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1

Macular pigment levels following successful macular hole surgery  

Microsoft Academic Search

Aim: Macular pigment (MP) is composed of two hydroxycarotenoids contained within the photoreceptors and the axons of the central neurosensory retina, with peak concentrations in the Henle layer. A full thickness macular hole (FTMH) is characterised by absence of all retinal layers in an area centred at the former centre of the fovea. The authors report the results of a

K Neelam; N O’Gorman; J Nolan; O O’Donovan; K G Au Eong; S Beatty

2005-01-01

2

Fast assessment of the central macular pigment density with natural pupil using the macular pigment reflectometer.  

PubMed

We built a new macular pigment reflectometer (MPR) for fast and objective measuring of the optical density of macular pigment in the human eye, using the undilated eye. The design is based on the spectral reflectance from a spot of white light at the fovea. To evaluate its performance, we measured the macular pigment of 20 healthy subjects, ages 18 to 79 years, under four conditions: (1) natural pupil in the dark, (2) natural pupil with dim room light, (3) dilated pupil in the dark, and for comparison with a different technique, (4) heterochromatic flicker photometry (HFP) in dim room light with natural pupil. Condition 1 was repeated in a subset of 10 subjects after an interval of at least 3 days. Data analysis with a model of reflectors and absorbers in the eye provided the density of the macular pigment in conditions 1 to 3. Dim room light and pupil dilatation had no influence on measured density. Mean within subjects variation was typically 7%. Mean difference between test and retest after at least 3 days was 1%. Correlation between MPR and HFP was r=0.56 (p=0.012). Mean within subjects variation with HFP was 19%. The new instrument holds promise for specific applications such as epidemiological research. PMID:17212554

van de Kraats, Jan; Berendschot, Tos T J M; Valen, Suze; van Norren, Dirk

2006-01-01

3

Reflection-based imaging of macular pigment distributions in infants and children  

PubMed Central

Abstract. We have developed a reflection-based capability of the RetCam® platform, an FDA-cleared pediatric retinal-imaging instrument, for the purpose of measuring macular pigment levels as well as their spatial distributions in infants and children. Our modifications include narrow-band blue-wavelength excitation of the macular pigment absorption in combination with spectrally selective blue-wavelength readout of the reflection signals received by the instrument’s CCD detector array. Furthermore, an algorithm is developed that allows the computation of optical density maps for the macular pigment relative to peripheral retinal areas. This made it possible for the first time to directly measure macular pigment levels and their spatial features in the developing human retina. In contrast to adults, infants with measurable pigment levels had almost exclusively a narrow, circularly symmetric, pigment distribution. The described methodology holds promise for future investigations into the role of macular pigment in the developing human retina and the effect of dietary interventions in diseases resulting from a lack of normal carotenoid levels. PMID:24196405

Sharifzadeh, Mohsen; Bernstein, Paul S.; Gellermann, Werner

2013-01-01

4

Basal body and striated rootlet changes in primate macular retinal pigmented epithelium after low level diffuse argon laser radiation. Final report 1981-1982  

SciTech Connect

Basal bodies or centrioles (BB - microtubule organizing centers) and striated rootlets (SR - bundles of 60 A action-like filaments) have a close association in primate retinal pigmented epithelial (RPE) cells. The frequency of occurrence of these structures was evaluated in the macular RPE after repeated exposure to low level diffuse argon laser radiation (DALR). The awake chaired animal's head was restrained and positioned near the center of the 0.75 m hemisphere which was diffusely irradiated with 514.5 nm laser radiation. The right eye of each subject was occluded during the two-hour exposure session. The first subject received 24 cumulative hours of exposure, the second, 40 hours and the third, 42 hours.

Schuschereba, S.T.; Zwick, H.; Stuck, B.E.; Beatrice, E.S.

1982-09-01

5

Measurement of macular pigment optical density in a healthy chinese population sample  

Technology Transfer Automated Retrieval System (TEKTRAN)

Macular pigment may protect against age-related macular degeneration (AMD) by its capability to absorb blue light and scavenge free radicals. Current information on human macular pigment density has been largely from studies on Caucasians populations. The purpose of this study was to assess macular ...

6

Quantification of reduced macular pigment optical density in the central retina in macular telangiectasia type 2  

Microsoft Academic Search

Recently, a unique distribution, namely a reduction of macular pigment optical density (MPOD) within the central retina with a surrounding ring-like structure of preserved MPOD at about 6 degrees eccentricity was suggested to be a common finding in macular telangiectasia (MacTel) type 2. In order to quantify this reduced MPOD, 28 eyes of 14 patients with MacTel type 2 were

Peter Charbel Issa; Rob L. P. van der Veen; Astrid Stijfs; Frank G. Holz; Hendrik P. N. Scholl; Tos T. J. M. Berendschot

2009-01-01

7

Macular pigment density measured by autofluorescence spectrometry: comparison with reflectometry and heterochromatic flicker photometry  

Microsoft Academic Search

We present a technique for estimating the density of the human macular pigment noninvasively that takes advantage of the autofluorescence of lipofuscin, which is normally present in the human retinal pigment epi- thelium. By measuring the intensity of fluorescence at 710 nm, where macular pigment has essentially zero absorption, and stimulating the fluorescence with two wavelengths, one well absorbed by

François C. Delori; Douglas G. Goger; Billy R. Hammond; D. Max Snodderly; Stephen A. Burns

2001-01-01

8

Historic perspectives. Macular yellow pigment. The first 200 years.  

PubMed

Since 1782 there has been continuing controversy concerning the curious central coloration referred to as "macular yellow," but no cumulative source of information on the subject exists. This paper reviews the research efforts of two centuries to determine the existence, nature, location, and function of a specialized pigment in the foveal region. Using white-light illumination, it is difficult to see a macular yellow spot in the living eye; it is best observed and documented by red-free ophthalmoscopy and blue-light monochromatic photography. Histologic, biochemical, and spectral absorption data suggest that the yellow color is due to a xanthophyllic pigment, lutein, that is distributed in all retinal layers internal to the outer nuclear layer, with greatest concentration in the outer and inner plexiform layers. Clinically absent in newborns, the pigment gradually accumulates from dietary sources and appears to serve both as an optical filter, by absorbing blue light and reducing chromatic aberration, and in a protective capacity, preventing actinic damage. The absorption characteristics of the yellow pigment contribute to the central dark spot seen during fluorescein angiography and to the risk of photocoagulation near the fovea. Its apparent absence in albinos and the reported functional improvement in certain degenerative retinopathies following supplemental xanthophyll administration suggest a possible role in hereditary or acquired maculopathies. PMID:6758089

Nussbaum, J J; Pruett, R C; Delori, F C

1981-01-01

9

Color Matching in Diabetes: Optical Density of the Crystalline Lens and Macular Pigments  

E-print Network

compared with that of age-matched normal lens. Autofluorescence is further increased in diabetic personsColor Matching in Diabetes: Optical Density of the Crystalline Lens and Macular Pigments Nigel lens and macular pigments in a group of patients with diabetes mellitus and compare the results

Morland, Antony

10

Macular Pigment Optical Density Measured by Heterochromatic Modulation Photometry  

PubMed Central

Purpose To psychophysically determine macular pigment optical density (MPOD) employing the heterochromatic modulation photometry (HMP) paradigm by estimating 460 nm absorption at central and peripheral retinal locations. Methods For the HMP measurements, two lights (B: 460 nm and R: 660 nm) were presented in a test field and were modulated in counterphase at medium or high frequencies. The contrasts of the two lights were varied in tandem to determine flicker detection thresholds. Detection thresholds were measured for different R:B modulation ratios. The modulation ratio with minimal sensitivity (maximal threshold) is the point of equiluminance. Measurements were performed in 25 normal subjects (11 male, 14 female; age: 30±11 years, mean ± sd) using an eight channel LED stimulator with Maxwellian view optics. The results were compared with those from two published techniques – one based on heterochromatic flicker photometry (Macular Densitometer) and the other on fundus reflectometry (MPR). Results We were able to estimate MPOD with HMP using a modified theoretical model that was fitted to the HMP data. The resultant MPODHMP values correlated significantly with the MPODMPR values and with the MPODHFP values obtained at 0.25° and 0.5° retinal eccentricity. Conclusions HMP is a flicker-based method with measurements taken at a constant mean chromaticity and luminance. The data can be well fit by a model that allows all data points to contribute to the photometric equality estimate. Therefore, we think that HMP may be a useful method for MPOD measurements, in basic and clinical vision experiments. PMID:25354049

Huchzermeyer, Cord; Schlomberg, Juliane; Welge-Lüssen, Ulrich; Berendschot, Tos T. J. M.; Pokorny, Joel; Kremers, Jan

2014-01-01

11

Macular function and morphology in acute retinal pigment epithelitis  

PubMed Central

A 20-year-old man applied with vision loss in the left eye. Right eye examination was unremarkable. Best-corrected visual acuity (BCVA) in the left eye was 20/200. Fundus examination revealed a few yellow spots within a round-shaped macular lesion. Autofluorescence imaging showed hyperautofluorescence in the lesion. Central amplitudes in multifocal electroretinogram (mfERG) were depressed. The patient reported a rhinopharyngitis 7–10 days before the visual loss. The patient was diagnosed as acute retinal pigment epithelitis. BCVA improved gradually up to 20/20 in 4 weeks. mfERG amplitudes returned to normal. A slight pigmentary distortion was the only residual fundus finding. PMID:25579361

Gundogan, Fatih C; Diner, Oktay; Tas, Ahmet; Ilhan, Abdullah; Yolcu, Umit

2014-01-01

12

Macular function and morphology in acute retinal pigment epithelitis.  

PubMed

A 20-year-old man applied with vision loss in the left eye. Right eye examination was unremarkable. Best-corrected visual acuity (BCVA) in the left eye was 20/200. Fundus examination revealed a few yellow spots within a round-shaped macular lesion. Autofluorescence imaging showed hyperautofluorescence in the lesion. Central amplitudes in multifocal electroretinogram (mfERG) were depressed. The patient reported a rhinopharyngitis 7-10 days before the visual loss. The patient was diagnosed as acute retinal pigment epithelitis. BCVA improved gradually up to 20/20 in 4 weeks. mfERG amplitudes returned to normal. A slight pigmentary distortion was the only residual fundus finding. PMID:25579361

Gundogan, Fatih C; Diner, Oktay; Tas, Ahmet; Ilhan, Abdullah; Yolcu, Umit

2014-12-01

13

Macular Pigment Optical Density in an Ageing Irish Population: The Irish Longitudinal Study on Ageing  

Microsoft Academic Search

Purpose: The 3 carotenoids lutein, zeaxanthin, and meso-zeaxanthin, which account for the ‘yellow spot’ at the macula and which are referred to as macular pigment (MP), are believed to play a role in visual function and protect against age-related macular degeneration (AMD) via their optical and antioxidant properties. This study was undertaken to compare MP optical density (MPOD) in a

John M. Nolan; Roseanne Kenny; Claire O’Regan; Hilary Cronin; James Loughman; Eithne E. Connolly; Patricia Kearney; Edward Loane; Stephen Beatty

2010-01-01

14

Staging of Macular Telangiectasia: Power-Doppler Optical Coherence Tomography and Macular Pigment Optical Density  

PubMed Central

Purpose. Two methods were used to study the stages of macular telangiectasia (MacTel): Power-Doppler optical coherence tomography (PD-OCT), which allows imaging of the retinal circulation in three dimensions, and macular pigment optical density (MPOD), which quantifies the distribution of macular carotenoids. Methods. Among 49 patients with MacTel identified, 12 eyes (6 patients) with MacTel and 7 age-matched control eyes (7 patients) were imaged with a custom-built Fourier-domain OCT instrument to acquire PD-OCT images. MPOD was measured using heterochromatic flicker photometry in 10 eyes (5 patients) with MacTel and compared with 44 age-matched control eyes (44 patients). Clinical staging of MacTel was based on best-corrected visual acuity, fundus biomicroscopy, fluorescein angiography, and OCT. Results. Stage 1 eyes (n = 2) had subtle punctate vascular signal confined to the inner portion of the outer plexiform layer (OPL) on PD-OCT. Stage 2 (n = 2) showed larger oblique vascular signal extending into deeper OPL. Stage 3 (n = 5) had disruption of outer retinal layers with abnormal vasculature extending into the outer nuclear layer. Stage 4 (n = 3) showed diffuse blurring of the retinal layers with vascular channels extending the full thickness of the retina. MPOD values in four eyes with stage 1 or 2 MacTel correlated well with age-matched controls. Six eyes with stage 3 or 4 MacTel had loss of MPOD especially at the fovea. Conclusions. PD-OCT shows penetration of the retinal capillaries into the deeper retinal layers in early stages of MacTel, with full thickness vascular proliferation in advanced disease. MPOD is commonly depleted but may appear normal in early stage MacTel. PMID:23716628

Chin, Eric K.; Kim, Dae Yu; Hunter, Allan A.; Pilli, Suman; Wilson, Machelle; Zawadzki, Robert J.; Werner, John S.; Park, Susanna S.

2013-01-01

15

Measuring macular pigment optical density in vivo: a review of techniques  

Microsoft Academic Search

Background  Macular pigment has been the focus of much attention in recent years, as a potential modifiable risk factor for age-related\\u000a macular degeneration. This interest has been heightened by the ability to measure macular pigment optical density (MPOD) in\\u000a vivo.\\u000a \\u000a \\u000a \\u000a \\u000a Method  A systematic literature search was undertaken to identify all available papers that have used in vivo MPOD techniques. The\\u000a papers were

Olivia Howells; Frank Eperjesi; Hannah Bartlett

2011-01-01

16

The distribution of unique green wavelengths and its relationship to macular pigment density.  

PubMed

Monochromatic unique green (UG) is more variable across the population than any other unique hue. Some researchers have reported that this broad distribution of UG settings is bimodal and that the distribution results from the superposition of two or more subpopulations. We have investigated this claim using a Wright colorimeter to measure the unique green wavelength of 58 participants and we have analyzed previous unique green literature by applying a rigorous statistical test to historical datasets. We have also explored the possibility that individual differences in macular pigment density may be responsible for the variation in unique green wavelength. Our results indicate that unique green wavelengths in our population are distributed unimodally and are correlated positively with macular pigment density; individuals with a higher density of macular pigment select longer wavelengths of light as unique green than individuals with a lower density of macular pigment. We model this effect using simulations of monochromatic unique green matching to broadband illuminations and show that matches in the region at approximately 500 nm exhibit particularly high variance both with respect to macular pigment density and also with respect to the precise shape of the broadband reference exemplar spectrum. PMID:23863508

Welbourne, Lauren E; Thompson, Peter G; Wade, Alex R; Morland, Antony B

2013-01-01

17

Individual variations in the spatial profile of human macular pigment.  

PubMed

Individual variations in the spatial profile of macular pigment (MP) density were measured for 32 subjects. Peak density of MP measured with a 460-nm, 12-arcmin stimulus averaged 0.58, standard deviation (SD) = 0.26, with a range of 0.175 to 1.39. To assess the symmetry of the MP distribution, MP density was measured on the horizontal and vertical meridians at +/-1 deg eccentricity. The density varied by no more than 16% at these four locations, indicating a basically symmetric distribution. Based on a linear interpolation between measured locations, the width of the spatial distribution of MP at half the maximal density averaged 1.03 deg, SD = 0.38, with a range of 0.25 to 1.9 deg. The average spatial profile of MP density across subjects was fitted with both an exponential and a Gaussian function. An exponential decay with eccentricity explained more variance in the data than did a Gaussian function. Assuming an exponential decay with eccentricity, once MP density has been measured in the center of the retina (denoted A), MP density at more eccentric locations (X, deg) can be predicted with a standardized equation (MP = A x 10(-0.42x)). For individual cases, small deviations from an exponential function suggest the existence of minor flanking peaks or shoulders for 40% of the subjects. We also examined the temporal stability of the MP profile of four subjects over a time span of 4-14 months and for a single spatial location for ten subjects over a time span of 1-16 years. These longitudinal data show that differences in MP density among subjects are maintained over time, if dietary patterns are stable. PMID:9168592

Hammond, B R; Wooten, B R; Snodderly, D M

1997-06-01

18

The effect of lutein- and zeaxanthin-rich foods v. supplements on macular pigment level and serological markers of endothelial activation, inflammation and oxidation: pilot studies in healthy volunteers.  

PubMed

The aim of the present study was to compare the effect of lutein- and zeaxanthin-rich foods and supplements on macular pigment level (MPL) and serological markers of endothelial activation, inflammation and oxidation in healthy volunteers. We conducted two 8-week intervention studies. Study 1 (n 52) subjects were randomised to receive either carrot juice (a carotene-rich food) or spinach powder (a lutein- and zeaxanthin-rich food) for 8 weeks. Study 2 subjects (n 75) received supplements containing lutein and zeaxanthin, ?-carotene, or placebo for 8 weeks in a randomised, double-blind, placebo-controlled trial. MPL, serum concentrations of lipid-soluble antioxidants, inter-cellular adhesion molecule 1, vascular cell adhesion molecule 1, C-reactive protein and F2-isoprostane levels were assessed at baseline and post-intervention in both studies. In these intervention studies, no effects on MPL or markers of endothelial activation, inflammation or oxidation were observed. However, the change in serum lutein and zeaxanthin was associated or tended to be associated with the change in MPL in those receiving lutein- and zeaxanthin-rich foods (lutein r 0.40, P = 0.05; zeaxanthin r 0.30, P = 0.14) or the lutein and zeaxanthin supplement (lutein r 0.43, P = 0.03; zeaxanthin r 0.22, P = 0.28). In both studies, the change in MPL was associated with baseline MPL (food study r - 0.54, P < 0.001; supplement study r - 0.40, P < 0.001). We conclude that this 8-week supplementation with lutein and zeaxanthin, whether as foods or as supplements, had no significant effect on MPL or serological markers of endothelial activation, inflammation and oxidation in healthy volunteers, but may improve MPL in the highest serum responders and in those with initially low MPL. PMID:22313522

Graydon, Ryan; Hogg, Ruth E; Chakravarthy, Usha; Young, Ian S; Woodside, Jayne V

2012-07-01

19

Macular pigment density and distribution: comparison of fundus autofluorescence with minimum motion photometry  

Microsoft Academic Search

Macular pigment (MP) distribution profiles were measured for 18 subjects using a Moreland anomaloscope modified for motion photometry. The total amount of MP within the central 7° was estimated from the distribution profile by numerical integration. Fundus autofluorescence images were obtained for eight of these subjects using a scanning laser ophthalmoscope. Peak optical density of MP increased with the total

Anthony G. Robson; Jack D. Moreland; Daniel Pauleikhoff; Tony Morrissey; Graham E. Holder; Fred W. Fitzke; Alan C Bird; Frederik J. G. M. van Kuijk

2003-01-01

20

Purpose. To evaluate the reliability and validity of a portable instrument for measuring macular pigment optical density.  

