WorldWideScience

Sample records for high quality retinal

  1. Retinal image quality during accommodation.

    Science.gov (United States)

    López-Gil, Norberto; Martin, Jesson; Liu, Tao; Bradley, Arthur; Díaz-Muñoz, David; Thibos, Larry N

    2013-07-01

    We asked if retinal image quality is maximum during accommodation, or sub-optimal due to accommodative error, when subjects perform an acuity task. Subjects viewed a monochromatic (552 nm), high-contrast letter target placed at various viewing distances. Wavefront aberrations of the accommodating eye were measured near the endpoint of an acuity staircase paradigm. Refractive state, defined as the optimum target vergence for maximising retinal image quality, was computed by through-focus wavefront analysis to find the power of the virtual correcting lens that maximizes visual Strehl ratio. Despite changes in ocular aberrations and pupil size during binocular viewing, retinal image quality and visual acuity typically remain high for all target vergences. When accommodative errors lead to sub-optimal retinal image quality, acuity and measured image quality both decline. However, the effect of accommodation errors of on visual acuity are mitigated by pupillary constriction associated with accommodation and binocular convergence and also to binocular summation of dissimilar retinal image blur. Under monocular viewing conditions some subjects displayed significant accommodative lag that reduced visual performance, an effect that was exacerbated by pharmacological dilation of the pupil. Spurious measurement of accommodative error can be avoided when the image quality metric used to determine refractive state is compatible with the focusing criteria used by the visual system to control accommodation. Real focusing errors of the accommodating eye do not necessarily produce a reliably measurable loss of image quality or clinically significant loss of visual performance, probably because of increased depth-of-focus due to pupil constriction. When retinal image quality is close to maximum achievable (given the eye's higher-order aberrations), acuity is also near maximum. A combination of accommodative lag, reduced image quality, and reduced visual function may be a useful

  2. Improving high resolution retinal image quality using speckle illumination HiLo imaging.

    Science.gov (United States)

    Zhou, Xiaolin; Bedggood, Phillip; Metha, Andrew

    2014-08-01

    Retinal image quality from flood illumination adaptive optics (AO) ophthalmoscopes is adversely affected by out-of-focus light scatter due to the lack of confocality. This effect is more pronounced in small eyes, such as that of rodents, because the requisite high optical power confers a large dioptric thickness to the retina. A recently-developed structured illumination microscopy (SIM) technique called HiLo imaging has been shown to reduce the effect of out-of-focus light scatter in flood illumination microscopes and produce pseudo-confocal images with significantly improved image quality. In this work, we adopted the HiLo technique to a flood AO ophthalmoscope and performed AO imaging in both (physical) model and live rat eyes. The improvement in image quality from HiLo imaging is shown both qualitatively and quantitatively by using spatial spectral analysis.

  3. Toward high-resolution optoelectronic retinal prosthesis

    Science.gov (United States)

    Palanker, Daniel; Huie, Philip; Vankov, Alexander; Asher, Alon; Baccus, Steven

    2005-04-01

    It has been already demonstrated that electrical stimulation of retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. Current retinal implants provide very low resolution (just a few electrodes), while several thousand pixels are required for functional restoration of sight. We present a design of the optoelectronic retinal prosthetic system that can activate a retinal stimulating array with pixel density up to 2,500 pix/mm2 (geometrically corresponding to a visual acuity of 20/80), and allows for natural eye scanning rather than scanning with a head-mounted camera. The system operates similarly to "virtual reality" imaging devices used in military and medical applications. An image from a video camera is projected by a goggle-mounted infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. Such a system provides a broad field of vision by allowing for natural eye scanning. The goggles are transparent to visible light, thus allowing for simultaneous utilization of remaining natural vision along with prosthetic stimulation. Optical control of the implant allows for simple adjustment of image processing algorithms and for learning. A major prerequisite for high resolution stimulation is the proximity of neural cells to the stimulation sites. This can be achieved with sub-retinal implants constructed in a manner that directs migration of retinal cells to target areas. Two basic implant geometries are described: perforated membranes and protruding electrode arrays. Possibility of the tactile neural stimulation is also examined.

  4. Retinal image quality assessment based on image clarity and content

    Science.gov (United States)

    Abdel-Hamid, Lamiaa; El-Rafei, Ahmed; El-Ramly, Salwa; Michelson, Georg; Hornegger, Joachim

    2016-09-01

    Retinal image quality assessment (RIQA) is an essential step in automated screening systems to avoid misdiagnosis caused by processing poor quality retinal images. A no-reference transform-based RIQA algorithm is introduced that assesses images based on five clarity and content quality issues: sharpness, illumination, homogeneity, field definition, and content. Transform-based RIQA algorithms have the advantage of considering retinal structures while being computationally inexpensive. Wavelet-based features are proposed to evaluate the sharpness and overall illumination of the images. A retinal saturation channel is designed and used along with wavelet-based features for homogeneity assessment. The presented sharpness and illumination features are utilized to assure adequate field definition, whereas color information is used to exclude nonretinal images. Several publicly available datasets of varying quality grades are utilized to evaluate the feature sets resulting in area under the receiver operating characteristic curve above 0.99 for each of the individual feature sets. The overall quality is assessed by a classifier that uses the collective features as an input vector. The classification results show superior performance of the algorithm in comparison to other methods from literature. Moreover, the algorithm addresses efficiently and comprehensively various quality issues and is suitable for automatic screening systems.

  5. Quality assurance in diabetic retinal screening in South Africa.

    Science.gov (United States)

    Cook, Steve; Staff, Roger T; Goatman, Keith A; Olson, John A

    2014-09-03

    Diabetic retinopathy (DR) is an important biomarker for microvascular disease and blindness. Digital fundus photography is a cost-effective way of screening for DR. Access to DR screening is difficult for many South Africans with diabetes. To perform external quality assurance (EQA) on graders registered in the Ophthalmological Society of South Africa DR screening programme. Graders registered on the South African (SA) Diabetic Register website were invited to participate in the study. The Scottish EQA software system was used to enable on-line grading of 100 retinal photographs. Expert National Health Service graders provided the consensus expert grading for the image set. Two hundred and sixty-one participants completed the EQA process, including nine ophthalmologists, 243 optometrists, and nine other graders. A wide range of outcomes were demonstrated, with a mean sensitivity of 0.905 (range 0.286 - 1.000) and mean specificity of 0.507 (0.000 - 0.935). The mean diagnostic odds ratio was calculated to be 12.3 (range 0.147 - 148.2). This is the first quality assurance study conducted with SA healthcare professionals. The outcomes are of interest to all stakeholders dealing with the diabetes epidemic. The disparity in grader performance indicates room for improvement. The results demonstrate a high referral rate to ophthalmology, suggesting that on average graders are performing safely, but with a high number of inappropriate referrals.

  6. Peripheral retinal changes in highly myopic young Asian eyes.

    Science.gov (United States)

    Chen, David Z; Koh, Victor; Tan, Marcus; Tan, Colin S; Nah, Gerard; Shen, Liang; Bhargava, Mayuri; Cheng, Ching-Yu; Zhao, Paul; Wong, Tien Yin; Saw, Seang-Mei

    2018-03-25

    To determine the type and prevalence of peripheral retinal changes and its relationship with axial length (AL) in a population of young Asian adult males. This was a cross-sectional study of male subjects aged between 19 and 25 years old. High myopes [spherical equivalent refraction, (SER) lattice degeneration (LD; n = 109, 14.6%) were the commonest findings, and their prevalence was significantly higher among high myopes (LD, 16.9% versus 5.8%; WWOP, 57.2% versus 5.8%; both p < 0.001). Among high myopes, temporal LD was more common (71%) and 35% had more than one area in the same eye. Increasing AL was associated with LD (odds ratio 1.28, p = 0.01) and retinal holes (odd's ratio 1.44, p = 0.02) on multivariate analysis. White without pressure (WWOP) and LD were the commonest peripheral retinal changes. One-third of high myopes with LD had more than one area in the same eye. Increasing AL was associated with LD and retinal holes. Studies in older adults should be conducted to develop clinical guidelines for the management of high myopes. © 2018 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  7. Retinal sensitivity and choroidal thickness in high myopia.

    Science.gov (United States)

    Zaben, Ahmad; Zapata, Miguel Á; Garcia-Arumi, Jose

    2015-03-01

    To estimate the association between choroidal thickness in the macular area and retinal sensitivity in eyes with high myopia. This investigation was a transversal study of patients with high myopia, all of whom had their retinal sensitivity measured with macular integrity assessment microperimetry. The choroidal thicknesses in the macular area were then measured by optical coherence tomography, and statistical correlations between their functionality and the anatomical structuralism, as assessed by both types of measurements, were analyzed. Ninety-six eyes from 77 patients with high myopia were studied. The patients had a mean age ± standard deviation of 38.9 ± 13.2 years, with spherical equivalent values ranging from -6.00 diopter to -20.00 diopter (8.74 ± 2.73 diopter). The mean central choroidal thickness was 159.00 ± 50.57. The mean choroidal thickness was directly correlated with sensitivity (r = 0.306; P = 0.004) and visual acuity but indirectly correlated with the spherical equivalent values and patient age. The mean sensitivity was not significantly correlated with the macular foveal thickness (r = -0.174; P = 0.101) or with the overall macular thickness (r = 0.103; P = 0.334); furthermore, the mean sensitivity was significantly correlated with visual acuity (r = 0.431; P < 0.001) and the spherical equivalent values (r = -0.306; P = 0.003). Retinal sensitivity in highly myopic eyes is directly correlated with choroidal thickness and does not seem to be associated with retinal thickness. Thus, in patients with high myopia, accurate measurements of choroidal thickness may provide more accurate information about this pathologic condition because choroidal thickness correlates to a greater degree with the functional parameters, patient age, and spherical equivalent values.

  8. Adaptive optics with pupil tracking for high resolution retinal imaging.

    Science.gov (United States)

    Sahin, Betul; Lamory, Barbara; Levecq, Xavier; Harms, Fabrice; Dainty, Chris

    2012-02-01

    Adaptive optics, when integrated into retinal imaging systems, compensates for rapidly changing ocular aberrations in real time and results in improved high resolution images that reveal the photoreceptor mosaic. Imaging the retina at high resolution has numerous potential medical applications, and yet for the development of commercial products that can be used in the clinic, the complexity and high cost of the present research systems have to be addressed. We present a new method to control the deformable mirror in real time based on pupil tracking measurements which uses the default camera for the alignment of the eye in the retinal imaging system and requires no extra cost or hardware. We also present the first experiments done with a compact adaptive optics flood illumination fundus camera where it was possible to compensate for the higher order aberrations of a moving model eye and in vivo in real time based on pupil tracking measurements, without the real time contribution of a wavefront sensor. As an outcome of this research, we showed that pupil tracking can be effectively used as a low cost and practical adaptive optics tool for high resolution retinal imaging because eye movements constitute an important part of the ocular wavefront dynamics.

  9. Dynamic simulation of the effect of soft toric contact lenses movement on retinal image quality.

    Science.gov (United States)

    Niu, Yafei; Sarver, Edwin J; Stevenson, Scott B; Marsack, Jason D; Parker, Katrina E; Applegate, Raymond A

    2008-04-01

    To report the development of a tool designed to dynamically simulate the effect of soft toric contact lens movement on retinal image quality, initial findings on three eyes, and the next steps to be taken to improve the utility of the tool. Three eyes of two subjects wearing soft toric contact lenses were cyclopleged with 1% cyclopentolate and 2.5% phenylephrine. Four hundred wavefront aberration measurements over a 5-mm pupil were recorded during soft contact lens wear at 30 Hz using a complete ophthalmic analysis system aberrometer. Each wavefront error measurement was input into Visual Optics Laboratory (version 7.15, Sarver and Associates, Inc.) to generate a retinal simulation of a high contrast log MAR visual acuity chart. The individual simulations were combined into a single dynamic movie using a custom MatLab PsychToolbox program. Visual acuity was measured for each eye reading the movie with best cycloplegic spectacle correction through a 3-mm artificial pupil to minimize the influence of the eyes' uncorrected aberrations. Comparison of the simulated acuity was made to values recorded while the subject read unaberrated charts with contact lenses through a 5-mm artificial pupil. For one study eye, average acuity was the same as the natural contact lens viewing condition. For the other two study eyes visual acuity of the best simulation was more than one line worse than natural viewing conditions. Dynamic simulation of retinal image quality, although not yet perfect, is a promising technique for visually illustrating the optical effects on image quality because of the movements of alignment-sensitive corrections.

  10. OCT as a convenient tool to assess the quality and application of organotypic retinal samples

    Science.gov (United States)

    Gater, Rachel; Khoshnaw, Nicholas; Nguyen, Dan; El Haj, Alicia J.; Yang, Ying

    2016-03-01

    Eye diseases such as macular degeneration and glaucoma have profound consequences on the quality of human life. Without treatment, these diseases can lead to loss of sight. To develop better treatments for retinal diseases, including cell therapies and drug intervention, establishment of an efficient and reproducible 3D native retinal tissue system, enabled over a prolonged culture duration, will be valuable. The retina is a complex tissue, consisting of ten layers with a different density and cellular composition to each. Uniquely, as a light transmitting tissue, retinal refraction of light differs among the layers, forming a good basis to use optical coherence tomography (OCT) in assessing the layered structure of the retina and its change during the culture and treatments. In this study, we develop a new methodology to generate retinal organotypic tissues and compare two substrates: filter paper and collagen hydrogel, to culture the organotypic tissue. Freshly slaughtered pig eyes have been obtained for use in this study. The layered morphology of intact organotypic retinal tissue cultured on two different substrates has been examined by spectral domain OCT. The viability of the tissues has been examined by live/dead fluorescence dye kit to cross validate the OCT images. For the first time, it is demonstrated that the use of a collagen hydrogel supports the viability of retinal organotypic tissue, capable of prolonged culture up to 2 weeks. OCT is a convenient tool for appraising the quality and application of organotypic retinal samples and is important in the development of current organotypic models.

  11. Retinal oximetry during treatment of retinal vein occlusion by ranibizumab in patients with high blood pressure and dyslipidemia.

    Science.gov (United States)

    Keilani, C; Halalchi, A; Wakpi Djeugue, D; Regis, A; Abada, S

    2016-12-01

    In the present study, we examined retinal vascular oxygen saturation in patients with retinal vein occlusion (RVO), high blood pressure (HBP) and dyslipidemia, before and during intravitreal vascular endothelial growth factor (VEGF) injection (ranibizumab). We retrospectively reviewed the medical records of six patients with visual acuity (VA) reduced by macular edema (ME) secondary to RVO with HBP and dyslipidemia, who underwent intravitreal anti-VEGF injection between October 2014 and February 2015 in the department of ophthalmology of François-Quesnay Hospital at Mantes-la-Jolie (France). The main inclusion criterion was the presence of RVO with ME and decreased VA. The primary endpoint was improvement of retinal venous oxygen saturation in patients with RVO before and 3 months after intravitreal ranibizumab injection. Secondary outcomes were improvement of retinal arterial oxygen saturation, improvement of best-corrected visual acuity (BCVA) on the Early Treatment Diabetic Retinopathy Study (ETDRS) scale, regression of ME measured by the central macular thickness (CMT) in nm and studying the correlation between blood pressure (BP) and retinal venous oxygen saturation before and after ranibizumab. Six eyes of six patients were included. Before treatment, the mean (standard deviation [SD]) of the retinal venous saturation (%) was 38.1±14.2. Three months after the injections, the mean (SD) of the retinal venous saturation (%) increased statistically significantly 49.2±11 (P=0.03). In this study, retinal venous oxygen saturation in patients with RVO, HBP and dyslipidemia was partially normalized during intravitreal ranibizumab treatment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. High glucose alters retinal astrocytes phenotype through increased production of inflammatory cytokines and oxidative stress.

    Directory of Open Access Journals (Sweden)

    Eui Seok Shin

    Full Text Available Astrocytes are macroglial cells that have a crucial role in development of the retinal vasculature and maintenance of the blood-retina-barrier (BRB. Diabetes affects the physiology and function of retinal vascular cells including astrocytes (AC leading to breakdown of BRB. However, the detailed cellular mechanisms leading to retinal AC dysfunction under high glucose conditions remain unclear. Here we show that high glucose conditions did not induce the apoptosis of retinal AC, but instead increased their rate of DNA synthesis and adhesion to extracellular matrix proteins. These alterations were associated with changes in intracellular signaling pathways involved in cell survival, migration and proliferation. High glucose conditions also affected the expression of inflammatory cytokines in retinal AC, activated NF-κB, and prevented their network formation on Matrigel. In addition, we showed that the attenuation of retinal AC migration under high glucose conditions, and capillary morphogenesis of retinal endothelial cells on Matrigel, was mediated through increased oxidative stress. Antioxidant proteins including heme oxygenase-1 and peroxiredoxin-2 levels were also increased in retinal AC under high glucose conditions through nuclear localization of transcription factor nuclear factor-erythroid 2-related factor-2. Together our results demonstrated that high glucose conditions alter the function of retinal AC by increased production of inflammatory cytokines and oxidative stress with significant impact on their proliferation, adhesion, and migration.

  13. Autofluorescence and high-definition optical coherence tomography of retinal artery occlusions

    OpenAIRE

    Mathew, Raeba; Papavasileiou, Evangelia; Sivaprasad, Sobha

    2010-01-01

    Raeba Mathew, Evangelia Papavasileiou, Sobha SivaprasadLaser and Retinal Research Unit, Department of Ophthalmology, King’s College Hospital, Denmark Hill, London, UKBackground: The purpose of this study is to illustrate the fundus autofluorescence and high-definition optical coherence tomography (HD-OCT) features of acute and long-standing retinal artery occlusions.Design: Retrospective case series.Participants: Patients with acute and chronic retinal and cilioretinal artery occlus...

  14. Adaptive Optics Technology for High-Resolution Retinal Imaging

    Science.gov (United States)

    Lombardo, Marco; Serrao, Sebastiano; Devaney, Nicholas; Parravano, Mariacristina; Lombardo, Giuseppe

    2013-01-01

    Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of optical aberrations. The direct visualization of the photoreceptor cells, capillaries and nerve fiber bundles represents the major benefit of adding AO to retinal imaging. Adaptive optics is opening a new frontier for clinical research in ophthalmology, providing new information on the early pathological changes of the retinal microstructures in various retinal diseases. We have reviewed AO technology for retinal imaging, providing information on the core components of an AO retinal camera. The most commonly used wavefront sensing and correcting elements are discussed. Furthermore, we discuss current applications of AO imaging to a population of healthy adults and to the most frequent causes of blindness, including diabetic retinopathy, age-related macular degeneration and glaucoma. We conclude our work with a discussion on future clinical prospects for AO retinal imaging. PMID:23271600

  15. HDR Image Quality Enhancement Based on Spatially Variant Retinal Response

    Directory of Open Access Journals (Sweden)

    Horiuchi Takahiko

    2010-01-01

    Full Text Available There is a growing demand for being able to display high dynamic range (HDR images on low dynamic range (LDR devices. Tone mapping is a process for enhancing HDR image quality on an LDR device by converting the tonal values of the original image from HDR to LDR. This paper proposes a new tone mapping algorithm for enhancing image quality by deriving a spatially-variant operator for imitating S-potential response in human retina, which efficiently improves local contrasts while conserving good global appearance. The proposed tone mapping operator is studied from a system construction point of view. It is found that the operator is regarded as a natural extension of the Retinex algorithm by adding a global adaptation process to the local adaptation. The feasibility of the proposed algorithm is examined in detail on experiments using standard HDR images and real HDR scene images, comparing with conventional tone mapping algorithms.

  16. High-speed adaptive optics line scan confocal retinal imaging for human eye.

    Science.gov (United States)

    Lu, Jing; Gu, Boyu; Wang, Xiaolin; Zhang, Yuhua

    2017-01-01

    Continuous and rapid eye movement causes significant intraframe distortion in adaptive optics high resolution retinal imaging. To minimize this artifact, we developed a high speed adaptive optics line scan confocal retinal imaging system. A high speed line camera was employed to acquire retinal image and custom adaptive optics was developed to compensate the wave aberration of the human eye's optics. The spatial resolution and signal to noise ratio were assessed in model eye and in living human eye. The improvement of imaging fidelity was estimated by reduction of intra-frame distortion of retinal images acquired in the living human eyes with frame rates at 30 frames/second (FPS), 100 FPS, and 200 FPS. The device produced retinal image with cellular level resolution at 200 FPS with a digitization of 512×512 pixels/frame in the living human eye. Cone photoreceptors in the central fovea and rod photoreceptors near the fovea were resolved in three human subjects in normal chorioretinal health. Compared with retinal images acquired at 30 FPS, the intra-frame distortion in images taken at 200 FPS was reduced by 50.9% to 79.7%. We demonstrated the feasibility of acquiring high resolution retinal images in the living human eye at a speed that minimizes retinal motion artifact. This device may facilitate research involving subjects with nystagmus or unsteady fixation due to central vision loss.

  17. [Clinical Characteristics of Rhegmatogenous Retinal Detachment in Highly Myopic and Phakic Eyes].

    Science.gov (United States)

    Orihara, Tadashi; Hirota, Kazunari; Yokota, Reiji; Kunita, Daisuke; Itoh, Yuji; Rii, Tosho; Koto, Takashi; Hiraoka, Tomoyuki; Inoue, Makoto; Hirakata, Akito

    2016-05-01

    To evaluate clinical characteristics of rhegmatogenous retinal detachment in high myopic and phakic eyes. The subjects were 1174 eyes of phakic rhegmatogenous retinal detachment detected in 1199 eyes that underwent initial vitreoretinal surgery between April 2006 and March 2011. Eyes with macular hole retinal detachment or secondary retinal detachment were excluded. The 486 eyes with high myopia (spherical equivalent ≤ -6.0 D or axial length ≥ 26.5 mm) and the 688 eyes with non-high myopia were compared. The mean age was significantly younger in the high myopia group (42.7 ± 14.2 years old, p lattice degeneration were more frequent (16.7%, 20.4%, respectively). The incidences of the retinal detachment in younger age and those caused by retinal holes were higher in the high myopia group. Higher incidence of retinal detachment and lattice degeneration in the fellow eyes of the high myopia group indicated that careful observation also in the fellow eyes was recommended.

  18. E2f1 mediates high glucose-induced neuronal death in cultured mouse retinal explants.

    Science.gov (United States)

    Wang, Yujiao; Zhou, Yi; Xiao, Lirong; Zheng, Shijie; Yan, Naihong; Chen, Danian

    2017-10-02

    Diabetic retinopathy (DR) is the most common complication of diabetes and remains one of the major causes of blindness in the world; infants born to diabetic mothers have higher risk of developing retinopathy of prematurity (ROP). While hyperglycemia is a major risk factor, the molecular and cellular mechanisms underlying DR and diabetic ROP are poorly understood. To explore the consequences of retinal cells under high glucose, we cultured wild type or E2f1 -/- mouse retinal explants from postnatal day 8 with normal glucose, high osmotic or high glucose media. Explants were also incubated with cobalt chloride (CoCl 2 ) to mimic the hypoxic condition. We showed that, at 7 days post exposure to high glucose, retinal explants displayed elevated cell death, ectopic cell division and intact retinal vascular plexus. Cell death mainly occurred in excitatory neurons, such as ganglion and bipolar cells, which were also ectopically dividing. Many Müller glial cells reentered the cell cycle; some had irregular morphology or migrated to other layers. High glucose inhibited the hyperoxia-induced blood vessel regression of retinal explants. Moreover, inactivation of E2f1 rescued high glucose-induced ectopic division and cell death of retinal neurons, but not ectopic cell division of Müller glial cells and vascular phenotypes. This suggests that high glucose has direct but distinct effects on retinal neurons, glial cells and blood vessels, and that E2f1 mediates its effects on retinal neurons. These findings shed new light onto mechanisms of DR and the fetal retinal abnormalities associated with maternal diabetes, and suggest possible new therapeutic strategies.

  19. Design of a high-resolution optoelectronic retinal prosthesis.

    Science.gov (United States)

    Palanker, Daniel; Vankov, Alexander; Huie, Phil; Baccus, Stephen

    2005-03-01

    It has been demonstrated that electrical stimulation of the retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. However, current retinal implants provide very low resolution (just a few electrodes), whereas at least several thousand pixels would be required for functional restoration of sight. This paper presents the design of an optoelectronic retinal prosthetic system with a stimulating pixel density of up to 2500 pix mm(-2) (corresponding geometrically to a maximum visual acuity of 20/80). Requirements on proximity of neural cells to the stimulation electrodes are described as a function of the desired resolution. Two basic geometries of sub-retinal implants providing required proximity are presented: perforated membranes and protruding electrode arrays. To provide for natural eye scanning of the scene, rather than scanning with a head-mounted camera, the system operates similar to 'virtual reality' devices. An image from a video camera is projected by a goggle-mounted collimated infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. The goggles are transparent to visible light, thus allowing for the simultaneous use of remaining natural vision along with prosthetic stimulation. Optical delivery of visual information to the implant allows for real-time image processing adjustable to retinal architecture, as well as flexible control of image processing algorithms and stimulation parameters.

  20. Design of a high-resolution optoelectronic retinal prosthesis

    Science.gov (United States)

    Palanker, Daniel; Vankov, Alexander; Huie, Phil; Baccus, Stephen

    2005-03-01

    It has been demonstrated that electrical stimulation of the retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. However, current retinal implants provide very low resolution (just a few electrodes), whereas at least several thousand pixels would be required for functional restoration of sight. This paper presents the design of an optoelectronic retinal prosthetic system with a stimulating pixel density of up to 2500 pix mm-2 (corresponding geometrically to a maximum visual acuity of 20/80). Requirements on proximity of neural cells to the stimulation electrodes are described as a function of the desired resolution. Two basic geometries of sub-retinal implants providing required proximity are presented: perforated membranes and protruding electrode arrays. To provide for natural eye scanning of the scene, rather than scanning with a head-mounted camera, the system operates similar to 'virtual reality' devices. An image from a video camera is projected by a goggle-mounted collimated infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. The goggles are transparent to visible light, thus allowing for the simultaneous use of remaining natural vision along with prosthetic stimulation. Optical delivery of visual information to the implant allows for real-time image processing adjustable to retinal architecture, as well as flexible control of image processing algorithms and stimulation parameters.

  1. PERIPHERAL RETINAL FINDINGS IN HIGHLY MYOPIC CHILDREN ≤10 YEARS OF AGE

    Science.gov (United States)

    Bansal, Alok S.; Hubbard, G. Baker

    2011-01-01

    Purpose The purpose of this study was to characterize the peripheral retinal findings in highly myopic young children without other known risk factors for retinal detachment. Methods A retrospective review of all cases of children ≤10 years of age with high myopia (>6.00 diopters) who were evaluated for presumed risk of retinal detachment by either an examination under anesthesia or office examination by a single retina specialist from January 2001 through December 2008. Patients with regressed retinopathy of pre-maturity, retinal detachment in the fellow eye, or known Stickler syndrome were excluded. Results Fifty-four eyes of 30 patients with high myopia were examined. Twenty-six eyes of 14 patients were examined under anesthesia because of the examiner’s inability to adequately visualize the peripheral retina during an office examination. Mean age at examination was 6 ± 3 (range, 1–10) years. Mean spherical equivalent refractive error was −13.88 ± 3.79 (range, −6.00 to −25.00) diopters. Peripheral retinal findings were identified in 33% of eyes, the most common being lattice degeneration (20%), white without pressure (11%), and retinal holes with subretinal fluid (4%). Conclusion Approximately one third of highly myopic children in our study showed peripheral retinal findings. If the peripheral retina is not adequately visualized during an office evaluation, examination under anesthesia should be considered. PMID:20224463

  2. Multi-frame super-resolution with quality self-assessment for retinal fundus videos.

    Science.gov (United States)

    Köhler, Thomas; Brost, Alexander; Mogalle, Katja; Zhang, Qianyi; Köhler, Christiane; Michelson, Georg; Hornegger, Joachim; Tornow, Ralf P

    2014-01-01

    This paper proposes a novel super-resolution framework to reconstruct high-resolution fundus images from multiple low-resolution video frames in retinal fundus imaging. Natural eye movements during an examination are used as a cue for super-resolution in a robust maximum a-posteriori scheme. In order to compensate heterogeneous illumination on the fundus, we integrate retrospective illumination correction for photometric registration to the underlying imaging model. Our method utilizes quality self-assessment to provide objective quality scores for reconstructed images as well as to select regularization parameters automatically. In our evaluation on real data acquired from six human subjects with a low-cost video camera, the proposed method achieved considerable enhancements of low-resolution frames and improved noise and sharpness characteristics by 74%. In terms of image analysis, we demonstrate the importance of our method for the improvement of automatic blood vessel segmentation as an example application, where the sensitivity was increased by 13% using super-resolution reconstruction.

  3. Ex vivo electroporation of retinal cells: a novel, high efficiency method for functional studies in primary retinal cultures.

    Science.gov (United States)

    Vergara, M Natalia; Gutierrez, Christian; O'Brien, David R; Canto-Soler, M Valeria

    2013-04-01

    Primary retinal cultures constitute valuable tools not only for basic research on retinal cell development and physiology, but also for the identification of factors or drugs that promote cell survival and differentiation. In order to take full advantage of the benefits of this system it is imperative to develop efficient and reliable techniques for the manipulation of gene expression. However, achieving appropriate transfection efficiencies in these cultures has remained challenging. The purpose of this work was to develop and optimize a technique that would allow the transfection of chick retinal cells with high efficiency and reproducibility for multiple applications. We developed an ex vivo electroporation method applied to dissociated retinal cell cultures that offers a significant improvement over other currently available transfection techniques, increasing efficiency by five-fold. In this method, eyes were enucleated, devoid of RPE, and electroporated with GFP-encoding plasmids using custom-made electrodes. Electroporated retinas were then dissociated into single cells and plated in low density conditions, to be analyzed after 4 days of incubation. Parameters such as voltage and number of electric pulses, as well as plasmid concentration and developmental stage of the animal were optimized for efficiency. The characteristics of the cultures were assessed by morphology and immunocytochemistry, and cell viability was determined by ethidium homodimer staining. Cell imaging and counting was performed using an automated high-throughput system. This procedure resulted in transfection efficiencies in the order of 22-25% of cultured cells, encompassing both photoreceptors and non-photoreceptor neurons, and without affecting normal cell survival and differentiation. Finally, the feasibility of the technique for cell-autonomous studies of gene function in a biologically relevant context was tested by carrying out gain and loss-of-function experiments for the

  4. Quality assurance in diabetic retinal screening in South Africa | Cook ...

    African Journals Online (AJOL)

    ... external quality assurance (EQA) on graders registered in the Ophthalmological Society of South Africa DR screening programme. Methods. Graders registered on the South African (SA) Diabetic Register website were invited to participate in the study. The Scottish EQA software system was used to enable on-line grading ...

  5. Quality control for retinal OCT in multiple sclerosis

    DEFF Research Database (Denmark)

    Schippling, S; Balk, Lj; Costello, F

    2015-01-01

    to provide guidance on the use of validated quality control (QC) criteria for the use of OCT in MS research and clinical trials. METHODS: A prospective multi-centre (n = 13) study. Peripapillary ring scan QC rating of an OCT training set (n = 50) was followed by a test set (n = 50). Inter-rater agreement...

  6. Quality assessment of cataract surgery in Denmark - risk of retinal detachment and postoperative endophthalmitis

    DEFF Research Database (Denmark)

    Bjerrum, Søren Solborg

    2015-01-01

    The main purpose of this thesis was to examine whether the Danish National Patient Registry (NPR) could be used to monitor and assess the quality of cataract surgery in Denmark by studying the risks of two serious postoperative complications following cataract surgery - retinal detachment (RD......) and postoperative endophthalmitis (PE). The thesis consists of four retrospective studies. In the first study (paper I), we used data from the NPR in the calendar period 2000-2010 to investigate the risk of pseudophakic retinal detachment (PRD) using the fellow non-operated eyes of the patients as reference....... The study showed that over a 10-year study period, the risk of PRD was increased by a factor of 4.2 irrespective of sex and age. The risk of PRD was highest in the first part of the postoperative period and then gradually decreased but remained statistically significantly higher than the risk of RD in non...

  7. Early rhegmatogenous retinal detachment following laser in situ keratomileusis for high myopia.

    Science.gov (United States)

    Farah, M E; Höfling-Lima, A L; Nascimento, E

    2000-01-01

    Four eyes had early rhegmatogenous retinal detachment within 3 months of laser in situ keratomileusis (LASIK) for correction of high myopia using the microkeratome, Clear Corneal Molder. In two eyes, retinal detachment resulted from horseshoe tears, one occurring in an otherwise normal region of the retina and the other at the margin of an area of lattice degeneration detected during preoperative examination. The first eye was treated with retinopexy using a 287 encircling scleral exoplant, drainage of subretinal fluid, and laser photocoagulation by indirect ophthalmoscopy. The other eye was treated with pneumatic retinopexy and cryotherapy. In the other eyes, retinal detachment was the result of giant tears with no evidence of prior retinal degeneration. These eyes were treated with pars plana vitrectomy, fluid-gas exchange with 15% perfluoropropane (C3F8), endolaser photocoagulation, and a 42 encircling scleral exoplant. After treatment, the first two eyes achieved spectacle-corrected visual acuity of 20/40. In the last two eyes, final spectacle-corrected visual acuity was 20/400 in one eye and light perception in the other. Although no cause-effect relationship between LASIK and retinal detachment can be stated, these cases suggest that LASIK may be associated with retinal detachment, particularly in highly myopic eyes. Further studies are necessary to determine high-risk patient characteristics.

  8. A case of atypical progressive outer retinal necrosis after highly active antiretroviral therapy.

    Science.gov (United States)

    Woo, Se Joon; Yu, Hyeong Gon; Chung, Hum

    2004-06-01

    This is a report of an atypical case of progressive outer retinal necrosis (PORN) and the effect of highly active antiretroviral therapy (HAART) on the clinical course of viral retinitis in an acquired immunodeficiency syndrome (AIDS) patient. A 22-year-old male patient infected with human immunodeficiency virus (HIV) presented with unilaterally reduced visual acuity and a dense cataract. After cataract extraction, retinal lesions involving the peripheral and macular areas were found with perivascular sparing and the mud-cracked, characteristic appearance of PORN. He was diagnosed as having PORN based on clinical features and was given combined antiviral treatment. With concurrent HAART, the retinal lesions regressed, with the regression being accelerated by further treatment with intravenous acyclovir and ganciclovir. This case suggests that HAART may change the clinical course of PORN in AIDS patients by improving host immunity. PORN should be included in the differential diagnosis of acute unilateral cataract in AIDS patients.

  9. Autofluorescence and high-definition optical coherence tomography of retinal artery occlusions

    Directory of Open Access Journals (Sweden)

    Raeba Mathew

    2010-10-01

    Full Text Available Raeba Mathew, Evangelia Papavasileiou, Sobha SivaprasadLaser and Retinal Research Unit, Department of Ophthalmology, King’s College Hospital, Denmark Hill, London, UKBackground: The purpose of this study is to illustrate the fundus autofluorescence and high-definition optical coherence tomography (HD-OCT features of acute and long-standing retinal artery occlusions.Design: Retrospective case series.Participants: Patients with acute and chronic retinal and cilioretinal artery occlusions are included in this series.Methods: A detailed clinical examination, color fundus photographs, autofluorescence, and HD-OCT of the subjects were performed.Results: HD-OCT demonstrates the localized and well-demarcated thickening of the inner retina in the acute phase of arterial occlusions that correlates with the areas of blocked autofluorescence caused by the cloudy swelling of the retina. The areas of blocked autofluorescence disappear with chronicity of the disease and this corresponds to the thinning of the inner retinal layers on HD-OCT.Conclusion: Heidelberg OCT and autofluorescence are useful tools to assess retinal arterial occlusions especially in subjects with unexplained visual field loss.Keywords: autofluorescence, high definition OCT, retinal artery occlusion

  10. 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.

  11. Rapid Onset of Retinal Toxicity From High-Dose Hydroxychloroquine Given for Cancer Therapy.

    Science.gov (United States)

    Leung, Loh-Shan B; Neal, Joel W; Wakelee, Heather A; Sequist, Lecia V; Marmor, Michael F

    2015-10-01

    To report rapid onset of retinal toxicity in a series of patients followed on high-dose (1000 mg daily) hydroxychloroquine during an oncologic clinical trial studying hydroxychloroquine with erlotinib for non-small cell lung cancer. Retrospective observational case series. Ophthalmic surveillance was performed on patients in a multicenter clinical trial testing high-dose (1000 mg daily) hydroxychloroquine for advanced non-small cell lung cancer. The US Food & Drug Administration-recommended screening protocol included only visual acuity testing, dilated fundus examination, Amsler grid testing, and color vision testing. In patients seen at Stanford, additional sensitive screening procedures were added at the discretion of the retinal physician: high-resolution spectral-domain optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, Humphrey visual field (HVF) testing, and multifocal electroretinography (mfERG). Out of the 7 patients having exposure of at least 6 months, 2 developed retinal toxicity (at 11 and 17 months of exposure). Damage was identified by OCT imaging, mfERG testing, and, in 1 case, visual field testing. Fundus autofluorescence imaging remained normal. Neither patient had symptomatic visual acuity loss. These cases show that high doses of hydroxychloroquine can initiate the development of retinal toxicity within 1-2 years. Although synergy with erlotinib is theoretically possible, there are no prior reports of erlotinib-associated retinal toxicity despite over a decade of use in oncology. These results also suggest that sensitive retinal screening tests should be added to ongoing and future clinical trials involving high-dose hydroxychloroquine to improve safety monitoring and preservation of vision. Published by Elsevier Inc.

  12. Image quality of the cat eye measured during retinal ganglion cell experiments.

    Science.gov (United States)

    Bonds, A B; Enroth-Cugell, C; Pinto, L H

    1972-01-01

    1. The modulation transfer function (MTF) of the dioptrics of fifteen cat eyes was determined. The aerial image, formed by the eye of a standard object (a 0.5-1.0 degrees annulus), was photographed. The transmission of the film negative was measured with a scanning microdensitometer to yield the light distribution within the aerial image. Correcting for the double passage, this experimentally determined light distribution and the known object light distribution were used to obtain the MTF, applying Fourier methods. Each MTF was used to calculate the light distribution within the retinal image of stimuli of various geometry used in experiments on retinal ganglion cells in the same eye.2. When the eye was equipped with an artificial pupil of the same size as that used in the neurophysiological experiments (4.0-4.8 mm diam.) the MTF had fallen to 0.5 at 2.43 c/deg. When the pupil was removed the MTF had fallen to 0.5 at a much lower spatial frequency (1.0 c/deg). This shows that even when one uses an artificial pupil too large to provide optimal image quality there is a vast improvement over using no pupil.3. These image quality measurements were prompted by the need to know the actual stimulus image in experiments on the functional organization of the receptive field, a need exemplified in this paper by a few specific physiological results. The full neurophysiological results appear in the next two papers.

  13. New approach to modulate retinal cellular toxic effects of high glucose using marine epa and dha

    Directory of Open Access Journals (Sweden)

    Fagon Roxane

    2011-06-01

    Full Text Available Abstract Background Protective effects of omega-3 fatty acids against cellular damages of high glucose were studied on retinal pigmented epithelial (RPE cells. Methods Retinal epithelial cells were incubated with omega-3 marine oils rich in EPA and DHA and then with high glucose (25 mM for 48 hours. Cellular responses were compared to normal glucose (5 mM: intracellular redox status, reactive oxygen species (ROS, mitochondrial succinate deshydrogenase activity, inflammatory cytokines release and caveolin-1 expression were evaluated using microplate cytometry, ELISA and flow cytometry techniques. Fatty acids incorporation in retinal cell membranes was analysed using chromatography. Results Preincubation of the cells with fish oil decreased ROS overproduction, mitochondrial alterations and TNFα release. These protective effects could be attributed to an increase in caveolin-1 expression induced by marine oil. Conclusion Marine formulations rich in omega-3 fatty acids represent a promising therapeutic approach for diabetic retinopathy.

  14. Reoperation for rhegmatogenous retinal detachment as quality indicator for disease management:

    DEFF Research Database (Denmark)

    Hajari, Javad N; Christensen, Ulrik; Kiilgaard, Jens Folke

    2015-01-01

    PURPOSE: To establish a quality indicator that could be used in optimizing treatment for rhegmatogenous retinal detachment (RRD). METHODS: The Danish National Patient Registry was used to identify surgery conducted in Denmark for RRD in the period 01 January 2001-31 December 2009. Cases were...... identified by diagnosis and surgical codes. RESULTS: A total of 6522 cases were operated for a primary RRD in the study period, and 22% (1434 patients) were reoperated for a redetachment. A Cox regression analysis showed that the risk of redetachment was equal to or less than detachment on the fellow eye 1...... year after primary surgery with techniques not using silicone oil. The same was true 1.5 years after surgery for techniques using silicone oil. Based on this, we established a quality indicator defining failure as the need for operation for redetachment within 1 year from initial surgery when using...

  15. Effect of doxycycline vs placebo on retinal function and diabetic retinopathy progression in patients with severe nonproliferative or non-high-risk proliferative diabetic retinopathy

    DEFF Research Database (Denmark)

    Scott, Ingrid U; Jackson, Gregory R; Quillen, David A

    2014-01-01

    IMPORTANCE: Inflammation may contribute to the pathogenesis of diabetic retinopathy (DR). OBJECTIVES: To investigate, in a proof-of-concept clinical trial, whether low-dose oral doxycycline monohydrate can (1) slow the deterioration of, or improve, retinal function or (2) induce regression or slow......: We conducted a randomized, double-masked, 24-month proof-of-concept clinical trial. Thirty patients (from hospital-based retina practices) with 1 or more eyes with severe NPDR or PDR less than Early Treatment Diabetic Retinopathy Study-defined high-risk PDR. INTERVENTIONS: Patients were randomized...... adaptation, visual acuity, and quality of life) and anatomic factors (Early Treatment Diabetic Retinopathy Study DR severity level, area of retinal thickening, central macular thickness, macular volume, and retinal vessel diameters). RESULTS: From baseline to month 24, mean FDP foveal sensitivity decreased...

  16. Prevalence and characteristics of peripheral retinal degeneration in Chinese adults with high myopia: a cross-sectional prevalence survey.

    Science.gov (United States)

    Lam, Dennis S C; Fan, Dorothy S P; Chan, Wai-Man; Tam, Barbara S M; Kwok, Alvin K H; Leung, Alfred T S; Parsons, Hugh

    2005-04-01

    The purpose of this study was to study the prevalence of peripheral retinal findings in adult Chinese patients with high myopia (refraction degeneration (51.2%), followed by lattice degeneration in 12.2% and retinal holes in 7.5% of eyes. A positive correlation was noted between axial length and the lesions of pigmentary degeneration and pavingstone degeneration. The prevalence of retinal holes was 6.4% and 30.0% in eyes with axial length of or = 30 mm, respectively (chi-squared test, p = 0.006). A high prevalence of peripheral retinal degenerations was found in adult Chinese high myopes. The presence of retinal holes was positively correlated with very high myopia of an axial length of > or = 30 mm.

  17. Retinal peripheral changes after laser in situ keratomileusis in patients with high myopia.

    Science.gov (United States)

    Suzuki, Cássia R; Farah, Michel E

    2004-02-01

    Retinal detachment has been reported after laser in situ keratomileusis (LASIK) in myopic eyes. This complication may be related to the risk from myopia before surgery or may be induced by LASIK surgery itself. We performed a study to evaluate retinal peripheral changes after LASIK in patients with high myopia and to correlate symptoms on presentation and vitreoretinal anatomic changes. The study was carried out at a university-affiliated hospital in São Paulo between November 1997 and February 1999. Patients scheduled to undergo LASIK were included if their spherical equivalent was greater than 6.00 dioptres. The exclusion criteria were previous retinal treatment and myopic macular degenerations. We performed binocular indirect ophthalmoscopy with scleral indentation and fundus biomicroscopy with Goldmann lens before LASIK and 1, 3 and 6 months after surgery. We examined 198 eyes preoperatively. Of the 198, 50 did not undergo LASIK surgery owing to refractive criteria, and 79 were lost to follow-up. We thus studied 69 eyes. The mean spherical equivalent preoperatively was -8.00 D (standard deviation 1.95 D). Twenty-four eyes had normal retinal periphery preoperatively; all 24 remained without alterations after LASIK. Forty-five eyes had peripheral alterations: 17 (24.6%) had cystic degeneration, 14 (20.3%) had lattice degeneration, 11 (15.9%) had white-without-pressure, 5 (7.2%) had cystic tufts, 3 (4.3%) had pavingstone degeneration, 2 (2.9%) had pigmentary alteration, 1 (1.4%) had holes with free operculum, and 1 (1.4%) had punctiform holes. The only alteration after surgery was almost punctiform holes around the previous cystic tuft 1 month after surgery in one patient. Retinal detachment did not develop in any of the eyes. In this group of patients it appears that LASIK did not lead to progressive peripheral retinal lesions in asymptomatic patients during the period studied.

  18. Impact of Retinitis Pigmentosa on Quality of Life, Mental Health, and Employment Among Young Adults.

    Science.gov (United States)

    Chaumet-Riffaud, Anne Elisabeth; Chaumet-Riffaud, Philippe; Cariou, Anaelle; Devisme, Céline; Audo, Isabelle; Sahel, José-Alain; Mohand-Said, Saddek

    2017-05-01

    To determine the relationship between visual function and quality of life, education, mental health, and employment among young adults with retinitis pigmentosa (RP). Cross-sectional study. Inclusion of 148 patients (mean age 38.2 ± 7.1 years) diagnosed with RP, living in France. Quality of life was assessed using the National Eye Institute Visual Function Questionnaire (VFQ-25), mental state with the Hospital and Anxiety and Depression Scale (HADS), and employment with a specifically designed questionnaire. Limited visual impairment was noted in 22.3%, low vision in 29.7%, and legal blindness in 48.0%. There was a correlation between quality-of-life scores and residual visual field (P employment rate did not significantly decrease with disability level (P = .276). It was lower in subjects reporting depression (P = .0414). Self-rated impact of RP on employment increased with disability level (P = .02642). Our results differ from previous results showing lower education rates and employment rates in young adults with RP. Further research is warranted focusing on the impact of mental health, education, workplace conditions, and employment aids on employment rate vs age- and education-matched normally sighted controls to guide visual disability strategies in RP. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. The relationship between the retinal image quality and the refractive index of defects arising in IOL: numerical analysis

    Science.gov (United States)

    Geniusz, Malwina

    2017-09-01

    The best treatment for cataract patients, which allows to restore clear vision is implanting an artificial intraocular lens (IOL). The image quality of the lens has a significant impact on the quality of patient's vision. After a long exposure the implant to aqueous environment some defects appear in the artificial lenses. The defects generated in the IOL have different refractive indices. For example, glistening phenomenon is based on light scattering on the oval microvacuoles filled with an aqueous humor which refractive index value is about 1.34. Calcium deposits are another example of lens defects and they can be characterized by the refractive index 1.63. In the presented studies it was calculated how the difference between the refractive indices of the defect and the refractive index of the lens material affects the quality of image. The OpticStudio Professional program (from Radiant Zemax, LLC) was used for the construction of the numerical model of the eye with IOL and to calculate the characteristics of the retinal image. Retinal image quality was described in such characteristics as Point Spread Function (PSF) and the Optical Transfer Function with amplitude and phase. The results show a strong correlation between the refractive indices difference and retinal image quality.

  20. Krypton yellow laser for the treatment of macular hole in high myopia without retinal detachment.

    Science.gov (United States)

    Cai, Ji-Ping; Cheng, Jin-Wei; Ma, Xiao-Ye; Li, Yu-Zhen; Li, You; Wei, Rui-Li

    2008-12-01

    To evaluate the prophylactic effect of krypton yellow laser for the treatment of macular holes in high myopic eyes in order to reduce the risk of retinal detachment. Twenty-seven eyes of 27 patients with high myopia and macular holes were randomly assigned to two groups. Fifteen patients (group A, 15 eyes) were subject to laser photocoagulation around the hole margin along with an oral placebo (vitamin B1), while 12 patients (group B, 12 eyes) were only given the oral placebo (vitamin B1). The incident rate of retinal detachment due to macular hole and the mean best-corrected visual acuity of the two groups before and after treatment were measured. The data were statistically tested by X2 test and Student's t test. The incident rates of retina1 detachment in group A and group B were 20%(3/15) and 58.3%(7/12), respectively (X2=4.201, P0.05). The mean BCVA of group B on the initial examination was 24/200, while the mean BCVA at the final follow-up was 30/200 (P>0.05). No significant difference in initial visual acuity (P>0.05) or final visual acuity (P>0.05) was found between the two groups. Krypton yellow laser photocoagulation could reduce the incidence of retinal detachment due to a macular hole in high myopia with acceptable functional results in this study.

  1. Genetic high throughput screening in Retinitis Pigmentosa based on high resolution melting (HRM) analysis.

    Science.gov (United States)

    Anasagasti, Ander; Barandika, Olatz; Irigoyen, Cristina; Benitez, Bruno A; Cooper, Breanna; Cruchaga, Carlos; López de Munain, Adolfo; Ruiz-Ederra, Javier

    2013-11-01

    Retinitis Pigmentosa (RP) involves a group of genetically determined retinal diseases caused by a large number of mutations that result in rod photoreceptor cell death followed by gradual death of cone cells. Most cases of RP are monogenic, with more than 80 associated genes identified so far. The high number of genes and variants involved in RP, among other factors, is making the molecular characterization of RP a real challenge for many patients. Although HRM has been used for the analysis of isolated variants or single RP genes, as far as we are concerned, this is the first study that uses HRM analysis for a high-throughput screening of several RP genes. Our main goal was to test the suitability of HRM analysis as a genetic screening technique in RP, and to compare its performance with two of the most widely used NGS platforms, Illumina and PGM-Ion Torrent technologies. RP patients (n = 96) were clinically diagnosed at the Ophthalmology Department of Donostia University Hospital, Spain. We analyzed a total of 16 RP genes that meet the following inclusion criteria: 1) size: genes with transcripts of less than 4 kb; 2) number of exons: genes with up to 22 exons; and 3) prevalence: genes reported to account for, at least, 0.4% of total RP cases worldwide. For comparison purposes, RHO gene was also sequenced with Illumina (GAII; Illumina), Ion semiconductor technologies (PGM; Life Technologies) and Sanger sequencing (ABI 3130xl platform; Applied Biosystems). Detected variants were confirmed in all cases by Sanger sequencing and tested for co-segregation in the family of affected probands. We identified a total of 65 genetic variants, 15 of which (23%) were novel, in 49 out of 96 patients. Among them, 14 (4 novel) are probable disease-causing genetic variants in 7 RP genes, affecting 15 patients. Our HRM analysis-based study, proved to be a cost-effective and rapid method that provides an accurate identification of genetic RP variants. This approach is effective for

  2. High-resolution retinal imaging using adaptive optics and Fourier-domain optical coherence tomography

    Science.gov (United States)

    Olivier, Scot S.; Werner, John S.; Zawadzki, Robert J.; Laut, Sophie P.; Jones, Steven M.

    2010-09-07

    This invention permits retinal images to be acquired at high speed and with unprecedented resolution in three dimensions (4.times.4.times.6 .mu.m). The instrument achieves high lateral resolution by using adaptive optics to correct optical aberrations of the human eye in real time. High axial resolution and high speed are made possible by the use of Fourier-domain optical coherence tomography. Using this system, we have demonstrated the ability to image microscopic blood vessels and the cone photoreceptor mosaic.

  3. Four corneal presbyopia corrections: simulations of optical consequences on retinal image quality.

    Science.gov (United States)

    Koller, Tobias; Seiler, Theo

    2006-12-01

    To investigate the possibility of multifocal or aspherical treatment of the cornea with optical ray tracing. Institute for Refractive and Ophthalmic Surgery, Zurich, Switzerland. The optical consequences of 4 corneal shapes-global optimum (GO) for curvature and asphericity, central steep island (CSI), decentered steep island (DSI), and centered steep annulus (CSA)-for presbyopia correction were analyzed using a modified Liou-Brennan eye model and ray tracing with a commercial optic design software (Zemax, Zemax Development Corp.). The ocular optical configuration for far vision was a point light source at a distance of 5 m, 1 degree up, and a pupil diameter of 5.0 mm and for near vision, 0.4 m distance, 1 degree up, and a pupil diameter of 2.5 mm. The curvature radius (R) of the cornea and its asphericity (Q) were used as operands to optimize (simultaneously for near and far vision) the quality of the retinal image described by means of the minimum spot diameter or the root-mean-square (RMS) wavefront error. Starting from an emmetropic eye optimized for R and Q, the RMS wavefront error in the retina was 0.07 microm (far) and 1.42 microm (near). The GO resulted in a wavefront error of 1.42 microm (far) and 0.52 microm (near); improvement of near vision using reading glasses is possible. The CSI yielded 0.91 microm (far) and 0.13 microm (near); spectacles did not improve far or near vision. The DSI and CSA had significantly worse results for near and far vision. Of the options studied, GO and CSI seemed the most promising alternatives for corneal presbyopia correction. Although reading glasses can improve near vision in GO, reading glasses did not improve near vision in CSI-treated eyes. The CSI treatment is critically dependent on centration and a reverse treatment is difficult to achieve.

  4. Downregulation of Lysyl Oxidase Protects Retinal Endothelial Cells From High Glucose-Induced Apoptosis.

    Science.gov (United States)

    Kim, Dongjoon; Mecham, Robert P; Trackman, Philip C; Roy, Sayon

    2017-05-01

    To investigate the effect of reducing high glucose (HG)-induced lysyl oxidase (LOX) overexpression and increased activity on retinal endothelial cell apoptosis. Rat retinal endothelial cells (RRECs) were grown in normal (N) or HG (30 mM glucose) medium for 7 days. In parallel, RRECs were grown in HG medium and transfected with LOX small interfering RNA (siRNA), scrambled siRNA as control, or exposed to β-aminopropionitrile (BAPN), a LOX inhibitor. LOX expression, AKT activation, and caspase-3 activity were determined by Western blot (WB) analysis and apoptosis by differential dye staining assay. Moreover, to determine whether diabetes-induced LOX overexpression alters AKT activation and promotes apoptosis, changes in LOX expression, AKT phosphorylation, caspase-3 activation, and Bax expression were assessed in retinas of streptozotocin (STZ)-induced diabetic mice and LOX heterozygous knockout (LOX+/-) mice. WB analysis indicated significant LOX overexpression and reduced AKT activation under HG condition in RRECs. Interestingly, when cells grown in HG were transfected with LOX siRNA or exposed to BAPN, the number of apoptotic cells was significantly decreased concomitant with increased AKT phosphorylation. Diabetic mouse retinas exhibited LOX overexpression, decreased AKT phosphorylation, and increased Bax and caspase-3 activation compared to values in nondiabetic mice. In LOX+/- mice, reduced LOX levels were observed with increased AKT activity, and reduced Bax and caspase-3 activity. Furthermore, decreased levels of LOX in the LOX+/- mice was protective against diabetes-induced apoptosis. Findings from this study indicate that preventing LOX overexpression may be protective against HG-induced apoptosis in retinal vascular cells associated with diabetic retinopathy.

  5. Histological Study on the Protective Effect of Simvastatin on the Retinal Changes Induced by High-Fat Diet in Mice

    Directory of Open Access Journals (Sweden)

    Fayza Ezz Ahmad

    2017-09-01

    Full Text Available Background: High-fat diet (HFD feeding is an important model to study the changes induced by insulin resistance, Type 2 diabetes mellitus and obesity including retinopathy. Vascular endothelial growth factor (VEGF and p53 have been implicated in the development of retinopathy. Objectives: The aim of his study was to analyze histological retinal changes in a high-fat atherogenic mouse model and to evaluate the possible protective effect of simvastatin on these changes including its effects on the expression of VEGF and p53. Materials and Methods: A total of 27 mice (6 weeks old were divided into 3 study groups according to their diet and treatment given; Group I - normal balanced diet-fed mice, Group II - HFD-fed mice, and Group III - HFD-fed mice treated with simvastatin daily for 30 weeks. All mice were followed up for 30 weeks. At the end of the study at 36 weeks of age, eye tissues were collected and retinal sections were examined using light microscopy. Comparison of the thickness of retinal layers in the three groups was carried out. The localization of VEGF in the retina was determined by immunohistochemical analysis, and apoptotic cell death was assessed using the p53. Results: In the HFD-fed mice, there was an increase in the retinal thickness associated with presence of wide intercellular spaces in the outer nuclear layer. Many cells in the inner nuclear layer showed cytoplasmic vacuolations. Expression of VEGF was significantly increased in the retinal ganglion cell layers and nuclear cell layers. Elevated p53 reaction was demonstrated within the inner retina. The histological changes were significantly improved in the simvastatin treated group. Conclusions: HFD-induced structural changes in the retinal layers and simultaneous upregulation of VEGF and p53. Administration of simvastatin improved these retinal alterations. [J Interdiscip Histopathol 2017; 5(3.000: 83-91

  6. Retinitis pigmentosa inversa with unilateral high myopia with fellow eye optic disc pitting.

    Science.gov (United States)

    Sheth, Saumil; Rush, Ryan; Narayanan, Raja

    2011-01-01

    To report a possible rare association of bilateral retinitis pigmentosa inversa (RPI) with unilateral high myopia with fellow eye optic disc pitting. A 55-year-old man with a history of reduced vision in the right eye since childhood presented with gradually decreasing vision in the left eye. On examination, a -23.00 diopter refractive error and diffuse chorioretinal atrophy consistent with pathologic myopia was found in the right eye. An optic disc pit with posterior pole pigmentary alterations thought to be consequent to a previous neurosensory detachment was found in the left eye. Though the retinal arteriolar attenuation seen in both eyes with an inconsistent history of night blindness since childhood pointed towards the possibility of a concurrently existing rod or rod-cone dystrophy, the posterior pole pigmentary alterations characteristic of RPI were clearly masked by the above pathologies. Optical coherence tomography demonstrated prominent foveal atrophy and an optic disc pit in the left eye. Electroretinography (ERG) demonstrated moderately attenuated amplitudes with prolonged implicit times of rod and cone responses bilaterally. The patient was diagnosed with bilateral RPI and anisometropic amblyopia in the right eye. This report documents a unique constellation of findings which include bilateral RPI and unilateral high myopia with an optic disc pit in the fellow eye. An ERG confirmation of a dystrophic etiology should be sought in suspicious cases, especially when findings are masked by the concurrent presence of other pathologies.

  7. A high dietary intake of sodium glutamate as flavoring (ajinomoto) causes gross changes in retinal morphology and function.

    Science.gov (United States)

    Ohguro, Hiroshi; Katsushima, Harumi; Maruyama, Ikuyo; Maeda, Tadao; Yanagihashi, Satsuki; Metoki, Tomomi; Nakazawa, Mitsuru

    2002-09-01

    The purpose of this study was to investigate the effects of glutamate accumulation in vitreous on retinal structure and function, due to a diet high in sodium glutamate. Three different diet groups were created, consisting of rats fed on a regular diet (diet A), a moderate excess of sodium glutamate diet (diet B) and a large excess of sodium glutamate diet (diet C). After 1, 3 and 6 months of the administration of these diets, amino acids concentrations in vitreous were analyzed. In addition, retinal morphology and function by electroretinogram (ERG) of three different diet groups were studied. Significant accumulation of glutamate in vitreous was observed in rats following addition of sodium glutamate to the diet as compared to levels with a regular diet. In the retinal morphology, thickness of retinal neuronal layers was remarkably thinner in rats fed on sodium glutamate diets than in those on a regular diet. TdT-dUTP terminal nick-end labelling (TUNEL) staining revealed significant accumulation of the positive staining cells within the retinal ganglion cell layers in retinas from diets B and C as compared with that from diet A. Similar to this, immunohistochemistry demonstrated increased expression of glial fibrillary acidic protein (GFAP) within the retinal inner layers from diets B and C as compared with diet A. Functionally, ERG responses were reduced in rats fed on a sodium glutamate diets as compared with those on a regular diet. The present study suggests that a diet with excess sodium glutamate over a period of several years may increase glutamate concentrations in vitreous and may cause retinal cell destruction.

  8. Retinal blood vessel segmentation in high resolution fundus photographs using automated feature parameter estimation

    Science.gov (United States)

    Orlando, José Ignacio; Fracchia, Marcos; del Río, Valeria; del Fresno, Mariana

    2017-11-01

    Several ophthalmological and systemic diseases are manifested through pathological changes in the properties and the distribution of the retinal blood vessels. The characterization of such alterations requires the segmentation of the vasculature, which is a tedious and time-consuming task that is infeasible to be performed manually. Numerous attempts have been made to propose automated methods for segmenting the retinal vasculature from fundus photographs, although their application in real clinical scenarios is usually limited by their ability to deal with images taken at different resolutions. This is likely due to the large number of parameters that have to be properly calibrated according to each image scale. In this paper we propose to apply a novel strategy for automated feature parameter estimation, combined with a vessel segmentation method based on fully connected conditional random fields. The estimation model is learned by linear regression from structural properties of the images and known optimal configurations, that were previously obtained for low resolution data sets. Our experiments in high resolution images show that this approach is able to estimate appropriate configurations that are suitable for performing the segmentation task without requiring to re-engineer parameters. Furthermore, our combined approach reported state of the art performance on the benchmark data set HRF, as measured in terms of the F1-score and the Matthews correlation coefficient.

  9. Spontaneous high frequency diameter oscillations of larger retinal arterioles are reduced in type 2 diabetes mellitus

    DEFF Research Database (Denmark)

    Bek, Toke; Jeppesen, Peter; Kanters, Jørgen K.

    2013-01-01

    Diabetic retinopathy is characterized by morphological changes in the retina secondary to disturbances in retinal blood flow. Vasomotion is a mechanism for regulating blood flow by spontaneous oscillations in the diameter of retinal resistance arterioles, and has been shown to be disturbed outside...... the eye in diabetic patients. Therefore, the purpose of the present study was to characterize spontaneous oscillations in the diameter of retinal arterioles in normal persons and in persons with different severity of diabetic retinopathy....

  10. Retinitis Pigmentosa.

    Science.gov (United States)

    Carr, Ronald E.

    1979-01-01

    The author describes the etiology of retinitis pigmentosa, a visual dysfunction which results from progressive loss of the retinal photoreceptors. Sections address signs and symptoms, ancillary findings, heredity, clinical diagnosis, therapy, and research. (SBH)

  11. Retinitis Pigmentosa

    Science.gov (United States)

    ... Linked Retinoschisis (XLRS) X-Linked Retinitis Pigmentosa (XLRP) Usher Syndrome Other Retinal Diseases Glossary News & Research News & Research ... degenerate. Forms of RP and related diseases include Usher syndrome, Leber congenital amaurosis, and Bardet-Biedl syndrome, among ...

  12. Retinal Diseases

    Science.gov (United States)

    ... Linked Retinoschisis (XLRS) X-Linked Retinitis Pigmentosa (XLRP) Usher Syndrome Other Retinal Diseases Glossary News & Research News & Research ... central portion of the retina called the macula. Usher Syndrome Usher syndrome is an inherited condition characterized by ...

  13. Extended depth of focus contact lenses vs. two commercial multifocals: Part 1. Optical performance evaluation via computed through-focus retinal image quality metrics

    Directory of Open Access Journals (Sweden)

    Ravi C. Bakaraju

    2018-01-01

    Conclusion: With the through focus retinal image quality as the gauge of optical performance, we demonstrated that the prototype EDOF designs were less susceptible to variations in pupil, inherent ocular aberrations and decentration, compared to the commercial designs. To ascertain whether these incremental improvements translate to a clinically palpable outcome requires investigation through human trials.

  14. Extended depth of focus contact lenses vs. two commercial multifocals: Part 1. Optical performance evaluation via computed through-focus retinal image quality metrics.

    Science.gov (United States)

    Bakaraju, Ravi C; Ehrmann, Klaus; Ho, Arthur

    To compare the computed optical performance of prototype lenses designed using deliberate manipulation of higher-order spherical aberrations to extend depth-of-focus (EDOF) with two commercial multifocals. Emmetropic, presbyopic, schematic eyes were coupled with prototype EDOF and commercial multifocal lenses (Acuvue Oasys for presbyopia, AOP, Johnson & Johnson & Air Optix Aqua multifocal, AOMF, Alcon). For each test configuration, the through-focus retinal image quality (TFRIQ) values were computed over 21 vergences, ranging from -0.50 to 2.00D, in 0.125D steps. Analysis was performed considering eyes with three different inherent aberration profiles: five different pupils and five different lens decentration levels. Except the LOW design, the AOP lenses offered 'bifocal' like TFRIQ performance. Lens performance was relatively independent to pupil and aberrations but not centration. Contrastingly, AOMF demonstrated distance centric performance, most dominant in LOW followed by MED and HIGH designs. AOMF lenses were the most sensitive to pupil, aberrations and centration. The prototypes demonstrated a 'lift-off' in the TFRIQ performance, particularly at intermediate and near, without trading performance at distance. When compared with AOP and AOMF, EDOF lenses demonstrated reduced sensitivity to pupil, aberrations and centration. With the through focus retinal image quality as the gauge of optical performance, we demonstrated that the prototype EDOF designs were less susceptible to variations in pupil, inherent ocular aberrations and decentration, compared to the commercial designs. To ascertain whether these incremental improvements translate to a clinically palpable outcome requires investigation through human trials. Copyright © 2017 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  15. Nonsyndromic retinitis pigmentosa is highly prevalent in the Jerusalem region with a high frequency of founder mutations.

    Science.gov (United States)

    Sharon, Dror; Banin, Eyal

    2015-01-01

    Nonsyndromic retinitis pigmentosa (RP) is the most common inherited retinal degeneration, and prevalence of the disease has been reported in populations of American and European origin with a relatively low consanguinity rate. Our aim was to determine the prevalence of nonsyndromic RP in the Jerusalem region, which has a population of about 1 million individuals with a high rate of consanguinity. The patients' clinical data included eye exam findings (visual acuity, anterior segment, and funduscopy) as well as electroretinographic (ERG) testing results under scotopic and photopic conditions. Mutation analysis on a subgroup of patients was performed mainly with candidate gene analysis and homozygosity mapping. We evaluated the medical records of patients with degenerative retinal diseases residing in the Jerusalem region who were examined over the past 20 years in a large tertiary medical center. A total of 453 individuals affected with nonsyndromic RP were diagnosed at our center, according to funduscopic findings and ERG testing. Based on the estimated population size of 945,000 individuals who reside in the vicinity of Jerusalem, the prevalence of nonsyndromic RP in this region is 1:2,086. The prevalence of RP was higher among Arab Muslims (1:1,798) compared to Jews (1:2,230), mainly due to consanguineous marriages that are more common in the Arab Muslim population. To identify the genetic causes of RP in our cohort, we recruited 383 patients from 183 different families for genetic analysis: 70 with autosomal recessive (AR) inheritance, 15 with autosomal dominant, 86 isolate cases, and 12 with an X-linked inheritance pattern. In 64 (35%) of the families, we identified the genetic cause of the disease, and we revised the inheritance pattern of 20 isolate cases to the AR pattern; 49% of the families in our cohort had AR inheritance. Interestingly, in 42 (66%) of the genetically identified families, the cause of disease was a founder mutation. Previous studies

  16. Retinal Prosthesis System for Advanced Retinitis Pigmentosa: A Health Technology Assessment

    Science.gov (United States)

    Lee, Christine; Tu, Hong Anh; Weir, Mark; Holubowich, Corinne

    2016-01-01

    -year. The 5-year budget impact of funding the Argus II system ranged from $800,404 to $837,596. Retinitis pigmentosa significantly affects people's ability to navigate physical and virtual environments. Argus II was described as enabling the fundamental elements of sight. As such, it had a positive impact on quality of life for people with retinitis pigmentosa. Conclusions Based on evidence of moderate quality, patients with advanced retinitis pigmentosa who were implanted with the Argus II retinal prosthesis system showed significant improvement in visual function, real-life functional outcomes, and quality of life, but there were complications associated with the surgery that could be managed through standard ophthalmologic treatments. The costs for the technology are high. PMID:27468325

  17. High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

    Energy Technology Data Exchange (ETDEWEB)

    Lengyel,I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

    2007-01-01

    One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD.

