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Sample records for eye lens protein

  1. Inter-specific and intraspecific eye lens protein differences in some sciaenid fishes from Goa coast

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    Soluble eye lens nuclei proteins of sciaenid fishes were studied by cellogel electrophoresis. Four distinct patterns characterized by the number of bands, mobility and staining intensity were observed. Morphological studies of these fishes showed...

  2. Photodamaging mechanisms of the eye structure: the aggregates appearance at UV-illumination of lens proteins

    International Nuclear Information System (INIS)

    El'chaninov, V.V.; Fedorovich, I.B.

    1989-01-01

    UV-light injury of individual crystallines (water soluble proteins of the cattle eye crystalline lens) were studied by SDS PSSG technique. Photodamage resulted in olygomer formation. The appearance of high molecular aggregates with the molecular mass as large as 10 5 D were seen in all fractions of the crystalline

  3. Radiocarbon Dating of the Human Eye Lens Crystallines Reveal Proteins without Carbon Turnover throughout Life

    Science.gov (United States)

    Lynnerup, Niels; Kjeldsen, Henrik; Heegaard, Steffen; Jacobsen, Christina; Heinemeier, Jan

    2008-01-01

    Background Lens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule) completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its 14C content from the atmospheric carbon dioxide. The 14C content of the lens proteins thus reflects the atmospheric content of 14C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the 14C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric 14C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating. Methodology/Principal Findings Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The close relationship may be further expressed as a mathematical model, which takes into account the timing of the crystalline formation. Conclusions/Significance Such a life-long permanence of human tissue has hitherto only been described for dental enamel. In confront to dental enamel it must be held in mind that the eye lens is a soft structure, subjected to almost continuous deformation, due to lens accommodation, yet its most important constituent, the lens crystalline, is never subject to turnover or remodelling once formed. The determination of the 14C content of various tissues may be used to assess turnover rates and degree of substitution (for example for brain cell DNA). Potential targets may be nervous tissues in terms of senile or pre-senile degradation, as well as other highly

  4. Radiocarbon dating of the human eye lens crystallines reveal proteins without carbon turnover throughout life.

    Directory of Open Access Journals (Sweden)

    Niels Lynnerup

    Full Text Available BACKGROUND: Lens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its (14C content from the atmospheric carbon dioxide. The (14C content of the lens proteins thus reflects the atmospheric content of (14C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the (14C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric (14C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating. METHODOLOGY/PRINCIPAL FINDINGS: Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The close relationship may be further expressed as a mathematical model, which takes into account the timing of the crystalline formation. CONCLUSIONS/SIGNIFICANCE: Such a life-long permanence of human tissue has hitherto only been described for dental enamel. In confront to dental enamel it must be held in mind that the eye lens is a soft structure, subjected to almost continuous deformation, due to lens accommodation, yet its most important constituent, the lens crystalline, is never subject to turnover or remodelling once formed. The determination of the (14C content of various tissues may be used to assess turnover rates and degree of substitution (for example for brain cell DNA. Potential targets may be nervous tissues in terms of senile or pre

  5. Lipid-protein interactions in plasma membranes of fiber cells isolated from the human eye lens.

    Science.gov (United States)

    Raguz, Marija; Mainali, Laxman; O'Brien, William J; Subczynski, Witold K

    2014-03-01

    The protein content in human lens membranes is extremely high, increases with age, and is higher in the nucleus as compared with the cortex, which should strongly affect the organization and properties of the lipid bilayer portion of intact membranes. To assess these effects, the intact cortical and nuclear fiber cell plasma membranes isolated from human lenses from 41- to 60-year-old donors were studied using electron paramagnetic resonance spin-labeling methods. Results were compared with those obtained for lens lipid membranes prepared from total lipid extracts from human eyes of the same age group [Mainali, L., Raguz, M., O'Brien, W. J., and Subczynski, W. K. (2013) Biochim. Biophys. Acta]. Differences were considered to be mainly due to the effect of membrane proteins. The lipid-bilayer portions of intact membranes were significantly less fluid than lipid bilayers of lens lipid membranes, prepared without proteins. The intact membranes were found to contain three distinct lipid environments termed the bulk lipid domain, boundary lipid domain, and trapped lipid domain. However, the cholesterol bilayer domain, which was detected in cortical and nuclear lens lipid membranes, was not detected in intact membranes. The relative amounts of bulk and trapped lipids were evaluated. The amount of lipids in domains uniquely formed due to the presence of membrane proteins was greater in nuclear membranes than in cortical membranes. Thus, it is evident that the rigidity of nuclear membranes is greater than that of cortical membranes. Also the permeability coefficients for oxygen measured in domains of nuclear membranes were significantly lower than appropriate coefficients measured in cortical membranes. Relationships between the organization of lipids into lipid domains in fiber cells plasma membranes and the organization of membrane proteins are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Radiocarbon dating of the human eye lens crystallines reveal proteins without carbon turnover throughout life

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Kjeldsen, Henrik; Heegaard, Steffen

    2008-01-01

    , there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its (14)C content from the atmospheric carbon dioxide. The (14)C content of the lens proteins thus reflects the atmospheric content of (14)C when the lens crystallines were formed. Precise radiocarbon...

  7. Photodamaging mechanism of the eye structure: UV effect on soluble proteins of the lens

    International Nuclear Information System (INIS)

    Korkhmazyan, M.M.; Fedorovich, I.B.; Ostrovskij, M.A.

    1983-01-01

    Damaging effect of UV-radiation on soluble proteins of bull lens has been studied. Irradiation results in lens proteins growing yellow, new absorption bands with the maxima 245 and 305 nm appear. It is shown that during photodamage oxidation of SH-groups takes place and protein aggregates are formed

  8. Photoaggregation of crystallins (main proteins of eye lens) under the effect of XeCl laser radiation

    Science.gov (United States)

    Soustov, Lev V.; Chelnokov, Evgeny V.; Bityurin, Nikita M.; Kiselev, A. L.; Nemov, V. V.; Sergeev, Yu. V.; Ostrovsky, Michail A.

    2004-07-01

    UV light is one of primary factors associated with cataract formation in the eye lens. α-, β-, γ-Crystallins maintain lens transparency, and damage to these proteins plays a major role in cataract formation. The effect of XeCl laser radiation (308 nm) on βL-crystallin solution is studied. The strong dependence of protein aggregation kinetics on both laser fluence (w) and repetition rate (F) is investigated. The kinetics features are similar to those of carbonic anhydrase photoaggregation studied previously.

  9. Contact Lens-Related Eye Infections

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Contact Lens-Related Eye Infections Sections Contact Lens-Related Eye ... Six Steps to Avoid Contact Lens Infections Contact Lens-Related Eye Infections Leer en Español: Infecciones relacionadas ...

  10. Protection of the eye lens

    International Nuclear Information System (INIS)

    2015-01-01

    The limit of radiation exposure for eye lens is going to decrease dramatically from 150 to 20 mSv as a transposition into the French law of a CIPR (International Commission for Radiation Protection) directive. Sanitary studies have shown that radiologists are more likely by a factor of 3.8 to get eye lens opacities than the rest of the population. The wearing of protective glasses is recommended and in order to get a better monitoring of the radiation dose new dosimeters have been designed, they can be worn on the glass frame of directly stuck on the skin near the eyes. A study has shown that veterinary surgeons that are accustomed to stay near animals to keep them quiet during radiological exams are prone to receive high doses as well as physicians that use hypnosis to decrease the level of anxiety of their patients during radiological exams. Radiation exposure of radiologists can be mitigated through: the use of protective shields and equipment and the optimization of the dose delivered to the patient. (A.C.)

  11. EDEL: ENEA dosemeter for eye lens

    International Nuclear Information System (INIS)

    Ferrari, Paolo; Mariotti, Francesca; Campani, Lorenzo

    2016-01-01

    Since the publication of International Commission on Radiological Protection statement in 2011 on tissue reaction, eye lens radiation protection played an important role in exposed personnel dosimetry. For this reason, the Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) Individual Monitoring Service decided to study a prototype to fulfil specific requests (e.g. for survey in interventional department and intercomparisons). On the basis of such preliminary investigation, a new eye lens dosemeter was developed. The new dosemeter, named EDEL (ENEA Dosemeter for Eye Lens), was characterised in terms of H p (3), the operational quantity related to eye lens monitoring. The investigation was performed experimentally and optimised using the Monte Carlo MCNP6 code. The new prototype was thought to fulfil two main requests: the reliability of the dosimetric data and the portability of the dosemeter itself. The new dosemeter will soon be supplied to the collaborating hospitals for workplace test measurements. (authors)

  12. Immunochemical analyses of soluble lens proteins in some marine fishes

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    Soluble eye lens proteins of 10 fishes, belonging to the families Clupeidae, Hemirhamphidae, Lactaridae, Scombridae, Stromatidae, Psettodidae, Bothidae and Soleidae were studied by immunoelectrophoresis using the lens antiserum of Sardinella...

  13. Model for screened, charge-regulated electrostatics of an eye lens protein: Bovine gammaB-crystallin

    Science.gov (United States)

    Wahle, Christopher W.; Martini, K. Michael; Hollenbeck, Dawn M.; Langner, Andreas; Ross, David S.; Hamilton, John F.; Thurston, George M.

    2017-09-01

    We model screened, site-specific charge regulation of the eye lens protein bovine gammaB-crystallin (γ B ) and study the probability distributions of its proton occupancy patterns. Using a simplified dielectric model, we solve the linearized Poisson-Boltzmann equation to calculate a 54 ×54 work-of-charging matrix, each entry being the modeled voltage at a given titratable site, due to an elementary charge at another site. The matrix quantifies interactions within patches of sites, including γ B charge pairs. We model intrinsic p K values that would occur hypothetically in the absence of other charges, with use of experimental data on the dependence of p K values on aqueous solution conditions, the dielectric model, and literature values. We use Monte Carlo simulations to calculate a model grand-canonical partition function that incorporates both the work-of-charging and the intrinsic p K values for isolated γ B molecules and we calculate the probabilities of leading proton occupancy configurations, for 4 Debye screening lengths from 6 to 20 Å. We select the interior dielectric value to model γ B titration data. At p H 7.1 and Debye length 6.0 Å, on a given γ B molecule the predicted top occupancy pattern is present nearly 20% of the time, and 90% of the time one or another of the first 100 patterns will be present. Many of these occupancy patterns differ in net charge sign as well as in surface voltage profile. We illustrate how charge pattern probabilities deviate from the multinomial distribution that would result from use of effective p K values alone and estimate the extents to which γ B charge pattern distributions broaden at lower p H and narrow as ionic strength is lowered. These results suggest that for accurate modeling of orientation-dependent γ B -γ B interactions, consideration of numerous pairs of proton occupancy patterns will be needed.

  14. Evolution and the Calcite Eye Lens

    OpenAIRE

    Williams, Vernon L.

    2013-01-01

    Calcite is a uniaxial, birefringent crystal, which in its optically transparent form, has been used for animal eye lenses, the trilobite being one such animal. Because of the calcite birefringence there is a difficulty in using calcite as a lens. When the propagation direction of incoming light is not exactly on the c-axis, the mages blur. In this paper, calcite blurring is evaluated, and the non-blurring by a crystallin eye lens is compared to a calcite one.

  15. Dating the time of birth: A radiocarbon calibration curve for human eye-lens crystallines

    DEFF Research Database (Denmark)

    Kjeldsen, Henrik; Heinemeier, Jan; Heegaard, Steffen

    2010-01-01

    Radiocarbon bomb-pulse dating has been used to measure the formation age of human eye-lens crystallines. Lens crystallines are special proteins in the eye-lens that consist of virtually inert tissue. The experimental data show that the radiocarbon ages to a large extent reflect the time of birth...

  16. Scleral lens use in dry eye syndrome.

    Science.gov (United States)

    Bavinger, J Clay; DeLoss, Karen; Mian, Shahzad I

    2015-07-01

    Dry eye syndrome can be difficult to manage in severe or refractory cases. In patients in whom traditional treatments have limited efficacy, alternative treatments may be considered for dry eye syndrome, including scleral lenses. The present review summarizes the evidence regarding scleral lens use in dry eye syndrome. Scleral lenses have become a viable option for severe dry eye syndrome, and have been shown to be efficacious and well tolerated, with most reports citing improved visual acuity and relief of symptoms. Currently, there are 18 manufacturers of scleral lenses, although published reports on scleral lenses primarily focus on the BostonSight PROSE and the Jupiter Lens. Scleral lenses are efficacious and well tolerated for use in severe dry eye syndrome. Further research is needed to compare different sizes and types of lenses, and to standardize outcome measures.

  17. Gamma crystallins of the human eye lens.

    Science.gov (United States)

    Vendra, Venkata Pulla Rao; Khan, Ismail; Chandani, Sushil; Muniyandi, Anbukkarasi; Balasubramanian, Dorairajan

    2016-01-01

    Protein crystallins co me in three types (α, β and γ) and are found predominantly in the eye, and particularly in the lens, where they are packed into a compact, plastic, elastic, and transparent globule of proper refractive power range that aids in focusing incoming light on to the retina. Of these, the γ-crystallins are found largely in the nuclear region of the lens at very high concentrations (>400 mg/ml). The connection between their structure and inter-molecular interactions and lens transparency is an issue of particular interest. We review the origin and phylogeny of the gamma crystallins, their special structure involving the use of Greek key supersecondary structural motif, and how they aid in offering the appropriate refractive index gradient, intermolecular short range attractive interactions (aiding in packing them into a transparent ball), the role that several of the constituent amino acid residues play in this process, the thermodynamic and kinetic stability and how even single point mutations can upset this delicate balance and lead to intermolecular aggregation, forming light-scattering particles which compromise transparency. We cite several examples of this, and illustrate this by cloning, expressing, isolating and comparing the properties of the mutant protein S39C of human γS-crystallin (associated with congenital cataract-microcornea), with those of the wild type molecule. In addition, we note that human γ-crystallins are also present in other parts of the eye (e.g., retina), where their functions are yet to be understood. There are several 'crucial' residues in and around the Greek key motifs which are essential to maintain the compact architecture of the crystallin molecules. We find that a mutation that replaces even one of these residues can lead to reduction in solubility, formation of light-scattering particles and loss of transparency in the molecular assembly. Such a molecular understanding of the process helps us construct the

  18. Radiation dose to the eye lens

    DEFF Research Database (Denmark)

    Baun, Christina; Falch Braas, Kirsten; D. Nielsen, Kamilla

    2015-01-01

    Radiation Dose to the Eye Lens: Does Positioning Really Matter? C. Baun1, K. Falch1, K.D. Nielsen2, S. Shanmuganathan1, O. Gerke1, P.F. Høilund-Carlsen1 1Department of Nuclear Medicine, Odense University Hospital, Odense C, Denmark. 2University College Lillebaelt, Odense, Denmark. Aim: The scan...... field in oncology patients undergoing eyes-to-thighs PET/CT must always include the base of the scull according to department guidelines. The eye lens is sensitive to radiation exposure and if possible it should be avoided to scan the eye. If the patient’s head is kipped backwards during the scan one...... might avoid including the eye in the CT scan without losing sufficient visualization of the scull base. The aim of this study was to evaluate the possibility of decreasing the radiation dose to the eye lens, simply by changing the head position, when doing the PET/CT scan from the base of the scull...

  19. Dating the time of birth: A radiocarbon calibration curve for human eye-lens crystallines

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, Henrik, E-mail: kjeldsen@phys.au.d [AMS 14C Dating Centre, Department of Physics and Astronomy, University of Aarhus, Aarhus (Denmark); Heinemeier, Jan [AMS 14C Dating Centre, Department of Physics and Astronomy, University of Aarhus, Aarhus (Denmark); Heegaard, Steffen [Eye Pathology Section, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen (Denmark); Jacobsen, Christina; Lynnerup, Niels [Department of Forensic Medicine, University of Copenhagen, Copenhagen (Denmark)

    2010-04-15

    Radiocarbon bomb-pulse dating has been used to measure the formation age of human eye-lens crystallines. Lens crystallines are special proteins in the eye-lens that consist of virtually inert tissue. The experimental data show that the radiocarbon ages to a large extent reflect the time of birth, in accordance with expectations. Moreover, it has been possible to develop an age model for the formation of the eye-lens crystallines. From this model a radiocarbon calibration curve for lens crystallines has been calculated. As a consequence, the time of birth of humans can be determined with an accuracy of a few years by radiocarbon dating.

  20. Dating the time of birth: A radiocarbon calibration curve for human eye-lens crystallines

    International Nuclear Information System (INIS)

    Kjeldsen, Henrik; Heinemeier, Jan; Heegaard, Steffen; Jacobsen, Christina; Lynnerup, Niels

    2010-01-01

    Radiocarbon bomb-pulse dating has been used to measure the formation age of human eye-lens crystallines. Lens crystallines are special proteins in the eye-lens that consist of virtually inert tissue. The experimental data show that the radiocarbon ages to a large extent reflect the time of birth, in accordance with expectations. Moreover, it has been possible to develop an age model for the formation of the eye-lens crystallines. From this model a radiocarbon calibration curve for lens crystallines has been calculated. As a consequence, the time of birth of humans can be determined with an accuracy of a few years by radiocarbon dating.

  1. Notes on electropherograms of eye-lens, muscle proteins and zymograms of muscle esterases of fish collected during the first Brazilian expedition to the Antarctica

    Directory of Open Access Journals (Sweden)

    Van Ngan Phan

    1985-01-01

    Full Text Available A preliminary study was carried out on electropherograms of eye-lens, muscle proteins and zymograms of muscle esterases of ten Notothenia larseni, six Notothenia nudifrons and one lanternfish, Electrona antarctica. The fish were collected by the R/V "Prof. W. Besnard" of the Institute of Oceanography, University of São Paulo, during the First Brazilian Expedition to Antarctica. Eye-lens proteins were analysed on cellulose acetate membrane, muscle proteins and esterases on gel of polyaorylamide. Eye-lens proteins showed three types of electropherograms for N. larseni, and two types for N. nudifrons. One of the electropherograms of N. larseni can be readily distinguished from those of N. nudifrons. Electropherograms of muscle proteins of N. larseni and N. nudifrons are very similar and, consist of sixteen to seventeen fractions. Electropherograms of muscle proteins of N. larseni are severely affected by the conservation of the extracts overnight under -20ºC. All N. nudifrons were of the same zymograms of esterases while those of N. larseni varied. Electropherograms of eye-lens and muscle proteins as well as zymograms of esterases of the lanternfish are different from those of nototheniids.Foi realizado um estudo preliminar sobre eletroferogramas de proteínas de cristalino e de músculo esquelético, e zimogramas de esterases de músculo esquelético de dez Notothenia larseni, seis Notothenia nudifrons e de um peixe-lanterna, Electrona antarctica. Os peixes foram coletados pelo N/Oc. "Prof. W. Besnard" do Instituto Oceanográfico da Universidade de São Paulo durante a I Expedição Brasileira à Antártica. As proteinas do cristalino foram analisadas em membranas de acetato de celulose, enquanto que as proteínas e esterases do músculo esquelético, em gel de poliacrilamida. As proteínas do cristalino apresentam três tipos distintos de eletroferogramas para N. larseni, e dois para N. nudifrons. Um dos eletroferogramas de N. larseni, pode ser

  2. Intraocular lens calculations in atypical eyes

    Directory of Open Access Journals (Sweden)

    Aazim A Siddiqui

    2017-01-01

    Full Text Available Cataract surgery is the most performed surgical procedure in the field of ophthalmology. The process of intraocular lens (IOL calculations is a critical step to achieving successful outcomes. Many IOL formulae exist to guide surgeons through the difficult process of picking the most appropriate lens to achieve a certain target refraction. However, these formulae reach within 0.50 diopters of the target refraction only 75% of the time, leaving 25% of the eyes with a significant refractive surprise. A literature review was performed to investigate all the relevant published material on the history, progress, and recent advancements of IOL calculations. Based on this review, the appropriate history, evolution, progress, limitations, and recent advancements are analyzed and explained. Although the modern IOL formulae and biometric devices perform well for average eyes, they are suboptimal for eyes with atypical biometric parameters and also those that are postrefractive and keratoconic. There has not been a single, perfect formula that can resolve the complexities of this process. Various methods of formula optimization and newer generation of IOL formulae and devices may hold the key to improving outcomes in both typical and atypical eyes. These solutions minimize refractive error by introducing new input parameters and complex mathematical techniques to better estimate postoperative lens position.

  3. Dose limits to the eye lens

    International Nuclear Information System (INIS)

    Sion, N.

    2016-01-01

    Protecting the human body from the effects of ionizing radiation is essential to forestall stochastic effects and require placing limits on the effective dose. Dose limits on specific organs are also necessary to reduce the deterministic effects and tissue reactions. The standard for radiation protection was ISO 15382 (2002) which mainly dealt with beta radiation for nuclear power plant workers. Clearly an update is required to allow for new technology and the proliferative use of radiation in medical practices. There is a need for more explicit radiation monitoring to operators and staff. ICRP118 (International Commission on Radiological Protection), Ref. 1, evolved their recommendations to include eye lens doses as a follow on to their publication 103 and to focus on radiation exposures. It provides updated estimates of 'practical' threshold doses for tissue injury at the level of 1% incidence. This paper discusses the current status and the recommendation for a drastic reduction of the dose limit to the eye lens. (author)

  4. Dose limits to the eye lens

    Energy Technology Data Exchange (ETDEWEB)

    Sion, N.

    2016-09-15

    Protecting the human body from the effects of ionizing radiation is essential to forestall stochastic effects and require placing limits on the effective dose. Dose limits on specific organs are also necessary to reduce the deterministic effects and tissue reactions. The standard for radiation protection was ISO 15382 (2002) which mainly dealt with beta radiation for nuclear power plant workers. Clearly an update is required to allow for new technology and the proliferative use of radiation in medical practices. There is a need for more explicit radiation monitoring to operators and staff. ICRP118 (International Commission on Radiological Protection), Ref. 1, evolved their recommendations to include eye lens doses as a follow on to their publication 103 and to focus on radiation exposures. It provides updated estimates of 'practical' threshold doses for tissue injury at the level of 1% incidence. This paper discusses the current status and the recommendation for a drastic reduction of the dose limit to the eye lens. (author)

  5. Status of eye lens radiation dose monitoring in European hospitals

    International Nuclear Information System (INIS)

    Carinou, Eleftheria; Ginjaume, Merce; O’Connor, Una; Kopec, Renata; Sans Merce, Marta

    2014-01-01

    A questionnaire was developed by the members of WG12 of EURADOS in order to establish an overview of the current status of eye lens radiation dose monitoring in hospitals. The questionnaire was sent to medical physicists and radiation protection officers in hospitals across Europe. Specific topics were addressed in the questionnaire such as: knowledge of the proposed eye lens dose limit; monitoring and dosimetry issues; training and radiation protection measures. The results of the survey highlighted that the new eye lens dose limit can be exceeded in interventional radiology procedures and that eye lens protection is crucial. Personnel should be properly trained in how to use protective equipment in order to keep eye lens doses as low as reasonably achievable. Finally, the results also highlighted the need to improve the design of eye dosemeters in order to ensure satisfactory use by workers. (paper)

  6. Treatment of contact lens related dry eye with antibacterial honey.

    Science.gov (United States)

    Wong, Daniel; Albietz, Julie M; Tran, Huan; Du Toit, Cimonette; Li, Anita Hui; Yun, Tina; Han, Jee; Schmid, Katrina L

    2017-12-01

    Contact lens induced dry eye affects approximately 50% of contact lens wearers. The aim was to assess the effects of Manuka (Leptospermum sp.) honey eye drops (Optimel, Melcare, Australia) on dry eye in contact lens wearers. The safety of the honey eye drops in contact lens wear and contact lens wearers' compliance were also evaluated. Prospective, randomised, cross over study, examiner masked, pilot treatment trial. Twenty-four participants aged 20 to 55 years with contact lens related dry eye were recruited and randomised to two treatment groups; 20 completed the study. One group used Optimel eye drops twice a day for two weeks followed by conventional lubricant (Systane Ultra, Alcon) therapy for two weeks; the other group completed the treatments in the reverse order. Before and after each treatment dry eye symptomology, ocular surface inflammation, and tear quantity and quality were assessed. Participants completed a daily log detailing their usage of treatments and any issues. Dry eye symptoms improved significantly after Optimel treatment. Patients with more severe symptoms at baseline showed a greater improvement in symptoms. No significant differences were observed in the objective signs of dry eye; presumably because of the short treatment duration. Seventy-five% of contact lens wearers reported good adherence to Optimel treatment and 95% reported no issues using this product. Optimel Eye Drops reduce the symptoms of dry eye in contact lens wearers and are safe to use. A longer treatment period to assess the effect on clinical signs of dry eye is required. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  7. Gram negative bacteria and contact lens induced acute red eye

    Directory of Open Access Journals (Sweden)

    Sankaridurg Padmaja

    1996-01-01

    Full Text Available Two patients using hydrogel contact lenses on a daily wear schedule slept overnight with the lenses and woke up with a Contact Lens Induced Acute Red Eye (CLARE. The contact lenses recovered aseptically at the time of the event grew significant colonies of Pseudomonas aeruginosa and Aeromonas hydrophila in patient A and Pseudomonas aeruginosa and Serratia liquefaciens from patient B. Similar organisams from the contact lenses were recovered from the lens case and lens care solutions of patient B. In both the patients the condition resolved on discontinuation of lens wear. Patient compliance as a requirement for successful contact lens wear is highlighted with the illustration of these cases.

  8. Eye lens radiation exposure in Greek interventional cardiology personnel

    International Nuclear Information System (INIS)

    Thrapsanioti, Zoi; Askounis, Panagiotis; Carinou, Eleftheria; Datseris, Ioannis; Diamanti, Ramza Anastasia; Papathanasiou, Miltiadis

    2017-01-01

    The lens of the eye is one of the radiosensitive tissues of the human body; if exposed to ionizing radiation can develop radiation-induced cataract at early ages. This study was held in Greece and included 44 Interventional Cardiologists (ICs) and an unexposed to radiation control group of 22 persons. Of the note, 26 ICs and the unexposed individuals underwent special eye examinations. The detected lens opacities were classified according to LOCS III protocol. Additionally, the lens doses of the ICs were measured using eye lens dosemeters. The mean dose to the lenses of the ICs per month was 0.83 ± 0.59 mSv for the left and 0.35 ± 0.38 mSv for the right eye, while the annual doses ranged between 0.7 and 11 mSv. Regarding the lens opacities, the two groups did not differ significantly in the prevalence of either nuclear or cortical lens opacities, whereas four ICs were detected with early stage subcapsular sclerosis. Though no statistically difference was observed in the cohort, the measured doses indicate that the eye doses received from the ICs can be significant. To minimize the radiation-induced risk at the eye lenses, the use of protective equipment and appropriate training on this issue is highly recommended. (authors)

  9. Transglutaminase involvement in UV-A damage to the eye lens

    International Nuclear Information System (INIS)

    Weinreb, Orly; Dovrat, A.

    1996-01-01

    Solar radiation is believed to be one of the major environmental factors involved in lens cataractogenesis. The purpose of the study was to investigate the mechanisms by which UV-A at 365 nm causes damage to the eye lens. Bovine lenses were placed in special culture cells for pre-incubation of 24 hr. The lenses were positioned so that the anterior surface faced the incident UV-A radiation source and were maintained in the cells during irradiation. After irradiation, lens optical quality was monitored throughout the culture period and lens epithelium, cortex and nuclear samples were taken for biochemical analysis. Transglutaminase activity in the lens was affected by the radiation. The activity of transglutaminase in lens epithelium cortex and nucleus increased as a result of the irradiation and then declined towards control levels during the culture period, as the lens recovered from the UV-A damage. Specific lens proteins αB and βB1 crystallins (the enzyme substrates) were analyzed by SDS polyacrylamid gel electrophoreses and immunoblotting with specific antibodies. Seventy-two hours after irradiation of 44.8 J cm -2 UV-A, αB crystallins were affected as was shown by the appearance of aggregation and degradation products. Some protein changes seem to be reversible. It appears that transglutaminase may be involved in the mechanism by which UV-A causes damage to the eye lens. (Author)

  10. On the operational quantity Hp(3) for eye lens dosimetry

    International Nuclear Information System (INIS)

    Behrens, R

    2012-01-01

    In the past the operational quantity H p (3) has been defined for calibration purposes in a slab phantom. Recently, an additional phantom in the form of a cylinder was suggested for eye lens dosimetry as a cylinder much better approximates the shape of a head than a slab. Therefore, this work investigates whether the quantity H p (3), when defined in the respective calibration phantom, adequately estimates the eye lens dose (or is at least conservative) depending on the phantom: it turns out that in most cases both calibration phantoms are similarly well suited. Finally, the definition of the eye lens dose is discussed together with possible consequences on the definition of H p (3): the consideration of only the radiation sensitive volume of the lens causes H p (3) not to be conservative in beta radiation fields. (paper)

  11. Electrophoretic study on intraspecific variations and interspecific relationships of marine catfishes (Siluriformes, Ariidae of Cananéia (São Paulo, Brazil: 1. General proteins of eye-lens and skeletic muscle

    Directory of Open Access Journals (Sweden)

    Hana Suzuki

    1990-06-01

    Full Text Available Cellulose acetate electrophoresis of eye-lens proteins and Polyacrylamide flat gel electrophoresis of skeletic muscle proteins of six species of marine catfishes were carried out. Genetic polymorphism only occured at one locus of the electropherograms of eye-lens of Cathorops spixii. Ontogenetic variations in the relative concentration of bands were found in the electropherograms of eye-lens and skeletic muscle proteins. The six species of catfishes can be identified by means of quantitative and qualitative differences in the electropherograms. Coefficients of similarity were determined by the band-counting method and UPGMA dendrograms were constructed to illustrate the interspecific relationships among the species.Eletroforeses de proteínas gerais de cristalinos e de músculo esquelético de seis espécies de bagres marinhos foram realizadas, respectivamente, em membranas de acetato de celulose e em géis de poliacrilamida. Polimorfismo genético ocorreu apenas em um locus de eletroferogramas do cristalino de Cathorops spixii. Variações ontogenéticas nas concentrações relativas das bandas foram observadas nos eletroferogramas do cristalino e do músculo esquelético. As seis espécies de bagres marinhos podem ser identificadas através das diferenças quantitativas e qualitativas nos eletroferogramas. Coeficientes de similaridade foram determinadas pelo método de contagem de bandas e dendrogramas UPGMA foram construídos para ilustrar as relações interespecíficas entre as espécies.

  12. Monitoring the eye lens: which dose quantity is adequate?

    International Nuclear Information System (INIS)

    Behrens, R; Dietze, G

    2010-01-01

    Recent epidemiological studies suggest a rather low dose threshold (below 0.5 Gy) for the induction of a cataract of the eye lens. Some other studies even assume that there is no threshold at all. Therefore, protection measures have to be optimized and current dose limits for the eye lens may be reduced in the future. The question of which personal dose equivalent quantity is appropriate for monitoring the dose to the eye lens arises from this situation. While in many countries dosemeters calibrated in terms of the dose equivalent quantity H p (0.07) have been seen as being adequate for monitoring the dose to the eye lens, this might be questionable in the case of reduced dose limits and, thus, it may become necessary to use the dose equivalent quantity H p (3) for this purpose. To discuss this question, the dose conversion coefficients for the equivalent dose of the eye lens (in the following eye lens dose) were determined for realistic photon and beta radiation fields and compared with the values of the corresponding conversion coefficients for the different operational quantities. The values obtained lead to the following conclusions: in radiation fields where most of the dose comes from photons, especially x-rays, it is appropriate to use dosemeters calibrated in terms of H p (0.07) on a slab phantom, while in other radiation fields (dominated by beta radiation or unknown contributions of photon and beta radiation) dosemeters calibrated in terms of H p (3) on a slab phantom should be used. As an alternative, dosemeters calibrated in terms of H p (0.07) on a slab phantom could also be used; however, in radiation fields containing beta radiation with the end point energy near 1 MeV, an overestimation of the eye lens dose by up to a factor of 550 is possible.

  13. Monitoring of eye lens doses in radiation protection

    International Nuclear Information System (INIS)

    Bordy, J.M.

    2015-01-01

    Mainly due to the ICRP recommendation to decrease the exposure limit for eye lenses, the eye lens dosimetry has to be reconsidered. This paper gives an overview of the issues raised after this recommendation; that is to say, the choice and definition of the operational quantity to be monitored, the type testing and calibration of dosimeters aimed at measuring eyes lens 'doses', the design of existing eye lens dosimeters and their wearing conditions. Finally, a criterion to choose between a direct measurement of the personal dose equivalent at three millimeters depth, H p (3), with a dedicated dosimeter, and an indirect evaluation of H p (3) through whole-body monitoring is presented. (authors)

  14. Radiation dose to physicians’ eye lens during interventional radiology

    International Nuclear Information System (INIS)

    Bahruddin, N A; Hashim, S; Karim, M K A; Ang, W C; Salehhon, N; Sabarudin, A; Bakar, K A

    2016-01-01

    The demand of interventional radiology has increased, leading to significant risk of radiation where eye lens dose assessment becomes a major concern. In this study, we investigate physicians' eye lens doses during interventional procedures. Measurement were made using TLD-100 (LiF: Mg, Ti) dosimeters and was recorded in equivalent dose at a depth of 0.07 mm, Hp(0.07). Annual Hp(0.07) and annual effective dose were estimated using workload estimation for a year and Von Boetticher algorithm. Our results showed the mean Hp(0.07) dose of 0.33 mSv and 0.20 mSv for left and right eye lens respectively. The highest estimated annual eye lens dose was 29.33 mSv per year, recorded on left eye lens during fistulogram procedure. Five physicians had exceeded 20 mSv dose limit as recommended by international commission of radiological protection (ICRP). It is suggested that frequent training and education on occupational radiation exposure are necessary to increase knowledge and awareness of the physicians’ thus reducing dose during the interventional procedure. (paper)

  15. Contact lens wear and dry eyes: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Markoulli M

    2017-02-01

    Full Text Available Maria Markoulli, Sailesh Kolanu School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia Abstract: The number of contact lens wearers worldwide has remained relatively stable over the past decade, despite the investment that has gone into contact lens technology. This is largely because 10%–50% of wearers dropout of contact lens wear within 3 years of commencement; the most common reason cited being contact lens discomfort (CLD. Of the symptoms reported, sensation of dry eye is the most common. Given the outcome of reduced wearing time, increased chair time, and ultimate contact lens discontinuation, the challenge is to identify the warning signs of CLD early on. Clinically detectable changes such as conjunctival staining, conjunctival indentation, conjunctival epithelial flap formation, lid wiper epitheliopathy, Demodex blepharitis, and meibomian gland dysfunction have been linked to CLD, highlighting the need to perform regular aftercare visits to identify these changes. At a cellular level, conjunctival metaplasia and reduced goblet cell density have been linked to CLD, leading to a downstream effect on the tear film breakup time of contact lens wearers. These factors suggest a strong link between CLD and friction, raising the need to target this as a means of minimizing CLD. The purpose of this review is to identify the clinical signs that relate to CLD as a means of earlier detection and management in order to combat contact lens dropout. Keywords: contact lens discomfort, dry eye disease, lid wiper epitheliopathy, tear film biomarkers, meibomian gland dysfunction

  16. Composite modified Luneburg model of human eye lens.

    Science.gov (United States)

    Gómez-Correa, J E; Balderas-Mata, S E; Pierscionek, B K; Chávez-Cerda, S

    2015-09-01

    A new lens model based on the gradient-index Luneburg lens and composed of two oblate half spheroids of different curvatures is presented. The spherically symmetric Luneburg lens is modified to create continuous isoindicial contours and to incorporate curvatures that are similar to those found in a human lens. The imaging capabilities of the model and the changes in the gradient index profile are tested for five object distances, for a fixed geometry and for a fixed image distance. The central refractive index decreases with decreasing object distance. This indicates that in order to focus at the same image distance as is required in the eye, a decrease in refractive power is needed for rays from closer objects that meet the lens surface at steeper angles compared to rays from more distant objects. This ensures a highly focused image with no spherical aberration.

  17. Retinal images in the human eye with implanted intraocular lens

    Science.gov (United States)

    Zając, Marek; Siedlecki, Damian; Nowak, Jerzy

    2007-04-01

    A typical proceeding in cataract is based on the removal of opaque crystalline lens and inserting in its place the artificial intraocular lens (IOL). The quality of retinal image after such procedure depends, among others, on the parameters of the IOL, so the design of the implanted lens is of great importance. An appropriate choice of the IOL material, especially in relation to its biocompatibility, is often considered. However the parameter, which is often omitted during the IOL design is its chromatic aberration. In particular lack of its adequacy to the chromatic aberration of a crystalline lens may cause problems. In order to fit better chromatic aberration of the eye with implanted IOL to that of the healthy eye we propose a hybrid - refractive-diffractive IOL. It can be designed in such way that the total longitudinal chromatic aberration of an eye with implanted IOL equals the total longitudinal chromatic aberration of a healthy eye. In this study we compare the retinal image quality calculated numerically on the basis of the well known Liou-Brennan eye model with typical IOL implanted with that obtained if the IOL is done as hybrid (refractive-diffractive) design.

  18. New device for the radiation protection of the eye lens

    International Nuclear Information System (INIS)

    Csobaly, S.; Zarand, P.

    1980-01-01

    Lenses of 50 mm diameter and 2 mm width were ground from lead glass, equivalent to 2 mm of lead. In the case of X-radiations of different intensity and different filtering the finished glasses are equivalent to 0.73-0.78 mm of lead and they decrease the radiation exposition of the eye lens 15-fold. (L.E.)

  19. An electrophoretic study of the soluble lens proteins from the Indian mackerel, Rastrelliger kanagurta (Cuv)

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    Soluble eye lens nuclei proteins of the Indian mackerel Rastrelliger kanagurta were studied by cellogel electrophoresis, to see whether there are any intra species variations. A distinct pattern characterised by the number of bands, mobility...

  20. Soluble lens protein polymorphism in flying fishes from the central Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.

    Soluble eye lens nuclei proteins of flying-fishes were studied by cellogel electrophoresis. Three distinct patterns characterized by the number of bands, mobility and staining intensity were observed. Morphological studies of these fishes showed...

  1. Eye lens membrane junctional microdomains: a comparison between healthy and pathological cases

    Energy Technology Data Exchange (ETDEWEB)

    Buzhynskyy, Nikolay; Scheuring, Simon [Institut Curie, Equipe Inserm Avenir, UMR168-CNRS, 26 Rue d' Ulm, 75248 Paris Cedex 05 (France); Sens, Pierre [ESPCI, CNRS-UMR 7083, 75231 Paris (France); Behar-Cohen, Francine, E-mail: simon.scheuring@curie.fr [UMRS Inserm 872, Universite Paris Descartes, Centre de Recherches des Cordeliers, 15 rue de l' Ecole de Medecine, 75270 Paris Cedex 06 (France)

    2011-08-15

    The eye lens is a transparent tissue constituted of tightly packed fiber cells. To maintain homeostasis and transparency of the lens, the circulation of water, ions and metabolites is required. Junctional microdomains connect the lens cells and ensure both tight cell-to-cell adhesion and intercellular flow of fluids through a microcirculation system. Here, we overview membrane morphology and tissue functional requirements of the mammalian lens. Atomic force microscopy (AFM) has opened up the possibility of visualizing the junctional microdomains at unprecedented submolecular resolution, revealing the supramolecular assembly of lens-specific aquaporin-0 (AQP0) and connexins (Cx). We compare the membrane protein assembly in healthy lenses with senile and diabetes-II cataract cases and novel data of the lens membranes from a congenital cataract. In the healthy case, AQP0s form characteristic square arrays confined by connexons. In the cases of senile and diabetes-II cataract patients, connexons were degraded, leading to malformation of AQP0 arrays and breakdown of the microcirculation system. In the congenital cataract, connexons are present, indicating probable non-membranous grounds for lens opacification. Further, we discuss the energetic aspects of the membrane organization in junctional microdomains. The AFM hence becomes a biomedical nano-imaging tool for the analysis of single-membrane protein supramolecular association in healthy and pathological membranes.

  2. Eye lens membrane junctional microdomains: a comparison between healthy and pathological cases

    Science.gov (United States)

    Buzhynskyy, Nikolay; Sens, Pierre; Behar-Cohen, Francine; Scheuring, Simon

    2011-08-01

    The eye lens is a transparent tissue constituted of tightly packed fiber cells. To maintain homeostasis and transparency of the lens, the circulation of water, ions and metabolites is required. Junctional microdomains connect the lens cells and ensure both tight cell-to-cell adhesion and intercellular flow of fluids through a microcirculation system. Here, we overview membrane morphology and tissue functional requirements of the mammalian lens. Atomic force microscopy (AFM) has opened up the possibility of visualizing the junctional microdomains at unprecedented submolecular resolution, revealing the supramolecular assembly of lens-specific aquaporin-0 (AQP0) and connexins (Cx). We compare the membrane protein assembly in healthy lenses with senile and diabetes-II cataract cases and novel data of the lens membranes from a congenital cataract. In the healthy case, AQP0s form characteristic square arrays confined by connexons. In the cases of senile and diabetes-II cataract patients, connexons were degraded, leading to malformation of AQP0 arrays and breakdown of the microcirculation system. In the congenital cataract, connexons are present, indicating probable non-membranous grounds for lens opacification. Further, we discuss the energetic aspects of the membrane organization in junctional microdomains. The AFM hence becomes a biomedical nano-imaging tool for the analysis of single-membrane protein supramolecular association in healthy and pathological membranes.

  3. Verification of eye lens dose in IMRT by MOSFET measurement.

    Science.gov (United States)

    Wang, Xuetao; Li, Guangjun; Zhao, Jianling; Song, Ying; Xiao, Jianghong; Bai, Sen

    2018-04-17

    The eye lens is recognized as one of the most radiosensitive structures in the human body. The widespread use of intensity-modulated radiotherapy (IMRT) complicates dose verification and necessitates high standards of dose computation. The purpose of this work was to assess the computed dose accuracy of eye lens through measurements using a metal-oxide-semiconductor field-effect transistor (MOSFET) dosimetry system. Sixteen clinical IMRT plans of head and neck patients were copied to an anthropomorphic head phantom. Measurements were performed using the MOSFET dosimetry system based on the head phantom. Two MOSFET detectors were imbedded in the eyes of the head phantom as the left and the right lens, covered by approximately 5-mm-thick paraffin wax. The measurement results were compared with the calculated values with a dose grid size of 1 mm. Sixteen IMRT plans were delivered, and 32 measured lens doses were obtained for analysis. The MOSFET dosimetry system can be used to verify the lens dose, and our measurements showed that the treatment planning system used in our clinic can provide adequate dose assessment in eye lenses. The average discrepancy between measurement and calculation was 6.7 ± 3.4%, and the largest discrepancy was 14.3%, which met the acceptability criterion set by the American Association of Physicists in Medicine Task Group 53 for external beam calculation for multileaf collimator-shaped fields in buildup regions. Copyright © 2018 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  4. Dose estimation for the eye lens dealing with radioactive wastes

    International Nuclear Information System (INIS)

    Krause, A.; Lorenz, B.; Wuertemberger, M.

    2013-01-01

    A significant reduction of the dose limit for the lens of the eye is currently discussed in international committees. The ICRP had recommended a reduction from 150 mSv to 20 mSv, the IAEA-BSS have already adopted this value and the Euratom-BSS propose this too. In the practice of radiation protection the compliance with the limit for the lens of the eye has played a minor role so far. This was in practice assured by the compliance with the limit for the effective dose. With a possible stipulation of a much lower value in the Radiation Protection Ordinance (StrlSchV), the question of compliance arises again. When handling radioactive waste where often gamma radiation is dominant it may happen that the (unshielded) eye region is much more exposed as the location of the (shielded) personal dosimeter. A theoretical study of typical GNS-workplaces in radioactive waste management has shown that up to a factor of 4 higher exposures may occur. A generic assessment under very conservative assumptions that was done first did not allow for the conclusion that the compliance of the new dose limit for the lens of the eye is given by complying with the limit for the effective dose. To get a more reliable basis the exposure situation will now be investigated by measurements that are carried out with specific TLDs provided by the MPA Dortmund. (orig.)

  5. Estimation of eye lens doses received by pediatric interventional cardiologists.

    Science.gov (United States)

    Alejo, L; Koren, C; Ferrer, C; Corredoira, E; Serrada, A

    2015-09-01

    Maximum Hp(0.07) dose to the eye lens received in a year by the pediatric interventional cardiologists has been estimated. Optically stimulated luminescence dosimeters were placed on the eyes of an anthropomorphic phantom, whose position in the room simulates the most common irradiation conditions. Maximum workload was considered with data collected from procedures performed in the Hospital. None of the maximum values obtained exceed the dose limit of 20 mSv recommended by ICRP. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. The Correlation between Daily Lens Wear Duration and Dry Eye Syndrome.

    Science.gov (United States)

    Lubis, Rodiah Rahmawaty; Gultom, Monica Tumiar Hanna

    2018-05-20

    To analyze the correlation between the daily lens wear duration and dry eye syndrome. This study was an analytic cross sectional study using consecutive sampling conducted among the students in Economy and Bussiness Faculty and Faculty of Humanities in University of Sumatera Utara aged between 17 to 23 that wore contact lens continously for at least a year and 5 days a week. The symptoms were assessed using Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) and interview about their contact lens comfort; eye drops usage, contact lens washing habit, daily circumstances, places to buy contact lens and personal experince in wearing contact lens. The questionnaire was completed by 53 students. All of them were female and wore softlens wearers. The mean duration of daily wear was 8.19 ± 2.20 hours. The most common symptom experienced was dry eye and the least symptom experienced was removing lens. The most frequent symptom experienced was closing eyes and the least frequent symptom experienced was removing lenses. This study used Exact Test as analysis statistic method. The result was p > 0.05 which means there is no correlation between daily lens wear duration and dry eye syndrome. This study showed that dry eye syndrome was not correlated with daily lens wear duration, but affected by many factors such as contact lens, lens care solution, eye drops usage and environment.

  7. Assessment of eye lens doses for workers during interventional radiology procedures

    International Nuclear Information System (INIS)

    Urboniene, A.; Sadzeviciene, E.; Ziliukas, J.

    2015-01-01

    The assessment of eye lens doses for workers during interventional radiology (IR) procedures was performed using a new eye lens dosemeter. In parallel, the results of routine individual monitoring were analysed and compared with the results obtained from measurements with a new eye lens dosemeter. The eye lens doses were assessed using H p (3) measured at the level of the eyes and were compared with H p (10) measured with the whole-body dosemeter above the lead collar. The information about use of protective measures, the number of performed interventional procedures per month and their fluoroscopy time was also collected. The assessment of doses to the lens of the eye was done for 50 IR workers at 9 Lithuanian hospitals for the period of 2012-2013. If the use of lead glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv. (authors)

  8. TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

    Energy Technology Data Exchange (ETDEWEB)

    Rehani, M. [Massachusetts General Hospital (United States)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  9. TU-E-201-03: Eye Lens Dosimetry in Radiotherapy Using Contact Lens-Shaped Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. [Seoul National University Hospital (Korea, Republic of)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  10. TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

    International Nuclear Information System (INIS)

    Rehani, M.

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  11. TU-E-201-03: Eye Lens Dosimetry in Radiotherapy Using Contact Lens-Shaped Applicator

    International Nuclear Information System (INIS)

    Park, J.

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  12. Design of a new two element OSLD Badge for eye lens monitoring

    International Nuclear Information System (INIS)

    Kulkarni, M.S.; Munish Kumar; Ratna, P.; Babu, D.A.R.; Muthe, K.P.; Biju, K.; Sunil, C.; Sharma, D.N.

    2014-01-01

    Normally the dose to the vicinity of the eye is received by the occupational radiation workers who handle radioisotopes or doctors who perform interventional radiographic procedures. The Eye dosimeters provide an estimate of the radiation dose to the lens of the eye. In the recent ICRP-2011 recommendations, the equivalent dose limit for the lens of the eye has been reduced from 150 mSv in a year to 20 mSv in a year for all the occupational workers. To ensure that the dose limit for the eye lens does not exceed the prescribed dose limits, various eye lens dosimeters have been designed and are being used internationally. All these eye dosimeters consist of one natural LiF based thermoluminescence dosimeter (TLD) element sealed in a plastic holder. The design of the eye dosimeter and place of wear (near the eye) plays an important role in correct estimation of the dose to the lens of the eye. It is generally seen that the eye dosimeter when worn with the head strap on the forehead near the eye, the dose the element receives can be easily correlated to the eye dose. This paper presents the design of a new Eye lens dosimeter based on optically stimulated luminescence (OSL) detectors for its possible use by the occupational workers covering the medical, industrial and nuclear facilities for assessing the Hp(3)

  13. Temporal properties of the lens eyes of the box jellyfish Tripedalia cystophora

    DEFF Research Database (Denmark)

    O'Connor, Megan; Nilsson, Dan-E; Garm, Anders Lydik

    2010-01-01

    Box jellyWsh (Cubomedusae) are visually orientating animals which posses a total of 24 eyes of 4 morphological types; 2 pigment cup eyes (pit eye and slit eye) and 2 lens eyes [upper lens-eye (ule) and lower lens-eye (lle)]. In this study, we use electroretinograms (ERGs) to explore temporal...... properties of the two lens eyes. We Wnd that the ERG of both lens eyes are complex and using sinusoidal Xicker stimuli we Wnd that both lens eyes have slow temporal resolution. The average Xicker fusion frequency (FFF) was found to be approximately 10 Hz for the ule and 8 Hz for the lle. Di......Verences in the FFF and response patterns between the two lens eyes suggest that the ule and lle Wlter information diVerently in the temporal domain and thus are tuned to perform diVerent visual tasks. The data collected in this study support the idea that the visual system of box jellyWsh is a collection of special...

  14. Control development of radiation protection and safety on personnel eye lens of interventional radiology

    International Nuclear Information System (INIS)

    Titik Kartika; Ishak

    2013-01-01

    The review on radiation protection and safety to the lens of personnel especially in interventional radiology activities has been carried out. The use of radiation in interventional radiology installations provide significant exposure to the lens of the eye, especially personnel. The results of the latest various surveys and researches on the effects of low dose radiation to the eye lens indicates that the eye lens dose threshold is less than the preconceived values. Based on these facts, recently, ICRP and IAEA provides recommendations regarding the reduction of the value of the eye lens dose limit for personnel. BAPETEN have adopted the value of the eye lens dose limit in the development of new regulations on radiation protection and safety. However, the application of this provision has various challenges that BAPETEN provide 3 (three) years transitional period. These challenges include the problem of monitoring the eye lens dose, the eye lens protective equipment which is not adequate, the lack of understanding of personnel related to the risk of low radiation to the eye lens, as well as the proper procedures to mitigate those risks. BAPETEN as a regulatory agency is expected to provide solutions to the problems faced by the stake holders. Therefore, to answer the challenge, it is necessary to develop better monitoring of radiation protection and safety. (author)

  15. Cholesterol Bilayer Domains in the Eye Lens Health: A Review.

    Science.gov (United States)

    Widomska, Justyna; Subczynski, Witold K; Mainali, Laxman; Raguz, Marija

    2017-12-01

    The most unique biochemical characteristic of the eye lens fiber cell plasma membrane is its extremely high cholesterol content, the need for which is still unclear. It is evident, however, that the disturbance of Chol homeostasis may result in damages associated with cataracts. Electron paramagnetic resonance methods allow discrimination of two types of lipid domains in model membranes overloaded with Chol, namely, phospholipid-cholesterol domains and pure Chol bilayer domains. These domains are also detected in human lens lipid membranes prepared from the total lipids extracted from lens cortices and nuclei of donors from different age groups. Independent of the age-related changes in phospholipid composition, the physical properties of phospholipid-Chol domains remain the same for all age groups and are practically identical for cortical and nuclear membranes. The presence of Chol bilayer domains in these membranes provides a buffering capacity for cholesterol concentration in the surrounding phospholipid-Chol domains, keeping it at a constant saturating level and thus keeping the physical properties of the membrane consistent with and independent of changes in phospholipid composition. It seems that the presence of Chol bilayer domains plays an integral role in the regulation of cholesterol-dependent processes in fiber cell plasm membranes and in the maintenance of fiber cell membrane homeostasis.

  16. Occupational eye lens doses in interventional cardiology. A multicentric study

    International Nuclear Information System (INIS)

    Sánchez, R M; Vano, E; Fernández, J M; Pifarré, X; Ordiales, J M; Rovira, J J; Carrera, F; Goicolea, J; Fernández-Ortiz, A

    2016-01-01

    New European regulation regarding radiological protection of workers and more specifically the new occupational dose limit for the eye lens recently reduced to 20 mSv yr −1 may affect interventional cardiologists. This paper presents a set of measurements of occupational doses performed in five interventional cardiology centres and then compared with the new dose limit. The measurement of occupational doses was performed over the apron at chest level using electronic dosemeters recording H p (10). In one of the centres, scatter dose at goggles was also measured with optically stimulated luminescence dosemeters calibrated in terms of H p (0.07). An average H p (10) over the apron of 46 μSv/procedure was measured for cardiologists. Lower doses were noted in other professionals like second cardiologists, nurses or anaesthetists. Procedures for valvular and other structural heart diseases involved the highest occupational doses, averaging over 100 μSv/procedure. Important differences in occupational doses among centres may be indicative of different radiation protection habits. The new occupational dose limit for the eye lens is likely to be exceeded by those among the interventionalists who do not use protection tools (ceiling suspended screen and/or goggles) even with standard workloads. (paper)

  17. An acoustic Maxwell’s fish-eye lens based on gradient-index metamaterials

    International Nuclear Information System (INIS)

    Yuan Bao-guo; Tian Ye; Cheng Ying; Liu Xiao-jun

    2016-01-01

    We have proposed a two-dimensional acoustic Maxwell’s fish-eye lens by using the gradient-index metamaterials with space-coiling units. By adjusting the structural parameters of the units, the refractive index can be gradually varied, which is key role to design the acoustic fish-eye lens. As predicted by ray trajectories on a virtual sphere, the proposed lens has the capability to focus the acoustic wave irradiated from a point source at the surface of the lens on the diametrically opposite side of the lens. The broadband and low loss performance is further demonstrated for the lens. The proposed acoustic fish-eye lens is expected to have the potential applications in directional acoustic coupler or coherent ultrasonic imaging. (paper)

  18. Monitoring the eye lens: how do the international organisations react?

    International Nuclear Information System (INIS)

    Behrens, R.

    2015-01-01

    The International Commission on Radiological Protection (ICRP) has recommended to lower the limit of the dose to the eye lens for occupationally exposed persons to a mean value of 20 mSv y -1 (averaged over 5 y, with a maximum of 50 mSv y -1 ); already in the autumn of 2011, both the European Commission and the International Atomic Energy Agency (IAEA) took over this reduction in their respective draft basic safety standards. Even prior to this (and since then, increasingly so), several international activities were started (among other things, the following ones): (1) the ICRP adopted a stylised model of the eye to calculate dose conversion coefficients for its report ICRP 116; (2) the European Commission has funded the ORAMED project dealing with radiation protection in medicine; (3) in its standard IEC 62387 on passive dosimetry systems, the International Electrotechnical Commission (IEC) has laid down requirements for Hp(3) eye dosemeters; (4) the International Organization for Standardization (ISO) and the IAEA provide a range of practical advice in the standard ISO 15382 (still a draft) and in a technical document IAEA TecDoc on both radiation protection and on dosimetry; (5) for most cases, the International Commission on Radiation Units and Measurements (ICRU) recommends both phantoms (the slab and the cylinder). In short: most national procedures can orientate themselves on international ones; some questions, however, remain open. (authors)

  19. The current status of eye lens dose measurement in interventional cardiology personnel in Thailand.

    Science.gov (United States)

    Krisanachinda, Anchali; Srimahachota, Suphot; Matsubara, Kosuke

    2017-06-01

    Workers involved in interventional cardiology procedures receive high eye lens doses if radiation protection tools are not properly utilized. Currently, there is no suitable method for routine measurement of eye dose. In Thailand, the eye lens equivalent doses in terms of Hp(3) of the interventional cardiologists, nurses, and radiographers participating in interventional cardiology procedures have been measured at 12 centers since 2015 in the pilot study. The optically stimulated luminescence (OSL) dosimeter was used for measurement of the occupational exposure and the eye lens dose of 42 interventional cardiology personnel at King Chulalongkorn Memorial Hospital as one of the pilot centers. For all personnel, it is recommended that a first In Light OSL badge is placed at waist level and under the lead apron for determination of Hp(10); a second badge is placed at the collar for determination of Hp(0.07) and estimation of Hp(3). Nano Dots OSL dosimeter has been used as an eye lens dosimeter for 16 interventional cardiology personnel, both with and without lead-glass eyewear. The mean effective dose at the body, equivalent dose at the collar, and estimated eye lens dose were 0.801, 5.88, and 5.70 mSv per year, respectively. The mean eye lens dose measured by the Nano Dots dosimeter was 8.059 mSv per year on the left eye and 3.552 mSv per year on the right eye. Two of 16 interventional cardiologists received annual eye lens doses on the left side without lead glass that were higher than 20 mSv per year, the new eye lens dose limit as recommended by ICRP with the risk of eye lens opacity and cataract.

  20. Studies on α-Al2O3: C based optically stimulated luminescence badge for eye lens monitoring applications

    International Nuclear Information System (INIS)

    Kumar, Munish; Kulkarni, M.S.; Ratna, P.; Gaikwad, N.; Tripathi, S.M.; Sharma, S.D.; Babu, D.A.R.; Bhatnagar, Amit; Muthe, K.P.; Sharma, D.N.

    2014-01-01

    The prototype two element eye-lens dosimeter badge based on indigenously developed α-Al 2 O 3 : C optically stimulated luminescence dosimeter was investigated comprehensively for its suitability for eye-lens monitoring applications. The badge is calibrated to measure the eye-lens dose in terms of H p (3). The minimum measurable dose using the eye-lens dosimeter badge is observed to be ∼ 35 μSv. This prototype eye-lens dosimeter badge was found to be suitable for measuring doses from X-rays, beta and gamma radiations to the eye-lens. The satisfactory performance of the prototype two element eye-lens dosimeter badge along with its attractive features such as multiple readout, less processing time, very good beta response uniquely position it for monitoring the eye-lens dose are presented. (author)

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

    Directory of Open Access Journals (Sweden)

    Claire M Elkins

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

  2. Application of the ELDO approach to assess cumulative eye lens doses for interventional cardiologists

    International Nuclear Information System (INIS)

    Farah, J.; Jacob, S.; Clairand, I.; Struelens, L.; Vanhavere, F.; Auvinen, A.; Koukorava, C.; Schnelzer, M.

    2015-01-01

    In preparation of a large European epidemiological study on the relation between eye lens dose and the occurrence of lens opacities, the European ELDO project focused on the development of practical methods to estimate retrospectively cumulative eye lens dose for interventional medical professionals exposed to radiation. The present paper applies one of the ELDO approaches, correlating eye lens dose to whole-body doses, to assess cumulative eye lens dose for 14 different Finnish interventional cardiologists for whom annual whole-body dose records were available for their entire working period. The estimated cumulative left and right eye lens dose ranged from 8 to 264 mSv and 6 to 225 mSv, respectively. In addition, calculations showed annual eye lens doses sometimes exceeding the new ICRP annual limit of 20 mSv. The work also highlights the large uncertainties associated with the application of such an approach proving the need for dedicated dosimetry systems in the routine monitoring of the eye lens dose. (authors)

  3. Addendum report of the JHPS expert committee on radiation protection of the lens of the eye (1). Eye lens dosimetry R and D, and radiation management and estimated eye-lens exposure for workers in Japanese nuclear power plants

    International Nuclear Information System (INIS)

    Akahane, Keiichi; Tatsuzaki, Hideo; Iimoto, Takeshi; Ichiji, Takeshi; Hamada, Nobuyuki; Iwai, Satoshi; Ohguchi, Hiroyuki; Ohno, Kazuko; Katoh, Masahiro; Kurosawa, Tadahiro; Kawaura, Chiyo; Tsujimura, Norio; Hayashida, Toshiyuki; Hotta, Yutaka; Yamasaki, Tadashi; Yokoyama, Sumi

    2015-01-01

    The Expert Committee on Radiation Protection of the Lens of the Eye was established under the Japan Health Physics Society in April, 2013 (completed, March, 2015). The Committee looked at new/revised documents and standards related to the eye lens published by international organizations such as the International Commission on Radiological Protection (ICRP) and the International Commission on Radiation Units and Measurements (ICRU). The Committee also examined recent and previous studies related to eye-lens radiation exposure and dosimetry in Japan. These findings were published in this journal as the Interim Report of the Committee. Since then, the Committee expanded its activity to give an overview the current progress of eye-lens dosimetry R and D at the National Institute of Advanced Industrial Science and Technology, along with research related to radiation management and estimated eye-lens exposure of Japanese nuclear-power-plant workers (including those at Fukushima Daiichi Nuclear Power Plant) for publishing an addendum Committee report. These additional findings are reported here. (author)

  4. Clinical study of foldable intraocular lens secondary implantation after lens-vitrectomy in residual capsular with traumatic eyes

    Directory of Open Access Journals (Sweden)

    Ru-Fa Meng

    2015-07-01

    Full Text Available AIM: To investigate the operation methods and clinical effects of foldable intraocular lens secondary implantation after lens-vitrectomy in residual capsular with traumatic eyes.METHODS: During January 2012 to January 2014, foldable intraocular lens was implanted on 47 cases following lens-vitrectomy in residual capsular with traumatic eyes 3~6mo. Follow-up period was 6~12mo, averaged(8.21±2.63mo. RESULTS:All of 47 eyes had successful operation at one time, and position deviation was not appeared. The naked vision of the last postoperative follow-up was(0.44±0.19. Compared with best corrected visual acuity(0.41±0.23, and There was no significant difference between visual acuity of preoperative and last follow-up period(t=0.879, P=0.342. No severe complication was found. CONCLUSION: Secondary implantation of foldable intraocular lens is a safe and reliable method for correcting ametropia after lens-vitrectomy in residual capsular with traumatic eyes.

  5. TU-E-201-02: Eye Lens Dosimetry From CT Perfusion Studies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D. [Toshiba America Medical Systems (United States)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  6. TU-E-201-00: Eye Lens Dosimetry for Patients and Staff

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  7. TU-E-201-02: Eye Lens Dosimetry From CT Perfusion Studies

    International Nuclear Information System (INIS)

    Zhang, D.

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  8. TU-E-201-00: Eye Lens Dosimetry for Patients and Staff

    International Nuclear Information System (INIS)

    2015-01-01

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  9. The spectral sensitivity of the lens eyes of a box jellyfish, Tripedalia cystophora (Conant)

    DEFF Research Database (Denmark)

    Coates, Melissa M; Garm, Anders; Theobald, Jamie C

    2006-01-01

    Box jellyfish, or cubomedusae (class Cubozoa), are unique among the Cnidaria in possessing lens eyes similar in morphology to those of vertebrates and cephalopods. Although these eyes were described over 100 years ago, there has been no work done on their electrophysiological responses to light. ...... result from the presence of a single receptor type containing a single opsin. The peak sensitivity is to blue-green light. Visual pigment template fits indicate a vitamin A-1 based opsin with peak sensitivity near 500 nm for both eye types.......Box jellyfish, or cubomedusae (class Cubozoa), are unique among the Cnidaria in possessing lens eyes similar in morphology to those of vertebrates and cephalopods. Although these eyes were described over 100 years ago, there has been no work done on their electrophysiological responses to light. We...... used an electroretinogram (ERG) technique to measure spectral sensitivity of the lens eyes of the Caribbean species Tripedalia cystophora. The cubomedusae have two kinds of lens eyes, the lower and upper lens eyes. We found that both lens eye types have similar spectral sensitivities, which likely...

  10. Ultrastructural effects of silicone oil on the clear crystalline lens of the human eye.

    Science.gov (United States)

    Soliman, Wael; Sharaf, Mohamed; Abdelazeem, Khaled; El-Gamal, Dalia; Nafady, Allam

    2018-03-01

    To evaluate light and electron microscopic changes of the anterior capsule and its epithelium after clear lens extraction of vitrectomized myopic eyes with silicone oil tamponade. This prospective, controlled, non-randomized, interventional study included 20 anterior lens capsular specimens that were excised during combined clear lens extraction and silicone oil removal from previously vitrectomized highly myopic patients with silicone oil tamponade for previous retinal detachment surgeries. The specimens were examined via light microscopy and electron microscopy and compared with 20 anterior capsule specimens removed during clear lens extraction of non-vitrectomized highly myopic eyes. Light microscopic examination of clear lens anterior capsule specimens of vitrectomized myopic eyes filled with silicone oil showed relatively more flat cells with irregular outline of lens' epithelial cells with wide intercellular spaces, deeply stained nuclei, and multiple intracytoplasmic vacuoles. Scanning electron microscopy revealed collagenous surfaces filled with multiple pits, depressions, and abnormal deposits. Transmission electron microscopy revealed lens epithelial cells with apoptotic changes, many cytoplasmic vacuoles, and filopodia-like protrusions between lens epithelial cells and the capsule. Epithelial proliferation and multilayering were also observed. silicone oil may play a role in the development of apoptotic and histopathological changes in clear lens epithelial cells. Clarity of the lens at the time of silicone oil removal does not indicate an absence of cataractous changes. We found justification of combined clear lens extraction and silicone oil removal or combined phacovitrectomy when silicone oil injection is planned, but further long-term studies with larger patient groups are required.

  11. Risk of eye lens radiation exposure for members of the public

    International Nuclear Information System (INIS)

    Chevallier, M.-A.; Rannou, A.; Villagrasa, C.; Clairand, I.

    2016-01-01

    In 2011, the International Commission on Radiological Protection (ICRP) reviewed its recommendation concerning the equivalent dose limit for the eye lens, lowering it to 20 mSv in a year, for occupational exposure in planned exposure situations. The ICRP's statement does not contain any explicit recommendations regarding the organ dose limit for the eye lens for public exposure. For the moment, no change is proposed. But, to be coherent in the overall approach, the current equivalent limit for the public might be lowered. A similar yardstick than in the former recommendation may be used, that is to say a reduction of 10 times lower than that for occupational exposure. In this context, additional data on potential scenarios for public exposure of the eye lens are necessary. This paper, mainly based on a literature study, aims to provide, as far as possible, an exhaustive list of the situations in which members of the public can be exposed at the level of the eye lens. Once these situations have been defined, some calculations, made to assess the associated doses to the eye lens, are presented. This literature study did not reveal any current situations where members of the public would receive significant radiation doses to the eye lens. Indeed, the situations in which the dose to the eye lens might reach around 1 mSv per year for the public are extremely rare. (authors)

  12. Measurements of eye lens doses in interventional radiology and cardiology: Final results of the ORAMED project

    International Nuclear Information System (INIS)

    Vanhavere, F.; Carinou, E.; Domienik, J.; Donadille, L.; Ginjaume, M.; Gualdrini, G.; Koukorava, C.; Krim, S.; Nikodemova, D.; Ruiz-Lopez, N.; Sans-Merce, M.; Struelens, L.

    2011-01-01

    Within the ORAMED project (Optimization of Radiation Protection of Medical Staff) a coordinated measurement program for occupationally exposed medical staff was performed in different hospitals in Europe ( (www.oramed-fp7.eu)). The main objective was to obtain a set of standardized data on extremity and eye lens doses for staff involved in interventional radiology and cardiology and to optimize radiation protection. Special attention was given to the measurement of the doses to the eye lenses. In this paper an overview will be given of the measured eye lens doses and the main influence factors for these doses. The measured eye lens doses are extrapolated to annual doses. The extrapolations showed that monitoring of the eye lens should be performed on routine basis.