E-print Network

to use in the clinic and has potential as a screening tool. Keywords: macular pigment; screening; smoking ). If the anti-oxidant and free radical scaveng- ing properties of MP, demonstrated in vitro,3,4 are also

21

Autofluorescence imaging of macular pigment: influence and correction of ocular media opacities.  

PubMed

The healthy adult human retina contains in its macular region a high concentration of blue-light absorbing carotenoid compounds, known as macular pigment (MP). Consisting of the carotenoids lutein, zeaxanthin, and meso-zeaxanthin, the MP is thought to shield the vulnerable tissue layers in the retina from lightinduced damage through its function as an optical attenuator and to protect the tissue cells within its immediate vicinity through its function as a potent antioxidant. Autofluorescence imaging (AFI) is emerging as a viable optical method for MP screening of large subject populations, for tracking of MP changes over time, and for monitoring MP uptake in response to dietary supplementation. To investigate the influence of ocular media opacities on AFI-based MP measurements, in particular, the influence of lens cataracts, we conducted a clinical trial with a large subject population (93 subjects) measured before and after cataract surgery. General AFI image contrast, retinal blood vessel contrast, and presurgery lens opacity scores [Lens Opacities Classification System III (LOCS III)] were investigated as potential predictors for image degradation. These clinical results show that lens cataracts can severely degrade the achievable pixel contrasts in the AFI images, which results in nominal MP optical density levels that are artifactually reduced. While LOCS III scores and blood vessel contrast are found to be only a weak predictor for this effect, a strong correlation exists between the reduction factor and the image contrast, which can be quantified via pixel intensity histogram parameters. Choosing the base width of the histogram, the presence or absence of ocular media opacities can be determined and, if needed, the nominal MP levels can be corrected with factors depending on the strength of the opacity. PMID:25223707

Sharifzadeh, Mohsen; Obana, Akira; Gohto, Yuko; Seto, Takahiko; Gellermann, Werner

2014-09-01

22

Autofluorescence imaging of macular pigment: influence and correction of ocular media opacities  

NASA Astrophysics Data System (ADS)

The healthy adult human retina contains in its macular region a high concentration of blue-light absorbing carotenoid compounds, known as macular pigment (MP). Consisting of the carotenoids lutein, zeaxanthin, and meso-zeaxanthin, the MP is thought to shield the vulnerable tissue layers in the retina from light-induced damage through its function as an optical attenuator and to protect the tissue cells within its immediate vicinity through its function as a potent antioxidant. Autofluorescence imaging (AFI) is emerging as a viable optical method for MP screening of large subject populations, for tracking of MP changes over time, and for monitoring MP uptake in response to dietary supplementation. To investigate the influence of ocular media opacities on AFI-based MP measurements, in particular, the influence of lens cataracts, we conducted a clinical trial with a large subject population (93 subjects) measured before and after cataract surgery. General AFI image contrast, retinal blood vessel contrast, and presurgery lens opacity scores [Lens Opacities Classification System III (LOCS III)] were investigated as potential predictors for image degradation. These clinical results show that lens cataracts can severely degrade the achievable pixel contrasts in the AFI images, which results in nominal MP optical density levels that are artifactually reduced. While LOCS III scores and blood vessel contrast are found to be only a weak predictor for this effect, a strong correlation exists between the reduction factor and the image contrast, which can be quantified via pixel intensity histogram parameters. Choosing the base width of the histogram, the presence or absence of ocular media opacities can be determined and, if needed, the nominal MP levels can be corrected with factors depending on the strength of the opacity.

Sharifzadeh, Mohsen; Obana, Akira; Gohto, Yuko; Seto, Takahiko; Gellermann, Werner

2014-09-01

23

Proteomics of the Retinal Pigment Epithelium Reveals Altered Protein Expression at Progressive Stages of Age-Related Macular Degeneration  

Microsoft Academic Search

PURPOSE. Age-related macular degeneration (AMD) is character- ized clinically by changes in the retinal pigment epithelium (RPE), formation of drusen between the RPE and the underly- ing vasculature, geographic atrophy, and choroidal neovascu- larization. Later clinical stages are accompanied by impaired central vision. A limited understanding of the molecular events responsible for AMD has constrained the development of ef- fective

Curtis L. Nordgaard; Kristin M. Berg; Rebecca J. Kapphahn; Cavan Reilly; Xiao Feng; Timothy W. Olsen; Deborah A. Ferrington

2006-01-01

24

Effect of Supplemental Lutein and Zeaxanthin on Serum, Macular Pigmentation, and Visual Performance in Patients with Early Age-Related Macular Degeneration  

PubMed Central

Purpose. To compare the 2-year effect of multiple doses of lutein/zeaxanthin on serum, macular pigmentation, and visual performance on patients with early age-related macular degeneration (AMD). Methods. In this randomized, double-blinded, and placebo-controlled trial, 112 early AMD patients randomly received either 10?mg lutein, 20?mg lutein, a combination of lutein (10?mg) and zeaxanthin (10?mg), or placebo daily for 2 years. Serum concentration of lutein/zeaxanthin, macular pigment optical density (MPOD), visual functions including best-spectacle corrected visual acuity (BCVA), contrast sensitivity (CS), flash recovery time (FRT), and vision-related quality of life (VFQ25) was quantified. Results. Serum lutein concentration and MPOD significantly increased in all the active treatment groups. Supplementation with 20?mg lutein was the most effective in increasing MPOD and CS at 3 cycles/degree for the first 48 weeks. However, they both significantly increased to the same peak value following supplementation with either 10?mg or 20?mg lutein during the intervention. No statistical changes of BCVA or FRT were observed during the trial. Conclusions. Long-term lutein supplementation could increase serum lutein concentration, MPOD, and visual sensitivities of early AMD patients. 10?mg lutein daily might be an advisable long-term dosage for early AMD treatment.

Huang, Yang-Mu; Dou, Hong-Liang; Huang, Fei-Fei; Xu, Xian-Rong; Zou, Zhi-Yong

2015-01-01

25

Caspase-14 Expression Impairs Retinal Pigment Epithelium Barrier Function: Potential Role in Diabetic Macular Edema  

PubMed Central

We recently showed that caspase-14 is a novel molecule in retina with potential role in accelerated vascular cell death during diabetic retinopathy (DR). Here, we evaluated whether caspase-14 is implicated in retinal pigment epithelial cells (RPE) dysfunction under hyperglycemia. The impact of high glucose (HG, 30?mM D-glucose) on caspase-14 expression in human RPE (ARPE-19) cells was tested, which showed significant increase in caspase-14 expression compared with normal glucose (5?mM D-glucose + 25?mM L-glucose). We also evaluated the impact of modulating caspase-14 expression on RPE cells barrier function, phagocytosis, and activation of other caspases using ARPE-19 cells transfected with caspase-14 plasmid or caspase-14 siRNA. We used FITC-dextran flux assay and electric cell substrate impedance sensing (ECIS) to test the changes in RPE cell barrier function. Similar to HG, caspase-14 expression in ARPE-19 cells increased FITC-dextran leakage through the confluent monolayer and decreased the transcellular electrical resistance (TER). These effects of HG were prevented by caspase-14 knockdown. Furthermore, caspase-14 knockdown prevented the HG-induced activation of caspase-1 and caspase-9, the only activated caspases by HG. Phagocytic activity was unaffected by caspase-14 expression. Our results suggest that caspase-14 contributes to RPE cell barrier disruption under hyperglycemic conditions and thus plays a role in the development of diabetic macular edema. PMID:25121097

Megyerdi, Sylvia; El-Shafey, Sally; Choksi, Karishma; Kaddour-Djebbar, Ismail; Sheibani, Nader; Hsu, Stephen

2014-01-01

26

Recovery of macular pigment spectrum in vivo using hyperspectral image analysis  

PubMed Central

We investigated the feasibility of a novel method for hyperspectral mapping of macular pigment (MP) in vivo. Six healthy subjects were recruited for noninvasive imaging using a snapshot hyperspectral system. The three-dimensional full spatial-spectral data cube was analyzed using non-negative matrix factorization (NMF), wherein the data was decomposed to give spectral signatures and spatial distribution, in search for the MP absorbance spectrum. The NMF was initialized with the in vitro MP spectrum and rank 4 spectral signature decomposition was used to recover the MP spectrum and optical density in vivo. The recovered MP spectra showed two peaks in the blue spectrum, characteristic of MP, giving a detailed in vivo demonstration of these absorbance peaks. The peak MP optical densities ranged from 0.08 to 0.22 (mean 0.15+/?0.05) and became spatially negligible at diameters 1100 to 1760 ?m (4 to 6 deg) in the normal subjects. This objective method was able to exploit prior knowledge (the in vitro MP spectrum) in order to extract an accurate in vivo spectral analysis and full MP spatial profile, while separating the MP spectra from other ocular absorbers. Snapshot hyperspectral imaging in combination with advanced mathematical analysis provides a simple cost-effective approach for MP mapping in vivo. PMID:22029355

Fawzi, Amani A.; Lee, Noah; Acton, Jennifer H.; Laine, Andrew F.; Smith, R. Theodore

2011-01-01

27

Mitochondrial proteomics of the retinal pigment epithelium at progressive stages of age-related macular degeneration  

PubMed Central

Purpose Age-related macular degeneration (AMD) is the leading cause of vision loss in individuals over the age of 65. Histopathological changes become evident in the retinal pigment epithelium (RPE), a monolayer that provides metabolic support for the overlying photoreceptors, even at the earliest stages of AMD that precede vision loss. In a previous global RPE proteome analysis, we identified changes in the content of several mitochondrial proteins associated with AMD. Herein, we analyzed the sub-proteome of mitochondria isolated from human donor RPE graded with the Minnesota Grading System (MGS). Methods Human donor eye bank eyes were categorized into one of four progressive stages (MGS 1–4) based upon the clinical features of AMD. Following dissection of the RPE, mitochondrial proteins were isolated and separated based upon their charge and mass using two-dimensional gel electrophoresis. Protein spot densities were compared between the four MGS stages. Peptides from spots that changed significantly with MGS stage were extracted and analyzed using mass spectrometry to identify the protein. Results Western blot analyses verified that mitochondria were consistently enriched between MGS stages. The densities of eight spots increased or decreased significantly as a function of MGS stage. These spots were identified as the alpha, beta, and delta ATP synthase subunits, subunit VIb of the cytochrome C oxidase complex, mitofilin, mtHsp70, and the mitochondrial translation factor Tu. Conclusions Our results are consistent with the hypothesis that mitochondrial dysfunction is associated with AMD and further suggest specific pathophysiological mechanisms involving altered mitochondrial translation, import of nuclear-encoded proteins, and ATP synthase activity. PMID:18344451

Nordgaard, Curtis L.; Karunadharma, Pabalu P.; Feng, Xiao; Olsen, Timothy W.; Ferrington, Deborah A.

2010-01-01

28

Vitreous estrogen levels in patients with an idiopathic macular hole  

PubMed Central

Purpose Estrogen, a female hormone, activates collagenase and might be associated with the pathogenesis of vitreoretinal collagen fiber disease. The purpose of the present study was to investigate the vitreous levels of estrone (E1) and estradiol (E2) in subjects with an idiopathic macular hole (IMH). Methods Vitreous samples were obtained from ten female patients with an IMH and from nine female patients with other retinal diseases (six with rhegmatogenous retinal detachment and three with age-related macular degeneration) as a control at the time of vitreous surgery. E1 and E2 levels in the vitreous samples were then determined using the Coat-A-Count® Estradiol Radioimmunoassay (RIA) Kit and the DSL-70 Estrone RIA Kit, respectively. Results The mean vitreous levels of E1 and E2 in the subjects with IMH were 1.83±2.00 pg/mL and 7.03±2.97 pg/mL, respectively, whereas in the control subjects they were 2.42±1.25 pg/mL and 4.90±2.90 pg/mL, respectively. Thus, the vitreous E2 levels in the subjects with IMH were significantly higher than in the controls (P<0.05). Conclusion The findings of this study suggest that E2 might be associated with the pathogenesis of IMH, but further investigation is needed to elucidate that association.

Inokuchi, Naoki; Ikeda, Tsunehiko; Nakamura, Kimitoshi; Morishita, Seita; Fukumoto, Masanori; Kida, Teruyo; Oku, Hidehiro

2015-01-01

29

Lutein and zeaxanthin: Role as macular pigment and factors that control bioavailability from egg yolks and nanoemulsions  

NASA Astrophysics Data System (ADS)

Lutein and zeaxanthin, two oxygenated carotenoids, exclusively accumulate in the macula, protecting the underlying photoreceptors and retinal pigment epithelial cells from damaging blue radiation of sunlight. As macular pigment, lutein and zeaxanthin are also potent antioxidants protecting the vulnerable regions of retina from free radical injury. Oxidative stress and cumulative light damage play an important role in pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss in the elderly population. Antioxidant and lutein supplementation has been shown to decrease the risk and prevent the progression of AMD. The egg yolk is a highly bioavailable source of lutein and zeaxanthin and thus a possible contender for AMD prevention and treatment. Consumption of 2 egg yolks/d for 5 weeks was shown herein to significantly increase serum lutein and zeaxanthin concentration and clinically improve macular pigment concentrations at 0.5° retinal eccentricity in an older adult population taking cholesterol-lowering statins. Four egg yolks/d not only raised serum lutein and zeaxanthin significantly but also macular pigment densities at 0.25°, 0.5° and 1° retinal eccentricity. A positive outcome of the 2 egg yolk consumption was the significant increase in serum HDL-C with a tendency of serum LDL-C to decrease, although not significantly. Four egg yolks/d seemed to cross the threshold for dietary cholesterol tolerance as serum LDL-C tended to increase, although not significantly, despite the significant increase in serum HDL-C. There is a strong possibility that greater build up of lutein and zeaxanthin in the macula may have been observed with 2 egg yolks/d if the intervention period was longer than 5 weeks. Addition of up to 2 eggs a day to the diet is suggested to benefit an older adult population, especially those who are already taking cholesterol-lowering statins by (a) building their macular pigment and possibly protect against AMD and (b) raising serum HDL-C without an adverse affect on serum LDL-C and TC:HDL-C ratio. Increased cholesterol, lutein and zeaxanthin intake from the 2 and 4 egg yolk interventions did not decrease the absorption of other carotenoids, such as alpha-cryptoxanthin, beta-cryptoxanthin, lycopene, alpha-carotene and beta-carotene, tocopherols and retinol from the diet. An unexpected increase was observed in serum alpha-cryptoxanthin and gamma-tocopherol concentrations during the 4 egg yolk phase, these carotenoids are normally present in low concentrations in serum. Lipoprotein distribution of carotenoids and tocopherols was also not affected by the increased egg consumption. In the pursuit of designing a highly bioavailable matrix for lutein/zeaxanthin, similar to the egg yolk micellar matrix, nanoemulsion formulations of lutein were developed using the MicrofluidizerRTM Processor technology. Lutein nanoemulsions are O/W emulsions of lutein which have particle sizes in the nanometer range (? 200 nm). Lutein consumed orally as a nanoemulsion was shown to have significantly greater bioavailability than lutein supplement-pills in pilot-scale clinical studies described here. However, lutein nanoemulsions did not raise plasma lutein concentrations to the same extent as egg yolks in a study performed on BALB/c mice. Formation of mixed micelles in the intestinal lumen during digestion and uptake of these micelles by enterocytes are crucial steps that dictate bioavailability i.e. the proportion of ingested lutein/carotenoid that enters the blood circulation and accumulates in the peripheral tissues such as the macula. In-vitro stomach and intestinal digestion experiments showed lutein nanoemulsions have significantly greater micellarization efficiency compared to egg yolks. Nanoemulsions with a phospholipid (PL) emulsifier containing 80% phosphatidyl choline (PC) or Polysorbate 80 as the emulsifier had better ability to form micelles during the intestinal digestion phase compared to a PL emulsifier with only 45% PC content. The micellar matrix coupled with nanometer sized parti

Vishwanathan, Rohini

30

In vivo imaging of retinal pigment epithelium cells in age related macular degeneration  

E-print Network

, 601 Elmwood Avenue, Rochester, NY 14642, USA 5 Department of Ophthalmology, Medical College; (170.4470) Ophthalmology. References and links 1. C. J. Blair, "Geographic atrophy of the retinal of senile macular degeneration," Ophthalmology 92(5), 615­627 (1985). 4. H. Kaneko, S. Dridi, V. Tarallo, B

31

Macular telangiectasia type 2  

PubMed Central

Macular telangiectasia type 2 is a bilateral disease of unknown cause with characteristic alterations of the macular capillary network and neurosensory atrophy. Its prevalence may be underestimated and has recently been shown to be as high as 0.1% in persons 40 years and older. Biomicroscopy may show reduced retinal transparency, crystalline deposits, mildly ectatic capillaries, blunted venules, retinal pigment plaques, foveal atrophy, and neovascular complexes. Fluorescein angiography shows telangiectatic capillaries predominantly temporal to the foveola in the early phase and a diffuse hyperfluorescence in the late phase. High-resolution optical coherence tomography (OCT) may reveal disruption of the photoreceptor inner segment–outer segment border, hyporeflective cavities at the level of the inner or outer retina, and atrophy of the retina in later stages. Macular telangiectasia type 2 shows a unique depletion of the macular pigment in the central retina and recent therapeutic trials showed that such depleted areas cannot re-accumulate lutein and zeaxanthin after oral supplementation. There have been various therapeutic approaches with limited or no efficacy. Recent clinical trials with compounds that block vascular endothelial growth factor (VEGF) have established the role of VEGF in the pathophysiology of the disease, but have not shown significant efficacy, at least for the nonneovascular disease stages. Recent progress in structure–function correlation may help to develop surrogate outcome measures for future clinical trials. In this review article, we summarize the current knowledge on macular telangiectasia type 2, including the epidemiology, the genetics, the clinical findings, the staging and the differential diagnosis of the disease. Findings using retinal imaging are discussed, including fluorescein angiography, OCT, adaptive optics imaging, confocal scanning laser ophthalmoscopy, and fundus autofluorescence, as are the findings using visual function testing including visual acuity and fundus-controlled microperimetry. We provide an overview of the therapeutic approaches for both non-neovascular and neovascular disease stages and provide a perspective of future directions including animal models and potential therapeutic approaches. PMID:23219692

Issa, Peter Charbel; Gillies, Mark C.; Chew, Emily Y.; Bird, Alan C.; Heeren, Tjebo F.C.; Peto, Tunde; Holz, Frank G.; Scholl, Hendrik P.N.

