes of 9 patients with keratoconus with an average keratometric (K) reading less than 54 D and minimal corneal thickness greater than 420 microns. The corneal epithelium was removed manually within the central 8.5 mm diameter area and the cornea was soaked with riboflavin eye drops (0.1% in 20% dextran τ-500) for 30 minutes followed by exposure to UVA radiation (365 nm, 3 mW/cm2) for 30 minutes. During the follow-up period, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, slit lamp examination and topographic changes were recorded at the first week, first month, 3 and 6 months. Results: There was statistically significant improvement of UCVA from a preoperative mean of 0.11 ± 0.07 (range 0.05–0.3) to a postoperative mean of 0.15 ± 0.06 (range 0.1–0.3) (P < 0.05). None of the eyes lost lines of preoperative UCVA but 1 eye lost 1 line of preoperative BSCVA. The preoperative mean K of 49.97 ± 2.81 D (range 47.20–51.75) changed to 48.34 ± 2.64 D (range 45.75–50.40). This decrease in K readings was statistically significant (P < 0.05). All eyes developed minimal faint stromal haze that cleared in 14 eyes within 1 month. In only 1 eye, this resulted in a very faint corneal scar. Other sight threatening complications were not encountered in this series. Progression of the original disease was not seen in any of the treated eyes within 6 months of follow-up. Conclusion: Riboflavin-UVA corneal cross-linking is a safe and promising method for keratoconus. Larger studies with longer follow up are recommended. PMID:20404993

  10. Oxygen transfer in the corneal-contact lens system.

    PubMed

    Garr-Peters, J M; Ho, C S

    1987-01-01

    The clinical results of contact lens wearers indicate that materials which theoretically are adequate to prevent corneal hypoxia and edema do not perform optimally under actual wearing conditions. Optimization of the cornea-tear-lens system requires an analysis of the modes of oxygen transport, mass transfer resistances, and characteristic dimensions. The lens properties are a function of polymer composition. Thus, investigations for ideal lens materials may result in limitless test copolymers and graft polymers of siloxane, methylmethacrylate, 2-hydroxyethyl-methacrylate, vinylpyrollidone, vinylacetate, and cellulose acetate butyrate of varying degrees of cross-linking and crystallinity. In an attempt to channel research efforts, this review will state the developments to date and the desirable properties of an optimal cornea-tear-lens system. The logic should encompass a theory and model whereby parameters are identified and varied within satisfactory physiological limitations, and experiments which provide data indicative of the in vivo conditions. The parameters must reflect the inherent transport properties of the corneal-contact lens system. Contact lenses may be categorized as soft, gas-permeable rigid/hydrophobic flexible, or hard. The major differences between these three categories are the properties: equilibrium water content or degree of hydration, tendency for water pervaporation and/or dehydration, surface hydrophobicity, thermal conductivity, oxygen diffusivity and solubility, lens thickness, rest height over corneal tear, flexibility, lens mobility over the cornea, cross-linking, crystallinity, stagnant boundary layer resistances, and manufacturing processes. Aside from complications presented by lens coatings and cleansing solutions, the most common problems experienced by lens wearers include corneal edema, dehydration involving the lens and the cornea, "blurry" vision due to localized corneal anoxia, debris trapped under the lens, and deposits on

  11. Differentiation of mild keratoconus from corneal warpage according to topographic inferior steepening based on corneal tomography data.

    PubMed

    Patrão, Lia Florim; Canedo, Ana Laura Caiado; Azevedo, João Luiz Peixoto Braga de; Correa, Rosane; Ambrósio, Renato

    2016-01-01

    We report two cases of suspicious asymmetric bow tie and inferior steepening on topographic evaluations with reflection (Placido) and projection (Scheimpflug). Rotating Scheimpflug corneal and anterior segment tomography (Oculus Pentacam HR, Wetzlar, Germany)® was performed in the first case, with a maximal keratometric value (Kmax) of 43.2 D and an overall deviation value from the Belin/Ambrósio Enhanced Ectasia Display (BAD-D) of 1.76, which was observed in the study eye (OD). BAD-D was 6.59 in the fellow eye, which had clinical findings that were consistent with keratoconus stage 2. The second case presented with a Kmax of 45.3 D and BAD-D of 0.76 in OD and 1.01 in OS. This patient had discontinued wearing soft contact lens less than 1 day prior to examination. Corneal tomographic data enabled us to distinguish mild or forme fruste keratoconus from contact lens-induced corneal warpage, and similar findings were observed on curvature maps. PMID:27626155

  12. Contact-mediated control of radial migration of corneal epithelial cells

    PubMed Central

    Walczysko, Petr; Rajnicek, Ann M.