  13. Staff exposure in pediatric interventional neuroradiology: focus on the operator's eye lens

    International Nuclear Information System (INIS)

    Bolomey, C.; Fasel, G.; Le Coultre, R.; Ryckx, N.

    2016-01-01

    Previously at 150 mSv year -1 , the ICRP now recommends limiting the equivalent dose to the eye lens to 20 mSv year -1 . For pediatric interventional neuroradiology, the exposure of the operator's eye lens may be increased by the use of a biplane fluoroscopy system and by the proximity of the physician to the patient. In practice, the efficiency of leaded glasses depends on many factors. This study addresses both aspects. First, the eye lens dose of a neuro-radiologist was measured during 12 procedures using 36 TLDs placed on his surgical cap. Secondly, in order to determine the efficiency of leaded glasses, measurements were carried out by reproducing the clinical conditions. A detector was placed on the left eye of a phantom representing the operator. Four pairs of leaded glasses were selected to test various parameters. During the 12 procedures, an individual dose equivalent Hp(0.07) of 45μSv was obtained for the eye lens closest to the tube. This study shows an eye lens dose to DAP ratio 5 times higher than for procedures performed on adult patients. The eye lens dose might be reduced by a factor of approximately 3 with the use of appropriate leaded glasses. The eye wear model with the most coverage reduces the dose by up to 50% more than the model with the least coverage. The addition of lateral protection increases the attenuation by up to 13% compared with the same model without side protection. (authors)

  14. A wide-angle gradient index optical model of the crystalline lens and eye of the octopus.

    Science.gov (United States)

    Jagger, W S; Sands, P J

    1999-08-01

    Cephalopods and fish have had no common ancestor since the Cambrian, and their eyes are a classic example of convergent evolution. The octopus has no cornea, and immerson renders the trout cornea optically ineffective. As a result, the nearly spherical lens is responsible for all refraction in these eyes. In spite of the fact that the octopus lens consists of two joined parts, while the trout lens consists of one part, we show here that their optical properties are very similar. An index gradient bends rays within these lenses, adding power and correcting spherical aberration. High spherical symmetry in both lenses strongly reduces other monochromatic aberrations and yields a wide field of vision, advantageous in attack and evasion. The octopus Mattheissen's ratio, 2.83, an inverse measure of light-gathering power, lies above the trout value of 2.38 but within the range of values reported for fish. Strong uncorrected longitudinal chromatic aberration is nearly identical in both animals as a result of similar lens protein optical properties, and will limit resolution. We discuss how animal lifestyle requirements and lens material properties influence the design of these eyes.

  15. Measurement of radiation dose to the eye-lens with bilateral whole brain irradiation

    International Nuclear Information System (INIS)

    Kim, Ki Hwan; Park, Charn Il; Kang, Wee Saing; Choo, Dong Woon

    1985-01-01

    In 40 patients with metastatic brain tumor and acute lymphoblastic leukemia received whole brain irradiation, the dose delivered to the eye lens was measured using T.L.D. chips applied on the eyes as usual shield. The dose to the eye lens was expressed the relative dose to the mid brain dose. Radiotherapy was administrated using Co-60 teletherapy with bilateral whole brain irradiation. The results are as follows: 1. The dose to the right eye from its incipient field is 16.6% of tumor dose while the dose to the same eye from the opposite field is 41.2%. On left eye, 19.2% from incipient field while 39.2% from the opposite field. 2. Total received dose to right and left eyes is 28.9%, 29.8% of tumor dose respectively. 3. Comparing lens shield group with orbit shield group dose is 22.5%, 15.8% of tumor dose, respectively. 4. The dose delivered to the eye lens in ipsilateral side depends upon internal scattering, location of lead shield and penetrating dose of lead in itself. The dose in contralateral side depends upon divergency of radiation beam and patient's malposition. 5. The dose to the eye lens should be less than 10% of tumor dose with adequate shield, also not missing the chance of leptomeningeal recurrence because of overshielding.

  16. Eye lens dosimetry for interventional procedures – Relation between the absorbed dose to the lens and dose at measurement positions

    International Nuclear Information System (INIS)

    Geber, Therese; Gunnarsson, Mikael; Mattsson, Sören

    2011-01-01

    This study investigated the relationship between the absorbed dose to the lens of the eye and the absorbed dose at different measurement positions near the eye of interventional radiologists. It also visualised the dose distribution inside the head, both when protective eyewear were used and without such protection. The best position for an eye lens dosimeter was found to be at the side of the head nearest to the radiation source, close to the eye. Positioning the dosimeter at the eyebrow could lead to an underestimation of the lens dose of as much as 45%. The measured dose distribution showed that the absorbed dose to the eye lenses was high compared to the other parts of the head, which stresses the importance of wearing protective eyewear. However, many models of eyewear were found to be deficient as the radiation could slip through at several places, e.g. at the cheek. The relationship between the absorbed dose to the lens and the kerma-area-product (P KA ) delivered to the patient was also studied.

  17. Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of Hp(3) monitoring. A 2015 review

    International Nuclear Information System (INIS)

    Carinou, Eleftheria; Ferrari, Paolo; Bjelac, Olivera Ciraj; Gingaume, Merce; Merce, Marta Sans; O’Connor, Una

    2015-01-01

    A thorough literature review about the current situation on the implementation of eye lens monitoring has been performed in order to provide recommendations regarding dosemeter types, calibration procedures and practical aspects of eye lens monitoring for interventional radiology personnel. Most relevant data and recommendations from about 100 papers have been analysed and classified in the following topics: challenges of today in eye lens monitoring; conversion coefficients, phantoms and calibration procedures for eye lens dose evaluation; correction factors and dosemeters for eye lens dose measurements; dosemeter position and influence of protective devices. The major findings of the review can be summarised as follows: the recommended operational quantity for the eye lens monitoring is H p (3). At present, several dosemeters are available for eye lens monitoring and calibration procedures are being developed. However, in practice, very often, alternative methods are used to assess the dose to the eye lens. A summary of correction factors found in the literature for the assessment of the eye lens dose is provided. These factors can give an estimation of the eye lens dose when alternative methods, such as the use of a whole body dosemeter, are used. A wide range of values is found, thus indicating the large uncertainty associated with these simplified methods. Reduction factors from most common protective devices obtained experimentally and using Monte Carlo calculations are presented. The paper concludes that the use of a dosemeter placed at collar level outside the lead apron can provide a useful first estimate of the eye lens exposure. However, for workplaces with estimated annual equivalent dose to the eye lens close to the dose limit, specific eye lens monitoring should be performed. Finally, training of the involved medical staff on the risks of ionising radiation for the eye lens and on the correct use of protective systems is strongly recommended. (review)

  18. Opaque iris claw lens in a phakic eye to correct acquired diplopia

    NARCIS (Netherlands)

    Landesz, M; Worst, JGF; Rij, GV; Houtman, WA

    1997-01-01

    A 25-year-old man had diplopia caused by abducens nerve paresis on both sides after cranial injury. Because of the patient's reports of persistent diplopia after surgical correction, a specially manufactured, tinted iris claw lens was implanted in the left eye, with the crystalline lens in situ.

  19. Oral omega-6 essential fatty acid treatment in contact lens associated dry eye.

    OpenAIRE

    Kokke, K. H.; Morris, J. A.; Lawrenson, J.

    2008-01-01

    Symptoms of dry eye are commonly reported in contact lens wearers and are a frequent cause of non-tolerance. The purpose of the present study is to evaluate the effects of oral treatment with particular omega-6 fatty acids in the form of evening primrose oil (EPO) on subjective symptoms, ocular surface signs and tear film characteristic in patients with contact lens associated dry eye.

  20. Lens subluxation after plasmin and SF6 injections in rabbit eyes.

    Directory of Open Access Journals (Sweden)

    Wei-Chi Wu

    Full Text Available To investigate the rate of lens subluxation following plasmin and/or SF6 injections in eyes, and whether a subsequent elevated level of vascular endothelial growth factor (VEGF and vitreous tap would aggravate subluxation.Four groups of rabbits were used. Group 1 received an intravitreal injection (IVI of plasmin and SF6 in the right eye; group 2 received an IVI of plasmin in the right eye; group 3 received an IVI of SF6 in the right eye; and group 4 received an IVI of balanced salt solution in the right eye. After treatment, IVIs of VEGF were given and vitreous tap was performed three times, followed by clinical observation of lens subluxation and scanning electronic microscope evaluation of the zonular fibers.After IVIs of plasmin and SF6, and VEGF and vitreous tap had been performed one to three times, lens subluxation was noted in 0%, 43%, 71%, 71%, and 86% of the eyes in group 1. After IVIs of plasmin, VEGF, and vitreous tap had been performed one to three times, lens subluxation was noted in 11%, 22%, 44%, 44%, and 67% of the eyes in group 2. The eyes in group 3 and 4 did not show signs of lens subluxation after VEGF IVIs and vitreous tap. Histology confirmed zonular fiber damage in the eyes treated with plasmin.The incidence of lens subluxation increased following plasmin injections in the eyes, and this was aggravated by the subsequent high VEGF level in the eyes and vitreous tapping. Zonular fibers were disrupted following plasmin treatment. These effects should be kept in mind when using plasmin enzymes in patients with vitreoretinal abnormalities.

  1. Treatment, material, care, and patient-related factors in contact lens-related dry eye.

    Science.gov (United States)

    Ramamoorthy, Padmapriya; Sinnott, Loraine T; Nichols, Jason J

    2008-08-01

    To examine the effect of general contact lens and material characteristics, care solutions, treatment, and patient-related factors on contact lens-related dry eye. The data were derived from the Contact Lens and Dry Eye Study, designed as a cross-sectional and nested case-control study including 360 subjects. In separate statistical models, logistic regression was used to examine general contact lens characteristics, specific hydrogel lens materials, care solutions, and patient-related factors associated with dry eye status (controlled for age, gender, and current treatments). Several factors were significantly associated with dry eye, including treatment factors such as a recent contact lens refitting (odds ratios [OR] = 5.75, 95% confidence intervals [CI] = 2.14 to 15.46) and use of artificial tears/rewetting drops (OR = 1.09, 95% CI = 1.02 to 1.16), in addition, currently worn materials including Food and Drug Administration (FDA) group II (OR = 2.98, 95% CI = 1.14 to 6.19) and IV (OR = 1.87, 95% CI = 1.08 to 3.24). Significant patient-related factors included decreased overall satisfaction (OR = 3.57, 95% CI = 2.08 to 5.88,), dry eye in the absence of contact lens wear (OR = 6.54, 95% CI = 2.57 to 16.62), reduced daily lens wear duration (OR = 1.16, 95% CI = 1.06 to 1.26), and reduced ability to wear lenses as long as desired (OR = 2.44, 95% CI = 1.30 to 4.54). Care solutions were not associated with contact lens-related dry eye. The strong association of common treatment factors with dry eye status in contact lens wearers suggests that these treatments are not entirely effective. The use of high water content materials was strongly related to dry eye in lens wearers, whereas care solutions were not. Contact lens-related dry eye was also associated with several patient-related factors such as greater ocular discomfort (without lenses), dissatisfaction, and inability to wear lenses for desired durations.

  2. Clinical assessment of diclofenac sodium eye drops in toric intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Yan Luo

    2013-05-01

    Full Text Available AIM:To evaluate the application of diclofenac sodium eye drops in toric intraocular lens implantation. METHODS: From January 2011 to February 2012, 38 eyes of 37 patients, who underwent toric intraocular lens implantation in this hospital, were randomly divided into diclofenac sodium eye drops group(trial groupand control group. Patient's degree of cooperation during surgery and inflammation postoperation after 1 day, 3,7, days, 1 month and 3 months were evaluated. RESULTS: Patient's degree of cooperation during surgery in the trial group(1.53±0.62was significantly better than in the control group(2.40±0.88, P<0.05. Inflammation reaction was gentle in the trial group 1 day postoperatively. CONCLUSION: Diclofenac sodium eye drops used during toric intraocular lens implantation can obviously alleviate eye irritation, and increase the cooperation of patients.

  3. Properties of Fiber Cell Plasma Membranes Isolated from the Cortex and Nucleus of the Porcine Eye Lens

    Science.gov (United States)

    Mainali, Laxman; Raguz, Marija; O’Brien, William J.; Subczynski, Witold K.

    2012-01-01

    The organization and physical properties of the lipid bilayer portion of intact cortical and nuclear fiber cell plasma membranes isolated from the eyes lenses of two-year-old pigs were studied using electron paramagnetic resonance (EPR) spin-labeling. Membrane fluidity, hydrophobicity, and the oxygen transport parameter (OTP) were assessed from the EPR spectra of precisely positioned spin labels. Intact cortical and nuclear membranes, which include membrane proteins, were found to contain three distinct lipid environments. These lipid environments were termed the bulk lipid domain, boundary lipid domain, and trapped lipid domain (lipids in protein aggregates). The amount of boundary and trapped lipids was greater in intact nuclear membranes than in cortical membranes. The properties of intact membranes were compared with the organization and properties of lens lipid membranes made of the total lipid extracts from the lens cortex or nucleus. In cortical lens lipid membranes, only one homogenous environment was detected, which was designated as a bulk lipid domain (phospholipid bilayer saturated with cholesterol). Lens lipid membranes prepared from the lens nucleus possessed two domains, assigned as a bulk lipid domain and a cholesterol bilayer domain (CBD). In intact nuclear membranes, it was difficult to discriminate the CBD, which was clearly detected in nuclear lens lipid membranes because the OTP measured in the CBD is the same as in the domain formed by trapped lipids. The two domains unique to intact membranes—namely, the domain formed by boundary lipids and the domain formed by trapped lipids—were most likely formed due to the presence of membrane proteins. It is concluded that formation of rigid and practically impermeable domains is enhanced in the lens nucleus, indicating changes in membrane composition that may help to maintain low oxygen concentration in this lens region. PMID:22326289

  4. 'Yellow lens' eyes of a stomiatoid deep-sea fish, Malacosteus niger.

    Science.gov (United States)

    Somiya, H

    1982-07-22

    Bright yellow lenses were found in the eyes of the stomiatoid deep-sea fish, Malacosteus niger Ayres. The optical properties of the yellow lens and the retinal specializations in the eyes were examined. Absorption spectra of the yellow lens revealed two peaks at wavelengths 425 and 460 nm. The photoreceptors were all rods and were arranged in two superimposed layers. An astaxanthin-type retinal tapetum was observed in the pigment epithelium. Some chemical evidence is presented showing that the tapetal material is an astaxanthin ester. The ecological significance of the yellow lens is discussed in connection with that of Malacosteus' orbital light organ which has a reddish filter.

  5. Oral omega-6 essential fatty acid treatment in contact lens associated dry eye.

    Science.gov (United States)

    Kokke, Karolien H; Morris, Judith A; Lawrenson, John G

    2008-06-01

    Symptoms of dry eye are commonly reported in contact lens wearers and are a frequent cause of non-tolerance. The purpose of the present study is to evaluate the effects of oral treatment with particular omega-6 fatty acids in the form of evening primrose oil (EPO) on subjective symptoms, ocular surface signs and tear film characteristic in patients with contact lens associated dry eye. The study design was randomised, double-masked and placebo controlled. 76 female soft contact lens wearers were treated for 6 months with either EPO or placebo (olive oil). Subjects underwent three examinations (baseline, 3 and 6 months). At each examination subjects were given a questionnaire relating to lens comfort and dry eye symptoms and underwent a series of tests of tear film characteristics (tear meniscus height, break-up time), meibomian gland function (lipid layer thickness and quality) and ocular surface parameters (hyperaemia and staining). The EPO group showed a significant improvement in the specific symptom of 'dryness' at 3 and 6 months (porally administered omega-6 fatty acids in alleviating dry eye symptoms and improving overall lens comfort in patients suffering from contact lens associated dry eye.

  6. Shielding effect of lead glasses on radiologists' eye lens exposure in interventional procedures

    International Nuclear Information System (INIS)

    Hu, Panpan; Kong, Yan; Chen, Bo; Liu, Qianqian; Zhuo, Weihai; Liu, Haikuan

    2017-01-01

    To study the shielding effect of radiologists' eye lens with lead glasses of different equivalent thicknesses and sizes in interventional radiology procedures. Using the human voxel phantom with a more accurate model of the eye and MCNPX software, eye lens doses of the radiologists who wearing different kinds of lead glasses were simulated, different beam projections were taken into consideration during the simulation. Measurements were also performed with the physical model to verify simulation results. Simulation results showed that the eye lens doses were reduced by a factor from 3 to 9 when wearing a 20 cm"2-sized lead glasses with the equivalent thickness ranging from 0.1 to 1.0 mm Pb. The increase of dose reduction factor (DRF) was not significant whenever increase the lead equivalent of glasses of which larger than 0.35 mm. Furthermore, the DRF was proportional to the size of glass lens from 6 to 30 cm"2 with the same lead equivalent. The simulation results were in well agreements with the measured ones. For more reasonable and effective protection of the eye lens of interventional radiologists, a pair of glasses with a lead equivalent of 0.5 mm Pb and large-sized (at least 27 cm"2 per glass) lens are recommended (authors)

  7. Shielding Effect of Lead Glasses on Radiologists' Eye Lens Exposure in Interventional Procedures.

    Science.gov (United States)

    Hu, Panpan; Kong, Yan; Chen, Bo; Liu, Qianqian; Zhuo, Weihai; Liu, Haikuan

    2017-04-20

    To study the shielding effect of radiologists' eye lens with lead glasses of different equivalent thicknesses and sizes in interventional radiology procedures. Using the human voxel phantom with a more accurate model of the eye and MCNPX software, eye lens doses of the radiologists who wearing different kinds of lead glasses were simulated, different beam projections were taken into consideration during the simulation. Measurements were also performed with the physical model to verify simulation results. Simulation results showed that the eye lens doses were reduced by a factor from 3 to 9 when wearing a 20 cm2-sized lead glasses with the equivalent thickness ranging from 0.1 to 1.0 mm Pb. The increase of dose reduction factor (DRF) was not significant whenever increase the lead equivalent of glasses of which larger than 0.35 mm. Furthermore, the DRF was proportional to the size of glass lens from 6 to 30 cm2 with the same lead equivalent. The simulation results were in well agreements with the measured ones. For more reasonable and effective protection of the eye lens of interventional radiologists, a pair of glasses with a lead equivalent of 0.5 mm Pb and large-sized (at least 27 cm2 per glass) lens are recommended. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Dose conversion coefficients for neutron exposure to the lens of the human eye

    International Nuclear Information System (INIS)

    Manger, Ryan P.; Bellamy, Michael B.; Eckerman, Keith F.

    2011-01-01

    Dose conversion coefficients for the lens of the human eye have been calculated for neutron exposure at energies from 1 x 10 -9 to 20 MeV and several standard orientations: anterior-to-posterior, rotational and right lateral. MCNPX version 2.6.0, a Monte Carlo-based particle transport package, was used to determine the energy deposited in the lens of the eye. The human eyeball model was updated by partitioning the lens into sensitive and insensitive volumes as the anterior portion (sensitive volume) of the lens being more radiosensitive and prone to cataract formation. The updated eye model was used with the adult UF-ORNL mathematical phantom in the MCNPX transport calculations.

  9. Dose conversion coefficients for neutron exposure to the lens of the human eye

    International Nuclear Information System (INIS)

    Manger, R. P.; Bellamy, M. B.; Eckerman, K. F.

    2012-01-01

    Dose conversion coefficients for the lens of the human eye have been calculated for neutron exposure at energies from 1 x 10 -9 to 20 MeV and several standard orientations: anterior-to-posterior, rotational and right lateral. MCNPX version 2.6.0, a Monte Carlo-based particle transport package, was used to determine the energy deposited in the lens of the eye. The human eyeball model was updated by partitioning the lens into sensitive and insensitive volumes as the anterior portion (sensitive volume) of the lens being more radiosensitive and prone to cataract formation. The updated eye model was used with the adult UF-ORNL mathematical phantom in the MCNPX transport calculations. (authors)

  10. Wide-field schematic eye models with gradient-index lens.

    Science.gov (United States)

    Goncharov, Alexander V; Dainty, Chris

    2007-08-01

    We propose a wide-field schematic eye model, which provides a more realistic description of the optical system of the eye in relation to its anatomical structure. The wide-field model incorporates a gradient-index (GRIN) lens, which enables it to fulfill properties of two well-known schematic eye models, namely, Navarro's model for off-axis aberrations and Thibos's chromatic on-axis model (the Indiana eye). These two models are based on extensive experimental data, which makes the derived wide-field eye model also consistent with that data. A mathematical method to construct a GRIN lens with its iso-indicial contours following the optical surfaces of given asphericity is presented. The efficiency of the method is demonstrated with three variants related to different age groups. The role of the GRIN structure in relation to the lens paradox is analyzed. The wide-field model with a GRIN lens can be used as a starting design for the eye inverse problem, i.e., reconstructing the optical structure of the eye from off-axis wavefront measurements. Anatomically more accurate age-dependent optical models of the eye could ultimately help an optical designer to improve wide-field retinal imaging.

  11. Lens artifacts in human fetal eyes - the challenge of interpreting the histomorphology of human fetal lenses.

    Science.gov (United States)

    Herwig, Martina C; Müller, Annette M; Klarmann-Schulz, Ute; Holz, Frank G; Loeffler, Karin U

    2014-01-01

    Evaluation of the lens, including cataractous changes, is often of paramount importance in the classification of fetal syndromes or forensic questions. On histology, the crystalline lens is - especially in fetal and infant eyes - an organ susceptible to numerous artifacts. Thus, the aim of our study was to study various factors (including fixatives) that might have an impact on lens histomorphology. Twenty eyes from ten fetuses (formalin fixation: n = 10, glutaraldehyde fixation: n = 10), matched for gestational age and abortion (spontaneous vs. induced), were investigated macroscopically and by light microscopy. Sections were stained with routine hematoxylin & eosin (H&E), and periodic acid schiff (PAS). The age of the fetal eyes ranged from 15 to 36 weeks of gestation. Lens artifacts were analyzed and compared to fetal and adult lenses with definitive cataractous changes. In addition, 34 eyes from 27 fetuses with trisomy 21 were investigated for lens changes. All lenses showed artifacts of varying extent, in particular globules, vacuoles, clefts, anterior/posterior capsular separation, subcapsular proteinaceous material, fragmentation of the lens capsule/epithelium, and a posterior umbilication. Glutaraldehyde-fixed lenses displayed less artifacts compared to those fixed in formalin. Slight differences in the appearance of artifacts were found dependent on the fixative (formaldehyde vs glutaraldehyde) and the kind of abortion (iatrogenous vs spontaneous). The gestational age did not have a significant influence on the type and extent of lens artifacts. The lenses from fetuses with trisomy 21 displayed similar lens artifacts with no specific findings. Alterations in fetal lens morphology are extremely frequent and variable. These artifacts have to be carefully taken into account when interpreting post-mortem findings. Thus, the postmortem diagnosis of a fetal cataract should be made with great caution, and should include, in adherence to our proposed

  12. Radiation exposure of the radiologist's eye lens during CT-guided interventions.

    Science.gov (United States)

    Heusch, Philipp; Kröpil, Patric; Buchbender, Christian; Aissa, Joel; Lanzman, Rotem S; Heusner, Till A; Ewen, Klaus; Antoch, Gerald; Fürst, Günther

    2014-02-01

    In the past decade the number of computed tomography (CT)-guided procedures performed by interventional radiologists have increased, leading to a significantly higher radiation exposure of the interventionalist's eye lens. Because of growing concern that there is a stochastic effect for the development of lens opacification, eye lens dose reduction for operators and patients should be of maximal interest. To determine the interventionalist's equivalent eye lens dose during CT-guided interventions and to relate the results to the maximum of the recommended equivalent dose limit. During 89 CT-guided interventions (e.g. biopsies, drainage procedures, etc.) measurements of eye lens' radiation doses were obtained from a dedicated dosimeter system for scattered radiation. The sensor of the personal dosimeter system was clipped onto the side of the lead glasses which was located nearest to the CT gantry. After the procedure, radiation dose (µSv), dose rate (µSv/min) and the total exposure time (s) were recorded. For all 89 interventions, the median total exposure lens dose was 3.3 µSv (range, 0.03-218.9 µSv) for a median exposure time of 26.2 s (range, 1.1-94.0 s). The median dose rate was 13.9 µSv/min (range, 1.1-335.5 µSv/min). Estimating 50-200 CT-guided interventions per year performed by one interventionalist, the median dose of the eye lens of the interventional radiologist does not exceed the maximum of the ICRP-recommended equivalent eye lens dose limit of 20 mSv per year.

  13. The Management of Refractory Dry Eye With Semi-Scleral Contact Lens.

    Science.gov (United States)

    Yuksel, Erdem; Bilgihan, Kamil; Novruzlu, Şahin; Yuksel, Nilay; Koksal, Murat

    2016-05-19

    We presented a case of refractory dry eye management with semi-scleral contact lens. Dry eye was associated with facial nerve (cranial nerve VII) palsy as a result of cerebellopontine angle tumor surgery. She was treated with several topical treatments and punctal plug. Despite the treatments, her symptoms still persisted. Her ophthalmic examination revealed scleral exposure because of lagophthalmos, conjunctival hyperemia, corneal debris, scar, and diffuse punctate epitheliopathy on her right eye. Lissamine green staining showed diffuse conjunctival and corneal staining. Therapeutic semi-scleral lenses were fitted. The corneal findings were resolved and the quality of patient life was improved with the aid of semi-scleral lens after 3 months.

  14. Isofocusing and immunological investigations on cephalopod lens proteins

    NARCIS (Netherlands)

    Brahma, S.K.; Lancieri, M.

    1979-01-01

    Soluble lens proteins from Octopus vulgaris, Sepia officinalis, and Loligo vulgaris were analyzed by thin-layer isoelectric focusing and compared by various immunochemical methods using antibodies directed against total soluble lens protein antigens from the said three species. The results show

  15. Conjunctival impression cytology versus routine tear function tests for dry eye evaluation in contact lens wearers.

    Science.gov (United States)

    Kumar, Prachi; Bhargava, Rahul; Arora, Yogesh C; Kaushal, Sidharth; Kumar, Manjushri

    2015-01-01

    Prolonged contact lens wear is often accompanied by dryness of the eyes. The aim of this study was to compare conjunctival impression cytology (CIC) and tear film tests such as tear film break up time (TBUT) and Schirmer test for dry eye evaluation in contact lens wearers and measure their correlation with dry eye symptoms. A case control study was done at three referral eye centers. The eyes of 230 contact lens users were compared to 250 eyes of age- and sex-matched controls. Participants were recruited based on their response to a questionnaire of dry eye symptoms, (Dry Eye Scoring System, DESS(©)) and measurements of TBUT, Schirmer test, and CIC was done. A correlation analysis between symptom severity and tear film tests was performed. Pearson's coefficient, R(2) > 0.5 was considered significant. As compared to controls (r (2) = 0.010), Nelson grade correlated significantly with dry eye symptoms (r (2) = 0.765), among cases. However, there was moderate correlation between dry eye symptoms, Schirmer test, and TBUT (r (2) = 0.557 and 0.530, respectively) among cases and a weak correlation among controls (r (2) = 0.130 and 0.054, respectively). The sensitivity of TBUT was 86.4%, specificity was 82.4%, positive likelihood ratio (LR) was 4.50 [95% confidence interval (CI) 3.46-5.85)], and negative LR was 0.09. The sensitivity of the Schirmer test was 48.2%, specificity 88%, LR 2.12 (95% CI 1.48-2.96), and negative LR 0.83. CIC correlates better than Schirmer and TBUT with dry eye symptoms. It may be the most appropriate test for dry-eye evaluation in contact lens wearers.

  16. Oral omega-3 fatty acid treatment for dry eye in contact lens wearers.

    Science.gov (United States)

    Bhargava, Rahul; Kumar, Prachi

    2015-04-01

    The aim of this study was to evaluate the effect of dietary omega-3 fatty acid (O3FA) supplementation on dry eye symptoms, tear film tests, and conjunctival impression cytology in patients with contact lens wear-associated dry eye. In this randomized, double-blind, multicentric trial, contact lens wearers (n = 496) were randomized to receive either O3FAs or placebo capsules (corn oil) twice daily for 6 months. Subjects underwent examinations at baseline, 3 months, and 6 months. At each visit, a questionnaire of dry eye symptoms and lens wear comfort was administered. Subjects further underwent measurement of tear film break-up time (TBUT) and a Schirmer test. Conjunctival impression cytology was performed by the transfer method. Improvement in symptoms and lens wear comfort were primary outcome measures. Changes from baseline in TBUT, Schirmer, and Nelson grade at 6 months were secondary outcome measures. The mean improvement in symptom score in the O3FA group was 4.7 ± 2 (2.0) as compared with 0.5 ± 2 (0.9) in the placebo group (P dry eye symptoms, improving lens wear comfort, and cytological changes in contact lens wearers.

  17. Regulating exposure of the lens of the eye to ionising radiations

    International Nuclear Information System (INIS)

    Thorne, M C

    2012-01-01

    The International Commission on Radiological Protection (ICRP) has reviewed recent epidemiological evidence suggesting that, for the lens of the eye, the threshold in absorbed dose for the induction of deleterious health effects is about 0.5 Gy. On this basis, the Commission recommends that for occupational exposure in planned exposure situations, the equivalent dose limit for the lens of the eye should be 20 mSv in a year, averaged over defined periods of 5 yr, with exposure not exceeding 50 mSv in any single year. This paper summarises the data that have been taken into account by the ICRP and critically examines whether the proposed downward revision of the dose limit is justified. Overall, it is concluded that the accumulating radiobiological and epidemiological evidence makes it more appropriate to treat cataract induction as a stochastic rather than a deterministic effect. Within this framework, it is illogical to have the same dose limit for the lens of the eye as for the whole body irradiated uniformly. This could be addressed either by removing the special dose limit for the lens of the eye, assigning it an appropriate tissue weighting factor and including it in the computation of the effective dose, or through a composite approach involving the use of a tissue weighting factor for effective dose computations together with a special limit on the equivalent dose to the lens of the eye to ensure that no individual was subject to an unacceptably high risk of induction of clinically significant cataracts.

  18. Radiation exposure to the eye lens of orthopaedic surgeons during various orthopaedic procedures

    International Nuclear Information System (INIS)

    Romanova, K.; Alyakov, M.; Vassileva, J.

    2015-01-01

    The aim of the present study was to assess the radiation dose to the eye lens of orthopaedic surgeons during various orthopaedic procedures and to make efforts to ensure that radiation protection is optimised. The study was performed for Fractura femoris and Fractura cruris procedures performed in orthopaedic operating theatres, as well as for fractures of wrist, ankle and hand/ shoulder performed in the emergency trauma room. The highest mean value of the eye lens dose of 47.2 μSv and higher mean fluoroscopy time of 3 min, as well as the corresponding highest maximum values of 77.1 μSv and 5.0 min were observed for the Fractura femoris procedure performed with the Biplanar 500e fluoroscopy systems. At a normal workload, the estimated mean annual dose values do not exceed the annual occupational dose limit for the lens of eye, but at a heavy workload in the department, this dose limit could be achieved or exceeded. The use of protective lead glasses is recommended as they could reduce the radiation exposure of the lens of the eye. The phantom measurements demonstrated that the use of half-dose mode could additionally reduce dose to the operator's eye lens. (authors)

  19. Study of the structure of buffalo's eye lens and scleroretinal rim in Tabriz by ultrasonography

    Directory of Open Access Journals (Sweden)

    GH Assadnassab

    2011-05-01

    Full Text Available In this study, ultrasonographic condition of lens and posterior wall of buffalo's eye in Tabriz area were investigated due to their important role in vision and also measurements were made in anterior-posterior axial B-mode display methods. The ultrasonographic images were similar to the images obtained from other particularly the cow. Total thickness of the lens was 1.133 ± 0.052 cm with the thickness being 1.135 ± 0.052 cm in the right eye and 1.132 ± 0.053 cm in the left eye. Thickness of the posterior wall of the right and left eyes were 1.677 ± 0.042 mm and 1.672 ± 0.041 mm respectively with the total thickness of the posterior wall measuring 1.674 ± 0.040 mm. There was no significant difference between the left and right eyes regarding these parameters.

  20. Dosimetry studies with 32P source and correlation of skin and eye lens doses

    International Nuclear Information System (INIS)

    Kumar, Munish; Gaonkar, U.P.; Koul, D.K.; Datta, D.; Saxena, S.K.; Kumar, Yogendra; Dash, A.

    2018-01-01

    Beta particles are one of the major contributors toward skin and eye lens doses at facilities handling beta sources. These sources find applications in industry, pharmaceuticals as well as in brachytherapy applications. The beta particles having maximum (E max ) energy > 0.07 MeV are capable of delivering skin dose whereas beta particles having maximum (E max ) energy > 0.7 MeV may also contribute towards dose to eye lens. Studies are performed using 32 P beta source as its maximum beta energy (E max ) is such that for sources having (E max ) of 1.71 MeV or beyond, there can be substantial contribution towards dose to eye lens even the dose limit recommended for skin is followed

  1. Radiation exposure to the lens of the eye in temporal bone radiography

    International Nuclear Information System (INIS)

    Paix, D.

    1980-01-01

    Both the sensitivity of the eye to radiation cataract and the doses delivered to it in petrous bone examination are ill-defined. However, the following guidelines are suggested: (1) radiation cataract is unlikely to be a contraindication in patients over 50; (2) lens exposure per film when using an AP projection should be about 5m Gy; this may be reduced tenfold when tomographic movements permit the use of eye shields containing 1mm of lead; (3) projections which do not include the eyes in the direct beam should entail lens doses of 0.2m Gy or less; (4) steps should be taken to prevent the accumulated dose to the patient's lens from reaching 300m Gy per year or 15 Gy in all

  2. Dose conversion coefficients for photon exposure of the human eye lens

    Science.gov (United States)

    Behrens, R.; Dietze, G.

    2011-01-01

    In recent years, several papers dealing with the eye lens dose have been published, because epidemiological studies implied that the induction of cataracts occurs even at eye lens doses of less than 500 mGy. Different questions were addressed: Which personal dose equivalent quantity is appropriate for monitoring the dose to the eye lens? Is a new definition of the dose quantity Hp(3) based on a cylinder phantom to represent the human head necessary? Are current conversion coefficients from fluence to equivalent dose to the lens sufficiently accurate? To investigate the latter question, a realistic model of the eye including the inner structure of the lens was developed. Using this eye model, conversion coefficients for electrons have already been presented. In this paper, the same eye model—with the addition of the whole body—was used to calculate conversion coefficients from fluence (and air kerma) to equivalent dose to the lens for photon radiation from 5 keV to 10 MeV. Compared to the values adopted in 1996 by the International Commission on Radiological Protection (ICRP), the new values are similar between 40 keV and 1 MeV and lower by up to a factor of 5 and 7 for photon energies at about 10 keV and 10 MeV, respectively. Above 1 MeV, the new values (calculated without kerma approximation) should be applied in pure photon radiation fields, while the values adopted by the ICRP in 1996 (calculated with kerma approximation) should be applied in case a significant contribution from secondary electrons originating outside the body is present.

  3. Dose conversion coefficients for photon exposure of the human eye lens

    International Nuclear Information System (INIS)

    Behrens, R; Dietze, G

    2011-01-01

    In recent years, several papers dealing with the eye lens dose have been published, because epidemiological studies implied that the induction of cataracts occurs even at eye lens doses of less than 500 mGy. Different questions were addressed: Which personal dose equivalent quantity is appropriate for monitoring the dose to the eye lens? Is a new definition of the dose quantity H p (3) based on a cylinder phantom to represent the human head necessary? Are current conversion coefficients from fluence to equivalent dose to the lens sufficiently accurate? To investigate the latter question, a realistic model of the eye including the inner structure of the lens was developed. Using this eye model, conversion coefficients for electrons have already been presented. In this paper, the same eye model-with the addition of the whole body-was used to calculate conversion coefficients from fluence (and air kerma) to equivalent dose to the lens for photon radiation from 5 keV to 10 MeV. Compared to the values adopted in 1996 by the International Commission on Radiological Protection (ICRP), the new values are similar between 40 keV and 1 MeV and lower by up to a factor of 5 and 7 for photon energies at about 10 keV and 10 MeV, respectively. Above 1 MeV, the new values (calculated without kerma approximation) should be applied in pure photon radiation fields, while the values adopted by the ICRP in 1996 (calculated with kerma approximation) should be applied in case a significant contribution from secondary electrons originating outside the body is present.

  4. Radiation-induced eye lens changes and risk for cataract in interventional cardiology.

    Science.gov (United States)

    Ciraj-Bjelac, O; Rehani, M; Minamoto, A; Sim, K H; Liew, H B; Vano, E

    2012-01-01

    Recent studies have reported a significant increase in eye lens opacities among staff in the cardiac catheterization laboratory but indicated further studies are needed to confirm the findings. To evaluate the prevalence of opacities in eyes of cardiologists, radiographers and nurses working in interventional cardiology. The eyes of 52 staff in interventional cardiology facilities and 34 age- and sex-matched unexposed controls were screened in a cardiology conference held in Kuala Lumpur by dilated slit-lamp examination, and posterior lens changes were graded. Individual cumulative lens X-ray exposures were calculated from responses to a questionnaire in terms of workload and working practice. The prevalence of posterior lens opacities among interventional cardiologists was 53%, while in nurses and radiographers it was 45%. Corresponding relative risks were 2.6 (95% CI: 1.2-5.4) and 2.2 (95% CI: 0.98-4.9), for interventional cardiologists and support staff, respectively. This study confirms a statistically significant increase in radiation-associated posterior lens changes in the eyes of interventional cardiology staff. Copyright © 2012 S. Karger AG, Basel.

  5. Metamaterial-based half Maxwell fish-eye lens for broadband directive emissions

    Science.gov (United States)

    Dhouibi, Abdallah; Nawaz Burokur, Shah; de Lustrac, André; Priou, Alain

    2013-01-01

    The broadband directive emission from a metamaterial surface is numerically and experimentally reported. The metasurface, composed of non-resonant complementary closed ring structures, is designed to obey the refractive index of a half Maxwell fish-eye lens. A planar microstrip Vivaldi antenna is used as transverse magnetic polarized wave launcher for the lens. A prototype of the lens associated with its feed structure has been fabricated using standard lithography techniques. To experimentally demonstrate the broadband focusing properties and directive emissions, both the far-field radiation patterns and the near-field distributions have been measured. Measurements agree quantitatively and qualitatively with theoretical simulations.

  6. Hard sphere-like glass transition in eye lens α-crystallin solutions.

    Science.gov (United States)

    Foffi, Giuseppe; Savin, Gabriela; Bucciarelli, Saskia; Dorsaz, Nicolas; Thurston, George M; Stradner, Anna; Schurtenberger, Peter

    2014-11-25

    We study the equilibrium liquid structure and dynamics of dilute and concentrated bovine eye lens α-crystallin solutions, using small-angle X-ray scattering, static and dynamic light scattering, viscometry, molecular dynamics simulations, and mode-coupling theory. We find that a polydisperse Percus-Yevick hard-sphere liquid-structure model accurately reproduces both static light scattering data and small-angle X-ray scattering liquid structure data from α-crystallin solutions over an extended range of protein concentrations up to 290 mg/mL or 49% vol fraction and up to ca. 330 mg/mL for static light scattering. The measured dynamic light scattering and viscosity properties are also consistent with those of hard-sphere colloids and show power laws characteristic of an approach toward a glass transition at α-crystallin volume fractions near 58%. Dynamic light scattering at a volume fraction beyond the glass transition indicates formation of an arrested state. We further perform event-driven molecular dynamics simulations of polydisperse hard-sphere systems and use mode-coupling theory to compare the measured dynamic power laws with those of hard-sphere models. The static and dynamic data, simulations, and analysis show that aqueous eye lens α-crystallin solutions exhibit a glass transition at high concentrations that is similar to those found in hard-sphere colloidal systems. The α-crystallin glass transition could have implications for the molecular basis of presbyopia and the kinetics of molecular change during cataractogenesis.

  7. Determination of absorbed dose to the lens of eye from external sources

    International Nuclear Information System (INIS)

    Chen Lishu

    1993-01-01

    The methods of determining absorbed dose distributions in human eyeball by means of the experiments and available theories have been reported. A water phantom was built up. The distributions of beta dose were measured by an extrapolation ionization chamber at some depths corresponding to components of human eyeball such as cornea, sclera, anterior chamber and the lens of eye. The ratios among superficial absorbed dose (at 0.07 mm) and average absorbed doses at the depths 1,2,3 mm are obtained. They can be used for confining the deterministic effects of superficial tissues and organs such as the lens of eye for weakly penetrating radiations

  8. Pseudophakic hyperopia in nanophthalmic eyes managed by a posterior chamber implantable collamer lens

    Directory of Open Access Journals (Sweden)

    Kothari Kulin

    2011-01-01

    Full Text Available We report a case of a bilateral posterior chamber implantable collamer lens (ICL implantation post-clear lens extraction, to reduce the residual hyperopia, in a patient with nanophthalmic eyes. A 30-year-old female patient, keen to reduce her dependency on glasses and contact lenses, came to our refractive surgery department. Her refractive error was +12.0 and +12.5 diopters in the right and left eye, respectively, with steep corneas on keratometry and a shallow anterior chamber depth. She underwent clear lens extraction with implantation of +35.0 D and +40.0 D IOL in the right eye and left eye, respectively. Her post-operative best-corrected visual acuity was 20/30 with +8.5 D in the right eye and +6 D in the left. She underwent bilateral ICL implantation. Postoperatively after 6 months, her unaided visual acuity was 20/30 in both eyes. In conclusion, ICL implantation can be considered to correct residual hypermetropic ametropia in pseudophakic eyes when other options have limitations.

  9. The influence of crystalline lens accommodation on post-saccadic oscillations in pupil-based eye trackers

    NARCIS (Netherlands)

    Nyström, Marcus; Andersson, Richard; Magnusson, Måns; Pansell, Tony; Hooge, Ignace; Hooge, Ignace

    2015-01-01

    It is well known that the crystalline lens (henceforth lens) can oscillate (or 'wobble') relative to the eyeball at the end of saccades. Recent research has proposed that such wobbling of the lens is a source of post-saccadic oscillations (PSOs) seen in data recorded by eye trackers that estimate

  10. Protein deposition on a lathe-cut silicone hydrogel contact lens material.

    Science.gov (United States)

    Subbaraman, Lakshman N; Woods, Jill; Teichroeb, Jonathan H; Jones, Lyndon

    2009-03-01

    To determine the quantity of total protein, total lysozyme, and the conformational state of lysozyme deposited on a novel, lathe-cut silicone hydrogel (SiHy) contact lens material (sifilcon A) after 3 months of wear. Twenty-four subjects completed a prospective, bilateral, daily-wear, 9-month clinical evaluation in which the subjects were fitted with a novel, custom-made, lathe-cut SiHy lens material. The lenses were worn for three consecutive 3-month periods, with lenses being replaced after each period of wear. After 3 months of wear, the lenses from the left eye were collected and assessed for protein analysis. The total protein deposited on the lenses was determined by a modified Bradford assay, total lysozyme using Western blotting and the lysozyme activity was determined using a modified micrococcal assay. The total protein recovered from the custom-made lenses was 5.3 +/- 2.3 microg/lens and the total lysozyme was 2.4 +/- 1.2 microg/lens. The denatured lysozyme found on the lenses was 1.9 +/- 1.0 microg/lens and the percentage of lysozyme denatured was 80 +/- 10%. Even after 3 months of wear, the quantity of protein and the conformational state of lysozyme deposited on these novel lens materials was very similar to that found on similar surface-coated SiHy lenses after 2 to 4 weeks of wear. These results indicate that extended use of the sifilcon A material is not deleterious in terms of the quantity and quality of protein deposited on the lens.

  11. A medieval fallacy: the crystalline lens in the center of the eye.

    Science.gov (United States)

    Leffler, Christopher T; Hadi, Tamer M; Udupa, Akrithi; Schwartz, Stephen G; Schwartz, Daniel

    2016-01-01

    To determine whether, as most modern historians have written, ancient Greco-Roman authors believed the crystalline lens is positioned in the center of the eye. Historians have written that statements about cataract couching by Celsus, or perhaps Galen of Pergamon, suggested a centrally located lens. Celsus specifically wrote that a couching needle placed intermediate between the corneal limbus and the lateral canthus enters an empty space, presumed to represent the posterior chamber. Ancient ophthalmic literature was analyzed to understand where these authors believed the crystalline lens was positioned. In order to estimate where Celsus proposed entering the eye during couching, we prospectively measured the distance from the temporal corneal limbus to the lateral canthus in 30 healthy adults. Rufus of Ephesus and Galen wrote that the lens is anterior enough to contact the iris. Galen wrote that the lens equator joins other ocular structures at the corneoscleral junction. In 30 subjects, half the distance from the temporal corneal limbus to the lateral canthus was a mean of 4.5 mm (range: 3.3-5.3 mm). Descriptions of couching by Celsus and others are consistent with pars plana entry of the couching needle. Anterior angulation of the needle would permit contact of the needle with the lens. Ancient descriptions of anatomy and couching do not establish the microanatomic relationships of the ciliary region with any modern degree of accuracy. Nonetheless, ancient authors, such as Galen and Rufus, clearly understood that the lens is located anteriorly. There is little reason to believe that Celsus or other ancient authors held a variant understanding of the anatomy of a healthy eye. The notion of the central location of the lens seems to have arisen with Arabic authors in 9th century Mesopotamia, and lasted for over 7 centuries.

  12. Complications and visual outcomes after glued foldable intraocular lens implantation in eyes with inadequate capsules.

    Science.gov (United States)

    Kumar, Dhivya Ashok; Agarwal, Amar; Packiyalakshmi, Sathiya; Jacob, Soosan; Agarwal, Athiya

    2013-08-01

    To evaluate the complications and visual outcomes of glued intrascleral-fixated foldable intraocular lens (IOL) in eyes with deficient capsules. Dr Agarwal's Eye Hospital and Eye Research Centre, Chennai, India. Case series. Data were evaluated from the records of patients with a primary glued foldable IOL for intraoperative capsular loss or subluxated lens or secondary glued foldable IOL for aphakia. Exclusion criteria included preoperative glaucoma, aniridia, macular scar, traumatic subluxation, combined surgeries, incomplete operative medical records, and postoperative follow-up less than 6 months. The intraoperative and postoperative complication rates, reoperation rate, and visual outcomes were analyzed. The study comprised 208 eyes (185 patients). The mean follow-up was 16.7 months ± 10.2 (SD). The intraoperative complications were hyphema (0.4%), haptic breakage (0.4%), and deformed haptics (0.9%). Early complications occurred in 29 eyes (13.9%) and included corneal edema (5.7%), epithelial defect (1.9%), and grade 2 anterior chamber reaction (2.4%). Late complications occurred in 39 eyes (18.7%) and included optic capture (4.3%), IOL decentration (3.3%), haptic extrusion (1.9%), subconjunctival haptic (1.4%), macular edema (1.9%), and pigment dispersion (1.9%). Reoperation was required in 16 eyes (7.7%). Haptic position was altered in eyes with IOL decentration. Corrected distance visual acuity (CDVA) improved or remained unchanged in 84.6% of eyes. The postoperative CDVA was 20/40 or better and 20/60 or better in 38.9% and 48.5% of eyes, respectively. The foldable glued-IOL procedure showed satisfactory visual outcomes without serious complications. Intraocular lens decentration was due to haptic-related problems. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  13. Black diaphragm intraocular lens implantation and penetrating keratoplasty in aphakic eyes with traumatic aniridia

    Directory of Open Access Journals (Sweden)

    Xiao-Guang Dong

    2013-04-01

    Full Text Available AIM: To evaluate the long-term outcome of implantation of black diaphragm intraocular (BDI lens combined with penetrating keratoplasty (PKP for managing aphakic eyes with traumatic aniridia and corneal damage. METHODS: Six aphakic eyes of six patients with traumatic aniridia and corneal damage had BDI lens implantation at Qingdao Eye Hospital, Shandong Eye Institute from June 2008 to November 2011. Medical records of the patients were reviewed. Three patients received PKP and after 12-18months were implanted with BDI lens. The other three patients completed PKP and BDI lens implantation at the same time. The corrected visual acuity, intraocular pressure and number of corneal endothelial cells were monitored. RESULTS: The patients were followed up for an average of 24.3±12.1months (range 14-48 months. All BDI lenses were located well. The best corrected visual acuity got improved in 5 patients (0.1-1.0 and decreased in 1 patient from 0.4 to 0.2. Three patients had normal intraocular pressure (IOP after implantation. Two patients required antiglaucoma medications to control IOP within the normal range and 1 patient implanted Ahmed glaucoma valve to control IOP. The corneal grafts kept transparent in all eyes and the corneal endothelial counting >1 000/mm2, although two patients experienced acute graft rejection and loss more than 30% corneal endothelial cells. CONCLUSION: Implantation of BDI lens combined with PKP is an effective option for managing aphakic eyes with traumatic aniridia and corneal damage. Although the results in our study are encouraging, additional studies of the long-term safety and efficacy are required. A larger study population and longer follow-up may be beneficial.

  14. Provision of dosimeters by official monitoring services for eye lens dose estimation

    International Nuclear Information System (INIS)

    Engelhardt, J.; Martini, E.

    2013-01-01

    Recent epidemiological studies are implying that the radio sensitivity of the eye lens is much higher than supposed in the past. International recommendations and standards demand to lower down the annual limit of the eye lens organ dose to 20 mSv. Since about 10 years German monitoring services offer partial-body dosimeters fixed on the head or on glasses for monitoring the eye lens dose. These dosimeters are optimized to measure the (surface) personal dose equivalent H p (0,07) from 0,5 mSv up to 10 Sv, which clearly overestimate the organ dose of the eye lens. With special features like different calibrations partial-body dosimeters should be applicable for legal dosimetry to avoid the development of special H p (3) dosimeters. Accepting the right way for wearing these dosimeters it is important to get the right results. Practical experiences are shown with measuring results and the difficulties of rounding the exact measuring values to discrete dose steps. Closing this article we point to still missing legal basis and open questions regarding to type testing procedures. (orig.)

  15. A Simple Model of the Accommodating Lens of the Human Eye

    Science.gov (United States)

    Oommen, Vinay; Kanthakumar, Praghalathan

    2014-01-01

    The human eye is often discussed as optically equivalent to a photographic camera. The iris is compared with the shutter, the pupil to the aperture, and the retina to the film, and both have lens systems to focus rays of light. Although many similarities exist, a major difference between the two systems is the mechanism involved in focusing an…

  16. Dose to the lens of the eye when scanning internal auditory meati

    International Nuclear Information System (INIS)

    English, P.T.

    1988-01-01

    With particular reference to the lens of the eye when CT scanning the internal auditory meati (IAMs), the practice of angling the scanner gantry to avoid the orbits completely justifies itself, reducing dosage to 5% of that given by a pre-orbital scan. (author)

  17. Eye evolution: lens and cornea as an upgrade of animal visual system

    Czech Academy of Sciences Publication Activity Database

    Jonášová, Kristýna; Kozmik, Zbyněk

    2008-01-01

    Roč. 19, č. 2 (2008), s. 71-81 ISSN 1084-9521 R&D Projects: GA AV ČR IAA500520604; GA MŠk(CZ) 1M0520 Institutional research plan: CEZ:AV0Z50520514 Keywords : eye * lens * cornea Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.528, year: 2008

  18. The effect of melatonin on eye lens of rats exposed to ultraviolet radiation.

    Science.gov (United States)

    Anwar, M M; Moustafa, M A

    2001-05-01

    We investigated the influence of exogenously administered melatonin on adult rats eye lenses exposed to ultraviolet radiation (UV) A and B ranging from 356-254 nm irradiation at 8 microW/cm(2). Rats exposed to this range of UV for 15 min for one week showed a significant (PUV-radiation significantly (PUV irradiation, may be the main cause of lens opacification. Melatonin injection with radiation significantly reduced (Pradiation, SOD and GSH-Px enzyme activities increased significantly (PUV radiation was as effective as melatonin treatment concurrent with UV irradiation. We conclude that melatonin may protect the eye lens from the damaging effects of UV exposure, and its actions protect lens from oxidative stress, elevating Ca(2+) levels, which are considered as an important causes of cataractogenesis.

  19. Eye-lens bismuth shielding in paediatric head CT: artefact evaluation and reduction

    International Nuclear Information System (INIS)

    Raissaki, Maria; Perisinakis, Kostas; Damilakis, John; Gourtsoyiannis, Nicholas

    2010-01-01

    CT scans of the brain, sinuses and petrous bones performed as the initial imaging test for a variety of indications have the potential to expose the eye-lens, considered among the most radiosensitive human tissues, to a radiation dose. There are several studies in adults discussing the reduction of orbital dose resulting from the use of commercially available bismuth-impregnated latex shields during CT examinations of the head. To evaluate bismuth shielding-induced artefacts and to provide suggestions for optimal eye-lens shielding in paediatric head CT. A bismuth shield was placed over the eyelids of 60 consecutive children undergoing head CT. Images were assessed for the presence and severity of artefacts with regard to eye-shield distance and shield wrinkling. An anthropomorphic paediatric phantom and thermoluminescence dosimeters (TLDs) were used to study the effect of eye lens-to-shield distance on shielding efficiency. Shields were tolerated by 56/60 children. Artefacts were absent in 45% of scans. Artefacts on orbits, not affecting and affecting orbit evaluation were noted in 39% and 14% of scans, respectively. Diagnostically insignificant artefacts on intracranial structures were noted in 1 case (2%) with shield misplacement. Mean eye-lens-to-shield distance was 8.8 mm in scans without artefacts, and 4.3 mm and 2.2 mm in scans with unimportant and diagnostically important artefacts, respectively. Artefacts occurred in 8 out of 9 cases with shield wrinkling. Dose reduction remained unchanged for different shield-to-eye distances. Bismuth shielding-related artefacts occurring in paediatric head CT are frequent, superficial and diagnostically insignificant when brain pathology is assessed. Shields should be placed 1 cm above the eyes when orbital pathology is addressed. Shield wrinkling should be avoided. (orig.)

  20. Dose conversion coefficients for electron exposure of the human eye lens

    International Nuclear Information System (INIS)

    Behrens, R; Dietze, G; Zankl, M

    2009-01-01

    Recent epidemiological studies suggest a rather low dose threshold (below 0.5 Gy) for the induction of a cataract of the eye lens. Some other studies even assume that there is no threshold at all. Therefore, protection measures have to be optimized and current dose limits for the eye lens may be reduced in the future. Two questions arise from this situation: first, which dose quantity is related to the risk of developing a cataract, and second, which personal dose equivalent quantity is appropriate for monitoring this dose quantity. While the dose equivalent quantity H p (0.07) has often been seen as being sufficiently accurate for monitoring the dose to the lens of the eye, this would be questionable in the case when the dose limits were reduced and, thus, it may be necessary to generally use the dose equivalent quantity H p (3) for this purpose. The basis for a decision, however, must be the knowledge of accurate conversion coefficients from fluence to equivalent dose to the lens. This is especially important for low-penetrating radiation, for example, electrons. Formerly published values of conversion coefficients are based on quite simple models of the eye. In this paper, quite a sophisticated model of the eye including the inner structure of the lens was used for the calculations and precise conversion coefficients for electrons with energies between 0.2 MeV and 12 MeV, and for angles of radiation incidence between 0 deg. and 45 deg. are presented. Compared to the values adopted in 1996 by the International Commission on Radiological Protection (ICRP), the new values are up to 1000 times smaller for electron energies below 1 MeV, nearly equal at 1 MeV and above 4 MeV, and by a factor of 1.5 larger at about 1.5 MeV electron energy.

  1. Reliability of eye lens dosimetry in workers of a positron emission tomography radiopharmaceutical production facility

    International Nuclear Information System (INIS)

    Silva, Teógenes A. da; Guimarães, Margarete C.; Meireles, Leonardo S.; Teles, Luciana L.D.; Lacerda, Marco Aurélio S.

    2016-01-01

    A new regulatory statement was issued concerning the eye lens radiation protection of persons in planned exposures. A debate was raised on the adequacy of the dosimetric quantity and on its method of measurement. The aim of this work was to establish the individual monitoring procedure with the EYE-D™ holder and a MCP-N LiF:Mg,Cu,P thermoluminescent chip detector for measuring the personal dose equivalent H_p(3) in workers of a Positron Emission Tomography Radiopharmaceutical Production Facility. - Highlights: • New regulatory statement was issued concerning eye lens radiation protection. • The calibration procedure of dosimeters for measuring H_p(3) was studied on a slab and cylindrical phantoms. • H_p(3) measurements in workers in a radiopharmaceutical production facility were done.

  2. Measurements of eye lens doses in interventional cardiology using OSL and electronic dosemeters

    International Nuclear Information System (INIS)

    Sanchez, R.M.; Vano, E.; Fernandez, J.M.; Ginjaume, M.; Duch, M.A.

    2014-01-01

    The purpose of this paper is to test the appropriateness of OSL and electronic dosemeters to estimate eye lens doses at interventional cardiology environment. Using TLD as reference detectors, personal dose equivalent was measured in phantoms and during clinical procedures. For phantom measurements, OSL dose values resulted in an average difference of 215 % vs. TLD. Tests carried out with other electronic dosemeters revealed differences up to ±20 % versus TLD. With dosemeters positioned outside the goggles and when TLD doses were >20 μSv, the average difference OSL vs. TLD was 29 %. Eye lens doses of almost 700 μSv per procedure were measured in two cases out of a sample of 33 measurements in individual clinical procedures, thus showing the risk of high exposure to the lenses of the eye when protection rules are not followed. The differences found between OSL and TLD are acceptable for the purpose and range of doses measured in the survey (authors)

  3. A medieval fallacy: the crystalline lens in the center of the eye

    Directory of Open Access Journals (Sweden)

    Leffler CT

    2016-04-01

    Full Text Available Christopher T Leffler,1 Tamer M Hadi,2 Akrithi Udupa,1 Stephen G Schwartz,3 Daniel Schwartz1 1Department of Ophthalmology, Virginia Commonwealth University, Richmond, VA, 2Graduate School of Medicine, University of Tennessee Medical Center, Knoxville, TN, 3Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA Objective: To determine whether, as most modern historians have written, ancient Greco-Roman authors believed the crystalline lens is positioned in the center of the eye. Background: Historians have written that statements about cataract couching by Celsus, or perhaps Galen of Pergamon, suggested a centrally located lens. Celsus specifically wrote that a couching needle placed intermediate between the corneal limbus and the lateral canthus enters an empty space, presumed to represent the posterior chamber. Methods: Ancient ophthalmic literature was analyzed to understand where these authors believed the crystalline lens was positioned. In order to estimate where Celsus proposed entering the eye during couching, we prospectively measured the distance from the temporal corneal limbus to the lateral canthus in 30 healthy adults. Results: Rufus of Ephesus and Galen wrote that the lens is anterior enough to contact the iris. Galen wrote that the lens equator joins other ocular structures at the corneoscleral junction. In 30 subjects, half the distance from the temporal corneal limbus to the lateral canthus was a mean of 4.5 mm (range: 3.3–5.3 mm. Descriptions of couching by Celsus and others are consistent with pars plana entry of the couching needle. Anterior angulation of the needle would permit contact of the needle with the lens. Conclusion: Ancient descriptions of anatomy and couching do not establish the microanatomic relationships of the ciliary region with any modern degree of accuracy. Nonetheless, ancient authors, such as Galen and Rufus, clearly understood that the lens is located anteriorly

  4. Protein synthesis in x-irradiated rabbit lens

    International Nuclear Information System (INIS)

    Garadi, R.; Foltyn, A.R.; Giblin, F.J.; Reddy, V.N.

    1984-01-01

    The present study deals with the incorporation of 35 S methionine into lens crystallins as a function of time after x-irradiation. Crystallin synthesis is first affected approximately 4 weeks following x-irradiation. This coincides with the time period at which the ratio of the two cations in the lens is affected, as shown in earlier studies. A greater decrease in 35 S-methionine incorporation into crystallins is observed between 5-7 weeks following x-irradiation in good agreement with a cation imbalance at these time intervals. These studies also revealed for the first time that the change in cation distribution can affect not only crystallin synthesis, but also the synthesis of certain polypeptides of lens membranes. No alteration in protein synthesis could be detected in lens epithelium even after 7 weeks following irradiation. In addition to the effect of Na+ and K+ levels on protein synthesis, an impaired transport of amino acids into the x-rayed lens was also found to be a factor in the observed reduction in synthesis of the crystallin, cytoskeletal and membrane proteins of the fiber cells. It is concluded that Na+/K+ ratio as well as the availability of amino acids in the lens are important factors in protein synthesis of x-ray cataracts

  5. Dosimetric studies of the eye lens using a new dosemeter – Surveys in interventional radiology departments

    International Nuclear Information System (INIS)

    Pirchio, R.; Sánchez, H.; Domazet, W.

    2014-01-01

    During interventional radiology (IR) and cardiology (IC) procedures, medical staff can receive high doses to their eye lenses. The Retrospective Evaluation of Lens Injuries and Dose study organized in Argentina in 2010 found incipient opacity in 50% of IC physicians and 41% of IC technicians/nurses. These results, added to the recommendations of the International Commission on Radiological Protection, which lowered their former occupational equivalent dose limit for the lens, led us to assess the eye lens dose, Hp(3), during interventional procedures. To this end, a new dosemeter was designed and calibrated at the National Atomic Energy Commission of Argentina to evaluate Hp(3). Personal dose equivalent (Hp(10)), and Hp(3) were assessed for 3 months in two IC and IR departments. An Alderson phantom was used to simulate monthly exposures of five occupational staff members. Hp(3) and Hp(10) were obtained monthly for 14 occupational staff members exposed to 121 IR and IC procedures. We concluded that the annual effective dose and Hp(3) were lower than 0.3 and 10 mSv, respectively and the average cumulative Hp(3) for working life was lower than 400 and 200 mSv for physicians and technicians/scrub nurse, respectively. An occupational annual dose constraint of 0.3 mSv was calculated. - Highlights: • An eye lens dosimeters was designed at the Personal Dosimetry Laboratory of CNEA. • A successful dosimetric survey in two interventional departments was done. • The annual effective dose and the annual eye lens dose are lower than the ICRP dose thresholds. • In order to reduce doses actions should be promoted to maximize radiation protection

  6. Interim report of the JHPS expert committee on radiation protection of the lens of the eye (1). Overview of the lens, radiogenic cataract, and equivalent dose limit for the lens newly recommended by the ICRP

    International Nuclear Information System (INIS)

    Akahane, Keiichi; Tatsuzaki, Hideo; Iimoto, Takeshi; Ichiji, Takeshi; Hamada, Nobuyuki; Fujimichi, Yuki; Iwai, Satoshi; Ohguchi, Hiroyuki; Ohno, Kazuko; Yamauchi, Chiyo; Tsujimura, Norio; Hotta, Yutaka; Yamasaki, Tadashi; Yokoyama, Sumi

    2014-01-01

    In April 2011, the International Commission on Radiological Protection (ICRP) issued the statement on tissue reactions. This stimulated interest in many countries. The Expert Committee on Radiation Protection of the Lens of the Eye was established in the Japanese Health Physics Society, and in April 2013, started discussion about the international developments and recent studies related to the dosimetry of the lens of the eye. This committee now publishes the interim report consisting of parts I-VI. Of these, this Part I overviews the structure of the eye and lens, cataract types and the scientific evidence of its new dose threshold and equivalent dose limit newly recommended by the ICRP. (author)

  7. Femtosecond laser-induced cavitations in the lens of the human eye

    DEFF Research Database (Denmark)

    Kessel, Line; Nymand, Jose; Harbst, Michael

    2007-01-01

    attempted to define the cavitation threshold in the human lens in vitro using multiphoton effects base d on radiation from a femtosecond 800 nm Ti:Sapphire laser. Cavitations were observed from pulse energy densities exceeding 16 mJ/cm2, but only after several minutes of exposure and not as a result...... laser effects in the len s that have a potential for therapeutic application and treatment of eye dis ease though further studies are needed to shed light on the nature of the formation of delayed cavitations....

  8. Contact Lens-Induced Discomfort and Protein Changes in Tears.

    Science.gov (United States)

    Masoudi, Simin; Stapleton, Fiona Jane; Willcox, Mark Duncan Perry

    2016-08-01

    Ocular discomfort is among the main causes of contact lens wear discontinuation. This study investigated the association between subjective ocular comfort ratings and diurnal changes in tear protein concentrations with and without contact lens wear. The study was a prospective, open-label, single-group two-staged investigation. Basal tears were collected from 30 experienced contact lens wearers twice a day (morning and evening) using a noninvasive method without lens wear (stage 1) and during wear of Etafilcon A contact lenses (stage 2) for 7 to 10 days. Subjects rated their ocular comfort on a scale of 1 to 100 (with 100 as extremely comfortable) at each time of tear collection. Tears were analyzed using liquid quadrupole mass spectrometry in conjunction with selected reaction monitoring (SRM) method. End-of-day comfort was reduced when wearing lenses (87.8 ± 14.3 AM vs. 79.2 ± 16.6 PM) compared to no lens wear (88.3 ± 12.6 AM vs. 84.7 ± 13.3 PM) (AM vs. PM, p tears (p < 0.05, r = -0.29). Only the absolute concentration of prolactin-induced protein correlated with subjective comfort ratings. Taking into consideration that prolactin-induced protein can be associated with disruption in water transport in lacrimal glands, our findings may indicate that changes to aqueous secretion are associated with contact lens discomfort.

  9. Effect of interface reflection in pseudophakic eyes with an additional refractive intraocular lens.

    Science.gov (United States)

    Schrecker, Jens; Zoric, Katja; Meßner, Arthur; Eppig, Timo

    2012-09-01

    To compare the surface reflections in a pseudophakic model eye with and without a monofocal additional refractive intraocular lens (add-on IOL). Department of Ophthalmology, Rudolf-Virchow-Klinikum Glauchau, Glauchau, and Experimental Ophthalmology, Saarland University, Homburg, Germany. Experimental study. The Liou and Brennan model eye was used to determine the retinal surface reflections in a pseudophakic model eye with and without an add-on IOL. The crystalline lens of the model eye was replaced by (1) a standard posterior chamber IOL (PC IOL) with a refractive power of 22.0 diopters (D) and (2) a PC IOL and an add-on IOL with refractive powers of 19.0 D and 2.5 D, respectively. To theoretically estimate the impact of the reflected images to visual impression, the signal-to-noise ratio (SNR) was calculated under 2 conditions: without and with straylight and double reflection effects. Compared with the pseudophakic model eye without an add-on IOL, the pseudophakic model eye with an add-on IOL showed no relevant differences in the SNR under both conditions. Findings indicate that implantation of monofocal add-on IOLs will not induce relevant additional disturbing glare compared with conventional pseudophakia. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  10. Real-time eye lens dose monitoring during cerebral angiography procedures

    International Nuclear Information System (INIS)

    Safari, M.J.; Wong, J.H.D.; Kadir, K.A.A.; Ng, K.H.; Thorpe, N.K.; Cutajar, D.L.; Petasecca, M.; Lerch, M.L.F.; Rosenfeld, A.B.