  18. High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

    International Nuclear Information System (INIS)

    Lengyel, I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

    2007-01-01

    One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD

  19. Retinal Vasculitis

    Science.gov (United States)

    Rosenbaum, James T.; Sibley, Cailin H.; Lin, Phoebe

    2016-01-01

    Purpose of review Ophthalmologists and rheumatologists frequently miscommunicate in consulting on patients with retinal vasculitis. This report seeks to establish a common understanding of the term, retinal vasculitis, and to review recent papers on this diagnosis. Recent findings 1) The genetic basis of some rare forms of retinal vascular disease have recently been described. Identified genes include CAPN5, TREX1, and TNFAIP3; 2) Behçet’s disease is a systemic illness that is very commonly associated with occlusive retinal vasculitis; 3) retinal imaging including fluorescein angiography and other newer imaging modalities has proven crucial to the identification and characterization of retinal vasculitis and its complications; 4) although monoclonal antibodies to IL-17A or IL-1 beta failed in trials for Behçet’s disease, antibodies to TNF alpha, either infliximab or adalimumab, have demonstrated consistent benefit in managing this disease. Interferon treatment and B cell depletion therapy via rituximab may be beneficial in certain types of retinal vasculitis. Summary Retinal vasculitis is an important entity for rheumatologists to understand. Retinal vasculitis associated with Behçet’s disease responds to monoclonal antibodies that neutralize TNF, but the many other forms of non-infectious retinal vasculitis may require alternate therapeutic management. PMID:26945335

  20. Expression and mechanism of high mobility group box protein-1 in retinal tissue of diabetic rats

    Directory of Open Access Journals (Sweden)

    Shuang Jiang

    2016-05-01

    Full Text Available AIM:To investigate the expression and mechanism of high mobility group box protein-1(HMGB1in the retina of diabetic rats. METHODS:Sixty SD rats were randomly divided into diabetic group and control group. Diabetic rat model was produced by intraperitioneal injection of 1% STZ with 60mg/Kg weight. The rats in control group received intraperitioneal injection of normal saline with same dosage. After injection, the rats were sacrificed and eyeballs were enucleated for HE staining, the retina fluorescence angiography, TUNEL and Western Blot detection at 1, 2 and 4mo for the expressions of HMGB1 and NF-κB. RESULTS:Compared with the control group, the retinal cells disorder, cell densities decreases, microvasculars occlusion were founded with inner and outer nuclear layer thinning and ganglion cell apoptosis. The fluorescence angiography showed that peripheral capillaries became circuitous and vascular occlusion and non-perfusion area could be seen. The expressions of HMGB1 and NF-κB were higher than those of control with time dependence and they had significant positive correlations(PCONCLUSION:The expression of HMGB1 increases in diabetic rat retina, which may involve in the occurrence of diabetic retinopathy through the NF- κB pathway.

  1. Retinal vasculitis.

    Science.gov (United States)

    Abu El-Asrar, Ahmed M; Herbort, Carl P; Tabbara, Khalid F

    2005-12-01

    Retinal vasculitis is a sight-threatening intraocular inflammation affecting the retinal vessels. It may occur as an isolated ocular condition, as a manifestation of infectious or neoplastic disorders, or in association with a systemic inflammatory disease. The search for an underlying etiology should be approached in a multidisciplinary fashion based on a thorough history, review of systems, physical examination, and laboratory evaluation. Discrimination between infectious and noninfectious etiologies of retinal vasculitis is important because their treatment is different. This review is based on recently published articles on retinal vasculitis and deals with its clinical diagnosis, its link with systemic diseases, and its laboratory investigation.

  2. High-fat diet enhanced retinal dehydrogenase activity, but suppressed retinol dehydrogenase activity in liver of rats

    Directory of Open Access Journals (Sweden)

    Mian Zhang

    2015-04-01

    Full Text Available Evidence has shown that hyperlipidemia is associated with retinoid dyshomeostasis. In liver, retinol is mainly oxidized to retinal by retinol dehydrogenases (RDHs and alcohol dehydrogenases (ADHs, further converted to retinoic acid by retinal dehydrogenases (RALDHs. The aim of this study was to investigate whether high-fat diet (HFD induced hyperlipidemia affected activity and expression of hepatic ADHs/RDHs and RALDHs in rats. Results showed that retinol levels in liver, kidney and adipose tissue of HFD rats were significantly increased, while plasma retinol and hepatic retinal levels were markedly decreased. HFD rats exhibited significantly downregulated hepatic ADHs/RDHs activity and Adh1, Rdh10 and Dhrs9 expression. Oppositely, hepatic RALDHs activity and Raldh1 expression were upregulated in HFD rats. In HepG2 cells, treatment of HFD rat serum inhibited ADHs/RDHs activity and induced RALDHs activity. Among the tested abnormally altered components in HFD rat serum, cholesterol reduced ADHs/RDHs activity and RDH10 expression, while induced RALDHs activity and RALDH1 expression in HepG2 cells. Contrary to the effect of cholesterol, cholesterol-lowering agent pravastatin upregulated ADHs/RDHs activity and RDH10 expression, while suppressed RALDHs activity and RALDH1 expression. In conclusion, hyperlipidemia oppositely altered activity and expression of hepatic ADHs/RDHs and RALDHs, which is partially due to the elevated cholesterol levels.

  3. Dual-conjugate adaptive optics for wide-field high-resolution retinal imaging.

    Science.gov (United States)

    Thaung, Jörgen; Knutsson, Per; Popovic, Zoran; Owner-Petersen, Mette

    2009-03-16

    We present analysis and preliminary laboratory testing of a real-time dual-conjugate adaptive optics (DCAO) instrument for ophthalmology that will enable wide-field high resolution imaging of the retina in vivo. The setup comprises five retinal guide stars (GS) and two deformable mirrors (DM), one conjugate to the pupil and one conjugate to a plane close to the retina. The DCAO instrument has a closed-loop wavefront sensing wavelength of 834 nm and an imaging wavelength of 575 nm. It incorporates an array of collimator lenses to spatially filter the light from all guide stars using one adjustable iris, and images the Hartmann patterns of multiple reference sources on a single detector. Zemax simulations were performed at 834 nm and 575 nm with the Navarro 99 and the Liou- Brennan eye models. Two correction alternatives were evaluated; conventional single conjugate AO (SCAO, using one GS and a pupil DM) and DCAO (using multiple GS and two DM). Zemax simulations at 575 nm based on the Navarro 99 eye model show that the diameter of the corrected field of view for diffraction-limited imaging (Strehl >or= 0.8) increases from 1.5 deg with SCAO to 6.5 deg using DCAO. The increase for the less stringent condition of a wavefront error of 1 rad or less (Strehl >or= 0.37) is from 3 deg with SCAO to approximately 7.4 deg using DCAO. Corresponding results for the Liou-Brennan eye model are 3.1 deg (SCAO) and 8.2 deg (DCAO) for Strehl >or= 0.8, and 4.8 deg (SCAO) and 9.6 deg (DCAO) for Strehl >or= 0.37. Potential gain in corrected field of view with DCAO is confirmed both by laboratory experiments on a model eye and by preliminary in vivo imaging of a human eye. (c) 2009 Optical Society of America

  4. Retinal image quality and visual stimuli processing by simulation of partial eye cataract

    Science.gov (United States)

    Ozolinsh, Maris; Danilenko, Olga; Zavjalova, Varvara

    2016-10-01

    Visual stimuli were demonstrated on a 4.3'' mobile phone screen inside a "Virtual Reality" adapter that allowed separation of the left and right eye visual fields. Contrast of the retina image thus can be controlled by the image on the phone screen and parallel to that at appropriate geometry by the AC voltage applied to scattering PDLC cell inside the adapter. Such optical pathway separation allows to demonstrate to both eyes spatially variant images, that after visual binocular fusion acquire their characteristic indications. As visual stimuli we used grey and different color (two opponent components to vision - red-green in L*a*b* color space) spatially periodical stimuli for left and right eyes; and with spatial content that by addition or subtraction resulted as clockwise or counter clockwise slanted Gabor gratings. We performed computer modeling with numerical addition or subtraction of signals similar to processing in brain via stimuli input decomposition in luminance and color opponency components. It revealed the dependence of the perception psychophysical equilibrium point between clockwise or counter clockwise perception of summation on one eye image contrast and color saturation, and on the strength of the retinal aftereffects. Existence of a psychophysical equilibrium point in perception of summation is only in the presence of a prior adaptation to a slanted periodical grating and at the appropriate slant orientation of adaptation grating and/or at appropriate spatial grating pattern phase according to grating nods. Actual observer perception experiments when one eye images were deteriorated by simulated cataract approved the shift of mentioned psychophysical equilibrium point on the degree of artificial cataract. We analyzed also the mobile devices stimuli emission spectra paying attention to areas sensitive to macula pigments absorption spectral maxima and blue areas where the intense irradiation can cause in abnormalities in periodic melatonin

  5. Fast High-Quality Noise

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Wyvill, Geoff

    2007-01-01

    At the moment the noise functions available in a graphics programmer's toolbox are either slow to compute or they involve grid-line artifacts making them of lower quality. In this paper we present a real-time noise computation with no grid-line artifacts or other regularity problems. In other words......, we put a new tool in the box that computes fast high-quality noise. In addition to being free of artifacts, the noise we present does not rely on tabulated data (everything is computed on the fly) and it is easy to adjust quality vs. quantity for the noise. The noise is based on point rendering (like...... spot noise), but it extends to more than two dimensions. The fact that it is based on point rendering makes art direction of the noise much easier....

  6. Elliptical local vessel density: a fast and robust quality metric for retinal images

    OpenAIRE

    Giancardo, L.; Abramoff, M.D.; Chaum, E.; Karnowski, T.P.; Meriaudeau, F.; Tobin, K.W.

    2008-01-01

    A great effort of the research community is geared towards the creation of an automatic screening system able to promptly detect diabetic retinopathy with the use of fundus cameras. In addition, there are some documented approaches for automatically judging the image quality. We propose a new set of features independent of field of view or resolution to describe the morphology of the patient's vessels. Our initial results suggest that these features can be used to estimate the image quality i...

  7. Peripheral retinal degenerations and the risk of retinal detachment.

    Science.gov (United States)

    Lewis, Hilel

    2003-07-01

    To review the degenerative diseases of the peripheral retina in relationship with the risk to develop a rhegmatogenous retinal detachment and to present recommendations for use in eyes at increased risk of developing a retinal detachment. Focused literature review and author's clinical experience. Retinal degenerations are common lesions involving the peripheral retina, and most of them are clinically insignificant. Lattice degeneration, degenerative retinoschisis, cystic retinal tufts, and, rarely, zonular traction tufts, can result in a rhegmatogenous retinal detachment. Therefore, these lesions have been considered for prophylactic therapy; however, adequate studies have not been performed to date. Well-designed, prospective, randomized clinical studies are necessary to determine the benefit-risk ratio of prophylactic treatment. In the meantime, the evidence available suggests that most of the peripheral retinal degenerations should not be treated except in rare, high-risk situations.

  8. Activation of autophagy in a rat model of retinal ischemia following high intraocular pressure.

    Directory of Open Access Journals (Sweden)

    Antonio Piras

    Full Text Available Acute primary open angle glaucoma is an optic neuropathy characterized by the elevation of intraocular pressure, which causes retinal ischemia and neuronal death. Rat ischemia/reperfusion enhances endocytosis of both horseradish peroxidase (HRP or fluorescent dextran into ganglion cell layer (GCL neurons 24 h after the insult. We investigated the activation of autophagy in GCL-neurons following ischemia/reperfusion, using acid phosphatase (AP histochemistry and immunofluorescence against LC3 and LAMP1. Retinal I/R lead to the appearance of AP-positive granules and LAMP1-positive vesicles 12 and 24 h after the insult, and LC3 labelling at 24 h, and induced a consistent retinal neuron death. At 48 h the retina was negative for autophagic markers. In addition, Western Blot analysis revealed an increase of LC3 levels after damage: the increase in the conjugated, LC3-II isoform is suggestive of autophagic activity. Inhibition of autophagy by 3-methyladenine partially prevented death of neurons and reduces apoptotic markers, 24 h post-lesion. The number of neurons in the GCL decreased significantly following I/R (I/R 12.21±1.13 vs controls 19.23±1.12 cells/500 µm; this decrease was partially prevented by 3-methyladenine (17.08±1.42 cells/500 µm, which potently inhibits maturation of autophagosomes. Treatment also prevented the increase in glial fibrillary acid protein immunoreactivity elicited by I/R. Therefore, targeting autophagy could represent a novel and promising treatment for glaucoma and retinal ischemia.

  9. High levels of retinal membrane docosahexaenoic acid increase susceptibility to stress-induced degenerations⃞

    Science.gov (United States)

    Tanito, Masaki; Brush, Richard S.; Elliott, Michael H.; Wicker, Lea D.; Henry, Kimberly R.; Anderson, Robert E.

    2009-01-01

    The fat-1 gene cloned from C. elegans encodes an n-3 fatty acid desaturase that converts n-6 to n-3 PUFA. Mice carrying the fat-1 transgene and wild-type controls were fed an n-3-deficient/n-6-enriched diet [fat-1- safflower oil (SFO) and wt-SFO, respectively]. Fatty acid profiles of rod outer segments (ROS), cerebellum, plasma, and liver demonstrated significantly lower n-6/n-3 ratios and higher docosahexaenoic acid (DHA) levels in fat-1-SFO compared with wt-SFO. When mice were exposed to light stress: 1) the outer nuclear layer (ONL) thickness was reduced; 2) amplitudes of the electroretinogram (ERG) were lower; 3) the number of apoptotic photoreceptor cells was greater; and 4) modification of retinal proteins by 4-hydroxyhexenal (4-HHE), an end-product of n-3 PUFA oxidation was increased in both fat-1-SFO and wt mice fed a regular lab chow diet compared with wt-SFO. The results indicate a positive correlation between the level of DHA, the degree of n-3 PUFA lipid peroxidation, and the vulnerability of the retina to photooxidative stress. In mice not exposed to intense light, the reduction in DHA resulted in reduced efficacy in phototransduction gain steps, while no differences in the retinal morphology or retinal biochemistry. These results highlight the dual roles of DHA in cellular physiology and pathology. PMID:19023138

  10. Chaetomium retinitis.

    Science.gov (United States)

    Tabbara, Khalid F; Wedin, Keith; Al Haddab, Saad

    2010-01-01

    To report a case of Chaetomium atrobrunneum retinitis in a patient with Hodgkin lymphoma. We studied the ocular manifestations of an 11-year-old boy with retinitis. Biomicroscopy, ophthalmoscopy, and fundus photography were done. Magnetic resonance imaging of the brain was performed. A vitreous biopsy was subjected to viral, bacterial, and fungal cultures. Vitreous culture grew C. atrobrunneum. Magnetic resonance imaging showed multiple cerebral lesions consistent with an infectious process. The patient was given intravenous voriconazole and showed improvement of the ocular and central nervous system lesions. We report a case of central nervous system and ocular lesions by C. atrobrunneum. The retinitis was initially misdiagnosed as cytomegaloviral retinitis. Vitreous biopsy helped in the early diagnosis and prompt treatment of a life- and vision-threatening infection.

  11. Retinitis pigmentosa

    Science.gov (United States)

    ... treatments for retinitis pigmentosa, including the use of DHA, which is an omega-3 fatty acid. Other ... Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016:chap 630. ...

  12. Cytomegalovirus retinitis

    Science.gov (United States)

    ... have weakened immune systems as a result of: HIV/AIDS Bone marrow transplant Chemotherapy Drugs that suppress the immune system Organ transplant Symptoms Some people with CMV retinitis have no symptoms. ...

  13. Retinal Detachment

    Science.gov (United States)

    ... to your brain. It provides the sharp, central vision needed for reading, driving, and seeing fine detail. A retinal detachment lifts or pulls the retina from its normal position. It can occur at ...

  14. Serial imaging and structure-function correlates of high-density rings of fundus autofluorescence in retinitis pigmentosa.

    Science.gov (United States)

    Robson, Anthony G; Tufail, Adnan; Fitzke, Fred; Bird, Alan C; Moore, Anthony T; Holder, Graham E; Webster, Andrew R

    2011-09-01

    To document the evolution and functional and structural significance of parafoveal rings of high-density fundus autofluorescence (AF) in patients with retinitis pigmentosa and preserved visual acuity. Fifty-two patients with nonsyndromic retinitis pigmentosa or Usher syndrome, who had a parafoveal ring of high-density AF and a visual acuity of 20/30 or better, were ascertained. All had international standard full-field electroretinography and pattern electroretinography. Autofluorescence imaging was repeated in 30 patients after periods of up to 9.3 years. Of the 52 patients, 35 underwent optical coherence tomography. Progressive constriction of the ring was detected in 17 patients. Ring radius reduced by up to 40% at a mean rate of between 0.8% and 15.8% per year. In 1 patient, a small ring was replaced by irregular AF; visual acuity deteriorated over the same period. There was a high correspondence between the lateral extent of the preserved optical coherence tomography inner segment/outer segment band and the diameter of the ring along the same optical coherence tomographic scan plane (slope, 0.9; r = 0.97; P retina and preserved photopic function. Serial fundus AF may provide prognostic indicators for preservation of central acuity and potentially assist in the identification and evaluation of patients suitable for treatment aimed at preservation of remaining function.

  15. Macular Buckling Surgery for Retinal Detachment Associated with Macular Hole in High Myopia Eye

    Directory of Open Access Journals (Sweden)

    Kenan Sönmez

    2017-12-01

    Full Text Available A 68-year-old woman presented to our clinic with a 1-month history of central scotoma and visual loss in her right eye. The best corrected visual acuity (BCVA was hand motion in her right eye. Fundus examination showed myopic chorioretinal degeneration in association with posterior staphyloma and the retina was slightly elevated throughout the macula. Optical coherence tomography (OCT revealed retinal detachment involving the posterior pole with a macular hole and staphyloma. The patient underwent pars plana vitrectomy, internal limiting membrane peeling, macular buckling, and perfluoropropane gas tamponade. At 3-month follow-up, her BCVA was improved to counting fingers at 1 meter and flattened retina with closed macular hole was observed by OCT. Myopic macular hole with retinal detachment associated with posterior staphyloma represent a challenge regarding their management and several surgical techniques have been described. Although satisfactory anatomical improvement is achieved in these eyes after surgery, the visual acuity outcomes may be poorer than expected due to the chorioretinal atrophy at the posterior pole.

  16. Necrotic enlargement of cone photoreceptor cells and the release of high-mobility group box-1 in retinitis pigmentosa

    Science.gov (United States)

    Murakami, Y; Ikeda, Y; Nakatake, S; Tachibana, T; Fujiwara, K; Yoshida, N; Notomi, S; Nakao, S; Hisatomi, T; Miller, J W; Vavvas, DG; Sonoda, KH; Ishibashi, T

    2015-01-01

    Retinitis pigmentosa (RP) refers to a group of inherited retinal degenerations resulting form rod and cone photoreceptor cell death. The rod cell death due to deleterious genetic mutations has been shown to occur mainly through apoptosis, whereas the mechanisms and features of the secondary cone cell death have not been fully elucidated. Our previous study showed that the cone cell death in rd10 mice, an animal model of RP, involves necrotic features and is partly mediated by the receptor interacting protein kinase. However, the relevancy of necrotic cone cell death in human RP patients remains unknown. In the present study, we showed that dying cone cells in rd10 mice exhibited cellular enlargement, along with necrotic changes such as cellular swelling and mitochondrial rupture. In human eyes, live imaging of cone cells by adaptive optics scanning laser ophthalmoscopy revealed significantly increased percentages of enlarged cone cells in the RP patients compared with the control subjects. The vitreous of the RP patients contained significantly higher levels of high-mobility group box-1, which is released extracellularly associated with necrotic cell death. These findings suggest that necrotic enlargement of cone cells is involved in the process of cone degeneration, and that necrosis may be a novel target to prevent or delay the loss of cone-mediated central vision in RP. PMID:27551484

  17. High prevalence of mutations affecting the splicing process in a Spanish cohort with autosomal dominant retinitis pigmentosa

    Science.gov (United States)

    Ezquerra-Inchausti, Maitane; Barandika, Olatz; Anasagasti, Ander; Irigoyen, Cristina; López de Munain, Adolfo; Ruiz-Ederra, Javier

    2017-01-01

    Retinitis pigmentosa is the most frequent group of inherited retinal dystrophies. It is highly heterogeneous, with more than 80 disease-causing genes 27 of which are known to cause autosomal dominant RP (adRP), having been identified. In this study a total of 29 index cases were ascertained based on a family tree compatible with adRP. A custom panel of 31 adRP genes was analysed by targeted next-generation sequencing using the Ion PGM platform in combination with Sanger sequencing. This allowed us to detect putative disease-causing mutations in 14 out of the 29 (48.28%) families analysed. Remarkably, around 38% of all adRP cases analysed showed mutations affecting the splicing process, mainly due to mutations in genes coding for spliceosome factors (SNRNP200 and PRPF8) but also due to splice-site mutations in RHO. Twelve of the 14 mutations found had been reported previously and two were novel mutations found in PRPF8 in two unrelated patients. In conclusion, our results will lead to more accurate genetic counselling and will contribute to a better characterisation of the disease. In addition, they may have a therapeutic impact in the future given the large number of studies currently underway based on targeted RNA splicing for therapeutic purposes. PMID:28045043

  18. Expression of Glutamate and GABA during the Process of Rat Retinal Synaptic Plasticity Induced by Acute High Intraocular Pressure

    International Nuclear Information System (INIS)

    Zhou, Lihong; Huang, Jufang; Wang, Hui; Luo, Jia; Zeng, Leping; Xiong, Kun; Chen, Dan

    2013-01-01

    Acute high intraocular pressure (HIOP) can induce plastic changes of retinal synapses during which the expression of the presynaptic marker synaptophysin (SYN) has a distinct spatiotemporal pattern from the inner plexiform layer to the outer plexiform layer. We identified the types of neurotransmitters in the retina that participated in this process and determined the response of these neurotransmitters to HIOP induction. The model of acute HIOP was established by injecting normal saline into the anterior chamber of the rat eye. We found that the number of glutamate-positive cells increased successively from the inner part to the outer part of the retina (from the ganglion cell layer to the inner nuclear layer to the outer nuclear layer) after HIOP, which was similar to the spatiotemporal pattern of SYN expression (internally to externally) following HIOP. However, the distribution and intensity of GABA immunoreactivity in the retina did not change significantly at different survival time post injury and had no direct correlation with SYN expression. Our results suggested that the excitatory neurotransmitter glutamate might participate in the plastic process of retinal synapses following acute HIOP, but no evidence was found for the role of the inhibitory neurotransmitter GABA

  19. The use of retinal photography in nonophthalmic settings and its potential for neurology.

    Science.gov (United States)

    Pérez, Mario A; Bruce, Beau B; Newman, Nancy J; Biousse, Valérie

    2012-11-01

    Ocular fundus examination is an important element of the neurological examination. However, direct ophthalmoscopy is difficult to perform without pupillary dilation and requires extensive practice to accurately recognize optic nerve and retinal abnormalities. Recent studies have suggested that digital retinal photography can replace direct ophthalmoscopy in many settings. Ocular fundus imaging is routinely used to document and monitor disease progression in ophthalmology. Advances in optical technology have made it easier to obtain high-quality retinal imaging, even without pupillary dilation. Retinal photography has a high sensitivity, specificity, and interexamination/intraexamination agreement compared with in-person ophthalmologist examination, suggesting that photographs can be used in lieu of ophthalmoscopy in many clinical situations. Nonmydriatic retinal photography has recently gained relevance as a helpful tool for diagnosing neuro-ophthalmologic disorders in the emergency department. In addition, several population-based studies have used retinal imaging to relate ophthalmic abnormalities to the risk of hypertension, renal dysfunction, cardiovascular mortality, subclinical and clinical stroke, and cognitive impairment. The possibility of telemedical consultation offered by digital retinal photography has already increased access to timely and accurate subspecialty care, particularly for underserved areas. Retinal photography (even without pupillary dilation) has become increasingly available to medical fields outside of ophthalmology, allowing for faster and more accurate diagnosis of various ocular, neurological, and systemic disorders. The potential for telemedicine may provide the additional benefits of improving access to appropriate urgent consultation in both clinical and research settings.

  20. The use of retinal photography in non-ophthalmic settings and its potential for neurology

    Science.gov (United States)

    Pérez, Mario A.; Bruce, Beau B.; Newman, Nancy J.; Biousse, Valérie

    2012-01-01

    Background Ocular fundus examination is an important element of the neurological examination. However, direct ophthalmoscopy is difficult to perform without pupillary dilation and requires extensive practice to accurately recognize optic nerve and retinal abnormalities. Recent studies have suggested that digital retinal photography can replace direct ophthalmoscopy in many settings. Review Summary Ocular fundus imaging is routinely used to document and monitor disease progression in ophthalmology. Advances in optical technology have made it easier to obtain high-quality retinal imaging, even without pupillary dilation. Retinal photography has a high sensitivity, specificity, and inter-/intra-examination agreement compared to in-person ophthalmologist examination, suggesting that photographs can be used in lieu of ophthalmoscopy in many clinical situations. Non-mydriatic retinal photography has recently gained relevance as a helpful tool for diagnosing neuro-ophthalmologic disorders in the emergency department. Additionally, several population-based studies have used retinal imaging to relate ophthalmic abnormalities to the risk of hypertension, renal dysfunction, cardiovascular mortality, subclinical and clinical stroke, and cognitive impairment. The possibility of telemedical consultation offered by digital retinal photography has already increased access to timely and accurate subspecialty care, particularly for underserved areas. Conclusion Retinal photography (even without pupillary dilation) has become increasingly available to medical fields outside of ophthalmology, allowing for faster and more accurate diagnosis of various ocular, neurologic and systemic disorders. The potential for telemedicine may provide the additional benefits of improving access to appropriate urgent consultation in both clinical and research settings. PMID:23114666

  1. Efficacy of vitrectomy with triamcinolone assistance versus internal limiting membrane peeling for highly myopic macular hole retinal detachment.

    Science.gov (United States)

    Wei, Yong; Wang, Ningli; Zu, Zhongqiao; Bi, Chuncao; Wang, Huaizhou; Chen, Fenghua; Yang, Xingguang

    2013-06-01

    To compare the outcomes of pars plana vitrectomy (PPV) with or without the adjuvant surgical procedures: triamcinolone acetonide (TA) assistance and/or internal limiting membrane (ILM) peeling for the treatment of highly myopic macular hole retinal detachment (MHRD). Case-control study. Pars plana vitrectomy combined with 2 kinds of adjuvant surgical procedures were used on 96 highly myopic eyes with MHRD. These eyes were assigned to 4 groups randomly: Group 1, non-TA-assisted PPV and without ILM peeling; Group 2, non-TA-assisted PPV with ILM peeling; Group 3, TA-assisted PPV and without ILM peeling; Group 4, TA-assisted PPV with ILM peeling. Anatomical reattachment of the retina, macular hole closure, and best-corrected visual acuity were measured. The rates of both retinal reattachment and macular hole closure were higher in Group 2 (84.0 and 44.0%) and Group 3 (80.8 and 46.2%) than Group 1 (73.9 and 17.4%); however, there were no differences between Group 2 and Group 3 (P > 0.05). The rates of macular hole closure were extremely low in Group 1 and also in eyes with extreme long axial lengths (≥29.0 mm), "severe" chorioretinal atrophy, and posterior staphyloma. Pars plana vitrectomy with either TA assistance or ILM peeling was effective for the treatment of highly myopic MHRD. If you peel the ILM, adding TA does not affect closure rates; and if TA is used to visualize the vitreous, ILM peeling may not be necessary in MHRD. There was a lower anatomical success rate in MHRD with extreme long axial lengths, severe chorioretinal atrophy, and posterior staphyloma.

  2. Retinal Image Preprocessing: Background and Noise Segmentation

    Directory of Open Access Journals (Sweden)

    Usman Akram

    2012-09-01

    Full Text Available Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse segmentation and fine segmentation. Standard retinal images databases Diaretdb0, Diaretdb1, DRIVE and STARE are used to test the validation of our preprocessing technique. The experimental results show the validity of proposed preprocessing technique.

  3. Anti-angiogenic mechanism of cordycepin on rhesus macaque choroid-retinal endothelial cell line cultured in high glucose condition

    Directory of Open Access Journals (Sweden)

    Xiao-Li Zhu*

    2016-07-01

    Full Text Available AIM: To investigate the angiogenesis effect and protective mechanism of cordycepin on rhesus macaque choroid-retinal endothelial(RF/6Acell line cultured in high glucose condition. METHODS: Cultured RF/6A cells were divided into normal control group, high glucose group and high glucose(HG+ different concentration cordycepin groups(HG+10μg/mL group, HG+50μg/mL group, HG+100μg/mL group. The cell proliferation was assessed using cholecystokinin octapeptide dye after treated for 48h. The cell migration was investigated by a Transwell assay. The tube formation was measured on Matrigel. Furthermore, the impact of cordycepin on high glucose-induced activation of VEGF and VEGF receptor 2(VEGFR-2was tested by Western blot analysis. RESULTS: Compared with normal control group, cell viability markedly increased in high glucose group(PPPPPPvs normal control group, oppositely gradually decreased with the increase of cordycepin concentrations, and had a statistically significant difference vs high glucose group(PCONCLUSION: Cordycepin can suppress the proliferation, migration and tubu formation of RF/6A in high glucose condition, might via inhibiting expression of VEGF and VEGFR-2.

  4. Thiamine and benfotiamine prevent apoptosis induced by high glucose-conditioned extracellular matrix in human retinal pericytes.

    Science.gov (United States)

    Beltramo, Elena; Nizheradze, Konstantin; Berrone, Elena; Tarallo, Sonia; Porta, Massimo

    2009-10-01

    Early and selective loss of pericytes and thickening of the basement membrane are hallmarks of diabetic retinopathy. We reported reduced adhesion, but no changes in apoptosis, of bovine retinal pericytes cultured on extracellular matrix (ECM) produced by endothelial cells in high glucose (HG). Since human and bovine pericytes may behave differently in conditions mimicking the diabetic milieu, we verified the behaviour of human retinal pericytes cultured on HG-conditioned ECM. Pericytes were cultured in physiological/HG on ECM produced by human umbilical vein endothelial cells in physiological/HG, alone or in the presence of thiamine and benfotiamine. Adhesion, proliferation, apoptosis, p53 and Bcl-2/Bax ratio (mRNA levels and protein concentrations) were measured in wild-type and immortalized human pericytes. Both types of pericytes adhered less to HG-conditioned ECM and plastic than to physiological glucose-conditioned ECM. DNA synthesis was impaired in pericytes cultured in HG on the three different surfaces but there were no differences in proliferation. DNA fragmentation and Bcl-2/Bax ratio were greatly enhanced by HG-conditioned ECM in pericytes kept in both physiological and HG. Addition of thiamine and benfotiamine to HG during ECM production completely prevented these damaging effects. Apoptosis is strongly increased in pericytes cultured on ECM produced by endothelium in HG, probably due to impairment of the Bcl-2/Bax ratio. Thiamine and benfotiamine completely revert this effect. This behaviour is therefore completely different from that of bovine pericytes, underlining the importance of establishing species-specific cell models to study the mechanisms of diabetic retinopathy. (c) 2009 John Wiley & Sons, Ltd.

  5. Multi-nucleate retinal pigment epithelium cells of the human macula exhibit a characteristic and highly specific distribution.

    Science.gov (United States)

    Starnes, Austin C; Huisingh, Carrie; McGwin, Gerald; Sloan, Kenneth R; Ablonczy, Zsolt; Smith, R Theodore; Curcio, Christine A; Ach, Thomas

    2016-01-01

    The human retinal pigment epithelium (RPE) is reportedly 3% bi-nucleated. The importance to human vision of multi-nucleated (MN)-RPE cells could be clarified with more data about their distribution in central retina. Nineteen human RPE-flatmounts (9 ≤ 51 years, 10 > 80 years) were imaged at 12 locations: 3 eccentricities (fovea, perifovea, near periphery) in 4 quadrants (superior, inferior, temporal, nasal). Image stacks of lipofuscin-attributable autofluorescence and phalloidin labeled F-actin cytoskeleton were obtained using a confocal fluorescence microscope. Nuclei were devoid of autofluorescence and were marked using morphometric software. Cell areas were approximated by Voronoi regions. Mean number of nuclei per cell among eccentricity/quadrant groups and by age were compared using Poisson and binominal regression models. A total of 11,403 RPE cells at 200 locations were analyzed: 94.66% mono-, 5.31% bi-, 0.02% tri-nucleate, and 0.01% with 5 nuclei. Age had no effect on number of nuclei. There were significant regional differences: highest frequencies of MN-cells were found at the perifovea (9.9%) and near periphery (6.8%). The fovea lacked MN-cells almost entirely. The nasal quadrant had significantly more MN-cells compared to other quadrants, at all eccentricities. This study demonstrates MN-RPE cells in human macula. MN-cells may arise due to endoreplication, cell fusion, or incomplete cell division. The topography of MN-RPE cells follows the topography of photoreceptors; with near-absence at the fovea (cones only) and high frequency at perifovea (highest rod density). This distribution might reflect specific requirements of retinal metabolism or other mechanisms addressable in further studies.

  6. Retinal Detachment

    Directory of Open Access Journals (Sweden)

    Adnan Riaz, MD

    2018-04-01

    Full Text Available History of present illness: A 58-year-old female presented to the emergency department reporting six days of progressive, atraumatic left eye vision loss. Her symptoms started with the appearance of dark spots and “spider webs,” and then progressed to darkening of vision in her left eye. She reports mild pain since yesterday. Her review of symptoms was otherwise negative. Ocular physical examination revealed normal external appearance, intact extraocular movements, and visual acuities of 20/25 OD and light/dark sensitivity OS. Fluorescein uptake was negative and slit lamp exam was unremarkable. Significant findings: Bedside ocular ultrasound revealed a serpentine, hyperechoic membrane that appeared tethered to the optic disc posteriorly with hyperechoic material underneath. These findings are consistent with retinal detachment (RD and associated retinal hemorrhage. Discussion: The retina is a layer of organized neurons that line the posterior portion of the posterior chamber of the eye. RD occurs when this layer separates from the underlying epithelium, resulting in ischemia and progressive photoreceptor degeneration, with potentially rapid and permanent vision loss if left untreated.1 Risk factors include advanced age, male sex (60%, race (Asians and Jews, and myopia and lattice degeneration.2 Bedside ultrasound (US performed by emergency physicians provides a valuable tool that has been used by ophthalmologists for decades to evaluate intraocular disease.1,3 Findings on bedside ultrasound consistent with RD include a hyperechoic membrane floating in the posterior chamber. RD usuallyremain tethered to the optic disc posteriorly and do not cross midline, a feature distinguishing them from posterior vitreous detachments. Associated retinal hemorrhage, seen as hyperechoic material under the retinal flap, can often be seen.1,2 US can also distinguish between “mac-on” and “mac-off” detachments. If the retina is still attached to the

  7. Retinal detachment and retinal holes in retinitis pigmentosa sine pigmento.

    Science.gov (United States)

    Csaky, K; Olk, R J; Mahl, C F; Bloom, S M

    1991-01-01

    Retinal detachment and retinal holes in two family members with retinitis pigmentosa sine pigmento are reported. We believe these are the first such cases reported in the literature. We describe the presenting symptoms and management, including cryotherapy, scleral buckling procedure, and sulfur hexafluoride injection (SF6), resulting in stable visual acuity in one case and retinal reattachment and improved visual acuity in the other case.

  8. Availability of high quality weather data measurements

    DEFF Research Database (Denmark)

    Andersen, Elsa; Johansen, Jakob Berg; Furbo, Simon

    In the period 2016-2017 the project “Availability of high quality weather data measurements” is carried out at Department of Civil Engineering at the Technical University of Denmark. The aim of the project is to establish measured high quality weather data which will be easily available...... for the building energy branch and the solar energy branch in their efforts to achieve energy savings and for researchers and students carrying out projects where measured high quality weather data are needed....

  9. Prevention and control of proliferative vitreoretinopathy: primary retinal detachment surgery using silicone oil as a planned two-stage procedure in high-risk cases.

    Science.gov (United States)

    Alexander, P; Prasad, R; Ang, A; Poulson, A V; Scott, J D; Snead, M P

    2008-06-01

    For rhegmatogenous retinal detachment, reattachment with a single procedure is associated with better visual outcomes. In the past, silicone oil has been used mostly as a last resort following failed primary surgery. This study evaluates a novel approach to patients at high risk of primary failure, using silicone tamponade as the primary stage of a planned two-stage procedure. We report a series of 140 eyes that underwent primary surgery for rhegmatogenous retinal detachment. Patients at higher risk of surgical failure (eg giant retinal tear, inability to posture, poor view, uncertainty of location of primary break, primary proliferative vitreoretinopathy (PVR), multiple tears with rolled posterior edges, retinoschisis/detachment, staphyloma with macular hole) were managed by a planned staged procedure using primary silicone oil tamponade. This was followed by silicone removal at a later date. Fifty-four eyes underwent scleral buckling alone, with primary success in 52/54 (96%). Fifty-three eyes underwent vitrectomy and gas, achieving primary success in 50/53 (94%). Thirty-three eyes were classified high risk and managed with primary silicone. Silicone was safely removed in 22/25. In eight eyes, silicone was retained without attempt at removal. In total, primary retinal reattachment was achieved in 128 of 140 eyes (91.4%). Of these, 124 (97%) did not require long-term tamponade. Only four eyes (2.9%) developed PVR. A planned two-stage approach to highrisk cases of retinal detachment using primary silicone oil tamponade followed by silicone removal can achieve a high primary reattachment rate with less than 3% incidence of PVR.

  10. Retinitis pigmentosa

    Directory of Open Access Journals (Sweden)

    Hamel Christian

    2006-10-01

    Full Text Available Abstract Retinitis pigmentosa (RP is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visual acuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms. Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema, and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis.

  11. In vivo integrated photoacoustic ophthalmoscopy, optical coherence tomography, and scanning laser ophthalmoscopy for retinal imaging

    Science.gov (United States)

    Song, Wei; Zhang, Rui; Zhang, Hao F.; Wei, Qing; Cao, Wenwu

    2012-12-01

    The physiological and pathological properties of retina are closely associated with various optical contrasts. Hence, integrating different ophthalmic imaging technologies is more beneficial in both fundamental investigation and clinical diagnosis of several blinding diseases. Recently, photoacoustic ophthalmoscopy (PAOM) was developed for in vivo retinal imaging in small animals, which demonstrated the capability of imaging retinal vascular networks and retinal pigment epithelium (RPE) at high sensitivity. We combined PAOM with traditional imaging modalities, such as fluorescein angiography (FA), spectral-domain optical coherence tomography (SD-OCT), and auto-fluorescence scanning laser ophthalmoscopy (AF-SLO), for imaging rats and mice. The multimodal imaging system provided more comprehensive evaluation of the retina based on the complementary imaging contrast mechanisms. The high-quality retinal images show that the integrated ophthalmic imaging system has great potential in the investigation of blinding disorders.

  12. Zerodur polishing process for high surface quality and high efficiency

    International Nuclear Information System (INIS)

    Tesar, A.; Fuchs, B.

    1992-08-01

    Zerodur is a glass-ceramic composite importance in applications where temperature instabilities influence optical and mechanical performance, such as in earthbound and spaceborne telescope mirror substrates. Polished Zerodur surfaces of high quality have been required for laser gyro mirrors. Polished surface quality of substrates affects performance of high reflection coatings. Thus, the interest in improving Zerodur polished surface quality has become more general. Beyond eliminating subsurface damage, high quality surfaces are produced by reducing the amount of hydrated material redeposited on the surface during polishing. With the proper control of polishing parameters, such surfaces exhibit roughnesses of < l Angstrom rms. Zerodur polishing was studied to recommend a high surface quality polishing process which could be easily adapted to standard planetary continuous polishing machines and spindles. This summary contains information on a polishing process developed at LLNL which reproducibly provides high quality polished Zerodur surfaces at very high polishing efficiencies

  13. Engineering high quality medical software

    CERN Document Server

    Coronato, Antonio

    2018-01-01

    This book focuses on high-confidence medical software in the growing field of e-health, telecare services and health technology. It covers the development of methodologies and engineering tasks together with standards and regulations for medical software.

  14. A multi-scale tensor voting approach for small retinal vessel segmentation in high resolution fundus images.

    Science.gov (United States)

    Christodoulidis, Argyrios; Hurtut, Thomas; Tahar, Houssem Ben; Cheriet, Farida

    2016-09-01

    Segmenting the retinal vessels from fundus images is a prerequisite for many CAD systems for the automatic detection of diabetic retinopathy lesions. So far, research efforts have concentrated mainly on the accurate localization of the large to medium diameter vessels. However, failure to detect the smallest vessels at the segmentation step can lead to false positive lesion detection counts in a subsequent lesion analysis stage. In this study, a new hybrid method for the segmentation of the smallest vessels is proposed. Line detection and perceptual organization techniques are combined in a multi-scale scheme. Small vessels are reconstructed from the perceptual-based approach via tracking and pixel painting. The segmentation was validated in a high resolution fundus image database including healthy and diabetic subjects using pixel-based as well as perceptual-based measures. The proposed method achieves 85.06% sensitivity rate, while the original multi-scale line detection method achieves 81.06% sensitivity rate for the corresponding images (p<0.05). The improvement in the sensitivity rate for the database is 6.47% when only the smallest vessels are considered (p<0.05). For the perceptual-based measure, the proposed method improves the detection of the vasculature by 7.8% against the original multi-scale line detection method (p<0.05). Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Quality management manual for production of high quality cassava flour

    DEFF Research Database (Denmark)

    Dziedzoave, Nanam Tay; Abass, Adebayo Busura; Amoa-Awua, Wisdom K.

    The high quality cassava flour (HQCF) industry has just started to evolve in Africa and elsewhere. The sustainability of the growing industry, the profitability of small- and medium-scale enterprises (SMEs) that are active in the industry and good-health of consumers can best be guaranteed through...... the adoption of proper quality and food safety procedures. Cassava processing enterprises involved in the productionof HQCF must therefore be commited to the quality and food safety of the HQCF. They must have the right technology, appropriate processing machhinery, standard testing instruments...... and the necessary technical expertise. This quality manual was therefore developed to guide small- to medium-scale cassava in the design and implematation of Hazard Analysis Critical Control Point (HACCP) system and Good manufacturing Practices (GMP) plans for HQCF production. It describes the HQCF production...

  16. [Peripheral retinal degenerations--treatment recommendations].

    Science.gov (United States)

    Joussen, A M; Kirchhof, B

    2004-10-01

    This report reviews the clinical appearance of degenerative diseases of the peripheral retina in relationship to the risk of developing a rhegmatogenous retinal detachment. We present recommendations for preventive treatment in eyes at increased risk of developing retinal detachment. Retinal degenerations are common lesions involving the peripheral retina but most of them are clinically insignificant. Lattice degeneration, degenerative retinoschisis, cystic retinal tufts, and very rarely zonular traction tufts can result in rhegmatogenous retinal detachment. Therefore, these lesions have been considered for prophylactic treatment; however, adequate studies have not been performed to date. Most of the peripheral retinal degenerations may not require treatment except in rare, high-risk situations. According to current knowledge there is no higher incidence of secondary pucker or other side effects after laser coagulation. Therefore, generous laser indication is recommended if risk factors apply.

  17. High quality-factor optical resonators

    International Nuclear Information System (INIS)

    Henriet, Rémi; Salzenstein, Patrice; Coillet, Aurélien; Saleh, Khaldoun; Chembo, Yanne K; Ristic, Davor; Ferrari, Maurizio; Mortier, Michel; Rasoloniaina, Alphonse; Dumeige, Yannick; Féron, Patrice; Cibiel, Gilles; Llopis, Olivier

    2014-01-01

    Various resonators are investigated for microwave photonic applications. Micro-sphere, disk and fiber ring resonators were designed, realized and characterized. Obtained quality factors are as high as Q = 10 10 . (paper)

  18. Retinal ganglion cells: mechanisms underlying depolarization block and differential responses to high frequency electrical stimulation of ON and OFF cells

    Science.gov (United States)

    Kameneva, T.; Maturana, M. I.; Hadjinicolaou, A. E.; Cloherty, S. L.; Ibbotson, M. R.; Grayden, D. B.; Burkitt, A. N.; Meffin, H.

    2016-02-01

    Objective. ON and OFF retinal ganglion cells (RGCs) are known to have non-monotonic responses to increasing amplitudes of high frequency (2 kHz) biphasic electrical stimulation. That is, an increase in stimulation amplitude causes an increase in the cell’s spike rate up to a peak value above which further increases in stimulation amplitude cause the cell to decrease its activity. The peak response for ON and OFF cells occurs at different stimulation amplitudes, which allows differential stimulation of these functional cell types. In this study, we investigate the mechanisms underlying the non-monotonic responses of ON and OFF brisk-transient RGCs and the mechanisms underlying their differential responses. Approach. Using in vitro patch-clamp recordings from rat RGCs, together with simulations of single and multiple compartment Hodgkin-Huxley models, we show that the non-monotonic response to increasing amplitudes of stimulation is due to depolarization block, a change in the membrane potential that prevents the cell from generating action potentials. Main results. We show that the onset for depolarization block depends on the amplitude and frequency of stimulation and reveal the biophysical mechanisms that lead to depolarization block during high frequency stimulation. Our results indicate that differences in transmembrane potassium conductance lead to shifts of the stimulus currents that generate peak spike rates, suggesting that the differential responses of ON and OFF cells may be due to differences in the expression of this current type. We also show that the length of the axon’s high sodium channel band (SOCB) affects non-monotonic responses and the stimulation amplitude that leads to the peak spike rate, suggesting that the length of the SOCB is shorter in ON cells. Significance. This may have important implications for stimulation strategies in visual prostheses.

  19. Analysis of visual appearance of retinal nerve fibers in high resolution fundus images: a study on normal subjects.

    Science.gov (United States)

    Kolar, Radim; Tornow, Ralf P; Laemmer, Robert; Odstrcilik, Jan; Mayer, Markus A; Gazarek, Jiri; Jan, Jiri; Kubena, Tomas; Cernosek, Pavel

    2013-01-01

    The retinal ganglion axons are an important part of the visual system, which can be directly observed by fundus camera. The layer they form together inside the retina is the retinal nerve fiber layer (RNFL). This paper describes results of a texture RNFL analysis in color fundus photographs and compares these results with quantitative measurement of RNFL thickness obtained from optical coherence tomography on normal subjects. It is shown that local mean value, standard deviation, and Shannon entropy extracted from the green and blue channel of fundus images are correlated with corresponding RNFL thickness. The linear correlation coefficients achieved values 0.694, 0.547, and 0.512 for respective features measured on 439 retinal positions in the peripapillary area from 23 eyes of 15 different normal subjects.

  20. Analysis of Visual Appearance of Retinal Nerve Fibers in High Resolution Fundus Images: A Study on Normal Subjects

    Directory of Open Access Journals (Sweden)

    Radim Kolar

    2013-01-01

    Full Text Available The retinal ganglion axons are an important part of the visual system, which can be directly observed by fundus camera. The layer they form together inside the retina is the retinal nerve fiber layer (RNFL. This paper describes results of a texture RNFL analysis in color fundus photographs and compares these results with quantitative measurement of RNFL thickness obtained from optical coherence tomography on normal subjects. It is shown that local mean value, standard deviation, and Shannon entropy extracted from the green and blue channel of fundus images are correlated with corresponding RNFL thickness. The linear correlation coefficients achieved values 0.694, 0.547, and 0.512 for respective features measured on 439 retinal positions in the peripapillary area from 23 eyes of 15 different normal subjects.

  1. High-quality compressive ghost imaging

    Science.gov (United States)

    Huang, Heyan; Zhou, Cheng; Tian, Tian; Liu, Dongqi; Song, Lijun

    2018-04-01

    We propose a high-quality compressive ghost imaging method based on projected Landweber regularization and guided filter, which effectively reduce the undersampling noise and improve the resolution. In our scheme, the original object is reconstructed by decomposing of regularization and denoising steps instead of solving a minimization problem in compressive reconstruction process. The simulation and experimental results show that our method can obtain high ghost imaging quality in terms of PSNR and visual observation.

  2. An optimized content-aware image retargeting method: toward expanding the perceived visual field of the high-density retinal prosthesis recipients

    Science.gov (United States)

    Li, Heng; Zeng, Yajie; Lu, Zhuofan; Cao, Xiaofei; Su, Xiaofan; Sui, Xiaohong; Wang, Jing; Chai, Xinyu

    2018-04-01

    Objective. Retinal prosthesis devices have shown great value in restoring some sight for individuals with profoundly impaired vision, but the visual acuity and visual field provided by prostheses greatly limit recipients’ visual experience. In this paper, we employ computer vision approaches to seek to expand the perceptible visual field in patients implanted potentially with a high-density retinal prosthesis while maintaining visual acuity as much as possible. Approach. We propose an optimized content-aware image retargeting method, by introducing salient object detection based on color and intensity-difference contrast, aiming to remap important information of a scene into a small visual field and preserve their original scale as much as possible. It may improve prosthetic recipients’ perceived visual field and aid in performing some visual tasks (e.g. object detection and object recognition). To verify our method, psychophysical experiments, detecting object number and recognizing objects, are conducted under simulated prosthetic vision. As control, we use three other image retargeting techniques, including Cropping, Scaling, and seam-assisted shrinkability. Main results. Results show that our method outperforms in preserving more key features and has significantly higher recognition accuracy in comparison with other three image retargeting methods under the condition of small visual field and low-resolution. Significance. The proposed method is beneficial to expand the perceived visual field of prosthesis recipients and improve their object detection and recognition performance. It suggests that our method may provide an effective option for image processing module in future high-density retinal implants.

  3. Missed retinal breaks in rhegmatogenous retinal detachment

    Directory of Open Access Journals (Sweden)

    Brijesh Takkar

    2016-12-01

    Full Text Available AIM: To evaluate the causes and associations of missed retinal breaks (MRBs and posterior vitreous detachment (PVD in patients with rhegmatogenous retinal detachment (RRD. METHODS: Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and 191 patients were included for analysis of PVD, depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations. RESULTS: Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs (P=0.033 with the odds of missing a retinal break being 1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy (PVR and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae, pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD. Traumatic RRDs were rarely associated with PVD. CONCLUSION: Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD.

  4. Effect of lycium barbarum polysaccharides on high glucose-induced retinal ganglion cell apoptosis, gene expression and delayed rectifier potassium current

    Directory of Open Access Journals (Sweden)

    Xiao-Fei Ma

    2017-05-01

    Full Text Available Objective: To study the effect of lycium barbarum polysaccharides (LBP on high glucoseinduced retinal ganglion cell apoptosis, gene expression and delayed rectifier potassium current. Methods: RGC-5 retinal ganglion cell lines were cultured and divided into control group, high glucose group and LBP group that were treated with normal DMEM, highglucose DMEM as well as high-glucose DMEM containing 500 ng/mL LBP respectively. After treatment, the Annexin V-FITC/PI kits were used to measure the number of apoptotic cells, fluorescence quantitative PCR kits were used to determine the expression of apoptosis genes and antioxidant genes, and patch clamp was used to test delayed rectifier potassium current. Results: 12, 24, 36 and 48 h after intervention, the number of apoptotic cells of high glucose group was significantly higher than that of control group, and the number of apoptotic cells of LBP group was significantly lower than that of high glucose group (P<0.05; 24 and 48 h after intervention, c-fos, c-jun, caspase-3, caspase-9, Nrf-2, NQO1 and HO-1 mRNA expression as well as potassium current amplitude (IK and maximum conductance (Gmax of high glucose group were significantly higher than those of control group while half maximum activation voltage (V1/2 was significantly lower than that of control group (P<0.05; c-fos, c-jun, caspase-3 and caspase-9 mRNA expression as well as IK and Gmax of LBP group were significantly lower than those of high glucose group, while Nrf-2, NQO1 and HO-1 mRNA expression as well as V1/2 of LBP group were significantly higher than those of high glucose group (P<0.05. Conclusions: LBP can reduce the high glucose-induced retinal ganglion cell apoptosis and inhibit the delayed rectifier potassium current amplitude.

  5. Antioxidant and Anti-Inflammatory Effects of Blueberry Anthocyanins on High Glucose-Induced Human Retinal Capillary Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Wuyang Huang

    2018-01-01

    Full Text Available Blueberries possess abundant anthocyanins, which benefit eye health. The purpose of this study was to explore the protective functional role of blueberry anthocyanin extract (BAE and its predominant constituents, malvidin (Mv, malvidin-3-glucoside (Mv-3-glc, and malvidin-3-galactoside (Mv-3-gal, on high glucose- (HG- induced injury in human retinal capillary endothelial cells (HRCECs. The results showed that BAE, Mv, Mv-3-glc, and Mv-3-gal enhanced cell viability (P<0.05 versus the HG group at 24 h; decreased the reactive oxygen species (ROS, P<0.01 versus the HG group both at 24 and 48 h; and increased the enzyme activity of catalase (CAT and superoxide dismutase (SOD (P<0.05 versus the HG group both at 24 and 48 h. Mv could greatly inhibit HG-induced Nox4 expression both at 24 and 48 h (P<0.05, while BAE and Mv-3-gal downregulated Nox4 only at 48 h (P<0.05. Mv, Mv-3-glc, and Mv-3-gal also changed nitric oxide (NO levels (P<0.05. BAE and Mv-3-glc also influenced angiogenesis by decreasing the vascular endothelial cell growth factor (VEGF level and inhibiting Akt pathway (P<0.05. Moreover, Mv and Mv-3-glc inhibited HG-induced intercellular adhesion molecule-1 (ICAM-1, P<0.001 and nuclear factor-kappa B (NF-κB (P<0.05. It indicated that blueberry anthocyanins protected HRCECs via antioxidant and anti-inflammatory mechanisms, which could be promising molecules for the development of nutraceuticals to prevent diabetic retinopathy.

  6. High-resolution imaging of the retinal nerve fiber layer in normal eyes using adaptive optics scanning laser ophthalmoscopy.

    Science.gov (United States)

    Takayama, Kohei; Ooto, Sotaro; Hangai, Masanori; Arakawa, Naoko; Oshima, Susumu; Shibata, Naohisa; Hanebuchi, Masaaki; Inoue, Takashi; Yoshimura, Nagahisa

    2012-01-01

    To conduct high-resolution imaging of the retinal nerve fiber layer (RNFL) in normal eyes using adaptive optics scanning laser ophthalmoscopy (AO-SLO). AO-SLO images were obtained in 20 normal eyes at multiple locations in the posterior polar area and a circular path with a 3-4-mm diameter around the optic disc. For each eye, images focused on the RNFL were recorded and a montage of AO-SLO images was created. AO-SLO images for all eyes showed many hyperreflective bundles in the RNFL. Hyperreflective bundles above or below the fovea were seen in an arch from the temporal periphery on either side of a horizontal dividing line to the optic disc. The dark lines among the hyperreflective bundles were narrower around the optic disc compared with those in the temporal raphe. The hyperreflective bundles corresponded with the direction of the striations on SLO red-free images. The resolution and contrast of the bundles were much higher in AO-SLO images than in red-free fundus photography or SLO red-free images. The mean hyperreflective bundle width around the optic disc had a double-humped shape; the bundles at the temporal and nasal sides of the optic disc were narrower than those above and below the optic disc (Poptical coherence tomography correlated with the hyperreflective bundle widths on AO-SLO (Pfiber bundles and Müller cell septa. The widths of the nerve fiber bundles appear to be proportional to the RNFL thickness at equivalent distances from the optic disc.

  7. High-resolution Fourier-Domain Optical Coherence Tomography and Microperimetric Findings After Macula-off Retinal Detachment Repair

    Science.gov (United States)

    Smith, Allison J.; Telander, David G.; Zawadzki, Robert J.; Choi, Stacey S.; Morse, Lawrence S.; Werner, John S.; Park, Susanna S.

    2009-01-01

    Objective To evaluate the morphologic changes in the macula of subjects with repaired macula-off retinal detachment (RD) using high-resolution Fourier-domain optical coherence tomography (FD OCT) and to perform functional correlation in a subset of patients using microperimetry (MP-1). Design Prospective observational case series. Participants Seventeen eyes from 17 subjects who had undergone anatomically successful repair for macula-off, rhegmatogenous RD at least 3 months earlier and without visually significant maculopathy on funduscopy. Methods FD OCT with axial and transverse resolution of 4.5 μm and 10 to 15 μm, respectively, was used to obtain rapid serial B-scans of the macula, which were compared with that from Stratus OCT. The FD OCT B-scans were used to create a 3-dimensional volume, from which en face C-scans were created. Among 11 patients, MP-1 was performed to correlate morphologic changes with visual function. Main Outcome Measures Stratus OCT scans, FD OCT scans, and MP-1 data. Results Stratus OCT and FD OCT images of the macula were obtained 3 to 30 months (mean 7 months) postoperatively in all eyes. Although Stratus OCT revealed photoreceptor disruption in 2 eyes (12%), FD OCT showed photoreceptor disruption in 13 eyes (76%). This difference was statistically significant (Pmacula-off RD repair is a common abnormality in the macula that is detected better with FD OCT than Stratus OCT. A good correlation between MP-1 abnormality and presence of photoreceptor disruption or subretinal fluid on FD OCT demonstrates that these anatomic abnormalities contribute to decreased visual function after successful repair. PMID:18672289

  8. Fabrication of high-quality brazed joints

    International Nuclear Information System (INIS)

    Orlov, A.V.

    1980-01-01

    Problem of ensuring of joint high-quality when brazing different parts in power engineering is considered. To obtain high-quality joints it is necessary to correctly design brazed joint and to choose a gap width, overlap length and fillet radius; to clean up carefully the surfaces to be brazed and fix them properly one relative to another; to apply a solder so as to provide its flowing into the gap and sticking in it; to exactly regulate thermal conditions of brazing. High quality and reliability of brazed joints are ensured by the application of solders based on noble metals, and cheap solders based on nickel, manganese and copper. Joints brazed with nickel base solders may operate at temperatures as high as 888 deg C

  9. TOTAL QUALITY MANAGEMENT IN HIGH EDUCATION

    Directory of Open Access Journals (Sweden)

    Hasan SERİN, Alper AYTEKİN

    2009-01-01

    Full Text Available The approach of Total Quality Management (TQM has been even more common and most recently its use in high education has been discussed. Likewise the enterprises producing various products, universities have also inputs, processes, and outputs. Due to conditions of competition, universities have to improve the qualities of these inputs, processes, and outputs, according to satisfaction, demands, and expectations of internal and external customers. If the TQM has been implemented in the universities with a manner that aims for customer satisfaction (students, lecturers, public and private establishments, and families, supports constant development, ensures participatory approach, and encourages working in groups, it will provide universities with effectiveness, efficiency, dynamics, and economics. In this study, common problems of universities, definitions of quality and TQM in high education, customer concept at universities, and factors affecting the quality of education have been explained. Besides, in order TQM approach to be successfully implemented in the universities, various suggestions have been presented.

  10. Determination of retinal surface area.

    Science.gov (United States)

    Nagra, Manbir; Gilmartin, Bernard; Thai, Ngoc Jade; Logan, Nicola S

    2017-09-01

    Previous attempts at determining retinal surface area and surface area of the whole eye have been based upon mathematical calculations derived from retinal photographs, schematic eyes and retinal biopsies of donor eyes. 3-dimensional (3-D) ocular magnetic resonance imaging (MRI) allows a more direct measurement, it can be used to image the eye in vivo, and there is no risk of tissue shrinkage. The primary purpose of this study is to compare, using T2-weighted 3D MRI, retinal surface areas for superior-temporal (ST), inferior-temporal (IT), superior-nasal (SN) and inferior-nasal (IN) retinal quadrants. An ancillary aim is to examine whether inter-quadrant variations in area are concordant with reported inter-quadrant patterns of susceptibility to retinal breaks associated with posterior vitreous detachment (PVD). Seventy-three adult participants presenting without retinal pathology (mean age 26.25 ± 6.06 years) were scanned using a Siemens 3-Tesla MRI scanner to provide T2-weighted MR images that demarcate fluid-filled internal structures for the whole eye and provide high-contrast delineation of the vitreous-retina interface. Integrated MRI software generated total internal ocular surface area (TSA). The second nodal point was used to demarcate the origin of the peripheral retina in order to calculate total retinal surface area (RSA) and quadrant retinal surface areas (QRSA) for ST, IT, SN, and IN quadrants. Mean spherical error (MSE) was -2.50 ± 4.03D and mean axial length (AL) 24.51 ± 1.57 mm. Mean TSA and RSA for the RE were 2058 ± 189 and 1363 ± 160 mm 2 , respectively. Repeated measures anova for QRSA data indicated a significant difference within-quadrants (P area/mm increase in AL. Although the differences between QRSAs are relatively small, there was evidence of concordance with reported inter-quadrant patterns of susceptibility to retinal breaks associated with PVD. The data allow AL to be converted to QRSAs, which will assist further

  11. Kaempferol targets estrogen-related receptor α and suppresses the angiogenesis of human retinal endothelial cells under high glucose conditions.

    Science.gov (United States)

    Wu, Yan; Zhang, Qinmei; Zhang, Rui

    2017-12-01

    Diabetic retinopathy (DR) is the most common complication of diabetes and a major cause of new-onset blindness in the developed world. The present study aimed to examine the effect of kaempferol on high glucose-induced human retinal endothelial cells (HRECs) in vitro . The expression levels of various mRNAs and proteins were measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting, respectively. The target of kaempferol was determined using a luciferase reporter assay. In addition, HREC proliferation, migration and cell sprouting were determined using Cell Counting kit-8, wound scratch and tube formation assays, respectively. RT-qPCR and western blotting results showed that treatment with 30 mM glucose for 12, 24 and 48 h increased the expression level of estrogen-related receptor α (ERRα) mRNA and protein. The luciferase reporter assay demonstrated that kaempferol inhibited ERRα activity in HRECs. Compared with 5 mM normal glucose treatment, high (30 mM) glucose significantly promoted the proliferation, migration and tube formation of HRECs, which was antagonized by 10 and 30 µM kaempferol in a dose-dependent manner. Treatment with 30 mM glucose also increased the expression of vascular endothelial growth factor (VEGF) mRNA and protein, and the expression levels of VEGF mRNA and protein were suppressed by kaempferol (10 and 30 µM). Kaempferol (30 µM) treatment also increased the expression levels of thrombospondin 1 (TSP-1) and a disintegrin and metalloproteinase with thrombospondin motifs 1 (ADAMTS-1) mRNA; however, TSP-1 and ADAMTS-1 levels did not differ between high glucose and normal (5 mM) glucose conditions. The results of this study suggest that kaempferol targets ERRα and suppresses the angiogenesis of HRECs under high glucose conditions. Kaempferol may be a potential drug for use in controlling the progression of DR; however, in vivo studies are required to evaluate its efficacy and safety.

  12. Clinical Abservation of Krypton Laser Photocoagulation Preventing Retinal Detachment after LASIK on High Myopia%眼底激光预防中高度近视LASIK术后视网膜脱离的临床观察

    Institute of Scientific and Technical Information of China (English)

    周建平; 胡莉群; 胡长青

    2014-01-01

    目的观察LASIK术前对中高度近视患者行预防性眼底激光光凝的疗效。方法准备接受LASIK手术的中高度近视患者作详细眼底检查,直接眼底镜、间接眼底镜和三面镜检查明确有视网膜变性或(和)干性裂孔的患者共61例(112眼)行氪激光光凝治疗。结果61例(112眼)患者氪激光光凝术后变性区及裂孔封闭良好,未发生视网膜脱离。结论对明确有视网膜变性和裂孔的中高度近视患者LASIK术前行氪激光光凝是预防LASIK术后发生孔源性视网膜脱离的一种安全有效的方法。%Objective To observe the effect of krypton laser photocoagulation before LASIK on high myopia. Methods Full fundus examination on high myopic patients was performed with direct ophthalmoscopy, indirect ophthalmoscopy and three mirror contact lens. 112 eyes of 61 patients with peripheral retinal degeneration or retinal hole were treated by krypton laser photocoagulation before LASIK. Results 112 eyes of 61 patients with peripheral retinal degeneration or retinal hole were stable after krypton laser photocoagulation.No retinal detachment was occurred. Conclusion The krypton laser photocoagulation is a safe and ef ective method to preventing retinal detachment for the patients with peripheral retinal degeneration or retinal hole.

  13. Diabetes and Retinal Vascular Dysfunction

    Directory of Open Access Journals (Sweden)

    Eui Seok Shin

    2014-01-01

    Full Text Available Diabetes predominantly affects the microvascular circulation of the retina resulting in a range of structural changes unique to this tissue. These changes ultimately lead to altered permeability, hyperproliferation of endothelial cells and edema, and abnormal vascularization of the retina with resulting loss of vision. Enhanced production of inflammatory mediators and oxidative stress are primary insults with significant contribution to the pathogenesis of diabetic retinopathy (DR. We have determined the identity of the retinal vascular cells affected by hyperglycemia, and have delineated the cell autonomous impact of high glucose on function of these cells. We discuss some of the high glucose specific changes in retinal vascular cells and their contribution to retinal vascular dysfunction. This knowledge provides novel insight into the molecular and cellular defects contributing to the development and progression of diabetic retinopathy, and will aid in the development of innovative, as well as target specific therapeutic approaches for prevention and treatment of DR.

  14. MR detection of retinal hemorrhages: correlation with graded ophthalmologic exam

    International Nuclear Information System (INIS)

    Beavers, Angela J.; Allbery, Sandra M.; Stagner, Anna M.; Hejkal, Thomas W.; Lyden, Elizabeth R.; Haney, Suzanne B.

