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Sample records for astigmatismo corneal inducido

  1. Astigmatismo interno : epidemiología, clasificación e influencia en los resultados de la cirugía refractiva corneal

    OpenAIRE

    2015-01-01

    Objetivos: Trabajos previos muestran que la corrección astigmática mediante cirugía láser en sujetos con grandes cantidades de astigmatismo interno (AI) es menos predecible. La influencia exacta del AI en los resultados de la cirugía refractiva, así como la exactitud en su medida o su relación con el resto de estructuras ópticas del ojo se desconoce. Ésta tesis pretende estudiar y analizar la epidemiología del AI y su influencia en los resultados de la cirugía refractiva. Si aumentamos el ...

  2. Astigmatismo induzido na cirurgia extracapsular da catarata: acompanhamento a longo prazo

    Directory of Open Access Journals (Sweden)

    Ghiaroni Almir

    2004-01-01

    Full Text Available OBJETIVO: Estudar o comportamento do astigmatismo induzido a longo prazo em uma série de pacientes submetidos à cirurgia extracapsular da catarata, nos quais foi utilizada incisão límbica posterior superior suturada com pontos separados de mononylon 10-0. MÉTODOS: Foram estudados 38 olhos, de 35 pacientes, sendo 21 do sexo feminino e 14 do sexo masculino, com idades variando entre 47 e 85 anos (média = 70,17 anos. Todos os casos foram operados pelo mesmo cirurgião. O período de acompanhamento pós-operatório variou de 15 a 33 meses (média = 22,07 meses. Nenhum dos casos teve qualquer dos pontos seccionado ou removido. Todos os pacientes atingiram acuidade visual corrigida igual ou superior a 0,5. Para o cálculo do astigmatismo induzido foram consideradas as medidas ceratométricas pré e pós-operatórias e foi utilizado um programa desenvolvido por Jaffe. RESULTADOS: O astigmatismo induzido variou de 0,13 dioptria (D a 2,74 D (média = 1,19 D. Em relação aos eixos, na maioria dos casos houve indução de astigmatismo a favor da regra (60,52%. Foi observada mudança significativa no valor dióptrico do astigmatismo quando foram comparadas as leituras ceratométricas registradas pré-operatoriamente até a segunda semana pós-operatória, entre o primeiro e o terceiro meses pós-operatórios, entre o terceiro e o sexto meses pós-operatórios e após o décimo-segundo mês pós-operatório. CONCLUSÃO: Quando o mononylon 10-0 é utilizado como material de sutura na cirurgia extracapsular da catarata, os valores de astigmatismo a favor da regra inicialmente observados tendem a diminuir com o tempo.

  3. Corneal Laceration

    Medline Plus

    Full Text Available ... your vision. Privacy Policy Related People with Advanced Keratoconus May Have A Future Alternative to Full Corneal ... 2016 Corneal Collagen Cross-linking Approved to Treat Keratoconus in U.S. Aug 01, 2016 Firework Blinds Teenager, ...

  4. Corneal Abrasions

    Science.gov (United States)

    ... and lead to a serious condition called a corneal ulcer . That's why it's important to see a doctor to get a corneal abrasion checked out. What Causes a Corneal ... and land on your cornea, tears help to wash the particles away. Sometimes, ...

  5. Corneal Laceration

    Medline Plus

    Full Text Available ... Health Find an Ophthalmologist Academy Store Eye Health A-Z Symptoms Glasses & Contacts Tips & Prevention News Ask ... Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Corneal Laceration Sections What Is Corneal Laceration? ...

  6. Corneal Laceration

    Science.gov (United States)

    ... drugs. These drugs thin the blood and may increase bleeding. After you have finished protecting the eye, see a physician immediately. Next Corneal Laceration Symptoms Related Ask an Ophthalmologist Answers I lost sight from a corneal scar as a child. Now that I’m older, ...

  7. Correção do astigmatismo irregular com lente intraocular tórica em um paciente com catarata e degeneração marginal pelúcida: relato de caso Toric intraocular lens implantation for cataract and irregular astigmatism related to pellucid marginal degeneration: case report

    Directory of Open Access Journals (Sweden)

    Ana Luiza Biancardi

    2012-12-01

    Full Text Available A degeneração marginal pelúcida (DMP é uma rara ectasia corneana cuja progressão resulta em astigmatismo irregular e baixa visual não corrigidos com óculos ou lentes de contato. O presente relato descreve um paciente com catarata e DMP que foi tratado com facoemulsificação e implante de lente intraocular tórica com recuperação da acuidade visual em ambos os olhos.Pellucid marginal degeneration (PMD is a rare corneal ectasia and its progression leads to irregular astigmatism and low vision that can not have spectacles or contact lens correction. This report describes a patient with low vision due to cataract and PMD that was treated with phacoemulsification and implantation of a toric intraocular lens with a satisfactory visual acuity outcome.

  8. Prevalência do astigmatismo e distribuição de seu eixo em pacientes de um serviço oftalmológico privado

    OpenAIRE

    Rayes,Tatiana Rocha; Rayes,Guilherme Rocha; Eing, Felipe; Guimarães Neto,Heriberto Pinto; Marquardt,Francisco Azevedo; Rayes,Assad

    2007-01-01

    OBJETIVO: Verificar a prevalência do astigmatismo e a variação de seu eixo nas várias faixas etárias (2-99 anos) em uma população de uma clínica oftalmológica privada na cidade de Florianópolis, Santa Catarina, Brasil. MÉTODOS: Foi realizado um estudo retrospectivo, descritivo, transversal com base na análise de prontuários. Foi considerado astigmatismo uma diferença entre o maior e menor meridiano da córnea de -0,50 dioptrias(D) ou mais. Quanto ao eixo, consideramos: astigmatismo a favor da ...

  9. Corneal transplant

    Science.gov (United States)

    ... lenses to achieve the best vision. Laser vision correction may be an option if you have nearsightedness, ... Editorial team. Related MedlinePlus Health Topics Corneal Disorders Refractive Errors Browse the Encyclopedia A.D.A.M., Inc. ...

  10. Corneal Laceration

    Medline Plus

    Full Text Available ... itself. A corneal laceration is a very serious injury and requires immediate medical attention to avoid severe ... 27, 2015 Dark Spot in Vision After Blunt Trauma Dec 21, 2014 Pain a Year After Eyelid ...

  11. Corneal topography

    DEFF Research Database (Denmark)

    Andersen, J.; Koch-Jensen, P.; Østerby, Ole

    1993-01-01

    The central corneal zone is depicted on keratoscope photographs using a small target aperture and a large object distance. Information on the peripheral area is included by employing a hemispherical target with a dense circular and radial pattern. On a 16 mm (R = 8 mm) reference steel sphere...

  12. Corneal Transplantation

    DEFF Research Database (Denmark)

    Hjortdal, Jesper Østergaard

    Corneal transplantation has been performed for more than 100 years. Until 15 years ago the state-of-the art type of transplantation was penetrating keratoplasty, but since the start of this millennium, newly designed surgical techniques have developed considerably. Today, the vast majority of ker...

  13. Perfil sociodemográfico del aborto inducido

    Directory of Open Access Journals (Sweden)

    Cabezas-García Evelio

    1998-01-01

    Full Text Available Objetivo. Identificar características sociodemográficas y su fuerza de asociación con el aborto inducido del primer embarazo. Material y métodos. Se realizó un estudio analítico con la información de una encuesta realizada en el municipio Diez de Octubre, de la ciudad de La Habana, en Cuba, durante todo el año de 1991 y el primer semestre de 1992. La población de estudio se dividió en dos grupos de comparación: uno formado por las mujeres cuyo primer embarazo terminó en un aborto inducido y el otro constituido por aquellas cuyo embarazo llegó a término. De las variables estudiadas que mostraron diferencias estadísticamente significativas se obtuvieron las razones de momios crudas y ajustadas por la variable que se consideró como confusora: la edad. Para esta última fase del análisis se utilizó la regresión logística multivariada. Resultados. Las características sociodemográficas identificadas como factores de riesgo asociados al aborto inducido del primer embarazo fueron la edad menor de 24 años (aunque el riesgo se incrementa en las menores de 20 años y ser solteras o unidas. Conclusiones. El riesgo de recurrir a la práctica del aborto inducido en el primer embarazo es elevado en mujeres muy jóvenes que aún no han cumplido sus expectativas profesionales, laborales y relacionadas con el matrimonio. Estas razones parecen incompatibles con la maternidad en el grupo de mujeres estudiadas.

  14. Feline corneal disease.

    Science.gov (United States)

    Moore, Phillip Anthony

    2005-05-01

    The cornea is naturally transparent. Anything that interferes with the cornea's stromal architecture, contributes to blood vessel migration, increases corneal pigmentation, or predisposes to corneal edema, disrupts the corneas transparency and indicates corneal disease. The color, location, and shape and pattern of a corneal lesion can help in determining the underlying cause for the disease. Corneal disease is typically divided into congenital or acquired disorders. Congenital disorders, such as corneal dermoids are rare in cats, whereas acquired corneal disease associated with nonulcerative or ulcerative keratitis is common. Primary ocular disease, such as tear film instability, adenexal disease (medial canthal entropion, lagophthalmus, eyelid agenesis), and herpes keratitis are associated with the majority of acquired corneal disease in cats. Proliferative/eosinophilic keratitis, acute bullous keratopathy, and Florida keratopathy are common feline nonulcerative disorders. Nonprogressive ulcerative disease in cats, such as chronic corneal epithelial defects and corneal sequestration are more common than progressive corneal ulcerations.

  15. ¿CÓMO CAMBIA EL CEREBRO UN ABORTO INDUCIDO?

    Directory of Open Access Journals (Sweden)

    Natalia López Moratalla

    2012-01-01

    Full Text Available Estudios epidemiológicos cuantitativos muestran un riesgo entre moderado y muy alto de trastornos psiquiátricos tras el aborto inducido, especialmente de conductas adictivas e ideación de suicidio. Las mujeres que se habían sometido a un aborto experimentaron tienen un 81% más de riesgo de problemas de salud mental. Y cerca del 10% de la incidencia de problemas de salud mental se demostró que es atribuible al aborto. Siempre son más altos y sobre todo más duraderos que los que pudieran producirse por un aborto espontáneo. El embarazo no deseado no provoca trastornos y no se ha encontrado que el aborto inducido se asocie a mejor evolución de la salud mental, por lo que no puedan invocarse, sobre bases empíricas, razones de salud mental de la embarazada para inducir un aborto. Estudios de neuroimagen han mostrado que el trastorno de estrés postraumático, que sufren algunas mujeres tras el aborto voluntario, alterara las áreas cerebrales que regulan las emociones negativas, y de la memoria emocional. Los médicos deben transmitir el estado actual de ausencia de datos relacionados con los beneficios del aborto, además de informar detenidamente sobre los riesgos para la salud mental estadísticamente validados.

  16. Corneal ulcers in horses.

    Science.gov (United States)

    Williams, Lynn B; Pinard, Chantale L

    2013-01-01

    Corneal ulceration is commonly diagnosed by equine veterinarians. A complete ophthalmic examination as well as fluorescein staining, corneal cytology, and corneal bacterial (aerobic) and fungal culture and sensitivity testing are necessary for all infected corneal ulcers. Appropriate topical antibiotics, topical atropine, and systemic NSAIDs are indicated for all corneal ulcers. If keratomalacia (melting) is observed, anticollagenase/antiprotease therapy, such as autologous serum, is indicated. If fungal infection is suspected, antifungal therapy is a necessity. Subpalpebral lavage systems allow convenient, frequent, and potentially long-term therapy. Referral corneal surgeries provide additional therapeutic options when the globe's integrity is threatened or when improvement has not been detected after appropriate therapy.

  17. Prevalência do astigmatismo e distribuição de seu eixo em pacientes de um serviço oftalmológico privado Prevalence of astigmatism and its axis in an ophthalmology private clinic

    OpenAIRE

    Tatiana Rocha Rayes; Guilherme Rocha Rayes; Felipe Eing; Heriberto Pinto Guimarães Neto; Francisco Azevedo Marquardt; Assad Rayes

    2007-01-01

    OBJETIVO: Verificar a prevalência do astigmatismo e a variação de seu eixo nas várias faixas etárias (2-99 anos) em uma população de uma clínica oftalmológica privada na cidade de Florianópolis, Santa Catarina, Brasil. MÉTODOS: Foi realizado um estudo retrospectivo, descritivo, transversal com base na análise de prontuários. Foi considerado astigmatismo uma diferença entre o maior e menor meridiano da córnea de -0,50 dioptrias(D) ou mais. Quanto ao eixo, consideramos: astigmatismo a favor da ...

  18. Corneal transplant - discharge

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000243.htm Corneal transplant - discharge To use the sharing features on this page, please enable JavaScript. You had a corneal transplant. Most of the tissue of your cornea (the ...

  19. Equine corneal stromal abscesses

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  20. Corneal mucus plaques.

    Science.gov (United States)

    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.

  1. ESTRÉS OXIDATIVO EN PECES INDUCIDO POR CONTAMINANTES AMBIENTALES

    Directory of Open Access Journals (Sweden)

    DM Ochoa

    2008-01-01

    Full Text Available el estrés oxidativo inducido por diversas clases de contaminantes como mecanismo de toxicidad ha sido un foco de interés en el campo de la toxicología acuática y ambiental durante la última década. numerosas evidencias indican que muchos de estos agentes con-taminantes al llegar a cuerpos de agua pueden desencadenar el proceso de estrés oxidativo en organismos que allí habitan, y son responsables de efectos en células y tejidos asociados a mutagénesis y carcinogénesis. el estrés oxidativo se genera cuando existe una sobrecar-ga en la formación de radicales libres o agentes prooxidantes, la cual no es debidamente compensada por los mecanismos de defensa antioxidante que posee el organismo. Los fac-tores que son importantes al momento de la presentación del proceso de estrés oxidativo en peces, así como los mecanismos de defensa contra el ataque de agentes prooxidantes y las consecuencias de dicho evento, se revisarán en el presente artículo.

  2. Characterization of Corneal Indentation Hysteresis.

    Science.gov (United States)

    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). 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.

  3. Current status of corneal xenotransplantation.

    Science.gov (United States)

    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.

  4. Corneal blindness and xenotransplantation.

    Science.gov (United States)

    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.

  5. Equine corneal surgery and transplantation.

    Science.gov (United States)

    Denis, Heidi M

    2004-08-01

    Corneal disease is common in equine ophthalmology and requires vigilant monitoring and appropriate therapy to optimize the outcome. Many equine corneal diseases, particularly those that progress rapidly, may benefit from surgical intervention. These include descemetoceles, deep corneal lacerations and ulcers, corneal perforation/iris prolapse, ulcerative keratitis, corneal stromal abscesses, and corneoscleral neoplasia. Indications for corneal transplantation include optical, tectonic, therapeutic, and cosmetic purposes. Corneal transplantation is most often implemented in equine patients for tectonic and therapeutic reasons when a cornea is compromised by corneal stromal abscess, iris prolapse, or neoplasia. This article provides an outline of when to consider surgical intervention for corneal disease, the procedures available and expected outcomes, and how appropriate early surgical intervention can dramatically improve the end result.

  6. Central corneal abscess.

    Science.gov (United States)

    van Bijsterveld, O P

    1976-05-01

    Central corneal abscess developed in the experimental animal after inoculation of biologically active staphylococcal strains in a paracentral epithelial lesion of the cornea. These abscesses did not ulcerate, developed only with high inocula, occurred more frequently in immunized rabbits. A serpiginous type of ulceration did not develop at the site of the initial epithelial lesion nor at any other place in the cornea. Histologically, the lesions consisted of densely packed polymorphonuclear leukocytes between the corneal lamellae.

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

    Science.gov (United States)

    Gao, Feng; Lin, Tao; Pan, Yingzhe

    2016-09-01

    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: 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.

  8. A corneal mold to restore normal corneal dimensions.

    Science.gov (United States)

    Swinger, C A; Kornmehl, E W; York, S; Forman, J S

    1986-01-01

    A corneal mold is described that provides an MK corneal button of normal thickness and curvature from an edematous, post-mortem button. The uniform, processed tissue can then be used for experimental refractive surgery.

  9. Corneal Topography Analysis of Stromal Corneal Dystrophies

    OpenAIRE

    Kocluk, Yusuf; Yalniz-Akkaya, Zuleyha; Burcu, Ayse; Ornek, Firdevs

    2015-01-01

    Objective: The aim was to compare the corneal topography and tomography parameters of macular corneal dystrophy (MCD), granular corneal dystrophy (GCD) and lattice corneal dystrophy (LCD) patients obtained by Scheimpflug imaging system. Methods: The charts, photographs and topography images of patients were reviewed retrospectively. This study included 73 eyes of 73 patients (28 MCD, 20 GCG and 25 LCD patients). Topography images were obtained by Pentacam (Oculus Optikgerate, Wetzlar, Germany...

  10. Tratamiento de agrandamiento gingival inducido por fenitoina asociado a placa bacteriana

    OpenAIRE

    Carmen Julia Rovira; Jennifer Orozco Páez; Antonio Díaz Caballero

    2013-01-01

    ResumenLa ingesta de algunos medicamentos puede producir un sobre crecimiento de las encías. Se reportan medicamentos tales como los bloqueadores de los canales de calcio, inmunosupresores, anticonvulsivantes que producen estos efectos adversos. Múltiples casos de agrandamientos gingivales están asociados a la ingesta de Fenitoína. El tratamiento de los agrandamientos gingivales inducidos por drogas por lo general es quirúrgico, pero mantener un buen control de placa bacteriana puede evitar e...

  11. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    OpenAIRE

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

    2012-01-01

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

  12. Genetics of corneal endothelial dystrophies

    Indian Academy of Sciences (India)

    Chitra Kannabiran

    2009-12-01

    The corneal endothelium maintains the level of hydration in the cornea. Dysfunction of the endothelium results in excess accumulation of water in the corneal stroma, leading to swelling of the stroma and loss of transparency. There are four different corneal endothelial dystrophies that are hereditary, progressive, non-inflammatory disorders involving dysfunction of the corneal endothelium. Each of the endothelial dystrophies is genetically heterogeneous with different modes of transmission and/or different genes involved in each subtype. Genes responsible for disease have been identified for only a subset of corneal endothelial dystrophies. Knowledge of genes involved and their function in the corneal endothelium can aid understanding the pathogenesis of the disorder as well as reveal pathways that are important for normal functioning of the endothelium.

  13. Bilateral acute corneal calcification.

    Science.gov (United States)

    Freddo, T F; Leibowitz, H M

    1985-04-01

    A 38-year-old man with brittle, juvenile onset diabetes mellitus and bilateral severe dry eyes with recurrent corneal ulcers developed atypical band-shaped calcifications of both corneas during a 24-hour period. Serum calcium, phosphate, and carbon dioxide levels all were within normal limits. The patient was mildly uremic but was not in renal failure. When EDTA chelation failed to clear the deposits, partial keratectomies were performed in both eyes and the specimens were examined by light and electron microscopy, including energy dispersive x-ray analysis. Microscopic studies revealed an atypical calcific keratopathy which involved neither Bowman's layer nor the most superficial stromal lamellae. The deposits were confined to deeper lamellae in the anterior stroma and by electron microscopy were composed of extracellular crystalline aggregates. Energy dispersive x-ray analysis of these aggregates confirmed the presence of calcium and phosphate. Corneal dessication appeared to be a major contributing factor in the rapid formation of these deposits.

  14. Corneal blindness: prevention, treatment and rehabilitation

    Directory of Open Access Journals (Sweden)

    Matthew J Burton

    2009-12-01

    Full Text Available Blindness from corneal disease is a major ophthalmic public health problem. There are three important elements to addressing corneal blindness: prevention, treatment, and rehabilitation.

  15. Síndrome de neurotoxicidad inducido por opioides (NIO) Opioid induced-neurotoxicity syndrome (OIN)

    OpenAIRE

    M. L. Cid

    2008-01-01

    El síndrome de neurotoxicidad inducido por opioides (NIO) es uno de los efectos adversos del uso de estos fármacos descrito en los últimos años. Su aparición de debe a la acumulación de metabolitos tóxicos, principalmente el M3 Glucurónido de la morfina; los cuáles pueden provocar hiperexcitabilidad neuronal, con desarrollo de alteraciones cognitivas, delirium, alucinaciones, mioclonias, convulsiones e hiperalgesia. Especialmente vulnerables a estos efectos son los pacientes mayores o con fac...

  16. Daño muscular inducido mediante ejercicio y sus efectos en el rendimiento

    OpenAIRE

    Valenzuela Tallón, Pedro Luis

    2014-01-01

    El presente trabajo pretende introducir un tema de gran controversia: el daño muscular inducido mediante ejercicio (DMIE). Se ha realizado una revisión bibliográfica de la literatura científica referente al DMIE para exponer la teoría más actual en cuanto al mecanismo que lo provoca y los cambios biológicos y funcionales producidos tras éste. El DMIE comienza como un proceso mecánico mediante el cual se dañan las estructuras de las fibras musculares, lo cual da lugar a un proceso inflamatorio...

  17. Creencias en torno al aborto inducido en un hospital público

    Directory of Open Access Journals (Sweden)

    Cruz García Lirios

    2013-06-01

    Full Text Available Objetivo: Establecer las propiedades psicométricas de un instrumento que pondera las creencias en torno al aborto inducido. Método: Se llevó a cabo un estudio correlacional y transversal con una muestra no probabilística de 120 derechohabientes de un hospital público ubicado en una entidad del centro de país. Materiales: Se construyó una Escala de Creencias en torno al Aborto Inducido la cual incluyó 17 reactivos con dos opciones de respuesta: falso o verdadero. Resultados: Para establecer la confiabilidad se estimó una curtosis multivariable de -2,578unaalfade0,73 y esfericidad de 0,832 con adecuación significativa. Se estableció un modelo estructural reflectivo (X² = 16,25; 11gl; p = 0,055; GFI = 0,975; RMR = 0,008 que se ajustó al modelo de medición (GFI = 0,90; RMR = 0,01. Discusión: Se recomienda la inclusión de otras variables tales como religión, usos y costumbres locales para explicar posibles modelos regionales de prácticas abortivas inducidas legalmente.

  18. [Methods for sealing of corneal perforations].

    Science.gov (United States)

    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 collagen crosslinking: a systematic review.

    Science.gov (United States)

    Sorkin, Nir; Varssano, David

    2014-01-01

    Keratoconus (KCN) is an ectatic disorder with progressive corneal thinning and a clinical picture of corneal protrusion, progressive irregular astigmatism, corneal fibrosis and visual deterioration. Other ectatic corneal disorders include: post-LASIK ectasia (PLE) and pellucid marginal degeneration (PMD). Corneal crosslinking (CXL) is a procedure whereby riboflavin sensitization with ultraviolet A radiation induces stromal crosslinks. This alters corneal biomechanics, causing an increase in corneal stiffness. In recent years, CXL has been an established treatment for the arrest of KCN, PLE and PMD progression. CXL has also been shown to be effective in the treatment of corneal infections, chemical burns, bullous keratopathy and other forms of corneal edema. This is a current review of CXL - its biomechanical principles, the evolution of CXL protocols in the past, present and future, indications for treatment, treatment efficacy and safety.

  20. El aborto inducido. Una visión histórica de su manejo.

    Directory of Open Access Journals (Sweden)

    Manuel Antonio Artuz

    2009-11-01

    Full Text Available El aborto inducido es un problema de interés para la salud pública mundial, tanto en los países donde las leyes lo permiten como en aquellos donde el procedimiento se practica en forma clandestina. El presente artículo es el resultado de una revisión bibliográfica de los métodos más comúnmente empleados en la inducción del aborto en los últimos 50 años, comparándolos con los métodos utilizados en la actualidad, analizando sus riesgos y complicaciones a corto y largo plazo y tratando de sistematizar y actualizar el conocimiento que se tiene al respecto.

  1. Perfil sociodemográfico del aborto inducido Sociodemographic profile of induced abortion

    Directory of Open Access Journals (Sweden)

    Evelio Cabezas-García

    1998-05-01

    Full Text Available Objetivo. Identificar características sociodemográficas y su fuerza de asociación con el aborto inducido del primer embarazo. Material y métodos. Se realizó un estudio analítico con la información de una encuesta realizada en el municipio Diez de Octubre, de la ciudad de La Habana, en Cuba, durante todo el año de 1991 y el primer semestre de 1992. La población de estudio se dividió en dos grupos de comparación: uno formado por las mujeres cuyo primer embarazo terminó en un aborto inducido y el otro constituido por aquellas cuyo embarazo llegó a término. De las variables estudiadas que mostraron diferencias estadísticamente significativas se obtuvieron las razones de momios crudas y ajustadas por la variable que se consideró como confusora: la edad. Para esta última fase del análisis se utilizó la regresión logística multivariada. Resultados. Las características sociodemográficas identificadas como factores de riesgo asociados al aborto inducido del primer embarazo fueron la edad menor de 24 años (aunque el riesgo se incrementa en las menores de 20 años y ser solteras o unidas. Conclusiones. El riesgo de recurrir a la práctica del aborto inducido en el primer embarazo es elevado en mujeres muy jóvenes que aún no han cumplido sus expectativas profesionales, laborales y relacionadas con el matrimonio. Estas razones parecen incompatibles con la maternidad en el grupo de mujeres estudiadas.Objective. To identify sociodemographic characteristics associated with induced abortion of the first pregnancy and quantify the strength of association between them. Material and methods. Data were gathered from a survey conducted in the district of Diez de Octubre, Havana, Cuba throughout 1991 and the beginning of 1992. The study population was divided into two comparable groups: one group of women whose first pregnancy terminated in induced abortion and a second group of women whose pregnancy terminated in childbirth. For the

  2. Corneal collagen cross-linking

    Directory of Open Access Journals (Sweden)

    Jankov II Mirko

    2010-01-01

    Full Text Available 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.

  3. Evaluation of Factors Limiting Corneal Donation.

    Science.gov (United States)

    Röck, Daniel; Wude, Johanna; Yoeruek, Efdal; Bartz-Schmidt, Karl Ulrich; Röck, Tobias

    2016-11-15

    BACKGROUND This study aimed to investigate factors limiting corneal donation at the University Hospital Tübingen. MATERIAL AND METHODS We retrospectively studied all hospital deaths from January 2012 to December 2015, considering each deceased patient as a potential corneal donor. During this period an ophthalmic resident managed corneal donor procurement on a full-time basis. Various factors limiting corneal donation were examined. RESULTS Among the 3412 deaths, 2937 (86.1%) displayed nonfulfillment of corneal donation. Consent for corneal donation was obtained in 475 cases (13.9%). The mean annual corneal donation rate was 13.9 donors per 100 deaths (range: 11.2-17.8). The leading causes of nonfulfillment of corneal donations were refusal to donate (49.8%, 1698 cases) and medical contraindications (23.6%, 805 cases). After next-of-kin interview of 2173 potential donors (109 potential donors were excluded because of logistical problems), willingness to participate in corneal donation was present in 475 cases (21.9%), whereas in 1698 cases (78.1%) corneal donation was refused. CONCLUSIONS Our study showed refusal to donate is the most important factor limiting corneal donation. It seems that increasing the knowledge of people about corneal donation through public education and media are necessary to address the corneal shortage.

  4. Corneal Biomechanical Findings in Contact Lens Induced Corneal Warpage

    Science.gov (United States)

    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

  5. Long-term results of photorefractive keratectomy for myopia and myopic astigmatism Resultados a longo prazo de ceratectomia fotorefrativa para miopia e astigmatismo miópico

    Directory of Open Access Journals (Sweden)

    Ester Sakae Yamazaki

    2007-12-01

    Full Text Available PURPOSE: To assess the long-term refractive outcomes of photorefractive keratectomy in myopia and myopic astigmatism. METHODS: A retrospective study of 120 photorefractive keratectomy operated eyes with at least four-year follow-up (maximum of 96 months, mean follow-up 55 months. We divided patients into group 1 (G1 spherical equivalent (SE up to -4.00 diopters (D and group 2 (G2 SE >-4.00 D. The Summit Apex Plus® excimer laser was used for ablation. All eyes were analyzed in terms of uncorrected and best spectacle corrected visual acuity (UCVA/BSCVA and cycloplegic refraction. Data were analyzed using the Refractive Surgery Consultant Elite database software. RESULTS: G1 with 85 eyes (49 patients presented mean SE -2.42 D and G2 with 35 eyes (22 patients and mean SE of -4.45 D. Ninety-four percent of eyes in G1 and 82.9% of G2 were within ±1.00 D of emmetropia at 4 years. The UCVA was 20/30 or better in 82.0% of G1 eyes and 77.0% of G2 in the last postoperative follow-up. No patient lost more than one line in G2 compared to 13.0% in G1. Eyes that gained one or more lines after 4-year follow-up were 11.9% G1 and 2.9% in G2, respectively. A statistically significant positive correlation was found between achieved versus attempted refractive correction in both groups (r=0.925, pOBJETIVO: Relatar os resultados a longo prazo da cirurgia de ceratectomia fotorefrativa em miopia e astigmatismo miópico. MÉTODOS: Estudo retrospectivo de120 olhos operados de ceratectomia fotorefrativa com um mínimo intervalo de 4 anos de seguimento pós-operatório (máximo de 96 meses e seguimento médio de 55 meses. Dividimos em grupo 1 (G1 com equivalente esférico (SE até -4.00 dioptrias (D e grupo 2(G2 SE > -4.00 D. O excimer laser Summit Apex Plus® foi usado na ablação. Foram obtidas acuidade visual não corrigida (UCVA e melhor acuidade visual corrigida (BSCVA e refração sob cicloplegia. Os dados foram analisados utilizando o programa Refractive Surgery

  6. Reconstruction of Rabbit Corneal Layer Composed of Corneal Fibroblasts and Corneal Epithelium on the Lyophilized Amniotic Membrane

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Many researchers have employed the cryopreserved amniotic membrane(CAM) and corneal epithelial cells in the treatment of a severely damaged burned cornea, with corneal epithelial cells cultured on an amniotic membrane (AM). The lyophilized amniotic membrane (LAM) has a higher graft take and a longer shelf life; it is easier to store and safer because of gamma irradiation. Two Teflon rings(Ahn's supporter) were made for culturing the cells on the LAM, and were then used to support the LAM. To reconstruct a corneal layer composed of corneal fibroblasts and epithelium, the corneal fibroblasts were first cultivated on the stromal side of LAM for five days, followed by epithelial cells culture on the epithelial side, by using the air-liquid interface culture. The reconstructed corneal layer composed of corneal fibroblasts and corneal epithelial cells has a much healthier basal layer of corneal epithelium than the reconstructed corneal epithelium, which was got by using only corneal epithelial cells, and resembles the epithelium of normal corneas, without the horny layer. Thus, the reconstruction of the corneal layer by using a LAM is considered to be a good in vitro model, not only for its application in toxicological test kits, but also for transplantation in patients with a severely damaged cornea.

  7. Corneal biomechanics: a review.

    Science.gov (United States)

    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.

  8. Corneal Decompensation after Selective Laser Trabeculoplasty

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    Ahmet Ozkok

    2014-01-01

    Full Text Available A 64-year-old Caucasian man referred for decreased vision after selective laser trabeculoplasty (SLT. Slit lamp examination revealed diffuse corneal edema. Despite intensive topical treatment including steroids, corneal edema did not resolve; on the contrary, it advanced to bullous keratopathy. Corneal edema after SLT is an exceptionally rare complication and in all of the previous reports edema resolved with medical treatment. To the best of our knowledge, this is the first report presenting persistent corneal edema after SLT.

  9. Posterior Corneal Surface Stability after Femtosecond Laser-Assisted Keratomileusis

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    Carlo Cagini

    2015-01-01

    Full Text Available The purpose of this study was to evaluate posterior corneal surface variation after femtosecond laser-assisted keratomileusis in patients with myopia and myopic astigmatism. Patients were evaluated by corneal tomography preoperatively and at 1, 6, and 12 months. We analyzed changes in the posterior corneal curvature, posterior corneal elevation, and anterior chamber depth. Moreover, we explored correlation between corneal ablation depth, residual corneal thickness, percentage of ablated corneal tissue, and preoperative corneal thickness. During follow-up, the posterior corneal surface did not have a significant forward corneal shift: no significant linear relationships emerged between the anterior displacement of the posterior corneal surface and corneal ablation depth, residual corneal thickness, or percentage of ablated corneal tissue.

  10. Acute corneal hydrops in keratoconus

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    Prafulla K Maharana

    2013-01-01

    Full Text Available Acute corneal hydrops is a condition characterized by stromal edema due to leakage of aqueous through a tear in descemet membrane. The patient presents with sudden onset decrease in vision, photophobia, and pain. Corneal thinning and ectasias combined with trivial trauma to the eye mostly by eye rubbing is considered as the underlying cause. With conservative approach self-resolution takes around 2 to 3 months. Surgical intervention is required in cases of non-resolution of corneal edema to avoid complications and for early visual rehabilitation. Intracameral injection of air or gas such as perflouropropane is the most common surgical procedure done. Recent investigative modality such as anterior segment optical coherence tomography is an extremely useful tool for diagnosis, surgical planning, and postoperative follow up. Resolution of hydrops may improve the contact lens tolerance and visual acuity but most cases require keratoplasty for visual rehabilitation.

  11. Correlations between corneal and total wavefront aberrations

    Science.gov (United States)

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

    2002-06-01

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

  12. [Corneal manifestations in systemic diseases].

    Science.gov (United States)

    Zarranz Ventura, J; De Nova, E; Moreno-Montañés, J

    2008-01-01

    Systemic diseases affecting the cornea have a wide range of manifestations. The detailed study of all pathologies that cause corneal alteration is unapproachable, so we have centered our interest in the most prevalent or characteristic of them. In this paper we have divided these pathologies in sections to facilitate their study. Pulmonar and conective tissue (like colagen, rheumatologic and idiopathic inflamatory diseases), dermatologic, cardiovascular, hematologic, digestive and hepatopancreatic diseases with corneal alteration are described. Endocrine and metabolic diseases, malnutrition and carential states are also studied, as well as some otorhinolaryngologic and genetic diseases that affect the cornea. Finally, a brief report of ocular toxicity induced by drugs is referred.

  13. Progress in corneal wound healing.

    Science.gov (United States)

    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

  14. Corneal stroma microfibrils

    KAUST Repository

    Hanlon, Samuel D.

    2015-03-01

    Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (~10nm diameter). Immunogold evidence clearly

  15. Síndrome de neurotoxicidad inducido por opioides (NIO Opioid induced-neurotoxicity syndrome (OIN

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    M. L. Cid

    2008-12-01

    Full Text Available El síndrome de neurotoxicidad inducido por opioides (NIO es uno de los efectos adversos del uso de estos fármacos descrito en los últimos años. Su aparición de debe a la acumulación de metabolitos tóxicos, principalmente el M3 Glucurónido de la morfina; los cuáles pueden provocar hiperexcitabilidad neuronal, con desarrollo de alteraciones cognitivas, delirium, alucinaciones, mioclonias, convulsiones e hiperalgesia. Especialmente vulnerables a estos efectos son los pacientes mayores o con factores de riesgo como insuficiencia renal o deshidratación. Su manejo incluye principalmente la prevención de su aparición, con el manejo de factores precipitantes; disminución o rotación de opioides y manejo sintomático, intentando mantener siempre un buen control del dolor.The opioid induced neurotoxicity (OIN is an adverse effect for opioids use, described in the last years. Because the accumulation of toxic metabolites, especially M3 Glucuronide of morphine, cause neuronal hiperexcitability, patients can develop cognitive failure, delirium, hallucinations, myoclonus, seizures and hyperalgesia. The most vulnerable patients are old people, patients with dehydration and renal failure. Its treatment include prevention, with the management of trigger factors, decrease or change opioids and symptomatic management, trying to keep the good control of pain.

  16. Terahertz sensing of corneal hydration.

    Science.gov (United States)

    Singh, Rahul S; Tewari, Priyamvada; Bourges, Jean Louis; Hubschman, Jean Pierre; Bennett, David B; Taylor, Zachary D; Lee, H; Brown, Elliott R; Grundfest, Warren S; Culjat, Martin O

    2010-01-01

    An indicator of ocular health is the hydrodyanmics of the cornea. Many corneal disorders deteriorate sight as they upset the normal hydrodynamics of the cornea. The mechanisms include the loss of endothelial pump function of corneal dystophies, swelling and immune response of corneal graft rejection, and inflammation and edema, which accompany trauma, burn, and irritation events. Due to high sensitivity to changes of water content in materials, a reflective terahertz (300 GHz and 3 THz) imaging system could be an ideal tool to measure the hydration level of the cornea. This paper presents the application of THz technology to visualize the hydration content across ex vivo porcine corneas. The corneas, with a thickness variation from 470 - 940 µm, were successfully imaged using a reflective pulsed THz imaging system, with a maximum SNR of 50 dB. To our knowledge, no prior studies have reported on the use of THz in measuring hydration in corneal tissues or other ocular tissues. These preliminary findings indicate that THz can be used to accurately sense hydration levels in the cornea using a pulsed, reflective THz imaging system.

  17. Corneale crosslinking voor progressieve keratoconus

    NARCIS (Netherlands)

    Wisse, Robert P L; Soeters, Nienke; Godefrooij, Daniel A.; De Koning-Tahzib, Nayyirih G.

    2016-01-01

    Keratoconus is a corneal disease with onset typically occurring during puberty or early adulthood. The cornea progressively thins and acquires a cone-like shape which negatively affects visual acuity. In the early stages, visual acuity can be corrected with glasses or contact lenses. In more advance

  18. Management of corneal bee sting

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    Razmjoo H

    2011-12-01

    Full Text Available Hassan Razmjoo1,2, Mohammad-Ali Abtahi1,2,4, Peyman Roomizadeh1,3, Zahra Mohammadi1,2, Seyed-Hossein Abtahi1,3,41Medical School, Isfahan University of Medical Sciences (IUMS; 2Ophthalmology Ward, Feiz Hospital, IUMS; 3Isfahan Medical Students Research Center (IMSRC, IUMS; 4Isfahan Ophthalmology Research Center (IORC, Feiz Hospital, IUMS, Isfahan, IranAbstract: Corneal bee sting is an uncommon environmental eye injury that can result in various ocular complications with an etiology of penetrating, immunologic, and toxic effects of the stinger and its injected venom. In this study we present our experience in the management of a middle-aged male with a right-sided deep corneal bee sting. On arrival, the patient was complaining of severe pain, blurry vision with acuity of 160/200, and tearing, which he had experienced soon after the injury. Firstly, we administered conventional drugs for eye injuries, including topical antibiotic, corticosteroid, and cycloplegic agents. After 2 days, corneal stromal infiltration and edema developed around the site of the sting, and visual acuity decreased to 100/200. These conditions led us to remove the stinger surgically. Within 25 days of follow-up, the corneal infiltration decreased gradually, and visual acuity improved to 180/200. We suggest a two-stage management approach for cases of corneal sting. For the first stage, if the stinger is readily accessible or primary dramatic reactions, including infiltration, especially on the visual axis, exist, manual or surgical removal would be indicated. Otherwise, we recommend conventional treatments for eye injuries. Given this situation, patients should be closely monitored for detection of any worsening. If the condition does not resolve or even deteriorates, for the second stage, surgical removal of the stinger under local or generalized anesthesia is indicated.Keywords: bee sting, stinger, cornea, removal, management, surgery

  19. Turning the tide of corneal blindness

    Directory of Open Access Journals (Sweden)

    Matthew S Oliva

    2012-01-01

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

  20. Turning the tide of corneal blindness.

    Science.gov (United States)

    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.

  1. Clinical applications of corneal confocal microscopy

    Directory of Open Access Journals (Sweden)

    Mitra Tavakoli

    2008-06-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  3. Genetics Home Reference: lattice corneal dystrophy type I

    Science.gov (United States)

    ... corneal dystrophy type I lattice corneal dystrophy type I Enable Javascript to view the expand/collapse boxes. ... All Close All Description Lattice corneal dystrophy type I is an eye disorder that affects the clear, ...

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

    OpenAIRE

    Chang Rae Rho; Min-Ji Kim; Choun-Ki Joo

    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 ...

  5. [Regeneration and fibrosis of corneal tissues].

    Science.gov (United States)

    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.

  6. Transformación de un programa de intervalo fijo de reforzamiento con agua en un procedimiento de beber inducido por el programa

    OpenAIRE

    Jorge A. Ruiz; Carlos A. Bruner

    2005-01-01

    Para determinar si los efectos específicos de las variables que controlan el beber inducido por el programa son ajenos o no al campo del condicionamien-to, en el presente estudio se añadieron una a una la privación de comida, la entrega periódica de comida y la entrega continua de agua a un programa de reforzamiento con agua de intervalo hasta transformar este procedi-miento operante en uno de beber inducido por el programa. En la primera condición experimental tres ratas privadas de agua le...

  7. DESARROLLO DE SOFTWARE PARA EL ANÁLISIS DE ESPECTROSCOPIA DE RUPTURA INDUCIDO POR LÁSER

    OpenAIRE

    PÉREZ BÁEZ, ZEFERINO

    2015-01-01

    El presente documento describe el desarrollo de un programa para el procesamiento de los datos generados mediante un sistema LIBS (Laser Induced Breakdown Spectroscopy). LIBS es una técnica micro destructiva para identificación de elementos mediante la formación de un plasma de alta temperatura inducido por un pulso láser corto, que emite espectros característicos de los elementos involucrados en la muestra. El procesamiento de los espectros supone un reto importante, por lo que el objetivo p...

  8. Posição viciosa de cabeça por astigmatismo mal corrigido: relato de caso Abnormal head position caused by incorrect prescription for astigmatism: case report

    Directory of Open Access Journals (Sweden)

    Flávia Augusta Attié de Castro

    2005-10-01

    Full Text Available A posição viciosa de cabeça é uma condição compensatória que visa proporcionar aos pacientes melhor rendimento visual. Pode ser causada por problemas oftalmológicos, como distúrbios oculomotores (nistagmos, estrabismos e altos astigmatismos. No entanto, compromete a estética e, a longo prazo, pode causar transtornos ortopédicos (coluna cervical e assimetrias faciais. Relatamos o caso de uma garota, JL, 8 anos, com cabeça inclinada para esquerda havia vários anos. Fazia uso de óculos prescritos em outro serviço para correção de astigmatismo misto: OD= +2,00 DE Ç -5,50 DC a 180º e OE= +2,25 DE Ç -5,75 DC a 180º. No exame oftálmico, a paciente apresentava cabeça inclinada para a esquerda e acuidade visual com correção de 0,5 no OD e 0,7 OE. Os testes de cobertura simples e alternado não evidenciaram desvio ocular. Rotações oculares, biomicroscopia e fundoscopia também não mostraram alterações. Na refratometria sob cicloplegia e teste de lentes foram encontrados: OD= +3,50 DE Ç -6,00 DC a 10º e OE= +3,50 DE Ç -6,00 DC a 170º, com acuidade visual igual a 1,0 nos olhos direito e esquerdo. Foram prescritas as lentes encontradas no exame e a paciente retornou com a correção nova sem a inclinação de cabeça. Erros refracionais mal corrigidos também podem gerar torcicolo e, muitas vezes, passam despercebidos. Refratometria sob cicloplegia e teste de lentes são fundamentais para um diagnóstico preciso.Abnormal head position is a compensatory condition which improves patients' vision. It can be caused by ophthalmological problems such as oculomotor imbalances (strabismus, nystagmus and high astigmatisms. However, it results in esthetic impairment, orthopedic trouble and facial asymmetries. We describe a case of a girl, JL, 8 years, with abnormal head position tilted to the left since the last glasses were prescribed. The correction used by the patient was: right eye = +2.00 sph à -5.5 cyl 180° and left eye = +2

  9. Lente de contato de material híbrido em pacientes com ceratocone e astigmatismo miópico composto Hybrid material contact lens in keratoconus and myopic astigmatism patients

    Directory of Open Access Journals (Sweden)

    Fernando Leal

    2007-03-01

    Full Text Available OBJETIVOS: Avaliar o desempenho visual e o conforto de lentes de contato de material híbrido, quanto ao apresentado por pacientes portadores de ceratocone e astigmatismo miópico composto, e comparar com a lente de contato rígida-gás-permeável nos dois grupos de pacientes. MÉTODOS: Foram submetidos à adaptação com lentes de contato 22 pacientes, sendo 8 portadores de astigmatismo miópico composto e 14 com diagnóstico de ceratocone. Entre os pacientes, 7 eram do sexo masculino e 15 do feminino, com idade média de 32,13 anos ± 8,12. Cada paciente recebeu uma lente de contato de material híbrido e, no contralateral, uma lente rígida-gás-permeável. A escolha da lente a ser adaptada no olho direito ou esquerdo foi feita aleatoriamente, sendo o trabalho duplo-mascarado. Os pacientes foram submetidos aos seguintes exames: medida do conforto por meio da escala visual analógica, tempo de ruptura do filme lacrimal, acuidade visual pela escala de Bailey-Lovie adaptada para quatro metros, sensibilidade ao contraste pelo "functional acuity contrast test" e análise das aberrações oculares pela análise de frentes de onda. RESULTADOS: Com relação ao conforto não houve associação com o tipo de lente (p=0,350. Houve variação no conforto referido ao longo do tempo até 7 dias (p=0,001, estabilizando-se após este período. A medida da acuidade visual sofreu aumento entre a adaptação e a medida obtida aos 7 dias, bem como desta para a medida de 15 dias, estabilizando-se então. A acuidade visual não apresentou diferenças com relação ao tipo de lente estudada. Verificou-se que não houve diferença no tempo de ruptura do filme lacrimal (p=0,989 com relação aos tipos de lentes, porém houve diminuição deste (p=0,001 quando comparadas as medidas antes do início do uso das lentes e com dois meses de uso. Os tipos de lentes não revelaram associação com a sensibilidade ao contraste e não diferiram das medidas feitas com o uso de

  10. Corneal laceration caused by river crab

    Directory of Open Access Journals (Sweden)

    Vinuthinee N

    2015-01-01

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

  11. Corneal cellular proliferation and wound healing

    OpenAIRE

    Gan, Lisha

    2000-01-01

    Background. Cellular proliferation plays an important role in both physiological and pathological processes. Epithelial hyperplasia in the epithelium, excessive scar formation in retrocorneal membrane formation and neovascularization are examples of excessive proliferation of cornea cells. Lack of proliferative ability causes corneal degeneration. The degree of proliferative and metabolic activity will directly influence corneal transparency and very evidently refractive res...

  12. Corynebacterium macginleyi isolated from a corneal ulcer

    Directory of Open Access Journals (Sweden)

    Kathryn Ruoff

    2010-02-01

    Full Text Available We report the isolation of Corynebacterium macginleyi from the corneal ulcer culture of a patient, later enrolled in the Steroids for Corneal Ulcer Trial (SCUT. To our knowledge this is the first published report from North America of the recovery of C. macginleyi from a serious ocular infection.

  13. Corneal staining after treatment with topical tetracycline

    NARCIS (Netherlands)

    R. Lapid-Gortzak; C.P. Nieuwendaal; A.R. Slomovic; L. Spanjaard

    2006-01-01

    Purpose: The purpose of this paper is to report a case of corneal staining after treatment with topical tetracycline. Methods: A patient with crystalline keratopathy caused by Streptococcus viridans after corneal transplantation was treated topically with tetracycline eye drops, based on results of

  14. Tratamiento de agrandamiento gingival inducido por fenitoina asociado a placa bacteriana

    Directory of Open Access Journals (Sweden)

    Carmen Julia Rovira

    2013-10-01

    Full Text Available ResumenLa ingesta de algunos medicamentos puede producir un sobre crecimiento de las encías. Se reportan medicamentos tales como los bloqueadores de los canales de calcio, inmunosupresores, anticonvulsivantes que producen estos efectos adversos. Múltiples casos de agrandamientos gingivales están asociados a la ingesta de Fenitoína. El tratamiento de los agrandamientos gingivales inducidos por drogas por lo general es quirúrgico, pero mantener un buen control de placa bacteriana puede evitar en muchos casos que se presente un exagerado aumento de volumen gingival. Se presenta un caso de agrandamiento gingival en paciente masculino de 22 años de edad, bajo tratamiento antiepiléptico con fenitoína. Al examen clínico se observó aumento del volumen gingival de forma generalizada, en maxilar superior e inferior, predominante en sector anterior, produciendo ardor y sangrado durante el cepillado y la ingestión de alimentos. Al sondaje presenta múltiples pseudobolsas en los diferentes cuadrantes. La radiografía panorámica reveló pérdida ósea moderada horizontal, predominante en el sector posterosuperior, posteroinferior y anteroinferior. El plan de tratamiento consistió en fase higiénica, instrucción y motivación en higiene oral a la madre, gingivectomía y gingivoplastía en ambos maxilares. (DUAZARY 2011 No. 2, 226 - 231Abstract The importance of endodontic treatment is to achieve a complete filling and sealing of the root canal to prevent the transport of contaminants to and from root canal, with materials compatible with the surrounding tissues. Occasionally a situation may arise in which the purpose of the maintenance of working length is compromised such as overenlargement. This situation allows the extrusion of filling materials, mainly sealer cements, causing post treatment complications such as inflammatory reactions, injury to adjacent structures (orbital pain, inferior alveolar nerve injury, headache, etc., and infections

  15. Corneal neovascularization and contemporary antiangiogenic therapeutics.

    Science.gov (United States)

    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.

  16. Dorsally located corneal dermoid in a cat

    Directory of Open Access Journals (Sweden)

    Alexander J LoPinto

    2016-04-01

    Full Text Available Case summary A 2-month-old, male kitten was presented for evaluation of unilateral blepharospasm and epiphora involving the right eye. Ocular examination revealed conjunctivitis, a superficial corneal ulcer, reflex anterior uveitis and a haired mass within the dorsal cornea of the right eye. The mass was subsequently removed surgically via a lamellar keratectomy. Histologic evaluation of the mass via light microscopy revealed it to be comprised of normal-haired skin with mild inflammation. One week after surgical removal and medical management of the corneal ulcer, all ocular clinical signs had resolved with minimal corneal scarring. On re-examination 6 months following surgical excision of the mass, the kitten was noted to be comfortable with no significant corneal scarring. Relevance and novel information To our knowledge, this is the first case report of a dorsally located corneal dermoid in a cat.

  17. Corneal Topographical Changes Flollowing Strabismus Surgery

    Institute of Scientific and Technical Information of China (English)

    MaiGH; WangZ

    1999-01-01

    Purpose:To study corneal topographical changes after strabismus surgery.Methods:Computer-aided corneal topography was used in 43 strabismus patients(45 eyes)one or two days prior to and six or seven ays after strabismus surgery.The spherical and cylindrical equivalents were calculated based on the simulated keratometry.Results:After the surgery,only the changes at 3mm in the inferior quadrant were statistically significant.The changes at 3mm in the rest quadrants and the changes at 7mm were no significant.Significant changes in spherical equivalent were found post-operatively.neither the horizontal nor the verical meridional equivalent showed significant changes after surgery.Conclusions:The results of corneal topographical changes following strabismus surgery in our preliminary study indicated the little effect of strabismus surgery on corneal curvature and corneal astigmatism.

  18. Reasons not to select patients for corneal refractive surgery Razões para recusar candidatos à cirurgia refrativa corneana

    Directory of Open Access Journals (Sweden)

    André Luiz Parolin Ribeiro

    2002-08-01

    Full Text Available Purpose: To present how the section of Refractive Surgery of the Federal University of São Paulo assesses the candidates and the reasons to indicate for corneal refractive surgery. Methods: We examined 1626 patients. Anamnesis, complete ophthalmologic examination and corneal topography were performed in all patients. The patients spontaneously seeked evaluation at the Refractive Surgery Section by telephone without a previous screening. Reasons to refuse patients for refractive surgery were previously established by the Refractive Surgery Section. Results: Based on current technology and clinical experience, 265 patients (16.29% were refused for excimer laser corneal refractive surgery. Myopia of patients who had insufficient preoperative corneal pachymetry for the laser treatment was the main cause for refusal (51 patients. Cataract (45 patients, keratoconus (31 patients, amblyopia (21 patients, hyperopia > 5 diopters and mixed astigmatism (19 patients, presbyopia (unaware ness of the need for optical correction after the procedure; 16 patients, pupillary diameter > 5mm (9 patients, single eye (9 patients, progressive myopia (8 patients, postradial keratotomy (7 patients and low ametropia (7 patients were among the reasons for the refusal. Conclusion: Candidates for excimer laser corneal refractive surgery may present risk factors that should be known in order to avoid complications.Objetivo: O objetivo deste estudo é mostrar como o setor de Cirurgia Refrativa da Escola Paulista de Medicina da Universidade Federal de São Paulo avalia seus candidatos e quais as razões para não selecioná-los para cirurgia refrativa. Métodos: Foram examinados 1626 pacientes. Anamnese, avaliação oftalmológica completa e topografia corneana foram realizadas em todos os pacientes. Os pacientes procuraram avaliação no setor de Cirurgia Refrativa espontaneamente sem triagem prévia. Resultados: Não foram selecionados 265 pacientes (16,29% para cirurgia

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

    Directory of Open Access Journals (Sweden)

    Yoshihide Hashimoto

    Full Text Available 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.

  20. First Identification of a Triple Corneal Dystrophy Association: Keratoconus, Epithelial Basement Membrane Corneal Dystrophy and Fuchs' Endothelial Corneal Dystrophy

    Directory of Open Access Journals (Sweden)

    Cosimo Mazzotta

    2014-09-01

    Full Text Available Purpose: To report the observation of a triple corneal dystrophy association consisting of keratoconus (KC, epithelial basement membrane corneal dystrophy (EBMCD and Fuchs' endothelial corneal dystrophy (FECD. Methods: A 55-year-old male patient was referred to our cornea service for blurred vision and recurrent foreign body sensation. He reported bilateral recurrent corneal erosions with diurnal visual fluctuations. He underwent corneal biomicroscopy, Scheimpflug tomography, in vivo HRT confocal laser scanning microscopy and genetic testing for TGFBI and ZEB1 mutations using direct DNA sequencing. Results: Biomicroscopic examination revealed the presence of subepithelial central and paracentral corneal opacities. The endothelium showed a bilateral flecked appearance, and the posterior corneal curvature suggested a possible concomitant ectatic disorder. Corneal tomography confirmed the presence of a stage II KC in both eyes. In vivo confocal laser scanning microscopy revealed a concomitant bilateral EBMCD with hyperreflective deposits in basal epithelial cells, subbasal Bowman's layer microfolds and ridges with truncated subbasal nerves as pseudodendritic elements. Stromal analysis revealed honeycomb edematous areas, and the endothelium showed a strawberry surface configuration typical of FECD. The genetic analysis resulted negative for TGFBI mutations and positive for a heterozygous mutation in exon 7 of the gene ZEB1. Conclusion: This is the first case reported in the literature in which KC, EBMCD and FECD are present in the same patient and associated with ZEB1 gene mutation. The triple association was previously established by means of morphological analysis of the cornea using corneal Scheimpflug tomography and in vivo HRT II confocal laser scanning microscopy.

  1. Corneal topographic changes following retinal surgery

    Directory of Open Access Journals (Sweden)

    Pandey RM

    2004-08-01

    Full Text Available Abstract Background To study the effect of retinal/ vitreoretinal surgeries on corneal elevations. Methods Patients who underwent retinal/ vitreoretinal surgeries were divided into 3 groups. Scleral buckling was performed in 11 eyes (Group 1. In 8 (25% eyes, vitreoretinal surgery was performed along with scleral buckling (Group 2. In 12 eyes, pars plana vitrectomy was performed for vitreous hemorrhage (Group 3. An encircling element was used in all the eyes. The parameters evaluated were best-corrected visual acuity (BCVA, change in axial length, and corneal topographic changes on Orbscan topography system II, preoperative and at 12 weeks following surgery. Results There was a statistically significant increase in anterior corneal elevation in all the three groups after surgery (p = 0.003, p = 0.008 & p = 0.003 respectively. The increase in posterior corneal elevation was highly significant in all the three groups after surgery (p = 0.0000, p = 0.0001 & p = 0.0001 respectively. The increase in the posterior corneal elevation was more than the increase in the anterior elevation and was significant statistically in all the three groups (group I: p = 0.02; group II: p = 0.01; group III: p = 0.008. Conclusions Retinal/ vitreoretinal surgeries cause a significant increase in the corneal elevations and have a greater effect on the posterior corneal surface.