    2016-01-01

    Purpose Patients with a heterozygous mutation in the gene encoding the transcription factor, PAX6, have a degenerative corneal opacity associated with failure of normal radial epithelial cell migration across the corneal surface and a reported wound healing defect. This study investigated the guidance mechanisms that drive the directed migration of corneal epithelial cells. Methods In vivo corneal epithelial wounding was performed in adult wild-type and Pax6+/− mice, and the healing migration rates were compared. To investigate the control of the cell migration direction, primary corneal epithelial cells from wild-type and Pax6+/− mice were plated on grooved quartz substrates, and alignment relative to the grooves was assayed. A reconstructed corneal culture system was developed in which dissociated wild-type and genetically mutant corneal epithelial cells could be cultured on a de-epithelialized corneal stroma or basement membrane and their migration assayed with time-lapse microscopy. Results The Pax6+/− cells efficiently re-epithelialized corneal wounds in vivo but had mild slowing of healing migration compared to the wild-type. Cells aligned parallel to quartz grooves in vitro, but the Pax6+/− cells were less robustly oriented than the wild-type. In the reconstructed corneal culture system, corneal epithelial cells continued to migrate radially, showing that the cells are guided by contact-mediated cues from the basement membrane. Recombining wild-type and Pax6 mutant corneal epithelial cells with wild-type and Pax6 mutant corneal stroma showed that normal Pax6 dosage was required autonomously in the epithelial cells for directed migration. Integrin-mediated attachment to the substrate, and intracellular PI3Kγ activity, were required for migration. Pharmacological inhibition of cAMP signaling randomized migration tracks in reconstructed corneas. Conclusions Striking patterns of centripetal migration of corneal epithelial cells observed in vivo are

  13. Concise Review: An Update on the Culture of Human Corneal Endothelial Cells for Transplantation.

    PubMed

    Parekh, Mohit; Ferrari, Stefano; Sheridan, Carl; Kaye, Stephen; Ahmad, Sajjad

    2016-02-01

    The cornea forms the front window of the eye, enabling the transmission of light to the retina through a crystalline lens. Many disorders of the cornea lead to partial or total blindness, and therefore corneal transplantation becomes mandatory. Recently, selective corneal layer (as opposed to full thickness) transplantation has become popular because this leads to earlier rehabilitation and visual outcomes. Corneal endothelial disorders are a common cause of corneal disease and transplantation. Corneal endothelial transplantation is successful but limited worldwide because of lower donor corneal supply. Alternatives to corneal tissue for endothelial transplantation therefore require immediate attention. The field of human corneal endothelial culture for transplantation is rapidly emerging as a possible viable option. This manuscript provides an update regarding these developments. Significance: The cornea is the front clear window of the eye. It needs to be kept transparent for normal vision. It is formed of various layers of which the posterior layer (the endothelium) is responsible for the transparency of the cornea because it allows the transport of ions and solutes to and from the other layers of the cornea. Corneal blindness that results from the corneal endothelial dysfunction can be treated using healthy donor tissues. There is a huge demand for human donor corneas but limited supply, and therefore there is a need to identify alternatives that would reduce this demand. Research is underway to understand the isolation techniques for corneal endothelial cells, culturing these cells in the laboratory, and finding possible options to transplant these cells in the patients. This review article is an update on the recent developments in this field. PMID:26702128

  14. Concise Review: An Update on the Culture of Human Corneal Endothelial Cells for Transplantation.

    PubMed

    Parekh, Mohit; Ferrari, Stefano; Sheridan, Carl; Kaye, Stephen; Ahmad, Sajjad

    2016-02-01

    The cornea forms the front window of the eye, enabling the transmission of light to the retina through a crystalline lens. Many disorders of the cornea lead to partial or total blindness, and therefore corneal transplantation becomes mandatory. Recently, selective corneal layer (as opposed to full thickness) transplantation has become popular because this leads to earlier rehabilitation and visual outcomes. Corneal endothelial disorders are a common cause of corneal disease and transplantation. Corneal endothelial transplantation is successful but limited worldwide because of lower donor corneal supply. Alternatives to corneal tissue for endothelial transplantation therefore require immediate attention. The field of human corneal endothelial culture for transplantation is rapidly emerging as a possible viable option. This manuscript provides an update regarding these developments. Significance: The cornea is the front clear window of the eye. It needs to be kept transparent for normal vision. It is formed of various layers of which the posterior layer (the endothelium) is responsible for the transparency of the cornea because it allows the transport of ions and solutes to and from the other layers of the cornea. Corneal blindness that results from the corneal endothelial dysfunction can be treated using healthy donor tissues. There is a huge demand for human donor corneas but limited supply, and therefore there is a need to identify alternatives that would reduce this demand. Research is underway to understand the isolation techniques for corneal endothelial cells, culturing these cells in the laboratory, and finding possible options to transplant these cells in the patients. This review article is an update on the recent developments in this field.