    2015-01-01

    Dilated fundoscopic exam is considered the gold standard for detecting retinal hemorrhage, but expertise in obtaining this exam is not always immediately available. MRI can detect retinal hemorrhages, but correlation of the grade or severity of retinal hemorrhage on dilated fundoscopic exam with retinal hemorrhage visibility on MRI has not been described. To determine the value of standard brain protocol MRI in detecting retinal hemorrhage and to determine whether there is any correlation with MR detection of retinal hemorrhage and the dilated fundoscopic exam grade of hemorrhage. We conducted a retrospective chart review of 77 children <2 years old who were seen for head trauma from April 2007 to July 2013 and had both brain MRI and dilated fundoscopic exam or retinal camera images. A staff pediatric radiologist and radiology resident reviewed the MR images. Retinal hemorrhages were graded by a chief ophthalmology resident on a 12-point scale based on the retinal hemorrhage type, size, location and extent as seen on review of retinal camera images and detailed reports by ophthalmologists. Higher scores indicated increased severity of retinal hemorrhages. There was a statistically significant difference in the median grade of retinal hemorrhage examination between children who had retinal hemorrhage detected on MRI and children who did not have retinal hemorrhage detected on MRI (P = 0.02). When examination grade was categorized as low-grade (1-4), moderate-grade (5-8) or high-grade (>8) hemorrhage, there was a statistically significant association between exam grade and diagnosis based on MRI (P = 0.008). For example, only 14% of children with low-grade retinal hemorrhages were identified on MRI compared to 76% of children with high-grade hemorrhages. MR detection of retinal hemorrhage demonstrated a sensitivity of 61%, specificity of 100%, positive predictive value of 100% and negative predictive value of 63%. Retinal hemorrhage was best seen on the gradient

  15. Effect of forage quality in faeces from different ruminant species fed high and low quality forage

    DEFF Research Database (Denmark)

    Jalali, A R; Nørgaard, P; Nielsen, M O

    2010-01-01

    Effect of forage quality in faeces from different ruminant species fed high and low quality forage......Effect of forage quality in faeces from different ruminant species fed high and low quality forage...

  16. Assuring quality in high-consequence engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hoover, Marcey L.; Kolb, Rachel R.

    2014-03-01

    In high-consequence engineering organizations, such as Sandia, quality assurance may be heavily dependent on staff competency. Competency-dependent quality assurance models are at risk when the environment changes, as it has with increasing attrition rates, budget and schedule cuts, and competing program priorities. Risks in Sandia's competency-dependent culture can be mitigated through changes to hiring, training, and customer engagement approaches to manage people, partners, and products. Sandia's technical quality engineering organization has been able to mitigate corporate-level risks by driving changes that benefit all departments, and in doing so has assured Sandia's commitment to excellence in high-consequence engineering and national service.

  17. Producing high-quality slash pine seeds

    Science.gov (United States)

    James Barnett; Sue Varela

    2003-01-01

    Slash pine is a desirable species. It serves many purposes and is well adapted to poorly drained flatwoods and seasonally flooded areas along the lower Coastal Plain of the Southeastern US. The use of high-quality seeds has been shown to produce uniform seedlings for outplanting, which is key to silvicultural success along the Coastal Plain and elsewhere. We present...

  18. Endorectal high dose rate brachytherapy quality assurance

    International Nuclear Information System (INIS)

    Devic, S.; Vuong, T.; Evans, M.; Podgorsak, E.

    2008-01-01

    We describe our quality assurance method for preoperative high dose rate (HDR) brachytherapy of endorectal tumours. Reproduction of the treatment planning dose distribution on a daily basis is crucial for treatment success. Due to the cylindrical symmetry, two types of adjustments are necessary: applicator rotation and dose distribution shift along the applicator axis. (author)

  19. Portable, low-priced retinal imager for eye disease screening

    Science.gov (United States)

    Soliz, Peter; Nemeth, Sheila; VanNess, Richard; Barriga, E. S.; Zamora, Gilberto

    2014-02-01

    The objective of this project was to develop and demonstrate a portable, low-priced, easy to use non-mydriatic retinal camera for eye disease screening in underserved urban and rural locations. Existing portable retinal imagers do not meet the requirements of a low-cost camera with sufficient technical capabilities (field of view, image quality, portability, battery power, and ease-of-use) to be distributed widely to low volume clinics, such as the offices of single primary care physicians serving rural communities or other economically stressed healthcare facilities. Our approach for Smart i-Rx is based primarily on a significant departure from current generations of desktop and hand-held commercial retinal cameras as well as those under development. Our techniques include: 1) Exclusive use of off-the-shelf components; 2) Integration of retinal imaging device into low-cost, high utility camera mount and chin rest; 3) Unique optical and illumination designed for small form factor; and 4) Exploitation of autofocus technology built into present digital SLR recreational cameras; and 5) Integration of a polarization technique to avoid the corneal reflex. In a prospective study, 41 out of 44 diabetics were imaged successfully. No imaging was attempted on three of the subjects due to noticeably small pupils (less than 2mm). The images were of sufficient quality to detect abnormalities related to diabetic retinopathy, such as microaneurysms and exudates. These images were compared with ones taken non-mydriatically with a Canon CR-1 Mark II camera. No cases identified as having DR by expert retinal graders were missed in the Smart i-Rx images.

  20. Evidence-based analysis of prophylactic treatment of asymptomatic retinal breaks and lattice degeneration.

    Science.gov (United States)

    Wilkinson, C P

    2000-01-01

    To assess the quality of information in the literature regarding the benefits of prophylactic treatment of asymptomatic retinal tears and lattice degeneration. Asymptomatic retinal breaks occur in approximately 7% of patients over age 40, and lattice degeneration is present in approximately 8% of the general population. Because retinal breaks cause retinal detachment and lattice degeneration is associated with approximately 30% of retinal detachments, prophylactic treatment of these lesions has sometimes been recommended. A panel of vitreoretinal experts performed a literature review of all publications regarding prevention of retinal detachment that have been published in English. These articles were then used to prepare recommendations for patient care in an American Academy of Ophthalmology Preferred Practice Pattern (PPP). Each recommendation was rated according to: (1) its importance in the care process and (2) the strength of evidence supporting the given recommendation. Most recommendations were rated as A (most important to patient care). Only a single publication was graded as I (providing strong evidence in support of a recommendation), and this was not a prospective trial. Of the few publications rated as II (substantial evidence), most were studies documenting a lack of treatment benefit. Because of an absence of level I and level II studies in the literature, level III (consensus of expert opinion) was the basis for most recommendations in the PPP. The current literature regarding prevention of retinal detachment does not provide sufficient information to support strongly prophylactic treatment of lesions other than symptomatic flap tears. Prospective randomized trials of prophylactic therapy are indicated. Eyes highly predisposed to retinal detachment should be considered for such studies.

  1. [To cognize retinitis pigmentosa with scientific view].

    Science.gov (United States)

    Li, Gen-lin

    2009-03-01

    Retinitis pigmentosa (RP) is the most common inherited eye disease that usually leads into blind, and is high simplex and clinical heterogeneity. Recent years, some new hereditary forms have been found, such as digenic RP, mitochondrial RP, incomplete dominant inheritance RP. The phenotype of RP is multiplicity. Incompatible phenomenon between genotype and phenotypes was shown in some genes such as peripherin/RDS, RHO, RP2 and RP3. The complicated phenotype was shown in the rare RP forms, such as centricity RP, stemma RP, retinitis pigmentosa sine pigmento, and retinal degeneration slow. Retinal transplantation, retinal implantation, drug and neurotrophic factor therapy, and gene therapy have been well studied worldwide and presented some hopeful efficacy. Ophthalmologists and practitioners should cognize the new advance and new knowledge on RP therapy with a scientific view for better serving the RP patients.

  2. High Quality Virtual Reality for Architectural Exhibitions

    DEFF Research Database (Denmark)

    Kreutzberg, Anette

    2016-01-01

    This paper will summarise the findings from creating and implementing a visually high quality Virtual Reality (VR) experiment as part of an international architecture exhibition. It was the aim to represent the architectural spatial qualities as well as the atmosphere created from combining natural...... and artificial lighting in a prominent not yet built project. The outcome is twofold: Findings concerning the integration of VR in an exhibition space and findings concerning the experience of the virtual space itself. In the exhibition, an important aspect was the unmanned exhibition space, requiring the VR...... experience to be self-explanatory. Observations of different visitor reactions to the unmanned VR experience compared with visitor reactions at guided tours with personal instructions are evaluated. Data on perception of realism, spatial quality and light in the VR model were collected with qualitative...

  3. High quality transportation fuels from renewable feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Lindfors, Lars Peter

    2010-09-15

    Hydrotreating of vegetable oils is novel process for producing high quality renewable diesel. Hydrotreated vegetable oils (HVO) are paraffinic hydrocarbons. They are free of aromatics, have high cetane numbers and reduce emissions. HVO can be used as component or as such. HVO processes can also be modified to produce jet fuel. GHG savings by HVO use are significant compared to fossil fuels. HVO is already in commercial production. Neste Oil is producing its NExBTL diesel in two plants. Production of renewable fuels will be limited by availability of sustainable feedstock. Therefore R and D efforts are made to expand feedstock base further.

  4. Boiling curve in high quality flow boiling

    International Nuclear Information System (INIS)

    Shiralkar, B.S.; Hein, R.A.; Yadigaroglu, G.

    1980-01-01

    The post dry-out heat transfer regime of the flow boiling curve was investigated experimentally for high pressure water at high qualities. The test section was a short round tube located downstream of a hot patch created by a temperature controlled segment of tubing. Results from the experiment showed that the distance from the dryout point has a significant effect on the downstream temperatures and there was no unique boiling curve. The heat transfer coefficients measured sufficiently downstream of the dryout point could be correlated using the Heineman correlation for superheated steam, indicating that the droplet deposition effects could be neglected in this region

  5. Breeding and maintaining high-quality insects

    DEFF Research Database (Denmark)

    Jensen, Kim; Kristensen, Torsten Nygård; Heckmann, Lars-Henrik

    2017-01-01

    Insects have a large potential for sustainably enhancing global food and feed production, and commercial insect production is a rising industry of high economic value. Insects suitable for production typically have fast growth, short generation time, efficient nutrient utilization, high...... reproductive potential, and thrive at high density. Insects may cost-efficiently convert agricultural and industrial food by-products into valuable protein once the technology is finetuned. However, since insect mass production is a new industry, the technology needed to efficiently farm these animals is still...... in a starting phase. Here, we discuss the challenges and precautions that need to be considered when breeding and maintaining high-quality insect populations for food and feed. This involves techniques typically used in domestic animal breeding programs including maintaining genetically healthy populations...

  6. Focal retinal phlebitis.

    Science.gov (United States)

    Hoang, Quan V; Freund, K Bailey; Klancnik, James M; Sorenson, John A; Cunningham, Emmett T; Yannuzzi, Lawrence A

    2012-01-01

    To report three cases of solitary, focal retinal phlebitis. An observational case series. Three eyes in three patients were noted to have unilateral decreased vision, macular edema, and a focal retinal phlebitis, which was not at an arteriovenous crossing. All three patients developed a branch retinal vein occlusion at the site of inflammation. These patients had no other evidence of intraocular inflammation, including vitritis, retinitis, retinal vasculitis, or choroiditis, nor was there any systemic disorder associated with inflammation, infection, or coagulation identified. Focal retinal phlebitis appears to be an uncommon and unique entity that produces macular edema and ultimately branch retinal vein occlusion. In our patients, the focal phlebitis and venous occlusion did not occur at an arteriovenous crossing, which is the typical site for branch retinal venous occlusive disease. This suggests that our cases represent a distinct clinical entity, which starts with a focal abnormality in the wall of a retinal venule, resulting in surrounding exudation and, ultimately, ends with branch retinal vein occlusion.

  7. Retinal detachment following endophthalmitis.

    Science.gov (United States)

    Nelsen, P T; Marcus, D A; Bovino, J A

    1985-08-01

    Fifty-five consecutive patients with a clinical diagnosis of bacterial endophthalmitis were reviewed. All patients were treated with systemic, periocular, topical, and intravitreal antibiotics. In addition, 33 of the patients underwent a pars plana vitrectomy. Nine retinal detachments occurred within six months of initial diagnosis. The higher frequency of retinal detachment in the vitrectomy group (21%) as compared to those patients managed without vitrectomy (9%) may be explained by a combination of surgical complications and the increased severity of endophthalmitis in the vitrectomy group. The two patients who developed retinal detachment during vitrectomy surgery rapidly progressed to no light perception. Conversely, the repair of retinal detachments diagnosed postoperatively had a good prognosis.

  8. Bilateral acute retinal necrosis after herpetic meningitis

    Directory of Open Access Journals (Sweden)

    Katsura T

    2012-04-01

    Full Text Available Keisho Hirota1,2, Masayuki Akimoto1,3, Toshiaki Katsura21Department of Ophthalmology, Kyoto Medical Center, National Hospital Organization, 2Internal Medicine, Kyoto Medical Center, 3Clinical Research Center, Kyoto Medical Center, Kyoto, JapanPurpose: The report of a case of bilateral acute retinal necrosis after herpetic meningitis.Case report: A 47-year-old man was admitted with the chief complaint of persistent high fever and transient loss of consciousness. Although his general condition improved after intravenous acyclovir administration, the patient presented with visual loss in both eyes 4 days after admission. Visual acuity in his right eye was 20/200 and his left eye had light perception alone. Both eyes showed panretinal arteritis diagnosed as acute retinal necrosis. Panretinal photocoagulation was performed for both eyes. Progression of retinal detachment was prevented in both eyes; however, visual acuity of the left eye was totally lost because of neovascular glaucoma. Visual acuity of the right eye recovered to 20/20.Conclusion: Although cases of bilateral acute retinal necrosis have been reported after herpetic encephalitis, this condition is rare after herpetic meningitis. Prophylactic acyclovir therapy and early panretinal photocoagulation may prevent retinal detachment and improve the prognosis. Neurologists and ophthalmologists should be aware that not only herpetic encephalitis but also herpetic meningitis can lead to acute retinal necrosis within a very short interval.Keywords: acute retinal necrosis, herpetic meningitis, herpes simplex, varicella zoster virus

  9. Genomic analysis of mouse retinal development.

    Directory of Open Access Journals (Sweden)

    Seth Blackshaw

    2004-09-01

    Full Text Available The vertebrate retina is comprised of seven major cell types that are generated in overlapping but well-defined intervals. To identify genes that might regulate retinal development, gene expression in the developing retina was profiled at multiple time points using serial analysis of gene expression (SAGE. The expression patterns of 1,051 genes that showed developmentally dynamic expression by SAGE were investigated using in situ hybridization. A molecular atlas of gene expression in the developing and mature retina was thereby constructed, along with a taxonomic classification of developmental gene expression patterns. Genes were identified that label both temporal and spatial subsets of mitotic progenitor cells. For each developing and mature major retinal cell type, genes selectively expressed in that cell type were identified. The gene expression profiles of retinal Müller glia and mitotic progenitor cells were found to be highly similar, suggesting that Müller glia might serve to produce multiple retinal cell types under the right conditions. In addition, multiple transcripts that were evolutionarily conserved that did not appear to encode open reading frames of more than 100 amino acids in length ("noncoding RNAs" were found to be dynamically and specifically expressed in developing and mature retinal cell types. Finally, many photoreceptor-enriched genes that mapped to chromosomal intervals containing retinal disease genes were identified. These data serve as a starting point for functional investigations of the roles of these genes in retinal development and physiology.

  10. Retinal oxygen saturation before and after glaucoma surgery.

    Science.gov (United States)

    Nitta, Eri; Hirooka, Kazuyuki; Shimazaki, Takeru; Sato, Shino; Ukegawa, Kaori; Nakano, Yuki; Tsujikawa, Akitaka

    2017-08-01

    This study compared retinal vessel oxygen saturation before and after glaucoma surgery. Retinal oxygen saturation in glaucoma patients was measured using a non-invasive spectrophotometric retinal oximeter. Adequate image quality was found in 49 of the 108 consecutive glaucoma patients recruited, with 30 undergoing trabeculectomy, 11 EX-PRESS and eight trabeculotomy. Retinal oxygen saturation measurements in the retinal arterioles and venules were performed at 1 day prior to and at approximately 10 days after surgery. Statistical analysis was performed using a Student's t-test. After glaucoma surgery, intraocular pressure (IOP) decreased from 19.8 ± 7.7 mmHg to 9.0 ± 5.7 mmHg (p glaucoma surgery had an effect on the retinal venous oxygen saturation. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  11. Retinal oximetry in patients with ischaemic retinal diseases

    DEFF Research Database (Denmark)

    Rilvén, Sandra; Torp, Thomas Lee; Grauslund, Jakob

    2017-01-01

    The retinal oximeter is a new tool for non-invasive measurement of retinal oxygen saturation in humans. Several studies have investigated the associations between retinal oxygen saturation and retinal diseases. In the present systematic review, we examine whether there are associations between...... retinal oxygen saturation and retinal ischaemic diseases. We used PubMed and Embase to search for retinal oxygen saturation and retinal ischaemic diseases. Three separate searches identified a total of 79 publications. After two levels of manual screening, 10 studies were included: six about diabetic...... retinopathy (DR) and four about retinal vein occlusion. No studies about retinal artery occlusion were included. In diabetes, all studies found that increases in retinal venous oxygen saturation (rvSatO2 ) were associated with present as well as increasing levels of DR. Four of six studies also found...

  12. Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells

    International Nuclear Information System (INIS)

    Eissa, Laila A.; Smith, Sylvia B.; El-sherbeny, Amira A.

    2006-01-01

    Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

  13. In 6- to 8-year-old children, hair cortisol is associated with body mass index and somatic complaints, but not with stress, health-related quality of life, blood pressure, retinal vessel diameters, and cardiorespiratory fitness.

    Science.gov (United States)

    Gerber, Markus; Endes, Katharina; Brand, Serge; Herrmann, Christian; Colledge, Flora; Donath, Lars; Faude, Oliver; Pühse, Uwe; Hanssen, Henner; Zahner, Lukas

    2017-02-01

    Hair cortisol measurement has become an increasingly accepted approach in endocrinology and biopsychology. However, while in adult research hair cortisol has been proposed as a relevant biomarker for chronic stress (and its adverse consequences), studies with children are scarce. Therefore, the goal of the present exploratory study was to examine the associations between hair cortisol concentrations (HCCs), stress, and a series of health-related outcomes in a sample of Swiss first grade schoolchildren. The sample consisted of 318 children (53% girls, M age =7.26, SD=0.35). Hair strands were taken near the scalp from a posterior vertex position, and HCCs were tested for the first 3-cm hair segment. Parents provided information about their children's age, gender, parental education, children's stress (recent critical life events, daily hassles), health-related quality of life, and psychosomatic complaints. Body composition, blood pressure, retinal vessel diameters, and cardiorespiratory fitness were measured with established methods. In multiple regression analyses, higher HCCs were weakly associated with increased BMI in girls (β=0.22, pstress, health-related quality of life, blood pressure, retinal vessel diameters, and cardiorespiratory fitness. Although small significant relationships were found between HCCs, BMI and somatic complaints, the findings of this exploratory study challenge the view that HCCs can be used as a reliable biomarker of recent critical life events, daily hassles, health-related quality of life, and cardiovascular health indicators in non-clinical young children. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. A novel MERTK deletion is a common founder mutation in the Faroe Islands and is responsible for a high proportion of retinitis pigmentosa cases

    DEFF Research Database (Denmark)

    Ostergaard, Elsebet; Duno, Morten; Batbayli, Mustafa

    2011-01-01

    The aim of the study was to elucidate the genetic background of retinitis pigmentosa (RP) in a Faroe Islands population, a genetic isolate in the North Atlantic Ocean.......The aim of the study was to elucidate the genetic background of retinitis pigmentosa (RP) in a Faroe Islands population, a genetic isolate in the North Atlantic Ocean....

  15. Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease

    NARCIS (Netherlands)

    Lambertus, S.; Bax, N.M.; Fakin, A.; Groenewoud, J.M.M.; Klevering, B.J.; Moore, A.T.; Michaelides, M.; Webster, A.R.; Wilt, G.J. van der; Hoyng, C.B.

    2017-01-01

    BACKGROUND: Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options-including gene therapy-are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt

  16. Method for synthesis of high quality graphene

    Science.gov (United States)

    Lanzara, Alessandra [Piedmont, CA; Schmid, Andreas K [Berkeley, CA; Yu, Xiaozhu [Berkeley, CA; Hwang, Choonkyu [Albany, CA; Kohl, Annemarie [Beneditkbeuern, DE; Jozwiak, Chris M [Oakland, CA

    2012-03-27

    A method is described herein for the providing of high quality graphene layers on silicon carbide wafers in a thermal process. With two wafers facing each other in close proximity, in a first vacuum heating stage, while maintained at a vacuum of around 10.sup.-6 Torr, the wafer temperature is raised to about 1500.degree. C., whereby silicon evaporates from the wafer leaving a carbon rich surface, the evaporated silicon trapped in the gap between the wafers, such that the higher vapor pressure of silicon above each of the wafers suppresses further silicon evaporation. As the temperature of the wafers is raised to about 1530.degree. C. or more, the carbon atoms self assemble themselves into graphene.

  17. High quality data: An evaluation of AIM data quality and data quality procedures

    Science.gov (United States)

    The goal of every monitoring program is to collect high-quality data which can then be used to provide information to decision makers. The Bureau of Land Management (BLM) Assessment, Inventory, and Monitoring (AIM) program is one such data set which provides rangeland status, condition, and trend in...

  18. High-picture quality industrial CT scanner

    International Nuclear Information System (INIS)

    Shoji, Takao; Nishide, Akihiko; Fujii, Masashi.

    1989-01-01

    Industrial X-ray-CT-scanners, which provide cross-sectional images of a tested sample without destroying it, are attracting attention as a new nondestructive inspection device. In 1982, Toshiba commenced the development of industrial CT scanners, and introduced the 'TOSCANER' -3000 and-4000 series. Now, the state of the art 'TOSCANER'-20000 series of CT systems has been developed incorporating the latest computer tomography and image processing technology, such as the T9506 image processor. One of the advantages of this system is its applicability to a wide range of X-ray energy . The 'TOSCANER'-20000 series can be utilized for inspecting castings and other materials with relatively low-transparency to X-rays, as well as ceramics, composite materials and other materials with high X-ray transparency. A further feature of the new system is its high-picture quality, with a high-spatial resolution resulting from a pixel size of 0.2x0.2(mm). (author)

  19. [Quality management is associated with high quality services in health care].

    Science.gov (United States)

    Nielsen, Tenna Hassert; Riis, Allan; Mainz, Jan; Jensen, Anne-Louise Degn

    2013-12-09

    In these years, quality management has been the focus in order to meet high quality services for the patients in Danish health care. This article provides information on quality management and quality improvement and it evaluates its effectiveness in achieving better organizational structures, processes and results in Danish health-care organizations. Our findings generally support that quality management is associated with high quality services in health care.

  20. Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion

    DEFF Research Database (Denmark)

    Noergaard, Michael Hove; Bach-Holm, Daniella; Scherfig, Erik

    2008-01-01

    To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs.......To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs....

  1. Optical studies of high quality synthetic diamond

    International Nuclear Information System (INIS)

    Sharp, S.J.

    1999-01-01

    This thesis is concerned with the study of fundamental and defect induced optical properties of synthetic diamond grown using high pressure, high temperature (HPHT) synthesis or chemical vapour deposition (CVD). The primary technique used for investigation is cathodoluminescence (including imaging and decay-time measurements) in addition to other forms of optical spectroscopy. This thesis is timely in that the crystallinity and purity of synthetic diamond has increased ten fold over the last few years. The diamond exciton emission, which is easily quenched by the presence of defects, is studied in high quality samples in detail. In addition the ability now exists to engineer the isotopic content of synthetic diamond to a high degree of accuracy. The experimental chapters are divided as follows: Chapter 2: High resolution, low temperature spectra reveal a splitting of the free-exciton phonon recombination emission peaks and the bound-exciton zero phonon line. Included are measurements of the variation in intensity and decay-time as a function of temperature. Chapter 3: The shift in energy of the phonon-assisted free-exciton phonon replicas with isotopic content has been measured. The shift is in agreement with the results of interatomic force model for phonon scattering due to isotope disorder. Chapter 4: A study of the shift in energy with isotopic content of the diamond of the GR1 band due to the neutral vacancy has allowed a verification of the theoretical predictions due to the Jahn Teller effect. Chapter 5: The spatial distribution of the free-exciton luminescence is studied in HPHT synthetic and CVD diamond. A variation in intensity with distance from the surface is interpreted as a significant non-radiative loss of excitons to the surface. Chapter 6: The decay-times of all known self-interstitial related centres have been measured in order to calculate the concentration of these centres present in electron irradiated diamond. (author)

  2. High Quality Data for Grid Integration Studies

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, Andrew; Draxl, Caroline; Sengupta, Manajit; Hodge, Bri-Mathias

    2017-01-22

    As variable renewable power penetration levels increase in power systems worldwide, renewable integration studies are crucial to ensure continued economic and reliable operation of the power grid. The existing electric grid infrastructure in the US in particular poses significant limitations on wind power expansion. In this presentation we will shed light on requirements for grid integration studies as far as wind and solar energy are concerned. Because wind and solar plants are strongly impacted by weather, high-resolution and high-quality weather data are required to drive power system simulations. Future data sets will have to push limits of numerical weather prediction to yield these high-resolution data sets, and wind data will have to be time-synchronized with solar data. Current wind and solar integration data sets are presented. The Wind Integration National Dataset (WIND) Toolkit is the largest and most complete grid integration data set publicly available to date. A meteorological data set, wind power production time series, and simulated forecasts created using the Weather Research and Forecasting Model run on a 2-km grid over the continental United States at a 5-min resolution is now publicly available for more than 126,000 land-based and offshore wind power production sites. The National Solar Radiation Database (NSRDB) is a similar high temporal- and spatial resolution database of 18 years of solar resource data for North America and India. The need for high-resolution weather data pushes modeling towards finer scales and closer synchronization. We also present how we anticipate such datasets developing in the future, their benefits, and the challenges with using and disseminating such large amounts of data.

  3. Automatic Detection of Retinal Exudates using a Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Nualsawat HIRANSAKOLWONG

    2013-02-01

    Full Text Available Retinal exudates are among the preliminary signs of diabetic retinopathy, a major cause of vision loss in diabetic patients. Correct and efficient screening of exudates is very expensive in professional time and may cause human error. Nowadays, the digital retinal image is frequently used to follow-up and diagnoses eye diseases. Therefore, the retinal image is crucial and essential for experts to detect exudates. Unfortunately, it is a normal situation that retinal images in Thailand are poor quality images. In this paper, we present a series of experiments on feature selection and exudates classification using the support vector machine classifiers. The retinal images are segmented following key preprocessing steps, i.e., color normalization, contrast enhancement, noise removal and color space selection. On data sets of poor quality images, sensitivity, specificity and accuracy is 94.46%, 89.52% and 92.14%, respectively.

  4. High efficiency non-viral transfection of retinal and iris pigment epithelial cells with pigment epithelium-derived factor.

    Science.gov (United States)

    Thumann, G; Stöcker, M; Maltusch, C; Salz, A K; Barth, S; Walter, P; Johnen, S

    2010-02-01

    Transplantation of pigment epithelial cells in patients with age-related macular degeneration and Parkinson's disease has the potential to improve functional rehabilitation. Genetic modification of cells before transplantation may allow the delivery of neuroprotective factors to achieve functional improvement. As transplantation of cells modified using viral vectors is complicated by the possible dissemination of viral particles and severe immune reactions, we have explored non-viral methods to insert genetic material in pigment epithelial cells. Using lipofection or nucleofection ARPE-19 cells, freshly isolated and primary retinal and iris pigment epithelial (IPE) cells were transfected with plasmids encoding green fluorescent protein (GFP) and with three plasmids encoding recombinant pigment epithelium-derived factor (PEDF) and GFP. Transfection efficiency was evaluated by fluorescence microscopy and stability of protein expression by immunoblotting. Pigment epithelial cells were successfully transfected with plasmid encoding GFP. Expression of GFP in ARPE-19 was transient, but was observed for up to 1 year in IPE cells. Analysis of pigment epithelial cells transfected with PEDF plasmids revealed that PEDF fusion proteins were successfully expressed and functionally active. In conclusion, efficient transfer of genetic information in pigment epithelial cells can be achieved using non-viral transfection protocols.

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

    Directory of Open Access Journals (Sweden)

    Xue Yang

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

  6. Detection of Clinically Significant Retinopathy of Prematurity Using Wide-angle Digital Retinal Photography

    Science.gov (United States)

    Chiang, Michael F.; Melia, Michele; Buffenn, Angela N.; Lambert, Scott R.; Recchia, Franco M.; Simpson, Jennifer L.; Yang, Michael B.

    2013-01-01

    Objective To evaluate the accuracy of detecting clinically significant retinopathy of prematurity (ROP) using wide-angle digital retinal photography. Methods Literature searches of PubMed and the Cochrane Library databases were conducted last on December 7, 2010, and yielded 414 unique citations. The authors assessed these 414 citations and marked 82 that potentially met the inclusion criteria. These 82 studies were reviewed in full text; 28 studies met inclusion criteria. The authors extracted from these studies information about study design, interventions, outcomes, and study quality. After data abstraction, 18 were excluded for study deficiencies or because they were superseded by a more recent publication. The methodologist reviewed the remaining 10 studies and assigned ratings of evidence quality; 7 studies were rated level I evidence and 3 studies were rated level III evidence. Results There is level I evidence from ≥5 studies demonstrating that digital retinal photography has high accuracy for detection of clinically significant ROP. Level III studies have reported high accuracy, without any detectable complications, from real-world operational programs intended to detect clinically significant ROP through remote site interpretation of wide-angle retinal photographs. Conclusions Wide-angle digital retinal photography has the potential to complement standard ROP care. It may provide advantages through objective documentation of clinical examination findings, improved recognition of disease progression by comparing previous photographs, and the creation of image libraries for education and research. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references. PMID:22541632

  7. Differential diagnosis of retinal vasculitis.

    Science.gov (United States)

    Abu El-Asrar, Ahmed M; Herbort, Carl P; Tabbara, Khalid F

    2009-10-01

    Retinal vaculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein angiographic findings.

  8. Risk of Retinal Detachment After Pediatric Cataract Surgery

    DEFF Research Database (Denmark)

    Haargaard, Birgitte; Andersen, Elisabeth W; Oudin, Anna

    2014-01-01

    PURPOSE: To determine the long-term risk of retinal detachment following pediatric cataract surgery and to identify risk factors for retinal detachment. METHODS: We included all children (aged 0 to 17 years) who during the time period of 1977 to 2005 underwent pediatric cataract surgery in Denmark...... was based on medical chart review. RESULTS: Among 1043 eyes of 656 children undergoing surgery for pediatric cataract, 25 eyes (23 children) developed retinal detachment at a median time of 9.1 years after surgery. The overall 20-year risk of retinal detachment was 7% (95% confidence interval [CI]: 3...... (16% [95% CI: 6%-24%]). CONCLUSIONS: The estimated overall risk of retinal detachment 20 years after pediatric cataract surgery was 7%, but only 3% for isolated cataract. Particularly high risks of retinal detachment after cataract surgery were associated with mental retardation and having other...

  9. Interventions for asymptomatic retinal breaks and lattice degeneration for preventing retinal detachment.

    Science.gov (United States)

    Wilkinson, Charles P

    2014-09-05

    Asymptomatic retinal breaks and lattice degeneration are visible lesions that are risk factors for later retinal detachment. Retinal detachments occur when fluid in the vitreous cavity passes through tears or holes in the retina and separates the retina from the underlying retinal pigment epithelium. Creation of an adhesion surrounding retinal breaks and lattice degeneration, with laser photocoagulation or cryotherapy, has been recommended as an effective means of preventing retinal detachment. This therapy is of value in the management of retinal tears associated with the symptoms of flashes and floaters and persistent vitreous traction upon the retina in the region of the retinal break, because such symptomatic retinal tears are associated with a high rate of progression to retinal detachment. Retinal tears and holes unassociated with acute symptoms and lattice degeneration are significantly less likely to be the sites of retinal breaks that are responsible for later retinal detachment. Nevertheless, treatment of these lesions frequently is recommended, in spite of the fact that the effectiveness of this therapy is unproven. The objective of this review was to assess the effectiveness and safety of techniques used to treat asymptomatic retinal breaks and lattice degeneration for the prevention of retinal detachment. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 2), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to February 2014), EMBASE (January 1980 to February 2014), PubMed (January 1948 to February 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials

  10. [Prophylactic treatment of retinal detachment].

    Science.gov (United States)

    Binder, S; Riss, B

    1981-08-01

    The indications for and results of prophylactic treatment of retinal detachment during a period of five years are reported and compared with the results in the literature. Half of the cases (3 out of 6 eyes) which developed a retinal detachment had been horse-shoe tears combined with a vitreous hemorrhage. For this reason a small buckle operation is recommended in these cases, to prevent further traction. Lattice degeneration should rather be observed than treated, except in special cases: This includes eyes where the fellow eye had a detachment from a lattice degeneration, cases in which one eye is blind from an uncured detachment or has no useful visual acuity, and eyes whose fellow eye has giant tears. In aphakic eyes treatment of lattice degeneration is recommended, because the incidence of detachment from these areas is high, especially in young aphakic cases. In one aphakic eye which had been photocoagulated several times the formation of a preretinal membrane was observed.

  11. High-resolution imaging of retinal nerve fiber bundles in glaucoma using adaptive optics scanning laser ophthalmoscopy.

    Science.gov (United States)

    Takayama, Kohei; Ooto, Sotaro; Hangai, Masanori; Ueda-Arakawa, Naoko; Yoshida, Sachiko; Akagi, Tadamichi; Ikeda, Hanako Ohashi; Nonaka, Atsushi; Hanebuchi, Masaaki; Inoue, Takashi; Yoshimura, Nagahisa

    2013-05-01

    To detect pathologic changes in retinal nerve fiber bundles in glaucomatous eyes seen on images obtained by adaptive optics (AO) scanning laser ophthalmoscopy (AO SLO). Prospective cross-sectional study. Twenty-eight eyes of 28 patients with open-angle glaucoma and 21 normal eyes of 21 volunteer subjects underwent a full ophthalmologic examination, visual field testing using a Humphrey Field Analyzer, fundus photography, red-free SLO imaging, spectral-domain optical coherence tomography, and imaging with an original prototype AO SLO system. The AO SLO images showed many hyperreflective bundles suggesting nerve fiber bundles. In glaucomatous eyes, the nerve fiber bundles were narrower than in normal eyes, and the nerve fiber layer thickness was correlated with the nerve fiber bundle widths on AO SLO (P fiber layer defect area on fundus photography, the nerve fiber bundles on AO SLO were narrower compared with those in normal eyes (P optic disc, the nerve fiber bundle width was significantly lower, even in areas without nerve fiber layer defect, in eyes with glaucomatous eyes compared with normal eyes (P = .026). The mean deviations of each cluster in visual field testing were correlated with the corresponding nerve fiber bundle widths (P = .017). AO SLO images showed reduced nerve fiber bundle widths both in clinically normal and abnormal areas of glaucomatous eyes, and these abnormalities were associated with visual field defects, suggesting that AO SLO may be useful for detecting early nerve fiber bundle abnormalities associated with loss of visual function. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Ensuring High-Quality Learning for All

    Science.gov (United States)

    Núñez, Elsa M.

    2018-01-01

    The Association of American Colleges and Universities (AAC&U) has embarked on a sustained program to enhance the quality of student learning on campuses, while also supporting AAC&U members' efforts to bring liberal education to all sectors of society. This commitment to quality and equity in service to democracy forms the basis for…

  13. Retinal detachment secondary to ocular perforation during retrobulbar Anaesthesia

    Directory of Open Access Journals (Sweden)

    Gopal Lingam

    1995-01-01

    Full Text Available The clinical characteristics and the retinal breaks associated with rhegmatogenous retinal detachments secondary to accidental globe perforation during local infiltration anaesthesia in five highly myopic eyes are presented. Retinal detachment was total with variable proliferative vitreoretinopathy. The pattern of retinal breaks was rather typical and predictable. Management involved vitreous surgery with internal tamponade by silicone oil in four eyes and perfluoropropane gas in one eye. At the last follow-up, all eyes had attached retina. One eye did not recover useful vision due to possible concurrent optic nerve damage.

  14. The Impact of Macronutrients on Retinal Microvasculature among Singapore Pregnant Women during the Mid-Late Gestation.

    Science.gov (United States)

    Li, Ling-Jun; Ong, Peng Guan; Colega, Marjorelee T; Han, Chad Yixian; Chen, Ling Wei; Man Eyn Kidd, Ryan; Lamoureux, Ecosse; Gluckman, Peter; Kwek, Kenneth; Chong, Yap Seng; Saw, Seang Mei; Godfrey, Keith M; Wong, Tien Yin; Chong Foong-Fong, Mary

    2016-01-01

    Imbalanced macronutrient intakes can induce impairment of endothelial and vascular function, and further lead to metabolic and cardiovascular disease. However, little is known about the influence of such diets on endothelial and vascular dysfunction in pregnant women, even though high-fat diet is a known risk for pregnancy complications such as gestational diabetes and pre-eclampsia. We aimed to assess the association between maternal macronutrient intakes (protein, fat and carbohydrates), dietary quality and retinal microvascular changes in a multi-ethnic Asian mother-offspring cohort. Pregnant women (n = 614) with singleton pregnancies were recruited during their first trimester from June 2009 to Sep 2010. Maternal diet quality and macronutrient intakes, expressed as a percentage of total energy during pregnancy, were ascertained using 24 hr recalls and 3 d food diaries at 26-28 weeks gestation. Retinal examination was completed at the same clinic visit. Dietary quality was assessed and scored using the Health Eating Index in Asian Pregnant women (HEI-AP), while macronutrients intakes ware expressed as percentages of total energy and further log transformed for analysis. Associations were examined cross-sectionally by substitution models with the use of multiple linear regression. In adjusted model, each 20 points decrease in HEI-AP score was associated with a significant increase of 1.70 μm (p<0.05) in retinal venular calibre. Each 0.1 log increase in percentage of total fat intake was associated with a significant increment of 1.84 μm (p<0.05) in retinal venular caliber. Additionally, each 0.1 log increase in percentage of mono-unsaturated fat intake was associated with an increment of 1.84 μm (p<0.01) in retinal venular caliber. In this cross-sectional study, we found that women with higher fat and lower protein intakes, and lower diet quality tended to have wider retinal venular caliber, which is suggestive of suboptimal microvasculature.

  15. Validation of Smartphone Based Retinal Photography for Diabetic Retinopathy Screening.

    Science.gov (United States)

    Rajalakshmi, Ramachandran; Arulmalar, Subramanian; Usha, Manoharan; Prathiba, Vijayaraghavan; Kareemuddin, Khaji Syed; Anjana, Ranjit Mohan; Mohan, Viswanathan

    2015-01-01

    To evaluate the sensitivity and specificity of "fundus on phone' (FOP) camera, a smartphone based retinal imaging system, as a screening tool for diabetic retinopathy (DR) detection and DR severity in comparison with 7-standard field digital retinal photography. Single-site, prospective, comparative, instrument validation study. 301 patients (602 eyes) with type 2 diabetes underwent standard seven-field digital fundus photography with both Carl Zeiss fundus camera and indigenous FOP at a tertiary care diabetes centre in South India. Grading of DR was performed by two independent retina specialists using modified Early Treatment of Diabetic Retinopathy Study grading system. Sight threatening DR (STDR) was defined by the presence of proliferative DR(PDR) or diabetic macular edema. The sensitivity, specificity and image quality were assessed. The mean age of the participants was 53.5 ±9.6 years and mean duration of diabetes 12.5±7.3 years. The Zeiss camera showed that 43.9% had non-proliferative DR(NPDR) and 15.3% had PDR while the FOP camera showed that 40.2% had NPDR and 15.3% had PDR. The sensitivity and specificity for detecting any DR by FOP was 92.7% (95%CI 87.8-96.1) and 98.4% (95%CI 94.3-99.8) respectively and the kappa (ĸ) agreement was 0.90 (95%CI-0.85-0.95 p<0.001) while for STDR, the sensitivity was 87.9% (95%CI 83.2-92.9), specificity 94.9% (95%CI 89.7-98.2) and ĸ agreement was 0.80 (95%CI 0.71-0.89 p<0.001), compared to conventional photography. Retinal photography using FOP camera is effective for screening and diagnosis of DR and STDR with high sensitivity and specificity and has substantial agreement with conventional retinal photography.

  16. Validation of Smartphone Based Retinal Photography for Diabetic Retinopathy Screening.

    Directory of Open Access Journals (Sweden)

    Ramachandran Rajalakshmi

    Full Text Available To evaluate the sensitivity and specificity of "fundus on phone' (FOP camera, a smartphone based retinal imaging system, as a screening tool for diabetic retinopathy (DR detection and DR severity in comparison with 7-standard field digital retinal photography.Single-site, prospective, comparative, instrument validation study.301 patients (602 eyes with type 2 diabetes underwent standard seven-field digital fundus photography with both Carl Zeiss fundus camera and indigenous FOP at a tertiary care diabetes centre in South India. Grading of DR was performed by two independent retina specialists using modified Early Treatment of Diabetic Retinopathy Study grading system. Sight threatening DR (STDR was defined by the presence of proliferative DR(PDR or diabetic macular edema. The sensitivity, specificity and image quality were assessed.The mean age of the participants was 53.5 ±9.6 years and mean duration of diabetes 12.5±7.3 years. The Zeiss camera showed that 43.9% had non-proliferative DR(NPDR and 15.3% had PDR while the FOP camera showed that 40.2% had NPDR and 15.3% had PDR. The sensitivity and specificity for detecting any DR by FOP was 92.7% (95%CI 87.8-96.1 and 98.4% (95%CI 94.3-99.8 respectively and the kappa (ĸ agreement was 0.90 (95%CI-0.85-0.95 p<0.001 while for STDR, the sensitivity was 87.9% (95%CI 83.2-92.9, specificity 94.9% (95%CI 89.7-98.2 and ĸ agreement was 0.80 (95%CI 0.71-0.89 p<0.001, compared to conventional photography.Retinal photography using FOP camera is effective for screening and diagnosis of DR and STDR with high sensitivity and specificity and has substantial agreement with conventional retinal photography.

  17. Retinal Detachment Vision Simulator

    Science.gov (United States)

    ... Feb 20, 2018 Gene Therapy May Be a Game-Changer for People With Inherited Retinal Disease Dec 19, 2017 ... the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For ...

  18. Learning about Retinitis Pigmentosa

    Science.gov (United States)

    Skip to main content Learning about Retinitis Pigmentosa Enter Search Term(s): Español Research Funding An Overview Bioinformatics Current Grants Education and Training Funding Extramural Research ...

  19. Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease

    OpenAIRE

    Lambertus, Stanley; Bax, Nathalie M.; Fakin, Ana; Groenewoud, Joannes M. M.; Klevering, B. Jeroen; Moore, Anthony T.; Michaelides, Michel; Webster, Andrew R.; van der Wilt, Gert Jan; Hoyng, Carel B.

    2017-01-01

    BACKGROUND: Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options-including gene therapy-are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt disease. In each case, the specific combination of ABCA4 variants (> 900 identified to date) and modifying factors is virtually unique. It accounts for the vast phenotypic heterogeneity including vari...

  20. Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease

    OpenAIRE

    Lambertus, S.; Bax, N. M.; Fakin, A.; Groenewoud, J. M. M.; Klevering, B. J.; Moore, A. T.; Michaelides, M.; Webster, A. R.; van der Wilt, G. J.; Hoyng, C. B.

    2017-01-01

    BACKGROUND: Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options—including gene therapy—are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt disease. In each case, the specific combination of ABCA4 variants (> 900 identified to date) and modifying factors is virtually unique. It accounts for the vast phenotypic heterogeneity including ...

  1. 7,8-Dihydroxyflavone ameliorates high-glucose induced diabetic apoptosis in human retinal pigment epithelial cells by activating TrkB.

    Science.gov (United States)

    Yu, Xiaoyi; Liu, Qiuhong; Wang, Xiaochuan; Liu, Hong; Wang, Yan

    2018-01-01

    In diabetic retinopathy, prolonged high-level blood glucose induced significant impairments among various retinal tissues, including retinal pigment epithelial (RPE) cells. In an in vitro model of human RPE cells, we evaluated whether 7,8-Dihydroxyflavone (DHF) may effectively prevent high glucose-induced diabetic apoptosis among human RPE cells. ARPE-19 cells, a Human RPE cell line, were treated with d-glucose (50 mM) to induce apoptosis in vitro. Prior to glucose, ARPE-19 cells were pre-incubated with various concentrations of DHF. The effect of DHF on d-glucose-induced apoptosis was examined by TUNEL assay, in a concentration-dependent manner. The biological effects of DHF on Caspase-9 (Casp-9) and TrkB signaling pathways in d-glucose-injured ARPE-19 cells were evaluated by qRT-PCR and western blot (WB) assays. A TrkB antagonist, K252a, was also applied in DHF and d-glucose treated ARPE-19 cells. Possible effect of K252a blocking TrkB signaling pathway, thus reversing DHF-modulated apoptosis prevention was also examined by TUNEL and WB assays. DHF ameliorated d-glucose-induced diabetic apoptosis in ARPE-19 cells. Apoptotic factor Casp-9, at both mRNA and protein levels, were drastically inhibited by DHF in d-glucose-injured ARPE-19 cells. Also, DHF activated TrkB signaling pathway through phosphorylation. K252a dramatically reversed the preventive effect of DHF on d-glucose-induced apoptosis in ARPE-19 cells. Further investigation showed that K252a functioned through de-activating or de-phosphorylating TrkB signaling pathway. This work demonstrates that DHF, through activation of TrkB signaling pathway, has a preventive function in d-glucose-induced apoptosis in PRE cells in diabetic retinopathy. Copyright © 2017. Published by Elsevier Inc.

  2. High Efficiency, Illumination Quality OLEDs for Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

    2008-03-31

    The goal of the program was to demonstrate a 45 lumen per watt white light device based upon the use of multiple emission colors through the use of solution processing. This performance level is a dramatic extension of the team's previous 15 LPW large area illumination device. The fundamental material system was based upon commercial polymer materials. The team was largely able to achieve these goals, and was able to deliver to DOE a 90 lumen illumination source that had an average performance of 34 LPW a 1000 cd/m{sup 2} with peak performances near 40LPW. The average color temperature is 3200K and the calculated CRI 85. The device operated at a brightness of approximately 1000cd/m{sup 2}. The use of multiple emission colors particularly red and blue, provided additional degrees of design flexibility in achieving white light, but also required the use of a multilayered structure to separate the different recombination zones and prevent interconversion of blue emission to red emission. The use of commercial materials had the advantage that improvements by the chemical manufacturers in charge transport efficiency, operating life and material purity could be rapidly incorporated without the expenditure of additional effort. The program was designed to take maximum advantage of the known characteristics of these material and proceeded in seven steps. (1) Identify the most promising materials, (2) assemble them into multi-layer structures to control excitation and transport within the OLED, (3) identify materials development needs that would optimize performance within multilayer structures, (4) build a prototype that demonstrates the potential entitlement of the novel multilayer OLED architecture (5) integrate all of the developments to find the single best materials set to implement the novel multilayer architecture, (6) further optimize the best materials set, (7) make a large area high illumination quality white OLED. A photo of the final deliverable is shown

  3. Analysis of high-quality modes in open chaotic microcavities

    International Nuclear Information System (INIS)

    Fang, W.; Yamilov, A.; Cao, H.

    2005-01-01

    We present a numerical study of the high-quality modes in two-dimensional dielectric stadium microcavities. Although the classical ray mechanics is fully chaotic in a stadium billiard, all of the high-quality modes show a 'strong scar' around unstable periodic orbits. When the deformation (ratio of the length of the straight segments over the diameter of the half circles) is small, the high-quality modes correspond to whispering-gallery-type trajectories and their quality factors decrease monotonically with increasing deformation. At large deformation, each high-quality mode is associated with multiple unstable periodic orbits. Its quality factor changes nonmonotonically with the deformation, and there exists an optimal deformation for each mode at which its quality factor reaches a local maximum. This unusual behavior is attributed to the interference of waves propagating along different constituent orbits that could minimize light leakage out of the cavity

  4. Progressive outer retinal necrosis-like retinitis in immunocompetent hosts.

    Science.gov (United States)

    Chawla, Rohan; Tripathy, Koushik; Gogia, Varun; Venkatesh, Pradeep

    2016-08-10

    We describe two young immunocompetent women presenting with bilateral retinitis with outer retinal necrosis involving posterior pole with centrifugal spread and multifocal lesions simulating progressive outer retinal necrosis (PORN) like retinitis. Serology was negative for HIV and CD4 counts were normal; however, both women were on oral steroids at presentation for suspected autoimmune chorioretinitis. The retinitis in both eyes responded well to oral valaciclovir therapy. However, the eye with the more fulminant involvement developed retinal detachment with a loss of vision. Retinal atrophy was seen in the less involved eye with preservation of vision. Through these cases, we aim to describe a unique evolution of PORN-like retinitis in immunocompetent women, which was probably aggravated by a short-term immunosuppression secondary to oral steroids. 2016 BMJ Publishing Group Ltd.

  5. High quality steel casting for energy technics

    International Nuclear Information System (INIS)

    Schuster, F.; Koefler, G.

    1982-01-01

    The casting of several chromium-molybdenum steels for steam and hydraulic turbines is discussed. Non-destructive testing of the castings is performed demonstrating the safety for use in nuclear technology. The effect of metallurgical parameters on steel casting quality, the heat treatment, and the effect of construction design on costs for fettling and repair weldings are considered. (Auth.)

  6. Variable retinal presentations in nanophthalmos

    International Nuclear Information System (INIS)

    Khan, A.; Zafar, S.N.

    2009-01-01

    Nanophthalmos is an uncommon developmental ocular disorder characterized by a small eye with short axial length, high hyperopia and high lens/eye volume ratio due to arrested development of the globe in all directions. Different types of fundus changes can rarely occur with nanophthalmos. We describe five cases of nanophthalmos, each of them presenting with a different fundus appearance. Our case series highlights variability of pigmentary changes from retinal flecks to bone spicules and bull's eye maculopathy, which are rare in the combinations described here. (author)

  7. Outcome of surgery in post-cytomegalovirus retinal detachment: Experience before and in the era of highly active anti-retroviral therapy in Indian eyes

    Directory of Open Access Journals (Sweden)

    Ramandeep Singh

    2013-01-01

    Full Text Available Purpose: To evaluate the outcome of surgery for cytomegalovirus associated retinal detachment (CMVRD in human immunodeficiency virus (HIV-infected patients in pre-highly active antiretroviral therapy (HAART and HAART era in Indian eyes. Materials and Methods: Retrospective, we reviewed medical records of all consecutive HIV patients, who underwent surgical repair for CMVRD from July 1998 to June 2011. We divided patients into two groups, i.e. group 1, pre HAART era and group 2, HAART era. We compared two groups for various parameters like visual outcome, surgical success, additional procedures, follow-up, etc., Results: Twenty-eight eyes of 26 patients were included; 12 eyes of the 11 patients in group 1 and 16 eyes of the 15 patients in group 2. Significant visual acuity improvement was seen in both groups. Complete anatomic success was seen in 11 eyes in group 1 and 15 eyes in group 2. One additional procedure in group 1 and 29 additional procedures were done in group 2. A mean follow-up was 16 months in group 1 and 41 months in group 2. Conclusion: There was no difference in outcome in pre-HAART and HAART group, except for longer follow-up and additional surgical procedures in HAART group.

  8. A meta-analysis of vitrectomy with or without internal limiting membrane peeling for macular hole retinal detachment in the highly myopic eyes.

    Science.gov (United States)

    Gao, Xinxiao; Guo, Jia; Meng, Xin; Wang, Jun; Peng, Xiaoyan; Ikuno, Yasushi

    2016-06-13

    To evaluate the anatomical and visual outcomes by par plana vitrectomy with or without internal limiting membrane (ILM) peeling in highly myopic eyes with macular hole retinal detachment (MHRD). MEDLINE (Ovid, PubMed) and EMBASE were used for data collection up to September 30, 2015. The parameters of anatomical success, macular hole closure and improved best corrected visual acuity (BCVA) at or beyond 6 months after operation were assessed as the primary outcome measurement. The meta-analysis was performed with the fixed-effects model. Seven comparative analyses involving a total of 373 patients were included in the present meta-analysis. Statistically the pooled data showed significant relative risk (RR) in terms of primary reattachment between ILM peeling and non-peeling groups (RR, 1.19; 95 % CI, 1.04 to 1.36; P = 0.012). An effect favoring ILM peeling with regard to macular hole closure was also detected (RR, 1.71; 95 % CI, 1.20 to 2.43; P = 0.003). However, no statistically significant difference was found in the improved BCVA (logarithm of the minimum angle of resolution) at 6 months or more (95 % CI, -0.31 to 0.44; P = 0.738). There is no proved benefit of postoperative visual improvement. However, the available evidences from this study suggested a superiority of ILM peeling over no peeling for myopic patients with MHRD.

  9. Retinal shows its true colours

    DEFF Research Database (Denmark)

    Coughlan, N. J.A.; Adamson, B. D.; Gamon, L.

    2015-01-01

    Retinal is one of Nature's most important and widespread chromophores, exhibiting remarkable versatility in its function and spectral response, depending on its protein environment. Reliable spectroscopic and photochemical data for the isolated retinal molecule are essential for calibrating theor...

  10. Retinal findings in membranoproliferative glomerulonephritis

    Directory of Open Access Journals (Sweden)

    Ahmad M. Mansour

    2017-09-01

    Conclusions and importance: Drusen remain the ocular stigmata for MPGN occuring at an early age. The retinal disease is progressive with gradual thickening of Bruch's membrane and occurrence of retinal pigment epithelium detachment.

  11. Indoor Air Quality in High Performance Schools

    Science.gov (United States)

    High performance schools are facilities that improve the learning environment while saving energy, resources, and money. The key is understanding the lifetime value of high performance schools and effectively managing priorities, time, and budget.

  12. Bioelectronic retinal prosthesis

    Science.gov (United States)

    Weiland, James D.

    2016-05-01

    Retinal prosthesis have been translated to clinical use over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa and one device is in clinical trials for treatment of age-related macular degeneration. These devices provide partial sight restoration and patients use this improved vision in their everyday lives to navigate and to detect large objects. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. In particular, current retinal prostheses do not provide peripheral visions due to technical and surgical limitations, thus limiting the effectiveness of the treatment. This paper reviews recent results from human implant patients and presents technical approaches for peripheral vision.

  13. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  14. Progressive outer retinal necrosis (PORN) in AIDS patients: a different appearance of varicella-zoster retinitis.

    Science.gov (United States)

    Pavesio, C E; Mitchell, S M; Barton, K; Schwartz, S D; Towler, H M; Lightman, S

    1995-01-01

    Retinal infections caused by the varicella-zoster virus (VZV) have been reported in immunocompetent and immunocompromised individuals. Two cases of a VZV-related retinitis are described with the characteristic features of the recently described progressive outer retinal necrosis (PORN) syndrome. Both patients suffered from the acquired immunodeficiency syndrome (AIDS) with greatly reduced peripheral blood CD4+ T lymphocyte counts, and presented with macular retinitis without vitritis. The disease was bilateral in one case and unilateral in the other. The clinical course was rapidly progressive with widespread retinal involvement and the development of rhegmatogenous retinal detachment with complete loss of vision in the affected eyes despite intensive intravenous antiviral therapy. VZV DNA was identified in vitreous biopsies, by molecular techniques based on the polymerase chain reaction (PCR), in both patients. At present, the use of very high-dose intravenous acyclovir may be the best therapeutic option in these patients for whom the visual prognosis is poor. Intravitreal antiviral drugs could also contribute to the management of these cases.

  15. Sector retinitis pigmentosa.

    Science.gov (United States)

    Van Woerkom, Craig; Ferrucci, Steven

    2005-05-01

    Retinitis pigmentosa (RP) is one of the most common hereditary retinal dystrophies and causes of visual impairment affecting all age groups. The reported incidence varies, but is considered to be between 1 in 3,000 to 1 in 7,000. Sector retinitis pigmentosa is an atypical form of RP that is characterized by regionalized areas of bone spicule pigmentation, usually in the inferior quadrants of the retina. A 57-year-old Hispanic man with a history of previously diagnosed retinitis pigmentosa came to the clinic with a longstanding symptom of decreased vision at night. Bone spicule pigmentation was found in the nasal and inferior quadrants in each eye. He demonstrated superior and temporal visual-field loss corresponding to the areas of the affected retina. Clinical measurements of visual-field loss, best-corrected visual acuity, and ophthalmoscopic appearance have remained stable during the five years the patient has been followed. Sector retinitis pigmentosa is an atypical form of RP that is characterized by bilateral pigmentary retinopathy, usually isolated to the inferior quadrants. The remainder of the retina appears clinically normal, although studies have found functional abnormalities in these areas as well. Sector RP is generally considered a stationary to slowly progressive disease, with subnormal electro-retinogram findings and visual-field defects corresponding to the involved retinal sectors. Management of RP is very difficult because there are no proven methods of treatment. Studies have shown 15,000 IU of vitamin A palmitate per day may slow the progression, though this result is controversial. Low vision rehabilitation, long wavelength pass filters, and pedigree counseling remain the mainstay of management.

  16. Rhegmatogenous retinal detachment and uveitis.

    Science.gov (United States)

    Kerkhoff, Frank T; Lamberts, Querin J; van den Biesen, Pieter R; Rothova, Aniki

    2003-02-01

    To evaluate the frequency, high-risk factors, and visual prognosis of rhegmatogenous retinal detachment (RRD) in patients with uveitis. Retrospective case-control study. We included 1387 consecutive patients with uveitis who consulted our uveitis clinic from January 1990 through December 1997 of whom 43 patients (46 eyes) with RRD were identified. The retinal detachment (RD) controls were 212 consecutive patients with RRD (221 eyes, first occurrence of RD, not associated with uveitis) who were admitted for surgery in the period from April 1999 to April 2000. The uveitis control group consisted of 150 age-matched patients (210 eyes) selected from the entire uveitis series. Retrospective analysis of clinical data. The presence of RRD and eventual risk factors for RRD, such as myopia, retinal lattice degeneration, prior intraocular surgery, anatomic location of uveitis, its specific diagnosis, and clinical manifestations. Furthermore, the surgical and nonsurgical outcomes of RRD, as well as the results of various treatment regimens, were analyzed. RRD was identified in 3.1% of the patients with uveitis. RRD was most frequently associated with panuveitis (6.6%). RRD was associated more frequently with infectious (7.6%) than noninfectious uveitis (2.1%). At the onset of RRD, uveitis was active in most (46%) affected eyes. Proliferative vitreoretinopathy was present in 30% of the uveitic RRD eyes at presentation in contrast to 12% of the RRD control eyes. In uveitic RRD, the retina was reattached in 59% of eyes with a single operation; the final anatomic reattachment rate was 88%. Finally, a visual acuity of less than 20/200 was present in 71% of the uveitic RRD eyes, 10% of which had no light perception. We discovered a high prevalence of RRD in patients with active panuveitis and infectious uveitis and document that uveitis in itself is a risk factor for the development of RRD. The visual prognosis of RRD in uveitis was poor because of the uveitis itself and the

  17. Quality Assurance Strategy for Existing Homes: Final Quality Management Primer for High Performing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Del Bianco, M.; Taggart, J.; Sikora, J.; Wood, A.

    2012-12-01

    This guide is designed to help Building America (BA) Teams understand quality management and its role in transitioning from conventional to high performance home building and remodeling. It explains what quality means, the value of quality management systems, the unique need for QMS when building high performing homes, and the first steps to a implementing a comprehensive QMS. This document provides a framework and context for BA teams when they encounter builders and remodelers.

  18. Quality Assurance Strategy for Existing Homes. Final Quality Management Primer for High Performing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Del Bianco, M. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Taggart, J. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Sikora, J. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States); Wood, A. [NAHB Research Center Industry Partnership, Upper Marlboro, MD (United States)

    2012-12-01

    This guide is designed to help Building America (BA) teams understand quality management and its role in transitioning from conventional to high performance home building and remodeling. It explains what quality means, the value of quality management systems, the unique need for QMS when building high performing homes, and the first steps to a implementing a comprehensive QMS. This document provides a framework and context for BA teams when they encounter builders and remodelers.

  19. Nondiabetic retinal pathology - prevalence in diabetic retinopathy screening.

    Science.gov (United States)

    Nielsen, Nathan; Jackson, Claire; Spurling, Geoffrey; Cranstoun, Peter

    2011-07-01

    To determine the prevalence of photographic signs of nondiabetic retinal pathology in Australian general practice patients with diabetes. Three hundred and seven patients with diabetes underwent retinal photography at two general practices, one of which was an indigenous health centre. The images were assessed for signs of pathology by an ophthalmologist. Signs of nondiabetic retinal pathology were detected in 31% of subjects with adequate photographs. Features suspicious of glaucoma were detected in 7.7% of subjects. Other abnormalities detected included signs of age related macular degeneration (1.9%), epiretinal membranes (2.4%), vascular pathology (9.6%), chorioretinal lesions (2.9%), and congenital disc anomalies (2.9%). Indigenous Australian patients were more likely to have signs of retinal pathology and glaucoma. Signs of nondiabetic retinal pathology were frequently encountered. In high risk groups, general practice based diabetic retinopathy screening may reduce the incidence of preventable visual impairment, beyond the benefits of detection of diabetic retinopathy alone.

  20. Retinal glia promote dorsal root ganglion axon regeneration.

    Directory of Open Access Journals (Sweden)

    Barbara Lorber

    Full Text Available Axon regeneration in the adult central nervous system (CNS is limited by several factors including a lack of neurotrophic support. Recent studies have shown that glia from the adult rat CNS, specifically retinal astrocytes and Müller glia, can promote regeneration of retinal ganglion cell axons. In the present study we investigated whether retinal glia also exert a growth promoting effect outside the visual system. We found that retinal glial conditioned medium significantly enhanced neurite growth and branching of adult rat dorsal root ganglion neurons (DRG in culture. Furthermore, transplantation of retinal glia significantly enhanced regeneration of DRG axons past the dorsal root entry zone after root crush in adult rats. To identify the factors that mediate the growth promoting effects of retinal glia, mass spectrometric analysis of retinal glial conditioned medium was performed. Apolipoprotein E and secreted protein acidic and rich in cysteine (SPARC were found to be present in high abundance, a finding further confirmed by western blotting. Inhibition of Apolipoprotein E and SPARC significantly reduced the neuritogenic effects of retinal glial conditioned medium on DRG in culture, suggesting that Apolipoprotein E and SPARC are the major mediators of this regenerative response.

  1. Inequality in Preschool Quality? Community-Level Disparities in Access to High-Quality Learning Environments

    Science.gov (United States)

    Bassok, Daphna; Galdo, Eva

    2016-01-01

    In recent years, unequal access to high-quality preschool has emerged as a growing public policy concern. Because of data limitations, it is notoriously difficult to measure disparities in access to early learning opportunities across communities and particularly challenging to quantify gaps in access to "high-quality" programs. Research…

  2. Layer-specific blood-flow MRI of retinitis pigmentosa in RCS rats☆

    Science.gov (United States)

    Li, Guang; Garza, Bryan De La; Shih, Yen-Yu I.; Muir, Eric R.; Duong, Timothy Q.

    2013-01-01

    The Royal College of Surgeons (RCS) rat is an established animal model of retinitis pigmentosa, a family of inherited retinal diseases which starts with loss of peripheral vision and progresses to eventual blindness. Blood flow (BF), an important physiological parameter, is intricately coupled to metabolic function under normal physiological conditions and is perturbed in many neurological and retinal diseases. This study reports non-invasive high-resolution MRI (44 × 44 × 600 μm) to image quantitative retinal and choroidal BF and layer-specific retinal thicknesses in RCS rat retinas at different stages of retinal degeneration compared with age-matched controls. The unique ability to separate retinal and choroidal BF was made possible by the depth-resolved MRI technique. RBF decreased with progressive retinal degeneration, but ChBF did not change in RCS rats up to post-natal day 90. We concluded that choroidal and retinal circulations have different susceptibility to progressive retinal degeneration in RCS rats. Layer-specific retinal thickness became progressively thinner and was corroborated by histological analysis in the same animals. MRI can detect progressive anatomical and BF changes during retinal degeneration with laminar resolution. PMID:22721720

  3. Layer-specific blood-flow MRI of retinitis pigmentosa in RCS rats.

    Science.gov (United States)

    Li, Guang; De La Garza, Bryan; Shih, Yen-Yu I; Muir, Eric R; Duong, Timothy Q

    2012-08-01

    The Royal College of Surgeons (RCS) rat is an established animal model of retinitis pigmentosa, a family of inherited retinal diseases which starts with loss of peripheral vision and progresses to eventual blindness. Blood flow (BF), an important physiological parameter, is intricately coupled to metabolic function under normal physiological conditions and is perturbed in many neurological and retinal diseases. This study reports non-invasive high-resolution MRI (44 × 44 × 600 μm) to image quantitative retinal and choroidal BF and layer-specific retinal thicknesses in RCS rat retinas at different stages of retinal degeneration compared with age-matched controls. The unique ability to separate retinal and choroidal BF was made possible by the depth-resolved MRI technique. RBF decreased with progressive retinal degeneration, but ChBF did not change in RCS rats up to post-natal day 90. We concluded that choroidal and retinal circulations have different susceptibility to progressive retinal degeneration in RCS rats. Layer-specific retinal thickness became progressively thinner and was corroborated by histological analysis in the same animals. MRI can detect progressive anatomical and BF changes during retinal degeneration with laminar resolution. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Oxygen-induced retinopathy in mice with retinal photoreceptor cell degeneration.

    Science.gov (United States)

    Zhang, Qian; Zhang, Zuo-Ming

    2014-04-25

    It is reported that retinal neovascularization seems to rarely co-exist with retinitis pigmentosa in patients and in some mouse models; however, it is not widely acknowledged as a universal phenomenon in all strains of all animal species. We aimed to further explore this phenomenon with an oxygen-induced retinopathy model in mice with retinal photoreceptor cell degeneration. Oxygen-induced retinopathy of colored and albino mice with rapid retinal degeneration were compared to homologous wild-type mice. The retinas were analyzed using high-molecular-weight FITC-dextran stained flat-mount preparation, hematoxylin and eosin (H&E) stained cross-sections, an immunohistochemical test for vascular endothelial growth factor (VEGF) distribution and Western blotting for VEGF expression after exposure to hyperoxia between postnatal days 17 (P17) and 21. Leakage and areas of non-perfusion of the retinal blood vessels were alleviated in the retinal degeneration mice. The number of preretinal vascular endothelial cell nuclei in the retinal degeneration mice was smaller than that in the homologous wild-type mice after exposure to hyperoxia (Poxygen-induced retinopathy was positively correlated with the VEGF expression level. However, the VEGF expression level was lower in the retinal degeneration mice. Proliferative retinopathy occurred in mice with rapid retinal degeneration, but retinal photoreceptor cell degeneration could partially restrain the retinal neovascularization in this rapid retinal degeneration mouse model. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. The effect of normal childbirth on eyes with abnormalities predisposing to rhegmatogenous retinal detachment.

    Science.gov (United States)

    Landau, D; Seelenfreund, M H; Tadmor, O; Silverstone, B Z; Diamant, Y

    1995-09-01

    Pregnant women who have high myopia, a history of retinal detachment or retinal holes, or have known lattice degeneration are frequently referred to an ophthalmologist for advice concerning the management of pregnancy and labor, i.e. whether a spontaneous vaginal delivery can be allowed and whether prophylaxis for high-risk retinal pathology is indicated. Many obstetricians still believe that pregnant women with ocular abnormalities predisposing to rhegmatogenous retinal detachment should have an instrumental delivery, and a few even advocate cesarian section. Very little has been written about the management of pregnant women with high-risk retinal pathology, and opinions differ considerably. Patient data on this subject are scarce. We studied 10 women who had 19 deliveries (10 prospective and 9 retrospective) and who had a history of retinal detachment, had been diagnosed as having extensive lattice degeneration, or had been treated for symptomatic retinal holes or breaks. The women were followed from the third trimester of pregnancy through labor and delivery into the postpartum period, looking for changes in the retinal status. We found no changes in the retinal status in the postpartum examination. We conclude that prenatal treatment of asymptomatic retinal pathology is not indicated and that spontaneous vaginal delivery may be allowed to take place in women with high-risk retinal pathology.