  2. Factors Affecting Corneal Hysteresis in Taiwanese Adults

    Institute of Scientific and Technical Information of China (English)

    Jia-Kang Wang; Tzu-Lun Huang; Pei-Yuan Su; Pei-Yao Chang

    2015-01-01

    Purpose: To investigate the correlation of various corneal hysteresis (CH) factors in Chinese adults. Methods: From January 2009 to November 2011, the healthy right eyes of a total of 292 adults were recruited into the study. Goldmann-correlated intraocular pressure (IOPG) and CH were measured using an ocular response analyzer (ORA). Central corneal thickness was measured using the ORA’s in-tegrated handheld ultrasonic pachymeter. The IOLMaster was used to obtain the ocular biometric measurements including axial length, anterior chamber depth, and keratometric values. The Pearson correlation coefficient was used to test correla-tions between CH and quantitative factors. The chi-square test was used to detect differences in categorical values. Results: Longer axial length (P=0.0001), lower IOPG (P=0.03), older age(P=0.003),and thinner central corneal thick-ness (P=0.0001) were significantly associated with lower CH. The anterior chamber depth (P=0.34), gender (P=0.23), and corneal curvature (P=0.18) had no relationship to CH. Conclusion:Various factors including axial length, intraocular pressure, age, and central corneal thickness can affect measure-ment of corneal biomechanical properties in Chinese adults. But the anterior chamber depth, gender, and corneal curvature were irrelevant to CH.

  3. Differences between real and predicted corneal shapes after aspherical corneal ablation

    Science.gov (United States)

    Anera, Rosario G.; Villa, César; Jiménez, José R.; Gutiérrez, Ramón; Jiménez del Barco, Luis

    2005-07-01

    We study the differences between real and expected corneal shapes, using an aspherical ablation algorithm with a known equation and avoiding the limitation imposed by most studies of refractive surgery in which the ablation equations are not known. We have calculated the theoretical corneal shape predicted by this algorithm, comparing this shape with the real corneal topography. The results indicate that the deviations that appear in the corneal shape are significant for visual performance and for the correction of eye aberrations. If we include in this analysis the effect of reflection losses and nonnormal incidence on the cornea, we can reduce corneal differences, but they will remain significant. These results confirm that it is essential to minimize corneal differences to achieve effective correction in refractive surgery.

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

    Science.gov (United States)

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

    Directory of Open Access Journals (Sweden)

    Chang Rae Rho

    2016-01-01

    Full Text Available 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.

  6. Surgical compensation of presbyopia with corneal inlays.

    Science.gov (United States)

    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.

  7. Conjunctival intraepithelial neoplasia with corneal furrow degeneration

    Directory of Open Access Journals (Sweden)

    Pukhraj Rishi

    2014-01-01

    Full Text Available A 68-year-old man presented with redness of left eye since six months. Examination revealed bilateral corneal furrow degeneration. Left eye lesion was suggestive of conjunctival squamous cell carcinoma, encroaching on to cornea. Anterior segment optical coherence tomography (AS-OCT confirmed peripheral corneal thinning. Fluorescein angiography confirmed intrinsic vascularity of lesion. Patient was managed with "no touch" surgical excision, dry keratectomy without alcohol, cryotherapy, and primary closure. Pathologic examination of removed tissue confirmed clinical diagnosis. Management of this particular case required modification of standard treatment protocol. Unlike the alcohol-assisted technique of tumor dissection described, ethyl alcohol was not used for risk of corneal perforation due to underlying peripheral corneal thinning. Likewise, topical steroids were withheld in the post-operative period. Three weeks post-operatively, left eye was healing well. Hence, per-operative usage of absolute alcohol and post-operative use of topical steroids may be best avoided in such eyes.

  8. Asphericity analysis using corneal wavefront and topographic meridional fits

    Science.gov (United States)

    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.

  9. Update on pathologic diagnosis of corneal infections and inflammations

    Directory of Open Access Journals (Sweden)

    Geeta K Vemuganti

    2011-01-01

    Full Text Available One of the most frequent types of corneal specimen that we received in our pathology laboratory is an excised corneal tissue following keratoplasty. Several of these cases are due to corneal infections or the sequelae, like corneal scar. Advances in the histological and molecular diagnosis of corneal infections and inflammations have resulted in rapid and accurate diagnosis of the infectious agent and in the overall understanding of the mechanisms in inflammatory diseases of the cornea. This review provides an update of histopathological findings in various corneal infections and inflammations.

  10. Survival and integration of tissue-engineered corneal stroma in a model of corneal ulcer.

    Science.gov (United States)

    Zhang, Chao; Nie, Xin; Hu, Dan; Liu, Yuan; Deng, Zhihong; Dong, Rui; Zhang, Yongjie; Jin, Yan

    2007-08-01

    Tissue-engineered replacement of diseased or damaged tissue has become a reality for some types of tissue, such as skin and cartilage. Tissue-engineered corneal stroma represents a promising concept to overcome the limitations of cornea replacement with allograft. In this study, porcine cornea was decellularized by a series of extraction methods, and the in vivo biocompatibility of the scaffold was measured subcutaneously in rabbits (n = 8). These were not acutely rejected and no abscesses were observed by hematoxylin and eosin staining at the 8th week, indicating that the scaffolds had good biocompatibility. To investigate the potential value of clinical applications, rabbit stromal keratocytes were implanted onto decellularized scaffolds to fabricate tissue-engineered corneal stroma. Allograft, tissue-engineered corneal stroma, or scaffolds were implanted into a model of corneal ulcer. The survival and reconstruction of corneal transplantation were morphologically evaluated by light and electron microscopy until the 32nd week after implantation. Experiments involving transplantation indicated that the epithelial and stromal defect healed quickly, with improvement in corneal clarity. The integration of the graft was accompanied by neurite ingrowth from the host tissue. By 16 weeks after transplantation, the cornea had gradually regained an intact state similar to that of normal cornea. Our results demonstrate that the tissue-engineered corneal stroma with allogenetic cells is a promising therapeutic method for corneal injury.

  11. Ultrasound biomicroscopy confirmation of corneal overriding due to improper suturing of full-thickness corneal laceration

    Directory of Open Access Journals (Sweden)

    Murat Kucukevcilioglu

    2014-12-01

    Full Text Available We herein present a case with corneal overriding due to improper suturing of a full-thickness corneal laceration. There was a 2.5-mm difference between horizontal and vertical white-to-white measurements in the cornea. However, slit lamp examination failed to demonstrate the exact architecture of the laceration. Ultrasound biomicroscopy defined the wound edges thoroughly and confirmed the presence of corneal overriding. Six weeks after suture enhancement, the abnormal oval appearance of the cornea was absent and correct apposition of the corneal edges was seen on ultrasound biomicroscopy. Ultrasound biomicroscopy can be used in preoperative surgical planning of cases with complicated corneal lacerations. It can be used to adjust and enhance wound architecture in eyes with penetrating injury.

  12. Changes on the corneal thickness and curvature after orthokeratology

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  16. Corneal reconstruction by stem cells and bioengineering

    Directory of Open Access Journals (Sweden)

    Arjamaa O

    2012-09-01

    Full Text Available Olli ArjamaaDepartment of Biology, University of Turku, Turku, FinlandAbstract: Almost 300 million people are visually impaired worldwide due to various eye diseases such as cataracts, glaucoma, age-related macular degeneration, diabetic retinopathy, and corneal diseases. Notably, ten million people are blind because of severe ocular surface diseases and the majority of cases occur in developing countries. Blinding ocular surface diseases have, however, become treatable by grafting of surface layers, or by full-thickness transplantation of the cornea. As the demand for human corneal tissue for surface reconstruction and transplantation far exceeds the supply, methods are being developed to supplement tissue donation. Xenotransplantation of the cornea or cells from genetically modified pigs may become one of the solutions. Transplantation of limbal stem cells within tissue biopsies, to restore the transparency of the cornea is another remarkable method, which has shown its potential in several clinical studies. The combination of stem cell technology and engineering of biocompatible tissue equivalent, still at preclinical stage, has shown us how synthetic corneal tissue is able to guide cultured corneal stromal stem cells of human origin, to become native-like stroma, the most important layer of the cornea. These findings give hope for a large-quantity production of biomaterial for corneal reconstruction. As such, clinical ophthalmologists should become more familiar with the methods of laboratory science.Keywords: eye, grafting, keratoplasty, xenotransplantation, cell reservoir, biocompatible tissue equivalent

  17. Contact lens rehabilitation following repaired corneal perforations

    Directory of Open Access Journals (Sweden)

    Sreenivas V

    2006-03-01

    Full Text Available Abstract Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60% required aphakic contact lenses. The best corrected visual acuity (BCVA of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25% eyes with spectacle correction and 37 (92.5% eyes with the use of contact lens (p Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries.

  18. Corneal Phaeohyphomycosis Caused by Bipolaris hawaiiensis

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    Winai Chaidaroon

    2016-07-01

    Full Text Available 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.

  19. Corneal Phaeohyphomycosis Caused by Bipolaris hawaiiensis

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Ozdemir Ozdemir

    2014-08-01

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

  1. 21 CFR 886.1450 - Corneal radius measuring device.

    Science.gov (United States)

    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...

  2. Corneal nerve microstructure in Parkinson's disease.

    Science.gov (United States)

    Misra, Stuti L; Kersten, Hannah M; Roxburgh, Richard H; Danesh-Meyer, Helen V; McGhee, Charles N J

    2017-03-03

    Ocular surface changes and blink abnormalities are well-established in Parkinson's disease. Blink rate may be influenced by corneal sub-basal nerve density, however, this relationship has not yet been investigated in Parkinson's disease. This case-control study examined the ocular surface in patients with moderately severe Parkinson's disease, including confocal microscopy of the cornea. Fifteen patients with moderately severe Parkinson's disease (modified Hoehn and Yahr grade 3 or 4) and fifteen control participants were recruited. Ophthalmic assessment included slit-lamp examination, blink rate assessment, central corneal aesthesiometry and in vivo corneal confocal microscopy. The effect of disease laterality was also investigated. Of the 15 patients with Parkinson's disease, ten were male and the mean age was 65.5±8.6years. The corneal sub-basal nerve plexus density was markedly reduced in patients with Parkinson's disease (7.56±2.4mm/mm(2)) compared with controls (15.91±2.6mm/mm(2)) (pParkinson's disease (0.79±1.2mBAR) and the control group (0.26±0.35mBAR), p=0.12. Sub-basal nerve density was not significantly different between the eye ipsilateral to the side of the body with most-severe motor symptoms, and the contralateral eye. There was a significant positive correlation between ACE-R scores and sub-basal corneal nerve density (R(2)=0.66, p=0.02). This is the first study to report a significant reduction in corneal sub-basal nerve density in Parkinson's disease and demonstrate an association with cognitive dysfunction. These results provide further evidence to support the involvement of the peripheral nervous system in Parkinson's disease, previously thought to be a central nervous system disorder.

  3. Corneal collagen crosslinking for keratoconus. A review

    Directory of Open Access Journals (Sweden)

    M. M. Bikbov

    2014-10-01

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

  4. Corneal collagen crosslinking for keratoconus. A review

    Directory of Open Access Journals (Sweden)

    M. M. Bikbov

    2014-01-01

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

  5. Corneal Topographic Analysis in Patients with Cataract

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    We studied the corneal curvature of 161 eyes in 101 patients, aged from 50 to 80 years (mean: 63 years), with senile cataract using the Topographic Modeling System (IMS) preoperatively. The results revealed that mean surface asymmetry index (SAD was 0. 36 and mean surface regularity index (SRI) 0. 79. Simulated keratometry reading (Sim K) was 44. 46 D, and 43. 56 D. Minimun K reading was 42. 60 D. The same patterns of corneal topography in both eyes were 50% in 60 patients who had binocular examination....

  6. Bessel Function Model for Corneal Topography

    CERN Document Server

    Okrasiński, Wojciech

    2011-01-01

    In this paper we consider a new nonlinear mathematical model for corneal topography formulated as two-point boudary value problem. We derive it from first physical principles and provide some mathematical analysis. The existence and uniqeness theorems are proved as well as various estimates on exact solution. At the end we fit the simplified model based on Modified Bessel Function of the First Kind with the real corneal data consisting of matrix of 123x123 points and obtain an error of order of 1%.

  7. Current status of accelerated corneal cross-linking

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    Michael Mrochen

    2013-01-01

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

  8. Reversible corneal toxicity of retained intracameral Perfluoro-n-octane

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    Saad S Alharbi

    2016-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  10. Congenital Unilateral Corneal Anaesthesia with Microphthalmos: A Case Report

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    George Voyatzis

    2012-01-01

    Full Text Available Congenital corneal anaesthesia (CCA is an uncommon condition difficult to diagnose. We report the case of a 20-month-old boy who presented with unilateral congenital corneal anaesthesia. The child was referred with a persistent corneal epithelial defect, unresponsive to symptomatic local treatment for over 10 months. Intensive topical treatment and strict corneal protection led to quick corneal healing. Congenital corneal anaesthesia occurs either alone or in association with neurological diseases or systemic congenital abnormalities. It is important to search for corneal anaesthesia in children with chronic ulcerations of the cornea and self-inflicted injuries. Early diagnosis and treatment are important due to the risk of poor visual prognosis. Management of CCA should aim for the prevention of epithelial defects and is a life-long process.

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

    Science.gov (United States)

    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 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 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

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

    Directory of Open Access Journals (Sweden)

    Alexandra X Crawford

    2013-01-01

    Full Text Available 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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  15. CORNEAL STROMAL THINNING: A RARE CORNEAL COMPLICATION AFTER BARE SCL ERA PTERYG I UM EXCISION TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Sulaiman Abdul

    2015-06-01

    Full Text Available INTRODUCTION : Bare sclera technique without using any anti - mitotic drugs are commonly employed in rural population. Corneal dellen formation and recurrence of pterygium are more common in these cases. But the corneal complication like stromal thinning, necrosis of corne a and sclera are not common. The corneal epithelium is a highly differentiated cell type that is self - renewing. Also corneal epithelium is important for the stromal replacement in the situations like chemical, thermal burns, ocular surgery like pterygium s urgery. Interference with status of stem cell replacement and as a consequent to it, stromal thinning is occurring in the pterygium surgery. P atient 1: A 68 yr s. old male patient underwent pterygium surgery ( B aresclera excision technique. After 30 days he developed corneal thinning with the punched out partial stromal loss without perforation or descmetocele or scleral thinning. Patient 2: A 60yr s. old male patient underwent pterygium surgery 2months back, he developed same type of corneal thinning. Both P atients were treated with tear drops and improved. CONCLUSION : The stromal thinning in these two cases is may be due to chemical factors like collagenase which might have been released from the traumatised conjunctival epithelial cells causing thinning wit hout replacement of stroma by limbal stem cells.

  16. Change in corneal curvature induced by surgery

    NARCIS (Netherlands)

    G. van Rij (Gabriel)

    1987-01-01

    textabstractThe first section deals with the mechanisms by which sutures, incisions and intracorneal contact lenses produce a change in corneal curvature. To clarify the mechanisms by which incisions and sutures produce astigmatism, we made incisions and placed sutures in the corneoscleral limbus of

  17. Aspergillus terreus recovered from a corneal scraping.

    Science.gov (United States)

    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.

  18. Corneal injuries from liquid detergent pods.

    Science.gov (United States)

    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.

  19. [Purulent corneal ulcers: etiology, pathogenesis, classification].

    Science.gov (United States)

    Kasparova, Evg A

    2015-01-01

    Advanced purulent corneal ulcer, as well as abscess, is a serious vision-threatening condition notable for its fulminant course and possible loss of the eye due to endophthalmitis. Its leading causes, pathogenesis, and classifications are described and analyzed in this paper.

  20. Autophagy in granular corneal dystrophy type 2.

    Science.gov (United States)

    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.

  1. Traumatic wound dehiscence after corneal keratoplasty

    Directory of Open Access Journals (Sweden)

    Patrick Frensel Tzelikis

    2015-10-01

    Full Text Available ABSTRACTPurpose:To assess patient characteristics, risk factors, outcomes, and the treatment of wound dehiscence (WD in patients after corneal keratoplasty.Methods:Retrospective chart review of 11 eyes of 11 patients with corneal grafts who underwent repair of WD from January 1, 2004 to December 31, 2012 at Hospital Oftalmologico de Brasilia.Results:Eight (72.7% patients were men and three were women. Six (54.5% patients had deep anterior lamellar keratoplasty (DALK and 5 had penetrating keratoplasty. The mean age at trauma was 31.1 years. The mean time from corneal keratoplasty to WD was 12.82 months (range, 3-33 months. The mean best-corrected visual acuity of patients before trauma was 20/60 (0.48 logMAR and after final treatment was 20/160 (0.90 logMAR (P=0.15. In one case, visual acuity decreased to no light perception because of retinal detachment and phthisis bulbi. Accidental blunt trauma and fall were the most common causes of WD.Conclusion:Patients who undergo corneal keratoplasty have a life-long risk of WD. The full-thickness rupture at the graft-host junction in our study suggests that the junction remains vulnerable, even following DALK, and can rupture with trauma. In our series, depending upon the severity of the trauma, postkeratoplastic WD can be associated with a good visual prognosis.

  2. Polysaccharide coating of human corneal endothelium

    DEFF Research Database (Denmark)

    Schroder, H D; Sperling, S

    1977-01-01

    Electron microscopy revealed the presence of a 600-1500 A thick layer of polysaccharide on the surface of human corneal endothelial cells. The surface layer was visualized by combined fixation and staining in a mixture of ruthenium red and osmium tetroxide. The coating material was stable...

  3. Serological profile of candidates for corneal donation

    Directory of Open Access Journals (Sweden)

    Adroaldo Lunardelli

    2014-10-01

    Full Text Available Objetive: The purpose of this study is to map the serological profile of candidates to corneal donation at Irmandade Santa Casa de Misericórdia de Porto Alegre, identifying the percentage of disposal by serology and the marker involved. Methods: There have been analised – retrospectively – the results of serology of all corneal donors, made between the period of 1st january 2006 and 31st december 2012. Data analised were related to age, gender and the results of serology pertinent to viral markers (HBsAg, anti-HBc, anti-HCV and anti-HIV, these, determined by immunosorbent tests (ELISA. Results: In the period of the study, there were 2476 corneal donors at the institution, with a major incidence on the male gender, on an average of 58.7 years old. 23% of retention because of serological unfitness was also identified, that is, 570 samples were non-negative to any of the used tests. The marker anti- HBc was the most prevalent on the studied population, followed by the Hepatitis C virus (HCV and by the Human Immunodeficiency Virus (HIV. Conclusion: From the data found through this study, it is essential to have the participation of an efficient service on the serological evaluation of the candidates to corneal donation, once the security of the receptor must be taken into consideration in a population of donors with 23% of unfitness prevalence, in which the most prevalent marker is the one of Hepatits B.

  4. Evaluation and Treatment of Perioperative Corneal Abrasions

    Directory of Open Access Journals (Sweden)

    Kira L. Segal

    2014-01-01

    Full Text Available Purpose. To evaluate perioperative risk factors for corneal abrasion (CA and to determine current care for perioperative CA in a tertiary care setting. Methods. Hospital-based, cross-sectional study. In Operating Room and Post-Anesthesia Care Units patients, a comparison of cases and controls was evaluated to elucidate risk factors, time to treatment, and most common treatments prescribed for corneal abrasions. Results. 86 cases of corneal abrasion and 89 controls were identified from the 78,542 surgical procedures performed over 2 years. Statistically significant risk factors were age (P=0.0037, general anesthesia (P<0.001, greater average estimated blood loss (P<0.001, eyes taped during surgery (P<0.001, prone position (P<0.001, trendelenburg position (P<0.001, and supplemental oxygen en route to and in the Post-Anesthesia Care Units (P<0.001. Average time to complaint was 129 minutes. 94% of cases had an inpatient ophthalmology consult, with an average time to consult of 164 minutes. The most common treatment was artificial tears alone (40%, followed by combination treatment of antibiotic ointment and artificial tears (35.3%. Conclusions. Trendelenburg positioning is a novel risk factor for CA. Diagnosis and treatment of perioperative corneal abrasions by an ophthalmologist typically require three hours in the tertiary care setting.

  5. Corneal topography measurements for biometric applications

    Science.gov (United States)

    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.

  6. [Future Innovative Medicine for Corneal Diseases].

    Science.gov (United States)

    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

  7. Oxygen-deficient metabolism and corneal edema.

    Science.gov (United States)

    Leung, B K; Bonanno, J A; Radke, C J

    2011-11-01

    Wear of low-oxygen-transmissible soft contact lenses swells the cornea significantly, even during open eye. Although oxygen-deficient corneal edema is well-documented, a self-consistent quantitative prediction based on the underlying metabolic reactions is not available. We present a biochemical description of the human cornea that quantifies hypoxic swelling through the coupled transport of water, salt, and respiratory metabolites. Aerobic and anaerobic consumption of glucose, as well as acidosis and pH buffering, are incorporated in a seven-layer corneal model (anterior chamber, endothelium, stroma, epithelium, postlens tear film, contact lens, and prelens tear film). Corneal swelling is predicted from coupled transport of water, dissolved salts, and especially metabolites, along with membrane-transport resistances at the endothelium and epithelium. At the endothelium, the Na+/K+ - ATPase electrogenic channel actively transports bicarbonate ion from the stroma into the anterior chamber. As captured by the Kedem-Katchalsky membrane-transport formalism, the active bicarbonate-ion flux provides the driving force for corneal fluid pump-out needed to match the leak-in tendency of the stroma. Increased lactate-ion production during hypoxia osmotically lowers the pump-out rate requiring the stroma to swell to higher water content. Concentration profiles are predicted for glucose, water, oxygen, carbon dioxide, and hydronium, lactate, bicarbonate, sodium, and chloride ions, along with electrostatic potential and pressure profiles. Although the active bicarbonate-ion pump at the endothelium drives bicarbonate into the aqueous humor, we find a net flux of bicarbonate ion into the cornea that safeguards against acidosis. For the first time, we predict corneal swelling upon soft-contact-lens wear from fundamental biophysico-chemical principles. We also successfully predict that hypertonic tear alleviates contact-lens-induced edema.

  8. Descripción, interpretación, análisis e importancia del nistagmus inducido por la hiperventilación en el estudio de patologías vestibulares periféricas y centrales

    OpenAIRE

    Peña M,Alejandro

    2012-01-01

    Recientes estudios clínicos han revelado la utilidad del test del nistagmus inducido por la hiperventilación aguda, en la investigación de patologías vestibulares retrolaberínticas, neurales y de origen central, con la aparición de nistagmus paréticos o bien excitatorios. El propósito de este estudio ha sido: primero, conocer la sensibilidad de este examen según el análisis de los estudios de diferentes autores; segundo, entender la fisiopatología de este nistagmus inducido por la hiperventil...

  9. Rol de la actvidad del NADPH oxidasa insular sobre los cambios en la secreción de insulina inducidos por una dieta rica en fructuosa

    OpenAIRE

    2010-01-01

    La dieta rica en fructosa (DRF) induce estrés oxidativo (EO), insulinorresistencia, tolerancia a la glucosa alterada y disminución de la masa de células β. Previamente ha sido demostrada la presencia de NADPHoxidasa (NOXi) a nivel insular; por otro lado, su actividad varía en función de diferentes estímulos de la secreción de insulina. Hasta el momento se desconoce el rol de la NOXi sobre los cambios inducidos por DRF en la función insular.

  10. MODULACION DE LA EXPRESION DE INTERLEUCINA-6 EN RESPUESTA AL MOVIMIENTO DENTARIO INDUCIDO POR EL ARCO .014 DE NiTi EN PACIENTES CON MALOCLUSION

    OpenAIRE

    Leon Romero, Luis Cenen

    2012-01-01

    El apiñamiento dentario es una anomalía dentomaxilar altamente frecuente, asociado con otros signos de maloclusión. El recurso clínico-ortodóntico para corregirlo es el movimiento dentario inducido por fuerzas mecánicas en los tejidos periodontales que bajo la fuerza mantenida, sufren una serie de modificaciones reguladas por procesos histológicos y fisiológicos que pueden dar como respuesta reacciones inflamatorias. La biología del movimiento dentario comprende el estudio de l...

  11. Ocular histopathological changes after eyeball enucleation induced by corneal trauma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To observe the ocular histopathological changes aftereyeball enucleation induced by corneal trauma.Methods: Light microscopic examination was done on 117 eyeball specimens enucleated after corneal trauma (18 with corneal fissure and 99 with corneal perforating trauma).Results: Acute, subacute or chronic inflammatory changes, and fibrous membrane formation were observed in well-closed corneal wounds, whereas inflammation, atrophy and scar were observed in the focal tissues. But at the late period, secondary glaucoma, retinal detachment, endophthalmitis and eyeball atrophy resulted in blindness. Corneal fistula was observed in those with inadequate cure of wounds caused by ingrowth of corneal epithelium, embedment of iris and vitreous body, and large area of centrally located tissue deficiency of the corneal. A high incidence of endophthalmitis was noted due to the presence of corneal fistula. Severe inflammation was observed in the anterior segmental tissues with fibrous infiltration in the anterior chamber, which might result in rapid destruction of the eyeballs.Conclusions: Ocular pathology varies with the difference of the position, form, size and closing conditions of the corneal laceration after trauma.

  12. Emodin ameliorates lipopolysaccharides-induced corneal inflammation in rats

    Institute of Scientific and Technical Information of China (English)

    Guo-Ling; Chen; Jing-Jing; Zhang; Xin; Kao; Lu-Wan; Wei; Zhi-Yu; Liu

    2015-01-01

    · AIM: To investigate the effect of emodin on pseudomonas aeruginosa lipopolysaccharides(LPS)-induced corneal inflammation in rats.· METHODS: Corneal infection was induced by pseudomonas aeruginosa LPS in Wistar rats. The inflammation induced by LPS were examined by slit lamp microscope and cytological checkup of aqueous humor.Corneal tissue structure was observed by hematoxylin and eosin(HE) staining. The activation of nuclear factor kappa B(NF-κB) was determined by Western blot.Messenger ribonucleic acid(m RNA) of tumor necrosis factor-α(TNF-α) and intercellular adhesion molecule-1(ICAM-1) in LPS-challenged rat corneas were measured with reverse transcription-polymerase chain reaction(RT-PCR).· RESULTS: Typical manifestations of acute corneal inflammation were observed in LPS-induce rat model,and the corneal inflammatory response and structure were improved in rats pretreated with emodin. Treatment with emodin could improve corneal structure, reduce corneal injure by reducing corneal inflammatory response. Emodin could inhibit the decreasing lever of inhibitor of kappa B alpha(IкBα) express, and the m RNA expression of TNF-α and ICAM-1 in corneal tissues was also inhibited by emodin. The differences were statistically significant between groups treated with emodin and those without treatment(P <0.01).·CONCLUSION: Emodin could ameliorate LPS-induced corneal inflammation, which might via inhibiting the activation of NF-κB.

  13. Partial-thickness corneal tissue restoration after a chemical burn

    Directory of Open Access Journals (Sweden)

    Galan A

    2016-04-01

    Full Text Available Alessandro Galan, Anton Giulio Catania, Giuseppe Lo Giudice San Paolo Ophthalmic Center, San Antonio Hospital, Padova, Italy Purpose: We describe a case of full-thickness corneal restoration after an acute corneal burn with an acid agent. Methods: A 32-year-old male reported painful discomfort, redness, photophobia, and a decrease in visual acuity in the left eye after a unilateral burn with an acid agent. Slit-lamp examination revealed massive corneal melting involving necrotic sequestrum of the entire corneal surface. Surgical approach was carried out in order to preserve residual ocular tissues. Results: Extensive corneal–conjunctival layer curettage of the necrotic tissue was performed showing perfectly clear undamaged deep lamellar corneal layers. The patient underwent multilayered amniotic membrane transplantation and total capsular–conjunctival flap in order to preserve ocular tissue from further melting or corneal perforation. A complete and spontaneous “restitutio ad integrum” of the corneal layers was shown during the follow-up. The cornea was perfectly clear with restored normal anatomical architecture. Conclusion: In this case, a spontaneous full-thickness corneal tissue restoration occurred after an acute chemical burn. Studies about the mechanisms whereby different cells interact and replicate within the stroma may unveil the biology behind corneal regeneration and transparency. Keywords: amniotic membrane, chemical burn, corneal healing

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

    Institute of Scientific and Technical Information of China (English)

    Federico; Saenz-Frances; Martha; Cecilia; Bermúdez-Vallecilla; Lara; Borrego-Sanz; Luis; Jaez; J; osé; Marìa; Martinez-de-la-Casa; Laura; Morales-Fernandez; Enrique; Santos-Bueso; Julián; Garcia-Sanchez; Julián; Garcia-Feijoo

    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 logisticregressions for MC and PC.·CONCLUSION: MT was typically located at the inferiortemporal quadrant of the cornea and its distance to the corneal apex tended to decrease with the increment of corneal volume.

  15. Manifestaciones corneales en las enfermedades sistémicas Corneal manifestations in systemic diseases

    Directory of Open Access Journals (Sweden)

    J. Zarranz-Ventura

    2008-01-01

    Full Text Available Un gran número de enfermedades sistémicas presentan manifestaciones corneales dentro de su espectro de enfermedad. El estudio detallado de todos los cuadros que asocian patología corneal resulta inabarcable, por ello se presentan las enfermedades más prevalentes o características. Este estudio contempla las enfermedades pulmonares y conectivopatías (colagenosis, enfermedades reumatológicas y enfermedades inflamatorias idiopáticas, las enfermedades dermatológicas, cardiovasculares, hematológicas y la patología digestiva y hepatopancreática. Se contemplan también, por ocasionar alteraciones corneales, las enfermedades endocrinas y metabólicas con algunas situaciones de malnutrición y estados carenciales, las infecciones sistémicas y las enfermedades renales. Otro área que produce afectación corneal es la patología otorrinolaringológica y las enfermedades genéticas. Se repasa brevemente la toxicidad y las alteraciones corneales provocadas por fármacos.Systemic diseases affecting the cornea have a wide range of manifestations. The detailed study of all pathologies that cause corneal alteration is unapproachable, so we have centered our interest in the most prevalent or characteristic of them. In this paper we have divided these pathologies in sections to facilitate their study. Pulmonar and conective tissue (like colagen, rheumatologic and idiopathic inflamatory diseases, dermatologic, cardiovascular, hematologic, digestive and hepatopancreatic diseases with corneal alteration are described. Endocrine and metabolic diseases, malnutrition and carential states are also studied, as well as some otorhinolaryngologic and genetic diseases that affect the cornea. Finally, a brief report of ocular toxicity induced by drugs is referred.

  16. Neural networks and statistical analysis for classification of corneal videokeratography maps based on Zernike coefficients: a quantitative comparison Redes neurais e análise estatística para classificação de mapas topográficos da córnea baseados em coeficientes de Zernike: uma comparação quantitativa

    Directory of Open Access Journals (Sweden)

    Luis Alberto Vieira de Carvalho

    2008-06-01

    Full Text Available PURPOSE: The main goal of this study was to develop and compare two different techniques for classification of specific types of corneal shapes when Zernike coefficients are used as inputs. A feed-forward artificial Neural Network (NN and discriminant analysis (DA techniques were used. METHODS: The inputs both for the NN and DA were the first 15 standard Zernike coefficients for 80 previously classified corneal elevation data files from an Eyesys System 2000 Videokeratograph (VK, installed at the Departamento de Oftalmologia of the Escola Paulista de Medicina, São Paulo. The NN had 5 output neurons which were associated with 5 typical corneal shapes: keratoconus, with-the-rule astigmatism, against-the-rule astigmatism, "regular" or "normal" shape and post-PRK. RESULTS: The NN and DA responses were statistically analyzed in terms of precision ([true positive+true negative]/total number of cases. Mean overall results for all cases for the NN and DA techniques were, respectively, 94% and 84.8%. CONCLUSION: Although we used a relatively small database, results obtained in the present study indicate that Zernike polynomials as descriptors of corneal shape may be a reliable parameter as input data for diagnostic automation of VK maps, using either NN or DA.OBJETIVOS: Nosso principal objetivo neste trabalho foi de desenvolver e comparar duas técnicas diferentes para classificação de superfícies corneanas. Uma rede neural artificial alimentada adiante e análise descriminante foram as técnicas de classificação comparadas neste trabalho. MÉTODOS: As entradas para ambos os métodos de classificação foram os primeiros 15 coeficientes de Zernike para 80 córneas mensuradas anteriormente em um topógrafo Eyesys instalado no Departamento de Oftalmologia da Escola Paulista de Medicina - UNIFESP. A rede neural tem 5 saídas que foram associados aos cinco casos típicos contidos na base de dados: ceratocone, astigmatismo a favor da regra, astigmatismo

  17. Interferometer for measuring dynamic corneal topography

    Science.gov (United States)

    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

  18. Systemic Immunomodulatory Strategies in High-risk Corneal Transplantation

    Science.gov (United States)

    Abud, Tulio B.; Di Zazzo, Antonio; Kheirkhah, Ahmad; Dana, Reza

    2017-01-01

    The cornea is the most commonly transplanted tissue in the body. Although corneal grafts generally have high success rates, transplantation onto inflamed and vascularized host beds, or so-called high-risk corneal transplantation, has a high rate of graft rejection. The management of this high-risk corneal transplantation is challenging and involves numerous measures. One of the key measures to prevent graft rejection in these cases is the use of systemic immunosuppressive agents. In this article, we will review the systemic immunosuppressive agents most commonly used for high-risk corneal transplantation, which include corticosteroids, cysclosporine A, tacrolimus, mycophenolate mofetil, and rapamycin. Benefits, risks, and published data on the use of these medications for high-risk corneal transplantation will be detailed. We will also summarize novel immunoregulatory approaches that may be used to prevent graft rejection in high-risk corneal transplantation.

  19. Spontaneous corneal melting in pregnancy: a case report

    Directory of Open Access Journals (Sweden)

    Arya Sudesh K

    2007-11-01

    Full Text Available Abstract Background To report a case of spontaneous corneal melting in pregnancy. We reviewed the literature on corneal melting and the effect of pregnancy on cornea and collagen containing tissues. Case presentation A 29-year-old woman who underwent radial keratotomy in both eyes followed by trabeculectomy in her left eye developed corneal melting in the same eye, in her seventh month of pregnancy. Despite screening, no infectious or immune mediated condition could be identified. She was managed conservatively with cyanoacrylate glue, bandage contact lens, lubricants and antibiotics. Conclusion It may not always be possible to find the underlying cause of corneal melting but the more common underlying causes should be ruled out by proper investigations. Pregnancy with its host of hormonal changes could potentially have some effect on corneal collagen leading to corneal melting in compromised corneas.

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

    Directory of Open Access Journals (Sweden)

    Marcello Colombo-Barboza

    2014-10-01

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

  1. Organism Isolation in Corneal Ulcer- Utility of Different Techniques

    OpenAIRE

    M Thapa; A.K. Sharma; D.N. Shah; S KC; Shrestha, S.

    2012-01-01

    Introduction: Various techniques are available for isolation of microorganism in cases of microbial keratitis including conventional methods of scraping, re-scraping inoculation in different media and corneal biopsy. Methods: This was a cross sectional descriptive study conducted from February 2002 to July 2003. A total of 161 eyes of corneal ulcers were evaluated with scraping inoculation. Re-scraping and corneal biopsy were performed in those cases which did not grow any organism in t...

  2. Retinal evaluation and treatment after refractive corneal surgery.

    Science.gov (United States)

    Swinger, C A; Kraushar, M F

    1985-08-01

    Refractive corneal surgery (a collective term used to describe a variety of surgical procedures that alter the refractive status of the eye through the surgical modification of corneal curvature) shows promise for use in situations where current methods of optical correction do not meet the patient's needs. This article reviews our experiences with the retinal evaluation of patients who have undergone corneal refractive surgery and offers recommendations for the treatment of retinal pathology after such surgery.

  3. EXPERIMENTAL STUDY ON THE CORNEAL ENDOTHELIUM OF TRAUMATIC CATARACT

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    The cell morphology of corneal endothelium in 84 mice with experimental traumatic cataract was investigated with stained corneal buttons. In the experimental group, the boundaries between adjacent corneal endothelial cells were significantly distorted, some cell boundaries manifested degenerative changes that led to coalescence of the cells. The mean density and mean area of endothelial cells of the controls showed significant difference from those of the experimental group during the 12 weeks of observ...

  4. Corneal Ectasis among Wrestlers: Report of Two Cases

    OpenAIRE

    Mohammad Ali Zare Mehrjardi; Hadi Zare Mehrjardi; Abasali Gaeeni; Elham Ashrafi; Homa Naderifar

    2014-01-01

    Report keratoconus in two patients with a long history of wrestling without any risk factor for corneal ectasia and reviewing the possible pathogenesis. To confirm suspicion of keratoconus, corneal topography was performed using scanning slit topography system and Orbscan. In two wrestlers with the complaint of visual loss in their eyes and IOP raising, corneal topography was performed and development of keratoconus (KCN) was detected. Athletes involved in sports with high strenuous exercises...

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

    OpenAIRE

    Alexandra X Crawford; Patel, Dipika V.; Charles NJ McGhee

    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 ...

  6. Corneal Chromoblastomycosis Caused by Fonsecaea pedrosoi

    Directory of Open Access Journals (Sweden)

    Winai Chaidaroon

    2015-02-01

    Full Text Available 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.

  7. New null screen design for corneal topography

    Science.gov (United States)

    Campos-García, Manuel; Estrada-Molina, Amilcar; Díaz-Uribe, Rufino

    2011-09-01

    In this work we report the design of a null screen for corneal topography. Here we assume that the corneal surface is an ellipsoid with a diameter of 12 mm and a curvature radius of 7.8 mm. To avoid the difficulties in the alignment of the test system due to the face contour (eyebrows, nose, or eyelids), we design a conical null-screen with spots (similar to ellipses) drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact radial array of circular spots if the surface is perfect. Additionally, we performed a numerical simulation introducing Gaussian random errors in the coordinates of the centroids of the spots on the image plane, and in the coordinates of the sources (spots on the null-screen) in order to obtain the conical null-screen that reduces the error in the evaluation of the topography.

  8. Corneal Neurotoxicity Due to Topical Benzalkonium Chloride

    Science.gov (United States)

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

    2012-01-01

    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

  9. RECURRENT CORNEAL EROSION SYNDROME (a review

    Directory of Open Access Journals (Sweden)

    S. V. Trufanov

    2015-01-01

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

  10. Prevalence of corneal astigmatism before cataract surgery.

    Science.gov (United States)

    Mohammadi, Mehran; Naderan, Mohammad; Pahlevani, Rozhin; Jahanrad, Ali

    2016-12-01

    The purpose of this study was to describe and analyze the prevalence and pattern of corneal astigmatism in cataract surgery candidates. In a prospective cross-sectional study, preoperative demographics, and keratometric and refractive values of cataract surgery candidates were collected from January 2013 to December 2014. Axial length (AL) and flat and steep keratometry measurements were optically measured by a partial coherence interferometry device (IOLMaster). This study consisted of 2156 eyes of 1317 patients with a mean age of 64.92 ± 11.48 (SD) (30-88 years). The mean of AL was 23.33 ± 1.37 mm, and the mean of corneal astigmatism was 1.12 ± 1.10 diopter (D) (range 0.0-7.00), in all patients. Furthermore, the mean of flat and steep keratometry were 43.70 ± 1.70 and 44.83 ± 1.79 D, respectively. Corneal astigmatism was 1.50 D or less in 1590 eyes (73.7 %), more than 1.50 D in 566 eyes (26.2 %), 3.00 D or more in 161 eyes (7.4 %), WTR in 796 eyes (36.9 %), ATR in 1010 eyes (46.8 %), and oblique in 350 eyes (16.2 %). ATR astigmatism axis significantly increased with the increase in age. Corneal astigmatism of most cataract surgery candidates fell between 0.50 and 1.50 D. The results of our study however is confined to our demographics might provide useful data for cataract patients, surgeons, and intraocular lens manufacturers for different purposes.

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

    A large subset of corneal pathologies involves the formation of new 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 treatment available so far.

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

    Science.gov (United States)

    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 (pcorneal asphericity (pcorneal 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 (PCorneal 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. Meretoja's Syndrome: Lattice Corneal Dystrophy, Gelsolin Type

    Science.gov (United States)

    Abreu, C.; Neves, M.; Oliveira, L.; Beirão, M.

    2017-01-01

    Lattice corneal dystrophy gelsolin type was first described in 1969 by Jouko Meretoja, a Finnish ophthalmologist. It is caused by an autosomal dominant mutation in gelsolin gene resulting in unstable protein fragments and amyloid deposition in various organs. The age of onset is usually after the third decade of life and typical diagnostic triad includes progressive bilateral facial paralysis, loose skin, and lattice corneal dystrophy. We report a case of a 53-year-old female patient referred to our Department of Ophthalmology by severe dry eye and incomplete eyelid closure. She had severe bilateral facial paresis, significant orbicularis, and perioral sagging as well as hypoesthesia of extremities and was diagnosed with Meretoja's syndrome at the age of 50, confirmed by the presence of gelsolin mutation. At our observation she had bilateral diminished tear film break-up time and Schirmer test, diffuse keratitis, corneal opacification, and neovascularization in the left eye. She was treated with preservative-free lubricants and topical cyclosporine, associated with nocturnal complete occlusion of both eyes, and underwent placement of lacrimal punctal plugs. Ocular symptoms are the first to appear and our role as ophthalmologists is essential for the diagnosis, treatment, and monitoring of ocular alterations in these patients. PMID:28250773

  14. Decreased central corneal thickness in ankylosing spondylitis.

    Science.gov (United States)

    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 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.

  15. Development of new therapeutic modalities for corneal endothelial disease focused on the proliferation of corneal endothelial cells using animal models.

    Science.gov (United States)

    Koizumi, Noriko; Okumura, Naoki; Kinoshita, Shigeru

    2012-02-01

    This review describes our recent attempts to develop new therapeutic modalities for corneal endothelial disease using animal models including non-human primate model in which the proliferative ability of corneal endothelial cells is severely limited, as is the case in humans. First, we describe our attempt to develop new surgical treatments using cultivated corneal endothelial cells for advanced corneal endothelial dysfunction. It includes two different approaches; a "corneal endothelial cell sheet transplantation" with cells grown on a type-I collagen carrier, and a "cell-injection therapy" combined with the application of Rho-kinase (ROCK) inhibitor. Recently, it was reported that the selective ROCK inhibitor, Y-27632, promotes cell adhesion and proliferation and inhibits the apoptosis of primate corneal endothelial cells in culture. When cultivated corneal endothelial cells were injected into the anterior chamber of animal eyes in the presence of ROCK inhibitor, endothelial cell adhesion was promoted and the cells achieved a high cell density and a morphology similar to corneal endothelial cells in vivo. We are also trying to develop a novel medical treatment for the early phase of corneal endothelial disease by the use of ROCK inhibitor eye drops. In rabbit and monkey experiments using partial endothelial dysfunction models, corneal endothelial wound healing was accelerated by the topical application of ROCK inhibitor to the ocular surface, and resulted in the regeneration of a corneal endothelial monolayer with a high endothelial cell density. We are now trying to advance the clinical application of these new therapies for patients with corneal endothelial dysfunction.

  16. Putative epidermal stem cell convert into corneal epithelium-like cell under corneal tissue in vitro

    Institute of Scientific and Technical Information of China (English)

    GAO Nan; CUI GuangHui; WANG ZhiChong; HUANG Bing; GE Jian; LU Rong; ZHANG KeFei; FAN ZhiGang; LU Li; PENG Zhan

    2007-01-01

    Rhesus putative epidermal stem cells are being investigated for their potential use in regenerative corneal epithelium-like cells, which may provide a practical source of autologous seed cells for the construction of bioengineered corneas. The goal of this study was to investigate the potential of epidermal stem cells for trans-differentiation into corneal epithelium-like cells. Rhesus putative epidermal stem cells were isolated by type IV collagen attachment method. Flow cytometry analysis, immunohistology and RT-PCR were conducted to identify the expression of specific markers (β1, α6 integrin, K15, K1/K10, K3/K12 and CD71) on the isolated rapid attaching cells. The isolated cells were cocultured with human corneal limbal stroma and corneal epithelial cells. After coculture, the expression of the same specific markers was evaluated in order to identify expression difference caused by the coculture conditions. K3/K12 expression was analyzed in coculture cells on day 2, 4, 6, 8 and 10. Putative epidermal stem cells in conditioned culture media were used as control. Putative epidermal stem cells were predominant in rapid attaching cells by type IV collagen attachment isolation. Before being cocultured, the rhesus putative epidermal stem cells expressed K15, α6 and β1 integrin, but no CD71, K1/K10 and K3/K12. After coculture, these cells expressed K3/K12 (a marker of corneal epithelial cells), K15 and β 1 integrin, but no K1/K10. Cells being not coculture converted into terminally differentiated cells expressing K1/K10. These results indicate that rhesus putative epidermal stem cells can trans-differentiate into corneal epithelium-like cells and, therefore, may have potential therapeutic application as autologous seed cells for the construction of bioengineered corneas.

  17. Putative epidermal stem cell convert into corneal epithelium-like cell under corneal tissue in vitro

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Rhesus putative epidermal stem cells are being investigated for their potential use in regenerative corneal epithelium-like cells, which may provide a practical source of autologous seed cells for the construction of bioengineered corneas. The goal of this study was to investigate the potential of epi-dermal stem cells for trans-differentiation into corneal epithelium-like cells. Rhesus putative epidermal stem cells were isolated by type IV collagen attachment method. Flow cytometry analysis, immuno-histology and RT-PCR were conducted to identify the expression of specific markers (β1, α6 integrin, K15, K1/K10, K3/K12 and CD71) on the isolated rapid attaching cells. The isolated cells were cocultured with human corneal limbal stroma and corneal epithelial cells. After coculture, the expression of the same specific markers was evaluated in order to identify expression difference caused by the coculture conditions. K3/K12 expression was analyzed in coculture cells on day 2, 4, 6, 8 and 10. Putative epi-dermal stem cells in conditioned culture media were used as control. Putative epidermal stem cells were predominant in rapid attaching cells by type IV collagen attachment isolation. Before being co-cultured, the rhesus putative epidermal stem cells expressed K15, α6 and β1 integrin, but no CD71, K1/K10 and K3/K12. After coculture, these cells expressed K3/K12 (a marker of corneal epithelial cells), K15 and β 1 integrin, but no K1/K10. Cells being not coculture converted into terminally differentiated cells expressing K1/K10. These results indicate that rhesus putative epidermal stem cells can trans-differentiate into corneal epithelium-like cells and, therefore, may have potential therapeutic application as autologous seed cells for the construction of bioengineered corneas.

  18. Manifestaciones corneales en las enfermedades sistémicas Corneal manifestations in systemic diseases

    OpenAIRE

    J. Zarranz-Ventura; E. De Nova; Moreno-Montañés, J

    2008-01-01

    Un gran número de enfermedades sistémicas presentan manifestaciones corneales dentro de su espectro de enfermedad. El estudio detallado de todos los cuadros que asocian patología corneal resulta inabarcable, por ello se presentan las enfermedades más prevalentes o características. Este estudio contempla las enfermedades pulmonares y conectivopatías (colagenosis, enfermedades reumatológicas y enfermedades inflamatorias idiopáticas), las enfermedades dermatológicas, cardiovasculares, hematológi...

  19. Corneal stem cells and tissue engineering: Current advancesand future perspectives

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Major advances are currently being made in regenerativemedicine for cornea. Stem cell-based therapiesrepresent a novel strategy that may substituteconventional corneal transplantation, albeit there aremany challenges ahead given the singularities of eachcellular layer of the cornea. This review recapitulatesthe current data on corneal epithelial stem cells,corneal stromal stem cells and corneal endothelialcell progenitors. Corneal limbal autografts containingepithelial stem cells have been transplanted in humansfor more than 20 years with great successful rates,and researchers now focus on ex vivo cultures andother cell lineages to transplant to the ocular surface.A small population of cells in the corneal endotheliumwas recently reported to have self-renewal capacity,although they do not proliferate in vivo . Two mainobstacles have hindered endothelial cell transplantationto date culture protocols and cell delivery methods tothe posterior cornea in vivo . Human corneal stromalstem cells have been identified shortly after therecognition of precursors of endothelial cells. Stromalstem cells may have the potential to provide a directcell-based therapeutic approach when injected tocorneal scars. Furthermore, they exhibit the ability todeposit organized connective tissue in vitro and maybe useful in corneal stroma engineering in the future.Recent advances and future perspectives in the field arediscussed.

  20. Genomics of corneal wound healing: a review of the literature.

    Science.gov (United States)

    Maycock, Nick J R; Marshall, John

    2014-05-01

    Corneal wound healing is a complex process: its mechanisms and the underlying genetic control are not fully understood. It involves the integrated actions of multiple growth factors, cytokines and proteases produced by epithelial cells, stromal keratocytes, inflammatory cells and lacrimal gland cells. Following an epithelial insult, multiple cytokines are released triggering a cascade of events that leads to repair the epithelial defect and remodelling of the stroma to minimize the loss of transparency and function. In this review, we examine the literature surrounding the genomics of corneal wound healing with respect to the following topics: epithelial and stromal wound healing (including inhibition); corneal neovascularisation; the role of corneal nerves in wound healing; the endothelium; the role of aquaporins and aptamers. We also examine the effect of ectasia on corneal wound healing with regard to keratoconus and following corneal surgery. A better understanding of the cellular and molecular changes that occur during repair of corneal wounds will provide the opportunity to design treatments that selectively modulate key phases of the healing process resulting in scars that more closely resemble normal corneal architecture.

  1. Applications and advantages of corneal crosslinking for treatment of keratoconus

    NARCIS (Netherlands)

    Soeters, N.

    2015-01-01

    Keratoconus is a corneal disorder in which the cornea becomes cone-shaped due to stromal thinning and corneal weakening. It mainly affects young individuals and although the prevalence is low (1:2000), the impact on quality of life is high. Despite much effort, still no cure has been found for kerat

  2. Gelatinous drop-like corneal dystrophy: a review.

    Science.gov (United States)

    Kaza, Hrishikesh; Barik, Manas R; Reddy, Mamatha M; Mittal, Ruchi; Das, Sujata

    2017-01-01

    Gelatinous drop-like corneal dystrophy (GDLD) is a rare autosomal recessive form of corneal dystrophy characterised by subepithelial and stromal amyloid deposits. It is relatively common in Japan. It usually presents in the first two decades of life with subepithelial nodular lesions that later coalesce to form mulberry-like opacities. Although various surgical modalities have been attempted, recurrence remains a major challenge.

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

    Directory of Open Access Journals (Sweden)

    R Bassily

    2010-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Ying Wu

    2016-01-01

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

  5. Evidence-based Homoeopathy: A case of corneal abscess

    Directory of Open Access Journals (Sweden)

    Sandeep Sudhakar Sathye

    2016-01-01

    Full Text Available Corneal abscess is a circumscribed collection of pus within the layers of cornea. It is usually endogenous in origin and commonly found near the limbal blood vessels close to corneal margin. Treatment in modern medicine is use of local and systemic antibiotics. Homoeopathy has mentioned medicines for corneal abscess. A case reported was a female of 68 years of age suffering from symptoms of redness, dull pain, and foreign body sensation in the right eye and was diagnosed as corneal abscess. The homoeopathic medicine Hepar sulphuris 200C was prescribed on the basis of pathology. Abscess was reduced considerably within 5 days and it was absorbed completely in 21 days. No recurrence of abscess was observed thereafter. Ocular photographs during follow-up visits have provided documentary evidence about the effectiveness of homoeopathic Hepar sulphuris 200C in corneal abscess.

  6. Paracentral Corneal Dellen:A Rare Sign of Graves Ophthalmopathy

    Institute of Scientific and Technical Information of China (English)

    Jianhua Yan; Zhongyao Wu

    2003-01-01

    Purpose: To report a rare sign, paracentral corneal dellen that developed in a middleaged female patient with Graves ophthalmopathy.Methods:A paracentral corneal dellen developed in the left eye in a 42-year-old woman who was diagnosed as Graves ophthalmopathy. The patient had remarkable upper eyelid retraction, upper eyelid lag and upward motility restriction. The Graves ophthalmopathy was classified as Grade V according to NOSPECS classification.Results:Local artificial tear film and 0.3% Tobramycin eye drops were administered to both eyes.Twenty-four hours later, the left corneal dellen disappeared.Conclusions:Graves ophthalmopathy can lead to paracentral corneal dellen because of severe upper eyelid retraction and upward motility restriction of the eye in spite of the lack of lagophthalmos. Artificial tear drop and antibiotic eye drop therapy helped even though the patient did not have corneal exposure.

  7. Mechanism of Corneal Endothelial Cells Lesion during Phacoemulsification and Aspiration

    Institute of Scientific and Technical Information of China (English)

    Songtao Yuan; Lina Xie; Qinghuai Liu; Nanrong Yuan

    2003-01-01

    Purpose: To evaluate the proportions of corneal endothelial lesion caused by differentfactors during phacoemulsification and aspiration.Methods: Fourteen cats (twenty eight eyes) were divided into four groups. The processedfactors were ultrasonic power, lens extraction by phacoemulsification or not, and lensextraction using different levels of ultrasonic power. The density of central cornealendothelial cells was measured before and after operation.Results: There is no statistic difference between pre-operation density and post-operationdensity for releasing ultrasonic power only without lens extraction group. But for the lensextraction group, there is difference in density of central corneal endothelial cells andthe higher level of ultrasonic power, the more the central corneal endothelial cells densitydecreased through operation.Conclusion: The primary factor that causes corneal endothelial lesion duringphacoemulsification and aspiration procedure is debris of lens nucleus, and the otherfactors cause the lesion of corneal endothelium in normal operations just in very smalldegree.

  8. Intrastromal corneal ring segments delay corneal grafting in patients with keratoconus

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    Luiz Arthur F. Beniz

    2016-02-01

    Full Text Available ABSTRACT Purpose: To assess the impact of intrastromal corneal ring segments (ICRS as a surgical alternative to corneal grafting in patients with keratoconus who were scheduled for a corneal transplant. Methods: This single-surgeon, single-center, retrospective, observational case series study included 19 eyes of 18 patients (mean age, 23.36 ± 6.22 years with a confirmed diagnosis of keratoconus. These patients were enrolled from the State of Goiás, Brazil corneal graft waiting list. Following extensive pre-operative testing, including the measurement of best-corrected visual acuity (BCVA, applanation tonometry, biomicroscopy, funduscopy, pachymetry, and corneal topography, patients were implanted with Keraring® ICRS. Patients underwent clinical examination at postoperative days 1, 7, 30, 90, and 180 and were examined again 2 years following surgery. Results: At the 2-year cut-off following ICRS implantation (mean follow-up, 28.72 ± 4.71 months, there was a statistically significant improvement in BCVA (logMAR from 0.59 ± 0.35 preoperatively to 0.35 ± 0.45 postoperatively ( p <0.01. Three of 19 eyes (15.8% still required keratoplasty. In the remaining patients (84.2%, BCVA was managed with spectacles (52.6% or contact lenses (31.6%. One patient developed infectious keratitis, requiring removal of ICR at the first postoperative visit. Conclusion: ICRS implantation may be a surgical alternative to keratoplasty in patients with keratoconus. This procedure may delay or even eliminate the need for keratoplasty in such patients.

  9. Fractal dimension based corneal fungal infection diagnosis

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    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.

  10. Mycotic corneal ulcers in upper Assam

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    Reema Nath

    2011-01-01

    Full Text Available Purpose : To study the association of various risk factors and epidemiological variables of mycotic keratitis treated at a tertiary referral hospital of upper Assam. Materials and Methods: In this hospital-based prospective study a total of 310 consecutive corneal ulcer cases attending the ophthalmology outpatient department of Assam Medical College were enrolled between April 2007 and March 2009. After clinical and slit-lamp biomicroscopic examination in all suspected cases, smears and culture examination for fungus was done to establish the etiology. Demographic information and associated probable risk factors of individual cases were noted in a predesigned questionnaire. Results: In 188 (60.6% cases fungal etiology could be established. Out of them 67.6% were males. The most commonly affected age group was 41-50 years (25.5%. The maximum (23.4% cases were reported during the paddy harvesting season in Assam (January and February. Fungal element could be demonstrated in 65.2% cases in direct potassium hydroxide (KOH mount. The commonest predisposing factor was corneal injury (74.5%. While diabetes was a significant systemic predisposing factor in mixed bacterial and fungal infections in 11.1% cases, blocked naso-lacrimal duct was the local predisposing factor in 11.1% of cases. Fusarium solani (25% was the commonest isolate followed by Aspergillus species (19%, Curvularia species (18.5% and Penicillium species (15.2%. Yeasts were isolated in 2.7% (n=5 cases. Conclusions : Ocular trauma was the commonest cause of fungal corneal ulcer in Assam and Fusarium solani was the commonest species responsible for it. Most of the mycotic ulcer cases come from rural areas including the tea gardens.