2013-01-01

32

Macular telangiectasia type 2.  

PubMed

Macular telangiectasia type 2 is a bilateral disease of unknown cause with characteristic alterations of the macular capillary network and neurosensory atrophy. Its prevalence may be underestimated and has recently been shown to be as high as 0.1% in persons 40 years and older. Biomicroscopy may show reduced retinal transparency, crystalline deposits, mildly ectatic capillaries, blunted venules, retinal pigment plaques, foveal atrophy, and neovascular complexes. Fluorescein angiography shows telangiectatic capillaries predominantly temporal to the foveola in the early phase and a diffuse hyperfluorescence in the late phase. High-resolution optical coherence tomography (OCT) may reveal disruption of the photoreceptor inner segment-outer segment border, hyporeflective cavities at the level of the inner or outer retina, and atrophy of the retina in later stages. Macular telangiectasia type 2 shows a unique depletion of the macular pigment in the central retina and recent therapeutic trials showed that such depleted areas cannot re-accumulate lutein and zeaxanthin after oral supplementation. There have been various therapeutic approaches with limited or no efficacy. Recent clinical trials with compounds that block vascular endothelial growth factor (VEGF) have established the role of VEGF in the pathophysiology of the disease, but have not shown significant efficacy, at least for the non-neovascular disease stages. Recent progress in structure-function correlation may help to develop surrogate outcome measures for future clinical trials. In this review article, we summarize the current knowledge on macular telangiectasia type 2, including the epidemiology, the genetics, the clinical findings, the staging and the differential diagnosis of the disease. Findings using retinal imaging are discussed, including fluorescein angiography, OCT, adaptive optics imaging, confocal scanning laser ophthalmoscopy, and fundus autofluorescence, as are the findings using visual function testing including visual acuity and fundus-controlled microperimetry. We provide an overview of the therapeutic approaches for both non-neovascular and neovascular disease stages and provide a perspective of future directions including animal models and potential therapeutic approaches. PMID:23219692

Charbel Issa, Peter; Gillies, Mark C; Chew, Emily Y; Bird, Alan C; Heeren, Tjebo F C; Peto, Tunde; Holz, Frank G; Scholl, Hendrik P N

2013-05-01

33

In vivo imaging of retinal pigment epithelium cells in age related macular degeneration  

PubMed Central

Morgan and colleagues demonstrated that the RPE cell mosaic can be resolved in the living human eye non-invasively by imaging the short-wavelength autofluorescence using an adaptive optics (AO) ophthalmoscope. This method, based on the assumption that all subjects have the same longitudinal chromatic aberration (LCA) correction, has proved difficult to use in diseased eyes, and in particular those affected by age-related macular degeneration (AMD). In this work, we improve Morgan’s method by accounting for chromatic aberration variations by optimizing the confocal aperture axial and transverse placement through an automated iterative maximization of image intensity. The increase in image intensity after algorithmic aperture placement varied depending upon patient and aperture position prior to optimization but increases as large as a factor of 10 were observed. When using a confocal aperture of 3.4 Airy disks in diameter, images were obtained using retinal radiant exposures of less than 2.44 J/cm2, which is ~22 times below the current ANSI maximum permissible exposure. RPE cell morphologies that were strikingly similar to those seen in postmortem histological studies were observed in AMD eyes, even in areas where the pattern of fluorescence appeared normal in commercial fundus autofluorescence (FAF) images. This new method can be used to study RPE morphology in AMD and other diseases, providing a powerful tool for understanding disease pathogenesis and progression, and offering a new means to assess the efficacy of treatments designed to restore RPE health. PMID:24298413

Rossi, Ethan A.; Rangel-Fonseca, Piero; Parkins, Keith; Fischer, William; Latchney, Lisa R.; Folwell, Margaret A.; Williams, David R.; Dubra, Alfredo; Chung, Mina M.

2013-01-01

34

Retinal pigment epithelial tears following ranibizumab therapy for fibrovascular retinal pigment epithelial detachment due to occult age-related macular degeneration  

PubMed Central

Summary Background The aim of this paper is to report the incidence of retinal pigment epithelial (RPE) tears in patients treated with ranibizumab for subfoveal fibrovascular retinal pigment epithelial detachment (FVPED) due to occult age-related macular degeneration (AMD). Material/Methods Thirty patients were treated according to the following schedule: saturation phase, further treatment was based on activity of the degeneration process. Visual acuity (VA), optical coherence tomography (OCT) and fluorescein angiography (FA) parameters were evaluated and compared. Results Patients had a mean improvement of +4.7±8.1 letters at month 12. The mean number of needed injections was 6.8±1.8 (range, 3 to 9). RPE tears in fovea occurred in 8 cases (27% of all patients). Analysis of variance revealed significant upper mean values of ETDRS letters for the subgroup without RPE tears. Mean values of PED height were significant upper for RPE tears without baseline. Statistical analysis revealed that in the subgroup without RPE tears mean values of VA significantly differed in succeeding periods compare to baseline (P<0.001). Visual improvement or stabilization was observed in 90.9% of patients without RPE tears (significant improvement of 15 or more letters in 22.7%–5/22) and in 87.5% of patients with RPE tears (significant improvement was not observed). Baseline leakage parameters, lesion and leakage parameters at month 12 were significantly higher in patients with RPE tears. The chi-square test revealed statistically significant associations between RPE tears and subretinal fluid in OCT (P<0.05) at month 12. Conclusions In eyes with FVPED and RPE tears treated with ranibizumab, stabilization of visual acuity without significant improvement is predictable. One of the risk factors common to RPE tears may be baseline leakage parameters and pretreatment distorted RPE contour in OCT. During ranibizumab therapy in eyes with RPE tears, upper parameters of FVPED height may occur without significant differences in fovea and macula volume compare to eyes without RPE tears. PMID:22207117

Figurska, Ma?gorzata

2012-01-01

35

Aqueous levels of erythropoietin in acute retinal vein occlusion with macular edema  

PubMed Central

AIM To investigate the aqueous erythropoietin (EPO) levels and associated factors in patients with acute retinal vein occlusion (RVO). METHODS The aqueous EPO level was measured in patients with macular edema (ME) secondary to acute branched retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO). Aqueous fluid from cataract patients served as the control. We also evaluated whether aqueous level of EPO was associated with factors such as serum EPO level, non-perfusion area, central macular thickness (CMT), and arterio-venous (AV) transit time RESULTS Twenty-seven RVO patients (16 BRVO, 11 CRVO) and 9 control subjects were enrolled in the study. The aqueous EPO level (mU/mL) was higher in RVO (68.2±54.3) than that in the control subjects (12.9±5.9). More specifically, the aqueous EPO level was higher in CRVO (118.9±52.1) than that in BRVO (33.3±10.8). However, no differences were found in serum EPO levels among three groups. CMT in RVO patients had a positive correlation with the aqueous EPO level (r=0.66). Also, in terms of non-perfusion area, the aqueous EPO levels were more elevated in the ischemic subgroup than in the non-ischemic subgroup in both BRVO and CRVO. CONCLUSION Aqueous EPO levels are elevated in patients with macular edema secondary to recent onset RVO. Patients with CRVO have higher EPO levels than those with BRVO. The aqueous EPO level in RVO has a positive correlation with CMT and is associated with non-perfusion area. These results suggest that the aqueous EPO level could be associated with retinal ischemia and may be involved in the pathogenesis of macular edema secondary to RVO. PMID:24967199

Shin, Hyun Jin; Kim, Hyung Chan; Moon, Jun Woong

2014-01-01

36

Incidence of Retinal Pigment Epithelial Tears and Associated Risk Factors After Treatment of Age-Related Macular Degeneration with Intravitreal Anti-VEGF Injections§  

PubMed Central

Purpose : To study the incidence and risk factors for retinal pigment epithelium tears following intravitreal anti-vascular endothelial growth factor (VEGF) injections. Methods : Retrospective longitudinal study. 4027 intravitreal anti-VEGF injections in 628 patients (676 eyes) for choroidal neovascularisation associated with age related macular degeneration in a period of 18 months were studied. Results : Seventeen patients (mean age 83.95±5.84) developed retinal pigment epithelium tears. The incidence rate was 0.4%. Fibrovascular pigment epithelium detachment (PED) was previously observed in all cases. In 88 % (15/17) of AMD patients that had a RPE tear, PED height was found to be less than 400 microns at presentation. In 5 of 7 patients with RPE tear grade <4, continuing of anti-VEGF treatment resulted to improvement of visual acuity. Conclusion : Critical risk factors for RPE tears are presence of PED as well as advanced age. Visual improvement appears to depend more on the extent and location of the RPE tear and less on the PED height. PMID:25674188

Empeslidis, Theodoros; Vardarinos, Athanasios; Konidaris, Vasileios; Ch'ng, Soon Wai; Kapoor, Bharat; Deane, James; Tsaousis, Konstantinos T

2014-01-01

37

Hereditary hemorrhagic macular dystrophy.  

PubMed

We treated two brothers who had a hemorrhagic macular lesion in one eye; a similar problem affected the fellow eye of both patients within eight months. Generalized fine granularity of the retinal pigment epithelium and peripheral iris transillumination defects were observed in both siblings. A study of the family suggested that the disorder was dominantly inherited and probably was Sorsby's pseudoinflammatory macular dystrophy. The macular lesions in one brother were treated by argon green laser photocoagulation and in the other brother by krypton red laser photocoagulation. Although the brother treated by krypton red laser photocoagulation attained better final visual function, additional differences in treatment methods also may have contributed to the final outcome. PMID:2000899

Wu, G; Pruett, R C; Baldinger, J; Hirose, T

1991-03-15

38

Changes in endocannabinoid and palmitoylethanolamide levels in eye tissues of patients with diabetic retinopathy and age-related macular degeneration  

Microsoft Academic Search

Cannabinoid receptors and the endocannabinoids (anandamide (N-arachidonoylethanolamine—AEA) and 2-arachidonoylglycerol (2-AG)), as well as the AEA congener, palmitoylethanolamide (PEA), are involved in ocular physiology. We measured endocannabinoid and PEA levels by isotope-dilution liquid chromatography-mass spectrometric analysis in post-mortem eye tissues of patients with diabetic retinopathy (DR) or age-related macular degeneration (AMD). In eyes with DR, significantly enhanced levels of AEA were

I. Matias; J. W. Wang; A. Schiano Moriello; A. Nieves; D. F. Woodward; V. Di Marzo

2006-01-01

39

Superoxide Dismutase1 Levels in North Indian Population with Age-Related Macular Degeneration  

PubMed Central

Aim. The aim of the study was to estimate the levels of superoxide dismutase1 (SOD1) in patients of age-related macular degeneration (AMD) and examine the role of oxidative stress, smoking, hypertension, and other factors involved in the pathogenesis of AMD. Methods. 115 AMD patients and 61 healthy controls were recruited for this study. Serum SOD1 levels were determined by ELISA and were correlated to various risk factors. Logistic regression model of authenticity, by considering SOD1 as independent variable, has been developed along with ROC curve. Results. The SOD1 levels were significantly higher in AMD patients as compared to those of the controls. The difference was not significant for wet and dry AMD. However, the difference was significant between wet AMD subtypes. Nonsignificance of the Hosmer-Lemeshow goodness of fit statistic (?2 = 10.516, df = 8, P = 0.231) indicates the appropriateness of logistic regression model to predict AMD. Conclusion. Oxidative stress in AMD patients may mount compensatory response resulting in increased levels of SOD1 in AMD patients. To predict the risk of AMD on the basis of SOD1, a logistic regression model shows authenticity of 78%, and area under the ROC curve (0.827, P = .0001) with less standard error of 0.033 coupled with 95% confidence interval of 0.762–0.891 further validates the model. PMID:24363822

Sharma, Neel K.; Gupta, Amod; Prabhakar, Sudesh; Sharma, Suresh K.; Singh, Ramandeep

2013-01-01

40

Identification of the gene responsible for Best macular dystrophy  

Microsoft Academic Search

Best macular dystrophy (BMD), also known as vitelliform macular dystrophy (VMD2; OMIM 153700), is an autosomal dominant form of macular degeneration characterized by an abnormal accumulation of lipofuscin within and beneath the retinal pigment epithelium cells. In pursuit of the disease gene, we limited the minimum genetic region by recombination breakpoint analysis and mapped to this region a novel retina-specific

Markus J. Koisti; Benjamin Bakall; Wen Li; Guochun Xie; Towa Marknell; Ola Sandgren; Kristina Forsman; Gösta Holmgren; Sten Andreasson; Mihailo Vujic; Arthur A. B. Bergen; Valarie McGarty-Dugan; David Figueroa; Christopher P. Austin; Michael L. Metzker; C. Thomas Caskey; Konstantin Petrukhin; Claes Wadelius

1998-01-01

41

Increased levels of vascular endothelial growth factor and interleukin-6 in the aqueous humor of diabetics with macular edema  

Microsoft Academic Search

PURPOSE: To investigate the relationship between diabetic macular edema and the levels of vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) in aqueous humor and plasma.DESIGN: Comparative cross-sectional study.METHODS: Fifty-four eyes from 54 diabetic patients were used. The concentrations of VEGF and IL-6 in undiluted aqueous specimens (obtained from the eyes during cataract surgery) and in plasma were measured by

Hideharu Funatsu; Hidetoshi Yamashita; Hidetaka Noma; Tatsuya Mimura; Tetsuji Yamashita; Sadao Hori

2002-01-01

42

Individuals homozygous for the age-related macular degeneration risk-conferring variant of complement factor H have elevated levels of CRP in the choroid  

PubMed Central

Polymorphisms in the complement factor H gene (CFH) are associated with a significantly increased risk for, or protection against, the development of age-related macular degeneration (AMD). The most documented risk-conferring single-nucleotide polymorphism results in a tyrosine-to-histidine substitution at position 402 (Y402H) of the CFH protein. In this work, we examined the ocular distributions and relative abundance of CFH, several CFH-binding proteins, and abundant serum proteins in the retinal pigmented epithelium (RPE), Bruch's membrane, and choroid (RPE–choroid) in CFH homozygotes possessing either the “at-risk” 402HH or “normal” 402YY variants. Although CFH immunoreactivity is high in the choroid and in drusen, no differences in CFH-labeling patterns between genotypes are apparent. In contrast, at-risk individuals have significantly higher levels of the CFH-binding protein, C-reactive protein (CRP), in the choroidal stroma. Immunoblots confirm that at-risk individuals have ?2.5-fold higher levels of CRP in the RPE–choroid; no significant differences in the levels of CFH or other serum proteins are detected. Similarly, we find no differences in CFH transcription levels in the RPE–choroid nor evidence for local ocular CRP transcription. Increased levels of CRP in the choroid may reflect a state of chronic inflammation that is a by-product of attenuated CFH complement-inhibitory activity in those who possess the CFH at-risk allele. Because the CRP-binding site in CFH lies within the domain containing the Y402H polymorphism, it is also possible that the AMD risk-conferring allele alters the binding properties of CFH, thereby leading to choroidal CRP deposition, contributing to AMD pathogenesis. PMID:17079491

Johnson, P. T.; Betts, K. E.; Radeke, M. J.; Hageman, G. S.; Anderson, D. H.; Johnson, L. V.

2006-01-01

43

Individuals homozygous for the age-related macular degeneration risk-conferring variant of complement factor H have elevated levels of CRP in the choroid.  

PubMed

Polymorphisms in the complement factor H gene (CFH) are associated with a significantly increased risk for, or protection against, the development of age-related macular degeneration (AMD). The most documented risk-conferring single-nucleotide polymorphism results in a tyrosine-to-histidine substitution at position 402 (Y402H) of the CFH protein. In this work, we examined the ocular distributions and relative abundance of CFH, several CFH-binding proteins, and abundant serum proteins in the retinal pigmented epithelium (RPE), Bruch's membrane, and choroid (RPE-choroid) in CFH homozygotes possessing either the "at-risk" 402HH or "normal" 402YY variants. Although CFH immunoreactivity is high in the choroid and in drusen, no differences in CFH-labeling patterns between genotypes are apparent. In contrast, at-risk individuals have significantly higher levels of the CFH-binding protein, C-reactive protein (CRP), in the choroidal stroma. Immunoblots confirm that at-risk individuals have approximately 2.5-fold higher levels of CRP in the RPE-choroid; no significant differences in the levels of CFH or other serum proteins are detected. Similarly, we find no differences in CFH transcription levels in the RPE-choroid nor evidence for local ocular CRP transcription. Increased levels of CRP in the choroid may reflect a state of chronic inflammation that is a by-product of attenuated CFH complement-inhibitory activity in those who possess the CFH at-risk allele. Because the CRP-binding site in CFH lies within the domain containing the Y402H polymorphism, it is also possible that the AMD risk-conferring allele alters the binding properties of CFH, thereby leading to choroidal CRP deposition, contributing to AMD pathogenesis. PMID:17079491

Johnson, P T; Betts, K E; Radeke, M J; Hageman, G S; Anderson, D H; Johnson, L V

2006-11-14

44

Macular lutein and zeaxanthin are related to brain lutein and zeaxanthin in primates  

Technology Transfer Automated Retrieval System (TEKTRAN)

The xanthophyll pigments lutein and zeaxanthin cross the blood-retina barrier to preferentially accumulate in the macular region of the neural retina. There they form macular pigment, protecting the retina from blue light damage and oxidative stress. Lutein and zeaxanthin also accumulate in brain t...

45

Nitrate-nitrogen levels in rural drinking water: Is there an association with age-related macular degeneration?  