  6. End-to-End Adversarial Retinal Image Synthesis.

    Science.gov (United States)

    Costa, Pedro; Galdran, Adrian; Meyer, Maria Ines; Niemeijer, Meindert; Abramoff, Michael; Mendonca, Ana Maria; Campilho, Aurelio

    2018-03-01

    In medical image analysis applications, the availability of the large amounts of annotated data is becoming increasingly critical. However, annotated medical data is often scarce and costly to obtain. In this paper, we address the problem of synthesizing retinal color images by applying recent techniques based on adversarial learning. In this setting, a generative model is trained to maximize a loss function provided by a second model attempting to classify its output into real or synthetic. In particular, we propose to implement an adversarial autoencoder for the task of retinal vessel network synthesis. We use the generated vessel trees as an intermediate stage for the generation of color retinal images, which is accomplished with a generative adversarial network. Both models require the optimization of almost everywhere differentiable loss functions, which allows us to train them jointly. The resulting model offers an end-to-end retinal image synthesis system capable of generating as many retinal images as the user requires, with their corresponding vessel networks, by sampling from a simple probability distribution that we impose to the associated latent space. We show that the learned latent space contains a well-defined semantic structure, implying that we can perform calculations in the space of retinal images, e.g., smoothly interpolating new data points between two retinal images. Visual and quantitative results demonstrate that the synthesized images are substantially different from those in the training set, while being also anatomically consistent and displaying a reasonable visual quality.

  7. Genetic characterization and disease mechanism of retinitis pigmentosa; current scenario.

    Science.gov (United States)

    Ali, Muhammad Umar; Rahman, Muhammad Saif Ur; Cao, Jiang; Yuan, Ping Xi

    2017-08-01

    Retinitis pigmentosa is a group of genetically transmitted disorders affecting 1 in 3000-8000 individual people worldwide ultimately affecting the quality of life. Retinitis pigmentosa is characterized as a heterogeneous genetic disorder which leads by progressive devolution of the retina leading to a progressive visual loss. It can occur in syndromic (with Usher syndrome and Bardet-Biedl syndrome) as well as non-syndromic nature. The mode of inheritance can be X-linked, autosomal dominant or autosomal recessive manner. To date 58 genes have been reported to associate with retinitis pigmentosa most of them are either expressed in photoreceptors or the retinal pigment epithelium. This review focuses on the disease mechanisms and genetics of retinitis pigmentosa. As retinitis pigmentosa is tremendously heterogeneous disorder expressing a multiplicity of mutations; different variations in the same gene might induce different disorders. In recent years, latest technologies including whole-exome sequencing contributing effectively to uncover the hidden genesis of retinitis pigmentosa by reporting new genetic mutations. In future, these advancements will help in better understanding the genotype-phenotype correlations of disease and likely to develop new therapies.

  8. Nanomaterials and Retinal Toxicity

    Science.gov (United States)

    The neuroretina should be considered as a potential site of nanomaterial toxicity. Engineered nanomaterials may reach the retina through three potential routes of exposure including; intra­ vitreal injection of therapeutics; blood-borne delivery in the retinal vasculature an...

  9. Highly sensitive in vitro methods for detection of residual undifferentiated cells in retinal pigment epithelial cells derived from human iPS cells.

    Directory of Open Access Journals (Sweden)

    Takuya Kuroda

    Full Text Available Human induced pluripotent stem cells (hiPSCs possess the capabilities of self-renewal and differentiation into multiple cell types, and they are free of the ethical problems associated with human embryonic stem cells (hESCs. These characteristics make hiPSCs a promising choice for future regenerative medicine research. There are significant obstacles, however, preventing the clinical use of hiPSCs. One of the most obvious safety issues is the presence of residual undifferentiated cells that have tumorigenic potential. To locate residual undifferentiated cells, in vivo teratoma formation assays have been performed with immunodeficient animals, which is both costly and time-consuming. Here, we examined three in vitro assay methods to detect undifferentiated cells (designated an in vitro tumorigenicity assay: soft agar colony formation assay, flow cytometry assay and quantitative real-time polymerase chain reaction assay (qRT-PCR. Although the soft agar colony formation assay was unable to detect hiPSCs even in the presence of a ROCK inhibitor that permits survival of dissociated hiPSCs/hESCs, the flow cytometry assay using anti-TRA-1-60 antibody detected 0.1% undifferentiated hiPSCs that were spiked in primary retinal pigment epithelial (RPE cells. Moreover, qRT-PCR with a specific probe and primers was found to detect a trace amount of Lin28 mRNA, which is equivalent to that present in a mixture of a single hiPSC and 5.0×10⁴ RPE cells. Our findings provide highly sensitive and quantitative in vitro assays essential for facilitating safety profiling of hiPSC-derived products for future regenerative medicine research.

  10. Application of a high-throughput genotyping method for loci exclusion in non-consanguineous Australian pedigrees with autosomal recessive retinitis pigmentosa.

    Science.gov (United States)

    Paterson, Rachel L; De Roach, John N; McLaren, Terri L; Hewitt, Alex W; Hoffmann, Ling; Lamey, Tina M

    2012-01-01

    Retinitis pigmentosa (RP) is the most common form of inherited blindness, caused by progressive degeneration of photoreceptor cells in the retina, and affects approximately 1 in 3,000 people. Over the past decade, significant progress has been made in gene therapy for RP and related diseases, making genetic characterization increasingly important. Recently, high-throughput technologies have provided an option for reasonably fast, cost-effective genetic characterization of autosomal recessive RP (arRP). The current study used a single nucleotide polymorphism (SNP) genotyping method to exclude up to 28 possible disease-causing genes in 31 non-consanguineous Australian families affected by arRP. DNA samples were collected from 59 individuals affected with arRP and 74 unaffected family members from 31 Australian families. Five to six SNPs were genotyped for 28 genes known to cause arRP or the related disease Leber congenital amaurosis (LCA). Cosegregation analyses were used to exclude possible causative genes from each of the 31 families. Bidirectional sequencing was used to identify disease-causing mutations in prioritized genes that were not excluded with cosegregation analyses. Two families were excluded from analysis due to identification of false paternity. An average of 28.9% of genes were excluded per family when only one affected individual was available, in contrast to an average of 71.4% or 89.8% of genes when either two, or three or more affected individuals were analyzed, respectively. A statistically significant relationship between the proportion of genes excluded and the number of affected individuals analyzed was identified using a multivariate regression model (pA) and USH2A in two families (c.2276 G>T). This study has shown that SNP genotyping cosegregation analysis can be successfully used to refine and expedite the genetic characterization of arRP in a non-consanguineous population; however, this method is effective only when DNA samples are

  11. A Comprehensive Review of Retinal Gene Therapy

    OpenAIRE

    Boye, Shannon E; Boye, Sanford L; Lewin, Alfred S; Hauswirth, William W

    2013-01-01

    Blindness, although not life threatening, is a debilitating disorder for which few, if any treatments exist. Ocular gene therapies have the potential to profoundly improve the quality of life in patients with inherited retinal disease. As such, tremendous focus has been given to develop such therapies. Several factors make the eye an ideal organ for gene-replacement therapy including its accessibility, immune privilege, small size, compartmentalization, and the existence of a contralateral co...

  12. Prediction of bread-making quality using size exclusion high ...

    African Journals Online (AJOL)

    Variation in the distribution of protein molecular weight in wheat (Triticum aestivum), influences breadmaking quality of wheat cultivars, resulting in either poor or good bread. The objective of this study was to predict breadmaking quality of wheat cultivars using size exclusion high performance liquid chromatography.

  13. Adoption and impact of high quality bambara flour (HQBF ...

    African Journals Online (AJOL)

    Adoption and impact of high quality bambara flour (HQBF) technology in the ... consumer acceptability/quality of products, credit, availability of raw materials, and ... as a result of 12.5 per cent increase in demand for bambara-based products.

  14. Preclinical evaluation and intraoperative human retinal imaging with a high-resolution microscope-integrated spectral domain optical coherence tomography device.

    Science.gov (United States)

    Hahn, Paul; Migacz, Justin; O'Donnell, Rachelle; Day, Shelley; Lee, Annie; Lin, Phoebe; Vann, Robin; Kuo, Anthony; Fekrat, Sharon; Mruthyunjaya, Prithvi; Postel, Eric A; Izatt, Joseph A; Toth, Cynthia A

    2013-01-01

    and vitreomacular traction, and demonstrated postsurgical changes in retinal morphology. Two cohorts of five patients were imaged. In the second cohort, the predefined end points were exceeded with ≥80% correlation between microscope-mounted OCT and HHOCT imaging in 100% of the patients. This report describes high-resolution MIOCT imaging using the prototype device in human eyes during vitreoretinal surgery, with successful achievement of predefined end points for imaging. Further refinements and investigations will be directed toward fully integrating MIOCT with vitreoretinal and other ocular surgery to image surgical maneuvers in real time.

  15. Peripapillary retinal thermal coagulation following electrical injury

    Directory of Open Access Journals (Sweden)

    Manjari Tandon

    2013-01-01

    Full Text Available In this study, we have presented the case report of a 20 year old boy who suffered an electric injury shock, following which he showed peripapillary retinal opacification and increased retinal thickening that subsequently progressed to retinal atrophy. The fluorescein angiogram revealed normal retinal circulation, thus indicating thermal damage to retina without any compromise to retinal circulation.

  16. Quack: A quality assurance tool for high throughput sequence data.

    Science.gov (United States)

    Thrash, Adam; Arick, Mark; Peterson, Daniel G

    2018-05-01

    The quality of data generated by high-throughput DNA sequencing tools must be rapidly assessed in order to determine how useful the data may be in making biological discoveries; higher quality data leads to more confident results and conclusions. Due to the ever-increasing size of data sets and the importance of rapid quality assessment, tools that analyze sequencing data should quickly produce easily interpretable graphics. Quack addresses these issues by generating information-dense visualizations from FASTQ files at a speed far surpassing other publicly available quality assurance tools in a manner independent of sequencing technology. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Innovative and high quality education through Open Education and OER

    OpenAIRE

    Stracke, Christian M.

    2017-01-01

    Online presentation and webinar by Stracke, C. M. (2017, 18 December) on "Innovative and high quality education through Open Education and OER" for the Belt and Road Open Education Learning Week by the Beijing Normal University, China.

  18. Improving high quality, equitable maternal health services in Malawi ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Improving high quality, equitable maternal health services in Malawi (IMCHA) ... In response, the Ministry of Health implemented a Standards-Based Management and Recognition for Reproductive Health initiative to improve ... Total funding.

  19. High Quality Education and Learning for All through Open Education

    NARCIS (Netherlands)

    Stracke, Christian M.

    2016-01-01

    Keynote at the International Lensky Education Forum 2016, Yakutsk, Republic of Sakha, Russian Federation, by Stracke, C. M. (2016, 16 August): "High Quality Education and Learning for All through Open Education"

  20. Correlation Factor Analysis of Retinal Microvascular Changes in Patients With Essential Hypertension

    Institute of Scientific and Technical Information of China (English)

    Huang Duru; Huang Zhongning

    2006-01-01

    Objectives To investigate correlation between retinal microvascular signs and essential hypertension classification. Methods The retinal microvascular signs in patients with essential hypertension were assessed with the indirect biomicroscopy lens, the direct and the indirect ophthalmoscopes were used to determine the hypertensive retinopathy grades and retinal arteriosclerosis grades.The rank correlation analysis was used to analysis the correlation these grades with the risk factors concerned with hypertension. Results Of 72 cases with essential hypertension, 28 cases complicated with coronary disease, 20 cases diabetes, 41 cases stroke,17 cases renal malfunction. Varying extent retinal arterioscleroses were found in 71 cases, 1 case with retinal hemorrhage, 2 cases with retina edema, 4 cases with retinal hard exudation, 5 cases with retinal hemorrhage complicated by hard exudation, 2 cases with retinal hemorrhage complicated by hard exudation and cotton wool spot, 1 case with retinal hemorrhage complicated by hard exudation and microaneurysms,1 case with retinal edema and hard exudation, 1 case with retinal microaneurysms, 1 case with branch retinal vein occlusion. The rank correlation analysis showed that either hypertensive retinopathy grades or retinal arteriosclerosis grades were correlated with risk factor lamination of hypertension (r=0.25 or 0.31, P<0.05), other correlation factors included age and blood high density lipoprotein concerned about hypertensive retinopathy grades or retinal arteriosclerosis grades, but other parameters, namely systolic or diastolic pressure, total cholesterol, triglyceride, low density lipoprotein cholesterol, fasting blood glucose,blood urea nitrogen and blood creatinine were not confirmed in this correlation analysis (P > 0.05).Conclusions Either hypertensive retinopathy grade or retinal arteriosclerosis grade is close with the hypertension risk factor lamination, suggesting that the fundus examination of patients with

  1. Effects of simvastatin on CAT-1-mediated arginine transport and NO level under high glucose conditions in conditionally immortalized rat inner blood-retinal barrier cell lines (TR-iBRB).

    Science.gov (United States)

    Tun, Temdara; Kang, Young-Sook

    2017-05-01

    Hyperglycemia causes the breakdown of the blood-retinal barrier by impairing endothelial nitric oxide synthase (eNOS) function. Statins have many pleiotropic effects such as improving endothelial barrier permeability and increasing eNOS mRNA stability. The objective of this study was to determine effect of simvastatin on l-arginine transport and NO production under high-glucose conditions in conditionally immortalized rat retinal capillary endothelial cell line (TR-iBRB). Changes in l-arginine transport uptake and, expression levels of cationic amino acid transporter 1 (CAT-1) and eNOS mRNA were investigated after pre-treatment with simvastatin and NOS inhibitors (l-NMMA and l-NAME) under high-glucose conditions using TR-iBRB, an in vitro model of iBRB. The NO level released from TR-iBRB cells was examined using Griess reagents. Under high glucose conditions, [ 3 H]l-arginine uptake was decreased in TR-iBRB cells. Simvastatin pretreatment elevated [ 3 H]l-arginine uptake, the expression levels of CAT-1 and eNOS mRNA, and NO production under high-glucose conditions. Moreover, the co-treatment with simvastatin and NOS inhibitors reduced [ 3 H]l-arginine uptake compared to pretreatment with simvastatin alone. Our results suggest that, in the presence of high-glucose levels, increased l-arginine uptake due to simvastatin treatment was associated with increased CAT-1 and eNOS mRNA levels, leading to higher NO production in TR-iBRB cells. Thus, simvastatin might be a good modulator for diabetic retinopathy therapy by increasing of the l-arginine uptake and improving endothelial function in retinal capillary endothelial cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Portable retinal imaging for eye disease screening using a consumer-grade digital camera

    Science.gov (United States)

    Barriga, Simon; Larichev, Andrey; Zamora, Gilberto; Soliz, Peter

    2012-03-01

    The development of affordable means to image the retina is an important step toward the implementation of eye disease screening programs. In this paper we present the i-RxCam, a low-cost, hand-held, retinal camera for widespread applications such as tele-retinal screening for eye diseases like diabetic retinopathy (DR), glaucoma, and age-related ocular diseases. Existing portable retinal imagers do not meet the requirements of a low-cost camera with sufficient technical capabilities (field of view, image quality, portability, battery power, and ease-of-use) to be distributed widely to low volume clinics, such as the offices of single primary care physicians serving rural communities. The i-RxCam uses a Nikon D3100 digital camera body. The camera has a CMOS sensor with 14.8 million pixels. We use a 50mm focal lens that gives a retinal field of view of 45 degrees. The internal autofocus can compensate for about 2D (diopters) of focusing error. The light source is an LED produced by Philips with a linear emitting area that is transformed using a light pipe to the optimal shape at the eye pupil, an annulus. To eliminate corneal reflex we use a polarization technique in which the light passes through a nano-wire polarizer plate. This is a novel type of polarizer featuring high polarization separation (contrast ratio of more than 1000) and very large acceptance angle (>45 degrees). The i-RxCam approach will yield a significantly more economical retinal imaging device that would allow mass screening of the at-risk population.

  3. Emblems of Quality in Higher Education. Developing and Sustaining High-Quality Programs.

    Science.gov (United States)

    Haworth, Jennifer Grant; Conrad, Clifton F.

    This book proposes an "engagement" theory of program quality to evaluate and improve higher education programs at all degree levels. Based on interviews with 781 participants in a national study of Masters degree programs, it focuses on the interactive roles of students, faculty, and administrators in developing high-quality programs…

  4. Retinal Prosthesis System for Advanced Retinitis Pigmentosa: A Health Technology Assessment Update

    Science.gov (United States)

    Lee, Christine; Tu, Hong Anh; Wells, David; Holubowich, Corinne

    2017-01-01

    Background Retinitis pigmentosa is a group of inherited disorders characterized by the degeneration of the photoreceptors in the retina, resulting in progressive vision loss. The Argus II system is designed to restore partial functional vision in patients with profound vision loss from advanced retinitis pigmentosa. At present, it is the only treatment option approved by Health Canada for this patient population. In June 2016, Health Quality Ontario published a health technology assessment of the Argus II retinal prosthesis system for patients with advanced retinitis pigmentosa. Based on that assessment, the Ontario Health Technology Advisory Committee recommended against publicly funding the Argus II system for this population. It also recommended that Health Quality Ontario re-evaluate the evidence in 1 year. The objective of this report was to examine new evidence published since the 2016 health technology assessment. Methods We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences related to the Argus II system. We performed a systematic literature search for studies published since the 2016 Argus II health technology assessment. We developed a Markov decision-analytic model to assess the cost-effectiveness of the Argus II system compared with standard care, and we calculated incremental cost-effectiveness ratios over a 20-year time horizon. We also conducted a five-year budget impact analysis. Finally, we interviewed people with retinitis pigmentosa about their lived experience with vision loss, and with the Argus II system. Results Four publications from one multicentre international study were included in the clinical review. Patients showed significant improvements in visual function and functional outcomes with the Argus II system, and these outcomes were sustained up to a 5-year follow-up (moderate quality of evidence). The safety profile was generally acceptable. In

  5. Type 3 Neovascularization Associated with Retinitis Pigmentosa.

    Science.gov (United States)

    Sayadi, Jihene; Miere, Alexandra; Souied, Eric H; Cohen, Salomon Y

    2017-01-01

    To report a case of type 3 neovascular lesion in a patient with retinitis pigmentosa (RP) complicated by macular edema. A 78-year-old man with a long follow-up for RP was referred for painless visual acuity decrease in the right eye. Best-corrected visual acuity was 20/125 in the right eye and 20/40 in the left. Fundus examination showed typical RP and macular edema in both eyes. In the right eye, spectral domain optical coherence tomography revealed a marked cystic macular edema associated with disruption of the Bruch membrane/retinal pigment epithelium complex overlying a pigmentary epithelium detachment, with a vascular structure which appeared to originate from the deep capillary plexus and to be connected with the subretinal pigment epithelium space. Optical coherence tomography angiography showed a high-flow vessel infiltrating the outer retinal layers in the deep capillary plexus segmentation, and a tuft-shaped, bright, high-flow network that seemed to be connected with the subretinal pigment epithelium space in the outer retinal layer segmentation. This presentation was consistent with an early type 3 neovascular lesion in the right eye. Type 3 neovascularization may be considered a possible complication of RP.

  6. Type 3 Neovascularization Associated with Retinitis Pigmentosa

    Directory of Open Access Journals (Sweden)

    Jihene Sayadi

    2017-04-01

    Full Text Available Purpose: To report a case of type 3 neovascular lesion in a patient with retinitis pigmentosa (RP complicated by macular edema. Case Report: A 78-year-old man with a long follow-up for RP was referred for painless visual acuity decrease in the right eye. Best-corrected visual acuity was 20/125 in the right eye and 20/40 in the left. Fundus examination showed typical RP and macular edema in both eyes. In the right eye, spectral domain optical coherence tomography revealed a marked cystic macular edema associated with disruption of the Bruch membrane/retinal pigment epithelium complex overlying a pigmentary epithelium detachment, with a vascular structure which appeared to originate from the deep capillary plexus and to be connected with the subretinal pigment epithelium space. Optical coherence tomography angiography showed a high-flow vessel infiltrating the outer retinal layers in the deep capillary plexus segmentation, and a tuft-shaped, bright, high-flow network that seemed to be connected with the subretinal pigment epithelium space in the outer retinal layer segmentation. This presentation was consistent with an early type 3 neovascular lesion in the right eye. Conclusion: Type 3 neovascularization may be considered a possible complication of RP.

  7. High quality, high efficiency welding technology for nuclear power plants

    International Nuclear Information System (INIS)

    Aoki, Shigeyuki; Nagura, Yasumi

    1996-01-01

    For nuclear power plants, it is required to ensure the safety under the high reliability and to attain the high rate of operation. In the manufacture and installation of the machinery and equipment, the welding techniques which become the basis exert large influence to them. For the purpose of improving joint performance and excluding human errors, welding heat input and the number of passes have been reduced, the automation of welding has been advanced, and at present, narrow gap arc welding and high energy density welding such as electron beam welding and laser welding have been put to practical use. Also in the welding of pipings, automatic gas metal arc welding is employed. As for the welding of main machinery and equipment, there are the welding of the joints that constitute pressure boundaries, the build-up welding on the internal surfaces of pressure vessels for separating primary water from them, and the sealing welding of heating tubes and tube plates in steam generators. These weldings are explained. The welding of pipings and the state of development and application of new welding methods are reported. (K.I.)

  8. Retinitis pigmentosa and deafness.

    OpenAIRE

    Mills, R P; Calver, D M

    1987-01-01

    Seventeen patients with retinitis pigmentosa (RP) have been investigated audiologically. Of 9 found to have a significant hearing loss, 6 were examples of Usher's syndrome; these patients had a cochlear pattern of hearing loss. The other 3 were examples of Senior's syndrome, Kearne-Sayre syndrome and Lawrence-Moon-Biedle syndrome respectively. Two of these patients had absent stapedius reflexes. It is suggested that patients with different RP-deafness syndromes may have lesions in different p...

  9. Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease.

    Science.gov (United States)

    Lambertus, Stanley; Bax, Nathalie M; Fakin, Ana; Groenewoud, Joannes M M; Klevering, B Jeroen; Moore, Anthony T; Michaelides, Michel; Webster, Andrew R; van der Wilt, Gert Jan; Hoyng, Carel B

    2017-01-01

    Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options-including gene therapy-are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt disease. In each case, the specific combination of ABCA4 variants (> 900 identified to date) and modifying factors is virtually unique. It accounts for the vast phenotypic heterogeneity including variable rates of functional and structural progression, thereby potentially limiting the ability of phase I/II clinical trials to assess efficacy of novel therapies with few patients. To accommodate this problem, we developed and validated a sensitive and reliable composite clinical trial endpoint for disease progression based on structural measurements of retinal degeneration. We used longitudinal data from early-onset Stargardt patients from the Netherlands (development cohort, n = 14) and the United Kingdom (external validation cohort, n = 18). The composite endpoint was derived from best-corrected visual acuity, fundus autofluorescence, and spectral-domain optical coherence tomography. Weighting optimization techniques excluded visual acuity from the composite endpoint. After optimization, the endpoint outperformed each univariable outcome, and showed an average progression of 0.41° retinal eccentricity per year (95% confidence interval, 0.30-0.52). Comparing with actual longitudinal values, the model accurately predicted progression (R2, 0.904). These properties were largely preserved in the validation cohort (0.43°/year [0.33-0.53]; prediction: R2, 0.872). We subsequently ran a two-year trial simulation with the composite endpoint, which detected a 25% decrease in disease progression with 80% statistical power using only 14 patients. These results suggest that a multimodal endpoint, reflecting structural macular changes, provides a sensitive measurement of disease progression in

  10. Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease.

    Directory of Open Access Journals (Sweden)

    Stanley Lambertus

    Full Text Available Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options-including gene therapy-are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt disease. In each case, the specific combination of ABCA4 variants (> 900 identified to date and modifying factors is virtually unique. It accounts for the vast phenotypic heterogeneity including variable rates of functional and structural progression, thereby potentially limiting the ability of phase I/II clinical trials to assess efficacy of novel therapies with few patients. To accommodate this problem, we developed and validated a sensitive and reliable composite clinical trial endpoint for disease progression based on structural measurements of retinal degeneration.We used longitudinal data from early-onset Stargardt patients from the Netherlands (development cohort, n = 14 and the United Kingdom (external validation cohort, n = 18. The composite endpoint was derived from best-corrected visual acuity, fundus autofluorescence, and spectral-domain optical coherence tomography. Weighting optimization techniques excluded visual acuity from the composite endpoint. After optimization, the endpoint outperformed each univariable outcome, and showed an average progression of 0.41° retinal eccentricity per year (95% confidence interval, 0.30-0.52. Comparing with actual longitudinal values, the model accurately predicted progression (R2, 0.904. These properties were largely preserved in the validation cohort (0.43°/year [0.33-0.53]; prediction: R2, 0.872. We subsequently ran a two-year trial simulation with the composite endpoint, which detected a 25% decrease in disease progression with 80% statistical power using only 14 patients.These results suggest that a multimodal endpoint, reflecting structural macular changes, provides a sensitive measurement of disease

  11. Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease

    Science.gov (United States)

    Bax, Nathalie M.; Fakin, Ana; Groenewoud, Joannes M. M.; Klevering, B. Jeroen; Moore, Anthony T.; Michaelides, Michel; Webster, Andrew R.; van der Wilt, Gert Jan; Hoyng, Carel B.

    2017-01-01

    Background Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options—including gene therapy—are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt disease. In each case, the specific combination of ABCA4 variants (> 900 identified to date) and modifying factors is virtually unique. It accounts for the vast phenotypic heterogeneity including variable rates of functional and structural progression, thereby potentially limiting the ability of phase I/II clinical trials to assess efficacy of novel therapies with few patients. To accommodate this problem, we developed and validated a sensitive and reliable composite clinical trial endpoint for disease progression based on structural measurements of retinal degeneration. Methods and findings We used longitudinal data from early-onset Stargardt patients from the Netherlands (development cohort, n = 14) and the United Kingdom (external validation cohort, n = 18). The composite endpoint was derived from best-corrected visual acuity, fundus autofluorescence, and spectral-domain optical coherence tomography. Weighting optimization techniques excluded visual acuity from the composite endpoint. After optimization, the endpoint outperformed each univariable outcome, and showed an average progression of 0.41° retinal eccentricity per year (95% confidence interval, 0.30–0.52). Comparing with actual longitudinal values, the model accurately predicted progression (R2, 0.904). These properties were largely preserved in the validation cohort (0.43°/year [0.33–0.53]; prediction: R2, 0.872). We subsequently ran a two-year trial simulation with the composite endpoint, which detected a 25% decrease in disease progression with 80% statistical power using only 14 patients. Conclusions These results suggest that a multimodal endpoint, reflecting structural macular changes, provides a

  12. Inherited Retinal Degenerative Disease Registry

    Science.gov (United States)

    2017-09-13

    Eye Diseases Hereditary; Retinal Disease; Achromatopsia; Bardet-Biedl Syndrome; Bassen-Kornzweig Syndrome; Batten Disease; Best Disease; Choroidal Dystrophy; Choroideremia; Cone Dystrophy; Cone-Rod Dystrophy; Congenital Stationary Night Blindness; Enhanced S-Cone Syndrome; Fundus Albipunctatus; Goldmann-Favre Syndrome; Gyrate Atrophy; Juvenile Macular Degeneration; Kearns-Sayre Syndrome; Leber Congenital Amaurosis; Refsum Syndrome; Retinitis Pigmentosa; Retinitis Punctata Albescens; Retinoschisis; Rod-Cone Dystrophy; Rod Dystrophy; Rod Monochromacy; Stargardt Disease; Usher Syndrome

  13. Concrete Waste Recycling Process for High Quality Aggregate

    International Nuclear Information System (INIS)

    Ishikura, Takeshi; Fujii, Shin-ichi

    2008-01-01

    Large amount of concrete waste generates during nuclear power plant (NPP) dismantling. Non-contaminated concrete waste is assumed to be disposed in a landfill site, but that will not be the solution especially in the future, because of decreasing tendency of the site availability and natural resources. Concerning concrete recycling, demand for roadbeds and backfill tends to be less than the amount of dismantled concrete generated in a single rural site, and conventional recycled aggregate is limited of its use to non-structural concrete, because of its inferior quality to ordinary natural aggregate. Therefore, it is vital to develop high quality recycled aggregate for general uses of dismantled concrete. If recycled aggregate is available for high structural concrete, the dismantling concrete is recyclable as aggregate for industry including nuclear field. Authors developed techniques on high quality aggregate reclamation for large amount of concrete generated during NPP decommissioning. Concrete of NPP buildings has good features for recycling aggregate; large quantity of high quality aggregate from same origin, record keeping of the aggregate origin, and little impurities in dismantled concrete such as wood and plastics. The target of recycled aggregate in this development is to meet the quality criteria for NPP concrete as prescribed in JASS 5N 'Specification for Nuclear Power Facility Reinforced Concrete' and JASS 5 'Specification for Reinforced Concrete Work'. The target of recycled aggregate concrete is to be comparable performance with ordinary aggregate concrete. The high quality recycled aggregate production techniques are assumed to apply for recycling for large amount of non-contaminated concrete. These techniques can also be applied for slightly contaminated concrete dismantled from radiological control area (RCA), together with free release survey. In conclusion: a technology on dismantled concrete recycling for high quality aggregate was developed

  14. Outcomes in bullous retinal detachment

    Directory of Open Access Journals (Sweden)

    Sarah P. Read

    2017-06-01

    Conclusions and importance: GRTs are an uncommon cause of retinal detachment. While pars plana vitrectomy with tamponade is standard in GRT management, there is variability in the use of scleral buckling and PFO in these cases. This is in contrast to retinal dialysis where scleral buckle alone can yield favorable results. Though a baseball ocular trauma is common, retinal involvement is rare compared to other sports injuries such as those occurring with tennis, soccer and golf. Sports trauma remains an important cause of retinal injury and patients should be counseled on the need for eye protection.

  15. Retinal Thickening and Photoreceptor Loss in HIV Eyes without Retinitis.

    Directory of Open Access Journals (Sweden)

    Cheryl A Arcinue

    Full Text Available To determine the presence of structural changes in HIV retinae (i.e., photoreceptor density and retinal thickness in the macula compared with age-matched HIV-negative controls.Cohort of patients with known HIV under CART (combination Antiretroviral Therapy treatment were examined with a flood-illuminated retinal AO camera to assess the cone photoreceptor mosaic and spectral-domain optical coherence tomography (SD-OCT to assess retinal layers and retinal thickness.Twenty-four eyes of 12 patients (n = 6 HIV-positive and 6 HIV-negative were imaged with the adaptive optics camera. In each of the regions of interest studied (nasal, temporal, superior, inferior, the HIV group had significantly less mean cone photoreceptor density compared with age-matched controls (difference range, 4,308-6,872 cones/mm2. A different subset of forty eyes of 20 patients (n = 10 HIV-positive and 10 HIV-negative was included in the retinal thickness measurements and retinal layer segmentation with the SD-OCT. We observed significant thickening in HIV positive eyes in the total retinal thickness at the foveal center, and in each of the three horizontal B-scans (through the macular center, superior, and inferior to the fovea. We also noted that the inner retina (combined thickness from ILM through RNFL to GCL layer was also significantly thickened in all the different locations scanned compared with HIV-negative controls.Our present study shows that the cone photoreceptor density is significantly reduced in HIV retinae compared with age-matched controls. HIV retinae also have increased macular retinal thickness that may be caused by inner retinal edema secondary to retinovascular disease in HIV. The interaction of photoreceptors with the aging RPE, as well as possible low-grade ocular inflammation causing diffuse inner retinal edema, may be the key to the progressive vision changes in HIV-positive patients without overt retinitis.

  16. Retinal nerve fiber layer in primary open-angle glaucoma with high myopia determined by optical coherence tomography and scanning laser polarimetry.

    Science.gov (United States)

    Wang, Xiao-en; Wang, Xiao-yu; Gu, Yang-shun; Huang, Zhu

    2013-01-01

    Fundus changes associated with high myopia (HM) may mask those associated with primary open-angle glaucoma (POAG). This study aim to determine the characteristics of RNFL thickness changes in patients with both POAG and HM and compare these to changes in patients with only HM. The diagnostic capabilities of both OCT and GDxVCC in this subset of patients are also evaluated. Twenty-two eyes with POAG and HM (spherical equivalent (SE) between -6.0 and -12.0 D) were evaluated, and 22 eyes with HM were used for comparison. Characteristic retinal nerve fiber layer (RNFL) thickness profiles in patients with POAG and HM were examined using optical coherence tomography (OCT) and scanning laser polarimetry with variable corneal compensation (GDxVCC), and the diagnostic capabilities of these imaging modalities were compared. RNFL parameters evaluated included superior average (Savg-GDx), inferior average (Iavg-GDx), temporal-superior-nasal- inferior-temporal (TSNIT) average, and nerve fiber indicator (NFI) on GDxVCC and superior average (Savg-OCT), inferior average (Iavg-OCT), nasal average (Navg-OCT), temporal average (Tavg-OCT), and average thickness (AvgThick-OCT) on OCT (fast RNFL scan). Visual field testing was performed and defects were evaluated using mean defect (MD) and pattern standard deviation (PSD). The RNFL parameters (P < 0.05) significantly different between groups included Savg-GDx, Iavg-GDx, TSNIT average, NFI, Savg-OCT, Iavg-OCT, Tavg-OCT, and AvgThick-OCT. Significant correlations existed between TSNIT average and AvgThick-OCT (r = 0.778), TSNIT average and MD (r = 0.749), AvgThick-OCT and MD (r = 0.647), TSNIT average and PSD (r = -0.756), and AvgThick-OCT and PSD (r = -0.784). The area under the receiver operating characteristic curve (AUROC) values of TSNIT average, Savg-GDx, Iavg-GDx, NFI, Savg-OCT, Iavg-OCT, Navg-OCT, Tavg-OCT, and AvgThick-OCT were 0.947, 0.962, 0.973, 0.994, 0.909, 0.917, 0.511, 0.906, and 0.913, respectively. The NFI AUROC was the

  17. Interocular symmetry of retinal nerve fiber layer and optic nerve head parameters measured by Cirrus high-definition optical coherence tomography in a normal pediatric population.

    Science.gov (United States)

    Pawar, Neelam; Maheshwari, Devendra; Ravindran, Meenakshi; Ramakrishnan, Renagappa

    2017-10-01

    To determine interocular differences in the retinal nerve fiber layer (RNFL) and optic nerve head (ONH) parameters in a pediatric population using Cirrus high-definition optical coherence tomography (HD-OCT). Seventy normal Indian children aged 5-17 years presenting to the Pediatric Clinic were included in this observational cross-sectional study. All subjects underwent a comprehensive ophthalmologic examination and an evaluation of the RNFL and ONH by Cirrus HD-OCT. Differences between the right and left eyes were calculated and values were compared by means of a paired t-test. Subjects were also divided into two groups based on age (under or over 10 years of age). Interocular differences in RNFL and ONH parameters together with sex and age variations for these differences were determined. The mean age of studied pediatric population was 11.83 ± 3.3 years (range 5-17). Average RNFL thickness was 94.46 ± 8.7 μm (± SD) (range 77-111). Differences in the average RNFL between right and left eyes were not statistically significant (P = 0.060). Superior quadrant RNFL was thicker in the left eye and temporal quadrant was thicker in the right eye. Among ONH parameters, there were no statistically significant differences in any parameters, except vertical cup-disc (CD) ratio which was significant (P = 0.007). The 2.5%-97.5% limits of asymmetry were 9 μm for average RNFL, 0.14 for average CD ratio, and 0.22 for vertical CD ratio. Mean interocular RNFL thickness differences in superior, superior nasal, and temporal superior quadrants were 10.61 (P sex, while only significant differences with age were observed in 12 clock hour sector analysis, mainly in nasal inferior and inferior quadrant. We report the degree of interocular symmetry of RNFL and ONH parameters measured by Cirrus HD-OCT in a healthy pediatric population. The normal interocular RNFL asymmetry should not exceed 9 μm and vertical CD ratio beyond 0.22 should be considered for further investigations. The

  18. Subclinical primary retinal pathology in neuromyelitis optica spectrum disorder.

    Science.gov (United States)

    Jeong, In Hye; Kim, Ho Jin; Kim, Nam-Hee; Jeong, Kyoung Sook; Park, Choul Yong

    2016-07-01

    Foveal thickness may be a more sensitive indicator of primary retinal pathology than retinal nerve fiber layer thickness since the fovea contains no or sparse retinal nerve fiber layer, which coalesces into axons of the optic nerve. To our knowledge, few quantitative in vivo studies have investigated foveal thickness. By using optical coherence tomography, we measured foveal thickness to evaluate intrinsic retinal pathology. Seventy-two neuromyelitis optica spectrum disorder patients (99 eyes with optic neuritis and 45 eyes without optic neuritis) and 34 age-matched controls were included. Foveal thinning was observed both in eyes with non-optic neuritis (185.1 µm, p optica spectrum disorder, foveal thickness correlated with 2.5 % low contrast visual acuity, while retinal nerve fiber layer thickness correlated with high or low contrast visual acuity, extended disability status scale, and disease duration. In this study, we observed foveal thinning irrespective of optic neuritis; thus, we believe that subclinical primary retinal pathology, prior to retinal nerve fiber layer thinning, may exist in neuromyelitis optica spectrum disorder.

  19. Critical Endothelial Regulation by LRP5 during Retinal Vascular Development

    Science.gov (United States)

    Huang, Wei; Li, Qing; Amiry-Moghaddam, Mahmood; Hokama, Madoka; Sardi, Sylvia H.; Nagao, Masashi; Warman, Matthew L.; Olsen, Bjorn R.

    2016-01-01

    Vascular abnormalities in the eye are the leading cause of many forms of inherited and acquired human blindness. Loss-of-function mutations in the Wnt-binding co-receptor LRP5 leads to aberrant ocular vascularization and loss of vision in genetic disorders such as osteoporosis-pseudoglioma syndrome. The canonical Wnt-β-catenin pathway is known to regulate retinal vascular development. However, it is unclear what precise role LPR5 plays in this process. Here, we show that loss of LRP5 function in mice causes retinal hypovascularization during development as well as retinal neovascularization in adulthood with disorganized and leaky vessels. Using a highly specific Flk1-CreBreier line for vascular endothelial cells, together with several genetic models, we demonstrate that loss of endothelium-derived LRP5 recapitulates the retinal vascular defects in Lrp5-/- mice. In addition, restoring LRP5 function only in endothelial cells in Lrp5-/- mice rescues their retinal vascular abnormalities. Furthermore, we show that retinal vascularization is regulated by LRP5 in a dosage dependent manner and does not depend on LRP6. Our study provides the first direct evidence that endothelium-derived LRP5 is both necessary and sufficient to mediate its critical role in the development and maintenance of retinal vasculature. PMID:27031698

  20. EFFECTUAL HUMAN AUTHENTICATION FOR CRITICAL SECURITY APPLICATIONS USING RETINAL IMAGES

    Directory of Open Access Journals (Sweden)

    L. Latha

    2010-11-01

    Full Text Available A robust method of human authentication based on the retinal blood vessel pattern is presented in this paper. This method entails a segmentation process to identify retinal blood vessel pattern, template generation consisting of the bifurcation points in the retina and matching of the intersection points in the template patterns. The number of matched blood vessel intersection points between the two patterns compared is used as a measure of similarity. As Liveness detection is a highly desirable anti-spoofing measure in biometric authentication, it is ensured while acquiring retinal images in realtime. The validity of our approach is verified with experimental results obtained from 603 comparisons made using 303 retinal images from three different publicly available databases, namely DRIVE, VARIA and STARE. We found that the proposed retinal recognition method gives 100%, 96.3% and 91.1% recognition rates respectively for the above databases. To the best of our knowledge, this is the first work that uses a large number of retinal images from different retinal databases for the authentication purpose.

  1. CERKL knockdown causes retinal degeneration in zebrafish.

    Directory of Open Access Journals (Sweden)

    Marina Riera

    Full Text Available The human CERKL gene is responsible for common and severe forms of retinal dystrophies. Despite intense in vitro studies at the molecular and cellular level and in vivo analyses of the retina of murine knockout models, CERKL function remains unknown. In this study, we aimed to approach the developmental and functional features of cerkl in Danio rerio within an Evo-Devo framework. We show that gene expression increases from early developmental stages until the formation of the retina in the optic cup. Unlike the high mRNA-CERKL isoform multiplicity shown in mammals, the moderate transcriptional complexity in fish facilitates phenotypic studies derived from gene silencing. Moreover, of relevance to pathogenicity, teleost CERKL shares the two main human protein isoforms. Morpholino injection has been used to generate a cerkl knockdown zebrafish model. The morphant phenotype results in abnormal eye development with lamination defects, failure to develop photoreceptor outer segments, increased apoptosis of retinal cells and small eyes. Our data support that zebrafish Cerkl does not interfere with proliferation and neural differentiation during early developmental stages but is relevant for survival and protection of the retinal tissue. Overall, we propose that this zebrafish model is a powerful tool to unveil CERKL contribution to human retinal degeneration.

  2. Retinal Layer Abnormalities as Biomarkers of Schizophrenia.

    Science.gov (United States)

    Samani, Niraj N; Proudlock, Frank A; Siram, Vasantha; Suraweera, Chathurie; Hutchinson, Claire; Nelson, Christopher P; Al-Uzri, Mohammed; Gottlob, Irene

    2018-06-06

    Schizophrenia is associated with several brain deficits, as well as visual processing deficits, but clinically useful biomarkers are elusive. We hypothesized that retinal layer changes, noninvasively visualized using spectral-domain optical coherence tomography (SD-OCT), may represent a possible "window" to these abnormalities. A Leica EnvisuTM SD-OCT device was used to obtain high-resolution central foveal B-scans in both eyes of 35 patients with schizophrenia and 50 demographically matched controls. Manual retinal layer segmentation was performed to acquire individual and combined layer thickness measurements in 3 macular regions. Contrast sensitivity was measured at 3 spatial frequencies in a subgroup of each cohort. Differences were compared using adjusted linear models and significantly different layer measures in patients underwent Spearman Rank correlations with contrast sensitivity, quantified symptoms severity, disease duration, and antipsychotic medication dose. Total retinal and photoreceptor complex thickness was reduced in all regions in patients (P layer (P layer (P layer thickness (R = -.47, P = .005). Our novel findings demonstrate considerable retinal layer abnormalities in schizophrenia that are related to clinical features and visual function. With time, SD-OCT could provide easily-measurable biomarkers to facilitate clinical assessment and further our understanding of the disease.

  3. High-quality planar high-Tc Josephson junctions

    International Nuclear Information System (INIS)

    Bergeal, N.; Grison, X.; Lesueur, J.; Faini, G.; Aprili, M.; Contour, J.P.

    2005-01-01

    Reproducible high-T c Josephson junctions have been made in a rather simple two-step process using ion irradiation. A microbridge (1 to 5 μm wide) is firstly designed by ion irradiating a c-axis-oriented YBa 2 Cu 3 O 7-δ film through a gold mask such as the nonprotected part becomes insulating. A lower T c part is then defined within the bridge by irradiating with a much lower fluence through a narrow slit (20 nm) opened in a standard electronic photoresist. These planar junctions, whose settings can be finely tuned, exhibit reproducible and nearly ideal Josephson characteristics. This process can be used to produce complex Josephson circuits

  4. Key factors for a high-quality VR experience

    Science.gov (United States)

    Champel, Mary-Luc; Doré, Renaud; Mollet, Nicolas

    2017-09-01

    For many years, Virtual Reality has been presented as a promising technology that could deliver a truly new experience to users. The media and entertainment industry is now investigating the possibility to offer a video-based VR 360 experience. Nevertheless, there is a substantial risk that VR 360 could have the same fate as 3DTV if it cannot offer more than just being the next fad. The present paper aims at presenting the various quality factors required for a high-quality VR experience. More specifically, this paper will focus on the main three VR quality pillars: visual, audio and immersion.

  5. In vivo fluorescence imaging of primate retinal ganglion cells and retinal pigment epithelial cells

    Science.gov (United States)

    Gray, Daniel C.; Merigan, William; Wolfing, Jessica I.; Gee, Bernard P.; Porter, Jason; Dubra, Alfredo; Twietmeyer, Ted H.; Ahamd, Kamran; Tumbar, Remy; Reinholz, Fred; Williams, David R.

    2006-08-01

    The ability to resolve single cells noninvasively in the living retina has important applications for the study of normal retina, diseased retina, and the efficacy of therapies for retinal disease. We describe a new instrument for high-resolution, in vivo imaging of the mammalian retina that combines the benefits of confocal detection, adaptive optics, multispectral, and fluorescence imaging. The instrument is capable of imaging single ganglion cells and their axons through retrograde transport in ganglion cells of fluorescent dyes injected into the monkey lateral geniculate nucleus (LGN). In addition, we demonstrate a method involving simultaneous imaging in two spectral bands that allows the integration of very weak signals across many frames despite inter-frame movement of the eye. With this method, we are also able to resolve the smallest retinal capillaries in fluorescein angiography and the mosaic of retinal pigment epithelium (RPE) cells with lipofuscin autofluorescence.

  6. Process to Continuously Melt, Refine and Cast High Quality Steel

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-01

    The purpose of this project is to conduct research and development targeted at designing a revolutionary steelmaking process. This process will deliver high quality steel from scrap to the casting mold in one continuous process and will be safer, more productive, and less capital intensive to build and operate than conventional steelmaking. The new process will produce higher quality steel faster than traditional batch processes while consuming less energy and other resources.

  7. High-quality cardiopulmonary resuscitation: current and future directions.

    Science.gov (United States)

    Abella, Benjamin S

    2016-06-01

    Cardiopulmonary resuscitation (CPR) represents the cornerstone of cardiac arrest resuscitation care. Prompt delivery of high-quality CPR can dramatically improve survival outcomes; however, the definitions of optimal CPR have evolved over several decades. The present review will discuss the metrics of CPR delivery, and the evidence supporting the importance of CPR quality to improve clinical outcomes. The introduction of new technologies to quantify metrics of CPR delivery has yielded important insights into CPR quality. Investigations using CPR recording devices have allowed the assessment of specific CPR performance parameters and their relative importance regarding return of spontaneous circulation and survival to hospital discharge. Additional work has suggested new opportunities to measure physiologic markers during CPR and potentially tailor CPR delivery to patient requirements. Through recent laboratory and clinical investigations, a more evidence-based definition of high-quality CPR continues to emerge. Exciting opportunities now exist to study quantitative metrics of CPR and potentially guide resuscitation care in a goal-directed fashion. Concepts of high-quality CPR have also informed new approaches to training and quality improvement efforts for cardiac arrest care.

  8. Dealings between Cataract and Retinal Reattachment Surgery in PVR

    Directory of Open Access Journals (Sweden)

    Svenja Deuchler

    2016-01-01

    Full Text Available Introduction. To evaluate the impact of the eye lens status and oil side effects on the outcome of vitreoretinal surgery in retinal detachment with proliferative vitreoretinopathy (PVR and a temporary silicone oil tamponade (SOT. Methods. 101 eyes were analyzed retrospectively and 103 eyes prospectively in regard to their retinal reattachment success rate and key factors for the outcome. Subgroup analysis of 27 eyes with Scheimpflug lens photography (SLP before and after retinal reattachment service with SOT was performed. For SLP (65% phakic eyes a Pentacam densitometry reference body with 3 mm diameter was chosen and 3 segments (anterior/mid/posterior were evaluated separately after a quality check. Results. The retinal reattachment rate was highest in the prospective pseudophakic group (p=0.039. Lens transparency loss occurred earlier in middle aged patients than in younger patients. Besides the nucleus, layers posterior and anterior to it showed specific transparency changes. The emulsification rate was higher when eyes had been operated on in the anterior chamber before retinal reattachment service. Conclusions. Retinal reattachment surgery seems to benefit from preoperative cataract removal. We found significant lens changes in the nucleus as well as in the layers anterior and posterior to it. This corresponds to the histology of the lens epithelium published before.

  9. Rhegmatogenous Retinal Detachment Associated with Choroidal Detachment

    Directory of Open Access Journals (Sweden)

    L. Sh. Bilandarli

    2017-01-01

    Full Text Available Review describes the theme of rhegmatogenous retinal dеtаchment associated with choroidal separation. It is rare, but quite severe eye pathology. In most cases it has a very poor prognosis. Most authors consider the retinal detachment as a primary pathogenetic part, which decompensates the production of aqueous humor by increasing the absorptive surface of the retinal pigment epithelium. Dilatation of choroidal arterioles occurs in hypotension, it leads to extravasation of protein-rich fluid in the choroidal and the suprachoroidal space. This helps to further swelling and separation of the ciliary body and the choroid with reduced production of aqueous humor and progressive hypotension. There is a high risk of developing “retino-choroidal” separation in patients with macular rupture due to localization of retinal separation and rupture rear hyaloid membrane. The protein level in aqueous humor can be increased to 70 times. It may be a result of reflux of suprachoroidal proteins through uveoscleral route and / or venous proteins through the trabecular network. In addition, the diffusion of proteins from the posterior camera and vitreous cavity is possible. This creates favorable conditions for cell proliferation that can lead to postoperative proliferative vitreoretinopathy. Typically patients have a pronounced signs of inflammation, pain, and “red eye”, which is accompanied with vision decrement. Rhegmatogenous retinal reparationcan be associated with such clinical symptoms as severe panuveit, deepening of the anterior camera and the inflammatory response in the moisture, concentric wrinkles and sagging back of the iris, posterior synechia, iridofakodenez, blurred vitreous detachment of the ciliary body, hypotension, and choroidal and retinal detachment in addition. Debatableness of etiopathogenesis and a clinical picture, which is similar to other eye diseases create significant difficulties in early diagnosis and proper treatment of

  10. Next Generation High Quality Videoconferencing Service for the LHC

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    In recent times, we have witnessed an explosion of video initiatives in the industry worldwide. Several advancements in video technology are currently improving the way we interact and collaborate. These advancements are forcing tendencies and overall experiences: any device in any network can be used to collaborate, in most cases with an overall high quality. To cope with this technology progresses, CERN IT Department has taken the leading role to establish strategies and directions to improve the user experience in remote dispersed meetings and remote collaboration at large in the worldwide LHC communities. Due to the high rate of dispersion in the LHC user communities, these are critically dependent of videoconferencing technology, with a need of robustness and high quality for the best possible user experience. We will present an analysis of the factors that influenced the technical and strategic choices to improve the reliability, efficiency and overall quality of the LHC remote sessions. In particular, ...

  11. IMPACT OF RESILIENCE, ICT SUPPORT AND QUALITY OF STUDENT'S LIFE ON QUALITY OF HIGH EDUCATION PROCESS

    Directory of Open Access Journals (Sweden)

    Zorica Lazic

    2016-12-01

    Full Text Available Answers to the questions of how and in what way the quality of life of students, resilience and ICT support affects the quality of high education we will get through this work where main objective is to define a network of processes and process management ensuring more quality and more innovative managing and service provision, therefore satisfying the needs of service users - in this case the students of the university. To collect the relevant data in the thematic analysis of this paper, the method of interviewing by questionnaires was applied. The sample survey was conducted among undergraduate students, teachers and staff of the Teacher Training Faculty in Uzice.

  12. Retinal astrocytoma in a dog.

    Science.gov (United States)

    Kuroki, Keiichi; Kice, Nathan; Ota-Kuroki, Juri

    2017-09-01

    A miniature schnauzer dog presenting with hyphema and glaucoma of the right eye had a retinal neoplasm. Neoplastic cells stained positively for glial fibrillary acidic protein, vimentin, and S-100 and largely negatively for oligodendrocyte transcription factor 2 by immunohistochemistry. The clinical and histopathological features of canine retinal astrocytomas are discussed.

  13. Non-syndromic retinitis pigmentosa

    NARCIS (Netherlands)

    Verbakel, S.K. (Sanne K.); R.A.C. van Huet (Ramon A. C.); C.J.F. Boon (Camiel); A.I. Hollander (Anneke); R.W.J. Collin (Rob); C.C.W. Klaver (Caroline); C. Hoyng (Carel); R. Roepman (Ronald); B.J. Klevering (Jeroen)

    2018-01-01

    textabstractRetinitis pigmentosa (RP) encompasses a group of inherited retinal dystrophies characterized by the primary degeneration of rod and cone photoreceptors. RP is a leading cause of visual disability, with a worldwide prevalence of 1:4000. Although the majority of RP cases are non-syndromic,

  14. Retinal Imaging and Image Analysis

    Science.gov (United States)

    Abràmoff, Michael D.; Garvin, Mona K.; Sonka, Milan

    2011-01-01

    Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of blindness in the industrialized world that includes age-related macular degeneration, diabetic retinopathy, and glaucoma, the review is devoted to retinal imaging and image analysis methods and their clinical implications. Methods for 2-D fundus imaging and techniques for 3-D optical coherence tomography (OCT) imaging are reviewed. Special attention is given to quantitative techniques for analysis of fundus photographs with a focus on clinically relevant assessment of retinal vasculature, identification of retinal lesions, assessment of optic nerve head (ONH) shape, building retinal atlases, and to automated methods for population screening for retinal diseases. A separate section is devoted to 3-D analysis of OCT images, describing methods for segmentation and analysis of retinal layers, retinal vasculature, and 2-D/3-D detection of symptomatic exudate-associated derangements, as well as to OCT-based analysis of ONH morphology and shape. Throughout the paper, aspects of image acquisition, image analysis, and clinical relevance are treated together considering their mutually interlinked relationships. PMID:22275207

  15. Spectrophotometric retinal oximetry in pigs

    DEFF Research Database (Denmark)

    Traustason, Sindri; Kiilgaard, Jens Folke; Karlsson, Robert

    2013-01-01

    PURPOSE: To assess the validity of spectrophotometric retinal oximetry, by comparison to blood gas analysis and intra-vitreal measurements of partial pressure of oxygen (pO2). METHODS: Female domestic pigs were used for all experiments (n=8). Oxygen fraction in inspired air was changed using...... a mixture of room air, pure oxygen and pure nitrogen, ranging from 5% to 100% oxygen. Femoral arterial blood gas analysis and retinal oximetry was performed at each level of inspiratory oxygen fraction. Retinal oximetry was performed using a commercial instrument, the Oxymap Retinal Oximeter T1 (Oxymap ehf...... arterial oxygen saturation and the optical density ratio over retinal arteries revealed an approximately linear relationship (R(2) = 0.74, p = 3.4 x 10(-9)). In order to test the validity of applying the arterial calibration to veins, we compared non-invasive oximetry measurements to invasive pO2...

  16. Learning Disabilities and Achieving High-Quality Education Standards

    Science.gov (United States)

    Gartland, Debi; Strosnider, Roberta

    2017-01-01

    This is an official document of the National Joint Committee on Learning Disabilities (NJCLD), of which Council for Learning Disabilities is a long-standing, active member. With this position paper, NJCLD advocates for the implementation of high-quality education standards (HQES) for students with learning disabilities (LD) and outlines the…

  17. extraction of high quality dna from polysaccharides-secreting ...

    African Journals Online (AJOL)

    cistvr

    A DNA extraction method using CTAB was used for the isolation of genomic DNA from ten. Xanthomonas campestris pathovars, ten isolates of Xanthomonas albilineans and one isolate of. Pseudomonas rubrisubalbicans. High quality DNA was obtained that was ideal for molecular analy- ses. Extracellular polysaccharides ...

  18. Negative Binomial charts for monitoring high-quality processes

    NARCIS (Netherlands)

    Albers, Willem/Wim

    Good control charts for high quality processes are often based on the number of successes between failures. Geometric charts are simplest in this respect, but slow in recognizing moderately increased failure rates p. Improvement can be achieved by waiting until r > 1 failures have occurred, i.e. by

  19. Synthesis and spectroscopic study of high quality alloy Cdx S ...

    Indian Academy of Sciences (India)

    Wintec

    In the present study, we report the synthesis of high quality CdxZn1–xS nanocrystals alloy at. 150°C with .... (XRD) using a Siemens model D 500, powder X-ray ... decays were analysed using IBH DAS6 software. 3. ... This alloying process is.

  20. Methods and systems for fabricating high quality superconducting tapes

    Science.gov (United States)

    Majkic, Goran; Selvamanickam, Venkat

    2018-02-13

    An MOCVD system fabricates high quality superconductor tapes with variable thicknesses. The MOCVD system can include a gas flow chamber between two parallel channels in a housing. A substrate tape is heated and then passed through the MOCVD housing such that the gas flow is perpendicular to the tape's surface. Precursors are injected into the gas flow for deposition on the substrate tape. In this way, superconductor tapes can be fabricated with variable thicknesses, uniform precursor deposition, and high critical current densities.

  1. Managing quality inside a high-technology project organization

    OpenAIRE

    Jokinen, T. (Tauno)

    2004-01-01

    Abstract This action research addresses the deployment of Total Quality Management (TQM) principles in a high-technology new product development organisation. During the period of study, the organisation grew fast. High-technology product development and hypergrowth provided a unique combination of extreme conditions for the study. The existing concepts of TQM are presented as an organised map enabling strategic analysis for an implementation plan. The history of TQM dates back to the ...

  2. [Quality of sleep and academic performance in high school students].

    Science.gov (United States)

    Bugueño, Maithe; Curihual, Carolina; Olivares, Paulina; Wallace, Josefa; López-AlegrÍa, Fanny; Rivera-López, Gonzalo; Oyanedel, Juan Carlos

    2017-09-01

    Sleeping and studying are the day-to-day activities of a teenager attending school. To determine the quality of sleep and its relationship to the academic performance among students attending morning and afternoon shifts in a public high school. Students of the first and second year of high school answered an interview about socio-demographic background, academic performance, student activities and subjective sleep quality; they were evaluated using the Pittsburgh Sleep Quality Index (PSQI). The interview was answered by 322 first year students aged 15 ± 5 years attending the morning shift and 364 second year students, aged 16 ± 0.5 years, attending the afternoon shift. The components: sleep latency, habitual sleep efficiency, sleep disturbance, drug use and daytime dysfunction were similar and classified as good in both school shifts. The components subjective sleep quality and duration of sleep had higher scores among students of the morning shift. The mean grades during the first semester of the students attending morning and afternoon shifts were 5.9 and 5.8, respectively (of a scale from 1 to 7). Among students of both shifts, the PSQI scale was associated inversely and significantly with academic performance. A bad sleep quality influences academic performance in these students.

  3. Highly qualified does not equal high quality: A study of urban stakeholders' perceptions of quality in science teaching

    Science.gov (United States)

    Miranda, Rommel Joseph

    By employing qualitative methods, this study sought to determine the perceptions that urban stakeholders hold about what characteristics should distinguish a high school science teacher whom they would consider to demonstrate high quality in science teaching. A maximum variation sample of six science teachers, three school administrators, six parents and six students from a large urban public school district were interviewed using semi-structured, in-depth interview techniques. From these data, a list of observable characteristics which urban stakeholders hold as evidence of high quality in science teaching was generated. Observational techniques were utilized to determine the extent to which six urban high school science teachers, who meet the NCLB Act criteria for being "highly qualified", actually possessed the characteristics which these stakeholders hold as evidence of high quality in science teaching. Constant comparative analysis was used to analyze the data set. The findings suggest that urban stakeholders perceive that a high school science teacher who demonstrates high quality in science teaching should be knowledgeable about their subject matter, their student population, and should be resourceful; should possess an academic background in science and professional experience in science teaching; should exhibit professionalism, a passion for science and teaching, and a dedication to teaching and student learning; should be skillful in planning and preparing science lessons and in organizing the classroom, in presenting the subject matter to students, in conducting a variety of hands-on activities, and in managing a classroom; and should assess whether students complete class goals and objectives, and provide feedback about grades for students promptly. The findings further reveal that some of the urban high school science teachers who were deemed to be "highly qualified", as defined by the NCLB Act, engaged in practices that threatened quality in science

  4. High quality digital holographic reconstruction on analog film

    Science.gov (United States)

    Nelsen, B.; Hartmann, P.

    2017-05-01

    High quality real-time digital holographic reconstruction, i.e. at 30 Hz frame rates, has been at the forefront of research and has been hailed as the holy grail of display systems. While these efforts have produced a fascinating array of computer algorithms and technology, many applications of reconstructing high quality digital holograms do not require such high frame rates. In fact, applications such as 3D holographic lithography even require a stationary mask. Typical devices used for digital hologram reconstruction are based on spatial-light-modulator technology and this technology is great for reconstructing arbitrary holograms on the fly; however, it lacks the high spatial resolution achievable by its analog counterpart, holographic film. Analog holographic film is therefore the method of choice for reconstructing highquality static holograms. The challenge lies in taking a static, high-quality digitally calculated hologram and effectively writing it to holographic film. We have developed a theoretical system based on a tunable phase plate, an intensity adjustable high-coherence laser and a slip-stick based piezo rotation stage to effectively produce a digitally calculated hologram on analog film. The configuration reproduces the individual components, both the amplitude and phase, of the hologram in the Fourier domain. These Fourier components are then individually written on the holographic film after interfering with a reference beam. The system is analogous to writing angularly multiplexed plane waves with individual component phase control.

  5. Atypical manifestation of progressive outer retinal necrosis in AIDS patient with CD4+ T-cell counts more than 100 cells/microL on highly active antiretroviral therapy.

    Science.gov (United States)

    Vichitvejpaisal, Pornpattana; Reeponmahar, Somporn; Tantisiriwat, Woraphot

    2009-06-01

    Typical progressive outer retinal necrosis (PORN) is an acute ocular infectious disease in acquired immunodeficiency syndrome (AIDS) patients with extremely low CD4+ T-cell counts. It is a form of the Varicella- zoster virus (VZV) infection. This destructive infection has an extremely rapid course that may lead to blindness in affected eyes within days or weeks. Attempts at its treatment have had limited success. We describe the case of a bilateral PORN in an AIDS patient with an initial CD4+ T-cell count >100 cells/microL that developed after initiation of highly active antiretroviral therapy (HAART). A 29-year-old Thai female initially diagnosed with human immunodeficiency virus (HIV) in 1998, presented with bilaterally decreased visual acuity after initiating HAART two months earlier. Multiple yellowish spots appeared in the deep retina without evidence of intraocular inflammation or retinal vasculitis. Her CD4+ T-cell count was 127 cells/microL. She was diagnosed as having PORN based on clinical features and positive VZV in the aqueous humor and vitreous by polymerase chain reaction (PCR). Despite combined treatment with intravenous acyclovir and intravitreous ganciclovir, the patient's visual acuity worsened with no light-perception in either eye. This case suggests that PORN should be included in the differential diagnosis of reduced visual acuity in AIDS patients initiating HAART with higher CD4+ T-cell counts. PORN may be a manifestation of the immune reconstitution syndrome.

  6. Long quantum channels for high-quality entanglement transfer

    International Nuclear Information System (INIS)

    Banchi, L; Apollaro, T J G; Cuccoli, A; Verrucchi, P; Vaia, R

    2011-01-01

    High-quality quantum-state and entanglement transfer can be achieved in an unmodulated spin bus operating in the ballistic regime, which occurs when the endpoint qubits A and B are nonperturbatively coupled to the chain by a suitable exchange interaction j 0 . Indeed, the transition amplitude characterizing the transfer quality exhibits a maximum for a finite optimal value j opt 0 (N), where N is the channel length. We show that j opt 0 (N) scales as N -1/6 for large N and that it ensures a high-quality entanglement transfer even in the limit of arbitrarily long channels, almost independently of the channel initialization. For instance, for any chain length the average quantum-state transmission fidelity exceeds 90% and decreases very little in a broad neighbourhood of j opt 0 (N). We emphasize that, taking the reverse point of view, should j 0 be experimentally constrained, high-quality transfer can still be obtained by adjusting the channel length to its optimal value. (paper)

  7. Integration study of high quality teaching resources in universities

    Directory of Open Access Journals (Sweden)

    Honglu Liu

    2012-12-01

    Full Text Available Purpose: The development level and quality of education depend on the merits and efficiency in the use of teaching resources, especially in the case of obvious contradiction between the demand and supply of teaching resources. So to integrate teaching resources, improve the efficiency in the use of high quality teaching resources, and take the road of content development to enhance the competitiveness of education has become very important and urgent.Design/methodology/approach: On the basis of analysis on the teaching resources of universities and the problems they faced, this paper introduced the basic concepts of cloud storage, and built the integration architecture of high quality teaching resources in universities based on the cloud storage.Findings and Originality/value: The HDFS-based cloud storage proposed in this paper is a dynamically adjustable and Internet-based storage solution, and the users can access storage targets using the network through a common and easy-to-use protocol and application programming interfaces. This new technology is useful for end users benefits. With the continuous development and improvement of cloud storage, it will necessarily result in more and more applications in the institutions of higher learning and education network.Originality/value: This paper introduced the cloud storage into the integration of high quality teaching resources in universities first and as a new form of service, it can be a good solution.

  8. Simultaneous Mutation Detection in 90 Retinal Disease Genes in Multiple Patients Using a Custom-designed 300-kb Retinal Resequencing Chip

    NARCIS (Netherlands)

    Booij, Judith C.; Bakker, Arne 1; Kulumbetova, Jamilia; Moutaoukil, Youssef; Smeets, Bert; Verheij, Joke; Kroes, Hester Y.; Klaver, Caroline C. W.; van Schooneveld, Mary; Bergen, Arthur A. B.; Florijn, Ralph J.

    Purpose: To develop a high-throughput, cost-effective diagnostic strategy for the identification of known and new mutations in 90 retinal disease genes. Design: Evidence-based study. Participants: Sixty patients with a variety of retinal disorders, including Leber's congenital amaurosis, ocular

  9. Examination of Operation Quality for High-frequent Railway Operation

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.

    2009-01-01

    take the first train in their direction. The article examines four different approaches to examine operation quality for high-frequent operation that are based on the experiences of the passengers. These approaches are the service frequency of the operation, travel time extension, a combination......The examination of operation quality for high-frequent operation requires other approaches than the typical evaluation of punctuality (trains on time) and reliability (operated trains). This is because passengers in high-frequent railway systems do not necessarily notice train delays as they just...... of the service frequency and travel time approaches, and passenger delays. The service frequency and travel time approaches are simple measurements with low complexity and complement each other. Therefore, the article recommends combining the service frequency and travel time approaches to get a more accurate...