  11. Production of Hypoxia-induced Corneal Edema in Aged Eyes

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    Alan K. Cheung; Andrew W. Siu; Digby W. Cheung; Edwin C. Mo

    2004-01-01

    Purpose:Corneal thickness assessment is a common clinical procedure applied in corneal and contact lens care. This study aims to investigate the effect of age on hypoxiainduced corneal swelling.Methods:Eighteen male subjects were equally divided into the younger [(23.7±0.8) and older [(74.4±2.5) years old]groups.Each subject wore a thick soft contact lens (uniform thickness of 0.3 mm) on the left cornea. With the contact lens in place, the baseline central corneal thickness was measured using a specially designed photo-pachometer. The lens was then patched behind the closed eyelids, producing an extremely hypoxic stress to the cornea. The change in central corneal thickness was monitored every 20 minutes with momentary disruptions to the hypoxic stress over the next 2 hours. The increase in thickness was taken as an index of corneal edema. The rate of change in corneal thickness, as derived from a non-linear mathematical model, was compared between groups. Results:The corneal thickness of both age groups increased significantly with time (P<0.000 1 ). The mean corneal swelling constant for the older subjects was 16.5 × 10-3 (S.E.M. = 2.65 × 10-3) and the value for the younger subjects was 46.5 × 10-3 (S.E.M. = 3.25× 10-3). The difference was statistically significant (P < 0.000 1 ).Conclusion:Aging cornea has a slower hypoxia-induced edema response compared with the younger group. Whether it is caused by a decreased corneal lactate production or an increased resistance to physical expansion deserves further investigation. Eye Science2004;20:1-5.

  12. Riboflavin concentration in corneal stroma after intracameral injection

    Institute of Scientific and Technical Information of China (English)

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

    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 8.5mm in diameter from each group were dissected at 30 min 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 24 h 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 for30 min on the corneal surface(8 without epithelium and 8with intact epithelium).RESULTS: The mean riboflavin concentrations were11.19, 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 30 min.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.

  13. Graft Biomechanics Following Three Corneal Transplantation Techniques

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    Feizi, Sepehr; Montahai, Talieh; Moein, Hamidreza

    2015-01-01

    Purpose: To compare corneal biomechanical properties following three different transplantation techniques, including Descemet stripping automated endothelial keratoplasty (DSAEK), deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in comparison to normal eyes. Methods: This cross-sectional comparative study included 118 eyes: 17 eyes of 17 patients received DSAEK, 23 eyes of 21 patients underwent DALK using Anwar's big bubble technique, and 45 eyes of 36 patients had PK; 33 right eyes of 33 normal subjects served as the control group. Using the ocular response analyzer (ORA, Reichert Ophthalmic Instruments, Buffalo, New York, USA), corneal hysteresis (CH) and corneal resistance factor (CRF) were measured and compared among the study groups at least 3 months after all sutures were removed. Results: Mean patient age was 26.9 ± 5.0 years in the control group, 28.8 ± 4.2 in the PK group, 27.2 ± 6.5 in the DALK group, and 62.5 ± 16.8 in the DSAEK group (P < 0.001). Central corneal thickness (CCT) was 539.0 ± 24.8, 567.5 ± 38.8, 547.0 ± 42.6 and 631.1 ± 84.8 μm, respectively (P < 0.001). CH and CRF were significantly lower in the DSAEK group (7.79 ± 2.0 and 7.88 ± 1.74 mmHg, respectively) as compared to the PK (10.23 ± 2.07 and 10.13 ± 2.22 mmHg, respectively) and DALK (9.64 ± 2.07 and 9.36 ± 2.09 mmHg, respectively) groups. The two latter groups demonstrated biomechanical parameters comparable to normal subjects (9.84 ± 1.59 and 9.89 ± 1.73 mmHg, respectively). Conclusion: Graft biomechanical parameters after DSAEK are lower than those following PK and DALK. After PK and DALK in keratoconic eyes, these metrics are increased to normal values. These differences may have implications for interpreting intraocular pressure or planning graft refractive surgery after keratoplasty. PMID:26730307

  14. Remoción de semillas en un borde inducido por un incendio forestal en el Chaco semiárido argentino

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    C.E. Trucco

    2008-01-01

    Full Text Available Estudiamos la importancia relativa de los insectos y vertebrados como agentes de remoción de semillas dentro de un borde inducido por un incendio forestal accidental en el bosque chaqueño semiárido del Parque Nacional Copo, Argentina. Estimamos las tasas de remoción de semillas y frutos a ambos lados del borde: en el bosque primario y en el bosque incendiado. Para identificar los posibles agentes de remoción relevamos las hormigas, micromamíferos y otros vertebrados. La remoción media de semillas fue similar en ambos sitios, pero fue significativamente menor en los comederos expuestos solo a vertebrados. Las semillas fueron más removidas que los frutos intactos. También discutimos la validez de la metodología para el estudio de la remoción de semillas en áreas de borde.

  15. The heritability of glaucoma-related traits corneal hysteresis, central corneal thickness, intraocular pressure, and choroidal blood flow pulsatility.

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    Ellen E Freeman

    Full Text Available PURPOSE: The purpose of this work was to investigate the heritability of potential glaucoma endophenotypes. We estimated for the first time the heritability of the pulsatility of choroidal blood flow. We also sought to confirm the heritability of corneal hysteresis, central corneal thickness, and 3 ways of measuring intraocular pressure. METHODS: Measurements were performed on 96 first-degree relatives recruited from Maisonneuve-Rosemont Hospital in Montreal. Corneal hysteresis was determined using the Reichert Ocular Response Analyser. Central corneal thickness was measured with an ultrasound pachymeter. Three measures of intraocular pressure were obtained: Goldmann-correlated and corneal compensated intraocular pressure using the Ocular Response Analyser, and Pascal intraocular pressure using the Pascal Dynamic Contour Tonometer. The pulsatility of choroidal blood velocity and flow were measured in the sub-foveolar choroid using single-point laser Doppler flowmetry (Oculix. We estimated heritability using maximum-likelihood variance components methods implemented in the SOLAR software. RESULTS: No significant heritability was detected for the pulsatility of choroidal blood flow or velocity. The Goldman-correlated, corneal compensated, and Pascal measures of intraocular pressure measures were all significantly heritable at 0.94, 0.79, and 0.53 after age and sex adjustment (p = 0.0003, p = 0.0023, p = 0.0239. Central corneal thickness was significantly heritable at 0.68 (p = 0.0078. Corneal hysteresis was highly heritable but the estimate was at the upper boundary of 1.00 preventing us from giving a precise estimate. CONCLUSION: Corneal hysteresis, central corneal thickness, and intraocular pressure are all heritable and may be suitable as glaucoma endophenotypes. The pulsatility of choroidal blood flow and blood velocity were not significantly heritable in this sample.

  16. IOL Power Calculation after Corneal Refractive Surgery

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    Maddalena De Bernardo

    2014-01-01

    Full Text Available Purpose. To describe the different formulas that try to overcome the problem of calculating the intraocular lens (IOL power in patients that underwent corneal refractive surgery (CRS. Methods. A Pubmed literature search review of all published articles, on keyword associated with IOL power calculation and corneal refractive surgery, as well as the reference lists of retrieved articles, was performed. Results. A total of 33 peer reviewed articles dealing with methods that try to overcome the problem of calculating the IOL power in patients that underwent CRS were found. According to the information needed to try to overcome this problem, the methods were divided in two main categories: 18 methods were based on the knowledge of the patient clinical history and 15 methods that do not require such knowledge. The first group was further divided into five subgroups based on the parameters needed to make such calculation. Conclusion. In the light of our findings, to avoid postoperative nasty surprises, we suggest using only those methods that have shown good results in a large number of patients, possibly by averaging the results obtained with these methods.

  17. Bilateral Keratectasia 34 Years after Corneal Transplant

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    Xavier Valldeperas

    2010-07-01

    Full Text Available We report the clinical findings of a patient with severe bilateral keratectasia 34 years after a penetrating keratoplasty (PK in both eyes. An otherwise healthy 67-year-old man complained of deterioration of the eyesight in both eyes over the last 6 months. The patient was diagnosed with bilateral keratoconus at the age of 32 years, and he underwent a bilateral PK. At presentation, visual acuity was 20/200 in the right eye and light perception in the left eye. A Pentacam pachymetric map revealed a central pachymetry of 720 µm in the right eye and of 710 µm in the left eye, as well as an average paracentral pachymetry of 436 and 270 µm in the 9-mm zone in the right and the left eye, respectively. Corneal topography revealed bilateral irregular and asymmetric bowing with generalized steepening and high corneal power. We describe a case of bilateral keratectasia 34 years after PK in a patient who was originally diagnosed with bilateral keratoconus.

  18. [New stimulants of corneal reparative regeneration].

    Science.gov (United States)

    Egorov, E A; Kalinin, N I; Kiiasov, A P

    1999-01-01

    The efficacy of corneregel, a drug containing pantothenic acid, a component of coenzyme A, in healing of corneal wounds has been evaluated. The study was carried out on 19 rabbits (38 eyes) with standard corneal defect made with a 5-mm trephine for lamellar transplantation of the cornea, divided into 2 groups: 1) instillations of corneregel (10 eyes) and 0.25% levomycetin solution (10 eyes) and 2) 20% solcoseryl gel (9 eyes) and 0.25% levomycetin (9 eyes). Time course of changes were evaluated by biomicroscopy (fluorescent test), histologically (hematoxylin-eosin staining), and immunohistochemically after 1, 2, 4, 7, 30, and 90 days. Proliferative activity was studied by expression of the proliferating cell nuclear antigen and the migration capacity of cells by expression of alpha-smooth muscle actin. The terms of epithelialization were as follows: corneregel 10 +/- 7 h, 20% solcoseryl gel 108 +/- 10 h, levomycetin 124 +/- 6.93 h. Earlier epithelialization in the corneregel group was apparently due to increased expression of alpha-smooth muscle actin and increase in the cell migration capacity. Hence, corneregel is recommended for practical use as a stimulant of reparative regeneration of the cornea.

  19. Clinical utility of the KAMRA corneal inlay.

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    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.

  20. Corneal surface reconstruction - a short review

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    Madhavan H N

    2009-01-01

    Full Text Available Cornea is the clear, dome-shaped surface that covers the front of the eye and when damage due to burns or injury and several other diseases, stem cells residing in its rim called "limbus" are stimulated to multiply to support growth of new epithelial cells over its surface. If this ready source of stem cells is damaged or destroyed the natural repair is not possible and such a condition is known as corneal limbal stem cell deficiency (CLSCD disease. Stem cell transplant helps such persons to regenerate the corneal surface. Human corneal limbal stem cell transplantation is at present an established procedure with reasonable good clinical outcome particularly when autologous limbal epithelial tissue from a fellow unaffected eye is used. 1, 2 A major concern related to the autograft is the possibility of CLSCD at the donor site, 3 techniques that allowed the expansion of a small limbal biopsy in the laboratory using cell cultures that could be then transplanted to the affected eye have been developed ,4, 5 Human amniotic membrane (HAM is used as a scaffold for both culturing the human limbal epithelial cells and for ocular surface reconstruction with the cultured limbal epithelial cells. 4-7 However, researchers have used alternative scaffolds like collagen 8, fibrin gel 9 and cross-linked gel of fibronectin and fibrin. 10 All these are biological materials and also need for animal 3T3 feeder layer for stem cell cultures. The properties of HAM are unique including antiadhesive effects, bacteriostatic effects, wound protection, pain reduction, and improvement of epithelialization and characteristically lacking imunogenicity. The use of amniotic membrane transplantation (AMT to treat ocular surface abnormalities was first reported by Graziella Pellegrini, chief of stem cell laboratory at Giovanni Paolo Hospital in Venice, Italy, who was the first to demonstrate the limbal stem cell transplant in 1997. Amniotic membrane has been successfully used in

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

    Science.gov (United States)

    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.

  2. 2-YEAR EXPERIENCE OF CORNEAL COLLAGEN CROSSLINKING IN KERATOCONUS TREATMENT

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    D. D. Dement’ev

    2015-01-01

    Full Text Available Aim. To assess reliability, efficacy, and stability of corneal collagen crosslinking (CXL results for stage I‑II keratoconus.Patients and methods. 2‑year (2012-2014 results of CXL were analyzed. CXL was performed on 20 eyes of 15 patients (13 men and 2 women, mean age 31 years. Stage 1 keratoconus was diagnosed in 13 eyes, stage 2 keratoconus was diagnosed in 2 eyes. Primary stage 1‑2 keratoconus was diagnosed in 17 eyes, keratoconus after corneal refractive surgery (LASIK, radial keratotomy was diagnosed in 3 eyes. Preoperative and postoperative examination included uncorrected (UCVA and best-corrected (BCVA visual acuity measurement, pachymetry, corneal topography (total astigmatism measurement, and biomicroscopy. Follow-up period varied from 1 to 24 months.Results. All patients reported on vision improvement. Preoperatively, mean UCVA and BCVA were 0.4 and 0.64, respectively. Postoperatively, mean UCVA and BCVA were 0.49 and 0.66, respectively. Preoperatively and postoperatively, total astigmatism was 2.1 D and 2.0 D, respectively, while mean central corneal thickness was 454 μm and 447 μm, respectively.Conclusions. Corneal collagen crosslinking for stage 1‑2 keratoconus provides mild UCVA and BCVA improvement, decrease in total astigmatism and central corneal thickness. CXL provides stable results of treatment of primary stage 1‑2 keratoconus and keratoconus after corneal refractive surgery. 

  3. Characteristics of corneal lens chitin in dragonfly compound eyes.

    Science.gov (United States)

    Kaya, Murat; Sargin, Idris; Al-Jaf, Ivan; Erdogan, Sevil; Arslan, Gulsin

    2016-08-01

    Chitin in the compound eyes of arthropods serves as a part of the visual system. The quality of chitin in such highly specialised body parts deserves more detailed examination. Chitin in the corneal (ommatidial) lenses of dragonfly (Sympetrum fonscolombii) compound eyes was isolated by using the classical chemical method. The chitin content of the corneal lenses was determined to be quite high (20.3±0.85%). The FT-IR analysis showed that corneal lens chitin was in the α-form as found in all arthropod species where mechanical strength is required. The surface morphology analysis by scanning electron microscopy revealed that the outer part of corneal lenses consisted of long chitin fibrils with regular arrays of papillary structures while the smoother inner part had concentric lamellated chitin formation with shorter chitin nanofibrils. Chitinase enzymatic digestion studies, elemental analysis results and the degree of acetylation value showed the purity of chitin samples from corneal lens. The maximum degradation temperature value of the corneal lens chitin was observed at 369.2°C. X-ray analysis revealed that corneal lens chitin has high crystallinity index; 96.4%. Identification of chitin found in ommaditia of insect compound eyes can provide insights into insect vision and chitin-based optical material design studies.

  4. Cytocompatibility of Three Corneal Cell Types with Amniotic Membrane

    Institute of Scientific and Technical Information of China (English)

    CHENJian-su; CHENRui; XUJin-tang; DINGYong; ZHAOSong-bin; LISui-lian

    2004-01-01

    Rabbit limbal corneal epithelial cells, corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopic examinations were carried out to observe the growth, arrangement and adhesion of cultivated cells. Results showed that three corneal cell types seeded on amniotic membrane grew well and had normal cell morphology. Cultured cells attached firmly on the surface of amniotic membrane. Corneal epithelial cells showed singular layer or stratification. Cell boundaries were formed and tightly opposed. Corneal endothelial cells showed cobblestone or polygonal morphologic characteristics that appeared uniform in size. The cellular arrangement was compact. Keratocytes elongated and showed triangle or dendritic morphology with many intercellular joints which could form networks. In conclusion, amniotic membrane has good scaffold property, diffusion effect and compatibility with corneal cells. The basement membrane side of amniotic membrane facilitated the growth of corneal epithelial cells and endothelial cells and cell junctions were tightly developed. The spongy layer of amniotic membrane facilitated the growth of keratocytes and intercellular joints were rich. Amniotic membrane is an ideal biomaterial for layering tissue engineered cornea.

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

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    Rowena M A Packer

    Full Text Available 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.

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

    Science.gov (United States)

    Packer, Rowena M A; Hendricks, Anke; Burn, Charlotte C

    2015-01-01

    Concern has arisen in recent years that selection for extreme facial morphology in the domestic dog may be leading to an increased frequency of eye disorders. Corneal ulcers are a common and painful eye problem in domestic dogs that can lead to scarring and/or perforation of the cornea, potentially causing blindness. Exaggerated juvenile-like craniofacial conformations and wide eyes have been suspected as risk factors for corneal ulceration. This study aimed to quantify the relationship between corneal ulceration risk and conformational factors including relative eyelid aperture width, brachycephalic (short-muzzled) skull shape, the presence of a nasal fold (wrinkle), and exposed eye-white. A 14 month cross-sectional study of dogs entering a large UK based small animal referral hospital for both corneal ulcers and unrelated disorders was carried out. Dogs were classed as affected if they were diagnosed with a corneal ulcer using fluorescein dye while at the hospital (whether referred for this disorder or not), or if a previous diagnosis of corneal ulcer(s) was documented in the dogs' histories. Of 700 dogs recruited, measured and clinically examined, 31 were affected by corneal ulcers. Most cases were male (71%), small breed dogs (mean± SE weight: 11.4±1.1 kg), with the most commonly diagnosed breed being the Pug. Dogs with nasal folds were nearly five times more likely to be affected by corneal ulcers than those without, and brachycephalic dogs (craniofacial ratio 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.

  7. Repositioning of pedicle conjunctival flap performed for refractory corneal ulcer

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    Ashok Sharma

    2014-01-01

    Full Text Available A 50-year-old male was referred with a previous history of conjunctival flap (CF for a nonhealing fungal corneal ulcer with extreme corneal thinning in the right eye. The peritomy for the CF extended from 6:30 to 9:30 clock h on the cornea. The CF was disengaged, peritomy area deepithelialized, and CF was repositioned. He later underwent penetrating keratoplasty and achieved 20/40 best corrected visual acuity. The authors present a new concept for surgically repositioning CF s to the original site immediately after healing of the corneal ulcer.

  8. Repositioning of pedicle conjunctival flap performed for refractory corneal ulcer.

    Science.gov (United States)

    Sharma, Ashok; Mohan, Kanwar; Sharma, Rajan; Nirankari, Verinder S

    2014-01-01

    A 50-year-old male was referred with a previous history of conjunctival flap (CF) for a nonhealing fungal corneal ulcer with extreme corneal thinning in the right eye. The peritomy for the CF extended from 6:30 to 9:30 clock h on the cornea. The CF was disengaged, peritomy area deepithelialized, and CF was repositioned. He later underwent penetrating keratoplasty and achieved 20/40 best corrected visual acuity. The authors present a new concept for surgically repositioning CF s to the original site immediately after healing of the corneal ulcer.

  9. Corneal modeling using conic section fits of PAR corneal topography system measurements

    Science.gov (United States)

    Zipper, Stanley; Manns, Fabrice; Fernandez, Viviana; Sandadi, Samith; Ho, Arthur; Parel, Jean-Marie A.

    2001-06-01

    The purpose of this study was to measure the average shape and variability of human corneas and to develop a tool for analyzing, height, curvature, and aberrations based on a conic section model. Fresh Eye Bank Eyes were placed in Dextran until the corneal thickness reached a physiological value. The eyes were placed in a custom made holder and measured using an intraoperative PAR Corneal Topography System (CTS) mounted on an operation microscope. Topography was measured before and after removal of the epithelium. A series of MATLAB functions were written to analyze the raw-z (height) data in polar coordinates. The functions fit conic sections to the PAR CTS data along hemi-meridians at 5 degree(s) intervals. The conic shape factor and apical radius were used to calculate and display the curvature. The dependence of these parameters with meridional position was examined.

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

    Directory of Open Access Journals (Sweden)

    Mehmet Balcı

    2015-08-01

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

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

    Science.gov (United States)

    Balcı, Mehmet; Yağcı, Ramazan; Güler, Emre; Haltaş, Hacer; Duman, Rahmi; Hepşen, İbrahim F

    2015-01-01

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

  12. Structural, Morphological, and Functional Correlates of Corneal Endothelial Toxicity Following Corneal Exposure to Sulfur Mustard Vapor

    Science.gov (United States)

    2013-10-01

    located .15 Because (1) the corneal epithelium regenerates an intact epithelial cap by 5 days after exposure that remains intact until after MGK onset and (2...cells of regular shape and size, with interdigitated borders, apical microvilli, and infrequent cilia (Fig. 4A). Within 24 hours of exposure, all...Fig. 4B). Most CECs exhibited atypical apical membrane morphologies and lacked cell-to-cell interdigitations (Figs. 4B, 4C). In regions of CEC

  13. Utilização do Anel de Ferrara na estabilização e correção da ectasia corneana pós PRK Use of Ferrara's ring in the stabilization and correction of corneal ectasia after PRK

    Directory of Open Access Journals (Sweden)

    Frederico Bicalho Dias da Silva

    2000-06-01

    Full Text Available Objetivo: Avaliar a ação do anel corneano intra-estromal de Ferrara no tratamento da ectasia corneana pós Excimer Laser. Métodos: O anel de Ferrara, que já vem sendo aplicado no tratamento do ceratocone, alta miopia e astigmatismo irregular, foi utilizado para estabilizar e corrigir a ectasia corneana de dois pacientes submetidos à PRK. Resultados: Após o procedimento cirúrgico, foi observado um aplainamento da córnea central de aproximadamente 6 dioptrias no 1º caso e de 10 dioptrias no 2º, com melhora na acuidade visual. Os resultados vêm se mantendo estáveis até o momento. O tempo de seguimento pós-operatório foi de 3 e 8 meses, respectivamente. Conclusões: Anel de Ferrara obteve sucesso no difícil tratamento desta complicação cirúrgica, permitindo que se retarde ou até mesmo se evite a evolução destes casos para um transplante de córnea com todos os seus riscos, lenta recuperação e dependência da agilidade das filas de doações.Purpose: To evaluate the action of Ferrara's Ring in the treatment of corneal ectasia after Excimer Laser. Methods: Ferrara's Ring, that is already being applied in the treatment of keratoconus, high myopia and irregular astigmatism, has been used to stabilize and to correct the corneal ectasia of 2 patients submitted to PRK. Results: After the surgical procedure, a flattening of the central cornea was observed, with approximately 6 D (first case and 10 D in the second, with visual acuity improvement. The results have remained stable until this moment. The postoperative follow-up was of 3 and 8 months, respectively. Conclusions: Ferrara's ring has obtained success in the difficult treatment of this surgical complication, allowing delay of or even avoiding the evolution of these cases to a corneal transplantation with all its risks, slow recovery and dependence on the agility of the donation lines.

  14. Generation of corneal epithelial cells from induced pluripotent stem cells derived from human dermal fibroblast and corneal limbal epithelium.

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    Ryuhei Hayashi

    Full Text Available Induced pluripotent stem (iPS cells can be established from somatic cells. However, there is currently no established strategy to generate corneal epithelial cells from iPS cells. In this study, we investigated whether corneal epithelial cells could be differentiated from iPS cells. We tested 2 distinct sources: human adult dermal fibroblast (HDF-derived iPS cells (253G1 and human adult corneal limbal epithelial cells (HLEC-derived iPS cells (L1B41. We first established iPS cells from HLEC by introducing the Yamanaka 4 factors. Corneal epithelial cells were successfully induced from the iPS cells by the stromal cell-derived inducing activity (SDIA differentiation method, as Pax6(+/K12(+ corneal epithelial colonies were observed after prolonged differentiation culture (12 weeks or later in both the L1B41 and 253G1 iPS cells following retinal pigment epithelial and lens cell induction. Interestingly, the corneal epithelial differentiation efficiency was higher in L1B41 than in 253G1. DNA methylation analysis revealed that a small proportion of differentially methylated regions still existed between L1B41 and 253G1 iPS cells even though no significant difference in methylation status was detected in the specific corneal epithelium-related genes such as K12, K3, and Pax6. The present study is the first to demonstrate a strategy for corneal epithelial cell differentiation from human iPS cells, and further suggests that the epigenomic status is associated with the propensity of iPS cells to differentiate into corneal epithelial cells.

  15. Papel de los polimorfismos genéticos para enzimas de reparación en el daño en el ADN inducido por el estireno y estireno-7,8-óxido

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    B. Laffon

    2004-01-01

    Full Text Available La respuesta individual al daño en el ADN inducido por agentes xenobióticos está condicionada por la eficacia de los sistemas de reparación. Algunos de los polimorfismos genéticos descritos en las enzimas de reparación del ADN pueden afectar a su función, determinando una variación en la susceptibilidad ante la exposición a agentes ambientales. El objetivo de este estudio ha consistido en investigar si las variantes alélicas más frecuentes de las enzimas de reparación XRCC1 (Arg194Trp y Arg399Gln, XRCC3 (Thr241Met o APE1 (Asp148Glu pueden condicionar el daño en el ADN inducido por el estireno y su principal metabolito, el estireno-7,8-óxido (EO. Leucocitos periféricos de 30 voluntarios sanos se trataron con estireno o EO, y el daño en el ADN inducido se evaluó mediante el ensayo del cometa. Tras el tratamiento con estireno, los individuos portadores de los alelos XRCC1 399Gln y XRCC3 241Met mostraron mayor nivel de roturas en el ADN, sugiriendo menor eficacia de los sistemas de reparación. Por el contrario, los portadores del alelo APE1 148Glu mostraron daño en el ADN significativamente menor que los individuos 148 Asp/Asp. Sin embargo, no se obtuvo ningún efecto significativo en las células expuestas a EO, debido probablemente a que el daño inducido es inicialmente mayor, y no permite que se pongan de manifiesto pequeñas diferencias en la eficacia de reparación de los genotipos analizados

  16. [Corneal collagen cross-linking for keratoconus].

    Science.gov (United States)

    Zotov, V V; Pashtaev, N P; Pozdeeva, N A

    2015-01-01

    Over the last decade, corneal collagen cross-linking (CXL) has become a conventional treatment method for progressive keratoconus. Laboratory studies have shown that CXL increases the diameter of collagen fibers and also the number of intra- and interfibrillar cross-links, thus, increasing biomechanical strength of the irradiated cornea. As confirmed by a series of clinical and randomized controlled trials, CXL is able to slow down and, perhaps, to stop the progression of keratoconus. In most post-CXL patients visual acuity improves, while keratometric readings, spherical equivalent, and higher order aberrations reduce. Although published results prove CXL effective in the treatment of progressive keratoconus, its late consequences are yet unknown. This article reviews the stages of CXL development and results of published experimental and clinical studies. Prospects for CXL modifications that do not require epithelial debridement are discussed.

  17. Another Risk From Cigarette Smoking: Corneal Burn

    Directory of Open Access Journals (Sweden)

    Volkan Hürmeriç

    2012-12-01

    Full Text Available A 21-year-old male presented with corneal injury in his left eye after one of his friends had moved his arm backwards and accidentally hit his eye with the lit end of a cigarette. Slit lamp examination revealed epithelial defect and significant stromal edema at the superior temporal quadrant of the cornea. Cigarette ashes were noted in his lashes and inferior conjunctival fornix at the initial examination in the emergency service. 6 weeks after the injury, slit lamp examination revealed stromal thinning and haze in the temporal part of the cornea. His best spectacle-corrected distance visual acuity was 20/25 with a refractive error of -6.75x135 diopters in the left eye. Our case demonstrates that ocular thermal injury due to cigarette smoking can cause serious damage to the ocular tissues. (Turk J Oph thal mol 2012; 42: 484-5

  18. Automatic system for corneal ulcer diagnostic: II

    Science.gov (United States)

    Ventura, Liliane; Chiaradia, Caio; Faria de Sousa, Sidney J.

    1998-06-01

    Corneal Ulcer is a deepithelization of the cornea and it is a very common disease in agricultural countries. The clinician most used parameter in order to identify a favorable ulcer evolution is the regress of the affected area. However, this kind of evaluation is subjective, once just the horizontal and vertical axes are measured based on a graduated scale and the affected area is estimated. Also, the registration of the disease is made by photographs. In order to overcome the subjectiveness and to register the images in a more accessible way (hard disks, floppy disks, etc.), we have developed an automatic system in order to evaluate the affected area (the ulcer). An optical system is implemented in a Slit Lamp (SL) and connected to a CCD detector. The image is displayed in PC monitor by a commercial frame grabber and a dedicated software for determining the area of the ulcer (precision of 20 mm) has been developed.

  19. Crystalline Subtype of Pre-Descemetic Corneal Dystrophy

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    Rosa Dolz-Marco

    2014-01-01

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

  20. Shadow photogrammetric apparatus for the quantitative evaluation of corneal buttons.

    Science.gov (United States)

    Denham, D; Mandelbaum, S; Parel, J M; Holland, S; Pflugfelder, S; Parel, J M

    1989-11-01

    We have developed a technique for the accurate, quantitative, geometric evaluation of trephined and punched corneal buttons. A magnified shadow of the frontal and edge views of a corneal button mounted on the rotary stage of a modified optical comparator is projected onto the screen of the comparator and photographed. This process takes approximately three minutes. The diameters and edge profile at any meridian photographed can subsequently be analyzed from the film. The precision in measuring the diameters of well cut corneal buttons is +/- 23 microns, and in measuring the angle of the edge profile is +/- 1 degree. Statistical analysis of inter observer variability indicated excellent reproducibility of measurements. Shadow photogrammetry offers a standardized, accurate, and reproducible method for analysis of corneal trephination.

  1. Review of photokeratitis: Corneal response to ultraviolet radiation (UVR exposure*

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    L A. Moore

    2010-12-01

    Full Text Available The development of photokeratitis in response to natural solar ultraviolet radiation (UVR is prevalent in individuals participating in outdoor recreational activities in environments with high reflective surfaces, such as beach activities, water sports and snow skiing. Eye care practitioners (ECPs are frequently encouraged by manufacturers and researchers to recommend UVR-blocking eyewear in the form of sunglasses and contact lenses. However, little is known about the precise nature of the corneal tissue response in the development of photokeratitis. This paper reviews the mechanisms responsible for the development of photokeratitis. Clinical signs and symptoms of photokeratitis, UVR corneal threshold and action spectra, corneal cellular changes and ocular protection from corneal UVR exposure are discussed. The content of this article will be useful to ECPs in making appropriate recommendations when prescribing UVR-protec-tive eyewear. (S Afr Optom 2010 69(3 123-131

  2. Putative Corneal Neuralgia Responding to Vitamin D Supplementation

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    Eric L. Singman

    2013-09-01

    Full Text Available A patient with putative corneal neuralgia was incidentally discovered to have hypovitaminosis D. Supplementation of vitamin D appears to have led to a resolution of the patient's pain, whereas other efforts to treat the patient were unsuccessful.

  3. Central Corneal Thickness in Adult Chinese

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The central corneal thickness (CCT) in age 48 years or less of Chinese was characterized and its relationship with gender, age, refraction and intraocular pressure (IOP) was investigated.Right eyes of 1669 participants were included in this study (880 men, 52.7 % and 789 women,47.3 %). Mean age of the samples was 23.8±5.9 years. After the examination of corneal topography and refraction, Goldman applanation tonometry was carried out by one physician. Tonometric values were the mean of three consecutive readings. Subsequently, another physician carried out ultrasonic pachymetry with the DGH 2000 AP ultrasonic pachymeter. Six measuremen ts were made at the center of the cornea of each eye. The mean value was used for analysis. The results showed that mean CCT of male participants was 551.33± 34. 62 μm, 5.79 μm more than that of female participants. Linear regression analyses revealed that CCT was negatively related with age only in female and no association was found between refractive status and CCT. IOP was positively related to CCT, and there was a difference in IOP of 1.5 mmHg (1 mmHg=0. 133 kPa) per 100 μm difference in CCT. Ocular hypertension group was prone to have thicker cornea than average. The results indicated that in adult Chinese CCT tended to decrease with aging in female only. IOP measured by Goldmann tonometry was positively related with CCT so that CCT should be measured along with IOP.

  4. Clinical utility of the KAMRA corneal inlay

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    Naroo SA

    2016-05-01

    Full Text Available Shehzad Anjam Naroo, Paramdeep Singh Bilkhu Ophthalmic Research Group, School of Life & Health Sciences, Aston University, Birmingham, UK Abstract: 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. Keywords: presbyopia, refractive surgery, implants, cornea

  5. Electrically assisted delivery of macromolecules into the corneal epithelium

    OpenAIRE

    HAO, JINSONG; Li, S. Kevin; Liu, Chia-Yang; Kao, Winston W. Y.

    2009-01-01

    Electrically assisted delivery is noninvasive and has been investigated in a number of ocular drug delivery studies. The objectives of this study were to examine the feasibility of electrically assisted delivery of macromolecules such as small interfering RNA (siRNA) into the corneal epithelium, to optimize the iontophoresis and electroporation methods, and to study the mechanisms of corneal iontophoresis for macromolecules. Anodal and cathodal iontophoresis, electroporation and their combina...

  6. ROLE OF CORNEAL COLLAGEN CROSS LINKING IN KERATOCONUS

    OpenAIRE

    Atul; Superna; Bhimasankar; Vijayleela

    2015-01-01

    To evaluate the outcome of collagen cross linkage using riboflavin 0.1% and ultraviolet A radiation of a wavelength 370nm . PURPOSE : To determine the effect of collagen cross linking for keratoconus on pachymetry , corneal topography, uncorrected visual acuity, specular count, IOP at 1, 3, 6 months . METHODS : The current study was designed as a prospective interventional trial of corneal collagen cross - linking in subjects w...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  9. The Active Metabolite of Leflunomide A771726 Inhibits Corneal Neovascularization

    Institute of Scientific and Technical Information of China (English)

    Mingchang ZHANG; Nian HAO; Fang BIAN

    2008-01-01

    The effects of A771726, the active metabolite of leflunomide, on experimental rat corneal neovascularization (NV) in vivo and on cultured human umbilical vein endothelial cells in vitro were studied. The corneal NV was induced by alkali burn in 40 SD rats. The rats were randomly divided into 4 groups with 10 rats in each group. Group A was treated with 0.9% sodium chloride (control group), and group B, group C and group D were given different concentrations of A771726 eye drops (0.5%,l.0%,2.0% respectively) 4 times daily during days 0-28. The occurrence and development of corneal NV were observed at 4,7,14,21 and 28 day after alkali burn by a slit lamp microscope. The cultured human umbilical vein endothelial cells (ECV-304) were incubated with A771726 solution at different concentrations (20,40,80,160,320μmol/L) for 36h. The proliferation of cells was assessed by methyl thiazolyl tetrazolium (MTT), and the expression of proliferating cell nuclear antigen (PCNA) in cells was detected by using immunofluorescence under the laser confocal microscope. The rat model showed that the onset of corneal NV was delayed and progression of corneal NV was inhibited in the groups C and D. The corneal NV areas in groups C and D were significantly smaller than in groups A and B (P0.05). A771726 solution (≥40μmol/L) could inhibit proliferation of human umbilical vein endothelial cells and decrease the expression of PCNA in cells significantly. A771726, as the active metabolite of leflunomide, strongly prevented corneal NV induced by alkali burn in the in vivo model, and inhibited proliferation of human umbilical vein endothelial cells in the in vitro model. Therefore, A771726 may serve as an angiogenic inhibitor in the treatment of corneal NV.

  10. On fractional Bessel equation and the description of corneal topography

    CERN Document Server

    Okrasiński, Wojciech

    2012-01-01

    In this note we apply a modified fractional Bessel differential equation to the problem of describing corneal topography. We find the solution in terms of the power series. This solution has an interesting behavior at infinity which is a generalization of the classical results for modified Bessel function of order 0. Our model fits the real corneal geometry data with an error of order of a few per cent.

  11. Analysis of corneal esthesia in patients undergoing photorefractive keratectomy

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    Elmar Torres Neto

    2015-12-01

    Full Text Available ABSTRACT Purpose: To quantitatively analyze corneal esthesia in patients undergoing photorefractive keratectomy (PRK surgery. Methods: Forty-five patients selected for PRK in one eye underwent corneal esthesia using a Cochet-Bonnet esthesiometer preoperatively and 30 and 90 days postoperatively. Patients with a refractive diopter error of 4 or greater received intraoperative 0.02% mitomycin C for 20 s. Results: Twenty-four (53.3% of the 45 eyes received intraoperative 0.02% mitomycin. Decreased sensitivity was observed on postoperative day 30. By postoperative day 90, corneal esthesia had normalized but remained 14.9% lower than preoperative levels. In the mitomycin group, no recovery of corneal esthesia to normal sensitivity levels was observed. The mean esthesiometer level was 39.2 mm on postoperative day 90 (P<0.001. Conclusions: The results of the present study demonstrate recovery of corneal esthesia to normal levels at 90 days postoperatively in patients who did not receive mitomycin C. In patients administered mitomycin C, a 23.59% reduction in the corneal touch threshold was observed compared with preoperative levels indicating a failure of recovery to normal levels.

  12. Inhibition of Corneal Neovascularization by Topical and Subconjunctival Tigecycline

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    Sertan Goktas

    2014-01-01

    Full Text Available Objective. To investigate the effects of topical and subconjunctival tigecycline on the prevention of corneal neovascularization. Materials and Methods. Following chemical burn, thirty-two rats were treated daily with topical instillation of 1 mg/mL tigecycline (group 1 or subconjunctival instillation of 1 mg/mL tigecycline (group 3 for 7 days. Control rats received topical (group 2 or subconjunctival (group 4 0.9% saline. Digital photographs of the cornea were taken on the eighth day after treatment and analyzed to determine the percentage area of the cornea covered by neovascularization. Corneal sections were analyzed histopathologically. Results. The median percentages of corneal neovascularization in groups 1 and 3 were 48% (95% confidence interval (CI, 44.2–55.8% and 33.5% (95% CI, 26.6–39.2%, respectively. The median percentages of corneal neovascularization of groups 1 and 3 were significantly lower than that of the control group (P=0.03 and P<0.001, resp.. Histologic examination of samples from groups 1 and 3 showed lower vascularity than that of control groups. Conclusion. Topical and subconjunctival administration of tigecycline seems to be showing promising therapeutic effects on the prevention of corneal neovascularization. Furthermore, subconjunctival administration of tigecycline is more potent than topical administration in the inhibition of corneal neovascularization.

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

    Science.gov (United States)

    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

  14. Limbal stem cells: Central concepts of corneal epithelial homeostasis

    Institute of Scientific and Technical Information of China (English)

    Jinny; J; Yoon; Salim; Ismail; Trevor; Sherwin

    2014-01-01

    A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent stud-ies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal surface

  15. Corneal pain activates a trigemino-parabrachial pathway in rats.

    Science.gov (United States)

    Aicher, Sue A; Hegarty, Deborah M; Hermes, Sam M

    2014-03-06

    Corneal pain is mediated by primary afferent fibers projecting to the dorsal horn of the medulla, specifically the trigeminal nucleus caudalis. In contrast to reflex responses, the conscious perception of pain requires transmission of neural activity to higher brain centers. Ascending pain transmission is mediated primarily by pathways to either the thalamus or parabrachial nuclei. We previously showed that some corneal afferent fibers preferentially contact parabrachial-projecting neurons in the rostral pole of the trigeminal nucleus caudalis, but the role of these projection neurons in transmitting noxious information from the cornea has not been established. In the present study, we show that noxious stimulation of the corneal surface activates neurons in the rostral pole of the nucleus caudalis, including parabrachially projecting neurons that receive direct input from corneal afferent fibers. We used immunocytochemical detection of c-Fos protein as an index of neuronal activation after noxious ocular stimulation. Animals had previously received injections of a retrograde tracer into either thalamic or parabrachial nuclei to identify projection neurons in the trigeminal dorsal horn. Noxious stimulation of the cornea induced c-Fos in neurons sending projections to parabrachial nuclei, but not thalamic nuclei. We also confirmed that corneal afferent fibers identified with cholera toxin B preferentially target trigeminal dorsal horn neurons projecting to the parabrachial nucleus. The parabrachial region sends ascending projections to brain regions involved in emotional and homeostatic responses. Activation of the ascending parabrachial system may explain the extraordinary salience of stimulation of corneal nociceptors.

  16. Corneal organ cultures in tyrosinemia release chemotactic factors.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

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    Flavio Mantelli

    2015-01-01

    Full Text Available Neurotrophic keratitis (NK is a rare degenerative disease of the cornea caused by an impairment of corneal sensory innervation, characterized by decreased or absent corneal sensitivity resulting in epithelial keratopathy, ulceration, and perforation. The aetiopathogenesis of corneal sensory innervation impairment in children recognizes the same range of causes as adults, although they are much less frequent in the pediatric population. Some extremely rare congenital diseases could be considered in the aetiopathogenesis of NK in children. Congenital corneal anesthesia is an extremely rare condition that carries considerable diagnostic and therapeutic problems. Typically the onset is up to 3 years of age and the cornea may be affected in isolation or the sensory deficit may exist as a component of a congenital syndrome, or it may be associated with systemic somatic anomalies. Accurate diagnosis and recognition of risk factors is important for lessening long-term sequelae of this condition. Treatment should include frequent topical lubrication and bandage corneal or scleral contact lenses. Surgery may be needed in refractory cases. The purpose of this review is to summarize and update data available on congenital causes and treatment of corneal hypo/anesthesia and, in turn, on congenital NK.

  19. The Study of Corneal Topography in Myopic and Hyperopic Children

    Institute of Scientific and Technical Information of China (English)

    Lei Gao; Xuying Zhuo; Lusheng Ma; Ning Yu; Zhonghao Wang; Pengfei Jiang

    2005-01-01

    Purpose: To compare the differences of corneal topographies in myopic and hyperopic children and study the effect of Atropin on their changes.Methods: The refractive components of 136 eyes with different refractive conditions were measured with A-Scan and their corneal topographies with and without cycloplegia were obtained respectively.Results: The mean corneal power of zones 3mm (MD3, P=0.031 ) and minor keratometer K2 (P=0.003) of myopia are greater than those of hyperopia without cycloplegia. MD3 (P=0.009) and Keratometer K1 (P = 0.025) increased in hyperopic eyes, while MD3(P=0.033), K1 (P = 0.035) and K2 (P = 0.002) decreased in myopic eyes significantly after cycloplegia. Similarly, the mean corneal power of zones 5mm (MD5) and 7mm (MD7) in myopic eyes decreased dramatically (P ≤ 0.001 ).Conclusions: The corneal power was found to be greater in myopia than that in hyperopia. The effect of Atropin on corneal shape of myopia and hyperopia was in the opposite direction.

  20. Evaluación de los efectos del policosanol sobre manifestaciones del daño pulmonar inducido por monocrotalina en ratas

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    Vivian Molina

    2009-01-01

    Full Text Available La hipertensión arterial pulmonar, (HTAP enfermedad crónica que afecta frecuentemente a la población adulta, conduce a una discapacidad importante y progresiva. Las estatinas, agentes hipolipemiantes que inhiben la síntesis de colesterol mediante la inhibición competitiva de la HMG-CoA reductasa que además inhiben la proliferación de las células musculares lisas (CML, han sido referidas como una opción actual para tratar esta enfermedad. El policosanol es una mezcla de alcoholes alifáticos superiores obtenida de la cera de caña que también inhibe la síntesis de colesterol mediante la regulación indirecta de la actividad de la HMG-CoA reductasa, con acción antiproliferativa sobre las CML. Resulta racional investigar si el policosanol protege el daño pulmonar inducido en modelos experimentales en los cuales las estatinas han mostrado ser efectivas. Este estudio investigó los efectos del tratamiento oral con policosanol sobre el daño pulmonar inducido por monocrotalina (MCT en ratas. Para ello, las ratas se distribuyeron en cuatro grupos: un control negativo tratado vía subcutánea (s.c. con disolución salina y por vía oral con el vehículo tween 20/agua y tres inyectados con dosis s.c. únicas de MCT (60 mg/kg, uno tratado por vía oral con el vehículo (control positivo y dos con policosanol (20 y 200 mg/kg. Los tratamientos comenzaron el día de la inyección con MCT y se administraron por 28 d . Se cuantificó el porcentaje de supervivencia, el peso corporal, el peso del pulmón completo, la hipertrofia ventricular y se realizó el estudio histológico. La MCT aumentó significativamente el peso del pulmón, redujo significativamente el peso corporal y produjo marcada hipertrofia ventricular derecha y severa hipertrofia de la capa media arterial, mostrando la validez del modelo. Contrario a lo esperado, al compararse con los datos del control positivo, el policosanol (20 y 200 mg/kg no modificó significativamente ninguna

  1. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    OpenAIRE

    Semra Tiryaki Demir; Mahmut Odabaşı; Mehmet Ersin Oba; Ayşe Burcu Dirim; Efe Can; Orhan Kara

    2014-01-01

    Objectives: Comparison of central corneal thickness (CCT) measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG), 41 patients with ocular hypertension (OHT), and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb) ...

  2. Comparison of Central Corneal Thickness Measurements by Ultrasonic Pachymetry and Orbscan II Corneal Topography and Evaluation of Ultrasonic Pachymetry Repeatability

    Directory of Open Access Journals (Sweden)

    Semra Tiryaki Demir

    2014-08-01

    Full Text Available Objectives: Comparison of central corneal thickness (CCT measurements by ultrasonic pachymetry and Orbscan II corneal topography and evaluation of ultrasonic pachymetry repeatability for same observer. Materials and Methods: The study included 132, 82, and 80 eyes of 66 patients with primary open-angle glaucoma (POAG, 41 patients with ocular hypertension (OHT, and 40 controls, respectively. All subjects were subjected to routine ophthalmic examination. Orbscan II (Bausch&Lomb corneal topography and ultrasonic pachymetry (Nidek Ultrasonic Pachymetry UP-1000 were used for measurement of CCT. ANOVA (Turkey test was used for variable distribution, paired sample t-test was used for repeated measurements, and the analyses were done by SPSS 20.0. Results: Mean CCT was 558.9±37.2 µm by ultrasonic pachymetry and 553.4±37 µm by corneal topography. There was a significant difference between the two measurements (p0.05. CCT was 555±39.2 µm, 564.3±28.4 µm, and 559.7±41.5 µm by ultrasonic pachymetry in POAG, OHT, and control subjects, respectively; CCT was 550.3±38.3 µm, 558.5±28 µm, and 553.2±42.5 µm by Orbscan II corneal topography in POAG, OHT, and control subjects, respectively. There was a significant linear correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements (r=0.975, p<0.0001. Repeatability of ultrasonic pachymetry for same observer was (ICC value 0.990. Conclusion: There is a significant correlation between Orbscan II corneal topography and ultrasonic pachymetry in CCT measurements. These two methods of measurements should not be substituted for each other, since ultrasonic pachymetry measures CCT greater than Orbscan II corneal topography. Repeatability of ultrasonic pachymetry for same observer is very high. (Turk J Ophthalmol 2014; 44: 263-7

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

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    Jie Hou

    2016-01-01

    Full Text Available 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. Precision and agreement of corneal power measurements obtained using a new corneal topographer OphthaTOP.

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    Jinhai Huang

    Full Text Available 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.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.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.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.

  5. Benzalkonium chloride suppresses rabbit corneal endothelium intercellular gap junction communication.

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    Zhenhao Zhang

    Full Text Available Gap junction intercellular communication (GJIC plays a critical role in the maintenance of corneal endothelium homeostasis. We determined if benzalkonium chloride (BAK alters GJIC activity in the rabbit corneal endothelium since it is commonly used as a drug preservative in ocular eyedrop preparations even though it can have cytotoxic effects.Thirty-six adult New Zealand albino rabbits were randomly divided into three groups. BAK at 0.01%, 0.05%, and 0.1% was applied twice daily to one eye of each of the rabbits in one of the three groups for seven days. The contralateral untreated eyes were used as controls. Corneal endothelial morphological features were observed by in vivo confocal microscopy (IVCM. Immunofluorescent staining resolved changes in gap junction integrity and localization. Western blot analysis and RT-PCR evaluated changes in levels of connexin43 (Cx43 and tight junction zonula occludens-1 (ZO-1 gene and protein expression, respectively. Cx43 and ZO-1 physical interaction was detected by immunoprecipitation (IP. Primary rabbit corneal endothelial cells were cultured in Dulbecco's Modified Eagle Medium (DMEM containing BAK for 24 hours. The scrape-loading dye transfer technique (SLDT was used to assess GJIC activity.Topical administration of BAK (0.05%, 0.1% dose dependently disrupted corneal endothelial cell morphology, altered Cx43 and ZO-1 distribution and reduced Cx43 expression. BAK also markedly induced increases in Cx43 phosphorylation status concomitant with decreases in the Cx43-ZO-1 protein-protein interaction. These changes were associated with marked declines in GJIC activity.The dose dependent declines in rabbit corneal endothelial GJIC activity induced by BAK are associated with less Cx43-ZO-1 interaction possibly arising from increases in Cx43 phosphorylation and declines in its protein expression. These novel changes provide additional evidence that BAK containing eyedrop preparations should be used with caution to

  6. An experimental model of mycobacterial infection under corneal flaps

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    C.B.D. Adan

    2004-07-01

    Full Text Available In order to develop a new experimental animal model of infection with Mycobacterium chelonae in keratomileusis, we conducted a double-blind prospective study on 24 adult male New Zealand rabbits. One eye of each rabbit was submitted to automatic lamellar keratotomy with the automatic corneal shaper under general anesthesia. Eyes were immunosuppressed by a single local injection of methyl prednisolone. Twelve animals were inoculated into the keratomileusis interface with 1 µl of 10(6 heat-inactivated bacteria (heat-inactivated inoculum controls and 12 with 1 µl of 10(6 live bacteria. Trimethoprim drops (0.1%, w/v were used as prophylaxis for the surgical procedure every 4 h (50 µl, qid. Animals were examined by 2 observers under a slit lamp on the 1st, 3rd, 5th, 7th, 11th, 16th, and 23rd postoperative days. Slit lamp photographs were taken to document clinical signs. Animals were sacrificed when corneal disease was detected and corneal samples were taken for microbiological analysis. Eleven of 12 experimental rabbits developed corneal disease, and M. chelonae could be isolated from nine rabbits. Eleven of the 12 controls receiving a heat-inactivated inoculum did not develop corneal disease. M. chelonae was not isolated from any of the control rabbits receiving a heat-inactivated inoculum, or from the healthy cornea of control rabbits. Corneal infection by M. chelonae was successfully induced in rabbits submitted to keratomileusis. To our knowledge, this is the first animal model of M. chelonae infection following corneal flaps for refractive surgery to be described in the literature and can be used for the analysis of therapeutic responses.

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

    Science.gov (United States)

    Hao, Zhao-Qin; Song, Jin-Xin; Pan, Shi-Yin; Zhang, Lin; Cheng, Yan; Liu, Xian-Ning; Wu, Jie; Xiao, Xiang-Hua; Gao, Wei; Zhu, Hai-Feng

    2016-01-01

    AIM To observe the therapeutic effect of corneal collagen cross-linking (CXL) in combination with liposomal amphotericin B in fungal corneal ulcers. METHODS New Zealand rabbits were induced fungal corneal ulcers by scratching and randomly divided into 3 groups, i.e. control, treated with CXL, and combined therapy of CXL with 0.25% liposomal amphotericin B (n=5 each). The corneal lesions were documented with slit-lamp and confocal microscopy on 3, 7, 14, 21 and 28d after treatment. The corneas were examined with transmission electron microscopy (TEM) at 4wk. RESULTS A rabbit corneal ulcer model of Fusarium was successfully established. The corneal epithelium defect areas in the two treatment groups were smaller than that in the control group on 3, 7, 14 and 21d (Pulcers. The combined therapy could alleviate corneal inflammattions, accelerate corneal repair, and shorten the course of disease. PMID:27990355

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

    Science.gov (United States)

    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. Analysis of the problems of induced draft fans in a carbo-electric power station; Analisis de la problematica de ventiladores de tiro inducido de una central carboelectrica

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Sanchez, Valentin de Jesus; Vital Flores, Francisco [LAPEM, Comision Federal de Electricidad (Mexico)

    2007-11-15

    The induced draft fans of the 350 MW units of a Thermo-electric power plant presented problems consisting of the failure of the capacity of gases extraction, together with the presence of cracks in the blades; this condition was observed since the stage of putting into service. Consequently, losses have been originated in the availability in two units, as well as, losses due to the manufacture of new impellers, which also originated that, in some cases, that the measures of the impellers, locally manufactured, differed from the originals, resulting in differences in the unit's efficiency. [Spanish] Los ventiladores tiro inducido de las unidades de 350 MW de una Central Termoelectrica presentaban una problematica consistente en la falla de capacidad de extraccion de gases, aunado a la presencia de fracturas en las aspas de los impulsores, esta condicion se observo desde la etapa de puesta en servicio. En consecuencia se han ocasionado perdidas de disponibilidad en dos unidades, asi como tambien, perdidas debido a la fabricacion de nuevos impulsores, lo que tambien origino que, en algunos casos, las medidas de los impulsores, fabricados localmente, diferian de los originales, dando como resultado diferencias en la eficiencia de las unidades.

  10. Physical Aspects of Photodynamic Corneal Collagen Crosslinking

    Science.gov (United States)

    Kornfield, Julia

    2012-02-01

    Healthy vision depends on the stability of the shape of the cornea, which provides most of the lens power of the optical system of the eye. Diseases in which the cornea progressively undergoes irregular deformation over time (e.g., keratoconus) can be treated clinically by inducing additional protein-protein crosslinks using a photosensitizing drug and a tailored dose of light. Unfortunately, the treatment moving through clinical trials is toxic to cells in and on the cornea. A path to a safer treatment is offered by the nanostructure of the corneal stroma---reminiscent of a HEX phase in block copolymers with 30nm diameter collagen cylinders spaced 60nm center-to-center in a hydrogel matrix of proteoglycans and water. We show that using a photosensitizing drug that sequesters itself in the collagen fibrils can minimize the toxicity of therapeutic protein-protein cross-linking. Photorheology and transport measurements are used to quantify the parameters of a simple physical model that is useful for optimizing clinical protocols.

  11. Corneal sensitivity and correlations between decreased sensitivity and anterior segment pathology in ocular leprosy.

    OpenAIRE

    Karaçorlu, M A; Cakiner, T; Saylan, T

    1991-01-01

    Leprosy is one of the leading causes of corneal hyposensitivity. In this article the corneal sensitivity of 143 leprosy patients was examined, and correlations between corneal hyposensitivity and anterior segment pathology were detected. Twenty four healthy volunteers were examined as controls. Various degrees of corneal loss of sensitivity were found in 46.2% of leprosy patients. Lagophthalmos, chronic lepromatous granulomatous uveitis, iris atrophy, and social blindness were found 4.5-16.6 ...

  12. [Macroscopic observations on corneal epithelial wound healing in the rabbit].

    Science.gov (United States)

    Hayashi, K

    1991-02-01

    A newly-developed macroscope was applied to observe the healing process of corneal epithelial wound in vivo. After removing epithelium of the central cornea, the changes of the corneal surface were observed with the macroscope and the findings were compared with histological examinations. At 12 hours after abrasion, areas unstained with Richardson's staining (R staining) appeared. In the histological section, a single layer of regenerating epithelial cells covered the same area. At 24 and 36 hours after abrasion, the epithelial defects became smaller but surrounding epithelium was rough and showed dot-like staining with R solution. By 2 days, the epithelial defects disappeared. On macroscopic observation, the central corneal surface showed a pavement-like appearance. Histology revealed that the regenerating epithelium still consisted of one or two layers. At 3 days, dot-like stainings were present only in the center and the corneal surface appeared considerably smooth. Histology also showed that regenerating epithelium became columnar and multilayered, thereby suggesting stratification. By 7 days, the abraded corneal surface had recovered its smooth appearance. Histologic sections also demonstrated that the epithelium had regained its normal structure. Thus, using this macroscope, findings suggesting the process of epithelial migration and proliferation could be observed.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  15. Spontaneous corneal perforation in an eye with Peters' anomaly

    Directory of Open Access Journals (Sweden)

    Kim M

    2013-07-01

    Full Text Available Moosang Kim, Seung-Chan Lee, Seung-Jun Lee Department of Ophthalmology, School of Medicine, Kangwon National University, Chuncheon, South Korea Abstract: A premature female infant underwent her first ophthalmologic examination at the age of 4 weeks. The initial examination of the baby was requested for evaluation of a ‘white spot’ on the surface of her right eye. She had been hospitalized in the neonatal intensive care unit because of systemic abnormalities, such as a right clavicle fracture and microcephaly. Slit-lamp examination of the right eye showed a central corneal opacity, corneal thinning, and an iridocorneal adhesion. The lens and fundus of the right eye could not be observed. We observed no pathologic findings in the left eye. The baby's parents were informed of the high risk for spontaneous corneal perforation without external pressure. At 42 days of age, an ophthalmologic examination of the infant was again requested for evaluation of ‘tears’ from her right eye 3 hours previously. Examination revealed corneal perforation, iris protrusion, and a flat anterior chamber. We performed emergent conjunctival flap surgery. Three months following surgery, the patient's right eye was successfully preserved with no sign of inflammation or leakage. Keywords: conjunctival flap, corneal perforation, Peters' anomaly

  16. Discovery of molecular markers to discriminate corneal endothelial cells in the human body

    NARCIS (Netherlands)

    Yoshihara, Masahito; Ohmiya, Hiroko; Hara, Susumu; Kawasaki, Satoshi; Hayashizaki, Yoshihide; Itoh, Masayoshi; Kawaji, Hideya; Tsujikawa, Motokazu; Nishida, Kohji; Clevers, J.C.; van de Wetering, M.L.