PubMed

We examined the association of nitrate-nitrogen exposure from rural private drinking water and incidence of age-related macular degeneration (AMD). All participants in the Beaver Dam Eye Study (53916 improvement plan code) completed a questionnaire and had an ocular examination including standardized, graded fundus photographs at five examinations. Only information from rural residents in that study are included in this report. Data from an environmental monitoring study with probabilistic-based agro-chemical sampling, including nitrate-nitrogen, of rural private drinking water were available. Incidence of early AMD was associated with elevated nitrate-nitrogen levels in rural private drinking water supply (10.0% for low, 19.2% for medium, and 26.1% for high nitrate-nitrogen level in the right eye). The odds ratios (ORs) were 1.77 (95% confidence interval [CI]: 1.12-2.78) for medium and 2.88 (95% CI: 1.59-5.23) for high nitrate-nitrogen level. Incidence of late AMD was increased for those with medium or high levels of nitrate-nitrogen compared to low levels (2.3% for low and 5.1% for the medium or high nitrate-nitrogen level, for the right eye). The OR for medium or high nitrate-nitrogen groups was 2.80 (95% CI: 1.07-7.31) compared to the low nitrate-nitrogen group. PMID:24007430

Klein, Barbara E K; McElroy, Jane A; Klein, Ronald; Howard, Kerri P; Lee, Kristine E

2013-01-01

46

[Morphological characteristics in macular telangiectasia type 2].  

PubMed

Macular telangiectasia type 2 is characterized by atrophic alterations of the central retina which is accompanied by a defined vascular phenotype. The disease manifests within an oval central retinal area the size of approximately two disc diameters, with a topographic predisposition temporal to the foveal center. Funduscopy reveals reduced retinal transparency, crystalline deposits, mildly ectatic capillaries, thickened venules and retinal pigment plaques. Secondary neovascularization and macular holes may occur during the disease course. Fluorescein angiography usually shows a diffuse leakage and often ectatic capillaries. On optical coherence tomography (OCT) examination, hyporeflective cavities and focal atrophy of the photoreceptor layer represent a frequent finding. A characteristic sign is an increased (para) central signal on fundus autofluorescence imaging due to a reduced density of macular pigment. PMID:25204527

Charbel Issa, P; Heeren, T F C; Krüger, E; Zeimer, M; Pauleikhoff, D; Holz, F G

2014-09-01

47

Genetic basis of continuous variation in the levels and modular inheritance of pigmentation in cichlid fishes  

PubMed Central

Variation in pigmentation type and levels is a hallmark of myriad evolutionary radiations, and biologists have long been fascinated by the factors that promote and maintain variation in coloration across populations. Here, we provide insights into the genetic basis of complex and continuous patterns of colour variation in cichlid fishes, which offer a vast diversity of pigmentation patterns that have evolved in response to both natural and sexual selection. Specifically, we crossed two divergent cichlid species to generate an F2 mapping population that exhibited extensive variation in pigmentation levels and patterns. Our experimental design is robust in that it combines traditional quantitative trait locus (QTL) analysis with population genomics, which has allowed us to move efficiently from QTL interval to candidate gene. In total, we detected 41 QTL and 13 epistatic interactions that underlie melanocyte- and xanthophore-based coloration across the fins and flanks of these fishes. We also identified 2 QTL and 1 interaction for variation in the magnitude of integration among these colour traits. This finding in particular is notable as there are marked differences both within and between species with respect to the complexity of pigmentation patterns. While certain individuals are characterized by more uniform ‘integrated’ colour patterns, others exhibit many more degrees of freedom with respect to the distribution of colour ‘modules’ across the fins and flank. Our data reveal, for the first time, a genetic basis for this difference. Finally, we implicate pax3a as a mediator of continuous variation in the levels of xanthophore-based colour along the cichlid flank. PMID:25156298

Albertson, R. Craig; Powder, Kara E.; Hu, Yinan; Coyle, Kaitlin P.; Roberts, Reade B.; Parsons, Kevin J.

2014-01-01

48

Macular Degeneration  

NSDL National Science Digital Library

This patient education program discusses age-related macular degeneration including the causes, risks, symptoms, diagnosis, treatment options, and management of the disease. It also reviews the anatomy of the eye and vision. This resource is a MedlinePlus Interactive Health Tutorial from the National Library of Medicine, designed and developed by the Patient Education Institute. NOTE: This tutorial requires a special Flash plug-in, version 4 or above. If you do not have Flash, you will be prompted to obtain a free download of the software before you start the tutorial. You will also need an Acrobat Reader, available as a free download, in order to view the Reference Summary.

Patient Education Institute

49

A rare presentation of pigmented paravenous retinochoroidal atrophy  

PubMed Central

A 21-year-old female patient presented with gradual progressive loss of vision in both eyes of 12 years duration. Funduscopic examination revealed bone-spicule pigmentation and choroidal and retinal pigment epithelium atrophy along the vascular arcades, with macular involvement in both eyes. The patient was diagnosed with pigmented paravenous retinochoroidal atrophy which is rare disease, uncommon in females, more commonly affecting the paravascular fundus. Very few cases of macular involvement have been reported. PMID:25709275

Ahmed, Arshee S.; Rishi, Pukhraj

2015-01-01

50

Understanding age-related macular degeneration (AMD): Relationships between the photoreceptor/retinal pigment epithelium/Bruch’s membrane/choriocapillaris complex  

PubMed Central

There is a mutualistic symbiotic relationship between the components of the photoreceptor/retinal pigment epithelium (RPE)/Bruch’s membrane (BrMb)/choriocapillaris (CC) complex that is lost in AMD. Which component in the photoreceptor/RPE/BrMb/CC complex is affected first appears to depend on the type of AMD. In atrophic AMD (~85–90% of cases), it appears that large confluent drusen formation and hyperpigmentation (presumably dysfunction in RPE) are the initial insult and the resorption of these drusen and loss of RPE (hypopigmentation) can be predictive for progression of geographic atrophy (GA). The death and dysfunction of photoreceptors and CC appear to be secondary events to loss in RPE. In neovascular AMD (~10–15% of cases), the loss of choroidal vasculature may be the initial insult to the complex. Loss of CC with an intact RPE monolayer in wet AMD has been observed. This may be due to reduction in blood supply because of large vessel stenosis. Furthermore, the environment of the CC, basement membrane and intercapillary septa, is a proinflammatory milieu with accumulation of complement components as well as proinflammatory molecules like CRP during AMD. In this toxic milieu, CC die or become dysfunction making adjacent RPE hypoxic. These hypoxic cells then produce angiogenic substances like VEGF that stimulate growth of new vessels from CC, resulting in choroidal neovascularization (CNV). The loss of CC might also be a stimulus for drusen formation since the disposal system for retinal debris and exocytosed material from RPE would be limited. Ultimately, the photoreceptors die of lack of nutrients, leakage of serum components from the neovascularization, and scar formation. Therefore, the mutualistic symbiotic relationship within the photoreceptor/RPE/BrMb/CC complex is lost in both forms of AMD. Loss of this functionally integrated relationship results in death and dysfunction of all of the components in the complex. PMID:22542780

Bhutto, Imran; Lutty, Gerard

2012-01-01

51

Omega-3 Supplementation Combined With Anti–Vascular Endothelial Growth Factor Lowers Vitreal Levels of Vascular Endothelial Growth Factor in Wet Age-Related Macular Degeneration  

PubMed Central

PURPOSE To determine the influence of omega-3 supplementation on vitreous vascular endothelial growth factor A (VEGF-A) levels in patients with exudative age-related macular degeneration (wet AMD) receiving intravitreal anti-VEGF treatment. DESIGN Prospective, randomized, open-label, single-center, clinical trial, consecutive interventional case series. METHODS The study included 3 cohorts with wet AMD and a control group with epiretinal membrane or macular hole. Twenty wet AMD patients being treated with anti-VEGF were randomized to daily supplementation of antioxidants, zinc, and carotenoids with omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid; group 1, n = 10) or without omega-3 fatty acids (group 2, n = 10). They were compared with an anti-VEGF treatment-naďve wet AMD group (group 3, n = 10) and an epiretinal membrane or macular hole group (group 4, n = 10). Primary outcome was vitreal VEGF-A levels (at the time of anti-VEGF injection). Secondary outcomes were plasma VEGF-A and central foveal thickness. Patients with new submacular hemorrhage or any other treatment within 3 months were excluded. Final analyses included 9, 6, 7, and 8 patients in groups 1 through 4, respectively. RESULTS Patients receiving omega-3s (group 1) had significantly lower levels of vitreal VEGF-A (141.11 ± 61.89 pg/mL) when compared with group 2 (626.09 ± 279.27 pg/mL; P = .036) and group 3 (735.48 ± 216.43 pg/mL; P = .013), but similar levels to group 4 (235.81 ± 33.99 pg/mL; P=.215). All groups showed similar values for plasma VEGF-A and central foveal thickness measurements. CONCLUSIONS This study demonstrated that omega-3 supplementation combined with anti-VEGF treatment is associated with decreased vitreal VEGF-A levels in wet AMD patients. PMID:25089351

REZENDE, FLAVIO A.; LAPALME, ERIC; QIAN, CYNTHIA X.; SMITH, LOIS E.; SANGIOVANNI, JOHN PAUL; SAPIEHA, PRZEMYSLAW

2015-01-01

52

Study of Ethane Level in Exhaled Breath in Patients with Age-Related Macular Degeneration: Preliminary Study  

Microsoft Academic Search

Purpose: A variety of factors have been implicated in the pathogenesis of age-related macular degeneration (ARMD), and oxidative stress plays an important role in the onset and progression of the disease. Breath ethane is now considered a specific and non-invasive test for determining and monitoring the trend of lipid peroxidation and free radical-induced damage in vivo. This test provides an

C. Cagini; A. Giordanelli; T. Fiore; R. Giardinieri; B. Malici; G. E. De Medio; M. A. Pelli; F. De Bellis; E. Capodicasa

2011-01-01

53

Pathophysiology of Macular Edema  

Microsoft Academic Search

Macular edema is defined as an accumulation of fluid in the outer plexiform layer and the inner nuclear layer as well as a swelling of Müller cells of the retina. It consists of a localized expansion of the retinal extracellular space (sometimes associated with the intracellular space) in the macular area. Macular edema is a common cause of a sudden

Stefan Scholl; Janna Kirchhof; Albert J. Augustin

2010-01-01

54

Changes of tocopherols, tocotrienols, ?-oryzanol, and ?-aminobutyric acid levels in the germinated brown rice of pigmented and nonpigmented cultivars.  

PubMed

This study examined the changes of tocopherols (Toc), tocotrienols (T3), ?-oryzanol (GO), and ?-aminobutyric acid (GABA) contents in germinated brown rice (GBR) of pigmented and nonpigmented cultivars under different germination conditions. Results showed that the Toc and T3 contents in GBR were significantly different between treatments in both rice cultivars. The pigmented GBR possessed higher total vitamin E, total Toc, total T3, and GO contents than the nonpigmented GBR; however, its level of GABA was lower. The order of the three highest vitamin E homologues in pigmented and nonpigmented GBR was ?-T3 > ?-Toc > ?-Toc and ?-Toc > ?-T3 > ?-T3, respectively; ?-Toc, ?-T3, ?-Toc, and ?-T3 were present in only small amounts (?1.0 mg/kg) in GBR of both cultivars. Although both cultivars showed an increase in GABA contents with increasing germination time, the GABA content in nonpigmented GBR was higher. PMID:24313881

Ng, Lean-Teik; Huang, Shao-Hua; Chen, Yen-Ting; Su, Chun-Han

2013-12-26

55

Skin pigmentation, sun exposure and vitamin D levels in children of the Avon Longitudinal Study of Parents and Children  

PubMed Central

Background It has been hypothesised that light skin pigmentation has arisen to ensure adequate levels of vitamin D as human populations moved out of Africa and into higher latitudes. Vitamin D, which is primarily obtained through exposure to sunlight (specifically ultraviolet radiation B (UVR-B)), has been inversely associated with several complex diseases. Greater sun exposure, on the other hand, is a well-known cause of skin cancer. The potential of UVR to be beneficial for some health outcomes but detrimental for others has prompted a public health debate on how to balance the positive and negative consequences of sun exposure. In this study we aimed to determine the validity of the evolutionary hypothesis linking lighter skin with higher vitamin D concentrations in a European population. Additionally, we aimed to examine the influence of pigmentation on personal behaviour towards sunlight exposure and the effects of this behaviour on vitamin D. Methods We combined genetic variants strongly associated with skin colour, tanning or freckling to create genetic scores for each of these phenotypes. We examined the association of the scores with pigmentary traits, sun exposure and serum 25-hydroxyvitamin D (25(OH)D) levels among children of the Avon Longitudinal Study of Parents and Children (ALSPAC, N?=?661 to 5649). Results We found that fairer-skinned children, i.e. those with higher pigmentation score values, had higher levels of 25(OH)D (0.6 nmol/l; 95% CI 0.2, 1.0; per unit increase in skin colour score; N?=?5649). These children also used more protection against the damaging effects of UVR. Conclusions In this population taking protective measures against sunburn and skin cancer does not seem to remove the positive effect that having a less pigmented skin has on vitamin D production. Our findings require further replication as skin pigmentation showed only a small effect on circulating 25(OH)D. PMID:24924479

2014-01-01

56

Ionizing radiation induced changes in phenotype, photosynthetic pigments and free polyamine levels in Vigna radiata (L.) Wilczek.  

PubMed

Effects of gamma rays on the free polyamine (PA) levels were studied in Vigna radiata (L.) Wilczek. Seeds exposed to different doses of gamma rays were checked for damage on phenotype, germination frequency and alteration in photosynthetic pigments. Free polyamine levels were estimated from seeds irradiated in dry and water imbibed conditions. Polyamine levels of seedlings grown from irradiated seeds, and irradiated seedlings from unexposed seeds were also measured. Damage caused by gamma irradiation resulted in decrease in final germination percentage and seedling height. Photosynthetic pigments decreased in a dose dependent manner as marker of stress. Polyamines decreased in irradiated dry seeds and in seedlings grown from irradiated seeds. Radiation stress induced increase in free polyamines was seen in irradiated imbibed seeds and irradiated seedlings. Response of polyamines towards gamma rays is dependent on the stage of the life cycle of the plant. PMID:23454839

Sengupta, Mandar; Chakraborty, Anindita; Raychaudhuri, Sarmistha Sen

2013-05-01

57

Analysis of glutathione S -transferase Pi isoform (GSTP1) single-nucleotide polymorphisms and macular telangiectasia type 2  

Microsoft Academic Search

Recent imaging studies have suggested that macular pigment is decreased centrally in macular telangiectasia type 2 (MT2).\\u000a The uptake of xanthophyll pigment into the macula is thought to be facilitated by a xanthophyll-binding protein (XBP). The\\u000a Pi isoform of glutathione S-transferase (GSTP1) represents one such XBP with high binding affinity. This case–control study aimed to determine whether\\u000a two common single-nucleotide

Joshua A. Szental; Paul N. Baird; Andrea J. Richardson; F. M. Amirul Islam; Hendrik P. N. Scholl; Peter Charbel Issa; Frank G. Holz; Mark Gillies; Robyn H. Guymer

2010-01-01

58

Delayed Macular Hole Closure  

PubMed Central

Purpose The presented case raises questions regarding the favorable scheduling of planned postoperative care and the ideal observation interval to decide for reoperations in macular hole surgery. Furthermore a discussion about the use of short- and long-acting gas tamponades in macular hole surgery is encouraged. Methods We present an interventional case report and a short review of the pertinent literature. Results We report a case of spontaneous delayed macular hole closure after vitreoretinal surgery had been performed initially without the expected success. A 73-year-old male Caucasian patient presented at our clinic with a stage 2 macular hole in his left eye. He underwent 23-gauge pars plana vitrectomy and internal limiting membrane peeling with a 20% C2F6-gas tamponade. Sixteen days after the procedure, an OCT scan revealed a persistent stage 2 macular hole, and the patient was scheduled for reoperation. Surprisingly, at the date of planned surgery, which was another 11 days later, the macular hole had resolved spontaneously without any further intervention. Conclusions So far no common opinion exists regarding the use of short- or long-acting gas in macular hole surgery. Our case of delayed macular hole closure after complete resorption of the gas tamponade raises questions about the need and duration of strict prone positioning after surgery. Furthermore short-acting gas might be as efficient as long-acting gas. We suggest to wait with a second intervention at least 4 weeks after the initial surgery, since a delayed macular hole closure is possible. PMID:24847257

Distelmaier, Peter; Meyer, Linda M.; Fischer, Marie T.; Philipp, Sebastian; Paquet, Patrick; Mammen, Antje; Haller, Katharina; Schönfeld, Carl-Ludwig

2014-01-01

59

The Impact of Macular Laser Photocoagulation on Contrast Sensitivity Function in Patients with Clinically Significant Macular Edema  

Microsoft Academic Search

Background: Contrast sensitivity is an important aspect of visual function and is even more important for ordinary daily tasks than visual acuity. Contrast sensitivity function may be deteriorated to a significant level in diabetic retinopathy, especially in diabetic macular edema. The objective of this study was to determine the impact of macular laser photocoagulation—as the standard treatment of clinically significant

Mohammad-Sadegh Farahvash; Amir-Hossein Mahmoudi; Mohammad-Mehdi Farahvash; Ali Tabatabaee; Mohammad Riazi; Shiva Mohammadzadeh; Houshang Faghihi; Mehdi Nilli-Ahmadabadi; Ahmad Mirshahi; Reza Karkhaneh; Zahra Aalami-Harandi; Ahmad Javadian; Ali Abdolahi; Alireza Lashey

2008-01-01

60

Clinicopathologic findings in Best vitelliform macular dystrophy  

PubMed Central

Purpose To correlate the clinical and histopathologic features of Best vitelliform macular dystrophy (BVMD). Methods Two eyes were obtained postmortem from a patient with BVMD. The patient’s clinical information was reviewed. Series sections of the globes were performed and sequentially stained with hematoxylin-eosin, periodic acid-Schiff or Masson trichrome. A section of the left macula was submitted for electron microscopic processing. Histopathologic findings were reconstructed in a scaled two-dimensional map and compared with fundus photography, fundus autofluorescence (FAF), fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) images. Results The macular lesion of the right eye was identified as a well-demarcated region with pigment, elevated submacular yellow material and subretinal fluid. This corresponded histopathologically to a well-circumscribed area of RPE hyperplasia, accumulation of lipofuscin in the RPE, deposition of granular material in the photoreceptors, macrophages and drusen. The left eye displayed a 1 disc diameter chorioretinal scar with surrounding shallow fluid and submacular pigment. This corresponded to RPE changes and a fibrocellular proliferation in the choriocapillaris. Conclusion Histopathologic mapping revealed retinal edema, RPE abnormalities, drusen and a chorioretinal scar in BVMD that correlated with the fundus, FFA, FAF and OCT findings. PMID:21136072

Zhang, Qing; Small, Kent W.