  10. Proposed clinical case definition for cytomegalovirus-immune recovery retinitis.

    Science.gov (United States)

    Ruiz-Cruz, Matilde; Alvarado-de la Barrera, Claudia; Ablanedo-Terrazas, Yuria; Reyes-Terán, Gustavo

    2014-07-15

    Cytomegalovirus (CMV) retinitis has been extensively described in patients with advanced or late human immunodeficiency virus (HIV) disease under ineffective treatment of opportunistic infection and antiretroviral therapy (ART) failure. However, there is limited information about patients who develop active cytomegalovirus retinitis as an immune reconstitution inflammatory syndrome (IRIS) after successful initiation of ART. Therefore, a case definition of cytomegalovirus-immune recovery retinitis (CMV-IRR) is proposed here. We reviewed medical records of 116 HIV-infected patients with CMV retinitis attending our institution during January 2003-June 2012. We retrospectively studied HIV-infected patients who had CMV retinitis on ART initiation or during the subsequent 6 months. Clinical and immunological characteristics of patients with active CMV retinitis were described. Of the 75 patients under successful ART included in the study, 20 had improvement of CMV retinitis. The remaining 55 patients experienced CMV-IRR; 35 of those developed CMV-IRR after ART initiation (unmasking CMV-IRR) and 20 experienced paradoxical clinical worsening of retinitis (paradoxical CMV-IRR). Nineteen patients with CMV-IRR had a CD4 count of ≥50 cells/µL. Six patients with CMV-IRR subsequently developed immune recovery uveitis. There is no case definition for CMV-IRR, although this condition is likely to occur after successful initiation of ART, even in patients with high CD4 T-cell counts. By consequence, we propose the case definitions for paradoxical and unmasking CMV-IRR. We recommend close follow-up of HIV-infected patients following ART initiation. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Quality and efficiency in high dimensional Nearest neighbor search

    KAUST Repository

    Tao, Yufei; Yi, Ke; Sheng, Cheng; Kalnis, Panos

    2009-01-01

    Nearest neighbor (NN) search in high dimensional space is an important problem in many applications. Ideally, a practical solution (i) should be implementable in a relational database, and (ii) its query cost should grow sub-linearly with the dataset size, regardless of the data and query distributions. Despite the bulk of NN literature, no solution fulfills both requirements, except locality sensitive hashing (LSH). The existing LSH implementations are either rigorous or adhoc. Rigorous-LSH ensures good quality of query results, but requires expensive space and query cost. Although adhoc-LSH is more efficient, it abandons quality control, i.e., the neighbor it outputs can be arbitrarily bad. As a result, currently no method is able to ensure both quality and efficiency simultaneously in practice. Motivated by this, we propose a new access method called the locality sensitive B-tree (LSB-tree) that enables fast highdimensional NN search with excellent quality. The combination of several LSB-trees leads to a structure called the LSB-forest that ensures the same result quality as rigorous-LSH, but reduces its space and query cost dramatically. The LSB-forest also outperforms adhoc-LSH, even though the latter has no quality guarantee. Besides its appealing theoretical properties, the LSB-tree itself also serves as an effective index that consumes linear space, and supports efficient updates. Our extensive experiments confirm that the LSB-tree is faster than (i) the state of the art of exact NN search by two orders of magnitude, and (ii) the best (linear-space) method of approximate retrieval by an order of magnitude, and at the same time, returns neighbors with much better quality. © 2009 ACM.

  12. [Factors related to intraoperative retinal breaks in macular hole surgery].

    Science.gov (United States)

    Kumagai, K; Ogino, N; Demizu, S; Atsumi, K; Kurihara, H; Iwaki, M; Ishigooka, H; Tachi, N

    2001-02-01

    To evaluate the factors of intraoperative retinal breaks in macular hole surgery. This study included 558 eyes of 506 patients who underwent idiopathic macular hole surgery by one surgeon. Multiple regression was performed using the variables of gender, age, affected eye, lens status, stage, duration of symptoms, hole size, axial length, and lattice degeneration. The rate of retinal breaks was higher in stage 3 (16.0%) than in stage 4 (8.2%) (p = 0.014). In eyes with lattice degeneration intraoperative retinal breaks occurred in about 40% of the cases. Major factors were as follows: lattice degeneration (r = 0.24, p lattice degeneration, and gender (r = -0.18, p = 0.035) in eyes of stage 4 without lattice degeneration. The factors of intraoperative retinal breaks in macular hole surgery were lattice degeneration in all eyes and stage 3 in eyes without lattice degeneration. The high incidence of intraoperative retinal breaks in stage 3 was mainly due to the occurrence of posterior vitreous detachment. Male gender was a significant factor associated with intraoperative retinal breaks.

  13. High quality flux control system for electron gun evaporation

    International Nuclear Information System (INIS)

    Appelbloom, A.M.; Hadley, P.; van der Marel, D.; Mooij, J.E.

    1991-01-01

    This paper reports on a high quality flux control system for electron gun evaporation developed and tested for the MBE growth of high temperature superconductors. The system can be applied to any electron gun without altering the electron gun itself. Essential elements of the system are a high bandwidth mass spectrometer, control electronics and a high voltage modulator to sweep the electron beam over the melt at high frequencies. the sweep amplitude of the electron beam is used to control the evaporation flux at high frequencies. The feedback loop of the system has a bandwidth of over 100 Hz, which makes it possible to grow superlattices and layered structures in a fast and precisely controlled manner

  14. Paeoniflorin Suppressed High Glucose-Induced Retinal Microglia MMP-9 Expression and Inflammatory Response via Inhibition of TLR4/NF-κB Pathway Through Upregulation of SOCS3 in Diabetic Retinopathy.

    Science.gov (United States)

    Zhu, Su-Hua; Liu, Bing-Qian; Hao, Mao-Juan; Fan, Yi-Xin; Qian, Cheng; Teng, Peng; Zhou, Xiao-Wei; Hu, Liang; Liu, Wen-Tao; Yuan, Zhi-Lan; Li, Qing-Ping

    2017-10-01

    Diabetic retinopathy (DR) is a serious-threatening complication of diabetes and urgently needed to be treated. Evidence has accumulated indicating that microglia inflammation within the retina plays a critical role in DR. Microglial matrix metalloproteinase 9 (MMP-9) has an important role in the destruction of the integrity of the blood-retinal barrier (BRB) associated with the development of DR. MMP-9 was also considered important for regulating inflammatory responses. Paeoniflorin, a monoterpene glucoside, has a potent immunomodulatory effect on microglia. We hypothesized that paeoniflorin could significantly suppress microglial MMP-9 activation induced by high glucose and further relieve DR. BV2 cells were used to investigate the effects and mechanism of paeoniflorin. The activation of MMP-9 was measured by gelatin zymography. Cell signaling was measured by western blot assay and immunofluorescence assay. High glucose increased the activation of MMP-9 in BV2 cells, which was abolished by HMGB1, TLR4, p38 MAPK, and NF-κB inhibition. Phosphorylation of p38 MAPK induced by high glucose was decreased by TLR4 inhibition in BV2 cells. Paeoniflorin induced suppressor of cytokine signaling 3 (SOCS3) expression and reduced MMP-9 activation in BV2 cells. The effect of paeoniflorin on SOCS3 was abolished by the TLR4 inhibitor. In streptozotocin (STZ)-induced diabetes mice, paeoniflorin induced SOCS3 expression and reduced MMP-9 activation. Paeoniflorin suppressed STZ-induced IBA-1 and IL-1β expression and decreased STZ-induced high blood glucose level. In conclusion, paeoniflorin suppressed high glucose-induced retinal microglia MMP-9 expression and inflammatory response via inhibition of the TLR4/NF-κB pathway through upregulation of SOCS3 in diabetic retinopathy.

  15. Safety and quality management at the high flux reactor Petten

    International Nuclear Information System (INIS)

    Zurita, A.; Ahlf, J.

    1995-01-01

    The High Flux Reactor (HFR) is one high power multi-purpose materials testing research reactor of the tank-in-pool type, cooled and moderated by light-water. It is operated at 45 MW at a prescribed schedule of 11 cycles per year, each comprising 25 operation days and three shut-down days. Since the licence for the operation of HFR was granted in 1962, a total of 14 amendments to the original licence have been made following different modifications in the installations. In the meantime, international nuclear standards were developed, especially in the framework of the NUSS programme of the IAEA, which were adopted by the Dutch Licensing Authorities. In order to implement the new standards, the situation at the HFR was comprehensively reviewed in the course of an audit performed by the Dutch Licensing Authorities in 1988. This also resulted in formulating the task of setting-up an 'HFR - Integral Quality Assurance Handbook' (HFR-IQAD) involving both organizations JRCIAM and ECN, which had the unique framework and basic guideline to assure the safe and efficient operation and exploitation of the HFR and to promote safety and quality in all aspects of HFR related activities. The assurance of safe and efficient operation and exploitation of the HFR is condensed together under the concepts of safety and quality of services and is achieved through the safety and quality management. (orig.)

  16. Bilateral patching in retinal detachment: fluid mechanics and retinal "settling".

    Science.gov (United States)

    Foster, William J

    2011-07-20

    When a patient suffers a retinal detachment and surgery is delayed, it is known clinically that bilaterally patching the patient may allow the retina to partially reattach or "settle." Although this procedure has been performed since the 1860s, there is still debate as to how such a maneuver facilitates the reattachment of the retina. Finite element calculations using commercially available analysis software are used to elucidate the influence of reduction in eye movement caused by bilateral patching on the flow of subretinal fluid in a physical model of retinal detachment. It was found that by coupling fluid mechanics with structural mechanics, a physically consistent explanation of increased retinal detachment with eye movements can be found in the case of traction on the retinal hole. Large eye movements increase vitreous traction and detachment forces on the edge of the retinal hole, creating a subretinal vacuum and facilitating increased subretinal fluid. Alternative models, in which intraocular fluid flow is redirected into the subretinal space, are not consistent with these simulations. The results of these simulations explain the physical principles behind bilateral patching and provide insight that can be used clinically. In particular, as is known clinically, bilateral patching may facilitate a decrease in the height of a retinal detachment. The results described here provide a description of a physical mechanism underlying this technique. The findings of this study may aid in deciding whether to bilaterally patch patients and in counseling patients on pre- and postoperative care.

  17. Wellbeing Understanding in High Quality Healthcare Informatics and Telepractice.

    Science.gov (United States)

    Fiorini, Rodolfo A; De Giacomo, Piero; L'Abate, Luciano

    2016-01-01

    The proper use of healthcare informatics technology and multidimensional conceptual clarity are fundamental to create and boost outstanding clinical and telepractice results. Avoiding even terminology ambiguities is mandatory for high quality of care service. For instance, well-being or wellbeing is a different way to write the same concept only, or there is a good deal of ambiguity around the meanings of these terms the way they are written. In personal health, healthcare and healthcare informatics, this kind of ambiguity and lack of conceptual clarity has been called out repeatedly over the past 50 years. It is time to get the right, terse scenario. We present a brief review to develop and achieve ultimate wellbeing understanding for practical high quality healthcare informatics and telepractice application. This article presents an innovative point of view on deeper wellbeing understanding towards its increased clinical effective application.

  18. Automated retinal fovea type distinction in spectral-domain optical coherence tomography of retinal vein occlusion

    Science.gov (United States)

    Wu, Jing; Waldstein, Sebastian M.; Gerendas, Bianca S.; Langs, Georg; Simader, Christian; Schmidt-Erfurth, Ursula

    2015-03-01

    Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high- resolution, three-dimensional (3D) cross-sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD), glaucoma and retinal vein occlusion (RVO). Disease diagnosis, assessment, and treatment will require a patient to undergo multiple OCT scans, possibly using multiple scanners, to accurately and precisely gauge disease activity, progression and treatment success. However, cross-vendor imaging and patient movement may result in poor scan spatial correlation potentially leading to incorrect diagnosis or treatment analysis. The retinal fovea is the location of the highest visual acuity and is present in all patients, thus it is critical to vision and highly suitable for use as a primary landmark for cross-vendor/cross-patient registration for precise comparison of disease states. However, the location of the fovea in diseased eyes is extremely challenging to locate due to varying appearance and the presence of retinal layer destroying pathology. Thus categorising and detecting the fovea type is an important prior stage to automatically computing the fovea position. Presented here is an automated cross-vendor method for fovea distinction in 3D SD-OCT scans of patients suffering from RVO, categorising scans into three distinct types. OCT scans are preprocessed by motion correction and noise filing followed by segmentation using a kernel graph-cut approach. A statistically derived mask is applied to the resulting scan creating an ROI around the probable fovea location from which the uppermost retinal surface is delineated. For a normal appearance retina, minimisation to zero thickness is computed using the top two retinal surfaces. 3D local minima detection and layer thickness analysis are used

  19. Retinal Protection and Distribution of Curcumin in Vitro and in Vivo

    Directory of Open Access Journals (Sweden)

    Chiara B. M. Platania

    2018-06-01

    Full Text Available Diabetic retinopathy (DR, a secondary complication of diabetes, is a leading cause of irreversible blindness accounting for 5% of world blindness cases in working age. Oxidative stress and inflammation are considered causes of DR. Curcumin, a product with anti-oxidant and anti-inflammatory properties, is currently proposed as oral supplementation therapy for retinal degenerative diseases, including DR. In this study we predicted the pharmacodynamic profile of curcumin through an in silico approach. Furthermore, we tested the anti-oxidant and anti-inflammatory activity of curcumin on human retinal pigmented epithelial cells exposed to oxidative stress, human retinal endothelial and human retinal pericytes (HRPCs cultured with high glucose. Because currently marketed curcumin nutraceutical products have not been so far evaluated for their ocular bioavailability; we assessed retinal distribution of curcumin, following oral administration, in rabbit eye. Curcumin (10 μM decreased significantly (p < 0.01 ROS concentration and TNF-α release in retinal pigmented epithelial cells and retinal endothelial cells, respectively. The same curcumin concentration significantly (p < 0.01 protected retinal pericytes from high glucose damage as assessed by cell viability and LDH release. Among the tested formulations, only that containing a hydrophilic carrier provided therapeutic levels of curcumin in rabbit retina. In conclusion, our data suggest that curcumin, when properly formulated, may be of value in clinical practice to manage retinal diseases.

  20. Quality assurance system for sitting high risk facilities

    International Nuclear Information System (INIS)

    Rodriguez, Aymee; Peralta, Jose L.; Fernandez, Manuel

    1999-01-01

    The paper shows how we have conceived and designed the quality assurance system for the site selection process of an area for sitting the facility of high risk in correspondence with the approved methodology. The results obtained in the implementation of the system have permitted the satisfactory performance of each one the expected stage, defining the most favorable sectors in order to continue the studies of the repository site for the disposal of low and intermedium. (author)

  1. High-quality uniform dry transfer of graphene to polymers.

    Science.gov (United States)

    Lock, Evgeniya H; Baraket, Mira; Laskoski, Matthew; Mulvaney, Shawn P; Lee, Woo K; Sheehan, Paul E; Hines, Daniel R; Robinson, Jeremy T; Tosado, Jacob; Fuhrer, Michael S; Hernández, Sandra C; Walton, Scott G

    2012-01-11

    In this paper we demonstrate high-quality, uniform dry transfer of graphene grown by chemical vapor deposition on copper foil to polystyrene. The dry transfer exploits an azide linker molecule to establish a covalent bond to graphene and to generate greater graphene-polymer adhesion compared to that of the graphene-metal foil. Thus, this transfer approach provides a novel alternative route for graphene transfer, which allows for the metal foils to be reused. © 2011 American Chemical Society

  2. Coupling of high-quality-factor optical resonators

    International Nuclear Information System (INIS)

    Salzenstein, Patrice; Henriet, Rémi; Coillet, Aurélien; Chembo, Yanne K; Mortier, Michel; Sérier-Brault, Hélène; Rasoloniaina, Alphonse; Dumeige, Yannick; Féron, Patrice

    2013-01-01

    We improve theoretically and experimentally the problem of the coupling between a high Q-factor resonator and its external coupler. We have observed oscillations of ringing induced by the sweeping of the excitation frequency of an active microsphere. Thanks to this approach, the quality factor of an optical resonator was measured and we obtained Q = 5.8 × 10 8 . (paper)

  3. A high throughput DNA extraction method with high yield and quality

    Directory of Open Access Journals (Sweden)

    Xin Zhanguo

    2012-07-01

    Full Text Available Abstract Background Preparation of large quantity and high quality genomic DNA from a large number of plant samples is a major bottleneck for most genetic and genomic analyses, such as, genetic mapping, TILLING (Targeting Induced Local Lesion IN Genome, and next-generation sequencing directly from sheared genomic DNA. A variety of DNA preparation methods and commercial kits are available. However, they are either low throughput, low yield, or costly. Here, we describe a method for high throughput genomic DNA isolation from sorghum [Sorghum bicolor (L. Moench] leaves and dry seeds with high yield, high quality, and affordable cost. Results We developed a high throughput DNA isolation method by combining a high yield CTAB extraction method with an improved cleanup procedure based on MagAttract kit. The method yielded large quantity and high quality DNA from both lyophilized sorghum leaves and dry seeds. The DNA yield was improved by nearly 30 fold with 4 times less consumption of MagAttract beads. The method can also be used in other plant species, including cotton leaves and pine needles. Conclusion A high throughput system for DNA extraction from sorghum leaves and seeds was developed and validated. The main advantages of the method are low cost, high yield, high quality, and high throughput. One person can process two 96-well plates in a working day at a cost of $0.10 per sample of magnetic beads plus other consumables that other methods will also need.

  4. Genetics Home Reference: retinitis pigmentosa

    Science.gov (United States)

    ... A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. ... in known genes account for 58% of autosomal dominant retinitis pigmentosa (adRP). Adv Exp Med Biol. 2008; ...

  5. Automated detection of retinal disease.

    Science.gov (United States)

    Helmchen, Lorens A; Lehmann, Harold P; Abràmoff, Michael D

    2014-11-01

    Nearly 4 in 10 Americans with diabetes currently fail to undergo recommended annual retinal exams, resulting in tens of thousands of cases of blindness that could have been prevented. Advances in automated retinal disease detection could greatly reduce the burden of labor-intensive dilated retinal examinations by ophthalmologists and optometrists and deliver diagnostic services at lower cost. As the current availability of ophthalmologists and optometrists is inadequate to screen all patients at risk every year, automated screening systems deployed in primary care settings and even in patients' homes could fill the current gap in supply. Expanding screens to all patients at risk by switching to automated detection systems would in turn yield significantly higher rates of detecting and treating diabetic retinopathy per dilated retinal examination. Fewer diabetic patients would develop complications such as blindness, while ophthalmologists could focus on more complex cases.

  6. Advances in Retinal Optical Imaging

    Directory of Open Access Journals (Sweden)

    Yanxiu Li

    2018-04-01

    Full Text Available Retinal imaging has undergone a revolution in the past 50 years to allow for better understanding of the eye in health and disease. Significant improvements have occurred both in hardware such as lasers and optics in addition to software image analysis. Optical imaging modalities include optical coherence tomography (OCT, OCT angiography (OCTA, photoacoustic microscopy (PAM, scanning laser ophthalmoscopy (SLO, adaptive optics (AO, fundus autofluorescence (FAF, and molecular imaging (MI. These imaging modalities have enabled improved visualization of retinal pathophysiology and have had a substantial impact on basic and translational medical research. These improvements in technology have translated into early disease detection, more accurate diagnosis, and improved management of numerous chorioretinal diseases. This article summarizes recent advances and applications of retinal optical imaging techniques, discusses current clinical challenges, and predicts future directions in retinal optical imaging.

  7. Prophylactic treatment of retinal breaks

    DEFF Research Database (Denmark)

    Blindbæk, Søren Leer; Grauslund, Jakob

    2015-01-01

    Prophylactic treatment of retinal breaks has been examined in several studies and reviews, but so far, no studies have successfully applied a systematic approach. In the present systematic review, we examined the need of follow-up after posterior vitreous detachment (PVD) - diagnosed by slit...... published before 2012. Four levels of screening identified 13 studies suitable for inclusion in this systematic review. No meta-analysis was conducted as no data suitable for statistical analysis were identified. In total, the initial examination after symptomatic PVD identified 85-95% of subsequent retinal......-47% of cases, respectively. The cumulated incidence of RRD despite prophylactic treatment was 2.1-8.8%. The findings in this review suggest that follow-up after symptomatic PVD is only necessary in cases of incomplete retinal examination at presentation. Prophylactic treatment of symptomatic retinal breaks...

  8. [Early therapeutic trials for retinitis pigmentosa].

    Science.gov (United States)

    Dufier, Jean-Louis

    2003-01-01

    Non syndromic forms of Retinitis Pigmentosa (RP) constitute a collection of clinically and genetically heterogeneous inherited retinal degenerative diseases. They are characterized by a bilateral progressive visual loss susceptible to cause blindness. These diseases are transmitted through pedigrees according to all known modes of inheritance. They are bilateral and usually start during infancy. However, very early clinical presentations exist, such as those observed in children affected by Leber Congenital Amaurosis, as well as late onset autosomal dominant forms of retinitis pigmentosa. The characteristic clinical aspect of the rod-cone RP dystrophies is marked by alterations of the peripheral retina associated with a night blindness and a progressive narrowing of the visual field. The ophthalmoscopic examination of RP patients commonly reveals thin retinal arteries and scattered pigmentary accumulations. In contrast, there are cone rod retinal dystrophies whose onset is marked by a decreased visual acuity before the appearance of any visual field alteration. Some forms of RPs display an ocular fundus devoid of any pigmentary alteration. Syndromic forms of RPs are not uncommon. The association of deafness with RP is detected in nearly 30% of the patients. Other associations with RP can include mental deficiency, facial dysmorphy, microcephaly, obesity, kidney deficiency, immune deficiencies, metabolic disorders. The existence of such syndromic forms of RP localizes RPs at the crossroad of several medical specialties. A long lasting collaboration between our department of ophthalmology and the department of medical genetics of the Necker-Sick Children Hospital has allowed us to establish numerous genotype-phenotype correlations, especially in LCA and Stargardt's disease. ABCR gene mutations cause Stargardt disease. ABCR mutations may also cause some types of Ages Related Macular Degenerations (AMD). Nowadays, there is no known efficient therapy available for

  9. Methods and systems for fabricating high quality superconducting tapes

    Energy Technology Data Exchange (ETDEWEB)

    Majkic, Goran; Selvamanickam, Venkat

    2018-02-13

    An MOCVD system fabricates high quality superconductor tapes with variable thicknesses. The MOCVD system can include a gas flow chamber between two parallel channels in a housing. A substrate tape is heated and then passed through the MOCVD housing such that the gas flow is perpendicular to the tape's surface. Precursors are injected into the gas flow for deposition on the substrate tape. In this way, superconductor tapes can be fabricated with variable thicknesses, uniform precursor deposition, and high critical current densities.

  10. High quality mask storage in an advanced Logic-Fab

    Science.gov (United States)

    Jähnert, Carmen; Fritsche, Silvio

    2012-02-01

    High efficient mask logistics as well as safe and high quality mask storage are essential requirements within an advanced lithography area of a modern logic waferfab. Fast operational availability of the required masks at the exposure tool with excellent mask condition requires a safe mask handling, safeguarding of high mask quality over the whole mask usage time without any quality degradation and an intelligent mask logistics. One big challenge is the prevention of haze on high advanced phase shift masks used in a high volume production line for some thousands of 248nm or 193nm exposures. In 2008 Infineon Dresden qualified a customer specific developed semi-bare mask storage system from DMSDynamic Micro Systems in combination with a high advanced mask handling and an interconnected complex logistic system. This high-capacity mask storage system DMS M1900.22 for more than 3000 masks with fully automated mask and box handling as well as full-blown XCDA purge has been developed and adapted to the Infineon Lithotoollandscape using Nikon and SMIF reticle cases. Advanced features for ESD safety and mask security, mask tracking via RFID and interactions with the exposure tools were developed and implemented. The stocker is remote controlled by the iCADA-RSM system, ordering of the requested mask directly from the affected exposure tool allows fast access. This paper discusses the advantages and challenges for this approach as well as the practical experience gained during the implementation of the new system which improves the fab performance with respect to mask quality, security and throughput. Especially the realization of an extremely low and stable humidity level in addition with a well controlled air flow at each mask surface, preventing masks from haze degradation and particle contamination, turns out to be a notable technical achievement. The longterm stability of haze critical masks has been improved significantly. Relevant environmental parameters like

  11. Concentric retinitis pigmentosa: clinicopathologic correlations.

    Science.gov (United States)

    Milam, A H; De Castro, E B; Smith, J E; Tang, W X; John, S K; Gorin, M B; Stone, E M; Aguirre, G D; Jacobson, S G

    2001-10-01

    Progressive concentric (centripetal) loss of vision is one pattern of visual field loss in retinitis pigmentosa. This study provides the first clinicopathologic correlations for this form of retinitis pigmentosa. A family with autosomal dominant concentric retinitis pigmentosa was examined clinically and with visual function tests. A post-mortem eye of an affected 94 year old family member was processed for histopathology and immunocytochemistry with retinal cell specific antibodies. Unrelated simplex/multiplex patients with concentric retinitis pigmentosa were also examined. Affected family members of the eye donor and patients from the other families had prominent peripheral pigmentary retinopathy with more normal appearing central retina, good visual acuity, concentric field loss, normal or near normal rod and cone sensitivity within the preserved visual field, and reduced rod and cone electroretinograms. The eye donor, at age 90, had good acuity and function in a central island. Grossly, the central region of the donor retina appeared thinned but otherwise normal, while the far periphery contained heavy bone spicule pigment. Microscopically the central retina showed photoreceptor outer segment shortening and some photoreceptor cell loss. The mid periphery had a sharp line of demarcation where more central photoreceptors were near normal except for very short outer segments and peripheral photoreceptors were absent. Rods and cones showed abrupt loss of outer segments and cell death at this interface. It is concluded that concentric retinitis pigmentosa is a rare but recognizable phenotype with slowly progressive photoreceptor death from the far periphery toward the central retina. The disease is retina-wide but shows regional variation in severity of degeneration; photoreceptor death is severe in the peripheral retina with an abrupt edge between viable and degenerate photoreceptors. Peripheral to central gradients of unknown retinal molecule(s) may be defective

  12. Unilateral retinitis pigmentosa sine pigmento.

    Science.gov (United States)

    Pearlman, J T; Saxton, J; Hoffman, G

    1976-05-01

    A patient presented with unilateral findings of night blindness shown by impaired rod function and dark adaptation, constricted visual fields with good central acuity, a barely recordable electro-retinographic b-wave, and a unilaterally impaired electro-oculogram. There were none of the pigmentary changes usually associated with retinitis pigmentosa. The unaffected right eye was normal in all respects. Therefore the case is most probably one of unilateral retinitis pigmentosa sine pigmento.

  13. Light and inherited retinal degeneration

    OpenAIRE

    Paskowitz, D M; LaVail, M M; Duncan, J L

    2006-01-01

    Light deprivation has long been considered a potential treatment for patients with inherited retinal degenerative diseases, but no therapeutic benefit has been demonstrated to date. In the few clinical studies that have addressed this issue, the underlying mutations were unknown. Our rapidly expanding knowledge of the genes and mechanisms involved in retinal degeneration have made it possible to reconsider the potential value of light restriction in specific genetic contexts. This review summ...

  14. Ethnic variation in rhegmatogenous retinal detachments

    Science.gov (United States)

    Chandra, A; Banerjee, P; Davis, D; Charteris, D

    2015-01-01

    Purpose We aimed to investigate the clinical variation of rhegmatogenous retinal detachments (RD) in patients of different ethnicities. Methods Patients presenting with a primary RD from two ethnic groups were recruited from our tertiary referral hospital between August 2010 and December 2012. Patients who self-reported their ethnic origin either as European Caucasian (EC) or South Asian (SA) were included. Exclusion criteria included trauma, previous vitreoretinal procedures, age under 18 years, complicated cataract surgery and the presence of syndromes known to be associated with a high prevalence of RD. Detailed phenotypic data were collected. Descriptive and comparative statistical analyses were undertaken. Results 1269 Patients were recruited. 1173 (92.4%) were EC. Mean age of onset was 58.3 years (EC) and 54.5 years (SA) (P=0.006). 75.3% EC and 58.4% SA were phakic (Plattice retinal degeneration in the affected eye (P=0.003). Refractive myopia was greater in SA patients (mean: −6.1DS) than EC (−4.2DS) (P=0.032). Additionally, SA patients had a greater mean axial length (25.65 mm) than EC (25.06 mm) (P=0.014). No differences were demonstrated in laterality, family history, type of retinal break or macular status. Conclusions SA patients present with RD at an earlier age and have a more severe phenotype than ECs. Future management strategies for RD may need to reflect these differences. PMID:25853394

  15. Myeloid differentiation protein 2-dependent mechanisms in retinal ischemia-reperfusion injury

    International Nuclear Information System (INIS)

    Ren, Luqing; Tao, Jianjian; Chen, Huaicheng; Bian, Yang; Yang, Xi; Chen, Gaozhi; Zhang, Xin; Liang, Guang; Wu, Wencan; Song, Zongming; Wang, Yi

    2017-01-01

    Retinal ischemia-reperfusion (I/R) injury is a common pathological process in many eye disorders. Oxidative stress and inflammation play a role in retinal I/R injury. Recent studies show that toll-like receptor 4 (TLR4) is involved in initiating sterile inflammatory response in retinal I/R. However, the molecular mechanism by which TLR4 is activated is not known. In this study, we show that retinal I/R injury involves a co-receptor of TLR4, myeloid differentiation 2 (MD2). Inhibition of MD2 prevented cell death and preserved retinal function following retinal I/R injury. We confirmed these findings using MD2 knockout mice. Furthermore, we utilized human retinal pigment epithelial cells (ARPE-19 cells) to show that oxidative stress-induced cell death as well as inflammatory response are mediated through MD2. Inhibition of MD2 through a chemical inhibitor or knockdown prevented oxidative stress-induced cell death and expression of inflammatory cytokines. Oxidative stress was found to activate TLR4 in a MD2-dependent manner via increasing the expression of high mobility group box 1. In summary, our study shows that oxidative stress in retinal I/R injury can activate TLR4 signaling via MD2, resulting in induction of inflammatory genes and retinal damage. MD2 may represent an attractive therapeutic target for retinal I/R injury. - Highlights: • MD2 inhibition reduced retinal damage after I/R induction in mice. • TBHP induced TLR4/MD2 binding via increasing HMGB-1 expression. • TLR4/MD2 initiated inflammatory response via activation of MAPKs and NF-κB. • MD2 could be the therapeutic target for the treatment of retinal I/R.

  16. Myeloid differentiation protein 2-dependent mechanisms in retinal ischemia-reperfusion injury

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Luqing [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Tao, Jianjian; Chen, Huaicheng; Bian, Yang; Yang, Xi [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang (China); Chen, Gaozhi; Zhang, Xin; Liang, Guang [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China); Wu, Wencan, E-mail: wuwencan118@163.com [The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang (China); Song, Zongming, E-mail: szmeyes@126.com [The Eye Hospital of Wenzhou Medical University, Wenzhou, Zhejiang (China); Wang, Yi, E-mail: yi.wang1122@wmu.edu.cn [Chemical Biology Research Center, School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang (China)

    2017-02-15

    Retinal ischemia-reperfusion (I/R) injury is a common pathological process in many eye disorders. Oxidative stress and inflammation play a role in retinal I/R injury. Recent studies show that toll-like receptor 4 (TLR4) is involved in initiating sterile inflammatory response in retinal I/R. However, the molecular mechanism by which TLR4 is activated is not known. In this study, we show that retinal I/R injury involves a co-receptor of TLR4, myeloid differentiation 2 (MD2). Inhibition of MD2 prevented cell death and preserved retinal function following retinal I/R injury. We confirmed these findings using MD2 knockout mice. Furthermore, we utilized human retinal pigment epithelial cells (ARPE-19 cells) to show that oxidative stress-induced cell death as well as inflammatory response are mediated through MD2. Inhibition of MD2 through a chemical inhibitor or knockdown prevented oxidative stress-induced cell death and expression of inflammatory cytokines. Oxidative stress was found to activate TLR4 in a MD2-dependent manner via increasing the expression of high mobility group box 1. In summary, our study shows that oxidative stress in retinal I/R injury can activate TLR4 signaling via MD2, resulting in induction of inflammatory genes and retinal damage. MD2 may represent an attractive therapeutic target for retinal I/R injury. - Highlights: • MD2 inhibition reduced retinal damage after I/R induction in mice. • TBHP induced TLR4/MD2 binding via increasing HMGB-1 expression. • TLR4/MD2 initiated inflammatory response via activation of MAPKs and NF-κB. • MD2 could be the therapeutic target for the treatment of retinal I/R.

  17. Construction of High-Quality Camel Immune Antibody Libraries.

    Science.gov (United States)

    Romão, Ema; Poignavent, Vianney; Vincke, Cécile; Ritzenthaler, Christophe; Muyldermans, Serge; Monsion, Baptiste

    2018-01-01

    Single-domain antibodies libraries of heavy-chain only immunoglobulins from camelids or shark are enriched for high-affinity antigen-specific binders by a short in vivo immunization. Thus, potent binders are readily retrieved from relatively small-sized libraries of 10 7 -10 8 individual transformants, mostly after phage display and panning on a purified target. However, the remaining drawback of this strategy arises from the need to generate a dedicated library, for nearly every envisaged target. Therefore, all the procedures that shorten and facilitate the construction of an immune library of best possible quality are definitely a step forward. In this chapter, we provide the protocol to generate a high-quality immune VHH library using the Golden Gate Cloning strategy employing an adapted phage display vector where a lethal ccdB gene has to be substituted by the VHH gene. With this procedure, the construction of the library can be shortened to less than a week starting from bleeding the animal. Our libraries exceed 10 8 individual transformants and close to 100% of the clones harbor a phage display vector having an insert with the length of a VHH gene. These libraries are also more economic to make than previous standard approaches using classical restriction enzymes and ligations. The quality of the Nanobodies that are retrieved from immune libraries obtained by Golden Gate Cloning is identical to those from immune libraries made according to the classical procedure.

  18. Retinal artery occlusion during carotid artery stenting with distal embolic protection device.

    Science.gov (United States)

    Kohara, Kotaro; Ishikawa, Tatsuya; Kobayashi, Tomonori; Kawamata, Takakazu

    2018-01-01

    Retinal artery occlusion associated with carotid artery stenosis is well known. Although it can also occur at the time of carotid artery stenting, retinal artery occlusion via the collateral circulation of the external carotid artery is rare. We encountered two cases of retinal artery occlusion that were thought to be caused by an embolus from the external carotid artery during carotid artery stenting with a distal embolic protection device for the internal carotid artery. A 71-year-old man presented with central retinal artery occlusion after carotid artery stenting using the Carotid Guardwire PS and a 77-year-old man presented with branch retinal artery occlusion after carotid artery stenting using the FilterWire EZ. Because additional new cerebral ischaemic lesions were not detected in either case by postoperative diffusion-weighted magnetic resonance imaging, it was highly likely that the debris that caused retinal artery occlusion passed through not the internal carotid artery but collaterals to retinal arteries from the external carotid artery, which was not protected by a distal embolic protection device. It is suggested that a distal protection device for the internal carotid artery alone cannot prevent retinal artery embolisation during carotid artery stenting and protection of the external carotid artery is important to avoid retinal artery occlusion.

  19. High beam quality and high energy short-pulse laser with MOPA

    Science.gov (United States)

    Jin, Quanwei; Pang, Yu; Jiang, JianFeng; Tan, Liang; Cui, Lingling; Wei, Bin; Sun, Yinhong; Tang, Chun

    2018-03-01

    A high energy, high beam quality short-pulse diode-pumped Nd:YAG master oscillator power-amplifier (MOPA) laser with two amplifier stages is demonstrated. The two-rod birefringence compensation was used as beam quality controlling methods, which presents a short-pulse energy of 40 mJ with a beam quality value of M2 = 1.2 at a repetition rate of 400Hz. The MOPA system delivers a short-pulse energy of 712.5 mJ with a pulse width of 12.4 ns.The method of spherical aberration compensation is improved the beam quality, a M2 factor of 2.3 and an optical-to-optical efficiency of 27.7% is obtained at the maximum laser out power.The laser obtained 1.4J out energy with polarization integration.

  20. Perspectives of Stem Cell-Based Therapy for Age-Related Retinal Degenerative Diseases.

    Science.gov (United States)

    Holan, Vladimir; Hermankova, Barbora; Kossl, Jan

    2017-09-01

    Retinal degenerative diseases, which include age-related macular degeneration, retinitis pigmentosa, diabetic retinopathy, and glaucoma, mostly affect the elderly population and are the most common cause of decreased quality of vision or even blindness. So far, there is no satisfactory treatment protocol to prevent, stop, or cure these disorders. A great hope and promise for patients suffering from retinal diseases is represented by stem cell-based therapy that could replace diseased or missing retinal cells and support regeneration. In this respect, mesenchymal stem cells (MSCs) that can be obtained from the particular patient and used as autologous cells have turned out to be a promising stem cell type for treatment. Here we show that MSCs can differentiate into cells expressing markers of retinal cells, inhibit production of pro-inflammatory cytokines by retinal tissue, and produce a number of growth and neuroprotective factors for retinal regeneration. All of these properties make MSCs a prospective cell type for cell-based therapy of age-related retinal degenerative diseases.

  1. Development of nuclear quality high pressure valve bellows in Canada

    International Nuclear Information System (INIS)

    Janzen, P.; Astill, C.J.

    1978-06-01

    Concurrent with the decision to use bellows stem sealed nuclear valves where feasible in commercial-scale CANDU plants, AECL undertook to develop an indigenous high pressure valve bellows technology. This program included developing the capability to fabricate improved high pressure valve bellows in conjunction with a Canadian manufacturer. This paper describes the evolution of a two-stage bellows fabrication process involving: (1) manufacture of discrete lengths of precision thin wall telescoping tubes - from preparation of strip blanks through edge grinding and edge forming to longitudinal welding; (2) forming of bellows from tube assemblies using a novel combination of mechanical inward forming followed by hydraulic outward forming. Bellows of Inconel 600 and Inconel 625 have been manufactured and evaluated. Test results indicate comparable to improved performance over alternative high quality bellows. (author)

  2. Fat Quality Influences the Obesogenic Effect of High Fat Diets

    Directory of Open Access Journals (Sweden)

    Raffaella Crescenzo

    2015-11-01

    Full Text Available High fat and/or carbohydrate intake are associated with an elevated risk for obesity and chronic diseases such as diabetes and cardiovascular diseases. The harmful effects of a high fat diet could be different, depending on dietary fat quality. In fact, high fat diets rich in unsaturated fatty acids are considered less deleterious for human health than those rich in saturated fat. In our previous studies, we have shown that rats fed a high fat diet developed obesity and exhibited a decrease in oxidative capacity and an increase in oxidative stress in liver mitochondria. To investigate whether polyunsaturated fats could attenuate the above deleterious effects of high fat diets, energy balance and body composition were assessed after two weeks in rats fed isocaloric amounts of a high-fat diet (58.2% by energy rich either in lard or safflower/linseed oil. Hepatic functionality, plasma parameters, and oxidative status were also measured. The results show that feeding on safflower/linseed oil diet attenuates the obesogenic effect of high fat diets and ameliorates the blood lipid profile. Conversely, hepatic steatosis and mitochondrial oxidative stress appear to be negatively affected by a diet rich in unsaturated fatty acids.

  3. Retinal pigmentary changes in chronic uveitis mimicking retinitis pigmentosa.

    Science.gov (United States)

    Sevgi, D Damla; Davoudi, Samaneh; Comander, Jason; Sobrin, Lucia

    2017-09-01

    To present retinal pigmentary changes mimicking retinitis pigmentosa (RP) as a finding of advanced uveitis. We retrospectively reviewed charts of patients without a family history of inherited retinal degenerations who presented with retinal pigment changes and signs of past or present intraocular inflammation. Comprehensive eye examination including best-corrected visual acuity, slit-lamp examination and dilated fundus examination was performed on all patients in addition to color fundus photography, optical coherence tomography, fluorescein angiography (FA), and full-field electroretinogram testing. We identified five patients with ages ranging from 33 to 66 years, who presented with RP-like retinal pigmentary changes which were eventually attributed to longstanding uveitis. The changes were bilateral in three cases and unilateral in two cases. Four of five cases presented with active inflammation, and the remaining case showed evidence of active intraocular inflammation during follow-up. This study highlights the overlapping features of advanced uveitis and RP including the extensive pigmentary changes. Careful review of possible past uveitis history, detailed examination of signs of past or present inflammation and ancillary testing, with FA often being most helpful, are required for the correct diagnosis. This is important, because intervention can prevent further damage if the cause of the pigmentary changes is destructive inflammation.

  4. High quality electron beams from a laser wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, S M; Issac, R C; Welsh, G H; Brunetti, E; Shanks, R P; Anania, M P; Cipiccia, S; Manahan, G G; Aniculaesei, C; Ersfeld, B; Islam, M R; Burgess, R T L; Vieux, G; Jaroszynski, D A [SUPA, Department of Physics, University of Strathclyde, Glasgow (United Kingdom); Gillespie, W A [SUPA, Division of Electronic Engineering and Physics, University of Dundee, Dundee (United Kingdom); MacLeod, A M [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee (United Kingdom); Van der Geer, S B; De Loos, M J, E-mail: m.wiggins@phys.strath.ac.u [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands)

    2010-12-15

    High quality electron beams have been produced in a laser-plasma accelerator driven by femtosecond laser pulses with a peak power of 26 TW. Electrons are produced with an energy up to 150 MeV from the 2 mm gas jet accelerator and the measured rms relative energy spread is less than 1%. Shot-to-shot stability in the central energy is 3%. Pepper-pot measurements have shown that the normalized transverse emittance is {approx}1{pi} mm mrad while the beam charge is in the range 2-10 pC. The generation of high quality electron beams is understood from simulations accounting for beam loading of the wakefield accelerating structure. Experiments and self-consistent simulations indicate that the beam peak current is several kiloamperes. Efficient transportation of the beam through an undulator is simulated and progress is being made towards the realization of a compact, high peak brilliance free-electron laser operating in the vacuum ultraviolet and soft x-ray wavelength ranges.

  5. Massive Bilateral Serous Retinal Detachment in a Case of Hypertensive Chorioretinopathy

    Directory of Open Access Journals (Sweden)

    Luis Villalba-Pinto

    2014-07-01

    Full Text Available Introduction: Systemic high blood pressure is related to a variety of retinal manifestations. We present an atypical case of hypertensive chorioretinopathy with massive bilateral serous retinal detachment. Case Report: A 26-year-old male with a genitourinary malformation and secondary grade IV chronic kidney failure as well as high blood pressure complained of acute vision loss. Dilated fundus examination evidenced a bilateral serous retinal detachment with macular involvement. The patient was unresponsive to oral antihypertensive therapy and dialysis treatment. The serous retinal detachment progressively decreased after the restoration of dialysis and antihypertensive therapy. The final visual acuity was 0.50 in both eyes. Discussion: In cases of serous macular detachment, it is mandatory to rule out different systemic and ocular diseases. The presence of uncontrolled high blood pressure may produce aggressive bilateral retinal changes, thus hypertension must be under early and strict control in order to improve the visual outcomes.

  6. Massive Bilateral Serous Retinal Detachment in a Case of Hypertensive Chorioretinopathy

    Science.gov (United States)

    Villalba-Pinto, Luis; Hernández-Ortega, M. Ángeles; de los Mozos, F. Javier Lavid; Pascual-Camps, Isabel; Dolz-Marco, Rosa; Arevalo, J. Fernando; Gallego-Pinazo, Roberto

    2014-01-01

    Introduction Systemic high blood pressure is related to a variety of retinal manifestations. We present an atypical case of hypertensive chorioretinopathy with massive bilateral serous retinal detachment. Case Report A 26-year-old male with a genitourinary malformation and secondary grade IV chronic kidney failure as well as high blood pressure complained of acute vision loss. Dilated fundus examination evidenced a bilateral serous retinal detachment with macular involvement. The patient was unresponsive to oral antihypertensive therapy and dialysis treatment. The serous retinal detachment progressively decreased after the restoration of dialysis and antihypertensive therapy. The final visual acuity was 0.50 in both eyes. Discussion In cases of serous macular detachment, it is mandatory to rule out different systemic and ocular diseases. The presence of uncontrolled high blood pressure may produce aggressive bilateral retinal changes, thus hypertension must be under early and strict control in order to improve the visual outcomes. PMID:25120474

  7. Sleep quality and its relationship with quality of life among high-risk pregnant women (gestational diabetes and hypertension).

    Science.gov (United States)

    Saadati, Fatemeh; Sehhatiei Shafaei, Fahimeh; Mirghafourvand, Mozhgan

    2018-01-01

    Sleep is one of the most basic human requirements. This research aims at determining the status of sleep quality and its relationship with quality of life among high-risk pregnant women in Tabriz, Iran, in 2015. This research was a sectional study done on 364 qualified women in 28-36 weeks of pregnancy suffering from mild preeclampsia and gestational diabetes. The sampling was done as convenience. Personal-social-midwifery questionnaire, Pittsburg sleep quality, and quality of life in pregnancy (QOL-ORAV) were used for gathering data. Multivariate linear regression model was used for determining the relationship between sleep quality and its subsets with quality of life and controlling confounders. In the current study, the prevalence of sleep disturbance was 96.4%. Mean (SD) of the total score of sleep quality was 10.1 (4.1) and the total score of quality of life was 61.7 (17.3). According to Pearson's correlation test, there was statistically significant relationship between quality of life and sleep quality and all its subsets except sleep duration and use of sleep medication (p quality of life. The findings of current research show that sleep quality is low among high-risk pregnant women and quality of life is medium. So, it is necessary that required training is given by health cares for improving sleep quality and quality of life to mothers.

  8. Retinal detachment in paediatric patients

    International Nuclear Information System (INIS)

    Zafar, S. N.; Qureshi, N.; Azad, N.; Khan, A.

    2013-01-01

    Objective: To assess the causes of retinal detachment in children and the various operative procedures requiring vitreoretinal surgical intervention for the same. Study Design: Case series. Place and Duration of Study: Department of Ophthalmology, Al-Shifa Trust Eye Hospital, Rawalpindi, from January 2006 to May 2009. Methodology: A total of 281 eyes of 258 patients, (aged 0 - 18 years) who underwent vitreo-retinal surgical intervention for retinal detachment were included. Surgical log was searched for the type of retinal detachment and its causes. Frequencies of various interventions done in these patients viz. vitrectomy, scleral buckle, use of tamponading agents, laser photocoagulation and cryotherapy were noted. Results were described as descriptive statistics. Results: Myopia was the cause in 62 (22.1%) and trauma in 51 (18.1%) of the eyes. Total retinal detachment (RD) was treated in 94 (33.5%) eyes, sub total RD in 36 (12.8%), recurrent RD in 32 (11.4%), giant retinal tear in 28 (10%), tractional RD in 15 (5.3%) and exudative RD in 2 (0.7%). Prophylactic laser or cryotherapy was applied in 74 (26.3%) of the eyes. Pars plana vitrectomy (PPV) was carried out in 159 (56.6%) eyes while scleral buckle procedure was done in 129 (45.9%) eyes. Silicon oil was used in 149 (53%), perfluorocarbon liquid in 32 (11.4%) and gas tamponade in 20 (7.1%) eyes. Conclusion: The most common cause of retinal detachment in paediatric patients was myopia, followed by trauma. Total RD was more common as compared to the other types. The most common procedure adopted was pars plana vitrectomy followed by scleral buckle procedure. (author)

  9. Present status of high quality beam facility at Waseda University

    International Nuclear Information System (INIS)

    Washio, M.; Kawai, H.; Hama, Y.; Kudo, N.; Kobayashi, M.; Kuribayasi, T.; Kawaguchi, M.; Kuroda, R.; Maeda, K.; Nagasawa, F.; Ueyama, D.; Hizume, K.; Wang, X.J.; Hayano, H.; Urakawa, J.; Kashiwagi, S.

    2004-01-01

    A research project named High-Tech Research Center Project has been conducted at Waseda University. In this project, an RF gun system has been used for production of low emittance and short bunched electron beam. The experiments for the electron beam quality measurement have been carried out by slit scan techniques, etc. Short pulsed x-ray with the energy range of so-called water window has been generation by the inverse compton scattering. Further, the pulse radiolysis system has been constructed, and the stroboscopic pulse radiolysis has been applied for the detection of hydrated electron in picosecond time region. (author)

  10. Anti-Stokes Luminescence in High Quality Quantum Wells

    Science.gov (United States)

    Vinattieri, A.; Bogani, F.; Miotto, A.; Ceccherini, S.

    1997-11-01

    We present a detailed investigation of the anti-Stokes (AS) luminescence which originates from exciton recombination when below gap excitation is used, in a set of high quality quantum well structures. We observe strong excitonic resonances in the AS signal as measured from photoluminescence and photoluminescence excitation spectra. We demonstrate that neither the electromagnetic coupling between the wells nor the morphological disorder can explain this up-conversion effect. Time-resolved luminescence data after ps excitation and fs correlation spectroscopy results provide clear evidence of the occurrence of a two-step absorption which is assisted by the exciton population resonantly excited by the first photon.

  11. The quality of high-energy X-ray beams

    International Nuclear Information System (INIS)

    LaRiviere, P.D.

    1989-01-01

    Supplement 17 of the British Journal of Radiology is a survey of central-axis depth doses for radiotherapy machines, patterned largely on BJR Supplement 11 (1972). Inspection of high-energy X-ray depth doses for a 10 x 10 cm field at an SSD of 100 cm disclosed large differences between the two sets of data, especially for qualities above 8 MV, e.g. a depth dose of 80% at 10 cm is rated at about 19 MV according to BJR Supplement 11, and 23 MV according to BJR Supplement 17. It was found that Supplement 17 depth-dose data above 8 MV were erratic, but Supplement 11 data could be represented by an analytical expression, providing a unique means of assigning MV quality. It was also found that dose-weighted average energy of the filtered beam plotted smoothly against depth dose. For dosimetric purposes, it is suggested that this parameter be used as a true measure of beam quality, removing discrepancies introduced by the use of nominal MV for this purpose. (author)

  12. CCD Astrophotography High-Quality Imaging from the Suburbs

    CERN Document Server

    Stuart, Adam

    2006-01-01

    This is a reference book for amateur astronomers who have become interested in CCD imaging. Those glorious astronomical images found in astronomy magazines might seem out of reach to newcomers to CCD imaging, but this is not the case. Great pictures are attainable with modest equipment. Adam Stuart’s many beautiful images, reproduced in this book, attest to the quality of – initially – a beginner’s efforts. Chilled-chip astronomical CCD-cameras and software are also wonderful tools for cutting through seemingly impenetrable light-pollution. CCD Astrophotography from the Suburbs describes one man’s successful approach to the problem of getting high-quality astronomical images under some of the most light-polluted conditions. Here is a complete and thoroughly tested program that will help every CCD-beginner to work towards digital imaging of the highest quality. It is equally useful to astronomers who have perfect observing conditions, as to those who have to observe from light-polluted city skies.

  13. Impaired Retinal Vasodilator Responses in Prediabetes and Type 2 Diabetes

    Science.gov (United States)

    Lott, Mary E.J.; Slocomb, Julia E.; Shivkumar, Vikram; Smith, Bruce; Quillen, David; Gabbay, Robert A.; Gardner, Thomas W.; Bettermann, Kerstin

    2013-01-01

    Purpose In diabetes, endothelial dysfunction and subsequent structural damage to blood vessels can lead to heart attacks, retinopathy and strokes. However, it is unclear whether prediabetic subjects exhibit microvascular dysfunction indicating early stages of arteriosclerosis and vascular risk. The purpose of this study was to examine whether retinal reactivity may be impaired early in the hyperglycemic continuum and may be associated with markers of inflammation. Methods Individuals with prediabetes (n = 22), type 2 diabetes (n = 25) and healthy age and body composition matched controls (n = 19) were studied. We used the Dynamic Vessel Analyzer to assess retinal vasoreactivity (percent change in vessel diameter) during a flickering light stimulation. Fasting highly sensitive c-reactive protein (hs-CRP), a marker of inflammation, was measured in blood plasma. Results Prediabetic and diabetic individuals had attenuated peak vasodilator and relative amplitude changes in retinal vein diameters to the flickering light stimulus compared to healthy controls (peak dilation: prediabetic subjects 3.3 ± 1.8 %, diabetic subjects 3.3 ± 2.1% controls 5.6 ± 2.6%, p = .001; relative amplitude: prediabetic subjects 4.3 ± 2.2%, diabetic subjects 5.0 ± 2.6% and control subjects 7.2 ± 3.2%, p = .003). Similar findings were observed in retinal arteries. Levels of hs-CRP were not associated with either retinal vessel response parameters. Conclusion Retinal reactivity was impaired in prediabetic and type 2 diabetic individuals in parallel with reduced insulin sensitivity but not associated with levels of hs-CRP. Retinal vasoreactivity measurements may be a sensitive tool to assess early vascular risk. PMID:23742315

  14. Raldh1 promotes adiposity during adolescence independently of retinal signaling.

    Directory of Open Access Journals (Sweden)

    Di Yang

    Full Text Available All-trans-retinoic acid (RA inhibits adipogenesis in established preadipocyte cell lines. Dosing pharmacological amounts of RA reduces weight gain in mice fed a high-fat diet, i.e. counteracts diet-induced obesity (DIO. The aldehyde dehydrogenase Raldh1 (Aldh1a1 functions as one of three enzymes that converts the retinol metabolite retinal into RA, and one of many proteins that contribute to RA homeostasis. Female Raldh1-ablated mice resist DIO. This phenotype contrasts with ablations of other enzymes and binding-proteins that maintain RA homeostasis, which gain adiposity. The phenotype observed prompted the conclusion that loss of Raldh1 causes an increase in adipose tissue retinal, and therefore, retinal functions independently of RA to prevent DIO. A second deduction proposed that low nM concentrations of RA stimulate adipogenesis, in contrast to higher concentrations. Using peer-reviewed LC/MS/MS assays developed and validated for quantifying tissue RA and retinal, we show that endogenous retinal and RA concentrations in adipose tissues from Raldh1-null mice do not correlate with the phenotype. Moreover, male Raldh1-null mice resist weight gain regardless of dietary fat content. Resistance to weight gain occurs during adolescence in both sexes. We show that RA concentrations as low as 1 nM, i.e. in the sub-physiological range, impair adipogenesis of embryonic fibroblasts from wild-type mice. Embryonic fibroblasts from Raldh1-null mice resist differentiating into adipocytes, but retain ability to generate RA. These fibroblasts remain sensitive to an RA receptor pan-agonist, and are not affected by an RA receptor pan-antagonist. Thus, the data do not support the hypothesis that retinal itself represses weight gain and adipogenesis independently of RA. Instead, the data indicate that Raldh1 functions as a retinal and atRA-independent promoter of adiposity during adolescence, and enhances adiposity through pre-adipocyte cell autonomous actions.

  15. Dorsal raphe nucleus projecting retinal ganglion cells: Why Y cells?

    Science.gov (United States)

    Pickard, Gary E.; So, Kwok-Fai; Pu, Mingliang

    2015-01-01

    Retinal ganglion Y (alpha) cells are found in retinas ranging from frogs to mice to primates. The highly conserved nature of the large, fast conducting retinal Y cell is a testament to its fundamental task, although precisely what this task is remained ill-defined. The recent discovery that Y-alpha retinal ganglion cells send axon collaterals to the serotonergic dorsal raphe nucleus (DRN) in addition to the lateral geniculate nucleus (LGN), medial interlaminar nucleus (MIN), pretectum and the superior colliculus (SC) has offered new insights into the important survival tasks performed by these cells with highly branched axons. We propose that in addition to its role in visual perception, the Y-alpha retinal ganglion cell provides concurrent signals via axon collaterals to the DRN, the major source of serotonergic afferents to the forebrain, to dramatically inhibit 5-HT activity during orientation or alerting/escape responses, which dis-facilitates ongoing tonic motor activity while dis-inhibiting sensory information processing throughout the visual system. The new data provide a fresh view of these evolutionarily old retinal ganglion cells. PMID:26363667

  16. Polycystic Ovary Syndrome: Aggressive or Protective Factor for the Retina? Evaluation of Macular Thickness and Retinal Nerve Fiber Layers Using High-Definition Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    José Edvan de Souza-Júnior

    2015-01-01

    Full Text Available Objective. To compare macular thickness (MT and retinal nerve fiber layers (RNFL between women with polycystic ovary syndrome (PCOS and healthy women. Materials and Methods. The study included 45 women with PCOS and 47 ovulatory women undergoing clinical-gynecological and ophthalmic evaluations, including measurement of MT, RNFL, and optic disc parameters using optical coherence tomography. Results. The superior RNFL around the optic nerve was significantly thicker in PCOS than in healthy volunteers (P=0.036. After stratification according to insulin resistance, the temporal inner macula (TIM, the inferior inner macula (IIM, the nasal inner macula (NIM, and the nasal outer macula (NOM were significantly thicker in PCOS group than in control group (P<0.05. Both the presence of obesity associated with insulin resistance (P=0.037 and glucose intolerance (P=0.001 were associated with significant increase in the PC1 mean score, relative to MT. A significant increase in the PC2 mean score occurred when considering the presence of metabolic syndrome (P<0.0001. There was a significant interaction between obesity and inflammation in a decreasing mean PC2 score relative to macular RNFL thickness (P=0.034. Conclusion. Decreased macular RNFL thickness and increased total MT are associated with metabolic abnormalities, while increased RNFL thickness around the optic nerve is associated with hormonal changes inherent in PCOS.

  17. Progressive outer retinal necrosis in the era of highly active antiretroviral therapy: successful management with intravitreal injections and monitoring with quantitative PCR.

    Science.gov (United States)

    Yin, Philip D; Kurup, Shree K; Fischer, Steven H; Rhee, Henry H; Byrnes, Gordon A; Levy-Clarke, Grace A; Buggage, Ronald R; Nussenblatt, Robert B; Mican, JoAnn M; Wright, Mary E

    2007-03-01

    Progressive outer retinal necrosis (PORN) is an ocular disease in individuals with AIDS and is associated with substantial morbidity. The optimal management of PORN and its clinical course in the HAART era is unclear. We report a case of successfully managed PORN that provides insight into the monitoring and treatment of this disease. Intravitreal injections and intravenous therapy targeted towards varicella zoster virus (VZV) were used to treat PORN. HAART was initiated for HIV-1 therapy. Serial PCR for VZV was performed on aqueous humor to monitor the clinical course. The presence of VZV DNA from aqueous humor correlated with clinical exacerbations of disease. Initiation of twice weekly intravitreal injections with dual antiviral drugs appeared to be an important therapeutic intervention that resulted in remission of PORN. Secondary prophylaxis against VZV was successfully withdrawn after HAART induced partial immune recovery. In addition to aggressive therapy with intravitreal injections, HAART and quantitative measurements of VZV DNA from aqueous humor have important roles in the management of PORN. A multidisciplinary approach involving specialists in infectious diseases, ophthalmology, and clinical microbiology will improve the chances for successful long-term outcomes.

  18. In vivo retinal imaging for fixational eye motion detection using a high-speed digital micromirror device (DMD)-based ophthalmoscope.

    Science.gov (United States)

    Vienola, Kari V; Damodaran, Mathi; Braaf, Boy; Vermeer, Koenraad A; de Boer, Johannes F

    2018-02-01

    Retinal motion detection with an accuracy of 0.77 arcmin corresponding to 3.7 µm on the retina is demonstrated with a novel digital micromirror device based ophthalmoscope. By generating a confocal image as a reference, eye motion could be measured from consecutively measured subsampled frames. The subsampled frames provide 7.7 millisecond snapshots of the retina without motion artifacts between the image points of the subsampled frame, distributed over the full field of view. An ophthalmoscope pattern projection speed of 130 Hz enabled a motion detection bandwidth of 65 Hz. A model eye with a scanning mirror was built to test the performance of the motion detection algorithm. Furthermore, an in vivo motion trace was obtained from a healthy volunteer. The obtained eye motion trace clearly shows the three main types of fixational eye movements. Lastly, the obtained eye motion trace was used to correct for the eye motion in consecutively obtained subsampled frames to produce an averaged confocal image correct for motion artefacts.

  19. Retinal vascular oximetry during ranibizumab treatment of central retinal vein occlusion

    DEFF Research Database (Denmark)

    Traustason, Sindri; la Cour, Morten; Larsen, Michael

    2014-01-01

    PURPOSE: To investigate the effect of intravitreal injections of the vascular endothelial growth factor inhibitor ranibizumab on retinal oxygenation in patients with central retinal vein occlusion (CRVO). METHODS: Retinal oxygen saturation in patients with CRVO was analysed using the Oxymap Retin...

  20. Noninvasive Retinal Markers in Diabetic Retinopathy

    DEFF Research Database (Denmark)

    Blindbæk, Søren Leer; Torp, Thomas Lee; Lundberg, Kristian

    2017-01-01

    The retinal vascular system is the only part of the human body available for direct, in vivo inspection. Noninvasive retinal markers are important to identity patients in risk of sight-threatening diabetic retinopathy. Studies have correlated structural features like retinal vascular caliber...... and fractals with micro- and macrovascular dysfunction in diabetes. Likewise, the retinal metabolism can be evaluated by retinal oximetry, and higher retinal venular oxygen saturation has been demonstrated in patients with diabetic retinopathy. So far, most studies have been cross-sectional, but these can only...... retinopathy and diabetic macular edema. The Department of Ophthalmology at Odense University Hospital, Denmark, has a strong tradition of studying the retinal microvasculature in diabetic retinopathy. In the present paper, we demonstrate the importance of the retinal vasculature not only as predictors of long...

  1. Mitochondrial dysfunction underlying outer retinal diseases

    DEFF Research Database (Denmark)

    Lefevere, Evy; Toft-Kehler, Anne Katrine; Vohra, Rupali

    2017-01-01

    Dysfunction of photoreceptors, retinal pigment epithelium (RPE) or both contribute to the initiation and progression of several outer retinal disorders. Disrupted Müller glia function might additionally subsidize to these diseases. Mitochondrial malfunctioning is importantly associated with outer...

  2. Percutaneous vertebroplasty with a high-quality rotational angiographic unit

    Energy Technology Data Exchange (ETDEWEB)

    Pedicelli, Alessandro [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: apedicelli@rm.unicatt.it; Rollo, Massimo [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: mrollo@rm.unicatt.it; Piano, Mariangela [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: mariangela.piano@gmail.com; Re, Thomas J. [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: tomjre@gmail.com; Cipriani, Maria C. [Department of Gerontology, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: alexped@yahoo.com; Colosimo, Cesare [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: colosimo@rm.unicatt.it; Bonomo, Lorenzo [Department of Bioimaging and Radiological Sciences, Catholic University of Sacred Heart, Policl. A.Gemelli, l.go Gemelli 1, 00168 Rome (Italy)], E-mail: lbonomo@rm.unicatt.it

    2009-02-15

    We evaluated the reliability of a rotational angiographic unit (RA) with flat-panel detector as a single technique to guide percutaneous vertebroplasty (PVP) and for post-procedure assessment by 2D and 3D reformatted images. Fifty-five consecutive patients (104 vertebral bodies) were treated under RA fluoroscopy. Rotational acquisitions with 2D and 3D reconstruction were obtained in all patients for immediate post-procedure assessment. In complex cases, this technique was also used to evaluate the needle position during the procedure. All patients underwent CT scan after the procedure. RA and CT findings were compared. In all cases, a safe trans-pedicular access and an accurate control of the bone-cement injection were successfully performed with high-quality fluoroscopy, even at the thoracic levels and in case of vertebra plana. 2D and 3D rotational reconstructions permitted CT-like images that clearly showed needle position and were similar to CT findings in depicting intrasomatic implant-distribution. RA detected 40 cement leakages compared to 42 demonstrated by CT and showed overall 95% sensitivity and 100% specificity compared to CT for final post-procedure assessment. Our preliminary results suggest that high-quality RA is reliable and safe as a single technique for PVP guidance, control and post-procedure assessment. It permits fast and cost-effective procedures avoiding multi-modality imaging.

  3. Computer-aided control of high-quality cast iron

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2008-04-01

    Full Text Available The study discusses the possibility of control of the high-quality grey cast iron and ductile iron using the author’s genuine computer programs. The programs have been developed with the help of algorithms based on statistical relationships that are said to exist between the characteristic parameters of DTA curves and properties, like Rp0,2, Rm, A5 and HB. It has been proved that the spheroidisation and inoculation treatment of cast iron changes in an important way the characteristic parameters of DTA curves, thus enabling a control of these operations as regards their correctness and effectiveness, along with the related changes in microstructure and mechanical properties of cast iron. Moreover, some examples of statistical relationships existing between the typical properties of ductile iron and its control process were given for cases of the melts consistent and inconsistent with the adopted technology.A test stand for control of the high-quality cast iron and respective melts has been schematically depicted.

  4. Automated high speed volume computed tomography for inline quality control

    International Nuclear Information System (INIS)

    Hanke, R.; Kugel, A.; Troup, P.

    2004-01-01

    Increasing complexity of innovative products as well as growing requirements on quality and reliability call for more detailed knowledge about internal structures of manufactured components rather by 100 % inspection than just by sampling test. A first-step solution, like radioscopic inline inspection machines, equipped with automated data evaluation software, have become state of the art in the production floor during the last years. However, these machines provide just ordinary two-dimensional information and deliver no volume data e.g. to evaluate exact position or shape of detected defects. One way to solve this problem is the application of X-ray computed tomography (CT). Compared to the performance of the first generation medical scanners (scanning times of many hours), today, modern Volume CT machines for industrial applications need about 5 minutes for a full object scan depending on the object size. Of course, this is still too long to introduce this powerful method into the inline production quality control. In order to gain acceptance, the scanning time including subsequent data evaluation must be decreased significantly and adapted to the manufacturing cycle times. This presentation demonstrates the new technical set up, reconstruction results and the methods for high-speed volume data evaluation of a new fully automated high-speed CT scanner with cycle times below one minute for an object size of less than 15 cm. This will directly create new opportunities in design and construction of more complex objects. (author)

  5. Production of high quality water for oil sands application

    Energy Technology Data Exchange (ETDEWEB)

    Beaudette-Hodsman, C.; Macleod, B. [Pall Corp., Mississauga, ON (Canada); Venkatadri, R. [Pall Corp., East Hills, NY (United States)

    2008-10-15

    This paper described a pressurized microfiltration membrane system installed at an oil sands extraction site in Alberta. The system was designed to complement a reverse osmosis (RO) system installed at the site to produce the high quality feed water required by the system's boilers. Groundwater in the region exhibited moderate total suspended solids and high alkalinity and hardness levels, and the RO system required feed water with a silt density index of 3 or less. The conventional pretreatment system used at the site was slowing down production due to the severe fouling of the RO membranes. The new microfiltration system contained an automated PVDF hollow fiber microfiltration membrane system contained in a trailer. Suspended particles and bacteria were captured within the filter, and permeate was sent to the RO unit. Within 6 hours of being installed, the unit was producing water with SDI values in the range of 1.0 to 2.5. It was concluded that the microfiltration system performed reliably regardless of wide variations in feed water quality and flow rates. 3 refs., 1 tab., 8 figs.

  6. Cnn Based Retinal Image Upscaling Using Zero Component Analysis

    Science.gov (United States)

    Nasonov, A.; Chesnakov, K.; Krylov, A.

    2017-05-01

    The aim of the paper is to obtain high quality of image upscaling for noisy images that are typical in medical image processing. A new training scenario for convolutional neural network based image upscaling method is proposed. Its main idea is a novel dataset preparation method for deep learning. The dataset contains pairs of noisy low-resolution images and corresponding noiseless highresolution images. To achieve better results at edges and textured areas, Zero Component Analysis is applied to these images. The upscaling results are compared with other state-of-the-art methods like DCCI, SI-3 and SRCNN on noisy medical ophthalmological images. Objective evaluation of the results confirms high quality of the proposed method. Visual analysis shows that fine details and structures like blood vessels are preserved, noise level is reduced and no artifacts or non-existing details are added. These properties are essential in retinal diagnosis establishment, so the proposed algorithm is recommended to be used in real medical applications.