    2015-01-01

    The corneal endothelium is a monolayer of hexagonal corneal endothelial cells (CECs) on the inner surface of the cornea. CECs are critical in maintaining corneal transparency through their barrier and pump functions. CECs in vivo have a limited capacity in proliferation, and loss of a significant nu

  17. Standard and hypoosmolar corneal cross-linking in various pachymetry groups

    NARCIS (Netherlands)

    Soeters, Nienke; Tahzib, Nayyirih G

    2015-01-01

    PURPOSE: To investigate the influence of corneal thickness on the outcome of corneal cross-linking (CXL) for progressive keratoconus. METHODS: In this cohort study, 72 unilateral eyes were treated by CXL and divided into three groups according to central corneal thickness (CCT) measured by ultrasoun

  18. Corneal endothelial cell density and morphology and central corneal thickness in Guangxi Maonan and Han adolescent students of China

    Institute of Scientific and Technical Information of China (English)

    Hao; Liang; Hui-Yi; Zuo; Jin-Mao; Chen; Jie; Cai; Yu-Zhua; Qin; Yu-Ping; Huang; Ying-Ying; Chen; Dong-Yong; Tang; Shao-Jian; Tan

    2015-01-01

    AIM: To investigate the corneal endothelial cell density and morphology and central corneal thickness in the Guangxi Maonan and Han adolescent students of China.METHODS: Noncontact specular microscope(Topcon SP3000 P, Tokyo, Japan) was performed in 133 adolescent students of Maonan nationality(M:F 54:79)and 105 adolescent students of Han nationality(M:F 50:55),5 to 20 y of age, who were randomly selected from 3schools in Huanjiang Maonan Autonomous County of Guangxi Zhuang Autonomous Region of China.Parameters studied included endothelial cell density,mean cell area, coefficient of variation in cell size,percentage hexagonality and central corneal thickness. RESULTS: Endothelial cell density, mean cell area,coefficient of variation in cell size, percentage hexagonality and central corneal thickness in the study population were(2969.50 ±253.93) cells/mm2,(339.23 ±29.44) μm2,(29.96 ±4.07) %,(64.58 ±9.41) % and(523.71 ±32.82) μm in Maonan and(2998.26 ±262.65) cells/mm2,(336.11±30.07) μm2,(29.89±5.03) %,(64.91±11.64) % and(524.39 ±33.15) μm in Han, respectively. No significant differences were observed in endothelial cell density,mean cell area, coefficient of variation in cell size,percentage hexagonality and central corneal thickness between Maonan and Han(P =0.615, 0.659, 0.528, 0.551,0.999). In Maonan and Han, we found age was negatively correlated with endothelial cell density and percentagehexagonality and positively correlated with mean cell area and coefficient of variation in cell size. Negative correlation was also found between central corneal thickness and age in Han, whereas no correlation was found in Maonan. CONCLUSION: There were no differences between Maonan and Han in corneal endothelial cell density and morphology and central corneal thickness. In these two nationalities, there were statistically significant decrease in endothelial cell density and percentage hexagonality with increasing age and statistically significant increase in

  19. Comparative study of visual acuity and aberrations after intralase femtosecond LASIK: small corneal flap versus big corneal flap

    Institute of Scientific and Technical Information of China (English)

    Ya-Li; Zhang; Lei; Liu; Chang-Xia; Cui; Ming; Hu; Zhao-Na; Li; Li-Jun; Cao; Xiu-Hua; Jing; Guo-Ying; Mu

    2014-01-01

    AIM:To study the effects of different flap sizes on visual acuity, refractive outcomes, and aberrations after femtosecond laser for laser keratomileusis (LASIK). ·METHODS: In each of the forty patients enrolled, 1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap, defined as the small flap, while the other eye was treated with a 8.6mm diameter corneal flap, defined as the big flap. Refractive errors, visual acuity, and higher -order aberrations were compared between the two groups at week 1, month 1 and 3 postoperatively. · RESULTS: The postoperative refractive errors and visual acuity all conformed to the intended goal. Postoperative higher -order aberrations were increased, especially in spherical aberration (Z12) and vertical coma (Z7). There were no statistically significant differences between the two groups in terms of postoperative refractive errors, visual acuity, root mean square of total HOAs (HO -RMS), trefoil 30° (Z6), vertical coma (Z7), horizontal coma (Z8), trefoil 0° (Z9), and spherical aberration (Z12) at any point during the postoperative follow-up. ·CONCLUSION: Both the small and big flaps are safe and effective procedures to correct myopia, provided the exposure stroma meets the excimer laser ablations. The personalized size corneal flap is feasible, as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Hirlana Gomes Almeida

    Full Text Available 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.

  2. Tectonic corneal graft for conjunctival rhinosporidiosis with scleral melt

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    Pushpa Jacob

    2011-01-01

    Full Text Available A 16 year old girl presented with irritation and watering of the right eye for 3 months. On examination, the superior perilimbal sclera was ectatic with incarcerated uveal tissue covered by conjunctiva. The conjunctiva showed discreet, yellow white mucoid spots. Excision biopsy of the conjunctiva showed subepithelial spherules of sporangia containing numerous endospores, suggestive of rhinosporidiosis. Diathermy was applied to flatten the staphyloma. The ectatic area was covered with a corneal patch graft. The patient was started on prednisolone acetate eye drops and oral dapsone for 6 months. Corneal graft was well incorporated and conjunctivalized by 3 months. Since the graft was not seen within the palpebral aperture, there was good cosmetic result. The corneal graft had the added advantage of transparency which allowed visualization of the underlying tissue to diagnose early recurrence. There was no recurrence at 6 months.

  3. Corneal wound healing is compromised by immunoproteasome deficiency.

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    Deborah A Ferrington

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

  4. Advances in corneal topography measurements with conical null-screens

    Science.gov (United States)

    Campos-García, Manuel; Cossio-Guerrero, Cesar; Huerta-Carranza, Oliver; Moreno-Oliva, Víctor I.

    2015-09-01

    In this work we report the design of a null-screen for corneal topography. To avoid the difficulties in the alignment of the test system due to the face contour (eyebrows, nose, or eyelids), we design a conical null-screen with a novel radial points distribution drawn on it in such a way that its image, which is formed by reflection on the test surface, becomes an exact array of circular spots if the surface is perfect. Additionally, an algorithm to compute the sagittal and meridional radii of curvature for the corneal surface is presented. The sagittal radius is obtained from the surface normal, and the meridional radius is calculated from a function fitted to the derivative of the sagittal curvature by using the surfacenormals raw data. Experimental results for the testing a calibration spherical surface are shown. Also, we perform some corneal topography measurements.

  5. Synchronous interferometric demodulation of Placido mires applied to corneal topography

    CERN Document Server

    Servin, Manuel

    2012-01-01

    This paper presents a novel digital interferometric method to demodulate Placido fringe patterns. This is a synchronous method which uses a computer-stored conic-wavefront as demodulating reference. Here we focuses on the experimental aspects to phase-demodulate Placido mires applied to corneal topography. This synchronous method is applied to two topographic Placido images and their de-modulated corneal-slope deformation is estimated. This conic-interferometric method is highly robust against typical "noisy" signals in Placido topography such as: reflected eyelashes and iris structures. That is because the eyelashes and the iris structure are high frequency "noisy" signals corrupting the reflected Placido mire, so they are filtered-out by this method. Digital synchronous interferometry is here applied for the first time to demodulate corneal topographic concentric-rings images (Patent pending at the USPTO).

  6. Cataract Surgery with a Refractive Corneal Inlay in Place

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    N. R. Stojanovic

    2015-01-01

    Full Text Available Purpose. To present a case of cataract surgery performed in a patient with a refractive corneal inlay in place. Methods. A 48-year-old female patient presented to our institute with bilateral cataract. The patient had undergone refractive corneal inlay implantation three years ago in her right, nondominant eye for presbyopia correction. Biometry and intraocular lens (IOL power calculation were performed without removing the inlay. Phacoemulsification and IOL insertion were carried out in both eyes in a usual manner. Results. On day one postoperatively, the patient achieved binocular uncorrected distance visual acuity 20/20 and uncorrected near visual acuity J1. The vision remained stable during the one-year follow-up period. Conclusion. Cataract surgery was performed in a standard manner in a patient with Presbia Microlens corneal inlay in place. Visual outcomes for both near and distance vision were satisfactory.

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

    Science.gov (United States)

    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.

  8. Intraoperative raster photogrammetry--the PAR Corneal Topography System.

    Science.gov (United States)

    Belin, M W

    1993-01-01

    The PAR Corneal Topography System (CTS) is a computer-driven corneal imaging system that uses close-range raster photogrammetry to measure and produce a topographic map of the corneal surface. The CTS determines distortion in a projected two-dimensional grid. Unlike Placido-disc-based videokeratoscopes, the PAR CTS produces a true topographic map (elevation map) and requires neither a smooth reflective surface nor precise spatial alignment for accurate imaging. Because the system uses two noncoaxial optical paths, it can be integrated into other optical devices. A modified CTS was integrated into an experimental erbium: YAG photoablative laser. The CTS successfully imaged corneas before, after, and during laser photoablation. Its ability to image nonreflective surfaces and to be integrated into other optical systems may make it suitable for intraoperative refractive monitoring.

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

    Science.gov (United States)

    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.

  10. MICRO DIATHERMOCOAGULATION IN THE TREATMENT OF INFECTIOUS CORNEAL ULCERS

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    E. A. Kasparova

    2016-01-01

    Full Text Available Aim. To improve the treatment of early infectious corneal ulcers by combining microdiathermocoagulation (MDC, external autocytokinotherapy, and antiviral and/or antibacterial therapy. patients and methods. The study enrolled 2 groups of outpatients (a total of 112 patients, 112 eyes who either showed no improvement or deteriorated under 7-day to 1.5-month therapeutic treatment. Group I included 70 patients (70 eyes with superficial corneal ulcers due to herpes virus infection under antiviral therapy (instillations and periocular injections of Poludan (PolyA:PoliU as well as Zovirax 3% ophthalmic ointment, group II — 42 patients (42 eyes with early-stage purulent corneal ulcers under instillations of modern antibiotics (current-generation fluoroquinolones. results and discussion. The combination of MDC and external autocytokinotherapy is the most effective treatment for torpid herpetic ulcerative keratitis that allows a reliable reduction in the recovery period: from 24.1±2.2 days (therapeutic treatment only down to 9.2±1.3 days (both methods plus antiviral therapy. Moreover, MDC is the treatment of choice in outpatients with purulent corneal ulcer in its early stage. The healing period in this case can be also reliably reduced (р<0.05 from 18.6±1.9 days (MDC plus antibacterial therapy. Hence, MDC is a highly effective urgent method of treatment available to ambulatory care patients with herpetic keratitis and early-stage purulent corneal ulcers. External autocytokinotherapy shows a pronounced anti-inflammatory and regenerative effect. When applied together, MDC and external autocytokinotherapy act synergistically and provide twice as short treatment periods. MDC as well as its combination with external autocytokinotherapy, if started early, allow to avoid keratoplasty in most patients with herpetic keratitis and early-stage purulent corneal ulcers.

  11. The theory and art of corneal cross-linking

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    Rebecca McQuaid

    2013-01-01

    Full Text Available 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. Traumatic Wound Dehiscence following Corneal Transplantation

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    Mohammad-Reza Jafarinasab

    2012-01-01

    Full Text Available Purpose: To investigate the incidence, mechanisms, characteristics, and visual outcomes of traumatic wound dehiscence following keratoplasty. Methods: Medical records of 32 consecutive patients with traumatic globe rupture following keratoplasty who had been treated at our center from 2001 to 2009 were retrospectively reviewed. Results: The study population consisted of 32 eyes of 32 patients including 25 men and 7 women with history of corneal transplantation who had sustained eye trauma leading to globe rupture. Mean patient age was 38.1 (range, 8 to 87 years and median interval between keratoplasty and the traumatic event was 9 months (range, 30 days to 20 years. Associated anterior segment findings included iris prolapse in 71.9%, lens extrusion in 34.4%, and hyphema in 40.6% of eyes. Posterior segment complications included vitreous prolapse (56%, vitreous hemorrhage (28% and retinal detachment (18%. Eyes which had undergone deep anterior lamellar keratoplasty (DALK; 5 cases, 15.6% tended to have less severe presentation and better final visual acuity. There was no correlation between the time interval from keratoplasty to the traumatic event, and final visual outcomes. Conclusion: The host-graft interface demonstrates decreased stability long after surgery and the visual prognosis of traumatic wound dehiscence is poor in many cases. An intact Descemet′s membrane in DALK may mitigate the severity of ocular injuries, but even in these cases, the visual outcome of globe rupture is not good and prevention of ocular trauma should be emphasized to all patients undergoing any kind of keratoplasty.

  13. Corneal topography matching by iterative registration.

    Science.gov (United States)

    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.

  14. Noninvasive spectroscopic diagnosis of superficial ocular lesions and corneal infections

    Energy Technology Data Exchange (ETDEWEB)

    Mourant, J.R.; Bigio, I.J.; Johnson, T.; Shimada, T. [Los Alamos National Lab., NM (United States); Gritz, D.C.; Storey-Held, K. [Texas Univ. Health Science Center, San Antonio, TX (United States). Dept. of Ophthalmology

    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.

  15. MicroRNA-145 regulates human corneal epithelial differentiation.

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    Sharon Ka-Wai Lee

    Full Text Available BACKGROUND: Epigenetic factors, such as microRNAs, are important regulators in the self-renewal and differentiation of stem cells and progenies. Here we investigated the microRNAs expressed in human limbal-peripheral corneal (LPC epithelia containing corneal epithelial progenitor cells (CEPCs and early transit amplifying cells, and their role in corneal epithelium. METHODOLOGY/PRINCIPAL FINDINGS: Human LPC epithelia was extracted for small RNAs or dissociated for CEPC culture. By Agilent Human microRNA Microarray V2 platform and GeneSpring GX11.0 analysis, we found differential expression of 18 microRNAs against central corneal (CC epithelia, which were devoid of CEPCs. Among them, miR-184 was up-regulated in CC epithelia, similar to reported finding. Cluster miR-143/145 was expressed strongly in LPC but weakly in CC epithelia (P = 0.0004, Mann-Whitney U-test. This was validated by quantitative polymerase chain reaction (qPCR. Locked nucleic acid-based in situ hybridization on corneal rim cryosections showed miR-143/145 presence localized to the parabasal cells of limbal epithelium but negligible in basal and superficial epithelia. With holoclone forming ability, CEPCs transfected with lentiviral plasmid containing mature miR-145 sequence gave rise to defective epithelium in organotypic culture and had increased cytokeratin-3/12 and connexin-43 expressions and decreased ABCG2 and p63 compared with cells transfected with scrambled sequences. Global gene expression was analyzed using Agilent Whole Human Genome Oligo Microarray and GeneSpring GX11.0. With a 5-fold difference compared to cells with scrambled sequences, miR-145 up-regulated 324 genes (containing genes for immune response and down-regulated 277 genes (containing genes for epithelial development and stem cell maintenance. As validated by qPCR and luciferase reporter assay, our results showed miR-145 suppressed integrin β8 (ITGB8 expression in both human corneal epithelial cells

  16. Resolution of persistent corneal erosion after administration of topical rebamipide

    Directory of Open Access Journals (Sweden)

    Kashima T

    2012-08-01

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

  17. Nationwide reduction in the number of corneal transplantations for keratoconus following the implementation of cross-linking

    NARCIS (Netherlands)

    Godefrooij, Daniel A; Gans, Renze; Imhof, Saskia M; Wisse, Robert P L

    2016-01-01

    PURPOSE: Keratoconus is characterized by corneal ectasia and irregular astigmatism, which can lead to diminished vision and corneal scarring. Approximately 10-20% of patients with keratoconus eventually require a corneal transplant. Corneal cross-linking (CXL) is a relatively new treatment that may

  18. The Influence of Central Corneal Thickness and Corneal Curvature and Axial Length on the Measurement of Intraocular Pressure

    Institute of Scientific and Technical Information of China (English)

    Qing Li; Minru Li; Zhigang Fan; Ningli Wang

    2002-01-01

    Purpose: To examine the influence of central corneal thickness (CCT), corneal curvature (CC), and axial length (AL) on intraocular pressure (IOP).Methods: Eighty-one clinically normal eyes were included in our study. The IOP, CCT, CC, AL were measured using a Goldmann applanation tonometer, optical pachymeter, keratometer and A-scan ultrasound biometer respectively in all subjects.Results: A highly significant positive correlation was identified between IOP and CCT. Linear regression analysis suggests that an increase in CCT of 0. 010 mm is associated with a 4. 946 mmHg increment in IOP. No significant positive correlation was identified between IOP and CC. P values are 0. 724 and 0.414 respectively for vertical and horizontal readings. A paradoxically reversed correlation was present between IOP and axial length.Conclusion: Corneal thickness is a very important confounding factor in the measurement of intraocular pressure, which warrants further attention in our clinical practice.

  19. Corneal sensitivity and correlations between decreased sensitivity and anterior segment pathology in ocular leprosy.

    Science.gov (United States)

    Karaçorlu, M A; Cakiner, T; Saylan, T

    1991-02-01

    Leprosy is one of the leading causes of corneal hyposensitivity. In this article the corneal sensitivity of 143 leprosy patients was examined, and correlations between corneal hyposensitivity and anterior segment pathology were detected. Twenty four healthy volunteers were examined as controls. Various degrees of corneal loss of sensitivity were found in 46.2% of leprosy patients. Lagophthalmos, chronic lepromatous granulomatous uveitis, iris atrophy, and social blindness were found 4.5-16.6 times more frequently in eyes which developed severe corneal hyposensitivity.

  20. Analysis of corneal morphologic and pathologic changes in early-stage congenital aniridic keratopathy

    Science.gov (United States)

    Du, Juan; Liu, Rong-Qiang; Ye, Lei; Li, Zhi-Hui; Zhao, Feng-Tu; Jiang, Nan; Ye, Lin-Hong; Shao, Yi

    2017-01-01

    AIM To determine typical corneal changes of congenital aniridic keratopathy (CAK) using corneal topography and confocal systems, and to identify characteristics that might assist in early diagnosis. METHODS Patients with CAK and healthy control subjects underwent detailed ophthalmic examinations including axial length, corneal thickness, tear film condition, corneal topography, and laser-scanning in vivo confocal microscopy (IVCM). RESULTS In early stage aniridic keratopathy, Schirmer I test (SIT), break-up time (BUT), mean keratometry (mean K) and simulated keratometry (sim K) were reduced relative to controls (Pcorneal astigmatism (sim A) and corneal thickness were increased (Pcorneal morphology in borderline situations can be useful to confirm the diagnosis of CAK. PMID:28393028

  1. Corneal astigmatism change and wavefront aberration evaluation after cataract surgery: "Single" versus "paired opposite" clear corneal incisions

    Directory of Open Access Journals (Sweden)

    Hasan Razmjoo

    2014-01-01

    Full Text Available Background: Correcting the pre-existing astigmatism is an optimal goal in cataract surgery. The aim of this study is to compare the astigmatic correcting effect of a single regular 3.2 mm clear corneal incision (CCI with paired opposite CCI in cataract patients and effect of these incisions on optical aberrations using the wavefront quantitative analysis. Materials and Methods: This was a randomized controlled trial study undertaken in an ophthalmology referral center on 50 patients planned for cataract surgery who were randomized to either single 3.2 mm CCI or paired opposite CCI group. Post-operative evaluation was performed at 12 weeks and included refraction, keratometery, corneal topography and wavefront analysis. Corneal astigmatism and post-operative values were compared in two groups. Results: The mean pre-operative corneal astigmatism was 2.58 ± 1.03 D in the single incision group and 2.70 ± 0.94 D in the paired opposite incisions group. After 12 weeks of surgery, the corneal astigmatism was reached to 2.15 ± 0.82 D in single incision group and 1.63 ± 1.21 in the paired opposite incisions group. There was a statistically significant difference in two arms of treatment regarding to surgically induced astigmatism after 3 months. The mean post-operative total and higher order aberrations and values were not significantly different in two groups. Conclusion: The results of our study showed that paired opposite incisions is an effective procedure for reducing pre-existing corneal astigmatism in cataract surgery. Paired incisions did not show any beneficial effect regarding wavefront aberrations compared with conventional single incision method.

  2. Proteomic analysis of the soluble fraction from human corneal fibroblasts with reference to ocular transparency.

    Science.gov (United States)

    Karring, Henrik; Thøgersen, Ida B; Klintworth, Gordon K; Enghild, Jan J; Møller-Pedersen, Torben

    2004-07-01

    The transparent corneal stroma contains a population of corneal fibroblasts termed keratocytes, which are interspersed between the collagen lamellae. Under normal conditions, the keratocytes are quiescent and transparent. However, after corneal injury the keratocytes become activated and transform into backscattering wound-healing fibroblasts resulting in corneal opacification. At present, the most popular hypothesis suggests that particular abundant water-soluble proteins called enzyme-crystallins are involved in maintaining corneal cellular transparency. Specifically, corneal haze development is thought to be related to low levels of cytoplasmic enzyme-crystallins in reflective corneal fibroblasts. To further investigate this hypothesis, we have used a proteomic approach to identify the most abundant water-soluble proteins in serum-cultured human corneal fibroblasts that represent an in vitro model of the reflective wound-healing keratocyte phenotype. Densitometry of one-dimensional gels revealed that no single protein isoform exceeded 5% of the total water-soluble protein fraction, which is the qualifying property of a corneal enzyme-crystallin according to the current definition. This result indicates that wound-healing corneal fibroblasts do not contain enzyme-crystallins. A total of 254 protein identifications from two-dimensional gels were performed representing 118 distinct proteins. Proteins protecting against oxidative stress and protein misfolding were prominent, suggesting that these processes may participate in the generation of cytoplasmic light-scattering from corneal fibroblasts.

  3. Hypocellular scar formation or aberrant fibrosis induced by an intrastromal corneal ring: a case report

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    Ramkumar Hema L

    2011-08-01

    Full Text Available Abstract Introduction Intrastromal corneal rings or segments are approved for the treatment of myopia and astigmatism associated with keratoconus. We describe a clinicopathological case of intrastromal corneal rings. For the first time, the molecular pathological findings of intrastromal corneal rings in the cornea are illustrated. Case presentation A 47-year-old African-American man with a history of keratoconus and failure in using a Rigid Gas Permeable contact lens received an intrastromal corneal ring implant in his left eye. Due to complications, penetrating keratoplasty was performed. The intrastromal corneal ring channels were surrounded by a dense acellular (channel haze and/or hypocellular (acidophilic densification collagen scar and slightly edematous keratocytes. Mild macrophage infiltration was found near the inner aspect of the intrastromal corneal rings. Molecular analyses of the microdissected cells surrounding the intrastromal corneal ring channels and central corneal stroma revealed 10 times lower relative expression of IP-10/CXCL10 mRNA and two times higher CCL5 mRNA in the cells surrounding the intrastromal corneal ring, as compared to the central corneal stroma. IP-10/CXCL10 is a fibrotic and angiostatic chemokine produced by macrophages, endothelial cells and fibroblasts. Conclusion An intrastromal corneal ring implant can induce hypocellular scar formation and mild inflammation, which may result from aberrant release of fibrosis-related chemokines.

  4. Corneal biomechanical properties after femtosecond laser assisted LASIK with the corneal visualization Scheimpflug technology and ocular response analyzer

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    Jing Li

    2017-02-01

    Full Text Available AIM: To investigate the changes of corneal biomechanical properties before and after femtosecond laser assisted LASIK(FS-LASIKusing Corneal Visualisation Scheimpflug Technology(Corvis STand Ocular Response Analyzer(ORA, and the correlation with other myopic parameters. METHODS:Sixty three patients(63 eyeswho had myopic femtosecond laser assisted LASIK(FS-LASIKwere enrolled in the study. The right eye of each patient was analyzed in this study. The corneal biomechanical parameters pre-operative and 1mo post-operative was measured with the Corvis ST(Oculus, Wetzlar, Germanyand ORA(Reichert, Buffalo, New York, USA. Comparison of the biomechanical property values before and after surgery was peformed using Paired t-test or Mann-Whitney U. Pearson or Spearman correlations were used to evaluate the relationship between parameters.RESULTS: The postoperative 1st A-time, Vin, 2nd A length, Vout, HC time and Radius demonstrate significant decreases comparing with preoperative values(P=0.00, P=0.00, P=0.00, P=0.00, P=0.00, P=0.00 respectively. The postoperative 2nd A-time, DA and PD significantly increases(P=0.00, P=0.00, P=0.00, however, the 1st A length had no significant difference after surgery. The CH and CRF were significantly lower after FS-LASIK(P=0.00, P=0.00. A statistically significant correlation coefficient was found between preoperative central corneal thickness(CCTwith postoperative-preoperative changes of 1st A-time, 2nd A-time, DA and Radius respectively(P=0.01, P=0.04, P=0.03, P=0.01. CONCLUSION:There were significantly changes of corneal biomechanical properties after FS-LASIK surgery. The changes of corneal biomechanical properties after FS-LASIK can be reflected by some parameters of Corvis ST and ORA. The mainly influence of corneal biomechanical alteration was possibly correlation with corneal thickness.

  5. Tolerancia al daño inducido bajo solicitaciones de contacto cíclicas en carburos cementados WC-Co//Tolerance induced damage under cyclic contact loading of WC-Co cemented carbides

    OpenAIRE

    2014-01-01

    El comportamiento mecánico de los carburos cementados WC-Co ha sido estudiado en detalle teniendo en cuenta los defectos preexistentes del material (daño intrínseco). Sin embargo, la información sobre los efectos del daño inducido en servicio (daño extrínseco) en la integridad estructural de estos materiales esescasa. En este contexto, en este trabajo se evalúa la influencia del daño extrínseco en la resistencia mecánica residual de dos calidades con microestructuras diferentes. Para ello, se...

  6. Analysis of human transforming growth factor β-induced gene mutation in corneal dystrophy

    Institute of Scientific and Technical Information of China (English)

    李杨; 孙旭光; 任慧媛; 董冰; 王智群; 孙秀英

    2004-01-01

    Background Corneal dystrophy is a group of inherited blinding diseases of the cornea. This study was to identify the mutations of the keratoepithelin (KE) gene for proper diagnosis of corneal dystrophy. Methods Three families with corneal dystrophy were analysed. Thirteen individuals at risk for corneal dystrophy in family A, the proband and her son in family B, and the proband in family C were examined after their blood samples were obtained. Mutation screening of human transforming growth factor β-induced gene (BIGH3 gene) was performed. Results Five individuals in family A were found by clinical evaluation to be affected with granular corneal dystrophy and carried the BIGH3 mutation W555R. However, both probands in families B and C, also diagnosed with granular corneal dystrophy, harboured the BIGH3 mutation R124H. Conclusion Molecular genetic analysis can improve accurate diagnosis of corneal dystrophy.

  7. Corneal Viscoelastic Properties from Finite-Element Analysis of In Vivo Air-Puff Deformation

    Science.gov (United States)

    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

  8. Nivel de corte de los ELISAs para cuantificación de anticuerpos inducidos por la vacuna antimeningocócica VA-MENGOC-BC

    Directory of Open Access Journals (Sweden)

    Rolando Ochoa

    2001-06-01

    Full Text Available Para medir el grado de protección inducido por vacunas antimeningocócicas se ha establecido el Ensayo Bactericida en Suero (EBS y se perfeccionan otros ensayos inmunobiológicos, sin embargo, es necesario contar con pruebas sencillas como el ELISA, capaz de evaluar un gran número de muestras. Se estimó el nivel de corte de los ELISAs para la cuantificación de IgG humana contra los antígenos de VA-MENGOC-BC, vacuna antimeningocócica compuesta por vesículas proteicas de membrana externa de meningococo B y polisacárido capsular de meningococo C, con respecto a un panel de muestras de suero de lactantes, caracterizado por Ensayo Bactericida en Sangre Total (EBST. Los valores correspondientes a la máxima sensibilidad y especificidad fueron respectivamente; 2 μg/mL y 12 μg/mL para antipolisacárido C, y 1000 U/mL y 7000 U/mL para antiproteínas de membrana externa. La mayor coincidencia se obtuvo con 6 μg/mL y 2500 U/mL. Se evaluó otro panel de muestras de suero de adolescentes entre 14 y 18 años, por ELISA y EBS para Neisseria meningitidis serogrupos B y C, alcanzándose una buena concordancia. Doce años después de la inmunización con VA-MENGOC-BC persiste una importante concentración de anticuerpos contra los antígenos vacunales en los sueros estudiados.

  9. A comparison between keratoconus and normal population based corneal endothelium

    Directory of Open Access Journals (Sweden)

    Mohamad Aghazade Amiri

    2015-07-01

    Conclusion: Keratoconus does not have any considerable effect on cell density, polymegethism and pleomorphism, in mild and moderate stages and corneal opacity risk caused by intraocular surgeries (such as: Cataract or Glaucoma surgeries and some diseases (such as diabetes and uveitis is similar in keratoconic and normal eyes.

  10. Gene Therapy and Gene Editing for the Corneal Dystrophies.

    Science.gov (United States)

    Williams, Keryn A; Irani, Yazad D

    2016-01-01

    Despite ever-increasing understanding of the genetic underpinnings of many corneal dystrophies, gene therapy designed to ameliorate disease has not yet been reported in any human patient. In this review, we explore the likely reasons for this apparent failure of translation. We identify the requirements for success: the genetic defect involved must have been identified and mapped, vision in the affected patient must be significantly impaired or likely to be impaired, no better or equivalently effective treatment must be available, the treatment must be capable of modulating corneal pathology, and delivery of the construct to the appropriate cell must be practicable. We consider which of the corneal dystrophies might be amenable to treatment by genetic manipulations, summarize existing therapeutic options for treatment, and explore gene editing using clustered regularly interspaced short palindromic repeat/Cas and other similar transformative technologies as the way of the future. We then summarize recent laboratory-based advances in gene delivery and the development of in vitro and in vivo models of the corneal dystrophies. Finally, we review recent experimental work that has increased our knowledge of the pathobiology of these conditions.

  11. Scleral lens tolerance after corneal cross-linking for keratoconus

    NARCIS (Netherlands)

    Visser, Esther Simone; Soeters, Nienke; Tahzib, Nayyirih G.

    2015-01-01

    Purpose. Subjective and objective evaluation of scleral lens tolerance and fitting before and after corneal cross-linking (CXL) for progressive keratoconus. Methods. In this prospective cohort, evaluations were made of 18 unilateral eyes in patients who underwent CXL and had been wearing scleral len

  12. Nerve regeneration by human corneal stromal keratocytes and stromal fibroblasts

    Science.gov (United States)

    Yam, Gary Hin-Fai; Williams, Geraint P.; Setiawan, Melina; Yusoff, Nur Zahirah Binte M.; Lee, Xiao-wen; Htoon, Hla Myint; Zhou, Lei; Fuest, Matthias; Mehta, Jodhbir S.

    2017-01-01

    Laser refractive surgeries reshape corneal stroma to correct refractive errors, but unavoidably affect corneal nerves. Slow nerve regeneration and atypical neurite morphology cause desensitization and neuro-epitheliopathy. Following injury, surviving corneal stromal keratocytes (CSKs) are activated to stromal fibroblasts (SFs). How these two different cell types influence nerve regeneration is elusive. Our study evaluated the neuro-regulatory effects of human SFs versus CSKs derived from the same corneal stroma using an in vitro chick dorsal root ganglion model. The neurite growth was assessed by a validated concentric circle intersection count method. Serum-free conditioned media (CM) from SFs promoted neurite growth dose-dependently, compared to that from CSKs. We detected neurotrophic and pro-inflammatory factors (interleukin-8, interleukin-15, monocyte chemoattractant protein-1, eotaxin, RANTES) in SFCM by Bio-Plex Human Cytokine assay. More than 130 proteins in SFCM and 49 in CSKCM were identified by nanoLC-MS/MS. Proteins uniquely present in SFCM had reported neuro-regulatory activities and were predicted to regulate neurogenesis, focal adhesion and wound healing. Conclusively, this was the first study showing a physiological relationship between nerve growth and the metabolically active SFs versus quiescent CSKs from the same cornea source. The dose-dependent effect on neurite growth indicated that nerve regeneration could be influenced by SF density. PMID:28349952

  13. Conjunctival-corneal melt in association with carotid artery stenosis

    Directory of Open Access Journals (Sweden)

    Rosalind MK Stewart

    2008-10-01

    Full Text Available Rosalind MK Stewart1, Say Aun Quah1, Dan Q Nguyen2, Stephen B Kaye11Royal Liverpool University Hospital, Liverpool, UK; 2Bristol Eye Hospital, Bristol, UKPurpose: To report a case of severe conjunctival-corneal melt in association with carotid artery stenosis.Methods: Observational case report.Results: A 76-year-old man with a history of bilateral severe carotid artery occlusion and nonarteritic ischemic optic neuropathy developed a spontaneous bulbar conjunctival defect. Despite intensive lubrication, and attempts at surgical closure including an amniotic membrane patch graft, it progressed with subsequent adjacent corneal perforation. Thorough investigations revealed no underlying disease, except markedly delayed episcleral vessel filling on anterior segment fluorescein angiography.Conclusions: Neovascularisation is a known factor in the inhibition of ulceration. In light of the findings in this report, ocular ischemia should be considered as a cause or contributing factor in the differential diagnosis of conjunctival-corneal melt.Keywords: conjunctival melt, corneal melt, ocular ischemia, carotid artery stenosis

  14. Intrastromal corneal ring segments for management of keratoconus

    Directory of Open Access Journals (Sweden)

    Sri Ganesh

    2013-01-01

    Full Text Available Keratoconus is a progressive corneal ectasia, which can be managed both by conservative measures like glasses or contact lenses in non-progressive cases or surgical procedures like collagen crosslinking (CXL with or without adjuvant measures like intrastromal corneal rings segments (ICRS or topography guided ablation. Various kinds of ICRS are available to the surgeon, but it is most essential to be able to plan the implantation of the ring to optimize outcomes. Aims: The aim of this study is to evaluate the visual outcome and progression in patients of keratoconus implanted with ICRS. Materials and Methods: Two different types of ICRS-Intacs (Addition Technology and Kerarings (Mediphacos Inc. were implanted in 2 different cohorts of patients and were followed-up to evaluate the outcome of the procedure. All patients underwent a complete ocular examination including best spectacle corrected visual acuity, slit lamp examination fundus examination, corneal topography and pachymetry. The ICRS implantation is done with CXL to stop the progression of the disease. Improvement in uncorrected visual acuity (UCVA, best spectacle corrected visual acuity and topographic changes were analyzed. Results: A significant improvement in keratometry and vision was seen in both groups. Conclusion: ICRS have been found to reduce corneal irregularity and flatten keratometry with improvement in UCVA and best corrected visual acuity.

  15. Rapid, automated mosaicking of the human corneal subbasal nerve plexus.

    Science.gov (United States)

    Vaishnav, Yash J; Rucker, Stuart A; Saharia, Keshav; McNamara, Nancy A

    2017-03-04

    Corneal confocal microscopy (CCM) is an in vivo technique used to study corneal nerve morphology. The largest proportion of nerves innervating the cornea lie within the subbasal nerve plexus, where their morphology is altered by refractive surgery, diabetes and dry eye. The main limitations to clinical use of CCM as a diagnostic tool are the small field of view of CCM images and the lengthy time needed to quantify nerves in collected images. Here, we present a novel, rapid, fully automated technique to mosaic individual CCM images into wide-field maps of corneal nerves. We implemented an OpenCV image stitcher that accounts for corneal deformation and uses feature detection to stitch CCM images into a montage. The method takes 3-5 min to process and stitch 40-100 frames on an Amazon EC2 Micro instance. The speed, automation and ease of use conferred by this technique is the first step toward point of care evaluation of wide-field subbasal plexus (SBP) maps in a clinical setting.

  16. Cartographic system for spatial distribution analysis of corneal endothelial cells.

    Science.gov (United States)

    Corkidi, G; Márquez, J; García-Ruiz, M; Díaz-Cintra, S; Graue, E

    1994-07-01

    A combined cartographic and morphometric endothelium analyser has been developed by integrating the HISTO 2000 histological imaging and analysis system with a prototype human corneal endothelium analyser. The complete system allows the elaboration and analysis of cartographies of corneal endothelial tissue, and hence the in vitro study of the spatial distribution of corneal endothelial cells, according to their regional morphometric characteristics (cell size and polygonality). The global cartographic reconstruction is obtained by sequential integration of the data analysed for each microscopic field. Subsequently, the location of each microscopically analysed field is referred to its real position on the histologic preparation by means of X-Y co-ordinates; both are provided by micrometric optoelectronic sensors installed on the optical microscope stage. Some cartographies of an excised human corneal keratoconus button in vitro are also presented. These cartographic images allow a macroscopic view of endothelial cells analysed microscopically. Parametric colour images show the spatial distribution of endothelial cells, according to their specific morphometric parameters, and exhibit the variability in size and cellular shape which depend on the analysed area.

  17. Electrothermal technique for the alteration of corneal curvature

    Energy Technology Data Exchange (ETDEWEB)

    Doss, J.D.; Hutson, R.L.; Albillar, J.I.

    1978-02-01

    Extreme cases of refractive error, such as those caused by keratoconus, are often not correctable by the addition of external refraction. In such cases, corneal transplant is the usual remedy. Alternatives have recently included modification of the corneal shape by thermal techniques which exploit the dramatic shrinkage of corneal collagen at temperatures of 55 to 63/sup 0/C. The use of conventional thermal techniques has been limited by damage to the epithelium and Bowman's membrane, and by the observation that the change in corneal shape is often temporary. Each of these problems appears to be related to the thermal dose profile that is generated by the conductive heating method; temperature is relatively high in the epithelium, but is below the critical shrinkage temperature in the deeper stromal collagen. A wide variability in treatment results has also been reported; this may be due to unintentional variation in technique, especially in timing the treatment. An alternative heating technique will be discussed that has a more desirable thermal dose distribution. In addition, the technique allows precise electronic control of treatment duration, and other parameters that affect thermal dose to the cornea.

  18. Isolation of Kingella kingae from a corneal ulcer.

    OpenAIRE

    Mollee, T; Kelly, P; Tilse, M.

    1992-01-01

    Kingella kingae was isolated from a corneal ulcer in an 11-month-old male. This organism has been previously reported from normally sterile sites, including sites of endophthalmitis, but this is the first time isolation from the cornea has been reported.

  19. Treatment of Corneal Neovascularization Using Anti-VEGF Bevacizumab

    Directory of Open Access Journals (Sweden)

    Deli Krizova

    2014-01-01

    Full Text Available Purpose. To evaluate antiangiogenic effect of local use of bevacizumab (anti-VEGF antibody in patients with corneal neovascularization. Methods. Patients were divided into two groups. All patients suffered from some form of corneal neovascularization (NV. Patients in group A received 0.2–0.5 mL of bevacizumab solution subconjunctivally (concentration 25 mg/mL in a single dose. Group A included 28 eyes from 27. Patients in group B applied bevacizumab eye drops twice daily (concentration 2.5 mg/mL for two weeks. Group B included 38 eyes from 35 patients. We evaluated the number of corneal segments affected by NV, CDVA, and the incidence of complications and subjective complaints related to the treatment. The minimum follow-up period was six months. Results. By the 6-month follow-up, in group A the percentage reduction of the affected peripheral segments was 21.6% and of the central segments was 9.6%; in group B the percentage reduction of the central segments was 22.7% and of the central segments was 38.04%. In both groups we noticed a statistically significant reduction in the extent of NV. Conclusion. The use of bevacizumab seems to be an effective and safe method in the treatment of corneal neovascularization, either in the subconjunctival or topical application form.

  20. Describing the Corneal Shape after Wavefront-Optimized Photorefractive Keratectomy

    NARCIS (Netherlands)

    de Jong, Tim; Wijdh, Robert H. J.; Koopmans, Steven A.; Jansonius, Nomdo M.

    2014-01-01

    PURPOSE: To develop a procedure for describing wavefront-optimized photorefractive keratectomy (PRK) corneas and to characterize PRK-induced changes in shape. METHODS: We analyzed preoperative and postoperative corneal elevation data of 41 eyes of 41 patients (mean [±SD] age, 38 [±11] years) who und

  1. Corneal topography: Image processing and numerical analysis of keratoscopy

    DEFF Research Database (Denmark)

    Andersen, J.; Koch-Jensen, P.; Østerby, Ole

    1993-01-01

    . The average difference between observed and expected values was 0.2% and the average coefficient of variation was 0.1%. The standard deviations on observed ring means decreased inversely with ring number with an average coefficient of variation of 0.2%. Likewise, on a corneal surface SD also decreased...

  2. Corneal manifestations of selected systemic diseases: A review

    Directory of Open Access Journals (Sweden)

    Wayne D.H. Gillan

    2015-03-01

    Full Text Available The corneal manifestations of several selected systemic diseases are reviewed. Metabolic, immunologic and inflammatory and infectious diseases are included. A brief overview of each disease and how it manifests in the cornea is discussed. The importance of conducting a slit-lamp examination on every patient is emphasised.

  3. Proteins of the corneal stroma: importance in visual function.

    Science.gov (United States)

    Xuan, Meng; Wang, Shurong; Liu, Xin; He, Yuxi; Li, Ying; Zhang, Yan

    2016-04-01

    The human cornea, consisting of five layers, is the transparent tissue that refracts and transmits light to the lens and retina, providing about two thirds of the refractive power of the eye. The stroma layer comprises nearly 90 % of the thickness of the cornea and thus plays a pivotal role in normal visual function. The bulk of this layer is constituted by proteins in the extracellular martrix secreted by the corneal epithelial, stroma, and endothelial cells. Clinical research has shown that corneal stroma diseases are common and involve conditions such as infections, injuries, and genetic defects, which cause severe visual disturbances or even blindness. To improve our understanding of the basic molecular mechanisms involved in the physiological and pathological activities of the corneal stroma, its proteins have been brought into the limelight to determine their crucial and irreplaceable roles. The data presented in a previous study have demonstrated the presence of 1679 proteins in the stroma, and this data set has subsequently been perfected by utilizing a highly sensitive isobaric peptide-labeling approach. According to their manifestations, these proteins can be classified as a gel-like organic material composed of proteoglycans, enzymes, and hemocyanin-binding proteins and a network of filaments composed of collagen, elastin, keratin, vimentin, and interconnected filaments comprising fibronectin and laminin. The aim of this review is to describe some corneal stroma proteins by highlighting their major functions and valuable applications in ophthalmologic research toward the better characterization and treatment of eye diseases.

  4. A circum-corneal conjunctival nevus in a child

    DEFF Research Database (Denmark)

    Svahn, T.F.; Heegaard, Steffen; Prause, Jan Ulrik;

    2012-01-01

    An amelanotic, circum-corneal nevus in a 2-year-old child is described. The nevus presented at birth as a red spot in the nasal conjunctiva that subsequently enlarged to completely encircle the cornea. The tumour was partially removed three times, but at the age of 6 years, the nevus still covers...

  5. In Vivo Confocal Microscopy expanding horizons in corneal imaging

    NARCIS (Netherlands)

    T. Hillenaar (Toine)

    2012-01-01

    textabstractConfocal microscopy is an emerging optical technique that allows the living human cornea to be imaged on a cellular level. As such, confocal microscopy enables morphologic and quantitative analysis of corneal resident cells in health and disease and provides an exciting bridge between in

  6. Molecular mechanism of fluoroquinolones modulation on corneal fibroblast motility.

    Science.gov (United States)

    Chen, Tsan-Chi; Tsai, Tzu-Yun; Chang, Shu-Wen

    2016-04-01

    Topical fluoroquinolones are widely used to prevent ocular infections after ophthalmic surgery. However, they have been shown to affect the corneal cell motility, whose mechanism remains indefinite. The purpose of this study was to investigate how fluoroquinolones affect corneal stromal cell motility. Human corneal fibroblasts (HCFs) were incubated in ciprofloxacin (CIP), levofloxacin (LEV), or moxifloxacin (MOX) at 0, 10, 50, and 100 μg/ml for up to 3 days. Effect of CIP, LEV, or MOX on HCF migration was monitored using migration assay. HCF viability was determined by WST-1 assay. Expression of focal adhesion kinase (FAK), paxillin (PXN), and their phosphorylated forms were analyzed by immunoblotting. Binding affinity between FAK and PXN was determined by co-immunoprecipitation. Our results revealed that CIP and MOX, but not LEV, noticeably retarded HCF migration. HCF proliferation was significantly reduced by CIP (38.2%), LEV (29.5%), and MOX (21.3%), respectively (p = 0.002). CIP and MOX suppressed the phosphorylation of PXN at tyrosines (10.2 ± 4.3%, p MOX diminished the binding affinity between FAK and PXN (8.2 ± 1.8%, p MOX, but not LEV, might delay corneal fibroblast migration via interfering with recruitment of PXN to focal adhesions and dephosphorylation of PXN at the tyrosines.

  7. Advanced Corneal Cross-Linking System with Fluorescence Dosimetry

    Directory of Open Access Journals (Sweden)

    Marc D. Friedman

    2012-01-01

    Full Text Available Purpose. This paper describes an advanced system that combines corneal cross-linking with riboflavin with fluorescence dosimetry, the ability to measure riboflavin diffusion within the cornea both before and during UVA treatment. Methods and Results. A corneal cross-linking system utilizing a digital micromirror device (DMD was assembled and used to measure diffusion coefficients of 0.1% riboflavin in 20% dextran in porcine eyes. A value of (3.3±0.2×10−7 cm2/s was obtained for the stroma. Diffusion coefficients for the transepithelial formulation of 0.1% riboflavin in 0.44% saline and 0.02% BAK were also measured to be 4.7±0.3×10−8 cm2/s for epithelium only and (4.6±0.4×10−7 cm2/s for stroma only. Riboflavin consumption during a UVA treatment was also demonstrated. Conclusion. A new advanced corneal cross-linking system with fluorescence dosimetry of riboflavin has been demonstrated. It is hoped that this method may play a significant role in determining the underlying mechanisms of corneal cross-linking and assist with the development of additional riboflavin formulations. Moreover, dosimetry may prove valuable in providing a method to account for the biological differences between individuals, potentially informing cornea-specific UVA treatment doses in real time.

  8. Vignetting and Field of View with the KAMRA Corneal Inlay

    Directory of Open Access Journals (Sweden)

    Achim Langenbucher

    2013-01-01

    Full Text Available Purpose. To evaluate the effect of the KAMRA corneal inlay on the retinal image brightness in the peripheral visual field. Methods. A KAMRA inlay was “implanted” into a theoretical eye model in a corneal depth of 200 microns. Corneal radius was varied to a steep, normal, and flat (7.37, 7.77, and 8.17 mm version keeping the proportion of anterior to posterior radius constant. Pupil size was varied from 2.0 to 5.0 mm. Image brightness was determined for field angles from −70° to 70° with and without KAMRA and proportion of light attenuation was recorded. Results. In our parameter space, the attenuation in brightness ranges in between 0 and 60%. The attenuation in brightness is not affected by corneal shape. For large field angles where the incident ray bundle is passing through the peripheral cornea, brightness is not affected. For combinations of small pupil sizes (2.0 and 2.5 mm and field angles of 20–40°, up to 60% of light may be blocked with the KAMRA. Conclusion. For combinations of pupil sizes and field angles, the attenuation of image brightness reaches levels up to 60%. Our theoretical findings have to be clinically validated with detailed investigation of this vignetting effect.

  9. Collagens and proteoglycans of the corneal extracellular matrix

    Directory of Open Access Journals (Sweden)

    Y.M. Michelacci

    2003-08-01

    Full Text Available The cornea is a curved and transparent structure that provides the initial focusing of a light image into the eye. It consists of a central stroma that constitutes 90% of the corneal depth, covered anteriorly with epithelium and posteriorly with endothelium. Its transparency is the result of the regular spacing of collagen fibers with remarkably uniform diameter and interfibrillar space. Corneal collagen is composed of heterotypic fibrils consisting of type I and type V collagen molecules. The cornea also contains unusually high amounts of type VI collagen, which form microfibrillar structures, FACIT collagens (XII and XIV, and other nonfibrillar collagens (XIII and XVIII. FACIT collagens and other molecules, such as leucine-rich repeat proteoglycans, play important roles in modifying the structure and function of collagen fibrils.Proteoglycans are macromolecules composed of a protein core with covalently linked glycosaminoglycan side chains. Four leucine-rich repeat proteoglycans are present in the extracellular matrix of corneal stroma: decorin, lumican, mimecan and keratocan. The first is a dermatan sulfate proteoglycan, and the other three are keratan sulfate proteoglycans. Experimental evidence indicates that the keratan sulfate proteoglycans are involved in the regulation of collagen fibril diameter, and dermatan sulfate proteoglycan participates in the control of interfibrillar spacing and in the lamellar adhesion properties of corneal collagens. Heparan sulfate proteoglycans are minor components of the cornea, and are synthesized mainly by epithelial cells. The effect of injuries on proteoglycan synthesis is discussed.

  10. AUTOMATED VIDEO IMAGE MORPHOMETRY OF THE CORNEAL ENDOTHELIUM

    NARCIS (Netherlands)

    SIERTSEMA, JV; LANDESZ, M; VANDENBROM, H; VANRIJ, G

    1993-01-01

    The central corneal endothelium of 13 eyes in 13 subjects was visualized with a non-contact specular microscope. This report describes the computer-assisted morphometric analysis of enhanced digitized images, using a direct input by means of a frame grabber. The output consisted of mean cell area, c

  11. Caveolin-1 associated adenovirus entry into human corneal cells.

    Directory of Open Access Journals (Sweden)

    Mohammad A Yousuf

    Full Text Available The cellular entry of viruses represents a critical area of study, not only for viral tropism, but also because viral entry dictates the nature of the immune response elicited upon infection. Epidemic keratoconjunctivitis (EKC, caused by viruses within human adenovirus species D (HAdV-D, is a severe, ocular surface infection associated with corneal inflammation. Clathrin-mediated endocytosis has previously been shown to play a critical role in entry of other HAdV species into many host cell types. However, HAdV-D endocytosis into corneal cells has not been extensively studied. Herein, we show an essential role for cholesterol rich, lipid raft microdomains and caveolin-1, in the entry of HAdV-D37 into primary human corneal fibroblasts. Cholesterol depletion using methyl-β-cyclodextrin (MβCD profoundly reduced viral infection. When replenished with soluble cholesterol, the effect of MβCD was reversed, allowing productive viral infection. HAdV-D37 DNA was identified in caveolin-1 rich endosomal fractions after infection. Src kinase activity was also increased in caveolin-1 rich endosomal fractions after infection, and Src phosphorylation and CXCL1 induction were both decreased in caveolin-1-/- mice corneas compared to wild type mice. siRNA knock down of caveolin-1 in corneal cells reduced chemokine induction upon viral infection, and caveolin-1-/- mouse corneas showed reduced cellular entry of HAdV-D37. As a control, HAdV-C2, a non-corneal pathogen, appeared to utilize the caveolar pathway for entry into A549 cells, but failed to infect corneal cells entirely, indicating virus and cell specific tropism. Immuno-electron microscopy confirmed the presence of caveolin-1 in HAdV-D37-containing vesicles during the earliest stages of viral entry. Collectively, these experiments indicate for the first time that HAdV-D37 uses a lipid raft mediated caveolin-1 associated pathway for entry into corneal cells, and connects the processes of viral entry with

  12. Corneal collagen crosslinking in keratoconus and other eye disease

    Institute of Scientific and Technical Information of China (English)

    Adel; Alhayek; Pei-Rong; Lu

    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 about1 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.

  13. Measuring Corneal Haze by Using Scheimpflug Photography and Confocal Microscopy

    Science.gov (United States)

    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

  14. Comparison of the Keratometric Corneal Astigmatic Power after Phacoemulsification: Clear Temporal Corneal Incision versus Superior Scleral Tunnel Incision

    Directory of Open Access Journals (Sweden)

    Yongqi He

    2009-01-01

    Full Text Available Objective. This is prospective randomized control trial to compare the mean keratometric corneal astigmatism diopter power (not surgical induced astigmatism among preop and one-month and three-month postop phacoemulcification of either a clear temporal corneal incision or a superior scleral tunnel Incision, using only keratometric astigmatic power reading to evaluate the difference between the two cataract surgery incisions. Methods. 120 patients (134 eyes underwent phacoemulcification were randomly assigned to two groups: Group A, the clear temporal corneal incision group, and Group B, the superior scleral tunnel incision group. SPSS11.5 Software was used for statistical analysis to compare the postsurgical changes of cornea astigmatism on keratometry. Results. The changes of corneal astigmatic diopter in Groups A and B after 3 month postop from keratometric reading were 1.04 + 0.76 and 0.94 + 0.27, respectively (=.84>.05, which showed no statistic significance difference. Conclusion. The incision through either temporal clear cornea or superior scleral tunnel in phacoemulcification shows no statistic difference in astigmatism change on keratometry 3-month postop.

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

    Science.gov (United States)

    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 ptransplants, 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. Hyaluronate Acid-Dependent Protection and Enhanced Corneal Wound Healing against Oxidative Damage in Corneal Epithelial Cells.

    Science.gov (United States)

    Zhong, Jing; Deng, Yuqing; Tian, Bishan; Wang, Bowen; Sun, Yifang; Huang, Haixiang; Chen, Ling; Ling, Shiqi; Yuan, Jin

    2016-01-01

    Purpose. To evaluate the effects and mechanism of exogenous hyaluronate (HA) in promoting corneal wound healing. Methods. Human corneal epithelial cells (HCECs) were incubated with different concentrations of HA to evaluate their efficiency in promoting cell migration and their modulation of repair factors. After inducing hyperosmolar conditions, the cell morphologies, cell apoptosis, and expression levels of TNF-α and MMP-9 were detected to assess the protective role of HA. Corneal epithelium-injured rat models were established to test the therapeutic effects of 0.3% HA. Then, the wound healing rates, the RNA expression levels of inflammatory cytokines, and repair factors were examined. Results. HCECs in the 0.03% and 0.3% HA groups showed fewer morphological alterations and lower rates of cell apoptosis following preincubation with HA under hyperosmolar conditions, as well as the expression levels of MMP-9 and TNF-α. In the rat model, the areas of fluorescein staining in the corneas of 0.3% HA group were significantly smaller than the control group. The expression levels of IL-1β and MMP-9 were decreased, while CD44 and FN were increased in the 0.3% HA group. Conclusion. HA enhanced corneal epithelial cell wound healing by promoting cell migration, upregulating repair responses, and suppressing inflammatory responses.

  17. Hyaluronate Acid-Dependent Protection and Enhanced Corneal Wound Healing against Oxidative Damage in Corneal Epithelial Cells

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    Jing Zhong

    2016-01-01

    Full Text Available Purpose. To evaluate the effects and mechanism of exogenous hyaluronate (HA in promoting corneal wound healing. Methods. Human corneal epithelial cells (HCECs were incubated with different concentrations of HA to evaluate their efficiency in promoting cell migration and their modulation of repair factors. After inducing hyperosmolar conditions, the cell morphologies, cell apoptosis, and expression levels of TNF-α and MMP-9 were detected to assess the protective role of HA. Corneal epithelium-injured rat models were established to test the therapeutic effects of 0.3% HA. Then, the wound healing rates, the RNA expression levels of inflammatory cytokines, and repair factors were examined. Results. HCECs in the 0.03% and 0.3% HA groups showed fewer morphological alterations and lower rates of cell apoptosis following preincubation with HA under hyperosmolar conditions, as well as the expression levels of MMP-9 and TNF-α. In the rat model, the areas of fluorescein staining in the corneas of 0.3% HA group were significantly smaller than the control group. The expression levels of IL-1β and MMP-9 were decreased, while CD44 and FN were increased in the 0.3% HA group. Conclusion. HA enhanced corneal epithelial cell wound healing by promoting cell migration, upregulating repair responses, and suppressing inflammatory responses.