    2016-01-01

    To develop a real-time dose-monitoring system to measure the patient's eye lens dose during neuro-interventional procedures. Radiation dose received at left outer canthus (LOC) and left eyelid (LE) were measured using Metal-Oxide-Semiconductor Field-Effect Transistor dosimeters on 35 patients who underwent diagnostic or cerebral embolization procedures. The radiation dose received at the LOC region was significantly higher than the dose received by the LE. The maximum eye lens dose of 1492 mGy was measured at LOC region for an AVM case, followed by 907 mGy for an aneurysm case and 665 mGy for a diagnostic angiography procedure. Strong correlations (shown as R 2 ) were observed between kerma-area-product and measured eye doses (LOC: 0.78, LE: 0.68). Lateral and frontal air-kerma showed strong correlations with measured dose at LOC (AK L : 0.93, AK F : 0.78) and a weak correlation with measured dose at LE. A moderate correlation was observed between fluoroscopic time and dose measured at LE and LOC regions. The MOSkin dose-monitoring system represents a new tool enabling real-time monitoring of eye lens dose during neuro-interventional procedures. This system can provide interventionalists with information needed to adjust the clinical procedure to control the patient's dose. (orig.)

  11. Real-time eye lens dose monitoring during cerebral angiography procedures

    Energy Technology Data Exchange (ETDEWEB)

    Safari, M.J.; Wong, J.H.D.; Kadir, K.A.A.; Ng, K.H. [University of Malaya, Department of Biomedical Imaging, Faculty of Medicine, Kuala Lumpur (Malaysia); University of Malaya, University of Malaya Research Imaging Centre (UMRIC), Faculty of Medicine, Kuala Lumpur (Malaysia); Thorpe, N.K.; Cutajar, D.L.; Petasecca, M.; Lerch, M.L.F.; Rosenfeld, A.B. [University of Wollongong, Centre for Medical Radiation Physics (CMRP), Wollongong, NSW (Australia)

    2016-01-15

    To develop a real-time dose-monitoring system to measure the patient's eye lens dose during neuro-interventional procedures. Radiation dose received at left outer canthus (LOC) and left eyelid (LE) were measured using Metal-Oxide-Semiconductor Field-Effect Transistor dosimeters on 35 patients who underwent diagnostic or cerebral embolization procedures. The radiation dose received at the LOC region was significantly higher than the dose received by the LE. The maximum eye lens dose of 1492 mGy was measured at LOC region for an AVM case, followed by 907 mGy for an aneurysm case and 665 mGy for a diagnostic angiography procedure. Strong correlations (shown as R{sup 2}) were observed between kerma-area-product and measured eye doses (LOC: 0.78, LE: 0.68). Lateral and frontal air-kerma showed strong correlations with measured dose at LOC (AK{sub L}: 0.93, AK{sub F}: 0.78) and a weak correlation with measured dose at LE. A moderate correlation was observed between fluoroscopic time and dose measured at LE and LOC regions. The MOSkin dose-monitoring system represents a new tool enabling real-time monitoring of eye lens dose during neuro-interventional procedures. This system can provide interventionalists with information needed to adjust the clinical procedure to control the patient's dose. (orig.)

  12. Corneal confocal microscopy and dry eye findings in contact lens discomfort patients.

    Science.gov (United States)

    Dogan, Aysun Sanal; Gurdal, Canan; Arslan, Nese

    2018-02-01

    To evaluate the corneal confocal microscopy and dry eye findings in patients with contact lens discomfort. The study included 3 groups of participants: Contact lens wearers using silicone hydrogel soft contact lenses who are symptomatic (CLD, n=15) or asymptomatic (ACL, n=11) and non-wearers as controls (n=14). Duration of contact lens wear, Ocular Surface Disease Index (OSDI) questionnaire responses, fluorescein tear break-uptime (FBUT), and corneal confocal microscopy findings were recorded. Mean age was 25.7±8.2 years and male/female ratio was 7/33. Demographic findings were similar regarding the groups. CLD patients had a longer lens use history than ACL (median 5 vs 2 years, pCLD group than ACL or controls (pCLD group, compared to controls and ACL (pCLD group compared to controls but similar to ACL (pCLD group than the ACL (p=0.014). Patients with CLD had been wearing contact lenses for longer than those without symptoms. OSDI and FBUT scores were worse in CLD patients. In contact lens discomfort patients, there were increased dendritiform cells, indicating intensified inflammatory status of the cornea. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  13. A method to reduce patient's eye lens dose in neuro-interventional radiology procedures

    International Nuclear Information System (INIS)

    Safari, M.J.; Wong, J.H.D.; Kadir, K.A.A.; Sani, F.M.; Ng, K.H.

    2016-01-01

    Complex and prolonged neuro-interventional radiology procedures using the biplane angiography system increase the patient's risk of radiation-induced cataract. Physical collimation is the most effective way of reducing the radiation dose to the patient's eye lens, but in instances where collimation is not possible, an attenuator may be useful in protecting the eyes. In this study, an eye lens protector was designed and fabricated to reduce the radiation dose to the patients’ eye lens during neuro-interventional procedures. The eye protector was characterised before being tested on its effectiveness in a simulated aneurysm procedure on an anthropomorphic phantom. Effects on the automatic dose rate control (ADRC) and image quality are also evaluated. The eye protector reduced the radiation dose by up to 62.1% at the eye lens. The eye protector is faintly visible in the fluoroscopy images and increased the tube current by a maximum of 3.7%. It is completely invisible in the acquisition mode and does not interfere with the clinical procedure. The eye protector placed within the radiation field of view was able to reduce the radiation dose to the eye lens by direct radiation beam of the lateral x-ray tube with minimal effect on the ADRC system. - Highlights: • The eye protector can considerably reduce the patient's eye lens dose during neuro-interventional procedures. • This protector does not significantly perturb the fluoroscopy image and was completely invisible on the acquisition image due to image subtraction. • The eye protector does not significantly change the exposure parameters (kV and mAs).

  14. Morphometry and Lens of Eyes Bilih Fish (mystacoleucus padangensis, Bleeker) from Lake Toba, North Sumatra and Lake Singkarak, West Sumatra

    Science.gov (United States)

    Razak, A.

    2018-04-01

    This research has been carried out 2015. Bilih fish today need conservation and attention for sustainability. Habitat this fish is treated by human activities in Lake Singkarak, West Sumatera and Lake Toba in North Sumatera. The objectives of the research are describes morphometry of the body and relation with lens of eyes. The methods of the reasearch for measure all parts of surface body fish according www.fishbase.org. For measure and chemical composition of lens of eyes Bilih Fish (M. padangensis) are according Razak (2005). T he result of the research are indicated the size of morphology body Bilih Fish from Lake Toba and from Lake Singkarak is diffrent. Furthermore, diameter of lens is trend linier follow the growth of the body Bilih Fish from Lake Singkarak and Lake Toba. The chemical composition of lens of eyes Bilih Fish from Lake Singkarak contains Sulfur until 73.77% per 100 ppm, another substances like Calcium, Silicone, Magnesium, Phosporus 4.09%-4.83% per 100 ppm. The chemical composition of lens of eyes Bilih Fish from Lake Toba contains Sulfur only 50.08% per 100 ppm, another substances like Kalium, Calcium, Silicone, Magnesium, Phosporus 1.09%-10.43% per 100 ppm. Kalium substance only found in lens of eyes Bilih Fish from Lake Toba. As conclusion, morphometry body Bilih Fish from Lake Toba is bigger better than Bilih Fish from Lake Singkarak and chemical composition lens of eyes Bilih Fish from Lake Toba is influenced by environmental waters factors.

  15. Principles for the design and calibration of radiation protection dosemeters for operational and protection quantities for eye lens dosimetry

    International Nuclear Information System (INIS)

    Bordy, J. M.; Gualdrini, G.; Daures, J.; Mariotti, F.

    2011-01-01

    The work package two of the ORAMED project-Collaborative Project (2008-2011) supported by the European Commission within its seventh Framework Programme-is devoted to the study of the eye lens dosimetry. A first approach is to implement the use of H p (3) by providing new sets of conversion coefficients and well suited calibration and type test procedures. This approach is presented in other papers in the proceedings of this conference. Taking into account that the eye lens is an organ close to the surface of the body, another approach would be to directly estimate the absorbed dose to the eye lens, D lens,est through a special calibration procedure although this quantity is not directly measurable. This paper is a methodological paper that tries to identify the critical aspects of a dosimetry in terms of D lens . (authors)

  16. Radiation Dose to the Lens of the Eye from Computed Tomography Scans of the Head

    Science.gov (United States)

    Januzis, Natalie Ann

    While it is well known that exposure to radiation can result in cataract formation, questions still remain about the presence of a dose threshold in radiation cataractogenesis. Since the exposure history from diagnostic CT exams is well documented in a patient's medical record, the population of patients chronically exposed to radiation from head CT exams may be an interesting area to explore for further research in this area. However, there are some challenges in estimating lens dose from head CT exams. An accurate lens dosimetry model would have to account for differences in imaging protocols, differences in head size, and the use of any dose reduction methods. The overall objective of this dissertation was to develop a comprehensive method to estimate radiation dose to the lens of the eye for patients receiving CT scans of the head. This research is comprised of a physics component, in which a lens dosimetry model was derived for head CT, and a clinical component, which involved the application of that dosimetry model to patient data. The physics component includes experiments related to the physical measurement of the radiation dose to the lens by various types of dosimeters placed within anthropomorphic phantoms. These dosimeters include high-sensitivity MOSFETs, TLDs, and radiochromic film. The six anthropomorphic phantoms used in these experiments range in age from newborn to adult. First, the lens dose from five clinically relevant head CT protocols was measured in the anthropomorphic phantoms with MOSFET dosimeters on two state-of-the-art CT scanners. The volume CT dose index (CTDIvol), which is a standard CT output index, was compared to the measured lens doses. Phantom age-specific CTDIvol-to-lens dose conversion factors were derived using linear regression analysis. Since head size can vary among individuals of the same age, a method was derived to estimate the CTDIvol-to-lens dose conversion factor using the effective head diameter. These conversion

  17. Exposition of the operator's eye lens and efficacy of radiation shielding in fluoroscopically guided interventions

    International Nuclear Information System (INIS)

    Galster, M.; Adamus, R.; Guhl, C.; Uder, M.

    2013-01-01

    Purpose: Efficacy of radiation protection tools for the eye lens dose of the radiologist in fluoroscopic interventions. Materials and Methods: A patient phantom was exposed using a fluoroscopic system. Dose measurements were made at the eye location of the radiologist using an ionization chamber. The setting followed typical fluoroscopic interventions. The reduction of scattered radiation by the equipment-mounted shielding (undercouch drapes and overcouch top) was evaluated. The ceiling-suspended lead acrylic glass screen was tested in scattered radiation generated by a slab phantom. The protective properties of different lead glass goggles and lead acrylic visors were evaluated by thermoluminescence measurements on a head phantom in the primary beam. Results: The exposition of the lens of about 110 to 550 μSv during radiologic interventions is only slightly reduced by the undercouch drapes. Applying the top in addition to the drapes reduces the lens dose by a factor of 2 for PA projections. In 25 LAO the dose is reduced by a factor between 1.2 and 5. The highest doses were measured for AP angulations furthermore the efficacy of the equipment-mounted shielding is minimal. The ceiling-suspended lead screen reduced scatter by a factor of about 30. The lead glass goggles and visors reduced the lens dose up to a factor of 8 to 10. Depending on the specific design, the tested models are less effective especially for radiation from lateral with cranial angulation of the beam. Occasionally the visors even caused an increase of dose. Conclusion: The exposition of the eye lens can be kept below the new occupational limit recommended by the ICRP if the radiation shielding equipment is used consistently. (orig.)

  18. [Exposition of the operator's eye lens and efficacy of radiation shielding in fluoroscopically guided interventions].

    Science.gov (United States)

    Galster, M; Guhl, C; Uder, M; Adamus, R

    2013-05-01

    Efficacy of radiation protection tools for the eye lens dose of the radiologist in fluoroscopic interventions. A patient phantom was exposed using a fluoroscopic system. Dose measurements were made at the eye location of the radiologist using an ionization chamber. The setting followed typical fluoroscopic interventions. The reduction of scattered radiation by the equipment-mounted shielding (undercouch drapes and overcouch top) was evaluated. The ceiling-suspended lead acrylic glass screen was tested in scattered radiation generated by a slab phantom. The protective properties of different lead glass goggles and lead acrylic visors were evaluated by thermoluminescence measurements on a head phantom in the primary beam. The exposition of the lens of about 110 to 550 μSv during radiologic interventions is only slightly reduced by the undercouch drapes. Applying the top in addition to the drapes reduces the lens dose by a factor of 2 for PA projections. In 25°LAO the dose is reduced by a factor between 1.2 and 5. The highest doses were measured for AP angulations furthermore the efficacy of the equipment-mounted shielding is minimal. The ceiling-suspended lead screen reduced scatter by a factor of about 30. The lead glass goggles and visors reduced the lens dose up to a factor of 8 to 10. Depending on the specific design, the tested models are less effective especially for radiation from lateral with cranial angulation of the beam. Occasionally the visors even caused an increase of dose. The exposition of the eye lens can be kept below the new occupational limit recommended by the ICRP if the radiation shielding equipment is used consistently. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Lens of the eye: regulatory limits, measurement, dosimetry and medical control. Technical sheets of the SFRP

    International Nuclear Information System (INIS)

    Bordy, J.M.

    2016-01-01

    As the lens of the eye are a radio-sensitive tissue which can be affected by ionizing radiations, and as epidemiological studies lead to the proposition of a revision of their exposure limit, this sheet first recalls regulatory limits and quantities to be measured. It proposes an overview of industrial and medical situations associated with an exposure risk for lens of the eye. It presents the conditions for bearing a specific individual dosimeter, and the design of dosimeters aimed at a direct measurement. It discusses the characteristics and performance of individual protection equipment, and the criterion for the choice between a direct measurement and an indirect assessment of a characteristic value of exposure for photons and for electrons. It addresses the issues of classification and monitoring for a professional medical follow-up: description of the pathological risk, elements for a medical follow-up (examinations), classification and dose monitoring

  20. First results of an eye lens dosimetry survey in an interventional cardiology department

    International Nuclear Information System (INIS)

    Ferrari, P; Mariotti, F; Campani, L; Castelluccio, D M; Pierotti, L; Pettinato, C; Golfieri, R; Marzocchi, A; De Palma, A

    2015-01-01

    The eye lens annual dose limit for exposed personnel to ionizing radiation has recently been revised by the ICRP—International Commission on Radiological Protection and the proposed new limit has been accepted by European legislation through the Council Directive 2013/59/EURATOM 2013.Among medical exposed personnel, the staff performing interventional cardiology are usually affected by relevant doses. For this reason a survey, employing dosemeters characterized in terms of H p (3), was performed in order to get the order of magnitude of the doses received by the eye lens, at least as a first guess.The survey showed that the annual dose limit can easily be reached if a proper radiation protection approach is not implemented. (practical matter)

  1. Lens oscillations in the human eye. Implications for post-saccadic suppression of vision.

    Directory of Open Access Journals (Sweden)

    Juan Tabernero

    Full Text Available The eye changes gaze continuously from one visual stimulus to another. Using a high speed camera to record eye and lens movements we demonstrate how the crystalline lens sustains an inertial oscillatory decay movement immediately after every change of gaze. This behavior fit precisely with the movement of a classical damped harmonic oscillator. The time course of the oscillations range from 50 to 60 msec with an oscillation frequency of around 20 Hz. That has dramatic implications on the image quality at the retina on the very short times (∼50 msec that follow the movement. However, it is well known that our vision is nearly suppressed on those periods (post-saccadic suppression. Both phenomenon follow similar time courses and therefore might be synchronized to avoid the visual impairment.

  2. On- and off-eye spherical aberration of soft contact lenses and consequent changes of effective lens power.

    Science.gov (United States)

    Dietze, Holger H; Cox, Michael J

    2003-02-01

    Soft contact lenses produce a significant level of spherical aberration affecting their power on-eye. A simple model assuming that a thin soft contact lens aligns to the cornea predicts that these effects are similar on-eye and off-eye. The wavefront aberration for 17 eyes and 33 soft contact lenses on-eye was measured with a Shack-Hartmann wavefront sensor. The Zernike coefficients describing the on-eye spherical aberration of the soft contact lens were compared with off-eye ray-tracing results. Paraxial and effective lens power changes were determined. The model predicts the on-eye spherical aberration of soft contact lenses closely. The resulting power change for a +/- 7.00 D spherical soft contact lens is +/- 0.5 D for a 6-mm pupil diameter and +/- 0.1 D for a 3-mm pupil diameter. Power change is negligible for soft contact lenses corrected for off-eye spherical aberration. For thin soft contact lenses, the level of spherical aberration and the consequent power change is similar on-eye and off-eye. Soft contact lenses corrected for spherical aberration in air will be expected to be aberration-free on-eye and produce only negligibly small power changes. For soft contact lenses without aberration correction, for higher levels of ametropia and large pupils, the soft contact lens power should be determined with trial lenses with their power and p value similar to the prescribed lens. The benefit of soft contact lenses corrected for spherical aberration depends on the level of ocular spherical aberration.

  3. Assessment of eye lens doses in interventional radiology: a simulation in laboratory conditions

    International Nuclear Information System (INIS)

    Cemusova, Z.; Ekendahl, D.; Judas, L.

    2016-01-01

    As workers in interventional radiology belong to one of the most occupationally exposed groups, methods for sufficiently accurate quantification of their external exposure are sought. The objective of the authors' experiment was to investigate the relations between eye lens dose and H p (10), H p (3) or H p (0.07) values measured with a conventional whole-body personal thermoluminescence dosemeter (TLD). Conditions of occupational exposure during common interventional procedures were simulated in laboratory. An anthropomorphic phantom represented a physician. The TLDs were fixed to the phantom in different locations that are common for purposes of personal dosimetry. In order to monitor the dose at the eye lens level during the exposures, a special thermoluminescence eye dosemeter was fixed to the phantom's temple. Correlations between doses measured with the whole-body and the eye dosemeters were found. There are indications that personnel in interventional radiology do not need to be unconditionally equipped with additional eye dosemeters, especially if an appropriate whole-body dosimetry system has been already put into practice. (authors)

  4. Design of retinal-projection-based near-eye display with contact lens.

    Science.gov (United States)

    Wu, Yuhang; Chen, Chao Ping; Mi, Lantian; Zhang, Wenbo; Zhao, Jingxin; Lu, Yifan; Guo, Weiqian; Yu, Bing; Li, Yang; Maitlo, Nizamuddin

    2018-04-30

    We propose a design of a retinal-projection-based near-eye display for achieving ultra-large field of view, vision correction, and occlusion. Our solution is highlighted by a contact lens combo, a transparent organic light-emitting diode panel, and a twisted nematic liquid crystal panel. Its design rules are set forth in detail, followed by the results and discussion regarding the field of view, angular resolution, modulation transfer function, contrast ratio, distortion, and simulated imaging.

  5. Exposure of the lens of the eye in nuclear medicine; Strahlenexposition der Augenlinse in der Nuklearmedizin

    Energy Technology Data Exchange (ETDEWEB)

    Szermerski, B.; Bruchmann, I.; Geworski, L. [Medizinische Hochschule Hannover (Germany). Stabsstelle Strahlenschutz und Abt. Medizinische Physik

    2015-07-01

    The dose threshold for the lens of the eye for occupationally radiation-exposed personnel will be reduced from 150 mSv to 20 mSv per year. Publications addressing the expected eye lens doses of personnel in nuclear medicine are only barely known. In this work, dose rate constants for the quantity H{sub p}(3) were determined and corresponding dose estimations were calculated. Therefore dosimeters measuring H{sub p}(3) were exposed at the surface of an Alderson head phantom. The exposure of the dosimeters with frequently used radionuclides (F-18, Ga-68, Y-90, Tc-99m, In-111, I-123, I-131 and Ra-223+) was performed under varying source-dosimeter distances from 20 cm to 50 cm. The dose rate constants were determined to be 0.021 mSv.m{sup 2}/(GBq.h) for Tc-99m (10 ml syringe) and 2.161 mSv.m{sup 2}/(GBq.h) for Y-90-spheres (5 ml syringe). The other results take values between these ranges. Using the determined dose rate constants, prospective doses to the eye lens could be calculated.

  6. Recommendations to reduce extremity and eye lens doses in interventional radiology and cardiology

    International Nuclear Information System (INIS)

    Carinou, E.; Brodecki, M.; Domienik, J.; Donadille, L.; Koukorava, C.; Krim, S.; Nikodemová, D.; Ruiz-Lopez, N.; Sans-Merce, M.; Struelens, L.; Vanhavere, F.

    2011-01-01

    The main aim of the Work Package 1 (WP1) of the ORAMED project, Collaborative Project (2008–2011), supported by the European Commission within its 7th Framework Programme, was to obtain a set of standardized data on extremity and eye lens doses for staff in interventional radiology and cardiology (IR/IC) workplaces and to recommend a series of guidelines on radiation protection in order to both guarantee and optimize staff protection. Within the project, coordinated measurements were performed in 34 hospitals in 6 European countries. Furthermore, simulations of the most representative workplaces in IR and IC were performed to determine the main parameters that influence the extremity and eye lens doses. The work presented in this paper shows the recommendations that were formulated by the results obtained from both measurements and simulations. The presented guidelines are directed to operators, assistant personnel, radiation protection officers and medical physics experts. They concern radiation protection issues, such as the use of room protective equipment, as well as the positioning of the extremity and eye lens dosemeters for routine monitoring.

  7. Monte Carlo calculations on extremity and eye lens dosimetry for medical staff at interventional radiology procedures

    International Nuclear Information System (INIS)

    Carinou, E.; Ferrari, P.; Koukorava, C.; Krim, S.; Struelens, L.

    2011-01-01

    There are many factors that can influence the extremity and eye lens doses of the medical staff during interventional radiology and cardiology procedures. Numerical simulations can play an important role in evaluating extremity and eye lens doses in correlation with many different parameters. In the present study, the first results of the ORAMED (Optimisation of Radiation protection of Medical staff) simulation campaign are presented. The parameters investigated for their influence on eye lens, hand, wrist and leg doses are: tube voltage, filtration, beam projection, field size and irradiated part of the patient's body. The tube voltage ranged from 60 to 110 kVp, filtration from 3 to 6 mm Al and from 0 to 0.9 mm Cu. For all projections, the results showed that doses received by the operator decreased with increasing tube voltage and filtration. The magnitude of the influence of the tube voltage and the filtration on the doses depends on the beam projection and the irradiated part of the patient's body. Finally, the influence of the field size is significant in decreasing the doses. (authors)

  8. Effectiveness of Bismuth Shield to Reduce Eye Lens Radiation Dose Using the Photoluminescence Dosimetry in Computed Tomography

    International Nuclear Information System (INIS)

    Jung, Mi Young; Kweon, Dae Cheol; Kwon, Soo Il

    2009-01-01

    The purpose of our study was to determine the eye radiation dose when performing routine multi-detector computed tomography (MDCT). We also evaluated dose reduction and the effect on image quality of using a bismuth eye shield when performing head MDCT. Examinations were performed with a 64MDCT scanner. To compare the shielded/unshielded lens dose, the examination was performed with and without bismuth shielding in anthropomorphic phantom. To determine the average lens radiation dose, we imaged an anthropomorphic phantom into which calibrated photoluminescence glass dosimeter (PLD) were placed to measure the dose to lens. The phantom was imaged using the same protocol. Radiation doses to the lens with and without the lens shielding were measured and compared using the Student t test. In the qualitative evaluation of the MDCT scans, all were considered to be of diagnostic quality. We did not see any differences in quality between the shielded and unshielded brain. The mean radiation doses to the eye with the shield and to those without the shield were 21.54 versus 10.46 mGy, respectively. The lens shield enabled a 51.3% decrease in radiation dose to the lens. Bismuth in-plane shielding for routine eye and head MDCT decreased radiation dose to the lens without qualitative changes in image quality. The other radiosensitive superficial organs specifically must be protected with shielding.

  9. Dry Eye Treatment Based on Contact Lens Drug Delivery: A Review.

    Science.gov (United States)

    Guzman-Aranguez, Ana; Fonseca, Begoña; Carracedo, Gonzalo; Martin-Gil, Alba; Martinez-Aguila, Alejandro; Pintor, Jesús

    2016-09-01

    Dry eye disease affects a substantial segment of the word population with increasing frequency. It is a multifactorial disease of the ocular surface and tear film, which causes ocular discomfort, visual disturbances, and tear instability with potential damage to the cornea and conjunctiva. Because of its multifactorial etiology, the use of different pharmacological treatment for dry eye treatment has been proposed, which include anti-inflammatory molecules, lubricants or comfort agents, and secretagogues. However, in some cases these pharmacological approaches only relieve symptoms temporarily, and consequently, eye care professionals continue to have difficulties managing dry eye. To improve pharmacological therapy that allows a more efficient and long-term action, effective ocular drug delivery of the currently available drugs for dry eye treatment is required. Contact lenses are emerging as alternative ophthalmic drugs delivery systems that provide an increased residence time of the drug at the eye, thus leading to enhanced bioavailability and more convenient and efficacious therapy. In this article, we reviewed the different techniques used to prepare contact lens-based drug delivery systems and focused on articles that describe the delivery of compounds for dry eye treatment through contact lenses.

  10. Extremity and eye lens dosimetry for medical staff performing vertebroplasty and kyphoplasty procedures

    International Nuclear Information System (INIS)

    Struelens, L; Schoonjans, W; Vanhavere, F; Schils, F; De Smedt, K

    2013-01-01

    Measurements of doses to hands, legs and eyes are reported for operators in four different hospitals performing vertebroplasty or kyphoplasty. The results confirm that occupational doses can be high for interventional spine procedures. Extremity and eye lens doses were measured with thermoluminescent dosimeters positioned on the ring fingers, wrists, legs and near the eyes of interventional radiologists and neurosurgeons, over a period of 15 months. Doses were generally larger on the left side for all positions monitored. The median dose to the left finger was 225 μSv per procedure, although a maximum of 7.3 mSv was found. The median dose to the right finger was 118 μSv, but with an even higher maximum of 7.7 mSv. A median left eye dose of 34 μSv (maximum 836 μSv) was found, while the legs received the lowest doses with a median of 13 μSv (maximum 332 μSv) to the left leg. Annual dose to the hand assessed by the cumulated doses almost reached the annual dose limit of 500 mSv, while annual dose to the eyes exceeded the eye lens dose limit of 20 mSv yr −1 . Different x-ray systems and radiation protection measures were tested, like the use of lead gloves and glasses, tweezers, cement delivery systems and a magnetic navigation system. These measurements showed that doses can be significantly reduced. The use of lead glasses is strongly recommended for protection of the eyes. (paper)

  11. On problems of the lens of the eye radiation dose monitoring

    Directory of Open Access Journals (Sweden)

    G. N. Kaydanovsky

    2016-01-01

    Full Text Available According to results of in-depth studies, the risk of the radiation-induced cataract is higher than it was considered earlier. In April 2011, ICRP released a statement on the tissue reactions. The statement recommends that for the case of for occupational exposure in planned exposure situations, an equivalent dose for the lens of the eye should be less than 20 mSv in a year, averaged over the defined periods of 5 years, with no single year exceeding the value of 50 mSv. In this regard, the new standard IAEA № GSR Part 3 provides the dose limit of 20 mSv in a year for occupational exposure for the lens of the eye. The dosimetric data on levels of exposure for personnel in the Russian Federation is practically absent. This paper performs a preliminary evaluation of equivalent dose for the lens of the eye for personnel working in X-ray operating rooms of medical facilities in Saint Petersburg and Kazan. This group of personnel was selected because of the fact that methodic of carrying out procedures forces medical staff to be not only in the zone of scattered radiation but also in the X-ray beam. This fact significantly increases exposure doses for the personnel. It is shown that actual annual dose can exceed the new dose limit (the highest recorded value Нр(3 in 3 months of work was 8,6 mSv. We made a conclusion on the necessity of the lens of the eye dose monitoring amongst interventional specialists on conditions that new limits will be established in the Russian Federation. The Russian and foreign dosimeters for measurement of individual dose equivalent for the lens of the eye Нр(3 which have been registered in the Russian State Register of Measuring Instruments, are descrivebed in the paper.

  12. The influence of crystalline lens accommodation on post-saccadic oscillations in pupil-based eye trackers.

    Science.gov (United States)

    Nyström, Marcus; Andersson, Richard; Magnusson, Måns; Pansell, Tony; Hooge, Ignace

    2015-02-01

    It is well known that the crystalline lens (henceforth lens) can oscillate (or 'wobble') relative to the eyeball at the end of saccades. Recent research has proposed that such wobbling of the lens is a source of post-saccadic oscillations (PSOs) seen in data recorded by eye trackers that estimate gaze direction from the location of the pupil. Since the size of the lens wobbles increases with accommodative effort, one would predict a similar increase of PSO-amplitude in data recorded with a pupil based eye tracker. In four experiments, we investigated the role of lens accommodation on PSOs in a video-based eye tracker. In Experiment 1, we replicated previous results showing that PSO-amplitudes increase at near viewing distances (large vergence angles), when the lens is highly accommodated. In Experiment 2a, we manipulated the accommodative state of the lens pharmacologically using eye drops at a fixed viewing distance and found, in contrast to Experiment 1, no significant difference in PSO-amplitude related to the accommodative state of the lens. Finally, in Experiment 2b, the effect of vergence angle was investigated by comparing PSO-amplitudes at near and far while maintaining a fixed lens accommodation. Despite the pharmacologically fixed degree of accommodation, PSO-amplitudes were systematically larger in the near condition. In summary, PSOs cannot exhaustively be explained by lens wobbles. Possible confounds related to pupil size and eye-camera angle are investigated in Experiments 3 and 4, and alternative mechanisms behind PSOs are probed in the discussion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Therapeutic efficiency of sodium hyaluronate eye drops on dry eye in juvenile with myopia wearing rigid gas permeable contact lens

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2016-03-01

    Full Text Available AIM:To investigate the therapeutic efficiency of preservative-free sodium hyaluronate eye drops on dry eye in juvenile myopia wearing rigid gas permeable contact lens(RGP.METHODS:Ninety cases with dry eye related to wearing RGP in juvenile with myopia from January to May 2015 were selected. The patients aged 12.75±4.15 years old,with diopter of -3.50±1.50D as spherical equivalent and received normalized RGP. They were divided into 3 groups randomly,each group of 30 cases(60 eyes:group A used rewetting drops,1 drop each time,4 times per day; group B used preservative-free sodium hyaluronate eye drops(1g/L,1 drop each time,4 times per day; group C used rewetting drops at first, then sodium hyaluronate eye drops was used 15 minutes later.All cases had been detected and evaluated by subjective symptoms of dry eye,Schirmer I test(SⅠt,break-up time(BUTand corneal fluorescent staining,at pre-therapy and 1, 2, 4wk of post-therapy.RESULTS:The subjective symptoms of dry eye,corneal fluorescent staining and BUT of three groups had been obviously improved at 1wk after therapies than those before therapies(PP>0.05.Every index of the three groups measured at 2 and 4wk after treatments had no significant differences compared to those measured at 1wk(P>0.05.There was no significant difference on subjective symptoms,SⅠt and BUT between group A and B(P>0.05,except on corneal fluorescent staining, on which group B was superior to group A and on which the difference was significant(PPPCONCLUSION:Preservative-free sodium hyaluronate eye drops(1g/Lcan stabilize the tear film and promote the repair of corneal epithelial defects and significantly improve dry eye symptoms and signs in juvenile myopia wearing RGP,so it has certain clinical application value.

  14. Goat′s eye integrated with a human cataractous lens: A training model for phacoemulsification

    Directory of Open Access Journals (Sweden)

    Sabyasachi Sengupta

    2015-01-01

    Full Text Available A relatively simple and inexpensive technique to train surgeons in phacoemulsification using a goat′s eye integrated with a human cataractous nucleus is described. The goat′s eye is placed on a bed of cotton within the lumen of a cylindrical container. This is then mounted on a rectangular thermocol so that the limbus is presented at the surgical field. After making a clear corneal entry with a keratome, the trainer makes a 5-5.5 mm continuous curvilinear capsulorhexis in the anterior lens capsule, creates a crater of adequate depth in the cortex and inserts the human nucleus within this crater in the goat′s capsular bag. The surgical wound is sutured, and the goat′s eye is ready for training. Creating the capsulorhexis with precision and making the crater of adequate depth to snugly accommodate the human nucleus are the most important steps to prevent excessive wobbling of the nucleus while training.

  15. Goat's eye integrated with a human cataractous lens: A training model for phacoemulsification.

    Science.gov (United States)

    Sengupta, Sabyasachi; Dhanapal, Praveen; Nath, Manas; Haripriya, Aravind; Venkatesh, Rengaraj

    2015-03-01

    A relatively simple and inexpensive technique to train surgeons in phacoemulsification using a goat's eye integrated with a human cataractous nucleus is described. The goat's eye is placed on a bed of cotton within the lumen of a cylindrical container. This is then mounted on a rectangular thermocol so that the limbus is presented at the surgical field. After making a clear corneal entry with a keratome, the trainer makes a 5-5.5 mm continuous curvilinear capsulorhexis in the anterior lens capsule, creates a crater of adequate depth in the cortex and inserts the human nucleus within this crater in the goat's capsular bag. The surgical wound is sutured, and the goat's eye is ready for training. Creating the capsulorhexis with precision and making the crater of adequate depth to snugly accommodate the human nucleus are the most important steps to prevent excessive wobbling of the nucleus while training.

  16. Maxwell's fish-eye lens and the mirage of perfect imaging

    International Nuclear Information System (INIS)

    Merlin, R

    2011-01-01

    Recent claims that Maxwell's fish-eye is a perfect lens, capable of providing images with deep subwavelength resolution, are examined. We show that the imaging properties of a dispersionless fish-eye are very similar to those of an ideal spherical cavity. Using this correspondence, we prove that the correct solution to Maxwell equations in the fish-eye gives image sizes that are consistent with the standard diffraction limit. Perfect focusing is an optical illusion that results from placing a time-reversed source at the position of the geometrical image which, when combined with the field due to the primary (object) source, mimics the behavior of a perfect drain. Issues of causality are briefly discussed. We also demonstrate that passive outlets are not a good alternative to time-reversed sources for broadband drain-like behavior and that, even if they were, they could not do a better job than conventional optical systems at providing high resolution

  17. Pigment dispersion glaucoma induced by the chafing effect of intraocular lens haptics in Asian eyes.

    Science.gov (United States)

    Hong, Ying; Sun, Yan-Xiu; Qi, Hong; Zhou, Ji-Chao; Hao, Yan-Sheng

    2013-03-01

    To study the possible mechanism and treatment for pigment dispersion glaucoma (PDG) caused by single-piece acrylic (SPA) intraocular lens (IOL) ciliary sulcus fixation in Asian eyes. Patients referred for PDG caused by SPA IOL ciliary sulcus fixation to our hospital from April 2005 to June 2011 were included. The patients' general information, IOL type, interval between initial surgery and PDG occurrence, examination findings, antiglaucoma medicine regimen and surgical interventions were recorded. In total, six eyes from five Chinese patients were included in this study. The intraocular pressure (IOP) increased 19-30 days after cataract surgery and was not satisfactorily controlled with antiglaucoma medication. Dense pigmentation was deposited on the IOLs and on the anterior chamber angle. IOL haptic chafing was noted on the rear iris surface. IOL repositioning in the capsular bag was performed in three eyes and was combined with trabeculectomy in two eyes with progressive glaucoma. An IOL exchange with three-piece IOL ciliary sulcus fixation was performed in the other three eyes. Scanning electron microscopy of the explanted IOLs demonstrated a rough edge on the IOL haptics. SPA IOLs were not suitable for ciliary sulcus fixation. The chafing effect of the IOL haptics on the posterior iris pigment epithelium could induce PDG in Asian eyes. IOLs should be positioned in the capsular bag or a three-piece IOL should be used instead.

  18. Ascorbic acid glycation of lens proteins produces UVA sensitizers similar to those in human lens

    International Nuclear Information System (INIS)

    Ortwerth, B.J.; Linetsky, Mikhail; Olesen, P.R.

    1995-01-01

    Soluble calf lens proteins were extensively glycated during a 4 week incubation with ascorbic acid in the presence of oxygen. Amino acids analysis of the dialyzed proteins removed at weekly intervals showed an increasing loss of lysine, arginine and histidine, consistent with the extensive protein cross-linking observed. Irradiation of the dialyzed samples with UVA light (1.0 kJ/cm 2 total illumination through a 338 nm cutoff filter) caused an increasing loss of tryptophan, an additional loss of histidine and the production of micromolar concentrations of hydrogen peroxide. No alteration in amino acid content and no photolytic effects were seen in proteins incubated without ascorbic acid in proteins incubated with glucose for 4 weeks. The rate of hydrogen peroxide formation was linear with each glycated sample with a maximum production of 25 nmol/mg protein illuminated. The possibility that the sensitizer activity was due to an ascorbate-induced oxidation of tryptophan was eliminated by the presence of a heavy metal ion chelator during the incubation and by showing equivalent effects with ascorbate-incubated ribonuclease A, which is devoid of tryptophan. The ascorbate-incubated samples displayed increasing absorbance at wavelengths above 300 nm and increasing fluorescence (340/430) as glycation proceeded. The spectra of the 4 week glycated proteins were identical to those obtained with a solubilized water-insoluble fraction from human lens, which is known to have UVA sensitizer activity. (Author)

  19. Eye lens radiation exposure and repeated head CT scans: A problem to keep in mind

    International Nuclear Information System (INIS)

    Michel, Morgane; Jacob, Sophie; Roger, Gilles; Pelosse, Béatrice; Laurier, Dominique; Le Pointe, Hubert Ducou; Bernier, Marie-Odile

    2012-01-01

    Objectives: The deterministic character of radiation-induced cataract is being called into question, raising the possibility of a risk in patients, especially children, exposed to ionizing radiation in case of repeated head CT-scans. This study aims to estimate the eye lens doses of a pediatric population exposed to repeated head CTs and to assess the feasibility of an epidemiological study. Methods: Children treated for a cholesteatoma, who had had at least one CT-scan of the middle ear before their tenth birthday, were included. Radiation exposure has been assessed from medical records and telephone interviews. Results: Out of the 39 subjects contacted, 32 accepted to participate. A total of 76 CT-scans were retrieved from medical records. At the time of the interview (mean age: 16 years), the mean number of CT per child was 3. Cumulative mean effective and eye lens doses were 1.7 mSv and 168 mGy, respectively. Conclusion: A relatively high lens radiation dose was observed in children exposed to repeated CT-scans. Due to that exposure and despite the difficulties met when trying to reach patients’ families, a large scale epidemiological study should be performed in order to assess the risk of radiation-induced cataracts associated with repeated head CT.

  20. Exposure of the thyroid and lens of the eye from scatter during mammography

    International Nuclear Information System (INIS)

    Ritenour, E.R.; Plott, C.M.; Ahrens, C.R.

    1987-01-01

    Exposure of the thyroid and lens of the eye of the patient during mammography was evaluated in a survey of mammographic units in the Denver area. Ion chambers calibrated for the mammographic energy range were used to measure exposure at standard distances superior and dorsal to Solid Water (R) phantoms placed in the compression device. Technique factors as used clinically for craniocaudal views were selected. A bimodal distribution of exposure values was found. Several units produced thyroid entrance surface exposures below 5 mR while the rest produced exposures exceeding 20 mR. Exposures to the lens of the eye were typically half the magnitude of the thyroid exposures. A table of results is presented in this paper along with evaluation of breast entrance exposure for each unit. The thyroid and lens exposures were found to be due to scatter from the patient's breast and the image receptor/compression device assembly of some of the units. The exposure in the high exposure group may be substantially reduced by the addition of a simple aluminum shield to the collimator or image receptor assembly

  1. Relationship of cumulative low-level dose of ionizing radiation on human eye lens and occurrence of cataract

    International Nuclear Information System (INIS)

    Deolalikar, Raghavendra

    2015-01-01

    International Commission on Radiological Protection (ICRP), issued a statement on Tissue Reaction, lowering the equivalent dose limit for eye lens for occupational exposure to 20 mSv per year. With a view to determine presence of any relationship between the cumulative low-level occupational radiation dose to the eye lens and occurrence of cataract, departmental records of the annual medical examination of employees of Narora Atomic Power Plant were examined along with the NAPS eye camps and surgical records of the employees. Analysis of the data showed no demonstrable definite relationship between the two. The analysis of the data and the observations are discussed in this paper. (author)

  2. Analysis of eye lens-specific genes in congenital hereditary cataracts and microphthalmia of the miniature schnauzer dog.

    Science.gov (United States)

    Zhang, R L; Samuelson, D A; Zhang, Z G; Reddy, V N; Shastry, B S

    1991-08-01

    The congenital hereditary cataracts and microphthalmia in the miniature schnauzer dog are inherited by an autosomal recessive mode. To understand the genetic basis of these diseases, the authors purified and analyzed leukocyte deoxyribonucleic acid (DNA) from affected and normal animals using a candidate gene approach. Because the genes that encode the lens-specific proteins, specifically, alpha, beta, and gamma crystallins and the membrane protein (MP26), are known to maintain the structure and function of the lens, the authors used complimentary DNA (cDNA) fragments that corresponded to the above genes to search for the mutations at their loci in the affected animals. They found no evidence of the gene deletion and rearrangement in any of the five loci. In addition, the hybridizable sequences of the dog DNA to the specific probes for the human chromosome 4 and 18 loci, which are reported to be involved in the abnormality of the human eye, seem to be unaffected. These data support the notion that the hereditary cataracts and microphthalmia in the dog may be associated with genes other than those reported for several animal systems.

  3. Optical transmission and laser ablation of pathologically changed eye lens capsule

    Energy Technology Data Exchange (ETDEWEB)

    Gamidov, A A; Bolshunov, A V [Research Institute of Eye Diseases, Russian Academy of Medical Sciences, Moscow (Russian Federation); Yuzhakov, A V; Shcherbakov, E M; Baum, O I; Sobol, E N [Institute on Laser and Information Technologies, Russian Academy of Sciences, Shatura, Moscow Region (Russian Federation)

    2015-02-28

    Optical transmission and ablation mechanisms in the secondary cataract films under the impact of 1.06-mm laser radiation are studied. The comparison of incident and transmitted (paraxial) radiation power at different values of the power density is carried out for two types of the eye lens capsule tissue (hard and soft) possessing different optical and mechanical properties. It is found that the effective attenuation coefficient for soft films is almost five times as large as that for the hard ones. The obtained measurement data on the transparency variation in the process of laser action allow the temperature evaluation and the determination of dominant mechanism of laser ablation, as well as the development of recommendations, providing the prevention or reduction of possible side effects. The obtained results can be used to optimise the regimes of laser impact in the process of the opacified lens capsule removal.

  4. Diquafosol Ophthalmic Solution Increases Pre- and Postlens Tear Film During Contact Lens Wear in Rabbit Eyes.

    Science.gov (United States)

    Nagahara, Yukiko; Koh, Shizuka; Oshita, Yoshihiro; Nagano, Takashi; Mano, Hidetoshi; Nishida, Kohji; Watanabe, Hitoshi

    2017-11-01

    To investigate the behavior of prelens tear film (PLTF) and postlens tear film (PoLTF) after the instillation of diquafosol using an experimental rabbit model of eyes with contact lens. Cross-sectional, anterior segment optical coherence tomographic images of the inferior midperipheral cornea were obtained at baseline and at 5, 15, 30, 60, 90, and 120 min after the instillation of 3% diquafosol ophthalmic solution in 10 Japanese white rabbits wearing contact lenses. From the obtained images, the areas of the PLTF and PoLTF were calculated. Both artificial tear solution and 0.1% sodium hyaluronate ophthalmic solution were used for comparison. Significant fluid accumulation in both the PLTF and PoLTF was observed after diquafosol instillation, whereas no fluid accumulation was visible after the instillation of artificial tear or sodium hyaluronate. The increase in PLTF area after diquafosol instillation was significantly higher (Pophthalmic solution increases PLTF and PoLTF in rabbit eyes with contact lenses. Diquafosol has potential as a treatment option for contact lens-related dry eye.

  5. EVALUATION OF EYE LENS DOSE TO WORKERS IN THE STEAM GENERATOR AT THE KOREAN OPTIMIZED POWER REACTOR 1000.

    Science.gov (United States)

    Maeng, Sung Jun; Kim, Jinhwan; Cho, Gyuseong

    2018-03-15

    ICRP (2011) revised the dose limit to the eye lens to 20 mSv/y based on a recent epidemiological study of radiation-induced cataracts. Maintenance of steam generators at nuclear power plants is one of the highest radiation-associated tasks within a non-uniform radiation field. This study aims to evaluate eye lens doses in the steam generators of the Korean OPR1000 design. The source term was characterized based on the CRUD-specific activity, and both the eye lens dose and organ dose were simulated using MCNP6 combined with an ICRP voxel phantom and a mesh phantom, respectively. The eye lens dose was determined to be 5.39E-02-9.43E-02 Sv/h, with a negligible effect by beta particles. As the effective dose was found to be 0.81-1.21 times the lens equivalent dose depending on the phantom angles, the former can be used to estimate the lens dose in the SG of the OPR1000 for radiation monitoring purposes.

  6. Does reproduction accelerate the growth of eye lens mass in female voles?

    Czech Academy of Sciences Publication Activity Database

    Jánová, Eva; Havelková, Dana; Tkadlec, Emil

    2007-01-01

    Roč. 137, č. 1 (2007), s. 85-88 ISSN 0777-6276 R&D Projects: GA ČR GA206/04/2003; GA ČR(CZ) GD524/05/H536 Institutional research plan: CEZ:AV0Z60930519 Keywords : age estimation * eye lens mass * reproduction Subject RIV: EH - Ecology, Behaviour Impact factor: 0.433, year: 2007 http://www.naturalsciences.be/institute/associations/rbzs_website/bjz/back/pdf/BJZ%20137(1)/Volume%20137(1),%20pp.%2085-88.pdf

  7. Dose conversion coefficients for monoenergetic electrons incident on a realistic human eye model with different lens cell populations.

    Science.gov (United States)

    Nogueira, P; Zankl, M; Schlattl, H; Vaz, P

    2011-11-07

    The radiation-induced posterior subcapsular cataract has long been generally accepted to be a deterministic effect that does not occur at doses below a threshold of at least 2 Gy. Recent epidemiological studies indicate that the threshold for cataract induction may be much lower or that there may be no threshold at all. A thorough study of this subject requires more accurate dose estimates for the eye lens than those available in ICRP Publication 74. Eye lens absorbed dose per unit fluence conversion coefficients for electron irradiation were calculated using a geometrical model of the eye that takes into account different cell populations of the lens epithelium, together with the MCNPX Monte Carlo radiation transport code package. For the cell population most sensitive to ionizing radiation-the germinative cells-absorbed dose per unit fluence conversion coefficients were determined that are up to a factor of 4.8 higher than the mean eye lens absorbed dose conversion coefficients for electron energies below 2 MeV. Comparison of the results with previously published values for a slightly different eye model showed generally good agreement for all electron energies. Finally, the influence of individual anatomical variability was quantified by positioning the lens at various depths below the cornea. A depth difference of 2 mm between the shallowest and the deepest location of the germinative zone can lead to a difference between the resulting absorbed doses of up to nearly a factor of 5000 for electron energy of 0.7 MeV.

  8. [Eye lens radiation exposure during ureteroscopy with and without a face protection shield: Investigations on a phantom model].

    Science.gov (United States)

    Zöller, G; Figel, M; Denk, J; Schulz, K; Sabo, A

    2016-03-01

    Eye lens radiation exposure during radiologically-guided endoscopic procedures may result in radiation-induced cataracts; therefore, we investigated the ocular radiation exposure during ureteroscopy on a phantom model. Using an Alderson phantom model and eye lens dosimeters, we measured the ocular radiation exposure depending on the number of X-ray images and on the duration of fluoroscopic imaging. The measurements were done with and without using a face protection shield. We could demonstrate that a significant ocular radiation exposure can occur, depending on the number of X-ray images and on the duration time of fluoroscopy. Eye lens doses up to 0.025 mSv were recorded even using modern digital X-ray systems. Using face protection shields this ocular radiation exposure can be reduced to a minimum. The International Commission on Radiological Protection (ICRP) recommendations of a mean eye lens dosage of 20 mSv/year may be exceeded during repeated ureteroscopy by a high volume surgeon. Using a face protection shield, the eye lens dose during ureteroscopy could be reduced to a minimum in a phantom model. Further investigations will show whether these results can be transferred to real life ureteroscopic procedures.

  9. Dose conversion coefficients for monoenergetic electrons incident on a realistic human eye model with different lens cell populations

    International Nuclear Information System (INIS)

    Nogueira, P; Vaz, P; Zankl, M; Schlattl, H

    2011-01-01

    The radiation-induced posterior subcapsular cataract has long been generally accepted to be a deterministic effect that does not occur at doses below a threshold of at least 2 Gy. Recent epidemiological studies indicate that the threshold for cataract induction may be much lower or that there may be no threshold at all. A thorough study of this subject requires more accurate dose estimates for the eye lens than those available in ICRP Publication 74. Eye lens absorbed dose per unit fluence conversion coefficients for electron irradiation were calculated using a geometrical model of the eye that takes into account different cell populations of the lens epithelium, together with the MCNPX Monte Carlo radiation transport code package. For the cell population most sensitive to ionizing radiation-the germinative cells-absorbed dose per unit fluence conversion coefficients were determined that are up to a factor of 4.8 higher than the mean eye lens absorbed dose conversion coefficients for electron energies below 2 MeV. Comparison of the results with previously published values for a slightly different eye model showed generally good agreement for all electron energies. Finally, the influence of individual anatomical variability was quantified by positioning the lens at various depths below the cornea. A depth difference of 2 mm between the shallowest and the deepest location of the germinative zone can lead to a difference between the resulting absorbed doses of up to nearly a factor of 5000 for electron energy of 0.7 MeV.

  10. Estimation of eye lens dose during brain scans using Gafchromic XR-QA2 film in various multidetector CT scanners

    International Nuclear Information System (INIS)

    Akhilesh, Philomina; Jamhale, Shramika H.; Sharma, S.D.; Kumar, Rajesh; Datta, D.; Kulkarni, Arti R.

    2017-01-01

    The purpose of this study was to estimate eye lens dose during brain scans in 16-, 64-, 128- and 256-slice multidetector computed tomography (CT) scanners in helical acquisition mode and to test the feasibility of using radiochromic film as eye lens dosemeter during CT scanning. Eye lens dose measurements were performed using Gafchromic XR-QA2 film on a polystyrene head phantom designed with outer dimensions equivalent to the head size of a reference Indian man. The response accuracy of XR-QA2 film was validated by using thermoluminescence dosemeters. The eye lens dose measured using XR-QA2 film on head phantom for plain brain scanning in helical mode ranged from 43.8 to 45.8 mGy. The XR-QA2 film measured dose values were in agreement with TLD measured dose values within a maximum variation of 8.9%. The good correlation between the two data sets confirms the viability of using XR-QA2 film for eye lens dosimetry. (authors)

  11. The G-protein-coupled receptor, GPR84, is important for eye development in Xenopus laevis.

    Science.gov (United States)

    Perry, Kimberly J; Johnson, Verity R; Malloch, Erica L; Fukui, Lisa; Wever, Jason; Thomas, Alvin G; Hamilton, Paul W; Henry, Jonathan J

    2010-11-01

    G-protein-coupled receptors (GPCRs) represent diverse, multifamily groups of cell signaling receptors involved in many cellular processes. We identified Xenopus laevis GPR84 as a member of the A18 subfamily of GPCRs. During development, GPR84 is detected in the embryonic lens placode, differentiating lens fiber cells, retina, and cornea. Anti-sense morpholino oligonucleotide-mediated knockdown and RNA rescue experiments demonstrate GPR84's importance in lens, cornea, and retinal development. Examination of cell proliferation using an antibody against histone H3 S10P reveals significant increases in the lens and retina following GPR84 knockdown. Additionally, there was also an increase in apoptosis in the retina and lens, as revealed by TUNEL assay. Reciprocal transplantation of the presumptive lens ectoderm between uninjected controls and morpholino-injected embryos demonstrates that GPR84 is necessary in the retina for proper development of the retina, as well as other eye tissues including the lens and cornea. © 2010 Wiley-Liss, Inc.

  12. Changes induced to eye lens membrane characterization after treatments with beta radiation from Sr90

    International Nuclear Information System (INIS)

    El-Refaei, F.M.; Morris, M.; Gamal, M.M.; Fadel, M.A.

    1994-12-01

    The effect of β-particles on Na + and k + content, Na + -k + ATPase and histopathological changes of cell membrane were studied in the present work. One of the two eyes of New Zealand rabbits from both sexes were irradiated with β-particles from Sr 90 source to 10, 20, 40 and 60 Gy. The effect of β-particles on lens membrane after 3 months of exposure to 20 and 60 Gy was also studied. The results indicated that the treated and untreated eyes suffered pronounced injuries which deduced from the distribution of ATPase in comparison with the normal control which showed a decrease (reached 52%). As well as uncontrolled transport of the Na + and k + through the membrane and injuries appeared in the histopathological studies. (author). 12 refs, 15 figs, 4 tabs

  13. An overview of equivalent doses in eye lens of occupational radiation workers in medical, industrial and nuclear areas

    International Nuclear Information System (INIS)

    Lima, A.R.; Silva, F.C.A. da; Hunt, J.G.

    2013-01-01

    Some epidemiological evidences were recently reviewed by the ICRP and it was suggested that, for the eye lens, the absorbed dose threshold for induction of late detriments is about 0.5 Gy. On this basis, on 2011, the ICRP has recommended changes to the occupational dose limit in planned exposure situations, reducing the eye lens dose equivalent limit of 150 mSv to 20 mSv per year, on average, during the period of 5 years, with exposure not exceeding 50 mSv in a single year. Following the ICRP recommendation, the Brazilian Commission of Nuclear Energy (CNEN) adopted immediately the new limit to the eyes lens. This study aimed to show an overview about the doses in eye lens of occupational radiation workers in situations of planned exposures in the medical, industrial and nuclear areas, emphasizing the greatest radiological risks applications. It was observed that there are some limitations, such as example, to use individual monitor calibrated on Hp(3), to assess the equivalent dose in the eye lens. This limitation obstructs some experimental studies and monitoring of the levels of radiation received in the eye lens of radiation workers. Recent studies have showed that the lenses of eyes monitoring of workers, mainly in the planned exposure, must be follow-up. However, such researches were obtained only in medical exposures, mainly in interventional medicine procedures. Studies with planned exposure on nuclear and industrial areas are really needed and will be very important due to the new recommended by ICRP dose limits. (author)

  14. SU-E-J-11: Measurement of Eye Lens Dose for Varian On-Board Imaging with Different CBCT Acquisition Techniques

    International Nuclear Information System (INIS)

    Deshpande, S; Dhote, D; Kumar, R; Thakur, K

    2015-01-01

    Purpose: To measure actual patient eye lens dose for different cone beam computed tomography (CBCT) acquisition protocol of Varian’s On Board Imagining (OBI) system using Optically Stimulated Luminescence (OSL) dosimeter and study the eye lens dose with patient geometry and distance of isocenter to the eye lens Methods: OSL dosimeter was used to measure eye lens dose of patient. OSL dosimeter was placed on patient forehead center during CBCT image acquisition to measure eye lens dose. For three different cone beam acquisition protocol (standard dose head, low dose head and high quality head) of Varian On-Board Imaging, eye lens doses were measured. Measured doses were correlated with patient geometry and distance between isocenter to eye lens. Results: Measured eye lens dose for standard dose head was in the range of 1.8 mGy to 3.2 mGy, for high quality head protocol dose was in range of 4.5mGy to 9.9 mGy whereas for low dose head was in the range of 0.3mGy to 0.7mGy. Dose to eye lens is depends upon position of isocenter. For posterioraly located tumor eye lens dose is less. Conclusion: From measured doses it can be concluded that by proper selection of imagining protocol and frequency of imaging, it is possible to restrict the eye lens dose below the new limit set by ICRP. However, undoubted advantages of imaging system should be counter balanced by careful consideration of imaging protocol especially for very intense imaging sequences for Adoptive Radiotherapy or IMRT

  15. Three-dimensional ray tracing in spherical and elliptical generalized Luneburg lenses for application in the human eye lens.

    Science.gov (United States)

    Gómez-Correa, J E; Coello, V; Garza-Rivera, A; Puente, N P; Chávez-Cerda, S

    2016-03-10

    Ray tracing in spherical Luneburg lenses has always been represented in 2D. All propagation planes in a 3D spherical Luneburg lens generate the same ray tracing, due to its radial symmetry. A geometry without radial symmetry generates a different ray tracing. For this reason, a new ray tracing method in 3D through spherical and elliptical Luneburg lenses using 2D methods is proposed. The physics of the propagation is shown here, which allows us to make a ray tracing associated with a vortex beam. A 3D ray tracing in a composite modified Luneburg lens that represents the human eye lens is also presented.

  16. Eye lens dosimetry in interventional cardiology: Results of staff dose measurements and link to patient dose levels

    International Nuclear Information System (INIS)

    Antic, V.; Ciraj-Bjelac, O.; Rehani, M.; Aleksandric, S.; Arandjic, D.; Ostojic, M.

    2013-01-01

    Workers involved in interventional cardiology procedures receive high eye lens dose if protection is not used. Currently, there is no suitable method for routine use for the measurement of eye dose. Since most angiography machines are equipped with suitable patient dosemeters, deriving factors linking staff eye doses to the patient doses can be helpful. In this study the patient kerma-area product, cumulative dose at an interventional reference point and eye dose in terms of Hp(3) of the cardiologists, nurses and radiographers for interventional cardiology procedures have been measured. Correlations between the patient dose and the staff eye dose were obtained. The mean eye dose was 121 mSv for the first operator, 33 mSv for the second operator/nurse and 12 mSv for radiographer. Normalised eye lens doses per unit kerma-area product were 0.94 mSv Gy -1 cm -2 for the first operator, 0.33 mSv Gy -1 cm -2 for the second operator/nurse and 0.16 mSv Gy -1 cm -2 for radiographers. Statistical analysis indicated that there is a weak but significant (p < 0.01) correlation between the eye dose and the kerma-area product for all three staff categories. These values are based on a local practice and may provide useful reference for other studies for validation and for wider utilisation in assessing the eye dose using patient dose values. (authors)

  17. Comparing the Zeiss Callisto Eye and the Alcon Verion Image Guided System Toric Lens Alignment Technologies.

    Science.gov (United States)

    Hura, Arjan S; Osher, Robert H

    2017-07-01

    To compare the alignment meridian generated by the Zeiss Callisto Eye (Carl Zeiss AG, Dublin, CA) and the Alcon Verion Image Guided System (Alcon Laboratories, Inc., Fort Worth, TX). In this retrospective comparative evaluation of technology, intraoperative images were captured at different steps in the same surgery, allowing the comparison of the guidance lines generated by the Verion system to the parallel guidance lines generated by the Callisto Eye system. Measurements of each hemi-meridian were quantified using Adobe Photoshop 2015 CC software (Adobe Systems, San Jose, CA). The numbers of degrees separating these alignment meridians were calculated, entered into a database, and analyzed. The authors found that of 98 captured images of 16 eyes, the two technologies were identical in 0 eyes (θ 1 = θ 2 = 0), similar by 3° in 52 (53%) captured images (θ 1 ≠ θ 2 ≠ 0), and different by at least 3° in 46 (47%) captured images (θ 1 ≠ θ 2 ≠ 0). The target meridians were superimposed, the target lines were minimally separated, and the target lines were dissimilar. It was noted that some intraoperative variation occurred from measurement to measurement. Within the small group of 16 cases of routine toric lens implantation in this study, the absolute average number of degrees of misalignment between the Verion and Callisto Eye systems was 3.355 for θ 1 and 3.838 for θ 2 . On average, the intraoperative variation termed "drift" was noted to be 3.963° for θ 1 , and 4.557° for θ 2 . The authors found that small deviations were frequent when comparing two sophisticated technologies. Although deviations greater than 3° occurred in less than 47% of captured images from 16 eyes, smaller but significant variations of less than 3° occurred in 53% of captured images from 16 eyes. It was rare to identify a large deviation. However, the authors identified "drift" in the same eye when measurements were taken at different times. The results indicate that the two

  18. Evaluation of the True Wavefront Aberrations in Eyes Implanted With a Rotationally Asymmetric Multifocal Intraocular Lens.

    Science.gov (United States)

    Akondi, Vyas; Pérez-Merino, Pablo; Martinez-Enriquez, Eduardo; Dorronsoro, Carlos; Alejandre, Nicolás; Jiménez-Alfaro, Ignacio; Marcos, Susana

    2017-04-01

    Standard evaluation of aberrations from wavefront slope measurements in patients implanted with a rotationally asymmetric multifocal intraocular lens (IOL), the Lentis Mplus (Oculentis GmbH, Berlin, Germany), results in large magnitude primary vertical coma, which is attributed to the intrinsic IOL design. The new proposed method analyzes aberrometry data, allowing disentangling the IOL power pupillary distribution from the true higher order aberrations of the eye. The new method of wavefront reconstruction uses retinal spots obtained at both the near and far foci. The method was tested using ray tracing optical simulations in a computer eye model virtually implanted with the Lentis Mplus IOL, with a generic cornea or with anterior segment geometry obtained from custom quantitative spectral-domain optical coherence tomography in a real patient. The method was applied to laser ray tracing aberrometry data at near and far fixation obtained in a patient implanted with the Lentis Mplus IOL. Higher order aberrations evaluated from simulated and real retinal spot diagrams following the new reconstruction approach matched the nominal aberrations (approximately 98%). Previously reported primary vertical coma in patients implanted with this IOL lost significance with the application of the proposed reconstruction. Custom analysis of ray tracing-based retinal spot diagrams allowed decoupling of the true higher order aberrations of the patient's eye from the power pupillary distribution of a rotationally asymmetric multifocal IOL, therefore providing the appropriate phase map to accurately evaluate through-focus optical quality. [J Refract Surg. 2017;33(4):257-265.]. Copyright 2017, SLACK Incorporated.

  19. Multifocal Intraocular Lens Results in Correcting Presbyopia in Eyes After Radial Keratotomy.

    Science.gov (United States)

    Kim, Kyeong Hwan; Seok, Kyung-Won; Kim, Wan Soo

    2017-11-01

    To report results of multifocal intraocular lens (IOL) implantation in 2 patients with refractive error and presbyopia after previous radial keratotomy (RK). A refractive multifocal IOL with rotational asymmetry (LS313-MF30; Oculentis, Berlin, Germany) was implanted. The first patient was a 60-year-old man with myopia who underwent unilateral RK 20 years before. His uncorrected distance visual acuity (UDVA) was 20/400, and his distance corrected near vision was J9 in both eyes. Six months after bilateral surgery, his binocular UDVA and uncorrected near visual acuity (UNVA) improved to 20/20 and J1, respectively, although he experienced diurnal fluctuation. The second patient was a 55-year-old woman with hyperopia who underwent bilateral RK 18 years before. Uncorrected distance visual acuity was 20/25 in both eyes, but UNVA was between J9 and J10. Three months after unilateral surgery, UDVA and UNVA of the postsurgical eye improved to 20/20 and J1, respectively. Neither patient reported any significant photic phenomena, and both were satisfied with the results of treatment. The desirable clinical outcomes and levels of satisfaction expressed by these patients indicate that surgery using this particular multifocal IOL may benefit presbyopic patients with previous RK.

  20. Implantation of a double iris-claw intraocular lens in an aphakic nanophthalmic eye

    Directory of Open Access Journals (Sweden)

    Filiz Avsin Ozdemir Sarioglu

    2017-01-01

    Full Text Available A 55-year-old female with an aphakic nanophthalmic eye underwent a secondary intraocular lens implantation (IOL with double Artisan aphakia iris claw IOLs (ICIOLs and was evaluated in this research. The patient's preoperative best-corrected visual acuity (BCVA of the right eye was 0.4 (0.4 logMAR (with + 21.00 D, postoperative 1st and 3rd month, 1st year, and 3 years BCVAs were 0.4 (0.4 logMAR. The intraocular pressure was 15 mmHg preoperatively, and 14, 12, 12, and 15 mmHg postoperatively at 1st and 3rd month, 1st year, and 3 years, respectively. The preoperative endothelial cell density (ECD was 2372 cells/mm2, and postoperative ECDs were 2352, 2391, 2246, and 2240 cells/mm2 at 1st and 3rd months, at 1st year, and 3 years respectively. In aphakic nanophthalmic eyes with inadequate capsular support, which require high IOL dioptry, the implantation of double ICIOLs (one in front of the iris and the other behind the iris seems to be safe and provides good visual rehabilitation.

  1. Influence of aspheric intraocular lens on frequency doubling technology and contrast sensitivity: a fellow eye study

    Directory of Open Access Journals (Sweden)

    Rodrigo França de Espíndola

    2014-12-01

    Full Text Available Purpose: To evaluate whether implantation of an aspheric intraocular lens (IOL results in reduced ocular aberrations and improved contrast sensitivity after cataract surgery and, therefore, changes on frequency-doubling technology (FDT testing. Methods: The present prospective clinical study enrolled 25 patients with bilateral cataract (50 eyes, who randomly received either an aspheric (Akreos AO or a spherical (Akreos Fit IOL in one eye and the other IOL in the second eye. Assessment 12 months postoperatively included photopic and mesopic contrast sensitivity testing. Higher-order aberrations (HOAs were computed. FDT testing was divided into four areas to evaluate the variation of the values at different points. The median values of the local pattern thresholds (median area contrast sensitivity [MACS] obtained with that division were calculated. Results: The Akreos AO group obtained statistically significantly lower values of HOAs and spherical aberration compared with the Akreos Fit group. There was a statistically significant between-group difference in contrast sensitivity under mesopic conditions at all spatial frequencies. No statistically significant differences were observed in mean deviation and pattern standard deviation. The aspheric IOL exhibited higher MACS in all areas, although a statistically significant difference was reached only in the 20-degree field area (P=0.043. Conclusion: Aspheric IOLs significantly reduced spherical aberration and HOAs, improving mesopic contrast sensitivity. Although there was a trend toward slightly improved FDT in the aspheric IOL group, it was not statistically significant.