  7. High Framingham risk score decreases quality of life in adults

    Directory of Open Access Journals (Sweden)

    Christian Yosaputra

    2010-04-01

    Full Text Available Cardiovascular disease (CVD risk factors, such as diabetes, hypertension, hypercholesterolemia, smoking, and obesity tend to occur together in the general population. Increasing prevalence of multiple CVD risk factors has been related to increased risk of death from coronary heart disease and stroke. Studies have suggested that people with several risk factors of CVD may have impaired health-related quality of life. The objective of this study was to assess the association of CVD risk factors with quality of life (QOL among adults aged 40 to 65 years. A cross-sectional study was conducted involving 220 subjects 40 - 65 years of age at a health center. The CVD risk factors were assessed using the Framingham risk score that is the standard instrument for assessment of the risk of a first cardiac event. The risk factors assessed were age, smoking, blood pressure, total cholesterol and high density lipoprotein cholesterol concentrations. QOL was assessed by means of the WHOQOL-BREF instrument that had been prevalidated. The results of the study showed that 28.2% of subjects were smokers, 56.4% had stage 1 hypertension, 42.8% high total cholesterol and 13.6% low HDL cholesterol. The high risk group amounted to 45.5% and 42.3% constitued an intermediate risk group. High CVD risk scores were significantly associated with a low QOL for all domains (physical, psychological, social and environment (p=0.000. Preventing or reducing the multiple CVD risk factors to improve QOL is necessary among adults.

  8. Optical coherence tomography in retinitis pigmentosa: reproducibility and capacity to detect macular and retinal nerve fiber layer thickness alterations.

    Science.gov (United States)

    Garcia-Martin, Elena; Pinilla, Isabel; Sancho, Eva; Almarcegui, Carmen; Dolz, Isabel; Rodriguez-Mena, Diego; Fuertes, Isabel; Cuenca, Nicolas

    2012-09-01

    To evaluate the ability of time-domain and Fourier-domain optical coherence tomographies (OCTs) to detect macular and retinal nerve fiber layer atrophies in retinitis pigmentosa (RP). To test the intrasession reproducibility using three OCT instruments (Stratus, Cirrus, and Spectralis). Eighty eyes of 80 subjects (40 RP patients and 40 healthy subjects) underwent a visual field examination, together with 3 macular scans and 3 optic disk evaluations by the same experienced examiner using 3 OCT instruments. Differences between healthy and RP eyes were compared. The relationship between measurements with each OCT instrument was evaluated. Repeatability was studied by intraclass correlation coefficients and coefficients of variation. Macular and retinal nerve fiber layer atrophies were detected in RP patients for all OCT parameters. Macular and retinal nerve fiber layer thicknesses, as determined by the different OCTs, were correlated but significantly different (P < 0.05). Reproducibility was moderately high using Stratus, good using Cirrus and Spectralis, and excellent using the Tru-track technology of Spectralis. In RP eyes, measurements showed higher variability compared with healthy eyes. Differences in thickness measurements existed between OCT instruments, despite there being a high degree of correlation. Fourier-domain OCT can be considered a valid and repeatability technique to detect retinal nerve fiber layer atrophy in RP patients.

  9. Wide-field optical coherence tomography based microangiography for retinal imaging

    Science.gov (United States)

    Zhang, Qinqin; Lee, Cecilia S.; Chao, Jennifer; Chen, Chieh-Li; Zhang, Thomas; Sharma, Utkarsh; Zhang, Anqi; Liu, Jin; Rezaei, Kasra; Pepple, Kathryn L.; Munsen, Richard; Kinyoun, James; Johnstone, Murray; van Gelder, Russell N.; Wang, Ruikang K.

    2016-02-01

    Optical coherence tomography angiography (OCTA) allows for the evaluation of functional retinal vascular networks without a need for contrast dyes. For sophisticated monitoring and diagnosis of retinal diseases, OCTA capable of providing wide-field and high definition images of retinal vasculature in a single image is desirable. We report OCTA with motion tracking through an auxiliary real-time line scan ophthalmoscope that is clinically feasible to image functional retinal vasculature in patients, with a coverage of more than 60 degrees of retina while still maintaining high definition and resolution. We demonstrate six illustrative cases with unprecedented details of vascular involvement in retinal diseases. In each case, OCTA yields images of the normal and diseased microvasculature at all levels of the retina, with higher resolution than observed with fluorescein angiography. Wide-field OCTA technology will be an important next step in augmenting the utility of OCT technology in clinical practice.

  10. Rhegmatogenous retinal detachment and conventional surgical treatment.

    Science.gov (United States)

    Golubovic, M

    2013-01-01

    . According to the present risk factor, high myopia was found in 5 patients, which has been emphasized to be a significant risk factor for onset of retinal detachment. Lattice degeneration was the most common peripheral degenerative change. The most frequently found was horseshoe retinal hole with vitreous traction and the break location was most common in the upper retinal quadrants. The most commonly applied type was limbus radial buckle with encircling band, depending on the pathological process in the eye. The retina was postoperatively attached in 31 eyes. In two cases, the retina was not attached; in one eye due to the inadequately inserted implant and in the other case due to the larger number of breaks (3) with more distinct PVR (C2), and postoperative inflammation and proliferative components were more intensified. In one patient who did not have a total detachment, but had a larger break placed posterior to the equator and PVR C1, redetachment appeared one month later due to a manifested fibroproliferative reaction, although the break was closed. Regarding visual acuity, the day following the surgery there was no improvement; moreover, there was a small decline of visual acuity due to exudates in the vitreous body and vitreous hemorrhage. After 3 months, there was a significant improvement in the largest number of eyes. Intraoperative complications included intravitreous hemorrhage, and postoperative more distinct proliferative component in the vitreous body was found in two patients. Timely diagnosis and intervention in retinal detachment by application of an adequate method and less invasive technique gives excellent results in postoperative morbidity rate and rehabilitation of the vision. The results of the conventional treatment of retinal detachment justify its application in the treatment of this disease.

  11. Chitosan oligosaccharides attenuates oxidative-stress related retinal degeneration in rats.

    Directory of Open Access Journals (Sweden)

    I-Mo Fang

    Full Text Available This study investigated the therapeutic potential and mechanisms of chitosan oligosaccharides (COS for oxidative stress-induced retinal diseases. Retinal oxidative damage was induced in Sprague-Dawley rats by intravitreal injection of paraquat (PQ. Low-dose (5 mg/kg or high-dose (10 mg/kg COS or PBS was intragastrically given for 14 days after PQ injection. Electroretinograms were performed to determine the functionality of the retinas. The surviving neurons in the retinal ganglion cell layer and retinal apoptosis were determined by counting Neu N-positive cells in whole-mounted retinas and TUNEL staining, respectively. The generation of reactive oxygen species (ROS was determined by lucigenin- and luminol-enhanced chemiluminescence. Retinal oxidative damages were assessed by staining with nitrotyrosine, acrolein, and 8-hydroxy-2'-deoxyguanosine (8-OHdG. Immunohistochemical studies were used to demonstrate the expression of nuclear factor-kappa B (NF-κB p65 in retinas. An in vitro study using RGC-5 cells was performed to verify the results. We demonstrated COS significantly enhanced the recovery of retinal function, preserved inner retinal thickness, and decreased retinal neurons loss in a dose-dependent manner. COS administration demonstrated anti-oxidative effects by reducing luminol- and lucigenin-dependent chemiluminenscense levels and activating superoxide dismutase and catalase, leading to decreased retinal apoptosis. COS markedly reduced retinal NF-κB p65. An in vitro study demonstrated COS increased IκB expression, attenuated the increase of p65 and thus decreased NF-κB/DNA binding activity in PQ-stimulated RGC-5 cells. In conclusion, COS attenuates oxidative stress-induced retinal damages, probably by decreasing free radicals, maintaining the activities of anti-oxidative enzymes, and inhibiting the activation of NF-κB.

  12. Retinal detachment in black South Africans

    African Journals Online (AJOL)

    low incidence of retinal detachment in black patients is not known. ... a retinal break. Predisposing factors include peripheral retinal degenerations, myopia, aphakia and trauma. Delay in presentation increases the difficulty in achieving adequate surgical ... On examination, note was taken of the visual acuity in both eyes, the ...

  13. Transcorneal Electrical Stimulation Therapy for Retinal Disease

    Science.gov (United States)

    2012-05-03

    Retinitis Pigmentosa; Macula Off; Primary Open Angle Glaucoma; Hereditary Macular Degeneration; Treated Retina Detachment; Retinal Artery Occlusion; Retinal Vein Occlusion; Non-Arthritic-Anterior-Ischemic Optic-Neuropathy; Hereditary Autosomal Dominant Optic Atrophy; Dry Age Related Macular Degeneration; Ischemic Macula Edema

  14. Retinal vessels caliber assessment in patients with arterial hypertension

    Directory of Open Access Journals (Sweden)

    N. S. Semenova

    2014-07-01

    Full Text Available Purpose: to evaluate the diagnostic capability of automated retinal vessels (RV caliber estimation for hypertensive angiopathy.Methods: this study included 146 patients (292 eyes with arterial hypertension. All the subjects underwent fundus photography and RV caliber estimation. the latter was performed using newly developed computer-based method for automated vessel detection and central retinal arteriolar and venular equivalents determination (CRAE & CRVE. Sensitivity, specificity, and reproducibility of the method were estimated.Results: the method of RV caliber assessment showed good reproducibility. the overall specificity and sensitivity were 74% and 80.77%, respectively. Computer-based method of retinal vascular caliber assessment revealed higher predictive value comparing with ophthalmoscopic assessment (AUC = 0.903 and 0.85, respectively. Retinal arteriolar and venular caliber and AVR tend to decrease with age. Higher blood pressure is associated with narrower retinal arterioles.Conclusion: Novel method of RV caliber estimation demonstrated high information value. these findings are in good agreementwith data from major population-based studies.

  15. Retinal vessels caliber assessment in patients with arterial hypertension

    Directory of Open Access Journals (Sweden)

    N. S. Semenova

    2012-01-01

    Full Text Available Purpose: to evaluate the diagnostic capability of automated retinal vessels (RV caliber estimation for hypertensive angiopathy.Methods: this study included 146 patients (292 eyes with arterial hypertension. All the subjects underwent fundus photography and RV caliber estimation. the latter was performed using newly developed computer-based method for automated vessel detection and central retinal arteriolar and venular equivalents determination (CRAE & CRVE. Sensitivity, specificity, and reproducibility of the method were estimated.Results: the method of RV caliber assessment showed good reproducibility. the overall specificity and sensitivity were 74% and 80.77%, respectively. Computer-based method of retinal vascular caliber assessment revealed higher predictive value comparing with ophthalmoscopic assessment (AUC = 0.903 and 0.85, respectively. Retinal arteriolar and venular caliber and AVR tend to decrease with age. Higher blood pressure is associated with narrower retinal arterioles.Conclusion: Novel method of RV caliber estimation demonstrated high information value. these findings are in good agreementwith data from major population-based studies.

  16. Automated Theorem Proving in High-Quality Software Design

    Science.gov (United States)

    Schumann, Johann; Swanson, Keith (Technical Monitor)

    2001-01-01

    The amount and complexity of software developed during the last few years has increased tremendously. In particular, programs are being used more and more in embedded systems (from car-brakes to plant-control). Many of these applications are safety-relevant, i.e. a malfunction of hardware or software can cause severe damage or loss. Tremendous risks are typically present in the area of aviation, (nuclear) power plants or (chemical) plant control. Here, even small problems can lead to thousands of casualties and huge financial losses. Large financial risks also exist when computer systems are used in the area of telecommunication (telephone, electronic commerce) or space exploration. Computer applications in this area are not only subject to safety considerations, but also security issues are important. All these systems must be designed and developed to guarantee high quality with respect to safety and security. Even in an industrial setting which is (or at least should be) aware of the high requirements in Software Engineering, many incidents occur. For example, the Warshaw Airbus crash, was caused by an incomplete requirements specification. Uncontrolled reuse of an Ariane 4 software module was the reason for the Ariane 5 disaster. Some recent incidents in the telecommunication area, like illegal "cloning" of smart-cards of D2GSM handies, or the extraction of (secret) passwords from German T-online users show that also in this area serious flaws can happen. Due to the inherent complexity of computer systems, most authors claim that only a rigorous application of formal methods in all stages of the software life cycle can ensure high quality of the software and lead to real safe and secure systems. In this paper, we will have a look, in how far automated theorem proving can contribute to a more widespread application of formal methods and their tools, and what automated theorem provers (ATPs) must provide in order to be useful.

  17. The retinal clock in mammals: role in health and disease

    Directory of Open Access Journals (Sweden)

    Felder-Schmittbuhl MP

    2017-05-01

    Full Text Available Marie-Paule Felder-Schmittbuhl,1,* Hugo Calligaro,2 Ouria Dkhissi-Benyahya2,* 1Institute of Cellular and Integratives Neurosciences, UPR3212, CNRS, Université de Strasbourg, Strasbourg, 2University of Lyon, Stem Cell and Brain Research Institute, INSERM U1208, Bron, France *These authors contributed equally to this work Abstract: The mammalian retina contains an extraordinary diversity of cell types that are highly organized into precise circuits to perceive and process visual information in a dynamic manner and transmit it to the brain. Above this builds up another level of complex dynamic, orchestrated by a circadian clock located within the retina, which allows retinal physiology, and hence visual function, to adapt to daily changes in light intensity. The mammalian retina is a remarkable model of circadian clock because it harbors photoreception, self-sustained oscillator function, and physiological outputs within the same tissue. However, the location of the retinal clock in mammals has been a matter of long debate. Current data have shown that clock properties are widely distributed among retinal cells and that the retina is composed of a network of circadian clocks located within distinct cellular layers. Nevertheless, the identity of the major pacemaker, if any, still warrants identification. In addition, the retina coordinates rhythmic behavior by providing visual input to the master hypothalamic circadian clock in the suprachiasmatic nuclei (SCN. This light entrainment of the SCN to the light/dark cycle involves a network of retinal photoreceptor cells: rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs. Although it was considered that these photoreceptors synchronized both retinal and SCN clocks, new data challenge this view, suggesting that none of these photoreceptors is involved in photic entrainment of the retinal clock. Because circadian organization is a ubiquitous feature of the retina and controls

  18. Automated detection of retinal whitening in malarial retinopathy

    Science.gov (United States)

    Joshi, V.; Agurto, C.; Barriga, S.; Nemeth, S.; Soliz, P.; MacCormick, I.; Taylor, T.; Lewallen, S.; Harding, S.

    2016-03-01

    Cerebral malaria (CM) is a severe neurological complication associated with malarial infection. Malaria affects approximately 200 million people worldwide, and claims 600,000 lives annually, 75% of whom are African children under five years of age. Because most of these mortalities are caused by the high incidence of CM misdiagnosis, there is a need for an accurate diagnostic to confirm the presence of CM. The retinal lesions associated with malarial retinopathy (MR) such as retinal whitening, vessel discoloration, and hemorrhages, are highly specific to CM, and their detection can improve the accuracy of CM diagnosis. This paper will focus on development of an automated method for the detection of retinal whitening which is a unique sign of MR that manifests due to retinal ischemia resulting from CM. We propose to detect the whitening region in retinal color images based on multiple color and textural features. First, we preprocess the image using color and textural features of the CMYK and CIE-XYZ color spaces to minimize camera reflex. Next, we utilize color features of the HSL, CMYK, and CIE-XYZ channels, along with the structural features of difference of Gaussians. A watershed segmentation algorithm is used to assign each image region a probability of being inside the whitening, based on extracted features. The algorithm was applied to a dataset of 54 images (40 with whitening and 14 controls) that resulted in an image-based (binary) classification with an AUC of 0.80. This provides 88% sensitivity at a specificity of 65%. For a clinical application that requires a high specificity setting, the algorithm can be tuned to a specificity of 89% at a sensitivity of 82%. This is the first published method for retinal whitening detection and combining it with the detection methods for vessel discoloration and hemorrhages can further improve the detection accuracy for malarial retinopathy.

  19. Recruiting and retaining high-quality teachers in rural areas.

    Science.gov (United States)

    Monk, David H

    2007-01-01

    In examining recruitment and retention of teachers in rural areas, David Monk begins by noting the numerous possible characteristics of rural communities--small size, sparse settlement, distance from population concentrations, and an economic reliance on agricultural industries that are increasingly using seasonal and immigrant workers to minimize labor costs. Many, though not all, rural areas, he says, are seriously impoverished. Classes in rural schools are relatively small, and teachers tend to report satisfaction with their work environments and relatively few problems with discipline. But teacher turnover is often high, and hiring can be difficult. Monk observes that rural schools have a below-average share of highly trained teachers. Compensation in rural schools tends to be low, perhaps because of a lower fiscal capacity in rural areas, thus complicating efforts to attract and retain teachers. Several student characteristics, including relatively large shares of students with special needs and with limited English skills and lower shares of students attending college, can also make it difficult to recruit and retain high-quality teachers. Other challenges include meeting the needs of highly mobile children of low-income migrant farm workers. With respect to public policy, Monk asserts a need to focus on a subcategory of what might be called hard-to-staff rural schools rather than to develop a blanket set of policies for all rural schools. In particular, he recommends a focus on such indicators as low teacher qualifications, teaching in fields far removed from the area of training, difficulty in hiring, high turnover, a lack of diversity among teachers in the school, and the presence of migrant farm workers' children. Successful efforts to stimulate economic growth in these areas would be highly beneficial. He also calls attention to the potential for modern telecommunication and computing technologies to offset some of the drawbacks associated with teaching

  20. Retinal dysfunction and refractive errors: an electrophysiological study of children

    Science.gov (United States)

    Flitcroft, D I; Adams, G G W; Robson, A G; Holder, G E

    2005-01-01

    Aims: To evaluate the relation between refractive error and electrophysiological retinal abnormalities in children referred for investigation of reduced vision. Methods: The study group comprised 123 consecutive patients referred over a 14 month period from the paediatric service of Moorfields Eye Hospital for electrophysiological investigation of reduced vision. Subjects were divided into five refractive categories according to their spectacle correction: high myopia (⩽−6D), low myopia (>−6D and ⩽−0.75D), emmetropia (>−0.75 and 1.5D) and ERG abnormalities (18/35 with high astigmatism v 20/88 without, χ2 test, p = 0.002). There was no significant variation in frequency of abnormalities between low myopes, emmetropes, and low hyperopes. The rate of abnormalities was very similar in both high myopes (8/15) and high hyperopes (5/10). Conclusions: High ametropia and astigmatism in children being investigated for poor vision are associated with a higher rate of retinal electrophysiological abnormalities. An increased rate of refractive errors in the presence of retinal pathology is consistent with the hypothesis that the retina is involved in the process of emmetropisation. Electrophysiological testing should be considered in cases of high ametropia in childhood to rule out associated retinal pathology. PMID:15774929

  1. Iron in hereditary retinal degeneration: PIXE microanalysis Preliminary results

    International Nuclear Information System (INIS)

    Sergeant, C.; Gouget, B.; Llabador, Y.; Simonoff, M.; Yefimova, M.; Courtois, Y.; Jeanny, J.C.

    1999-01-01

    Several types of hereditary retinal degeneration with progressive alteration of photoreceptors exist in men and animals. Recent immunohistochemical results have shown strong degradation of transferrin, the protein responsible for iron transport, in retinas of rats with hereditary retinal degeneration. Freeze-dried thin sections of rat retinas from different stages of the disease, and respective coeval control sections, have been analyzed using nuclear microprobe. In this first part of the study, the rat retinas at post-natal stages of 35 and 45 days have been analyzed. The sample preparation and the post-irradiation staining to determine precisely the retinal layers involved are described. Preliminary results of element distributions (K, Ca, Fe) in the rat retina layers are discussed. A very high content of calcium in the choriocapillaris of dystrophic rat retinas was observed. Preliminary results on iron distribution in the rat retina layers are presented

  2. Progressive outer retinal necrosis: manifestation of human immunodeficiency virus infection.

    Science.gov (United States)

    Lo, Phey Feng; Lim, Rongxuan; Antonakis, Serafeim N; Almeida, Goncalo C

    2015-05-06

    We present the case of a 54-year-old man who developed progressive outer retinal necrosis (PORN) as an initial manifestation of HIV infection without any significant risk factors for infection with HIV. PORN is usually found as a manifestation of known AIDS late in the disease. Our patient presented with transient visual loss followed by decrease in visual acuity and facial rash. Subsequent investigation revealed anterior chamber tap positive for varicella zoster virus (VZV), as well as HIV positivity, with an initial CD4 count of 48 cells/µL. Systemic and intravitreal antivirals against VZV, and highly active antiretroviral therapy against HIV were started, which halted further progression of retinal necrosis. This case highlights the importance of suspecting PORN where there is a rapidly progressive retinitis, and also testing the patient for HIV, so appropriate treatment can be started. 2015 BMJ Publishing Group Ltd.

  3. Distributions of elements in the human retinal pigment epithelium

    International Nuclear Information System (INIS)

    Ulshafer, R.J.; Allen, C.B.; Rubin, M.L.

    1990-01-01

    Distributions of elements above the atomic number of sodium were mapped in the retinal pigment epithelia of eight human eyes. X-ray energy spectra and maps were collected from cryofixed, freeze-dried, and epoxy-embedded tissues using energy-dispersive x-ray microanalysis. All eyes had high concentrations of phosphorus in the nuclei of retinal pigment epithelial cells. Melanosomes were rich in sulfur, zinc, calcium, and iron. Lipofuscin and cytoplasm contained only phosphorus and sulfur in detectable amounts. Drusen, when present, contained phosphorus and calcium. Six eyes had a prominent aluminum peak recorded from melanosomes, nuclei, and Bruch's membrane. In one pair of 90-year-old eyes, small, electron-dense deposits surrounded many melanosomes and contained mercury and selenium. Retinal pigment epithelial melanosomes may bind and accumulate metals and other potentially toxic ions over time, preventing them from reaching the neural retina

  4. Routine quality control of high dose rate brachytherapy equipment

    International Nuclear Information System (INIS)

    Guzman Calcina, Carmen S.; Almeida, Adelaide de; Rocha, Jose R. Oliveira

    2001-01-01

    A Quality Assurance program should be installed also for High Dose Rate brachytherapy, in the order to achieve a correct dose administration to the patient and for the safety to those involved directly with the treatment. The work presented here has the following purposes: Analyze the types of equipment tests presented by the official protocols (TG40, TG56 e ARCAL XXX), evaluate the brachytherapy routine tests of protocols from various national and international radiotherapy services and compare the latter with those presented in the official protocols. As a result, we conclude the following: TG56 presents a higher number of tests when compared to the other official protocols and most of the tests presented by the analyzed services are present in TG56. A suggestion for a basic protocol is presented, emphasizing the periodicity and tolerance level of each of the tests. (author)

  5. High quality diesel fuels by VO-LSGO hydrotreatment

    Energy Technology Data Exchange (ETDEWEB)

    Stanica-Ezeanu, Dorin; Juganaru, Traian [Petroleum and Gas Univ. of Ploiesti (Romania)

    2013-06-01

    The aim of the paper is to obtain a high quality Diesel fuel by hydro-deoxigenation of vegetable oils (VO) mixed with a low sulfur gasoil (LSGO). The process is possible by using a bi-functional catalyst Ni-Mo supported by an activated Al{sub 2}O{sub 3} containing 2% Ultrastable Y-zeolite. The experimental conditions were: T =340 - 380 C, Pressure = 50 bar, LHSV = 1,5 h{sup -1}, H{sub 2}/Feed ratio = 15 mole H{sub 2} /mole liquid feed. The liquid product was separated in two fractions: a light distillate (similar to gasoline) and a heavy distillate (boiling point > 200 C) with very good characteristics for Diesel engines. The reaction chemistry is very complex, but the de-oxygenation process is decisive for the chemical structure of hydrocarbons from final product. Finally, a schema for the reaction mechanism is proposed. (orig.)

  6. Supercapacitors based on high-quality graphene scrolls

    Science.gov (United States)

    Zeng, Fanyan; Kuang, Yafei; Liu, Gaoqin; Liu, Rui; Huang, Zhongyuan; Fu, Chaopeng; Zhou, Haihui

    2012-06-01

    High-quality graphene scrolls (GSS) with a unique scrolled topography are designed using a microexplosion method. Their capacitance properties are investigated by cyclic voltammetry, galvanostatic charge-discharge and electrical impedance spectroscopy. Compared with the specific capacity of 110 F g-1 for graphene sheets, a remarkable capacity of 162.2 F g-1 is obtained at the current density of 1.0 A g-1 in 6 M KOH aqueous solution owing to the unique scrolled structure of GSS. The capacity value is increased by about 50% only because of the topological change of graphene sheets. Meanwhile, GSS exhibit excellent long-term cycling stability along with 96.8% retained after 1000 cycles at 1.0 A g-1. These encouraging results indicate that GSS based on the topological structure of graphene sheets are a kind of promising material for supercapacitors.

  7. A roadmap to high quality chemically prepared graphene

    Energy Technology Data Exchange (ETDEWEB)

    Gengler, Regis Y N; Spyrou, Konstantinos; Rudolf, Petra, E-mail: r.gengler@rug.n, E-mail: p.rudolf@rug.n [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)

    2010-09-22

    Graphene was discovered half a decade ago and proved the existence of a two-dimensional system which becomes stable as a result of 3D corrugation. It appeared very quickly that this exceptional material had truly outstanding electronic, mechanical, thermal and optical properties. Consequently a broad range of applications appeared, as the graphene science speedily moved forward. Since then, a lot of effort has been devoted not only to the study of graphene but also to its fabrication. Here we review the chemical approaches to graphene production, their advantages as well as their downsides. Our aim is to draw a roadmap of today's most reliable path to high quality graphene via chemical preparation.

  8. High quality factor HTS Josephson junctions on low loss substrates

    Energy Technology Data Exchange (ETDEWEB)

    Stornaiuolo, D; Longobardi, L; Massarotti, D; Barone, A; Tafuri, F [CNR-SPIN Napoli, Complesso Universitario di Monte Sant' Angelo, via Cinthia, 80126 Napoli (Italy); Papari, G; Carillo, F [NEST, CNR-NANO and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa (Italy); Cennamo, N [Dipartimento Ingegneria dell' Informazione, Seconda Universita degli Studi di Napoli, via Roma 29, 81031 Aversa (Italy)

    2011-04-15

    We have extended the off-axis biepitaxial technique to produce YBCO grain boundary junctions on low loss substrates. Excellent transport properties have been reproducibly found, with remarkable values of the quality factor I{sub c}R{sub n} (with I{sub c} the critical current and R{sub n} the normal state resistance) above 10 mV, far higher than the values commonly reported in the literature for high temperature superconductor (HTS) based Josephson junctions. The outcomes are consistent with a picture of a more uniform grain boundary region along the current path. This work supports a possible implementation of grain boundary junctions for various applications including terahertz sensors and HTS quantum circuits in the presence of microwaves.

  9. A roadmap to high quality chemically prepared graphene

    International Nuclear Information System (INIS)

    Gengler, Regis Y N; Spyrou, Konstantinos; Rudolf, Petra

    2010-01-01

    Graphene was discovered half a decade ago and proved the existence of a two-dimensional system which becomes stable as a result of 3D corrugation. It appeared very quickly that this exceptional material had truly outstanding electronic, mechanical, thermal and optical properties. Consequently a broad range of applications appeared, as the graphene science speedily moved forward. Since then, a lot of effort has been devoted not only to the study of graphene but also to its fabrication. Here we review the chemical approaches to graphene production, their advantages as well as their downsides. Our aim is to draw a roadmap of today's most reliable path to high quality graphene via chemical preparation.

  10. CHOREOGRAPHIC METHODS FOR CREATING NOVEL, HIGH QUALITY DANCE

    Directory of Open Access Journals (Sweden)

    David Kirsh

    2016-02-01

    Full Text Available We undertook a detailed ethnographic study of the dance creation process of a noted choreographer and his distinguished troupe. All choreographer dancer interactions were videoed, the choreographer and dancers were interviewed extensively each day, as well as other observations and tests performed. The choreographer used three main methods to produce high quality and novel content: showing, making-on, and tasking. We present, analyze and evaluate these methods, and show how these approaches allow the choreographer to increase the creative output of the dancers and him. His methods, although designed for dance, apply more generally to other creative endeavors, especially where brainstorming is involved, and where the creative process is distributed over many individuals. His approach is also a case study in multi-modal direction, owing to the range of mechanisms he uses to communicate and direct.

  11. Biotransformation of Organic Waste into High Quality Fertilizer

    DEFF Research Database (Denmark)

    Bryndum, Sofie

    Agriculture faces several challenges of future provision of nutrients such as limited P reserves and increasing prices of synthetic fertilizers and recycling of nutrients from organic waste can be an important strategy for the long-term sustainability of the agricultural systems. Organically...... and S, is often low; and (3) the unbalanced composition of nutrients rarely matches crop demands. Therefore the objective of this project was to investigate the potential for (1) recycling nutrients from agro-industrial wastes and (2) compost biotransformation into high-quality organic fertilizers...... other uses into fertilizer use would be unlikely. An estimated ~50 % of the total organic waste pool, primarily consisting of animal manure and waste from the processing of sugar cane, coffee, oil palm and oranges, is currently being re-used as “fertilizers”, meaning it is eventually returned...

  12. Spatial-temporal patterns of retinal waves underlying activity-dependent refinement of retinofugal projections.

    Science.gov (United States)

    Stafford, Ben K; Sher, Alexander; Litke, Alan M; Feldheim, David A

    2009-10-29

    During development, retinal axons project coarsely within their visual targets before refining to form organized synaptic connections. Spontaneous retinal activity, in the form of acetylcholine-driven retinal waves, is proposed to be necessary for establishing these projection patterns. In particular, both axonal terminations of retinal ganglion cells (RGCs) and the size of receptive fields of target neurons are larger in mice that lack the beta2 subunit of the nicotinic acetylcholine receptor (beta2KO). Here, using a large-scale, high-density multielectrode array to record activity from hundreds of RGCs simultaneously, we present analysis of early postnatal retinal activity from both wild-type (WT) and beta2KO retinas. We find that beta2KO retinas have correlated patterns of activity, but many aspects of these patterns differ from those of WT retina. Quantitative analysis suggests that wave directionality, coupled with short-range correlated bursting patterns of RGCs, work together to refine retinofugal projections.

  13. In vivo retinal optical coherence tomography at 1030 nm with enhanced penetration into the choroid

    Science.gov (United States)

    Unterhuber, A.; Povazay, B.; Hermann, B.; Sattmann, H.; Michels, S.; Sacu, S.; Ahlers, C.; Scholda, C.; Chavez-Pirson, A.; Schmidt-Erfurth, U.; Fercher, Adolf F.; Drexler, W.

    2005-08-01

    In vivo retinal imaging with ~ 8 μm axial resolution at 1030 nm is demonstrated for the first time, enabling enhanced penetration into the choroid. A new high power, broad bandwidth light source based on amplified spontaneous emission (NP Photonics, λc = 1030 nm, Δλ= 50 nm, Pout = 25 mW) has been interfaced to a time domain ophthalmic OCT system. In vivo retinal OCT tomograms performed at 800 nm are compared to those achieved at 1030 nm. Retinal OCT at longer wavelengths, e.g. 1030 nm significantly improves the visualization of the retinal pigment epithelium/choriocapillaris/choroid interface and might therefore provide new insight into choroidal/choriocapillary changes in age-related macular degeneration and other diseases of the retinal pigment epithelium (RPE)-choroid complex. 1030 nm OCT could also become a valuable tool in monitoring treatment effects on the choroids as in Verteporfin therapy.

  14. Risk factor profile in retinal detachment

    Directory of Open Access Journals (Sweden)

    Azad Raj

    1988-01-01

    Full Text Available 150 cases of retinal detachment comprising 50 patients each of bilateral retinal detachment, unilateral retinal detachment without any retinal lesions in the fellow eve and unilateral retinal detachment with retinal lesions in the fellow eye were studied and the various associated risk factors were statistically analysed. The findings are discussed in relation to their aetiological and prognostic significance in the different types of retinal detachment. Based on these observations certain guidelines are offered which may be of value in decision making, in prophylactic detachment surgery. Tractional breaks in the superior temporal quadrant especially when symptomatic. mandate prophylactic treatment. Urgency is enhanced it′ the patient is aphakic. Associated myopia adds to the urgency. The higher incidence of initial right e′ e involvement in all groups suggests a vascular original possibly ischaemic.

  15. Consumption of Polyphenol-Rich Zingiber Zerumbet Rhizome Extracts Protects against the Breakdown of the Blood-Retinal Barrier and Retinal Inflammation Induced by Diabetes

    Directory of Open Access Journals (Sweden)

    Thing-Fong Tzeng

    2015-09-01

    Full Text Available The present study investigates the amelioration of diabetic retinopathy (DR by Zingiber zerumbet rhizome ethanol extracts (ZZRext in streptozotocin-induced diabetic rats (STZ-diabetic rats. ZZRext contains high phenolic and flavonoid contents. STZ-diabetic rats were treated orally with ZZRext (200, 300 mg/kg per day for three months. Blood-retinal barrier (BRB breakdown and increased vascular permeability were found in diabetic rats, with downregulation of occludin, and claudin-5. ZZRext treatment effectively preserved the expression of occludin, and claudin-5, leading to less BRB breakdown and less vascular permeability. Retinal histopathological observation showed that the disarrangement and reduction in thickness of retinal layers were reversed in ZZRext-treated diabetic rats. Retinal gene expression of tumor necrosis factor-α, interleukin (IL-1β, IL-6, vascular endothelial growth factor, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were all decreased in ZZRext-treated diabetic rats. Moreover, ZZRext treatment not only inhibited the nuclear factor κB (NF-κB activation, but also downregulated the protein expression of p38 mitogen-activated protein kinase (MAPK in diabetic retina. In conclusion, the results suggest that the retinal protective effects of ZZRext occur through improved retinal structural change and inhibiting retinal inflammation. The antiretinopathy property of ZZRext might be related to the downregulation of p38 MAPK and NF-κB signal transduction induced by diabetes.

  16. Telemedicine for a General Screening of Retinal Disease Using Nonmydriatic Fundus Cameras in Optometry Centers: Three-Year Results.

    Science.gov (United States)

    Zapata, Miguel A; Arcos, Gabriel; Fonollosa, Alex; Abraldes, Maximino; Oleñik, Andrea; Gutierrez, Estanislao; Garcia-Arumi, Jose

    2017-01-01

    Describe the first 3 years of highly specialized retinal screening through a web platform using a retinologists' network for image reading. All patients who came to centers in the network and consented to fundus photography were included. Images were evaluated by ophthalmologists. We describe number of patients, age, visual acuity, retinal abnormalities, medical recommendations, and factors associated with abnormal retinographies. Fifty thousand three hundred eighty-four patients were included; mean age 52.3 years (range 3-99). Mean visual acuity 20/25. Of the total cohort, 75% had normal retinographies, 22% had abnormalities, 1% referred acute floaters, 1% referred acute symptoms with normal retinography, and 1% could not be assessed. Ophthalmological referral was recommended in 12,634 patients: 9% urgent visit, 11% preferential (2-3 weeks), and 80% an ordinary visit. Age-related maculopathy signs were the most common abnormalities (2,456 patients, 4.8%). Epiretinal membrane was the second (764 cases, 1.5%). Diabetic retinopathy was suspected in 543 patients (1%), and nevi in 358 patients (0.7%). Patients older than 50 years had significantly more retinal abnormalities (31.5%) than younger ones (11.1%) (p < 0.0001; odds ratio [OR] 2.47; confidence interval [CI] 2.37-2.57). Patients with almost one eye with a myopic defect greater than -5 spherical equivalent had a higher risk of presenting abnormalities (p < 0.001; OR 1.04; CI 1.03-1.05). A high rate of asymptomatic retinal abnormalities was detected in this general screening, justifying this practice. Many patients who visit optometrists in Spain are unaware that they would benefit from ophthalmological monitoring. The ophthalmic community should lead initiatives of the type presented to preserve and guarantee quality standards.

  17. Retinal detachment repair

    Science.gov (United States)

    ... medicines Problems breathing You may not recover full vision. ... detachments can be repaired. Failure to repair the retina always results in loss of vision to some degree. After surgery, the quality of ...

  18. Retinal ischemic injury rescued by sodium 4-phenylbutyrate in a rat model.

    Science.gov (United States)

    Jeng, Yung-Yue; Lin, Nien-Ting; Chang, Pen-Heng; Huang, Yuan-Ping; Pang, Victor Fei; Liu, Chen-Hsuan; Lin, Chung-Tien

    2007-03-01

    Retinal ischemia is a common cause of visual impairment for humans and animals. Herein, the neuroprotective effects of phenylbutyrate (PBA) upon retinal ischemic injury were investigated using a rat model. Retinal ganglion cells (RGCs) were retrograde labeled with the fluorescent tracer fluorogold (FG) applied to the superior collicoli of test Sprague-Dawley rats. High intraocular pressure and retinal ischemia were induced seven days subsequent to such FG labeling. A dose of either 100 or 400 mg/kg PBA was administered intraperitoneally to test rats at two time points, namely 30 min prior to the induction of retinal ischemia and 1 h subsequent to the cessation of the procedure inducing retinal ischemia. The test-rat retinas were collected seven days subsequent to the induction of retinal ischemia, and densities of surviving RGCs were estimated by counting FG-labeled RGCs within the retina. Histological analysis revealed that ischemic injury caused the loss of retinal RGCs and a net decrease in retinal thickness. For PBA-treated groups, almost 100% of the RGCs were preserved by a pre-ischemia treatment with PBA (at a dose of either 100 or 400 mg/kg), while post-ischemia treatment of RGCs with PBA did not lead to the preservation of RGCs from ischemic injury by PBA as determined by the counting of whole-mount retinas. Pre-ischemia treatment of RGCs with PBA (at a dose of either 100 or 400 mg/kg) significantly reduced the level of ischemia-associated loss of thickness of the total retina, especially the inner retina, and the inner plexiform layer of retina. Besides, PBA treatment significantly reduced the ischemia-induced loss of cells in the ganglion-cell layer of the retina. Taken together, these results suggest that PBA demonstrates a marked neuroprotective effect upon high intraocular pressure-induced retinal ischemia when the PBA is administered prior to ischemia induction.

  19. All-optical recording and stimulation of retinal neurons in vivo in retinal degeneration mice

    Science.gov (United States)

    Strazzeri, Jennifer M.; Williams, David R.; Merigan, William H.

    2018-01-01

    Here we demonstrate the application of a method that could accelerate the development of novel therapies by allowing direct and repeatable visualization of cellular function in the living eye, to study loss of vision in animal models of retinal disease, as well as evaluate the time course of retinal function following therapeutic intervention. We use high-resolution adaptive optics scanning light ophthalmoscopy to image fluorescence from the calcium sensor GCaMP6s. In mice with photoreceptor degeneration (rd10), we measured restored visual responses in ganglion cell layer neurons expressing the red-shifted channelrhodopsin ChrimsonR over a six-week period following significant loss of visual responses. Combining a fluorescent calcium sensor, a channelrhodopsin, and adaptive optics enables all-optical stimulation and recording of retinal neurons in the living eye. Because the retina is an accessible portal to the central nervous system, our method also provides a novel non-invasive method of dissecting neuronal processing in the brain. PMID:29596518

  20. High quality protein microarray using in situ protein purification

    Directory of Open Access Journals (Sweden)

    Fleischmann Robert D

    2009-08-01

    Full Text Available Abstract Background In the postgenomic era, high throughput protein expression and protein microarray technologies have progressed markedly permitting screening of therapeutic reagents and discovery of novel protein functions. Hexa-histidine is one of the most commonly used fusion tags for protein expression due to its small size and convenient purification via immobilized metal ion affinity chromatography (IMAC. This purification process has been adapted to the protein microarray format, but the quality of in situ His-tagged protein purification on slides has not been systematically evaluated. We established methods to determine the level of purification of such proteins on metal chelate-modified slide surfaces. Optimized in situ purification of His-tagged recombinant proteins has the potential to become the new gold standard for cost-effective generation of high-quality and high-density protein microarrays. Results Two slide surfaces were examined, chelated Cu2+ slides suspended on a polyethylene glycol (PEG coating and chelated Ni2+ slides immobilized on a support without PEG coating. Using PEG-coated chelated Cu2+ slides, consistently higher purities of recombinant proteins were measured. An optimized wash buffer (PBST composed of 10 mM phosphate buffer, 2.7 mM KCl, 140 mM NaCl and 0.05% Tween 20, pH 7.4, further improved protein purity levels. Using Escherichia coli cell lysates expressing 90 recombinant Streptococcus pneumoniae proteins, 73 proteins were successfully immobilized, and 66 proteins were in situ purified with greater than 90% purity. We identified several antigens among the in situ-purified proteins via assays with anti-S. pneumoniae rabbit antibodies and a human patient antiserum, as a demonstration project of large scale microarray-based immunoproteomics profiling. The methodology is compatible with higher throughput formats of in vivo protein expression, eliminates the need for resin-based purification and circumvents

  1. Retinitis Pigmentosa and Education Issues

    Science.gov (United States)

    Brown, Thomas J.

    2005-01-01

    Retinitis Pigmentosa includes a number of inherited diseases which usually result in blindness. The disease is progressive in nature and begins with the deterioration of cells in the eye responsible for peripheral vision. As the condition worsens there is a gradual loss of peripheral vision and night blindness. Proper educational planning requires…

  2. [Surgical managment of retinal detachment].

    Science.gov (United States)

    Haritoglou, C; Wolf, A

    2015-05-01

    The detachment of the neurosensory retina from the underlying retinal pigment epithelium can be related to breaks of the retina allowing vitreous fluid to gain access to the subretinal space, to exudative changes of the choroid such as tumours or inflammatory diseases or to excessive tractional forces exerted by interactions of the collagenous vitreous and the retina. Tractional retinal detachment is usually treated by vitrectomy and exudative detachment can be addressed by treatment of the underlying condition in many cases. In rhegmatogenous retinal detachment two different surgical procedures, vitrectomy and scleral buckling, can be applied for functional and anatomic rehabilitation of our patients. The choice of the surgical procedure is not really standardised and often depends on the experience of the surgeon and other more ocular factors including lens status, the number of retinal breaks, the extent of the detachment and the amount of preexisting PVR. Using both techniques, anatomic success rates of over 90 % can be achieved. Especially in young phakic patients scleral buckling offers the true advantage to prevent the progression of cataract formation requiring cataract extraction and intraocular lens implantation. Therefore, scleral buckling should be considered in selected cases as an alternative surgical option in spite of the very important technical refinements in modern vitrectomy techniques. Georg Thieme Verlag KG Stuttgart · New York.

  3. Retinal imaging and image analysis

    NARCIS (Netherlands)

    Abramoff, M.D.; Garvin, Mona K.; Sonka, Milan

    2010-01-01

    Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of

  4. The structure of high-quality aluminium cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2012-01-01

    Full Text Available In this study presents the analyse of aluminium iron cast structure (as-cast condition which are used in high temperature. While producing the casts of aluminium iron major influence has been preserve the structure of technological process parameters. The addition to Fe-C-Al alloy V, Ti, Cr leads to the improvement of functional and mechanical cast qualities. In this study, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a aluminium cast iron structure and thus improve the production process. V and Ti additions in aluminium cast iron allows to development of FeAl - VC or TiC alloys. In particular, V or Ti contents above 5 wt.% were found to totally eliminate the presence of Al4C3. In addition, preliminary work indicates that the alloy with the FeAl - VC or TiC structure reveals high oxidation resistance. The introduction of 5 wt.% chromium to aluminium cast iron strengthened Al4C3 precipitate. Thus, the resultant alloy can be considered an intermetallic FeAl matrix strengthened by VC and TiC or modified Al4C3 reinforcements.

  5. High-Quality Seismic Observations of Sonic Booms

    Science.gov (United States)

    Wurman, Gilead; Haering, Edward A., Jr.; Price, Michael J.

    2011-01-01

    The SonicBREWS project (Sonic Boom Resistant Earthquake Warning Systems) is a collaborative effort between Seismic Warning Systems, Inc. and NASA Dryden Flight Research Center. This project aims to evaluate the effects of sonic booms on Earthquake Warning Systems in order to prevent such systems from experiencing false alarms due to sonic booms. The airspace above the Antelope Valley, California includes the High Altitude Supersonic Corridor and the Black Mountain Supersonic Corridor. These corridors are among the few places in the US where supersonic flight is permitted, and sonic booms are commonplace in the Antelope Valley. One result of this project is a rich dataset of high-quality accelerometer records of sonic booms which can shed light on the interaction between these atmospheric phenomena and the solid earth. Nearly 100 sonic booms were recorded with low-noise triaxial MEMS accelerometers recording 1000 samples per second. The sonic booms had peak overpressures ranging up to approximately 10 psf and were recorded in three flight series in 2010 and 2011. Each boom was recorded with up to four accelerometers in various array configurations up to 100 meter baseline lengths, both in the built environment and the free field. All sonic booms were also recorded by nearby microphones. We present the results of the project in terms of the potential for sonic-boom-induced false alarms in Earthquake Warning Systems, and highlight some of the interesting features of the dataset.

  6. High-quality remote interactive imaging in the operating theatre

    Science.gov (United States)

    Grimstead, Ian J.; Avis, Nick J.; Evans, Peter L.; Bocca, Alan

    2009-02-01

    We present a high-quality display system that enables the remote access within an operating theatre of high-end medical imaging and surgical planning software. Currently, surgeons often use printouts from such software for reference during surgery; our system enables surgeons to access and review patient data in a sterile environment, viewing real-time renderings of MRI & CT data as required. Once calibrated, our system displays shades of grey in Operating Room lighting conditions (removing any gamma correction artefacts). Our system does not require any expensive display hardware, is unobtrusive to the remote workstation and works with any application without requiring additional software licenses. To extend the native 256 levels of grey supported by a standard LCD monitor, we have used the concept of "PseudoGrey" where slightly off-white shades of grey are used to extend the intensity range from 256 to 1,785 shades of grey. Remote access is facilitated by a customized version of UltraVNC, which corrects remote shades of grey for display in the Operating Room. The system is successfully deployed at Morriston Hospital, Swansea, UK, and is in daily use during Maxillofacial surgery. More formal user trials and quantitative assessments are being planned for the future.

  7. Blueprint for action: steps toward a high-quality, high-value maternity care system.

    Science.gov (United States)

    Angood, Peter B; Armstrong, Elizabeth Mitchell; Ashton, Diane; Burstin, Helen; Corry, Maureen P; Delbanco, Suzanne F; Fildes, Barbara; Fox, Daniel M; Gluck, Paul A; Gullo, Sue Leavitt; Howes, Joanne; Jolivet, R Rima; Laube, Douglas W; Lynne, Donna; Main, Elliott; Markus, Anne Rossier; Mayberry, Linda; Mitchell, Lynn V; Ness, Debra L; Nuzum, Rachel; Quinlan, Jeffrey D; Sakala, Carol; Salganicoff, Alina

    2010-01-01

    Childbirth Connection hosted a 90th Anniversary national policy symposium, Transforming Maternity Care: A High Value Proposition, on April 3, 2009, in Washington, DC. Over 100 leaders from across the range of stakeholder perspectives were actively engaged in the symposium work to improve the quality and value of U.S. maternity care through broad system improvement. A multi-disciplinary symposium steering committee guided the strategy from its inception and contributed to every phase of the project. The "Blueprint for Action: Steps Toward a High Quality, High Value Maternity Care System", issued by the Transforming Maternity Care Symposium Steering Committee, answers the fundamental question, "Who needs to do what, to, for, and with whom to improve the quality of maternity care over the next five years?" Five stakeholder workgroups collaborated to propose actionable strategies in 11 critical focus areas for moving expeditiously toward the realization of the long term "2020 Vision for a High Quality, High Value Maternity Care System", also published in this issue. Following the symposium these workgroup reports and recommendations were synthesized into the current blueprint. For each critical focus area, the "Blueprint for Action" presents a brief problem statement, a set of system goals for improvement in that area, and major recommendations with proposed action steps to achieve them. This process created a clear sightline to action that if enacted could improve the structure, process, experiences of care, and outcomes of the maternity care system in ways that when anchored in the culture can indeed transform maternity care. Copyright 2010 Jacobs Institute of Women

  8. Stress and sleep quality in high school brazilian adolescents

    Directory of Open Access Journals (Sweden)

    Gema Mesquita

    2010-06-01

    Full Text Available OBJECTIVE: The objective of the present study is to analyze the effect of stress on sleep quality in a group of adolescents. METHOD: Two high schools in Alfenas, southern Minas Gerais State, Brazil, were chosen to participate in the study. The sample consisted of both genders (n=160 with 65.63% females. The age range of participants was 15 to18 years. The Pittsburgh Sleep Quality Index (PSQI was applied for collection of data to quantify sleep quality. The Lipp Inventory of Stress Symptoms that objectively identifies symptoms of stress was applied. RESULTS: It was observed that 23.53% of stressed students and 45.33% of unstressed ones sleep well; 76.47% of stressed pupils and 54.67% of those unstressed do not sleep well. With regard to school performance, a mean of 0.65 was found for stressed students and 0.60 for those without stress, Mann-Whitney (p=0.0596. CONCLUSION: Stress contributed to raising the percentage of poor sleepers, as ell as increasing ean school performance.OBJETIVO: O objetivo do presente estudo foi analisar a influência do stress sobre a qualidade do sono em um grupo de adolescentes. MÉTODO: Foram escolhidas duas instituições educacionais do ensino médio, na cidade de Alfenas, sul de Minas Gerais, Brasil. A amostra foi composta por ambos os sexos (n=160, com 65,63% do sexo feminino. A faixa etária dos participantes foi de 15 a 18 anos. Para a coleta de dados aplicou-se: Índice de Qualidade de Sono de Pittsburgh (IQSP utilizado para quantificar a qualidade do sono; o Inventário de Sintomas de Stress para Adultos de Lipp (ISSL que identifica de modo objetivo a sintomatologia de stress foi aplicado. RESULTADOS: Observou-se que 23,53% dos estressados dormem bem e 45,33% dos não estressados dormem bem; 76,47% dos estressados não dormem bem e 54,67% dos não estressados não dormem bem. Quanto ao rendimento escolar têm-se as médias 0,65 para os alunos estressados e 0,60 para aqueles que não sofrem de stress, Mann

  9. High-quality endoscope reprocessing decreases endoscope contamination.

    Science.gov (United States)

    Decristoforo, P; Kaltseis, J; Fritz, A; Edlinger, M; Posch, W; Wilflingseder, D; Lass-Flörl, C; Orth-Höller, D

    2018-02-24

    Several outbreaks of severe infections due to contamination of gastrointestinal (GI) endoscopes, mainly duodenoscopes, have been described. The rate of microbial endoscope contamination varies dramatically in literature. The aim of this multicentre prospective study was to evaluate the hygiene quality of endoscopes and automated endoscope reprocessors (AERs) in Tyrol/Austria. In 2015 and 2016, a total of 463 GI endoscopes and 105 AERs from 29 endoscopy centres were analysed by a routine (R) and a combined routine and advanced (CRA) sampling procedure and investigated for microbial contamination by culture-based and molecular-based analyses. The contamination rate of GI endoscopes was 1.3%-4.6% according to the national guideline, suggesting that 1.3-4.6 patients out of 100 could have had contacts with hygiene-relevant microorganisms through an endoscopic intervention. Comparison of R and CRA sampling showed 1.8% of R versus 4.6% of CRA failing the acceptance criteria in phase I and 1.3% of R versus 3.0% of CRA samples failing in phase II. The most commonly identified indicator organism was Pseudomonas spp., mainly Pseudomonas oleovorans. None of the tested viruses were detected in 40 samples. While AERs in phase I failed (n = 9, 17.6%) mainly due to technical faults, phase II revealed lapses (n = 6, 11.5%) only on account of microbial contamination of the last rinsing water, mainly with Pseudomonas spp. In the present study the contamination rate of endoscopes was low compared with results from other European countries, possibly due to the high quality of endoscope reprocessing, drying and storage. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  10. 76 FR 45397 - Export Inspection and Weighing Waiver for High Quality Specialty Grain Transported in Containers

    Science.gov (United States)

    2011-07-29

    ...-AB18 Export Inspection and Weighing Waiver for High Quality Specialty Grain Transported in Containers... permanent a waiver due to expire on July 31, 2012, for high quality specialty grain exported in containers... of high quality specialty grain exported in containers are small entities that up until recently...

  11. Chorioretinal coloboma complications: retinal detachment and choroidal neovascular membrane

    Directory of Open Access Journals (Sweden)

    Rehan M Hussain

    2017-01-01

    Conclusion: RD and CNV were present in a high percentage of eyes with chorioretinal coloboma in these series. The frequent finding of retinal breaks outside the coloboma bed suggests that vitreoretinal interface abnormalities may play a role in development of RD in these eyes.

  12. Enhanced Visualization of Subtle Outer Retinal Pathology by En Face Optical Coherence Tomography and Correlation with Multi-Modal Imaging.

    Directory of Open Access Journals (Sweden)

    Danuta M Sampson

    Full Text Available To present en face optical coherence tomography (OCT images generated by graph-search theory algorithm-based custom software and examine correlation with other imaging modalities.En face OCT images derived from high density OCT volumetric scans of 3 healthy subjects and 4 patients using a custom algorithm (graph-search theory and commercial software (Heidelberg Eye Explorer software (Heidelberg Engineering were compared and correlated with near infrared reflectance, fundus autofluorescence, adaptive optics flood-illumination ophthalmoscopy (AO-FIO and microperimetry.Commercial software was unable to generate accurate en face OCT images in eyes with retinal pigment epithelium (RPE pathology due to segmentation error at the level of Bruch's membrane (BM. Accurate segmentation of the basal RPE and BM was achieved using custom software. The en face OCT images from eyes with isolated interdigitation or ellipsoid zone pathology were of similar quality between custom software and Heidelberg Eye Explorer software in the absence of any other significant outer retinal pathology. En face OCT images demonstrated angioid streaks, lesions of acute macular neuroretinopathy, hydroxychloroquine toxicity and Bietti crystalline deposits that correlated with other imaging modalities.Graph-search theory algorithm helps to overcome the limitations of outer retinal segmentation inaccuracies in commercial software. En face OCT images can provide detailed topography of the reflectivity within a specific layer of the retina which correlates with other forms of fundus imaging. Our results highlight the need for standardization of image reflectivity to facilitate quantification of en face OCT images and longitudinal analysis.

  13. Fundus autofluorescence in retinal artery occlusion: A more precise diagnosis.

    Science.gov (United States)

    Bacquet, J-L; Sarov-Rivière, M; Denier, C; Querques, G; Riou, B; Bonin, L; Barreau, E; Labetoulle, M; Rousseau, A

    2017-10-01

    Retinal artery occlusion (RAO) is a medical emergency associated with a high risk of cerebral vascular accident and other cardiovascular events. Among patients with non-arteritic RAO, a retinal embolus is observed in approximately 40% of cases. Fundus examination and retinography are not reliable to predict the nature of the emboli. We report three consecutive cases of central and branch RAO that were investigated with fundus autofluorescence, fluorescein angiography and color retinal photographs. All patients underwent complete neurological and cardiovascular workups, with brain imaging, cardiac Doppler ultrasound, carotid Dopplers and Holter ECG's, to determine the underlying mechanism of retinal embolism. In the three cases, aged 77.7±4 years (2 women and 1 man), fundus autofluorescence demonstrated hyperautofluorescent emboli. In two cases, it allowed visualization of emboli that were not detected with fundus examination or retinography. The cardiovascular work-up demonstrated atheromatous carotid or aortic plaques in all patients. In one case, it permitted the diagnosis of RAO. Two of the three cases were considered to be of atherosclerotic origin and one of undefined origin. Fundus autofluorescence may help to detect and characterize retinal emboli. Since lipofuscin, which is present in large quantity in atherosclerotic plaques, is the main fluorophore detected with fundus autofluorescence, this non-invasive and simple examination may give information about the underlying mechanism of retinal embolism, and thus impact the etiologic assessment of RAO. Additional studies are necessary to confirm this potential role of autofluorescence. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Advances in Bone Marrow Stem Cell Therapy for Retinal Dysfunction

    Science.gov (United States)

    Park, Susanna S.; Moisseiev, Elad; Bauer, Gerhard; Anderson, Johnathon D.; Grant, Maria B.; Zam, Azhar; Zawadzki, Robert J.; Werner, John S.; Nolta, Jan A.

    2016-01-01

    The most common cause of untreatable vision loss is dysfunction of the retina. Conditions, such as age-related macular degeneration, diabetic retinopathy and glaucoma remain leading causes of untreatable blindness worldwide. Various stem cell approaches are being explored for treatment of retinal regeneration. The rationale for using bone marrow stem cells to treat retinal dysfunction is based on preclinical evidence showing that bone marrow stem cells can rescue degenerating and ischemic retina. These stem cells have primarily paracrine trophic effects although some cells can directly incorporate into damaged tissue. Since the paracrine trophic effects can have regenerative effects on multiple cells in the retina, the use of this cell therapy is not limited to a particular retinal condition. Autologous bone marrow-derived stem cells are being explored in early clinical trials as therapy for various retinal conditions. These bone marrow stem cells include mesenchymal stem cells, mononuclear cells and CD34+ cells. Autologous therapy requires no systemic immunosuppression or donor matching. Intravitreal delivery of CD34+ cells and mononuclear cells appears to be tolerated and is being explored since some of these cells can home into the damaged retina after intravitreal administration. The safety of intravitreal delivery of mesenchymal stem cells has not been well established. This review provides an update of the current evidence in support of the use of bone marrow stem cells as treatment for retinal dysfunction. The potential limitations and complications of using certain forms of bone marrow stem cells as therapy are discussed. Future directions of research include methods to optimize the therapeutic potential of these stem cells, non-cellular alternatives using extracellular vesicles, and in vivo high-resolution retinal imaging to detect cellular changes in the retina following cell therapy. PMID:27784628

  15. A chick model of retinal detachment: cone rich and novel.

    Directory of Open Access Journals (Sweden)

    Colleen M Cebulla

    Full Text Available Development of retinal detachment models in small animals can be difficult and expensive. Here we create and characterize a novel, cone-rich retinal detachment (RD model in the chick.Retinal detachments were created in chicks between postnatal days 7 and 21 by subretinal injections of either saline (SA or hyaluronic acid (HA. Injections were performed through a dilated pupil with observation via surgical microscope, using the fellow eye as a control. Immunohistochemical analyses were performed at days 1, 3, 7, 10 and 14 after retinal detachment to evaluate the cellular responses of photoreceptors, Müller glia, microglia and nonastrocytic inner retinal glia (NIRG. Cell proliferation was detected with bromodeoxyuridine (BrdU-incorporation and by the expression of proliferating cell nuclear antigen (PCNA. Cell death was detected with terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL. As in mammalian models of RD, there is shortening of photoreceptor outer segments and mis-trafficking of photoreceptor opsins in areas of RD. Photoreceptor cell death was maximal 1 day after RD, but continued until 14 days after RD. Müller glia up-regulated glial fibriliary acidic protein (GFAP, proliferated, showed interkinetic nuclear migration, and migrated to the subretinal space in areas of detachment. Microglia became reactive; they up-regulated CD45, acquired amoeboid morphology, and migrated toward outer retina in areas of RD. Reactive NIRG cells accumulated in detached areas.Subretinal injections of SA or HA in the chick eye successfully produced retinal detachments and cellular responses similar to those seen in standard mammalian models. Given the relatively large eye size, and considering the low cost, the chick model of RD offers advantages for high-throughput studies.

  16. Long-Run Benefits from Universal High-Quality Preschooling

    DEFF Research Database (Denmark)

    Bauchmüller, Robert; Gørtz, Mette; Rasmussen, Astrid Würtz

    2014-01-01

    This paper investigates the role of preschool quality for children's school performance at the end of primary school. We construct five structural quality indicators based on unique Danish administrative register data. 30,444 children finishing primary school's 9th grade in 2008 and who attended ...... in children's test results in Danish. Boys benefit more from preschool quality than girls. Ethnic minority children benefit from higher staff stability....

  17. Low-quality birds do not display high-quality signals: The cysteine-pheomelanin mechanism of honesty

    Science.gov (United States)

    Galván, Ismael; Wakamatsu, Kazumasa; Camarero, Pablo R; Mateo, Rafael; Alonso-Alvarez, Carlos

    2015-01-01

    The mechanisms that make that the costs of producing high-quality signals are unaffordable to low-quality signalers are a current issue in animal communication. The size of the melanin-based bib of male house sparrows Passer domesticus honestly signals quality. We induced the development of new bibs while treating males with buthionine-sulfoximine (BSO), a substance that depletes the levels of the antioxidant glutathione (GSH) and the amino acid cysteine, two elements that switch melanogenesis from eumelanin to pheomelanin. Final bib size is negatively related to pheomelanin levels in the bib feathers. BSO reduced cysteine and GSH levels in all birds, but improved phenotypes (bibs larger than controls) were only expressed by high-quality birds (BSO birds with largest bibs initially). Negative associations between final bib size and cysteine levels in erythrocytes, and between pheomelanin and cysteine levels, were observed in high-quality birds only. These findings suggest that a mechanism uncoupling pheomelanin and cysteine levels may have evolved in low-quality birds to avoid producing bibs of size not corresponding to their quality and greater relative costs. Indeed, greater oxidative stress in cells was not observed in low-quality birds. This may represent the first mechanism maintaining signal honesty without producing greater relative costs on low-quality signalers. PMID:25330349

  18. Systems and processes that ensure high quality care.

    Science.gov (United States)

    Bassett, Sally; Westmore, Kathryn

    2012-10-01

    This is the second in a series of articles examining the components of good corporate governance. It considers how the structures and processes for quality governance can affect an organisation's ability to be assured about the quality of care. Complex information systems and procedures can lead to poor quality care, but sound structures and processes alone are insufficient to ensure good governance, and behavioural factors play a significant part in making sure that staff are enabled to provide good quality care. The next article in this series looks at how the information reporting of an organisation can affect its governance.

  19. Screening for retinitis in children with probable systemic ...

    African Journals Online (AJOL)

    CMV retinitis may be prevented by timely diagnosis and treatment. This study aimed to .... retinitis are: 'a fulminant picture of retinal vasculitis and vascular sheathing with areas of yellow-white, full thickness, retinal necrosis producing retinal oedema associated ... and intravenous foscarnet as alternatives.[4] Although CMV- ...

  20. Characterization of non equilibrium effects on high quality critical flows

    International Nuclear Information System (INIS)

    Camelo, E.; Lemonnier, H.; Ochterbeck, J.

    1995-01-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness

  1. Characterization of non equilibrium effects on high quality critical flows

    Energy Technology Data Exchange (ETDEWEB)

    Camelo, E.; Lemonnier, H.; Ochterbeck, J. [Commissariat a l Energie Atomique, Grenoble (France)] [and others

    1995-09-01

    The appropriate design of various pieces of safety equipment such as relief systems, relies on the accurate description of critical flow phenomena. Most of the systems of industrial interest are willing to be described by one-dimensional area-averaged models and a large fraction of them involves multi-component high gas quality flows. Within these circumstances, the flow is very likely to be of an annular dispersed nature and its description by two-fluid models requires various closure relations. Among the most sensitive closures, there is the interfacial area and the liquid entrained fraction. The critical flowrate depends tremendously on the accurate description of the non equilibrium which results from the correctness of the closure equations. In this study, two-component flows are emphasized and non equilibrium results mainly form the differences in the phase velocities. It is therefore of the utmost importance to have reliable data to characterize non equilibrium phenomena and to assess the validity of the closure models. A comprehensive description of air-water nozzle flows, with emphasis on the effect of the nozzle geometry, has been undertaken and some of the results are presented here which helps understanding the overall flow dynamics. Besides the critical flowrate, the presented material includes pressure profiles, droplet size and velocity, liquid film flowrate and liquid film thickness.

  2. Image Quality in High-resolution and High-cadence Solar Imaging

    Science.gov (United States)

    Denker, C.; Dineva, E.; Balthasar, H.; Verma, M.; Kuckein, C.; Diercke, A.; González Manrique, S. J.

    2018-03-01

    Broad-band imaging and even imaging with a moderate bandpass (about 1 nm) provides a photon-rich environment, where frame selection (lucky imaging) becomes a helpful tool in image restoration, allowing us to perform a cost-benefit analysis on how to design observing sequences for imaging with high spatial resolution in combination with real-time correction provided by an adaptive optics (AO) system. This study presents high-cadence (160 Hz) G-band and blue continuum image sequences obtained with the High-resolution Fast Imager (HiFI) at the 1.5-meter GREGOR solar telescope, where the speckle-masking technique is used to restore images with nearly diffraction-limited resolution. The HiFI employs two synchronized large-format and high-cadence sCMOS detectors. The median filter gradient similarity (MFGS) image-quality metric is applied, among others, to AO-corrected image sequences of a pore and a small sunspot observed on 2017 June 4 and 5. A small region of interest, which was selected for fast-imaging performance, covered these contrast-rich features and their neighborhood, which were part of Active Region NOAA 12661. Modifications of the MFGS algorithm uncover the field- and structure-dependency of this image-quality metric. However, MFGS still remains a good choice for determining image quality without a priori knowledge, which is an important characteristic when classifying the huge number of high-resolution images contained in data archives. In addition, this investigation demonstrates that a fast cadence and millisecond exposure times are still insufficient to reach the coherence time of daytime seeing. Nonetheless, the analysis shows that data acquisition rates exceeding 50 Hz are required to capture a substantial fraction of the best seeing moments, significantly boosting the performance of post-facto image restoration.

  3. Feature-Based Retinal Image Registration Using D-Saddle Feature

    Directory of Open Access Journals (Sweden)

    Roziana Ramli

    2017-01-01

    Full Text Available Retinal image registration is important to assist diagnosis and monitor retinal diseases, such as diabetic retinopathy and glaucoma. However, registering retinal images for various registration applications requires the detection and distribution of feature points on the low-quality region that consists of vessels of varying contrast and sizes. A recent feature detector known as Saddle detects feature points on vessels that are poorly distributed and densely positioned on strong contrast vessels. Therefore, we propose a multiresolution difference of Gaussian pyramid with Saddle detector (D-Saddle to detect feature points on the low-quality region that consists of vessels with varying contrast and sizes. D-Saddle is tested on Fundus Image Registration (FIRE Dataset that consists of 134 retinal image pairs. Experimental results show that D-Saddle successfully registered 43% of retinal image pairs with average registration accuracy of 2.329 pixels while a lower success rate is observed in other four state-of-the-art retinal image registration methods GDB-ICP (28%, Harris-PIIFD (4%, H-M (16%, and Saddle (16%. Furthermore, the registration accuracy of D-Saddle has the weakest correlation (Spearman with the intensity uniformity metric among all methods. Finally, the paired t-test shows that D-Saddle significantly improved the overall registration accuracy of the original Saddle.

  4. Quality Assurance Roadmap for High Performance Residential Buildings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2008-10-05

    This report outlines the approach to quality assurance in the construction process for new residential construction, including seven process steps from the assessment of current construction practice, through design and documentation changes, to training and quality control for on-site personnel.