2012-01-01

61

Macular Thickness and Amblyopia  

PubMed Central

Purpose: To compare macular thickness in children with functional amblyopia and those without amblyopia using optical coherence tomography (OCT). Methods: This case-control study was conducted on 93 children aged 3–10 years including 44 cases with unilateral amblyopia and 49 subjects without amblyopia. Amblyopic eyes were considered as the case group and their fellow eyes as internal controls; eyes of non-amblyopic children served as the external control. Macular thickness of all eyes were measured by optical coherence tomography in the center (foveola), 1 mm ring (fovea), and 3 and 6 mm rings and compared. Results: Although macular thickness was generally not different between the study groups, there was a significant difference in central macular thickness between eyes with moderate to severe amblyopia and the external controls (P = 0.037). Foveal thickness difference exceeding 10 microns between fellow eyes was detected in a larger number of amblyopic children as compared to non-amblyopic controls (P = 0.002). Mean foveal thickness was greater in boys (P = 0.037) but there was no significant difference in foveal thickness among various types of refractive errors. Conclusion: Although there was no significant relationship between macular thickness and amblyopia, foveolar thickness in eyes with moderate to severe amblyopia was significantly greater than the external controls. Further studies with more cases of moderate to severe amblyopia are recommended. PMID:25709774

Rajavi, Zhale; Moghadasifar, Hossein; Feizi, Mohadese; Haftabadi, Narges; Hadavand, Reza; Yaseri, Mehdi; Sheibani, Kourosh; Norouzi, Ghazal

2014-01-01

62

A level-set method for pathology segmentation in fluorescein angiograms and en face retinal images of patients with age-related macular degeneration  

NASA Astrophysics Data System (ADS)

The visibility and continuity of the inner segment outer segment (ISOS) junction layer of the photoreceptors on spectral domain optical coherence tomography images is known to be related to visual acuity in patients with age-related macular degeneration (AMD). Automatic detection and segmentation of lesions and pathologies in retinal images is crucial for the screening, diagnosis, and follow-up of patients with retinal diseases. One of the challenges of using the classical level-set algorithms for segmentation involves the placement of the initial contour. Manually defining the contour or randomly placing it in the image may lead to segmentation of erroneous structures. It is important to be able to automatically define the contour by using information provided by image features. We explored a level-set method which is based on the classical Chan-Vese model and which utilizes image feature information for automatic contour placement for the segmentation of pathologies in fluorescein angiograms and en face retinal images of the ISOS layer. This was accomplished by exploiting a priori knowledge of the shape and intensity distribution allowing the use of projection profiles to detect the presence of pathologies that are characterized by intensity differences with surrounding areas in retinal images. We first tested our method by applying it to fluorescein angiograms. We then applied our method to en face retinal images of patients with AMD. The experimental results included demonstrate that the proposed method provided a quick and improved outcome as compared to the classical Chan-Vese method in which the initial contour is randomly placed, thus indicating the potential to provide a more accurate and detailed view of changes in pathologies due to disease progression and treatment.

Mohammad, Fatimah; Ansari, Rashid; Shahidi, Mahnaz

2013-03-01

63

Levels of Aqueous Humor Trace Elements in Patients with Non-Exsudative Age-related Macular Degeneration: A Case-control Study  

PubMed Central

Trace elements might play a role in the complex multifactorial pathogenesis of age-related macular degeneration (AMD). The aim of this study was to measure alterations of trace elements levels in aqueous humor of patients with non-exsudative (dry) AMD. For this pilot study, aqueous humor samples were collected from patients undergoing cataract surgery. 12 patients with dry AMD (age 77.9±6.62, female 8, male 4) and 11 patients without AMD (age 66.6±16.7, female 7, male 4) were included. Aqueous levels of cadmium, cobalt, copper, iron, manganese, selenium, and zinc were measured by use of Flow-Injection-Inductively-Coupled-Plasma-Mass-Spectrometry (FI-ICP-MS), quality controlled with certified standards. Patients with AMD had significantly higher aqueous humor levels of cadmium (median: 0.70 µmol/L, IQR: 0.40–0.84 vs. 0.06 µmol/L; IQR: 0.01–.018; p?=?0.002), cobalt (median: 3.1 µmol/L, IQR: 2.62–3.15 vs. 1.17 µmol/L; IQR: 0.95–1.27; p<0.001), iron (median: 311 µmol/L, IQR: 289–329 vs. 129 µmol/L; IQR: 111–145; p<0.001) and zinc (median: 23.1 µmol/L, IQR: 12.9–32.6 vs. 5.1 µmol/L; IQR: 4.4–9.4; p?=?0.020) when compared with patients without AMD. Copper levels were significantly reduced in patients with AMD (median: 16.2 µmol/L, IQR: 11.4–31.3 vs. 49.9 µmol/L; IQR: 32.0–.142.0; p?=?0.022) when compared to those without. No significant differences were observed in aqueous humor levels of manganese and selenium between patients with and without AMD. After an adjustment for multiple testing, cadmium, cobalt, copper and iron remained a significant factor in GLM models (adjusted for age and gender of the patients) for AMD. Alterations of trace element levels support the hypothesis that cadmium, cobalt, iron, and copper are involved in the pathogenesis of AMD. PMID:23457607

Jünemann, Anselm G. M.; Stopa, Piotr; Michalke, Bernhard; Chaudhri, Anwar; Reulbach, Udo; Huchzermeyer, Cord; Schlötzer-Schrehardt, Ursula; Kruse, Friedrich E.; Zrenner, Eberhart; Rejdak, Robert

2013-01-01

64

Skin Pigment  

MedlinePLUS

... Resources for Help and Information The One-Page Merck Manual of Health Medical Terms Conversion Tables Manuals available ... Disorders Overview of Skin Pigment Albinism Vitiligo Melasma Merck Manual > Patients & Caregivers > Skin Disorders > Pigment Disorders 4 Overview ...

65

[Uveitic macular edema].  

PubMed

Macular edema may complicate anterior, intermediate, and posterior uveitis, which may be due to various infectious, tumoral, or autoimmune etiologies. Breakdown of the internal or external blood-retinal barrier is involved in the pathogenesis of inflammatory macular edema. Optical coherence tomography has become standard in confirming the diagnosis of macular thickening, due to its non-invasive, reproducible and sensitivity characteristics. Fluorescein and indocyanine green angiography allows for, in addition to study of the macula, screening for associated vasculitis, detection of ischemic areas, easy diagnosis of preretinal, prepaillary or choroidal neovascular complications, and it can provide etiological information and may be required to evaluate the therapeutic response. Treatment of inflammatory macular edema requires specific treatment in cases of infectious or tumoral etiologies. If it remains persistent, or occurs in other etiologies, anti-inflammatory treatments are needed. Steroid treatment, available in intravitreal, subconjunctival and sub-Tenon's routes, are widely used. Limitations of local use include induced cataract and glaucoma, and their short-lasting action. Such products may reveal retinal infection. Thus, bilateral chronic sight-threatening posterior uveitis often requires systemic treatment, and steroids represent the classic first-line therapy. In order to reduce the daily steroid dose, immunosuppressant or immunomodulatory drugs may be added. Certain of these compounds are now available intravitreally. PMID:25547721

Fardeau, C; Champion, E; Massamba, N; LeHoang, P

2015-01-01

66

Carotenoid accumulation in orange-pigmented Capsicum annuum fruit, regulated at multiple levels  

PubMed Central

The pericarp of Capsicum fruit is a rich dietary source of carotenoids. Accumulation of these compounds may be controlled, in part, by gene transcription of biosynthetic enzymes. The carotenoid composition in a number of orange-coloured C. annuum cultivars was determined using HPLC and compared with transcript abundances for four carotenogenic enzymes, Psy, LcyB, CrtZ-2, and Ccs determined by qRT-PCR. There were unique carotenoid profiles as well as distinct patterns of transcription of carotenogenic enzymes within the seven orange-coloured cultivars. In one cultivar, ‘Fogo’, carrying the mutant ccs-3 allele, transcripts were detected for this gene, but no CCS protein accumulated. The premature stop termination in ccs-3 prevented expression of the biosynthetic activity to synthesize the capsanthin and capsorubin forms of carotenoids. In two other orange-coloured cultivars, ‘Orange Grande’ and ‘Oriole’, both with wild-type versions of all four carotenogenic enzymes, no transcripts for Ccs were detected and no red pigments accumulated. Finally, in a third case, the orange-coloured cultivar, Canary, transcripts for all four of the wild-type carotenogenic enzymes were readily detected yet no CCS protein appeared to accumulate and no red carotenoids were synthesized. In the past, mutations in Psy and Ccs have been identified as the loci controlling colour in the fruit. Now there is evidence that a non-structural gene may control colour development in Capsicum. PMID:21948863

Rodriguez-Uribe, Laura; Guzman, Ivette; Rajapakse, Wathsala; Richins, Richard D.; O’Connell, Mary A.

2012-01-01

67

Low-level night-time light therapy for age-related macular degeneration (ALight): study protocol for a randomized controlled trial  

PubMed Central

Background Age-related macular degeneration (AMD) is the leading cause of blindness among older adults in the developed world. The only treatments currently available, such as ranibizumab injections, are for neovascular AMD, which accounts for only 10 to 15% of people with the condition. Hypoxia has been implicated as one of the primary causes of AMD, and is most acute at night when the retina is most metabolically active. By increasing light levels at night, the metabolic requirements of the retina and hence the hypoxia will be considerably reduced. This trial seeks to determine whether wearing a light mask that emits a dim, green light during the night can prevent the progression of early AMD. Methods/design ALight is a Phase I/IIa, multicentre, randomized controlled trial. Sixty participants (55 to 88 years old) with early AMD in one eye and neovascular AMD (nAMD) in the fellow eye will be recruited from nAMD clinics. They will be randomized (in the ratio 1:1), either to receive the intervention or to be in the untreated control group, stratified according to risk of disease progression. An additional 40 participants with healthy retinal appearance, or early AMD only, will be recruited for a baseline cross-sectional analysis. The intervention is an eye mask that emits a dim green light to illuminate the retina through closed eyelids at night. This is designed to reduce the metabolic activity of the retina, thereby reducing the potential risk of hypoxia. Participants will wear the mask every night for 12 months. Ophthalmologists carrying out monthly assessments will be masked to the treatment group, but participants will be aware of their treatment group. The primary outcome measure is the proportion of people who show disease progression during the trial period in the eye with early AMD. A co-primary outcome measure is the rate of retinal adaptation. As this is a trial of a CE-marked device for an off-label indication, a further main aim of this trial is to assess safety of the mask in the cohort of participants with AMD. Trial registration International Standard Randomised Controlled Trials Register: ISRCTN82148651 PMID:24965385

2014-01-01

68

Aging Is Not a Disease: Distinguishing Age-Related Macular Degeneration from Aging  

PubMed Central

Age-related macular degeneration (AMD) is a disease of the outer retina, characterized most significantly by atrophy of photoreceptors and retinal pigment epithelium accompanied with or without choroidal neovascularization. Development of AMD has been recognized as contingent on environmental and genetic risk factors, the strongest being advanced age. In this review, we highlight pathogenic changes that destabilize ocular homeostasis and promote AMD development. With normal aging, photoreceptors are steadily lost, Bruch's membrane thickens, the choroid thins, and hard drusen may form in the periphery. In AMD, many of these changes are exacerbated in addition to the development of disease-specific factors such as soft macular drusen. Para-inflammation, which can be thought of as an intermediate between basal and robust levels of inflammation, develops within the retina in an attempt to maintain ocular homeostasis, reflected by increased expression of the anti-inflammatory cytokine IL-10 coupled with shifts in macrophage plasticity from the pro-inflammatory M1 to the anti-inflammatory M2 polarization. In AMD, imbalances in the M1 and M2 populations together with activation of retinal microglia are observed and potentially contribute to tissue degeneration. Nonetheless, the retina persists in a state of chronic inflammation and increased expression of certain cytokines and inflammasomes is observed. Since not everyone develops AMD, the vital question to ask is how the body establishes a balance between normal age-related changes and the pathological phenotypes in AMD. PMID:23933169

Ardeljan, Daniel; Chan, Chi-Chao

2013-01-01

69

Investigating a C1QTNF5 mutation associated with macular degeneration   

E-print Network

C1QTNF5 is a 25kDa short chain collagen of unknown function which is mutated in late-onset retinal macular degeneration (L-ORMD). L-ORMD is an autosomal dominant disease characterised by sub-retinal pigment epithelial ...

Slingsby, Fern

2009-01-01

70

Prematurely senescent ARPE-19 cells display features of age-related macular degeneration  

Microsoft Academic Search

The etiology of age-related macular degeneration (AMD), the leading cause of blindness in the developed world, remains poorly understood, but may be related to cumulative oxidative stress. The prime target of the disease is the retinal pigmented epithelium (RPE). To study the molecular mechanisms underlying RPE degeneration, we investigated whether repetitive oxidative stress induced premature senescence in RPE cells from

Anne-Lise Glotin; Florence Debacq-Chainiaux; Jean-Yves Brossas; Anne-Marie Faussat; Jacques Tréton; Anna Zubielewicz; Olivier Toussaint; Frédéric Mascarelli

2008-01-01

71

Dependence of Photosynthetic Capacity, Photosynthetic Pigment Allocation, and Carbon Storage on Nitrogen Levels in Foliage of Aspen Stands  

NASA Technical Reports Server (NTRS)

The role of foliar nitrogen (N) in the seasonal dynamics and vertical canopy distribution of photosynthetic pigments, photosynthetic capacity, and carbon (C) storage was investigated in boreal broadleaved species. The study was conducted at two different aged stands (60 y and 15 y) in 1994 and 1996 in Saskatchewan, Canada as part of the Boreal Ecosystem-Atmosphere Study (BOREAS). Foliage in upper and lower strata was examined for aspen (Populus tremuloides Michx.) and its associated hazelnut shrub (Corylus americana Walt.). We determined that C accumulation, expressed as dry mass per unit leaf area (mg C cm (exp -2)), was linearly dependent on N content (approximately 0.3- 3.5 mg N cm (exp -2))(r (exp 2) = 0.93, n=383, P less than 0.001) when eleven foliage groups were defined according to species, site, and developmental stage. C assembly was greatest in the upper aspen strata of both sites (seasonal average, 40.1 plus or minus 0.6 mg C cm (exp -2)), intermediate in the lower aspen strata (32.7 plus or minus 0.6), and considerably lower, and similar, in the hazelnut shrub layers (23.7 plus or minus 0.6) and in expanding aspen leaves (23.8 plus or minus 0.5); the lowest C assembly per unit N occurred in the two youngest, emerging leaf groups (17.1 plus or minus 0.6). Other relationships among physiological and biochemical variables were typically non-linear and were confounded by inclusion of the three groups of young (i.e., emerging or expanding) leaves, unless these were separately identified. Net C uptake, measured as photosynthetic capacity (A (sub max), micromole CO2 m (exp -2) s (exp -1)), was greater in aspen throughout the season, and optimal in mid-summer at a C:N ratio of approximately 18 (approximately 2.3 %N). When young leaves were excluded and logarithms of both variables were used, A (sub max) was approximately linearly dependent on N (mg N cm (exp-2) (r (exp 2) = 0.85, n= 193, P less than 0.001), attributed to incorporation of N into photosynthetic complexes and enzymes. In mature leaves, differences in pigment content vs. N among canopy strata were accentuated when N was expressed per unit leaf area (Mg cm (exp -2)) . However, the simplest log-linear relationship between a pigment variable and N was obtained for a ratio describing the relative allocation of photosynthetic pigment to Chl a (Chl a/[Chl b + carotenoids], microgram cm (exp -2)/ microgram cm-2) vs. %N (r (exp 2) = 0.90, n=343, P less than 0.001). Attainment of comparable A (sub max) Chl a content and relative Chl a allocation per unit N (mg cm (exp -2)) was achieved at different foliar N levels per canopy group: the lowest N requirement was for hazelnut leaves in the lowest, shaded stratum at the older, closed canopy site; the highest N requirement was in aspen leaves of the upper-most stratum at the younger, more open canopy site. These results highlight the differences in physiological responses between young and fully expanded leaves and show that sustaining those foliar constituents and processes important to C balance may require higher foliar N levels in leaves of establishing vs. mature aspen stands. There may be implications for remote-sensing assessments made for carbon balance in springtime, or over a landscape mosaic comprised of different aged stands.

Middleton, Elizabeth M.; Sullivan, Joseph H.; Papagno, Andrea J.

2000-01-01

72

Atypical vitelliform macular dystrophy in a 5-generation family.  

PubMed Central

Five generations of a family with autosomal dominant atypical vitelliform macular dystrophy (A-VMD) were studied. This dystrophy is similar to autosomal dominant Best's vitelliform dystrophy (B-VMD) but clinically more closely resembles sporadic pseudovitelliform macular degeneration (P-VMD). Of the family members who were 14 years or older 43 (24 females and 19 males) of the 101 at risk (43%) were affected. Vision varied from 20/20 to 20/200. Field defects and tritan colour defects were invariably present only when vision was less than or equal to 20/200, but these defects were sometimes present when vision was good. The electrooculographic studies (LP/DT ratios) in this family were found to be normal or reduced and did not correlate with visual acuity. Minimal retinal findings consisted of macular or extramacular punctate yellow lesions or both in the retinal pigment epithelium, which were hypofluorescent by angiography, and retinal pigment epithelial defects in the temporal nerve fibre bundle, which were hyperfluorescent by angiography. Fluorescein angiographic changes were invariably present when retinal lesions were noted, and this was the most reliable test in identifying genotypically affected family members with minimal phenotypic expression. Images PMID:6607743

Hittner, H. M.; Ferrell, R. E.; Borda, R. P.; Justice, J.