  2. Interim report of the JHPS expert committee on radiation protection of the lens of the eye (2). The dosimetry method for the lens of the eye of workers in Japan

    International Nuclear Information System (INIS)

    Akahane, Keiichi; Tatsuzaki, Hideo; Iimoto, Takeshi; Ichiji, Takeshi; Hamada, Nobuyuki; Fujimichi, Yuki; Iwai, Satoshi; Ohguchi, Hiroyuki; Ohno, Kazuko; Yamauchi, Chiyo; Tsujimura, Norio; Hotta, Yutaka; Yamasaki, Tadashi; Yokoyama, Sumi

    2014-01-01

    A brief review is given of the history and methodology of external dosimetry for the lens of the eye. Under the 1989 revision to domestic radiological protection regulations, the concept on the effective dose equivalent and the dose limit to the lens of the eye (150 mSv/y) both introduced in the ICRP 1977 recommendations has changed nationwide the external monitoring methodology in non-uniform exposure situations to the trunk of a radiological worker. In such situations, which are often created by the presence of a protective apron, the worker is required to use at least two personal dosemeters, one worn on the trunk under the apron and the other, typically, at the collar over the apron. The latter dosemeter serves the dual purpose of providing the dose profile across the trunk for improved effective dose equivalent assessment and of estimating the dose to lens of the eye. The greater or appropriate value between H p (10) and H p (0.07), given by the dosemeter, is generally used as a surrogate of H p (3) for recording the dose to the lens of the eye. The above-mentioned methodology was continued in the latest 2001 revision to the relevant regulations. (author)

  3. Aquaporin 0 plays a pivotal role in refractive index gradient development in mammalian eye lens to prevent spherical aberration

    International Nuclear Information System (INIS)

    Kumari, S. Sindhu; Varadaraj, Kulandaiappan

    2014-01-01

    Highlights: • Intact AQP0 functions as fiber cell-to-fiber cell adhesion protein. • AQP0 facilitates reduction in extracellular space and lens water content. • AQP0 adhesion function aids in lens refractive index gradient (RING) formation. • AQP0 prevents lens spherical aberration by establishing RING. • AQP0 is critical for lens transparency and homeostasis. - Abstract: Aquaporin 0 (AQP0) is a transmembrane channel that constitutes ∼45% of the total membrane protein of the fiber cells in mammalian lens. It is critical for lens transparency and homeostasis as mutations and knockout cause autosomal dominant lens cataract. AQP0 functions as a water channel and as a cell-to-cell adhesion (CTCA) molecule in the lens. Our recent in vitro studies showed that the CTCA function of AQP0 could be crucial to establish lens refractive index gradient (RING). However, there is a lack of in vivo data to corroborate the role of AQP0 as a fiber CTCA molecule which is critical for creating lens RING. The present investigation is undertaken to gather in vivo evidence for the involvement of AQP0 in developing lens RING. Lenses of wild type (WT) mouse, AQP0 knockout (heterozygous, AQP0 +/− ) and AQP0 knockout lens transgenically expressing AQP1 (heterozygous AQP0 +/− /AQP1 +/− ) mouse models were used for the study. Data on AQP0 protein profile of intact and N- and/or C-terminal cleaved AQP0 in the lens by MALDI-TOF mass spectrometry and SDS–PAGE revealed that outer cortex fiber cells have only intact AQP0 of ∼28 kDa, inner cortical and outer nuclear fiber cells have both intact and cleaved forms, and inner nuclear fiber cells have only cleaved forms (∼26–24 kDa). Knocking out of 50% of AQP0 protein caused light scattering, spherical aberration (SA) and cataract. Restoring the lost fiber cell membrane water permeability (P f ) by transgene AQP1 did not reinstate complete lens transparency and the mouse lenses showed light scattering and SA. Transmission and

  4. Aquaporin 0 plays a pivotal role in refractive index gradient development in mammalian eye lens to prevent spherical aberration

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, S. Sindhu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, New York, NY (United States)

    2014-10-03

    Highlights: • Intact AQP0 functions as fiber cell-to-fiber cell adhesion protein. • AQP0 facilitates reduction in extracellular space and lens water content. • AQP0 adhesion function aids in lens refractive index gradient (RING) formation. • AQP0 prevents lens spherical aberration by establishing RING. • AQP0 is critical for lens transparency and homeostasis. - Abstract: Aquaporin 0 (AQP0) is a transmembrane channel that constitutes ∼45% of the total membrane protein of the fiber cells in mammalian lens. It is critical for lens transparency and homeostasis as mutations and knockout cause autosomal dominant lens cataract. AQP0 functions as a water channel and as a cell-to-cell adhesion (CTCA) molecule in the lens. Our recent in vitro studies showed that the CTCA function of AQP0 could be crucial to establish lens refractive index gradient (RING). However, there is a lack of in vivo data to corroborate the role of AQP0 as a fiber CTCA molecule which is critical for creating lens RING. The present investigation is undertaken to gather in vivo evidence for the involvement of AQP0 in developing lens RING. Lenses of wild type (WT) mouse, AQP0 knockout (heterozygous, AQP0{sup +/−}) and AQP0 knockout lens transgenically expressing AQP1 (heterozygous AQP0{sup +/−}/AQP1{sup +/−}) mouse models were used for the study. Data on AQP0 protein profile of intact and N- and/or C-terminal cleaved AQP0 in the lens by MALDI-TOF mass spectrometry and SDS–PAGE revealed that outer cortex fiber cells have only intact AQP0 of ∼28 kDa, inner cortical and outer nuclear fiber cells have both intact and cleaved forms, and inner nuclear fiber cells have only cleaved forms (∼26–24 kDa). Knocking out of 50% of AQP0 protein caused light scattering, spherical aberration (SA) and cataract. Restoring the lost fiber cell membrane water permeability (P{sub f}) by transgene AQP1 did not reinstate complete lens transparency and the mouse lenses showed light scattering and SA

  5. Navigation system for a mobile robot with a visual sensor using a fish-eye lens

    Science.gov (United States)

    Kurata, Junichi; Grattan, Kenneth T. V.; Uchiyama, Hironobu

    1998-02-01

    Various position sensing and navigation systems have been proposed for the autonomous control of mobile robots. Some of these systems have been installed with an omnidirectional visual sensor system that proved very useful in obtaining information on the environment around the mobile robot for position reckoning. In this article, this type of navigation system is discussed. The sensor is composed of one TV camera with a fish-eye lens, using a reference target on a ceiling and hybrid image processing circuits. The position of the robot, with respect to the floor, is calculated by integrating the information obtained from a visual sensor and a gyroscope mounted in the mobile robot, and the use of a simple algorithm based on PTP control for guidance is discussed. An experimental trial showed that the proposed system was both valid and useful for the navigation of an indoor vehicle.

  6. Influence of different types of phantoms on the calibration of dosemeters for eye lens dosimetry

    International Nuclear Information System (INIS)

    Yoshitomi, H.; Kowatari, M.

    2016-01-01

    Both a cylinder and a slab phantom have been recommended to be used as calibration phantoms for eye lens dosimetry in the International Atomic Energy Agency TECDOC. This study describes investigations on the influence of the type of phantom on the calibration of dosemeters. In order to fulfil the purpose, backscatter radiation from practically used water-filled phantoms was evaluated by calculations and experiments. For photons, the calculations showed that the cylinder phantom had 10 % lower backscattered effect at maximum than a slab phantom, and simulated well the backscattered effect of the human head or neck to within ±10 %. The irradiation results of non-filtered optically stimulated luminescence and radio-photoluminescence glass dosemeters indicated that the differences of the calibration factors between the two types of phantoms were up to 20 and 10 %, respectively, reflecting the response to backscattered photons. For electrons, no difference was found between the two types of phantoms. (authors)

  7. Estimation of deep, eye lens and skin doses for high energy electron beams for dosimetry and protection purpose

    International Nuclear Information System (INIS)

    Reena Kumari; Rakesh, R.B.

    2018-01-01

    In the radiological protection especially for individual as well as area monitoring, it is generally considered that beta sources deposit skin and eye lens doses only as they do not have enough energy for depositing doses at 10 mm depth. Also, the skin and eye lens doses differ substantially due to attenuation of beta particles at 0.07 mm (skin) and 3 mm (eye lens) depths and the surface doses are always greater than eye lens doses even for the highest energy beta source used in brachytherapy applications. However, worldwide increase in the use of high energy electron accelerators, new challenges are being posed for radiological protection and the operational quantities defined previously by ICRU are being reviewed. In view of these developments, studies have been performed for different electron beams in the energy range from (4 - 20) MeV generated using a medical linear accelerator. The aim of the study is to measure doses deposited at various depths as defined by ICRU 39 for individual and area monitoring purposes

  8. Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus)

    DEFF Research Database (Denmark)

    Nielsen, Julius; Hedeholm, Rasmus B.; Heinemeier, Jan

    2016-01-01

    The Greenland shark (Somniosus microcephalus), an iconic species of the Arctic Seas, grows slowly and reaches >500 centimeters (cm) in total length, suggesting a life span well beyond those of other vertebrates. Radiocarbon dating of eye lens nuclei from 28 female Greenland sharks (81 to 502 cm i...

  9. Modulation transfer function of a fish-eye lens based on the sixth-order wave aberration theory.

    Science.gov (United States)

    Jia, Han; Lu, Lijun; Cao, Yiqing

    2018-01-10

    A calculation program of the modulation transfer function (MTF) of a fish-eye lens is developed with the autocorrelation method, in which the sixth-order wave aberration theory of ultra-wide-angle optical systems is used to simulate the wave aberration distribution at the exit pupil of the optical systems. The autocorrelation integral is processed with the Gauss-Legendre integral, and the magnification chromatic aberration is discussed to calculate polychromatic MTF. The MTF calculation results of a given example are then compared with those previously obtained based on the fourth-order wave aberration theory of plane-symmetrical optical systems and with those from the Zemax program. The study shows that MTF based on the sixth-order wave aberration theory has satisfactory calculation accuracy even for a fish-eye lens with a large acceptance aperture. And the impacts of different types of aberrations on the MTF of a fish-eye lens are analyzed. Finally, we apply the self-adaptive and normalized real-coded genetic algorithm and the MTF developed in the paper to optimize the Nikon F/2.8 fish-eye lens; consequently, the optimized system shows better MTF performances than those of the original design.

  10. Public Health England survey of eye lens doses in the UK medical sector

    International Nuclear Information System (INIS)

    Ainsbury, E A; Bouffler, S; Gilvin, P; Peters, S; Slack, K; Cocker, M; Holt, E; Williamson, A

    2014-01-01

    The ICRP has recently recommended that the occupational exposure limit for the lens of the eye be reduced to 20 mSv in a year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. There has been concern amongst some groups of individuals, particularly interventional cardiologists and radiologists as well as relevant professional bodies, that implementation of these recommendations into UK law will adversely affect working patterns. However, despite a number of informative European studies, there is currently little UK dosimetry data available upon which judgements can effectively be based. In order to address this knowledge gap, Public Health England has carried out a small, targeted survey of UK lens doses to medical staff undertaking procedures likely to involve the highest levels of radiation exposure. Two out of a total of 61 individuals surveyed had projected annual doses which could be close to 20 mSv, measured outside lead glasses. Use of protective equipment was generally good; however, lead glasses were only used by 9 participants. The results of this survey suggest that compliance with the ICRP recommendations is likely to be possible for most individuals in the UK medical sector. (paper)

  11. The Use of the Esclera Scleral Contact Lens in the Treatment of Moderate to Severe Dry Eye Disease.

    Science.gov (United States)

    La Porta Weber, Sarah; Becco de Souza, Rodrigo; Gomes, José Álvaro Pereira; Hofling-Lima, Ana Luisa

    2016-03-01

    To evaluate the efficacy of the Esclera scleral contact lens (SCL) treatment and its impact on clinical testing for moderate to severe dry eye disease (DED). Prospective interventional case series. A total of 41 eyes from 25 patients with moderate to severe DED were evaluated for the Esclera SCL treatment. Best-corrected visual acuity (BCVA), tear osmolarity, the Schirmer I test, tear film breakup time (TBUT), corneal and conjunctival staining, meibomian grading, and Ocular Surface Disease Index and SF-36v2 questionnaires were assessed before and after the SCL treatment. These values were compared to assess the real benefit of using SCL as a treatment for DED. Forty-one eyes from 25 patients were fitted with SCL for management of DED. The underlying diseases were Stevens-Johnson syndrome (22 eyes), Sjogren syndrome (11 eyes), graft-vs-host disease (2 eyes), dry eye after keratomileusis in situ (2 eyes), and undifferentiated ocular surface disease (4 eyes). BCVA improved from 0.703 ± 0.55 logMAR with habitual correction to 0.406 ± 0.43 logMAR with SCL (P dry eye symptoms and quality of life as assessed by the OSDI and SF-36v2 questionnaires (both with P dry eye symptoms, and quality of life. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Establishment of a recessive mutant small-eye rat with lens involution and retinal detachment associated with partial deletion and rearrangement of the Cryba1 gene.

    Science.gov (United States)

    Yamada, Toshiyuki; Nanashima, Naoki; Shimizu, Takeshi; Nakazawa, Yosuke; Nakazawa, Mitsuru; Tsuchida, Shigeki

    2015-10-15

    From our stock of SDRs (Sprague-Dawley rats), we established a mutant strain having small opaque eyes and named it HiSER (Hirosaki small-eye rat). The HiSER phenotype is progressive and autosomal recessive. In HiSER eyes, disruption and involution of the lens, thickening of the inner nuclear layer, detachment and aggregation of the retina, rudimentary muscle in the ciliary body and cell infiltration in the vitreous humour were observed. Genetic linkage analysis using crossing with Brown Norway rat suggested that the causative gene(s) is located on chromosome 10. Microarray analysis showed that the expression level of the Cryba1 gene encoding βA3/A1-crystallin on chromosome 10 was markedly decreased in HiSER eyes. Genomic PCR revealed deletion of a 3.6-kb DNA region encompassing exons 4-6 of the gene in HiSERs. In HiSER eyes, a chimaeric transcript of the gene containing exons 1-3 and an approximately 250-bp sequence originating from the 3'-UTR of the Nufip2 gene, located downstream of the breakpoint in the opposite direction, was present. Whereas the chimaeric transcript was expressed in HiSER eyes, neither normal nor chimaeric βA3/A1-crystallin proteins were detected by Western blot analysis. Real-time RT (reverse transcription)-PCR analysis revealed that expression level of the Nufip2 gene in the HiSER eye was 40% of that in the SDR eye. These results suggest that the disappearance of the βA3/A1-crystallin protein and, in addition, down-regulation of the Nufip2 gene as a consequence of gene rearrangement causes the HiSER phenotype. © 2015 Authors; published by Portland Press Limited.

  13. Impact of radiation protection means on the dose to the lens of the eye while handling radionuclides in nuclear medicine

    Energy Technology Data Exchange (ETDEWEB)

    Bruchmann, Iris; Szermerski, Bastian; Geworski, Lilli [Medical School Hannover (Germany). Dept. for Radiation Protection and Medical Physics; Behrens, Rolf [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany)

    2016-07-01

    The human eye lens appears to be more radiosensitive than previously assumed. The reduction of the limit for the dose to the lens of the eye to 20 mSv per year has been passed in the current Euratom Directives (2013). Therefore, in this work the impact of laboratory glasses and X-ray protective goggles was investigated and reciprocal attenuation factors (i.e. transmission factors) for different nuclides (Tc-99m, I-131, Y-90, F-18 and Ga-68) were determined. The radionuclides in typical geometry (syringe, applicator) were positioned at a distance of 50 cm to the eyes of four Alderson-Head-Phantoms. Different dosemeters measuring H{sub p}(3) respective H{sub p}(0.07) were fixed to the eyes of the phantoms, either behind the glasses or without any protection means, respectively. The mean reciprocal attenuation factors were determined to be between unity for F-18 and I-131 using laboratory glasses (no attenuation effect) and < 0.01 for Y-90 using X-ray protective goggles. All other results were between these extremes. It has been shown, that prospective doses to the lens of the eye can be reduced significantly by using appropriate radiation protection means, especially for those dose-relevant beta radiation emitting nuclides such as Y-90.

  14. How do hospital sterilisation procedures affect the response of personal extremity rings and of eye lens TL dosemeters?

    International Nuclear Information System (INIS)

    Kopec, Renata; Bubak, Anna; Budzanowski, Maciej; Sas-Bieniarz, Anna; Szumska, Agnieszka

    2016-01-01

    Stringent standards of hygiene must be applied in medical institutions, especially at operating blocks or during interventional radiology procedures. Medical equipment, including personal dosemeters that have to be worn by medical staff during such procedures, needs therefore to be sterilised. In this study, the effect of various sterilisation procedures has been tested on the dose response of extremity rings and of eye lens dosemeters in which thermoluminescent (TL) detectors (of types MTS-N and MCP-N, respectively) are used. The effects of medical sterilisation procedures were studied: by chemicals, by steam or by ultraviolet (UV), on the dose assessment by extremity rings and by eye lens dosemeters. Since it often happens that a dosemeter is accidentally machine-washed together with protective clothing, the effect of laundering on dose assessment by these dosemeters was also tested. The sterilisation by chemicals is mostly safe for TL detectors assuming that the dosemeters are waterproofed. Following sterilisation by water vapour, the response of these dosemeters diminished by some 30 %, irrespectively of the period of sterilisation; therefore, this method is not recommended. UV sterilisation can be applied to EYE-D TM eye lens dosemeters if their encapsulation is in black. The accidental dosemeter laundry in a washing machine has no impact on measured dose. (authors)

  15. Multiple origin of diurnality in geckos: evidence from eye lens crystallins

    Science.gov (United States)

    Röll, Beate

    2001-05-01

    The large lizard family Gekkonidae comprises about 90 genera (1000 species). While most geckos are nocturnal, the members of about 15 genera are diurnal. All of these species are 'tertiarily' diurnal, i.e. they are descended from 'secondarily' nocturnal ancestors. They have adapted to a diurnal lifestyle in quite different ways, as can be deduced by the crystallin proteins in their lenses. Evaluation of the heterogeneous lens crystallin compositions of diurnal geckos reveals that there are at least three lineages that regained diurnality independently.

  16. Secondary Angle Closure due to Crystalline Lens Dislocation in a Patient with Atopic Dermatitis and Chronic Eye Rubbing

    Directory of Open Access Journals (Sweden)

    Justin Kuiper

    2018-03-01

    Full Text Available Purpose: To report an unusual case of ectopia lentis and angle closure in a patient with chronic eye rubbing. Methods: A 57-year-old male with a history of poorly controlled atopic dermatitis presented with right eye pain, decreased vision, and an intraocular pressure (IOP of 55 mm Hg. He had no past history of ocular disease and no reported history of trauma. He did report a history of chronic eye rubbing. Results: Best corrected visual acuity was hand motions. The examination revealed severe atopic keratoconjunctivitis in both eyes, microcystic corneal edema of the right eye, and 2+ nuclear sclerosis in both eyes. Gonioscopy showed no visible angle structures OD and an open angle OS. Topical and oral IOP-lowering medications and a laser iridotomy were unsuccessful at lowering IOP. He was taken to the operating room for a lensectomy and was found to have 9 clock hours of zonular dehiscence and a dislocated lens. After lensectomy, the IOP improved to 9 mm Hg on postoperative day 1. A follow-up examination at 2 weeks showed improved acuity to 20/150 with a pinhole and an IOP of 10 mm Hg. A dilated examination OS did not reveal significant phacodonesis, and the patient was referred for a possible sutured sulcus lens or anterior chamber intraocular lens. Conclusions: It is important for the provider to consider ectopia lentis in the differential for patients with pupillary block angle closure. For patients with atopic disease, one should be aware that eye rubbing may be a cause of zonular dehiscence, even in the absence of reported trauma or prior intraocular surgery.

  17. HOW DO HOSPITAL STERILISATION PROCEDURES AFFECT THE RESPONSE OF PERSONAL EXTREMITY RINGS AND OF EYE LENS TL DOSEMETERS?

    Science.gov (United States)

    Kopeć, Renata; Bubak, Anna; Budzanowski, Maciej; Sas-Bieniarz, Anna; Szumska, Agnieszka

    2016-09-01

    Stringent standards of hygiene must be applied in medical institutions, especially at operating blocks or during interventional radiology procedures. Medical equipment, including personal dosemeters that have to be worn by medical staff during such procedures, needs therefore to be sterilised. In this study, the effect of various sterilisation procedures has been tested on the dose response of extremity rings and of eye lens dosemeters in which thermoluminescent (TL) detectors (of types MTS-N and MCP-N, respectively) are used. The effects of medical sterilisation procedures were studied: by chemicals, by steam or by ultraviolet (UV), on the dose assessment by extremity rings and by eye lens dosemeters. Since it often happens that a dosemeter is accidentally machine-washed together with protective clothing, the effect of laundering on dose assessment by these dosemeters was also tested. The sterilisation by chemicals is mostly safe for TL detectors assuming that the dosemeters are waterproofed. Following sterilisation by water vapour, the response of these dosemeters diminished by some 30 %, irrespectively of the period of sterilisation; therefore, this method is not recommended. UV sterilisation can be applied to EYE-D™ eye lens dosemeters if their encapsulation is in black. The accidental dosemeter laundry in a washing machine has no impact on measured dose. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. A and B mode ultrasonography in preoperative evaluation of lens and posterior segment of dogs eyes with cataract

    Directory of Open Access Journals (Sweden)

    Bianca C. Martins

    2010-02-01

    Full Text Available Ultrasonography of the lens and posterior segment is an indispensable step in the preoperative evaluation of dogs with cataracts, since ophthalmoscopy is not feasible when there is opacification of the lens. This study evaluated the echographic conditions of cataractous lens and fundus of the eye in dogs affected by cataracts. The study was conducted in 30 dogs (56 eyes, 10 males and 20 females, with different types of cataracts at different stages of development. Echography in A and B modes, simultaneously, was carried out for the examination of the lens and posterior segment. The examinations revealed anterior cortical, posterior cortical and nuclear cataract in 12 eyes (21.4%, anterior cortical, posterior cortical, nuclear and posterior capsular in 23 eyes (41%, anterior cortical, posterior cortical and posterior capsular cataract in one eye (1.7%, anterior cortical and nuclear cataract in one eye (1.7%, anterior cortical, nuclear and posterior capsular cataract in five eyes (8.9%, and anterior cortical cataract in seven eyes (12.5%. Abnormal ultrasonographic alterations were observed in the posterior segment in 26 eyes evaluated (46.4%. Vitreal degeneration was detected in 12 eyes (21.4%, images of vitreal exudate or hemorrhage in seven eyes (12.5%, persistence of hyaloid artery in four eyes (7.1% and lens subluxation in three eyes (5.3%. The results obtained reiterate the importance of ultrasonography in canine patients presented for cataract surgery given that alterations of the posterior segment are difficult to identify in a clinical examination when the lens is opacified.A ultrassonografia do segmento posterior do bulbo do olho é etapa indispensável na avaliação de cães com catarata que serão submetidos à facectomia, uma vez que a oftalmoscopia não é factível quando há opacificação da lente, notadamente nas cataratas maduras. Este estudo avaliou as condições ecográficas da lente cataratogênica e do fundo de olho de c

  19. Expression of c-Fos and c-Jun in the cornea, lens, and retina after ultraviolet irradiation of the rat eye and effect of topical antisense oligodeoxynucleotides

    International Nuclear Information System (INIS)

    Gillardon, F.; Zimmermann, M.

    1995-01-01

    Aims - Immunohistochemical techniques were used to investigate c-Fos and c-Jun proto-oncogene expression in the cornea, lens, and retina after ultraviolet irradiation of the rat eye. Methods -Eyes of anaesthetised rats were exposed to 1.5 J/cm 2 of ultraviolet radiation (280-380 nm). Animals were perfused 1, 6, or 24 hours after irradiation and tissue sections were incubated with specific antiserum to c-Fos and c-Jun, respectively. Non-irradiated contralateral eyes displayed no c-Fos and c-Jun immunoreactivity. One and 6 hours after ultraviolet exposure numerous c-Fos and c-Jun immunopositive nuclei were observed mainly in the epithelial cell layers of the cornea and the lens epithelium. Scattered labelled nuclei were detectable in the retinal ganglion cell layer and the inner nuclear layer. Twenty four hours after irradiation c-Fos and c-Jun protein expression returned to near control levels. Histological signs of ultraviolet damage (for example, chromatin condensation, nuclear fragmentation) were first recognisable in the corneal epithelium 6 hours after irradiation and became more apparent at later times. The rapid and sustained activation of c-Fos and c-Jun expression in the eye after single ultraviolet exposure may represent the molecular mechanism underlying ultraviolet induced photodamage and initiation of cell death. Furthermore, topical application of a c-fos antisense oligode-oxynucleotide to the ultraviolet exposed rat eye inhibited the increase in c-Fos expression in the cornea, suggesting therapeutic activity of antisense drugs in corneal malignant and infectious diseases. (author)

  20. DYNAMIC CHANGES OF THE POSTERIOR POLE OF THE EYE AFTER CATARACT PHACOEMULSIFICATION WITH INTRAOCULAR LENS IMPLANTATION

    Directory of Open Access Journals (Sweden)

    M. Р. Yugay

    2017-01-01

    Full Text Available Objective. To study the effect of uncomplicated phacoemulsification through the corneal incision with implantation of the intraocular lens (IOL for changes in the macular region of the retina. Methods: The study included 35 eyes of 35 patients who underwent uncomplicated phacoemulsification with IOL implantation. The average age of the patients was 67±2,3 years, among them were 19 women and 16 men. Exclusion criteria: retinal pathology (postthrombotic and diabetic retinopathy, wet form of age-related macular degeneration and other diseases of the retina, previous eye injuries, uveitis, intra-operative complications. Retinal thickness in the fovea, the macula, and macular volume were measured by optical coherence tomography on the first day, after 2 weeks, 1 and 3 months after surgery. Results. In the period between the first day and two weeks after surgery there were the statistically significant incensement in retinal thickness in the macula from 306,64±21,15 mkm to 321,46±27,83 mkm (p <0.05, in the fovea from 211,45±20,24 mkm to 218,69±17,84 mkm (p<0.05, macular volume from 8,08±0,35 cubic mm to 8,46±0,54 cubic mm were registered. By the end of the first month after surgery maximum retinal thickness was 327,23±27,16 mkm, thickness in the fovea 220,31±18,63 mkm, macular volume 8,61±0,55 cubic mm. After 3 months, the maximum thickness of the retina reached 325,11±26,13 mkm, in the fovea 220,31±18,63 mkm, macular volume 8,55±0,49 cubic mm. Conclusion. There was an incensement of macular volume and retinal thickness in the period between the first day and two weeks after uncomplicated cataract phacoemulsification with intraocular lens implantation. The growth of these indicators continued within the first month after surgery, three months after phacoemulsification there was a downward trend. This can be important in determining the duration of drug therapy in the postoperative period.

  1. Interim report of the JHPS expert committee on radiation protection of the lens of the eye (4). Current activities of ICRP and ICU: External dosimetric concepts for the lens of the eye

    International Nuclear Information System (INIS)

    Akahane, Keiichi; Tatsuzaki, Hideo; Iimoto, Takeshi; Ichiji, Takeshi; Hamada, Nobuyuki; Fujimichi, Yuki; Iwai, Satoshi; Ohguchi, Hiroyuki; Ohno, Kazuko; Yamauchi-Kawaura, Chiyo; Tsujimura, Norio; Hotta, Yutaka; Yamasaki, Tadashi; Yokoyama, Sumi

    2015-01-01

    The International Commission on Radiological Protection (ICRP) and the International Commission on Radiation Units and Measurements (ICRU) have been defined operational quantities and protection quantities. Dose limits have been also recommended by the ICRP using protection quantities. These quantities and some related values for main radiation such as photons, electrons, and neutrons, are summarized in this article with some historical considerations. The ICRP indicated conversion coefficients for the lens of the eye as absorbed dose per fluence as protection quantities. equivalent dose is not used because a protection quantity that uses radiation weighting factors is not intended to be calculated for tissue reactions. So far, the ICRP has not indicated a specific RBE value for cataract formation. Operational quantities are used for measurements. There have been three types of phantoms, namely a slab phantom, a reduced phantom, and a cylindrical phantom, but none of them has been definitely recommended for the lens of the eye by the ICRP or the ICRU. Although conversion coefficients to personal dose equivalent, H p (3), for electrons have been recommended, no other conversion coefficients to personal dose equivalent for the lens of the eye has been indicated by the ICRP or the ICRU. However, there have been several studies described personal dose equivalent. Ambient dose equivalent, H * (3), and directional dose equivalent, H(3, α), have been indicated in several limited conditions by the ICRP and the ICRU. These status are overviewed in this article. (author)

  2. Imaging properties of the light sword optical element used as a contact lens in a presbyopic eye model.

    Science.gov (United States)

    Petelczyc, K; Bará, S; Lopez, A Ciro; Jaroszewicz, Z; Kakarenko, K; Kolodziejczyk, A; Sypek, M

    2011-12-05

    The paper analyzes the imaging properties of the light sword optical element (LSOE) applied as a contact lens to the presbyopic human eye. We performed our studies with a human eye model based on the Gullstrand parameterization. In order to quantify the discussion concerning imaging with extended depth of focus, we introduced quantitative parameters characterizing output images of optotypes obtained in numerical simulations. The quality of the images formed by the LSOE were compared with those created by a presbyopic human eye, reading glasses and a quartic inverse axicon. Then we complemented the numerical results by an experiment where a 3D scene was imaged by means of the refractive LSOE correcting an artificial eye based on the Gullstrand model. According to performed simulations and experiments the LSOE exhibits abilities for presbyopia correction in a wide range of functional vision distances.

  3. Implications in dosimetry of the implementation of the revised dose limit to the lens of the eye

    International Nuclear Information System (INIS)

    Broughton, J.; Shah, B.; Cantone, M.C.; Ginjaume, M.; Czarwinski, R.

    2015-01-01

    In 2012, International Radiation Protection Association (IRPA) established a Task Group to provide an assessment of the impact of the implementation of the ICRP-revised dose limit for the lens of the eye for occupational exposure. Associated Societies (ASs) of IRPA were asked to provide views and comments on the basis of a questionnaire addressing three principal topics: (i) implications for dosimetry, (ii) implications for methods of protection and (iii) wider implications of implementing the revised limits. A summary of the collated responses regarding dosimetry is presented and discussed. There is large agreement on the most critical aspects and difficulties in setting up an appropriate monitoring programme for the lens of the eyes. The recent international standards and technical documents provide guidance for some of the concerns but other challenges remain in terms of awareness, acceptance and practicalities. (authors)

  4. SU-E-I-57: Estimating the Occupational Eye Lens Dose in Interventional Radiology Using Active Personal Dosimeters Worn On the Chest

    Energy Technology Data Exchange (ETDEWEB)

    Omar, A; Marteinsdottir, M; Kadesjo, N; Fransson, A [Dept. of Medical Physics, Karolinska University Hospital, Stockholm (Sweden)

    2015-06-15

    Purpose: To provide a general formalism for determination of occupational eye lens dose based on the response of an active personal dosimeter (APD) worn at chest level above the radiation protection apron. Methods: The formalism consists of three factors: (1) APD conversion factor converting the reading at chest level (APDchest) to the corresponding personal dose equivalent at eye level, (2) Dose conversion factor transferring the measured dose quantity, Hp(10), into a dose quantity relevant for the eye lens dose, (3) Correction factor accounting for differences in exposure of the eye(s) compared to the exposure at chest level (e.g., due to protective lead glasses).The different factors were investigated and evaluated based on phantom and clinical measurements performed in an x-ray angiography suite for interventional cardiology. Results: The eye lens dose can be conservatively estimated by assigning an appropriate numerical value to each factor entering the formalism that in most circumstances overestimates the dose. Doing so, the eye lens dose to the primary operator and assisting staff was estimated in this work as D-eye,primary = 2.0 APDchest and D-eye,assisting = 1.0 APDchest, respectively.The annual eye lens dose to three nurses and one cardiologist was estimated to be 2, 2, 2, and 13 mSv (Hp(0.07)), respectively, using a TLD dosimeter worn at eye level. In comparison, using the formalism and APDchest measurements, the respective doses were 2, 2, 2, and 16 mSv (Hp(3)). Conclusion: The formalism outlined in this work can be used to estimate the occupational eye lens dose from the response of an APD worn on the chest. The formalism is general and could be applied also to other types of dosimeters. However, the numerical value of the different factors may differ from those obtained with the APD’s used in this work due to differences in dosimeter properties.

  5. SU-E-I-57: Estimating the Occupational Eye Lens Dose in Interventional Radiology Using Active Personal Dosimeters Worn On the Chest

    International Nuclear Information System (INIS)

    Omar, A; Marteinsdottir, M; Kadesjo, N; Fransson, A

    2015-01-01

    Purpose: To provide a general formalism for determination of occupational eye lens dose based on the response of an active personal dosimeter (APD) worn at chest level above the radiation protection apron. Methods: The formalism consists of three factors: (1) APD conversion factor converting the reading at chest level (APDchest) to the corresponding personal dose equivalent at eye level, (2) Dose conversion factor transferring the measured dose quantity, Hp(10), into a dose quantity relevant for the eye lens dose, (3) Correction factor accounting for differences in exposure of the eye(s) compared to the exposure at chest level (e.g., due to protective lead glasses).The different factors were investigated and evaluated based on phantom and clinical measurements performed in an x-ray angiography suite for interventional cardiology. Results: The eye lens dose can be conservatively estimated by assigning an appropriate numerical value to each factor entering the formalism that in most circumstances overestimates the dose. Doing so, the eye lens dose to the primary operator and assisting staff was estimated in this work as D-eye,primary = 2.0 APDchest and D-eye,assisting = 1.0 APDchest, respectively.The annual eye lens dose to three nurses and one cardiologist was estimated to be 2, 2, 2, and 13 mSv (Hp(0.07)), respectively, using a TLD dosimeter worn at eye level. In comparison, using the formalism and APDchest measurements, the respective doses were 2, 2, 2, and 16 mSv (Hp(3)). Conclusion: The formalism outlined in this work can be used to estimate the occupational eye lens dose from the response of an APD worn on the chest. The formalism is general and could be applied also to other types of dosimeters. However, the numerical value of the different factors may differ from those obtained with the APD’s used in this work due to differences in dosimeter properties

  6. Rybp, a polycomb complex-associated protein, is required for mouse eye development

    Directory of Open Access Journals (Sweden)

    Schreiber-Agus Nicole

    2007-04-01

    Full Text Available Abstract Background Rybp (Ring1 and YY1 binding protein is a zinc finger protein which interacts with the members of the mammalian polycomb complexes. Previously we have shown that Rybp is critical for early embryogenesis and that haploinsufficiency of Rybp in a subset of embryos causes failure of neural tube closure. Here we investigated the requirement for Rybp in ocular development using four in vivo mouse models which resulted in either the ablation or overexpression of Rybp. Results Our results demonstrate that loss of a single Rybp allele in conventional knockout mice often resulted in retinal coloboma, an incomplete closure of the optic fissure, characterized by perturbed localization of Pax6 but not of Pax2. In addition, about one half of Rybp-/- Rybp+/+ chimeric embryos also developed retinal colobomas and malformed lenses. Tissue-specific transgenic overexpression of Rybp in the lens resulted in abnormal fiber cell differentiation and severe lens opacification with increased levels of AP-2α and Sox2, and reduced levels of βA4-crystallin gene expression. Ubiquitous transgenic overexpression of Rybp in the entire eye caused abnormal retinal folds, corneal neovascularization, and lens opacification. Additional changes included defects in anterior eye development. Conclusion These studies establish Rybp as a novel gene that has been associated with coloboma. Other genes linked to coloboma encode various classes of transcription factors such as BCOR, CBP, Chx10, Pax2, Pax6, Six3, Ski, Vax1 and Vax2. We propose that the multiple functions for Rybp in regulating mouse retinal and lens development are mediated by genetic, epigenetic and physical interactions between these genes and proteins.

  7. Retropupillary Fixation of Iris-Claw Intraocular Lens for Aphakic Eyes in Children.

    Directory of Open Access Journals (Sweden)

    Martina Brandner

    Full Text Available To report outcome, complications and safety of retropupillary fixated iris-claw intraocular lenses in a pediatric population.Retrospective study.Ten consecutive pediatric patients (15 eyes underwent placement of retropupillary fixated iris-claw intraocular lenses between October 2007 and July 2013 at the Department of Ophthalmology, Medical University Graz and General Hospital Klagenfurt, Austria. Postoperative visual acuity and complications were analyzed.Median final best-corrected visual acuity improved by 0.12 logMAR from preoperative baseline. Mean postoperative spherical equivalent was -0.05 ± 1.76 D. No serious complications were observed intra- or postoperatively during the entire follow-up period of up to 40 months. One patient experienced a haptic disenclavation with IOL subluxation immediately after a car accident.Our study demonstrates that iris-claw intraocular lens implantation behind the iris is safe in children with lack of capsular support and yields excellent visual outcome with low complication rate.

  8. Spontaneous bilateral anterior partial in-the-bag intraocular lens dislocation following routine annual eye examination.

    Science.gov (United States)

    Ford, Joshua R; Werner, Liliana; Owen, Leah; Vasavada, Shail A; Crandall, Alan

    2014-09-01

    We present the case of an 81-year-old man with pseudoexfoliation syndrome (PXF) in whom spontaneous bilateral anterior partial in-the-bag intraocular lens (IOL) dislocation was diagnosed following a routine dilated examination that demonstrated only mild pseudophacodonesis with no evidence of subluxation. Uneventful cataract surgery with placement of single-piece hydrophobic acrylic posterior chamber IOLs had been performed in both eyes 7 years previously. Bilateral IOL repositioning with scleral fixation was performed to correct the dislocation. Postoperative examinations showed remarkable improvement in visual acuity and IOL stability. We hypothesize that zonular weakness secondary to PXF predisposed the patient to bilateral IOL partial dislocation. Pupil dilation in the setting of mild pseudophacodonesis at the time of routine examination may have been a precipitating factor. To our knowledge, bilateral IOL subluxation/dislocation has been described in a limited number of case reports. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  9. Retropupillary Fixation of Iris-Claw Intraocular Lens for Aphakic Eyes in Children

    Science.gov (United States)

    Brandner, Martina; Thaler-Saliba, Sarah; Plainer, Sophie; Vidic, Bertram; El-Shabrawi, Yosuf; Ardjomand, Navid

    2015-01-01

    Purpose To report outcome, complications and safety of retropupillary fixated iris-claw intraocular lenses in a pediatric population. Design Retrospective study. Patients and Methods Ten consecutive pediatric patients (15 eyes) underwent placement of retropupillary fixated iris-claw intraocular lenses between October 2007 and July 2013 at the Department of Ophthalmology, Medical University Graz and General Hospital Klagenfurt, Austria. Postoperative visual acuity and complications were analyzed. Results Median final best-corrected visual acuity improved by 0.12 logMAR from preoperative baseline. Mean postoperative spherical equivalent was -0.05 ± 1.76 D. No serious complications were observed intra- or postoperatively during the entire follow-up period of up to 40 months. One patient experienced a haptic disenclavation with IOL subluxation immediately after a car accident. Conclusion Our study demonstrates that iris-claw intraocular lens implantation behind the iris is safe in children with lack of capsular support and yields excellent visual outcome with low complication rate. PMID:26110864

  10. Crystalline lens - Eyes under high radiological protection. From regulation to acts. With neuro-radiologists of the Pitie-Salpetriere

    International Nuclear Information System (INIS)

    2014-01-01

    As the limit exposure of workers' crystalline lens to ionizing radiations is about to be lowered, this set of three articles proposes an overview of this specific issue. A recent study performed by the IRSN revealed that interventional cardiologists display four more crystalline lens opacification that the rest of the population, and also revealed that other incidents could affect the eyes of some operators of nuclear medicine. In interventional radiology, fingers, fists and eyes are the most exposed and have not been so well protected as the rest of the body. After dosimetry measurements, the use of protective glasses has been introduced. These protective measures could be applied in other nuclear activities. Studies are being performed on the eyes of children living in areas contaminated by the Chernobyl accident. A second article comments the various actions and initiatives aiming at limiting the dose received by the crystalline lens: preparation of a new regulation for the follow-up of exposed workers, definition of standards for dose measurement devices, risk assessments, recommendation to interventional radiologists to optimize their exposure (process, protective clothes, and so on). A last article briefly reports the implementation of a dose follow-up for interventional neuro-radiologists in a Parisian hospital

  11. Micropogonias furnieri (Desmarest, 1823: estudo quali-quantitativo da variação ontogenética do padrão eletroforético de proteínas gerais do cristalino Micropogonias furnieri (Desmarest, 1823 quali-quantitative studies on ontogenetic variation of the electrophoretic patterns of eye-lens proteins

    Directory of Open Access Journals (Sweden)

    Anna Emília Amato de Moraes Vazzoler

    1985-01-01

    -1, III-2, IV-1; b - comparar padrões de exemplares dentro de um estreito intervalo de comprimentos; c - comparar frações que variam, apenas para indivíduos com comprimentos a partir dos quais a concentração dessas frações já se estabilizou (II-2 e III-3 a partir de 300 mm, e I e IV-2 de 450 mm; d - comparar os padrões globais de indivíduos que integram o extrato adulto da populaçao, quando já ocorreu estabilização do número e da concentração das frações protéicas. Esta ultima estratégia (d parece ser a mais viável, tanto a nível interespecífico quando a finalidade é restrita à delimitação espacial de populações, como em estudos taxonomicos de níveis superiores, quando nao há problemas na classificação de formas jovens.In population studies based on genetic-biochemical markers, variations induced by ontogenetic development, sex and gonad maturation act as a potencial source of bias. These aspects were analysed for patterns of eye-lens proteins of Micropogonias furnieri (Sciaenidae, following electrophoregrams obtained from 546 specimens ranging from 98 and 710 mm in length, collected along the southeastern Brazilian coast (23º S - 29º21'S. Proteins were extracted in 0.9% NaCl solution, processed on cellulose acetate membranes in a bridge buffer discontinuous system trisglicine-barbital, for 25 minutes at 300 V, and stained with Ponceau S. The basic pattern obtained was divided into 4 sets and 8 fractions, that were evaluated by scanning in a ATAGO-QUICK densitometer. No differences were found in the patterns of right and left eye-lens, male and female and maturity stages for the same length class. Patterns variations related to ontogenetic development were found: set I present a decrease, while sets II, III and IV show an increase in their relative concentration. Set II showed two fractions for young (until 300-350 mm and only one for adults. Fractions I, II-1, II-2, III-3 become stable above 300-350 mm and I and IV-2 above 450

  12. Efficiency of radiation protection equipment in interventional radiology: a systematic Monte Carlo study of eye lens and whole body doses

    International Nuclear Information System (INIS)

    Koukorava, C; Farah, J; Clairand, I; Donadille, L; Struelens, L; Vanhavere, F; Dimitriou, P

    2014-01-01

    Monte Carlo calculations were used to investigate the efficiency of radiation protection equipment in reducing eye and whole body doses during fluoroscopically guided interventional procedures. Eye lens doses were determined considering different models of eyewear with various shapes, sizes and lead thickness. The origin of scattered radiation reaching the eyes was also assessed to explain the variation in the protection efficiency of the different eyewear models with exposure conditions. The work also investigates the variation of eye and whole body doses with ceiling-suspended shields of various shapes and positioning. For all simulations, a broad spectrum of configurations typical for most interventional procedures was considered. Calculations showed that ‘wrap around’ glasses are the most efficient eyewear models reducing, on average, the dose by 74% and 21% for the left and right eyes respectively. The air gap between the glasses and the eyes was found to be the primary source of scattered radiation reaching the eyes. The ceiling-suspended screens were more efficient when positioned close to the patient’s skin and to the x-ray field. With the use of such shields, the H p (10) values recorded at the collar, chest and waist level and the H p (3) values for both eyes were reduced on average by 47%, 37%, 20% and 56% respectively. Finally, simulations proved that beam quality and lead thickness have little influence on eye dose while beam projection, the position and head orientation of the operator as well as the distance between the image detector and the patient are key parameters affecting eye and whole body doses. (paper)

  13. Reactive Oxygen Species and the Aging Eye: Specific Role of Metabolically Active Mitochondria in Maintaining Lens Function and in the Initiation of the Oxidation-Induced Maturity Onset Cataract--A Novel Platform of Mitochondria-Targeted Antioxidants With Broad Therapeutic Potential for Redox Regulation and Detoxification of Oxidants in Eye Diseases.

    Science.gov (United States)

    Babizhayev, Mark A; Yegorov, Yegor E

    2016-01-01

    The aging eye appears to be at considerable risk from oxidative stress. A great deal of research indicates that dysfunctional mitochondria are the primary site of reactive oxygen species (ROS). More than 95% of O2 produced during normal metabolism is generated by the electron transport chain in the inner mitochondrial membrane. Mitochondria are also the major target of ROS. Cataract formation, the opacification of the eye lens, is one of the leading causes of human blindness worldwide, accounting for 47.8% of all causes of blindness. Cataracts result from the deposition of aggregated proteins in the eye lens and lens fiber cell plasma membrane damage, which causes clouding of the lens, light scattering, and obstruction of vision. ROS-induced damage in the lens cell may consist of oxidation of proteins, DNA damage, and/or lipid peroxidation, all of which have been implicated in cataractogenesis. This article is an attempt to integrate how mitochondrial ROS are altered in the aging eye along with those protective and repair therapeutic systems believed to regulate ROS levels in ocular tissues and how damage to these systems contributes to age-onset eye disease and cataract formation. Mitochondria-targeted antioxidants might be used to effectively prevent ROS-induced oxidation of lipids and proteins in the inner mitochondrial membrane in vivo. As a result of the combination of weak metal chelating, OH and lipid peroxyl radicals scavenging, reducing activities to liberated fatty acid, and phospholipid hydroperoxides, carnosine and carcinine appear to be physiological antioxidants able to efficiently protect the lipid phase of biologic membranes and aqueous environments and act as the antiapoptotic natural drug compounds The authors developed and patented the new ophthalmic compositions, including N-acetylcarnosine, acting as a prodrug of naturally targeted to mitochondria L-carnosine endowed with pluripotent antioxidant activities combined with mitochondria

  14. SU-F-T-86: Electron Dosimetric Effects of Bolus and Lens Shielding in Treating Superficial Eye Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Young, L [University of Washington Medical Center, Seattle, WA (United States); Wootton, L [University of Washington School of Medicine, Seattle, WA (United States); Gopan, O; Liao, J [University of Washington, Seattle, WA (United States)

    2016-06-15

    Purpose: Electron therapy for the treatment of ocular lymphomas requires the lens to be shielded to prevent secondary cataracts. This work evaluates the dosimetry under a suspended eyeshield with and without bolus for low energy electron fields. Methods: Film (GafChromic EBT3) dosimetry and relative output factors were measured for 6, 8, and 10 MeV electron energies. A customized 5 cm diameter circle electron orbital cutout was constructed for a 6×6 cm applicator with a lens shield, 1 cm diameter Cerrobend cylinder with 2.2 cm length, suspended from an XV film covering the open field. Relative output factors were measured using a Scanditronix electron diode in a solid water phantom. Depth dose profiles were collected for bolus thicknesses of 0, 3, and 5 mm in solid water at a source to surface distance (SSD) of 100 cm. These measurements were repeated in a Rando phantom. Results: At 5 mm, the approximate distance of the lens from the surface of the cornea, the estimated dose in solid water under the suspended lens shield was reduced to 16%, 14%, and 13% of the unblocked dose at the same depth, for electron energies of 6, 8, and 10 MeV, respectively. Applying bolus increased estimated doses under the block to 22% for 3-mm and 32% for 5-mm thicknesses for a 6 MeV incident electron beam. This effect is reduced for higher energies where the corresponding values were 15.5% and 18% for 3-mm and 5-mm for an 8 MeV electron beam. Conclusion: The application of bolus to treat superficial eye lesions of the conjunctiva increases lens dose at a depth of 5-mm under the shielding block with decreasing electron energy. Careful selection of electron energy is needed to account for electron scatter under the lens shield with the application of bolus in order to prevent cataracts.

  15. Cross-linking of lens crystallin proteins induced by tryptophan metabolites and metal ions

    DEFF Research Database (Denmark)

    Tweeddale, Helen J; Hawkins, Clare Louise; Janmie, Joane F

    2016-01-01

    Long-wavelength solar UV radiation is implicated in photodamage to the human eye. The human lens contains multiple tryptophan-derived compounds that have significant absorbance bands in the UVA region (λ 315-400 nm) that act as efficient physical filters for these wavelengths. The concentrations...

  16. Interim report of the JHPS expert committee on radiation protection of the lens of the eye (5). Current occupational radiation exposure of the lens of the eye in Japan

    International Nuclear Information System (INIS)

    Akahane, Keiichi; Tatsuzaki, Hideo; Iimoto, Takeshi; Ichiji, Takeshi; Hamada, Nobuyuki; Fujimichi, Yuki; Iwai, Satoshi; Ohguchi, Hiroyuki; Ohno, Kazuko; Yamauchi-Kawaura, Chiyo; Tsujimura, Norio; Hotta, Yutaka; Yamasaki, Tadashi; Yokoyama, Sumi

    2015-01-01

    For many Japanese radiation workers in the medical, nuclear and other industrial fields, the equivalent dose of the lens of the eye will be sufficiently lower than the new ICRP dose limit. However, the dose of the eye for medical staff members who are engaged in interventional radiology and cardiology may exceed the new ICRP dose limit, especially when they are exposed closely to higher scatter radiation for a long time. In addition, the radiation dosimetry and radiation protection for emergency and recovery workers in the Fukushima Daiichi Nuclear Power Plant (FNPP1) are important issues. Thus gathering information related to the radiation dose and protection for Japanese radiation workers is important to a discussion regarding implementation of the new ICRP dose limit for the lens of the eye for Japanese regulations and planning radiation dose reduction measures. In this paper, recent studies and issues regarding radiation exposure and protection in the medical, nuclear and other industrial fields, as well as for emergency and recovery workers in the FNPP1 were summarized. (author)

  17. Combination of confocal principle and aperture stop separation improves suppression of crystalline lens fluorescence in an eye model.

    Science.gov (United States)

    Klemm, Matthias; Blum, Johannes; Link, Dietmar; Hammer, Martin; Haueisen, Jens; Schweitzer, Dietrich

    2016-09-01

    Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a new technique to detect changes in the human retina. The autofluorescence decay over time, generated by endogenous fluorophores, is measured in vivo. The strong autofluorescence of the crystalline lens, however, superimposes the intensity decay of the retina fluorescence, as the confocal principle is not able to suppress it sufficiently. Thus, the crystalline lens autofluorescence causes artifacts in the retinal fluorescence lifetimes determined from the intensity decays. Here, we present a new technique to suppress the autofluorescence of the crystalline lens by introducing an annular stop into the detection light path, which we call Schweitzer's principle. The efficacy of annular stops with an outer diameter of 7 mm and inner diameters of 1 to 5 mm are analyzed in an experimental setup using a model eye based on fluorescent dyes. Compared to the confocal principle, Schweitzer's principle with an inner diameter of 3 mm is able to reduce the simulated crystalline lens fluorescence to 4%, while 42% of the simulated retina fluorescence is preserved. Thus, we recommend the implementation of Schweitzer's principle in scanning laser ophthalmoscopes used for fundus autofluorescence measurements, especially the FLIO device, for improved image quality.

  18. Your Eyes

    Science.gov (United States)

    ... away? If you guessed the eye, you're right! Your eyes are at work from the moment you wake up to the ... the eye is seeing. A Muscle Makes It Work The lens is suspended in ... of the lens. That's right — the lens actually changes shape right inside your ...

  19. Clinical evaluation of a dose monitoring software tool based on Monte Carlo Simulation in assessment of eye lens doses for cranial CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Guberina, Nika; Suntharalingam, Saravanabavaan; Nassenstein, Kai; Forsting, Michael; Theysohn, Jens; Wetter, Axel; Ringelstein, Adrian [University Hospital Essen, Institute of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

    2016-10-15

    The aim of this study was to verify the results of a dose monitoring software tool based on Monte Carlo Simulation (MCS) in assessment of eye lens doses for cranial CT scans. In cooperation with the Federal Office for Radiation Protection (Neuherberg, Germany), phantom measurements were performed with thermoluminescence dosimeters (TLD LiF:Mg,Ti) using cranial CT protocols: (I) CT angiography; (II) unenhanced, cranial CT scans with gantry angulation at a single and (III) without gantry angulation at a dual source CT scanner. Eye lens doses calculated by the dose monitoring tool based on MCS and assessed with TLDs were compared. Eye lens doses are summarized as follows: (I) CT angiography (a) MCS 7 mSv, (b) TLD 5 mSv; (II) unenhanced, cranial CT scan with gantry angulation, (c) MCS 45 mSv, (d) TLD 5 mSv; (III) unenhanced, cranial CT scan without gantry angulation (e) MCS 38 mSv, (f) TLD 35 mSv. Intermodality comparison shows an inaccurate calculation of eye lens doses in unenhanced cranial CT protocols at the single source CT scanner due to the disregard of gantry angulation. On the contrary, the dose monitoring tool showed an accurate calculation of eye lens doses at the dual source CT scanner without gantry angulation and for CT angiography examinations. The dose monitoring software tool based on MCS gave accurate estimates of eye lens doses in cranial CT protocols. However, knowledge of protocol and software specific influences is crucial for correct assessment of eye lens doses in routine clinical use. (orig.)

  20. Clinical evaluation of a dose monitoring software tool based on Monte Carlo Simulation in assessment of eye lens doses for cranial CT scans

    International Nuclear Information System (INIS)

    Guberina, Nika; Suntharalingam, Saravanabavaan; Nassenstein, Kai; Forsting, Michael; Theysohn, Jens; Wetter, Axel; Ringelstein, Adrian

    2016-01-01

    The aim of this study was to verify the results of a dose monitoring software tool based on Monte Carlo Simulation (MCS) in assessment of eye lens doses for cranial CT scans. In cooperation with the Federal Office for Radiation Protection (Neuherberg, Germany), phantom measurements were performed with thermoluminescence dosimeters (TLD LiF:Mg,Ti) using cranial CT protocols: (I) CT angiography; (II) unenhanced, cranial CT scans with gantry angulation at a single and (III) without gantry angulation at a dual source CT scanner. Eye lens doses calculated by the dose monitoring tool based on MCS and assessed with TLDs were compared. Eye lens doses are summarized as follows: (I) CT angiography (a) MCS 7 mSv, (b) TLD 5 mSv; (II) unenhanced, cranial CT scan with gantry angulation, (c) MCS 45 mSv, (d) TLD 5 mSv; (III) unenhanced, cranial CT scan without gantry angulation (e) MCS 38 mSv, (f) TLD 35 mSv. Intermodality comparison shows an inaccurate calculation of eye lens doses in unenhanced cranial CT protocols at the single source CT scanner due to the disregard of gantry angulation. On the contrary, the dose monitoring tool showed an accurate calculation of eye lens doses at the dual source CT scanner without gantry angulation and for CT angiography examinations. The dose monitoring software tool based on MCS gave accurate estimates of eye lens doses in cranial CT protocols. However, knowledge of protocol and software specific influences is crucial for correct assessment of eye lens doses in routine clinical use. (orig.)

  1. Low-dose CT of the paranasal sinuses with eye lens protection: effect on image quality and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Hein, Eike; Rogalla, Patrik; Klingebiel, Randolph; Hamm, Bernd [Department of Diagnostic and Interventional Radiology, Charite Hospital, Humboldt-Universitaet zu Berlin (Germany)

    2002-07-01

    The purpose of the study was to assess the effect of lens protection on image quality and radiation dose to the eye lenses in CT of the paranasal sinuses. In 127 patients referred to rule out sinusitis, an axial spiral CT with a lens protection placed on the patients eyes was obtained (1.5/2/1, 50 mAs, 120 kV). Coronal views were reconstructed at 5-mm interval. To quantify a subjective impression of image quality, three regions of interest within the eyeball were plotted along a line perpendicular to the protection at 2, 5, and 9 mm beneath skin level on the axial images. Additionally, dose reduction of a bismuth-containing latex shield was measured using a film-dosimetry technique. The average eyeball density was 17.97 HU (SD 3.7 HU). The relative increase in CT density was 180.6 (17.7), 103.3 (11.7), and 53.6 HU (9.2), respectively. There was no diagnostic information loss on axial and coronal views observed. Artifacts were practically invisible on images viewed in a bone window/level setting. The use of the shield reduced skin radiation from 7.5 to 4.5 mGy. The utilization of a radioprotection to the eye lenses in paranasal CT is a suitable and effective means of reducing skin radiation by 40%. (orig.)

  2. Low-dose CT of the paranasal sinuses with eye lens protection: effect on image quality and radiation dose

    International Nuclear Information System (INIS)

    Hein, Eike; Rogalla, Patrik; Klingebiel, Randolph; Hamm, Bernd

    2002-01-01

    The purpose of the study was to assess the effect of lens protection on image quality and radiation dose to the eye lenses in CT of the paranasal sinuses. In 127 patients referred to rule out sinusitis, an axial spiral CT with a lens protection placed on the patients eyes was obtained (1.5/2/1, 50 mAs, 120 kV). Coronal views were reconstructed at 5-mm interval. To quantify a subjective impression of image quality, three regions of interest within the eyeball were plotted along a line perpendicular to the protection at 2, 5, and 9 mm beneath skin level on the axial images. Additionally, dose reduction of a bismuth-containing latex shield was measured using a film-dosimetry technique. The average eyeball density was 17.97 HU (SD 3.7 HU). The relative increase in CT density was 180.6 (17.7), 103.3 (11.7), and 53.6 HU (9.2), respectively. There was no diagnostic information loss on axial and coronal views observed. Artifacts were practically invisible on images viewed in a bone window/level setting. The use of the shield reduced skin radiation from 7.5 to 4.5 mGy. The utilization of a radioprotection to the eye lenses in paranasal CT is a suitable and effective means of reducing skin radiation by 40%. (orig.)

  3. The Major Chromophore Arising from Glucose Degradation and Oxidative Stress Occurrence during Lens Proteins Glycation Induced by Glucose

    Directory of Open Access Journals (Sweden)

    Felipe Ávila

    2017-12-01

    Full Text Available Glucose autoxidation has been proposed as a key reaction associated with deleterious effects induced by hyperglycemia in the eye lens. Little is known about chromophores generated during glucose autoxidation. In this study, we analyzed the effect of oxidative and dicarbonyl stress in the generation of a major chromophore arising from glucose degradation (GDC and its association with oxidative damage in lens proteins. Glucose (5 mM was incubated with H2O2 (0.5–5 mM, Cu2+ (5–50 μM, glyoxal (0.5–5 mM or methylglyoxal (0.5–5 mM at pH 7.4, 5% O2, 37 °C, from 0 to 30 days. GDC concentration increased with incubation time, as well as when incubated in the presence of H2O2 and/or Cu2+, which were effective even at the lowest concentrations. Dicarbonylic compounds did not increase the levels of GDC during incubations. 1H, 13C and FT-IR spectra from the purified fraction containing the chromophore (detected by UV/vis spectroscopy showed oxidation products of glucose, including gluconic acid. Lens proteins solutions (10 mg/mL incubated with glucose (30 mM presented increased levels of carboxymethyl-lysine and hydrogen peroxide that were associated with GDC increase. Our results suggest a possible use of GDC as a marker of autoxidative reactions occurring during lens proteins glycation induced by glucose.

  4. The incorporation of 2-[14C]glycine into porcine lens protein

    International Nuclear Information System (INIS)

    Lee, Y.B.; Kauffman, R.G.; DeVenecia, G.

    1977-01-01

    A series of experiments was conducted to estimate the apparent turnover rate of lens soluble protein, the incorporation rate of 2-[ 14 C]glycine into various soluble protein components and the effect of nutritional stress on the disappearance of radioactivity with time. Evidence is presented that there are two fractions of soluble lens protein with different turnover rates: one is a fast turnover fraction with a half-life of 20.8 hr and the other is a metabolically inert fraction with an infinitely long half-life. It is postulated that the fast turnover fraction is present in the newly-formed younger fibers in the periphery, whereas the inert fraction is in the old lens fibers of the cortex and nucleus. Sephadex G-200 column chromatography was used to separate the soluble lens protein into four components: A, B, C and D in the order of elution. The changes in specific activities of the four components with the time course after injection were followed. Prolonged starvation did not affect the disappearance of carbon incorporated into lens protein with the time course after injection, suggesting normal synthesis and degradation of lens protein without regard to dietary stress. (author)

  5. The influence of protein free calf blood extract eye gel on dry eye after pterygium surgery

    Directory of Open Access Journals (Sweden)

    Cai-Ni Ji

    2013-07-01

    Full Text Available AIM: To investigate the influence of protein free calf blood extract eye gel on dry eye after pterygium surgery. METHODS: Thirty six patients(40 eyeswith primary nasal pterygium were enrolled in this study, which were divided into study group and control group randomly, with 20 eyes in each group. All patients received pterygium excision and limbal stem cell autograft surgery and tobramicin dexamethasone eye drops after surgery. Patients of the study group received protein free calf blood extract eye gel while those of the control group received 0.1% sodium hyaluronate eye drops furthermore. Ocular surface disease index(OSDIquestionnaire, tear film break-up time(BUTand Schirmer's Ⅰ test Ⅰ(SⅠtwere carried before and 3 months after surgery to evaluate the dry eye degree of the patients. RESULTS: There was no statistical difference between the age, gender and size of the pterygium of the study and control groups preoperatively. There was no statistical difference between the OSDI(2.33±1.02 vs 2.32±0.93, BUT(8.80±2.48 vs 8.35±2.28seconds and SⅠt(4.30±2.30 vs 4.40±2.44of the two groups preoperatively. There was statistical difference between the OSDI(1.45±0.47 vs 1.81±0.60, BUT(11.20±2.07 vs 9.50±2.40seconds and SⅠt(8.35±3.13 vs 6.35±2.18of the two groups 3 months postoperatively, which was also different from that of the preoperative data correspondingly. CONCLUSION: Protein free calf blood extract eye gel could reduce the dry eye after pterygium surgery.

  6. Aspartic acid racemization rate in narwhal (Monodon monoceros) eye lens nuclei estimated by counting of growth layers in tusks

    DEFF Research Database (Denmark)

    Garde, Eva; Heide-Jørgensen, Mads Peter; Ditlevsen, Susanne

    2012-01-01

    Ages of marine mammals have traditionally been estimated by counting dentinal growth layers in teeth. However, this method is difficult to use on narwhals (Monodon monoceros) because of their special tooth structures. Alternative methods are therefore needed. The aspartic acid racemization (AAR......) technique has been used in age estimation studies of cetaceans, including narwhals. The purpose of this study was to estimate a species-specific racemization rate for narwhals by regressing aspartic acid D/L ratios in eye lens nuclei against growth layer groups in tusks (n=9). Two racemization rates were...

  7. Occupational dose constraints for the lens of the eye for interventional radiologists and interventional cardiologists in the UK.

    Science.gov (United States)

    Mairs, William DA

    2016-06-01

    The International Commission on Radiological Protection (ICRP) has recommended a 20 mSv year(-1) dose limit for the lens of the eye, which has been adopted in the European Union Basic Safety Standards. Interventional radiologists (IRs) and interventional cardiologists (ICs) are likely to be affected by this. The effects of radiation in the lens are somewhat uncertain, and the ICRP explicitly recommend optimization. Occupational dose constraints are part of the optimization process and define a level of dose which ought to be achievable in a well-managed practice. This commentary calls on the professional bodies to review a need for national constraints to guide local decisions. Consideration is given to developing such constraints using maximum expected doses in high-workload facilities with good radiation protection practices and application of a factor allowing for attenuation by lead glasses (LG). Doses are based on a Public Health England survey of eye dose in the UK. Maximum expected doses for ICs are approximately 21 mSv year(-1), neglecting LG. However, the extent of IR exposure is not yet fully known, and further evidence is required before conclusions are drawn. A Health and Safety Laboratory review of LG established a conservative dose reduction factor of 3 for models available in 2012. Application of this factor provides a dose constraint of 7 mSv year(-1) to the eye for ICs. To achieve this constraint, those employers with the most exposed ICs will have to provide and ensure the correct use of a ceiling-suspended eye shield and LG.

  8. Refractive error, ocular biometry, and lens opalescence in an adult population: the Los Angeles Latino Eye Study.

    Science.gov (United States)

    Shufelt, Chrisandra; Fraser-Bell, Samantha; Ying-Lai, Mei; Torres, Mina; Varma, Rohit

    2005-12-01

    To characterize age- and gender-related differences in refractive error, ocular biometry, and lens opalescence (NOP) in a population-based sample of adult Latinos. Also assessed were the determinants of age-related refractive differences. Participants in the Los Angeles Latino Eye Study (LALES), a population-based study of Latinos aged 40 years and more, underwent an ophthalmic examination, including ultrasonic measurements of axial length (AL), vitreous chamber depth (VCD), anterior chamber depth (ACD), lens thickness (LT), and noncycloplegic automated and subjective refraction. Corneal curvature/power (CP) was measured using an autorefractor. NOP was graded at the slit lamp by an ophthalmologist using the Lens Opacity Classification System II. Age- and gender-related differences were calculated. Multiple regression models were used to identify the determinants of age-related refractive differences. Of the 6357 LALES participants, 5588 phakic individuals with biometric data were included in this analysis. Older individuals had shallower ACDs, thicker lenses, more NOP, and more hyperopia compared to younger individuals (P or = 0.05). Women had significantly shorter AL, shallower ACD and VCD, than did men (P < or = 0.01). The strongest determinants of refractive error were AL (primarily VCD) and CP. NOP was a small but significant determinant of refractive error in older individuals. Age- and gender-related differences in ocular biometric, refractive error, and NOP measurements are present in adult Latinos. While the relative contribution of NOP in determining refractive error is small, it is greater in older persons compared to younger individuals.

  9. Effects of near-UV radiation on the protein of the grey squirrel lens

    International Nuclear Information System (INIS)

    Zigman, S.; Paxhia, T.; Waldron, W.

    1988-01-01

    In vivo exposure of grey squirrels to 40W BLB illumination resulted in alterations in the state of the lens crystallins, mainly in the outer layer of the lens. HPLC revealed an increase of the void volume or crosslinked crystallins and an increase in peptides with molecular weights lower than 20,000 d. In vitro exposure of squirrel lens aqueous extracts to Woods lamp radiation (predominantly 365 nm) led to similar but more exaggerated changes as viewed by high performance liquid chromatography. When viewed by polyacrylamide gel electrophoresis (PAGE), soluble protein crosslinking was also observed. The near-UV absorbing chromophores of low molecular weight present in the lens served as photosensitizers that enhanced the protein changes. Sodium azide inhibited the changes, indicating a role for singlet oxygen in the crosslinking. (author)

  10. Effects of near-UV radiation on the protein of the grey squirrel lens.

    Science.gov (United States)

    Zigman, S; Paxhia, T; Waldron, W

    1988-06-01

    In vivo exposure of grey squirrels to 40W BLB illumination resulted in alterations in the state of the lens crystallins, mainly in the outer layer of the lens. HPLC revealed an increase of the void volume or crosslinked crystallins and an increase in peptides with molecular weights lower than 20,000 d. In vitro exposure of squirrel lens aqueous extracts to Woods lamp radiation (predominantly 365 nm) led to similar but more exaggerated changes as viewed by high performance liquid chromatography. When viewed by polyacrylamide gel electrophoresis (PAGE), soluble protein crosslinking was also observed. The near-UV absorbing chromophores of low molecular weight present in the lens served as photosensitizers that enhanced the protein changes. Sodium azide inhibited the changes, indicating a role for singlet oxygen in the crosslinking.

  11. Effects of near-UV radiation on the protein of the grey squirrel lens

    Energy Technology Data Exchange (ETDEWEB)

    Zigman, S; Paxhia, T; Waldron, W

    1988-06-01

    In vivo exposure of grey squirrels to 40W BLB illumination resulted in alterations in the state of the lens crystallins, mainly in the outer layer of the lens. HPLC revealed an increase of the void volume or crosslinked crystallins and an increase in peptides with molecular weights lower than 20,000 d. In vitro exposure of squirrel lens aqueous extracts to Woods lamp radiation (predominantly 365 nm) led to similar but more exaggerated changes as viewed by high performance liquid chromatography. When viewed by polyacrylamide gel electrophoresis (PAGE), soluble protein crosslinking was also observed. The near-UV absorbing chromophores of low molecular weight present in the lens served as photosensitizers that enhanced the protein changes. Sodium azide inhibited the changes, indicating a role for singlet oxygen in the crosslinking.