  15. Role of Frequency Doubled Nd: Yag Laser in Treatment of Corneal Neovascularisation

    PubMed Central

    Gehra, Aakanksha; Sirohi, Naveen

    2016-01-01

    Introduction Cornea is the outermost transparent coat of eye along with sclera, for which its avascularity is essential for maintaining its transparency to have normal visual acuity. Corneal neovascularization is characterized by the invasion of new blood vessels into the cornea from the limbus interfering with corneal transparency, resulting in reduction in visual acuity. It also increases the risk of graft rejection. So their being a dire need to treat corneal neovascularisation, with laser photocoagulation being an effective means of treating it. Aim To evaluate the efficacy and safety of frequency doubled Nd:Yag laser photocoagulation in treatment of corneal neovascularisation. Materials and Methods A single centre prospective study was carried out on patients attending the outpatient department of ophthalmology in Maharani Laxmi Bai Medical College, Jhansi. Forty eyes of 40 patients having corneal neovascularisation with quiescent eyes satisfying the inclusion criteria were selected and treated with laser. The efficacy of the procedure was noted in terms of area of corneal neovascularisation, status of treated vessels, area of corneal opacity, visual acuity. The above parameters of selected patients were recorded before treatment and subsequent follow up visits at 1 week, 1 month, 2 month and 3 month after laser. Paired t-test was used to calculate the p-value. Results There was a statistically significant difference in the percentage mean area of corneal neovascularisation with a pre laser value of 31.93% to 17.62% after 3 months of laser treatment (p-value<0.0001). The percentage mean area of corneal opacity decreased from 30.75% to 23.74% (p<0.0001). Out of 185 corneal vessels, 99 (53.51%) vessels were completely occluded,17(9.18%) vessels were partially occluded and 69(37.29%) vessels were recanalised at the end of 3 months after laser treatment. Conclusion Frequency doubled Nd:Yag laser is an effective and safe method for the treatment of corneal

  16. Intraocular Pressure Measurements Referring to the Corneal Thickness in Keratoconic Eyes After Corneal Crosslinking with Riboflavin and Ultraviolet A

    PubMed Central

    Kasumovic, Sanja Sefic; Mavija, Milka; Kasumovic, Aida; Lepara, Orhan; Duric-Colic, Belkisa; Cabric, Emir; Muhamedagic, Lejla; Sakovic-Racic, Adisa; Jankov, Mirko

    2015-01-01

    Aim: To determine the possible relation between intraocular pressure (IOP), central corneal thickness (CCT) and corneal resistance (CR) in kerotoconic eyes before, 3,6 and 12 months after collagen crosslinking procedure (CXL) with aim to find out does the thicker cornea means already more resistance cornea followed with higher IOP. Methods: Thirty eyes (30 patients) with central keratoconus (KC)were evaluated in retrospective cross sectional study. The corneal biomechanical parameters were taken with Wave Light Allegro Oculyzer produced by Alcon before the CXL, 3, 6 and 12 months after the procedure. IOP were checked by Goldmann applanation tonometry (GAT) before, 3, 6 and 12 months after CXL. Results: The value of IOP before the CXL was 12,0 mmHg (10,62-15,25 mmHg), 3 months later 13,5 mmHg (11,0-16,0 mmHg), 6 months 14,0 mmHg (11,0-16,0 mmHg) and 12 months later 15,0 mmHg (10,37-17,25 mmHg) and was statistically significant higher (p=0,015) comparing to the value of IOP 3 months after the CXL, IOP 12 months after CXL procedure was statistically significant higher comparing to preoperative values (p=0,010). There were no statistically significant difference between the values 3 and 6 months after CXL. The CCT before the CXL procedure was 449 (433-505,75 microns), 3 months after CXL was 420 (383-473microns, p < 0,005), 6 months later 437 (401,25-480,25, p=0,001), 12 months after CXL 437 (401-503 microns, p=0,001). However there is statistically significant difference in CCT 12 months after CXL 437 (401-503microns p=0,032) and the value of CCT 3 months later the procedure (p=0,004) and the CCT 12 months after CXL and the value of CXL 6 months after CXL (p=0,036). The value of CCT did not show any statistically significant difference 3 and 6 months postoperatively. Conclusion: After riboflavin-UVA CXL in eyes with KC there was significant decrease in central corneal thickness 3 and 6 months after the procedure and the thickness is almost the same 12 months later

  17. Study of corneal epithelial progenitor origin and the Yap1 requirement using keratin 12 lineage tracing transgenic mice

    PubMed Central

    Kasetti, Ramesh Babu; Gaddipati, Subhash; Tian, Shifu; Xue, Lei; Kao, Winston W.-Y.; Lu, Qingxian; Li, Qiutang