  5. Paying for High- and Low-Quality Teaching

    Science.gov (United States)

    Schacter, John; Thum, Yeow Meng

    2004-01-01

    The extensive research on teacher quality has led to two conclusions. First, there are large and significant differences among teachers in terms of their capacity to improve student achievement. Second, these differences are not captured by common measures of teacher qualifications (E.A. Hanushek, Teacher quality, in: L.T. Izumi, W.M. Evers…

  6. Teaching quality: High school students' autonomy and competence.

    Science.gov (United States)

    León, Jaime; Medina-Garrido, Elena; Ortega, Miriam

    2018-05-01

    How teachers manage class learning and interact with students affects students’ motivation and engagement. However, it could be that the effect of students’ representation of teaching quality on the students’ motivation varies between classes. Students from 90 classes participated in the study. We used multilevel random structural equation modeling to analyze whether the relationship of the students’ perception of teaching quality (as an indicator of the students’ mental representation) and students’ motivation varies between classes, and if this variability depends on the class assessment of teaching quality (as an indicator of teaching quality). The effect of teachers’ structure on the regression slope of student perception of student competence was .127. The effect of teachers’ autonomy support on the regression slope of student perception of student autonomy was .066. With this study we contribute a more detailed description of the relationship between teaching quality, competence and autonomy.

  7. Comparison of low-cost handheld retinal camera and traditional table top retinal camera in the detection of retinal features indicating a risk of cardiovascular disease

    Science.gov (United States)

    Joshi, V.; Wigdahl, J.; Nemeth, S.; Zamora, G.; Ebrahim, E.; Soliz, P.

    2018-02-01

    Retinal abnormalities associated with hypertensive retinopathy are useful in assessing the risk of cardiovascular disease, heart failure, and stroke. Assessing these risks as part of primary care can lead to a decrease in the incidence of cardiovascular disease-related deaths. Primary care is a resource limited setting where low cost retinal cameras may bring needed help without compromising care. We compared a low-cost handheld retinal camera to a traditional table top retinal camera on their optical characteristics and performance to detect hypertensive retinopathy. A retrospective dataset of N=40 subjects (28 with hypertensive retinopathy, 12 controls) was used from a clinical study conducted at a primary care clinic in Texas. Non-mydriatic retinal fundus images were acquired using a Pictor Plus hand held camera (Volk Optical Inc.) and a Canon CR1-Mark II tabletop camera (Canon USA) during the same encounter. The images from each camera were graded by a licensed optometrist according to the universally accepted Keith-Wagener-Barker Hypertensive Retinopathy Classification System, three weeks apart to minimize memory bias. The sensitivity of the hand-held camera to detect any level of hypertensive retinopathy was 86% compared to the Canon. Insufficient photographer's skills produced 70% of the false negative cases. The other 30% were due to the handheld camera's insufficient spatial resolution to resolve the vascular changes such as minor A/V nicking and copper wiring, but these were associated with non-referable disease. Physician evaluation of the performance of the handheld camera indicates it is sufficient to provide high risk patients with adequate follow up and management.

  8. New developments in high quality grey cast irons

    Directory of Open Access Journals (Sweden)

    Iulian Riposan

    2014-07-01

    Full Text Available The paper reviews original data obtained by the present authors, revealed in recent separate publications, describing specific procedures for high quality grey irons, and reflecting the forecast needs of the worldwide iron foundry industry. High power, medium frequency coreless induction furnaces are commonly used in electric melting grey iron foundries. This has resulted in low sulphur (1,500 °C, contributing to unfavourable conditions for graphite nucleation. Thin wall castings are increasingly produced by these electric melt shops with a risk of greater eutectic undercooling during solidification. The paper focused on two groups of grey cast irons and their specific problems: carbides and graphite morphology control in lower carbon equivalent high strength irons (CE=3.4%-3.8%, and austenite dendrite promotion in eutectic and slightly hypereutectic irons (CE=4.1%-4.5%, in order to increase their strength characteristics. There are 3 stages and 3 steps involving graphite formation, iron chemistry and iron processing that appear to be important. The concept in the present paper sustains a threestage model for nucleating flake graphite [(Mn,XS type nuclei]. There are three important groups of elements (deoxidizer, Mn/S, and inoculant and three technological stages in electric melting of iron (superheat, pre-conditioning of base iron, final inoculation. Attention is drawn to a control factor (%Mn x (%S ensuring it equals to 0.03 – 0.06, accompanied by 0.005wt.%–0.010wt.% Al and/or Zr content in inoculated irons. It was found that iron powder addition promotes austenite dendrite formation in eutectic and slightly eutectic, acting as reinforcement for the eutectic cells. But, there is an accompanying possible negative influence on the characteristics of the (Mn,XS type graphite nuclei (change the morphology of nuclei from polygonal compact to irregular polygonal, and therefore promote chill tendency in treated irons. A double addition (iron

  9. A high yielding, better quality chickpea mutant variety 'NIFA-95'

    International Nuclear Information System (INIS)

    Hassan, S.; Javed, M.A.; Khattak, S.U.K.; Iqbal, M.M.

    2001-01-01

    Chickpea or gram (Cicer arietinum L.) is an important legume crop of Pakistan, grown on over one million hectares annually. The national average yield of the crop is very low (0.5 t/ha) and thus the country had to spent about 2 billion rupees ($ 50 million) on import of pulses. The main causes of low yield are non-availability of genetic sources for resistance to various diseases especially gram blight Ascochyta rabiei (Pass.) Lab., insect pest (Pod borer) and non-adoption of proper production technology by the farmers. This calls for earnest efforts of breeders to evolve high yielding and disease resistant varieties of chickpea for provision of quality seeds to the farming community to increase production of this important crop. Seeds of a highly blight susceptible variety '6153' were irradiated at 200 Gy dose of gamma radiation in 1985 and the promising mutant line CMN-446-4 was selected in M3 generation on the basis of disease resistance, greater number of pods and better plant type. After confirmation of its resistance to blight in M 4 and M 5 , the mutant line was evaluated in various trials at different locations. In the advanced and zonal yield trials during 1993-95, the line CMN-446-4 produced the highest grain yield of 2,600 kg/ha as compared to the rest of the mutants and varieties. The line was also evaluated in the chickpea national uniform yield trial, conducted on over 11 locations in the country during 1993-94. In this trial, the mutant line ranked 3rd by producing an average yield of 1,528 kg/ha as compared to the two check varieties 'Punjab-91' (1,316 kg/ha) and 'Paidar-91' (1,391 kg/ha). The mutant line CMN-446-4 is moderately resistant to gram blight, highly resistant to stored pest (pulse beetle), contains 25.3% more protein as compared to the parental variety 6153 and is also better in nitrogen fixing capacity.The proposal for release of the mutant line CMN-446-4 as a new variety under the name 'NIFA-95' for general cultivation in the rainfed

  10. Perfluorocarbon-perfused 23 gauge three-dimensional vitrectomy for complicated diabetic tractional retinal detachment

    Science.gov (United States)

    Velez-Montoya, Raul; Guerrero-Naranjo, Jose Luis; Garcia-Aguirre, Gerardo; Morales-Cantón, Virgilio; Fromow-Guerra, Jans; Quiroz-Mercado, Hugo

    2011-01-01

    Background Perfluorocarbon liquid (PCL)-perfused vitrectomy has been shown in previous studies to be feasible, safe, and to have advantages in managing complicated cases of tractional retinal detachment. The present study had the objectives of describing the anatomical results and measuring surgical time and PCL consumption when combining PCL-perfused techniques with modern vitrectomy equipment. Methods A prospective, interventional consecutive case series was investigated. We enrolled patients with diabetic tractional retinal detachment, complicated by proliferative vitreoretinopathy and poor vision. A 23 gauge PCL-perfused vitrectomy was done with three-dimensional settings. During the procedure, we assessed the degree of surgical bleeding, visualization quality, and difficulty of membrane dissections. Visual acuity, intraocular pressure, and anatomical success were assessed at one and 3 months of follow-up. Results Twelve patients were enrolled in this study. There were no statistical significant changes in intraocular pressure and visual acuity throughout the follow-up period. Surgery was performed in a hemorrhage-free environment in almost all cases, with good visualization and low technical difficulty. The mean complete surgical time was 94.92 ± 25.03 minutes. The mean effective vitrectomy time was 22.50 ± 19.04 minutes and the mean PCL consumption was 25.08 ± 9.76 mL, with a speed of 1.11 mL/minute. Anatomical success was 67% at 3 months. Conclusion Although the technique proved to have some advantages in managing complicated cases of diabetic tractional retinal detachment, there was a high consumption of PCL. A redesign of the entire system is needed in order to decrease the amount of PCL needed for the technique. PMID:22267907

  11. Physics and quality assurance for high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Anderson, Lowell L.

    1995-01-01

    Purpose: To review the physical aspects of high dose rate (HDR) brachytherapy, including commissioning and quality assurance, source calibration and dose distribution measurements, and treatment planning methods. Following the introduction of afterloading in brachytherapy, development efforts to make it 'remote' culminated in 1964 with the near-simultaneous appearance of remote afterloaders in five major medical centers. Four of these machines were 'high dose rate', three employing 60Co and one (the GammaMed) using a single, cable-mounted 192Ir source. Stepping-motor source control was added to the GammaMed in 1974, making it the precursor of modern remote afterloaders, which are now suitable for interstitial as well as intracavitary brachytherapy by virtue of small source-diameter and indexer-accessed multiple channels. Because the 192Ir sources currently used in HDR remote afterloaders are supplied at a nominal air-kerma strength of 11.4 cGy cm2 s-1 (10 Ci), are not collimated in clinical use, and emit a significant fraction (15%) of photons at energies greater than 600 keV, shielding and facility design must be undertaken as carefully and thoroughly as for external beam installations. Licensing requirements of regulatory agencies must be met with respect both to maximum permissible dose limits and to the existence and functionality of safety devices (door interlocks, radiation monitors, etc.). Commissioning and quality assurance procedures that must be documented for HDR remote afterloading relate to (1) machine, applicator, guide-tube, and facility functionality checks, (2) source calibration, (3) emergency response readiness, (4) planning software evaluation, and (5) independent checks of clinical dose calculations. Source calibration checks must be performed locally, either by in-air measurement of air kerma strength or with a well ionization chamber calibrated (by an accredited standards laboratory) against an in-air measurement of air kerma strength for the

  12. Twin pregnancy possibly associated with high semen quality

    DEFF Research Database (Denmark)

    Asklund, Camilla; Jensen, Tina Kold; Jørgensen, Niels

    2007-01-01

    BACKGROUND: Recent studies found an association between a long waiting time to pregnancy (TTP) and reduced probability of twinning and a reduced dizygotic (DZ) twinning rate in subfertile men. However, it remains unsolved whether semen quality is associated with twin offspring. We therefore studied...... the semen quality in a group of fathers of naturally conceived twins. METHODS: In this study, 37 fathers of DZ twins and 15 fathers of monozygotic (MZ) twins participated, and 349 normal fertile men served as a reference group. All men delivered a semen sample, underwent a physical examination and completed...... points higher than the reference group (P semen quality than the reference group, which supports...

  13. Advances in Retinal Stem Cell Biology

    Directory of Open Access Journals (Sweden)

    Andrea S Viczian

    2013-01-01

    Full Text Available Tremendous progress has been made in recent years to generate retinal cells from pluripotent cell sources. These advances provide hope for those suffering from blindness due to lost retinal cells. Understanding the intrinsic genetic network in model organisms, like fly and frog, has led to a better understanding of the extrinsic signaling pathways necessary for retinal progenitor cell formation in mouse and human cell cultures. This review focuses on the culture methods used by different groups, which has culminated in the generation of laminated retinal tissue from both embryonic and induced pluripotent cells. The review also briefly describes advances made in transplantation studies using donor retinal progenitor and cultured retinal cells.

  14. Prevalence of generalized retinal dystrophy in Denmark

    DEFF Research Database (Denmark)

    Bertelsen, Mette; Jensen, Hanne; Bregnhøj, Jesper F

    2014-01-01

    of this study was to examine the prevalence and diagnostic spectrum of generalized retinal dystrophy in the Danish population. METHODS: A population-based cross-sectional study with data from the Danish Retinitis Pigmentosa Registry that comprises all patients in Denmark with generalized retinal......PURPOSE: Generalized retinal dystrophy is a frequent cause of visual impairment and blindness in younger individuals and a subject of new clinical intervention trials. Nonetheless, there are few nation-wide population-based epidemiological data of generalized retinal dystrophy. The purpose...... and chorioretinal dystrophies from the 19th century to the present. Among 3076 registered cases, the primary diagnosis of generalized retinal dystrophy was assessed by chart review, including fundus photographs and electroretinograms. Demographic data on the Danish population were retrieved from Statistics Denmark...

  15. Automatic Vessel Segmentation on Retinal Images

    Institute of Scientific and Technical Information of China (English)

    Chun-Yuan Yu; Chia-Jen Chang; Yen-Ju Yao; Shyr-Shen Yu

    2014-01-01

    Several features of retinal vessels can be used to monitor the progression of diseases. Changes in vascular structures, for example, vessel caliber, branching angle, and tortuosity, are portents of many diseases such as diabetic retinopathy and arterial hyper-tension. This paper proposes an automatic retinal vessel segmentation method based on morphological closing and multi-scale line detection. First, an illumination correction is performed on the green band retinal image. Next, the morphological closing and subtraction processing are applied to obtain the crude retinal vessel image. Then, the multi-scale line detection is used to fine the vessel image. Finally, the binary vasculature is extracted by the Otsu algorithm. In this paper, for improving the drawbacks of multi-scale line detection, only the line detectors at 4 scales are used. The experimental results show that the accuracy is 0.939 for DRIVE (digital retinal images for vessel extraction) retinal database, which is much better than other methods.

  16. High quality ceramic coatings sprayed by high efficiency hypersonic plasma spraying gun

    International Nuclear Information System (INIS)

    Zhu Sheng; Xu Binshi; Yao JiuKun

    2005-01-01

    This paper introduced the structure of the high efficiency hypersonic plasma spraying gun and the effects of hypersonic plasma jet on the sprayed particles. The optimised spraying process parameters for several ceramic powders such as Al 2 O 3 , Cr 2 O 3 , ZrO 2 , Cr 3 C 2 and Co-WC were listed. The properties and microstructure of the sprayed ceramic coatings were investigated. Nano Al 2 O 3 -TiO 2 ceramic coating sprayed by using the high efficiency hypersonic plasma spraying was also studied. Compared with the conventional air plasma spraying, high efficiency hypersonic plasma spraying improves greatly the ceramic coatings quality but at low cost. (orig.)

  17. Blood pressure modifies retinal susceptibility to intraocular pressure elevation.

    Directory of Open Access Journals (Sweden)

    Zheng He

    Full Text Available Primary open angle glaucoma affects more than 67 million people. Elevated intraocular pressure (IOP is a risk factor for glaucoma and may reduce nutrient availability by decreasing ocular perfusion pressure (OPP. An interaction between arterial blood pressure and IOP determines OPP; but the exact contribution that these factors have for retinal function is not fully understood. Here we sought to determine how acute modifications of arterial pressure will affect the susceptibility of neuronal function and blood flow to IOP challenge. Anaesthetized (ketamine:xylazine Long-Evan rats with low (∼60 mmHg, sodium nitroprusside infusion, moderate (∼100 mmHg, saline, or high levels (∼160 mmHg, angiotensin II of mean arterial pressure (MAP, n = 5-10 per group were subjected to IOP challenge (10-120 mmHg, 5 mmHg steps every 3 minutes. Electroretinograms were measured at each IOP step to assess bipolar cell (b-wave and inner retinal function (scotopic threshold response or STR. Ocular blood flow was measured using laser-Doppler flowmetry in groups with similar MAP level and the same IOP challenge protocol. Both b-wave and STR amplitudes decreased with IOP elevation. Retinal function was less susceptible to IOP challenge when MAP was high, whereas the converse was true for low MAP. Consistent with the effects on retinal function, higher IOP was needed to attenuated ocular blood flow in animals with higher MAP. The susceptibility of retinal function to IOP challenge can be ameliorated by acute high BP, and exacerbated by low BP. This is partially mediated by modifications in ocular blood flow.

  18. Safe and high quality food production using low quality waters and improved irrigation systems and management

    DEFF Research Database (Denmark)

    Plauborg, Finn; Andersen, Mathias Neumann; Liu, Fulai

    2010-01-01

    uneven irrigation patterns can increase the water use efficiency as well as the quality of vegetable crops. Furthermore, recent innovations in the water treatment and irrigation industry have shown potential for the use of low quality water resources, such as reclaimed water or surface water in peri...

  19. MULTIFOCAL RETINAL INFILTRATES WITH PHLEBITIS AND OPTIC NEUROPATHY IN AN HIV-POSITIVE PEDIATRIC PATIENT.

    Science.gov (United States)

    Kasi, Sundeep K; Vora, Robin A; Martin, Taliva; Cunningham, Emmett T

    2015-01-01

    To describe an unusual presentation of bilateral HIV-associated multifocal retinal infiltrates with phlebitis and optic neuropathy in a pediatric patient from Zimbabwe, Africa. Retrospective case report of a 15-year-old boy from Zimbabwe, Africa. The patient was found to have bilateral vitritis, multifocal retinitis with phlebitis, and optic neuropathy in the setting of previously unrecognized HIV infection. Vision improved and the clinical findings resolved after treatment with intravenous corticosteroids and highly active retroviral therapy (HAART). The authors describe the occurrence and treatment of bilateral, HIV-associated multifocal retinal infiltrates with phlebitis and HIV-associated optic neuropathy in a pediatric patient from Zimbabwe, Africa.

  20. Comparative Study of Retinal Vessel Segmentation Based on Global Thresholding Techniques

    Directory of Open Access Journals (Sweden)

    Temitope Mapayi

    2015-01-01

    Full Text Available Due to noise from uneven contrast and illumination during acquisition process of retinal fundus images, the use of efficient preprocessing techniques is highly desirable to produce good retinal vessel segmentation results. This paper develops and compares the performance of different vessel segmentation techniques based on global thresholding using phase congruency and contrast limited adaptive histogram equalization (CLAHE for the preprocessing of the retinal images. The results obtained show that the combination of preprocessing technique, global thresholding, and postprocessing techniques must be carefully chosen to achieve a good segmentation performance.

  1. Inherited Retinal Degenerative Clinical Trial Network. Addendum

    Science.gov (United States)

    2013-10-01

    inherited orphan retinal degenerative diseases and dry age-related macular degeneration (AMD) through the conduct of clinical trials and other...design and conduct of effective and efficient clinical trials for inherited orphan retinal degenerative diseases and dry AMD; • Limited number and...linica l trial in the NEER network for autosomal dominant retinitis pigmentosa, and the ProgSTAR studies for Stargardt disease ) . As new interventions b

  2. High throughput electrospinning of high-quality nanofibers via an aluminum disk spinneret

    Science.gov (United States)

    Zheng, Guokuo

    In this work, a simple and efficient needleless high throughput electrospinning process using an aluminum disk spinneret with 24 holes is described. Electrospun mats produced by this setup consisted of fine fibers (nano-sized) of the highest quality while the productivity (yield) was many times that obtained from conventional single-needle electrospinning. The goal was to produce scaled-up amounts of the same or better quality nanofibers under variable concentration, voltage, and the working distance than those produced with the single needle lab setting. The fiber mats produced were either polymer or ceramic (such as molybdenum trioxide nanofibers). Through experimentation the optimum process conditions were defined to be: 24 kilovolt, a distance to collector of 15cm. More diluted solutions resulted in smaller diameter fibers. Comparing the morphologies of the nanofibers of MoO3 produced by both the traditional and the high throughput set up it was found that they were very similar. Moreover, the nanofibers production rate is nearly 10 times than that of traditional needle electrospinning. Thus, the high throughput process has the potential to become an industrial nanomanufacturing process and the materials processed by it may be used as filtration devices, in tissue engineering, and as sensors.

  3. Frequency of lattice degeneration and retinal breaks in the fellow eye in retinal detachment.

    Science.gov (United States)

    Lorentzen, S E

    1988-04-01

    The fellow eye of 100 consecutively admitted cases of retinal detachment was studied with three-mirror examination for the presence of lattice degeneration and retinal breaks. Lattice degeneration was found in 18% and retinal breaks in 20% of fellow eyes.

  4. Improving the quality of pork and pork products for the consumer : development of innovative, integrated, and sustainable food production chains of high quality pork products matching consumer demands

    NARCIS (Netherlands)

    Heimann, B.; Christensen, M.; Rosendal Rasmussen, S.; Bonneau, M.; Grunert, K.G.; Arnau, J.; Trienekens, J.H.; Oksbjerg, N.; Greef, de K.H.; Petersen, B.

    2012-01-01

    Improving the quality of pork and pork products for the consumer: development of innovative, integrated, and sustainable food production chains of high quality pork products matching consumer demands.

  5. Retinal Cell Degeneration in Animal Models

    Directory of Open Access Journals (Sweden)

    Masayuki Niwa

    2016-01-01

    Full Text Available The aim of this review is to provide an overview of various retinal cell degeneration models in animal induced by chemicals (N-methyl-d-aspartate- and CoCl2-induced, autoimmune (experimental autoimmune encephalomyelitis, mechanical stress (optic nerve crush-induced, light-induced and ischemia (transient retinal ischemia-induced. The target regions, pathology and proposed mechanism of each model are described in a comparative fashion. Animal models of retinal cell degeneration provide insight into the underlying mechanisms of the disease, and will facilitate the development of novel effective therapeutic drugs to treat retinal cell damage.

  6. Retinal Macroglial Responses in Health and Disease

    Directory of Open Access Journals (Sweden)

    Rosa de Hoz

    2016-01-01

    Full Text Available Due to their permanent and close proximity to neurons, glial cells perform essential tasks for the normal physiology of the retina. Astrocytes and Müller cells (retinal macroglia provide physical support to neurons and supplement them with several metabolites and growth factors. Macroglia are involved in maintaining the homeostasis of extracellular ions and neurotransmitters, are essential for information processing in neural circuits, participate in retinal glucose metabolism and in removing metabolic waste products, regulate local blood flow, induce the blood-retinal barrier (BRB, play fundamental roles in local immune response, and protect neurons from oxidative damage. In response to polyetiological insults, glia cells react with a process called reactive gliosis, seeking to maintain retinal homeostasis. When malfunctioning, macroglial cells can become primary pathogenic elements. A reactive gliosis has been described in different retinal pathologies, including age-related macular degeneration (AMD, diabetes, glaucoma, retinal detachment, or retinitis pigmentosa. A better understanding of the dual, neuroprotective, or cytotoxic effect of macroglial involvement in retinal pathologies would help in treating the physiopathology of these diseases. The extensive participation of the macroglia in retinal diseases points to these cells as innovative targets for new drug therapies.

  7. Coincidence of retinitis pigmentosa and pseudoexfoliative glaucoma

    Directory of Open Access Journals (Sweden)

    Božić Marija

    2017-01-01

    Full Text Available Introduction. This is an observational case report presenting retinitis pigmentosa associated with pseudoexfoliative glaucoma. Case outline. A 69-year-old man presented with retinitis pigmentosa. On examination, pseudoexfoliative material was detected on anterior segment structures, and intraocular pressure was 26 mmHg in the right and 24 mmHg in the left eye. The patient was commenced on topical antiglaucomatous therapy (timolol + dorzolamide twice daily, latanoprost once in the evening to both eyes. Conclusion. To the best of our knowledge, this is the first reported case of retinitis pigmentosa associated with pseudoexfoliative glaucoma. Although rare, retinitis pigmentosa and glaucoma can occur in the same eye.

  8. Retinal phlebitis associated with autoimmune hemolytic anemia.

    Science.gov (United States)

    Chew, Fiona L M; Tajunisah, Iqbal

    2009-01-01

    To describe a case of retinal phlebitis associated with autoimmune hemolytic anemia. Observational case report. A 44-year-old Indian man diagnosed with autoimmune hemolytic anemia presented with a 1-week history of blurred vision in both eyes. Fundus biomicroscopy revealed bilateral peripheral retinal venous sheathing and cellophane maculopathy. Fundus fluorescent angiogram showed bilateral late leakage from the peripheral venous arcades and submacular fluid accumulation. The retinal phlebitis resolved following a blood transfusion and administration of systemic steroids. Retinopathy associated with autoimmune hemolytic anemia is not well known. This is thought to be the first documentation of retinal phlebitis occurring in this condition.

  9. Tractional retinal detachment in Usher syndrome type II.

    Science.gov (United States)

    Rani, Alka; Pal, Nikhil; Azad, Raj Vardhan; Sharma, Yog Raj; Chandra, Parijat; Vikram Singh, Deependra

    2005-08-01

    Retinal detachment is a rare complication in patients with retinitis pigmentosa. A case is reported of tractional retinal detachment in a patient with retinitis pigmentosa and sensorineural hearing loss, which was diagnosed as Usher syndrome type II. Because of the poor visual prognosis, the patient refused surgery in that eye. Tractional retinal detachment should be added to the differential diagnoses of visual loss in patients with retinitis pigmentosa.

  10. Stem Cell-Based Therapeutic Applications in Retinal Degenerative Diseases.

    OpenAIRE

    Huang Yiming; Enzmann Volker; Ildstad Suzanne T

    2011-01-01

    Retinal degenerative diseases that target photoreceptors or the adjacent retinal pigment epithelium (RPE) affect millions of people worldwide. Retinal degeneration (RD) is found in many different forms of retinal diseases including retinitis pigmentosa (RP), age-related macular degeneration (AMD), diabetic retinopathy, cataracts, and glaucoma. Effective treatment for retinal degeneration has been widely investigated. Gene-replacement therapy has been shown to improve visual function in inheri...

  11. Synthesis and Use of Stable Isotope Enriched Retinals in the Field of Vitamin A

    Directory of Open Access Journals (Sweden)

    Johan Lugtenburg

    2010-03-01

    Full Text Available The role of vitamin A and its metabolites in the life processes starting with the historical background and its up to date information is discussed in the introduction. Also the role of 11Z-retinal in vision and retinoic acid in the biological processes is elucidated. The essential role of isotopically enriched systems in the progress of vision research, nutrition research etc. is discussed. In part B industrial commercial syntheses of vitamin A by the two leading companies Hoffmann-La Roche (now DSM and BASF are discussed. The knowledge obtained via these pioneering syntheses has been essential for the further synthetic efforts in vitamin A field by other scientific groups. The rest of the paper is devoted to the synthetic efforts of the Leiden group that gives an access to the preparation of site directed high level isotope enrichment in retinals. First the synthesis of the retinals with deuterium incorporation in the conjugated side chain is reviewed. Then, 13C-labeled retinals are discussed. This is followed by the discussion of a convergent synthetic scheme that allows a rational access to prepare any isotopomer of retinals. The schemes that provide access to prepare any possible isotope enriched chemically modified systems are discussed. Finally, nor-retinals and bridged retinals that give access to a whole (as yet incomplete library of possible isotopomers are reviewed.

  12. Discovery of a Cynomolgus Monkey Family With Retinitis Pigmentosa.

    Science.gov (United States)

    Ikeda, Yasuhiro; Nishiguchi, Koji M; Miya, Fuyuki; Shimozawa, Nobuhiro; Funatsu, Jun; Nakatake, Shunji; Fujiwara, Kohta; Tachibana, Takashi; Murakami, Yusuke; Hisatomi, Toshio; Yoshida, Shigeo; Yasutomi, Yasuhiro; Tsunoda, Tatsuhiko; Nakazawa, Toru; Ishibashi, Tatsuro; Sonoda, Koh-Hei

    2018-02-01

    To accelerate the development of new therapies, an inherited retinal degeneration model in a nonhuman primate would be useful to confirm the efficacy in preclinical studies. In this study, we describe the discovery of retinitis pigmentosa in a cynomolgus monkey (Macaca fascicularis) pedigree. First, screening with fundus photography was performed on 1443 monkeys at the Tsukuba Primate Research Center. Ophthalmic examinations, such as indirect ophthalmoscopy, ERGs using RETeval, and optic coherent tomography (OCT) measurement, were then performed to confirm diagnosis. Retinal degeneration with cystoid macular edema was observed in both eyes of one 14-year-old female monkey. In her examinations, the full-field ERGs were nonrecordable and the outer layer of the retina in the parafoveal area was not visible on OCT imaging. Moreover, less frequent pigmentary retinal anomalies also were observed in her 3-year-old nephew. His full-field ERGs were almost nonrecordable and the outer layer was not visible in the peripheral retina. His father was her cousin (the son of her mother's older brother) and his mother was her younger half-sibling sister with a different father. The hereditary nature is highly probable (autosomal recessive inheritance suspected). However, whole-exome analysis performed identified no pathogenic mutations in these monkeys.

  13. Exploring Raman spectroscopy for the evaluation of glaucomatous retinal changes

    Science.gov (United States)

    Wang, Qi; Grozdanic, Sinisa D.; Harper, Matthew M.; Hamouche, Nicolas; Kecova, Helga; Lazic, Tatjana; Yu, Chenxu

    2011-10-01

    Glaucoma is a chronic neurodegenerative disease characterized by apoptosis of retinal ganglion cells and subsequent loss of visual function. Early detection of glaucoma is critical for the prevention of permanent structural damage and irreversible vision loss. Raman spectroscopy is a technique that provides rapid biochemical characterization of tissues in a nondestructive and noninvasive fashion. In this study, we explored the potential of using Raman spectroscopy for detection of glaucomatous changes in vitro. Raman spectroscopic imaging was conducted on retinal tissues of dogs with hereditary glaucoma and healthy control dogs. The Raman spectra were subjected to multivariate discriminant analysis with a support vector machine algorithm, and a classification model was developed to differentiate disease tissues versus healthy tissues. Spectroscopic analysis of 105 retinal ganglion cells (RGCs) from glaucomatous dogs and 267 RGCs from healthy dogs revealed spectroscopic markers that differentiated glaucomatous specimens from healthy controls. Furthermore, the multivariate discriminant model differentiated healthy samples and glaucomatous samples with good accuracy [healthy 89.5% and glaucomatous 97.6% for the same breed (Basset Hounds); and healthy 85.0% and glaucomatous 85.5% for different breeds (Beagles versus Basset Hounds)]. Raman spectroscopic screening can be used for in vitro detection of glaucomatous changes in retinal tissue with a high specificity.

  14. Retinal dopamine mediates multiple dimensions of light-adapted vision.

    Science.gov (United States)

    Jackson, Chad R; Ruan, Guo-Xiang; Aseem, Fazila; Abey, Jane; Gamble, Karen; Stanwood, Greg; Palmiter, Richard D; Iuvone, P Michael; McMahon, Douglas G

    2012-07-04

    Dopamine is a key neuromodulator in the retina and brain that supports motor, cognitive, and visual function. Here, we developed a mouse model on a C57 background in which expression of the rate-limiting enzyme for dopamine synthesis, tyrosine hydroxylase, is specifically disrupted in the retina. This model enabled assessment of the overall role of retinal dopamine in vision using electrophysiological (electroretinogram), psychophysical (optokinetic tracking), and pharmacological techniques. Significant disruptions were observed in high-resolution, light-adapted vision caused by specific deficits in light responses, contrast sensitivity, acuity, and circadian rhythms in this retinal dopamine-depleted mouse model. These global effects of retinal dopamine on vision are driven by the differential actions of dopamine D1 and D4 receptors on specific retinal functions and appear to be due to the ongoing bioavailability of dopamine rather than developmental effects. Together, our data indicate that dopamine is necessary for the circadian nature of light-adapted vision as well as optimal contrast detection and acuity.

  15. Real time speckle monitoring to control retinal photocoagulation

    Science.gov (United States)

    Bliedtner, Katharina; Seifert, Eric; Brinkmann, Ralf

    2017-07-01

    Photocoagulation is a treatment modality for several retinal diseases. Intra- and inter-individual variations of the retinal absorption as well as ocular transmission and light scattering makes it impossible to achieve a uniform effective exposure with one set of laser parameters. To guarantee a uniform damage throughout the therapy a real-time control is highly requested. Here, an approach to realize a real-time optical feedback using dynamic speckle analysis in-vivo is presented. A 532 nm continuous wave Nd:YAG laser is used for coagulation. During coagulation, speckle dynamics are monitored by a coherent object illumination using a 633 nm diode laser and analyzed by a CMOS camera with a frame rate up to 1 kHz. An algorithm is presented that can discriminate between different categories of retinal pigment epithelial damage ex-vivo in enucleated porcine eyes and that seems to be robust to noise in-vivo. Tissue changes in rabbits during retinal coagulation could be observed for different lesion strengths. This algorithm can run on a FPGA and is able to calculate a feedback value which is correlated to the thermal and coagulation induced tissue motion and thus the achieved damage.

  16. The application of optical coherence tomography angiography in retinal diseases.

    Science.gov (United States)

    Sambhav, Kumar; Grover, Sandeep; Chalam, Kakarla V

    Optical coherence tomography angiography (OCTA) is a new, noninvasive imaging technique that generates real-time volumetric data on chorioretinal vasculature and its flow pattern. With the advent of high-speed optical coherence tomography, established enface chorioretinal segmentation, and efficient algorithms, OCTA generates images that resemble an angiogram. The principle of OCTA involves determining the change in backscattering between consecutive B-scans and then attributing the differences to the flow of erythrocytes through retinal blood vessels. OCTA has shown promise in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age-related macular degeneration, and retinal vascular occlusions. It quantifies vascular compromise reflecting the severity of diabetic retinopathy. OCTA detects the presence of choroidal neovascularization in exudative age-related macular degeneration and maps loss of choriocapillaris in nonexudative age-related macular degeneration. We describe principles of OCTA and findings in common and some uncommon retinal pathologies. Finally, we summarize its potential future applications. Its current limitations include a relatively small field of view, inability to show leakage, and a tendency for image artifacts. Further larger studies will define OCTAs utility in clinical settings and establish if the technology may offer its utility in decreasing morbidity through early detection and guide therapeutic interventions in retinal diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. [Prevention of retinal detachment and treatment of retinoschisis].

    Science.gov (United States)

    Messmer, E P

    1990-01-01

    The necessity for prophylactic treatment for degenerative disease in the peripheral retina cannot be evaluated merely on the basis of the ophthalmoscopic findings. Factors such as the patient's history, refraction, the status of the vitreous, and prospective future cataract extraction all have a major impact on the risk of developing retinal detachment. The latter condition can be classified in to three groups: (1) low risk (patients with no history of retinal detachment, intraocular surgery or posterior vitreous detachment, myopia less than three diopters): treatment of atrophic holes and lattice degeneration is not justified, treatment of flap tears according to the circumstances; (2) medium risk (patients with no history of retinal or posterior vitreous detachment; however, myopia of more than three diopters and/or aphakia): the treatment of lattice degeneration is not justified; treatment of breaks according to the circumstances; (3) high risk: (patients with symptoms of posterior vitreous detachment): the treatment of lattice degeneration and atrophic holes is not justified: treatment of tears is necessary; fellow eyes: the treatment of retinal breaks is necessary; treatment of lattice degeneration seems advisable in cases with bilateral symmetric findings or prior to cataract extraction. Treatment of senile retinoschisis is only justified in cases with large and centrally located holes in the outer wall or in the presence of symptomatic schisis detachment.

  18. Hmga2 regulates self-renewal of retinal progenitors.

    Science.gov (United States)

    Parameswaran, Sowmya; Xia, Xiaohuan; Hegde, Ganapati; Ahmad, Iqbal

    2014-11-01

    In vertebrate retina, histogenesis occurs over an extended period. To sustain the temporal generation of diverse cell types, retinal progenitor cells (RPCs) must self-renew. However, self-renewal and regulation of RPCs remain poorly understood. Here, we demonstrate that cell-extrinsic factors coordinate with the epigenetic regulator high-mobility group AT-hook 2 (Hmga2) to regulate self-renewal of late retinal progenitor cells (RPCs). We observed that a small subset of RPCs was capable of clonal propagation and retained multipotentiality of parents in the presence of endothelial cells (ECs), known self-renewal regulators in various stem cell niches. The self-renewing effects, also observed in vivo, involve multiple intercellular signaling pathways, engaging Hmga2. As progenitors exhaust during retinal development, expression of Hmga2 progressively decreases. Analyses of Hmga2-expression perturbation, in vitro and in vivo, revealed that Hmga2 functionally helps to mediate cell-extrinsic influences on late-retinal progenitor self-renewal. Our results provide a framework for integrating the diverse intercellular influences elicited by epigenetic regulators for self-renewal in a dynamic stem cell niche: the developing vertebrate retina. © 2014. Published by The Company of Biologists Ltd.

  19. Risk of progression in macula-on rhegmatogenous retinal detachment.

    Science.gov (United States)

    Callizo, Josep; Pfeiffer, Sebastian; Lahme, Eva; van Oterendorp, Christian; Khattab, Mohammed; Bemme, Sebastian; Kulanga, Miroslav; Hoerauf, Hans; Feltgen, Nicolas

    2017-08-01

    To identify factors that may lead to a rapid progression in macula-on rhegmatogenous retinal detachment (RRD), in particular, those that may lead to macular involvement. Observational, prospective, single-center study. Patients referred for surgery due to primary rhegmatogenous retinal detachment with the macula on between 2009 and 2013 were included. Relevant factors analyzed included age, time delay until surgery, lens status, myopia, the detachment's location and configuration as well as number, size and type of retinal breaks. Eyes underwent optical coherence tomography to detect macular detachment. A multivariate analysis was performed to investigate the effect of several factors in the progression of retinal detachment. A total of 116 eyes of 116 patients were included. Mean time delay between admission and surgery was 1.8 ± 1.4 days. Progression was observed in 19.8% of the eyes. Of those, 47.8% presented macular detachment. Ten of the 11 (90.9%) eyes presenting progression involving the macula also exhibited a bullous configuration, which was the only parameter that correlated significantly with detachment progression in patients with (p = 0.0036) and without (p = 0.0014) macular involvement. For the first time in a prospective trial, a bullous configuration was found to be a highly significant predictor for progression in macula-on detachments. Our data support prompt surgery in patients diagnosed with bullous macula-on RRD.

  20. High Yield Chemical Vapor Deposition Growth of High Quality Large-Area AB Stacked Bilayer Graphene

    Science.gov (United States)

    Liu, Lixin; Zhou, Hailong; Cheng, Rui; Yu, Woo Jong; Liu, Yuan; Chen, Yu; Shaw, Jonathan; Zhong, Xing; Huang, Yu; Duan, Xiangfeng

    2012-01-01

    Bernal stacked (AB stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electrical field. Mechanical exfoliation can be used to produce AB stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB and randomly stacked structures. Herein we report a rational approach to produce large-area high quality AB stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H2/CH4 ratio in a low pressure CVD process to enable the continued growth of bilayer graphene. A high temperature and low pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90 %) and high coverage (up to 99 %). The electrical transport studies demonstrated that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB stacked bilayer graphene with the highest carrier mobility exceeding 4,000 cm2/V·s at room temperature, comparable to that of the exfoliated bilayer graphene. PMID:22906199

  1. Nondamaging Retinal Laser Therapy: Rationale and Applications to the Macula.

    Science.gov (United States)

    Lavinsky, Daniel; Wang, Jenny; Huie, Philip; Dalal, Roopa; Lee, Seung Jun; Lee, Dae Yeong; Palanker, Daniel

    2016-05-01

    Retinal photocoagulation and nondamaging laser therapy are used for treatment of macular disorders, without understanding of the response mechanism and with no rationale for dosimetry. To establish a proper titration algorithm, we measured the range of tissue response and damage threshold. We then evaluated safety and efficacy of nondamaging retinal therapy (NRT) based on this algorithm for chronic central serous chorioretinopathy (CSCR) and macular telangiectasia (MacTel). Retinal response to laser treatment below damage threshold was assessed in pigmented rabbits by expression of the heat shock protein HSP70 and glial fibrillary acidic protein (GFAP). Energy was adjusted relative to visible titration using the Endpoint Management (EpM) algorithm. In clinical studies, 21 eyes with CSCR and 10 eyes with MacTel were treated at 30% EpM energy with high spot density (0.25-diameter spacing). Visual acuity, retinal and choroidal thickness, and subretinal fluid were monitored for 1 year. At 25% EpM energy and higher, HSP70 was expressed acutely in RPE, and GFAP upregulation in Müller cells was observed at 1 month. Damage appeared starting at 40% setting. Subretinal fluid resolved completely in 81% and partially in 19% of the CSCR patients, and visual acuity improved by 12 ± 3 letters. Lacunae in the majority of MacTel patients decreased while preserving the retinal thickness, and vision improved by 10 letters. Heat shock protein expression in response to hyperthermia helps define the therapeutic window for NRT. Lack of tissue damage enables high-density treatment to boost clinical efficacy, therapy in the fovea, and retreatments to manage chronic diseases.

  2. Consumers' expected quality and intention to purchase high quality pork meat.

    Science.gov (United States)

    Papanagiotou, P; Tzimitra-Kalogianni, I; Melfou, K

    2013-03-01

    Expected quality is believed to be one of the most important factors that influence consumers' intention to purchase food. The present study seeks to explore the concept of pork meat expected quality and compare it with self-stated consumer intention to purchase pork meat. The aim is attempted by means of a field research conducted in Greece, following a conjoint analytic procedure. Results show that quality expectations comply with intention to buy pork, in many aspects. However, several differences have been identified. More specifically, country of origin and marbling appear to be more important for respondents' purchase decisions than they are for their quality evaluations, while the opposite appears to be true for price. Finally, socio-demographic factors such as gender, level of education, place of purchase and consumption habits seem to influence perceptions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Safe and High Quality Food Production using Low Quality Waters and Improved Irrigation Systems and Management, EU Project

    DEFF Research Database (Denmark)

    Plauborg, Finn; Jensen, Christian Richardt; Dalsgaard, Anders

    2009-01-01

    : the safety and quality of food products, and the increasing competition for clean freshwater. SAFIR is funded for the period 2005-2009 under the Food Quality and Safety thematic area of the EU 6th Framework Research Programme. The challenge for the next years will be to produce safe and high quality foods...... a multi-disciplinary team, with food safety and quality experts, engineers, agronomists and economists from17 research institutes and private companies in Europe, Israel and China working together. The project assesses potential risks to farmers. Coupled with farm management and economic models, a new...... intelligent tool for efficient and safe use and re-use of low-quality water are being developed. Already published results indicate water saving in the order of 25-30% in agricultural crops as potatoes and tomatoes are possible without yield reduction. Slightly treated waste water can be used safely when...

  4. High-resolution retinal swept source optical coherence tomography with an ultra-wideband Fourier-domain mode-locked laser at MHz A-scan rates.

    Science.gov (United States)

    Kolb, Jan Philip; Pfeiffer, Tom; Eibl, Matthias; Hakert, Hubertus; Huber, Robert

    2018-01-01

    We present a new 1060 nm Fourier domain mode locked laser (FDML laser) with a record 143 nm sweep bandwidth at 2∙ 417 kHz  =  834 kHz and 120 nm at 1.67 MHz, respectively. We show that not only the bandwidth alone, but also the shape of the spectrum is critical for the resulting axial resolution, because of the specific wavelength-dependent absorption of the vitreous. The theoretical limit of our setup lies at 5.9 µm axial resolution. In vivo MHz-OCT imaging of human retina is performed and the image quality is compared to the previous results acquired with 70 nm sweep range, as well as to existing spectral domain OCT data with 2.1 µm axial resolution from literature. We identify benefits of the higher resolution, for example the improved visualization of small blood vessels in the retina besides several others.

  5. Noninvasive, in vivo assessment of mouse retinal structure using optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    M Dominik Fischer

    Full Text Available BACKGROUND: Optical coherence tomography (OCT is a novel method of retinal in vivo imaging. In this study, we assessed the potential of OCT to yield histology-analogue sections in mouse models of retinal degeneration. METHODOLOGY/PRINCIPAL FINDINGS: We achieved to adapt a commercial 3(rd generation OCT system to obtain and quantify high-resolution morphological sections of the mouse retina which so far required in vitro histology. OCT and histology were compared in models with developmental defects, light damage, and inherited retinal degenerations. In conditional knockout mice deficient in retinal retinoblastoma protein Rb, the gradient of Cre expression from center to periphery, leading to a gradual reduction of retinal thickness, was clearly visible and well topographically quantifiable. In Nrl knockout mice, the layer involvement in the formation of rosette-like structures was similarly clear as in histology. OCT examination of focal light damage, well demarcated by the autofluorescence pattern, revealed a practically complete loss of photoreceptors with preservation of inner retinal layers, but also more subtle changes like edema formation. In Crb1 knockout mice (a model for Leber's congenital amaurosis, retinal vessels slipping through the outer nuclear layer towards the retinal pigment epithelium (RPE due to the lack of adhesion in the subapical region of the photoreceptor inner segments could be well identified. CONCLUSIONS/SIGNIFICANCE: We found that with the OCT we were able to detect and analyze a wide range of mouse retinal pathology, and the results compared well to histological sections. In addition, the technique allows to follow individual animals over time, thereby reducing the numbers of study animals needed, and to assess dynamic processes like edema formation. The results clearly indicate that OCT has the potential to revolutionize the future design of respective short- and long-term studies, as well as the preclinical

  6. Impact of injection therapy on retinal patients with diabetic macular edema or retinal vein occlusion.

    Science.gov (United States)

    Sivaprasad, Sobha; Oyetunde, Sesan

    2016-01-01

    An important factor in the choice of therapy is the impact it has on the patient's quality of life. This survey aimed to understand treatment burden, treatment-related anxiety and worry, and practical issues such as appointment attendance and work absence in patients receiving injection therapy for diabetic macular edema (DME) or retinal vein occlusion (RVO). A European sample of 131 retinal patients completed a detailed questionnaire to elucidate the impact of injection therapy on individuals with DME or RVO. RVO and DME greatly impact a patient's quality of life. An intensive injection regimen and the requirements for multiple hospital visits place a large practical burden on the patient. Each intravitreal injection appointment (including travel time) was reported to take an average of 4.5 hours, with a total appointment burden over 6 months of 13.5 hours and 20 hours for RVO and DME patients, respectively. This creates a significant burden on patient time and may make appointment attendance difficult. Indeed, 53% of working patients needed to take at least 1 day off work per appointment and 71% of patients required a carer's assistance at the time of the injection appointment, ~6.3 hours per injection. In addition to practical issues, three-quarters of patients reported experiencing anxiety about their most recent injection treatment, with 54% of patients reporting that they were anxious for at least 2 days prior to the injection. Patients' most desired improvement to their treatment regimen was to have fewer injections and to require fewer appointments, to achieve the same visual results. Patients' quality of life is clearly very affected by having to manage an intensive intravitreal injection regimen, with a considerable treatment burden having a large negative effect. Reducing the appointment burden to achieve the same visual outcomes and the provision of additional support for patients to attend appointments would greatly benefit those receiving intravitreal

  7. Normal central retinal function and structure preserved in retinitis pigmentosa.

    Science.gov (United States)

    Jacobson, Samuel G; Roman, Alejandro J; Aleman, Tomas S; Sumaroka, Alexander; Herrera, Waldo; Windsor, Elizabeth A M; Atkinson, Lori A; Schwartz, Sharon B; Steinberg, Janet D; Cideciyan, Artur V

    2010-02-01

    To determine whether normal function and structure, as recently found in forms of Usher syndrome, also occur in a population of patients with nonsyndromic retinitis pigmentosa (RP). Patients with simplex, multiplex, or autosomal recessive RP (n = 238; ages 9-82 years) were studied with static chromatic perimetry. A subset was evaluated with optical coherence tomography (OCT). Co-localized visual sensitivity and photoreceptor nuclear layer thickness were measured across the central retina to establish the relationship of function and structure. Comparisons were made to patients with Usher syndrome (n = 83, ages 10-69 years). Cross-sectional psychophysical data identified patients with RP who had normal rod- and cone-mediated function in the central retina. There were two other patterns with greater dysfunction, and longitudinal data confirmed that progression can occur from normal rod and cone function to cone-only central islands. The retinal extent of normal laminar architecture by OCT corresponded to the extent of normal visual function in patients with RP. Central retinal preservation of normal function and structure did not show a relationship with age or retained peripheral function. Usher syndrome results were like those in nonsyndromic RP. Regional disease variation is a well-known finding in RP. Unexpected was the observation that patients with presumed recessive RP can have regions with functionally and structurally normal retina. Such patients will require special consideration in future clinical trials of either focal or systemic treatment. Whether there is a common molecular mechanism shared by forms of RP with normal regions of retina warrants further study.

  8. Quality assessment and potential utilization of high amylolytic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... This study was carried out to compare the qualities of two acclaimed Nigerian amylolytic maize cultivars; SPMAT ... growing demand for usage as a gluten-free cereal. (Sweeny ... The grain was malted and the malting loss was calculated using the .... also confirmed that there was no significant difference in.

  9. Quality Alternative Certification Programs in Special Education Ensure High Retention

    Science.gov (United States)

    Karge, Belinda D.; McCabe, Marjorie

    2014-01-01

    Market driven alternative routes to teaching have evolved into a quality program option and not just an answer to the teacher shortage. Alternative certification is a viable means of recruiting, training, and certifying those who have a bachelor's degree and a strong desire to enter the field of teaching. California has been a leader in the…

  10. Innovation in Business Education: Developing a High Quality Online MBA

    Science.gov (United States)

    Roe, C. William; Toma, Alfred G.; Yallapragada, RamMohan R.

    2015-01-01

    Online degree programs were probably pioneered by for-profit universities such as University of Phoenix. Many online degree programs were initially considered low quality academic programs compared to traditional programs. Therefore, many public and private universities were slow to adopt the online programs. However, gradually more and more…

  11. Noninvasive Quantification of Retinal Microglia Using Widefield Autofluorescence Imaging.

    Science.gov (United States)

    Kokona, Despina; Schneider, Nadia; Giannakaki-Zimmermann, Helena; Jovanovic, Joel; Ebneter, Andreas; Zinkernagel, Martin

    2017-04-01

    To validate widefield autofluorescence (AF) in vivo imaging of the retina in mice expressing green fluorescent protein (gfp) in microglia, and to monitor retinal microglia reconstitution in vivo after lethal irradiation and bone marrow transplantation. Transgenic Cx3cr1gfp/gfp and wildtype Balb/c mice were used in this study. A confocal scanning laser ophthalmoscope was used for AF imaging with a 55° and a widefield 102° lens. Intrasession reproducibility was assessed for each lens. To investigate reconstitution in vivo, bone marrow from Cx3cr1gfp/gfp mice was used to rescue lethally irradiated wildtype mice. Data were compared to confocal microscopy of retinal flat mounts. Both the 55° and the 102° lens produced high resolution images of retinal microglia with similar microglia density. However, compared to the 55° lens, the widefield 102° lens captured approximately 3.6 times more microglia cells (1515 ± 123 cells versus 445 ± 76 cells [mean ± SD], for 102° and 55°, respectively, P < 0.001). No statistical difference in the number of gfp positive cells within corresponding areas was observed within the same imaging session. Imaging of microglia reconstitution showed a similar time course compared to flat mount preparations with an excellent correlation between microglia cell numbers in AF and gfp-stained flat mounts (R = 0.92, P < 0.0001). Widefield AF imaging of mice with gfp expressing microglia can be used to quantify retinal microglia. In vivo microglia counts corresponded very well with ex vivo counts on retinal flat mounts. As such, AF imaging can largely replace ex vivo quantification.

  12. Transplanting Retinal Cells using Bucky Paper for Support

    Science.gov (United States)

    Loftus, David J.; Cinke, Martin; Meyyappan, Meyya; Fishman, Harvey; Leng, Ted; Huie, Philip; Bilbao, Kalayaan

    2004-01-01

    A novel treatment for retinal degenerative disorders involving transplantation of cells into the eye is currently under development at NASA Ames Research Center and Stanford University School of Medicine. The technique uses bucky paper as a support material for retinal pigment epithelial (RPE) cells, iris pigment epithelial (IPE) cells, and/or stem cells. This technology is envisioned as a treatment for age-related macular degeneration, which is the leading cause of blindness in persons over age 65 in Western nations. Additionally, patients with other retinal degenerative disorders, such as retinitis pigmentosa, may be treated by this strategy. Bucky paper is a mesh of carbon nanotubes (CNTs), as shown in Figure 1, that can be made from any of the commercial sources of CNTs. Bucky paper is biocompatible and capable of supporting the growth of biological cells. Because bucky paper is highly porous, nutrients, oxygen, carbon dioxide, and waste can readily diffuse through it. The thickness, density, and porosity of bucky paper can be tailored in manufacturing. For transplantation of cells into the retina, bucky paper serves simultaneously as a substrate for cell growth and as a barrier for new blood vessel formation, which can be a problem in the exudative type of macular degeneration. Bucky paper is easily handled during surgical implantation into the eye. Through appropriate choice of manufacturing processes, bucky paper can be made relatively rigid yet able to conform to the retina when the bucky paper is implanted. Bucky paper offers a distinct advantage over other materials that have been investigated for retinal cell transplantation - lens capsule and Descemet's membrane - which are difficult to handle during surgery because they are flimsy and do not stay flat.

  13. Quality of life of people living with HIV/AIDS and on highly active ...

    African Journals Online (AJOL)

    Quality of life of people living with HIV/AIDS and on highly active ... the Short Form-36 Health Survey (SF-36) was used to measure quality of life among patients on ... instrument for use in Ethiopia to assess the quality of life of people living with ...

  14. Does High School Facility Quality Affect Student Achievement? A Two-Level Hierarchical Linear Model

    Science.gov (United States)

    Bowers, Alex J.; Urick, Angela

    2011-01-01

    The purpose of this study is to isolate the independent effects of high school facility quality on student achievement using a large, nationally representative U.S. database of student achievement and school facility quality. Prior research on linking school facility quality to student achievement has been mixed. Studies that relate overall…

  15. Manufacturing High-Quality Carbon Nanotubes at Lower Cost

    Science.gov (United States)

    Benavides, Jeanette M.; Lidecker, Henning

    2004-01-01

    A modified electric-arc welding process has been developed for manufacturing high-quality batches of carbon nanotubes at relatively low cost. Unlike in some other processes for making carbon nanotubes, metal catalysts are not used and, consequently, it is not necessary to perform extensive cleaning and purification. Also, unlike some other processes, this process is carried out at atmospheric pressure under a hood instead of in a closed, pressurized chamber; as a result, the present process can be implemented more easily. Although the present welding-based process includes an electric arc, it differs from a prior electric-arc nanotube-production process. The welding equipment used in this process includes an AC/DC welding power source with an integral helium-gas delivery system and circulating water for cooling an assembly that holds one of the welding electrodes (in this case, the anode). The cathode is a hollow carbon (optionally, graphite) rod having an outside diameter of 2 in. (approximately equal to 5.1 cm) and an inside diameter of 5/8 in. (approximately equal to 1.6 cm). The cathode is partly immersed in a water bath, such that it protrudes about 2 in. (about 5.1 cm) above the surface of the water. The bottom end of the cathode is held underwater by a clamp, to which is connected the grounding cable of the welding power source. The anode is a carbon rod 1/8 in. (approximately equal to 0.3 cm) in diameter. The assembly that holds the anode includes a thumbknob- driven mechanism for controlling the height of the anode. A small hood is placed over the anode to direct a flow of helium downward from the anode to the cathode during the welding process. A bell-shaped exhaust hood collects the helium and other gases from the process. During the process, as the anode is consumed, the height of the anode is adjusted to maintain an anode-to-cathode gap of 1 mm. The arc-welding process is continued until the upper end of the anode has been lowered to a specified height

  16. Retinal vein occlusion: pathophysiology and treatment options

    OpenAIRE

    Karia, Niral

    2010-01-01

    Niral KariaDepartment of Ophthalmology, Southend Hospital, Prittlewell Chase, Westcliff on Sea, Essex, United KingdomAbstract: This paper reviews the current thinking about retinal vein occlusion. It gives an overview of its pathophysiology and discusses the evidence behind the various established and emerging treatment paradigms.Keywords: central, hemispheric, branch, retinal vein occlusion, visual loss

  17. Retinitis pigmentosa, Coats disease and uveitis.

    Science.gov (United States)

    Solomon, A; Banin, E; Anteby, I; Benezra, D

    1999-01-01

    To study the anamnestic immune response to retinal specific antigens of two patients suffering from a rare triad of retinitis pigmentosa, Coats disease and uveitis. 17-year-old girl presented with an acute episode of panuveitis, and her 19-year-old brother suffered from chronic uveitis. On examination, both patients showed retinal vascular changes and subretinal exudations typical of Coats disease, with bone-spicule pigmentary changes as observed in retinitis pigmentosa. All routine examinations were unrevealing. However, the peripheral lymphocytes from these two siblings gave a specific anamnestic response to retinal antigens in vitro. A stimulation index of 4.6 was obtained when the sister's lymphocytes were stimulated with interphotoreceptor binding protein, IRBP--during the acute stage of the uveitis. The brother's lymphocytes showed a stimulation index of 2.7 towards S-Ag during the chronic phase of his uveitic condition. These results indicate that autoimmunity towards retinal antigens may play some role in specific types of retinitis pigmentosa. Whether these autoimmune reactions are a primary pathological mechanism or are secondary to the extensive destruction of the photoreceptor layer resulting from the retinitis pigmentosa remains debatable.

  18. Fundus autofluorescence applications in retinal imaging

    Science.gov (United States)

    Gabai, Andrea; Veritti, Daniele; Lanzetta, Paolo

    2015-01-01

    Fundus autofluorescence (FAF) is a relatively new imaging technique that can be used to study retinal diseases. It provides information on retinal metabolism and health. Several different pathologies can be detected. Peculiar AF alterations can help the clinician to monitor disease progression and to better understand its pathogenesis. In the present article, we review FAF principles and clinical applications. PMID:26139802

  19. Fundus autofluorescence applications in retinal imaging

    Directory of Open Access Journals (Sweden)

    Andrea Gabai

    2015-01-01

    Full Text Available Fundus autofluorescence (FAF is a relatively new imaging technique that can be used to study retinal diseases. It provides information on retinal metabolism and health. Several different pathologies can be detected. Peculiar AF alterations can help the clinician to monitor disease progression and to better understand its pathogenesis. In the present article, we review FAF principles and clinical applications.

  20. Numerical determination of injector design for high beam quality

    International Nuclear Information System (INIS)

    Boyd, J.K.

    1985-01-01

    The performance of a free electron laser strongly depends on the electron beam quality or brightness. The electron beam is transported into the free electron laser after it has been accelerated to the desired energy. Typically the maximum beam brightness produced by an accelerator is constrained by the beam brightness deliverd by the accelerator injector. Thus it is important to design the accelerator injector to yield the required electron beam brightness. The DPC (Darwin Particle Code) computer code has been written to numerically model accelerator injectors. DPC solves for the transport of a beam from emission through acceleration up to the full energy of the injector. The relativistic force equation is solved to determine particle orbits. Field equations are solved for self consistent electric and magnetic fields in the Darwin approximation. DPC has been used to investigate the beam quality consequences of A-K gap, accelerating stress, electrode configuration and axial magnetic field profile

  1. Prevalence of comorbid retinal disease in patients with glaucoma at an academic medical center

    Directory of Open Access Journals (Sweden)

    Griffith JF

    2015-07-01

    retinal disease (1.97% versus 1.02%, P=0.02.Conclusion: The high prevalence of comorbid retinal disease and the nearly twofold increase in blindness and low vision in this population demonstrate the need for ophthalmologists to determine if patients have multiple etiologies for their vision loss. The higher prevalence of certain retinal diseases in POAG patients may reflect common pathophysiological processes that warrant further investigation. Keywords: glaucoma frequency, retina frequency, comorbid retinal disease, glaucoma prevalence, retina prevalence

  2. 'Radiooncology 2007: High quality of life, the ultimate goal'. Abstracts

    International Nuclear Information System (INIS)

    2007-01-01

    The 13th annual congress of Deutsche Gesellschaft fuer Radioonkologie e.V. discussed clinical radiotherapy, medical physics and radiation biology, as well as an extensive programme of working groups on radiology in medical technology, care, and office. The focus was on new equipment (from image-supported to image-guided radiotherapy) and new approaches of targeted tumour therapy. Aspects of life quality are coming to the fore and will get even more important in the future. (orig.)

  3. High image quality sub 100 picosecond gated framing camera development

    International Nuclear Information System (INIS)

    Price, R.H.; Wiedwald, J.D.

    1983-01-01

    A major challenge for laser fusion is the study of the symmetry and hydrodynamic stability of imploding fuel capsules. Framed x-radiographs of 10-100 ps duration, excellent image quality, minimum geometrical distortion (< 1%), dynamic range greater than 1000, and more than 200 x 200 pixels are required for this application. Recent progress on a gated proximity focused intensifier which meets these requirements is presented

  4. The High Flying Leadership Qualities: What Matters the Most

    Science.gov (United States)

    2016-04-01

    operational and functional background of its personnel steeped in both DoD and industry experience. Research Methodology Based on their experiences...DeLorean Motors, Levitz Furniture , Enron, and many other corporations like these learned what happens when key leadership qualities lose all lift...graduate of the Canadian Force Command and Staff College in Toronto, Ontario, Canada; and the U.S. Army War College in Carlisle Barracks

  5. Eye Morphology and Retinal Topography in Hummingbirds (Trochilidae: Aves).

    Science.gov (United States)

    Lisney, Thomas J; Wylie, Douglas R; Kolominsky, Jeffrey; Iwaniuk, Andrew N

    2015-01-01

    Hummingbirds are a group of small, highly specialized birds that display a range of adaptations to their nectarivorous lifestyle. Vision plays a key role in hummingbird feeding and hovering behaviours, yet very little is known about the visual systems of these birds. In this study, we measured eye morphology in 5 hummingbird species. For 2 of these species, we used stereology and retinal whole mounts to study the topographic distribution of neurons in the ganglion cell layer. Eye morphology (expressed as the ratio of corneal diameter to eye transverse diameter) was similar among all 5 species and was within the range previously documented for diurnal birds. Retinal topography was similar in Amazilia tzacatl and Calypte anna. Both species had 2 specialized retinal regions of high neuron density: a central region located slightly dorso-nasal to the superior pole of the pecten, where densities reached ∼ 45,000 cells · mm(-2), and a temporal area with lower densities (38,000-39,000 cells · mm(-2)). A weak visual streak bridged the two high-density areas. A retina from Phaethornis superciliosus also had a central high-density area with a similar peak neuron density. Estimates of spatial resolving power for all 3 species were similar, at approximately 5-6 cycles · degree(-1). Retinal cross sections confirmed that the central high-density region in C. anna contains a fovea, but not the temporal area. We found no evidence of a second, less well-developed fovea located close to the temporal retina margin. The central and temporal areas of high neuron density allow for increased spatial resolution in the lateral and frontal visual fields, respectively. Increased resolution in the frontal field in particular may be important for mediating feeding behaviors such as aerial docking with flowers and catching small insects. © 2015 S. Karger AG, Basel.

  6. [Indications for Retinal Laser Therapy Revisited].

    Science.gov (United States)

    Enders, P; Schaub, F; Fauser, S

    2017-02-10

    Background Laser therapy is an important treatment option in retinal diseases, especially in cases of vascular involvement. Most approaches are based on coagulation of retinal structures. As there is increasing use of agents targetting vascular endothelial growth factor in the treatment of macular diseases, indications for the use of laser treatment need to be reviewed carefully, especially with respect to their significance in first line therapy. This article explains recent strategies and treatment protocols. Materials and Methods Review of current literature in PubMed as well as synopsis of relevant guidelines. Results and Conclusion Retinal laser therapy is still widely used within retinal opthalmology and covers a large spectrum of indications. Despite the success of medical approaches, retinal laser therapy remains an indispensable treatment option for proliferative diabetic retinopathy, central or peripheral vein occlusion and less frequent pathologies, such as retinopathy of prematurity or Coats's disease. Georg Thieme Verlag KG Stuttgart · New York.

  7. Water Quality: A Field-Based Quality Testing Program for Middle Schools and High Schools.

    Science.gov (United States)

    Massachusetts State Water Resources Authority, Boston.

    This manual contains background information, lesson ideas, procedures, data collection and reporting forms, suggestions for interpreting results, and extension activities to complement a water quality field testing program. Information on testing water temperature, water pH, dissolved oxygen content, biochemical oxygen demand, nitrates, total…

  8. Regenerative Therapy for Retinal Disorders

    Directory of Open Access Journals (Sweden)

    Narsis Daftarian

    2010-01-01

    Full Text Available Major advances in various disciplines of basic sciences including embryology, molecular and cell biology, genetics, and nanotechnology, as well as stem cell biology have opened new horizons for regenerative therapy. The unique characteristics of stem cells prompt a sound understanding for their use in modern regenerative therapies. This review article discusses stem cells, developmental stages of the eye field, eye field transcriptional factors, and endogenous and exogenous sources of stem cells. Recent studies and challenges in the application of stem cells for retinal pigment epithelial degeneration models will be summarized followed by obstacles facing regenerative therapy.

  9. Heritability of Retinal Vascular Fractals

    DEFF Research Database (Denmark)

    Vergmann, Anna Stage; Broe, Rebecca; Kessel, Line

    2017-01-01

    , the retinal vascular fractal dimension was measured using the box-counting method and compared within monozygotic and dizygotic twin pairs using Pearson correlation coefficients. Falconer's formula and quantitative genetic models were used to determine the genetic component of variation. Results: The mean...... fractal dimension did not differ statistically significantly between monozygotic and dizygotic twin pairs (1.505 vs. 1.495, P = 0.06), supporting that the study population was suitable for quantitative analysis of heritability. The intrapair correlation was markedly higher (0.505, P = 0...

  10. Retinal peripheral changes after LASIK

    OpenAIRE

    Nassaralla Junior,João Jorge; Santos,Regina Cândido Ribeiro dos; Nassaralla,Belquiz Amaral

    2008-01-01

    PURPOSE: To better define the effect of laser in situ keratomileusis (LASIK) on myopic eyes and the risk and incidence of retinal complications after surgery. METHODS: In a prospective study, 200 eyes of 100 patients, 49 male and 51 female, with a mean age of 29.7 years, had a complete posterior pole examination before and at 1 week, 1, 3 and 12 months after bilateral simultaneous LASIK for the correction of myopia. Mean spherical equivalent was 7.75D (range 1.00 to -17.25D). Before LASIK, pr...

  11. Real-World Solutions for Developing High-Quality PHP Frameworks and Applications

    CERN Document Server

    Bergmann, Sebastian

    2011-01-01

    Learn to develop high-quality applications and frameworks in PHP Packed with in-depth information and step-by-step guidance, this book escorts you through the process of creating, maintaining and extending sustainable software of high quality with PHP. World-renowned PHP experts present real-world case studies for developing high-quality applications and frameworks in PHP that can easily be adapted to changing business requirements. . They offer different approaches to solving  typical development and quality assurance problems that every developer needs to know and master.Details the process

  12. Idea on patent ; It is high time to stress quality

    International Nuclear Information System (INIS)

    2012-03-01

    This book deals with patent stressing on the quality, which includes from idea to technical business, It's simple to register the computer program, why do patent lawyer appoint the patent attorney's office? construction of patent right range, a good patent and a bad patent, strong patent and weak patent. It doesn't allow for Dus to use as we like, each patent has different value, Let's write technical specifications, advice on talking for invention with a patent attorney's office and what kind of task do intellectual property division do?