  12. Addendum report of the JHPS expert committee on radiation protection of the lens of the eye (3). Recent related overseas activities

    International Nuclear Information System (INIS)

    Akahane, Keiichi; Tatsuzaki, Hideo; Iimoto, Takeshi; Ichiji, Takeshi; Hamada, Nobuyuki; Iwai, Satoshi; Ohguchi, Hiroyuki; Ohno, Kazuko; Kawaura, Chiyo; Tsujimura, Norio; Hotta, Yutaka; Yamasaki, Tadashi; Yokoyama, Sumi

    2015-01-01

    Following the Statement on Tissue Reaction issued by the International Commission on Radiological Protection (ICRP), revisions and discussions are underway in various international organizations about the standards, guidelines and methods for the eye dosimetry. We have previously discussed these issues in six interim reports, followed by two addendum reports on lens dosimetry. This addendum report reviews ongoing overseas discussion and work in relation to research on radiogenic cataracts and implementation of the new eye lens dose limit, such as those in the European Commission, Low Dose Research towards Multidisciplinary Integration (DoReMi), Open Project for European Radiation Research Area (OPERRA), and the Unite Sates National Council on Radiation Protection and Measurements (NCRP). This report serves as the last part of a series of reports by the Japan Health Physics Society Expert Committee on Radiation Protection of the Lens of the Eye. (author)

  13. The Endocytic Recycling Regulatory Protein EHD1 Is Required for Ocular Lens Development

    Science.gov (United States)

    Arya, Priyanka; Rainey, Mark A.; Bhattacharyya, Sohinee; Mohapatra, Bhopal; George, Manju; Kuracha, Murali R; Storck, Matthew D.; Band, Vimla; Govindarajan, Venkatesh; Band, Hamid

    2015-01-01

    The C-terminal Eps15 homology domain-containing (EHD) proteins play a key role in endocytic recycling, a fundamental cellular process that ensures the return of endocytosed membrane components and receptors back to the cell surface. To define the in vivo biological functions of EHD1, we have generated Ehd1 knockout mice and previously reported a requirement of EHD1 for spermatogenesis. Here, we show that approximately 56% of the Ehd1-null mice displayed gross ocular abnormalities, including anophthalmia, aphakia, microphthalmia and congenital cataracts. Histological characterization of ocular abnormalities showed pleiotropic defects that include a smaller or absent lens, persistence of lens stalk and hyaloid vasculature, and deformed optic cups. To test whether these profound ocular defects resulted from the loss of EHD1 in the lens or in non-lenticular tissues, we deleted the Ehd1 gene selectively in the presumptive lens ectoderm using Le-Cre. Conditional Ehd1 deletion in the lens resulted in developmental defects that included thin epithelial layers, small lenses and absence of corneal endothelium. Ehd1 deletion in the lens also resulted in reduced lens epithelial proliferation, survival and expression of junctional proteins E-cadherin and ZO-1. Finally, Le-Cre-mediated deletion of Ehd1 in the lens led to defects in corneal endothelial differentiation. Taken together, these data reveal a unique role for EHD1 in early lens development and suggest a previously unknown link between the endocytic recycling pathway and regulation of key developmental processes including proliferation, differentiation and morphogenesis. PMID:26455409

  14. Test of ring, eye lens and whole body dosemeters for the dose quantity Hp(3) to be used in interventional radiology

    Science.gov (United States)

    Szumska, A.; Budzanowski, M.; Kopeć, R.

    2017-11-01

    In its statement on tissue reactions approved on 21st April 2011, the International Commission on Radiological Protection (ICRP, 2012) reviewed its recommendation concerning the equivalent dose limit for the eye lens and reduced the dose limits for occupationally exposed persons to 20 mSv in a year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. This limit was approved and written down in the new EURATOM (European Atomic Energy Community) directive 2013/59 and in the IAEA (International Atomic Energy Agency) BSS (Basic Safety Standard) of July 2014. For that reason, the necessity to monitor the eye lens may become more important than it was before. However, specially dedicated dosemeters for the dose quantity Hp(3) are using very rarely. Commonly use are only whole body personal dosemeters for the personal dose equivalent quantities Hp(10) worn on the trunk and ring dosemeters worn on finger to measure the quantity Hp(0.07). Therefore, in this work it was investigated whether dosemeters from routine use calibrated in terms of Hp(10) and Hp(0.07) and worn on thyroid collar and protective apron could deliver similar results like dedicated eye lens dosemeter worn close to the eyes. The results show that the best method if dedicated eye lens dosimeters is not used is to measure doses in terms of Hp(0.07) on the thyroid collar (Pearson product, r=0.85). Obtained results shows also importance of proper localization of eye lens dosimeter (close to the eye, from side of the X-ray source).

  15. Eye lens dosimetry for fluoroscopically guided clinical procedures: practical approaches to protection and dose monitoring

    International Nuclear Information System (INIS)

    Martin, Colin J.

    2016-01-01

    Doses to the eye lenses of clinicians undertaking fluoroscopically guided procedures can exceed the dose annual limit of 20 mSv, so optimisation of radiation protection is essential. Ceiling-suspended shields and disposable radiation absorbing pads can reduce eye dose by factors of 2-7. Lead glasses that shield against exposures from the side can lower doses by 2.5-4.5 times. Training in effective use of protective devices is an essential element in achieving good protection and acceptable eye doses. Effective methods for dose monitoring are required to identify protection issues. Dosemeters worn adjacent to the eye provide the better option for interventional clinicians, but an unprotected dosemeter worn at the neck will give an indication of eye dose that is adequate for most interventional staff. Potential requirements for protective devices and dose monitoring can be determined from risk assessments using generic values for dose linked to examination workload. (author)

  16. Eye lens exposure to medical staff performing electrophysiology procedures: dose assessment and correlation to patient dose

    International Nuclear Information System (INIS)

    Ciraj-Bjelac, Olivera; Bozovic, Predrag; Arandjic, Danijela; Antic, Vojislav; Selakovic, Jovana; Pavlovic, Sinisa

    2016-01-01

    The purpose of this study was to assess the patient exposure and staff eye dose levels during implantation procedures for all types of pacemaker therapy devices performed under fluoroscopic guidance and to investigate potential correlation between patients and staff dose levels. The mean eye dose during pacemaker/defibrillator implementation was 12 μSv for the first operator, 8.7 μSv for the second operator/nurse and 0.50 μSv for radiographer. Corresponding values for cardiac re-synchronisation therapy procedures were 30, 26 and 2.0 μSv, respectively. Significant (p < 0.01) correlation between the eye dose and the kerma-area product was found for the first operator and radiographers, but not for other staff categories. The study revealed eye dose per procedure and eye dose normalised to patient dose indices for different staff categories and provided an input for radiation protection in electrophysiology procedures. (authors)

  17. Vitreous Humor Changes Expression of Iron-Handling Proteins in Lens Epithelial Cells

    Science.gov (United States)

    Goralska, Malgorzata; Fleisher, Lloyd N.; McGahan, M. Christine

    2017-01-01

    Purpose In humans, vitrectomy is associated with development of nuclear cataracts. Iron catalyzes free radical formation causing oxidative damage, which is implicated in cataract formation. This study was designed to determine if vitreous humor, which can initiate differentiation of lens epithelial cells, would have an effect on iron-handling proteins. Methods Cultured canine lens epithelial cells were treated with collected canine vitreous humor. Lysates of treated and control cells were separated by SDS-PAGE. Ferritin H- and L-chains, transferrin receptor 1, and aquaporin 0 were immunodetected and quantitated with specific antibodies. Morphologic changes in treated cells were assessed. Results Treatment of lens epithelial cells with a 33% (vol/vol) solution of vitreous humor changed the morphology of lens cells and induced expression of aquaporin 0, a marker of fiber cell differentiation that was undetectable in control cells. Treatment did not modify the size of iron-handling proteins but significantly increased content of ferritin from 2.9- to 8.8-fold over control and decreased levels of transferrin receptor by 37% to 59%. Conclusions Vitreous humor may significantly limit iron uptake by transferrin/transferrin receptor pathway, and by increasing ferritin levels could profoundly increase the iron-storage capacity of ferritin in lens cells. Vitreous humor may play a significant protective role against iron-catalyzed oxidative damage of lens epithelial cells and therefore in the formation of cataracts. PMID:28245299

  18. Eye lens dose correlations with personal dose equivalent and patient exposure in paediatric interventional cardiology performed with a fluoroscopic biplane system.

    Science.gov (United States)

    Alejo, L; Koren, C; Corredoira, E; Sánchez, F; Bayón, J; Serrada, A; Guibelalde, E

    2017-04-01

    To analyse the correlations between the eye lens dose estimates performed with dosimeters placed next to the eyes of paediatric interventional cardiologists working with a biplane system, the personal dose equivalent measured on the thorax and the patient dose. The eye lens dose was estimated in terms of H p (0.07) on a monthly basis, placing optically stimulated luminescence dosimeters (OSLDs) on goggles. The H p (0.07) personal dose equivalent was measured over aprons with whole-body OSLDs. Data on patient dose as recorded by the kerma-area product (P KA ) were collected using an automatic dose management system. The 2 paediatric cardiologists working in the facility were involved in the study, and 222 interventions in a 1-year period were evaluated. The ceiling-suspended screen was often disregarded during interventions. The annual eye lens doses estimated on goggles were 4.13±0.93 and 4.98±1.28mSv. Over the aprons, the doses obtained were 10.83±0.99 and 11.97±1.44mSv. The correlation between the goggles and the apron dose was R 2 =0.89, with a ratio of 0.38. The correlation with the patient dose was R 2 =0.40, with a ratio of 1.79μSvGy -1 cm -2 . The dose per procedure obtained over the aprons was 102±16μSv, and on goggles 40±9μSv. The eye lens dose normalized to P KA was 2.21±0.58μSvGy -1 cm -2 . Measurements of personal dose equivalent over the paediatric cardiologist's apron are useful to estimate eye lens dose levels if no radiation protection devices are typically used. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  19. Droplets on posterior surface of intraocular lens in silicone oil filled eye.

    Directory of Open Access Journals (Sweden)

    Sharma Y

    2003-01-01

    Full Text Available Silicone oil adherence to silicone IOLs after silicone oil removal is a known complication in pseudophakic patients. Droplet removal is difficult and may require IOL exchange. We describe two cases in which silicone oil droplets were observed early in the postoperative period in PMMA pseudophakic eyes and disappeared during silicone oil-fluid exchange--a phenomenon that has not been reported earlier in human PMMA pseudophakic eyes.

  20. Effect of gamma irradiation on in vitro bovine lens proteins

    International Nuclear Information System (INIS)

    Bernardes, D.M.L.; Mastro, N.L. del.

    1988-07-01

    The radiosensitivity of the ocular lens manifested by cataract formation has been of considerable interest in the study on the biological efects of radiations. Cataract can ben produced by different causes and also for the normal process of ageing. The aim of this work was to develop an in vitro system similar to in vivo cataract formation. It was used an aqueous solution of bovine lenses. The lenses after surgical removal mechanical and ultrasonic disrupted. The suspension was centrifuged and the supernatant was dialyzed and irradiated with different doses of 60 Co radiation. The opacification extent was measured in an spectrophotometer. (author) [pt

  1. Dislocation of polyfocal full-optics accommodative intraocular lens after neodymium-doped yttrium aluminum garnet capsulotomy in vitrectomized eye

    Directory of Open Access Journals (Sweden)

    Kyung Tae Kang

    2013-01-01

    Full Text Available We report a case of dislocation of WIOL-CF® polyfocal full-optics intraocular lens (IOL after neodymium-doped yttrium aluminum garnet (Nd: YAG laser capsulotomy in the vitrectomized eye. At 22 months before the dislocation of the IOL, a 55-year-old male patient underwent phacoemulsification with WIOL-CF® IOL implantation in a local clinic and 10 months after the cataract surgery the patient underwent pars plana vitrectomy, endolaser photocoagulation and 14% C 3 F 8 gas tamponade for the treatment of rhegmatogenous retinal detachment. At 9 months after the vitrectomy, the patient visited our clinic for a sudden decrease of vision after Nd: YAG capsulotomy in the local clinic. On fundus examination, the dislocated IOL was identified and the Nd: YAG capsulotomy site and the larger break, which is suspected to have been a route of the dislocation were observed in the posterior capsule.

  2. Provision of dosimeters by official monitoring services for eye lens dose estimation; Die Bereitstellung von Dosimetern durch die amtlichen Messstellen zur Abschaetzung der Augenlinsendosis

    Energy Technology Data Exchange (ETDEWEB)

    Engelhardt, J.; Martini, E. [Landesanstalt fuer Personendosimetrie und Strahlenschutzausbildung Mecklenburg-Vorpommern, Berlin (Germany)

    2013-07-01

    Recent epidemiological studies are implying that the radio sensitivity of the eye lens is much higher than supposed in the past. International recommendations and standards demand to lower down the annual limit of the eye lens organ dose to 20 mSv. Since about 10 years German monitoring services offer partial-body dosimeters fixed on the head or on glasses for monitoring the eye lens dose. These dosimeters are optimized to measure the (surface) personal dose equivalent H{sub p}(0,07) from 0,5 mSv up to 10 Sv, which clearly overestimate the organ dose of the eye lens. With special features like different calibrations partial-body dosimeters should be applicable for legal dosimetry to avoid the development of special H{sub p}(3) dosimeters. Accepting the right way for wearing these dosimeters it is important to get the right results. Practical experiences are shown with measuring results and the difficulties of rounding the exact measuring values to discrete dose steps. Closing this article we point to still missing legal basis and open questions regarding to type testing procedures. (orig.)

  3. Proposals for the type tests criteria and calibration conditions of passive eye lens dosemeters to be used in interventional cardiology and radiology workplaces

    International Nuclear Information System (INIS)

    Bordy, J.M.; Daures, J.; Denozière, M.; Gualdrini, G.; Ginjaume, M.; Carinou, E.; Vanhavere, F.

    2011-01-01

    The paper is aimed at making a proposal for the type test and calibration of eye lens passive dosemeters especially used in the interventional cardiology/radiology (IC/IR). Starting from the only existing standard dealing with eye lens dosimetry using TLDs (), parameters such as, detection threshold, energy and angle dependence of response criteria have been reviewed and it has been tried to harmonise them as much as possible with the IEC 62387 requirements, taking into account the particular use at IC/IR workplaces. Conversion coefficients from air kerma to dose equivalent at 3 mm depth for RQR and ISO radiation qualities, employed for type test and calibration purposes, have been calculated in a new phantom introduced within the ORAMED (Optimization of RAdiation protection for MEDical staff) project. This phantom is more representative of the head so that the estimation of H lens by H p (3) is more accurate.

  4. Conserved chemosensory proteins in the proboscis and eyes of Lepidoptera.

    Science.gov (United States)

    Zhu, Jiao; Iovinella, Immacolata; Dani, Francesca Romana; Liu, Yu-Ling; Huang, Ling-Qiao; Liu, Yang; Wang, Chen-Zhu; Pelosi, Paolo; Wang, Guirong

    2016-01-01

    Odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) are endowed with several different functions besides being carriers for pheromones and odorants. Based on a previous report of a CSP acting as surfactant in the proboscis of the moth Helicoverpa armigera , we revealed the presence of orthologue proteins in two other moths Plutella xylostella and Chilo suppressalis , as well as two butterflies Papilio machaon and Pieris rapae , using immunodetection and proteomic analysis. The unusual conservation of these proteins across large phylogenetic distances indicated a common specific function for these CSPs. This fact prompted us to search for other functions of these proteins and discovered that CSPs are abundantly expressed in the eyes of H. armigera and possibly involved as carriers for carotenoids and visual pigments. This hypothesis is supported by ligand-binding experiments and docking simulations with retinol and β-carotene. This last orange pigment, occurring in many fruits and vegetables, is an antioxidant and the precursor of visual pigments. We propose that structurally related CSPs solubilise nutritionally important carotenoids in the proboscis, while they act as carriers of both β-carotene and its derived products 3-hydroxyretinol and 3-hydroxyretinal in the eye. The use of soluble olfactory proteins, such as CSPs, as carriers for visual pigments in insects, here reported for the first time, parallels the function of retinol-binding protein in vertebrates, a lipocalin structurally related to vertebrate odorant-binding proteins.

  5. Reducing the radiation dose to the eye lens region during CT brain examination: the potential beneficial effect of the combined use of bolus and a bismuth shield

    International Nuclear Information System (INIS)

    Lai, C.W.K.; Chan, T.P.; Cheung, H.Y.; Wong, T.H.

    2015-01-01

    Objective: Computed Tomography (CT) is the leading contributor to medical exposure to ionizing radiation. Although the use of CT brain scans for patients with head injuries and convulsions has shown a tremendous growth, it has raised substantial concerns in the general public because of the risk of radiation-induced cataracts: the current available strategies to reduce the radiation dose to the eye lens region are limited. Therefore, the present research project was initiated with the aim of evaluating the potential benefit of the combined use of bolus and a bismuth shield on reducing the radiation dose to the eye lens region during CT brain examination. Materials and methods: We conducted a series of phantom studies to measure the entrance surface dose (ESD) that is delivered to the eye lens region during CT brain examination under the effect of different scanning and shielding setups. Results: Our results indicated, during CT brain examination: (1) a drastic reduction of 92.5% in the ESD to the eye lens region was found when the CT gantry was tilted from 0 deg. (overall ESD = 30.7 mGy) to 30 deg. cranially (overall ESD = 2.4 mGy), and (2) when the CT gantry was positioned at 0 deg. (the common practice in the clinical setting), the setups with the application of a) a bismuth shield, b) a bismuth shield with a face shield (air gap), c) a bismuth shield with bolus, and d) a bismuth shield with bolus and an air gap can result in an acceptable level of image quality with a smaller overall ESD delivered to the eye lens region (overall ESD = 23.2 mGy, 24 mGy, 21 mGy and 19.9 mGy, respectively) than the setup without the bismuth shield applied (overall ESD = 30.7 mGy). Conclusion: When the primary beam scanning through the eye lens region is unavoidable during CT brain examination, the combined use of a bismuth shield with bolus and a face shield is an easy-to-use and inexpensive shielding setup to reduce the radiation dose delivered to the eye lens region while

  6. Implantation of refractive multifocal intraocular lens with a surface-embedded near section for cataract eyes complicated with a coexisting ocular pathology.

    Science.gov (United States)

    Ouchi, M; Kinoshita, S

    2015-05-01

    To evaluate the postoperative outcomes of cataract eyes complicated with coexisting ocular pathologies that underwent implantation of a refractive multifocal intraocular lens (MIOL) with a surface-embedded near section. LENTIS MPlus (Oculentis GmbH) refractive MIOLs were implanted in 15 eyes with ocular pathologies other than cataract (ie, six high-myopia eyes with an axial length longer than 28 mm, two fundus albipunctatus eyes, two branch retinal-vein occlusion eyes, four glaucoma eyes (one with high myopia), and two keratoconus eyes). Uncorrected or corrected distance and near visual acuity (VA) (UDVA, UNVA, CDVA, and CNVA), contrast sensitivity, and defocus curve were measured at 1 day and 6 months postoperatively, and each patient completed a 6-month postoperative questionnaire regarding vision quality and eyeglass use. Thirteen eyes (87%) registered 0 or better in CDVA and 12 eyes (73%) registered better than 0 in CNVA. Contrast sensitivity in the eyes of all patients was comparable to that of normal healthy subjects. No patient required eyeglasses for distance vision, but three patients (20%) required them for near vision. No patient reported poor or very poor vision quality. With careful case selection, sectorial refractive MIOL implantation is effective for treating cataract eyes complicated with ocular pathologies.

  7. Comparison of axial length, anterior chamber depth and intraocular lens power between IOLMaster and ultrasound in normal, long and short eyes.

    Science.gov (United States)

    Dong, Jing; Zhang, Yaqin; Zhang, Haining; Jia, Zhijie; Zhang, Suhua; Wang, Xiaogang

    2018-01-01

    To compare the axial length (AL), anterior chamber depth (ACD) and intraocular lens power (IOLP) of IOLMaster and Ultrasound in normal, long and short eyes. Seventy-four normal eyes (≥ 22 mm and ≤ 25 mm), 74 long eyes (> 25 mm) and 78 short eyes (devices in the order of IOLMaster followed by Ultrasound. The IOLP were calculated using a free online LADAS IOL formula calculator. The difference in AL and IOLP between IOLMaster and Ultrasound was statistically significant when all three groups were combined. The difference in ACD between IOLMaster and Ultrasound was statistically significant in the normal group (Peye group (Peye group (P = 0.465). For the IOLP difference between IOLMaster and Ultrasound in the normal group, the percentage of IOLP differences eye group, they were 90.5%, 5.4%, 4.1% and 0%, respectively. For the short eye group, they were 61.5%, 23.1%, 10.3%, and 5.1%, respectively. IOLMaster and Ultrasound have statistically significant differences in AL measurements and IOLP (using LADAS formula) for normal, long eye and short eye. The two instruments agree regarding ACD measurements for the long eye group, but differ for the normal and short eye groups. Moreover, the high percentage of IOLP differences greater than |0.5|D in the short eye group is noteworthy.

  8. Implications for Occupational Radiation Protection of the New Dose Limit for the Lens of the Eye. Interim Guidance for Use and Comment

    International Nuclear Information System (INIS)

    2013-12-01

    The IAEA Safety Requirements Safety Standards Series No. GSR Part 3 (Interim), Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, was approved by the IAEA Board of Governors at its meeting in September 2011 and published in November 2011. The equivalent dose limit for the lens of the eye for occupational exposure in planned exposure situations was reduced from 150 mSv per year to 20 mSv per year, averaged over defined periods of five years, with no annual dose in a single year exceeding 50 mSv. This reduction in the dose limit for the lens of the eye follows the recommendation of the International Commission on Radiological Protection (ICRP) in its statement on tissue reactions on 21 April 2011. At the time when the draft General Safety Requirements (GSR) Part 3 was approved by the Commission on Safety Standards, the Secretariat was asked to develop guidance as early as possible to assist Member States in the observance of the new dose limit. In the longer term, the guidance provided in this TECDOC will form the basis for the consensus guidance in relation to the new dose limit for the lens of the eye that is to be provided in two safety guides currently being developed, Occupational Radiation Protection and Radiation Safety in the Medical Uses of Ionizing Radiation. It is expected that these will be published in 2015-2016. It is recognized that guidance material is required before the two safety guides are finalized in order to give Member States the opportunity to put appropriate actions in place and to plan for the introduction of the new dose limit for the lens of the eye. The purpose of the current publication is to provide advice on the implications for occupational radiation protection of the new dose limit for the lens of the eye and to allow comment on detailed recommendations that may be incorporated into the safety guides

  9. The RNA-binding protein Celf1 post-transcriptionally regulates p27Kip1 and Dnase2b to control fiber cell nuclear degradation in lens development.

    Directory of Open Access Journals (Sweden)

    Archana D Siddam

    2018-03-01

    Full Text Available Opacification of the ocular lens, termed cataract, is a common cause of blindness. To become transparent, lens fiber cells undergo degradation of their organelles, including their nuclei, presenting a fundamental question: does signaling/transcription sufficiently explain differentiation of cells progressing toward compromised transcriptional potential? We report that a conserved RNA-binding protein Celf1 post-transcriptionally controls key genes to regulate lens fiber cell differentiation. Celf1-targeted knockout mice and celf1-knockdown zebrafish and Xenopus morphants have severe eye defects/cataract. Celf1 spatiotemporally down-regulates the cyclin-dependent kinase (Cdk inhibitor p27Kip1 by interacting with its 5' UTR and mediating translation inhibition. Celf1 deficiency causes ectopic up-regulation of p21Cip1. Further, Celf1 directly binds to the mRNA of the nuclease Dnase2b to maintain its high levels. Together these events are necessary for Cdk1-mediated lamin A/C phosphorylation to initiate nuclear envelope breakdown and DNA degradation in fiber cells. Moreover, Celf1 controls alternative splicing of the membrane-organization factor beta-spectrin and regulates F-actin-crosslinking factor Actn2 mRNA levels, thereby controlling fiber cell morphology. Thus, we illustrate new Celf1-regulated molecular mechanisms in lens development, suggesting that post-transcriptional regulatory RNA-binding proteins have evolved conserved functions to control vertebrate oculogenesis.

  10. Simulation of airbag impact on eyes with different axial lengths after transsclerally fixated posterior chamber intraocular lens by using finite element analysis

    Directory of Open Access Journals (Sweden)

    Huang J

    2015-02-01

    Full Text Available Jane Huang,1 Eiichi Uchio,1 Satoru Goto2 1Department of Ophthalmology, Fukuoka University School of Medicine, Fukuoka, 2Nihon ESI KK Technical Division, Tokyo, Japan Purpose: To determine the biomechanical response of an impacting airbag on eyes with different axial lengths with transsclerally fixated posterior chamber intraocular lens (PC IOL.Materials and methods: Simulations in a model human eye were performed with a computer using a finite element analysis program created by Nihon, ESI Group. The airbag was set to be deployed at five different velocities and to impact on eyes with three different axial lengths. These eyes were set to have transsclerally fixated PC IOL by a 10-0 polypropylene possessing a tensile force limit of 0.16 N according to the United States Pharmacopeia XXII.Results: The corneoscleral opening was observed at a speed of 40 m/second or more in all model eyes. Eyes with the longest axial length of 25.85 mm had the greatest extent of deformity at any given impact velocity. The impact force exceeded the tensile force of 10-0 polypropylene at an impact velocity of 60 m/second in all eyes, causing breakage of the suture. Conclusion: Eyes with transsclerally fixated PC IOL could rupture from airbag impact at high velocities. Eyes with long axial lengths experienced a greater deformity upon airbag impact due to a thinner eye wall. Further basic research on the biomechanical response for assessing eye injuries could help in developing a better airbag and in the further understanding of ocular traumas. Keywords: airbag, ocular trauma, computer simulation, transsclerally fixated posterior chamber intraocular lens, finite element analysis

  11. A Pseudomonas aeruginosa strain isolated from a contact lens-induced acute red eye (CLARE) is protease-deficient.

    Science.gov (United States)

    Estrellas, P S; Alionte, L G; Hobden, J A

    2000-03-01

    Pseudomonas aeruginosa proteases are thought to be important virulence factors in the pathogenesis of corneal disease. This study examined protease production from two strains of P. aeruginosa responsible for two very distinct clinical diseases: strain Paer1, isolated from a Contact Lens-induced Acute Red Eye (CLARE), and strain KEI 1025, isolated from a corneal ulcer. Strains were compared to a laboratory strain (ATCC 19660) known to produce severe keratitis in experimentally infected mice for protease production and for ocular virulence. Protease production was examined with colorimetric assays, gelatin zymography and western blots. Elastase A activity was quantitated with a staphylolytic assay. Ocular virulence was examined using a mouse scratch model of keratitis. In contrast to strains KEI 1025 or ATCC 19660, Paer1 was unable to produce enzymatically active elastase A, elastase, and protease IV. All three strains produced active alkaline protease. Strains KEI 1025 and ATCC 19660 produced a fulminant keratitis in mice whereas Paer1 produced a mild transient infection. Restoration of elastase activity in Paer1 via genetic complementation did not result in a virulent phenotype. Co-infection of mouse eyes with strains Paer1 and ATCC 19660 resulted in the eventual loss of Paer1 from corneal tissue. These studies suggest that P. aeruginosa elastase A and/or protease IV, but not alkaline protease or elastase, contribute to the ocular virulence of this organism.

  12. Insulin and IGF receptors are developmentally regulated in the chick embry eye lens

    International Nuclear Information System (INIS)

    Bassas, L.; Zelenka, P.S.; Serrano, J.; de Pablo, F.

    1987-01-01

    The authors have previously reported that insulin-like growth factor (IGF) receptors appear to predominate over insulin receptors in early stages of embryogenesis in the chick (days 2-3 whole embryo membranes). Overall, [ 125 I]IGF and II binding to specific receptors was maximal when the rate of brain growth is highest. In the present study they used the embryonic chick lens, a well-defined tissue composed of a single type of cell, to analyze whether changes of insulin and IGFI binding are correlated with changes in growth rate and differentiation state of the cells. They show that both insulin receptors and IGF receptors are present in the lens epithelial cells, and that each type is distinctly regulated throughout development. While there is a direct correlation between IFG-binding capability and growth rate of the cells, there is less relation to differentiation status and embryo age. Insulin receptors, by contrast, appear to be mostly related to the differentiated state of cells, decreasing sharply in fibers, irrespective of their developmental age

  13. Ocular lens availability of glutathione from collagen inserts for protection of eye from radiation

    International Nuclear Information System (INIS)

    Omer, S.A.

    2003-01-01

    Full text: Ocular inserts of glutathione ( G ) were prepared using 1 % collagen solution containing free G ,liposomal G and liposomal G with Concanavalin A ,a specific targeting agent of G to ocular lens. These inserts have to be sterilized for in-vivo ophthalmic application by exposure to U V radiation for 2 hr. using dry ice and acetone for protection of G from thermal degradation. In vitro release characteristics of G (17.0 μ mole) from the prepared inserts were investigated at 37deg C in phosphate buffer pH 7.4 . The results of release data showed that the release of G from inserts were arranged in the following order, free G, liposomal G with or without Concanavalin A. The extent of uptake of G from the collagen inserts by rabbit cornea was also tested. The results of ocular lens availability of G from collagen inserts revealed that a highly significant increase in the uptake of G by ocular lenses,where the percentages drug uptake from the applied doses at T max were 1.12% (p(0.05), 2.12% (p(0.01) and 3.4% (p(0.001) in case of using collagen inserts containing free G, liposomal G and liposomal G with Concanavalin A respectively. That is to say,lipid nature of liposomes together with Concanavlin A improved the penetration of the entrapped hydrophilic G through corneal barrier to the ocular lenses

  14. Characterization of upstream sequences of the LIM2 gene that bind developmentally regulated and lens-specific proteins

    Institute of Scientific and Technical Information of China (English)

    HSU Heng; Robert L. CHURCH

    2004-01-01

    During lens development, lens epithelial cells differentiate into fiber cells. To date, four major lens fiber cell intrinsic membrane proteins (MIP) ranging in size from 70 kD to 19 kD have been characterized. The second most abundant lens fiber cell intrinsic membrane protein is MP19. This protein probably is involved with lens cell communication and relates with cataractogenesis. The aim of this research is to characterize upstream sequences of the MP19 (also called LIM2) gene that bind developmentally regulated and lens-specific proteins. We have used the gel mobility assays and corresponding competition experiments to identify and characterize cis elements within approximately 500 bases of LIM2 upstream sequences. Our studies locate the positions of some cis elements, including a "CA" repeat, a methylation Hha I island, an FnuD II site, an Ap1 and an Ap2 consensus sequences, and identify some specific cis elements which relate to lens-specific transcription of LIM2. Our experiments also preliminarily identify trans factors which bind to specific cis elements of the LIM2 promoter and/or regulate transcription of LIM2. We conclude that developmental regulation and coordination of the MP 19 gene in ocular lens fiber cells is controlled by the presence of specific cis elements that bind regulatory trans factors that affect LIM2 gene expression. DNA methylation is one mechanism of controlling LIM2 gene expression during lens development.

  15. Surface refractive index of the eye lens determined with an optic fiber sensor

    International Nuclear Information System (INIS)

    Pierscionek, B.K.

    1993-01-01

    The use of a fiber optic sensor for measurement of refractive index on the surface of eye lenses is described. The technique makes use of the fact that the amount of light reflected at the interface of two media (Fresnel reflectance) depends on the refractive-index difference between them. The sample is probed with a single-mode fiber, and the refractive index is calculated from the proportion of light reflected at the probe--sample interface

  16. [Effect of UV-radiation on the level of ascorbic acid, SH-groups, and activity of glutathione reductase in the eye lens].

    Science.gov (United States)

    Byshneva, L N; Senchuk, V V

    2002-01-01

    The effect of UV radiation in vitro on the level of ascorbate, SH-groups and glutathione reductase activity in the soluble fraction of bovine eye lens was studied. UV-Irradiation increased NADPH-oxidoreductase activity, the level of ascorbate oxidation and decreased the content of SH-groups and activity of glutathione reductase. Significant activation of the NADPH-oxidoreductase activity in the presence of ascorbate and Cu2+ was observed after UV-irradiation. It is suggested that ascorbate may play an important role in the UV-induced lens pathology.

  17. The G-protein-coupled receptor, GPR84, is important for eye development in Xenopus laevis

    OpenAIRE

    Perry, Kimberly J.; Johnson, Verity R.; Malloch, Erica L.; Fukui, Lisa; Wever, Jason; Thomas, Alvin G.; Hamilton, Paul W.; Henry, Jonathan J.

    2010-01-01

    G-protein-coupled receptors (GPCRs) represent diverse, multifamily groups of cell signaling receptors involved in many cellular processes. We identified Xenopus laevis GPR84 as a member of the A18 subfamily of GPCRs. During development, GPR84 is detected in the embryonic lens placode, differentiating lens fiber cells, retina and cornea. Anti-sense morpholino oligonucleotide-mediated knockdown and RNA rescue experiments demonstrate GPR84’s importance in lens, cornea and retinal development. Ex...

  18. The impact of x-ray tube configuration on the eye lens and extremity doses received by cardiologists in electrophysiology room

    International Nuclear Information System (INIS)

    Domienik, J; Zmyślony, M; Bissinger, A

    2014-01-01

    The aim of the study was to analyse the influence of the x-ray tube configuration on the radiation doses to eye lens and extremities of cardiologists performing pacemaker implantation procedures in electrophysiology laboratory. The measurements were performed on one, widely used, portable C-arm system, first with x-ray tube mounted above the patient table and image intensifier below it and then on a reinstalled (but essentially the same) system with under-table x-ray tube configuration. Thermoluminescent dosimeters, placed in various positions near the eye lens, on the hands and ankle, were used during every procedure. The comparison of doses received by cardiologists after changing the x-ray tube configuration from over- to under-table shows statistically significant dose reduction (p < 0.009) for the eye lens closest to the x-ray tube, left finger, left wrist, while for the ankle a dose increase is observed. The corresponding over- to under-table x-ray tube median dose ratios are 4.1 for the right eye, 4.8 for the left finger, 3.0 for left wrist and, finally, 0.13 for the right ankle. Systems with under-table x-ray tube are preferable from a radiation protection point of view. The observed significant increase in doses to the legs should be partially compensated by the use of a protective lead curtain. (note)

  19. TU-D-209-07: Monte Carlo Assessment of Dose to the Lens of the Eye of Radiologist Using Realistic Phantoms and Eyeglass Models

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X [Rensselaer Polytechnic Inst., Troy, NY (United States); Lin, H [Rensselaer Polytechnic Institute, Troy, NY (United States); Gao, Y; Caracappa, P [RPI, Troy, NY (United States); Wang, Y; Huo, W; Pi, Y; Feng, M; Chen, Z [USTC, Hefei, Anhui (China); Dauer, L [Memorial Sloan-Kettering Cancer Ctr, New York, NY (United States); Thornton, R; Dauer, Z; Alvarado, K [Memorial Sloan Kettering Cancer Center, New York, NY (United States); St Germain, J [Mem Sloan-Kettering Cancer Ctr, New York, NY (United States); Solomon, S [Rensselaer Polytechnic Inst., Troy, NY (United States); USTC, Hefei, Anhui (China)

    2016-06-15

    Purpose: To study how eyeglass design features and postures of the interventional radiologist affect the radiation dose to the lens of the eye. Methods: A mesh-based deformable phantom, consisting of an ultra-fine eye model, was used to simulate postures of a radiologist in fluoroscopically guided interventional procedure (facing the patient, 45 degree to the left, and 45 degree to the right). Various eyewear design features were studied, including the shape, lead-equivalent thickness, and separation from the face. The MCNPX Monte Carlo code was used to simulate the X-ray source used for the transcatheter arterial chemoembolization procedure (The X-ray tube is located 35 cm from the ground, emitting X-rays toward to the ceiling; Field size is 40cm X 40cm; X-ray tube voltage is 90 kVp). Experiments were also performed using dosimeter placed on a physical phantom behind eyeglasses. Results: Without protective eyewear, the radiologist’s eye lens can receive an annual dose equivalent of about 80 mSv. When wearing a pair of lead eyeglasses with lead-equivalent of 0.5-mm Pb, the annual dose equivalent of the eye lens is reduced to 31.47 mSv, but both exceed the new ICRP limit of 20 mSv. A face shield with a lead-equivalent of 0.125-mm Pb in the shape of a semi-cylinder (13cm in radius and 20-cm in height) would further reduce the exposure to the lens of the eye. Examination of postures and eyeglass features reveal surprising information, including that the glass-to-eye separation also plays an important role in the dose to the eye lens from scattered X-ray from underneath and the side. Results are in general agreement with measurements. Conclusion: There is an urgent need to further understand the relationship between the radiation environment and the radiologist’s eyewear and posture in order to provide necessary protection to the interventional radiologists under newly reduced dose limits.

  20. TU-D-209-07: Monte Carlo Assessment of Dose to the Lens of the Eye of Radiologist Using Realistic Phantoms and Eyeglass Models

    International Nuclear Information System (INIS)

    Xu, X; Lin, H; Gao, Y; Caracappa, P; Wang, Y; Huo, W; Pi, Y; Feng, M; Chen, Z; Dauer, L; Thornton, R; Dauer, Z; Alvarado, K; St Germain, J; Solomon, S

    2016-01-01

    Purpose: To study how eyeglass design features and postures of the interventional radiologist affect the radiation dose to the lens of the eye. Methods: A mesh-based deformable phantom, consisting of an ultra-fine eye model, was used to simulate postures of a radiologist in fluoroscopically guided interventional procedure (facing the patient, 45 degree to the left, and 45 degree to the right). Various eyewear design features were studied, including the shape, lead-equivalent thickness, and separation from the face. The MCNPX Monte Carlo code was used to simulate the X-ray source used for the transcatheter arterial chemoembolization procedure (The X-ray tube is located 35 cm from the ground, emitting X-rays toward to the ceiling; Field size is 40cm X 40cm; X-ray tube voltage is 90 kVp). Experiments were also performed using dosimeter placed on a physical phantom behind eyeglasses. Results: Without protective eyewear, the radiologist’s eye lens can receive an annual dose equivalent of about 80 mSv. When wearing a pair of lead eyeglasses with lead-equivalent of 0.5-mm Pb, the annual dose equivalent of the eye lens is reduced to 31.47 mSv, but both exceed the new ICRP limit of 20 mSv. A face shield with a lead-equivalent of 0.125-mm Pb in the shape of a semi-cylinder (13cm in radius and 20-cm in height) would further reduce the exposure to the lens of the eye. Examination of postures and eyeglass features reveal surprising information, including that the glass-to-eye separation also plays an important role in the dose to the eye lens from scattered X-ray from underneath and the side. Results are in general agreement with measurements. Conclusion: There is an urgent need to further understand the relationship between the radiation environment and the radiologist’s eyewear and posture in order to provide necessary protection to the interventional radiologists under newly reduced dose limits.

  1. Proper balance of omega-3 and omega-6 fatty acid supplements with topical cyclosporine attenuated contact lens-related dry eye syndrome.

    Science.gov (United States)

    Wang, Ling; Chen, Xi; Hao, Jingfang; Yang, Lu

    2016-12-01

    Essential fatty acids had been applied in the treatment of dry eye syndrome (DES), but the effects of different combinations of fatty acids have not been investigated. 360 long-term contact lens wearers were included in this double-blinded study. Omega-3 and omega-6 fatty acids were combined in different ratios and supplied to the participants that were randomly divided into six groups, and the effects of different essential fatty acids mixture on DES with or without topical cyclosporine were investigated. More than half of long-term contact lens wearers suffered from DES, which were found to be attenuated by oral supplement of properly balanced O3FA and O6FA fatty acid. The topical cyclosporine treatment considerably inhibited the production of cytokines compared to the cyclosporine negative groups, which further relieved DES. Proper balance of omega-3 and omega-6 fatty acid combination significantly alleviated contact lens-related DES.

  2. Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

    Energy Technology Data Exchange (ETDEWEB)

    Salleh, H.; Matori, M. K.; Isa, M. J. M. [Agensi Nuklear Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Samat, S. B. [Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-09-25

    Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube.

  3. A study of the dose distribution in the region of the eye lens and extremities for staff working in interventional cardiology

    International Nuclear Information System (INIS)

    Domienik, J.; Brodecki, M.; Rusicka, D.

    2012-01-01

    The dose distributions at the region of eye lens and extremities of staff working in interventional cardiology were analyzed. The doses to physicians and nurses from three hospitals in Poland were measured with TL dosimeters (MCP-N) located on various places near eyebrows, on both fingers, wrists, knees and on the ankle. The procedures under investigation were coronary angiography (CA) and percutaneous coronary intervention (PCI), peacemaker and defibrillator implantations (PM/ICDs), cardiac resynchronization therapy with or without defibrillator implantations (CRT-D or CRT) and radiofrequency ablations (RFA). The study aimed at analyzing the distribution of radiation in selected anatomic regions, determining the typical locations of highest doses and estimating the dose ranges for selected types of procedures. The maximum registered doses per procedure to eye lens and ankle were 1.21 mSv and 1.46 mSv for CA PCI procedures, 0.02 mSv and 0.05 mSv for RFA and 0.13 mSv and 0.51 mSv for PM/ICDs, respectively. The maximum doses to fingers, wrists and knees were, accordingly, 2.11 mSv, 1.07 mSv and 0.77 mSv for CA PCI procedures, 0.38 mSv, 0.20 mSv and 0.04 mSv for RFA ones, 0.50 mSv, 0.25 mSv and 0.01 mSv for PM/ICDs procedures and 2.25 mSv, 1.12 mSv and 0.58 mSv for CRT and CRT-D ones. The factors which might influence the dose like utilized radiation, availability of additional protective equipment and position of the staff with respect to X-ray source were also analyzed. The annual doses for eye lens and extremities were estimated on the basis of individual annual workloads of the physicians participating in the study. The highest annual doses were revealed for physicians performing CA PCI procedures. Annual eye lens doses range up to 247 mSv indicating that the occupational limit for eye lens 150 mSv has been surpassed. In case of extremities the maximal estimated annual doses were 355 mSv, 136 mSv, 55 mSv and 328 mSv, for fingers, wrists, knees and for ankle

  4. Scattered radiation risk to the lens of the eyes for staff involved in using mobile C-arm fluoroscopy unit: Which position is riskiest?

    International Nuclear Information System (INIS)

    Salleh, H.; Matori, M. K.; Isa, M. J. M.; Samat, S. B.

    2015-01-01

    Cataractogenesis is something to be concerned by radiologist and radiographer who work extensively in fluoroscopy. The increasing use of fluoroscopy or interventional fluoroscopy has to come with safety awareness on scattered radiation risk for staff performing the procedure. This study is looking into the radiation risk to the lens of the eyes for staff involved in fluoroscopy using the mobile C-arm fluoroscopy unit. The Toshiba SXT-1000A and Alderson Rando phantom were used in this study. Based on the results, it is found clearly that over couch (OC) procedure is riskier than under couch (UC) procedure. The cathode bound area is clearly riskier than anode bound area especially for UC procedure. More doses (at least +1,568 % of safest position) are received by the lens of the eyes for staff standing at the cathode bound area especially the position opposite to the x-ray tube

  5. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... had not been properly fitted by an eye care professional, the lenses stuck to my eye like ... lenses do not require the same level of care or consideration as a standard contact lens because ...

  6. Histopathologic evaluation of the anterior segment of eyes enucleated due to glaucoma secondary to primary lens displacement in 13 canine globes.

    Science.gov (United States)

    Alario, Anthony F; Pizzirani, Stefano; Pirie, Christopher G

    2013-07-01

    PURPOSE  To describe histologic anterior segment changes in eyes affected with primary lens displacement (PLD) and secondary glaucoma. METHODS  Histologic sections stained with H&E from canine eyes enucleated because of PLD and secondary glaucoma were examined. RESULTS  Thirteen eyes from 12 patients were evaluated. Four dogs were castrated males and eight spayed females. Median age was 8 years of age (range 3-13). Breeds included seven terriers and five other breeds. All eyes examined demonstrated varying degrees of inflammation involving the iris and cleft. Mononuclear and melanophagic infiltration of the cleft was found in all specimens. Four globes also showed polymorphonuclear infiltrate. Pre-iridal fibrovascular membranes were clearly identified in 10 of 13 eyes. Total inflammatory score was significantly greater in all globes examined compared with an age-matched group of normal dogs. The posterior pigmented iris epithelium demonstrated a consistent pattern of hyperplasia and/or hypertrophy and cystic degeneration, more prominent in the more central regions. In some cases, hyperplasia was of greatest severity in the mid-iris and associated with thinning or flattening of the pupillary region. CONCLUSIONS  These results suggest that lens instability may be associated with chronic inflammation and secondary glaucoma. Mechanical irritation from an unstable lens may result in hypertrophy and/or hyperplasia of the posterior pigmented iris epithelium and subsequent cellular exfoliation and release of melanin. An inflammatory reaction directly or indirectly related to melanin release may obstruct the outflow pathways ultimately leading to glaucoma and loss of vision. Use of topical steroids may be warranted in dogs with PLD. © 2012 American College of Veterinary Ophthalmologists.

  7. Analysis of the post-translational modifications of the individual amino acids in lens proteins which were induced by aging and irradiation

    International Nuclear Information System (INIS)

    Fujii, Noriko; Kim, Ingu; Saito, Takeshi; Takata, Takumi

    2017-01-01

    The eye lens is a transparent organ that functions to focus light and images on the retina. The transparency and high refraction of the lens are maintained by the function of α-, β- and γ-crystallins. These long-lived proteins are subject to various post-translational modifications, such as oxidation, deamidation, truncation and isomerization, which occur gradually during the aging process. Such modifications, which are generated by UV light and oxidative stress, decrease crystallin solubility and lens transparency, and ultimately lead to the development of age-related cataracts. Here, we irradiated young rat lenses with γ-rays (5-500 Gy) and extracted the water-soluble (WS) and insoluble (WI) protein fractions. The WS and WI lens proteins were digested with trypsin, and the resulting peptides were analyzed by one-shot LC-MS/MS to determine the specific sites of oxidation of methionine and tryptophan, deamidation of asparagine and glutamine, and isomerization of aspartyl in rat α- and β-crystallins in the WS and WI fractions. Oxidation and deamidation occurred in several crystallins after irradiation at more than, respectively, 50 Gy and 5 Gy; however, isomerization did not occur in any crystallin even after exposure to 500 Gy of irradiation. The number of oxidation and deamidation sites was much higher in the WI than in the WS fraction. Furthermore, the oxidation and deamidation sites in rat crystallins resemble those reported in crystallins from human age-related cataracts. Thus, this study on post-translational modifications of crystallins induced by ionizing irradiation may provide useful information relevant to the formation of human age-related cataracts. (author)

  8. UVA photolysis using the protein-bound sensitizers present in human lens

    International Nuclear Information System (INIS)

    Ortwerth, B.J.; Olesen, P.R.

    1994-01-01

    This research was undertaken to demonstrate that the protein-bound chromophores in aged human lens can act as sensitizers for protein damage by UVA light. The water-insoluble (WI) proteins from pooled human and bovine lenses were solubilized by sonication in water and illuminated with UV light similar in output to that transmitted by the cornea. Analysis of the irradiated proteins showed a linear decrease in sulfhydryl groups with a 30% loss after 2 h. No loss was seen when native α-crystallin was irradiated under the same conditions. A 25% loss of histidine residues was also observed with the human lens WI fraction, and sodium dodecyl sulfate polyacrylamide gels indicated considerable protein cross-linking. Similar photodamage was seen with a WI fraction from old bovine lenses. While the data show the presence of UVA sensitizers, some histidine destruction and protein cross-linking were also obtained with α-crystallin and with lysozyme which argue that part of the histidine loss in the human WISS was likely due to tryptophan acting as a sensitizer. (Author)

  9. Purification, identification and preliminary crystallographic studies of a 2S albumin seed protein from Lens culinaris

    International Nuclear Information System (INIS)

    Gupta, Pankaj; Gaur, Vineet; Salunke, Dinakar M.

    2008-01-01

    A 2S albumin from L. culinaris was purified and crystallized and preliminary crystallographic studies were carried out. Lens culinaris (lentil) is a widely consumed high-protein-content leguminous crop. A 2S albumin protein (26.5 kDa) has been identified using NH 2 -terminal sequencing from a 90% ammonium sulfate saturation fraction of total L. culinaris seed protein extract. The NH 2 -terminal sequence shows very high homology to PA2, an allergy-related protein from Pisum sativum. The 2S albumin protein was purified using a combination of size-exclusion and ion-exchange chromatography. Crystals of the 2S seed albumin obtained using the hanging-drop vapour-diffusion method diffracted to 2.5 Å resolution and were indexed in space group P4 1 (or P4 3 ), with unit-cell parameters a = b = 78.6, c = 135.2 Å

  10. Photoreactivity of biologically active compounds. VIII. Photosensitized polymerization of lens proteins by antimalarial drugs in vitro.

    Science.gov (United States)

    Kristensen, S; Wang, R H; Tønnesen, H H; Dillon, J; Roberts, J E

    1995-02-01

    The drugs commonly used in the treatment of malaria are photochemically unstable. Several of these compounds cause dermal and ocular toxic reactions that may be light induced. The in vitro photopolymerization of calf lens proteins in the presence of antimalarial drugs was studied as part of a screening of the photochemical properties and phototoxic capabilities of these compounds. The pseudo-first-order rate constant for the reaction was calculated, and related to the amount of light absorbed by the compounds in order to determine the relative photosensitizing effect of each drug. The reaction mechanisms were evaluated by adding a variety of quenchers to the reaction medium during irradiation. Based on the results obtained in this study and previous knowledge about the pharmacokinetic behavior of these compounds, several of the drugs investigated have to be considered as potential photosensitizers in the human lens, the retina and the skin.

  11. Determination of eye lens doses and identification of risk groups among radiation exposed workers. An Austrian pilot study; Bestimmung der Augenlinsen-Dosis und Identifizierung von Risikogruppen bei beruflich strahlenexponierten Personen. Eine Pilotstudie in Oesterreich

    Energy Technology Data Exchange (ETDEWEB)

    Stadtmann, H.; Hranitzky, C.; Willer, H. [Seibersdorf Labor GmbH, Seibersdorf (Austria). Radiation Protection Dosimetry; Strebl, F.; Ernst, G. [Seibersdorf Labor GmbH, Seibersdorf (Austria). Radiation Safety and Applications; Aspek, W. [Allgemeine Unfallversicherungsanstalt (AUVA), Wien (Austria). Abt. Unfallverhuetung und Berufskrankheitenbekaempfung (HUB)

    2015-07-01

    On European level, in 2014 the dose limit for the lens of the eye of radiation exposed workers has been reduced from 150 to 20 mSv per year (2013/59/Euratom). Data about eye lens exposition measured under realistic operational conditions of Austrian radiation exposed workers is sparse and there is no information to verify, if all professional groups identified to be at risk for elevated eye doses will remain below the new annual dose limit. Therefore, financed by the Austrian Workers Compensation Board, AUVA, a pilot study has been initiated to answer this question. Based on published information professional groups of radiation exposed workers and operational tasks with an enhanced risk of elevated eye lens doses have been identified. By dosimetric measurements with volunteers (forehead dose meters and parallel measurements with whole-body TL-dose meters above and under the lead apron) realistic lens doses will be estimated during selected radiation exposed tasks. Comparison of yielded doses will show whether a TLD outside the apron could serve as an alternative to forehead dose meters dedicated to measure eye lens doses. Measurements with leaded protective eyewear based on IEC61331 yield results for lead equivalent in good agreement with manufacturers' information. Results for eye lens doses determined by use of a RANDO head phantom and a standardized phantom simulating a body in a typical exposition situation for interventional radiologists show that wearing of leaded goggles allows for a 90% dose reduction. Under such conditions the eye lens dose is dominated by backscatter and stray radiation from the operator's head and patient body. This has to be considered for the evaluation of protective effectiveness for leaded eye wear.

  12. MO-F-CAMPUS-I-04: Patient Eye-Lens Dose Reduction in Routine Brain CT Examinations Using Organ-Based Tube Current Modulation and In-Plane Bismuth Shielding

    International Nuclear Information System (INIS)

    Tsai, Hui-Yu; Liao, Ying-Lan; Lai, Nan-Ku; Chen, Tou-Rong; Chen, Jun-Rong

    2015-01-01

    Purpose: The purpose of this study is to assess eye-lens dose for patients who underwent brain CT examinations using two dose reduction Methods: organ-based tube current modulation (OBTCM) and in-plane bismuth shielding method. Methods: This study received institutional review board approval; written informed consent to participate was obtained from all patients. Ninety patients who underwent the routine brain CT examination were randomly assigned to three groups, ie. routine, OBTCM, and bismuth shield. The OBTCM technique reduced the tube current when the X-ray tube rotates in front of patients’ eye-lens region. The patients in the bismuth shield group were covered one-ply bismuth shield in the eyes’ region. Eye-lens doses were measured using TLD-100H chips and the total effective doses were calculated using CT-Expo according to the CT scanning parameters. The surface doses for patients at off-center positions were assessed to evaluate the off-centering effect. Results: Phantom measurements indicates that OBTCM technique could reduced by 26% to 28% of the surface dose to the eye lens, and increased by 25% of the surface dose at the opposed incident direction at the angle of 180°. Patients’ eye-lens doses were reduced 16.9% and 30.5% dose of bismuth shield scan and OBTCM scan, respectively compared to the routine scan. The eye-lens doses were apparently increased when the table position was lower than isocenter. Conclusion: Reducing the dose to the radiosensitive organs, such as eye lens, during routine brain CT examinations could lower the radiation risks. The OBTCM technique and in-plane bismuth shielding could be used to reduce the eye-lens dose. The eye-lens dose could be effectively reduced using OBTCM scan without interfering the diagnostic image quality. Patient position relative the CT gantry also affects the dose level of the eye lens. This study was supported by the grants from the Ministry of Science and Technology of Taiwan (MOST103-2314-B-182

  13. Role of Aquaporin 0 in lens biomechanics

    International Nuclear Information System (INIS)

    Sindhu Kumari, S.; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G.; Menon, Anil G.; Mathias, Richard T.; Varadaraj, Kulandaiappan

    2015-01-01

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5 −/− ), AQP0 KO (heterozygous KO: AQP0 +/− ; homozygous KO: AQP0 −/− ; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0 +/− lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to

  14. [Visual rehabilitation of patients with large post-traumatic defects of the anterior eye segment through iris-lens diaphragm implantation].

    Science.gov (United States)

    Khodzhaev, N S; Sobolev, N P; Mushkova, I A; Izmaylova, S B; Karimova, A N

    The diversity of methodological approaches and lack of pathogenetically reasonable tactics for patients with combined ocular injuries became the basis for the development and systematization of surgical rehabilitation stages of patients, in whom post-traumatic cataract is combined with post-traumatic aniridia and corneal scarring. to construct a visual rehabilitation approach to patients with post-traumatic defects of the anterior eye segment following optical-reconstructive surgery that involved implantation of an iris-lens diaphragm (ILD). We have analyzed 80 reconstructive cases with ILD implantation in patients with post-traumatic aniridia and corneal damage. These patients constituted the first study group (Group 1). We have also investigated 58 eyes with residual ametropy and stable visual function 1 year after ILD implantation before and after conducting a laser keratorefractive surgery. These patients were assigned to the second study group (Group 2). Rehabilitation approach to patients after anterior segment injuries that has been proposed allows to achieve high clinical and functional results and reduce the risk of intra- and postoperative complications. The proposed approach to patients after optical-reconstructive surgery with iris-lens diaphragm implantation followed by keratorefractive surgery is an effective method of visual rehabilitation of anterior eye segment post-traumatic defects.

  15. Radiation-induced cataracts: the Health Protection Agency's response to the ICRP statement on tissue reactions and recommendation on the dose limit for the eye lens.

    Science.gov (United States)

    Bouffler, Simon; Ainsbury, Elizabeth; Gilvin, Phil; Harrison, John

    2012-12-01

    This paper presents the response of the Health Protection Agency (HPA) to the 2011 statement from the International Commission on Radiological Protection (ICRP) on tissue reactions and recommendation of a reduced dose limit for the lens of the eye. The response takes the form of a brief review of the most recent epidemiological and mechanistic evidence. This is presented together with a discussion of dose limits in the context of the related risk and the current status of eye dosimetry, which is relevant for implementation of the limits. It is concluded that although further work is desirable to quantify better the risk at low doses and following protracted exposures, along with research into the mechanistic basis for radiation cataractogenesis to inform selection of risk projection models, the HPA endorses the conclusion reached by the ICRP in their 2011 statement that the equivalent dose limit for the lens of the eye should be reduced from 150 to 20 mSv per year, averaged over a five year period, with no year's dose exceeding 50 mSv.

  16. Factors Determining the Oxygen Permeability of Biological Membranes: Oxygen Transport Across Eye Lens Fiber-Cell Plasma Membranes.

    Science.gov (United States)

    Subczynski, Witold Karol; Widomska, Justyna; Mainali, Laxman

    2017-01-01

    Electron paramagnetic resonance (EPR) spin-label oximetry allows the oxygen permeability coefficient to be evaluated across homogeneous lipid bilayer membranes and, in some cases, across coexisting membrane domains without their physical separation. The most pronounced effect on oxygen permeability is observed for cholesterol, which additionally induces the formation of membrane domains. In intact biological membranes, integral proteins induce the formation of boundary and trapped lipid domains with a low oxygen permeability. The effective oxygen permeability coefficient across the intact biological membrane is affected not only by the oxygen permeability coefficients evaluated for each lipid domain but also by the surface area occupied by these domains in the membrane. All these factors observed in fiber cell plasma membranes of clear human eye lenses are reviewed here.

  17. Dosimetric studies of the lens of the eye using a new dosimeter - polls in two departments of Interventional Radiology of the autonomous city of Buenos Aires

    International Nuclear Information System (INIS)

    Pirchio, R.; Sánchez, H.; Domazet, W

    2013-01-01

    During interventional radiology (IR) and cardiology (IC) procedures, medical staff can receive high doses to their eye lenses. The Retrospective Evaluation of Lens Injuries and Dose (RELID) study organized in Argentina in 2010 found incipient opacity in 50% of IC physicians and 41% of IC technicians/nurses. These results, added to the recommendations of the International Commission on Radiological Protection (ICRP), which lowered their former occupational equivalent dose limit for the lens, led us to assess the eye lens dose, Hp(3), during interventional procedures. To this end, a new dosemeter was designed and calibrated at the National Atomic Energy Commission (CNEA) of Argentina to evaluate Hp(3). Personal dose equivalent (Hp(10)), and Hp(3) were assessed for 3 months in two IC and IR departments of Buenos Aires City using thermoluminescent dosimeters (TLD) and electronic personal dosimeter (EPD). An Rando Alderson phantom was used to simulate monthly exposures of five occupational staff members. Hp(3) and Hp(10) were obtained monthly for 14 occupational staff members exposed to 121 IR and IC procedures. We concluded that the annual effective dose and Hp(3) were lower than 0.3 and 10 mSv, respectively. An occupational annual dose constraint of 0.3 mSv was calculated. Average cumulative Hp(3) for working life of 40 years should be lower than 400 and 200 mSv for physicians and technicians/scrub nurse, respectively. Also we concluded that a calibrated EPD worn on a pocket in the lead apron and a TLD dosemeter worn on the collar thyroid (both at the maximal radiation side) could be used as guidance to the lens dose. Finally, To reduce doses of medical staff, actions should be promoted to maximize radiation protection in interventional procedures with appropriate training, using personal dosimetry and protection instruments as lead glasses, ceiling-suspended shields and others. (author)

  18. Safety and efficacy of topical azithromycin ophthalmic solution 1.0% in the treatment of contact lens-related dry eye.

    Science.gov (United States)

    Nichols, Jason J; Bickle, Katherine M; Zink, Richard C; Schiewe, Michael D; Haque, Reza M; Nichols, Kelly K

    2012-03-01

    The purpose of this pilot study was to evaluate the safety and efficacy of azithromycin ophthalmic solution 1% in patients with contact lens-related dry eye (CLDE). This was a 4-week, single-center, open-label clinical trial in patients diagnosed with CLDE using the Contact Lens Dry Eye Questionnaire (CLDEQ). Fifty patients were enrolled in this study. The patients were randomized to 1 of 2 treatment groups: azithromycin ophthalmic solution administered bid on days 1 and 2 and on days 3 to 29±1 or Visine for Contacts rewetting drops administered qid on days 1 to 29±1. The patient diaries were used daily to collect data on comfortable and total contact lens wear time and ocular dryness throughout the treatment period. Tear osmolarity, fluorescein corneal staining, and visual acuity were also assessed during clinic visits. Fifty patients were enrolled, and 44 completed the study. One patient discontinued in the azithromycin group, and five patients discontinued in the rewetting drops group because of adverse events. A statistically significant increase in mean comfortable contact lens wear time from baseline was observed for the subjects treated with azithromycin ophthalmic solution as compared with the subjects treated with rewetting drops at week 4 (P=0.004; primary endpoint), in addition to weeks 2 and 3. The improvement in the mean comfortable wear time for the patients in the azithromycin treatment group exceeded 2 hrs throughout the treatment period (weeks 1-4). No significant differences were observed between the groups for total wear time, low contrast visual acuity, or tear osmolarity. Subject-rated ocular dryness (PM time assessments) was significantly improved from baseline in the subjects treated with azithromycin ophthalmic solution as compared with those treated with rewetting drops at weeks 2 and 3 endpoints (P=0.015 for each week). Additionally, a statistical difference was observed in favor of the azithromycin treatment group at week 2 for the

  19. UVA Light-excited Kynurenines Oxidize Ascorbate and Modify Lens Proteins through the Formation of Advanced Glycation End Products

    Science.gov (United States)

    Linetsky, Mikhail; Raghavan, Cibin T.; Johar, Kaid; Fan, Xingjun; Monnier, Vincent M.; Vasavada, Abhay R.; Nagaraj, Ram H.

    2014-01-01

    Advanced glycation end products (AGEs) contribute to lens protein pigmentation and cross-linking during aging and cataract formation. In vitro experiments have shown that ascorbate (ASC) oxidation products can form AGEs in proteins. However, the mechanisms of ASC oxidation and AGE formation in the human lens are poorly understood. Kynurenines are tryptophan oxidation products produced from the indoleamine 2,3-dioxygenase (IDO)-mediated kynurenine pathway and are present in the human lens. This study investigated the ability of UVA light-excited kynurenines to photooxidize ASC and to form AGEs in lens proteins. UVA light-excited kynurenines in both free and protein-bound forms rapidly oxidized ASC, and such oxidation occurred even in the absence of oxygen. High levels of GSH inhibited but did not completely block ASC oxidation. Upon UVA irradiation, pigmented proteins from human cataractous lenses also oxidized ASC. When exposed to UVA light (320–400 nm, 100 milliwatts/cm2, 45 min to 2 h), young human lenses (20–36 years), which contain high levels of free kynurenines, lost a significant portion of their ASC content and accumulated AGEs. A similar formation of AGEs was observed in UVA-irradiated lenses from human IDO/human sodium-dependent vitamin C transporter-2 mice, which contain high levels of kynurenines and ASC. Our data suggest that kynurenine-mediated ASC oxidation followed by AGE formation may be an important mechanism for lens aging and the development of senile cataracts in humans. PMID:24798334

  20. Topogram-based tube current modulation of head computed tomography for optimizing image quality while protecting the eye lens with shielding.

    Science.gov (United States)

    Lin, Ming-Fang; Chen, Chia-Yuen; Lee, Yuan-Hao; Li, Chia-Wei; Gerweck, Leo E; Wang, Hao; Chan, Wing P

    2018-01-01

    Background Multiple rounds of head computed tomography (CT) scans increase the risk of radiation-induced lens opacification. Purpose To investigate the effects of CT eye shielding and topogram-based tube current modulation (TCM) on the radiation dose received by the lens and the image quality of nasal and periorbital imaging. Material and Methods An anthropomorphic phantom was CT-scanned using either automatic tube current modulation or a fixed tube current. The lens radiation dose was estimated using cropped Gafchromic films irradiated with or without a shield over the orbit. Image quality, assessed using regions of interest drawn on the bilateral extraorbital areas and the nasal bone with a water-based marker, was evaluated using both a signal-to-noise ratio (SNR) and contrast-noise ratio (CNR). Two CT specialists independently assessed image artifacts using a three-point Likert scale. Results The estimated radiation dose received by the lens was significantly lower when barium sulfate or bismuth-antimony shields were used in conjunction with a fixed tube current (22.0% and 35.6% reduction, respectively). Topogram-based TCM mitigated the beam hardening-associated artifacts of bismuth-antimony and barium sulfate shields. This increased the SNR by 21.6% in the extraorbital region and the CNR by 7.2% between the nasal bones and extraorbital regions. The combination of topogram-based TCM and barium sulfate or bismuth-antimony shields reduced lens doses by 12.2% and 27.2%, respectively. Conclusion Image artifacts induced by the bismuth-antimony shield at a fixed tube current for lenticular radioprotection were significantly reduced by topogram-based TCM, which increased the SNR of the anthropomorphic nasal bones and periorbital tissues.

  1. Determination of the dose in eyes lens by TLD, in PET/CT by technicians in PET/CT service

    International Nuclear Information System (INIS)

    Marino, Emiliano A.

    2013-01-01

    This work was supported, on the one hand, in a part of the project ORAMED which consisted of a design of a TLD dosimeter for measurements of Hp (3) in areas close to the lens, for interventional radiology physicians. On the other hand, Berhens work proposes using calibrated TLDs Hp (0.07) and Hp (10) to estimate Hp (3) crystal. This resulted in dosimeters calibrated using Hp (10) slab, and mount them on glasses, to estimate the dose to the lens of the technical staff of the Service PET / CT. The value obtained 29mSv/year of Lens Dose Equivalent exceeds the recommended limit. We also demonstrate that, under the current working conditions, the values of Hp (3) reported from whole body dosimeter does not represent faithfully the lens dose

  2. Combination of confocal principle and aperture stop separation improves suppression of crystalline lens fluorescence in an eye model

    OpenAIRE

    Klemm, Matthias; Blum, Johannes; Link, Dietmar; Hammer, Martin; Haueisen, Jens; Schweitzer, Dietrich

    2016-01-01

    Fluorescence lifetime imaging ophthalmoscopy (FLIO) is a new technique to detect changes in the human retina. The autofluorescence decay over time, generated by endogenous fluorophores, is measured in vivo. The strong autofluorescence of the crystalline lens, however, superimposes the intensity decay of the retina fluorescence, as the confocal principle is not able to suppress it sufficiently. Thus, the crystalline lens autofluorescence causes artifacts in the retinal fluorescence lifetimes d...

  3. Myotonic dystrophy protein kinase (DMPK) induces actin cytoskeletal reorganization and apoptotic-like blebbing in lens cells

    Science.gov (United States)

    Jin, S.; Shimizu, M.; Balasubramanyam, A.; Epstein, H. F.

    2000-01-01

    DMPK, the product of the DM locus, is a member of the same family of serine-threonine protein kinases as the Rho-associated enzymes. In DM, membrane inclusions accumulate in lens fiber cells producing cataracts. Overexpression of DMPK in cultured lens epithelial cells led to apoptotic-like blebbing of the plasma membrane and reorganization of the actin cytoskeleton. Enzymatically active DMPK was necessary for both effects; inactive mutant DMPK protein did not produce either effect. Active RhoA but not constitutive GDP-state mutant protein produced similar effects as DMPK. The similar actions of DMPK and RhoA suggest that they may function in the same regulatory network. The observed effects of DMPK may be relevant to the removal of membrane organelles during normal lens differentiation and the retention of intracellular membranes in DM lenses. Copyright 2000 Wiley-Liss, Inc.

  4. Contact Lens Risks

    Science.gov (United States)

    ... There is a risk of eye infection from bacteria in swimming pool water, hot tubs, lakes and the ocean Replace your contact lens storage case every 3 months or as directed by your eye care professional. Other Risks of Contact Lenses Other risks of contact lenses include pink eye ( ...