  18. Il fenomeno della "goccia nera" e l'astigmatismo

    Science.gov (United States)

    Horn D'Arturo, Guido

    2004-03-01

    The Venus transit on the Solar disc was for the first time observed in 1639, using "modern" instruments, by Gassendi. Yet since the following transit, an effect was perceived which modified Venus and Sun profiles at the moments of the first and second visual contact between the two celestial bodies. This effect was called "gutta nigra", i.e. black drop. Horn d'Arturo was widely interested in studies on the vision and on its effects on astronomical observations. In the following paper, he suggested what probably was the first correct explanation of the black drop effect. As stated on the Dictionary of Scientific Biography (ad vocem), Horn "clarified the effect on vision, especially in the astigmatic eye, of the suture of the eye lens and the formation of the so-called black drop".

  19. Corneal biomechanical data and biometric parameters measured with Scheimpflug-based devices on normal corneas

    Science.gov (United States)

    Nemeth, Gabor; Szalai, Eszter; Hassan, Ziad; Lipecz, Agnes; Flasko, Zsuzsa; Modis, Laszlo

    2017-01-01

    AIM To analyze the correlations between ocular biomechanical and biometric data of the eye, measured by Scheimpflug-based devices on healthy subjects. METHODS Three consecutive measurements were carried out using the corneal visualization Scheimpflug technology (CorVis ST) device on healthy eyes and the 10 device-specific parameters were recorded. Pentacam HR-derived parameters (corneal curvature radii on the anterior and posterior surfaces; apical pachymetry; corneal volume; corneal aberration data; depth, volume and angle of the anterior chamber) and axial length (AL) from IOLMaster were correlated with the 10 specific CorVis ST parameters. RESULTS Measurements were conducted in 43 eyes of 43 volunteers (age 61.24±15.72y). The 10 specific CorVis ST data showed significant relationships with corneal curvature radii both on the anterior and posterior surface, pachymetric data, root mean square (RMS) data of lower-order aberrations, and posterior RMS of higher-order aberrations and spherical aberration of the posterior cornea. Anterior chamber depth showed a significant relationship, but there were no significant correlations between corneal volume, anterior chamber volume, mean chamber angle or AL and the 10 specific CorVis ST parameters. CONCLUSIONS CorVis ST-generated parameters are influenced by corneal curvature radii, some corneal RMS data, but corneal volume, anterior chamber volume, chamber angle and AL have no correlation with the biomechanical parameters. The parameters measured by CorVis ST seem to refer mostly to corneal properties of the eye. PMID:28251079

  20. Estudio crítico de un nuevo dilema en el sistema jurídico mexicano. La regulación del aborto inducido: ¿Derecho del nasciturus a nacer o derecho de la mujer a la libre determinación sobre su propio cuerpo?

    OpenAIRE

    Navarro González, Luis Ignacio

    2015-01-01

    Los complejos problemas del aborto inducido se han convertido en uno de los temas nacionales de muchos países, incluido México. Los tres ejes metodológicos fundamentales sobre los que se asienta el presente trabajo son: La defensa de la teoría crític

  1. Hevin plays a pivotal role in corneal wound healing.

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    Shyam S Chaurasia

    Full Text Available 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

  2. TO STUDY THE RESULT OF EMPIRICAL TREATMENT OUTCOME OF CORNEAL ULCER PATIENTS WHO REFUSED CORNEAL SCRAPING IN EASTERN PART OF RURAL INDIA

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    Debdas Mukherjee

    2016-08-01

    Full Text Available AIM To study the epidemiological characteristics, predisposing factors and treatment outcome of corneal ulcer in consecutive 150 patients who refused corneal scraping for microbacteriological examination in eastern part of rural India. METHOD It was a prospective study, which was conducted on 150 patients presenting with corneal ulcer. These patients refused corneal scraping for their apprehension for the further damage to eye. The study was conducted from March 2014 to March 2015. Demographic factors such as age, sex, occupation and predisposing factors were also recorded. RESULTS A total of 150 patients with corneal ulcer were enrolled in the study. Majority of patients were in the age group of 41-50 (22% years followed by patients in the age group 31-40 (21% years. 77.33% patients were males and 22.67% were females. 63 (42% were farmers, 14 (9% were labourers. Most common traumatic agent was paddy leaf 62 (41%. Most patients presented with mild corneal ulcer 90 (61%, followed by severe corneal ulcer with hypopyon 38 (25%. Maximum patients already had taken treatment earlier before their first visit to our hospital, out of which maximum patients received unknown treatment from quacks (42% followed by steroid use (14%. As s per month wise distribution, maximum cases were found in December 28 (19% followed by month of January 20 (13%. Maximum patients recovered with our treatment 84 (56%. CONCLUSION Corneal ulcer is a serious eye problem in rural areas, which may cause severe visual morbidity if not blindness. It must be treated very energetically to reduce ocular morbidity. In rural India, most cases are mixed infection and standard book/teaching managements of corneal ulcer are often scary to the illiterate village people, so the patients should be started on simple empirical therapy in order to prevent ocular morbidity and complication. A community-based awareness should be done to prevent corneal ulcer.

  3. Utilización de plasma rico en plaquetas en la profilaxisdel daño cutáneo inducido por radioterapia: modelo experimental

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    Lucía D'Oliveira-Pazos

    Full Text Available Introducción y Objetivos. La radioterapia conlleva la aparición de complicaciones cutáneas que afectan a la calidad de vida del paciente y en algunos casos condicionan la reconstrucción. El plasma rico en plaquetas (PRP es una terapia emergente; se trata de una sustancia autóloga, biocompatible, segura y económica. Está descrito su uso en disminución de la inflamación local, de los tiempos de curación de las heridas, en el tratamiento de lesiones por radioterapia y últimamente en el campo de la Medicina Estética mejorando la calidad de la piel. Nuestro estudio analiza el uso del PRP en la profilaxis de las lesiones cutáneas inducidas por radioterapia evaluando un modelo experimental. Material y Método. Realizamos un ensayo clínico controlado, doble ciego, en animales: 12 ratas Wistar, 2 para la obtención del PRP y 10 para el análisis clínico e histológico. Resultados. Del análisis clínico destacamos que de los sectores sin PRP previo a la radioterapia: 8 ratas presentaron alopecia y 7 hipopigmentación. La alopecia fue total en un 60%, parcial en 20% y un 20% no presentó alopecia. En los sectores con PRP: 4 presentaron alopecia y 3 hipopigmentación. La alopecia fue parcial en un 40%, un 60% no presentó alopecia y no hubo casos de alopecia total. Los resultados del análisis histológico demostraron un 100% de atrofia leve-moderada para los sectores con PRP. Por contrapartida, los sectores sin PRP presentaron 80% de atrofia moderada-severa y un 20% de atrofia leve-moderada. Conclusiones. Existe un beneficio en el uso del PRP como profilaxis de la alopecia (p < 0.05 e hipopigmentación (p < 0.1 inducido por radioterapia en un modelo experimental.

  4. Thermosensitive chitosan-based hydrogels for sustained release of ferulic acid on corneal wound healing.

    Science.gov (United States)

    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.

  5. Inhibitory effects of polysaccharide extract from Spirulina platensis on corneal neovascularization

    OpenAIRE

    Yang, LingLing; Wang, Yao; Zhou, Qingjun; Chen, Peng; Wang, Yiqiang; Wang, Ye; Liu, Ting; Xie, Lixin

    2009-01-01

    Purpose To assess the effects of polysaccharide extract from Spirulina platensis (PSP) on corneal neovascularization (CNV) in vivo and in vitro. Methods PSP was extracted from dry powder of Spirulina platensis. Its anti-angiogenic activity was evaluated in the mouse corneal alkali burn model after topical administration of PSP four times daily for up to seven days. Corneal samples were processed for histochemical, immunohistochemical, and gene expression analyses. The effects of PSP on prolif...

  6. Pirfenidone nanoparticles improve corneal wound healing and prevent scarring following alkali burn.

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    Sushovan Chowdhury

    Full Text Available PURPOSE: To evaluate the effects of pirfenidone nanoparticles on corneal re-epithelialization and scarring, major clinical challenges after alkali burn. METHODS: Effect of pirfenidone on collagen I and α-smooth muscle actin (α-SMA synthesis by TGFβ induced primary corneal fibroblast cells was evaluated by immunoblotting and immunocytochemistry. Pirfenidone loaded poly (lactide-co-glycolide (PLGA nanoparticles were prepared, characterized and their cellular entry was examined in primary corneal fibroblast cells by fluorescence microscopy. Alkali burn was induced in one eye of Sprague Dawley rats followed by daily topical treatment with free pirfenidone, pirfenidone nanoparticles or vehicle. Corneal re-epithelialization was assessed daily by flourescein dye test; absence of stained area indicated complete re-epithelialization and the time for complete re-epithelialization was determined. Corneal haze was assessed daily for 7 days under slit lamp microscope and graded using a standard method. After 7 days, collagen I deposition in the superficial layer of cornea was examined by immunohistochemistry. RESULTS: Pirfenidone prevented (P<0.05 increase in TGF β induced collagen I and α-SMA synthesis by corneal fibroblasts in a dose dependent manner. Pirfenidone could be loaded successfully within PLGA nanoparticles, which entered the corneal fibroblasts within 5 minutes. Pirfenidone nanoparticles but not free pirfenidone significantly (P<0.05 reduced collagen I level, corneal haze and the time for corneal re-epithelialization following alkali burn. CONCLUSION: Pirfenidone decreases collagen synthesis and prevents myofibroblast formation. Pirfenidone nanoparticles improve corneal wound healing and prevent fibrosis. Pirfenidone nanoparticles are of potential value in treating corneal chemical burns and other corneal fibrotic diseases.

  7. Successful transplantation of in vitro expanded human corneal endothelial precursors to corneal endothelial surface using a nanocomposite sheet

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    Parikumar P

    2011-01-01

    Full Text Available Background: Though the transplantation of in vitro expanded human corneal endothelial precursors in animal models of endothelial damage by injecting into the anterior chamber has been reported, the practical difficulties of accomplishing such procedure in human patients have been a hurdle to clinical translation. Here we report the successful transplantation of in vitro expanded human corneal precursor cells to an animal eye using a transparent Nano-composite sheet and their engraftment.Materials and Methods: Human Corneal endothelial cells (HCEC were isolated from human cadaver eyes with informed consent and expanded in the lab using a sphere forming assay in a novel Thermoreversible Gelation Polymer (TGP for 26 days. HCEC obtained by sphere forming assay were seeded in a novel Nano-composite sheet, which was made of PNIPA-NC gels by in-situ, free-radical polymerization of NIPA monomer in the presence of exfoliated clay (synthetic hectorite “Laponite XLG” uniformly dispersed in aqueous media. After a further seven days in vitro culture of HCEC in the Nano-composite sheet, cells were harvested and transplanted on cadaver-bovine eyes (n=3. The cells were injected between the corneal endothelial layer and the Nano-composite sheet that had been placed prior to the injection in close proximity to the endothelial layer. After three hours, the transplanted Nano-composite sheets were removed from the bovine eyes and subjected to microscopic examination. The corneas were subjected to Histo-pathological studies along with controls. Results: HCEC formed sphere like colonies in TGP which expressed relevant markers as confirmed by RT-PCR. Microscopic studies of the Nanosheets and histopathological studies of the cornea of the Bull’s eye revealed that the HCEC got engrafted to the corneal endothelial layer of the bovine eyes with no remnant cells in the Nanosheet. Conclusion: Transplantation of in vitro expanded donor human corneal endothelial cells

  8. Phototoxic effects of 8-methoxypsoralen on rabbit corneal endothelium

    Energy Technology Data Exchange (ETDEWEB)

    Menon, I.A.; Basu, P.K.; Hasany, S.M.; Persad, S.D. (Univ. of Toronto, Ontario (Canada))

    1989-01-01

    The phototoxic effects of 8-methoxypsoralen (8-MOP) were investigated using the rabbit corneal endothelium in organ culture. The corneas were divided into four groups: (a) irradiated with a mercury vapor lamp (emitting UVA and visible radiation) in the presence of 8-MOP (experimental), (b) irradiated without 8-MOP (control A), (c) incubated with 8-MOP (control B) and (d) incubated without 8-MOP (control C). Specular and light microscopic examination showed that the experimental corneas had greater cellular damage compared to the control corneas. The effects of 8-MOP were restricted to certain localized areas of the cornea. However there was no significant difference in the amounts of 51Cr released from the labelled experimental and control corneas. These results show phototoxic damage of the corneal endothelial cells.

  9. Recurrent corneal ulceration in presence of synthetic microfibrils

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    Barsam A

    2011-06-01

    Full Text Available A Barsam1, N Patel1, H Laganowski2, HD Perry31Moorfields Eye Hospital, London, UK; 2Department of Ophthalmology, Queen Mary's Hospital, Sidcup, Kent, UK; 3Ophthalmic Consultants of Long Island, Nassau University, Long Island, NY, USAAbstract: Recurrence of microbial keratitis in the presence of protozoal infection is very rare and infrequently reported unless predisposing factors are present. The association of recurrent microbial keratitis and synthetic microfibrils has never previously been reported to our knowledge. This single interventional case study describes the clinical course and treatment of a contact lens wearer who was treated for Acanthamoeba keratitis with superinfection from bacterial organisms in the presence of synthetic microfibrils. The presence of synthetic fibrils on a corneal ulcer base may act as a nidus for pathological organisms and interfere with normal corneal healing. This may result in infection recurrence and the growth of resistant opportunistic organisms.Keywords: Acanthamoeba, microbial keratitis, cornea ulcer, contact lens infection, synthetic microfibrils

  10. Toxicity of methods of implant material sterilization on corneal endothelium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, G.; Boehnke, Mv.; von Domarus, D.; Draeger, J.

    1985-11-01

    The toxicity of different procedures utilized for the sterilization of intraocular implant material was assessed on the endothelium of organ-cultured porcine corneas. Polymethylmethacrylate lenses sterilized by treatment with sodium hydroxide (NaOH), ethylene oxide, formaldehyde, and gamma radiation were added to a culture medium containing normal porcine corneas. Considering the viability of endothelial cells, appearance of intracellular degenerative vacuoles, and denudation of corneal Descemet's membrane as criterion for the evaluation of toxicity of different methods of sterilization, the NaOH-treated lenses were found to be the least toxic to porcine corneal endothelium. Phase-contrast microscopy and vital staining of the endothelium permitted direct viewing of the endothelium aiding in the assessment of toxicity.

  11. Transient Anisocoria after Corneal Collagen Cross-Linking

    Science.gov (United States)

    Kymionis, George D.; Grentzelos, Michael A.; Stojanovic, Nela; Paraskevopoulos, Theodore A.; Detorakis, Efstathios T.

    2014-01-01

    Purpose. To report a case with transient anisocoria after corneal collagen cross-linking (CXL). Methods. Case report. Results. A 24-year-old male underwent corneal collagen cross-linking (CXL) in his right eye for keratoconus. At the end of the procedure, the pupil of the treated eye was irregular and dilated, while the pupil of the fellow eye was round, regular, and reactive (anisocoria). The following day, pupils were round, regular, and reactive in both eyes. Conclusion. Anisocoria may be a transient and innocuous complication after CXL. A possible cause for this complication might be the anesthetic drops used before and during the surgical procedure or/and the ultraviolet A irradiation during the treatment. PMID:25276451

  12. Research Progress in Corneal Cross-linking Agents

    Institute of Scientific and Technical Information of China (English)

    Na Li; Xiujun Peng; Zhengjun Fan

    2014-01-01

    Corneal collagen cross-linking with UVA-riboflavin is cur-rently the only method for preventing the progression of kera-toconus from the pathological perspective. Topical application of a direct cross-linking agent is now attracting widespread at-tention in clinical settings..This article reviews the research progress in the application of indirect or direct cross-linking agents (e.g., riboflavin, glucose, ribose, glutaraldehyde, formaldehyde,.glyceraldehyde,.short chain aliphatic β-nitro alcohol, and genipin) in the treatment of corneal diseases and analyzes the cross-linking efficacy,.toxicity,.and merits and disadvantages of each cross-linking agent,.providing clinical information for further studies.

  13. Transient Anisocoria after Corneal Collagen Cross-Linking

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    George D. Kymionis

    2014-01-01

    Full Text Available Purpose. To report a case with transient anisocoria after corneal collagen cross-linking (CXL. Methods. Case report. Results. A 24-year-old male underwent corneal collagen cross-linking (CXL in his right eye for keratoconus. At the end of the procedure, the pupil of the treated eye was irregular and dilated, while the pupil of the fellow eye was round, regular, and reactive (anisocoria. The following day, pupils were round, regular, and reactive in both eyes. Conclusion. Anisocoria may be a transient and innocuous complication after CXL. A possible cause for this complication might be the anesthetic drops used before and during the surgical procedure or/and the ultraviolet A irradiation during the treatment.

  14. Keratometry and corneal topography using multiple delay element OCT

    Science.gov (United States)

    Plesea, Lucian; Podoleanu, Adrian G.

    2008-02-01

    We have presented previously a novel method for the evaluation of the surface shape of an object, with immediate application to measurement of cornea shape. This method uses single shot C-scans obtained by using a multiple delay element (MDE) in the reference path of an OCT system. A calibrated MDE-OCT system can be used to measure the elevation of points on the cornea, in contrast to existing methods which are based on measurement of the cornea slope. The associated algorithm for extracting corneal topography data points from the MDE-OCT C-Scan image will be presented, data points which can then be used to calculate the Zernike coefficients for the cornea shape. The differences between the existing systems and the MDE-OCT method for keratometry and corneal topography are discussed.

  15. Topical antibiotics in the management of corneal ulcer

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    Reddy P

    1988-01-01

    Full Text Available A total of 82 patients suffering from corneal ulcer were treated with framycetin 0.5%, gentamicin 3 mg./ml, chloramphenicol 0.4% and a neomycin combination containing Polymixin B sulphate 5000 u, neomycin sulphate 1700 u and gramicidin 0.025 mg/mL in a Randomised comparative study. The commonest organism isolated was Staphylococcus followed by Pneumococcus, Streptococcus and Pseudomonas. The in vitro sensitivity of these isolates to framycetin was higher than that to others Framycetin produced both earlier and a greater degree of improvement in mean score of signs and symptoms than the other antibiotics. It can thus be concluded that framycetin has a better profile of antibacterial activity and clinical efficacy than some other commonly used topical antibiotics in the treatment of corneal ulcer.

  16. SYNTHESIS OF ROBOTIC MECHANISM FOR MICROSURGICAL CORNEAL GRAFTING

    Institute of Scientific and Technical Information of China (English)

    Hu Yida; Zhao Zhiwen; Li Dazhai; Zong Guanghua

    2005-01-01

    In order to enhance the effect of corneal grafting, an assisting microsurgical robot has been developed. As one of principal issues for the robotic system design, type and size synthesis of the robotic mechanism is discussed. For this purpose, timeline subtask is analyzed with surgical component motion in manual corneal grafting microsurgery, as the reference of robotic mechanism synthesis. On the basis of study on the kinematic correlation between the arm structures and the wrist structures, configuration of joint is determined for the surgical task and motion in type synthesis of the mechanism. The objective for size synthesis of robotic mechanism is optimization of the mechanism dexterity as a manipulation capability. The condition number based on Jacob matrix is chosen as dexterity measure of the mechanism. The prototype is developed.

  17. Granular Corneal Dystrophy Manifesting after Radial Keratotomy

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    Sepehr Feizi

    2008-12-01

    Full Text Available

    PURPOSE: To report manifestation of granular corneal dystrophy after radial keratotomy (RK. CASE REPORT: A 32-year-old man presented with white radial lines in both corneas. He had undergone uncomplicated RK in both eyes 8 years ago. Preoperative refraction had been OD: -3.5 -0.75@180 and OS: -3.0 -0.5@175. Uncorrected visual acuity was OD: 8/10 and OS: 7/10; best corrected visual acuity was 9/10 in both eyes with OD: -0.5 -0.5@60 and OS: -0.75 -0.5@80. Slit lamp examination revealed discrete well-demarcated whitish lesions with clear intervening stroma in the central anterior cornea consistent with granular dystrophy. Similar opacities were present within the RK incisions. CONCLUSION: Granular dystrophy deposits may appear within RK incisions besides other previously reported locations.

  1. Perforating corneal injury in rat and pentadecapeptide BPC 157.

    Science.gov (United States)

    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.

  2. Ketamine/Xylazine-Induced Corneal Damage in Mice.

    Directory of Open Access Journals (Sweden)

    Demelza Koehn

    Full Text Available We have observed that the commonly used ketamine/xylazine anesthesia mix can induce a focally severe and permanent corneal opacity. The purpose of this study was to establish the clinical and histological features of this deleterious side effect, its sensitivity with respect to age and anesthesia protocol, and approaches for avoiding it.Young C57BL/6J, C57BLKS/J, and SJL/J mice were treated with permutations of anesthesia protocols and compared using slit-lamp exams, optical coherence tomography, histologic analyses, and telemetric measurements of body temperature.Ketamine/xylazine induces corneal damage in mice with a variable frequency. Among 12 experimental cohorts, corneal damage associated with ketamine/xylazine was observed in 9 of them. Despite various treatments to avoid corneal dehydration during anesthesia, the frequency of corneas experiencing damage among responding cohorts was 42% (26% inclusive of all cohorts, which is significantly greater than the natural prevalence (5%. The damage was consistent with band keratopathy. It appeared as a white or gray horizontal band located proximal to the pupil and was positive for subepithelial calcium deposition with von Kossa stain.The sum of our clinical and histological observations is consistent with ketamine/xylazine-induced band keratopathy in mice. This finding is relevant for mouse studies involving the eye and/or vision-dependent behavioral assays, which would both be prone to artifact without appreciation of the damage caused by ketamine/xylazine anesthesia. Use of yohimbine is suggested as a practical means of avoiding this complication.

  3. Effect of a cyclosporine A delivery system in corneal transplantation

    Institute of Scientific and Technical Information of China (English)

    谢立信; 史伟云; 王治宇; 贝建中; 王身国

    2002-01-01

    Objective To test the immunosuppressive effect of cyclosporine (Cs) in a polymer placed in the anterior chamber of corneal allograft recipients. Methods Wistar inbred rats with vascularized corneas were recipients of corneal allografts from Sprague-Dawley donor rats. Rats underwent penetrating keratoplasty and were divided randomly into four groups: untreated control animals (UCA); Cs-polymer anterior chamber recipients (CPA); co-polymer subconjunctival recipients (CPS); and Cs-olive oil drop recipients (COO). Grafts were examined by slit lamp every 3 days and clinical conditions were scored. Cs concentration in the aqueous humor was assayed at 1, 2, and 4 weeks. At 1, 2 and 4 weeks after transplantation, the operated eyes were collected for histopathological evaluation of the grafts. Results The median survival time of the allografts was 8.2±1.48 days for the UCA group, 11.4±2.50 days for the CPS group, and 17.0±2.00 days for the CPA group. There was a statistically significant difference (P<0.05) between survival time of the allografts in the animals of the CPA group compared to the other groups of graft recipients. Significantly higher concentrations of Cs were found in the eyes given an anterior chamber implant of Cs-polymer, compared to other treatment groups or untreated rats. A transient inflammatory response in the anterior chamber was observed in the CPA group. Conclusions Cs-polymer placed in the anterior chamber significantly prolongs corneal allograft survival time in a high risk corneal graft rejection model. This intraocular delivery system may be a valuable adjunct for the suppression of immune graft rejection.

  4. Central corneal thickness in children with adenotonsillary hypertrophy

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    Emine Cinici

    2015-12-01

    Conclusions: We could not find a statistically significant distinction between the corneal thickness and ATH. Further stud- ies in more advanced age groups or using a wider range of patients series will test whether this result is also observed in the children who have been exposed to the disease for longer periods of time. [Arch Clin Exp Surg 2015; 4(4.000: 208-214

  5. Robust automatic segmentation of corneal layer boundaries in SDOCT images using graph theory and dynamic programming.

    Science.gov (United States)

    Larocca, Francesco; Chiu, Stephanie J; McNabb, Ryan P; Kuo, Anthony N; Izatt, Joseph A; Farsiu, Sina

    2011-06-01

    Segmentation of anatomical structures in corneal images is crucial for the diagnosis and study of anterior segment diseases. However, manual segmentation is a time-consuming and subjective process. This paper presents an automatic approach for segmenting corneal layer boundaries in Spectral Domain Optical Coherence Tomography images using graph theory and dynamic programming. Our approach is robust to the low-SNR and different artifact types that can appear in clinical corneal images. We show that our method segments three corneal layer boundaries in normal adult eyes more accurately compared to an expert grader than a second grader-even in the presence of significant imaging outliers.

  6. Derivation of Corneal Keratocyte-Like Cells from Human Induced Pluripotent Stem Cells

    Science.gov (United States)

    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

  7. Corneal stem cells and tissue engineering: Current advances and future perspectives.

    Science.gov (United States)

    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.

  8. PROFILE OF CORNEAL ULCER IN A TERTIARY EYE CARE CENTRE

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    Gupta

    2013-06-01

    Full Text Available ABSTRACT: To review the epidemiological characteristics, microbiological profile, and treatment outcome of patient with microbial keratitis. METHODS AND MATERIALS: All the patients presenting with chief complains of pain, redness, photophobia, watering, and who on examination were stain positive with corneal stromal infiltrate underwent standard microbiological evaluation of their corneal scrapings. Patients were divided into bacterial, viral, and fungal keratitis as diagnosed on the basis of clinical and microbiological findings and treatment was started. RESULTS: Out of 67 cases of microbial keratitis 12 (17.9% were culture-proven. Patients with agriculture-based activities were at greater risk of developing microbial keratitis and patients with ocular trauma were more likely to develop microbial keratitis. A significantly larger number of patients with fungal keratitis required surgical intervention compared to bacterial and viral keratitis. Healed corneal scar was observed in 36 (53.7% of patients with bacterial, fungal and viral keratitis. CONCLUSION: While diagnostic and treatment modalities are well in place the final outcome is suboptimal in fungal keratitis. With more effective treatment available for bacterial and viral keratitis, the treatment of fungal keratitis is truly a challenge.

  9. New Trends in Quantitative Assessment of the Corneal Barrier Function

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    Anton Guimerà

    2014-05-01

    Full Text Available 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.

  10. Protective Effects of Trehalose on the Corneal Epithelial Cells

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    Pasquale Aragona

    2014-01-01

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

  11. Corneal relaxing incision combined with phacoemulsification and IOL implantation

    Institute of Scientific and Technical Information of China (English)

    沈晔; 童剑萍; 李毓敏

    2004-01-01

    Objective: To analyze the effectiveness and safety of corneal relaxing incisions (CRI) in correcting keratometric astigmatism during cataract surgery. Methods: A prospective study of two groups: control group and treatment group. A treatment group included 25 eyes of 25 patients who had combined clear corneal phacoemulsification, IOL implantation and CRI. A control group included 25 eyes of 25 patients who had clear corneal phacoemulsification and IOL implantation.Postoperative keratometric astigmatism was measured at 1 week, 1 month, 3 months and 6 months. Results: CRI signifi-cantly decreased keratometric astigmatism in patients with preexisting astigmatism compared with astigmatic changes in the control group. In eyes with CRI, the mean keratometric astigmatism was 0.29±0.17 D(range 0 to 0.5 D) at 1 week, 0.41±0.21 D (range 0 to 0.82 D) at 1 month, respectively reduced by 2.42 D and 2.30 D at 1 week and 1 month postoperatively (P=0.000, P=0.000), and postoperative astigmatism was stable until 6 months follow-up. The keratometric astigmatism of all patients decreased to less than 1.00 D postoperatively. Conclusions: CRI is a practical, simple, safe and effective method to reduce preexisting astigmatism during cataract surgery. A modified nomogram is proposed. The long-term effect of CRI should be investigated.

  12. Novel Lutein Loaded Lipid Nanoparticles on Porcine Corneal Distribution

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    Chi-Hsien Liu

    2014-01-01

    Full Text Available 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.

  13. Videokeratograph (VKS for monitoring corneal curvature during surgery

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    Carvalho Luis Alberto Vieira de

    2002-01-01

    Full Text Available Purpose: We have developed an instrument for computerized surgical videokeratography. A corneal central region of approximately 7.00 mm in diameter may be analyzed, providing the surgeon with information of the power and the astigmatism. Methods: The system is based on a fiber optic Placido disc projecting cone, which is attached to the objective lens of a Zeiss compatible surgical microscope. At the beam splitter we installed a monochromatic high resolution camera. A frame grabber is installed on a PC and images are digitized at a 480x640 resolution. Image processing is used for edge detection of rings. Results: Calibrating curves based on 4 spherical surfaces were generated and approximately 3600 points are calculated for each examination. Preliminary measurements on 10 healthy corneas were compared with those of an EyeSys System 2000 Corneal Topographer. Mean deviation was 0.05 for radius of curvature, 0.24 D for the power and 5.0 degrees for the cylinder. Conclusions: This surgical VKS, with some hardware and software improvements, may be used to reduce residual astigmatisms in conventional cataract and keratoplasty. It could also be used to gather preoperative data in corneal topography assisted LASIK.

  14. Experiment Study of Effect of Perfiuorohexyloctane on Corneal Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Ding; Chunfang Li; Lin Lu; Guanguang Feng; Huling Zheng

    2001-01-01

    Purpose: To investigate the effect of Perfluorohexyloctane (F6H8)on corneal endothelial celIs(CEC) of rabbit eyes. Methods: Fifteen New Zealand white rabbits were devided into two groups:experimental group(F6H8) and control group(BSS) . All rabbits underwent anterior chamber injection of 0. 15ml F6H8 or BSS. Slit-lamp biomicroscopy and corneal endothelium photography were performed pre-operatively and postoperatively. Histopathological examination and Transmission electron microscopy(TEM) were done after the rabbits were sacrificed. Results: All the corneas were clear. Since 4 weeks after operation, the endothelial cells were markedly irregular in size and shape and the number of endothelial cells was markedly decreased. Multilayered retrocorneal membranes (RCM)grew gradually 2 weeks after surgery. Vacuolar degeneration was seen in some endothelial cells. Nuclear degeneration and edema of plasma were seen in TEM. Conclusion: Corneal endothelial cell degenerated after contacting with F6H8 for 2 ~4weeks. As a silicone solvent, it should be removed completely after injection. We don't recommend it to be used as a new intraocular temponade. Eye Science 2001: 17:21 ~ 26.

  15. Meretoja’s Syndrome: Lattice Corneal Dystrophy, Gelsolin Type

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    I. Casal

    2017-01-01

    Full Text Available Lattice corneal dystrophy gelsolin type was first described in 1969 by Jouko Meretoja, a Finnish ophthalmologist. It is caused by an autosomal dominant mutation in gelsolin gene resulting in unstable protein fragments and amyloid deposition in various organs. The age of onset is usually after the third decade of life and typical diagnostic triad includes progressive bilateral facial paralysis, loose skin, and lattice corneal dystrophy. We report a case of a 53-year-old female patient referred to our Department of Ophthalmology by severe dry eye and incomplete eyelid closure. She had severe bilateral facial paresis, significant orbicularis, and perioral sagging as well as hypoesthesia of extremities and was diagnosed with Meretoja’s syndrome at the age of 50, confirmed by the presence of gelsolin mutation. At our observation she had bilateral diminished tear film break-up time and Schirmer test, diffuse keratitis, corneal opacification, and neovascularization in the left eye. She was treated with preservative-free lubricants and topical cyclosporine, associated with nocturnal complete occlusion of both eyes, and underwent placement of lacrimal punctal plugs. Ocular symptoms are the first to appear and our role as ophthalmologists is essential for the diagnosis, treatment, and monitoring of ocular alterations in these patients.

  16. Neutrophil extracellular traps involvement in corneal fungal infection

    Science.gov (United States)

    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

  17. Corneal topography reinterpretation through separate analysis of the projected rings

    Science.gov (United States)

    Espinosa, Julian; Roig, Ana B.; Mas, David; Hernández, Consuelo; Illueca, Carlos

    2012-06-01

    We present a new algorithm to process captured images of reflected Placido rings. Up to our knowledge, conventional topographers transform from Cartesian to polar coordinates and vice-versa, thus extrapolating corneal data and introducing noise and image artefacts. Moreover, captured data are processed by the device according to proprietary algorithms and offering a final map of corneal curvature. Corneal topography images consists of concentric rings of approximately elliptical shape. Our proposal consists of considering the information that provides each separate ring. A snake-annealing-like method permits identifying the ring even with discontinuities due to eye-lashes and reflections. By analysing the geometrical parameters of rings (centre, semi-axis and orientation), one can obtain information about small morphological micro-fluctuations and local astigmatisms. These parameters can be obtained with sub-pixel accuracy so the method results of high precision. The method can be easily adapted to work on any topographer, so that it can provide additional information about the cornea at no additional cost.

  18. Data acquisition time constraints in elevation mapping corneal topography

    Science.gov (United States)

    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.

  19. Tectonic DSAEK for the Management of Impending Corneal Perforation

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    Enrique O. Graue-Hernandez

    2012-01-01

    Full Text Available Purpose. To report a case of severe corneal thinning secondary to dry eye treated with a tectonic Descemet stripping automated lamellar keratoplasty (DSAEK and amniotic membrane graft. Methods. A 72-year-old man with a history of long standing diabetes mellitus type 2 and dry eye presented with 80% corneal thinning and edema on the right eye and no signs of infectious disease, initially managed with topical unpreserved lubrication and 20% autologous serum drops. Eight weeks after, the defect advanced in size and depth until Descemetocele was formed. Thereafter, he underwent DSAEK for tectonic purposes. One month after the procedure, the posterior lamellar graft was well adhered but a 4 mm epithelial defect was still present. A multilayered amniotic membrane graft was then performed. Results. Ocular surface healed quickly and reepithelization occurred over a 2-week period. Eight months after, the ocular surface remained stable and structurally adequate. Conclusion. Tectonic DSAEK in conjunction with multilayered amniotic graft may not only provide structural support and avoid corneal perforation, but may also promote reepithelization and ocular surface healing and decrease concomitant inflammation.

  20. Tectonic DSAEK for the Management of Impending Corneal Perforation

    Science.gov (United States)

    Graue-Hernandez, Enrique O.; Zuñiga-Gonzalez, Isaac; Hernandez-Camarena, Julio C.; Jaimes, Martha; Chirinos-Saldaña, Patricia; Navas, Alejandro; Ramirez-Miranda, Arturo

    2012-01-01

    Purpose. To report a case of severe corneal thinning secondary to dry eye treated with a tectonic Descemet stripping automated lamellar keratoplasty (DSAEK) and amniotic membrane graft. Methods. A 72-year-old man with a history of long standing diabetes mellitus type 2 and dry eye presented with 80% corneal thinning and edema on the right eye and no signs of infectious disease, initially managed with topical unpreserved lubrication and 20% autologous serum drops. Eight weeks after, the defect advanced in size and depth until Descemetocele was formed. Thereafter, he underwent DSAEK for tectonic purposes. One month after the procedure, the posterior lamellar graft was well adhered but a 4 mm epithelial defect was still present. A multilayered amniotic membrane graft was then performed. Results. Ocular surface healed quickly and reepithelization occurred over a 2-week period. Eight months after, the ocular surface remained stable and structurally adequate. Conclusion. Tectonic DSAEK in conjunction with multilayered amniotic graft may not only provide structural support and avoid corneal perforation, but may also promote reepithelization and ocular surface healing and decrease concomitant inflammation. PMID:23259100

  1. Accuracy of the PAR corneal topography system with spatial misalignment.

    Science.gov (United States)

    Belin, M W; Zloty, P

    1993-01-01

    The PAR Corneal Topography System is a computerized corneal imaging system which uses close-range raster photogrammetry to measure and produce a topographic map of the corneal surface. Raster photogrammetry is a standard method of extracting object information by projecting a known pattern onto an object and recording the distortion when viewed from an oblique angle. Unlike placido disc based videokeratoscopes, the PAR system requires neither a smooth reflective surface nor precise spatial alignment for accurate imaging. We studied both the accuracy of the system with purposeful misalignment (defocusing) of the test object and determined the ability to image freshly deepithelialized, keratectomized, and photoablated corneas. The PAR system was both accurate and reproducible in imaging calibrated spheres within a defined zone in space. Whole cadaver eyes were imaged both before and immediately after removal of the epithelium, lamellar keratectomy, and laser photoablation. The system demonstrated the ability to image irregular, deepithelialized, and keratectomized corneas. The ability to maintain accuracy without precise alignment and the facility to image freshly deepithelialized and keratectomized corneas may make the system suitable for intraoperative refractive monitoring.

  2. Oxidative Stress to the Cornea, Changes in Corneal Optical Properties, and Advances in Treatment of Corneal Oxidative Injuries

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    Cestmir Cejka

    2015-01-01

    Full Text Available 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.

  3. Central Corneal Thickness, Corneal Endothelial Characteristics and Intraocular Pressure after Pediatric Cataract Surgery

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    Naveed Nilforushan

    2008-11-01

    Full Text Available

    PURPOSE: To investigate central corneal thickness (CCT, endothelial cell characteristics and intraocular pressure (IOP in eyes with prior pediatric cataract surgery and to compare them with eyes of normal age and sex matched controls. METHODS: Specular microscopy CCT and IOP measurements were performed in 31 eyes of 17 patients with prior congenital cataract extraction and 40 eyes of 20 age and sex matched subjects. The mean of three pachymetric and specular microscopic measurements were recorded. IOP was measured using Goldmann applanation tonometry. RESULTS: Mean CCT was 632±45 µm in eyes with prior pediatric cataract surgery vs 546±33 µm in control eyes (P < 0.001, independent t test and Mann Whitney U-test. Mean IOP was 22.1±3.9 mmHg in eyes with prior pediatric cataract surgery and 14.0±1.6 mmHg in the control group (P < 0.001, independent t-test. There was no significant difference between the two groups in cell count, polymegethism and mean cell area of corneal endothelial cells. CONCLUSIONS: Although the corneas were clinically clear and there was no significant difference in endothelial characteristics in eyes with prior pediatric cataract surgery as compared to normal controls, central corneal thickness in the operated eyes was significantly greater. To differentiate actual glaucoma from artifactual IOP

  4. Using femtosecond laser to create customized corneal flaps for patients with low and moderate refractive error differing in corneal thickness.

    Science.gov (United States)

    Zhang, Chi; Che, Jingbin; Yu, Jianhong; Yu, Linli; Yu, Dan; Zhao, Gangping

    2015-01-01

    This study is designed to evaluate the visual outcomes, accuracy, and predictability of corneal flaps with different thicknesses created by 60-kHz femtosecond laser according to different corneal thicknesses in the patients with low and moderate refractive error. A total of 182 eyes were divided according to the central corneal thickness (470 μm-499 μm in Group A, 500 μm-549 μm in Group B, and 550 μm-599 μm in Group C) and underwent femtosecond laser-assisted LASIK for a target corneal flap thickness (100 μm for Group A, 110 μm for Group B, and 120 μm for Group C). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refractive status were examined. The flap thickness of each eye was measured by anterior segment optical coherence tomography (AS-OCT) on 30 points at 1-month follow-up to assess the accuracy and predictability. Postoperatively, at least 75% of eyes had a UDVA of 20/16 or better, less than 2% of eyes lost one line, over 30% of eyes gained one or more lines in CDVA, at least 95% of eyes had astigmatism of less than 0.25 D, all eyes achieved a correction within ± 1.00 D from the target spherical equivalent refraction. The visual and refractive outcomes did not differ significantly in all groups (P >0.05). The mean flap thickness was 100.36 ± 4.32 μm (range: 95-113 μm) in Group A, 111.64 ± 3.62 μm (range: 108-125 μm) in Group B, and 122.32 ± 2.88 μm (range: 112-128 μm) in Group C. The difference at each measured point among the three groups was significant (P refractive error.

  5. Swelling studies of camel and bovine corneal stroma

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    Turki Almubrad

    2010-09-01

    Full Text Available Turki Almubrad, Mohammad Faisal Jamal Khan, Saeed AkhtarCornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Saudi ArabiaAbstract: In the present study we investigated the swelling characteristics of fresh camel and bovine cornea in sodium salt solutions. Swelling studies were carried out at 20 minutes, 14 hours, and 46 hours on five fresh camel and 5 five fresh bovine corneas. During the 20-minute hydration of fresh corneal stroma was investigated using sodium chloride (NaCl, sodium bicarbonate (NaHCO3, sodium acetate (CH3COONa, sodium thiocyanate (NaSCN, and sodium floride (NaF at 2-minute time intervals. During a 46-hour time period, the hydration study was carried out using NaCl (150, 300 mM and NaF (150 mM at random intervals. The 14-hour study was carried out to assess the rehydration of corneal stroma after 6 hours of drying. During the 20-minute swelling studies in the first 2 minutes the rate of hydration in both camel and bovine corneas was high but gradually reduced in the 2–20-minute period. The rates and levels of hydration of camel and bovine cornea were not significantly different from each other in all the strengths of solutions. During the 46-hour swelling studies, the initial rate of hydration (0–2 hours of camel and bovine stroma, in all solutions was significantly higher (Z = 0.056 compared to hydration during later hours (2–46 hours. Camel stromal hydration (high in 150 mM NaCl was significantly higher compared to bovine stromal hydration in the same solution during the 10–24, and 24–46-hour time periods. Rehydration in camel stroma was significantly lower than bovine in 150 mM NaF. The 20-minute study showed that there was no selective affinity for particular ions in camel or bovine corneal stroma. Initial swelling in both corneal and bovine stroma is faster and more prominant compared to later swelling. The swelling in camel cornea is more prominant compared

  6. Riboflavin-ultraviolet a corneal cross-linking for keratoconus

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    El-Raggal Tamer

    2009-01-01

    Full Text Available 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 t-500 for 30 minutes followed by exposure to UVA radiation (365 nm, 3 mW/cm 2 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.

  7. Optimization of Human Corneal Endothelial Cells for Culture: The Removal of Corneal Stromal Fibroblast Contamination Using Magnetic Cell Separation

    Directory of Open Access Journals (Sweden)

    Gary S. L. Peh

    2012-01-01

    Full Text Available The culture of human corneal endothelial cells (CECs is critical for the development of suitable graft alternative on biodegradable material, specifically for endothelial keratoplasty, which can potentially alleviate the global shortage of transplant-grade donor corneas available. However, the propagation of slow proliferative CECs in vitro can be hindered by rapid growing stromal corneal fibroblasts (CSFs that may be coisolated in some cases. The purpose of this study was to evaluate a strategy using magnetic cell separation (MACS technique to deplete the contaminating CSFs from CEC cultures using antifibroblast magnetic microbeads. Separated “labeled” and “flow-through” cell fractions were collected separately, cultured, and morphologically assessed. Cells from the “flow-through” fraction displayed compact polygonal morphology and expressed Na+/K+ATPase indicative of corneal endothelial cells, whilst cells from the “labeled” fraction were mostly elongated and fibroblastic. A separation efficacy of 96.88% was observed. Hence, MACS technique can be useful in the depletion of contaminating CSFs from within a culture of CECs.

  8. Differentiation of mild keratoconus from corneal warpage according to topographic inferior steepening based on corneal tomography data

    Directory of Open Access Journals (Sweden)

    Lia Florim Patrão

    Full Text Available ABSTRACT 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.

  9. Effects of N-acetylcysteine on matrix metalloproteinase-9 secretion and cell migration of human corneal epithelial cells

    OpenAIRE

    Ramaesh, T; Ramaesh, K; Riley, S C; West, J.D.; Dhillon, B

    2012-01-01

    Matrix metalloproteinase-9 (MMP-9) secreted by corneal epithelial cells has a role in the remodelling of extracellular matrix and migration of epithelial cells. Elevated levels of MMP-9 activity in the ocular surface may be involved in the pathogenesis of corneal diseases. N-acetylcysteine (NAC) has been used to treat corneal diseases, including recurrent epithelial erosions. In this study, its effects on the MMP-9 secretion and human corneal epithelial (HCE) cell migration were evaluated in ...

  10. The Influence of Soft Contact Lens Wear and Two Weeks Cessation of Lens Wear on Corneal Curvature

    OpenAIRE

    Lloyd McKernan, Aoife; O'Dwyer, Veronica; Simo Mannion, Luisa

    2014-01-01

    Abstract Introduction Accurate corneal measurements are crucial in corneal refractive surgery (CRS) to ensure successful outcomes. Soft contact lens (SCL) wear may result in changes to corneal curvature and structure. United States Food and Drug Administration (FDA) pre-operative guidelines recommend that prior to CRS, SCL wearers cease SCL wear for “at least two weeks before examination and treatment”[1]. Corneal curvature changes induced by SCL wear may take longer than two weeks to reso...

  11. Evaluating approaches to measuring ocular pain in bovine calves with corneal scarification and infectious bovine keratoconjunctivitis-associated corneal ulcerations.

    Science.gov (United States)

    Dewell, R D; Millman, S T; Gould, S A; Tofflemire, K L; Whitley, R D; Parsons, R L; Rowe, E W; Liu, F; Wang, C; O'Connor, A M

    2014-03-01

    Infectious bovine keratoconjunctivitis (IBK) is a common ocular disease in cattle, associated with a 6.8 to 13.6 kg decrease in weaning weight. Antibiotic therapy is available but it is unclear if pain mitigation as an adjunct therapy would reduce the weight loss associated with IBK. Before assessing the impact of pain mitigation therapies, it is first necessary to validate approaches to qualifying ocular pain. The objective of this study was to evaluate approaches to qualifying ocular pain in bovine calves (Bos taurus) with IBK. Our a priori assumption was that scarification or corneal ulcerations consistent with IBK are painful compared to normal eyes. To quantify this difference in pain, we assessed 4 tools: pressure algometry-mechanical nociceptive threshold (PA-MNT), corneal touch thresholds (CTT) obtained with the use of a Cochet-Bonnet aesthesiometer, and assessment for the presence of blepharospasm and photophobia as metrics for pain. Using a 1-eye randomized controlled challenge trial, 31 calves with healthy eyes were randomly allocated to treatment groups, and then a left or right eye was randomly assigned for corneal scarification and inoculation with Moraxella bovoculi or Moraxella bovis. A repeated measures analysis of variance was used for PA-MNT, with significance set at P < 0.05. A log (base 10) transformation was used to stabilize the variance, and Tukey's t tests were used to test differences between assessment days for each landmark. Calves had statistically significantly lower PA-MNT scores (which indicates more pain) the day after scarification relative to baseline measurements (4 d before scarification). For example, at 1 landmark the median PA-MNT (kg/force) prescarification was 4.82 (95% confidence interval [CI]: 3.92-5.93) and 3.43 (95% CI: 2.79-4.22) postscarification. These data suggest PA-MNT may be a tool for quantifying ocular pain in calves. No differences (P < 0.1) in PA-MNT scores between scarified and not-scarified eyes were

  12. Medición del daño genético inducido por el basuco en linfocitos humanos empleando la prueba de micronúcleos con Citocalasina B

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    Ocampo AP.

    2001-06-01

    Full Text Available El bazuco es una mezcla compleja que se deriva del proceso de extracción de la cocaína. El frecuente consumo de bazuco constituye un problema de salud pública. La prueba de micronúcleos en linfocitos humanos de sangre periférica por bloqueo de la citocinesis con Citocalasina B, es más sensible y precisa para evaluar daño  cromosómico porque permite registrar micronúcleos originados de fragmentos de cromosomas o cromosomas enteros en células que se han dividido una sola vez. El objetivo del presente estudio fue evaluar el daño genético, inducido por el bazuco en linfocitos humanos in vitro empleando la prueba de micronúcleos con Citocalasina B.

  13. Espectroscopía de Plasmas Inducidos por Láser (LIBS) aplicada a la caracterización de piezas únicas y productos de interés industrial

    OpenAIRE

    Alvira, Fernando Carlos

    2010-01-01

    La Espectroscopia de Plasmas Inducidos por Láser (LIBS) es una técnica espectroscópica que se basa en la generación de plasmas por ablación láser. En esta tesis se desarrolló e implementó la técnica LIBS para la determinación de la composición de superficies y sustratos de productos industriales y piezas únicas de interés patrimonial. Se aplicó la técnica desarrollada para la caracterización de la composición de piezas sometidas a tratamientos superficiales, para la determinación de elementos...

  14. Diferencias en el número de cesáreas en los partos que comienzan espontáneamente y en los inducidos

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    Antonio Hernández Martínez

    2014-01-01

    Full Text Available Fundamentos: La inducción del parto (IDP puede estar asociada a mayores complicaciones para la mujer gestante. El objetivo de este trabajo fue determinar las diferencias en el número de cesáreas entre partos espontáneos y partos inducidos. Métodos: Cohortes históricas sobre un total de 841 inducciones y 2.534 partos espontáneos realizados entre 2009 y 2011 en el Hospital "Mancha-Centro" de Alcázar de San Juan. Se empleó análisis multivariante por medio de regresión logística binaria para control de la confusión. Resultados: La prevalencia de IDP fue del 22,9%, presentándose como indicaciones más frecuentes la rotura prematura de membranas (RPM de más de 12 horas (22,7% y diabetes mellitus mal controlada con un 22,5%. Se observó relación entre inducción y riesgo de cesárea tanto en mujeres nulíparas (OR= 2,68; Intervalo de confianza [IC] 95%: 2,15-3,34 como en multíparas (OR=2,10; [IC] 95%:1,72-2,57. La indicación con mayor riesgo de cesárea fue la gestación cronológicamente prolongada (GCP (37,1% seguida del registro cardiotográfico (RCTG patológico (35,3% y estados hipertensivos del embarazo (EHE (4,0%. La IDP también se relacionó con la mayor duración de la dilatación (OR=6,00; IC 95%:4,02-8,95, empleo de epidural (OR=3,10;IC95%: 2,24-4,29 y necesidades de transfusión sanguínea (OR=3,33; IC 95%:1,70-9,67. Conclusiones: La IDP es un factor de riesgo para una mayor duración de la dilatación, empleo de analgesia epidural, necesidad de transfusión sanguínea y de cesárea tanto en mujeres nulíparas como en multíparas, especialmente en las indicaciones de gestación cronológicamente prolongada, registro cardiotocográfico patológico y estados hipertensivos del embarazo. No se encontró relación con la duración del período expulsivo, la práctica de episiotomía, desgarros, sangrado excesivo y rotura uterina.

  15. Study of corneal epithelial progenitor origin and the Yap1 requirement using keratin 12 lineage tracing transgenic mice

    Science.gov (United States)

    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

  16. Daño inducido en el ADN plasmidial por la radiación mixta de neutrones térmicos + rayos gamma en presencia y ausencia de capturador de radicales libres

    Directory of Open Access Journals (Sweden)

    Maritza Rodríguez-Gual

    2010-01-01

    Full Text Available En este trabajo se cuantifica por primera vez el daño en ADN plasmidial inducido por la radiación mixta de neutrones térmicos + rayos gamma. Para el estudio fue utilizado el plasmidio pBs KS+ de 2 961 pb en disolución acuosa a 88 ng/¿L a concentraciones de 0, 2 y 20 mmol/L de glicerina que actúa como un capturador de radicales libres. Este plasmidio cambia su forma superenrollada para circular cuando es producida una rotura simple en su cadena y adquiere una forma linear cuando se produce una rotura doble en su cadena. Cuantificando las fracciones que se producen de cada una de estas formas es posible estimar el efecto de la radiación en el ADN. Las irradiaciones fueron realizadas en el canal radial # 3 del reactor de investigaciones IEA-R1 del Instituto de Pesquisas Energéticas y Nucleares de São Paulo, Brasil. Las formas del ADN fueron separadas mediante la electroforesis en gel de agarosa. En la cuantificación se utilizó el programa GelAnalis. Las fracciones de ADN en sus diferentes formas fueron graficadas en función de la dosis y ajustadas a funciones exponenciales y lineares para obtener las probabilidades de roturas simples y dobles en la cadena de ADN normalizadas por dosis y por masa molecular. Los resultados evidenciaron la acción protectora del capturador de radicales libres contra el daño inducido por la radiación, lo cual corrobora resultados anteriores obtenidos con otras radiaciones ionizantes. Los rendimientos de SSB y DSB serán de interés para la validación de diferentes modelos que intentan reproducir los resultados experimentales.

  17. Central and Peripheral Corneal Thickness Measurement in Normal and Keratoconic Eyes Using Three Corneal Pachymeters

    Science.gov (United States)

    Feizi, Sepehr; Jafarinasab, Mohammad Reza; Karimian, Farid; Hasanpour, Hosein; Masudi, Ali

    2014-01-01

    Purpose: To assess the agreement among ultrasonic pachymetry, the Galilei dual Scheimpflug analyzer, and Orbscan II for central and peripheral (Galilei vs. Orbscan) corneal thickness (CCT and PCT) measurement in normal and keratoconic eyes. Methods: In this prospective study, CCT and PCT were measured in 88 eyes of 88 refractive surgery candidates and 128 eyes of 69 keratoconic patients with ultrasonic pachymetry, the Galilei, and Orbscan II. The readings by the three instruments were compared using one-way analysis of normal variance. Agreement among the three devices was assessed using Pearson and intraclass correlation coefficients, and Bland–Altman plots. The same analyses were employed to evaluate agreement between Galilei and Orbscan II for PCT measurement. Results: In the normal group, mean CCT was 551.0±39.4, 566.9±33.5, and 565.5±40.9 μm measured by ultrasonic pachymetry, the Galilei, and Orbscan II, respectively (P<0.001). The corresponding figures in the keratoconus group were 492.0±61.7, 502.0±42.1, and 470.6±56.9 μm, respectively (P<0.001). Mean PCT was 612.5±35.3 and 640.9±38.0 μm in the normal group (P<0.001) and 567.6±35.2 and 595.1±41.4 μm in the keratoconus group (P<0.001) by the Galilei and Orbscan II, respectively. CCT and PCT measurements obtained by different devices were significantly correlated in both groups. Conclusion: To measure CCT, the Galilei and Orbscan II can be used interchangeably in normal eyes, but not in keratoconic eyes. For PCT, there is a systematic error between measurements obtained by the Galilei and Orbscan II. However, it is possible to change optical pachymeter readings into those obtained by ultrasonic pachymetry using a constant. PMID:25667728

  18. Corneal endothelial cell changes associated with cataract surgery in patients with type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Hugod, Mikkel; Storr-Paulsen, Allan; Norregaard, Jens Christian;

    2011-01-01

    To investigate the corneal endothelial cell density and morphology in patients with and without diabetes after phacoemulsification with intraocular lens implantation.......To investigate the corneal endothelial cell density and morphology in patients with and without diabetes after phacoemulsification with intraocular lens implantation....

  19. Application of corneal tomography before keratorefractive procedure for laser vision correction.

    Science.gov (United States)

    Luz, Allan; Lopes, Bernardo; Salomão, Marcela; Ambrósio, Renato

    2016-05-01

    Ectasia after refractive surgery represents a major concern among refractive surgeons. Corneal abnormalities and preexisting corneal ectasia are the most important risk factors. Corneal topography and central corneal thickness are the factors traditionally screening for in refractive surgery candidates. Study of the anterior surface by Placido topography allows for identification of keratoconus before biomicroscopy. However, this is insufficient for the evaluation of pre-operative refractive surgery. There are cases of ectasia after laser in situ keratomilusis (LASIK) without identifiable risk factors such that there is a need to go beyond the corneal surface. A key requirement is quantifying susceptibility to corneal biomechanical instability and progression to ectasia. Tomographic indices derived from elevation maps and pachymetry spatial variation produce a Belin Ambrosio display final D index (BAD-D index), which has shown better results compared to surface curvature indices for detecting very mild forms of ectasia. A logistic regression formula, integrating age, residual stromal bed, and BAD-D (Ectasia Susceptibility Score, ESS) resulted in a significant improvement in accuracy, leading to 100% sensitivity and 94% specificity for detecting susceptible cases. A comprehensive corneal structural analysis based on corneal segmental tomography can detect susceptible corneas, which increases safety for refractive surgery patients.

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

    Directory of Open Access Journals (Sweden)

    Yifeng Ke

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

  1. Isolated corneal pseudodendrites as the initial manifestation of tyrosinemia type II in monozygotic twins.

    Science.gov (United States)

    Kymionis, George D; Kankariya, Vardhaman P; Kontadakis, Georgios A; Ziakas, Nikolas G

    2012-05-08

    Fifteen-month-old twins presented with photophobia and bilateral corneal pseudodendrites, and tyrosinemia type II was suspected. Plasma tyrosine levels were elevated. After therapy with tyrosine-restricted diet, corneal lesions resolved. Bilateral pseudodendritic keratitis may be the initial or only manifestation of tyrosinemia type II.

  2. Shape of the anterior cornea : Comparison of height data from 4 corneal topographers

    NARCIS (Netherlands)

    de Jong, Tim; Sheehan, Matthew T.; Dubbelman, Michiel; Koopmans, Steven A.; Jansonius, Nomdo M.