1984-01-01

73

High levels of pigment epithelium-derived factor in diabetes impair wound healing through suppression of wnt signaling.  

PubMed

Diabetic foot ulcer (DFU) caused by impaired wound healing is a common vascular complication of diabetes. The current study revealed that plasma levels of pigment epithelium-derived factor (PEDF) were elevated in type 2 diabetic patients with DFU and in db/db mice. To test whether elevated PEDF levels contribute to skin wound-healing delay in diabetes, endogenous PEDF was neutralized with an anti-PEDF antibody in db/db mice. Our results showed that neutralization of PEDF accelerated wound healing, increased angiogenesis in the wound skin, and improved the functions and numbers of endothelial progenitor cells (EPCs) in the diabetic mice. Further, PEDF-deficient mice showed higher baseline blood flow in the skin, higher density of cutaneous microvessels, increased skin thickness, improved numbers and functions of circulating EPCs, and accelerated wound healing compared with wild-type mice. Overexpression of PEDF suppressed the Wnt signaling pathway in the wound skin. Lithium chloride-induced Wnt signaling activation downstream of the PEDF interaction site attenuated the inhibitory effect of PEDF on EPCs and rescued the wound-healing deficiency in diabetic mice. Taken together, these results suggest that elevated circulating PEDF levels contribute to impaired wound healing in the process of angiogenesis and vasculogenesis through the inhibition of Wnt/?-catenin signaling. PMID:25368097

Qi, Weiwei; Yang, Chuan; Dai, Zhiyu; Che, Di; Feng, Juan; Mao, Yuling; Cheng, Rui; Wang, Zhongxiao; He, Xuemin; Zhou, Ti; Gu, Xiaoqiong; Yan, Li; Yang, Xia; Ma, Jian-Xing; Gao, Guoquan

2015-04-01

74

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

Microsoft Academic Search

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

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

2010-01-01

75

FOOD LEVEL IN RELATION TO RATE OF DEVELOPMENT AND EYE PIGMENTATION IN DROSOPHILA MELANOGASTER  

Microsoft Academic Search

Beadle and Law (1938) have shown that the eye color hormones concerned in the differentiation of vermilion and cinmibar eye colors in Drosophila melanogaster are effective when administered with larval food. In attempting to develop a standardized method of feeding these hormones quantitatively, it became evident that information was needed on the relation between food-level and rate of development (see

G. W. BEADLE; EDWARD L TATUM; C. W. CLANCY

76

Age-Related Macular Degeneration  

MedlinePLUS

... related Macular Degeneration: What is AMD? In This Topic What is AMD? Wet AMD Dry AMD Risk ... for More Information National Institute on Aging Related Topics Low Vision More Vision Topics The information in ...

77

B-Scan and “En-Face” Spectral-Domain Optical Coherence Tomography Imaging for the Diagnosis and Followup of Acute Retinal Pigment Epitheliitis  

PubMed Central

Purpose. To report B-scan and “En-face” spectral-domain optical coherence tomography (SD-OCT) findings in acute retinal pigment epitheliitis (ARPE). Methods. Two patients (3 eyes) with ARPE were examined. Fluorescein and indocyanine green (ICGA) angiography, B-scan, and “En-face” SD-OCT were performed in each patient at initial and follow-up visits. Results. Both patients presented with acute onset of blurred vision, and one with bilateral involvement. B-can OCT revealed disruption of the macular retinal pigment epithelial (RPE) inner band layer and photoreceptors' inner and outer segment (IS-OS) junction. Hyperreflective dots were observed in the outer nuclear layer (ONL) above the RPE/IS-OS disruption. Just around these hyperreflective dots, slight thickening of the hyperreflective IS/OS junction was observed. During the late phase, indocyanine green angiography (ICGA) showed a macular cockade-like hyperfluorescent halo. “En-face” OCT showed the same cockade-like appearance with a hyporeflective center and a hyperreflective border matching the pattern observed on ICGA. At followup, as vision improved without treatment, B-scan OCT demonstrated progressive resolution of the hyperreflective and disrupted lesions; “en-face” OCT also showed disappearance of the macular cockade-like halo with a transient discrete hyperreflective macular star at the RPE level in one eye. Conclusion. “En-face” OCT associated with B-scan SD-OCT analysis appears to be very helpful in the diagnosis and followup of ARPE. The pathophysiology of ARPE remains complex and still poorly understood. These techniques help define the location and extent of structural damage occurring in this disease. PMID:23476659

De Bats, Flore; Wolff, Benjamin; Mauget-Fa˙sse, Martine; Scemama, Claire; Kodjikian, Laurent

2013-01-01

78

Mechanism of Inflammation in Age-Related Macular Degeneration: An Up-to-Date on Genetic Landmarks  

PubMed Central

Age-related macular degeneration (AMD) is the most common cause of irreversible visual impairment among people over 50 years of age, accounting for up to 50% of all cases of legal blindness in Western countries. Although the aging represents the main determinant of AMD, it must be considered a multifaceted disease caused by interactions among environmental risk factors and genetic backgrounds. Mounting evidence and/or arguments document the crucial role of inflammation and immune-mediated processes in the pathogenesis of AMD. Proinflammatory effects secondary to chronic inflammation (e.g., alternative complement activation) and heterogeneous types of oxidative stress (e.g., impaired cholesterol homeostasis) can result in degenerative damages at the level of crucial macular structures, that is photoreceptors, retinal pigment epithelium, and Bruch's membrane. In the most recent years, the association of AMD with genes, directly or indirectly, involved in immunoinflammatory pathways is increasingly becoming an essential core for AMD knowledge. Starting from the key basic-research notions detectable at the root of AMD pathogenesis, the present up-to-date paper reviews the best-known and/or the most attractive genetic findings linked to the mechanisms of inflammation of this complex disease. PMID:24369445

Parmeggiani, Francesco; Sorrentino, Francesco S.; Romano, Mario R.; Incorvaia, Carlo; D'Angelo, Sergio; Perri, Paolo; De Nadai, Katia; Bonomo Roversi, Elia; Franceschelli, Paola; Sebastiani, Adolfo

2013-01-01

79

Elevated plasma levels of pigment epithelium-derived factor correlated with inflammation and lung function in COPD patients  

PubMed Central

Rationale Pigment epithelium-derived factor (PEDF) is a 50 kD small secreting glycoprotein that participates in multiple physiological and pathological processes. Recent studies have reported that PEDF plays an important role in inflammatory responses in several diseases. However, the role of PEDF in the pathogenesis of chronic obstructive pulmonary disease (COPD) remains unclear. Objective The aim of the present study is to explore the potential relationship between PEDF and COPD. Methods We used differential proteomics – stable isotope labeling with amino acids in cell culture – to investigate protein expression profile changes in cigarette smoke extract-treated pulmonary cells and found that the neurotrophic and antiangiogenic protein PEDF was abnormally expressed. Furthermore, Western blotting was used to detect the expression of PEDF in the lung tissue of rats that were exposed to cigarette smoke. Eighty subjects between the ages of 40–90 years, including 20 healthy nonsmokers, ten smoking volunteers, and 50 COPD patients, were recruited from September 2012 until August 2013 in Sichuan Province, People’s Republic of China. We measured the plasma PEDF concentration and classic proinflammatory cytokines by multiplex enzyme-linked immunosorbent assay. In addition, we performed a spirometry examination to diagnose COPD patients and we also analyzed the correlation between PEDF and lung function. Results First, we found that the expression of PEDF in cigarette smoke extract-treated cells increased 16.2-fold when compared with the control group. Next, we confirmed that 4 weeks’ exposure to cigarette smoke can upregulate PEDF levels in rat lung tissues. We also discovered that plasma PEDF in COPD patients was significantly increased when compared with either healthy nonsmoking or smoking subjects. Furthermore, circulating PEDF was correlated with inflammatory cytokine and blood neutrophil numbers, but it was reversely associated with a decline in forced expiratory volume in 1 second percent predicted. Conclusion Our findings provide a novel link between PEDF and COPD. Elevated PEDF levels may be involved in promoting the development of COPD by performing proinflamma-tory functions.

Li, Xiaoou; Wang, Tao; Yang, Ting; Shen, Yongchun; An, Jing; Liu, Lian; Dong, Jiajia; Guo, Lingli; Li, Diandian; Zhang, Xue; Chen, Lei; Xu, Dan; Wen, Fuqiang

2015-01-01

80

What Is Age-Related Macular Degeneration?  

MedlinePLUS

... regimen for dry macular degeneration . Using an Amsler grid to test for macular degeneration If you have ... you should use a chart called an Amsler grid every day to monitor your vision, as dry ...

81

Sunlight Exposure, Pigmentation, and Incident Age-Related Macular Degeneration  

PubMed Central

Purpose. Examine potential effects of sunlight exposure, hair color, eye color, and selected gene single-nucleotide polymorphisms (SNPs) on incidence of AMD. Methods. Subjects participated in up to five examinations over a 20-year period. Eye color, self-reported hair color as a teenager, and sunlight exposure were ascertained at the baseline examination. Presence and severity of AMD and its lesions were determined via fundus photographs. Genetic data were available on a subset of participants. The SNPs CFH Y402H rs1061170 and ARMS2 A69S rs10490924 were used to analyze genetic risk of AMD; OCA2 rs4778241 and HERC2 rs12913832 represented genetic determinants of eye color. Results. Incidence of early AMD was higher in blond/red-haired persons compared with brown/black-haired persons (hazard ratio [HR] 1.25, P = 0.02) and in persons with high sun exposure in their thirties (HR 1.41, P = 0.02). However, neither was significant after adjustment for multiple comparisons. Eye (HR 1.36, P = 0.006) and hair color (HR 1.42, P = 0.003) were associated with incidence of any retinal pigmentary abnormalities (RPAs). Both remained significant after adjustment for multiple comparisons. Neither presence of alleles for light-colored eyes nor those associated with high risk of late AMD altered the association of eye or hair color with early AMD. None of the characteristics studied were significantly associated with late AMD. Conclusions. Modest associations of eye color, hair color, and HERC2 genotype with any RPAs were found. Genes for AMD did not affect these associations. Eye color phenotype was more strongly associated with outcomes than HERC2 or OCA2 genotype. PMID:25125603

Klein, Barbara E. K.; Howard, Kerri P.; Iyengar, Sudha K.; Sivakumaran, Theru A.; Meyers, Kristin J.; Cruickshanks, Karen J.; Klein, Ronald

2014-01-01

82

Age-related macular degeneration  

PubMed Central

Age-related macular degeneration is the leading cause of blindness in elderly populations of European descent. The most consistent risk factors associated with this ocular condition are increasing age and cigarette smoking. Genetic investigations have shown that complement factor H, a regulator of the alternative complement pathway, and LOC387715/HtrA1 are the most consistent genetic risk factors for age-related macular degeneration. Although the pathogenesis of this disease is unknown, oxidative stress might have an important role. Treatment with antioxidant vitamins and zinc can reduce the risk of developing advanced age-related macular degeneration by about a quarter in those at least at moderate risk. Intravitreal injections of ranibizumab, a monoclonal antibody that inhibits all forms of vascular endothelial growth factor, have been shown to stabilise loss of vision and, in some cases, improve vision in individuals with neovascular age-related macular degeneration. These findings, combined with assessments of possible environmental and genetic interactions and new approaches to modulate inflammatory pathways, will hopefully further expand our ability to understand and treat age-related macular degeneration. PMID:19027484

Coleman, Hanna R; Chan, Chi-Chao; Ferris, Frederick L; Chew, Emily Y

2008-01-01

83

Age-related macular degeneration.  

PubMed

Age-related macular degeneration is the leading cause of blindness in elderly populations of European descent. The most consistent risk factors associated with this ocular condition are increasing age and cigarette smoking. Genetic investigations have shown that complement factor H, a regulator of the alternative complement pathway, and LOC387715/HtrA1 are the most consistent genetic risk factors for age-related macular degeneration. Although the pathogenesis of this disease is unknown, oxidative stress might have an important role. Treatment with antioxidant vitamins and zinc can reduce the risk of developing advanced age-related macular degeneration by about a quarter in those at least at moderate risk. Intravitreal injections of ranibizumab, a monoclonal antibody that inhibits all forms of vascular endothelial growth factor, have been shown to stabilise loss of vision and, in some cases, improve vision in individuals with neovascular age-related macular degeneration. These findings, combined with assessments of possible environmental and genetic interactions and new approaches to modulate inflammatory pathways, will hopefully further expand our ability to understand and treat age-related macular degeneration. PMID:19027484

Coleman, Hanna R; Chan, Chi-Chao; Ferris, Frederick L; Chew, Emily Y

2008-11-22

84

Idiopathic macular telangiectasia type 2 (idiopathic juxtafoveolar retinal telangiectasis type 2A, Mac Tel 2).  

PubMed

Macular telangiectasia type 2-also known as idiopathic perifoveal telangiectasia and juxtafoveolar retinal telangiectasis type 2A or Mac Tel 2-is an acquired bilateral neurodegenerative macular disease that usually manifests itself during the fourth to sixth decades of life and is characterized by minimal dilatation of the parafoveal capillaries with graying of the retinal area involved, a lack of lipid exudation, right-angled retinal venules, refractile deposits in the superficial retina, hyperplasia of the retinal pigment epithelium, foveal atrophy, and subretinal neovascularization (SRNV). Optical coherence tomography images typically demonstrate intraretinal hyporeflective spaces that are usually not related to retinal thickening or fluorescein leakage. The typical fluorescein angiographic finding is a deep intraretinal hyperfluorescent leakage in the temporal parafoveal area. With time the leakage may involve the whole parafovea, but does not extend to the center of the fovea. Long-term prognosis for central vision is variable and depends on the development of SRNV or macular atrophy. Pathogenesis remains unclear, but Müller cells and macular pigment appear to play a central role. Currently there is no known treatment for the underlying cause of this condition, but treatment of the SRNV may be beneficial. PMID:24160729

Wu, Lihteh; Evans, Teodoro; Arevalo, J Fernando

2013-01-01

85

Awareness, Knowledge, and Concern about Age-Related Macular Degeneration  

ERIC Educational Resources Information Center

Age-related macular degeneration (AMD)--a common eye disease causing vision loss--can be detected early through regular eye-health examinations, and measures can be taken to prevent visual decline. Getting eye examinations requires certain levels of awareness, knowledge, and concern related to AMD. However, little is known about AMD-related…

Cimarolli, Verena R.; Laban-Baker, Allie; Hamilton, Wanda S.; Stuen, Cynthia

2012-01-01

86

Non-invasive in vivo measurement of macular carotenoids  

NASA Technical Reports Server (NTRS)

A non-invasive in vivo method for assessing macular carotenoids includes performing Optical Coherence Tomography (OCT) on a retina of a subject. A spatial representation of carotenoid levels in the macula based on data from the OCT of the retina can be generated.

Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

2009-01-01

87

Mitotropic Compounds for the Treatment of Age-Related Macular Degeneration  

Microsoft Academic Search

Recent histopathologic studies have shown that mitochondria and peroxisomes of the retinal pigment epithelium may play a central role in the pathophysiology of age-related macular degeneration (AMD). We supposed that compounds which improve mitochondrial functions (mitotropic compounds) may show beneficial effects in preventing AMD. Fourteen patients affected by early AMD were treated with a mixture containing acetyl-L-carnitine (ALC), polyunsaturated fatty

J. Feher; A. Papale; G. Mannino; L. Gualdi; C. Balacco Gabrieli

2003-01-01

88

Immunohistochemical localization of blood-retinal barrier breakdown sites associated with post-surgical macular oedema  

Microsoft Academic Search

Summary  Post-surgical macular oedema results from blood-retinal barrier breakdown, but it is not accompanied by structural abnormalities in the retinal vessels or retinal pigmented epithelium. Previous studies, using horseradish peroxidase in a primate model, suggested that leakage occurs primarily through this epithelium. This study was conducted to localize sites of the barrier breakdown in humans following different types of intra-ocular surgery

Abha Amin; Nancy L. Derevjanik; W. Richard Green; Peter A. Campochiaro

1994-01-01

89

Spontaneous Closure of a Fully Developed Macular Hole in a Severely Myopic Eye  

PubMed Central

Purpose. Myopic macular holes can be difficult to close with surgery and are frequently associated with retinal detachment. We report on a case of a macular hole in a severely myopic eye that underwent spontaneous closure. Methods. An observational case study. Results. A 55-year-old female was referred to Ophthalmology for a central scotoma and metamorphopsia in the right eye. Visual acuity was 1/20 in both eyes. Fundus examination showed loss of the foveal depression, with a small yellow ring in the center of the fovea in the right eye, and a tilted optic disc and peripapillary staphyloma bilaterally. Spectral domain optical coherence tomography (SD-OCT) revealed a fully developed macular hole with a rim of thickened and slightly elevated retina in the right eye. The patient refused surgery. After 4 years of follow-up, her visual acuity improved to 20/40 in the right eye, and SD-OCT revealed spontaneous sealing of the macular hole without bare retinal pigment epithelium. Conclusions. Myopic macular holes represent a challenge regarding their management, and the prognosis is often poor. PMID:24744932

Bruč, C.; Rossiello, I.; Guidotti, J. M.; Mariotti, C.

2014-01-01

90

Immune function is related to adult carotenoid and bile pigment levels, but not to dietary carotenoid access during development, in female mallard ducks.  