  5. Telomere Attrition in Human Lens Epithelial Cells Associated with Oxidative Stress Provide a New Therapeutic Target for the Treatment, Dissolving and Prevention of Cataract with N-Acetylcarnosine Lubricant Eye Drops. Kinetic, Pharmacological and Activity-Dependent Separation of Therapeutic Targeting: Transcorneal Penetration and Delivery of L-Carnosine in the Aqueous Humor and Hormone-Like Hypothalamic Antiaging Effects of the Instilled Ophthalmic Drug Through a Safe Eye Medication Technique.

    Science.gov (United States)

    Babizhayev, Mark A; Yegorov, Yegor E

    2016-01-01

    Visual impairment broadly impacts the ability of affected people to maintain their function and to remain independent during their daily occupations as they grow older. Visual impairment affects survival of older patients, quality of life, can affect a person's self-ranking of health, may be associated with social and functional decline, use of community support services, depression, falls, nursing home placement, and increased mortality. It has been hypothesized that senile cataract may serve as a marker for generalised tissue aging, since structural changes occurring in the proteins of the lens during cataract formation are similar to those which occur elsewhere as part of the aging process. The published analysis revealed a strong age-dependent relationship between undergoing cataract surgery and subsequent mortality. Nuclear opacity, particularly severe nuclear opacity, and mixed opacities with nuclear were significant predictors of mortality independent of body mass index, comorbid conditions, smoking, age, race, and sex. The lens opacity status is considered as an independent predictor of 2-year mortality, an association that could not be explained by potential confounders. Telomeres have become important biomarkers for aging as well as for oxidative stress-related disease. The lens epithelium is especially vulnerable to oxidative stress. Oxidative damage to the cuboidal epithelial cells on the anterior surface of the lens mediated by reactive oxygen species and phospholipid hydroperoxides can precede and contribute to human lens cataract formation. The erosion and shortening of telomeres in human lens epithelial cells in the lack of telomerase activity has been recognized as a primary cause of premature lens senescence phenotype that trigger human cataractogenesis. In this study we aimed to be focused on research defining the mechanisms that underlie linkages among telomere attrition in human lens epithelial cells associated with oxidative stress, biology of

  6. A comparison of basal and eye-flush tears for the analysis of cat tear proteins.

    Science.gov (United States)

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

    2011-02-01

    To identify a rapid and effective tear collection method providing sufficient tear volume and total protein content (TPC) for analysis of individual proteins in cats. Domestic adult short-haired cats (12-37 months; 2.7-6.6 kg) were used in the study. Basal tears without stimulation and eye-flush tears after instillation of saline (10 μl) were collected using microcapillary tubes from animal eyes either unwounded control or wounded with 9-mm central epithelial debridement giving four groups with n = 3. Tear comparisons were based on total time and rate for tear collection, TPC using micro bicinchoninic acid (BCA), tear immunoglobulin A (IgA), total matrix-metalloproteinase (MMP)-9 concentration using sandwich enzyme-linked immunosorbent assay (ELISA) and MMP-9 activity. Eye-flush tears were collected significantly faster than basal tears in wounded eyes with higher rates for tear collection in unwounded control and wounded eyes. TPC was significantly lower in eye-flush tears compared to basal tears. The relative proportion of tear IgA normalized to TPC (% IgA of TPC) was not significantly different between basal and eye-flush tears. In unwounded control eyes, MMP-9 was slightly higher in eye-flush than in basal tears; activity of MMP-9 in both tear types was similar. In wounded eyes, eye-flush tears showed highest MMP-9 levels and activity on Day 1, which subsequently decreased to Day 7. MMP-9 activity in basal tears from wounded eyes did not display changes in expression. Eye-flush tears can be collected rapidly providing sufficient tear volume and TPC. This study also indicates that eye-flush tears may be more suitable than basal tears for the analysis of MMPs following corneal wounding. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

  7. Gamma and x radiation and thermal neutrons effects in lens solutions and the relation with proteins concentration

    International Nuclear Information System (INIS)

    Ramirez A, M.; Alarcon C, A.

    1996-01-01

    Radiation effects have been studied irradiating porcine lens solutions with doses which range between 52 Gy to 1042 Gy in the case of x-rays (30 kVp), 631 Gy to 4001 Gy in the case of 60 Co gamma rays and 314 Gy to 7596 Gy for thermal neutrons. The optics density time variation of solutions was determined using a Spectronic-501 spectrophotometer, and with this data an equation which describes the behavior in the mentioned cases was found. A phenomenological model is postulated which connects the optical time variation density increment macroscopic effect with proteins concentration in the crystalline lens obtaining relative biological effectiveness using the supra-molecular aggregate formation due to the denaturalization and destruction of lens proteins by radiation criteria. (authors). 5 refs., 3 figs

  8. Comparing Hp(3) evaluated from the conversion coefficients from air kerma to personal dose equivalent for eye lens dosimetry calibrated on a new cylindrical PMMA phantom

    Science.gov (United States)

    Esor, J.; Sudchai, W.; Monthonwattana, S.; Pungkun, V.; Intang, A.

    2017-06-01

    Based on a new occupational dose limit recommended by ICRP (2011), the annual dose limit for the lens of the eye for workers should be reduced from 150 mSv/y to 20 mSv/y averaged over 5 consecutive years in which no single year exceeding 50 mSv. This new dose limit directly affects radiologists and cardiologists whose work involves high radiation exposure over 20 mSv/y. Eye lens dosimetry (Hp(3)) has become increasingly important and should be evaluated directly based on dosimeters that are worn closely to the eye. Normally, Hp(3) dose algorithm was carried out by the combination of Hp(0.07) and Hp(10) values while dosimeters were calibrated on slab PMMA phantom. Recently, there were three reports from European Union that have shown the conversion coefficients from air kerma to Hp(3). These conversion coefficients carried out by ORAMED, PTB and CEA Saclay projects were performed by using a new cylindrical head phantom. In this study, various delivered doses were calculated using those three conversion coefficients while nanoDot, small OSL dosimeters, were used for Hp(3) measurement. These calibrations were performed with a standard X-ray generator at Secondary Standard Dosimetry Laboratory (SSDL). Delivered doses (Hp(3)) using those three conversion coefficients were compared with Hp(3) from nanoDot measurements. The results showed that percentage differences between delivered doses evaluated from the conversion coefficient of each project and Hp(3) doses evaluated from the nanoDots were found to be not exceeding -11.48 %, -8.85 % and -8.85 % for ORAMED, PTB and CEA Saclay project, respectively.

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

    Science.gov (United States)

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

    2016-01-01

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

  10. Effect of infrared radiation on the lens

    Directory of Open Access Journals (Sweden)

    Aly Eman

    2011-01-01

    Full Text Available Background: Infrared (IR radiation is becoming more popular in industrial manufacturing processes and in many instruments used for diagnostic and therapeutic application to the human eye. Aim : The present study was designed to investigate the effect of IR radiation on rabbit′s crystalline lens and lens membrane. Materials and Methods: Fifteen New Zealand rabbits were used in the present work. The rabbits were classified into three groups; one of them served as control. The other two groups were exposed to IR radiation for 5 or 10 minutes. Animals from these two irradiated groups were subdivided into two subgroups; one of them was decapitated directly after IR exposure, while the other subgroup was decapitated 1 hour post exposure. IR was delivered from a General Electric Lamp model 250R 50/10, placed 20 cm from the rabbit and aimed at each eye. The activity of Na + -K + ATPase was measured in the lens membrane. Soluble lens proteins were extracted and the following measurements were carried out: estimation of total soluble protein, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE and Fourier transform infrared (FTIR spectroscopy. For comparison between multiple groups, analysis of variance was used with significance level set at P < 0.001. Results: The results indicated a change in the molecular weight of different lens crystalline accompanied with changes in protein backbone structure. These changes increased for the groups exposed to IR for 10 minutes. Moreover, the activity of Na + -K + ATPase significantly decreased for all groups. Conclusions: The protein of eye lens is very sensitive to IR radiation which is hazardous and may lead to cataract.

  11. Visual outcome and changes in corneal endothelial cell density following aphakic iris-fixated intraocular lens implantation in pediatric eyes with subluxated lenses.

    Science.gov (United States)

    Siddiqui, Sorath Noorani; Khan, Ayesha

    2013-01-01

    To evaluate the visual outcome and corneal endothelial cell density after Artisan aphakic intraocular lens (IOL) implantation (Ophtec, Groningen, the Netherlands) in pediatric eyes with subluxated lenses. Artisan aphakic IOLs were implanted in 18 eyes of 11 children with subluxated lenses. Idiopathic subluxations and ectopia lentis due to Marfan syndrome were included, whereas subluxations due to trauma or buphthalmos were excluded. Best-corrected visual acuity (BCVA) and endothelial cell density were monitored. Mean postoperative BCVA and endothelial cell density at last follow-up visit were calculated. The age of children at the time of Artisan aphakic IOL implantation ranged from 8 to 16 years (mean: 11.58 ± 2.9 years). Mean follow-up was 9.12 ± 4.30 months. Mean postoperative logarithm of the minimum angle of resolution BCVA was 0.26 ± 0.13 (P = .001) and mean postoperative endothelial cell density was 2,860 ± 435 cells/mm(2) (P = .000). Mean endothelial cell loss was 17.1%. Artisan aphakic IOL implantation is a safe surgical choice in the management of ectopia lentis in the pediatric age group. It has minimal complications and is less traumatic to pediatric eyes. However, long-term follow-up of these children is required.[J Pediatr Ophthalmol Strabismus 2013;50(3):178-182.]. Copyright 2013, SLACK Incorporated.

  12. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... Costume Contact Lenses Can Ruin Vision Eye Makeup Safety In fact, it is illegal to sell colored ...

  13. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... One Use Facts About Colored Contacts and Halloween Safety Colored Contact Lens Facts Over-the-Counter Costume ... new application of artificial intelligence shows whether a patient’s eyes point to high blood pressure or risk ...

  14. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... With Proper Contact Lens Care Apr 23, 2018 Solar Eclipse Inflicts Damage in the Shape of the ... edging closer, thanks to a wave of new technologies aiming to fix failing eye parts with human- ...

  15. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... glow-in-the-dark lizard lenses, costume contacts can certainly add a spooky, eye-popping touch. But ... consideration as a standard contact lens because they can be purchased over-the-counter or on the ...

  16. Comparison of the Retinal Straylight in Pseudophakic Eyes with PMMA, Hydrophobic Acrylic, and Hydrophilic Acrylic Spherical Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Ya-wen Guo

    2014-01-01

    Full Text Available Purpose. To investigate the intraocular straylight value after cataract surgery. Methods. In this study, 76 eyes from 62 patients were subdivided into three groups. A hydrophobic acrylic, a hydrophilic acrylic, and a PMMA IOL were respectively, implanted in 24 eyes, 28 eyes, and 24 eyes. Straylight was measured using C-Quant at 1 week and 1 month postoperatively in natural and dilated pupils. Results. The hydrophilic acrylic IOLs showed significantly lower straylight values than those of the hydrophobic acrylic IOLs in dilated pupils at 1 week and 1 month after surgery (P0.05. Moreover, no significant difference was found in straylight between natural and dilated pupils in each group at 1 week and 1 month postoperatively (P>0.05. Conclusions. Although the hydrophobic acrylic IOL induced more intraocular straylight, straylight differences among the 3 IOLs were minimal. Pupil size showed no effect on intraocular straylight; the intraocular straylight was stable 1 week after surgery.

  17. Recombinant production and solution structure of lipid transfer protein from lentil Lens culinaris

    Energy Technology Data Exchange (ETDEWEB)

    Gizatullina, Albina K. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Moscow Institute of Physics and Technology (State University), Department of Physicochemical Biology and Biotechnology, Institutskii per., 9, 141700, Dolgoprudny, Moscow Region (Russian Federation); Finkina, Ekaterina I.; Mineev, Konstantin S.; Melnikova, Daria N.; Bogdanov, Ivan V. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Telezhinskaya, Irina N.; Balandin, Sergey V. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Moscow Institute of Physics and Technology (State University), Department of Physicochemical Biology and Biotechnology, Institutskii per., 9, 141700, Dolgoprudny, Moscow Region (Russian Federation); Shenkarev, Zakhar O. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Arseniev, Alexander S. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Moscow Institute of Physics and Technology (State University), Department of Physicochemical Biology and Biotechnology, Institutskii per., 9, 141700, Dolgoprudny, Moscow Region (Russian Federation); Ovchinnikova, Tatiana V., E-mail: ovch@ibch.ru [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str., 16/10, 117997 Moscow (Russian Federation); Moscow Institute of Physics and Technology (State University), Department of Physicochemical Biology and Biotechnology, Institutskii per., 9, 141700, Dolgoprudny, Moscow Region (Russian Federation)

    2013-10-04

    Highlights: •Lipid transfer protein from lentil seeds (Lc-LTP2) was overexpressed in E. coli. •Antimicrobial activity and spatial structure of the recombinant Lc-LTP2 were examined. •Internal tunnel-like lipid-binding cavity occupies ∼7% of the total Lc-LTP2 volume. •Binding of DMPG lipid induces moderate rearrangements in the Lc-LTP2 structure. •Lc-LTP2/DMPG complex has limited lifetime and dissociates within tens of hours. -- Abstract: Lipid transfer protein, designated as Lc-LTP2, was isolated from seeds of the lentil Lens culinaris. The protein has molecular mass 9282.7 Da, consists of 93 amino acid residues including 8 cysteines forming 4 disulfide bonds. Lc-LTP2 and its stable isotope labeled analogues were overexpressed in Escherichia coli and purified. Antimicrobial activity of the recombinant protein was examined, and its spatial structure was studied by NMR spectroscopy. The polypeptide chain of Lc-LTP2 forms four α-helices (Cys4-Leu18, Pro26-Ala37, Thr42-Ala56, Thr64-Lys73) and a long C-terminal tail without regular secondary structure. Side chains of the hydrophobic residues form a relatively large internal tunnel-like lipid-binding cavity (van der Waals volume comes up to ∼600 Å{sup 3}). The side-chains of Arg45, Pro79, and Tyr80 are located near an assumed mouth of the cavity. Titration with dimyristoyl phosphatidylglycerol (DMPG) revealed formation of the Lc-LTP2/lipid non-covalent complex accompanied by rearrangements in the protein spatial structure and expansion of the internal cavity. The resultant Lc-LTP2/DMPG complex demonstrates limited lifetime and dissociates within tens of hours.

  18. Recombinant production and solution structure of lipid transfer protein from lentil Lens culinaris

    International Nuclear Information System (INIS)

    Gizatullina, Albina K.; Finkina, Ekaterina I.; Mineev, Konstantin S.; Melnikova, Daria N.; Bogdanov, Ivan V.; Telezhinskaya, Irina N.; Balandin, Sergey V.; Shenkarev, Zakhar O.; Arseniev, Alexander S.; Ovchinnikova, Tatiana V.

    2013-01-01

    Highlights: •Lipid transfer protein from lentil seeds (Lc-LTP2) was overexpressed in E. coli. •Antimicrobial activity and spatial structure of the recombinant Lc-LTP2 were examined. •Internal tunnel-like lipid-binding cavity occupies ∼7% of the total Lc-LTP2 volume. •Binding of DMPG lipid induces moderate rearrangements in the Lc-LTP2 structure. •Lc-LTP2/DMPG complex has limited lifetime and dissociates within tens of hours. -- Abstract: Lipid transfer protein, designated as Lc-LTP2, was isolated from seeds of the lentil Lens culinaris. The protein has molecular mass 9282.7 Da, consists of 93 amino acid residues including 8 cysteines forming 4 disulfide bonds. Lc-LTP2 and its stable isotope labeled analogues were overexpressed in Escherichia coli and purified. Antimicrobial activity of the recombinant protein was examined, and its spatial structure was studied by NMR spectroscopy. The polypeptide chain of Lc-LTP2 forms four α-helices (Cys4-Leu18, Pro26-Ala37, Thr42-Ala56, Thr64-Lys73) and a long C-terminal tail without regular secondary structure. Side chains of the hydrophobic residues form a relatively large internal tunnel-like lipid-binding cavity (van der Waals volume comes up to ∼600 Å 3 ). The side-chains of Arg45, Pro79, and Tyr80 are located near an assumed mouth of the cavity. Titration with dimyristoyl phosphatidylglycerol (DMPG) revealed formation of the Lc-LTP2/lipid non-covalent complex accompanied by rearrangements in the protein spatial structure and expansion of the internal cavity. The resultant Lc-LTP2/DMPG complex demonstrates limited lifetime and dissociates within tens of hours

  19. Effects of Long-Term Exposure to 60 GHz Millimeter-Wavelength Radiation on the Genotoxicity and Heat Shock Protein (Hsp Expression of Cells Derived from Human Eye

    Directory of Open Access Journals (Sweden)

    Shin Koyama

    2016-08-01

    Full Text Available Human corneal epithelial (HCE-T and human lens epithelial (SRA01/04 cells derived from the human eye were exposed to 60 gigahertz (GHz millimeter-wavelength radiation for 24 h. There was no statistically significant increase in the micronucleus (MN frequency in cells exposed to 60 GHz millimeter-wavelength radiation at 1 mW/cm2 compared with sham-exposed controls and incubator controls. The MN frequency of cells treated with bleomycin for 1 h provided positive controls. The comet assay, used to detect DNA strand breaks, and heat shock protein (Hsp expression also showed no statistically significant effects of exposure. These results indicate that exposure to millimeter-wavelength radiation has no effect on genotoxicity in human eye cells.

  20. Effective radiation dose and eye lens dose in dental cone beam CT: effect of field of view and angle of rotation.

    Science.gov (United States)

    Pauwels, R; Zhang, G; Theodorakou, C; Walker, A; Bosmans, H; Jacobs, R; Bogaerts, R; Horner, K

    2014-10-01

    To quantify the effect of field of view (FOV) and angle of rotation on radiation dose in dental cone beam CT (CBCT) and to define a preliminary volume-dose model. Organ and effective doses were estimated using 148 thermoluminescent dosemeters placed in an anthropomorphic phantom. Dose measurements were undertaken on a 3D Accuitomo 170 dental CBCT unit (J. Morita, Kyoto, Japan) using six FOVs as well as full-rotation (360°) and half-rotation (180°) protocols. For the 360° rotation protocols, effective dose ranged between 54 µSv (4 × 4 cm, upper canine) and 303 µSv (17 × 12 cm, maxillofacial). An empirical relationship between FOV dimension and effective dose was derived. The use of a 180° rotation resulted in an average dose reduction of 45% compared with a 360° rotation. Eye lens doses ranged between 95 and 6861 µGy. Significant dose reduction can be achieved by reducing the FOV size, particularly the FOV height, of CBCT examinations to the actual region of interest. In some cases, a 180° rotation can be preferred, as it has the added value of reducing the scan time. Eye lens doses should be reduced by decreasing the height of the FOV rather than using inferior FOV positioning, as the latter would increase the effective dose considerably. The effect of the FOV and rotation angle on the effective dose in dental CBCT was quantified. The dominant effect of FOV height was demonstrated. A preliminary model has been proposed, which could be used to predict effective dose as a function of FOV size and position.

  1. Biomarkers of oxidative stress and cataract. Novel drug delivery therapeutic strategies targeting telomere reduction and the expression of telomerase activity in the lens epithelial cells with N-acetylcarnosine lubricant eye drops: anti-cataract which helps to prevent and treat cataracts in the eyes of dogs and other animals.

    Science.gov (United States)

    Babizhayev, Mark A; Yegorov, Yegor E

    2014-01-01

    Cataracts in small animals are shown to be at least partially caused by oxidative damage to lens epithelial cells (LECs) and the internal lens; biomarkers of oxidative stress in the lens are considered as general biomarkers for life expectancy in the canine and other animals. Telomeres lengths and expressed telomerase activity in canine LECs may serve as important monitors of oxidative damage in normal LECs with documented higher levels of telomerase activity in cataractous LECs during cells' lifespan. Loss of functional telomere length below a critical threshold in LECs of canines during the effect of UV and chronic oxidative stress or metabolic failure, can activate programs leading to LEC senescence or death. Telomerase is induced in LECs of canines at critical stages of cataractogenesis initiation and exposure to oxidative stress through the involvement of catalytically active prooxidant transition metal (iron) ions. This work documents that transition metal ions (such as, ferrous ions- catalytic oxidants) might induce premature senescence in LECs of canines, telomere shortening with increased telomerase activity as adaptive response to UV light, oxidative and metabolic stresses. The therapeutic treatment with 1% N-acetylcarnosine (NAC) prodrug delivery is beneficial for prevention and dissolution of ripe cataracts in canines. This biological activity is based on the findings of ferroxidase activity pertinent to the dipeptide carnosine released ophthalmically from NAC prodrug of L-carnosine, stabilizing properties of carnosine on biological membranes based on the ability of the imidazole-containing dipeptides to interact with lipid peroxidation products and reactive oxygen species (ROS), to prevent membrane damage and delute the associated with membrane fragements protein aggregates. The advent of therapeutic treatment of cataracts in canines with N-acetylcarnosine lubricant eye drops through targeting the prevention of loss of functional telomere length below

  2. Viewing Eye Movements During Reading through the Lens of Chaos Theory: How Reading Is Like the Weather

    Science.gov (United States)

    Paulson, Eric J.

    2005-01-01

    This theoretical article examines reading processes using chaos theory as an analogy. Three principles of chaos theory are identified and discussed, then related to reading processes as revealed through eye movement research. Used as an analogy, the chaos theory principle of sensitive dependence contributes to understanding the difficulty in…

  3. Molecular eyes: proteins that transform light into biological information

    NARCIS (Netherlands)

    Kennis, J.T.M.; Mathes, T.

    2013-01-01

    Most biological photoreceptors are protein/cofactor complexes that induce a physiological reaction upon absorption of a photon. Therefore, these proteins represent signal converters that translate light into biological information. Researchers use this property to stimulate and study various

  4. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... prescription. There is no such thing as a "one size fits all" contact lens. Lenses that are not properly fitted may scratch the eye or cause blood vessels to grow into the cornea. Even if you have perfect vision, you need to get an eye exam and a prescription ...

  5. Role of pirenoxine in the effects of catalin on in vitro ultraviolet-induced lens protein turbidity and selenite-induced cataractogenesis in vivo.

    Science.gov (United States)

    Hu, Chao-Chien; Liao, Jiahn-Haur; Hsu, Kuang-Yang; Lin, I-Lin; Tsai, Ming-Hsuan; Wu, Wen-Hsin; Wei, Tzu-Tang; Huang, Yi-Shiang; Chiu, Shih-Jiuan; Chen, Hsiang-Yin; Wu, Shih-Hsiung; Wu, Tzu-Hua

    2011-01-01

    In this study, we investigated the biochemical pharmacology of pirenoxine (PRX) and catalin under in vitro selenite/calcium- and ultraviolet (UV)-induced lens protein turbidity challenges. The systemic effects of catalin were determined using a selenite-induced cataractogenesis rat model. In vitro cataractogenesis assay systems (including UVB/C photo-oxidation of lens crystallins, calpain-induced proteolysis, and selenite/calcium-induced turbidity of lens crystallin solutions) were used to screen the activity of PRX and catalin eye drop solutions. Turbidity was identified as the optical density measured using spectroscopy at 405 nm. We also determined the in vivo effects of catalin on cataract severity in a selenite-induced cataract rat model. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was applied to analyze the integrity of crystallin samples. PRX at 1,000 μM significantly delayed UVC-induced turbidity formation compared to controls after 4 h of UVC exposure (pturbidity induced by 4 h of UVC exposure was ameliorated in the presence of catalin equivalent to 1~100 μM PRX in a concentration-dependent manner. Samples with catalin-formulated vehicle only (CataV) and those containing PRX equivalent to 100 μM had a similar protective effect after 4 h of UVC exposure compared to the controls (pturbidity formation compared to controls on days 0~4 (pturbidity on day 1 (pturbidity but required millimolar levels to protect against UVC irradiation. The observed inhibition of UVC-induced turbidity of lens crystallins by catalin at micromolar concentrations may have been a result of the catalin-formulated vehicle. Transient protection by catalin against selenite-induced turbidity of crystallin solutions in vitro was supported by the ameliorated cataract scores in the early stage of cataractogenesis in vivo by subcutaneously administered catalin. PRX could not inhibit calpain-induced proteolysis activated by calcium or catalin itself, and may be

  6. Role of Aquaporin 0 in lens biomechanics.

    Science.gov (United States)

    Sindhu Kumari, S; Gupta, Neha; Shiels, Alan; FitzGerald, Paul G; Menon, Anil G; Mathias, Richard T; Varadaraj, Kulandaiappan

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5(-/-)), AQP0 KO (heterozygous KO: AQP0(+/-); homozygous KO: AQP0(-/-); all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0(+/-) lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and together they help to confer

  7. Recurrent uveitis and pigment dispersion in an eye with in-the-bag acrylic foldable intraocular lens.

    Science.gov (United States)

    Thakur, Monica; Bhatia, Prashant; Chandrasekhar, Garudadri; Senthil, Sirisha

    2016-02-26

    Phacoemulsification with in-the-bag intraocular lens (IOL) implantation is the standard procedure for cataract surgery. Pigment dispersion and uveitis can result when an IOL is placed in the sulcus. We report a case of a 64-year-old woman, with pigmentary glaucoma, who developed recurrent uveitis following uneventful cataract surgery and an in-the-bag hydrophobic acrylic IOL implant. Recurrent uveitis did not subside despite use of topical steroids over 3 months. Dilated examination revealed capsulophimosis with anterior dislocation of the IOL haptic. The mechanical trauma to the iris due to the displaced haptic was implicated as the cause of recurrent uveitis, which completely resolved after capsular excision and IOL repositioning. This case illustrates a rare cause of recurrent uveitis due to IOL haptic dislocation following severe capsulophimosis. 2016 BMJ Publishing Group Ltd.

  8. Nanoceria have no genotoxic effect on human lens epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pierscionek, Barbara K; Yasseen, Akeel A [School of Biomedical Sciences, University of Ulster, Coleraine, BT52 1SA (United Kingdom); Li, Yuebin; Schachar, Ronald A; Chen, Wei [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Colhoun, Liza M, E-mail: b.pierscionek@ulster.ac.uk, E-mail: weichen@uta.edu [Centre for Vision and Vascular Sciences, School of Medicine, Dentistry and Biomedical Sciences, Queen' s University Belfast, Grosvenor Road, Belfast, BT12 6BA (United Kingdom)

    2010-01-22

    There are no treatments for reversing or halting cataract, a disease of the structural proteins in the eye lens, that has associations with other age-related degenerative conditions such as Alzheimer's disease. The incidence of cataract and associated conditions is increasing as the average age of the population rises. Protein folding diseases are difficult to assess in vivo as proteins and their age-related changes are assessed after extraction. Nanotechnology can be used to investigate protein changes in the intact lens as well as for a potential means of drug delivery. Nanoparticles, such as cerium oxide (CeO{sub 2}) which have antioxidant properties, may even be used as a means of treating cataract directly. Prior to use in treatments, nanoparticle genotoxicity must be tested to assess the extent of any DNA or chromosomal damage. Sister chromatid exchanges were measured and DNA damage investigated using the alkaline COMET assay on cultured human lens epithelial cells, exposed to 5 and 10 {mu}g ml{sup -1} of CeO{sub 2} nanoparticles (nanoceria). Nanoceria at these dosages did not cause any DNA damage or significant increases in the number of sister chromatid exchanges. The absence of genotoxic effects on lens cells suggests that nanoceria, in the doses and exposures tested in this study, are not deleterious to the eye lens and have the potential for use in studying structural alterations, in developing non-surgical cataract treatments and in investigating other protein folding diseases.

  9. Eye lens dose estimation during interventional radiology and its impact on the existing radiation protection and safety program: in the context with new International Commission on Radiological Protection guidelines

    International Nuclear Information System (INIS)

    Chaudhari, Suresh

    2014-01-01

    Interventional radiology procedures are used for diagnosing certain medical conditions. The radiologists and medical professionals are exposed to ionizing radiation from X-rays of the equipments and also from scattered radiation during these procedures. The radiation exposure to the eye is more important to be assessed while performing such procedures. ICRP has revised the annual dose limit to the lens of the eye from 150 mSv to 20 mSv. In view of this revision, a study was carried out to evaluate the dose to the lens of the eye during interventional radiology. The paper gives the details of calibration of TLDs using a head phantom, predict annual equivalent dose and also highlight the dependence of dose on the position of TLD on the head. It is observed the predicted annual equivalent doses to the lens of eye are in the range of 25 mGy to 37 mGy. The selection of dosimeter placement may also result in an uncertainty of -14% to 20%. (author)

  10. Effects of punctal occlusion on global tear proteins in patients with dry eye.

    Science.gov (United States)

    Tong, Louis; Zhou, Lei; Beuerman, Roger; Simonyi, Susan; Hollander, David A; Stern, Michael E

    2017-10-01

    To investigate effects of punctal occlusion on global tear protein levels in patients with dry eye. In this prospective, longitudinal, single-center study, nonabsorbable punctal plugs were inserted bilaterally into the lower punctum of 30 patients with moderate dry eye. Dry eye symptoms, fluorescein corneal staining, Schirmer I test, tear film break-up time, and safety were assessed in the more severely affected eye. Tear proteins at weeks 1 and 3 were quantified by iTRAQ relative to baseline preocclusion levels. Of 29 patients who completed the study, 23 (mean age 49.8 years) had sufficient tear samples for analysis. After 3 weeks, punctal occlusion significantly upregulated tear proteins, including glutathione synthase (mean of 1.6-fold, P = 0.01) and interleukin-1 receptor antagonist (1.7-fold, P = 0.032) and downregulated cholinergic receptor (neuronal) alpha-7 (0.79-fold, P = 0.039) and lymphocyte cytosolic protein-1 (0.66-fold, P = 0.012). Clustering analysis of global tear proteins revealed two clear profile changes; the first group of patients (cluster 1, n = 10) had a reduction in the inflammatory proteins (e.g., S100A8) and rise in lacrimal proteins supporting the ocular surface (e.g., lysozyme), whereas the second group (cluster 2, n = 13) had an increase in inflammatory proteins and a decrease in lacrimal proteins. Logistic regression analysis revealed that cluster 1 patients had significantly (P = 0.006) lower Schirmer scores at baseline (mean [standard deviation]: 4.3 [4.3] mm) than cluster 2 (6.8 [2.6] mm). Punctal plugs produced a beneficial pattern of tear protein change in patients with relatively low Schirmer scores within 3 weeks of punctal occlusion. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Exposition of the operator's eye lens and efficacy of radiation shielding in fluoroscopically guided interventions; Exposition der Augenlinse des Untersuchers und Effizienz der Strahlenschutzmittel bei fluoroskopischen Interventionen

    Energy Technology Data Exchange (ETDEWEB)

    Galster, M.; Adamus, R. [Klinikum Nuernberg-Nord, Nuernberg (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Guhl, C. [Klinikum Nuernberg (Germany). Inst. fuer Medizinische Physik; Uder, M. [Erlangen Univ. (Germany). Radiologisches Inst.

    2013-05-15

    Purpose: Efficacy of radiation protection tools for the eye lens dose of the radiologist in fluoroscopic interventions. Materials and Methods: A patient phantom was exposed using a fluoroscopic system. Dose measurements were made at the eye location of the radiologist using an ionization chamber. The setting followed typical fluoroscopic interventions. The reduction of scattered radiation by the equipment-mounted shielding (undercouch drapes and overcouch top) was evaluated. The ceiling-suspended lead acrylic glass screen was tested in scattered radiation generated by a slab phantom. The protective properties of different lead glass goggles and lead acrylic visors were evaluated by thermoluminescence measurements on a head phantom in the primary beam. Results: The exposition of the lens of about 110 to 550 {mu}Sv during radiologic interventions is only slightly reduced by the undercouch drapes. Applying the top in addition to the drapes reduces the lens dose by a factor of 2 for PA projections. In 25 LAO the dose is reduced by a factor between 1.2 and 5. The highest doses were measured for AP angulations furthermore the efficacy of the equipment-mounted shielding is minimal. The ceiling-suspended lead screen reduced scatter by a factor of about 30. The lead glass goggles and visors reduced the lens dose up to a factor of 8 to 10. Depending on the specific design, the tested models are less effective especially for radiation from lateral with cranial angulation of the beam. Occasionally the visors even caused an increase of dose. Conclusion: The exposition of the eye lens can be kept below the new occupational limit recommended by the ICRP if the radiation shielding equipment is used consistently. (orig.)

  12. Addendum report of the JHPS expert committee on radiation protection of the lens of the eye (2). When and how should the dosimetry of beta H_p(3) be made?

    International Nuclear Information System (INIS)

    Akahane, Keiichi; Tatsuzaki, Hideo; Iimoto, Takeshi; Ichiji, Takeshi; Hamada, Nobuyuki; Iwai, Satoshi; Ohguchi, Hiroyuki; Ohno, Kazuko; Kawaura, Chiyo; Kurosawa, Tadahiro; Tsujimura, Norio; Hayashida, Toshiyuki; Hotta, Yutaka; Yamasaki, Tadashi; Yokoyama, Sumi

    2015-01-01

    In a mixed field of photon and beta radiations, the same dose assigned to skin is normally assigned to the dose to the lens of the eye as a conservative estimate of H_p(3). In exceptional cases where a very high beta dose might be imparted of the same order with the dose limit, however, the conservatively biased dose must be too limiting, and thereby an accurate estimate of beta H_p(3) is desirable. This addendum report of the Japan Health Physics Society Expert Committee on Radiation Protection of the Lens of the Eye presents a practical proposal of when and how the dosimetry of beta H_p(3) should be made. (author)

  13. EURADOS intercomparisons in external radiation dosimetry: similarities and differences among exercises for whole-body photon, whole-body neutron, extremity, eye-lens and passive area dosemeters

    International Nuclear Information System (INIS)

    Romero, Ana M.; Grimbergen, Tom; McWhan, Andrew; Stadtmann, Hannes; Fantuzzi, Elena; Clairand, Isabelle; Neumaier, Stefan; Dombrowski, Harald; Figel, Markus

    2016-01-01

    The European Radiation Dosimetry Group (EURADOS) has been organising dosimetry intercomparisons for many years in response to an identified requirement from individual monitoring services (IMS) for independent performance tests for dosimetry systems. The participation in intercomparisons gives IMS the opportunity to show compliance with their own quality management system, compare results with other participants and develop plans for improving their dosimetry systems. In response to growing demand, EURADOS has increased the number of intercomparisons for external radiation dosimetry. Most of these fit into the programme of self-financing intercomparisons for dosemeters routinely used by IMS. This programme is being coordinated by EURADOS working group 2 (WG2). Up to now, this programme has included four intercomparisons for whole-body dosemeters in photon fields, one for extremity dosemeters in photon and beta fields, and one for whole-body dosemeters in neutron fields. Other EURADOS working groups have organised additional intercomparisons including events in 2014 for eye-lens dosemeters and passive area dosemeters for environmental monitoring. In this paper, the organisation and achievements of these intercomparisons are compared in detail focusing on the similarities and differences in their execution. (authors)

  14. Differences in Dry Eye Questionnaire Symptoms in Two Different Modalities of Contact Lens Wear: Silicone-Hydrogel in Daily Wear Basis and Overnight Orthokeratology

    Directory of Open Access Journals (Sweden)

    Nery García-Porta

    2016-01-01

    Full Text Available Purpose. To compare the ocular surface symptoms and signs in an adult population of silicone-hydrogel (Si-Hy contact lens (CL wearers with another modality of CL wear, overnight orthokeratology (OK. Materials and Methods. This was a prospective and comparative study in which 31 myopic subjects were fitted with the same Si-Hy CL and 23 underwent OK treatment for 3 months. Dry eye questionnaire (DEQ was filled in at the beginning of the study and then after 15 days, 1 month, and 3 months using each CL modality. The tear quality was evaluated with noninvasive tear break-up time. Tear production was measured with Schirmer test. Tear samples were collected with Schirmer strips being frozen to analyze the dinucleotide diadenosine tetraphosphate (Ap4A concentration with High-Performance Liquid Chromatography (HPLC. Results. After refitting with ortho-k, a reduction in discomfort and dryness symptoms at the end of the day (p<0.05, χ2 was observed. No significant changes were observed in Ap4A concentration in any group. Bulbar redness, limbal redness, and conjunctival staining increased significantly in the Si-Hy group (p<0.05, Kruskal–Wallis test. Conclusion. Discomfort and dryness symptoms at the end of the day are lower in the OK CL group than in the Si-Hy CL group.

  15. Role of Aquaporin 0 in lens biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Sindhu Kumari, S.; Gupta, Neha [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); Shiels, Alan [Washington University School of Medicine, St. Louis, MO (United States); FitzGerald, Paul G. [Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA (United States); Menon, Anil G. [University of Cincinnati College of Medicine, Cincinnati, OH (United States); Mathias, Richard T. [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States); Varadaraj, Kulandaiappan, E-mail: kulandaiappan.varadaraj@stonybrook.edu [Physiology and Biophysics, Stony Brook University, Stony Brook, NY (United States); SUNY Eye Institute, NY (United States)

    2015-07-10

    Maintenance of proper biomechanics of the eye lens is important for its structural integrity and for the process of accommodation to focus near and far objects. Several studies have shown that specialized cytoskeletal systems such as the beaded filament (BF) and spectrin-actin networks contribute to mammalian lens biomechanics; mutations or deletion in these proteins alters lens biomechanics. Aquaporin 0 (AQP0), which constitutes ∼45% of the total membrane proteins of lens fiber cells, has been shown to function as a water channel and a structural cell-to-cell adhesion (CTCA) protein. Our recent ex vivo study on AQP0 knockout (AQP0 KO) mouse lenses showed the CTCA function of AQP0 could be crucial for establishing the refractive index gradient. However, biomechanical studies on the role of AQP0 are lacking. The present investigation used wild type (WT), AQP5 KO (AQP5{sup −/−}), AQP0 KO (heterozygous KO: AQP0{sup +/−}; homozygous KO: AQP0{sup −/−}; all in C57BL/6J) and WT-FVB/N mouse lenses to learn more about the role of fiber cell AQPs in lens biomechanics. Electron microscopic images exhibited decreases in lens fiber cell compaction and increases in extracellular space due to deletion of even one allele of AQP0. Biomechanical assay revealed that loss of one or both alleles of AQP0 caused a significant reduction in the compressive load-bearing capacity of the lenses compared to WT lenses. Conversely, loss of AQP5 did not alter the lens load-bearing ability. Compressive load-bearing at the suture area of AQP0{sup +/−} lenses showed easy separation while WT lens suture remained intact. These data from KO mouse lenses in conjunction with previous studies on lens-specific BF proteins (CP49 and filensin) suggest that AQP0 and BF proteins could act co-operatively in establishing normal lens biomechanics. We hypothesize that AQP0, with its prolific expression at the fiber cell membrane, could provide anchorage for cytoskeletal structures like BFs and

  16. Radiation effects on eye components

    Science.gov (United States)

    Durchschlag, H.; Fochler, C.; Abraham, K.; Kulawik, B.

    1999-08-01

    The most important water-soluble components of the vertebrate eye (lens proteins, aqueous humor, vitreous, hyaluronic acid, ascorbic acid) have been investigated in aqueous solution, after preceding X- or UV-irradiation. Spectroscopic, chromatographic, electrophoretic, hydrodynamic and analytic techniques have been applied, to monitor several radiation damages such as destruction of aromatic and sulfur-containing amino acids, aggregation, crosslinking, dissociation, fragmentation, and partial unfolding. Various substances were found which were able to protect eye components effectively against radiation, some of them being also of medical relevance.

  17. RNA Binding Proteins in Eye Development and Disease: Implication of Conserved RNA Granule Components

    Science.gov (United States)

    Dash, Soma; Siddam, Archana D.; Barnum, Carrie E.; Janga, Sarath Chandra

    2016-01-01

    The molecular biology of metazoan eye development is an area of intense investigation. These efforts have led to the surprising recognition that although insect and vertebrate eyes have dramatically different structures, the orthologs or family members of several conserved transcription and signaling regulators such as Pax6, Six3, Prox1 and Bmp4 are commonly required for their development. In contrast, our understanding of post-transcriptional regulation in eye development and disease, particularly regarding the function of RNA binding proteins (RBPs), is limited. We examine the present knowledge of RBPs in eye development in the insect model Drosophila, as well as several vertebrate models such as fish, frog, chicken and mouse. Interestingly, of the 42 RBPs that have been investigated with for their expression or function in vertebrate eye development, 24 (~60%) are recognized in eukaryotic cells as components of RNA granules such as Processing bodies (P-bodies), Stress granules, or other specialized ribonucleoprotein (RNP) complexes. We discuss the distinct developmental and cellular events that may necessitate potential RBP/RNA granule-associated RNA regulon models to facilitate post-transcriptional control of gene expression in eye morphogenesis. In support of these hypotheses, three RBPs and RNP/RNA granule components Tdrd7, Caprin2 and Stau2 are linked to ocular developmental defects such as congenital cataract, Peters anomaly and microphthalmia in human patients or animal models. We conclude by discussing the utility of interdisciplinary approaches such as the bioinformatics tool iSyTE (integrated Systems Tool for Eye gene discovery) to prioritize RBPs for deriving post-transcriptional regulatory networks in eye development and disease. PMID:27133484

  18. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, Mike A. (Albuquerque, NM); Foreman, Larry R. (Los Alamos, NM)

    1997-01-01

    This invention describes a method for fabricating an intraocular lens made rom clear Teflon.TM., Mylar.TM., or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube.

  19. Intraocular lens fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.A.; Foreman, L.R.

    1997-07-08

    This invention describes a method for fabricating an intraocular lens made from clear Teflon{trademark}, Mylar{trademark}, or other thermoplastic material having a thickness of about 0.025 millimeters. These plastic materials are thermoformable and biocompatable with the human eye. The two shaped lenses are bonded together with a variety of procedures which may include thermosetting and solvent based adhesives, laser and impulse welding, and ultrasonic bonding. The fill tube, which is used to inject a refractive filling material is formed with the lens so as not to damage the lens shape. A hypodermic tube may be included inside the fill tube. 13 figs.

  20. Common and distinctive localization patterns of Crumbs polarity complex proteins in the mammalian eye.

    Science.gov (United States)

    Kim, Jin Young; Song, Ji Yun; Karnam, Santi; Park, Jun Young; Lee, Jamie J H; Kim, Seonhee; Cho, Seo-Hee

    2015-01-01

    Crumbs polarity complex proteins are essential for cellular and tissue polarity, and for adhesion of epithelial cells. In epithelial tissues deletion of any of three core proteins disrupts localization of the other proteins, indicating structural and functional interdependence among core components. Despite previous studies of function and co-localization that illustrated the properties that these proteins share, it is not known whether an individual component of the complex plays a distinct role in a unique cellular and developmental context. In order to investigate this question, we primarily used confocal imaging to determine the expression and subcellular localization of the core Crumbs polarity complex proteins during ocular development. Here we show that in developing ocular tissues core Crumbs polarity complex proteins, Crb, Pals1 and Patj, generally appear in an overlapping pattern with some exceptions. All three core complex proteins localize to the apical junction of the retinal and lens epithelia. Pals1 is also localized in the Golgi of the retinal cells and Patj localizes to the nuclei of the apically located subset of progenitor cells. These findings suggest that core Crumbs polarity complex proteins exert common and independent functions depending on cellular context. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Comparison of lens oxidative damage induced by vitrectomy and/or hyperoxia in rabbits

    Directory of Open Access Journals (Sweden)

    Hong Yan

    2017-02-01

    Full Text Available AIM: To compare of lens oxidative damage induced by vitrectomy and/or hyperoxia in rabbit. METHODS: Sixteen New Zealand rabbits (2.4-2.5 kg were randomly divided into two groups (Group A, n=12; Group B, n=4. In Group A, the right eyes were treated with vitrectomy and systemic hyperoxia (oxygen concentration: 80%-85%, 1 ATA, 4h/d (Group A-right, and the left eyes were treated with hyperoxia without vitrectomy surgery (Group A-left. Four rabbits in group B (eight eyes were untreated as the controls. Lens transparency was monitored with a slit lamp and recorded before and after vitrectomy. After hyperoxic treatment for 6mo, the eyeballs were removed and the lens cortices (containing the capsules and nuclei were separated for further morphological and biochemical evaluation. RESULTS: Six months after treatments, there were no significant morphological changes in the lenses in any experimental group when observed with a slit lamp. However, the levels of water-soluble proteins and ascorbate, and the activities of catalase and Na+-K+-ATPase were significantly reduced, whereas the levels of malondialdehyde and transforming growth factor β2 (TGF-β2 were significantly elevated, in both the cortices and nuclei of eyes treated with vitrectomy and hyperoxia. The increase in protein-glutathione mixed disulfides and the reduction in water-soluble proteins were more obvious in the lens nuclei. The levels of ascorbate in the vitreous fluid were also reduced after vitrectomy, whereas TGF-β2 increased after vitrectomy and hyperoxia. Systemic hyperoxia exposure increased these effects. CONCLUSION: Removal of the intact vitreous gel with vitrectomy and exposing the lens to increased oxygen from the retina induce lens oxidation and aggregation. Thus, an intact vitreous gel structure may protect the lens from oxidative insult and maintain lens transparency.

  2. Eye trauma

    African Journals Online (AJOL)

    2011-02-02

    Feb 2, 2011 ... Note your findings in an orderly fashion: orbit, lids, conjunctiva, cornea, anterior chamber, iris, pupil reaction, lens, fundus. • Stain cornea with fluorescein. It is advisable to examine the eye as soon as possible since a delay will invariably lead to lid swelling, making the examination far more difficult. This can ...

  3. 21 CFR 886.3600 - Intraocular lens.

    Science.gov (United States)

    2010-04-01

    ... DEVICES OPHTHALMIC DEVICES Prosthetic Devices § 886.3600 Intraocular lens. (a) Identification. An intraocular lens is a device made of materials such as glass or plastic intended to be implanted to replace the natural lens of an eye. (b) Classification. Class III. (c) Date PMA or notice of completion of a...

  4. Quantification of surfactant proteins in tears of patients suffering from dry eye disease compared to healthy subjects.

    Science.gov (United States)

    Posa, Andreas; Paulsen, Friedrich; Dietz, Richard; Garreis, Fabian; Sander, Ralph; Schicht, Martin; Sel, Saadettin; Scholz, Michael; Hammer, Christian M; Bräuer, Lars

    2018-03-01

    To quantify and compare the amounts of surfactant proteins SP-A, SP-B, SP-C and SP-D in the tear fluid collected from patients with dry eye syndrome and from individuals with a healthy ocular surface. Schirmer strips were used to collect tear fluid from both eyes of 241 volunteers (99 men, 142 women; age range: 18-87 years). Dry eye syndrome was diagnosed by ophthalmologists in 125 patients, whereas the healthy control group comprised 116 individuals. The total protein concentration was determined via Bradford assay. The relative concentration of surfactant proteins SP-A through -D was measured by enzyme-linked immuno-sorbent assay (ELISA). The mean relative concentrations of SP-A, SP-C and SP-D were significantly higher in the dry eye group as compared to the healthy controls (pdry eye group, but the difference to the control group was not statistically significant. The upregulation of SP-A and SP-D in the dry eye group is probably related to these proteins' known antimicrobial and immunomodulatory effects at the ocular surface. It may represent a pathophysiological response to the inflammatory condition of the ocular surface in dry eye. The upregulation of SP-B and SP-C may represent an effort of the lacrimal system to reduce surface tension and thus to counteract the increased tendency of the tear film to tear in dry eye. Copyright © 2017 Elsevier GmbH. All rights reserved.

  5. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... can be purchased over-the-counter or on the Internet," says Thomas Steinemann, MD, professor of ophthalmology at ... ask for a prescription. There is no such thing as a "one size fits all" contact lens. Lenses that are not properly fitted may scratch the eye or cause blood vessels to grow into ...

  6. The lens and cataracts.

    Science.gov (United States)

    Matthews, Andrew G

    2004-08-01

    It is conservatively estimated that some form of lens opacity is present in 5% to 7% of horses with otherwise clinically normal eyes.These opacities can range from small epicapsular remnants of the fetal vasculature to dense and extensive cataract. A cataract is defined technically as any opacity or alteration in the optical homogeneity of the lens involving one or more of the following: anterior epithelium, capsule, cortex, or nucleus. In the horse, cataracts rarely involve the entire lens structure (ie, complete cataracts) and are more usually localized to one anatomic landmark or sector of the lens. Complete cataracts are invariably associated with overt and significant visual disability. Focal or incomplete cataracts alone seldom cause any apparent visual dysfunction in affected horses,however.

  7. Dystroglycan and mitochondrial ribosomal protein L34 regulate differentiation in the Drosophila eye.

    Directory of Open Access Journals (Sweden)

    Yougen Zhan

    2010-05-01

    Full Text Available Mutations that diminish the function of the extracellular matrix receptor Dystroglycan (DG result in muscular dystrophies, with associated neuronal migration defects in the brain and mental retardation e.g. Muscle Eye Brain Disease. To gain insight into the function of DG in the nervous system we initiated a study to examine its contribution to development of the eye of Drosophila melanogaster. Immuno-histochemistry showed that DG is concentrated on the apical surface of photoreceptors (R cells during specification of cell-fate in the third instar larva and is maintained at this location through early pupal stages. In point mutations that are null for DG we see abortive R cell elongation during differentiation that first appears in the pupa and results in stunted R cells in the adult. Overexpression of DG in R cells results in a small but significant increase in their size. R cell differentiation defects appear at the same stage in a deficiency line Df(2RDg(248 that affects Dg and the neighboring mitochondrial ribosomal gene, mRpL34. In the adult, these flies have severely disrupted R cells as well as defects in the lens and ommatidia. Expression of an mRpL34 transgene rescues much of this phenotype. We conclude that DG does not affect neuronal commitment but functions R cell autonomously to regulate neuronal elongation during differentiation in the pupa. We discuss these findings in view of recent work implicating DG as a regulator of cell metabolism and its genetic interaction with mRpL34, a member of a class of mitochondrial genes essential for normal metabolic function.

  8. Changes in the ionic and protein contents of adult Schistocerca Gregaria compound eyes due to He-Ne laser exposure

    International Nuclear Information System (INIS)

    El-Gindi, A.M.; Osiris, W.G.; El-kes, N.; Abd El-Meguid, A.

    1996-01-01

    The induced change in the concentration of the ionic content such as Na, K, and Ca in the compound eyes of Schistocerca Gregaria was carried out before and after exposure for different periodic times to He-Ne ;laser beam. Total protein and albumin contents in the compound eyes were also determined. The Data indicated that the ionic contents (Na, K and Ca) showed acceptable and significant changes in both the right (R) and left (L) eyes after exposure to different periodic times up to 60 minutes in comparison with the control ones. Moreover, very high significant increase in the total protein content (about 70.2%) as well as significant decrease in the albumin content (about 39.1%) in the right (R) eyes after exposure to He-Ne laser beam for 30 minutes in comparison with the control (unexposed) eyes, were detected. 2 tabs

  9. Localization of multidrug resistance-associated protein 2 in the nonpigmented ciliary epithelium of the eye.

    Science.gov (United States)

    Pelis, Ryan M; Shahidullah, Mohammad; Ghosh, Sikha; Coca-Prados, Miguel; Wright, Stephen H; Delamere, Nicholas A

    2009-05-01

    The nonpigmented epithelium (NPE) of the ciliary body represents an important component of the blood-aqueous barrier of the eye. Many therapeutic drugs penetrate poorly across the NPE into the aqueous humor of the eye interior. Several of these therapeutic drugs, such as methotrexate, vincristine, and etoposide, are substrates of the multidrug resistance-associated protein 2 (MRP2). Abundant MRP2 protein was detected by Western blot in homogenates of human ciliary body and freshly dissected porcine NPE. In cultured porcine NPE, the intracellular accumulation of the MRP2 substrates calcein (1.8-fold), 5-(and-6)-carboxy-2',7'-dichlorofluorescein (22.1-fold), and doxorubicin (1.9-fold) was significantly increased in the presence of 50 microM MK571 ((E)-3-[[[3-[2-(7-chloro-2-quinolinyl)-ethenyl]phenyl]-[[3-dimethylamino)-3-oxopropyl]thio]methyl]thio]-propanoic acid), an MRP inhibitor. In addition, the intracellular accumulation of the MRP2 substrate glutathione methylfluorescein was increased by 50 microM MK571 (4.3-fold), 500 microM indomethacin (2.6-fold), and 50 microM cyclosporin A (2.1-fold) but not by 500 microM sulfinpyrazone. These data are consistent with MRP2-mediated transport activity in cultured NPE, and MRP2 mRNA (reverse transcriptase-polymerase chain reaction) and protein (Western blot) were detected in the cultured cells. Immunolocalization studies in native human and porcine eyes showed MRP2 protein at the apical interface of the NPE and pigmented cell layers. Close examination of MRP2 immunoreactivity supported the conclusion that MRP2 is localized in the apical membrane of the NPE. MRP2 at the apical membrane of NPE cells may be involved in protecting intraocular tissues from exposure to potentially harmful toxins.

  10. In vitro cross-linking of bovine lens proteins photosensitized by promazines

    International Nuclear Information System (INIS)

    Merville, M.P.; Decuyper, J.; Piette, J.; Calberg-Bacq, C.M.; Van de Vorst, A.

    1984-01-01

    Promazine derivatives induce cross-linking of bovine lens crystallins in vitro by irradiation with near-ultraviolet (UV) light in the presence of O 2 , as revealed by electrophoresis after denaturation. With the five derivatives tested (promazine [PZ], chlorpromazine [CPZ], triflupromazine [TFPZ], methoxypromazine [MTPZ], and acepromazine [ACPZ]), single-hit kinetics are observed. Evidence implicating the cation radicals of the PZ derivatives as the causative agent of this in vitro effect is presented. Hydroxyl radicals do not appear to be involved in the photo-cross-linking reaction. Sodium ascorbate protects against damage induced either by PZ derivatives plus light or by PZ cation radicals in the dark. These findings are discussed with respect to development of cataracts induced by these drugs in vivo

  11. Dynamic light scattering study on phase separation of a protein-water mixture: Application on cold cataract development in the ocular lens

    Science.gov (United States)

    Petta, V.; Pharmakakis, N.; Papatheodorou, G. N.; Yannopoulos, S. N.

    2008-06-01

    We present a detailed dynamic light scattering study of the phase separation in the ocular lens emerging during cold cataract development. Cold cataract is a phase separation effect that proceeds via spinodal decomposition of the lens cytoplasm with cooling. The intensity autocorrelation functions of the lens protein content are analyzed with the aid of two methods, providing information on the populations and dynamics of the scattering elements associated with cold cataract. It is found that the temperature dependence of many measurable parameters changes appreciably at the characteristic temperature ˜16±1°C which is associated with the onset of cold cataract. By extending the temperature range of this work to previously inaccessible regimes, i.e., well below the phase separation or coexistence curve at Tcc , we have been able to accurately determine the temperature dependence of the collective and self-diffusion coefficients of proteins near the spinodal. The analysis showed that the dynamics of proteins bears some resemblance to the dynamics of structural glasses, where the apparent activation energy for particle diffusion increases below Tcc , indicating a highly cooperative motion. Application of ideas developed for studying the critical dynamics of binary protein-solvent mixtures, as well as the use of a modified Arrhenius equation, enabled us to estimate the spinodal temperature Tsp of the lens nucleus. The applicability of dynamic light scattering as a noninvasive, early-diagnostic tool for ocular diseases is also demonstrated in light of the findings of the present paper.

  12. Crystalline lens power and refractive error.

    Science.gov (United States)

    Iribarren, Rafael; Morgan, Ian G; Nangia, Vinay; Jonas, Jost B

    2012-02-01

    To study the relationships between the refractive power of the crystalline lens, overall refractive error of the eye, and degree of nuclear cataract. All phakic participants of the population-based Central India Eye and Medical Study with an age of 50+ years were included. Calculation of the refractive lens power was based on distance noncycloplegic refractive error, corneal refractive power, anterior chamber depth, lens thickness, and axial length according to Bennett's formula. The study included 1885 subjects. Mean refractive lens power was 25.5 ± 3.0 D (range, 13.9-36.6). After adjustment for age and sex, the standardized correlation coefficients (β) of the association with the ocular refractive error were highest for crystalline lens power (β = -0.41; P lens opacity grade (β = -0.42; P lens power (β = -0.95), lower corneal refractive power (β = -0.76), higher lens thickness (β = 0.30), deeper anterior chamber (β = 0.28), and less marked nuclear lens opacity (β = -0.05). Lens thickness was significantly lower in eyes with greater nuclear opacity. Variations in refractive error in adults aged 50+ years were mostly influenced by variations in axial length and in crystalline lens refractive power, followed by variations in corneal refractive power, and, to a minor degree, by variations in lens thickness and anterior chamber depth.

  13. About the Eye

    Medline Plus

    Full Text Available ... about each part of your eye and what it does. Macula (MACK-yoo-luh) is the small, ... area of the retina needed for central vision. It contains the fovea. Lens is the clear part ...

  14. Original Article Effect of Soft Contact Lens Materials on Tear Film ...

    African Journals Online (AJOL)

    problems, results in intolerance of contact lens wear and damage (Foulks, ... reported that contact lens-related dry eye may be ... eliminating or modifying the refractive error ..... risk of eye infection, easier handling due to ... Adv Exp Med Biol.

  15. Structure of a Highly Active Cephalopod S-crystallin Mutant: New Molecular Evidence for Evolution from an Active Enzyme into Lens-Refractive Protein.

    Science.gov (United States)

    Tan, Wei-Hung; Cheng, Shu-Chun; Liu, Yu-Tung; Wu, Cheng-Guo; Lin, Min-Han; Chen, Chiao-Che; Lin, Chao-Hsiung; Chou, Chi-Yuan

    2016-08-08

    Crystallins are found widely in animal lenses and have important functions due to their refractive properties. In the coleoid cephalopods, a lens with a graded refractive index provides good vision and is required for survival. Cephalopod S-crystallin is thought to have evolved from glutathione S-transferase (GST) with various homologs differentially expressed in the lens. However, there is no direct structural information that helps to delineate the mechanisms by which S-crystallin could have evolved. Here we report the structural and biochemical characterization of novel S-crystallin-glutathione complex. The 2.35-Å crystal structure of a S-crystallin mutant from Octopus vulgaris reveals an active-site architecture that is different from that of GST. S-crystallin has a preference for glutathione binding, although almost lost its GST enzymatic activity. We've also identified four historical mutations that are able to produce a "GST-like" S-crystallin that has regained activity. This protein recapitulates the evolution of S-crystallin from GST. Protein stability studies suggest that S-crystallin is stabilized by glutathione binding to prevent its aggregation; this contrasts with GST-σ, which do not possess this protection. We suggest that a tradeoff between enzyme activity and the stability of the lens protein might have been one of the major driving force behind lens evolution.

  16. The Effect of the Crystalline Lens on Central Vault After Implantable Collamer Lens Implantation.

    Science.gov (United States)

    Qi, Meng-Ying; Chen, Qian; Zeng, Qing-Yan

    2017-08-01

    To identify associations between crystalline lens-related factors and central vault after Implantable Collamer Lens (ICL) (Staar Surgical, Monrovia, CA) implantation. This retrospective clinical study included 320 eyes from 186 patients who underwent ICL implantation surgery. At 1 year after surgery, the central vault was measured using anterior segment optical coherence tomography. Preoperative anterior chamber depth, lens thickness, lens position (lens position = anterior chamber depth + 1/2 lens thickness), and vault were analyzed to investigate the effects of lens-related factors on postoperative vault. The mean vault was 513 ± 215 µm at 1 year after surgery. Vault was positively correlated with preoperative anterior chamber depth (r = 0.495, P lens position (r = 0.371, P lens thickness (r = -0.262, P lens position than eyes in the other two vault groups (which had vaults ≥ 250 µm) (P lens position less than 5.1 mm had greatly reduced vaults (P lens could have an important influence on postoperative vault. Eyes with a shallower anterior chamber and a forward lens position will have lower vaults. [J Refract Surg. 2017;33(8):519-523.]. Copyright 2017, SLACK Incorporated.

  17. A Class I UV-Blocking (senofilcon A) Soft Contact Lens Prevents UVA-induced Yellow Fluorescence and NADH loss in the Rabbit Lens Nucleus in vivo

    Science.gov (United States)

    Giblin, Frank J.; Lin, Li-Ren; Simpanya, Mukoma F.; Leverenz, Victor R.; Fick, Catherine E.

    2012-01-01

    It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm2 on the cornea) for 1 hour using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 hour. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear

  18. Hp(3)/Φ conversion coefficients for neutrons: discussion on the basis of the new ICRP recommended limit for the eye lens

    International Nuclear Information System (INIS)

    Ferrari, P.; Gualdrini, G.; Fantuzzi, E.; Tanner, R.

    2014-01-01

    The new recommendation issued by the International Commission on Radiological Protection (ICRP) introducing a 20-mSv annual dose limit for the eye lens stimulated an interesting debate among the radiation protection community. In the present work the problem of estimating H p (3) for neutron realistic workplace spectra is treated, employing the recently published H p (3)/Φ conversion coefficients with the aim of establishing a workplace-dependent relationship between H p (10) and H p (3). The results demonstrate that, whilst the two quantities can differ by less than 10 %, in general, H p (10) cannot be considered a conservative estimate of H p (3). The present study was conducted to find out whether it is possible to derive H p (3) from H p (10) measurements/determinations in neutron workplace fields using the relationship that can be established between the conversion coefficients H p (3)/Φ and H p (10)/Φ evaluated for monoenergetic neutron beams. Several real cases, taken from the IAEA neutron source compendium, were investigated and, in general, it can be conclude that H p (10) is seldom a conservative estimate of H p (3) (only at 0 deg. and in one case, among the treated spectra, H p (10)/Φ is higher than H p (3)/Φ). Indeed, care should be taken if one tries to derive directly such a correction factor from tabulations of neutron monoenergetic plots of conversion coefficients, on the basis of the mean energy, because in case of really degraded spectra (as in the heavy shielded situation) the mean energy, as expected, could be a too rough a parameter. However, in general, for 0 deg., antero-posterior irradiation condition, which is expected to be a quite common working condition, H p (10) underestimation is of the order of 10 % thus, at least, a correction factor of 1.1 should be applied to H p (10) in order to estimate the 'corresponding' H p (3). For irradiation conditions far from the normal incidence for which the underestimation can be as high as 60

  19. Clinical light damage to the eye

    International Nuclear Information System (INIS)

    Miller, D.

    1987-01-01

    This book contains four sections: The Nature of Light and of Light Damage to Biological Tissues; Light Damage to the Eye; Protecting the Eye from Light Damage; and Overview of Light Damage to the Eye. Some of the paper titles are: Ultraviolet-Absorbing Intraocular Lens Implants; Phototoxic Changes in the Retina; Light Damage to the Lens; and Radiation, Light, and Sight

  20. Contact Lens Related Corneal Ulcer

    OpenAIRE

    Loh, KY; Agarwal, P

    2010-01-01

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

  1. About the Eye

    Medline Plus

    Full Text Available ... luh) is the small, sensitive area of the retina needed for central vision. It contains the fovea. Lens is the clear part of the eye behind the iris that helps to focus light on the retina. It allows the eye to focus on both ...

  2. Polycomb group (PcG) proteins and Pax6 cooperate to inhibit in vivo reprogramming of the developing Drosophila eye.

    Science.gov (United States)

    Zhu, Jinjin; Ordway, Alison J; Weber, Lena; Buddika, Kasun; Kumar, Justin P

    2018-04-04

    How different cells and tissues commit to and determine their fates has been a central question in developmental biology since the seminal embryological experiments conducted by Wilhelm Roux and Hans Driesch in sea urchins and frogs. Here, we demonstrate that Polycomb group (PcG) proteins maintain Drosophila eye specification by suppressing the activation of alternative fate choices. The loss of PcG in the developing eye results in a cellular reprogramming event in which the eye is redirected to a wing fate. This fate transformation occurs with either the individual loss of Polycomb proteins or the simultaneous reduction of the Pleiohomeotic repressive complex and Pax6. Interestingly, the requirement for retinal selector genes is limited to Pax6, as the removal of more downstream members does not lead to the eye-wing transformation. We also show that distinct PcG complexes are required during different developmental windows throughout eye formation. These findings build on earlier observations that the eye can be reprogrammed to initiate head epidermis, antennal and leg development. © 2018. Published by The Company of Biologists Ltd.

  3. Facoemulsificação, vitrectomia via pars plana e implante de lente intra-ocular em olhos com retinopatia diabética proliferativa Phacoemulsification, pars plana vitrectomy and intraocular lens implant in eyes with proliferative diabetic retinopathy

    Directory of Open Access Journals (Sweden)

    Armando Belfort Mattos

    2004-06-01

    realizar a vitrectomia via pars plana, ao invés de se realizar uma segunda cirurgia, que seria somente para a remoção da catarata após a vitrectomia pars plana, é técnica segura e capaz de promover a melhora da acuidade visual além de ser menos agressiva para o paciente. O potencial para melhora da acuidade visual final é limitado pela gravidade da retinopatia diabética.PURPOSE: To evaluate the outcomes and the best technique for a combined phacoemulsification (PHACO, pars plana vitrectomy (PPV and posterior chamber intraocular lens insertion (PCIOL in one single procedure for patients with proliferative diabetic retinopathy. METHODS: We reviewed charts of 47 (53 eyes patients with proliferative diabetic retinopathy who underwent combined phacoemulsification with posterior chamber intraocular lens implant and pars plana vitrectomy performed between January 1991 and September 1998 at the Bascom Palmer Eye Institute, eye hospital affiliated with the University of Miami. The study was done in conjunction with the Federal University of São Paulo. A total of 43 eyes from 40 patients were elected to participate in the study. RESULTS: The follow-up range was three to 60 months (mean 20 months. The age ranged from 37 to 77 years with a mean of 59. Preoperative visual acuity improved two lines or more in 26 (60.4% eyes, remained the same in 9 (20.9% and got worse in 8 (18.6%. In 10 (23.2% eyes visual acuity improved to 20/40. The study showed to be statistically significant for the improvement of the final visual acuity. Recurrent vitreous hemorrhage was the most frequent postoperative complication found in 12 (27.9% eyes and it was followed by transient anterior chamber reaction in 9 (20.9% eyes. Intraoperative and postoperative complications related to phacoemulsification were rare. IOL capture was found in 2 (4.6% eyes and intraocular lens subluxation in 1 (2.3% eye. CONCLUSION: Combined phacoemulsification with posterior chamber intraocular lens implant and pars plana

  4. Expression of truncated PITX3 in the developing lens leads to microphthalmia and aphakia in mice.

    Directory of Open Access Journals (Sweden)

    Kenta Wada

    Full Text Available Microphthalmia is a severe ocular disorder, and this condition is typically caused by mutations in transcription factors that are involved in eye development. Mice carrying mutations in these transcription factors would be useful tools for defining the mechanisms underlying developmental eye disorders. We discovered a new spontaneous recessive microphthalmos mouse mutant in the Japanese wild-derived inbred strain KOR1/Stm. The homozygous mutant mice were histologically characterized as microphthalmic by the absence of crystallin in the lens, a condition referred to as aphakia. By positional cloning, we identified the nonsense mutation c.444C>A outside the genomic region that encodes the homeodomain of the paired-like homeodomain transcription factor 3 gene (Pitx3 as the mutation responsible for the microphthalmia and aphakia. We examined Pitx3 mRNA expression of mutant mice during embryonic stages using RT-PCR and found that the expression levels are higher than in wild-type mice. Pitx3 over-expression in the lens during developmental stages was also confirmed at the protein level in the microphthalmos mutants via immunohistochemical analyses. Although lens fiber differentiation was not observed in the mutants, strong PITX3 protein signals were observed in the lens vesicles of the mutant lens. Thus, we speculated that abnormal PITX3, which lacks the C-terminus (including the OAR domain as a result of the nonsense mutation, is expressed in mutant lenses. We showed that the expression of the downstream genes Foxe3, Prox1, and Mip was altered because of the Pitx3 mutation, with large reductions in the lens vesicles in the mutants. Similar profiles were observed by immunohistochemical analysis of these proteins. The expression profiles of crystallins were also altered in the mutants. Therefore, we speculated that the microphthalmos/aphakia in this mutant is caused by the expression of truncated PITX3, resulting in the abnormal expression of

  5. Night Vision Goggles Objectives Lens Focusing Methodology

    National Research Council Canada - National Science Library

    Pinkus, Alan; Task, H. L

    2000-01-01

    ...: interpupillary distance, tilt, eye relief, height, eyepiece and objective lens focus. Currently, aircrew use a Hoffman 20/20 test unit to pre-focus their NVG objective lenses at optical infinity before boarding their aircraft...