    2013-01-01

    PURPOSE: To compare the ability of clinical corneal topographers to describe the shape of the anterior cornea for optical modeling. SETTING: University Medical Center Groningen, Groningen, Netherlands. DESIGN: Cross-sectional study. METHODS: The anterior corneal shape of healthy subjects was assesse

  3. Persistent corneal edema secondary to presumed dead adult filarial worm in the anterior chamber

    Directory of Open Access Journals (Sweden)

    Basak Samar

    2007-01-01

    Full Text Available We present three cases of persistent corneal edema secondary to presumed dead adult filarial worms lying in the anterior chamber with their attachment to the endothelium. Two of them were initially diagnosed as descemet′s fold with corneal edema. Two patients underwent penetrating keratoplasty and in one case, surgical removal was partly possible with clearing of cornea.

  4. [Protection of corneal endothelium from apoptosis by gene and cell therapy].

    Science.gov (United States)

    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.

  5. Self-inflicted corneal injuries in a child with congenital sensory neuropathy (A case report

    Directory of Open Access Journals (Sweden)

    Gaonker C

    1991-01-01

    Full Text Available An interesting clinical, report of a rare case of bilateral congeni-tal corneal anaesthesia associated with Congenital Sensory Neuropathy (CSN in a 11sub/2 year old child with corneal ulceration secondary to self-inflicted trauma is reported.

  6. The attitude toward xenocorneal transplantation in wait-listed subjects for corneal transplantation in Korea.

    Science.gov (United States)

    Lee, Jong Joo; Kim, Dong Hyun; Jang, Young Eun; Choi, Hyuk Jin; Kim, Mee Kum; Wee, Won Ryang

    2014-01-01

    Shortage of donor cornea is a significant problem in Asia, and xenocorneal transplantation is being actively studied to alleviate this problem. However, the attitudes of subjects who await corneal transplants toward xenocorneal transplantation are not known at all. Thus, this study aimed to investigate the attitudes of subjects on the waiting lists for corneal transplants, toward corneal xenotransplantation. A telephone questionnaire survey comprising six items was conducted in 132 subjects among the wait-listed individuals (n = 590) who were awaiting corneal transplantation or had undergone corneal transplantation at Seoul National University Hospital from July, 2003 to August, 2012. Among six inquiries, four questions were used to analyze attitudes toward corneal xenotransplantation. Each question pertained to (1) the acceptance of xenocorneal transplantation, (2) willingness to participate in clinical trials, (3) worries in xenocorneal transplantation, and (4) the concern of self-identity or social life after xenocorneal transplantation. To analyze demographic factors influencing the question, the subjects were arbitrarily divided into two groups: the young (age xenotransplantation. Younger subjects expressed more worry about xenotransplantation than elderly subjects. The well-educated expressed less concern over self-identity and social life than the less-educated. This survey among subjects who are wait-listed for corneal transplant or who have received a corneal transplant demonstrates that there is an interest in xenocorneal transplantation as an alternate procedure, although there are worries about the procedure that should be further explored in educational campaigns and future studies of the general population.

  7. Measurement of central corneal thickness using ultrasound pachymetry and Orbscan II in normal eyes

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Sadoughi

    2015-01-01

    Conclusion: Orbscan II has good correlation with ultrasound pachymetry for measurement of CCT in normal eyes; however Orbscan II should not be used to evaluate corneal thickness before keratorefractive surgeries, as it tends to overestimate corneal thickness and may result in undesirable, low residual stromal thickness.

  8. Changes in corneal sensitivity following cross-linking for progressive early-stage keratoconus

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    Anelise de Medeiros Lago

    2014-04-01

    Full Text Available Purpose: To evaluate changes in corneal sensitivity following corneal cross-linking (CXL in patients with progressive earlier stage keratoconus. Methods: Thirty-eight eyes of 19 patients (11 women, 8 men were included in a prospective, nonrandomized clinical study. The mean patient age was 22 years (range, 18-26 years. Inclusion criteria were early stage bilateral progressive keratoconus, a transparent cornea, and a thickness of ≥440 µm in the thinnest area of the cornea. Using the Cochet-Bonnet esthesiometer, central corneal sensitivity was measured before surgery, 7 days after surgery, and once a month thereafter until recovery of baseline preoperative levels. Central corneal sensitivity >40 mm was considered normal. Results: Corneal sensitivity gradually returned to preoperative levels in all treated eyes. The mean central corneal sensitivity was 52.2, 24.0, 38.2, 42.5, 50.0, and 52.5 mm before surgery, 7 days after surgery, and at 1, 2, 3, and 4 months after surgery, respectively. Normal levels of corneal sensation, but not baseline (preoperative levels, were observed 2 months after surgery. The preoperative levels were observed 3 months after surgery. Conclusions: Our results suggest that central corneal sensitivity can be decreased for as long as 3 months after CXL for progressive earlier stage keratoconus.

  9. Influence of corneal collagen crosslinking with riboflavin and ultraviolet-a irradiation on excimer laser surgery.

    NARCIS (Netherlands)

    Kampik, D.; Ralla, B.; Keller, S.; Hirschberg, M.; Friedl, P.H.A.; Geerling, G.

    2010-01-01

    PURPOSE: Riboflavin/ultraviolet A (UVA) cross-linking (CXL) of corneal collagen is a novel method of stabilizing corneal mechanical properties and preventing progression of keratectasias. This study was conducted to investigate whether CXL influences ablation rate, flap thickness, and refractive res

  10. Corneal Biomechanical Properties in Myopic Eyes Measured by a Dynamic Scheimpflug Analyzer

    Directory of Open Access Journals (Sweden)

    Jingyi Wang

    2015-01-01

    Full Text Available Purpose. To evaluate the corneal biomechanical parameters in myopic and emmetropic eyes using Corneal Visualization Scheimpflug Technology (CorVis ST. Methods. 103 myopic and emmetropic eyes of 103 patients were examined. Corneal biomechanical parameters, axial length, and mean keratometry were measured using CorVis ST, IOL Master, and topography, respectively. Corneal biomechanical properties were compared within four groups. Bivariate correlation analysis was used to assess the relationship between corneal biomechanical parameters and ocular characteristics. Results. Four of ten corneal biomechanical parameters, namely, deformation amplitude (DA, first- and second-applanation time (A1-time, A2-time, and radius at highest concavity (HC radius, were significantly different within the four groups (P<0.05. In correlation analysis, DA was positively correlated with axial length (r=0.20, P=0.04; A2-time was positively correlated with spherical equivalent (SE (r=0.24, P=0.02; HC radius was positively correlated with SE (r=0.24, P=0.02 and was negatively correlated with mean keratometry (r=-0.20, P=0.046 and axial length (r=-0.21, P=0.03. Conclusions. The corneal refraction-related biomechanical alterations were associated with ocular characteristics. Highly myopic eyes exhibited longer DA and smaller HC radius than do moderately myopic eyes; the eyes with longer axial length tend to have less corneal stiffness and are easier to deform under stress.

  11. Corneal confocal microscopy reveals trigeminal small sensory fiber neuropathy in Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Giulio eFerrari

    2014-10-01

    Full Text Available Although subclinical involvement of sensory neurons in amyotrophic lateral sclerosis (ALS has been previously demonstrated, corneal small fiber sensory neuropathy has not been reported to-date. We examined a group of sporadic ALS patients with corneal confocal microscopy, a recently developed imaging technique allowing in vivo observation of corneal small sensory fibers. Corneal confocal microscopy examination revealed a reduction of corneal small fiber sensory nerve number and branching in ALS patients. Quantitative analysis demonstrated an increase in tortuosity and reduction in length and fractal dimension of ALS patients’ corneal nerve fibers compared to age-matched controls. Moreover, bulbar function disability scores were significantly related to measures of corneal nerve fibers anatomical damage.Our study demonstrates for the first time a corneal small fiber sensory neuropathy in ALS patients. This finding further suggests a link between sporadic ALS and facial-onset sensory and motor neuronopathy (FOSMN syndrome, a rare condition characterized by early sensory symptoms (with trigeminal nerve distribution, followed by wasting and weakness of bulbar and upper limb muscles. In addition, the finding supports a model of neurodegeneration in ALS as a focally advancing process.

  12. Corneal confocal microscopy reveals trigeminal small sensory fiber neuropathy in amyotrophic lateral sclerosis

    Science.gov (United States)

    Ferrari, Giulio; Grisan, Enrico; Scarpa, Fabio; Fazio, Raffaella; Comola, Mauro; Quattrini, Angelo; Comi, Giancarlo; Rama, Paolo; Riva, Nilo

    2014-01-01

    Although subclinical involvement of sensory neurons in amyotrophic lateral sclerosis (ALS) has been previously demonstrated, corneal small fiber sensory neuropathy has not been reported to-date. We examined a group of sporadic ALS patients with corneal confocal microscopy, a recently developed imaging technique allowing in vivo observation of corneal small sensory fibers. Corneal confocal microscopy (CCM) examination revealed a reduction of corneal small fiber sensory nerve number and branching in ALS patients. Quantitative analysis demonstrated an increase in tortuosity and reduction in length and fractal dimension of ALS patients’ corneal nerve fibers compared to age-matched controls. Moreover, bulbar function disability scores were significantly related to measures of corneal nerve fibers anatomical damage. Our study demonstrates for the first time a corneal small fiber sensory neuropathy in ALS patients. This finding further suggests a link between sporadic ALS and facial-onset sensory and motor neuronopathy (FOSMN) syndrome, a rare condition characterized by early sensory symptoms (with trigeminal nerve distribution), followed by wasting and weakness of bulbar and upper limb muscles. In addition, the finding supports a model of neurodegeneration in ALS as a focally advancing process. PMID:25360111

  13. Active Pedicle Epithelial Flap Transposition Combined with Amniotic Membrane Transplantation for Treatment of Nonhealing Corneal Ulcers

    Directory of Open Access Journals (Sweden)

    Ting Zhang

    2016-01-01

    Full Text Available Introduction. The objective was to evaluate the efficacy of active pedicle epithelial flap transposition combined with amniotic membrane transplantation (AMT in treating nonhealing corneal ulcers. Material and Methods. Eleven patients (11 eyes with nonhealing corneal ulcer who underwent the combined surgery were included. Postoperatively, ulcer healing time was detected by corneal fluorescein staining. Visual acuity, intraocular pressure, surgical complications, and recurrence were recorded. Corneal status was inspected by the laser scanning confocal microscopy and anterior segment optical coherence tomography (AS-OCT. Results. The primary diseases were herpes simplex keratitis (8 eyes, corneal graft ulcer (2 eyes, and Stevens-Johnson syndrome (1 eye. All epithelial flaps were intact following surgery, without shedding or displacement. Mean ulcer healing time was 10.8±3.1 days, with a healing rate of 91%. Vision significantly improved from 1.70 to 0.82 log MAR (P=0.001. A significant decrease in inflammatory cell infiltration and corneal stromal edema was revealed 2 months postoperatively by confocal microscopy and AS-OCT. Corneal ulcer recurred in 1 eye. None of the patients developed major complications. Conclusion. Active pedicle epithelial flap transposition combined with AMT is a simple and effective treatment for nonhealing corneal ulcers.

  14. Femtosecond laser-assisted keratoplasty in a child with corneal opacity:case report

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    E. Yu. Markova

    2014-01-01

    Full Text Available Corneal opacities are the fourth cause of blindness world-wide. Over the past two centuries, various corneal transplantation (i.e., keratoplasty methods have been developed and improved. Nowadays, femtolaserssisted keratoplasty is one of most promising techniques. Femtosecond laser have several advantages that provide additional surgical benefits. Among them, no thermal injury, the ability to cut deeply on a single plane and to perform various corneal profiles should be mentioned. In children, corneal disorders are of special importance while femtosecondassisted keraatoplasty case reports are rare. Here, we describe femtosecond laserssisted penetrating keratoplasty in a girl with a rough central corneal opacity.

  15. Optical coherence tomography-based topography determination of corneal grafts in eye bank cultivation

    Science.gov (United States)

    Damian, Angela; Seitz, Berthold; Langenbucher, Achim; Eppig, Timo

    2017-01-01

    Vision loss due to corneal injuries or diseases can be treated by transplantation of human corneal grafts (keratoplasty). However, quality assurance in retrieving and cultivating the tissue transplants is confined to visual and microbiological testing. To identify previous refractive surgery or morphological alterations, an automatic, noncontact, sterile screening procedure is required. Twenty-three corneal grafts have been measured in organ culture with a clinical spectral-domain optical coherence tomographer. Employing a biconic surface fit with 10 degrees of freedom, the radii of curvature and conic constants could be estimated for the anterior and posterior corneal surfaces. Thereupon, central corneal thickness, refractive values, and astigmatism have been calculated. Clinical investigations are required to elaborate specific donor-host matching in the future.

  16. Corneal Confocal Microscopy Anomalies Associated with Cowden Syndrome: A Case Report

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    Sandro Sbordone

    2013-08-01

    Full Text Available Purpose: To describe bilateral corneal alterations through confocal microscopy in a patient affected by Cowden syndrome (CS. Methods: Evaluation of Schirmer's, fluorescein, and lissamine green dye tests. Confocal microscopy was performed in both eyes to investigate corneal abnormalities. Results: Slit lamp observation showed the focal involvement of anterior stromal and epithelial layers. Schirmer's, fluorescein, and lissamine green dye test results were regular, while corneal confocal examination confirmed the disorganization of anterior stromal and epithelial layers in both eyes. Conclusion: CS is a rare autosomal-dominant systemic disorder. In our case, confocal analysis revealed predominance of alterations in the anterior stromal corneal layer, showing an increase of reflectivity, and a totally unstructured architecture in the epithelium layer. Even though the main purpose remains the prevention and the early diagnosis of different systemic tumors that could occur in affected patients, corneal confocal evaluation could play an important role in the early diagnosis of this rare disease.

  17. Correction of low corneal astigmatism in cataract surgery

    Institute of Scientific and Technical Information of China (English)

    Pia; Leon; Marco; Rocco; Pastore; Andrea; Zanei; Ingrid; Umari; Meriem; Messai; Corrado; Negro; Daniele; Tognetto

    2015-01-01

    · AIM: To evaluate and compare aspheric toric intraocular lens(IOL) implantation and aspheric monofocal IOL implantation with limbal relaxing incisions(LRI) to manage low corneal astigmatism(1.0-2.0 D) in cataract surgery.· METHODS: A prospective randomized comparative clinical study was performed. There were randomly recruited 102 eyes(102 patients) with cataracts associated with corneal astigmatism and divided into two groups. The first group received toric IOL implantation and the second one monofocal IOL implantation with peripheral corneal relaxing incisions. Outcomes considered were: visual acuity, postoperative residual astigmatism, endothelial cell count, the need for spectacles, and patient satisfaction. To determine the postoperative toric axis, all patients who underwent the toric IOL implantation were further evaluated using an OPD Scan III(Nidek Co, Japan). Follow-up lasted 6mo.· RESULTS: The mean uncorrected distance visual acuity(UCVA) and the best corrected visual acuity(BCVA) demonstrated statistically significant improvement after surgery in both groups. At the end of the follow-up the UCVA was statistically better in the patients with toric IOL implants compared to those patients who underwent implantation of monofocal IOL plus LRI. The mean residual refractive astigmatism was of 0.4 D for the toric IOL group and 1.1 D for the LRI group(P <0.01). No difference was observed in the postoperative endothelial cell count between the two groups.· CONCLUSION: The two surgical procedures demonstrated a significant decrease in refractive astigmatism. Toric IOL implantation was more effective and predictable compared to the limbal relaxing incision.

  18. Differentiation of embryonic stem cells into corneal epithelium

    Institute of Scientific and Technical Information of China (English)

    WANG Zhichong; LIU Jingbo; GE Jian; HUANG Bing; GAO Qianying; LIU Bingqian; WANG Linghua; YU Ling; FAN Zhigang; LU Xiaoming

    2005-01-01

    Our project was to determine whether embryonic stem (ES) cells could be induced to differentiate into corneal epithelia by superficial corneoscleral limbal stroma. To achieve this goal, ES-GFP cell line D3 was pre-induced by retinoic acid (RA). The pre-induced cells were seeded on deepithelialized superficial corneoscleral slices (SCSS) to form a monolayer, and divided into three groups. Group 1 was cultured and passaged in vitro for direct detection. Group 2 was exposed to air-liquid interfaces for 10 days and implanted into the subcutaneous layer of nude mice for 2 weeks for further induction in vivo. Group 3 was cultured in vitro without any inducing factors for control. There were no teratomas found in nude mice which were implanted with differentiated ES cells after two weeks. The differentiated cells showed an appearance of epithelia both in vitro and in vivo. Expression of CK3, P63 and PCNA was detected by immunohistochemical staining in the differentiated cells in group 1 and 2. Microvillis and zonula occludens were observed on the surface of the differentiated cells under an electron microscope. In the control group, ES cells differentiated freely without any inducing factors. Most cells were shed and formed a neuronal dendrite-like structure, and a minority of cells appeared polymorphic. These results demonstrate that ES cells can differentiate into corneal epithelia on the surface of SCSS under the controlled condition. Differentiated ES cells could be used as epithelial seeding cells for the reconstruction of ocular surface and corneal tissue engineering in the future.

  19. Corneal endothelial cell density and morphology in Phramongkutklao Hospital

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    Narumon Sopapornamorn

    2008-03-01

    Full Text Available Narumon Sopapornamorn1, Manapon Lekskul1, Suthee Panichkul21Department of Ophthalmology, Phramongkutklao Hospital, Bangkok, Thailand; 2Department of Obstetrics and Gynecology, Phramongkutklao College of Medicine, Bangkok, ThailandObjective: To describe the corneal endothelial density and morphology in patients of Phramongkutklao Hospital and the relationship between endothelial cell parameters and other factors.Methods: Four hundred and four eyes of 202 volunteers were included. Noncontact specular microscopy was performed after taking a history and testing the visual acuity, intraocular pressure measurement, Schirmer’s test and routine eye examination by slit lamp microscope. The studied parameters included mean endothelial cell density (MCD, coefficient of variation (CV, and percentage of hexagonality.Results: The mean age of volunteers was 45.73 years; the range being 20 to 80 years old. Their MCD (SD, mean percentage of CV (SD and mean (SD percentage of hexagonality were 2623.49(325 cell/mm2, 39.43(8.23% and 51.50(10.99%, respectively. Statistically, MCD decreased significantly with age (p < 0.01. There was a significant difference in the percentage of CV between genders. There was no statistical significance between parameters and other factors.Conclusion: The normative data of the corneal endothelium of Thai eyes indicated that, statistically, MCD decreased significantly with age. Previous studies have reported no difference in MCD, percentage of CV, and percentage of hexagonality between gender. Nevertheless, significantly different percentages of CV between genders were presented in this study.Keywords: Corneal endothelial cell, parameters, age, gender, smoking, Thailand

  20. Time-gated FLIM microscope for corneal metabolic imaging

    Science.gov (United States)

    Silva, Susana F.; Batista, Ana; Domingues, José Paulo; Quadrado, Maria João.; Morgado, António Miguel

    2016-03-01

    Detecting corneal cells metabolic alterations may prove a valuable tool in the early diagnosis of corneal diseases. Nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are autofluorescent metabolic co-factors that allow the assessment of metabolic changes through non-invasive optical methods. These co-factors exhibit double-exponential fluorescence decays, with well-separated short and lifetime components, which are related to their protein-bound and free-states. Corneal metabolism can be assessed by measuring the relative contributions of these two components. For that purpose, we have developed a wide-field time-gated fluorescence lifetime microscope based on structured illumination and one-photon excitation to record FAD lifetime images from corneas. NADH imaging was not considered as its UV excitation peak is regarded as not safe for in vivo measurements. The microscope relies on a pulsed blue diode laser (λ=443 nm) as excitation source, an ultra-high speed gated image intensifier coupled to a CCD camera to acquire fluorescence signals and a Digital Micromirror Device (DMD) to implement the Structured Illumination technique. The system has a lateral resolution better than 2.4 μm, a field of view of 160 per 120 μm and an optical sectioning of 6.91 +/- 0.45 μm when used with a 40x, 0.75 NA, Water Immersion Objective. With this setup we were able to measure FAD contributions from ex-vivo chicken corneas collected from a local slaughterhouse..

  1. A clinical microbiological study of corneal ulcer patients at western Gujarat, India.

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    Rajesh Somabhai Katara

    2013-06-01

    Full Text Available Corneal ulcer is a major cause of blindness throughout the world. When the cornea is injured by foreign particles, there are chances of infection by the organism and development of ulcer. Bacterial infection in the cornea is invariably an alteration of the defense mechanism of the outer eye. It is essential to determine the local etiology within a given region when planning a corneal ulcer management strategy. Laboratory evaluation is necessary to establish the diagnosis and to guide the antibiotic therapy. One hundred corneal ulcer patients were studied by collecting their corneal scraping samples and processing at Clinical Microbiology department of Shree Meghaji Petharaj Shah Medical College, Jamnagar, Gujarat, India during a period of 17 months. All clinical microbiology laboratory procedures followed standard protocols described in the literature. 40 (40% patients from the age group of 20-70 years had been confirmed as - any organism culture positive - within the corneal ulcer patient population. Fungi were isolated from 26 (26% corneal ulcer patients. The bacterial etiology was confirmed in 14 (14% corneal ulcer patients. The major risk factors for mycotic keratitis were vegetative injury (16, (62%, followed by conjunctivitis (4, (15%, and blunt trauma (3, (11%. Pseudomonas aeruginosa was the most commonly isolated bacterium (6, (43%, followed by Proteus spp. (4, (29%. Corneal Infections due to bacteria and filamentous fungi are a frequent cause of corneal damage. Microbiological investigation is an essential tool in the diagnosis of these infections. The frequency of fungal keratitis has risen over the past 20 to 30 years. Prognosis of bacterial corneal infection has improved since the introduction of specific antibacterial therapy.

  2. Effects of vitamin B12 on the corneal nerve regeneration in rats.

    Science.gov (United States)

    Romano, Maria Rosaria; Biagioni, Francesca; Carrizzo, Albino; Lorusso, Massimo; Spadaro, Angelo; Micelli Ferrari, Tommaso; Vecchione, Carmine; Zurria, Monia; Marrazzo, Giuseppina; Mascio, Giada; Sacchetti, Benedetto; Madonna, Michele; Fornai, Francesco; Nicoletti, Ferdinando; Lograno, Marcello Diego

    2014-03-01

    The study was designed to investigate the effects of a new ophthalmic solution containing 0.05% vitamin B12 0.05% on corneal nerve regeneration in rats after corneal injury. Eyes of anesthetized male Wistar rats were subjected to corneal injury by removing the corneal epithelium with corneal brush (Algerbrush). After the epithelial debridement, the right eye of each animal received the instillation of one drop of the ophthalmic solution containing vitamin B12 0.05% plus taurine 0.5% and sodium hyaluronate 0.5% four time per day for 10 or 30 days. Left eyes were used as control and treated with solution containing taurine 0.5% and sodium hyaluronate 0.5% alone following the same regimen. Fluorescein staining by slit-lamp and morphological analysis was used to determine corneal wound healing. Immunohistochemistry, immunoblot and confocal microscopy were used to examine corneal re-innervation. Slit-lamp and histological analyses showed that re-epithelization of the corneas was accelerated in rats treated with vitamin B12. A clear-cut difference between the two groups of rats was seen after 10 days of treatment, whereas a near-to-complete re-epithelization was observed in both groups at 30 days. Vitamin B12 treatment had also a remarkable effect on corneal re-innervation, as shown by substantial increased in the expression of neurofilament 160 and β-III tubulin at both 10 and 30 days. The presence of SV2A-positive nerve endings suggests the presence of synapse-like specialized structures in corneal epithelium of the eye treated with vitamin B12. Our findings suggest that vitamin B12 treatment represents a powerful strategy to accelerate not only re-epithelization but also corneal re-innervation after mechanical injury.

  3. Surgical therapies for corneal perforations: 10 years of cases in a tertiary referral hospital

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    Yokogawa H

    2014-10-01

    Full Text Available Hideaki Yokogawa, Akira Kobayashi, Natsuko Yamazaki, Toshinori Masaki, Kazuhisa Sugiyama Department of Ophthalmology, Kanazawa University Graduate School of Medical Science, Kanazawa, JapanPurpose: To report surgical therapies for corneal perforations in a tertiary referral hospital.Methods: Thirty-one eyes of 31 patients (aged 62.4±18.3 years with surgically treated corneal perforations from January 2002 to July 2013 were included in this study. Demographic data such as cause of corneal perforation, surgical procedures, and visual outcomes were retrospectively analyzed.Results: The causes of corneal perforation (n=31 were divided into infectious (n=8, 26% and noninfectious (n=23, 74% categories. Infectious causes included fungal ulcer, herpetic stromal necrotizing keratitis, and bacterial ulcer. The causes of noninfectious keratopathy included corneal melting after removal of a metal foreign body, severe dry eye, lagophthalmos, canaliculitis, the oral anticancer drug S-1, keratoconus, rheumatoid arthritis, neurotrophic ulcer, atopic keratoconjunctivitis, and unknown causes. Initial surgical procedures included central large corneal graft (n=17, small corneal graft (n=7, and amniotic membrane transplantation (n=7. In two cases the perforation could not be sealed during the first surgical treatment and required subsequent procedures. All infectious keratitis required central large penetrating keratoplasty to obtain anatomical cure. In contrast, several surgical options were used for the treatment of noninfectious keratitis. After surgical treatment, anatomical cure was obtained in all cases. Mean postoperative best corrected visual acuity was better at 6 months (logMAR 1.3 than preoperatively (logMAR 1.8.Conclusion: Surgical therapies for corneal perforations in our hospital included central large lamellar/penetrating keratoplasty, small peripheral patch graft, and amniotic membrane transplantation. All treatments were effective. Corneal

  4. Indications for Corneal Transplantation at a Tertiary Referral Center in Tehran

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    Mohammad Zare

    2010-01-01

    Full Text Available Purpose: To report the indications and techniques of corneal transplantation at a tertiary referral center in Tehran over a 3-year period. Methods: Records of patients who had undergone any kind of corneal transplantation at Labbafinejad Medical Center, Tehran, Iran from March 2004 to March 2007 were reviewed to determine the indications and types of corneal transplantation. Results: During this period, 776 eyes of 756 patients (including 504 male subjects with mean age of 41.3±21.3 years underwent corneal transplantation. The most common indication was keratoconus (n=317, 40.8% followed by bullous keratopathy (n=90, 11.6%, non-herpetic corneal scars (n=62, 8.0%, infectious corneal ulcers (n=61, 7.9%, previously failed grafts (n=61, 7.9%, endothelial and stromal corneal dystrophies (n=28, 3.6%, and trachoma keratopathy (n=26, 3.3%. Other indications including Terrien′s marginal degeneration, post-LASIK keratectasia, trauma, chemical burns, and peripheral ulcerative keratitis constituted the rest of cases. Techniques of corneal transplantation included penetrating keratoplasty (n=607, 78.2%, deep anterior lamellar keratoplasty (n=108, 13.9%, conventional lamellar keratoplasty (n=44, 5.7%, automated lamellar therapeutic keratoplasty (n=8, 1.0%, and Descemet stripping endothelial keratoplasty (n=6, 0.8% in descending order. The remaining cases were endothelial keratoplasty and sclerokeratoplasty. Conclusion: In this study, keratoconus was the most common indication for penetrating keratoplasty which was the most prevalent technique of corneal transplantation. However, deep anterior lamellar keratoplasty is emerging as a growing alternative for corneal pathologies not involving the endothelium.

  5. Indications for Corneal Transplantation at a Tertiary Referral Center in Tehran

    Science.gov (United States)

    Zare, Mohammad; Javadi, Mohammad-Ali; Einollahi, Bahram; Baradaran-Rafii, Alireza; Ghanavati, Siamak Zarei; Farsani, Mohammad-Reza Jamshidi; Mohammadi, Parviz; Feizi, Sepehr

    2010-01-01

    Purpose To report the indications and techniques of corneal transplantation at a tertiary referral center in Tehran over a 3-year period. Methods Records of patients who had undergone any kind of corneal transplantation at Labbafinejad Medical Center, Tehran, Iran from March 2004 to March 2007 were reviewed to determine the indications and types of corneal transplantation. Results During this period, 776 eyes of 756 patients (including 504 male subjects) with mean age of 41.3±21.3 years underwent corneal transplantation. The most common indication was keratoconus (n=317, 40.8%) followed by bullous keratopathy (n=90, 11.6%), non-herpetic corneal scars (n=62, 8.0%), infectious corneal ulcers (n=61, 7.9%), previously failed grafts (n=61, 7.9%), endothelial and stromal corneal dystrophies (n=28, 3.6%), and trachoma keratopathy (n=26, 3.3%). Other indications including Terrien’s marginal degeneration, post-LASIK keratectasia, trauma, chemical burns, and peripheral ulcerative keratitis constituted the rest of cases. Techniques of corneal transplantation included penetrating keratoplasty (n=607, 78.2%), deep anterior lamellar keratoplasty (n=108, 13.9%), conventional lamellar keratoplasty (n=44, 5.7%), automated lamellar therapeutic keratoplasty (n=8, 1.0%), and Descemet stripping endothelial keratoplasty (n=6, 0.8%) in descending order. The remaining cases were endothelial keratoplasty and sclerokeratoplasty. Conclusion In this study, keratoconus was the most common indication for penetrating keratoplasty which was the most prevalent technique of corneal transplantation. However, deep anterior lamellar keratoplasty is emerging as a growing alternative for corneal pathologies not involving the endothelium. PMID:22737335

  6. A Clinical Microbiological Study of Corneal Ulcer Patients at Western Gujarat, India

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    Nilesh Dhanjibhai Patel

    2013-06-01

    Full Text Available Corneal ulcer is a major cause of blindness throughout the world. When the cornea is injured by foreign particles, there are chances of infection by the organism and development of ulcer. Bacterial infection in the cornea is invariably an alteration of the defense mechanism of the outer eye. It is essential to determine the local etiology within a given region when planning a corneal ulcer management strategy. Laboratory evaluation is necessary to establish the diagnosis and to guide the antibiotic therapy. One hundred corneal ulcer patients were studied by collecting their corneal scraping samples and processing at Clinical Microbiology department of Shree Meghaji Petharaj Shah Medical College, Jamnagar, Gujarat, India during a period of 17 months. All clinical microbiology laboratory procedures followed standard protocols described in the literature. 40 (40% patients from the age group of 20-70 years had been confirmed as - any organism culture positive - within the corneal ulcer patient population. Fungi were isolated from 26 (26% corneal ulcer patients. The bacterial etiology was confirmed in 14 (14% corneal ulcer patients. The major risk factors for mycotic keratitis were vegetative injury (16, (62%, followed by conjunctivitis (4, (15%, and blunt trauma (3, (11%. Pseudomonas aeruginosa was the most commonly isolated bacterium (6, (43%, followed by Proteus spp. (4, (29%. Corneal Infections due to bacteria and filamentous fungi are a frequent cause of corneal damage. Microbiological investigation is an essential tool in the diagnosis of these infections. The frequency of fungal keratitis has risen over the past 20 to 30 years. Prognosis of bacterial corneal infection has improved since the introduction of specific antibacterial therapy.

  7. Evaluating the effectiveness of treatment of corneal ulcers via computer-based automatic image analysis

    Science.gov (United States)

    Otoum, Nesreen A.; Edirisinghe, Eran A.; Dua, Harminder; Faraj, Lana

    2012-06-01

    Corneal Ulcers are a common eye disease that requires prompt treatment. Recently a number of treatment approaches have been introduced that have been proven to be very effective. Unfortunately, the monitoring process of the treatment procedure remains manual and hence time consuming and prone to human errors. In this research we propose an automatic image analysis based approach to measure the size of an ulcer and its subsequent further investigation to determine the effectiveness of any treatment process followed. In Ophthalmology an ulcer area is detected for further inspection via luminous excitation of a dye. Usually in the imaging systems utilised for this purpose (i.e. a slit lamp with an appropriate dye) the ulcer area is excited to be luminous green in colour as compared to rest of the cornea which appears blue/brown. In the proposed approach we analyse the image in the HVS colour space. Initially a pre-processing stage that carries out a local histogram equalisation is used to bring back detail in any over or under exposed areas. Secondly we deal with the removal of potential reflections from the affected areas by making use of image registration of two candidate corneal images based on the detected corneal areas. Thirdly the exact corneal boundary is detected by initially registering an ellipse to the candidate corneal boundary detected via edge detection and subsequently allowing the user to modify the boundary to overlap with the boundary of the ulcer being observed. Although this step makes the approach semi automatic, it removes the impact of breakages of the corneal boundary due to occlusion, noise, image quality degradations. The ratio between the ulcer area confined within the corneal area to the corneal area is used as a measure of comparison. We demonstrate the use of the proposed tool in the analysis of the effectiveness of a treatment procedure adopted for corneal ulcers in patients by comparing the variation of corneal size over time.

  8. A clinical microbiological study of corneal ulcer patients at western Gujarat, India.

    Science.gov (United States)

    Somabhai Katara, Rajesh; Dhanjibhai Patel, Nilesh; Sinha, Mala

    2013-07-13

    Corneal ulcer is a major cause of blindness throughout the world. When the cornea is injured by foreign particles, there are chances of infection by the organism and development of ulcer. Bacterial infection in the cornea is invariably an alteration of the defense mechanism of the outer eye. It is essential to determine the local etiology within a given region when planning a corneal ulcer management strategy. Laboratory evaluation is necessary to establish the diagnosis and to guide the antibiotic therapy. One hundred corneal ulcer patients were studied by collecting their corneal scraping samples and processing at Clinical Microbiology department of Shree Meghaji Petharaj Shah Medical College, Jamnagar, Gujarat, India during a period of 17 months. All clinical microbiology laboratory procedures followed standard protocols described in the literature. 40 (40%) patients from the age group of 20-70 years had been confirmed as - any organism culture positive - within the corneal ulcer patient population. Fungi were isolated from 26 (26%) corneal ulcer patients. The bacterial etiology was confirmed in 14 (14%) corneal ulcer patients. The major risk factors for mycotic keratitis were vegetative injury (16, (62%)), followed by conjunctivitis (4, (15%)), and blunt trauma (3, (11%)). Pseudomonas aeruginosa was the most commonly isolated bacterium (6, (43%)), followed by Proteus spp. (4, (29%)). Corneal Infections due to bacteria and filamentous fungi are a frequent cause of corneal damage. Microbiological investigation is an essential tool in the diagnosis of these infections. The frequency of fungal keratitis has risen over the past 20 to 30 years. Prognosis of bacterial corneal infection has improved since the introduction of specific antibacterial therapy.

  9. The effect of Gonioscopy on keratometry and corneal surface topography

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    DeBroff Brian M

    2006-06-01

    Full Text Available Abstract Background Biometric procedures such as keratometry performed shortly after contact procedures like gonioscopy and applanation tonometry could affect the validity of the measurement. This study was conducted to understand the short-term effect of gonioscopy on corneal curvature measurements and surface topography based Simulated Keratometry and whether this would alter the power of an intraocular lens implant calculated using post-gonioscopy measurements. We further compared the effect of the 2-mirror (Goldmann and the 4-mirror (Sussman Gonioscopes. Methods A prospective clinic-based self-controlled comparative study. 198 eyes of 99 patients, above 50 years of age, were studied. Exclusion criteria included documented dry eye, history of ocular surgery or trauma, diabetes mellitus and connective tissue disorders. Auto-Keratometry and corneal topography measurements were obtained at baseline and at three follow-up times – within the first 5 minutes, between the 10th-15th minute and between the 20th-25th minute after intervention. One eye was randomized for intervention with the 2-mirror gonioscope and the other underwent the 4-mirror after baseline measurements. t-tests were used to examine differences between interventions and between the measurement methods. The sample size was calculated using an estimate of clinically significant lens implant power changes based on the SRK-II formula. Results Clinically and statistically significant steepening was observed in the first 5 minutes and in the 10–15 minute interval using topography-based Sim K. These changes were not present with the Auto-Keratometer measurements. Although changes from baseline were noted between 20 and 25 minutes topographically, these were not clinically or statistically significant. There was no significant difference between the two types of gonioscopes. There was greater variability in the changes from baseline using the topography-based Sim K readings

  10. Diffuse corneal abrasion after ocular exposure to laundry detergent pod.

    Science.gov (United States)

    Whitney, Rachel E; Baum, Carl R; Aronson, Paul L

    2015-02-01

    Although ocular injury from alkaline household cleaning products is well described, there is less known about the significance and extent of injury with ocular exposure to detergent pods. We report a 12-month-old with diffuse corneal abrasion caused by ocular contact with a laundry detergent pod. In addition to the known risks with aspiration with detergent pods, the potential for severe ocular injury is important for parents and clinicians to recognize. Children with ocular exposure to detergent pods should seek immediate medical care.

  11. Pathogenesis, clinical features and management of recurrent corneal erosions.

    Science.gov (United States)

    Ramamurthi, S; Rahman, M Q; Dutton, G N; Ramaesh, K

    2006-06-01

    Recurrent corneal erosions (RCE) are common. They are characterised by repeated episodes of pain, difficulty in opening the eyes, watering, and photophobia resulting from poor epithelial adhesion. In the majority of patients with RCE, trauma is the initiating factor. Epithelial, stromal, and endothelial corneal dystrophies have all been described in association with RCE. Other causes that may lead to RCE include chemical and thermal injuries, previous herpetic keratitis, meibomian gland dysfunction, ocular rosacea, diabetes mellitus, Salzmann's nodular degeneration, band keratopathy, previous bacterial ulceration, kerato-conjunctivitis sicca, and epidermolysis bullosa. The conditions that are associated with RCE can be either primary or secondary depending on whether the basement membrane complex abnormality is intrinsic or acquired. Primary types tend to be bilateral, symmetrical and develop in multiple corneal locations. The pathogenetic mechanism of this disorder is related to poor adhesion of the corneal epithelium to the underlying stroma. Excessive matrix metalloproteinase (MMP) activity may play a role in the pathogenesis. Although the majority of patients will respond to simple measures such as padding and antibiotic ointment, RCE resistant to simple measures require approaches that are more elaborate. The common goal of these approaches is to encourage proper formation of adhesion complexes between the epithelium and the stroma. The use of long-term contact lenses, autologous serum eye drops, botulinum toxin, induced ptosis, oral MMP inhibitors, diamond burr polishing of Bowman's membrane have been reported with varying degree of success in treating RCE. Anterior stromal puncture with insulin needles or Neodymium : aluminium-yttrium-garnet may enhance the epithelial adhesion to the basement membrane by scar formation and success rates of up to 80% have been reported in the treatment of recalcitrant RCE. Excimer laser photo-therapeutic keratectomy (PTK) is

  12. Dry Eye and Corneal Langerhans Cells in Systemic Lupus Erythematosus

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    Miklós D. Resch

    2015-01-01

    Full Text Available Purpose. Investigation of dry eye and corneal Langerhans cells (LCs in systemic lupus erythematosus (SLE. Methods. Prospective consecutive case series of 27 SLE patients and 27 control subjects. Dry eye was evaluated by lid-parallel conjunctival folds (LIPCOF, Schirmer test, tear break-up time (TBUT, and ocular surface disease index (OSDI questionnaire. In vivo investigation of corneal LCs density and morphology (LCM was performed with confocal corneal microscopy (Heidelberg Retina Tomograph with Rostock Cornea Module. Results. Tear production and stability were pathological in SLE subjects compared to control (Schirmer: 8.45 ± 9.82 mm/5 min versus 11.67 ± 3.21 mm/5 min; TBUT: 6.86 ± 3.53 s versus 11.09 ± 3.37 s. OSDI was significantly greater in SLE patients (25.95 ± 17.92 than in controls (11.06 ± 7.18. Central LC density was greater in SLE patients (43.08 ± 48.67 cell/mm2 than in controls (20.57 ± 21.04 cell/mm2. There was no difference in the peripheral LC density (124.78 ± 165.39 versus 78.00 ± 39.51 cell/mm2. LCM was higher in SLE patients in the centre (1.43 ± 0.79 and in the periphery (2.89 ± 0.42 compared to controls (centre: 1.00 ± 0.69, periphery: 2.35 ± 0.54. Conclusions. Significant changes in dry eye parameters and marked increase of central LCs could be demonstrated in SLE patients. SLE alters not only the LC density but also the morphology, modifies corneal homeostasis, and might contribute to the development of dry eye.

  13. Pink hypopyon in a patient with Serratia marcescens corneal ulceration.

    Science.gov (United States)

    Stefater, James A; Borkar, Durga S; Chodosh, James

    2015-01-01

    A 65-year-old woman presented to the emergency ward at the Massachusetts Eye and Ear Infirmary with 2 days of redness, irritation, photophobia, and diminished vision in her left eye. She was found to have a large central corneal ulcer with a small hypopyon. On the following day, after initiation of broad-spectrum antibiotics, the patient had improved symptoms but now had a 2-mm hypopyon that was distinctly pink in color. Cultures were positive for Serratia marcescens. A pink hypopyon, a rare occurrence, alerted the authors to a causative agent of Enterobacteriacae, either Klebsiella or Serratia. Immediate and intensive treatment was subsequently initiated.

  14. Viability of human corneal keratocytes during organ culture

    DEFF Research Database (Denmark)

    Møller-Pedersen, T; Møller, H J

    1996-01-01

    The viability of human corneal keratocytes was assessed during four weeks of 'closed system' organ culture at 31 degrees C. After 28 days of culturing, the entire keratocyte population was still alive and viable because all cells incorporated uridine; a parameter for RNA-synthesis. During the first...... of keratan sulphate proteoglycan suggested that approximately 1% of the total content was lost during the period. In conclusion, our current organ culture technique can maintain a viable keratocyte population for four weeks; a viable stroma can be grafted within this period....

  15. Low temperature corneal laser welding investigated by atomic force microscopy

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    Matteini, Paolo; Sbrana, Francesca; Tiribilli, Bruno; Pini, Roberto

    2009-02-01

    The structural modifications in the stromal matrix induced by low-temperature corneal laser welding were investigated by atomic force microscopy (AFM). This procedure consists of staining the wound with Indocyanine Green (ICG), followed by irradiation with a near-infrared laser operated at low-power densities. This induces a local heating in the 55-65 °C range. In welded tissue, extracellular components undergo heat-induced structural modifications, resulting in a joining effect between the cut edges. However, the exact mechanism generating the welding, to date, is not completely understood. Full-thickness cuts, 3.5 mm in length, were made in fresh porcine cornea samples, and these were then subjected to laser welding operated at 16.7 W/cm2 power density. AFM imaging was performed on resin-embedded semi-thin slices once they had been cleared by chemical etching, in order to expose the stromal bulk of the tissue within the section. We then carried out a morphological analysis of characteristic fibrillar features in the laser-treated and control samples. AFM images of control stromal regions highlighted well-organized collagen fibrils (36.2 +/- 8.7 nm in size) running parallel to each other as in a typical lamellar domain. The fibrils exhibited a beaded pattern with a 22-39 nm axial periodicity. Laser-treated corneal regions were characterized by a significant disorganization of the intralamellar architecture. At the weld site, groups of interwoven fibrils joined the cut edges, showing structural properties that were fully comparable with those of control regions. This suggested that fibrillar collagen is not denatured by low-temperature laser welding, confirming previous transmission electron microscopy (TEM) observations, and thus it is probably not involved in the closure mechanism of corneal cuts. The loss of fibrillar organization may be related to some structural modifications in some interfibrillar substance as proteoglycans or collagen VI. Furthermore, AFM

  16. Evaluation of Corneal Stromal Demarcation Line after Two Different Protocols of Accelerated Corneal Collagen Cross-Linking Procedures Using Anterior Segment Optical Coherence Tomography and Confocal Microscopy

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    Engin Bilge Ozgurhan

    2014-01-01

    Full Text Available Purpose. To evaluate the depth of corneal stromal demarcation line using AS-OCT and confocal microscopy after two different protocols of accelerated corneal collagen cross-linking procedures (CXL. Methods. Patients with keratoconus were divided into two groups. Peschke CXL device (Peschke CCL-VARIO Meditrade GmbH applied UVA light with an intended irradiance of 18.0 mW/cm2 for 5 minutes after applying riboflavin for 20 minutes (group 1 and 30 minutes (group 2. One month postoperatively, corneal stromal demarcation line was measured using AS-OCT and confocal microscopy. Results. This study enrolled 34 eyes of 34 patients (17 eyes in group 1 and 17 eyes in group 2. The mean depth of the corneal stromal demarcation line was 208.64±18.41 μm in group 1 and 240.37±18.89 μm in group 2 measured with AS OCT, while it was 210.29±18.66 μm in group 1 and 239.37±20.07 μm in group 2 measured with confocal microscopy. Corneal stromal demarcation line depth measured with AS OCT or confocal microscopy was significantly deeper in group 2 than group 1 (P<0.01. Conclusion. The group in which riboflavin was applied for 30 minutes showed significantly deeper corneal stromal demarcation line than the group in which riboflavin was applied for 20 minutes.

  17. Effects of Silicone Hydrogel Contact Lens Application on Corneal High-order Aberration and Visual Guality in Patients with Corneal Opacities

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    Sevda Aydın Kurna

    2012-03-01

    Full Text Available Pur po se: Evaluation of the corneal high-order aberrations and visual quality changes after application of silicone hydrogel contact lenses in patients with corneal opacities due to various etiologies. Ma te ri al and Met hod: Fifteen eyes of 13 patients with corneal opacities were included in the study. During the ophthalmologic examination before and after contact lens application, visual acuity was measured with Snellen acuity chart and contrast sensitivity - with Bailey-Lowie Charts in letters. Aberrations were measured with corneal aberrometer (NIDEK Magellan Mapper under a naturally dilated pupil. Spherical aberration, coma, trefoil, irregular astigmatism and total high-order root mean square (RMS values were recorded. Measurements were repeated with balafilcon A lenses (PureVision 2 HD, B&L on all patients. Re sults: Patient age varied between 23 and 50 years. Two eyes had subepithelial infiltrates due to adenoviral keratitis, 1 had nebulae due to previous infections or trauma, and 2 had Salzmann’s nodular degeneration. We observed a mean increase of 1 line in visual acuity and 5 letters in contrast sensitivity with contact lenses versus glasses in the patients. Mean RMS values of spherical aberration, irregular astigmatism and total high-order aberrations decreased significantly with contact lenses. Dis cus si on: Silicone hydrogel soft contact lenses may improve visual quality by decreasing the corneal aberrations in patients with corneal opacities. (Turk J Ophthalmol 2012; 42: 97-102

  18. Superficial corneal foreign body: laboratory and epidemiologic aspects Corpo estranho corneal superficial: aspectos laboratoriais e epidemiológicos

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    Ednajar Tavares Macedo Filho

    2005-12-01

    Full Text Available PURPOSE: To determine by bacterioscopy and culture the microorganisms carried by corneal foreign body and their sensitivity to antibiotics by antibiotic sensitivity test. METHODS: A prospective study was carried out and information was collected on 101 patients who presented with corneal foreign body at the São Paulo Hospital Eye Emergency Service. Prior to any treatment, a sample of the ipsilateral inferior conjunctival fornix and the foreign body were collected and immersed in thioglycolate broth. Samples were sown on solid culture media including blood, chocolate and Sabouraud agar. Bacterioscopic examination using Gram and Giemsa staining and sensitivity test were performed. Positive foreign body culture results were compared to ipsilateral conjunctival fornix culture to exclude possible normal flora growth. RESULTS: Approximately 92% of patients were males with a mean age of 35 years and in 62.4% (95% confidence interval: 52.2 - 71.8% had the right eye was affected. Foreign body positive cultures were achieved in 32.7% (95% confidence interval: 23.7 - 42.7% of the cases. The microorganisms isolated from the foreign body culture were identified as: Streptococcus, alpha-hemolytic (n=4, Staphylococcus aureus (n=4, Staphylococcus, coagulase-negative (n=4, Corynebacterium xerosis (n=3, unidentified Gram-positive bacillus (n=2, Moraxella sp (n=1, Serratia sp (n=1, Acynetobacter sp (n=1. The microbial sensitivity test showed that 95% of the cases were sensitive to chloramphenicol and 90% were sensitive to ciprofloxacin, these being antibiotics used in our routine service. CONCLUSION: Superficial corneal foreign body acts as important contaminant vector and the great majority of isolated bacteria were sensitive to the antibiotic prophylaxis used in the treatment.OBJETIVOS: Identificar por meio de cultura e bacterioscopia os microrganismos veiculados por corpo estranho corneal e sua sensibilidade aos antibióticos em teste de antibiograma. M

  19. The effects of the presence of the corneal epithelium and supplemental hydrocortisone on ß-glucuronidase levels with corneal preservation

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    Mauger TF

    2011-03-01

    Full Text Available Thomas Mauger, Eric QuartettiHavener Eye Institute, Department of Ophthalmology, The Ohio State University, OH, USAPurpose: To analyze the levels of ß-glucuronidase during prolonged (14 day corneal preservation with epithelialized (EPI and deepithelialized (DEP corneas and the effect of supplemental hydrocortisone (HCT on these levels.Methods: Thirty-six freshly excised bovine corneas were preserved in Optisol solution (4°C for 14 days with the following conditions EPI/no supplemental HCT, DEP no supplemental HCT, EPI/10-8 M HCT, and EPI 10-4 M HCT. ß-glucuronidase activity levels were measured at the end of this period.Results: ß-glucuronidase levels (nmol/mL/h for each group were found to be: EPI – No HCT: 4.302, SEM 0.586; DEP – No HCT: 2.178, SEM 0.271; EPI – 10-8 M HCT: 4.472, SEM 0.435; EPI – 10-4 M HCT: 2.072, SEM 0.437. The EPI – No HCT and EPI – 10-8 M HCT were not significantly different as were the DEP – No HCT and EPI – 10-4 M HCT groups. The EPI – No HCT group and the EPI – 10-8 M HCT group were independently significantly different from the DEP – No HCT and the EPI – 10-4 M HCT groups.Conclusions: The corneal epithelium contributes significantly to the formation of the lysosomal enzyme, ß-glucuronidase, during preservation. The addition of 10-4 M HCT decreases the production of ß-glucuronidase during corneal preservation in this model.Keywords: ß-glucuronidase, preservation 

  20. Using femtosecond laser to create customized corneal flaps for patients with low and moderate refractive error differing in corneal thickness.

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    Chi Zhang

    Full Text Available This study is designed to evaluate the visual outcomes, accuracy, and predictability of corneal flaps with different thicknesses created by 60-kHz femtosecond laser according to different corneal thicknesses in the patients with low and moderate refractive error. A total of 182 eyes were divided according to the central corneal thickness (470 μm-499 μm in Group A, 500 μm-549 μm in Group B, and 550 μm-599 μm in Group C and underwent femtosecond laser-assisted LASIK for a target corneal flap thickness (100 μm for Group A, 110 μm for Group B, and 120 μm for Group C. Uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, and refractive status were examined. The flap thickness of each eye was measured by anterior segment optical coherence tomography (AS-OCT on 30 points at 1-month follow-up to assess the accuracy and predictability. Postoperatively, at least 75% of eyes had a UDVA of 20/16 or better, less than 2% of eyes lost one line, over 30% of eyes gained one or more lines in CDVA, at least 95% of eyes had astigmatism of less than 0.25 D, all eyes achieved a correction within ± 1.00 D from the target spherical equivalent refraction. The visual and refractive outcomes did not differ significantly in all groups (P >0.05. The mean flap thickness was 100.36 ± 4.32 μm (range: 95-113 μm in Group A, 111.64 ± 3.62 μm (range: 108-125 μm in Group B, and 122.32 ± 2.88 μm (range: 112-128 μm in Group C. The difference at each measured point among the three groups was significant (P < 0.05. The accuracy and predictability were satisfactory in all three groups. In conclusion, this customized treatment yielded satisfactory clinical outcomes with accurate and predictable flap thickness for patients with low and moderate refractive error.

  1. Nanotechnology in corneal neovascularization therapy--a review.

    Science.gov (United States)

    Gonzalez, Lilian; Loza, Raymond J; Han, Kyu-Yeon; Sunoqrot, Suhair; Cunningham, Christy; Purta, Patryk; Drake, James; Jain, Sandeep; Hong, Seungpyo; Chang, Jin-Hong

    2013-03-01

    Nanotechnology is an up-and-coming branch of science that studies and designs materials with at least one dimension sized from 1-100 nm. These nanomaterials have unique functions at the cellular, atomic, and molecular levels. The term "nanotechnology" was first coined in 1974. Since then, it has evolved dramatically and now consists of distinct and independent scientific fields. Nanotechnology is a highly studied topic of interest, as nanoparticles can be applied to various fields ranging from medicine and pharmacology, to chemistry and agriculture, to environmental science and consumer goods. The rapidly evolving field of nanomedicine incorporates nanotechnology with medical applications, seeking to give rise to new diagnostic means, treatments, and tools. Over the past two decades, numerous studies that underscore the successful fusion of nanotechnology with novel medical applications have emerged. This has given rise to promising new therapies for a variety of diseases, especially cancer. It is becoming abundantly clear that nanotechnology has found a place in the medical field by providing new and more efficient ways to deliver treatment. Ophthalmology can also stand to benefit significantly from the advances in nanotechnology research. As it relates to the eye, research in the nanomedicine field has been particularly focused on developing various treatments to prevent and/or reduce corneal neovascularization among other ophthalmologic disorders. This review article aims to provide an overview of corneal neovascularization, currently available treatments, and where nanotechnology comes into play.

  2. Incorporating corneal pachymetry into the management of glaucoma.

    Science.gov (United States)

    Iester, Michele; Mete, Maurizio; Figus, Michele; Frezzotti, Paolo

    2009-09-01

    Intraocular pressure (IOP) results from a dynamic balance between aqueous humor formation and outflow. The simplest technique to measure IOP is indentation tonometry. Another technique is applanation. These methods are related to the elasticity of the eye, which mainly depends on its thickness and hysteresis. For several decades, Goldmann applanation tonometry has been the most accepted method of measuring IOP; the Goldmann tonometer is still used in all important trials. The relationship between IOP values and central corneal thickness (CCT) is well known; Goldmann stated that this relationship only holds for an average corneal thickness of 520 microm measured by optical pachymetry. The Ocular Hypertension Treatment Study (OHTS) showed that CCT is an important risk factor for a change from ocular hypertension to primary open-angle glaucoma. In a multivariate model that included IOP, CCT was the most powerful component of the predictive model. In the Early Manifest Glaucoma Trial (EMGT) with an 11-year follow-up, CCT was a significant predictive factor for glaucoma progression in patients with higher baseline IOP but not in those with lower baseline IOP. Clinical trials such as the OHTS and EMGT cannot prove that CCT is linked to a risk for glaucoma on a biological level. Thus, in eyes with glaucoma, IOP must be treated because it has a significant influence on progression of glaucoma, regardless of the baseline IOP and CCT.

  3. Novel characterization of lymphatic valve formation during corneal inflammation.

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    Tan Truong

    Full Text Available Lymphatic research has progressed rapidly in recent years. Though lymphatic dysfunction has been found in a wide array of disorders from transplant rejection to cancer metastasis, to date, there is still little effective treatment for lymphatic diseases. The cornea offers an optimal site for lymphatic research due to its accessible location, transparent nature, and lymphatic-free but inducible features. However, it still remains unknown whether lymphatic valves exist in newly formed lymphatic vessels in the cornea, and how this relates to an inflammatory response. In this study, we provide the first evidence showing that lymphatic valves were formed in mouse cornea during suture-induced inflammation with the up-regulation of integrin alpha 9. The number of corneal valves increased with the progression of inflammatory lymphangiogenesis. Moreover, we have detected lymphatic valves at various developmental stages, from incomplete to more developed ones. In addition to defining the average diameter of lymphatic vessels equipped with lymphatic valves, we also report that lymphatic valves were more often located near the branching points. Taken together, these novel findings not only provide new insights into corneal lymphatic formation and maturation, but also identify a new model for future investigation on lymphatic valve formation and possibly therapeutic intervention.