PubMed

Immune function can be modulated by multiple physiological factors, including nutrition and reproductive state. Because these factors can vary throughout an individual's lifetime as a result of environmental conditions (affecting nutrition) or life-history stage (e.g. entering the adult reproduction stage), we must carefully examine the degree to which developmental versus adult conditions shape performance of the immune system. We investigated how variation in dietary access to carotenoid pigments - a class of molecules with immunostimulatory properties that females deposit into egg yolks - during three different developmental time points affected adult immunological and reproductive traits in female mallard ducks (Anas platyrhynchos). In males and females of other avian species, carotenoid access during development affects carotenoid assimilation ability, adult sexual ornamentation and immune function, while carotenoid access during adulthood can increase immune response and reproductive investment (e.g. egg-laying capacity, biliverdin deposition in eggshells). We failed to detect effects of developmental carotenoid supplementation on adult immune function [phytohemagglutinin-induced cutaneous immune response, antibody production in response to the novel antigen keyhole limpet hemocyanin (KLH), or oxidative burst, assessed by changes in circulating nitric oxide levels], carotenoid-pigmented beak coloration, ovarian development, circulating carotenoid levels or concentration of bile pigments in the gall bladder. However, we did uncover positive relationships between circulating carotenoid levels during adulthood and KLH-specific antibody production, and a negative relationship between biliverdin concentration in bile and KLH-specific antibody production. These results are consistent with the view that adult physiological parameters better predict current immune function than do developmental conditions, and highlight a possible, previously unstudied relationship between biliverdin and immune system performance. PMID:23531827

Butler, Michael W; McGraw, Kevin J

2013-07-15

91

Microbial Pigments  

Microsoft Academic Search

Recent increasing concern regarding the use of edible coloring agents has banned various synthetic coloring agents, which\\u000a have a potential of carcinogenicity and terratogenicity. This circumstance has inevitably increased the demands for safe and\\u000a naturally occurring natural (edible) coloring agents, one of which is pigment from the fungus Monascus purpureus. It has long been known that the microorganisms of the

Sumathy Babitha

92

Diabetic macular edema.  

PubMed

A variety of treatment options are available for the treatment of diabetic macular edema. They include laser photocoagulation, anti-VEGF drugs, intravitreal steroids, and vitrectomy with or without release of vitreoretinal traction. A full understanding of the physiological mechanisms of these treatment modalities allows sensible combination of treatment options. Retinal photocoagulation has repeatedly been shown to improve retinal oxygenation, as does vitrectomy. Oxygen naturally reduces VEGF production and thereby decreases leakage of plasma proteins from capillaries into the tissue. In addition, vitrectomy allows faster clearance of cytokines, such as VEGF, from the retina into the vitreous cavity. The VEGF-lowering effect of photocoagulation and vitrectomy can be augmented with anti-VEGF drugs and corticosteroids reduce the effect of VEGF on capillary permeability. Starling's law explains vasogenic edema, which is controlled by osmotic and hydrostatic gradients between vessel and tissue. It explains how VEGF-induced vascular permeability causes plasma protein to leak into the tissue interstitial space, thus decreasing the osmotic pressure gradient between vessel and tissue, resulting in water accumulation, i.e. edema. This is reversed by reducing VEGF production, which is achieved with laser treatment; or by removing VEGF with antibodies or vitrectomy; or by reducing the permeability effect with steroids. At the same time, Starling's law takes into account hemodynamic changes that affect the hydrostatic gradient. High arterial blood pressure and hypoxic vasodilatation increase the hydrostatic pressure in the microcirculation, which increases water flux from vessel to tissue and induce edema. Treatment of arterial hypertension or reversal of retinal hypoxia with laser reverses this pathophysiology and reduces edema. Newton's third law explains, that vitreoretinal traction decreases hydrostatic tissue pressure in the retina, increases the pressure gradient between vessel and tissue, and stimulates water fluxes from vessel into tissue, leading to edema. Release of vitreoretinal traction reverses this mechanism and reduces edema. PMID:23960851

Stefánsson, Einar

2009-07-01

93

Apolipoprotein E promotes subretinal mononuclear phagocyte survival and chronic inflammation in age-related macular degeneration  

PubMed Central

Physiologically, the retinal pigment epithelium (RPE) expresses immunosuppressive signals such as FAS ligand (FASL), which prevents the accumulation of leukocytes in the subretinal space. Age-related macular degeneration (AMD) is associated with a breakdown of the subretinal immunosuppressive environment and chronic accumulation of mononuclear phagocytes (MPs). We show that subretinal MPs in AMD patients accumulate on the RPE and express high levels of APOE. MPs of Cx3cr1?/? mice that develop MP accumulation on the RPE, photoreceptor degeneration, and increased choroidal neovascularization similarly express high levels of APOE. ApoE deletion in Cx3cr1?/? mice prevents pathogenic age- and stress-induced subretinal MP accumulation. We demonstrate that increased APOE levels induce IL-6 in MPs via the activation of the TLR2-CD14-dependent innate immunity receptor cluster. IL-6 in turn represses RPE FasL expression and prolongs subretinal MP survival. This mechanism may account, in part, for the MP accumulation observed in Cx3cr1?/? mice. Our results underline the inflammatory role of APOE in sterile inflammation in the immunosuppressive subretinal space. They provide rationale for the implication of IL-6 in AMD and open avenues toward therapies inhibiting pathogenic chronic inflammation in late AMD. PMID:25604058

Levy, Olivier; Calippe, Bertrand; Lavalette, Sophie; Hu, Shulong J; Raoul, William; Dominguez, Elisa; Housset, Michael; Paques, Michel; Sahel, José-Alain; Bemelmans, Alexis-Pierre; Combadiere, Christophe; Guillonneau, Xavier; Sennlaub, Florian

2015-01-01

94

Macular Oedema in Idiopathic Macular Telangiectasia Type 1 Responsive to Aflibercept but Not Bevacizumab  

PubMed Central

We report a patient with macular oedema due to type 1 macular telangiectasia responding to intravitreal aflibercept injection. A 51-year-old man was diagnosed with type 1 idiopathic macular telangiectasia (IMT) in the right eye. The macular oedema was refractory to initial treatment with intravitreal bevacizumab and argon laser photocoagulation. The patient was then treated with intravitreal aflibercept injections, following which the macular oedema was completely resolved and his vision was significantly improved. Intravitreal aflibercept injection appears to improve vision and reduce persistent macular oedema secondary to type 1 IMT and demonstrated promising anatomical and visual outcomes. PMID:25349755

Shibeeb, O'Sam; Gillies, Mark; Gray, Timothy

2014-01-01

95

Macular oedema in idiopathic macular telangiectasia type 1 responsive to aflibercept but not bevacizumab.  

PubMed

We report a patient with macular oedema due to type 1 macular telangiectasia responding to intravitreal aflibercept injection. A 51-year-old man was diagnosed with type 1 idiopathic macular telangiectasia (IMT) in the right eye. The macular oedema was refractory to initial treatment with intravitreal bevacizumab and argon laser photocoagulation. The patient was then treated with intravitreal aflibercept injections, following which the macular oedema was completely resolved and his vision was significantly improved. Intravitreal aflibercept injection appears to improve vision and reduce persistent macular oedema secondary to type 1 IMT and demonstrated promising anatomical and visual outcomes. PMID:25349755

Shibeeb, O'Sam; Vaze, Anagha; Gillies, Mark; Gray, Timothy

2014-01-01

96

Visual acuity and foveal thickness after vitrectomy for macular edema associated with branch retinal vein occlusion: a case series  

Microsoft Academic Search

BACKGROUND: The mechanism by which vitrectomy improves macular edema in patients with branch retinal vein occlusion remains unclear, although intraocular levels of vascular endothelial growth factor have been suggested to influence the visual prognosis and macular edema. METHODS: A series of 54 consecutive patients (54 eyes) with branch retinal vein occlusion was studied prospectively. All patients underwent pars plana vitrectomy

Hidetaka Noma; Hideharu Funatsu; Tatsuya Mimura; Shuichiro Eguchi; Katsunori Shimada

2010-01-01

97

High glucose-induced barrier impairment of human retinal pigment epithelium is ameliorated by treatment with Goji berry extracts through modulation of cAMP levels.  

PubMed

Human retinal pigment epithelium cells were used to investigate the mechanisms underlying blood-retinal barrier disruption under conditions of chronic hyperglycemia. The treatment with 25 mM glucose caused a rapid drop in the transepithelial electrical resistance (TEER), which was reversed by the addition of either a methanolic extract from Goji (Lycium barbarum L.) berries or its main component, taurine. Intracellular cAMP levels increased concurrently with the high glucose-induced TEER decrease, and were correlated to an increased activity of the cytosolic isoform of the enzyme adenylyl cyclase. The treatment with plant extract or taurine restored control levels. Data are discussed in view of a possible prevention approach for diabetic retinopathy. PMID:24345371

Pavan, Barbara; Capuzzo, Antonio; Forlani, Giuseppe

2014-03-01

98

Laser therapy and macular degeneration  

NASA Astrophysics Data System (ADS)

Among macular diseases, choroidal neovascularization (CNV) is one of the most common causes of visual loss, especially in the form associated with age-related macular degeneration and pathologic myopia. Research on these diseases has recently evaluated new treatment modalities that use laser light differently; among these, photodynamic therapy (PDT) has been introduced in the clinical practice, allowing us to expand the possibility of reducing visual loss in patients affected by CNV. With PDT, a photosensitizer (verteporfin, VisudyneTM) is injected intravenously, and it selectively binds to new vessels; low-power laser light exposure then activates the drug, leading to oxidative damage of the endothelium and new vessels thrombosis. Yet, other therapies, such as transpupillary termotherapy, or the use of photocoagulation to cause feeder-vessel occlusion, could proof effective, but they need further investigation.

Menchini, Ugo; Virgili, Gianni; Giansanti, Fabrizio; Giacomelli, Giovanni; Cappelli, Stefania

2001-10-01

99

Aqueous flare and inflammatory factors in macular edema with central retinal vein occlusion: a case series  

PubMed Central

Background The association of inflammatory factors and the aqueous flare value with macular edema in central retinal vein occlusion (CRVO) patients remains unclear. We investigated the relations between the aqueous flare value and vitreous levels of vascular endothelial growth factor (VEGF), soluble intercellular adhesion molecule-1 (sICAM-1), and interleukin-6 (IL-6) in patients with CRVO and macular edema or patients with idiopathic macular hole (MH). Methods In 38 patients who underwent unilateral vitrectomy (21 CRVO patients and 17 MH patients), vitreous samples were obtained during vitrectomy to measure VEGF, sICAM-1, and IL-6. Retinal ischemia was evaluated from capillary non-perfusion on fluorescein angiography, and the CRVO patients were classified into nonischemic or ischemic groups. Aqueous flare values were measured with a laser flare meter and macular edema was examined by optical coherence tomography. Results The median aqueous flare value increased significantly across the three groups (MH group?levels of VEGF, sICAM-1, and IL-6 in the CRVO group. The flare value was also significantly correlated with the severity of macular edema in the CRVO group. Conclusions Inflammation and/or ischemia may increase vascular permeability and disrupt the blood-aqueous barrier by increasing levels of inflammatory factors in patients with CRVO and macular edema. PMID:24325604

2013-01-01

100

The Alzheimer's A-peptide is deposited at sites of complement activation in pathologic deposits associated with aging and age-related macular degeneration  

Microsoft Academic Search

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in older individuals worldwide. The disease is characterized by abnormal extracellular deposits, known as drusen, that accumulate along the basal surface of the retinal pigmented epithelium. Although drusen deposition is common in older individuals, large numbers of drusen and\\/or extensive areas of confluent drusen represent a significant risk

Lincoln V. Johnson; William P. Leitner; Alexander J. Rivest; Michelle K. Staples; Monte J. Radeke; Don H. Anderson

2002-01-01

101

Age-related macular degeneration.  

PubMed

Age-related macular degeneration (AMD) is a common and painless eye condition that is the leading cause of vision loss for people older than 50 years. Occupational and environmental health nurses can aid in slowing the progression of AMD by encouraging workers to have periodic eye examinations, maintain good health practices, and notify health care professionals if they notice blurred vision or blind spots in central vision. PMID:25093372

Randolph, Susan A

2014-08-01

102

[Treatment of serous macular retinal detachment with antihistamines].  

PubMed

The etiology of retinal detachment in central serous retinopathy (CSR) is unknown; however, three facts are generally accepted: (1) the serous exudate which raises the layers of the receptors/pigment epithelium is formed due to hyperpermeability in the choriocapillaries, (2) patients frequently suffer from headaches and (3) stress promotes the incidence of CSR. A high blood plasma histamine concentration can cause the abovementioned symptoms which suggests that histamine might provoke CSR. Within 1 week after administration of the antihistamine loratadin a considerable reduction in the retinal exudate and restoration of vision were observed. This supports the hypothesis that histamine could be involved in the process of retinal detachment. Further investigations and large scale clinical trials should clarify if this hypothesis can be proved or disproved and whether antihistamines can be used for age-related macular degeneration (AMD). PMID:25278347

Kirschfeld, K

2015-01-01

103

Identification of spectral phenotypes in age-related macular degeneration patients  

NASA Astrophysics Data System (ADS)

The purpose of this study is to show that there exists a spectral characteristic that differentiates normal macular tissue from various types of genetic-based macular diseases. This paper demonstrates statistically that hyperspectral images of macular and other retinal tissue can be used to spectrally differentiate different forms of age-related macular degeneration. A hyperspectral fundus imaging device has been developed and tested for the purpose of collecting hyperspectral images of the human retina. A methodology based on partial least squares and ANOVA has been applied to determine the hyperspectral representation of individual spectral characteristics of retinal features. Each discrete tissue type in the retina has an identifiable spectral shape or signature which, when combined with spatial context, aids in detection of pathological features. Variations in the amount and distribution of various ocular pigments or the inclusion of additional biochemical substances will allow detection of pathological conditions prior to traditional histological presentation. Fundus imaging cameras are ubiquitous and are one of the most common imaging modalities used in documenting a patient's retinal state for diagnosis, e.g. remotely, or for monitoring the progression of an ocular disease. The added diagnostic information obtained with only a minor retro-fit of a specialized spectral camera will lead to new diagnostic information to the clinical ophthalmologist or eye-care specialist.

Davis, Bert; Russell, Steven; Abramoff, Michael; Nemeth, Sheila C.; Barriga, E. Simon; Soliz, Peter

2007-02-01

104

Pulsed dye laser for the treatment of macular amyloidosis: a case report.  

PubMed

Macular amyloidosis causes an eruption of brown pigment in the skin when keratin is altered. The resulting hyperpigmentation, which often leads to patient distress, generally has unsatisfactory treatment options. Among the treatment modalities that have been used for amyloidosis, the pulsed dye laser (PDL) has shown success in the treatment of nodular amyloidosis, and the Q-switched Nd:YAG laser has reduced the appearance of amyloid plaques in macular amyloidosis. We investigated the effects of repeated PDL treatments in a 57-year-old man with recalcitrant macular amyloidosis. The patient was treated with 3 treatment sessions of PDL at 2-week intervals. Based on patient self-assessment and our own photographic analysis, improvement of the lesions was noted with each treatment. Macular amyloidosis can be successfully treated using the PDL, which decreases amyloid aggregation and skin hyperpigmentation. This effect from a decrease in collagen and dermatan sulfate synthesis is similar to the mechanism behind the reduction of size of hypertrophic scars using PDL. PMID:24818178

Barsky, Maya; Buka, Robert L

2014-04-01

105

Complications associated with limited macular translocation  

Microsoft Academic Search

PURPOSE: To report the ocular complications associated with the limited macular translocation procedure.METHODS: Retrospective review of 153 consecutive eyes of 151 patients that had the limited macular translocation procedure for subfoveal choroidal neovascularization between April 1996 and February 1999. The major study variables investigated included the incidence of specific ocular complications and their impact on visual acuity at 3 months

Gildo Y Fujii; Dante J Pieramici; Mark S Humayun; Andrew P Schachat; Sandra M Reynolds; Michele Melia; Eugene De Juan

2000-01-01

106

Combined Therapy for Diabetic Macular Edema  

PubMed Central

Diabetic macular edema (DME) is the main cause of visual impairment in diabetic patients. Macular edema within 1 disk diameter of the fovea is present in 9% of the diabetic population. The management of DME is complex and often multiple treatment approaches are needed. This review demonstrates the benefits of intravitreal triamcinolone, bevacizumab and ranibizumab as adjunctive therapy to macular laser treatment in DME. The published results indicate that intravitreal injections of these agents may have a beneficial effect on macular thickness and visual acuity, independent of the type of macular edema that is present. Therefore, pharmacotherapy could complement focal/grid laser photocoagulation in the management of DME. For this review, we performed a literature search and summarized recent findings regarding combined therapy for DME. PMID:24339681

Al Rashaed, Saba; Arevalo, J. Fernando

2013-01-01

107

Cataract surgery and the development or progression of age-related macular degeneration: a systematic review.  

PubMed

Age-related macular degeneration and cataract are the most frequent eye disorders of elderly people worldwide. The aim of this systematic review was to evaluate the effect of cataract surgery on the development and progression of age-related macular degeneration. Data were collected by means of a systematic literature search in 28 databases and an additional update in Pubmed. Search results were evaluated using pre-defined inclusion and exclusion criteria. All relevant publications were rated in terms of scientific quality and analyzed regarding their results. The literature search generated a total of 2,827 hits. Seven publications on five observational studies and two non-randomized clinical trials were eligible for analysis. The observational studies provided some evidence for an increased incidence of late age-related macular degeneration, respectively, for a promoting influence of cataract surgery on the progression of early types of age-related macular degeneration. The clinical trials did yield inconsistent results. In conclusion, only a small number of published studies investigated the development or progression of age-related macular degeneration following cataract surgery. The scientific level of evidence of these articles was not high and results were inconsistent, nevertheless a promoting influence of cataract surgery on the progression of early age-related macular degeneration can be assumed. PMID:18572053

Bockelbrink, Angelina; Roll, Stephanie; Ruether, Klaus; Rasch, Andrej; Greiner, Wolfgang; Willich, Stefan N

2008-01-01

108

Alterations of retinal pigment epithelium cause AMD-like retinopathy in senescence-accelerated OXYS rats  

PubMed Central

Pathogenesis of age-related macular degeneration (AMD), the leading cause of blindness in the world, remains poorly understood. This makes it necessary to create animal models for studying AMD pathogenesis and to design new therapeutic approaches. Here we showed that retinopathy in OXYS rats is similar to human AMD according to clinical signs, morphology, and vascular endothelium growth factor (VEGF) and pigment epithelium-derived factor (PEDF) genes expression. Clinical signs of retinopathy OXYS rats manifest by the age 3 months against the background of significantly reduced expression level of VEGF and PEDF genes due to the decline of the amount of retinal pigment epithelium (RPE) cells and alteration of choroidal microcirculation. The disruption in OXYS rats' retina starts at the age of 20 days and appears as reduce the area of RPE cells but does not affect their ultrastructure. Ultrastructural pathological alterations of RPE as well as develop forms of retinopathy are observed in OXYS rats from age 12 months and manifested as excessive accumulation of lipofuscin in RPE regions adjacent to the rod cells, whirling extentions of the basement membrane into the cytoplasm. These data suggest that primary cellular degenerative alterations in the RPE cells secondarily lead to choriocapillaris atrophy and results in complete loss of photoreceptor cells in the OXYS rats' retina by the age of 24 months. PMID:21191149

Markovets, Anton M.; Saprunova, Valeriya B.; Zhdankina, Anna A.; Fursova, Anzhella Zh.; Bakeeva, Lora E.; Kolosova, Natalia G.