  6. Objective lens

    Science.gov (United States)

    Olczak, Eugene G. (Inventor)

    2011-01-01

    An objective lens and a method for using same. The objective lens has a first end, a second end, and a plurality of optical elements. The optical elements are positioned between the first end and the second end and are at least substantially symmetric about a plane centered between the first end and the second end.

  7. Gold nanoparticles for the bare-eye based and spectrophotometric detection of proteins, polynucleotides and DNA

    International Nuclear Information System (INIS)

    Lepoitevin, Mathilde; Lemouel, Marie; Bechelany, Mikhael; Janot, Jean-Marc; Balme, Sebastien

    2015-01-01

    We have explored the potential of using gold nanoparticles (Au-NPs) in optical and bare-eye discrimination of (a) proteins (such as bovine serum albumin and lysozyme), (b) homo-polynucleotides (such as poly-adenylic acid, poly-cytidylic acid, poly-uridylic acid and poly-inosinic acid), and (c) long chain DNA (from salmon, herring and thym). Such biomacromolecules can be detected and discriminated due to their ability to prevent the formation of blue aggregates from red (non-aggregated) citrate capped Au-NPs on addition of NaCl. The effect of these biomacromolecules on the aggregation was investigated by colorimetry and UV–vis spectrometry. The results show that the two proteins can be differentiated by colorimetry, and also salmon ssDNA and dsDNA. The Au-NPs can also discriminate the dsDNAs of salmon and herring. We conclude that the use of Au-NPs represent a viable candidate to future methods of DNA analysis on the basis of visual testing, particularly in the area of food analysis. (author)

  8. Lacrimal proline rich 4 (LPRR4 protein in the tear fluid is a potential biomarker of dry eye syndrome.

    Directory of Open Access Journals (Sweden)

    Saijyothi Venkata Aluru

    Full Text Available Dry eye syndrome (DES is a complex, multifactorial, immune-associated disorder of the tear and ocular surface. DES with a high prevalence world over needs identification of potential biomarkers so as to understand not only the disease mechanism but also to identify drug targets. In this study we looked for differentially expressed proteins in tear samples of DES to arrive at characteristic biomarkers. As part of a prospective case-control study, tear specimen were collected using Schirmer strips from 129 dry eye cases and 73 age matched controls. 2D electrophoresis (2DE and Differential gel electrophoresis (DIGE was done to identify differentially expressed proteins. One of the differentially expressed protein in DES is lacrimal proline rich 4 protein (LPRR4. LPRR4 protein expression was quantified by enzyme immune sorbent assay (ELISA. LPRR4 was down regulated significantly in all types of dry eye cases, correlating with the disease severity as measured by clinical investigations. Further characterization of the protein is required to assess its therapeutic potential in DES.

  9. Exchange of tears under a contact lens is driven by distortions of the contact lens.

    Science.gov (United States)

    Maki, Kara L; Ross, David S

    2014-12-01

    We studied the flow of the post-lens tear film under a soft contact lens to understand how the design parameters of contact lenses can affect ocular health. When a soft contact lens is inserted, the blinking eyelid causes the lens to stretch in order to conform to the shape of the eye. The deformed contact lens acts to assume its un-deformed shape and thus generates a suction pressure in the post-lens tear film. In consequence, the post-lens tear fluid moves; it responds to the suction pressure. The suction pressure may draw in fresh fluid from the edge of the lens, or it may eject fluid there, as the lens reassumes its un-deformed shape. In this article, we develop a mathematical model of the flow of the post-lens tear fluid in response to the mechanical suction pressure of a deformed contact lens. We predict the amount of exchange of fluid exchange under a contact lens and we explore the influence of the eye's shape on the rate of exchange of fluid. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  10. Contact lens rehabilitation following repaired corneal perforations

    Science.gov (United States)

    Titiyal, Jeewan S; Sinha, Rajesh; Sharma, Namrata; Sreenivas, V; Vajpayee, Rasik B

    2006-01-01

    Background Visual outcome following repair of post-traumatic corneal perforation may not be optimal due to presence of irregular keratometric astigmatism. We performed a study to evaluate and compare rigid gas permeable contact lens and spectacles in visual rehabilitation following perforating corneal injuries. Method Eyes that had undergone repair for corneal perforating injuries with or without lens aspiration were fitted rigid gas permeable contact lenses. The fitting pattern and the improvement in visual acuity by contact lens over spectacle correction were noted. Results Forty eyes of 40 patients that had undergone surgical repair of posttraumatic corneal perforations were fitted rigid gas permeable contact lenses for visual rehabilitation. Twenty-four eyes (60%) required aphakic contact lenses. The best corrected visual acuity (BCVA) of ≥ 6/18 in the snellen's acuity chart was seen in 10 (25%) eyes with spectacle correction and 37 (92.5%) eyes with the use of contact lens (p < 0.001). The best-corrected visual acuity with spectacles was 0.20 ± 0.13 while the same with contact lens was 0.58 ± 0.26. All the patients showed an improvement of ≥ 2 lines over spectacles in the snellen's acuity chart with contact lens. Conclusion Rigid gas permeable contact lenses are better means of rehabilitation in eyes that have an irregular cornea due to scars caused by perforating corneal injuries. PMID:16536877

  11. Primary anterior chamber intraocular lens for the treatment of severe crystalline lens subluxation.

    Science.gov (United States)

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2009-10-01

    Subluxated cataractous and clear lenses are commonly treated by limbal or pars plana lensectomy followed by primary or secondary intraocular lens (IOL) implantation. Adjunctive capsular prosthetic devices have facilitated lens removal and IOL centration in these challenging cases but have also added complexity and potential complications to the procedure. Although crystalline lens extraction may be required to clear the visual axis in mild to moderate lens subluxations, we propose insertion of a primary anterior chamber IOL without lens extraction in severe subluxations when the eye is optically aphakic or can be made functionally aphakic following neodymium:YAG laser zonulysis. Two cases demonstrating this approach are presented.

  12. [Phacoemulsification of subluxated lens with capsular tension ring implantation].

    Science.gov (United States)

    Dorecka, Mariola; Rokicki, Wojciech; Nita, Malgorzata; Krysik, Katarzyna; Nita, Ewa; Sikorska, Aleksandra; Romaniuk, Wanda

    2007-01-01

    To evaluate long term results of phacoemulsification with PC IOL and capsular tension ring (CTR) implantation in lens subluxation. The study comprised of 134 patients--146 eyes with subluxated lens. In all cases phacoemulsification with PC IOL and CTR implantation was performed. No intaroperative complications has occured. Postoperative complications included: inflammation in the anterior chamber in 3 eyes (2.1%), retinal detachment in 2 eyes (1.4%). In all cases there was no PC IOL decentration. (1) CTR facilitates phacoemulsification with PC IOL implantation in lens subluxation. (2) Phacoemulsification of subluxated lens with PC IOL and CTR implantation seems to be safe and effective procedure.

  13. Protective Effects of Acetylation on the Pathological Reactions of the Lens Crystallins with Homocysteine Thiolactone.

    Directory of Open Access Journals (Sweden)

    Zeinab Moafian

    Full Text Available Various post-translational lens crystallins modifications result in structural and functional insults, contributing to the development of lens opacity and cataract disorders. Lens crystallins are potential targets of homocysteinylation, particularly under hyperhomocysteinemia which has been indicated in various eye diseases. Since both homocysteinylation and acetylation primarily occur on protein free amino groups, we applied different spectroscopic methods and gel mobility shift analysis to examine the possible preventive role of acetylation against homocysteinylation. Lens crystallins were extensively acetylated in the presence of acetic anhydride and then subjected to homocysteinylation in the presence of homocysteine thiolactone (HCTL. Extensive acetylation of the lens crystallins results in partial structural alteration and enhancement of their stability, as well as improvement of α-crystallin chaperone-like activity. In addition, acetylation partially prevents HCTL-induced structural alteration and aggregation of lens crystallins. Also, acetylation protects against HCTL-induced loss of α-crystallin chaperone activity. Additionally, subsequent acetylation and homocysteinylation cause significant proteolytic degradation of crystallins. Therefore, further experimentation is required in order to judge effectively the preventative role of acetylation on the structural and functional insults induced by homocysteinylation of lens crystallins.

  14. MP20, the second most abundant lens membrane protein and member of the tetraspanin superfamily, joins the list of ligands of galectin-3

    Directory of Open Access Journals (Sweden)

    Donaldson Paul J

    2001-08-01

    Full Text Available Abstract Background Although MP20 is the second most highly expressed membrane protein in the lens its function remains an enigma. Putative functions for MP20 have recently been inferred from its assignment to the tetraspanin superfamily of integral membrane proteins. Members of this family have been shown to be involved in cellular proliferation, differentiation, migration, and adhesion. In this study, we show that MP20 associates with galectin-3, a known adhesion modulator. Results MP20 and galectin-3 co-localized in selected areas of the lens fiber cell plasma membrane. Individually, these proteins purified with apparent molecular masses of 60 kDa and 22 kDa, respectively. A 104 kDa complex was formed in vitro upon mixing the purified proteins. A 102 kDa complex of MP20 and galectin-3 could also be isolated from detergent-solubilized native fiber cell membranes. Binding between MP20 and galectin-3 was disrupted by lactose suggesting the lectin site was involved in the interaction. Conclusions MP20 adds to a growing list of ligands of galectin-3 and appears to be the first representative of the tetraspanin superfamily identified to possess this specificity.

  15. CREB Binding Protein Functions During Successive Stages of Eye Development in Drosophila

    OpenAIRE

    Kumar, Justin P.; Jamal, Tazeen; Doetsch, Alex; Turner, F. Rudolf; Duffy, Joseph B.

    2004-01-01

    During the development of the compound eye of Drosophila several signaling pathways exert both positive and inhibitory influences upon an array of nuclear transcription factors to produce a near-perfect lattice of unit eyes or ommatidia. Individual cells within the eye are exposed to many extracellular signals, express multiple surface receptors, and make use of a large complement of cell-subtype-specific DNA-binding transcription factors. Despite this enormous complexity, each cell will make...

  16. Analysis of phakic before intraocular lens implantation for fundus examination

    OpenAIRE

    Juan Chen; Zhong-Ping Chen; Rui-Ling Zhu

    2014-01-01

    AIM:To investigate the findings of the eyes which were examined preoperatively by three mirror contact lens before the implantation of implantable collamer lens(ICL). To analysis the retinal pathological changes and to explore the clinical analysis of early diagnosis and treatment in retinopathy on fundus examination before operation. METHODS:The retrospective case series study included 127 eyes of 64 patients who underwent phakic intraocular lens implantation were received the fundus examina...

  17. Alignment modification for pencil eye shields

    International Nuclear Information System (INIS)

    Evans, M.D.; Pla, M.; Podgorsak, E.B.

    1989-01-01

    Accurate alignment of pencil beam eye shields to protect the lens of the eye may be made easier by means of a simple modification of existing apparatus. This involves drilling a small hole through the center of the shield to isolate the rayline directed to the lens and fabricating a suitable plug for this hole

  18. A Class I UV-blocking (senofilcon A) soft contact lens prevents UVA-induced yellow fluorescence and NADH loss in the rabbit lens nucleus in vivo.

    Science.gov (United States)

    Giblin, Frank J; Lin, Li-Ren; Simpanya, Mukoma F; Leverenz, Victor R; Fick, Catherine E

    2012-09-01

    It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm(2) on the cornea) for 1 h using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 h. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear

  19. Antioxidant status of dog aqueous humor after extracapsular lens extraction

    Directory of Open Access Journals (Sweden)

    Barros P.S.M.

    2003-01-01

    Full Text Available We determined the antioxidant status of the aqueous humor after extracapsular lens extraction in 14 mongrel dogs weighing about 10 kg. The animals were examined by slit lamp biomicroscopy, applanation tonometry and indirect ophthalmoscopy. One eye was submitted to conventional extracapsular lens extraction and the other was used as control. Samples of aqueous humor were obtained by anterior chamber paracentesis before and at days 1, 2, 3, 7 and 15 after surgery. Total antioxidant status was determined as the capacity of aqueous humor to inhibit free radical generation by 2,2-azobis(2-amidopropane chlorine. Ascorbic acid concentration was measured by HPLC with UV detection. Protein content was determined with the biuret reagent. Statistical analysis was performed by ANOVA followed by the Tukey-Kramer test. Protein concentration increased from 0.61 to 22 mg/ml 24 h after surgery. These levels were maintained and returned to normal at day 7. Total antioxidant capacity was reduced from 50 to about 30 min until day 3 and at day 7 it was equal to control. Ascorbic acid levels were reduced from 252 to about 110 µM and then returned to control values at day 15. Considering the importance of ascorbic acid concentration in aqueous humor for the maintenance of the antioxidant status of the anterior segment of the eye, the decrease of antioxidant defenses suggests that the surgical procedures promote an oxidative stress condition in the eye.

  20. Effect of infusion bottle height on lens power after lens refilling with and without a plug

    NARCIS (Netherlands)

    Koopmans, SA; Terwee, T; Haitjema, HJ; Kooijman, AC; Barkhof, J

    2003-01-01

    Purpose: To evaluate the influence of intraoperative infusion bottle height on the power of refilled pig lenses. Setting: Research Laboratory, Pharmacia Intraocular Lens Manufacturing Plant, Groningen, The Netherlands. Methods: This study comprised 2 groups of pig eyes. In 1 group, the lens was

  1. Disassembly of the lens fiber cell nucleus to create a clear lens: the p27 descent

    Science.gov (United States)

    The eye lens is unique among tissues: it is transparent, does not form tumors, and the majority of its cells degrade their organelles, including their cell nuclei. A mystery for over a century, there has been considerable recent progress in elucidating mechanisms of lens fiber cell denucleation (LFC...

  2. Refractive lens exchange with a multifocal diffractive aspheric intraocular lens

    Directory of Open Access Journals (Sweden)

    Teresa Ferrer-Blasco

    2012-06-01

    Full Text Available PURPOSE: To evaluate the safety, efficacy and predictability after refractive lens exchange with multifocal diffractive aspheric intraocular lens implantation. METHODS: Sixty eyes of 30 patients underwent bilateral implantation with AcrySof® ReSTOR® SN6AD3 intraocular lens with +4.00 D near addition. Patients were divided into myopic and hyperopic groups. Monocular best corrected visual acuity at distance and near and monocular uncorrected visual acuity at distance and near were measured before and 6 months postoperatively. RESULTS: After surgery, uncorrected visual acuity was 0.08 ± 0.15 and 0.11 ± 0.14 logMAR for the myopic and hyperopic groups, respectively (50% and 46.67% of patients had an uncorrected visual acuity of 20/20 or better in the myopic and hyperopic groups, respectively. The safety and efficacy indexes were 1.05 and 0.88 for the myopic and 1.01 and 0.86 for the hyperopic groups at distance vision. Within the myopic group, 20 eyes remained unchanged after the surgery, and 3 gained >2 lines of best corrected visual acuity. For the hyperopic group, 2 eyes lost 2 lines of best corrected visual acuity, 21 did not change, and 3 eyes gained 2 lines. At near vision, the safety and efficacy indexes were 1.23 and 1.17 for the myopic and 1.16 and 1.13 for the hyperopic groups. Best corrected near visual acuity improved after surgery in both groups (from 0.10 logMAR to 0.01 logMAR in the myopic group, and from 0.10 logMAR to 0.04 logMAR in the hyperopic group. CONCLUSIONS: The ReSTOR® SN6AD3 intraocular lens in refractive lens exchange demonstrated good safety, efficacy, and predictability in correcting high ametropia and presbyopia.

  3. Surgical effect of traumatic lens dislocation with secondary glaucoma

    Directory of Open Access Journals (Sweden)

    Xiao-Dan Zhang

    2014-10-01

    Full Text Available AIM: To retrospectively evaluate the effect of lens extraction combined with vitrectomy to treat traumatic lens dislocation with secondary glaucoma.METHODS:Thirty-one eyes(31 casesof lens dislocation caused by blunt trauma with secondary glaucoma were treated respectively with cataract extraction combined with anterior vitrectomy, trabeculectomy and intraocular lens implantation. The visual acuity and pressure were observed 1wk, 1 and 3mo after operative. RESULTS:Thirty-one eyes were all complete the operation successfully, and 6 eyes were given combined trabeculectomy, 9 eyes were implanted anterior chamber intraocular lens implantation(IOLand 15 eyes were given posterior chamber suture fixation. Sixteen eyes were implanted in one-stage operation, while 8 eyes were implanted in two-stage operation. All intraocular pressure(IOPwere controlled to the normal level after operation and 23 eyes had visual acuity of more than 0.3.CONCLUSION:Lens extraction combined with vitrectomy is an effective method for treatment of lens dislocation with secondary glaucoma. In order to control the IOP and get well visual function, we should choose IOL implantation or trabeculectomy according to the patient's condition.

  4. ECTOPIC LENS EXTRACTION IN CHILDREN

    Directory of Open Access Journals (Sweden)

    Vladimir Pfeifer

    2002-12-01

    Full Text Available Background. Ectopia lentis continues to be a therapeutic challenge for ophthalmologists. It can occur as an isolated condition, after ocular trauma, in association with other ocular disorders, as part of a systemic mesodermal disease or a complication of general metabolic disorders. Minimal subluxation of the lens may cause no visual symptoms, but in more advanced cases serious optical disturbances arise. The most important is amblyopia. Surgical treatment options include iris manipulation, lens discission, aspiration, intracapsular or extracapsular extraction, and pars plana lensectomy. The choice of surgical technique remains controversial, in part because of the historically poor visual results and high rate of perioperative complications, including vitreous loss and retinal detachment.Methods. We describe a surgical technique based on the use of the Cionni endocapsular tension ring, dry irrigation aspiration of lens material, centration of the capsular bag and foldable intraocular lens implantation into the bag. With mentioned surgical technique 8 patients were operated; 4 boys and 4 girls, together 11 eyes.Results. The final BCVA after follow up period improved in 9 eyes and it remained the same as before operation in one eye. Statistical comparison of preoperative and postoperative visual acuities showed significant improvement. On the other hand there was no correlation between preoperative and postoperative visual acuity.Conclusions. This surgical procedure is an alternative approach in solving this challenging cases of ectopia lentis with good postoperative visual rehabilitation.

  5. Resistance of Pseudomonas aeruginosa isolates to hydrogel contact lens disinfection correlates with cytotoxic activity.

    Science.gov (United States)

    Lakkis, C; Fleiszig, S M

    2001-04-01

    One of the most common pathogens in infection of hydrogel contact lens wearers is Pseudomonas aeruginosa, which can gain access to the eye via contamination of the lens, lens case, and lens care solutions. Only one strain per species is used in current regulatory testing for the marketing of chemical contact lens disinfectants. The aim of this study was to determine whether P. aeruginosa strains vary in their susceptibility to hydrogel contact lens disinfectants. A method for rapidly screening bacterial susceptibility to contact lens disinfectants was developed, based on measurement of the MIC. The susceptibility of 35 P. aeruginosa isolates to two chemical disinfectants was found to vary among strains. MICs ranged from 6.25 to 100% for both disinfectants at 37 degrees C, and a number of strains were not inhibited by a 100% disinfectant concentration in the lens case environment at room temperature (22 degrees C). Resistance to disinfection appeared to be an inherent rather than acquired trait, since some resistant strains had been isolated prior to the introduction of the disinfectants and some susceptible P. aeruginosa strains could not be made more resistant by repeated disinfectant exposure. A number of P. aeruginosa strains which were comparatively more resistant to short-term disinfectant exposure also demonstrated the ability to grow to levels above the initial inoculum in one chemical disinfectant after long-term (24 to 48 h) disinfectant exposure. Resistance was correlated with acute cytotoxic activity toward corneal epithelial cells and with exsA, which encodes a protein that regulates cytotoxicity via a complex type III secretion system. These results suggest that chemical disinfection solutions may select for contamination with cytotoxic strains. Further investigation of the mechanisms and factors responsible for resistance may also lead to strategies for reducing adverse responses to contact lens wear.

  6. Lune/eye gone, a Pax-like protein, uses a partial paired domain and a homeodomain for DNA recognition.

    Science.gov (United States)

    Jun, S; Wallen, R V; Goriely, A; Kalionis, B; Desplan, C

    1998-11-10

    Pax proteins, characterized by the presence of a paired domain, play key regulatory roles during development. The paired domain is a bipartite DNA-binding domain that contains two helix-turn-helix domains joined by a linker region. Each of the subdomains, the PAI and RED domains, has been shown to be a distinct DNA-binding domain. The PAI domain is the most critical, but in specific circumstances, the RED domain is involved in DNA recognition. We describe a Pax protein, originally called Lune, that is the product of the Drosophila eye gone gene (eyg). It is unique among Pax proteins, because it contains only the RED domain. eyg seems to play a role both in the organogenesis of the salivary gland during embryogenesis and in the development of the eye. A high-affinity binding site for the Eyg RED domain was identified by using systematic evolution of ligands by exponential enrichment techniques. This binding site is related to a binding site previously identified for the RED domain of the Pax-6 5a isoform. Eyg also contains another DNA-binding domain, a Prd-class homeodomain (HD), whose palindromic binding site is similar to other Prd-class HDs. The ability of Pax proteins to use the PAI, RED, and HD, or combinations thereof, may be one mechanism that allows them to be used at different stages of development to regulate various developmental processes through the activation of specific target genes.

  7. Iris reconstruction combined with iris-claw intraocular lens implantation for the management of iris-lens injured patients.

    Science.gov (United States)

    Hu, Shufang; Wang, Mingling; Xiao, Tianlin; Zhao, Zhenquan

    2016-03-01

    To study the efficiency and safety of iris reconstruction combined with iris-claw intraocular lens (IOL) implantation in the patients with iris-lens injuries. Retrospective, noncomparable consecutive case series study. Eleven patients (11 eyes) following iris-lens injuries underwent iris reconstructions combined with iris-claw IOL implantations. Clinical data, such as cause and time of injury, visual acuity (VA), iris and lens injuries, surgical intervention, follow-up period, corneal endothelial cell count, and optical coherence tomography, were collected. Uncorrected VA (UCVA) in all injured eyes before combined surgery was equal to or iris returned to its natural round shape or smaller pupil, and the iris-claw IOLs in the 11 eyes were well-positioned on the anterior surface of reconstructed iris. No complications occurred in those patients. Iris reconstruction combined with iris-claw IOL implantation is a safe and efficient procedure for an eye with iris-lens injury in the absence of capsular support.

  8. Lens Model

    DEFF Research Database (Denmark)

    Nash, Ulrik William

    2014-01-01

    Firms consist of people who make decisions to achieve goals. How do these people develop the expectations which underpin the choices they make? The lens model provides one answer to this question. It was developed by cognitive psychologist Egon Brunswik (1952) to illustrate his theory of probabil...

  9. Placement of a crystalline lens and intraocular lens: Retinal image quality.

    Science.gov (United States)

    Siedlecki, Damian; Nowak, Jerzy; Zajac, Marek

    2006-01-01

    The influence of changes of both crystalline lens and intraocular lens (IOL) misalignment on the retinal image quality was investigated. The optical model of the eye used in investigations was the Liou-Brennan model, which is commonly considered as one of the most anatomically accurate. The original crystalline lens from this model was replaced with an IOL, made of rigid polymethylmethacrylate, in a way that recommend obligatory procedures. The modifications that were made both for crystalline lens and IOL were the longitudinal, the transversal, and the angular displacement.

  10. Biochemical studies on the ocular lens in relation to cataractogenesis. Final report, July 1, 1968--December 31, 1978J

    International Nuclear Information System (INIS)

    Kinsey, V.E.; Reddy, V.N.

    1978-01-01

    As indicated in the scope and purpose of this program, the broad aim of these investigations was to provide an understanding of the mechanisms by which various inorganic ions and a number of organic substances, particularly amino acids, enter and leave the ocular lens and to assay the role of these mechanisms in the physiological and pathological conditions of the eye. The studies also dealt with the mechanisms of glutathione in the lens and its relationship to amino acid transport, the effect of x-ray on the protein aggregation mechanism as well as the studies of the biochemical changes associated with the development of the experimentally induced galactose cataract

  11. Inhibition of hypoxia inducible factor-1α downregulates the expression of epithelial to mesenchymal transition early marker proteins without undermining cell survival in hypoxic lens epithelial cells.

    Science.gov (United States)

    Cammarata, Patrick R; Neelam, Sudha; Brooks, Morgan M

    2015-01-01

    The purpose of this study was to identify potential therapeutic strategies to slow down or prevent the expression of early-onset epithelial to mesenchymal transition (EMT) marker proteins (fibronectin and alpha smooth muscle actin, α-SMA) without sacrificing the synthesis and accumulation of the prosurvival protein vascular endothelial growth factor (VEGF) in cultured virally transformed human lens epithelial (HLE) cells. HLE-B3 cells, maintained in a continuous hypoxic environment (1% oxygen), were treated with SB216763, a specific inhibitor of glycogen synthase kinase-3β (GSK-3β) catalytic activity. Western blot analysis was employed to detect the cytoplasmic and nuclear levels of β-catenin, as well as the total lysate content of fibronectin and α-SMA. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of VEGF in cell culture medium. A hypoxia-inducible factor-1α (HIF-1α) translation inhibitor and an HIF-2α translation inhibitor were independently employed to evaluate the effect of hypoxia inducible factor inhibition on EMT marker protein and VEGF expression. XAV932 was used to assess the suppression of nuclear β-catenin and its downstream effect on EMT marker proteins and VEGF expression. SB216763-treated HLE-B3 cells caused marked inhibition of GSK-3β activity prompting a significant increase in the translocation of cytoplasmic β-catenin to the nucleus. The enhancement of nuclear β-catenin looked as if it positively correlated with a significant increase in the basal expression of VEGF as well as increased expression of fibronectin and α-SMA. In conjunction with SB216763, coadministration of an HIF-1α translation inhibitor, but not an HIF-2α translation inhibitor, markedly suppressed the expression of fibronectin and α-SMA without affecting VEGF levels. Treatment with XAV932 significantly reduced the level of nuclear β-catenin, but the levels of neither the EMT marker proteins nor VEGF were changed. Recently, we reported

  12. Crystalline lens and refractive development.

    Science.gov (United States)

    Iribarren, Rafael

    2015-07-01

    Individual refractive errors usually change along lifespan. Most children are hyperopic in early life. This hyperopia is usually lost during growth years, leading to emmetropia in adults, but myopia also develops in children during school years or during early adult life. Those subjects who remain emmetropic are prone to have hyperopic shifts in middle life. And even later, at older ages, myopic shifts are developed with nuclear cataract. The eye grows from 15 mm in premature newborns to approximately 24 mm in early adult years, but, in most cases, refractions are maintained stable in a clustered distribution. This growth in axial length would represent a refractive change of more than 40 diopters, which is compensated by changes in corneal and lens powers. The process which maintains the balance between the ocular components of refraction during growth is still under study. As the lens power cannot be measured in vivo, but can only be calculated based on the other ocular components, there have not been many studies of lens power in humans. Yet, recent studies have confirmed that the lens loses power during growth in children, and that hyperopic and myopic shifts in adulthood may be also produced by changes in the lens. These studies in children and adults give a picture of the changing power of the lens along lifespan. Other recent studies about the growth of the lens and the complexity of its internal structure give clues about how these changes in lens power are produced along life. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The ocular response to extended wear of a high Dk silicone hydrogel contact lens.

    Science.gov (United States)

    Fonn, Desmond; MacDonald, Karen E; Richter, Doris; Pritchard, Nicola

    2002-05-01

    A four-month extended wear clinical trial was conducted to compare the ocular effects of a high Dk Balafilcon A silicone hydrogel lens and a low Dk HEMA 38.6 per cent H20 soft lens. Twenty-four subjects who were adapted to daily wear of soft lenses wore a high Dk lens in one eye and a low Dk HEMA lens in the other eye for four months on an extended wear basis after one week of daily wear. Thirteen progress evaluations were conducted using standard clinical procedures. Eighteen subjects (75 per cent) completed the study. The high Dk lens induced significantly less bulbar and limbal injection and corneal vascularisation than the low Dk HEMA lens (p Dk lens. A significant increase in myopia was found in the eyes wearing the low Dk HEMA lens (mean = 0.50 D, p Dk lens. Three subjects developed small infiltrates in the high Dk lens wearing eyes and significantly more post-lens debris was observed under the high Dk lens. Six subjects developed papillary conjunctivitis in the eye wearing silicone hydrogel lenses but only two of those were discontinued from the study. No hypoxia-related effects were observed with extended wear of the high Dk Balafilcon A silicone hydrogel lens.

  14. Surgical treatment of hereditary lens subluxations.

    Science.gov (United States)

    Ozdek, Sengul; Sari, Ayca; Bilgihan, Kamil; Akata, Fikret; Hasanreisoglu, Berati

    2002-01-01

    To evaluate the effectiveness and results of pars plana vitreolensectomy approach with transscleral fixation of intraocular lens in hereditary lens subluxations. Fifteen eyes of 9 consecutive patients with a mean age of 12.8+/-6.2 years (6-26 years) with hereditary lens subluxation were operated on and the results were evaluated in a prospective study. Surgery was considered if best spectacle corrected visual acuity (BSCVA) was less than 20/70. All eyes underwent a 2-port pars plana vitreolensectomy and transscleral fixation of an intraocular lens (IOL). The mean follow-up period was 12.6+/-7.5 months (6-22 months). There was no major intraoperative complication. Preoperatively, 8 eyes (53.3%) had a BSCVA of counting fingers (CF) and 7 eyes (46.6%) had a BSCVA of 20/200 to 20/70. Postoperatively, 14 eyes (93.3%) had a BSCVA of 20/50 or better. None of the patients had IOL decentration or intraocular pressure (IOP) increase during the follow-up period. There was a macular hole formation in 1 eye postoperatively. The early results of pars plana vitreolensectomy with IOL implantation using scleral fixation technique had shown that it not only promises a rapid visual rehabilitation but it is also a relatively safe method. More serious complications, however, may occur in the long term.

  15. Dry Eye

    Science.gov (United States)

    ... Eye » Facts About Dry Eye Listen Facts About Dry Eye Fact Sheet Blurb The National Eye Institute (NEI) ... and their families search for general information about dry eye. An eye care professional who has examined the ...

  16. Structure and optics of the eyes of the box jellyfish Chiropsella bronzie

    DEFF Research Database (Denmark)

    O’Connor, Megan; Garm, Anders Lydik; Nilsson, Dan-E.

    2009-01-01

    Cubomedusae have a total of 24 eyes of four morphologically different types. Two of these eye types are camera-type eyes (upper and lower lens-eye), while the other two eye types are simpler pigment pit eyes (pit and slit eye). Here, we give a description of the visual system of the box jellyfish...... those in the previously investigated species Tripedalia cystophora. In the lower lens-eye of C. bronzie, blur circles subtend 20 and 52° for closed and open pupil, respectively, effectively removing all but the coarsest structures of the image. Histology reveals that the retina of the lower lens...

  17. A Model of the Human Eye

    Science.gov (United States)

    Colicchia, G.; Wiesner, H.; Waltner, C.; Zollman, D.

    2008-01-01

    We describe a model of the human eye that incorporates a variable converging lens. The model can be easily constructed by students with low-cost materials. It shows in a comprehensible way the functionality of the eye's optical system. Images of near and far objects can be focused. Also, the defects of near and farsighted eyes can be demonstrated.

  18. CONTACT LENS RELATED CORNEAL ULCER

    Directory of Open Access Journals (Sweden)

    AGARWAL P

    2010-01-01

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

  19. Autorefraction versus subjective refraction in a radially asymmetric multifocal intraocular lens

    NARCIS (Netherlands)

    van der Linden, Jan Willem; Vrijman, Violette; Al-Saady, Rana; El-Saady, Rana; van der Meulen, Ivanka J.; Mourits, Maarten P.; Lapid-Gortzak, Ruth

    2014-01-01

    To evaluate whether the automated refraction (AR) correlates with subjective manifest (MR) refraction in eyes implanted with radially asymmetric multifocal intraocular lens (IOLs). This retrospective study evaluated 52 eyes (52 patients) implanted with a radially asymmetric multifocal IOL (LS-312

  20. Autorefraction versus subjective refraction in a radially asymmetric multifocal intraocular lens

    NARCIS (Netherlands)

    Linden, J.W.M. van der; Vrijman, V.; El-Saady, R.; Meulen, I.J. van der; Mourits, M.P.; Lapid-Gortzak, R.

    2014-01-01

    PURPOSE: To evaluate whether the automated refraction (AR) correlates with subjective manifest (MR) refraction in eyes implanted with radially asymmetric multifocal intraocular lens (IOLs). METHODS: This retrospective study evaluated 52 eyes (52 patients) implanted with a radially asymmetric

  1. Eye dose assessment and management: overview

    International Nuclear Information System (INIS)

    Rehani, M.M.

    2015-01-01

    Some publications have shown that Hp( 0.07 ) or even Hp( 10 ) can be used as good operational quantities for X-rays in view of difficulties with Hp( 3 ). With increasing awareness, there is tendency to use whatever dosimeter is available with correction factor to estimate eye lens dose. The best position for an eye lens dosimeter has been reported to be at the side of the head nearest to the radiation source, close to the eye. Recent studies have reported eye doses with cone beam CT (CBCT) both for patients and staff, and there are many papers reporting eye lens doses to staff in nuclear medicine. To minimise the dose to eyes, the user can take advantage of a feature of CBCT of projections acquired over an angular span of 1808 plus cone angle of the X-ray tube and with tube under scan arcs. (authors)

  2. Near UV radiation effect on the lens and retina

    International Nuclear Information System (INIS)

    Zigman, S.

    1987-01-01

    The discussion presented in this paper indicates that the retina of a diurnal animal with a natural UV-absorbing lens (ie: the gray squirrel) is susceptible to near-UV damage from environmental sources only after the lens has been removed. This suggests that it is very important to protect against near-UV exposure of human eyes after cataract surgery

  3. 21 CFR 886.4300 - Intraocular lens guide.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4300 Intraocular lens guide. (a) Identification. An intraocular lens guide is a device intended to be inserted into the eye during surgery to direct... lenses, the device is exempt from the premarket notification procedures in subpart E of part 807 of this...

  4. Visual outcome with the Oculentis Mplus intraocular lens

    OpenAIRE

    Si-Yuan Liu; Xu Yang

    2017-01-01

    AIM: To evaluate the visual outcome of Oculentis Mplus intraocular lens(IOL).METHODS: Totally 20 eyes in 20 patients received phacoemulsification and Oculentis Mplus intraocular lens implantation were as test group, and 20 eyes(Aspira-aA IOL)were as control group. The following postoperative examinations were performed after operation for 3mo: uncorrected visual acuity of distance and near, refractive results, UBM examination, the rate of wearing spectacles and the complications. RESULTS: At ...

  5. Intravitreal Phacoemulsification Using Torsional Handpiece for Retained Lens Fragments

    OpenAIRE

    Kumar, Vinod; Takkar, Brijesh

    2016-01-01

    Purpose: To evaluate the results of intravitreal phacoemulsification with torsional hand piece in eyes with posteriorly dislocated lens fragments. Methods: In this prospective, interventional case series, 15 eyes with retained lens fragments following phacoemulsification were included. All patients underwent standard three-port pars plana vitrectomy and intravitreal phacoemulsification using sleeveless, torsional hand piece (OZiL™, Alcon's Infiniti Vision System). Patients were followed up...

  6. Peripheral Defocus of the Monkey Crystalline Lens With Accommodation in a Lens Stretcher

    Science.gov (United States)

    Maceo Heilman, Bianca; Manns, Fabrice; Ruggeri, Marco; Ho, Arthur; Gonzalez, Alex; Rowaan, Cor; Bernal, Andres; Arrieta, Esdras; Parel, Jean-Marie

    2018-01-01

    Purpose To characterize the peripheral defocus of the monkey crystalline lens and its changes with accommodation. Methods Experiments were performed on 15 lenses from 11 cynomolgus monkey eyes (age: 3.8–12.4 years, postmortem time: 33.5 ± 15.3 hours). The tissue was mounted in a motorized lens stretcher to allow for measurements of the lens in the accommodated (unstretched) and unaccommodated (stretched) states. A custom-built combined laser ray tracing and optical coherence tomography system was used to measure the paraxial on-axis and off-axis lens power for delivery angles ranging from −20° to +20° (in air). For each delivery angle, peripheral defocus was quantified as the difference between paraxial off-axis and on-axis power. The peripheral defocus of the lens was compared in the unstretched and stretched states. Results On average, the paraxial on-axis lens power was 52.0 ± 3.4 D in the unstretched state and 32.5 ± 5.1 D in the stretched state. In both states, the lens power increased with increasing delivery angle. From 0° to +20°, the relative peripheral lens power increased by 10.7 ± 1.4 D in the unstretched state and 7.5 ± 1.6 D in the stretched state. The change in field curvature with accommodation was statistically significant (P lens has greater curvature or relative peripheral power. Conclusions The cynomolgus monkey lens has significant accommodation-dependent curvature of field, which suggests that the lens asserts a significant contribution to the peripheral optical performance of the eye that also varies with the state of accommodation.

  7. Lubricant effects on low Dk and silicone hydrogel lens comfort.

    Science.gov (United States)

    Ozkan, Jerome; Papas, Eric

    2008-08-01

    To investigate the influence of three lubricants of varying viscosity, on postinsertion and 6 h comfort with contact lens wear. Comfort and associated symptoms of dryness were assessed in 15 experienced contact lens wearers. Subjects wore a low Dk lens in one eye and a silicone hydrogel in the other and participated in four separate trials involving no lubricant (baseline), saline, and two commercially available lubricants of differing viscosity. The in-eye lubricants were used immediately following lens insertion and every 2 h postinsertion for a 6 h wear period. Postlens insertion comfort was significantly better for both lens types when lubricants or saline were used compared with no lubricant use. After 6 h lens wear, comfort was influenced by lens type and not by in-eye lubricant or saline use. Also after 6 h lens wear, less dryness sensation was reported for silicone hydrogel lenses when using lubricants but not saline. Although lubricant use does help reduce dryness symptoms with silicone hydrogel lens wear, there appears to be minimal longer-term benefit to comfort. Furthermore, increased lubricant viscosity did not lead to improved longer-term comfort.

  8. Proteomic analysis revealed the altered tear protein profile in a rabbit model of Sjögren's syndrome-associated dry eye.

    Science.gov (United States)

    Zhou, Lei; Wei, Ruihua; Zhao, Ping; Koh, Siew Kwan; Beuerman, Roger W; Ding, Chuanqing

    2013-08-01

    Sjögren's syndrome (SS) is an autoimmune disease that results in pathological dryness of mouth and eye. The diagnosis of SS depends on both clinical evaluation and specific antibodies. The goal of this study was to use quantitative proteomics to investigate changes in tear proteins in a rabbit model of SS-associated dry eye, induced autoimmune dacryoadenitis (IAD). Proteomic analysis was performed by iTRAQ and nano LC-MS/MS on tears collected from the ocular surface, and specific proteins were verified by high resolution MRM. It was found that in the tears of IAD rabbits at 2 and 4 weeks after induction, S100 A6, S100 A9, and serum albumin were upregulated, whereas serotransferrin (TF), prolactin-inducible protein (PIP), polymeric immunoglobulin receptor (pIgR), and Ig gamma chain C region were downregulated. High resolution MRM with mTRAQ labeling verified the changes in S100 A6, TF, PIP, and pIgR. Our results indicated significant changes of tear proteins in IAD rabbits, suggesting these proteins could potentially be used as biomarkers for the diagnosis and prognosis of dry eye. Several of these proteins were also found in the tears of non-SS dry eye patients indicating a common basis of ocular surface pathology, however, pIgR appears to be unique to SS. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Differential metabolism and leakage of protein in an inherited cataract and a normal lens cultured with ouabain

    International Nuclear Information System (INIS)

    Piatigorsky, J.; Fukui, H.N.; Kinoshita, J.H.

    1978-01-01

    Ocular lenses in Nakano mice showed marked changes in synthesis, degradation and leakage of protein during cataractogenesis. The cataract-associated changes included the differential lowering of crystalline synthesis, the cleavage of crystallin polypeptides to lower molecular weight forms and the leakage of crystallins from cultured lenses. Ouabain treatment of normal lenses induced these alterations, suggesting that changes in the intracellular levels of Na + and K + affect the anabolism and catabolism of protein during cataract formation. 35 S-methionine was used during the course of the experiments as a method of protein identification. (author)

  10. Escape from X-ray-induced arrest for lens cells stimulated from quiescence: time relationship to RNA, protein, and DNA synthesis

    International Nuclear Information System (INIS)

    Lindgren, A.L.; Miller, R.C.; Guernsey, D.L.; Riley, E.F.

    1988-01-01

    Quiescent cells of the central zone region of the rat lens epithelium were stimulated to enter the proliferation cycle by wounding. RNA synthesis and a corresponding increase in poly(A)+/total RNA reached a peak by Hour 4. Cells progressed into the G1B compartment by Hour 10. A rise in protein synthesis began at Hour 8, and onset of DNA synthesis occurred by Hour 14. The timing of cell cycle progression that allowed escape from a dose of X irradiation that completely inhibited DNA synthesis was investigated. A growth-arrest point was identified at Hour 9 where 10 GY of X irradiation given before, but not after, completely inhibited earliest responding cells from entering DNA synthesis on schedule. Increased quantities of cells entered DNA synthesis on schedule as timing of the X irradiation was moved closer to the end of G1. Based on time relationships, the rise in protein synthesis is correlated with the sufficient event for the escape

  11. Identification and quantification of major maillard cross-links in human serum albumin and lens protein. Evidence for glucosepane as the dominant compound.

    Science.gov (United States)

    Biemel, Klaus M; Friedl, D Alexander; Lederer, Markus O

    2002-07-12

    Glycation reactions leading to protein modifications (advanced glycation end products) contribute to various pathologies associated with the general aging process and long term complications of diabetes. However, only few relevant compounds have so far been detected in vivo. We now report on the first unequivocal identification of the lysine-arginine cross-links glucosepane 5, DOGDIC 6, MODIC 7, and GODIC 8 in human material. For their accurate quantification by coupled liquid chromatography-electrospray ionization mass spectrometry, (13)C-labeled reference compounds were synthesized independently. Compounds 5-8 are formed via the alpha-dicarbonyl compounds N(6)-(2,3-dihydroxy-5,6-dioxohexyl)-l-lysinate (1a,b), 3-deoxyglucosone (), methylglyoxal (), and glyoxal (), respectively. The protein-bound dideoxyosone 1a,b seems to be of prime significance for cross-linking because it presumably is not detoxified by mammalian enzymes as readily as 2-4. Hence, the follow-up product glucosepane 5 was found to be the dominant compound. Up to 42.3 pmol of 5/mg of protein was identified in human serum albumin of diabetics; the level of 5 correlates markedly with the glycated hemoglobin HbA(1c). In the water-insoluble fraction of lens proteins from normoglycemics, concentration of 5 ranges between 132.3 and 241.7 pmol/mg. The advanced glycoxidation end product GODIC 8 is elevated significantly in brunescent lenses, indicating enhanced oxidative stress in this material. Compounds 5-8 thus appear predestined as markers for pathophysiological processes.

  12. Method for producing an isoplanatic aspheric monofocal intraocular lens, and resul ting lens

    OpenAIRE

    Barbero, Sergio; Marcos, Susana; Dorronsoro, Carlos; Montejo, Javier; Salazar Salegui, Pedro

    2010-01-01

    [EN] The invention can be used to obtain isoplanatic aspheric mono focal intraocular lenses in a viewing range of up to 25° (preferably up to 10°). The method comprises the following steps: l. mathematical defmition of an aphakic eye model; 2. mathematical definition of an intraocular lens model; 3. mathematical defmition of the implantation of the lens; 4. mathematical defmition of the merit function; 5. definition of the contour conditions; 6. defmition of a measurement for charact...

  13. Biochemical studies on the ocular lens in relation to cataractogenesis. Final report, July 1, 1968--December 31, 1978J. [X radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kinsey, V.E.; Reddy, V.N.

    1978-01-01

    As indicated in the scope and purpose of this program, the broad aim of these investigations was to provide an understanding of the mechanisms by which various inorganic ions and a number of organic substances, particularly amino acids, enter and leave the ocular lens and to assay the role of these mechanisms in the physiological and pathological conditions of the eye. The studies also dealt with the mechanisms of glutathione in the lens and its relationship to amino acid transport, the effect of x-ray on the protein aggregation mechanism as well as the studies of the biochemical changes associated with the development of the experimentally induced galactose cataract.

  14. Lens proteome map and alpha-crystallin profile of the catfish Rita rita.

    Science.gov (United States)

    Mohanty, Bimal Prasanna; Bhattacharjee, Soma; Das, Manas Kumar

    2011-02-01

    Crystallins are a diverse group of proteins that constitute nearly 90% of the total soluble proteins of the vertebrate eye lens and these tightly packed crystallins are responsible for transparency of the lens. These proteins have been studied in different model and non-model species for understanding the modifications they undergo with ageing that lead to cataract, a disease of protein aggregation. In the present investigation, we studied the lens crystallin profile of the tropical freshwater catfish Rita rita. Profiles of lens crystallins were analyzed and crystallin proteome maps of Rita rita were generated for the first time. alphaA-crystallins, member of the alpha-crystallin family, which are molecular chaperons and play crucial role in maintaining lens transparency were identified by 1- and 2-D immunoblot analysis with anti-alphaA-crystallin antibody. Two protein bands of 19-20 kDa were identified as alphaA-crystallins on 1-D immunoblots and these bands separated into 10 discrete spots on 2-D immunoblot. However, anti-alphaB-crystallin and antiphospho-alphaB-crystallin antibodies were not able to detect any immunoreactive bands on 1- and 2-D immunoblots, indicating alphaB-crystallin was either absent or present in extremely low concentration in Rita rita lens. Thus, Rita rita alpha-crystallins are more like that of the catfish Clarias batrachus and the mammal kangaroo in its alphaA- and alphaB-crystallin content (contain low amount from 5-9% of alphaB-crystallin) and unlike the dogfish, zebrafish, human, bovine and mouse alpha-crystallins (contain higher amount of alphaB-crystallin from 25% in mouse and bovine to 85% in dogfish). Results of the present study can be the baseline information for stimulating further investigation on Rita rita lens crystallins for comparative lens proteomics. Comparing and contrasting the alpha-crystallins of the dogfish and Rita rita may provide valuable information on the functional attributes of alphaA- and alphaB-isoforms, as

  15. Eye Allergies

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Eye Allergies Sections What Are Eye Allergies? Eye Allergy Symptoms ... allergy diagnosis Eye allergy treatment What Are Eye Allergies? Leer en Español: ¿Qué son las alergias de ...

  16. [Congenital lens subluxation: visual acuity outcomes and intraocular lens postoperative position].

    Science.gov (United States)

    Arraes, Caroline; Endriss, Daniela; Lobato, Francisco; Arraes, João; Ventura, Marcelo

    2010-01-01

    To evaluate the visual acuity outcomes and to investigate the intraocular lens (IOL) and endocapsular ring positions with ultrasound biomicroscopy in 17 eyes of 10 patients with congenital lens subluxation who underwent the same surgical technique, by the same surgeon. The study was performed in the ''Hospital de Olhos de Pernambuco'' and ''Fundação Altino Ventura''. The surgical technique consisted of phacoaspiration with implant of endocapsular ring and intraocular lens with one loop haptic amputated. The age varied from 7 to 22 years. Data on visual acuity (VA) before and after surgery, surgery follow-up period, and complications were analyzed. All patients underwent ultrasound biomicroscopy. The mean follow-up period was 2.8 years. There was a VA improvement in 17 (100%) eyes: in 12 eyes (70.6%) the visual acuity was better than 20/40; 4 (23.5%) ranged from 20/40 to 20/100, and 1 (5.9%) had visual acuity worse than 20/100, however better than the preoperative visual acuity. The posterior capsular opacification occurred in 10 eyes (58.9%). Ultrasound biomicroscopy showed that all IOL were partially decentralized, however without surpassing the pupil border limit. Endocapsular ring position was correct and there was a good capsular support in all cases. The evaluated surgical treatment provided good intraocular lens and endocapsular ring position, with VA improvement Thus, this technique is a viable, effective and safe option for the visual rehabilitation of patients with congenital lens subluxation.

  17. Determination of the dose in eyes lens by TLD, in PET/CT by technicians in PET/CT service; Determinacion de la dosis en cristalino por medio de TLD, en personal tecnico de servicio PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Marino, Emiliano A., E-mail: eam.marino@gmail.com [Universidad Nacional de Cuyo (UNC), Rio Negro (Argentina). Instituto Balseiro; Arenas, German M. [Fundacion Escuela de Medicina Nuclear (FUESMEN), Mendoza (Argentina)

    2013-11-01

    This work was supported, on the one hand, in a part of the project ORAMED which consisted of a design of a TLD dosimeter for measurements of Hp (3) in areas close to the lens, for interventional radiology physicians. On the other hand, Berhens work proposes using calibrated TLDs Hp (0.07) and Hp (10) to estimate Hp (3) crystal. This resulted in dosimeters calibrated using Hp (10) slab, and mount them on glasses, to estimate the dose to the lens of the technical staff of the Service PET / CT. The value obtained 29mSv/year of Lens Dose Equivalent exceeds the recommended limit. We also demonstrate that, under the current working conditions, the values of Hp (3) reported from whole body dosimeter does not represent faithfully the lens dose.

  18. Converging or Diverging Lens?

    Science.gov (United States)

    Branca, Mario

    2013-01-01

    Why does a lens magnify? Why does it shrink objects? Why does this happen? The activities that we propose here are useful in helping us to understand how lenses work, and they show that the same lens can have different magnification capabilities. A converging lens can also act as a diverging lens. (Contains 4 figures.)

  19. Unfolded-protein response-associated stabilization of p27(Cdkn1b) interferes with lens fiber cell denucleation, leading to cataract

    Science.gov (United States)

    Failure of lens fiber cell denucleation (LFCD) is associated with congenital cataracts, but the pathobiology awaits elucidation. Recent work has suggested that mechanisms that direct the unidirectional process of LFCD are analogous to the cyclic processes associated with mitosis. We found that lens-...

  20. Efficacy on chopping with lens loop-pad in the small incision extracapsular cataract surgery with intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Xiao-Ning Peng

    2014-04-01

    Full Text Available AIM: To study the clinical effects of chopping with lens loop-pad in the small incision extracapsular cataract surgery with intraocular lens implantation.METHODS:A total of 75 cases(80 eyes, in which loop-pad and chop knife were performed to chop nucleus before implanting intraocular lens. Visual acuity, postoperative astigmatism degree, intraoperative and postoperative complications were observed. The post-operative follow-up periods ranged from 3 to 12mo.RESULTS: The visual acuity was 0.3-0.5 in 37 eyes and 0.6 or better in 21 eyes at 1d, while was respectively in 43 eyes and in 26 eyes at 1mo. Compared with preoperative astigmatism(0.85±0.29D, there were significant difference at postoperative 1wk(1.75±0.55D(PP>0.05. Intraoperative posterior capsule rupture occurred in 4 eyes, which implantation was successful in 1 eye and 3 eyes was managed viaciliary sulcus. Two eyes had dermatoglyphic pattern edema in corneal endothelium which recovered after about 3d. Two eyes had local patchy opacities which recovered in 2wk. Two eyes had transient high intraocular pressure.CONCLUSION: The surgery is efficient, low cost, easy process and less complications, it is worth to be popularized.

  1. Bioinspired adaptive gradient refractive index distribution lens

    Science.gov (United States)

    Yin, Kezhen; Lai, Chuan-Yar; Wang, Jia; Ji, Shanzuo; Aldridge, James; Feng, Jingxing; Olah, Andrew; Baer, Eric; Ponting, Michael

    2018-02-01

    Inspired by the soft, deformable human eye lens, a synthetic polymer gradient refractive index distribution (GRIN) lens with an adaptive geometry and focal power has been demonstrated via multilayer coextrusion and thermoforming of nanolayered elastomeric polymer films. A set of 30 polymer nanolayered films comprised of two thermoplastic polyurethanes having a refractive index difference of 0.05 were coextruded via forced-assembly technique. The set of 30 nanolayered polymer films exhibited transmission near 90% with each film varying in refractive index by 0.0017. An adaptive GRIN lens was fabricated from a laminated stack of the variable refractive index films with a 0.05 spherical GRIN. This lens was subsequently deformed by mechanical ring compression of the lens. Variation in the optical properties of the deformable GRIN lens was determined, including 20% variation in focal length and reduced spherical aberration. These properties were measured and compared to simulated results by placido-cone topography and ANSYS methods. The demonstration of a solid-state, dynamic focal length, GRIN lens with improved aberration correction was discussed relative to the potential future use in implantable devices.

  2. Biochemical and functional characterization of an albumin protein belonging to the hemopexin superfamily from Lens culinaris seeds.

    Science.gov (United States)

    Scarafoni, Alessio; Gualtieri, Elisa; Barbiroli, Alberto; Carpen, Aristodemo; Negri, Armando; Duranti, Marcello

    2011-09-14

    The present paper reports the purification and biochemical characterization of an albumin identified in mature lentil seeds with high sequence similarity to pea PA2. These proteins are found in many edible seeds and are considered potentially detrimental for human health due to the potential allergenicity and lectin-like activity. Thus, the description of their possible presence in food and the assessment of the molecular properties are relevant. The M(r), pI, and N-terminal sequence of this protein have been determined. The work included the study of (i) the binding properties to hemine to assess the presence of hemopexin structural domains and (ii) the binding properties of the protein to thiamin. In addition, the structural changes induced by heating have been evaluated by means of spectroscopic techniques. Denaturation temperature has also been determined. The present work provides new insights about the structural molecular features and the ligand-binding properties and dynamics of this kind of seed albumin.

  3. Intravitreal Phacoemulsification Using Torsional Handpiece for Retained Lens Fragments.

    Science.gov (United States)

    Kumar, Vinod; Takkar, Brijesh

    2016-01-01

    To evaluate the results of intravitreal phacoemulsification with torsional hand piece in eyes with posteriorly dislocated lens fragments. In this prospective, interventional case series, 15 eyes with retained lens fragments following phacoemulsification were included. All patients underwent standard three-port pars plana vitrectomy and intravitreal phacoemulsification using sleeveless, torsional hand piece (OZiL™, Alcon's Infiniti Vision System). Patients were followed up for a minimum of six months to evaluate the visual outcomes and complications. The preoperative best-corrected visual acuity (BCVA) ranged from light perception to 0.3. No complications such as thermal burns of the scleral wound, retinal damage due to flying lens fragments, or difficult lens aspiration occurred during intravitreal phacoemulsification. Mean post-operative BCVA at the final follow-up was 0.5. Two eyes developed cystoid macular edema, which was managed medically. No retinal detachment was noted. Intravitreal phacoemulsification using torsional hand piece is a safe and effective alternative to conventional longitudinal phacofragmentation.

  4. Lens subluxation grading system: predictive value for ectopia lentis surgical outcomes

    OpenAIRE

    Mauro Waiswol; Niro Kasahara

    2009-01-01

    Objective: To present a classification system to grade ectopia lentis and to assess its usefulness as a predictor for surgical outcomes. Methods: Fifty-one eyes of 28 patients with either simple (19 patients) or Marfan syndrome-associated ectopia lentis (nine patients) with variable degrees of subluxation were operated on. Lens subluxation intensity was graded according to the lens subluxation grading system (LSGS) from grade 1 (lens on the whole pupillary area) up to grade 4 (lens absent fro...

  5. Equivalent refractive index of the human lens upon accommodative response

    NARCIS (Netherlands)

    Hermans, E.A.; Dubbelman, M.; van der Heijde, R.G.L.; Heethaar, R.M.

    2008-01-01

    PURPOSE.: To experimentally verify the suggestion of Gullstrand (1909), i.e., that the equivalent refractive index of the human lens increases with accommodation. METHODS.: The left eye of five subjects was focused on different accommodation stimuli, while the right eye was imaged with Scheimpflug

  6. Phototoxicity and cytotoxicity of fullerol in human lens epithelial cells

    International Nuclear Information System (INIS)

    Roberts, Joan E.; Wielgus, Albert R.; Boyes, William K.; Andley, Usha; Chignell, Colin F.

    2008-01-01

    The water-soluble, hydroxylated fullerene [fullerol, nano-C 60 (OH) 22-26 ] has several clinical applications including use as a drug carrier to bypass the blood ocular barriers. We have assessed fullerol's potential ocular toxicity by measuring its cytotoxicity and phototoxicity induced by UVA and visible light in vitro with human lens epithelial cells (HLE B-3). Accumulation of nano-C 60 (OH) 22-26 in the cells was confirmed spectrophotometrically at 405 nm and cell viability estimated using MTS and LDH assays. Fullerol was cytotoxic to HLE B-3 cells maintained in the dark at concentrations higher than 20 μM. Exposure to either UVA or visible light in the presence of > 5 μM fullerol-induced phototoxic damage. When cells were pretreated with non-toxic antioxidants: 20 μM lutein, 1 mM N-acetyl cysteine, or 1 mM L-ascorbic acid prior to irradiation, only the singlet oxygen quencher-lutein significantly protected against fullerol photodamage. Apoptosis was observed in lens cells treated with fullerol whether or not the cells were irradiated, in the order UVA > visible light > dark. Dynamic light scattering (DLS) showed that in the presence of the endogenous lens protein α-crystallin, large aggregates of fullerol were reduced. In conclusion, fullerol is both cytotoxic and phototoxic to human lens epithelial cells. Although the acute toxicity of water-soluble nano-C 60 (OH) 22-26 is low, these compounds are retained in the body for long periods, raising concern for their chronic toxic effect. Before fullerols are used to deliver drugs to the eye, they should be tested for photo- and cytotoxicity in vivo

  7. Glycation precedes lens crystallin aggregation

    International Nuclear Information System (INIS)

    Swamy, M.S.; Perry, R.E.; Abraham, E.C.

    1987-01-01

    Non-enzymatic glycosylation (glycation) seems to have the potential to alter the structure of crystallins and make them susceptible to thiol oxidation leading to disulfide-linked high molecular weight (HMW) aggregate formation. They used streptozotocin diabetic rats during precataract and cataract stages and long-term cell-free glycation of bovine lens crystallins to study the relationship between glycation and lens crystallin aggregation. HMW aggregates and other protein components of the water-soluble (WS) and urea-soluble (US) fractions were separated by molecular sieve high performance liquid chromatography. Glycation was estimated by both [ 3 H]NaBH 4 reduction and phenylboronate agarose affinity chromatography. Levels of total glycated protein (GP) in the US fractions were about 2-fold higher than in the WS fractions and there was a linear increase in GP in both WS and US fractions. This increase was parallelled by a corresponding increase in HMW aggregates. Total GP extracted by the affinity method from the US fraction showed a predominance of HMW aggregates and vice versa. Cell-free glycation studies with bovine crystallins confirmed the results of the animals studies. Increasing glycation caused a corresponding increase in protein insolubilization and the insoluble fraction thus formed also contained more glycated protein. It appears that lens protein glycation, HMW aggregate formation, and protein insolubilization are interrelated

  8. Connecting eye to eye

    DEFF Research Database (Denmark)

    Dau, Susanne; Rask, Anders Bindslev

    2017-01-01

    Computer Supported Collaborative Learning (CSCL) is used a frame for supporting online and blended learning in educations. The online communication and collaboration are afforded by the social collaboration. However, the social collaboration is based on the establishment of direct eye contact...... (Khalid, Deska & Hugenberg, 2016), but direct eye contact is challenged by the position of the digital devices and thus CSCL. Lack of eye contact is the chief contributor to the negative effects of online disinhibition (Lapidot-Lefler & Barak, 2012) and the problem is the location of the web camera...... at the computer. Eye contact is challenged by the displacement between the senders´ and receivers´ focus on the screen picture and the camera's location at the top or bottom of screens on all digital devices. The aim of this paper is accordingly to investigate the influence of the displacement in eye contact...

  9. Pigment dispersion syndrome associated with spontaneous subluxation of crystalline lens

    Directory of Open Access Journals (Sweden)

    Vikas Veerwal

    2017-01-01

    Full Text Available Pigment dispersion syndrome (PDS is an ocular condition characterized by a dispersion of iris pigment throughout the eye. This pigment is deposited in a characteristic manner on the corneal endothelium as Krukenberg's spindle, anterior surface of the iris, in the trabecular meshwork, on the lens and zonule and occasionally on the anterior hyaloid face. Even with deposition of pigment on zonular fibers, no zonular weakness, or zonular dehiscence has been reported in these cases. We report a unique case of PDS with bilateral spontaneous subluxation of crystalline lens. With characteristic findings of pigment distribution in both his eyes, the patient had concave iris configuration with heavily pigmented trabecular meshwork confirming the diagnosis of PDS. The patient had bilateral 180° temporal subluxation of crystalline lens in both his eyes. The usual cause of lens subluxation such as Marfan's Syndrome and Ehler's Danlos Syndrome was ruled out. The patient underwent right eye followed by left eye intracapsular cataract extraction with ab-interno technique with postoperative best-corrected visual acuity (BCVA of 6/9 in both eyes. Spontaneous subluxation of crystalline lens in isolated PDS is not known to occur and has been reported by means of this case. We recommend a thorough assessment of zonular status in all cases of PDS.

  10. Pigment dispersion syndrome associated with spontaneous subluxation of crystalline lens.

    Science.gov (United States)

    Veerwal, Vikas; Goyal, Jawahar Lal; Jain, Parul; Arora, Ritu

    2017-01-01

    Pigment dispersion syndrome (PDS) is an ocular condition characterized by a dispersion of iris pigment throughout the eye. This pigment is deposited in a characteristic manner on the corneal endothelium as Krukenberg's spindle, anterior surface of the iris, in the trabecular meshwork, on the lens and zonule and occasionally on the anterior hyaloid face. Even with deposition of pigment on zonular fibers, no zonular weakness, or zonular dehiscence has been reported in these cases. We report a unique case of PDS with bilateral spontaneous subluxation of crystalline lens. With characteristic findings of pigment distribution in both his eyes, the patient had concave iris configuration with heavily pigmented trabecular meshwork confirming the diagnosis of PDS. The patient had bilateral 180° temporal subluxation of crystalline lens in both his eyes. The usual cause of lens subluxation such as Marfan's Syndrome and Ehler's Danlos Syndrome was ruled out. The patient underwent right eye followed by left eye intracapsular cataract extraction with ab-interno technique with postoperative best-corrected visual acuity (BCVA) of 6/9 in both eyes. Spontaneous subluxation of crystalline lens in isolated PDS is not known to occur and has been reported by means of this case. We recommend a thorough assessment of zonular status in all cases of PDS.

  11. Different schematic eyes and their accuracy to the in vivo eye: a quantitative comparison study

    OpenAIRE

    Almeida, Marina Storani de; Carvalho, Luis Alberto

    2007-01-01

    Current ophthalmic technology allows the manipulation of eye components, such as anterior cornea and lens, of the human eye with a considerable precision and customization. This technology opens up the possibility of exploiting some characteristics of the eye in order to improve the methods of correcting optical aberrations. Moreover, product development and research for the eye-care professional has reached very high standards, since there is nowadays software available to design and simulat...

  12. Antibodies to a novel leptospiral protein, LruC, in the eye fluids and sera of horses with Leptospira-associated uveitis.

    Science.gov (United States)

    Verma, Ashutosh; Matsunaga, James; Artiushin, Sergey; Pinne, Marija; Houwers, Dirk J; Haake, David A; Stevenson, Brian; Timoney, John F

    2012-03-01

    Screening of an expression library of Leptospira interrogans with eye fluids from uveitic horses resulted in identification of a novel protein, LruC. LruC is located in the inner leaflet of the leptospiral outer membrane, and an lruC gene was detected in all tested pathogenic L. interrogans strains. LruC-specific antibody levels were significantly higher in eye fluids and sera of uveitic horses than healthy horses. These findings suggest that LruC may play a role in equine leptospiral uveitis.

  13. Aqueous humor from traumatized eyes triggers cell division in the epithelia of cultured lenses

    International Nuclear Information System (INIS)

    Reddan, J.R.; Weinsieder, A.; Wilson, D.

    1979-01-01

    Experiments were designed to gain a better understanding of the relationship between ocular inflammation and cell proliferation in the lens epithelium. Aqueous humor (AH) was collected from rabbit eyes that had been subjected to a variety of traumata, including paracentesis, needle injury, X-irradiation and the intravitreal administration of an antigen. In all cases the protein content of the AH increased, reflecting a breakdown in the blood aqueous barrier. Rabbit lenses from non-traumatized eyes were isolated and cultured in medium KEI-4 containing samples of the various aqueous humors noted above. Control lenses were cultured in medium KEI-4 alone or in KEI-4 containing rabbit serum albumen at a protein concentration equivalent to that used in the AH studies. In contrast to controls, the epithelial cells of lenses exposed to AH from injured or inflamed eyes exhibited mitosis throughout the normally amitotic regions of epithelium. Moreover, the specific activity of AH collected 15 min after initial paracentesis, relative to both DNA synthesis and mitosis, exceeded that of rabbit serum. An identification of the mitogenic factor(s) in the AH may help in understanding the environmental conditions that regulate the mitotic response which normally precedes wound healing in the lens in situ, and may help in elucidating the mechanism which controls mitosis and differentiation in the lens in vivo. (author)

  14. N-epsilon-(carboxyethyl)lysine, a product of the chemical modification of proteins by methylglyoxal, increases with age in human lens proteins.

    OpenAIRE

    Ahmed, M U; Brinkmann Frye, E; Degenhardt, T P; Thorpe, S R; Baynes, J W

    1997-01-01

    Advanced glycation end-products and glycoxidation products, such as Nepsilon-(carboxymethyl)lysine (CML) and pentosidine, accumulate in long-lived tissue proteins with age and are implicated in the aging of tissue proteins and in the development of pathology in diabetes, atherosclerosis and other diseases. In this paper we describe a new advanced glycation end-product, Nepsilon-(carboxyethyl)lysine (CEL), which is formed during the reaction of methylglyoxal with lysine residues in model compo...

  15. Combined 23-gauge transconjunctival vitrectomy and scleral fixation of intraocular lens without conjunctival dissection in managing lens complications.