  13. High-quality PWO crystals for the PANDA-EMC

    International Nuclear Information System (INIS)

    Novotny, R W; Bremer, D; Dormenev, V; Drexler, P; Eissner, T; Kuske, T; Moritz, M

    2011-01-01

    The paper provides a status report on the crystal production and quality control of a major part of the PbWO 4 crystals for the PANDA-EMC. The results confirm the excellent performance of the new generation of PWO-II. The mechanism of stimulated recovery provides an additional tool to recover radiation damage at room and low temperatures by applying an external infrared light source. Even on-line recovery can be considered if the photo sensor is insensitive in that particular wavelength region.

  14. Measurement system with high accuracy for laser beam quality.

    Science.gov (United States)

    Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

    2015-05-20

    Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M2 factor is less than 0.6%.

  15. Rehosting of Bacterial Chaperones for High-Quality Protein Production▿

    Science.gov (United States)

    Martínez-Alonso, Mónica; Toledo-Rubio, Verónica; Noad, Rob; Unzueta, Ugutz; Ferrer-Miralles, Neus; Roy, Polly; Villaverde, Antonio

    2009-01-01

    Coproduction of DnaK/DnaJ in Escherichia coli enhances solubility but promotes proteolytic degradation of their substrates, minimizing the yield of unstable polypeptides. Higher eukaryotes have orthologs of DnaK/DnaJ but lack the linked bacterial proteolytic system. By coexpression of DnaK and DnaJ in insect cells with inherently misfolding-prone recombinant proteins, we demonstrate simultaneous improvement of soluble protein yield and quality and proteolytic stability. Thus, undesired side effects of bacterial folding modulators can be avoided by appropriate rehosting in heterologous cell expression systems. PMID:19820142

  16. Health-Related Quality of Life in Children with High-Functioning Autism

    Science.gov (United States)

    Potvin, Marie-Christine; Snider, Laurie; Prelock, Patricia A.; Wood-Dauphinee, Sharon; Kehayia, Eva

    2015-01-01

    The health-related quality of life of school-aged children with high-functioning autism is poorly understood. The objectives of this study were to compare the health-related quality of life of children with high-functioning autism to that of typically developing peers and to compare child-self and parent-proxy reports of health-related quality of…

  17. Publishing high-quality climate data on the semantic web

    Science.gov (United States)

    Woolf, Andrew; Haller, Armin; Lefort, Laurent; Taylor, Kerry

    2013-04-01

    The effort over more than a decade to establish the semantic web [Berners-Lee et. al., 2001] has received a major boost in recent years through the Open Government movement. Governments around the world are seeking technical solutions to enable more open and transparent access to Public Sector Information (PSI) they hold. Existing technical protocols and data standards tend to be domain specific, and so limit the ability to publish and integrate data across domains (health, environment, statistics, education, etc.). The web provides a domain-neutral platform for information publishing, and has proven itself beyond expectations for publishing and linking human-readable electronic documents. Extending the web pattern to data (often called Web 3.0) offers enormous potential. The semantic web applies the basic web principles to data [Berners-Lee, 2006]: using URIs as identifiers (for data objects and real-world 'things', instead of documents) making the URIs actionable by providing useful information via HTTP using a common exchange standard (serialised RDF for data instead of HTML for documents) establishing typed links between information objects to enable linking and integration Leading examples of 'linked data' for publishing PSI may be found in both the UK (http://data.gov.uk/linked-data) and US (http://www.data.gov/page/semantic-web). The Bureau of Meteorology (BoM) is Australia's national meteorological agency, and has a new mandate to establish a national environmental information infrastructure (under the National Plan for Environmental Information, NPEI [BoM, 2012a]). While the initial approach is based on the existing best practice Spatial Data Infrastructure (SDI) architecture, linked-data is being explored as a technological alternative that shows great promise for the future. We report here the first trial of government linked-data in Australia under data.gov.au. In this initial pilot study, we have taken BoM's new high-quality reference surface

  18. Quality Improvement, Inventory Management, Lead Time Reduction and Production Scheduling in High-Mix Manufacturing Environments

    Science.gov (United States)

    2017-01-13

    Quality Improvement , Inventory Management, Lead Time Reduction and Production Scheduling in High-mix Manufacturing Environments by Sean Daigle B.S...Mechanical Engineering Chairman, Department Committee on Graduate Theses 2 Quality Improvement , Inventory Management, Lead Time Reduction and... Production Scheduling in High-mix Manufacturing Environments by Sean Daigle Submitted to the Department of Mechanical Engineering on January 13, 2017, in

  19. Optimization of nitridation conditions for high quality inter-polysilicon dielectric layers

    NARCIS (Netherlands)

    Klootwijk, J.H.; Bergveld, H.J.; van Kranenburg, H.; Woerlee, P.H.; Wallinga, Hans

    1996-01-01

    Nitridation of deposited high temperature oxides (HTO) was studied to form high quality inter-polysilicon dielectric layers for embedded non volatile memories. Good quality dielectric layers were obtained earlier by using an optimized deposition of polysilicon and by performing a post-dielectric

  20. Bridges to Excellence--recognizing high-quality care: analysis of physician quality and resource use.

    Science.gov (United States)

    Rosenthal, Meredith B; de Brantes, Francois S; Sinaiko, Anna D; Frankel, Matthew; Robbins, Russell D; Young, Sara

    2008-10-01

    To examine whether physicians who sought and received Bridges to Excellence (BTE) recognition performed better than similar physicians on a standardized set of population-based performance measures. Cross-sectional comparison of performance data. Using a claims dataset of all commercially insured members from 6 health plans in Massachusetts, we examined population-based measures of quality and resource use for physicians recognized by the BTE programs Physician Office Link and Diabetes Care Link, compared with nonrecognized physicians in the same specialties. Differences in performance were tested using generalized linear models. Physician Office Link-recognized physicians performed significantly better than their nonrecognized peers on measures of cervical cancer screening, mammography, and glycosylated hemoglobin testing. Diabetes Care Link-recognized physicians performed significantly better on all 4 diabetes process measures of quality, with the largest differences observed in microalbumin screening (17.7%). Patients of Physician Office Link-recognized physicians had a significantly greater percentage of their resource use accounted for by evaluation and management services (3.4%), and a smaller percentage accounted for by facility (-1.6%), inpatient ancillary (-0.1%), and nonmanagement outpatient services (-1.0%). After adjustment for patient age and sex, and case mix, Physician Office Link-recognized physicians had significantly fewer episodes per patient (0.13) and lower resource use per episode (dollars 130), but findings were mixed for Diabetes Care Link-recognized physicians. Our findings suggest that the BTE approach to ascertaining physician quality identifies physicians who perform better on claims-based quality measures and primary care physicians who use a less resource-intensive practice style.

  1. Cell Therapy Applications for Retinal Vascular Diseases: Diabetic Retinopathy and Retinal Vein Occlusion.

    Science.gov (United States)

    Park, Susanna S

    2016-04-01

    Retinal vascular conditions, such as diabetic retinopathy and retinal vein occlusion, remain leading causes of vision loss. No therapy exists to restore vision loss resulting from retinal ischemia and associated retinal degeneration. Tissue regeneration is possible with cell therapy. The goal would be to restore or replace the damaged retinal vasculature and the retinal neurons that are damaged and/or degenerating from the hypoxic insult. Currently, various adult cell therapies have been explored as potential treatment. They include mesenchymal stem cells, vascular precursor cells (i.e., CD34+ cells, hematopoietic cells or endothelial progenitor cells), and adipose stromal cells. Preclinical studies show that all these cells have a paracrine trophic effect on damaged ischemic tissue, leading to tissue preservation. Endothelial progenitor cells and adipose stromal cells integrate into the damaged retinal vascular wall in preclinical models of diabetic retinopathy and ischemia-reperfusion injury. Mesenchymal stem cells do not integrate as readily but appear to have a primary paracrine trophic effect. Early phase clinical trials have been initiated and ongoing using mesenchymal stem cells or autologous bone marrow CD34+ cells injected intravitreally as potential therapy for diabetic retinopathy or retinal vein occlusion. Adipose stromal cells or pluripotent stem cells differentiated into endothelial colony-forming cells have been explored in preclinical studies and show promise as possible therapies for retinal vascular disorders. The relative safety or efficacy of these various cell therapies for treating retinal vascular disorders have yet to be determined.

  2. High-pass filtering of input signals by the Ih current in a non-spiking neuron, the retinal rod bipolar cell.

    Directory of Open Access Journals (Sweden)

    Lorenzo Cangiano

    Full Text Available Hyperpolarization-activated cyclic nucleotide-sensitive (HCN channels mediate the I(f current in heart and I(h throughout the nervous system. In spiking neurons I(h participates primarily in different forms of rhythmic activity. Little is known, however, about its role in neurons operating with graded potentials as in the retina, where all four channel isoforms are expressed. Intriguing evidence for an involvement of I(h in early visual processing are the side effects reported, in dim light or darkness, by cardiac patients treated with HCN inhibitors. Moreover, electroretinographic recordings indicate that these drugs affect temporal processing in the outer retina. Here we analyzed the functional role of HCN channels in rod bipolar cells (RBCs of the mouse. Perforated-patch recordings in the dark-adapted slice found that RBCs exhibit I(h, and that this is sensitive to the specific blocker ZD7288. RBC input impedance, explored by sinusoidal frequency-modulated current stimuli (0.1-30 Hz, displays band-pass behavior in the range of I(h activation. Theoretical modeling and pharmacological blockade demonstrate that high-pass filtering of input signals by I(h, in combination with low-pass filtering by passive properties, fully accounts for this frequency-tuning. Correcting for the depolarization introduced by shunting through the pipette-membrane seal, leads to predict that in darkness I(h is tonically active in RBCs and quickens their responses to dim light stimuli. Immunohistochemistry targeting candidate subunit isoforms HCN1-2, in combination with markers of RBCs (PKC and rod-RBC synaptic contacts (bassoon, mGluR6, Kv1.3, suggests that RBCs express HCN2 on the tip of their dendrites. The functional properties conferred by I(h onto RBCs may contribute to shape the retina's light response and explain the visual side effects of HCN inhibitors.

  3. Academic coordination at university: Strategies for high quality education

    Directory of Open Access Journals (Sweden)

    Maria del Mar Durán Bellonch

    2009-08-01

    Full Text Available Most lecturers and professors involved in teaching School Management and Education Management courses have been engaged in developing some innovative actions to improve the training quality that we offer to students in the Pedagogy degree at the Autonomous University of Barcelona. These actions are aimed at increasing co-ordination among the teaching staff when designing and implementing the course curricula. Co-ordination meetings, exchanges of teaching experiences, discussions about what, how and when to teach the different contents, in which courses and at what level, methodological issues pointed out through technical description cards or the elaboration of study cases to be solved have become the basis of relevant actions during the last academic years. This paper explains each one of them, and provides useful information about the theoretical background, the process carried out, some of the results obtained, the output and the tools created.

  4. Possibilities of obtaining and controlling high-quality pressure castings

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2011-07-01

    Full Text Available The paper presents the influence of the type of furnace charging melting, refining and modification silumins 226 and 231 on the porosity and microstructure of castings. It was shown that in order to reduce or eliminate the porosity of the castings is necessary to the refining ECOSAL-AL113 of liquid silumin both in the melting furnace, and in the ladle and an additional nitrogen, in the heat furnace modified and refining with nitrogen. To control the effects of refining and modifying the TDA method was used. It was found that based on crystal- lization curve can be qualitatively assess the gas porosity of the castings. In order to control and quality control silumins author developed a computer program using the method of TDA, which sets out: Rm, A5, HB and casting porosity P and the concentration of hydrogen in them. The program also informs the technological procedures to be performed for liquid silumin improper preparation.

  5. Chitosan Feasibility to Retain Retinal Stem Cell Phenotype and Slow Proliferation for Retinal Transplantation

    Directory of Open Access Journals (Sweden)

    Girish K. Srivastava

    2014-01-01

    Full Text Available Retinal stem cells (RSCs are promising in cell replacement strategies for retinal diseases. RSCs can migrate, differentiate, and integrate into retina. However, RSCs transplantation needs an adequate support; chitosan membrane (ChM could be one, which can carry RSCs with high feasibility to support their integration into retina. RSCs were isolated, evaluated for phenotype, and subsequently grown on sterilized ChM and polystyrene surface for 8 hours, 1, 4, and 11 days for analysing cell adhesion, proliferation, viability, and phenotype. Isolated RSCs expressed GFAP, PKC, isolectin, recoverin, RPE65, PAX-6, cytokeratin 8/18, and nestin proteins. They adhered (28 ± 16%, 8 hours and proliferated (40 ± 20 cells/field, day 1 and 244 ± 100 cells/field, day 4 significantly low (P95% and phenotype (cytokeratin 8/18, PAX6, and nestin proteins expression, day 11 on both surfaces (ChM and polystyrene. RSCs did not express alpha-SMA protein on both surfaces. RSCs express proteins belonging to epithelial, glial, and neural cells, confirming that they need further stimulus to reach a final destination of differentiation that could be provided in in vivo condition. ChM does not alternate RSCs behaviour and therefore can be used as a cell carrier so that slow proliferating RSCs can migrate and integrate into retina.

  6. prediction of bread-making quality using size exclusion high

    African Journals Online (AJOL)

    ACSS

    Variation in the distribution of protein molecular weight in wheat (Triticum aestivum), influences ... with high G/G ratios in SDS-insoluble protein fraction were Sceptre x Nata and Kariega x Sceptre. ...... Molecular characterisation and dynamic.

  7. High-quality single crystals for neutron experiments

    Indian Academy of Sciences (India)

    studies and our collaborative research projects with other UK and international groups will be discussed. Keywords. Crystal growth; floating zone method; neutron scattering. ... of single crystals of new materials is a highly competitive business.

  8. A Coding Variant in the Gene Bardet-Biedl Syndrome 4 (BBS4 Is Associated with a Novel Form of Canine Progressive Retinal Atrophy

    Directory of Open Access Journals (Sweden)

    Tracy Chew

    2017-07-01

    Full Text Available Progressive retinal atrophy is a common cause of blindness in the dog and affects >100 breeds. It is characterized by gradual vision loss that occurs due to the degeneration of photoreceptor cells in the retina. Similar to the human counterpart retinitis pigmentosa, the canine disorder is clinically and genetically heterogeneous and the underlying cause remains unknown for many cases. We use a positional candidate gene approach to identify putative variants in the Hungarian Puli breed using genotyping data of 14 family-based samples (CanineHD BeadChip array, Illumina and whole-genome sequencing data of two proband and two parental samples (Illumina HiSeq 2000. A single nonsense SNP in exon 2 of BBS4 (c.58A > T, p.Lys20* was identified following filtering of high quality variants. This allele is highly associated (PCHISQ = 3.425e−14, n = 103 and segregates perfectly with progressive retinal atrophy in the Hungarian Puli. In humans, BBS4 is known to cause Bardet–Biedl syndrome which includes a retinitis pigmentosa phenotype. From the observed coding change we expect that no functional BBS4 can be produced in the affected dogs. We identified canine phenotypes comparable with Bbs4-null mice including obesity and spermatozoa flagella defects. Knockout mice fail to form spermatozoa flagella. In the affected Hungarian Puli spermatozoa flagella are present, however a large proportion of sperm are morphologically abnormal and <5% are motile. This suggests that BBS4 contributes to flagella motility but not formation in the dog. Our results suggest a promising opportunity for studying Bardet–Biedl syndrome in a large animal model.

  9. Retinitis pigmentosa, pigmentary retinopathies, and neurologic diseases.

    Science.gov (United States)

    Bhatti, M Tariq

    2006-09-01

    Retinitis pigmentosa (RP) refers to a group of inherited retinal diseases with phenotypic and genetic heterogeneity. The pathophysiologic basis of the progressive visual loss in patients with RP is not completely understood but is felt to be due to a primary retinal photoreceptor cell degenerative process mainly affecting the rods of the peripheral retina. In most cases RP is seen in isolation (nonsyndromic), but in some other cases it may be a part of a genetic, metabolic, or neurologic syndrome or disorder. Nyctalopia, or night blindness, is the most common symptom of RP. The classic fundus appearance of RP includes retinal pigment epithelial cell changes resulting in retinal hypo- or hyperpigmentation ("salt-and-pepper"), retinal granularity, and bone spicule formation. The retinal vessels are often narrowed or attenuated and there is a waxy pallor appearance of the optic nerve head. Electroretinography will demonstrate rod and cone photoreceptor cell dysfunction and is a helpful test in the diagnosis and monitoring of patients with RP. A detailed history with pedigree analysis, a complete ocular examination, and the appropriate paraclinical testing should be performed in patients complaining of visual difficulties at night or in dim light. This review discusses the clinical manifestations of RP as well as describing the various systemic diseases, with a special emphasis on neurologic diseases, associated with a pigmentary retinopathy.

  10. Optical Coherence Tomography Angiography in Retinal Diseases.

    Science.gov (United States)

    Chalam, K V; Sambhav, Kumar

    2016-01-01

    Optical coherence tomography angiography (OCTA) is a new, non-invasive imaging system that generates volumetric data of retinal and choroidal layers. It has the ability to show both structural and blood flow information. Split-spectrum amplitude-decorrelation angiography (SSADA) algorithm (a vital component of OCTA software) helps to decrease the signal to noise ratio of flow detection thus enhancing visualization of retinal vasculature using motion contrast. Published studies describe potential efficacy for OCTA in the evaluation of common ophthalmologic diseases such as diabetic retinopathy, age related macular degeneration (AMD), retinal vascular occlusions and sickle cell disease. OCTA provides a detailed view of the retinal vasculature, which allows accurate delineation of microvascular abnormalities in diabetic eyes and vascular occlusions. It helps quantify vascular compromise depending upon the severity of diabetic retinopathy. OCTA can also elucidate the presence of choroidal neovascularization (CNV) in wet AMD. In this paper, we review the knowledge, available in English language publications regarding OCTA, and compare it with the conventional angiographic standard, fluorescein angiography (FA). Finally, we summarize its potential applications to retinal vascular diseases. Its current limitations include a relatively small field of view, inability to show leakage, and tendency for image artifacts. Further larger studies will define OCTA's utility in clinical settings and establish if the technology may offer a non-invasive option of visualizing the retinal vasculature, enabling us to decrease morbidity through early detection and intervention in retinal diseases.

  11. Silver nano - a trove for retinal therapies.

    Science.gov (United States)

    Kalishwaralal, Kalimuthu; Barathmanikanth, Selvaraj; Pandian, Sureshbabu Ram Kumar; Deepak, Venkatraman; Gurunathan, Sangiliyandi

    2010-07-14

    Pathological retinal angiogenesis (neovascularization) is one of the most feared complications among retinal diseases, leading to visual impairment and irreversible blindness. Recent findings made by us on therapeutic applications of biologically synthesized silver nanoparticles (AgNPs) against VEGF induced retinal endothelial cells, elucidates the effectual inhibitory activities of AgNPs over the downstream signaling pathways (Src and AKT/PI3K) leading to retinal angiogenesis. The current review focuses on the imperative role of VEGF induced angiogenesis in the development of retinal neovascularization and despite the fact that several VEGF targeting ocular drugs are available; the review examines the need for a cost economic alternative, thereby suggesting the role of AgNPs as an emerging economic ocular drug for retinal therapies. The current technologies available for the development of targeted and controlled release of drugs is being discussed and a model has been proposed for the amenable targeting mechanism, by which Poly gamma glutamic acid (PGA) capsulated AgNPs conjugated to cyclic RGD peptides carry out a sustained controlled release specifically targeting the neovascularization cells and induce apoptosis unaffecting the normal retinal cells. These constructs consequently affirm the futuristic application of silver nanoparticles as a boon to ocular therapies. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  12. Quality

    International Nuclear Information System (INIS)

    Burnett, N.; Jeffries, J.; Mach, J.; Robson, M.; Pajot, D.; Harrigan, J.; Lebsack, T.; Mullen, D.; Rat, F.; Theys, P.

    1993-01-01

    What is quality? How do you achieve it? How do you keep it once you have got it. The answer for industry at large is the three-step hierarchy of quality control, quality assurance and Total quality Management. An overview is given of the history of quality movement, illustrated with examples from Schlumberger operations, as well as the oil industry's approach to quality. An introduction of the Schlumberger's quality-associated ClientLink program is presented. 15 figs., 4 ills., 16 refs

  13. Functional annotation of the human retinal pigment epithelium transcriptome

    Directory of Open Access Journals (Sweden)

    Gorgels Theo GMF

    2009-04-01

    Full Text Available Abstract Background To determine level, variability and functional annotation of gene expression of the human retinal pigment epithelium (RPE, the key tissue involved in retinal diseases like age-related macular degeneration and retinitis pigmentosa. Macular RPE cells from six selected healthy human donor eyes (aged 63–78 years were laser dissected and used for 22k microarray studies (Agilent technologies. Data were analyzed with Rosetta Resolver, the web tool DAVID and Ingenuity software. Results In total, we identified 19,746 array entries with significant expression in the RPE. Gene expression was analyzed according to expression levels, interindividual variability and functionality. A group of highly (n = 2,194 expressed RPE genes showed an overrepresentation of genes of the oxidative phosphorylation, ATP synthesis and ribosome pathways. In the group of moderately expressed genes (n = 8,776 genes of the phosphatidylinositol signaling system and aminosugars metabolism were overrepresented. As expected, the top 10 percent (n = 2,194 of genes with the highest interindividual differences in expression showed functional overrepresentation of the complement cascade, essential in inflammation in age-related macular degeneration, and other signaling pathways. Surprisingly, this same category also includes the genes involved in Bruch's membrane (BM composition. Among the top 10 percent of genes with low interindividual differences, there was an overrepresentation of genes involved in local glycosaminoglycan turnover. Conclusion Our study expands current knowledge of the RPE transcriptome by assigning new genes, and adding data about expression level and interindividual variation. Functional annotation suggests that the RPE has high levels of protein synthesis, strong energy demands, and is exposed to high levels of oxidative stress and a variable degree of inflammation. Our data sheds new light on the molecular composition of BM, adjacent to the

  14. Paediatric retinal detachment: aetiology, characteristics and outcomes

    Directory of Open Access Journals (Sweden)

    Elizabeth McElnea

    2018-02-01

    Full Text Available AIM: To provide contemporary data on the aetiology, clinical features and outcomes of paediatric retinal detachment. METHODS: A retrospective review of all those under 16y who underwent surgical repair for retinal detachment at a single centre between the years 2008 and 2015 inclusive was performed. In each case the cause of retinal detachment, the type of detachment, the presence or absence of macular involvement, the number and form of reparative surgeries undertaken, and the surgical outcome achieved was recorded. RESULTS: Twenty-eight eyes of 24 patients, 15 (62.5% of whom were male and 9 (37.5% of whom were female, their mean age being 11.6y and range 2-16y developed retinal detachment over the eight year period studied. Trauma featured in the development of retinal detachment in 14 (50.0% cases. Retinal detachment was associated with other ocular and/or systemic conditions in 11 (39.3% cases. A mean of 3.0 procedures with a range of 1-9 procedures per patient were undertaken in the management of retinal detachment. Complex vitrectomy combined with scleral buckling or complex vitrectomy alone were those most frequently performed. Mean postoperative visual acuity was 1.2 logMAR with range 0.0-3.0 logMAR. In 22 of 26 (84.6% cases which underwent surgical repair the retina was attached at last follow-up. CONCLUSION: Aggressive management of paediatric retinal detachment including re-operation increases the likelihood of anatomical success. In cases where the retinal detachment can be repaired by an external approach alone there is a more favourable visual outcome.

  15. Paediatric retinal detachment: aetiology, characteristics and outcomes.

    Science.gov (United States)

    McElnea, Elizabeth; Stephenson, Kirk; Gilmore, Sarah; O'Keefe, Michael; Keegan, David

    2018-01-01

    To provide contemporary data on the aetiology, clinical features and outcomes of paediatric retinal detachment. A retrospective review of all those under 16y who underwent surgical repair for retinal detachment at a single centre between the years 2008 and 2015 inclusive was performed. In each case the cause of retinal detachment, the type of detachment, the presence or absence of macular involvement, the number and form of reparative surgeries undertaken, and the surgical outcome achieved was recorded. Twenty-eight eyes of 24 patients, 15 (62.5%) of whom were male and 9 (37.5%) of whom were female, their mean age being 11.6y and range 2-16y developed retinal detachment over the eight year period studied. Trauma featured in the development of retinal detachment in 14 (50.0%) cases. Retinal detachment was associated with other ocular and/or systemic conditions in 11 (39.3%) cases. A mean of 3.0 procedures with a range of 1-9 procedures per patient were undertaken in the management of retinal detachment. Complex vitrectomy combined with scleral buckling or complex vitrectomy alone were those most frequently performed. Mean postoperative visual acuity was 1.2 logMAR with range 0.0-3.0 logMAR. In 22 of 26 (84.6%) cases which underwent surgical repair the retina was attached at last follow-up. Aggressive management of paediatric retinal detachment including re-operation increases the likelihood of anatomical success. In cases where the retinal detachment can be repaired by an external approach alone there is a more favourable visual outcome.

  16. A clinical approach to the diagnosis of retinal vasculitis.

    Science.gov (United States)

    El-Asrar, Ahmed M Abu; Herbort, Carl P; Tabbara, Khalid F

    2010-04-01

    Retinal vasculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and is confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein angiographic findings.

  17. An Unusual Case of Extensive Lattice Degeneration and Retinal Detachment

    OpenAIRE

    Mathew, David J.; Sarma, Saurabh Kumar; Basaiawmoit, Jennifer V.

    2016-01-01

    Lattice degeneration of the retina is not infrequently encountered on a dilated retinal examination and many of them do not need any intervention. We report a case of atypical lattice degeneration variant with peripheral retinal detachment. An asymptomatic 35-year-old lady with minimal refractive error was found to have extensive lattice degeneration, peripheral retinal detachment and fibrotic changes peripherally with elevation of retinal vessels on dilated retinal examination. There were al...

  18. Prophylactic treatment of the fellow eye of patients with retinal detachment: a retrospective study.

    Science.gov (United States)

    Avitabile, Teresio; Bonfiglio, Vincenza; Reibaldi, Michele; Torrisi, Benedetto; Reibaldi, Alfredo

    2004-03-01

    Controversy exists over the prophylactic treatment of predisposing lesions to prevent retinal detachment. Seven hundred sixty consecutive phakic fellow eyes with rhegmatogenous retinal detachment in the first eye were examined by the same vitreoretinal surgeon before detachment surgery and for a follow-up period ranging from 1 to 72 months, with a mean of 36 months. During this period, in 305 fellow eyes (40.1%) predisposing retinal lesions were present and prophylactic treatments (photocoagulation, cryotherapy or scleral buckle) were performed independently of vitreous status. The results were then compared with the incidence of bilateral RD without prophylaxis reported in Folk and Burton's study of 1982; the two study's data were well matched and showed no significant difference in regards to age, sex, incidence myopia > or =-2.5 and incidence of lattice degeneration. The objective was to investigate whether or not prophylactic treatment is able to avert retinal detachment in the fellow eye. The age of the patients with peripheral retinal lesions was correlated inversely with the presence of myopia. Nine eyes out of 305 eyes treated (2.9%) developed a retinal detachment, reducing the rate of bilateral retinal detachment to 1.2% (9 eyes out of 760). This incidence of bilaterality (1.2%) was lower than the incidence of retinal detachment in fellow eyes not prophylactically treated as reported in the literature, and there exists a highly statistically significant difference between this study's data of 1.2% after prophylaxis and a 13.4% rate of bilaterality as reported by Folk without prophylaxis (P=0.0000).

  19. High quality actively cooled plasma-facing components for fusion

    International Nuclear Information System (INIS)

    Nygren, R.E.

    1995-01-01

    This paper interweaves some suggestions for developing actively cooled plasma-facing components (PFCs) for future fusion devices, with supporting examples taken from the design, fabrication and operation of Tore Supra's Phase III outboard pump limiter (OPL). This actively cooled midplane limiter, designed for heat and particle removal during long-pulse operation, has been operated under essentially thermally steady state conditions. Testing to identify braze flaws, analysis of the impact of joining flaws on the thermal-hydraulic performance of the OPL, and the extensive calorimetry and IR thermography used to confirm and update safe operating limits for power handling of the OPL are reviewed. This experience suggests that, for PFCs in future fusion devices, flaw-tolerant designs are possible; analyses of the impacts of flaws on performance can provide criteria for quality assurance; and validating appropriate methods of inspection for such flaws early in the design development of PFCs is prudent. The need for in-service monitoring is also discussed. (orig.)

  20. Health care in small prisons: incorporating high-quality standards.

    Science.gov (United States)

    Rieder, Jean-Pierre; Casillas, Alejandra; Mary, Gérard; Secretan, Anne-Dominique; Gaspoz, Jean-Michel; Wolff, Hans

    2013-01-01

    In the past, health management in Geneva's six post-trial prisons had been variable and inconsistent. In 2008, the unit of penitentiary medicine of the Geneva University Hospitals was mandated to re-organize and provide health care at all six prison facilities. The specific aim of this paper is to outline the example as a practical solution to some of the common challenges in unifying the structure and process of health services across multiple small facilities, while meeting European prison health and local quality standards. Geneva's post-trial prisons are small and close to one another in geographical proximity - ideal conditions for the construction of a health mobile team (HMT). This multidisciplinary mobile team operated like a community ambulatory care model; it was progressively launched in all prison facilities in Geneva. The authors incorporated an implementation strategy where health providers partnered with prison and community stakeholders in the health delivery model's development and adaption process. The model's strategic initiatives are described along the following areas, in light of other international prison health activity and prior care models: access to a health care professional, equivalence of care, patient consent, confidentiality, humanitarian interventions, and professional competence and independence. From the perspective of the HMT members, the authors provide the "lessons learned" through this experience, especially to providers who are working on prison health services reform and coordination improvement. The paper particularly stresses the importance of partnering with community health stakeholders and prison staff, a key component to the approach.

  1. Neuroprotective Effects of Citicoline in in Vitro Models of Retinal Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Andrea Matteucci

    2014-04-01

    Full Text Available In recent years, citicoline has been the object of remarkable interest as a possible neuroprotectant. The aim of this study was to investigate if citicoline affected cell survival in primary retinal cultures and if it exerted neuroprotective activity in conditions modeling retinal neurodegeneration. Primary retinal cultures, obtained from rat embryos, were first treated with increasing concentrations of citicoline (up to 1000 µM and analyzed in terms of apoptosis and caspase activation and characterized by immunocytochemistry to identify neuronal and glial cells. Subsequently, excitotoxic concentration of glutamate or High Glucose-containing cell culture medium (HG was administered as well-known conditions modeling neurodegeneration. Glutamate or HG treatments were performed in the presence or not of citicoline. Neuronal degeneration was evaluated in terms of apoptosis and loss of synapses. The results showed that citicoline did not cause any damage to the retinal neuroglial population up to 1000 µM. At the concentration of 100 µM, it was able to counteract neuronal cell damage both in glutamate- and HG-treated retinal cultures by decreasing proapoptotic effects and contrasting synapse loss. These data confirm that citicoline can efficiently exert a neuroprotective activity. In addition, the results suggest that primary retinal cultures, under conditions inducing neurodegeneration, may represent a useful system to investigate citicoline neuroprotective mechanisms.

  2. Enface Thickness Mapping and Reflectance Imaging of Retinal Layers in Diabetic Retinopathy.

    Science.gov (United States)

    Francis, Andrew W; Wanek, Justin; Lim, Jennifer I; Shahidi, Mahnaz

    2015-01-01

    To present a method for image segmentation and generation of enface thickness maps and reflectance images of retinal layers in healthy and diabetic retinopathy (DR) subjects. High density spectral domain optical coherence tomography (SDOCT) images were acquired in 10 healthy and 4 DR subjects. Customized image analysis software identified 5 retinal cell layer interfaces and generated thickness maps and reflectance images of the total retina (TR), inner retina (IR), outer retina (OR), and the inner segment ellipsoid (ISe) band. Thickness maps in DR subjects were compared to those of healthy subjects by generating deviation maps which displayed retinal locations with thickness below, within, and above the normal 95% confidence interval. In healthy subjects, TR and IR thickness maps displayed the foveal depression and increased thickness in the parafoveal region. OR and ISe thickness maps showed increased thickness at the fovea, consistent with normal retinal anatomy. In DR subjects, thickening and thinning in localized regions were demonstrated on TR, IR, OR, and ISe thickness maps, corresponding to retinal edema and atrophy, respectively. TR and OR reflectance images showed reduced reflectivity in regions of increased thickness. Hard exudates appeared as hyper-reflective spots in IR reflectance images and casted shadows on the deeper OR and ISe reflectance images. The ISe reflectance image clearly showed the presence of focal laser scars. Enface thickness mapping and reflectance imaging of retinal layers is a potentially useful method for quantifying the spatial and axial extent of pathologies due to DR.

  3. An automated retinal imaging method for the early diagnosis of diabetic retinopathy.

    Science.gov (United States)

    Franklin, S Wilfred; Rajan, S Edward

    2013-01-01

    Diabetic retinopathy is a microvascular complication of long-term diabetes and is the major cause for eyesight loss due to changes in blood vessels of the retina. Major vision loss due to diabetic retinopathy is highly preventable with regular screening and timely intervention at the earlier stages. Retinal blood vessel segmentation methods help to identify the successive stages of such sight threatening diseases like diabetes. To develop and test a novel retinal imaging method which segments the blood vessels automatically from retinal images, which helps the ophthalmologists in the diagnosis and follow-up of diabetic retinopathy. This method segments each image pixel as vessel or nonvessel, which in turn, used for automatic recognition of the vasculature in retinal images. Retinal blood vessels were identified by means of a multilayer perceptron neural network, for which the inputs were derived from the Gabor and moment invariants-based features. Back propagation algorithm, which provides an efficient technique to change the weights in a feed forward network, is utilized in our method. Quantitative results of sensitivity, specificity and predictive values were obtained in our method and the measured accuracy of our segmentation algorithm was 95.3%, which is better than that presented by state-of-the-art approaches. The evaluation procedure used and the demonstrated effectiveness of our automated retinal imaging method proves itself as the most powerful tool to diagnose diabetic retinopathy in the earlier stages.

  4. Laser speckle imaging of rat retinal blood flow with hybrid temporal and spatial analysis method

    Science.gov (United States)

    Cheng, Haiying; Yan, Yumei; Duong, Timothy Q.

    2009-02-01

    Noninvasive monitoring of blood flow in retinal circulation will reveal the progression and treatment of ocular disorders, such as diabetic retinopathy, age-related macular degeneration and glaucoma. A non-invasive and direct BF measurement technique with high spatial-temporal resolution is needed for retinal imaging. Laser speckle imaging (LSI) is such a method. Currently, there are two analysis methods for LSI: spatial statistics LSI (SS-LSI) and temporal statistical LSI (TS-LSI). Comparing these two analysis methods, SS-LSI has higher signal to noise ratio (SNR) and TSLSI is less susceptible to artifacts from stationary speckle. We proposed a hybrid temporal and spatial analysis method (HTS-LSI) to measure the retinal blood flow. Gas challenge experiment was performed and images were analyzed by HTS-LSI. Results showed that HTS-LSI can not only remove the stationary speckle but also increase the SNR. Under 100% O2, retinal BF decreased by 20-30%. This was consistent with the results observed with laser Doppler technique. As retinal blood flow is a critical physiological parameter and its perturbation has been implicated in the early stages of many retinal diseases, HTS-LSI will be an efficient method in early detection of retina diseases.

  5. Smart image processing system for retinal prosthesis.

    Science.gov (United States)

    Weiland, James D; Parikh, Neha; Pradeep, Vivek; Medioni, Gerard

    2012-01-01

    Retinal prostheses for the blind have demonstrated the ability to provide the sensation of light in otherwise blind individuals. However, visual task performance in these patients remains poor relative to someone with normal vision. Computer vision algorithms for navigation and object detection were evaluated for their ability to improve task performance. Blind subjects navigating a mobility course had fewer collisions when using a wearable camera system that guided them on a safe path. Subjects using a retinal prosthesis simulator could locate objects more quickly when an object detection algorithm assisted them. Computer vision algorithms can assist retinal prosthesis patients and low-vision patients in general.

  6. Photostress Testing Device for Diagnosing Retinal Disease

    Directory of Open Access Journals (Sweden)

    Elizabeth Swan

    2014-08-01

    Full Text Available Retinal diseases such as Age-Related Macular Degeneration (ARMD affect nearly one in three elderly patients. ARMD damages the central vision photoreceptors in the fovea. The Photostress Test is a simple technique for testing for the early effects of ARMD. Here, the illumination sources in a novel self-administered Photostress Testing device were modeled for safety and distribution in illumination software. After satisfying the design constraints in the model, a prototype of the illumination system was fabricated and tested to confirm the modeling results. The resultant prototype can be used to aid in the diagnosis of retinal disease and is well within retinal safety levels.

  7. A high-quality catalog of the Drosophila melanogaster proteome

    DEFF Research Database (Denmark)

    Brunner, Erich; Ahrens, Christian H.; Mohanty, Sonaly

    2007-01-01

    % of the predicted Drosophila melanogaster proteome by detecting 9,124 proteins from 498,000 redundant and 72,281 distinct peptide identifications. This unprecedented high proteome coverage for a complex eukaryote was achieved by combining sample diversity, multidimensional biochemical fractionation and analysis...

  8. Bust economics: foragers choose high quality habitats in lean times

    Directory of Open Access Journals (Sweden)

    Sonny S. Bleicher

    2016-01-01

    Full Text Available In environments where food resources are spatially variable and temporarily impoverished, consumers that encounter habitat patches with different food density should focus their foraging initially where food density is highest before they move to patches where food density is lower. Increasing missed opportunity costs should drive individuals progressively to patches with lower food density as resources in the initially high food density patches deplete. To test these expectations, we assessed the foraging decisions of two species of dasyurid marsupials (dunnarts: Sminthopsis hirtipes and S. youngsoni during a deep drought, or bust period, in the Simpson Desert of central Australia. Dunnarts were allowed access to three patches containing different food densities using an interview chamber experiment. Both species exhibited clear preference for the high density over the lower food density patches as measured in total harvested resources. Similarly, when measuring the proportion of resources harvested within the patches, we observed a marginal preference for patches with initially high densities. Models analyzing behavioral choices at the population level found no differences in behavior between the two species, but models analyzing choices at the individual level uncovered some variation. We conclude that dunnarts can distinguish between habitat patches with different densities of food and preferentially exploit the most valuable. As our observations were made during bust conditions, experiments should be repeated during boom times to assess the foraging economics of dunnarts when environmental resources are high.

  9. Whole high-quality light environment for humans and plants

    Science.gov (United States)

    Sharakshane, Anton

    2017-11-01

    Plants sharing a single light environment on a spaceship with a human being and bearing a decorative function should look as natural and attractive as possible. And consequently they can be illuminated only with white light with a high color rendering index. Can lighting optimized for a human eye be effective and appropriate for plants? Spectrum-based effects have been compared under artificial lighting of plants by high-pressure sodium lamps and general-purpose white LEDs. It has been shown that for the survey sample phytochrome photo-equilibria does not depend significantly on the parameters of white LED light, while the share of phytoactive blue light grows significantly as the color temperature increases. It has been revealed that yield photon flux is proportional to luminous efficacy and increases as the color temperature decreases, general color rendering index Ra and the special color rendering index R14 (green leaf) increase. General-purpose white LED lamps with a color temperature of 2700 K, Ra > 90 and luminous efficacy of 100 lm/W are as efficient as the best high-pressure sodium lamps, and at a higher luminous efficacy their yield photon flux per joule is even bigger in proportion. Here we show that demand for high color rendering white LED light is not contradictory to the agro-technical objectives.

  10. The influence of knowledge management implementation toward the quality of high schools

    Directory of Open Access Journals (Sweden)

    Hilda Ainissyifa

    2012-09-01

    Full Text Available The purpose of this study is to analyze the influence of knowledge management implementation toward the quality of high schools. This study was conducted among five high schools under an education foundation. The analysis models used in the study were correlation analysis and t-test. The respondents were used as the profession references are 86 teachers. The result of the study shows that knowledge management implementation has a positive and significant influence toward the quality of high schools.

  11. Comparison of the effectiveness of three retinal camera technologies for malarial retinopathy detection in Malawi

    Science.gov (United States)

    Soliz, Peter; Nemeth, Sheila C.; Barriga, E. Simon; Harding, Simon P.; Lewallen, Susan; Taylor, Terrie E.; MacCormick, Ian J.; Joshi, Vinayak S.

    2016-03-01

    The purpose of this study was to test the suitability of three available camera technologies (desktop, portable, and iphone based) for imaging comatose children who presented with clinical symptoms of malaria. Ultimately, the results of the project would form the basis for a design of a future camera to screen for malaria retinopathy (MR) in a resource challenged environment. The desktop, portable, and i-phone based cameras were represented by the Topcon, Pictor Plus, and Peek cameras, respectively. These cameras were tested on N=23 children presenting with symptoms of cerebral malaria (CM) at a malaria clinic, Queen Elizabeth Teaching Hospital in Malawi, Africa. Each patient was dilated for binocular indirect ophthalmoscopy (BIO) exam by an ophthalmologist followed by imaging with all three cameras. Each of the cases was graded according to an internationally established protocol and compared to the BIO as the clinical ground truth. The reader used three principal retinal lesions as markers for MR: hemorrhages, retinal whitening, and vessel discoloration. The study found that the mid-priced Pictor Plus hand-held camera performed considerably better than the lower price mobile phone-based camera, and slightly the higher priced table top camera. When comparing the readings of digital images against the clinical reference standard (BIO), the Pictor Plus camera had sensitivity and specificity for MR of 100% and 87%, respectively. This compares to a sensitivity and specificity of 87% and 75% for the i-phone based camera and 100% and 75% for the desktop camera. The drawback of all the cameras were their limited field of view which did not allow complete view of the periphery where vessel discoloration occurs most frequently. The consequence was that vessel discoloration was not addressed in this study. None of the cameras offered real-time image quality assessment to ensure high quality images to afford the best possible opportunity for reading by a remotely located

  12. Achieving high-quality care: a view from NICE.

    Science.gov (United States)

    Leng, Gillian; Partridge, Gemma

    2018-01-01

    The National Institute for Health and Care Excellence (NICE) was established in 1999 to provide evidence-based guidance. The task of producing guidance by reviewing primary research data and using an advisory committee to develop evidence-based recommendations, is not straightforward. Guidance production is, however, less challenging than the task of putting evidence-based recommendations into practice.NICE is very sensitive to this challenge as, since 1999, over 1500 pieces of NICE guidance have been published. A number of pieces of guidance relate to heart disease, including pharmaceutical agents, new medical technologies and clinical guidelines. Examples include guidelines on acute heart failure and atrial fibrillation, and advice on technologies including edoxaban and implantable cardioverter defibrillators.The research evidence is clear that a change in practice rarely comes about as a result of simply disseminating guidance on best practice. Simple dissemination is particularly ineffective if the guidance has not been produced by a well-respected, credible organisation. It is also clear from the literature that implementation is more successful when more than one approach is taken, and when there is alignment between efforts at organisational, local and national levels.At an organisational level, there should be support from the Board for quality improvement, with ongoing measurement of progress. Resources should be provided for targeted change programmes, particularly where new guidance suggests improvements are required. A systematic process for putting change in place should include identifying barriers to change, agreeing interventions to overcome the barriers and drive forward improvement and planning for implementation and evaluation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Modern High Technology Solutions for Quality and Longterm Vegetable Preservation

    International Nuclear Information System (INIS)

    Nacheva, I.; Miteva, D.; Todorov, Y.; Loginovska, K.; Tsvetkov, Ts.

    2012-01-01

    In the publication the authors present the results of the applying of two modern technologies for long term and safe vegetable preservation – freeze-drying and gamma sterilization. The freeze-dried vegetables feature minimum moisture – from 2 – 5% and taste-aroma complex preserved to the highest degree. The carried out gamma sterilization ensures a high microbial purity of the vegetables and guarantees for their long term preservation - up to 5 years in polymer packing, under usual conditions

  14. High quality factor gigahertz frequencies in nanomechanical diamond resonators

    OpenAIRE

    Gaidarzhy, Alexei; Imboden, Matthias; Mohanty, Pritiraj; Rankin, Janet; Sheldon, Brian W.

    2007-01-01

    We report actuation and detection of gigahertz-range resonance frequencies in nano-crystalline diamond mechanical resonators. High order transverse vibration modes are measured in coupled-beam resonators exhibiting frequencies up to 1.441 GHz. The cantilever-array design of the resonators translates the gigahertz-range resonant motion of micron-long cantilever elements to the displacement of the central supporting structure. Use of nano-crystalline diamond further increases the frequency comp...

  15. Treatment of Retinal Separation in HIV-infected Patients with Cytomegalovirus Retinitis

    Directory of Open Access Journals (Sweden)

    A. L. Onischenko

    2017-01-01

    Full Text Available HIV infection — is a socially significant problem for many countries, as the infected die in an average of 10-11 years due to the immunodeficiency virus. Up to 20% of patients with AIDS lose their sight because of cytomegalovirus retinitis (CMV retinitis, which occurs in 70% of HIV-infected people. In some patients with HIV infection blindness occurs because of acute retinal necrosis of CMV etiology. The algorithm of CMV retinitis treatment in HIV-infected patients is described in modern manuals (ganciclovir, valganciclovir, foscarnet and others on the background of antiretroviral therapy, but the tactics of treatment of retinal separation in these patients is not clearly defined. It may be “wait and see”, providing conservative treatment with antiviral drugs, and the active tactics — vitreoretinal surgery. In this article the authors present their personal clinical observations of three HIV-infected patients with CMV retinitis at the age of 8 to 36 years with a detailed analysis of the clinical data and the results of the laboratory tests. In particular, the authors give their own results of intravitreal introduction of ganciclovir in patients with CMV retinitis. Given the poor prognosis for the life of these patients, the authors put a deontological question of justification of active treatment of retinal separation in AIDS patients with CMV retinitis.

  16. Retinal Endovascular Surgery with Tissue Plasminogen Activator Injection for Central Retinal Artery Occlusion

    Directory of Open Access Journals (Sweden)

    Yuta Takata

    2018-06-01

    Full Text Available Purpose: To report 2 cases of central retinal artery occlusion (CRAO who underwent retinal endovascular surgery with injection of tissue plasminogen activator (tPA into the retinal artery and showed a remarkable improvement in visual acuity and retinal circulation. Methods: Standard 25-G vitrectomy was performed under local anesthesia. Simultaneously, tPA (80,000 units/mL solution was injected into the retinal artery of the optic disc for 2–3 min using a microneedle. Changes in visual acuity, fundus photography, optical coherence tomography (OCT, fluorescein angiography, and laser speckle flowgraphy (LSFG results were examined. Results: Both cases could be treated within 12 h after the onset of CRAO. Case 1 was a 47-year-old woman. Her visual acuity improved from counting fingers before operation to 0.08 logMAR 1 month after the surgery. However, thinning of the retina at the macula was observed by OCT. Case 2 was a 70-year-old man. His visual acuity improved from counting fingers to 0.1 logMAR 2 months after the surgery. Both fluorescein angiography and LSFG showed improvement in retinal circulation after the surgery in case 2. Conclusions: Retinal endovascular surgery with injection of tPA into the retinal artery was feasible and may be a way to improve visual acuity and retinal circulation when performed in the acute phase of CRAO.

  17. Impact of injection therapy on retinal patients with diabetic macular edema or retinal vein occlusion

    Directory of Open Access Journals (Sweden)

    Sivaprasad S

    2016-05-01

    Full Text Available Sobha Sivaprasad,1 Sesan Oyetunde2 1NIHR Biomedical Research Centre, Moorfields Eye Hospital, London, 2Allergan Holdings Ltd., Marlow, UK Purpose: An important factor in the choice of therapy is the impact it has on the patient’s quality of life. This survey aimed to understand treatment burden, treatment-related anxiety and worry, and practical issues such as appointment attendance and work absence in patients receiving injection therapy for diabetic macular edema (DME or retinal vein occlusion (RVO.Patients and methods: A European sample of 131 retinal patients completed a detailed questionnaire to elucidate the impact of injection therapy on individuals with DME or RVO.Results: RVO and DME greatly impact a patient’s quality of life. An intensive injection regimen and the requirements for multiple hospital visits place a large practical burden on the patient. Each intravitreal injection appointment (including travel time was reported to take an average of 4.5 hours, with a total appointment burden over 6 months of 13.5 hours and 20 hours for RVO and DME patients, respectively. This creates a significant burden on patient time and may make appointment attendance difficult. Indeed, 53% of working patients needed to take at least 1 day off work per appointment and 71% of patients required a carer’s assistance at the time of the injection appointment, ~6.3 hours per injection. In addition to practical issues, three-quarters of patients reported experiencing anxiety about their most recent injection treatment, with 54% of patients reporting that they were anxious for at least 2 days prior to the injection. Patients’ most desired improvement to their treatment regimen was to have fewer injections and to require fewer appointments, to achieve the same visual results.Conclusion: Patients’ quality of life is clearly very affected by having to manage an intensive intravitreal injection regimen, with a considerable treatment burden

  18. Heritability of Retinal Vascular Fractals

    DEFF Research Database (Denmark)

    Vergmann, Anna Stage; Broe, Rebecca; Kessel, Line

    2017-01-01

    Purpose: To determine the genetic contribution to the pattern of retinal vascular branching expressed by its fractal dimension. Methods: This was a cross-sectional study of 50 monozygotic and 49 dizygotic, same-sex twin pairs aged 20 to 46 years. In 50°, disc-centered fundus photographs, the reti...... fractal dimension did not differ statistically significantly between monozygotic and dizygotic twin pairs (1.505 vs. 1.495, P = 0.06), supporting that the study population was suitable for quantitative analysis of heritability. The intrapair correlation was markedly higher (0.505, P = 0.......0002) in monozygotic twins than in dizygotic twins (0.108, P = 0.46), corresponding to a heritability h2 for the fractal dimension of 0.79. In quantitative genetic models, dominant genetic effects explained 54% of the variation and 46% was individually environmentally determined. Conclusions: In young adult twins...

  19. Accommodative loss after retinal cryotherapy.

    Science.gov (United States)

    Uno, Tsuyoshi; Okuyama, Michiko; Tanabe, Tatsuro; Kawamura, Ryosuke; Ideta, Hidenao

    2009-01-01

    To investigate the effects of peripheral retinal cryotherapy on accommodative amplitude in patients with retinal lattice degeneration. Prospective, observational case series. We studied 92 eyes in 69 patients (age range, 13 to 79 years) treated with cryotherapy for lattice degeneration between December 2001 and September 2004. Pretreatment and posttreatment accommodative amplitudes were measured. Acute accommodative loss was calculated from the difference between accommodative amplitudes before treatment and one week after treatment. We investigated the time course of accommodative amplitudes, acute accommodative loss in different age groups and in pretreatment accommodative amplitude groups, the influence of cryotherapy numbers on accommodative amplitude, and the influence of cryotherapy sites on accommodative amplitude. No significant difference was noted between pretreatment and posttreatment accommodative amplitudes in the overall subject cohort. Dividing subjects by age revealed significant decreases in accommodative amplitude only among patients in their 10s and 20s at one and three weeks after treatment. Accommodative amplitude was lowest among those in their 10s, followed by that among those in their 20s (P < .01). Accommodative amplitudes recovered to pretreatment level by six weeks. Acute accommodative loss was greatest in those in their 10s compared with other age groups (P < .01). A significant correlation was observed between acute accommodative loss and cryotherapy numbers (P = .03; r = 0.41). The decrease in accommodative amplitude was greatest at one week after treatment and recovered to pretreatment levels after six weeks. Accommodative amplitude showed the greatest decrease after cryotherapy among patients in their 10s and 20s. A decrease in accommodative amplitude was observed with increased numbers of cryotherapy spots administered.

  20. Health-related quality of life in children with high-functioning autism.

    Science.gov (United States)

    Potvin, Marie-Christine; Snider, Laurie; Prelock, Patricia A; Wood-Dauphinee, Sharon; Kehayia, Eva

    2015-01-01

    The health-related quality of life of school-aged children with high-functioning autism is poorly understood. The objectives of this study were to compare the health-related quality of life of children with high-functioning autism to that of typically developing peers and to compare child-self and parent-proxy reports of health-related quality of life of children. A cross-sectional study of children with high-functioning autism (n = 30) and peers (n = 31) was conducted using the Pediatric Quality of Life Inventory 4.0 Generic Core Scales. Children with high-functioning autism had significantly poorer health-related quality of life than peers whether reported by themselves (p children and parental scores suggested variance in points of view. This study specifically investigated health-related quality of life in children with high-functioning autism as compared to a sample of peers, from the child's perspective. It strengthens earlier findings that children with high-functioning autism experience poorer health-related quality of life than those without this disorder and points to the importance of clinicians working with families to identify areas in a child's life that promote or hinder their sense of well-being. © The Author(s) 2013.

  1. Differentiation of Pluripotent Stem Cells to Retinal Pigment Epithelial Cells: An Approach Toward Retinal Degenerative Diseases Treatment

    Directory of Open Access Journals (Sweden)

    Maryam Parvini

    2013-10-01

    Full Text Available Pluripotent stem cells as the cells with a capacity for self-renewal and differentiation into various specificcell types have been highly regarded in regenerative medicine studies. To repair the eye disease damages, thedifferentiation into retinal pigment epithelial cells of pluripotent stem cells has gained great importance inrecent decades because the inappropriate function of these cells is the main cause of degenerative diseases suchas the age-related macular degeneration. Millions of people in the world suffer this disease.To restore the damaged cells and, finally, to improve the vision, numerous studies have been conducted on usingpluripotent stem cells, their differentiation into retinal pigment epithelial cells, and finally, their applicationin cell therapy. Based on this, many researchers have attempted to produce highly efficient retinal pigmentepithelial cells, such that they show a proper function after transplant, along with the host cells. In this reviewarticle, the importance and the role of pigment epithelial cells, as well as, the studies on the in vitro productionof these cells were examined

  2. Rhegmatogenous retinal detachment following intravitreal ocriplasmin

    NARCIS (Netherlands)

    Madi, Haifa A.; Haynes, Richard J.; Depla, Diana; de la Cour, Morten D.; Lesnik-Oberstein, Sarit; Muqit, Mahi M. K.; Patton, Niall; Price, Nick; Steel, David H. W.

    2016-01-01

    To describe the characteristics and outcomes of patients presenting with rhegmatogenous retinal detachment (RRD) after ocriplasmin (OCP) injection. Retrospective, multi-centre, observational case series with case note review. Eight patients with symptomatic vitreomacular traction (six with

  3. [Paediatric retinal detachment and hereditary vitreoretinal disorders].

    Science.gov (United States)

    Meier, P

    2013-09-01

    The number of retinal detachments in children is very low in comparison to the number in adults. One predisposing factor for development of paediatric retinal detachment is suffering from hereditary vitreoretinal degeneration (e.g., Stickler syndrome, Wagner syndrome, Kniest dysplasia, familial exudative vitreoretinopathy, congenital X-linked retinoschisis, Knobloch syndrome, incontinentia pigmenti, Norrie disease). Hereditary vitreoretinopathies are characterised by an abnormal-appearing vitreous gel with associated retinal changes. In most of these eyes further ocular abnormalities can be diagnosed. A group of hereditary disorders is associated with characteristic systemic abnormalities. Allied conditions should be considered in the clinical diagnosis. Vitreoretinopathies are the most common cause of inherited retinal detachment. In most eyes primary vitrectomy is necessary, and disease-specific surgical treatment is discussed. Georg Thieme Verlag KG Stuttgart · New York.

  4. Retinal Detachment: Torn or Detached Retina Diagnosis

    Science.gov (United States)

    ... Feb 20, 2018 Gene Therapy May Be a Game-Changer for People With Inherited Retinal Disease Dec 19, 2017 ... the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For ...

  5. Retinal Detachment: Torn or Detached Retina Treatment

    Science.gov (United States)

    ... Feb 20, 2018 Gene Therapy May Be a Game-Changer for People With Inherited Retinal Disease Dec 19, 2017 ... the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For ...

  6. Retinal Detachment: Torn or Detached Retina Symptoms

    Science.gov (United States)

    ... Feb 20, 2018 Gene Therapy May Be a Game-Changer for People With Inherited Retinal Disease Dec 19, 2017 ... the Academy Jobs at the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For ...

  7. Adaptive optics imaging of inherited retinal diseases.

    Science.gov (United States)

    Georgiou, Michalis; Kalitzeos, Angelos; Patterson, Emily J; Dubra, Alfredo; Carroll, Joseph; Michaelides, Michel

    2017-11-15

    Adaptive optics (AO) ophthalmoscopy allows for non-invasive retinal phenotyping on a microscopic scale, thereby helping to improve our understanding of retinal diseases. An increasing number of natural history studies and ongoing/planned interventional clinical trials exploit AO ophthalmoscopy both for participant selection, stratification and monitoring treatment safety and efficacy. In this review, we briefly discuss the evolution of AO ophthalmoscopy, recent developments and its application to a broad range of inherited retinal diseases, including Stargardt disease, retinitis pigmentosa and achromatopsia. Finally, we describe the impact of this in vivo microscopic imaging on our understanding of disease pathogenesis, clinical trial design and outcome metrics, while recognising the limitation of the small cohorts reported to date. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Regulatory and Economic Considerations of Retinal Drugs.

    Science.gov (United States)

    Shah, Ankoor R; Williams, George A

    2016-01-01

    The advent of anti-VEGF therapy for neovascular age-related macular degeneration and macular edema secondary to retinal vein occlusion and diabetes mellitus has prevented blindness in tens of thousands of people. However, the costs of these drugs are without precedent in ophthalmic drug therapeutics. An analysis of the financial implications of retinal drugs and the impact of the Food and Drug Administration on treatment of retinal disease must include not only an evaluation of the direct costs of the drugs and the costs associated with their administration, but also the cost savings which accrue from their clinical benefit. This chapter will discuss the financial and regulatory issues associated with retinal drugs. © 2016 S. Karger AG, Basel.

  9. High oleic sunflower biodiesel: quality control and different purification methods

    Directory of Open Access Journals (Sweden)

    Pighinelli, Anna L.M.T.

    2011-06-01

    Full Text Available The objective of the present work is to evaluate the production of biodiesel using ethanol and sunflower oil. The extraction of the sunflower oil was evaluated first. An experimental design was used to estimate the influence of the independent variables grain temperature (25º to 110ºC and expeller rotation (85 to 119rpm on the crude oil. The best result obtained was 68.38%, achieved with a rotation from 100 to 115rpm, grain temperature ranging from 25º to 30ºC and moisture content of around 7%. The next study consisted of transesterification, evaluating the influence of the ethanol, oil molar ratio and the catalyst concentration (sodium methylate on the ester-rich phase yield. The highest yield was 98.39% obtained with a molar ratio of 9:1 and 3% catalyst. An experiment was then carried out on a small reactor and the biodiesel produced was purified by three different methods: acidified water, silica and distillation. The quality aspects of the purified biodiesel samples were evaluated according to the Brazilian specifications for biodiesel, and distillation was shown to be the best method of purification.

    El objetivo del presente trabajo es evaluar la producción de biodiesel usando etanol y aceite de girasol. La extracción del aceite de girasol fue evaluada primero. Un diseño experimental fue usado para estimar la influencia de las variables independientes: temperatura del grano (25º a 110ºC y rotación del expeller (85 a 119 rpm en la obtención del aceite crudo. El mejor resultado obtenido fue un 68,38%, conseguido con una rotación de 100 a 115 rpm, una temperatura del grano de 25º a 30ºC y un contenido de humedad de alrededor del 7%. El siguiente estudio mediante transesterificación, evaluó la influencia de la relación molar etanol: aceite y concentración de catalizador (metilato sódico en el rendimiento de la fase rica en esteres. El rendimiento más alto fue 98,39% obtenido con una relación molar de 9.1 y 3% de

  10. A safe inexpensive method to isolate high quality plant and fungal ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... quality DNA from plant and fungal species. This method uses potassium acetate to remove proteins and polysaccharides in an SDS extraction buffer. Further DNA purification is achieved using a low salt. CTAB treatment. This SDS/CTAB protocol was used to isolate high quality genomic DNA subject to.

  11. Dual-Readout Calorimetry for High-Quality Energy

    CERN Multimedia

    During the past seven years, the DREAM collaboration has systematically investigated all factors that determine and limit the precision with which the properties of hadrons and jets can be measured in calorimeters. Using simultaneous detection of the deposited energy and the Cerenkov light produced in hadronic shower development ${(dual}$ ${readout}$), the fluctuations in the electromagnetic shower fraction could be measured event by event their effects on signal linearity, response function and energy resolution eliminated. Detailed measurement of the time structure of the signals made it possible to measure the contirbutions of nuclear evaporation neutrons to the signals and thus reduce the effects of fluctuations in "invisible energy". We are now embarking on the construction of a full-scale calorimeter which incorporates all these elements and which should make it possible to measure the four-vectors of both electrons, hadrons and jets with very high precision, in an instrument that can be simply calibrat...

  12. Export is necessary to maintain high quality supply

    International Nuclear Information System (INIS)

    Sirugue, S.

    2016-01-01

    Nuclear industry achieves about 20% of its turnover with the export of equipment and services but nuclear trade is submitted to specific constrains like non-proliferation policies. According to IAEA the world capacity of nuclear power is expected to double allowing the development of emerging countries while reducing CO_2 emissions. The French commercial offer focuses on the high-end market with the EPR reactor and an intermediate power range reactor ATMEA-1 designed with MHI (Mitsubishi Heavy Industries). AREVA is the unique world operator able to master the entire chain of spent fuel reprocessing thanks to the La Hague plant. In the framework of the rebuilding of the French nuclear industry, discussions are ongoing to achieve partnerships with foreign partners in exchange of shares in AREVA and AREVA NP. Today's main challenges of AREVA are to reduce EPR cost, to speed EPR construction and to benefit fully of the move into the digital age. (A.C.)

  13. Access High Quality Imagery from the NOAA View Portal

    Science.gov (United States)

    Pisut, D.; Powell, A. M.; Loomis, T.; Goel, V.; Mills, B.; Cowan, D.

    2013-12-01

    NOAA curates a vast treasure trove of environmental data, but one that is sometimes not easily accessed, especially for education, outreach, and media purposes. Traditional data portals in NOAA require extensive knowledge of the specific names of observation platforms, models, and analyses, along with nomenclature for variable outputs. A new website and web mapping service (WMS) from NOAA attempts to remedy such issues. The NOAA View data imagery portal provides a seamless entry point into data from across the agency: satellite, models, in-situ analysis, etc. The system provides the user with ability to browse, animate, and download high resolution (e.g., 4,000 x 2,000 pixel) imagery, Google Earth, and even proxy data files. The WMS architecture also allows the resources to be ingested into other software systems or applications.

  14. High Quality Rapeseed Products as Feed for Sensitive Monogastrics

    DEFF Research Database (Denmark)

    Frandsen, Heidi Blok

    in plants of the order Brassicales (former known as Capparales), which include rapeseed, rype (Brassica campestris L.) Indian mustard (Brassica juncea L.), broccoli (Brassica oleracea L.var. italica) and many other plants. Glucosinolates have been studied widely for their biologic effects ranging from...... by xenobiotica enzymes in the liver. The last study (manuscript IV) deals with the novel processing techniques, pulsed electric field (PEF) and high pressure treatment (HPT) and the processing effects on glucosinolates in broccoli. The largest effects were observed to be a result of the different handling...... of the plant materials prior to the process treatment. It was thus found that a great amount of the glucosinolate loss has occurred in the broccoli juice and purée prior to PEF processing. Only a minor loss was observed in broccoli flowers prior to processing, and HP treatment at 700 MPa for 10 min. was found...

  15. Improvement of retinal blood vessel detection by spur removal and Gaussian matched filtering compensation

    Science.gov (United States)

    Xiao, Di; Vignarajan, Janardhan; An, Dong; Tay-Kearney, Mei-Ling; Kanagasingam, Yogi

    2016-03-01

    Retinal photography is a non-invasive and well-accepted clinical diagnosis of ocular diseases. Qualitative and quantitative assessment of retinal images is crucial in ocular diseases related clinical application. In this paper, we proposed approaches for improving the quality of blood vessel detection based on our initial blood vessel detection methods. A blood vessel spur pruning method has been developed for removing the blood vessel spurs both on vessel medial lines and binary vessel masks, which are caused by artifacts and side-effect of Gaussian matched vessel enhancement. A Gaussian matched filtering compensation method has been developed for removing incorrect vessel branches in the areas of low illumination. The proposed approaches were applied and tested on the color fundus images from one publicly available database and our diabetic retinopathy screening dataset. A preliminary result has demonstrated the robustness and good performance of the proposed approaches and their potential application for improving retinal blood vessel detection.

  16. Optic Disc Pit with Sectorial Retinitis Pigmentosa

    OpenAIRE

    Balikoglu-Yilmaz, Melike; Taskapili, Muhittin; Yilmaz, Tolga; Teke, Mehmet Yasin

    2013-01-01

    Sectorial retinitis pigmentosa (RP) and optic disc pit (ODP) are rare clinical conditions. We present a 40-year-old woman with a history of mild night blindness and decreased vision in the right eye for about 5 years. Fundus examination revealed retinal pigmentary changes in the superior and inferotemporal sectors covering the macula and reduced arterial calibre and ODP at the temporal edge of the optic disc. In addition, fundus autofluorescence, spectral-domain optical coherence tomography, ...

  17. Retinal function in deaf-blind syndromes

    OpenAIRE

    Malm, Eva

    2011-01-01

    A variety of disorders can cause retinal degeneration and hearing impairment, and it is of great value to have an early diagnosis since there is a large variation in phenotype and prognosis both within and between the different disorders. The general aim of this thesis was to characterize the retinal function, to describe the phenotype, and – where appropriate – to relate the phenotype to genotype in patients with combined visual and hearing impairment. Alström syndrome is a rare auto...

  18. Branch retinal artery occlusion in Susac's syndrome

    Directory of Open Access Journals (Sweden)

    Ricardo Evangelista Marrocos de Aragão

    2015-02-01

    Full Text Available Susac's syndrome is a rare disease attribuited to a microangiopathy involving the arterioles of the cochlea, retina and brain. Encefalopathy, hearing loss, and visual deficits are the hallmarks of the disease. Visual loss is due to multiple, recurrent branch arterial retinal occlusions. We report a case of a 20-year-old women with Susac syndrome presented with peripheral vestibular syndrome, hearing loss, ataxia, vertigo, and vision loss due occlusion of the retinal branch artery.

  19. Current surgery of retinal detachment recurrence. Review

    Directory of Open Access Journals (Sweden)

    V. D. Zakharov

    2012-01-01

    Full Text Available this review presents a detailed analysis and an experience of surgical treatment of retinal detachment recurrence associated with light silicone oil tamponade of vitreous cavity. Approaches and variants of treatment were described in the historical aspect and till now. there are considered general and particular issues in case of retinal detachment recurrence appearance, expediency and volume of intraoperative manipulations, time of operation and choice of temporary substitute of vitreous body for a purpose of postoperative tamponade of vitreous cavity.

  20. CCR7 signaling pathway and retinal neovascularization

    Directory of Open Access Journals (Sweden)

    Lin-Hui Yuan

    2015-11-01

    Full Text Available Retinal neovascularization diseases are the major causes of blindness. C-C chemokine receptor type 7(CCR7can promote the expression of vascular endothelial growth factor(VEGFthrough the extracellular signal regulated kinase(ERKpathway, leading to vascular leakage, proliferation of vascular endothelial cell, neovascularization and etc. The detection of CCR7 can guide the diagnosis and treatments of retinal neovascularization diseases.