    2016-01-01

    Key issues in corneal epithelium biology are the mechanism for corneal epithelium stem cells to maintain the corneal epithelial homeostasis and wound healing responses, and what are the regulatory molecular pathways involved. There are apparent discrepancies about the locations of the progenitor populations responsible for corneal epithelial self-renewal. We have developed a genetic mouse model to trace the corneal epithelial progenitor lineages during adult corneal epithelial homeostasis and wound healing response. Our data revealed that the early corneal epithelial progenitor cells expressing keratin-12 originated from limbus, and gave rise to the transit amplifying cells that migrated centripetally to differentiate into corneal epithelial cells. Our results support a model that both corneal epithelial homeostasis and wound healing are mainly maintained by the activated limbal stem cells originating form limbus, but not from the corneal basal epithelial layer. In the present study, we further demonstrated the nuclear expression of transcriptional coactivator YAP1 in the limbal and corneal basal epithelial cells and its essential role for maintaining the high proliferative potential of those corneal epithelial progenitor cells in vivo. PMID:27734924

  18. NK Cells Promote Th-17 Mediated Corneal Barrier Disruption in Dry Eye

    PubMed Central

    Zhang, Xiaobo; Volpe, Eugene A.; Gandhi, Niral B.; Schaumburg, Chris S.; Siemasko, Karyn F.; Pangelinan, Solherny B.; Kelly, Scott D.; Hayday, Adrian C.; Li, De-Quan; Stern, Michael E.; Niederkorn, Jerry Y.; Pflugfelder, Stephen C.; De Paiva, Cintia S.

    2012-01-01

    Background The conjunctiva contains a specialized population of lymphocytes that reside in the epithelium, named intraepithelial lymphocytes (IEL). Methodology/Principal Findings Here we characterized the IEL population prior to and after experimental desiccating stress (DS) for 5 or 10 days (DS5, DS10) and evaluated the effect of NK depletion on DS. The frequency of IELs in normal murine conjunctiva was CD3+CD103+ (∼22%), CD3+γδ+ (∼9.6%), CD3+NK+ (2%), CD3−NK+ (∼4.4%), CD3+CD8α (∼0.9%), and CD4 (∼0.6%). Systemic depletion of NK cells prior and during DS led to a decrease in the frequency of total and activated DCs, a decrease in T helper-17+ cells in the cervical lymph nodes and generation of less pathogenic CD4+T cells. B6.nude recipient mice of adoptively transferred CD4+T cells isolated from NK-depleted DS5 donor mice showed significantly less corneal barrier disruption, lower levels of IL-17A, CCL20 and MMP-3 in the cornea epithelia compared to recipients of control CD4+T cells. Conclusions/Significance Taken together, these results show that the NK IELs are involved in the acute immune response to desiccation-induced dry eye by activating DC, which in turn coordinate generation of the pathogenic Th-17 response. PMID:22590618

  19. [Protection of corneal endothelium from apoptosis by gene and cell therapy].

    PubMed

    Fuchsluger, T A

    2016-06-01

    Protection of corneal endothelium from apoptosis using gene and cell therapy is in a translational phase. This approach offers advantages for eye banking and after transplantation. Safe vehicles for gene or cell therapeutic transduction of corneal endothelium with nucleic acids are available. This strategy will be further developed in consultation with the Paul Ehrlich Institute and European regulatory authorities.

  20. Efficient Generation of Human Embryonic Stem Cell-Derived Corneal Endothelial Cells by Directed Differentiation

    PubMed Central

    McCabe, Kathryn L.; Kunzevitzky, Noelia J.; Chiswell, Brian P.; Xia, Xin; Goldberg, Jeffrey L.; Lanza, Robert

    2015-01-01

    Aim To generate human embryonic stem cell derived corneal endothelial cells (hESC-CECs) for transplantation in patients with corneal endothelial dystrophies. Materials and Methods Feeder-free hESC-CECs were generated by a directed differentiation protocol. hESC-CECs were characterized by morphology, expression of corneal endothelial markers, and microarray analysis of gene expression. Results hESC-CECs were nearly identical morphologically to primary human corneal endothelial cells, expressed Zona Occludens 1 (ZO-1) and Na+/K+ATPaseα1 (ATPA1) on the apical surface in monolayer culture, and produced the key proteins of Descemet’s membrane, Collagen VIIIα1 and VIIIα2 (COL8A1 and 8A2). Quantitative PCR analysis revealed expression of all corneal endothelial pump transcripts. hESC-CECs were 96% similar to primary human adult CECs by microarray analysis. Conclusion hESC-CECs are morphologically similar, express corneal endothelial cell markers and express a nearly identical complement of genes compared to human adult corneal endothelial cells. hESC-CECs may be a suitable alternative to donor-derived corneal endothelium. PMID:26689688