    Science.gov (United States)

    Yeung, Ling; Wang, Nan-Kai; Wu, Wei-Chi; Chen, Kuan-Jen

    2018-04-23

    To evaluate the safety and efficacy of combined 23-gauge transconjunctival pars plana vitrectomy and scleral fixation of intraocular lens (IOL) without conjunctival dissection. A retrospective study in Chang Gung Memorial Hospital, Keelung and Taoyuan, Taiwan. Patients receiving combined 23-gauge transconjunctival pars plana vitrectomy and scleral fixation of IOL without conjunctival dissection were enrolled. The ocular findings, causes of lens complication, surgical procedures, type of IOL used, and complications were documented. We included 40 eyes from 39 patients (27 male, 12 female) with a mean age of 59.5 [standard deviation (±) 14.8] years old. The mean follow-up duration was 6.8 ± 5.4 months. The cause of lens complications was ocular trauma in 24 (60%) eyes, cataract surgery complications in 11 (28%) eyes, and spontaneous subluxation of crystalline lens in 5 (13%) eyes. The overall best corrected visual acuity (BCVA) (logMAR) improved from 1.359 ± 0.735 to 0.514 ± 0.582 (p IOL decentration was found in 3 (8%) eyes and 1 (3%) eye respectively. Combined 23-gauge transconjunctival vitrectomy and scleral fixation of IOL without conjunctival dissection is effective and safe in managing a wide variety of lens complications, with good postoperative comfort and visual recovery. Retrospective study, not applicable.

  16. Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3) Mutants in Drosophila melanogaster.

    Science.gov (United States)

    Rodriguez-Fernandez, Imilce A; Dell'Angelica, Esteban C

    2015-01-01

    The Adaptor Protein (AP)-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs) such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with molecules implicated in

  17. Review of application of mass spectrometry for analyses of anterior eye proteome

    Institute of Scientific and Technical Information of China (English)

    Sherif; Elsobky; Ashley; M; Crane; Michael; Margolis; Teresia; A; Carreon; Sanjoy; K; Bhattacharya

    2014-01-01

    Proteins have important functional roles in the body, which can be altered in disease states. The eye is a complex organ rich in proteins; in particular, the anterior eye is very sophisticated in function and is most commonly involved in ophthalmic diseases. Proteomics, the large scale study of proteins, has greatly impacted our knowledge and understanding of gene function in the post-genomic period. The most significant breakthrough in proteomics has been mass spectrometric identification of proteins, which extends analysis far beyond the mere display of proteins that classical techniques provide. Mass spectrometry functions as a "mass analyzer" which simplifies the identification and quantification of proteins extracted from biological tissue. Mass spectrometric analysis of the anterior eye proteome provides a differential display for protein comparison of normal and diseased tissue. In this article wepresent the key proteomic findings in the recent literature related to the cornea, aqueous humor, trabecular meshwork, iris, ciliary body and lens. Through this we identified unique proteins specific to diseases related to the anterior eye.

  18. Single lens to lens duplication: The missing link

    OpenAIRE

    Bhatt, Rupal; Jethani, Jitendra; Saluja, Praveen; Bharti, Vinay

    2008-01-01

    Congenital anomalies of the lens include a wide range from lens coloboma to primary aphakia and doubling of lens. There have been few case reports of double lens; the etiology suggested is metaplastic changes in the surface ectoderm that leads to formation of two lens vesicles and hence resulting in double lens. We report a case with bilobed lens, which raises the possibility of explaining the etiology of double lens.

  19. Differences in daily disposable circle lens performance characteristics

    Directory of Open Access Journals (Sweden)

    Schafer JM

    2014-04-01

    Full Text Available Jeffery M Schafer, William T Reindel, Marjorie J Rah, Osbert Chan, Lening Zhang Bausch & Lomb Incorporated, Rochester, NY, USA Purpose: The purpose of this evaluation was to compare the performance characteristics of two cosmetically tinted contact lenses in the circle lens category that differ in lens design, lens material, and pigment print pattern: etafilcon A (1-Day Acuvue Define; Johnson & Johnson Vision Care and hilafilcon B (Naturelle; Bausch & Lomb Incorporated. Methods: Two hundred Asian subjects (400 eyes were enrolled in this 1-month parallel, bilateral, randomized study at ten investigative sites. Study lenses were dispensed at a screening/dispensing visit, and follow-up visits occurred at 2 weeks and 1 month. Lenses were worn on a daily disposable basis. Fit characteristics were evaluated at each visit, and slit-lamp evaluations were completed at each follow-up visit. Results: Of the 200 patients enrolled, 172 (344 eyes completed the study. The proportion of eyes with fully centered lenses was statistically significantly higher for the hilafilcon B group at the 2-week and 1-month visits, P<0.05. Over all visits, 0.6% of hilafilcon B eyes demonstrated incomplete corneal coverage, whereas for the etafilcon A group, 8.5% of eyes demonstrated incomplete corneal coverage and/or edge lift. The proportion of eyes with adequate lens movement was statistically significantly higher for the hilafilcon B group, P<0.05. Over all visits, none of the hilafilcon B eyes was reported to have excessive movement, whereas for etafilcon A lenses, 10.2% of eyes were reported to have excessive movement. Conclusions: Etafilcon A lenses were significantly less likely to be fully centered and significantly more likely to have incomplete corneal coverage and/or edge lift compared with the hilafilcon B lenses. Keywords: cosmetic contact lens, circle contact lens

  20. Autophagy in the eye: implications for ocular cell health.

    Science.gov (United States)

    Frost, Laura S; Mitchell, Claire H; Boesze-Battaglia, Kathleen

    2014-07-01

    Autophagy, a catabolic process by which a cell "eats" itself, turning over its own cellular constituents, plays a key role in cellular homeostasis. In an effort to maintain normal cellular function, autophagy is often up-regulated in response to environmental stresses and excessive organelle damage to facilitate aggregated protein removal. In the eye, virtually all cell types from those comprising the cornea in the front of the eye to the retinal pigment epithelium (RPE) providing a protective barrier for the retina at the back of the eye, rely on one or more aspects of autophagy to maintain structure and/or normal physiological function. In the lens autophagy plays a critical role in lens fiber cell maturation and the formation of the organelle free zone. Numerous studies delineating the role of Atg5, Vsp34 as well as FYCO1 in maintenance of lens transparency are discussed. Corneal endothelial dystrophies are also characterized as having elevated levels of autophagic proteins. Therefore, novel modulators of autophagy such as lithium and melatonin are proposed as new therapeutic strategies for this group of dystrophies. In addition, we summarize how corneal Herpes Simplex Virus (HSV-1) infection subverts the cornea's response to infection by inhibiting the normal autophagic response. Using glaucoma models we analyze the relative contribution of autophagy to cell death and cell survival. The cytoprotective role of autophagy is further discussed in an analysis of photoreceptor cell heath and function. We focus our analysis on the current understanding of autophagy in photoreceptor and RPE health, specifically on the diverse role of autophagy in rods and cones as well as its protective role in light induced degeneration. Lastly, in the RPE we highlight hybrid phagocytosis-autophagy pathways. This comprehensive review allows us to speculate on how alterations in various stages of autophagy contribute to glaucoma and retinal degenerations. Copyright © 2014 Elsevier Ltd

  1. Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine Lens.

    Science.gov (United States)

    Lim, Julie C; Vaghefi, Ehsan; Li, Bo; Nye-Wood, Mitchell G; Donaldson, Paul J

    2016-04-01

    To assess the morphologic, biochemical, and optical properties of bovine lenses treated with hyperbaric oxygen. Lenses were exposed to hyperbaric nitrogen (HBN) or hyperbaric oxygen (HBO) for 5 or 15 hours, lens transparency was assessed using bright field microscopy and lens morphology was visualized using confocal microscopy. Lenses were dissected into the outer cortex, inner cortex, and core, and glutathione (GSH) and malondialdehyde (MDA) measured. Gel electrophoresis and Western blotting were used to detect high molecular weight aggregates (HMW) and glutathione mixed protein disulfides (PSSG). T2-weighted MRI was used to measure lens geometry and map the water/protein ratio to allow gradient refractive index (GRIN) profiles to be calculated. Optical modeling software calculated the change in lens optical power, and an anatomically correct model of the light pathway of the bovine eye was used to determine the effects of HBN and HBO on focal length and overall image quality. Lenses were transparent and lens morphology similar between HBN- and HBO-treated lenses. At 5- and 15-hour HBO exposure, GSH and GSSG were depleted and MDA increased in the core. Glutathione mixed protein disulfides were detected in the outer and inner cortex only with no appearance of HMW. Optical changes were detectable only with 15-hour HBO treatment with a decrease in the refractive index of the core, slightly reduced lens thickness, and an increase in optimal focal length, consistent with a hyperopic shift. This system may serve as a model to study changes that occur with advanced aging rather than nuclear cataract formation per se.

  2. Contact Lens Care

    Science.gov (United States)

    ... Consumers Consumer Information by Audience For Women Contact Lens Care Share Tweet Linkedin Pin it More sharing ... www.fda.gov/medwatch Learn More about Contact Lens Care Other Tips on Contact Lenses Decorative Contact ...

  3. [From dualism to multiplicity: seeing BCL-2 family proteins and cell death with new eyes].

    Science.gov (United States)

    Aouacheria, Abdel

    2015-01-01

    The concept of cell death has many links to the concept of death itself, defined as the opposite of life. Achievements obtained through research on apoptosis have apparently allowed us to transcend this Manichean view. Death is no longer outside, but rather inside living systems, as a constitutive force at work within the living matter. Whereas the death of cells can be positive and breed "creation" (e.g. during morphogenesis), its dysregulation can also cause or contribute to fatal diseases including cancer. It is tempting to apply this biological discourse to illuminate the relations between life and death, taken in general terms, but does this generalization actually hold? Is this discourse not essentially a metaphor? If cell death is considered as a vital aspect of various biological processes, then are we not faced with some vitalistic conception of death? Are there one or more meanings to the word "death"? Does the power to self-destruct act in opposition to other key features of living entities, or rather in juxtaposition to them? In this article, we first describe how the field of cell death has been developed on the basis of perceived and built dichotomies, mirroring the original opposition between life and death. We detail the limitations of the current paradigm of apoptosis regulation by BCL-2 family proteins, which nicely illustrate the problem of binary thinking in biology. Last, we try to show a way out of this dualistic matrix, by drawing on the notions of multiplicity, complexity, diversity, evolution and contingency. © Société de Biologie, 2016.

  4. Goldmann applanation tonometry over daily disposable contact lens: accuracy and safety of procedure.

    Science.gov (United States)

    Zeri, Fabrizio; Lupelli, Luigi; Formichella, Paolo; Masci, Carlo; Fletcher, Robert

    2007-09-01

    To study accuracy and safety, related to sensation (discomfort) and trauma, when using Goldmann applanation tonometry (GAT) on eyes wearing daily disposable soft contact lenses. The intra-ocular pressure (IOP) of 136 normal eyes of 68 subjects was measured by Goldmann tonometer. Measurements were made in one eye with a contact lens (hilafilcon A) without anaesthetic drops and then without the contact lens using one drop of 0.4% oxybuprocaine hydrochloride. Each contact lens used was identical as to back optic zone, back vertex power. Standard Goldmann procedure only was used for the fellow eye of each subject. Subjective sensation (discomfort) responses to both procedures were studied in a subgroup (66 eyes) using a scale of discomfort, from 1 (no sensation) to 5 (highest sensation). Epithelial staining after tonometry was evaluated for this subgroup. No significant differences were found for the IOP with and without contact lens (tcontact lens insertion, tonometry on contact lens and application of topical anaesthetic). Corneal epithelial staining following the standard tonometry procedure was significantly higher than following the procedure with a contact lens (pcontact lens is accurate, compared to the standard procedure and within the IOP's normal range studied here. Also using a contact lens results in less trauma whilst discomfort is similar.

  5. Calculation of crystalline lens power in chickens with a customized version of Bennett's equation.

    Science.gov (United States)

    Iribarren, Rafael; Rozema, Jos J; Schaeffel, Frank; Morgan, Ian G

    2014-03-01

    This paper customizes Bennett's equation for calculating lens power in chicken eyes from refraction, keratometry and biometry. Previously published data on refraction, corneal power, anterior chamber depth, lens thickness, lens radii of curvature, axial length and eye power in chickens aged 10-90 days were used to estimate Gullstrand's lens power and Bennett's lens power for chicken eyes, and to calculate the lens equivalent refractive index. Bennett's A and B constants for the front and back surface powers of the lens were calculated for data measured from day 10 to 90 at 10 day intervals, and mean customized constants were calculated. The mean customized constants for Bennett's equation for chicks were A=0.574±0.023 and B=0.379±0.021. As found previously, lens power decreases with age in chicks, while corneal power decreases and axial length increases. The lens equivalent refractive index decreases with age from 10 to 90 days after hatching. Bennett's equation can be used to calculate lens power in chicken eyes for studies on animal myopia, using standard biometry. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Effect of aspherical and yellow tinted intraocular lens on blue-on-yellow perimetry

    Directory of Open Access Journals (Sweden)

    Rodrigo França de Espíndola

    2012-10-01

    Full Text Available PURPOSE: To investigate the possible effect of aspherical or yellow tinted intraocular lens (IOL on contrast sensitivity and blue-on-yellow perimetry. METHODS: This prospective randomized bilateral double-masked clinical study included 52 patients with visually significant bilateral cataracts divided in two groups; 25 patients (50 eyes received aspherical intraocular lens in one eye and spherical intraocular lens in the fellow eye; and 27 patients (54 eyes received ultraviolet and blue light filter (yellow tinted IOL implantation in one eye and acrylic ultraviolet filter IOL in the fellow eye. The primary outcome measures were contrast sensitivity and blue-on-yellow perimetry values (mean deviation [MD] and pattern standard deviation [PSD] investigated two years after surgery. The results were compared intra-individually. RESULTS: There was a statistically significant between-group (aspherical and spherical intraocular lens difference in contrast sensitivity under photopic conditions at 12 cycles per degree and under mesopic conditions at all spatial frequencies. There were no between-group significant differences (yellow tinted and clear intraocular lens under photopic or mesopic conditions. There was no statistically significant difference between all intraocular lens in MD or PSD. CONCLUSION: Contrast sensitivity was better under mesopic conditions with aspherical intraocular lens. Blue-on-yellow perimetry did not appear to be affected by aspherical or yellow tinted intraocular lens. Further studies with a larger sample should be carried out to confirm or not that hypotheses.

  7. Different alpha crystallin expression in human age-related and congenital cataract lens epithelium.

    Science.gov (United States)

    Yang, Jing; Zhou, Sheng; Guo, Minfei; Li, Yuting; Gu, Jianjun

    2016-05-28

    The purpose of this study was to investigate the different expressions of αA-crystallin and αB-crystallin in human lens epithelium of age-related and congenital cataracts. The central part of the human anterior lens capsule approximately 5 mm in diameter together with the adhering epithelial cells, were harvested and processed within 6 hours after cataract surgery from age-related and congenital cataract patients or from normal eyes of fresh cadavers. The mRNA and soluble protein levels of αA-crystallin and αB-crystallin in the human lens epithelium were detected by real-time PCR and western blots, respectively. The mRNA and soluble protein expressions of αA-crystallin and αB-crystallin in the lens epithelium were both reduced in age-related and congenital cataract groups when compared with the normal control group. However, the degree of α-crystallin loss in the lens epithelium was highly correlated with different cataract types. The α-crystallin expression of the lens epithelium was greatly reduced in the congenital cataract group but only moderately decreased in the age-related cataract group. The reduction of αA-crystallin soluble protein levels in the congenital cataract group was approximately 2.4 fold decrease compared with that of the age-related cataract group, while an mRNA fold change of 1.67 decrease was observed for the age-related cataract group. Similarly, the reduction of soluble protein levels of αB-crystallin in the congenital cataract group was approximately a 1.57 fold change compared with that of the age-related cataract group. A 1.75 fold change for mRNA levels compared with that of the age-related cataract group was observed. The results suggest that the differential loss of α-crystallin in the human lens epithelium could be associated with the different mechanisms of cataractogenesis in age-related versus congenital cataracts, subsequently resulting in different clinical presentations.

  8. Aberration design of zoom lens systems using thick lens modules.

    Science.gov (United States)

    Zhang, Jinkai; Chen, Xiaobo; Xi, Juntong; Wu, Zhuoqi

    2014-12-20

    A systematic approach for the aberration design of a zoom lens system using a thick lens module is presented. Each component is treated as a thick lens module at the beginning of the design. A thick lens module refers to a thick lens component with a real lens structure, like lens materials, lens curvatures, lens thicknesses, and lens interval distances. All nine third-order aberrations of a thick lens component are considered during the design. The relationship of component aberrations in different zoom positions can be approximated from the aberration shift. After minimizing the aberrations of the zoom lens system, the nine third-order aberrations of every lens component can be determined. Then the thick lens structure of every lens component can be determined after optimization according to their first-order properties and third-order aberration targets. After a third optimization for minimum practical third-order aberrations of a zoom lens system, the aberration design using the thick lens module is complete, which provides a practical zoom lens system with thick lens structures. A double-sided telecentric zoom lens system is designed using the thick lens module in this paper, which shows that this method is practical for zoom lens design.

  9. Radiation dose to the lens and cataract formation

    International Nuclear Information System (INIS)

    Henk, J.M.; Whitelocke, R.A.F.; Warrington, A.P.; Bessell, E.M.

    1993-01-01

    The purpose of this work was to determine the radiation tolerance of the lens of the eye and the incidence of radiation-induced lens changes in patients treated by fractionated supervoltage radiation therapy for orbital tumors. Forty patients treated for orbital lymphoma and pseudotumor with tumor doses of 20--40 Gy were studied. The lens was partly shielded using lead cylinders in most cases. The dose to the germinative zone of the lens was estimated by measurements in a tissue equivalent phantom using both film densitometry and thermoluminescent dosimetry. Opthalmological examination was performed at 6 monthly intervals after treatment. The lead shield was found to reduce the dose to the germinative zone of the lens to between 36--50% of the tumor dose for Cobalt beam therapy, and to between 11--18% for 5 MeV x-rays. Consequently, the lens doses were in the range 4.5--30 Gy in 10--20 fractions. Lens opacities first appeared from between 3 and 9 years after irradiation. Impairment of visual acuity ensued in 74% of the patients who developed lens opacities. The incidence of lens changes was strongly dose-related. None was seen after doses of 5 Gy or lower, whereas doses of 16.5 Gy or higher were all followed by lens opacities which impaired visual acuity. The largest number of patients received a maximum lens dose of 15 Gy; in this group the actuarial incidence of lens opacities at 8 years was 57% with visual impairment in 38%. The adult lens can tolerate a total dose of 5 Gy during a fractionated course of supervoltage radiation therapy without showing any changes. Doses of 16.5 Gy or higher will almost invariably lead to visual impairment. The dose which causes a 50% probability of visual impairment is approximately 15 Gy. 10 refs., 4 figs., 1 tab

  10. The significance of oxygen during contact lens wear.

    Science.gov (United States)

    Papas, Eric B

    2014-12-01

    In order to establish the relevance of oxygen to contemporary contact lens practice, a review of the literature was conducted. The results indicate that there are a number of processes occurring in the normal healthy eye where oxygen is required and which are potentially affected by the presence of a contact lens. These activities appear to take place at all corneal levels, as well as at the limbus. Evidence from laboratory, clinical and modelling studies indicates that what constitutes normal oxygenation (normoxia) depends on, among other things, the physiological system under consideration, corneal location and the state of eye closure. This diversity is reflected in the wide range of minimum lens oxygen transmissibility (Dk/t) requirements that are present in a literature. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  11. A Model of the Effect of Lens Development on Refraction in Schoolchildren.

    Science.gov (United States)

    He, Ji C

    2017-12-01

    The study provides a new theory on the mechanism underlying myopia development, and it could be useful in clinical practice to control myopia development in schoolchildren. To model the effect of the crystalline lens on refractive development in schoolchildren. The Zemax 13 was used to calculate Zernike aberrations and refractions across 50° horizontal visual fields. Optical effects of the anterior chamber depth, lens thickness, and radii of curvature of the lens surfaces on refractions were modeled. Refractive changes induced by lens development in emmetropic and myopic eyes, based on a previous longitudinal study from literature, were calculated. A lens thickness reduction with an anterior chamber depth deepening caused a hyperopic shift over the visual fields and even more at the periphery. Opposite effects were found when the lens was thinned without any change of the anterior chamber depth. While a flattening of the anterior lens surface produced hyperopic refractions overall, a posterior lens flattening caused a myopic shift at the periphery, but a hyperopic shift of the central refraction. In the myopic eye, lens development induced refractive change toward more hyperopic over the visual fields and more at the periphery. Lens thinning and lens axial movement participate in peripheral refractive development in schoolchildren, and lens development with a deeper anterior chamber depth and a flatter lens surface in the myopic eye could generate extra hyperopia over visual fields. The myopic lens development could be due to a backward movement of the lens, driven by a backward growth of the ciliary process, which might be a causative factor of myopia development.

  12. Analysis of phakic before intraocular lens implantation for fundus examination

    Directory of Open Access Journals (Sweden)

    Juan Chen

    2014-10-01

    Full Text Available AIM:To investigate the findings of the eyes which were examined preoperatively by three mirror contact lens before the implantation of implantable collamer lens(ICL. To analysis the retinal pathological changes and to explore the clinical analysis of early diagnosis and treatment in retinopathy on fundus examination before operation. METHODS:The retrospective case series study included 127 eyes of 64 patients who underwent phakic intraocular lens implantation were received the fundus examination by three mirror from April 2011 to April 2012 in our hospital. The age, refractive diopter, the findings of Goldmann three mirror examination and the condition of retinal photocoagulation were analysed and concluded.RESULTS: A total of 34 eyes(26.8%out of all 127 eyes(64 caseswere found to have peripheral retinal pathological changes. Eight eyes(6.3%with retinal holes, 15 eyes(11.8%with retinal lattice degeneration, 5 eyes(3.9%with retina cream degeneration, 3 eyes(2.4%with retinal paving stone degeneration,2 eyes with vitreoretinal adhesion and traction,1 eye(0.8%with retinal hemorrhage. Twenty-five cases were given retinal photocoagulation and then received the ICL implantation after 3mo. The follow-up time was 1a. No retinal detachment happened.CONCLUSION:Phakic before intraocular lens implantation for fundus examination by three mirror is contributed to find the peripheral retinal pathological changes and abnormity. And make the appropriate treatment before operation for improving the security of operation, it can also give help to the postoperative follow-up of the fundus of these patients.

  13. Phacoemulsification using iris hooks and scleral fixation of the intraocular lens in patients with secondary glaucoma associated with lens subluxation.

    Science.gov (United States)

    Ma, K T; Lee, H K; Seong, G J; Kim, C Y

    2008-09-01

    We described the techniques and results of phacoemulsification using iris hook and scleral fixation of intraocular lens (IOL) in patients with secondary glaucoma associated with lens subluxation. Eight eyes of seven patients with secondary glaucoma associated with lens dislocation, who had undergone the surgery, were retrospectively reviewed. At a mean of 23.5 months+/-13.6 (SD) after the surgery, the mean best-corrected visual acuity improved from 0.24+/-0.21 to 0.83+/-0.3, and mean intraocular pressure (IOP) was changed from 38.4+/-11.4 to 15.5+/-1.8 mmHg at the final examination. There were no vitreoretinal complications except cystoid macular oedema in one eye. The technique appears to be safe and effective in terms of visual rehabilitation and controlling IOP in patients with secondary glaucoma associated with lens subluxation.

  14. A bandage contact lens prevents extrusion of ocular contents.

    Science.gov (United States)

    Ramjiani, Vipul; Fearnley, Thomas; Tan, Jennifer

    2016-02-01

    A 76 year old male presents with a corneal perforation in a phthisical eye. Definitive treatment in the form of an evisceration was delayed by 38 days. During this period a bandage contact lens prevented extrusion of ocular contents through an enlarging corneal perforation. This case demonstrates that a bandage contact lens can be effective in the immediate management of large corneal perforations whilst awaiting urgent definitive treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. High Dk piggyback contact lens system for contact lens-intolerant keratoconus patients.

    Science.gov (United States)

    Sengor, Tomris; Kurna, Sevda Aydin; Aki, Suat; Ozkurt, Yelda

    2011-01-01

    The aim of the study was to examine the clinical success of high Dk (oxygen permeability) piggyback contact lens (PBCL) systems for the correction of contact lens intolerant keratoconus patients. Sixteen patients (29 eyes) who were not able to wear gas-permeable rigid lenses were included in this study. Hyper Dk silicone hydrogel (oxygen transmissibility or Dk/t = 150 units) and fluorosilicone methacrylate copolymer (Dk/t = 100 units) lenses were chosen as the PBCL systems. The clinical examinations included visual acuity and corneal observation by biomicroscopy, keratometer reading, and fluorescein staining before and after fitting the PBCL system. INDICATIONS FOR USING PBCL SYSTEM WERE: lens stabilization and comfort, improving comfort, and adding protection to the cone. Visual acuities increased significantly in all of the patients compared with spectacles (P = 0). Improvement in visual acuity compared with rigid lenses alone was recorded in 89.7% of eyes and no alteration of the visual acuity was observed in 10.3% of the eyes. Wearing time of PBCL systems for most of the patients was limited time (mean 6 months, range 3-12 months); thereafter they tolerated rigid lenses alone except for 2 patients. The PBCL system is a safe and effective method to provide centering and corneal protection against mechanical trauma by the rigid lenses for keratoconus patients and may increase contact lens tolerance.

  16. Lens regeneration in axolotl: new evidence of developmental plasticity

    Directory of Open Access Journals (Sweden)

    Suetsugu-Maki Rinako

    2012-12-01

    Full Text Available Abstract Background Among vertebrates lens regeneration is most pronounced in newts, which have the ability to regenerate the entire lens throughout their lives. Regeneration occurs from the dorsal iris by transdifferentiation of the pigment epithelial cells. Interestingly, the ventral iris never contributes to regeneration. Frogs have limited lens regeneration capacity elicited from the cornea during pre-metamorphic stages. The axolotl is another salamander which, like the newt, regenerates its limbs or its tail with the spinal cord, but up until now all reports have shown that it does not regenerate the lens. Results Here we present a detailed analysis during different stages of axolotl development, and we show that despite previous beliefs the axolotl does regenerate the lens, however, only during a limited time after hatching. We have found that starting at stage 44 (forelimb bud stage lens regeneration is possible for nearly two weeks. Regeneration occurs from the iris but, in contrast to the newt, regeneration can be elicited from either the dorsal or the ventral iris and, occasionally, even from both in the same eye. Similar studies in the zebra fish concluded that lens regeneration is not possible. Conclusions Regeneration of the lens is possible in the axolotl, but differs from both frogs and newts. Thus the axolotl iris provides a novel and more plastic strategy for lens regeneration.

  17. Influence of changes in an eye's optical system on refraction

    Science.gov (United States)

    Bartkowska, Janina

    1998-10-01

    The optical system of eye is composed of cornea, lens, anterior chamber, and vitreous body. In the standard schematic eye there are 6 refracting surfaces. The changes of the curvature radii, of the distances between them, of the refractive indices influence the ametropia, refractive power of the eye and retinal image size. The influence of these changes can be appreciated by ray tracing or by an analytical method. There are presented simplified formulae for the differentials of ametropia and refractive power of the eye with respect to the surfaces curvatures, refracting power of cornea and lens, refractive indices. The relations are valid too for bigger changes if ametropia is measured in the cornea vertex. The formulae for the differentials with respect to distances, lens translation, eye axis length are valid if ametropia is measured in the object focus of the eye.

  18. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... not been properly fitted by an eye care professional, the lenses stuck to my eye like a ... prescription and proper fitting by an eye-care professional. Retailers that sell contacts without a prescription are ...

  19. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Management Member Services Advocacy Foundation About Subspecialties & More Eye Health Home Annual Meeting Clinical Education Practice Management ... Education Center Redmond Ethics Center Global Ophthalmology Guide Eye Health Find an Ophthalmologist Academy Store Eye Health ...

  20. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Services Advocacy Foundation About Subspecialties & More Eye Health Home Annual Meeting Clinical Education Practice Management Member Services ... had not been properly fitted by an eye care professional, the lenses stuck to my eye like ...

  1. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Member Services Advocacy Foundation About Subspecialties & More Eye Health Home Annual Meeting Clinical Education Practice Management Member ... Center Redmond Ethics Center Global Ophthalmology Guide Eye Health Find an Ophthalmologist Academy Store Eye Health A- ...

  2. Photosensitized oxidation in the ocular lens: evidence for photosensitizers endogenous to the human lens

    International Nuclear Information System (INIS)

    Zigler, J.S. Jr.; Goosey, J.D.

    1981-01-01

    Numerous investigators have attempted to associate near UV light exposure with various changes which occur to lens crystallins during aging and cataractogenesis. Recently it was shown that in vitro singlet oxygen mediated oxidation of lens crystallins produces effects very similar to those documented for crystallins from old or cataractous lenses and it was suggested that near UV photodynamic effects may play a major role in vivo in aging in the human lens. It has now been shown that certain oxidation products of tryptophan which have been identified in human lens can act as near UV photosensitizers, producing singlet oxygen. The insoluble protein fraction from human cataracts was shown to have the capacity to act as a photosensitizer. An age-related increase in photosensitizing capacity was also demonstrated in the soluble crystallins from human lens. These findings are discussed with respect to development of pigmented nuclear cataracts. (author)

  3. Pigment dispersion and Artisan phakic intraocular lenses: crystalline lens rise as a safety criterion.

    Science.gov (United States)

    Baïkoff, Georges; Bourgeon, Grégoire; Jodai, Horacio Jitsuo; Fontaine, Aline; Lellis, Fernando Viera; Trinquet, Laure

    2005-04-01

    To validate the theory that crystalline lens rise can be used as a safety criterion to prevent pigment dispersion in eyes with an Artisan phakic intraocular lens (IOL) (Ophtec BV). Monticelli Clinic, Marseilles, France. A comparative analysis of crystalline lens rise in 9 eyes with pigment dispersion and 78 eyes without dispersion was performed. All eyes had previous implantation of an Artisan IOL. Anterior segment imaging was done using an anterior chamber optical coherence tomography (AC OCT) prototype. Crystalline lens rise was defined by the distance between the anterior pole of the crystalline lens and the horizontal plane joining the opposite iridocorneal recesses. The study confirmed that crystalline lens rise can be considered a safety criterion for implantation of Artisan-type phakic IOLs. The higher the crystalline lens rise, the greater the risk for developing pigment dispersion in the area of the pupil. This complication occurred more frequently in hyperopic eyes than in myopic eyes. Results indicate there is little or no risk for pigment dispersion if the rise is less than 600 microm; 67% of eyes with a rise of 600 microm or more developed pupillary pigment dispersion. In some cases in which the IOL was loosely fixated, there was no traction on the iris root and dispersion was prevented or delayed. Crystalline lens rise should be considered a new safety criterion for Artisan phakic IOL implantation and should also be applied to other types of phakic IOLs. The distance remaining between the crystalline lens rise and a 600 microm theoretical safety level allows one to calculate how long the IOL can safely remain in the eye.

  4. Applanation tonometry in silicone hydrogel contact lens wearers.

    Science.gov (United States)

    Allen, R J; Dev Borman, A; Saleh, G M

    2007-12-01

    Previous studies have investigated intraocular pressure (IOP) measurements through conventional soft (hydrogel) therapeutic contact lenses, and have found that an accurate IOP can be recorded in normal eyes, and in eyes with abnormal anterior segments. The IOP measurement through soft contact lenses may be affected by the water content and centre thickness of the lens. Silicone hydrogel contact lenses are now being used as therapeutic contact lenses due to their high oxygen permeability. The purpose of this study is to investigate if IOP can be accurately measured in a subject wearing a silicone hydrogel contact lens. In a cohort study, the IOP was measured with a Goldmann applanation tonometer without a contact lens and then repeated with a hydrogel contact lens in situ. The IOP of 20 eyes of 10 volunteers with no ocular pathology was measured. The mean difference (+/-S.D.) found between IOP measurement with (mean 15.55+/-1.70 mmHg) and without (mean 16.05+/-1.90 mmHg) contact lens was found to be -0.5+/-0.89 mmHg. Statistical analysis was performed which revealed a correlation coefficient of 0.89. No significant statistical difference was found between the two groups with paired t-test (p=0.19). Accurate measurement of IOP by applanation tonometry can be achieved through a silicone hydrogel contact lens.

  5. Optofluidic lens actuated by laser-induced solutocapillary forces

    Science.gov (United States)

    Malyuk, A. Yu.; Ivanova, N. A.

    2017-06-01

    We demonstrate an adaptive liquid lens controlled by laser-induced solutocapillary forces. The liquid droplet serving as a lens is formed in a thin layer of binary liquid mixture by surface tension driven flows caused by the thermal action of laser irradiation. The shape of droplet, its aperture and the focal length are reversibly changed without hysteresis by varying the intensity of the laser beam. The focal length variation range of the droplet-lens lies in between infinity (a flat layer) to 15 mm (a curved interface). The droplet-lens is capable to adjust the in-plane lateral position in response to a displacement of the laser beam. The proposed laser controlled droplet-lens will enable to develop smart liquid optical devices, which can imitate the accommodation reflex and pupillary light reflex of the eye.

  6. Piggyback intraocular lens implantation to correct pseudophakic refractive error after segmental multifocal intraocular lens implantation.

    Science.gov (United States)

    Venter, Jan A; Oberholster, Andre; Schallhorn, Steven C; Pelouskova, Martina

    2014-04-01

    To evaluate refractive and visual outcomes of secondary piggyback intraocular lens implantation in patients diagnosed as having residual ametropia following segmental multifocal lens implantation. Data of 80 pseudophakic eyes with ametropia that underwent Sulcoflex aspheric 653L intraocular lens implantation (Rayner Intraocular Lenses Ltd., East Sussex, United Kingdom) to correct residual refractive error were analyzed. All eyes previously had in-the-bag zonal refractive multifocal intraocular lens implantation (Lentis Mplus MF30, models LS-312 and LS-313; Oculentis GmbH, Berlin, Germany) and required residual refractive error correction. Outcome measurements included uncorrected distance visual acuity, corrected distance visual acuity, uncorrected near visual acuity, distance-corrected near visual acuity, manifest refraction, and complications. One-year data are presented in this study. The mean spherical equivalent ranged from -1.75 to +3.25 diopters (D) preoperatively (mean: +0.58 ± 1.15 D) and reduced to -1.25 to +0.50 D (mean: -0.14 ± 0.28 D; P < .01). Postoperatively, 93.8% of eyes were within ±0.50 D and 98.8% were within ±1.00 D of emmetropia. The mean uncorrected distance visual acuity improved significantly from 0.28 ± 0.16 to 0.01 ± 0.10 logMAR and 78.8% of eyes achieved 6/6 (Snellen 20/20) or better postoperatively. The mean uncorrected near visual acuity changed from 0.43 ± 0.28 to 0.19 ± 0.15 logMAR. There was no significant change in corrected distance visual acuity or distance-corrected near visual acuity. No serious intraoperative or postoperative complications requiring secondary intraocular lens removal occurred. Sulcoflex lenses proved to be a predictable and safe option for correcting residual refractive error in patients diagnosed as having pseudophakia. Copyright 2014, SLACK Incorporated.

  7. A model for investigating developmental eye repair in Xenopus laevis.

    Science.gov (United States)

    Kha, Cindy X; Son, Philip H; Lauper, Julia; Tseng, Kelly Ai-Sun

    2018-04-01

    Vertebrate eye development is complex and requires early interactions between neuroectoderm and surface ectoderm during embryogenesis. In the African clawed frog, Xenopus laevis, individual eye tissues such as the retina and lens can undergo regeneration. However, it has been reported that removal of either the specified eye field at the neurula stage or the eye during tadpole stage does not induce replacement. Here we describe a model for investigating Xenopus developmental eye repair. We found that tailbud embryos can readily regrow eyes after surgical removal of over 83% of the specified eye and lens tissues. The regrown eye reached a comparable size to the contralateral control by 5 days and overall animal development was normal. It contained the expected complement of eye cell types (including the pigmented epithelium, retina and lens), and is connected to the brain. Our data also demonstrate that apoptosis, an early mechanism that regulates appendage regeneration, is also required for eye regrowth. Treatment with apoptosis inhibitors (M50054 or NS3694) blocked eye regrowth by inhibiting caspase activation. Together, our findings indicate that frog embryos can undergo successful eye repair after considerable tissue loss and reveals a required role for apoptosis in this process. Furthermore, this Xenopus model allows for rapid comparisons of productive eye repair and developmental pathways. It can also facilitate the molecular dissection of signaling mechanisms necessary for initiating repair. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3 Mutants in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Imilce A Rodriguez-Fernandez

    Full Text Available The Adaptor Protein (AP-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with

  9. Lens dislocation has a possible relationship with laser iridotomy

    Directory of Open Access Journals (Sweden)

    Mutoh T

    2012-12-01

    Full Text Available Tetsuya Mutoh,1,2 Kevin F Barrette,2 Yukihiro Matsumoto,1 Makoto Chikuda11Department of Ophthalmology, Dokkyo Medical University Koshigaya Hospital, Koshigaya City, Saitama, Japan; 2Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USAAbstract: We report our recent experience of four eyes with spontaneous lens dislocation in four patients with no history of trauma or any systemic disease associated with zonular dialysis. Lens dislocation developed with 0.5 to 6 months following laser iridotomy. All patients were male and two eyes were complicated with acute primary angle closure glaucoma preoperatively. Case 1 showed bilateral lens dislocation, while cases 2 and 3 involved unilateral lens dislocation. Cases 2 and 3 showed lenses completely dislocated into the vitreous cavity. All cases needed lens removal and scleral fixation of intraocular lenses. Final visual acuity was 1.2 in all cases. We suspect that laser iridotomy may induce localized zonular dialysis that results in progressive zonular weakness, leading to lens dislocation.Keywords: lens dislocation, laser iridotomy, primary angle closure glaucoma

  10. Crystalline lens thickness determines the perceived chromatic difference in magnification.

    Science.gov (United States)

    Chen, Yun; Schaeffel, Frank

    2014-03-01

    Since the origin of the high interindividual variability of the chromatic difference in retinal image magnification (CDM) in the human eye is not well understood, optical parameters that might determine its magnitude were studied in 21 healthy subjects with ages ranging from 21 to 58 years. Two psychophysical procedures were used to quantify CDM. They produced highly correlated results. First, a red and a blue square, presented on a black screen, had to be matched in size by the subjects with their right eyes. Second, a filled red and blue square, flickering on top of each other at 2 Hz, had to be adjusted in perceived brightness and then in size to minimize the impression of flicker. CDM varied widely among subjects from 0.0% to 3.6%. Biometric ocular parameters were measured with low coherence interferometry and crystalline lens tilt and decentration with a custom-built Purkinjemeter. Correlations were studied between CDM and corneal power, anterior chamber depth, lens thickness, lens tilt and lens decentration, and vitreous chamber depths. Lens thickness was found significantly correlated with CDM and accounted for 64% of its variance. Vertical lens tilt and decentration were also significantly correlated. It was also found that CDM increased by 3.5% per year, and part of this change can be attributed to the age-related increase in lens thickness.

  11. Transient anterior subcapsular vacuolar change of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation.

    Science.gov (United States)

    Chung, Jin Kwon; Shin, Jin Hee; Lee, Sung Jin

    2013-10-25

    We present two cases of transient vacuolar changes in the anterior subcapsular space of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation. Implantable collamer lenses (ICL) were implanted in healthy myopic patients. Vacuolar changes developed just after the irrigating procedure through the narrow space between the ICL and the crystalline lens. Slit-lamp examinations and spectral domain optical coherence tomography showed bleb-like lesions in the anterior subcapsular space of one eye in each case, though the lesions gradually improved without visual deterioration. Consequently, the lesions turned into a few anterior subcapsular small faint opacities. Direct irrigation of the narrow space confined by the ICL and the crystalline lens is at risk for the development of vacuolar changes in the crystalline lens. The observed spontaneous reversal indicates that surgeons should not rush to surgical intervention but rather opt for close follow over several weeks.

  12. [Intraocular lens implantation with one loop haptic amputated: a new propose to the subluxation lens surgical treatment].

    Science.gov (United States)

    Ventura, Marcelo; Endriss, Daniela

    2010-01-01

    To evaluate the postoperative results of congenital lens subluxation corrected by a new technique. Retrospective chart review of 21 eyes of 13 patients with no traumatic lens subluxation who underwent surgery in Altino Ventura Foundation from April, 1999 to April, 2004. The mean age was 8.7 +/- 5.4 years old, and the mean follow-up period was 21.5 +/- 19.3 months. Patients underwent phacoaspiration, endocapsular ring and intraocular lens (IOL) implantation. The implanted IOL had one loop haptic excised and was supported above the ring, inside the capsular bag promoting intraocular lens centralization. Visual acuity improvement was observed in all cases. There was a significant reduction of the spherical equivalent and spherical component comparing the pre and postoperative refraction (psubluxation surgical treatment, promoting lens centralization and postoperative visual acuity improvement.

  13. Eye Protection

    OpenAIRE

    Pashby, Tom

    1986-01-01

    Eye injuries frequently occur in the home, at work and at play. Many result in legally blind eyes, and most are preventable. Awareness of potential hazards is essential to preventing eye injuries, particularly in children. In addition, protective devices must be used appropriately. We have developed eye protectors that have proved effective in reducing both the overall incidence and the severity of sports eye injuries.

  14. Analysis of causes of intraocular lens explantations in the material of Department of Ophthalmology, Medical University of Lodz.

    Science.gov (United States)

    Wilczyński, Michał; Wilczyńska, Olena; Omulecki, Wojciech

    2009-01-01

    Implantation of intraocular lenses (IOLS) has become a standard practice in cataract surgery, however, similar to any other type of surgery, using IOLs is not complication-free and sometimes explantation of intraocular lenses may be necessary. This study was to gather data and analyze causes of intraocular lens explantations, performed in the Department of Ophthalmology, Medical University of Łódź. The data were gathered from medical documentation of all patients who underwent intraocular lens removal from January 2003 to July 2006. The examined group consisted of 16 patients (16 eyes): 9 women (fraction 0.56), and 7 men (fraction 0.44), at the age from 21 to 82 years (mean age 62.4 years, SD +/- 15.5). In all patients IOL explantation was performed under local, peribulbar anaesthesia. Two groups of patients were distinguished: patients who had an anterior chamber lens explanted (3 patients, fraction 0.19) and patients who underwent posterior chamber lens explantation (13 patients, fraction 0.81). Causes of AC IOL explantations were: vaulting of the IOL (1 eye, fraction 0.06), luxation of the IOL to the vitreous cavity (1 eye, fraction 0.06), and painful eyeball after anterior chamber lens implantation (1 eye, fraction 0.06). Causes of PC IOL explantations were: subluxation of the IOL (6 eyes, fraction 0.38), luxation of the lens to the vitreous cavity (3 eyes, fraction 0.19), luxation of the lens to the anterior chamber (1 eye, fraction 0.06), endophthalmitis (2 eyes, fraction 0.13) and incorrect lens power (1 eye, fraction 0.06). In the majority of eyes (n = 13, fraction 0.81) the removed implant was replaced by another intraocular lens, but 3 eyes (fraction 0.19) were left aphakic. We did not observe serious intra- or early postoperative complications which might influence the final result of the operation.

  15. Disruption of the podosome adaptor protein TKS4 (SH3PXD2B) causes the skeletal dysplasia, eye, and cardiac abnormalities of Frank-Ter Haar Syndrome.

    Science.gov (United States)

    Iqbal, Zafar; Cejudo-Martin, Pilar; de Brouwer, Arjan; van der Zwaag, Bert; Ruiz-Lozano, Pilar; Scimia, M Cecilia; Lindsey, James D; Weinreb, Robert; Albrecht, Beate; Megarbane, Andre; Alanay, Yasemin; Ben-Neriah, Ziva; Amenduni, Mariangela; Artuso, Rosangela; Veltman, Joris A; van Beusekom, Ellen; Oudakker, Astrid; Millán, José Luis; Hennekam, Raoul; Hamel, Ben; Courtneidge, Sara A; van Bokhoven, Hans

    2010-02-12

    Frank-Ter Haar syndrome (FTHS), also known as Ter Haar syndrome, is an autosomal-recessive disorder characterized by skeletal, cardiovascular, and eye abnormalities, such as increased intraocular pressure, prominent eyes, and hypertelorism. We have conducted homozygosity mapping on patients representing 12 FTHS families. A locus on chromosome 5q35.1 was identified for which patients from nine families shared homozygosity. For one family, a homozygous deletion mapped exactly to the smallest region of overlapping homozygosity, which contains a single gene, SH3PXD2B. This gene encodes the TKS4 protein, a phox homology (PX) and Src homology 3 (SH3) domain-containing adaptor protein and Src substrate. This protein was recently shown to be involved in the formation of actin-rich membrane protrusions called podosomes or invadopodia, which coordinate pericellular proteolysis with cell migration. Mice lacking Tks4 also showed pronounced skeletal, eye, and cardiac abnormalities and phenocopied the majority of the defects associated with FTHS. These findings establish a role for TKS4 in FTHS and embryonic development. Mutation analysis revealed five different homozygous mutations in SH3PXD2B in seven FTHS families. No SH3PXD2B mutations were detected in six other FTHS families, demonstrating the genetic heterogeneity of this condition. Interestingly however, dermal fibroblasts from one of the individuals without an SH3PXD2B mutation nevertheless expressed lower levels of the TKS4 protein, suggesting a common mechanism underlying disease causation. Copyright (c) 2010 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  16. Changes of the eye optics after iris constriction

    Directory of Open Access Journals (Sweden)

    Robert Montés-Micó

    2010-10-01

    Conclusion: Iris constriction slightly modifies the optics of the eye. The small hyperopic shift of the best image plane after iris constriction may be explained by a change in the lens shape and/or position.

  17. Refractive neutron lens

    International Nuclear Information System (INIS)

    Petrov, P.V.; Kolchevsky, N.N.

    2013-01-01

    Model of the refractive neutron lens is proposed. System of N lenses acts as one thin lens with a complex refraction index n*. The maximum number N max of individual lenses for 'thick' neutron lens is calculated. Refractive neutron lens properties (resolution, focal depth) as function of resolution factor F 0 =ρbc/μ and depth of field factor dF 0 =λF 0 =λρbc/μ are calculated. It is shown that micro resolution of the refractive neutron optics is far from the wavelength in size and its open possibilities for progress in refractive neutron optics. (authors)

  18. Clinical research on high oxygen permeable contact lens used after photorefractive keratectomy surgery

    Directory of Open Access Journals (Sweden)

    Hao-Jiang Yang

    2013-07-01

    Full Text Available AIM: To evaluate the outcome of high oxygen permeable contact lens used after photorefractive keratectomy(PRKsurgery.METHODS: Totally 95 patients(190 eyesafter PRK were included. Patients were randomly assigned to wear high oxygen permeable contact lens in one eye and normal lens in the fellow eye after surgery. The subjective symptoms and corneal epithelial status after PRK were evaluated. Uncorrected visual acuity(UCVAand haze were assessed at 6 months after PRK.RESULTS: Complaints of blurred vision, pain and photophobia were statistically more among the normal lens group than high oxygen permeable contact lens group(PPP=0.35. There was no difference in UCVA and haze 6 months after surgery(P=0.55. CONCLUSION: High oxygen permeable contact lens can significantly produce less the corneal irritated symptoms, reduce the discomfort feeling and promote healing of corneal epithelium after PRK.

  19. On-field evaluation of operator lens protective devices in interventional radiology

    International Nuclear Information System (INIS)

    Strocchi, S.; Chiaravalli, A.; Veronese, I.; Novario, R.

    2016-01-01

    The recent publication of the Euratom Directive 2013/59, adopting the reduction of eye lens dose limits from 150 to 20 mSv y"-"1, calls for the development of new tools and methodologies for evaluating the eye lens dose absorbed by the medical staff involved in interventional radiology practices. Moreover, the effectiveness of the protective devices, like leaded glasses, which can be employed for radiation protection purposes, must be tested under typical exposure scenarios. In this work, eye lens dose measurements were carried out on an anthropomorphic phantom simulating a physician bound to perform standard interventional neuroradiology angiographic procedures. The correlation between eye lens doses, in terms of Hp(0.07), and the equivalent dose [again in terms of Hp(0.07)] monthly measured with thermoluminescent dosemeters placed above the lead apron at the chest level was studied, in the presence and in the absence of different types of leaded glasses. (authors)

  20. Colored Contact Lens Dangers

    Medline Plus

    Full Text Available ... Services Advocacy Foundation About Subspecialties & More Eye Health ... W.Va., had "extreme pain in both eyes," she said. "Because I had not been properly fitted by an eye care professional, the lenses stuck to my eye like ...

  1. Disposable contact lens use as a risk factor for microbial keratitis

    OpenAIRE

    Radford, C.; Minassian, D.; Dart, J.

    1998-01-01

    AIMS—A case-control study was performed to evaluate soft contact lens (SCL) wear modality as a risk factor for microbial keratitis.
METHODS—Contact lens wearers presenting as new patients to Moorfields Eye Hospital accident and emergency department during a 12 month period completed a self administered questionnaire detailing demographic data and contact lens use habits. Cases were patients with a clinical diagnosis of SCL related microbial keratitis. Controls were SCL users attending with di...

  2. Lens thickness assessment: anterior segment optical coherence tomography versus A-scan ultrasonography

    Directory of Open Access Journals (Sweden)

    Nikoo Hamzeh

    2015-12-01

    Full Text Available AIM: To assess lens thickness measurements with anterior segment-optical coherence tomography (AS-OCT in comparison with A-scan ultrasonography (A-scan US. METHODS: There were 218 adult subjects (218 eyes aged 59.2±9.2y enrolled in this prospective cross-sectional study. Forty-three eyes had open angles and 175 eyes had narrow angles. Routine ophthalmic exam was performed and nuclear opacity was graded using the Lens Opacities Classification System III (LOCS III. Lens thickness was measured by AS-OCT (Visante OCT, Carl Zeiss Meditec, Dublin, CA, USA. The highest quality image was selected for each eye and lens thickness was calculated using ImageJ software. Lens thickness was also measured by A-scan US. RESULTS: Interclass correlations showed a value of 99.7% for intra-visit measurements and 95.3% for inter-visit measurements. The mean lens thickness measured by AS-OCT was not significantly different from that of A-scan US (4.861±0.404 vs 4.866±0.351 mm, P=0.74. Lens thickness values obtained from the two instruments were highly correlated overall (Pearson correlation coefficient=0.81, P<0.001, and in all LOCS III specific subgroups except in grade 5 of nuclear opacity. Bland-Altman analysis revealed a 95% limit of agreement from -0.45 to 0.46 mm. Lens thickness difference between the two instruments became smaller as the lens thickness increased and AS-OCT yielded smaller values than A-scan US in thicker lens (β=-0.29, P<0.001 CONCLUSION: AS-OCT-derived lens thickness measurement is valid and comparable to the results obtained by A-scan US. It can be used as a reliable noncontact method for measuring lens thickness in adults with or without significant cataract.

  3. A rare case of traumatic subretinal migration of crystalline lens, corroborated histologically.

    Science.gov (United States)

    Bawankar, Pritam; Das, Dipankar; Agarwal, Balmukund; Bhattacharjee, Kasturi; Tayab, Shahinur; Deka, Panna; Singh, Anshul; Borah, Erani; Dhar, Shriya

    2017-12-01

    Blunt trauma is the most common cause of posterior dislocation of the crystalline lens. We describe a rare case of subretinal migration of crystalline lens through the giant retinal tear following blunt ocular trauma. This incidental finding of subretinal dislocation of lens following blunt ocular trauma was confirmed on histopathological examination of the enucleated eye. This complication has not been described by histopathological examination in literature so far.

  4. Lens Accommodation, Ocular Convergence and the Brain(Physiology of Vision)

    OpenAIRE

    坂東, 武彦; 戸田, 春男; 安藤, 誠男; 高木, 峰夫; 吉沢, 豊久; 原, 直人; Bando, Takehiko; Toda, Haruo; Ando, Tomoo; Takagi, Mineo; Yoshizawa, Toyohisa; Hara, Naoto

    1993-01-01

    Experimental findings obtained by our group were reviewed, and functional significance of the visual association cortex in controlling lens accommodation and ocular convergence was discussed. By intracortical microstimulation in an extrastriate visual area in the cat, lens accommodation and vergence eye movement were evoked. In the same cortical area, a group of neurons was also activated in correlation with lens accommodation or ocular convergence. In addition, after the lesion in this area,...

  5. A rare case of traumatic subretinal migration of crystalline lens, corroborated histologically

    Directory of Open Access Journals (Sweden)

    Pritam Bawankar

    2017-01-01

    Full Text Available Blunt trauma is the most common cause of posterior dislocation of the crystalline lens. We describe a rare case of subretinal migration of crystalline lens through the giant retinal tear following blunt ocular trauma. This incidental finding of subretinal dislocation of lens following blunt ocular trauma was confirmed on histopathological examination of the enucleated eye. This complication has not been described by histopathological examination in literature so far.

  6. EVALUATION OF IRIDOCILIARY AND LENTICULAR ELASTICITY USING SHEAR-WAVE ELASTOGRAPHY IN RABBIT EYES

    OpenAIRE

    Efstathios T. Detorakis; Eleni E. Drakonaki; Harilaos Ginis; Nikolaos Karyotakis; Ioannis G. Pallikaris

    2014-01-01

    Introduction: A previous study has employed shear-wave ultrasound elastographic imaging to assess corneal rigidity in an ex-vivo porcine eye model. This study employs the same modality in vivo in a rabbit eye model in order to assess lens, ciliary body and total ocular rigidity changes following the instillation of atropine and pilocarpine. Methods: Ten non-pigmented female rabbits were examined. Measurements of the lens, ciliary body and total ocular rigidity as well as lens thickness and an...

  7. Ampicillin penetration into the rabbit eye

    International Nuclear Information System (INIS)

    Salminen, L.

    1978-01-01

    Distribution of intravenously injected ampicillin of 50 mg/kg was studied in the rabbit eye using radioactive tracer method. Antibiotic concentration regarded as therapeutic in the treatment of gram-negative organisms was obtained in all vascularized ocular structures. Intermediate values were measured from the cornea and aqueous humour. In the vitreous body and lens, ampicillin was unable to approach a concentration that would be effective against the common gram-negative organisms. The low ampicillin concentration in the vitreous body and lens was unchanged by systemically administered probenecid, which in other parts of the eye caused significantly higher ampicillin levels. (author)

  8. Potentiation of intraocular absorption and drug metabolism of N-acetylcarnosine lubricant eye drops: drug interaction with sight threatening lipid peroxides in the treatment for age-related eye diseases.

    Science.gov (United States)

    Babizhayev, Mark A

    2009-01-01

    Cataract is the dominant cause of blindness worldwide. Studies of the morphological structure and biophysical changes of the lens in human senile cataracts have demonstrated the disappearance of normal fiber structure in the opaque region of the lens and the disintegration of the lens fiber plasma membrane in the lens tissue. Morphological and biochemical techniques have revealed the regions in human cataractous lenses in which the plasma membrane derangement occurs as the primary light scattering centers which cause the observed lens opacity. Human cataract formation is mostly considered to be a multifactorial disease; however, oxidative stress might be one of the leading causes for both nuclear and cortical cataract. Phospholipid molecules modified with oxygen, accumulating in the lipid bilayer, change its geometry and impair lipid-lipid and protein-lipid interactions in lenticular fiber membranes. Electron microscopy data of human lenses at various stages of age-related cataract document that these disruptions were globules, vacuoles, multilamellar membranes, and clusters of highly undulating membranes. The opaque shades of cortical cataracts represent cohorts of locally affected fibres segregated from unaffected neighbouring fibres by plasma membranes. Other potential scattering centers found throughout the mature cataract nucleus included variations in staining density between adjacent cells, enlarged extracellular spaces between undulating membrane pairs, and protein-like deposits in the extracellular space. These affected parts had membranes with a fine globular aspect and in cross-section proved to be filled with medium to large globular elements. Lipid peroxidation (LPO) is a pathogenetic and causative factor of cataract. Increased concentrations of primary molecular LPO products (diene conjugates, lipid hydroperoxides, fatty acid oxy-derivatives) and end fluorescent LPO products were detected in the lipid moieties of the aqueous humor samples and human

  9. Arthropod eyes: The early Cambrian fossil record and divergent evolution of visual systems.

    Science.gov (United States)

    Strausfeld, Nicholas J; Ma, Xiaoya; Edgecombe, Gregory D; Fortey, Richard A; Land, Michael F; Liu, Yu; Cong, Peiyun; Hou, Xianguang

    2016-03-01

    Four types of eyes serve the visual neuropils of extant arthropods: compound retinas composed of adjacent facets; a visual surface populated by spaced eyelets; a smooth transparent cuticle providing inwardly directed lens cylinders; and single-lens eyes. The first type is a characteristic of pancrustaceans, the eyes of which comprise lenses arranged as hexagonal or rectilinear arrays, each lens crowning 8-9 photoreceptor neurons. Except for Scutigeromorpha, the second type typifies Myriapoda whose relatively large eyelets surmount numerous photoreceptive rhabdoms stacked together as tiers. Scutigeromorph eyes are facetted, each lens crowning some dozen photoreceptor neurons of a modified apposition-type eye. Extant chelicerate eyes are single-lensed except in xiphosurans, whose lateral eyes comprise a cuticle with a smooth outer surface and an inner one providing regular arrays of lens cylinders. This account discusses whether these disparate eye types speak for or against divergence from one ancestral eye type. Previous considerations of eye evolution, focusing on the eyes of trilobites and on facet proliferation in xiphosurans and myriapods, have proposed that the mode of development of eyes in those taxa is distinct from that of pancrustaceans and is the plesiomorphic condition from which facetted eyes have evolved. But the recent discovery of enormous regularly facetted compound eyes belonging to early Cambrian radiodontans suggests that high-resolution facetted eyes with superior optics may be the ground pattern organization for arthropods, predating the evolution of arthrodization and jointed post-protocerebral appendages. Here we provide evidence that compound eye organization in stem-group euarthropods of the Cambrian can be understood in terms of eye morphologies diverging from this ancestral radiodontan-type ground pattern. We show that in certain Cambrian groups apposition eyes relate to fixed or mobile eyestalks, whereas other groups reveal concomitant

  10. Clinical observation of capsular tension ring implantation in congenital lens subluxation treating by phacoemulsification

    OpenAIRE

    Liang-Nan Sun; Bai-Jun Li; Yuan-Fei Zhu; Xin-Hua Liu

    2017-01-01

    AIM: To evaluate the clinical results of capsular tension ring(CTR)implantation in phacoemulsification for eyes with congenital lens subluxation. METHODS: This study comprised 18 patients(31 eyes)with congenital ectopia lentis. All patients received phacoemulsification with CTR and intraocular lens(IOL)implantation. Visual acuity before and after surgery were examined. IOL decentration were measured with Image-Pro Plus image processing software. The complications were also recorded preoperati...

  11. Time-specific blockade of PDGFR with Imatinib (Glivec®) causes cataract and disruption of lens fiber cells in neonatal mice.

    Science.gov (United States)

    Zhou, Yin-Pin; He, Yang-Tao; Chen, Cheng-Li; Ji, Jun; Niu, Jian-Qin; Wang, Han-Zhi; Li, Shi-Feng; Huang, Lan; Mei, Feng

    2011-03-01

    This study aimed at investigating the response of lens epithelial cells in postnatal mice to Imatinib (Glivec®, a potent inhibitor of platelet-derived growth factor receptor (PDGFR)) treatment. Mouse eyes were sampled 10 days after administration of Imatinib (0.5 mg·g(-1)·day(-1)) for 3 days, at either 7, 14, or 21 days postpartum. Structural changes of lens were revealed by routine H.E. staining. Levels of proliferation and apoptosis were revealed by BrdU incorporation and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively, and immunofluorescent staining with anti-PDGFRα antibody was carried out on the sections of eyeball. PDGFRα and p-PDGFRαprotein levels were evaluated by Western blot. Our results indicated that administration of Imatinib led to blockade of PDGFR signaling. Formation of cataracts was found only in those mice where treatment started from 7 days postpartum (P7), but was not observed in those samples from P14 nor P21. Fiber cells were disorganized in cataract lens core as observed histologically, and migration of epithelial cells was also inhibited. No apoptosis was detected with the TUNEL method. Our results indicated blockade of PDGFR at the neonatal stage (P7) would lead to cataracts and lens fiber cells disorganization, suggesting that PDGFR signaling plays a time-specific and crucial role in the postnatal development of lens in the mouse, and also may provide a new approach to produce a congenital cataract animal model.

  12. Which soft lens power is better for piggyback in keratoconus? Part II.

    Science.gov (United States)

    Romero-Jiménez, Miguel; Santodomingo-Rubido, Jacinto; González-Meijóme, Jose-Manuel; Flores-Rodriguez, Patricia; Villa-Collar, Cesar

    2015-02-01

    To evaluate how soft lens power affects rigid gas-permeable (RGP) lens power and visual acuity (VA) in piggyback fittings for keratoconus. Sixteen keratoconus subjects (30 eyes) were included in the study. Piggyback contact lens fittings combining Senofilcon-A soft lenses of -6.00, -3.00, +3.00 and +6.00 D with Rose K2 RGP contact lenses were performed. Corneal topography was taken on the naked eye and over each soft contact lens before fitting RGP lenses. Mean central keratometry, over-refraction, RGP back optic zone radius (BOZR) and estimated final power as well as VA were recorded and analyzed. In comparison to the naked eye, the mean central keratometry flattened with both negative lens powers (psoft lens power (p=1.0); and steepened with the +6.00 soft lens power (p=0.02). Rigid gas-permeable over-refraction did not change significantly between different soft lens powers (all p>0.05). RGP's BOZR decreased significantly with both positive in comparison with both negative soft lens powers (all ppowers separately (both p>0.05). Estimated RGP's final power increased significantly with positive in comparison with negative lens powers (all ppowers separately (both p>0.05). Visual acuity did not change significantly between the different soft lens powers assessed (all p>0.05). The use of negative-powered soft lenses in piggyback fitting reduces RGP lens power without impacting VA in keratoconus subjects. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  13. Eye Cancer

    Science.gov (United States)

    Cancer of the eye is uncommon. It can affect the outer parts of the eye, such as the eyelid, which are made up ... and nerves. If the cancer starts inside the eyeball it's called intraocular cancer. The most common intraocular ...

  14. Black Eye

    Science.gov (United States)

    ... Your Eyes Sep 20, 2017 Eye Injuries from Laundry Packets On the Rise Jun 30, 2017 ... Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media Ophthalmology Job Center © American ...

  15. Eye Anatomy

    Science.gov (United States)

    ... News About Us Donate In This Section Eye Anatomy en Español email Send this article to a ... You at Risk For Glaucoma? Childhood Glaucoma Eye Anatomy Five Common Glaucoma Tests Glaucoma Facts and Stats ...

  16. Eye Emergencies

    Science.gov (United States)

    ... The Marfan Foundation Marfan & Related Disorders What is Marfan Syndrome? What are Related Disorders? What are the Signs? ... Emergencies Eye Emergencies Lung Emergencies Surgeries Eye Emergencies Marfan syndrome significantly increases your risk of retinal detachment, a ...

  17. Pentacam Scheimpflug quantitative imaging of the crystalline lens and intraocular lens.

    Science.gov (United States)

    Rosales, Patricia; Marcos, Susana

    2009-05-01

    To implement geometrical and optical distortion correction methods for anterior segment Scheimpflug images obtained with a commercially available system (Pentacam, Oculus Optikgeräte GmbH). Ray tracing algorithms were implemented to obtain corrected ocular surface geometry from the original images captured by the Pentacam's CCD camera. As details of the optical layout were not fully provided by the manufacturer, an iterative procedure (based on imaging of calibrated spheres) was developed to estimate the camera lens specifications. The correction procedure was tested on Scheimpflug images of a physical water cell model eye (with polymethylmethacrylate cornea and a commercial IOL of known dimensions) and of a normal human eye previously measured with a corrected optical and geometrical distortion Scheimpflug camera (Topcon SL-45 [Topcon Medical Systems Inc] from the Vrije University, Amsterdam, Holland). Uncorrected Scheimpflug images show flatter surfaces and thinner lenses than in reality. The application of geometrical and optical distortion correction algorithms improves the accuracy of the estimated anterior lens radii of curvature by 30% to 40% and of the estimated posterior lens by 50% to 100%. The average error in the retrieved radii was 0.37 and 0.46 mm for the anterior and posterior lens radii of curvature, respectively, and 0.048 mm for lens thickness. The Pentacam Scheimpflug system can be used to obtain quantitative information on the geometry of the crystalline lens, provided that geometrical and optical distortion correction algorithms are applied, within the accuracy of state-of-the art phakometry and biometry. The techniques could improve with exact knowledge of the technical specifications of the instrument, improved edge detection algorithms, consideration of aspheric and non-rotationally symmetrical surfaces, and introduction of a crystalline gradient index.

  18. Capsular 'pits' in the human lens.

    OpenAIRE

    Harris, M. L.; Brown, N. A.; Shun-Shin, G. A.; Smith, G. T.

    1992-01-01

    The lens capsule is an atypical basement membrane surrounding the lens epithelial cells and lens fibres which make up the remainder of the human lens. A seemingly unreported morphological change visible in the lens capsule with the biomicroscope is described.

  19. Intraocular Lens Calcification; a Clinicopathologic Report

    Directory of Open Access Journals (Sweden)

    Mozhgan Rezaei-Kanavi

    2009-04-01

    Full Text Available

    PURPOSE: To describe the clinical and pathological features of a case of hydrogel intraocular lens (IOL calcification. CASE REPORT: A 48-year-old man underwent explantation of a single-piece hydrophilic acrylic intraocular lens in his left eye because of decreased visual acuity and milky white opalescence of the IOL. The opacified lens was exchanged uneventfully with a hydrophobic acrylic IOL. Gross examination of the explanted IOL disclosed opacification of the optic and haptics. Full-thickness sections of the lens optic were stained with hematoxylin and eosin (H&E, von Kossa and Gram Tworts'. Microscopic examination of the sections revealed fine and diffuse basophilic granular deposits of variable size within the lens optic parallel to the lens curvature but separated from the surface by a moderately clear zone. The deposits were of high calcium content as evident by dark brown staining with von Kossa. Gram Tworts' staining disclosed no microorganisms. CONCLUSION: This report further contributes to the existing literature on hydrogel IOL calcification.

  20. Citation parameters of contact lens-related articles published in the ophthalmic literature.

    Science.gov (United States)

    Cardona, Genís; Sanz, Joan P

    2014-09-01

    This study aimed at exploring the citation parameters of contact lenses articles published in the Ophthalmology thematic category of the Journal Citation Reports (JCR). The Thompson Reuters Web of Science database was accessed to record bibliometric information and citation parameters of all journals listed under the Ophthalmology area of the 2011 JCR edition, including the journals with main publication interests in the contact lens field. In addition, the same database was used to unveil all contact lens-related articles published in 2011 in the same thematic area, whereupon differences in citation parameters between those articles published in contact lens and non-contact lens-related journals were explored. Significant differences in some bibliometric indicators such as half-life and overall citation count were found between contact lens-related journals (shorter half-life and fewer citations) and the median values for the Ophthalmology thematic area of the JCR. Visual examination of all Ophthalmology journals uncovered a total of 156 contact lens-related articles, published in 28 different journals, with 27 articles each for Contact Lens & Anterior Eye, Eye & Contact Lens, and Optometry and Vision Science. Significant differences in citation parameters were encountered between those articles published in contact lens and non-contact lens source journals. These findings, which disclosed contact lenses to be a fertile area of research, may be of interest to researchers and institutions. Differences in bibliometric indicators are of relevance to avoid unwanted bias when conducting between- and within-discipline comparisons of articles, journals, and researchers.