  4. Outcomes of corneal crosslinking for central and paracentral keratoconus

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    Tian, Mingxia; Ma, Ping; Zhou, Weiyan; Feng, Jie; Mu, Guoying

    2017-01-01

    Abstract Background: The aim of the study was to compare the therapy of corneal collagen crosslinking (CXL) for central and paracentral keratoconus. Methods: 64 eyes of 43 central keratoconus patients whose highest power of the cornea located in the central 3 mm zone and 24 eyes of 16 paracentral keratoconus patients whose highest power located out of the central 3 mm zone received standard corneal CXL were included. Maximum keratometry (Kmax) and astigmatism according to topography, uncorrected distant visual acuity (UDVA), corrected distant visual acuity (CDVA) were studied preoperatively and 2 years postoperatively. Results: Central group: Preoperative UDVA and CDVA were 0.9 ± 0.4 and 0.5 ± 0.4 logMAR, respectively. At 2 years, UDVA and CDVA significantly improved to 0.8 ± 0.4 and 0.4 ± 0.3 logMAR(P  0.05). Preoperative Kmax and astigmatism were 50.3 ± 5.3 and 2.4 ± 1.7 D, respectively. At 2 years, Kmax significantly decreased to 48.8 ± 4.6 (P  0.05). Conclusion: This study indicated that CXL was more effective for central keratoconus than paracentral keratoconus. PMID:28272223

  5. Histological evaluation of corneal scar formation in pseudophakic bullous keratopathy.

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    Ting Liu

    Full Text Available PURPOSE: To evaluate histological changes in the corneal stroma in pseudophakic bullous keratopathy. METHODS: Twenty-eight patients (28 eyes with pseudophakic bullous keratopathy underwent therapeutic penetrating keratoplasty at Shandong Eye Institute between January 2006 and November 2011. The patients were divided into two groups according to the duration of bullous keratopathy (1.0 year group, and three buttons from enucleated eyes with choroidal melanoma served as a control. In vivo confocal microscopy examination, hematoxylin-eosin, Masson's trichrome stain and Van Gieson staining were used for microscopic examination. The histological evaluation and scoring of the buttons for morphological changes, including the degree of stromal scars, neovascularization and inflammatory cells within the corneal buttons, were compared. To study the underlying mechanism, connective tissue growth factor (CTGF and TGF-β immunohistochemistry were performed. RESULTS: Confocal microscopy examination and histological evaluation and scoring of the buttons showed that compared with the 1.0 year group (P1.0 year group. CONCLUSIONS: During the progression of pseudophakic bullous keratopathy, stromal scars occurred more often in the patients that had a longer duration of disease. Cytokines such as CTGF and TGF-β1 may play a role in this pathological process and deserve further investigation.

  6. Corneal Wound Healing Requires IKB kinase β Signaling in Keratocytes.

    Science.gov (United States)

    Chen, Liang; Mongan, Maureen; Meng, Qinghang; Wang, Qin; Kao, Winston; Xia, Ying

    2016-01-01

    IkB kinase β (IKKβ) is a key signaling kinase for inflammatory responses, but it also plays diverse cell type-specific roles that are not yet fully understood. Here we investigated the role of IKKβ in the cornea using Ikkβ(ΔCS) mice in which the Ikkβ gene was specifically deleted in the corneal stromal keratocytes. The Ikkβ(ΔCS) corneas had normal morphology, transparency and thickness; however, they did not heal well from mild alkali burn injury. In contrast to the Ikkβ(F/F) corneas that restored transparency in 2 weeks after injury, over 50% of the Ikkβ(ΔCS) corneas failed to fully recover. They instead developed recurrent haze with increased stromal thickness, severe inflammation and apoptosis. This pathogenesis correlated with sustained myofibroblast transformation with increased α smooth muscle actin (α-SMA) expression, higher levels of senescence β-Gal activity and scar tissue formation at the late stage of wound healing. In addition, the Ikkβ(ΔCS) corneas displayed elevated expression of hemo-oxygenase-1 (HO-1), a marker of oxidative stress, and activation of stress signaling pathways with increased JNK, c-Jun and SMAD2/3 phosphorylation. These data suggest that IKKβ in keratocytes is required to repress oxidative stress and attenuate fibrogenesis and senescence in corneal wound healing.

  7. Corneal Wound Healing Requires IKB kinase β Signaling in Keratocytes.

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    Liang Chen

    Full Text Available IkB kinase β (IKKβ is a key signaling kinase for inflammatory responses, but it also plays diverse cell type-specific roles that are not yet fully understood. Here we investigated the role of IKKβ in the cornea using Ikkβ(ΔCS mice in which the Ikkβ gene was specifically deleted in the corneal stromal keratocytes. The Ikkβ(ΔCS corneas had normal morphology, transparency and thickness; however, they did not heal well from mild alkali burn injury. In contrast to the Ikkβ(F/F corneas that restored transparency in 2 weeks after injury, over 50% of the Ikkβ(ΔCS corneas failed to fully recover. They instead developed recurrent haze with increased stromal thickness, severe inflammation and apoptosis. This pathogenesis correlated with sustained myofibroblast transformation with increased α smooth muscle actin (α-SMA expression, higher levels of senescence β-Gal activity and scar tissue formation at the late stage of wound healing. In addition, the Ikkβ(ΔCS corneas displayed elevated expression of hemo-oxygenase-1 (HO-1, a marker of oxidative stress, and activation of stress signaling pathways with increased JNK, c-Jun and SMAD2/3 phosphorylation. These data suggest that IKKβ in keratocytes is required to repress oxidative stress and attenuate fibrogenesis and senescence in corneal wound healing.

  8. Mesenchymal stem cells: Potential role in corneal wound repair and transplantation

    Institute of Scientific and Technical Information of China (English)

    Fei; Li; Shao-Zhen; Zhao

    2014-01-01

    Corneal diseases are a major cause of blindness in the world. Although great progress has been achieved in the treatment of corneal diseases, wound healing after severe corneal damage and immunosuppressive therapy after corneal transplantation remain prob-lematic. Mesenchymal stem cells(MSCs) derived from bone marrow or other adult tissues can differentiate into various types of mesenchymal lineages, such as osteocytes, adipocytes, and chondrocytes, both in vivo and in vitro. These cells can further differentiate into specific cell types under specific conditions. MSCs migrate to injury sites and promote wound healing by secreting anti-inflammatory and growth factors. In ad-dition, MSCs interact with innate and acquired immune cells and modulate the immune response through their powerful paracrine function. Over the last decade, MSCs have drawn considerable attention because of their beneficial properties and promising therapeutic prospective. Furthermore, MSCs have been applied to various studies related to wound healing, autoim-mune diseases, and organ transplantation. This review discusses the potential functions of MSCs in protecting corneal tissue and their possible mechanisms in corneal wound healing and corneal transplantation.

  9. Association of Electroencephalography (EEG) Power Spectra with Corneal Nerve Fiber Injury in Retinoblastoma Patients.

    Science.gov (United States)

    Liu, Jianliang; Sun, Juanjuan; Diao, Yumei; Deng, Aijun

    2016-09-04

    BACKGROUND In our clinical experience we discovered that EEG band power may be correlated with corneal nerve injury in retinoblastoma patients. This study aimed to investigate biomarkers obtained from electroencephalography (EEG) recordings to reflect corneal nerve injury in retinoblastoma patients. MATERIAL AND METHODS Our study included 20 retinoblastoma patients treated at the Department of Ophthalmology, Affiliated Hospital of Weifang Medical University between 2010 and 2014. Twenty normal individuals were included in the control group. EEG activity was recorded continuously with 32 electrodes using standard EEG electrode placement for detecting EEG power. A cornea confocal microscope was used to examine corneal nerve injury in retinoblastoma patients and normal individuals. Spearman rank correlation analysis was used to analyze the correlation between corneal nerve injury and EEG power changes. The sensitivity and specificity of changed EEG power in diagnosis of corneal nerve injury were also analyzed. RESULTS The predominantly slow EEG oscillations changed gradually into faster waves in retinoblastoma patients. The EEG pattern in retinoblastoma patients was characterized by a distinct increase of delta (PEEG spectra power and negatively correlated with theta EEG spectra power. The diagnostic sensitivity and specificity by compounding in the series were 60% and 67%, respectively. CONCLUSIONS Changes in delta and theta of EEG appear to be associated with occurrence of corneal nerve injury. Useful information can be provided for evaluating corneal nerve damage in retinoblastoma patients through analyzing EEG power bands.

  10. Dynamic ultra high speed Scheimpflug imaging for assessing corneal biomechanical properties

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    Renato Ambrósio Jr

    2013-04-01

    Full Text Available OBJECTIVE: To describe a novel technique for clinical characterization of corneal biomechanics using non-invasive dynamic imaging. METHODS: Corneal deformation response during non contact tonometry (NCT is monitored by ultra-high-speed (UHS photography. The Oculus Corvis ST (Scheimpflug Technology; Wetzlar, Germany has a UHS Scheimpflug camera, taking over 4,300 frames per second and of a single 8mm horizontal slit, for monitoring corneal deformation response to NCT. The metered collimated air pulse or puff has a symmetrical configuration and fixed maximal internal pump pressure of 25 kPa. The bidirectional movement of the cornea in response to the air puff is monitored. RESULTS: Measurement time is 30ms, with 140 frames acquired. Advanced algorithms for edge detection of the front and back corneal contours are applied for every frame. IOP is calculated based on the first applanation moment. Deformation amplitude (DA is determined as the highest displacement of the apex in the highest concavity (HC moment. Applanation length (AL and corneal velocity (CVel are recorded during ingoing and outgoing phases. CONCLUSION: Corneal deformation can be monitored during non contact tonometry. The parameters generated provide clinical in vivo characterization of corneal biomechanical properties in two dimensions, which is relevant for different applications in Ophthalmology.

  11. Corneal refractive surgery: Is intracorneal the way to go and what are the needs for technology?

    Science.gov (United States)

    Hjortdal, Jesper; Ivarsen, Anders

    2014-02-01

    Corneal refractive surgery aims to reduce or eliminate refractive errors of the eye by changing the refractive power of the cornea. For the last 20 years controlled excimer laser ablation of corneal tissue, either directly from the corneal stromal surface or from the corneal interior after creation of a superficial corneal flap has become widely used to correct myopia, hyperopia, and astigmatism. Recently, an intrastromal refractive procedure whereby a tissue lenticule is cut free in the corneal stroma by a femtosecond laser and removed through a small peripheral incision has been introduced. This procedure avoids creation of a corneal flap and the potential associated risks while avoiding the slow visual recovery of surface ablation procedures. Precise intrastromal femtosecond laser cutting of the fine lenticule requires very controlled laser energy delivery in order to avoid lenticule irregularities, which would compromise the refractive result and visual acuity. This newly introduced all-femtosecond based flap-free intracorneal refractive procedure has been documented to be a predictable, efficient, and safe procedure for correction of myopia and astigmatism. Technological developments related to further improved cutting quality, hyperopic and individualized treatments are desirable.

  12. Effects of edible bird's nest (EBN on cultured rabbit corneal keratocytes

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    Hun Lee

    2011-10-01

    Full Text Available Abstract Background There has been no effective treatment or agent that is available for corneal injury in promoting corneal wound healing. Previous studies on edible bird's nest extract (EBN had reported the presence of hormone-like substance; avian epidermal growth factor that could stimulate cell division and enhance regeneration. This study aimed to investigate the effects of EBN on corneal keratocytes proliferative capacity and phenotypical changes. Methods Corneal keratocytes from six New Zealand White Rabbits were isolated and cultured until Passage 1. The proliferative effects of EBN on corneal keratocytes were determined by MTT assay in serum-containing medium (FDS and serum-free medium (FD. Keratocytes phenotypical changes were morphologically assessed and gene expression of aldehyde dehydrogenase (ALDH, collagen type 1 and lumican were determined through RT-PCR. Results The highest cell proliferation was observed when both media were supplemented with 0.05% and 0.1% EBN. Cell proliferation was also consistently higher in FDS compared to FD. Both phase contrast micrographs and gene expression analysis confirmed the corneal keratocytes retained their phenotypes with the addition of EBN. Conclusions These results suggested that low concentration of EBN could synergistically induce cell proliferation, especially in serum-containing medium. This could be a novel breakthrough as both cell proliferation and functional maintenance are important during corneal wound healing. The in vitro test is considered as a crucial first step for nutri-pharmaceutical formation of EBN-based eye drops before in vivo application.

  13. Application value of corneal limbus stem cells transplantation to treat pterygium

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    Miao-Ying Zhang

    2017-02-01

    Full Text Available AIM: To analyze the application value of corneal limbus stem cells transplantation in the treatment of pterygium. METHODS: Totally 300 patients(318 eyeswith pterygium were divided into 2 groups according to treatment methods. Patients of the control group(70 patients with 77 eyeswere given simple surgical resection, while patients of the observation group(230 patients with 241 eyeswere given corneal limbus stem cells transplantation after surgical resection. The postoperative recurrent rate, corneal epithelium incision healing time, corneal epithelium healing degree, pain score and tear film break-up time were observed. RESULTS: The corneal epithelium incision healing time of the observation group and control group were respectively 5.2±1.9d and 6.4±1.7d, and the difference had statistical significance(PPP>0.05. At 2wk after treatment, the corneal epithelium healing degree of the observation group was better, and the pain score of the observation group was lower than those of the control group, the differences between groups had statistical significance(PP>0.05. At 1 and 2wk after treatment, the tear film break-up time of the observation group was longer than that of the control group(PCONCLUSION: Corneal limbus stem cell transplantation can prevent postoperative recurrence of pterygium effectively, and its postoperative tissue repair effect is superior to simple surgery.

  14. Comparison of Corneal Topographical and Biomechanical Properties in Cases with Atopic Dermatitis and Healthy Subjects

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    Yusuf Yıldırım

    2013-06-01

    Full Text Available Pur po se: To compare the topographic, biomechanical, and thickness properties of corneas of patients with atopic dermatitis (AD and of healthy individuals. Ma te ri al and Met hod: In this prospective, cross-sectional, and comparative study, 28 healthy individuals (control group and 28 patients with AD (study group were enrolled. Corneal topographical measurements using Scheimpflug camera with a Placido disc topographer (Sirius, corneal biomechanical properties using Ocular Response Analyzer (ORA, and central corneal thickness (CCT using ultrasonic pachymeter were obtained for each participant. Re sults: Topographic parameters were not significantly different between both groups (p>0.05. Corneal hysteresis (CH and corneal resistance factor (CRF were found same in both groups. CCT measured with ultrasonic pachymeter was significantly lower in patients with AD compared to health controls (p<0.05. Dis cus si on: No significant difference was found between patients with AD and age-matched healthy individuals regarding the corneal topographic findings and corneal biomechanical parameters. CCT was found to be lower in cases with AD than in healthy controls. (Turk J Ophthalmol 2013; 43: 140-4

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

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    Hongshan Liu

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

  16. Fully automated corneal endothelial morphometry of images captured by clinical specular microscopy

    Science.gov (United States)

    Bucht, Curry; Söderberg, Per; Manneberg, Göran

    2010-02-01

    The corneal endothelium serves as the posterior barrier of the cornea. Factors such as clarity and refractive properties of the cornea are in direct relationship to the quality of the endothelium. The endothelial cell density is considered the most important morphological factor of the corneal endothelium. Pathological conditions and physical trauma may threaten the endothelial cell density to such an extent that the optical property of the cornea and thus clear eyesight is threatened. Diagnosis of the corneal endothelium through morphometry is an important part of several clinical applications. Morphometry of the corneal endothelium is presently carried out by semi automated analysis of pictures captured by a Clinical Specular Microscope (CSM). Because of the occasional need of operator involvement, this process can be tedious, having a negative impact on sampling size. This study was dedicated to the development and use of fully automated analysis of a very large range of images of the corneal endothelium, captured by CSM, using Fourier analysis. Software was developed in the mathematical programming language Matlab. Pictures of the corneal endothelium, captured by CSM, were read into the analysis software. The software automatically performed digital enhancement of the images, normalizing lights and contrasts. The digitally enhanced images of the corneal endothelium were Fourier transformed, using the fast Fourier transform (FFT) and stored as new images. Tools were developed and applied for identification and analysis of relevant characteristics of the Fourier transformed images. The data obtained from each Fourier transformed image was used to calculate the mean cell density of its corresponding corneal endothelium. The calculation was based on well known diffraction theory. Results in form of estimated cell density of the corneal endothelium were obtained, using fully automated analysis software on 292 images captured by CSM. The cell density obtained by the

  17. Adipose-derived mesenchymal stem cell administration does not improve corneal graft survival outcome.

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    Sherezade Fuentes-Julián

    Full Text Available The effect of local and systemic injections of mesenchymal stem cells derived from adipose tissue (AD-MSC into rabbit models of corneal allograft rejection with either normal-risk or high-risk vascularized corneal beds was investigated. The models we present in this study are more similar to human corneal transplants than previously reported murine models. Our aim was to prevent transplant rejection and increase the length of graft survival. In the normal-risk transplant model, in contrast to our expectations, the injection of AD-MSC into the graft junction during surgery resulted in the induction of increased signs of inflammation such as corneal edema with increased thickness, and a higher level of infiltration of leukocytes. This process led to a lower survival of the graft compared with the sham-treated corneal transplants. In the high-risk transplant model, in which immune ocular privilege was undermined by the induction of neovascularization prior to graft surgery, we found the use of systemic rabbit AD-MSCs prior to surgery, during surgery, and at various time points after surgery resulted in a shorter survival of the graft compared with the non-treated corneal grafts. Based on our results, local or systemic treatment with AD-MSCs to prevent corneal rejection in rabbit corneal models at normal or high risk of rejection does not increase survival but rather can increase inflammation and neovascularization and break the innate ocular immune privilege. This result can be partially explained by the immunomarkers, lack of immunosuppressive ability and immunophenotypical secretion molecules characterization of AD-MSC used in this study. Parameters including the risk of rejection, the inflammatory/vascularization environment, the cell source, the time of injection, the immunosuppression, the number of cells, and the mode of delivery must be established before translating the possible benefits of the use of MSCs in corneal transplants to clinical

  18. Edge detection and mathematic fitting for corneal surface with Matlab software

    Science.gov (United States)

    Di, Yue; Li, Mei-Yan; Qiao, Tong; Lu, Na

    2017-01-01

    AIM To select the optimal edge detection methods to identify the corneal surface, and compare three fitting curve equations with Matlab software. METHODS Fifteen subjects were recruited. The corneal images from optical coherence tomography (OCT) were imported into Matlab software. Five edge detection methods (Canny, Log, Prewitt, Roberts, Sobel) were used to identify the corneal surface. Then two manual identifying methods (ginput and getpts) were applied to identify the edge coordinates respectively. The differences among these methods were compared. Binomial curve (y=Ax2+Bx+C), Polynomial curve [p(x)=p1xn+p2xn−1 +....+pnx+pn+1] and Conic section (Ax2+Bxy+Cy2+Dx+Ey+F=0) were used for curve fitting the corneal surface respectively. The relative merits among three fitting curves were analyzed. Finally, the eccentricity (e) obtained by corneal topography and conic section were compared with paired t-test. RESULTS Five edge detection algorithms all had continuous coordinates which indicated the edge of the corneal surface. The ordinates of manual identifying were close to the inside of the actual edges. Binomial curve was greatly affected by tilt angle. Polynomial curve was lack of geometrical properties and unstable. Conic section could calculate the tilted symmetry axis, eccentricity, circle center, etc. There were no significant differences between ‘e’ values by corneal topography and conic section (t=0.9143, P=0.3760 >0.05). CONCLUSION It is feasible to simulate the corneal surface with mathematical curve with Matlab software. Edge detection has better repeatability and higher efficiency. The manual identifying approach is an indispensable complement for detection. Polynomial and conic section are both the alternative methods for corneal curve fitting. Conic curve was the optimal choice based on the specific geometrical properties. PMID:28393021

  19. Evaluation of central and peripheral corneal thicknesses in patients with rheumatoid arthritis

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    Alime Gunes

    2015-08-01

    Full Text Available ABSTRACTPurpose:To evaluate central corneal thickness (CCT and peripheral corneal thickness (PCT in patients with rheumatoid arthritis (RA and to assess the relationships among the corneal parameters, dry eye disease, and clinical variables of RA.Methods:A total of 58 RA patients and 58 control subjects participated in this study. A detailed ophthalmological examination was performed on each subject. Dry eye evaluation was performed using Schirmer’s test, tear break-up time (TBUT, corneal fluorescein staining, and Ocular Surface Disease Index (OSDI. Corneal thickness at the apex point, the center of the pupil, the thinnest point, and PCT (3 mm from the apex to the superior, inferior, nasal, and temporal locations were evaluated using Scheimpflug imaging (Pentacam®. Additionally, the relative peripheral index (RPI was calculated by dividing the PCT by the CCT. The disease severity and quality of life were evaluated with DAS28 and HAQ, respectively. The laboratory evaluation comprised ESR and CRP.Results:The mean corneal thicknesses at the apex point, the center of the pupil, the thinnest point, and the superior, inferior, nasal, and temporal points were significantly thinner in RA patients than controls. Schirmer’s test scores and TBUT were significantly lower, and corneal staining and OSDI scores were significantly higher in RA patients. There were no significant correlations between the corneal parameters and the clinical variables of RA or dry eye tests.Conclusion:The CCT and PCT were thinner in RA patients compared to those in control subjects. However, there were no significant correlations between the corneal parameters and the clinical variables of RA or dry eye tests.

  20. Efectos de las Ramificaciones y de los Edificios en los Voltajes Inducidos por Rayos en Líneas de Distribución Urbanas The Effects of Line Laterals and Nearby Buildings on Lightning-Induced Voltages in Urban Distribution Lines

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    A. Piantini

    2004-01-01

    Full Text Available Se presentan algunos resultados experimentales, de los efectos de las ramificaciones y de los edificios cercanos, en los voltajes inducidos por rayos en líneas de distribución urbanas. Usando un modelo en escala reducida de 1:50, las pruebas fueron realizadas considerando una típica configuración de línea de distribución, incluyendo la simulación del conductor neutral, ramificaciones, edificios y equipos como los pararrayos y transformadores. Se presentan comparaciones entre voltajes inducidos en los terminales de alto voltaje del transformador para diferentes alturas de los edificios y situaciones del transformador. Los resultados muestran que en algunas circunstancias las ramificaciones y la presencia de estructuras cercanas a la línea pueden afectar significativamente los voltajes inducidos por descargas atmosféricasSome experimental results are presented from research on the effects of laterals and nearby buildings on the lightning-induced voltages in urban overhead distribution lines. By making use of a 1:50 scale model, tests were performed considering a typical distribution line configuration, including the simulation of the neutral conductor, laterals, buildings, and equipment such as arresters and transformers. Comparisons between voltages induced at the HV transformer terminals are presented for different building heights and transformer locations. The results show that in some circumstances the laterals and the presence of structures close to the lines may significantly affect the induced voltages

  1. Corneal endothelial changes after accelerated corneal collagen cross-linking in keratoconus and postLASIK ectasia

    Science.gov (United States)

    Badawi, Amani E

    2016-01-01

    Purpose The purpose of this study was to evaluate the effects of accelerated cross-linking (CXL) on corneal endothelium in keratoconus and postlaser-assisted in situ keratomileusis (LASIK) ectasia. Design This study is a prospective nonrandomized controlled study. Setting This study was conducted in Mansoura Ophthalmic Center (Mansoura University) and Al-Mostakbal Ophthalmic Center, Mansoura, Egypt. Methods In total, 40 eyes with progressive keratoconus and 10 eyes with postLASIK ectasia were subjected to an accelerated CXL (10 mW/cm2 for 9 minutes). Qualitative and quantitative analyses of the corneal endothelial cells were conducted before CXL and 3, 6, and 12 months after CXL by using a specular microscope (Tomy EM-3000). Results There was a significant reduction in endothelial cell count particularly at 3 and 6 months postCXL. In addition, the coefficient of variance was also statistically significantly higher at 3 and 6 months postoperatively than the preCXL value. There was a slight change in the percentage of hexagonal cells. Conclusion The use of accelerated CXL (10 mW/cm2 for 9 minutes) has a transient negative impact on endothelial cell density and/or endothelial morphology. PMID:27757009

  2. Image Analysis on Corneal Opacity:A Novel Method to Estimate Postmortem Interval in Rabbits

    Institute of Scientific and Technical Information of China (English)

    周兰; 刘艳; 刘良; 卓荦; 梁曼; 杨帆; 任亮; 朱少华

    2010-01-01

    Corneal opacity is one of the most commonly used parameters for estimating postmortem interval(PMI).This paper proposes a new method to study the relationship between changes of corneal opacity and PMI by processing and analyzing cornea images.Corneal regions were extracted from images of rabbits' eyes and described by color-based and texture-based features,which could represent the changes of cornea at different PMI.A KNN classifier was used to reveal the association of image features and PMI.The result of...

  3. [The causes of necrobiosis and apoptosis of corneal epithelial cells during primary acquired keratoconus].

    Science.gov (United States)

    Ziangirova, G G; Antonova, O V

    2002-01-01

    We studied 56 biopsy samples of conjunctiva and 50 corneal discs excised from 28 patients with acquired keratoconus cornea. The conjunctivas in all biopsy samples showed various stages of immune inflammation. Necrobiotic changes have been revealed in epithelium of the corneal discs going by the pathways of apoptosis--programmed cell death--and oncosis--initial edematic stage of necrobiosis. At the stage of acute inflammation they are due to cytotoxic effect of the lymphocytes, monocytes, and macrophages. Antibody-dependent cytotoxicity mediated by plasma and lymphoid cells predominates at this stage. At the reparative stage of inflammation ischemia, an inductor of apoptosis and oncosis, underlies necrobiotic changes in corneal epithelium.

  4. A case of corneal cystinosis in a patient with rickets and chronic renal failure

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    Jae Yon Won

    2015-01-01

    Full Text Available A 22-year-old man diagnosed with nephropathic cystinosis at the age of 4 years was found to have progressive bilateral corneal crystal deposition. He presented with severe photophobia and decreased visual acuity. Ocular cystinosis was diagnosed on observing the typical crystals. Optical coherence tomography showed multiple areas of stromal hyperreflectivity due to crystal deposits within the corneal stroma. Ex vivo transmission electron microscopy of the cornea showed pathognomonic crystal deposits in corneal stromal keratocytes. Using polymerase chain reaction sequencing of the entire coding region, we identified five gene mutations, including two unreported mutations.

  5. Changes in Corneal Biomechanical Properties after Long-Term Topical Prostaglandin Therapy.

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    Na Wu

    Full Text Available To compare corneal biomechanical properties, measured by a newly developed tonometer (Corneal Visualization Scheimpflug Technology, Corvis ST, in untreated primary open angle glaucoma (POAG patients, POAG patients with long-term topical prostaglandin analog (PGA therapy and in normal controls. Further is to investigate the potential effects of PGA on corneal biomechanics.In this case-control study, 35 consecutive medication naïve eyes with POAG, 34 POAG eyes with at least 2 years treatment by PGA and 19 normal eyes were included. Intraocular pressure (IOP, central corneal thickness (CCT and corneal biomechanical parameters, including deformation amplitude (DA, applanation time (AT1 and AT2, applanation length (AL1 and AL2, applanation velocity (AV1 and AV2, and peak distance and radius were measured using Corvis ST. Axial length and corneal curvature were measured with partial coherence interferometry (IOLMaster, Zeiss, Germany. General linear model analysis was performed to investigate the corneal biomechanical property changes among the normal controls, newly diagnosed POAG patients and POAG patients with long-term PGA treatment, and among the subgroups of different types of PGA treatment, including bimatoprost, latanoprost and travoprost. Furthermore, pairwise comparisons using Bonferroni correction for least squares means were employed.AT1 (p<0.0001, AV1 (p<0.0001, AT2 (p = 0.0001, AV2 (p<0.0001 and DA (p = 0.0004 in newly diagnosed glaucoma patients were significantly different from those in normal subjects and in patients underwent at least 2 years topical PGA therapy after adjusting for age and gender. After adjusting for age, gender, IOP, CCT, axial length and corneal curvature, a significant difference was detected for DA between glaucoma patients without PGA treatment and patients with long-term PGA therapy (p = 0.0387. Furthermore, there were no statistical significant differences in all of the corneal biomechanical parameters among

  6. Measurement of fine dynamic changes of corneal topography by use of interferometry

    Science.gov (United States)

    Kasprzak, Henryk T.; Jaronski, Jaroslaw W.

    2002-06-01

    Paper presents results of in vivo measurements of dynamic variations of the corneal topography by use of the Twyman Green interferometer. Sequence of interferograms were recorded by the CCD camera and stored in the computer memory. Then the fringe tracking method was used separately to each interferogram giving the phase surface of the wave reflected from the cornea in the numerical form. Results from neighboring interferograms were subtracted giving new sequence of changes of the corneal topography within 40 ms. Obtained results show the complex space distribution of the corneal topography variations.

  7. OCT corneal topography within ¼ diopter in the presence of saccadic eye movements

    Science.gov (United States)

    Sayegh, Samir I.

    2013-03-01

    Refractive surgeons and cataract surgeons need accurate measurements of corneal curvature/power. Increased expectations of patients, the increasing number of patients having undergone prior surgeries and patients with corneal pathologies dictate the need for reliable curvature measurements to enhance the predictability and the quality of surgical outcomes. Eye movements can negatively influence these measurements. We present a model of eye movements based on peak saccade velocities and formulate criteria for obtaining OCT topography within ¼ of a diopter. Using these criteria we illustrate how next generation MHz systems will allow full corneal OCT topography in both healthy and pathological corneas

  8. [Neurotrophic keratopathy--studies on substance P and the clinical significance of corneal sensation].

    Science.gov (United States)

    Nishida, T; Nakamura, M; Konma, T; Ofuji, K; Nagano, K; Tanaka, T; Enoki, M; Reid, T W; Brown, S M; Murphy, C J; Mannis, M J

    1997-12-01

    Neurotrophic keratopathy, which often follows damage to the trigeminal nerve, is clinically characterized by various types of epithelial disorders and melting of corneal stroma. To understand both the pathology of neurotrophic keratopathy and the physiological significance of corneal sensation, we investigated both the cellular and molecular functions of a sensory neurotransmitter, substance P, in corneal epithelial cells. Our findings prompted us to try a new mode of treatment for neurotrophic keratopathy. Substance P, a member of the tachykinin family, is an 11-amino-acid peptide. In an organ culture system using rabbit corneas, substance P alone had no effect on corneal epithelial migration. In the presence of insulin-like growth factor-1 (IGF-1), however, substance P synergistically facilitated corneal epithelial migration in proportion to the concentration of substance P or of IGF-1. Other neurotransmitters (acetylcholine, norepinephrine, serotonin etc.) or tachykinins (neurokinin A, eledoisin etc.) did not show this synergistic effect with IGF-1. Among receptors for the tachykinin family (NK-1, NK-2, or NK-3) only the NK-1 receptor system was involved in the synergistic effect of substance P and IGF-1 on corneal epithelial migration. IGF-1 affected neither the binding constant nor the number of sites of substance P receptors in corneal epithelial cells, suggesting that the synergistic effect was not regulated at the receptor level. Various extracellular signals activate the intracellular signal transduction system, thus amplifying specific biological functions. We found that the addition of inhibitors of protein kinase C or tyrosine kinase clearly inhibited the synergistic effect of substance P and IGF-1 on corneal epithelial migration, demonstrating that protein kinase C and tyrosine kinase are involved in the synergistic effect. During corneal epithelial wound healing, epithelial cells must attach to a provisional, extracellular fibronectin matrix. We

  9. In vivo corneal confocal microscopic analysis in patients with keratoconus

    Institute of Scientific and Technical Information of China (English)

    Gulfidan; Bitirgen; Ahmet; Ozkagnici; Banu; Bozkurt; Rayaz; A; Malik

    2015-01-01

    AIM: To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy(IVCM) in patients with keratoconus and control subjects. METHODS: Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36age-matched control subjects were evaluated with slit-lamp examination(SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte,endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated.RESULTS: IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub-basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density( 5817 ± 306 cells / mm2 vs 4802 ±508 cells/mm2,P < 0. 001), anterior stromal keratocyte density(800 ±111 cells/mm2 vs 555 ±115 cells/mm2, P <0.001),posterior stromal keratocyte density(333±34 cells/mm2vs270 ±47 cells/mm2, P <0.001), endothelial cell density(2875 ±223 cells/mm2 vs 2686 ±265 cells/mm2, P <0.001),sub-basal nerve fiber density(31.2 ±8.4 nerves/mm2vs18.1 ±9.2 nerves/mm2, P <0.001), sub-basal nerve fiber length(21.4±3.4 mm/mm2 vs 16.1±5.1 mm/mm2, P <0.001),and sub-basal nerve branch density(median 50.0(first quartile 31.2- third quartile 68.7) nerve branches/mm2 vs median 25.0(first quartile 6.2- third quartile 45.3) nerve branches/mm2, P <0.001) were observed in patients with keratoconus.CONCLUSION: Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non-invasive in vivo technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus.

  10. Keratoconus: A biomechanical perspective on loss of corneal stiffness

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    Abhijit Sinha Roy

    2013-01-01

    Full Text Available Keratoconus (KC is progressive disease of corneal thinning, steepening and collagen degradation. Biomechanics of the cornea is maintained by the intricate collagen network, which is responsible for its unique shape and function. With the disruption of this collagen network, the cornea loses its shape and function, resulting in progressive visual degradation. While KC is essentially a stromal disease, there is evidence that the epithelium undergoes significant thinning similar to the stroma. Several topographical approaches have been developed to detect KC early. However, it is now hypothesized that biomechanical destabilization of the cornea may precede topographic evidence of KC. Biomechanics of KC has been investigated only to a limited extent due to lack of in vivo measurement techniques and/or devices. In this review, we focus on recent work performed to characterize the biomechanical characteristics of KC.

  11. Anesthesia for Traumatic Diaphragmatic Hernia Associated with Corneal Laceration.

    Science.gov (United States)

    Safaeian, Reza; Hassani, Valiollah; Faiz, Hamid Reza

    2016-09-06

    BACKGROUND Diaphragmatic rupture can be seen in up to 5% of car accidents, and 80%-100% of diaphragmatic hernias are associated with other vital organ injuries. Brain, pelvis, long bones, liver, spleen, and aorta are some other organs that can be severely damaged and need different anesthetic managements. CASE REPORT A 37-year-old male victim of a head-on collision who was suffering diaphragmatic rupture and corneal laceration was prepared for an emergency operation 11 hours after the car accident. Gastric decompression, pre-oxygenation, rapid sequence induction with succinylcholine, immediate use of non-depolarizing muscle relaxant, and mechanical ventilation with low tidal volume after intubation were used in anesthetic management of the patient. CONCLUSIONS Because of the high prevalence of coexisting pathologies with traumatic diaphragmatic hernia, anesthetic management must be tailored to the associated pathologies.

  12. Stabilization of Bilateral Progressive Rheumatoid Corneal Melt with Infliximab

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    Sheelah F. Antao

    2012-01-01

    Results. A patient with rheumatoid arthritis presented with bilateral PUK following a 2-month history of ocular discomfort and redness. His systemic prednisolone (PDN and methotrexate (MTX were increased and, despite an initial favorable response, bilateral recurrent corneal perforations ensued. Both eyes underwent cyanoacrylate glue repair, amniotic membrane transplantation (AMT, and penetrating keratoplasty (PKP. Recurrence of the disease and bilateral perforations of the second PKP in both eyes prompted administration of intravenous infliximab immediately after the fourth PKP. The disease activity rapidly settled in both eyes, and at eighteen-month followup, after 12 infliximab infusions, the PUK remains quiescent with no further graft thinning or perforation. Conclusion. Infliximab can be used to arrest the progression of severe bilateral rheumatoid PUK in cases that are refractory to conventional treatment.

  13. Contact Lens Visual Rehabilitation in Keratoconus and Corneal Keratoplasty

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    Yelda Ozkurt

    2012-01-01

    Full Text Available Keratoconus is the most common corneal distrophy. It’s a noninflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. Many treatment choices include spectacle correction and contact lens wear, collagen cross linking, intracorneal ring segments implantation and finally keratoplasty. Contact lenses are commonly used to reduce astigmatism and increase vision. There are various types of lenses are available. We reviewed soft contact lenses, rigid gas permeable contact lenses, piggyback contact lenses, hybrid contact lenses and scleral-semiscleral contact lenses in keratoconus management. The surgical option is keratoplasty, but even after sutur removal, high astigmatism may stil exists. Therefore, contact lens is an adequate treatment option to correct astigmatism after keratoplasty.

  14. In vitro adherence of Moraxella bovis to intact corneal epithelium.

    Science.gov (United States)

    Jackman, S H; Rosenbusch, R F

    1984-09-01

    An in vitro assay is described using radiolabeled Moraxella bovis for studying adherence to intact bovine corneal epithelial surfaces. The assay was optimized for time (45 min) and for the ratio of epithelial cells to bacteria (1:1000) that demonstrated a significant difference in adherence between M. bovis strain 118F, a piliated organism and a nonpiliated variant, strain 118F/4-2. Adherence of these organisms correlated with previous pathogenicity studies involving experimental infection of calves. Scanning electron microscopy of tissues treated in the assay revealed a predilection of M. bovis for dark epithelial cells and for association with depressions in the tissue surface. This assay technique is discussed in comparison with other in vitro adherence assay methods.

  15. Scanning laser system to determine the corneal shape

    Science.gov (United States)

    Ascanio, Gabriel; Caballero-Ruiz, Alberto; Ruiz-Huerta, Leopoldo; Gonzalez-Cardel, Mario; Diaz-Uribe, Rufino

    2005-07-01

    The development and tests of a scanning system to be used to determine the corneal topography with the laser deflectometry method are presented. In this equipment, a He-Ne laser beam scans the cornea by describing a spiral trajectory generated by two components: radial and angular. The first component is produced by the displacement of a plane mirror moved by a linear pneumatic actuator. The second component is produced by passing the beam through a Dove prism which is rotating by means of a belt drive coupled to a high-speed electric motor. Tests were first performed by analyzing both components independently and then they were characterized by combining the two components. Results are discussed and compared to those of an earlier cited work.

  16. Novel double path shearing interferometer in corneal topography measurements

    Science.gov (United States)

    Licznerski, Tomasz J.; Jaronski, Jaroslaw; Kosz, Dariusz

    2005-09-01

    The paper presents an approach for measurements of corneal topography by use of a patent pending double path shearing interferometer (DPSI). Laser light reflected from the surface of the cornea is divided and directed to the inputs of two interferometers. The interferometers use lateral shearing of wavefronts in two orthogonal directions. A tilt of one of the mirrors in each interferometric setup perpendicularly to the lateral shear introduces parallel carrier frequency fringes at the output of each interferometer. There is orthogonal linear polarization of the laser light used in two DPSI. Two images of fringe patters are recorded by a high resolution digital camera. The obtained fringe patterns are used for phase difference reconstruction. The phase of the wavefront was reconstructed by use of algorithms for a large grid based on discrete integration. The in vivo method can also be used for tear film stability measurement, artificial tears and contact lens tests.

  17. Infectious Keratitis: Secreted Bacterial Proteins That Mediate Corneal Damage

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    Mary E. Marquart

    2013-01-01

    Full Text Available Ocular bacterial infections are universally treated with antibiotics, which can eliminate the organism but cannot reverse the damage caused by bacterial products already present. The three very common causes of bacterial keratitis—Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pneumoniae—all produce proteins that directly or indirectly cause damage to the cornea that can result in reduced vision despite antibiotic treatment. Most, but not all, of these proteins are secreted toxins and enzymes that mediate host cell death, degradation of stromal collagen, cleavage of host cell surface molecules, or induction of a damaging inflammatory response. Studies of these bacterial pathogens have determined the proteins of interest that could be targets for future therapeutic options for decreasing corneal damage.

  18. Acinetobacter junii as an aetiological agent of corneal ulcer.

    Science.gov (United States)

    Broniek, G; Langwińska-Wośko, E; Szaflik, J; Wróblewska, M

    2014-12-01

    Rods of the Acinetobacter genus are present mainly in the external environment (e.g. water, soil) and in animals, while in humans they may comprise physiological flora. The main pathogenic species is Acinetobacter baumannii complex, which constitutes a common cause of nosocomial infections, particularly in patients with underlying diseases and risk factors (e.g. prior broad-spectrum antibiotic therapy, malignancy, central venous catheter, mechanical ventilation); however, infections of the eye caused by strains of Acinetobacter spp. are very rare. We report a unique case of community-acquired corneal ulcer caused by Acinetobacter non-baumannii (possibly A. junii), in a patient with no risk factors identified. The case highlights the need for obtaining a sample from the cornea for bacteriological culture in the case of suspected ophthalmic infection as identification of the pathogen, and assessment of its susceptibility profile enables proper antibiotic therapy, improves the outcome and may constitute an eyesight-saving management.

  19. Generation of Corneal Keratocytes from Human Embryonic Stem Cells.

    Science.gov (United States)

    Hertsenberg, Andrew J; Funderburgh, James L

    2016-01-01

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

  20. The Preliminary Experimental Study of Induced Differentiation of Embryonic Stem Cells into Corneal Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    Ling Yu; Jian Ge; Zhichong Wang; Bing Huang; Keming Yu; Chongde Long; Xigu Chen

    2001-01-01

    Purpose:To study preliminarily induced differentiation of embryonic stem cells intocorneal epithelial cells in vitro.Methods: Murine embryonic stem cells were co-cultured with Rabbit limbal cornealepithelial cells in Transwell system to induce differentiation. Mophological andimmunohistochemical examination were implemented.Results: The induced cells from embryonic stem cells have an epithelial appearance.The cells formed a network and were confluent into film gradually after beingco-cultured with rabbit limbal corneal epithelial cells for 24 ~ 96 hours. The cells rangedmosaic structure and localized together with clear rim. Most of the cells showedpolygonal appearance. Transmission electron microscope showed lots of microvilli on thesurface of induced cells and tight junctions between them. These epithelial-like cellsexpressed the corneal epithelial cell specific marker cytokeratin3/cytokeratinl2.Conclusion: The potential mechanism of the differentiation of murine embryonic stemcells into corneal epithelial cells induced by limbal corneal epithelial cell-derivedinducing activity is to be further verified.

  1. A clinical study to evaluate therapeutic efficacy of soft contact lenses in corneal diseases

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    Sharda Punjabi

    2016-10-01

    Conclusions: Soft contact lenses can be safely advocated as a part of therapy along with adjuvant conventional management with well expected improvement in the ocular corneal diseases. [Int J Res Med Sci 2016; 4(10.000: 4632-4636

  2. Visual, keratometric and corneal biomechanical changes after intacs SK implantation for moderate to severe keratoconus

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    Mohammad Ali Zare

    2016-01-01

    Conclusion: Visual, refractive and keratometric indices remarkably improved in a parallel fashion. CRF was inversely associated with CCT. Changes in CRF represent the trend of changes in corneal biomechanics and thickness during the early postoperative months.

  3. Consideration of corneal biomechanics in the diagnosis and management of keratoconus: is it important?

    Science.gov (United States)

    Bao, FangJun; Geraghty, Brendan; Wang, QinMei; Elsheikh, Ahmed

    2016-01-01

    Keratoconus is a bilateral, non-inflammatory, degenerative corneal disease. The occurrence and development of keratoconus is associated with corneal thinning and conical protrusion, which causes irregular astigmatism. With the disruption of the collagen organization, the cornea loses its shape and function resulting in progressive visual degradation. Currently, corneal topography is the most important tool for the diagnosis of keratoconus, which may lead to false negatives among the patient population in the subclinical phase. However, it is now hypothesised that biomechanical destabilisation of the cornea may take place ahead of the topographic evidence of keratoconus, hence possibly assisting with disease diagnosis and management. This article provides a review of the definition, diagnosis, and management strategies for keratoconus based on corneal biomechanics.

  4. Investigation the Porous Collagen-Chitosan /Glycosaminoglycans for Corneal Cell Culture as Tissue Engineering Scaffold

    Institute of Scientific and Technical Information of China (English)

    LI Qin-Hua; CHEN Jian-Su

    2005-01-01

    The objective of this study was to produce the porous collagen-chitosan/Glycosanminglycans (GAG) for corneal ceil-seed implant as a three-dimensional tissue engineering scaffold to improve the regeneration corneas. The effect of various content of glycerol as form porous agent to collagen-chitosan/GAG preserved a porous dimensional structure was investigated. The heat-drying was used to prepare porous collagen-chitosan /GAG scaffold. The pore morphology of collagenchitosan/GAG was controlled by changing the concentration of glycerol solution and drying methods. The porous structure morphology was observed by SEM. The diameter of the pores form 10 to 50 μm. The highly porous scaffold had interconnecting pores. The corneal cell morphology was observed under the light microscope. These results suggest that collagen-chitosan/GAG showed that corneal cell have formed confluent layers and resemble the surface of normal corneal cell surface.

  5. Pseudophakodonesis and corneal endothelial contact: direct observations by high-speed cinematography.

    Science.gov (United States)

    Jacobs, P M; Cheng, H; Price, N C

    1983-10-01

    High-speed cinematography was used to observe the movement of Federov type I lens implants within the anterior chamber. Our measurements suggest that in most patients contact between the lens implant and corneal endothelium does not occur.

  6. Effect of Mitomycin-C augmented trabeculectomy on corneal endothelial cells

    Directory of Open Access Journals (Sweden)

    Reza Zarei

    2015-01-01

    Conclusion: MMC application in trabeculectomy seems to cause a small but significant corneal endothelial loss. Most of the damage occurs intraoperatively, or in the early postoperative period, however progressive endothelial cell loss is not a major concern.

  7. Trends in penetrating and anterior lamellar corneal grafting techniques for keratoconus : A national registry study

    NARCIS (Netherlands)

    Godefrooij, Daniel A.; Gans, Renze; Imhof, Saskia M.; Wisse, Robert P L

    2016-01-01

    Purpose: Keratoconus is a progressive disorder and one of the primary indications for corneal transplantation. Anterior lamellar keratoplasty offers several advantages over other techniques, including endothelial preservation and longer graft survival. In this study, we examined the recent trend of

  8. Corneal topography measurement by means of radial shearing interference: Part II - experiment results

    Science.gov (United States)

    Garncarz, Beata E.; Kowalik, Waldemar W.; Kasprzak, Henryk T.

    The method of the measurement of the corneal topography was worked out. This measurement system uses an interferometer based on radial shearing. This paper presents the preliminary results of the experiments. The results are compared with other methods.

  9. Primary corneal papilloma and squamous cell carcinoma associated with pigmentary keratitis in four dogs.

    Science.gov (United States)

    Bernays, M E; Flemming, D; Peiffer, R L

    1999-01-15

    Squamous cell carcinoma (SCC) and squamous papilloma are rarely reported as primary lesions of the cornea in dogs. One case of corneal papilloma and 3 cases of SCC, each arising as a primary central corneal neoplasm rather than spreading from adjacent limbal conjunctiva, were reviewed. The most common cause of SCC in animals is chronic exposure of lightly pigmented epithelium to UV light; however, all dogs in this study had a history of chronic pigmentary keratitis. Three of the 4 dogs were of brachycephalic breeds with naturally proptotic eyes and oversized palpebral fissures that may have exposed the cornea to greater excessive solar radiation. Alternatively, mechanical factors that caused chronic changes in the cornea may have been causative factors for induction of primary dysplastic or neoplastic changes. Primary corneal neoplasia should be considered in the differential diagnosis of corneal masses.

  10. Corneal decompensation following filtering surgery with the Ex-PRESS® mini glaucoma shunt device

    Directory of Open Access Journals (Sweden)

    Tojo N

    2015-03-01

    Full Text Available Naoki Tojo, Atsushi Hayashi, Akio Miyakoshi Department of Ophthalmology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan Purpose: To report a case of corneal decompensation due to the Ex-PRESS® mini glaucoma shunt device (Ex-PRESS.Patient and methods: A 75-year-old man had pseudoexfoliation glaucoma in his right eye. He underwent filtration surgery with Ex-PRESS. His intraocular pressure was 7 mmHg after 9 months.Results: We observed partial decompensation of the corneal endothelium adjacent to the filtering bleb. Specular microscopy revealed a marked decrease in the endothelial cell density at the center of the cornea.Conclusion: Anterior segment optical coherence tomography is very useful for evaluating corneal edema and the position of Ex-PRESS. It is important to follow up with an examination of the corneal endothelial cells. Keywords: Ex-PRESS, bullous keratopathy, trabeculectomy, complication, cornea 

  11. A new, band-shaped and whorled microcystic dystrophy of the corneal epithelium.

    Science.gov (United States)

    Lisch, W; Steuhl, K P; Lisch, C; Weidle, E G; Emmig, C T; Cohen, K L; Perry, H D

    1992-07-15

    Five family members and three unrelated patients (four women, four men, 23 to 71 years old) had a dystrophy of the corneal epithelium. Direct slit-lamp examination showed bilateral or unilateral, gray, band-shaped, and feathery opacities that sometimes appeared in whorled patterns. Retroillumination showed intraepithelial, densely crowded, clear microcysts. Light and electron microscopy disclosed diffuse vacuolization of the cytoplasm of epithelial cells in the affected area. Visual acuity was so reduced in three patients that abrasion of the corneal epithelium was performed. The corneal abnormalities recurred within months, with the same reduction in visual acuity as before. The corneal opacities were progressive in two patients but diminished noticeably in another after he began using a hard contact lens. We found no other ophthalmic irregularities or associated systemic abnormalities and no indication of drug-induced keratopathy.

  12. Keratocyte loss in corneal infection through apoptosis: a histologic study of 59 cases

    Directory of Open Access Journals (Sweden)

    Garg Prashant

    2004-12-01

    Full Text Available Abstract Background Keratocyte loss by apoptosis following epithelial debridement is a well-recognized entity. In a study of corneal buttons obtained from patients of corneal ulcer undergoing therapeutic keratoplasty, we observed loss of keratocytes in the normal appearing corneal stroma, surrounding the zone of inflammation. Based on these observations, we hypothesized that the cell loss in the inflammatory free zone of corneal stroma is by apoptosis that could possibly be a non-specific host response, independent of the nature of infectious agent. Methods To test our hypothesis, in this study, we performed Terminal deoxyribonucleotidyl transferase-mediated d-Uridine 5" triphosphate Nick End Labelling (TUNEL staining on 59 corneal buttons from patients diagnosed as bacterial, fungal, viral and Acanthamoeba keratitis. The corneal sections were reviewed for morphologic changes in the epithelium, stroma, type, degree and depth of inflammation, loss of keratocytes in the surrounding stroma (posterior or peripheral. TUNEL positivity was evaluated in the corneal sections, both in the zone of inflammation as well as the surrounding stroma. A correlation was attempted between the keratocyte loss, histologic, microbiologic and clinical features. Results The corneal tissues were from 59 patients aged between 16 years and 85 years (mean 46 years and included fungal (22, viral (15, bacterial (14 and Acanthamoeba (8 keratitis. The morphological changes in corneal tissues noted were: epithelial ulceration (52, 88.1%, destruction of Bowman's layer (58, 99%, mild to moderate (28; 47.5% to severe inflammation (31; 52.5%. Morphologic evidence of disappearance or reduced number of keratocytic nuclei in the corneal stroma was noted in 49 (83% cases; while the TUNEL positive brown cells were identified in all cases 53/54 (98%, including cases of fungal (19, bacterial (14, viral (13, and Acanthamoeba keratitis. TUNEL staining was located mostly in the deeper stroma

  13. Keratocyte loss in corneal infection through apoptosis: a histologic study of 59 cases

    Science.gov (United States)

    Vemuganti, Geeta K; Reddy, Kishore; Iftekhar, Ghazala; Garg, Prashant; Sharma, Savitri

    2004-01-01

    Background Keratocyte loss by apoptosis following epithelial debridement is a well-recognized entity. In a study of corneal buttons obtained from patients of corneal ulcer undergoing therapeutic keratoplasty, we observed loss of keratocytes in the normal appearing corneal stroma, surrounding the zone of inflammation. Based on these observations, we hypothesized that the cell loss in the inflammatory free zone of corneal stroma is by apoptosis that could possibly be a non-specific host response, independent of the nature of infectious agent. Methods To test our hypothesis, in this study, we performed Terminal deoxyribonucleotidyl transferase-mediated d-Uridine 5" triphosphate Nick End Labelling (TUNEL) staining on 59 corneal buttons from patients diagnosed as bacterial, fungal, viral and Acanthamoeba keratitis. The corneal sections were reviewed for morphologic changes in the epithelium, stroma, type, degree and depth of inflammation, loss of keratocytes in the surrounding stroma (posterior or peripheral). TUNEL positivity was evaluated in the corneal sections, both in the zone of inflammation as well as the surrounding stroma. A correlation was attempted between the keratocyte loss, histologic, microbiologic and clinical features. Results The corneal tissues were from 59 patients aged between 16 years and 85 years (mean 46 years) and included fungal (22), viral (15), bacterial (14) and Acanthamoeba (8) keratitis. The morphological changes in corneal tissues noted were: epithelial ulceration (52, 88.1%), destruction of Bowman's layer (58, 99%), mild to moderate (28; 47.5%) to severe inflammation (31; 52.5%). Morphologic evidence of disappearance or reduced number of keratocytic nuclei in the corneal stroma was noted in 49 (83%) cases; while the TUNEL positive brown cells were identified in all cases 53/54 (98%), including cases of fungal (19), bacterial (14), viral (13), and Acanthamoeba keratitis. TUNEL staining was located mostly in the deeper stroma and in few

  14. Cataract surgery in a patient with severe chronic iritis and corneal endothelial damage.

    Science.gov (United States)

    Yasukawa, T; Suga, K; Yokoo, N; Asada, S

    1998-07-01

    We report a patient with broad anterior synechias and corneal endothelial damage. The patient had chronic iritis and cataracts secondary to chronic iritis in both eyes. Because the right eye had broad anterior synechias and severe corneal endothelial damage, extracapsular cataract extraction and intraocular lens implantation were performed through the basal iris. Good postoperative visual acuity was obtained. The cornea showed little trauma from the surgery and remained clear 36 months postoperatively.

  15. Ultrastructure Organization of Collagen Fibrils and Proteoglycans of Stingray and Shark Corneal Stroma

    OpenAIRE

    Alanazi, Saud A.; Turki Almubrad; AlIbrahim, Ahmad I. A.; Khan, Adnan A; Saeed Akhtar

    2015-01-01

    We report here the ultrastructural organization of collagen fibrils (CF) and proteoglycans (PGs) of the corneal stroma of both the stingray and the shark. Three corneas from three stingrays and three corneas from three sharks were processed for electron microscopy. Tissues were embedded in TAAB 031 resin. The corneal stroma of both the stingray and shark consisted of parallel running lamellae of CFs which were decorated with PGs. In the stingray, the mean area of PGs in the posterior stroma w...

  16. Femtosecond Corneal Collagen Crosslinking in Treatment of Patients with Progressive Keratoconus Stages I–II

    OpenAIRE

    K.B. Letnikova; A.T. Khandjan; O.G. Oganesyan; A.V. Penkina; V.V. Neroyev

    2016-01-01

    The aim of the investigation was to assess safety and efficacy of corneal collagen crosslinking technique using femtosecond laser for intrastromal pocket creation in patients with progressive keratoconus. Materials and Methods. Thirty-three patients (34 eyes) with progressive keratoconus stages I–II underwent femto-crosslinking of the corneal collagen. FEMTO LDV Z6 femtosecond laser was used to create an intrastromal pocket of 8.0 mm diameter and 140 μm depth. Normotonic riboflavin solution (...

  17. Galectin-3 Inhibition by a Small-Molecule Inhibitor Reduces Both Pathological Corneal Neovascularization and Fibrosis

    Science.gov (United States)

    Chen*, Wei-Sheng; Cao, Zhiyi; Leffler, Hakon; Nilsson, Ulf J.; Panjwani, Noorjahan

    2017-01-01

    Purpose Corneal neovascularization and scarring commonly lead to significant vision loss. This study was designed to determine whether a small-molecule inhibitor of galectin-3 can inhibit both corneal angiogenesis and fibrosis in experimental mouse models. Methods Animal models of silver nitrate cautery and alkaline burn were used to induce mouse corneal angiogenesis and fibrosis, respectively. Corneas were treated with the galectin-3 inhibitor, 33DFTG, or vehicle alone and were processed for whole-mount immunofluorescence staining and Western blot analysis to quantify the density of blood vessels and markers of fibrosis. In addition, human umbilical vein endothelial cells (HUVECs) and primary human corneal fibroblasts were used to analyze the role of galectin-3 in the process of angiogenesis and fibrosis in vitro. Results Robust angiogenesis was observed in silver nitrate–cauterized corneas on day 5 post injury, and markedly increased corneal opacification was demonstrated in alkaline burn–injured corneas on days 7 and 14 post injury. Treatment with the inhibitor substantially reduced corneal angiogenesis and opacification with a concomitant decrease in α-smooth muscle actin (α-SMA) expression and distribution. In vitro studies revealed that 33DFTG inhibited VEGF-A–induced HUVEC migration and sprouting without cytotoxic effects. The addition of exogenous galectin-3 to corneal fibroblasts in culture induced the expression of fibrosis-related proteins, including α-SMA and connective tissue growth factor. Conclusions Our data provide proof of concept that targeting galectin-3 by the novel, small-molecule inhibitor, 33DFTG, ameliorates pathological corneal angiogenesis as well as fibrosis. These findings suggest a potential new therapeutic strategy for treating ocular disorders related to pathological angiogenesis and fibrosis. PMID:28055102

  18. Corneal alterations induced by topical application of commercial latanoprost, travoprost and bimatoprost in rabbit.

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    Wensheng Chen

    Full Text Available Prostaglandin (PG analogs, including latanoprost, travoprost, and bimatoprost, are currently the most commonly used topical ocular hypotensive medications. The purpose of this study was to investigate the corneal alterations in rabbits following exposure to commercial solution of latanoprost, travoprost and bimatoprost. A total of 64 New Zealand albino rabbits were used and four groups of treatments were constituted. Commercial latanoprost, travoprost, bimatoprost or 0.02% benzalkonium chloride (BAK was applied once daily to one eye each of rabbits for 30 days. The contralateral untreated eyes used as controls. Schirmer test, tear break-up time (BUT, rose Bengal and fluorescein staining were performed on days 5, 10, 20, and 30. Central corneal changes were analyzed by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance on day 5. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of tight-junction (ZO-1, occludin and adherens-junction (E-cadherin, β-catenin proteins, actin cytoskeleton, proliferative marker Ki67 and cell apoptosis in the epithelium. Topical application of commercial PG analogs resulted in significant corneal epithelial and stromal defects while no significant changes in aqueous tear production, BUT, rose bengal and fluorescein staining scores on day 5. Commercial PG analogs induced dislocation of ZO-1 and occludin from their normal locus, disorganization of cortical actin cytoskeleton at the superficial layer, and disruption of epithelial barrier function. The eyes treated with 0.02% BAK and latanoprost exhibited significantly reduced Schirmer scores, BUT, and increased fluorescein staining scores on days 10 and 30, respectively. Topical application of commercial PG analogs can quickly impair the corneal epithelium and stroma without tear deficiency. Commercial PG analogs break down the barrier

  19. An unusual case of spontaneous Mycobacterium chelonae corneal ulcer in a healthy middle-aged adult

    OpenAIRE

    Bhandari V; Sriganesh R; Relekar K

    2016-01-01

    Vipul Bhandari, R Sriganesh, Kirti RelekarDepartment of Cornea, Nethradhama Eye Hospital, Bengaluru, IndiaBackground: To report a rare presentation of culture-positive Mycobacterium chelonae corneal ulcer and its management.Findings: We report a rare case of a patient with a history of chronic pain and blurriness of vision. Examination revealed a chronic nonhealing paracentral corneal ulcer inferiorly at the 5–7 o'clock meridian with anterior chamber reaction unresponsive to...

  20. Corneal alterations induced by topical application of commercial latanoprost, travoprost and bimatoprost in rabbit.

    Science.gov (United States)

    Chen, Wensheng; Dong, Nuo; Huang, Caihong; Zhang, Zhenhao; Hu, Jiaoyue; Xie, Hui; Pan, Juxin; Liu, Zuguo

    2014-01-01

    Prostaglandin (PG) analogs, including latanoprost, travoprost, and bimatoprost, are currently the most commonly used topical ocular hypotensive medications. The purpose of this study was to investigate the corneal alterations in rabbits following exposure to commercial solution of latanoprost, travoprost and bimatoprost. A total of 64 New Zealand albino rabbits were used and four groups of treatments were constituted. Commercial latanoprost, travoprost, bimatoprost or 0.02% benzalkonium chloride (BAK) was applied once daily to one eye each of rabbits for 30 days. The contralateral untreated eyes used as controls. Schirmer test, tear break-up time (BUT), rose Bengal and fluorescein staining were performed on days 5, 10, 20, and 30. Central corneal changes were analyzed by in vivo confocal microscopy, and the corneal barrier function was evaluated by measurement of corneal transepithelial electrical resistance on day 5. Whole mount corneas were analyzed by using fluorescence confocal microscopy for the presence of tight-junction (ZO-1, occludin) and adherens-junction (E-cadherin, β-catenin) proteins, actin cytoskeleton, proliferative marker Ki67 and cell apoptosis in the epithelium. Topical application of commercial PG analogs resulted in significant corneal epithelial and stromal defects while no significant changes in aqueous tear production, BUT, rose bengal and fluorescein staining scores on day 5. Commercial PG analogs induced dislocation of ZO-1 and occludin from their normal locus, disorganization of cortical actin cytoskeleton at the superficial layer, and disruption of epithelial barrier function. The eyes treated with 0.02% BAK and latanoprost exhibited significantly reduced Schirmer scores, BUT, and increased fluorescein staining scores on days 10 and 30, respectively. Topical application of commercial PG analogs can quickly impair the corneal epithelium and stroma without tear deficiency. Commercial PG analogs break down the barrier integrity of corneal

  1. Ecuación hiperbólica de transmisión del calor para el estudio de la ablación corneal

    OpenAIRE

    2007-01-01

    En este trabajo presentamos el estudio del problema de transmisión del calor que se produce en el proceso de ablación de la córnea humana por radiofrecuencia, tal es el caso de la queratoplastia conductiva para la corrección de la hipermetropía y/o el astigmatismo mediante el empleo de electrodos intracorneales de muy pequeñas dimensiones. En estos casos, las distancias de interés son lo suficientemente pequeñas y los tiempos de excitación lo suficientemente cortos, como para que el est...

  2. Progenitors for the Corneal Endothelium and Trabecular Meshwork: A Potential Source for Personalized Stem Cell Therapy in Corneal Endothelial Diseases and Glaucoma

    Directory of Open Access Journals (Sweden)

    Wing Yan Yu

    2011-01-01

    Full Text Available Several adult stem cell types have been found in different parts of the eye, including the corneal epithelium, conjunctiva, and retina. In addition to these, there have been accumulating evidence that some stem-like cells reside in the transition area between the peripheral corneal endothelium (CE and the anterior nonfiltering portion of the trabecular meshwork (TM, which is known as the Schwalbe's Ring region. These stem/progenitor cells may supply new cells for the CE and TM. In fact, the CE and TM share certain similarities in terms of their embryonic origin and proliferative capacity in vivo. In this paper, we discuss the putative stem cell source which has the potential for replacement of lost and nonfunctional cells in CE diseases and glaucoma. The future development of personalized stem cell therapies for the CE and TM may reduce the requirement of corneal grafts and surgical treatments in glaucoma.

  3. Deletion of JAM-A causes morphological defects in the corneal epithelium.

    Science.gov (United States)

    Kang, Liang I; Wang, Yan; Suckow, Arthur T; Czymmek, Kirk J; Cooke, Vesselina G; Naik, Ulhas P; Duncan, Melinda K

    2007-01-01

    Junctional adhesion molecule-A (JAM-A, JAM-1, F11R) is an Ig domain containing transmembrane protein that has been proposed to function in diverse processes including platelet activation and adhesion, leukocyte transmigration, angiogenesis, epithelial cell shape and endothelial cell migration although its function in vivo is less well established. In the mouse eye, JAM-A protein expression is first detected at 12.5 dpc in the blood vessels of the tunica vasculosa, while it is first detected in both the corneal epithelium and lens between 13.5 and 14.5 dpc. In the corneal epithelium, JAM-A levels remain appreciable throughout life, while JAM-A immunostaining becomes stronger in the lens as the animals age. Both the cornea and lens of mice lacking an intact JAM-A gene are transparent until at least a year of age, although the cells of the JAM-A null corneal epithelium are irregularly shaped. In wild-type mice, JAM-A protein is found at the leading edge of repairing corneal epithelial wounds, however, corneal epithelial wound repair was qualitatively normal in JAM-A null animals. In summary, JAM-A is expressed in the corneal epithelium where it appears to regulate cell shape.

  4. The graft of autologous adipose-derived stem cells in the corneal stromal after mechanic damage.

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    Xiao-Yun Ma

    Full Text Available This study was designed to explore the feasibility of using autologous rabbit adipose derived stem cells (rASCs as seed cells and polylactic-co-glycolic acid (PLGA as a scaffold for repairing corneal stromal defects. rASCs isolated from rabbit nape adipose tissue were expanded and seeded on a PLGA scaffold to fabricate cell-scaffold constructs. After 1 week of cultivation in vitro, the cell-scaffold complexes were transplanted into corneal stromal defects in rabbits. In vivo, the autologous rASCs-PLGA constructed corneal stroma gradually became transparent without corneal neovascularization after 12 weeks. Hematoxylin and eosin staining and transmission electron microscopy examination revealed that their histological structure and collagen fibril distribution at 24 weeks after implantation were similar to native counterparts. As to the defect treated with PLGA alone, the stromal defects remained. And scar tissue was observed in the untreated-group. The implanted autologous ASCs survived up to 24 weeks post-transplantation and differentiated into functional keratocytes, as assessed by the expression of aldehyde-3-dehydrogenase1A1 (ALDH1A1 and cornea-specific proteoglycan keratocan. Our results revealed that autologous rASCs could be one of the cell sources for corneal stromal restoration in diseased corneas or for tissue engineering of a corneal equivalent.

  5. A retrospective study of fungal corneal ulcer from the western part of Uttar Pradesh

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    Dharmendra Prasad Singh

    2015-04-01

    Full Text Available Background: Infectious keratitis is a major cause of avoidable blindness worldwide. Fungus is an important aetiological agent of infectious keratitis following corneal trauma with vegetative matter. This infection should be promptly treated to limit the morbidity and dangerous sequelae. The purpose of this study was to detect causative agents from corneal scrapings and to identify the predisposing factors of mycotic keratitis. Methods: Corneal scrapings were taken in full aseptic precautions in total 112 suspected patients for fungal etiology and were subjected to direct examination by 10% KOH mount, gram stain and culture. Results: A total 112 cases of suspected corneal ulcers were subjected to KOH mount to detect fungal elements in corneal scraping and culture to isolate aetiological agents. In our study 29 (25.8% samples were found positive in KOH mount and fungus was isolated from the all KOH positive samples. Males were more commonly affected and were mostly in the age group of 30-50 years. Fusarium species was the most common fungus isolated followed by Aspergillus species. Conclusion: Mycotic keratitis is a serious problem usually following corneal trauma, it requires rapid detection and identification of fugal agents for treatment to prevent disastrous consequences. [Int J Res Med Sci 2015; 3(4.000: 880-882

  6. Long‐term recovery of the human corneal endothelium after toxic injury by benzalkonium chloride

    Science.gov (United States)

    Hughes, E H; Pretorius, M; Eleftheriadis, H; Liu, C S C

    2007-01-01

    Introduction The inadvertent intra‐ocular administration of benzalkonium chloride‐preserved hydroxypropyl methylcellulose during cataract surgery at another hospital in 1999 resulted in toxic corneal endothelial injury and profound postoperative corneal oedema as a result of endothelial decompensation. The long‐term effect of this adverse event was assessed. Methods All 19 patients were invited to return for examination including corneal endothelial specular microscopy and pachymetry seven years after the incident. Results were compared with data from one year after the incident. Results Five patients attended for examination, one had received a penetrating keratoplasty and was, therefore, excluded. Ten patients had died and four had moved out of the region and were unable to attend. All four study patients were pain free and achieved 6/12 or better. Mean central corneal thickness reduced by 13% from 652.6 μm at one year to 563.4 μm. Mean central corneal endothelial cell density (n  =  3) increased 28% from 663.7 cells/mm2 at one year to 835.7 cells/mm2 (p<0.05). Conclusions After toxic injury, corneal endothelial function may have a remarkable capacity for recovery even after the first postoperative year. The rise in central endothelial cell density may represent cell migration from less affected areas or cellular proliferation. Should this unfortunate event recur, clinicians may expect continued recovery beyond one year. PMID:17504856

  7. Benzalkonium Chloride Accelerates the Formation of the Amyloid Fibrils of Corneal Dystrophy-associated Peptides*

    Science.gov (United States)

    Kato, Yusuke; Yagi, Hisashi; Kaji, Yuichi; Oshika, Tetsuro; Goto, Yuji

    2013-01-01

    Corneal dystrophies are genetic disorders resulting in progressive corneal clouding due to the deposition of amyloid fibrils derived from keratoepithelin, also called transforming growth factor β-induced protein (TGFBI). The formation of amyloid fibrils is often accelerated by surfactants such as sodium dodecyl sulfate (SDS). Most eye drops contain benzalkonium chloride (BAC), a cationic surfactant, as a preservative substance. In the present study, we aimed to reveal the role of BAC in the amyloid fibrillation of keratoepithelin-derived peptides in vitro. We used three types of 22-residue synthetic peptides covering Leu110-Glu131 of the keratoepithelin sequence: an R-type peptide with wild-type R124, a C-type peptide with C124 associated with lattice corneal dystrophy type I, and a H-type peptide with H124 associated with granular corneal dystrophy type II. The time courses of spontaneous amyloid fibrillation and seed-dependent fibril elongation were monitored in the presence of various concentrations of BAC or SDS using thioflavin T fluorescence. BAC and SDS accelerated the fibrillation of all synthetic peptides in the absence and presence of seeds. Optimal acceleration occurred near the CMC, which suggests that the unstable and dynamic interactions of keratoepithelin peptides with amphipathic surfactants led to the formation of fibrils. These results suggest that eye drops containing BAC may deteriorate corneal dystrophies and that those without BAC are preferred especially for patients with corneal dystrophies. PMID:23861389

  8. IL-8 and MCP Gene Expression and Production by LPS-Stimulated Human Corneal Stromal Cells

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    Roni M. Shtein

    2012-01-01

    Full Text Available Purpose. To determine time course of effect of lipopolysaccharide (LPS on production of interleukin-8 (IL-8 and monocyte chemotactic protein (MCP by cultured human corneal stromal cells. Methods. Human corneal stromal cells were harvested from donor corneal specimens, and fourth to sixth passaged cells were used. Cell cultures were stimulated with LPS for 2, 4, 8, and 24 hours. Northern blot analysis of IL-8 and MCP gene expression and ELISA for IL-8 and MCP secretion were performed. ELISA results were analyzed for statistical significance using two-tailed Student's t-test. Results. Northern blot analysis demonstrated significantly increased IL-8 and MCP gene expression after 4 and 8 hours of exposure to LPS. ELISA for secreted IL-8 and MCP demonstrated statistically significant increases (P<0.05 after corneal stromal cell stimulation with LPS. Conclusions. This paper suggests that human corneal stromal cells may participate in corneal inflammation by secreting potent leukocyte chemotactic and activating proteins in a time-dependent manner when exposed to LPS.

  9. Endothelial keratoplasty for corneal decompensation leaded by a dexamethasone implant dislocation in anterior chamber

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    Fernanda Pacella

    2016-06-01

    Full Text Available Background: Dexamethasone intravitreal implant (DEX largely showed his safety and efficacy for the treatment of cases of macular edema. Even if uncommon, delivery dislocation in anterior chamber has been described in Literaure as complication of the injection procedure, leading to irreversible endothelial cell loss in the majority of cases. We report a case of a 66-year-old man with pain and vision loss in his left eye. The anamnesis revealed a recent intravitreal injection of DEX implant for a persistent cystoid macular edema related to central retinal vein occlusion. Anterior segment examination showed corneal edema and the rod implant adherent to corneal endothelium. A large peripheral iridectomy was evident with retroillumination and IOL appeared good centered in the bag. The implant was removed but corneal decompensation was irreversible. One month later, an endothelial keratoplasty was successfully performed restoring corneal transparency. DEX intravitreal implant can migrate from vitreous cavity to anterior chamber and lead to irreversible corneal decompensation by mechanical and chemical toxicity on corneal endothelium. Removeal of the implant is necessary to avoid total endothelial decompensation. Despite this, in some cases endothelial keratoplasty had to be performed.

  10. "Double bubble" deep anterior lamellar keratoplasty for management of corneal stromal pathologies.

    Science.gov (United States)

    Jhanji, Vishal; Beltz, Jacqueline; Sharma, Namrata; Graue, Enrique; Vajpayee, Rasik B

    2011-08-01

    'Big Bubble' deep anterior lamellar keratoplasty (DALK) is becoming an accepted corneal transplantation technique for keratoconus and other anterior stromal corneal pathologies that spare the Descemet's membrane (DM) and endothelium. However, it is not always possible to conclusively recognise formation and identification of the 'Big Bubble'. We describe the surgical technique of DALK called 'Double Bubble' technique that allows the surgeon to definitely and immediately identify the formation of an adequate big bubble. DALK was performed using the 'Double Bubble' technique in twelve eyes of twelve patients with corneal stromal pathologies (keratoconus, 9 eyes; macular corneal dystrophy, 2 eyes; postinfectious keratitis corneal stromal scar, 1 eye) at the Royal Victorian Eye and Ear Hospital, Melbourne. Big bubble was successfully formed in 10 eyes. Maximum-depth deep lamellar keratoplasty was performed in two eyes. There were no instances of intraoperative perforation of the DM. All grafts were clear at last follow-up. Best-corrected visual acuity of ≥20/40 was achieved in all the cases at last follow-up (6-12 months). 'Double Bubble' DALK helps in identification of the big bubble and has the potential to increase the success of standard 'Big Bubble' DALK in patients with corneal stromal pathologies sparing the DM and endothelium.

  11. Topical 100% Serum Eye Drops for Treating Corneal Epithelial Defect after Ocular Surgery

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    Kaevalin Lekhanont

    2013-01-01

    Full Text Available The purpose of this study was to investigate the efficacy and safety of topical 100% serum eye drops for corneal epithelial defect after ocular surgery. A total of 181 patients who received topical 100% serum therapy for the treatment of corneal epithelial defect following several different types of ocular surgery were recruited into this study. Each patient already failed conventional medical therapy before being prescribed 100% serum eye drops. Slit-lamp biomicroscopic examination with fluorescein staining was performed at baseline and all follow-up visits. The main outcome measures were the rate of complete healing of the corneal epithelial defect and incidence of adverse events. One hundred and seventy-eight eyes (98.34% received autologous serum eye drops, and 3 (1.66% received allogeneic serum eye drops. The overall success rate of treating persistent postoperative epithelial defect using 100% serum eye drops was 93.92% (95% CI 0.88–0.98. The median time to complete corneal epithelialization was 4 days (95% CI 4-5. Adverse reactions were observed in 3 patients (1.66%, including sticky sensation with minimal eye discomfort and asymptomatic trace corneal subepithelial infiltration. No serious complications were reported. In conclusion, 100% serum eye drops are effective, safe, and tolerable for treating postoperative corneal epithelial defect following ocular surgeries.

  12. Bilateral Mooren's ulcer - Customised corneal graft with additional amniotic membrane graft.

    Science.gov (United States)

    Bhandari, Vipul; Siddharthan, K S

    2015-01-01

    Mooren's ulcer (MU) is a rare and painful peripheral corneal ulceration which occurs in the absence of any associated scleritis, and any detectable systemic disease. A 60-year-old male patient was referred to us with bilateral peripheral corneal ulceration. Best corrected visual acuity (BCVA) in both eyes was counting finger at one metre. The right eye showed a 180° thinning with perforation at 8 o'clock position. The left eye showed a 360° thinning with central contact lens type cornea. After complete blood analysis we started the patient on cyclophosphamide orally along with high doses of oral steroids. A crescentic excision of the thinned cornea and crescentic customised corneal graft with additional amniotic membrane graft (AMG) was done first for the right eye and a 360° peripheral lamellar corneal graft with additional AMG for the left eye. The BCVA of RE was 1/60 improving to 6/36 with plus ten aphakic glasses and LE was 3/60. Hand fashioned full thickness crescentic customised corneal graft with additional AMG and a peripheral 360° lamellar corneal graft with additional AMG in these cases are a novel approach to Mooren's ulcer with gratifying results.

  13. Segmentation of 830- and 1310-nm LASIK corneal optical coherence tomography images

    Science.gov (United States)

    Li, Yan; Shekhar, Raj; Huang, David

    2002-05-01

    Optical coherence tomography (OCT) provides a non-contact and non-invasive means to visualize the corneal anatomy at micron scale resolution. We obtained corneal images from an arc-scanning (converging) OCT system operating at a wavelength of 830nm and a fan-shaped-scanning high-speed OCT system with an operating wavelength of 1310nm. Different scan protocols (arc/fan) and data acquisition rates, as well as wavelength dependent bio-tissue backscatter contrast and optical absorption, make the images acquired using the two systems different. We developed image-processing algorithms to automatically detect the air-tear interface, epithelium-Bowman's layer interface, laser in-situ keratomileusis (LASIK) flap interface, and the cornea-aqueous interface in both kinds of images. The overall segmentation scheme for 830nm and 1310nm OCT images was similar, although different strategies were adopted for specific processing approaches. Ultrasound pachymetry measurements of the corneal thickness and Placido-ring based corneal topography measurements of the corneal curvature were made on the same day as the OCT examination. Anterior/posterior corneal surface curvature measurement with OCT was also investigated. Results showed that automated segmentation of OCT images could evaluate anatomic outcome of LASIK surgery.

  14. Treatment of corneal squamous cell carcinoma using topical 1% 5-fluorouracil as monotherapy.

    Science.gov (United States)

    Dorbandt, Daniel M; Driskell, Elizabeth A; Hamor, Ralph E

    2016-05-01

    The purpose of this report is to discuss the use of topical 1% 5-fluorouracil as a sole therapy for canine corneal squamous cell carcinoma (SCC). A 12-year-old castrated male pug was evaluated for a well-demarcated, central, 3 mm in diameter, pale pink, raised, right corneal mass. An incisional biopsy was obtained using a #64 beaver blade after topical anesthesia and without sedation. A definitive diagnosis of corneal SCC was obtained after histopathologic evaluation of the biopsy. Topical 1% 5-fluorouracil ointment was applied to the right eye four times daily for 2 weeks followed by no treatment for 2 weeks, then treatment again twice daily for 2 weeks. The cornea remained free of recurrence 10 months after cessation of treatment. In dogs affected with corneal SCC, topical 1% 5-fluorouracil monotherapy may be a viable and cost-effective treatment option with minimal side effects. This chemotherapy agent may also have an effect on corneal pigmentation. Chronic cyclosporine therapy did not contribute to the pathogenesis of corneal SCC in the case described.

  15. In vivo Confocal Microscopy Report after Lasik with Sequential Accelerated Corneal Collagen Cross-Linking Treatment

    Directory of Open Access Journals (Sweden)

    Cosimo Mazzotta

    2014-04-01

    Full Text Available We report the first pilot qualitative confocal microscopic analysis of a laser in situ keratomileusis (Lasik treatment combined with sequential high-fluence accelerated corneal collagen cross-linking, denominated Lasik XTra, by means of HRT II laser scanning in vivo confocal microscopy after a 6-month follow-up. After obtaining approval from the Siena University Hospital Institutional Review Board, a 33-year-old female patient underwent a Lasik XTra procedure in her left eye. Confocal analysis demonstrated induced slight corneal microstructural changes by the interaction between UV-A, riboflavin and corneal stromal collagen, beyond the interface to a depth of 160 µm, without adverse events at the interface and endothelial levels. This application may be considered a prophylactic biomechanical treatment, stiffening the intermediate corneal stroma to prevent corneal ectasia and stabilizing the clinical results of refractive surgery. According to our preliminary experiences, this combined approach may be useful in higher-risk Lasik patients for hyperopic treatments, high myopia and lower corneal thicknesses.

  16. In Vitro and In Vivo Models to Study Corneal Endothelial-mesenchymal Transition.

    Science.gov (United States)

    Ho, Wei-Ting; Su, Chien-Chia; Chang, Jung-Shen; Chang, Shu-Wen; Hu, Fung-Rong; Jou, Tzuu-Shuh; Wang, I-Jong

    2016-08-20

    Corneal endothelial cells (CECs) play a crucial role in maintaining corneal clarity through active pumping. A reduced CEC count may lead to corneal edema and diminished visual acuity. However, human CECs are prone to compromised proliferative potential. Furthermore, stimulation of cell growth is often complicated by gradual endothelial-mesenchymal transition (EnMT). Therefore, understanding the mechanism of EnMT is necessary for facilitating the regeneration of CECs with competent function. In this study, we prepared a primary culture of bovine CECs by peeling the CECs with Descemet's membrane from the corneal button and demonstrated that bovine CECs exhibited the EnMT process, including phenotypic change, nuclear translocation of β-catenin, and EMT regulators snail and slug, in the in vitro culture. Furthermore, we used a rat corneal endothelium cryoinjury model to demonstrate the EnMT process in vivo. Collectively, the in vitro primary culture of bovine CECs and in vivo rat corneal endothelium cryoinjury models offers useful platforms for investigating the mechanism of EnMT.

  17. Differentiation and molecular profiling of human embryonic stem cell-derived corneal epithelial cells.

    Science.gov (United States)

    Brzeszczynska, J; Samuel, K; Greenhough, S; Ramaesh, K; Dhillon, B; Hay, D C; Ross, J A

    2014-06-01

    It has been suggested that the isolation of scalable populations of limbal stem cells may lead to radical changes in ocular therapy. In particular, the derivation and transplantation of corneal stem cells from these populations may result in therapies providing clinical normality of the diseased or damaged cornea. Although feasible in theory, the lack of donor material in sufficient quantity and quality currently limits such a strategy. A potential scalable source of corneal cells could be derived from pluripotent stem cells (PSCs). We developed an in vitro and serum-free corneal differentiation model which displays significant promise. Our stepwise differentiation model was designed with reference to development and gave rise to cells which displayed similarities to epithelial progenitor cells which can be specified to cells displaying a corneal epithelial phenotype. We believe our approach is novel, provides a robust model of human development and in the future, may facilitate the generation of corneal epithelial cells that are suitable for clinical use. Additionally, we demonstrate that following continued cell culture, stem cell-derived corneal epithelial cells undergo transdifferentiation and exhibit squamous metaplasia and therefore, also offer an in vitro model of disease.

  18. Comparison of corneal epithelial and stromal thickness distributions between eyes with keratoconus and healthy eyes with corneal astigmatism ≥ 2.0 D.

    Directory of Open Access Journals (Sweden)

    Wen Zhou

    Full Text Available PURPOSE: To identify corneal epithelial- and stromal-thickness distribution patterns in keratoconus using spectral-domain optical coherence tomography (SD-OCT. PATIENTS AND METHODS: We analyzed SD-OCT findings in 20 confirmed cases of keratoconus (group 1 and in 20 healthy subjects with corneal astigmatism ≥ 2 D (group 2. Epithelial and stromal thicknesses were measured at 11 strategic locations along the steepest and flattest meridians, previously located by corneal topography. Vertical mirrored symmetry superimposition was used in the statistical analysis. RESULTS: The mean maximum keratometry measurements in groups 1 and 2 were 47.9 ± 2.9 D (range, 41.8-52.8 and 45.6 ± 1.1 D (range, 42.3-47.5, respectively, with mean corneal cylinders of 3.3 ± 2.2 D (range, 0.5-9.5 and 3.6 ± 1.2 D (range, 2.0-6.4, respectively. The mean epithelial thickness along the steepest meridian in group 1 was the lowest (37.4 ± 4.4 µm at 1.2 mm inferotemporally and the highest (59.3 ± 4.4 µm at 1.4 mm supranasally from the corneal vertex. There was only a small deviation in thickness along the steepest meridian in group 2, as well as along the flattest meridians in both groups. The stromal thickness distribution in the two groups was similar to the epithelial, while the stromal thickness was generally lower in group 1 than in group 2. CONCLUSIONS: SD-OCT provides details about the distribution of corneal epithelial and stromal thicknesses. The epithelium and stroma in keratoconic eyes were thinner inferotemporally and thicker supranasally compared with control eyes. The distribution pattern was more distinct in epithelium than in stroma. This finding may help improve the early diagnosis of keratoconus. TRIAL REGISTRATION: ClinicalTrials.gov NCT02023619.

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

    Directory of Open Access Journals (Sweden)

    Belquiz Amaral Nassaralla

    2013-06-01

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

  20. Corneal Cross-Linking (with a Partial Deepithelization) in Keratoconus with Five Years of Follow-Up

    Science.gov (United States)

    Galvis, Virgilio; Tello, Alejandro; Carreño, Néstor I.; Ortiz, Alvaro I.; Barrera, Rodrigo; Rodriguez, Carlos Julián; Ochoa, Miguel E.

    2016-01-01

    We performed a retrospective interventional case series including 80 eyes of 48 patients with keratoconus (KC) who were treated with modified corneal cross-linking (CXL) for KC (with a partial deepithelization in a pattern of stripes). The average follow-up was 5.8 years (with a minimum of 5 years). At the last follow-up visit, compared with preoperative values, there were no significant changes in spherical equivalent, average keratometry, corneal thickness, corneal hysteresis, or corneal resistance factor. The distance-corrected visual acuity was 20/39 preoperatively and 20/36 postoperatively (P = 0.3). The endothelial cell count decreased by 4.7% (P < 0.005). These findings suggest that this modified corneal CXL technique is a safe and effective alternative to halt the progression of KC up to five years after the procedure. However, some concerns remain as to whether this technique can affect in some degree the corneal endothelial cells. PMID:27199574

  1. 基于精确中心定位的角膜复原算法%An Algorithm of Corneal Reconstruction Based on Precise Location of Corneal Center

    Institute of Scientific and Technical Information of China (English)

    周洪亚; 沈建新; 高绍雷; 唐志豪

    2011-01-01

    Placido盘在角膜地形图系统中应用最为广泛.针对Placido角膜地形图系统中角膜中心定位不准的问题,提出了一种基于Placido盘的角膜复原算法.关键技术是利用图像最内环的数据精确求解角膜中心顶点曲率半径.该方法根据图像分析的结果,利用圆弧连接角膜顶点和第一个反射点,通过迭代精确求解角膜顶点的曲率半径,进而求解角膜各反射点的位置以及屈光度,建立真实人眼的伪彩图.利用标准钢球模拟人眼角膜,结果误差小于0.25 D,表明所采用的算法具有较好的精度和稳定性.%Placido disk is widely used in corneal topography. In order to solve the problem that the convex of the cor-neal can not be precisely located in the Placido corneal topography system, an algorithm of corneal reconstruction based on the Placido disk was introduced. The key of this method is the calculation of radius of corneal convex by u-sing the innermost ring data. Based on image analysis result, we precisely calculated the radius of corneal convex it-eratively by connecting the convex and the first ring using a circle, and then calculated the location of all the reflect point and its power. At last we created the pseudo color map of the human corneal. The corneal was simulated by u-sing standard steel sphere, and the calculating errors of the result were all below 0. 25D. It showed that the algorithm used in this work could get relatively accurate powers and would have fair stability.

  2. An X-Ray Scattering Study into the Structural Basis of Corneal Refractive Function in an Avian Model

    OpenAIRE

    Morgan, Siân R.; Dooley, Erin P.; Hocking, Paul M.; Inglehearn, Chris F.; Ali, Manir; Sorensen, Thomas L.-M.; Meek, Keith M.; Boote, Craig

    2013-01-01

    Avian vision diseases in which eye growth is compromised are helping to define what governs corneal shape and ultrastructural organization. The highly specific collagen architecture of the main corneal layer, the stroma, is believed to be important for the maintenance of corneal curvature and hence visual quality. Blindness enlarged globe (beg) is a recessively inherited condition of chickens characterized by retinal dystrophy and blindness at hatch, with secondary globe enlargement and loss ...

  3. Rates of and Experiences with Corneal Donation at the University Hospital Tübingen From 2002 To 2015.

    Science.gov (United States)

    Röck, Daniel; Bartz-Schmidt, Karl Ulrich; Röck, Tobias

    2016-07-12

    BACKGROUND This study aimed to report the rates and experiences of corneal donation at the University Hospital Tübingen. MATERIAL AND METHODS Data from all cornea donors from January 2002 to December 2015 were analyzed. The rates of corneal donation were examined. From 2002 to 2008, an ophthalmic resident handled the corneal donor procurement in addition to his ward work. From 2009 to 2015, an ophthalmic resident handled the corneal donor procurement on a full-time basis. RESULTS Among the 10 260 deaths, consent for corneal donation was obtained in 892 cases. The mean annual corneal donation rate was 8.7 donors per 100 deaths (range: 2.0-17.8). The mean corneal donation rate in the first period without a full-time ophthalmic resident in the eye bank team was 4.0 donors per 100 deaths (95 % confidence interval [CI]: 1.0-6.9) and in the second period 12.3 donors per 100 deaths (95 % CI: 3.2-21.5) (Pdonation rate was increased by more than 3 times. CONCLUSIONS Our study showed the influence of the eye banking team on the corneal donation rate. Modification of the eye bank team, by recruiting a full-time resident at a University Hospital with 1500 beds, increased the corneal donation rate by more than 3 times. It appears necessary to strengthen this team with sufficient staff levels to improve donor rates.

  4. Comparison of the effects of various lubricant eye drops on the in vitro rabbit corneal healing and toxicity.

    Science.gov (United States)

    Dutescu, R Michael; Panfil, Claudia; Schrage, Norbert

    2017-03-02

    Ingredients of lubricant eye drops are potentially harmful to the ocular surface. The products Optive, Optive Fusion, Neopt were tested regarding corneal irritability versus Vismed Multi and 0.01% benzalkonium chloride as negative and positive control, respectively. Formulas (30-40μl per hour) were applied hourly in-vitro for six days on rabbit corneas (n=5, per product) cultured in artificial anterior chambers (EVEIT system). Initially, four corneal abrasions (2.4-4.6mm(2)) were induced. All defects were monitored during drop application by fluorescein stains and photographs. To ensure corneal vitality, glucose and lactate concentrations in artificial anterior chamber fluids were determined photometrically. All products showed a complete corneal healing on day 2. Thereafter, all five Optive-treated corneas developed progressive fluorescein-positive epithelial lesions until day six (24.96μm, ±21.45μm, p0.5) while Vismed Multi did not adversely affect the corneal integrity. Glucose/lactate concentrations remained unchanged while lubricants were applied. Histology revealed epithelial loss and severe alterations of the superficial stroma for Optive. Optive Fusion displayed a comparable pathology. Neopt did not significantly affect the corneal healing and integrity. This study suggested a cumulative corneal toxicity of Optive and, to a lesser extent, Optive Fusion most likely caused by its oxidative preservative, SOC. Clinical data are needed to clarify the application frequency at which corneal toxicity might occur. Neopt and Vismed Multi did not affect the corneal integrity.

  5. ROLE OF CORNEAL COLLAGEN CROSS LINKING IN KERATOCONUS

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    Atul

    2015-09-01

    Full Text Available To evaluate the outcome of collagen cross linkage using riboflavin 0.1% and ultraviolet A radiation of a wavelength 370nm . PURPOSE : To determine the effect of collagen cross linking for keratoconus on pachymetry , corneal topography, uncorrected visual acuity, specular count, IOP at 1, 3, 6 months . METHODS : The current study was designed as a prospective interventional trial of corneal collagen cross - linking in subjects with progressive keratoconus between a period of J anuary 2013 to J uly 2014 including 50 eyes of 30 patients. This study rece ived approval from Ethics committee. Informed written consent was obtained from all patients prior to treatment. RESULTS: Mean follow up period of 6 months. There was statistically significant decline in effective k readings from mean pre op (51.7D to pos t op value (49.65D . Pachymetry showed initial increase post operatively followed by reduction in corneal thickness in 3 month s follow up , followed by gradual increase in thickness over a period of 6 months though it was not equivalent to pre - operative values. paired t test p value was 0.00 1 in 1 n 3 month and 0. 043 in 6 month, concluding significant reduction in early post op period with im provement over time . Specular count reduced from pre - op (2673.80 levels to post - op (2654.60 levels ,the reduction in specular count was not statistically significant P value (0.014 The uncorrected visual acuity showed decrease in refractive error with in crease in visual acuity gradually over 6 months, log MAR scale visual acuity was used for statistical analysis with P value (0.001 which was statistically significant .visual acuity improved by 1.5 lines in snellens equivalence or from 0.5 to 0.4 in log MA R char y ± 20cells/mm 3 , P value(0. 001 . IOP statically show ed no significant change in pre - operative and post operatively , paired t test p value was 0. 44 showing it was not significant . CONCLUSIONS : 1. Visual acuity improved in

  6. IκB kinase β regulates epithelium migration during corneal wound healing.

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    Liang Chen

    Full Text Available The IKKβ is known to regulate transcription factor NF-κB activation leading to inflammatory responses. Recent gene knockout studies have shown that IKKβ can orchestrate local inflammatory responses and regulate homeostasis of epithelial tissues. To investigate whether IKKβ has an intrinsic role in epithelial cells, we established an in vivo system in the immune privileged corneal epithelium. We generated triple transgenic Krt12(rtTA/rtTAt/tet-O-Cre/Ikkβ(F/F (Ikkβ(ΔCE/ΔCE mice by crossing the Krt12-rtTA knock-in mice, which express the reverse tetracycline transcription activator in corneal epithelial cells, with the tet-O-Cre and Ikkβ(F/F mice. Doxycycline-induced IKKβ ablation occurred in corneal epithelial cells of triple transgenic Ikkβ(ΔCE/ΔCE mice, but loss of IKKβ did not cause ocular abnormalities in fetal development and postnatal maintenance. Instead, loss of IKKβ significantly delayed healing of corneal epithelial debridement without affecting cell proliferation, apoptosis or macrophage infiltration. In vitro studies with human corneal epithelial cells (HCEpi also showed that IKKβ was required for cytokine-induced cell migration and wound closure but was dispensable for cell proliferation. In both in vivo and in vitro settings, IKKβ was required for optimal activation of NF-κB and p38 signaling in corneal epithelial cells, and p38 activation is likely mediated through formation of an IKKβ-p38 protein complex. Thus, our studies in corneal epithelium reveal a previously un-recognized role for IKKβ in the control of epithelial cell motility and wound healing.

  7. A Fast and Efficient Technique for the Automatic Tracing of Corneal Nerves in Confocal Microscopy

    Science.gov (United States)

    Guimarães, Pedro; Wigdahl, Jeffrey; Ruggeri, Alfredo

    2016-01-01

    Purpose We describe a novel fully automatic method capable of tracing the subbasal plexus nerves from human corneal confocal images. Methods Following an increasing interest in the automatic analysis of corneal nerves, a few approaches have been proposed. These, however, cannot cope with large images, such as mosaics, in due time. The rationale of the proposed method is to minimize required computing time while still providing accurate results. Our method consists of two sequential steps – a thresholding step followed by a supervised classification. For the classification we use a support vector machines (SVM) approach. Initially, a large set of features is computed, which is later reduced using a backward-elimination based on segmentation accuracy. To validate the obtained tracings, we evaluated the tracing accuracy and reliability of extracted clinical parameters (corneal nerves density and tortuosity). Results The proposed algorithm proved capable to correctly trace 0.89 ± 0.07 of the corneal nerves. The obtained performance level was comparable to a second human grader. Furthermore, the proposed approach compares favorably to other methods. For both evaluated clinical parameters the proposed approach performed well. An execution time of 0.61 ± 0.07 seconds per image was achieved. The proposed algorithm was applied successfully to mosaic images, with run times of the order of tens of seconds. Conclusions The achieved quality and processing time of the proposed method appear adequate for the application of this technique to clinical practice. Translational Relevance The automatic tracing of corneal nerves is an important step for the quantitative analysis of corneal nerves in daily clinical practice. The proposed fast technique allows features, such as corneal nerve density and tortuosity, to be computed in a few seconds. The application of nerve tracing to mosaics covering a large area can be a key component in clinical studies aimed at investigating

  8. Epidemiological Aspect and common Bacterial and Fungal isolates from Suppurative Corneal Ulcer in Mymensingh Region.

    Science.gov (United States)

    Moid, M A; Akhanda, A H; Islam, S; Halder, S K; Islam, R

    2015-04-01

    This prospective study was done to find out the epidemiological factors of suppurative corneal ulcer and the common causative bacterial and fungal isolates from the, patients with suppurative corneal ulcer in secondary and tertiary level hospital at Mymensingh region. A total 100 samples of corneal scrapings were collected purposively from clinically diagnosed suppurative corneal ulcer patients from March 18, 2012 to March 17, 2013. Out of the total 100 samples, bacterial species were 29(29%) cases and the fungal spacies were 71(71%) identified by the culture in blood agar, chocolate agar and sabouraud's agar media and also by microscopic examination. The bacterial species were streptococcus pneumonae 12 cases (12%), Staphylococcus aureus 9 cases (9%), pseudomonas in 6 cases (6%), and Streptococcus pyoganes 2 cases (2%). Fungal species were aspergillus fumigatus 61 cases (61%), aspergillus niger 10 cases (10%). Out of the study populations, most of the populations were from the age group of 41 to 60 years (39 %), followed 21 to 40 years (34%) age group. Considering the sex, male were 67%, female were 33%. The majority of patients came from the rural area of Mymensingh region; occupationally they were farmers (44%). Ocular trauma due to agricultural materials was the most common associated factor (71%). The etiological and epidemiological pattern of suppurative corneal ulcer varies significantly with geographical region, patient population and health of the cornea. The present study was carried out to explore the epidemiological pattern, causative bacterial and fungal specie by laboratory procedure from corneal scraping and to invent a prospective guide line for the management of corneal ulcer in the community.

  9. Changing indications and surgical techniques for corneal transplantation between 2004 and 2009 at a tertiary referral center

    Directory of Open Access Journals (Sweden)

    Mohammad Zare

    2012-01-01

    Full Text Available Purpose: The aim of this study is to report the indications, techniques, and clinical outcomes of corneal transplantation and investigate any changing trends in surgical techniques over a 6 year period. Materials and Methods: Records of patients who had undergone any kind of corneal transplantation at Labbafinejad Medical Center, Tehran, Iran, from January 2004 to December 2009 were reviewed to determine the indications and types of corneal transplantation. Postoperative best-corrected visual acuity, refractive error, graft clarity, and complications were reported. Results: During this period, 1859 eyes of 1624 patients with a mean age of 41.3 ± 21.3 years underwent corneal transplantation. The most common indication was keratoconus (38.4% followed by aphakic/pseudophakic bullous keratopathy (11.7%, previous failed grafts (10.6%, infectious corneal ulcers (10.1%, non-herpetic corneal scars (7.6%, trachoma keratopathy (4.7%, stromal corneal dystrophies (4.6%, post-herpetic corneal scar (3.7%, Fuchs′ endothelial dystrophy (0.8%, and congenital hereditary endothelial dystrophy (0.4%. Techniques of corneal transplantation included penetrating keratoplasty (PKP; 70.9%, deep anterior lamellar keratoplasty (DALK; 20.1%, conventional lamellar keratoplasty (LKP; 4.4%, and Descemet′s stripping automated endothelial keratoplasty (DSAEK; 2.3%. Over the study period, there was a significant increase in the relative frequency of infectious corneal ulcers, failed grafts, and trachoma keratopathy. Additionally, a significant reduction was observed in PKP and LKP procedures, and volume of DALK and DSAEK increased significantly. At final follow-up, 69.0% of grafts were clear in the PKP group. This figure was 82.6%, 82.7%, and 97.6% in the DALK, LKP, and DSAEK groups, respectively. Conclusion: Keratoconus was the most common indication and PKP was the most prevalent technique used for corneal transplantation. However, significant changes in the indications

  10. Changing Indications and Surgical Techniques for Corneal Transplantation Between 2004 and 2009 at a Tertiary Referral Center

    Science.gov (United States)

    Zare, Mohammad; Javadi, Mohammad A.; Einollahi, Bahram; Karimian, Farid; Rafie, Ali R. B.; Feizi, Sepehr; Azimzadeh, Ahmad

    2012-01-01

    Purpose: The aim of this study is to report the indications, techniques, and clinical outcomes of corneal transplantation and investigate any changing trends in surgical techniques over a 6 year period. Materials and Methods: Records of patients who had undergone any kind of corneal transplantation at Labbafinejad Medical Center, Tehran, Iran, from January 2004 to December 2009 were reviewed to determine the indications and types of corneal transplantation. Postoperative best-corrected visual acuity, refractive error, graft clarity, and complications were reported. Results: During this period, 1859 eyes of 1624 patients with a mean age of 41.3 ± 21.3 years underwent corneal transplantation. The most common indication was keratoconus (38.4%) followed by aphakic/pseudophakic bullous keratopathy (11.7%), previous failed grafts (10.6%), infectious corneal ulcers (10.1%), non-herpetic corneal scars (7.6%), trachoma keratopathy (4.7%), stromal corneal dystrophies (4.6%), post-herpetic corneal scar (3.7%), Fuchs’ endothelial dystrophy (0.8%), and congenital hereditary endothelial dystrophy (0.4%). Techniques of corneal transplantation included penetrating keratoplasty (PKP; 70.9%), deep anterior lamellar keratoplasty (DALK; 20.1%), conventional lamellar keratoplasty (LKP; 4.4%), and Descemet's stripping automated endothelial keratoplasty (DSAEK; 2.3%). Over the study period, there was a significant increase in the relative frequency of infectious corneal ulcers, failed grafts, and trachoma keratopathy. Additionally, a significant reduction was observed in PKP and LKP procedures, and volume of DALK and DSAEK increased significantly. At final follow-up, 69.0% of grafts were clear in the PKP group. This figure was 82.6%, 82.7%, and 97.6% in the DALK, LKP, and DSAEK groups, respectively. Conclusion: Keratoconus was the most common indication and PKP was the most prevalent technique used for corneal transplantation. However, significant changes in the indications and

  11. Anesthesia for Traumatic Diaphragmatic Hernia Associated with Corneal Laceration

    Science.gov (United States)

    Safaeian, Reza; Hassani, Valiollah; Faiz, Hamid Reza

    2016-01-01

    Patient: Male, 37 Final Diagnosis: Diaphragmatic hernia Symptoms: Dyspnea Medication: — Clinical Procedure: CT-scan Specialty: Anesthesiology Objective: Rare co-existance of disease or pathology Background: Diaphragmatic rupture can be seen in up to 5% of car accidents, and 80%–100% of diaphragmatic hernias are associated with other vital organ injuries. Brain, pelvis, long bones, liver, spleen, and aorta are some other organs that can be severely damaged and need different anesthetic managements. Case Report: A 37-year-old male victim of a head-on collision who was suffering diaphragmatic rupture and corneal laceration was prepared for an emergency operation 11 hours after the car accident. Gastric decompression, preoxygenation, rapid sequence induction with succinylcholine, immediate use of non-depolarizing muscle relaxant, and mechanical ventilation with low tidal volume after intubation were used in anesthetic management of the patient. Conclusions: Because of the high prevalence of coexisting pathologies with traumatic diaphragmatic hernia, anesthetic management must be tailored to the associated pathologies. PMID:27595907

  12. Dual interferometer for dynamic measurement of corneal topography

    Science.gov (United States)

    Micali, Jason D.; Greivenkamp, John E.

    2016-08-01

    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. A dual interferometer system for measuring the dynamic corneal topography is designed, built, verified, and qualified by testing on human subjects. The system consists of two coaligned simultaneous phase-shifting polarization-splitting Twyman-Green interferometers. The primary interferometer measures the surface of the tear film while the secondary interferometer tracks the absolute position of the cornea, which provides enough information to reconstruct the absolute shape of the cornea. The results are high-resolution and high-accuracy surface topography measurements of the in vivo tear film and cornea that are captured at standard camera frame rates.

  13. Adaptive preprocessing algorithms of corneal topography in polar coordinate system

    Institute of Scientific and Technical Information of China (English)

    郭雁文

    2014-01-01

    New adaptive preprocessing algorithms based on the polar coordinate system were put forward to get high-precision corneal topography calculation results. Adaptive locating algorithms of concentric circle center were created to accurately capture the circle center of original Placido-based image, expand the image into matrix centered around the circle center, and convert the matrix into the polar coordinate system with the circle center as pole. Adaptive image smoothing treatment was followed and the characteristics of useful circles were extracted via horizontal edge detection, based on useful circles presenting approximate horizontal lines while noise signals presenting vertical lines or different angles. Effective combination of different operators of morphology were designed to remedy data loss caused by noise disturbances, get complete image about circle edge detection to satisfy the requests of precise calculation on follow-up parameters. The experimental data show that the algorithms meet the requirements of practical detection with characteristics of less data loss, higher data accuracy and easier availability.

  14. Adjuvant corneal crosslinking to prevent hyperopic LASIK regression

    Directory of Open Access Journals (Sweden)

    Aslanides IM

    2013-03-01

    Full Text Available Ioannis M Aslanides, Achyut N MukherjeeEmmetropia Mediterranean Eye Clinic, Heraklion, Crete, GreecePurpose: To report the long term outcomes, safety, stability, and efficacy in a pilot series of simultaneous hyperopic laser assisted in situ keratomileusis (LASIK and corneal crosslinking (CXL.Method: A small cohort series of five eyes, with clinically suboptimal topography and/or thickness, underwent LASIK surgery with immediate riboflavin application under the flap, followed by UV light irradiation. Postoperative assessment was performed at 1, 3, 6, and 12 months, with late follow up at 4 years, and results were compared with a matched cohort that received LASIK only.Results: The average age of the LASIK-CXL group was 39 years (26–46, and the average spherical equivalent hyperopic refractive error was +3.45 diopters (standard deviation 0.76; range 2.5 to 4.5. All eyes maintained refractive stability over the 4 years. There were no complications related to CXL, and topographic and clinical outcomes were as expected for standard LASIK.Conclusion: This limited series suggests that simultaneous LASIK and CXL for hyperopia is safe. Outcomes of the small cohort suggest that this technique may be promising for ameliorating hyperopic regression, presumed to be biomechanical in origin, and may also address ectasia risk.Keyword: CXL

  15. Microfabricated instruments and methods to treat recurrent corneal erosion

    Energy Technology Data Exchange (ETDEWEB)

    Britton, Charles L; D& #x27; Urso, Brian R; Chaum, Edward; Simpson, John T; Baba, Justin S; Ericson, M. Nance; Warmack, Robert J

    2013-11-26

    In one embodiment, the present invention provides a device and method for treating recurrent corneal erosion. In one embodiment, the method includes the steps of contacting an epithelium layer of a cornea with an array of glass micro-rods including a plurality of sharp features having a length that penetrates a Bowman's layer of the eye, wherein the plurality of sharp features of the array of glass micro-rods produces a plurality of punctures in the Bowman's layer of the eye that are of micro-scale or less. In another embodiment, the present invention provides a method and device for drug delivery. In one embodiment, the device includes an array of glass micro-rods, wherein at least one glass micro-rod of the array of glass micro-rods includes a sharp feature opposite a base of the array of glass micro-rods, wherein the sharp feature includes a treated surface for delivering a chemical compound to the eye.

  16. Microfabricated instruments and methods to treat recurrent corneal erosions

    Energy Technology Data Exchange (ETDEWEB)

    Britton, Jr., Charles L.; D' urso, Brian R.; Chaum, Edward; Simpson, John T.; Baba, Justin S.; Ericson, M. Nance; Warmack, Robert J.

    2015-06-02

    In one embodiment, the present invention provides a device and method for treating recurrent corneal erosion. In one embodiment, the method includes the steps of contacting an epithelium layer of a cornea with an array of glass micro-rods including a plurality of sharp features having a length that penetrates a Bowman's layer of the eye, wherein the plurality of sharp features of the array of glass micro-rods produces a plurality of punctures in the Bowman's layer of the eye that are of micro-scale or less. In another embodiment, the present invention provides a method and device for drug delivery. In one embodiment, the device includes an array of glass micro-rods, wherein at least one glass micro-rod of the array of glass micro-rods includes a sharp feature opposite a base of the array of glass micro-rods, wherein the sharp feature includes a treated surface for delivering a chemical compound to the eye.

  17. Hypobaric Hypoxia: Effects on Intraocular Pressure and Corneal Thickness

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    Marcella Nebbioso

    2014-01-01

    Full Text Available Objective. The purpose of this study focused on understanding the mechanisms underlying ocular hydrodynamics and the changes which occur in the eyes of subjects exposed to hypobaric hypoxia (HH to permit the achievement of more detailed knowledge in glaucomatous disease. Methods. Twenty male subjects, aged 32±5 years, attending the Italian Air Force, were enrolled for this study. The research derived from hypobaric chamber, using helmet and mask supplied to jet pilotes connected to oxygen cylinder and equipped with a preset automatic mixer. Results. The baseline values of intraocular pressure (IOP, recorded at T1, showed a mean of 16±2.23 mmHg, while climbing up to 18,000 feet the mean value was 13.7±4.17 mmHg, recorded at T2. The last assessment was performed returning to sea level (T4 where the mean IOP value was 12.8±2.57 mmHg, with a significant change (P<0.05 compared to T1. Pachymetry values related to corneal thickness in conditions of hypobarism revealed a statistically significant increase (P<0.05. Conclusions. The data collected in this research seem to confirm the increasing outflow of aqueous humor (AH in the trabecular meshwork (TM under conditions of HH.

  18. Limbal and corneal calcification in patients with chronic renal failure.

    Science.gov (United States)

    Klaassen-Broekema, N; van Bijsterveld, O P

    1993-09-01

    In patients with chronic renal failure on regular dialysis treatment, limboconjunctival degenerations and calcifications are commonly observed. In this study three groups of patients were followed over a period of 6 years. The first group consisted of 47 patients with renal failure, the second group of 17 patients with renal failure and hyperparathyroidism not controlled by drugs, and the third group seven patients with primary hyperparathyroidism without renal failure. The aim of this study was to determine the progression of the limboconjunctival changes over time. The hypothesis that an increase in serum calcium and phosphorus concentrations, as a result of tertiary hyperparathyroidism, could possibly add a corneal component to the limbal calcification was also tested. All patients with renal failure (in as much as the degenerative limbal features were not obscured by deposits of lime salts), had a type II white limbus girdle of Vogt. This limbal degeneration was observed in only 45% of controls. In all 47 patients with renal failure conjunctival calcification was observed; 26 of them also had limbal calcification. After 6 years 41 patients had developed limbal calcification. This progression was statistically significant. In 15 out of 17 patients with tertiary hyperparathyroidism a band-shaped keratopathy developed in addition to the limboconjunctival calcification.

  19. Efficacy of cultivated corneal epithelial stem cells for ocular surface reconstruction

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    Prabhasawat P

    2012-09-01

    Full Text Available Pinnita Prabhasawat,1 Pattama Ekpo,2 Mongkol Uiprasertkul,3 Suksri Chotikavanich,1 Nattaporn Tesavibul11Department of Ophthalmology, 2Department of Immunology, 3Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, ThailandPurpose: To investigate the clinical outcomes of cultivated corneal limbal epithelial transplantation (CLET using human amniotic membrane for corneal limbal stem-cell deficiency.Methods: Prospective, noncomparative case series. Eighteen patients (19 eyes with severe ocular surface diseases were chosen to undergo CLET using human amniotic membrane. Twelve eyes received auto-CLET, and seven eyes received allo-CLET. Clinical outcomes of corneal surface epithelialization, conjunctivalization, inflammation, visual acuity, graft status, and complications were observed.Results: Corneal epithelium cultivated on amniotic membrane (two to four layers was positive for molecular markers p63, ABCG2, CK3, and CK12. The mean patient age was 44.7 ± 15.2 years. A successful clinical outcome, defined as corneal epithelialization without central conjunctivalization or severe inflammation, was obtained in 14 (73.7% of 19 eyes (mean follow-up 26.1 ± 13.5 months; range 6–47. A histopathologic success, defined as absence of goblet cells at the central cornea, was achieved in 12 (63.2% eyes. Clinical failures occurred in five (26.3% of 19 eyes, and histopathologic failures occurred in seven (36.8% of 19 eyes. Survival analysis at 1 year showed that the clinical success rate was 77.9% and the pathological success rate was 72.3%. Fourteen of 19 (73.7% eyes had visual acuity improvements after CLET. Six cases underwent penetrating keratoplasty; five of these grafts remained clear after 20.4 ± 6.9 months (range, 12–31 of follow-up. Complications included infectious keratitis (three cases and recurrent symblepharon (one case. All complicated cases had lid abnormalities. Factors affecting the final clinical

  20. Nerve growth factor modulate proliferation of cultured rabbit corneal endothelial cells and epithelial cells.

    Science.gov (United States)

    Li, Xinyu; Li, Zhongguo; Qiu, Liangxiu; Zhao, Changsong; Hu, Zhulin

    2005-01-01

    In order to investigate the effect of nerve growth factor (NGF) on the proliferation of rabbit corneal endothelial cells and epithelial cells, the in vitro cultured rabbit corneal endothelial cells and epithelial cells were treated with different concentrations of NGF. MTT assay was used to examine the clonal growth and proliferation of the cells by determining the absorbency values at 570 nm. The results showed that NGF with three concentrations ranging from 5 U/mL to 500 U/mL enhanced the proliferation of rabbit corneal endothelial cells in a concentration-dependent manner. 50 U/mL and 500 U/mL NGF got more increase of proliferation than that of 5 U/mL NGF did. Meanwhile, 50 U/mL and 500 U/mL NGF could promote the proliferation of the rabbit corneal epithelial cells significantly in a concentration-dependent manner. However, 5 U/mL NGF did not enhance the proliferation of epithelial cells. It was suggested that exogenous NGF can stimulate the proliferation of both rabbit corneal endothelial and epithelial cells, but the extent of modulation is different.