2011-01-01

109

The etiology and molecular genetics of human pigmentation disorders  

PubMed Central

Pigmentation, defined as the placement of pigment in skin, hair, and eyes for coloration, is distinctive because the location, amount, and type of pigmentation provides a visual manifestation of genetic heterogeneity in pathways regulating the pigment-producing cells, melanocytes. The scope of this genetic heterogeneity in humans ranges from normal to pathological pigmentation phenotypes. Clinically normal human pigmentation encompasses a variety of skin and hair color as well as with punctate pigmentation such as melanocytic nevi (moles) or ephelides (freckles), while clinically abnormal human pigmentation exhibits markedly reduced or increased pigment levels, known as hypopigmentation and hyperpigmentation, respectively. Elucidation of the molecular genetics underlying pigmentation has revealed genes important for melanocyte development and function. Furthermore, many pigmentation disorders show additional defects in cells other than melanocytes, and identification of the genetic insults in these disorders has revealed pleiotropic genes, where a single gene is required for various functions, often in different cell types. Thus unravelling the genetics of easily visualized pigmentation disorders has identified molecular similarities between melanocytes and less visible cell types/tissues, revealing a common cellular origin and/or common genetic regulatory pathways. Herein we discuss notable human pigmentation disorders and their associated genetic alterations, focusing on the fact that the developmental genetics of pigmentation abnormalities is instructive for understanding normal pathways governing development and function of melanocytes. PMID:23799582

Baxter, Laura L.; Pavan, William J.

2012-01-01

110

Macular full-thickness and lamellar holes in association with type 2 idiopathic macular telangiectasia  

Microsoft Academic Search

PurposeTo describe patients with full-thickness macular holes (FTMHs) and lamellar macular holes (LMHs) in association with type 2 idiopathic macular telangiectasia (type 2 IMT).MethodsSix patients with either FTMH or LMH and type 2 IMT were evaluated by means of optical coherence tomography (OCT) imaging, funduscopy, and fluorescein angiography.ResultsThe age of the examined patients ranged from 57 to 70 years (mean

P Charbel Issa; H P N Scholl; A Gaudric; P Massin; A E Kreiger; S Schwartz; F G Holz

2009-01-01

111

Skin Pigmentation Disorders  

MedlinePLUS

... skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or unhealthy, it affects melanin production. Some pigmentation disorders affect just patches of ...

112

Global vitamin D levels in relation to age, gender, skin pigmentation and latitude: an ecologic meta-regression analysis  

Microsoft Academic Search

Summary  We performed a meta-analysis of cross-sectional studies on serum 25(OH)D status globally. Serum 25(OH)D levels on average\\u000a were 54 nmol\\/l, were higher in women than men, and higher in Caucasians than in non-Caucasians. There was no trend in serum\\u000a 25(OH)D level with latitude. Vitamin D deficiency was widespread.\\u000a \\u000a \\u000a \\u000a Introduction  We studied vitamin D status (expressed as serum 25-hydroxy-vitamin D [25(OH)D]) in native

T. Hagenau; R. Vest; T. N. Gissel; C. S. Poulsen; M. Erlandsen; L. Mosekilde; P. Vestergaard

2009-01-01

113

The Pathogenic Role of the Canonical Wnt Pathway in Age-Related Macular Degeneration  

PubMed Central

Purpose. The authors' previous studies showed that the Wnt signaling pathway is activated in the retinas and retinal pigment epithelia of animal models of age-related macular degeneration (AMD) and diabetic retinopathy (DR). The purpose of this study was to investigate the role of the canonical Wnt pathway in pathogenesis of these diseases. Methods. The Wnt pathway was activated using the Wnt3a-conditioned medium and adenovirus expressing a constitutively active mutant of ?-catenin (Ad-S37A) in ARPE19, a cell line derived from human RPE. Ad-S37A was injected into the vitreous of normal rats to activate the Wnt pathway in the retina. Accumulation of ?-catenin was determined by Western blot analysis, and its nuclear translocation was revealed by immunocytochemistry. Inflammatory factors were quantified by Western blot analysis and ELISA. Oxidative stress was determined by measuring intracellular reactive oxygen species (ROS) generation and nitrotyrosine levels. Results. The Wnt3a-conditioned medium and Ad-S37A both increased ?-catenin levels and its nuclear translocation in ARPE19 cells, suggesting activation of the canonical Wnt pathway. Activation of the Wnt pathway significantly upregulated the expression of VEGF, NF-?B, and TNF-?. Further, Ad-S37A induced ROS generation in a dose-dependent manner. Wnt3a also induced a twofold increase of ROS generation. Intravitreal injection of Ad-S37A upregulated the expression of VEGF, ICAM-1, NF-?B, and TNF-? and increased protein nitrotyrosine levels in the retinas of normal rats. Conclusions. Activation of the canonical Wnt pathway is sufficient to induce retinal inflammation and oxidative stress and plays a pathogenic role in AMD and DR. PMID:19875668

Zhou, Ti; Hu, Yang; Chen, Ying; Zhou, Kevin K.; Zhang, Bin; Gao, Guoquan; Ma, Jian-xing

2010-01-01

114

Circulating levels and subcutaneous adipose tissue gene expression of pigment epithelium-derived factor in polycystic ovary syndrome and normal women: a case control study  

PubMed Central

Background Polycystic ovary syndrome (PCOS) has been recognized as a metabolic disorder, manifested by abdominal obesity, insulin resistance, dyslipidemia and hypertension. Pigment epithelium-derived factor (PEDF), a member of the serine protease inhibitor family, is a pleiotropic protein known for its antiangiogenic, antioxidant, and neuroprotective properties and has been shown to induce insulin resistance and play a role in glucose metabolism. Recent studies investigating circulating PEDF levels show elevated serum PEDF in association with insulin resistance in normal-weight women with PCOS, but not in obese PCOS patients. The aims of this study were 1) to assess PEDF gene expression in subcutaneous adipose tissue (scAT) from women with PCOS and nonhirsute, ovulatory controls, and 2) to determine the circulating levels of PEDF in these groups. Methods Total RNA was extracted from adipose tissue biopsy samples and reverse-transcribed to cDNA. Real-time quantitative PCR was performed to determine relative gene expression levels. Results The 22 women with PCOS and 14 non-PCOS controls included in the study had similar age, BMI, and fasting glucose, triglycerides, and HDL-cholesterol levels. Participants with PCOS exhibited higher 2 h oral glucose tolerance test levels (p?=?0.006), total (p?=?0.026) and LDL-cholesterol (p?=?0.036), Ferriman-Gallwey score (p?=?0.003) and total testosterone (p?=?0.001) as compared to controls. BMI-adjusted PEDF serum levels and scAT gene expression were similar in the PCOS and control groups (p?=?0.622 and p?=?0.509, respectively). Circulating PEDF levels were not associated with scAT PEDF gene expression. Multiple regression analysis revealed that, in women with PCOS, insulin contributed positively and significantly to serum PEDF (p = 0.027), independently of testosterone. Conclusion Serum PEDF levels and scAT gene expression were associated with metabolic risk factors, but did not differ between women with PCOS and age- and BMI-matched controls. Circulating levels and scAT gene expression of PEDF were not associated in the study subjects, suggesting additional sources for PEDF in addition to or instead of fat tissue. PMID:23941060

2013-01-01

115

Aryl hydrocarbon receptor deficiency causes dysregulated cellular matrix metabolism and age-related macular degeneration-like pathology  

PubMed Central

The aryl hydrocarbon receptor (AhR) is a nuclear receptor that regulates xenobiotic metabolism and detoxification. Herein, we report a previously undescribed role for the AhR signaling pathway as an essential defense mechanism in the pathogenesis of early dry age-related macular degeneration (AMD), the leading cause of vision loss in the elderly. We found that AhR activity and protein levels in human retinal pigment epithelial (RPE) cells, cells vulnerable in AMD, decrease with age. This finding is significant given that age is the most established risk factor for development of AMD. Moreover, AhR?/? mice exhibit decreased visual function and develop dry AMD-like pathology, including disrupted RPE cell tight junctions, accumulation of RPE cell lipofuscin, basal laminar and linear-like deposit material, Bruch’s membrane thickening, and progressive RPE and choroidal atrophy. High-serum low-density lipoprotein levels were also observed in AhR?/? mice. In its oxidized form, this lipoprotein can stimulate increased secretion of extracellular matrix molecules commonly found in deposits from RPE cells, in an AhR-dependent manner. This study demonstrates the importance of cellular clearance via the AhR signaling pathway in dry AMD pathogenesis, implicating AhR as a potential target, and the mouse model as a useful platform for validating future therapies. PMID:24106308

Hu, Peng; Herrmann, Rolf; Bednar, Amanda; Saloupis, Peter; Dwyer, Mary A.; Yang, Ping; Qi, Xiaoping; Thomas, Russell S.; Jaffe, Glenn J.; Boulton, Michael E.; McDonnell, Donald P.; Malek, Goldis

2013-01-01

116

The effect of soil aeration on superoxide dismutase activity, malondialdehyde level, pigment content and stomatal diffusive resistance in maize seedlings  

Microsoft Academic Search

Deficient soil aeration that causes hypoxia of maize roots frequently decreases plant biomass production. Characterizing relationships among maize physiological responses to varying levels of root hypoxia is critical to predicting maize plant biomass production. Maize seedlings 12 days old were subjected to increasing root hypoxia over a 12 day period by increasing soil water content in 0.06–0.07 m3 m?3 intervals

R. P Bennicelli; D. A Zakrzhevsky; T. I Balakhnina; J Lipiec

1998-01-01

117

A primer on pigmentation.  

PubMed

There is at least a temporary loss of skin pigmentation with all but first-degree burns. Commonly, pigment changes persist for months, and sometimes, permanent changes in skin color add to the ultimate change in appearance that commonly affects burn patients. There are many different treatment modalities for the treatment of pigment changes, but most of them have little scientific basis and often lead to disappointing results. The purpose of this review is to discuss the molecular and cellular mechanisms of skin pigmentation, mechanisms of repigmentation after burns, treatment options for dealing with pigmentation changes, and advice for dealing with the sun after burn injury. PMID:25501768

Greenhalgh, David G

2015-01-01

118

Nonlinear optical absorption of photosynthetic pigment molecules in leaves.  

PubMed

A mathematical formulation of the relationship between optical absorption coefficient of photosynthetic pigment molecules and light intensity was developed. It showed that physical parameters of photosynthetic pigment molecule (i.e., light absorption cross-section of photosynthetic pigment molecule, its average lifetime in the excited state, total photosynthetic pigment molecules, the statistical weight, or degeneracy of energy level of photosynthetic pigment molecules in the ground state and in the excited state) influenced on both the light absorption coefficient and effective light absorption cross-section of photosynthetic pigment molecules. Moreover, it also showed that both the light absorption coefficient and effective light absorption cross-section of photosynthetic pigment molecules were not constant, they decreased nonlinearly with light intensity increasing. The occupation numbers of photosynthetic pigment molecules in the excited states increased nonlinearly with light intensity increasing. PMID:22430129

Ye, Zi-Piao

2012-04-01

119

Chronic delivery of low-level exogenous current preserves retinal function in pigmented P23H rat.  

PubMed

Diffuse electrical currents delivered to the eye were investigated in a rat model of retinitis pigmentosa for potentially therapeutic effects. Low-level currents were passed between electrodes placed on the cornea and in the mouth during 30-min sessions two times per week from 4 to 16 weeks of age. Single-flash electroretinograms (ERG) were recorded and analyzed for amplitude and measures of sensitivity, and basic histology was performed. ERG a-wave amplitudes were slightly greater in treated vs. age-matched controls at 16 weeks of age, but the combined thicknesses of the outer nuclear layer and outer segment layer were similar at this age. Treated animals exhibited a significant preservation of b-wave amplitudes, and a striking preservation of rod sensitivity, measured as the stimulus strength required to reach half-saturation of the a-wave. Analysis of the leading edge of the a-wave using a delayed Gaussian function revealed a decrease in the parameter reflecting gain of the phototransduction cascade over the 12-week course of treatment, and no significant change in control animals over the same period. These results suggest that while the exogenous currents failed to preserve the number or gross structure of rods, the responsivity of individual photoreceptors was relatively preserved, perhaps via an increase in efficiency of photon capture (R/photon). This preserved functionality may delay the retraction of bipolar cell dendrites from degenerating photoreceptors. PMID:23147691

Rahmani, Safa; Bogdanowicz, Les; Thomas, Joel; Hetling, John R

2013-01-14

120

Age-related macular degeneration and changes in the extracellular matrix  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of permanent, irreversible, central blindness (scotoma in the central visual field that makes reading and writing impossible, stereoscopic vision, recognition of colors and details) in patients over the age of 50 years in European and North America countries, and an important role is attributed to disorders in the regulation of the extracellular matrix (ECM). The main aim of this article is to present the crucial processes that occur on the level of Bruch’s membrane, with special consideration of the metalloproteinase substrates, metalloproteinase, and tissue inhibitor of metalloproteinase (TIMP). A comprehensive review of the literature was performed through MEDLINE and PubMed searches, covering the years 2005–2012, using the following keywords: AMD, extracellular matrix, metalloproteinases, tissue inhibitors of metalloproteinases, Bruch’s membrane, collagen, elastin. In the pathogenesis of AMD, a significant role is played by collagen type I and type IV; elastin; fibulin-3, -5, and -6; matrix metalloproteinase (MMP)-2, MMP-9, MMP-14, and MMP-1; and TIMP-3. Other important mechanisms include: ARMS2 and HTR1 proteins, the complement system, the urokinase plasminogen activator system, and pro-renin receptor activation. Continuous rebuilding of the extracellular matrix occurs in both early and advanced AMD, simultaneously with the dysfunction of retinal pigment epithelium (RPE) cells and endothelial cells. The pathological degradation or accumulation of ECM structural components are caused by impairment or hyperactivity of specific MMPs/TIMPs complexes, and is also endangered by the influence of other mechanisms connected with both genetic and environmental factors. PMID:24938626

Nita, Ma?gorzata; Strza?ka-Mrozik, Barbara; Grzybowski, Andrzej; Mazurek, Urszula; Romaniuk, Wanda

2014-01-01

121

Discrete pigmentation after chemotherapy.  

PubMed

Discrete areas of cutaneous hyperpigmentation were seen in two children with metastatic sarcoma who received chemotherapeutic bone marrow ablation with cyclophosphamide, etoposide, and carboplatin prior to autologous bone marrow transplantation. The hyperpigmented patches occurred only in areas of skin occluded by tape, electrocardiogram pads, or elastic bandages. Identical skin findings were reported in five adult women who received intravenous thiotepa and cyclophosphamide. Measurable levels of thiotepa were detected in these patients' serum, skin, sweat, and occluded gauze, suggesting that the chemical was excreted onto the skin surface in sweat and accumulated under occlusive dressing, thus producing some toxic effect on the epidermis or melanocytes resulting in abnormal pigmentation. We suspect that a similar mechanism was operative in our patients to produce the unusual patterned hyperpigmentation, and suggest that this complication may be prevented by minimizing sweat accumulation in areas occluded by adhesive materials. PMID:1745634

Singal, R; Tunnessen, W W; Wiley, J M; Hood, A F

1991-09-01

122

Early structural changes during spontaneous closure of idiopathic full-thickness macular hole determined by optical coherence tomography: a case report  

PubMed Central

Background Spontaneous closure of an idiopathic full-thickness macular hole has been reported to occasionally occur. However, the cells involved in plugging the macular hole have not been determined conclusively. We aimed to report the early structural changes that occur during a spontaneous closure of an idiopathic full-thickness macular hole determined by spectral-domain optical coherence tomography. Case presentation A 71-year-old Japanese man with an idiopathic full-thickness macular hole and subclinical posterior vitreous detachment in the left eye was followed. Three weeks after the identification of the macular hole, optical coherence tomography showed tissue that protruded from the interior wall of the macular hole at the level of the external limiting membrane toward the center of the macular hole. Five months after the first examination, he returned with improvements of his visual symptoms, and the macular hole was closed by a thin retinal tissue which included the restored external limiting membrane that bridged across the macular hole. However, the inner segment/outer segment junction line was not intact and the fovea was detached. Two months later, optical coherence tomography showed an almost normal foveal configuration with an essentially restored inner segment/outer segment junction line and foveal reattachment. Conclusion Our results suggest that Müller cells proliferate and/or extend at the level of the end of the external limiting membrane to form a tissue bridge across the macular hole associated with the external limiting membrane restoration first of all. This leads to the adhesion of other retinal layers and resolution of the foveal detachment. PMID:24083650

2013-01-01

123

Contrasting levels of DNA polymorphism at the autosomal and X-linked visual color pigment loci in humans and squirrel monkeys.  

PubMed

The X-linked color pigment (opsin) locus is known to be highly polymorphic in the squirrel monkey and other New World monkeys. To see whether this is also the case for the autosomal (blue) opsin locus, we obtained 32 squirrel monkey and 30 human blue opsin gene sequences. No amino acid polymorphism was found in either the squirrel monkey sample or the human sample, contrary to the situation at the X-linked opsin locus. This sharp contrast in the level of polymorphism might be due to differences in gene expression between the autosomal and the X-linked loci. At the X-linked locus, heterozygote advantage can occur because, owing to X-inactivation, the two alleles in a heterozygote are expressed in different cone cells, producing two types of cone cell, whereas at the autosomal locus, heterozygote advantage cannot occur because the two alleles in a heterozygote are expressed in the same cone cells, producing only one type of cone cell (i.e., phenotypically a homozygote). From the sequence data, the levels of nucleotide diversity (pi, i.e., the number of nucleotide differences per site) are estimated: for the human sample, pi = 0.00% per nondegenerate site, 0.00% per twofold degenerate site, and 0.04% per fourfold degenerate site in the coding regions and 0.01% per site in intron 4; for the squirrel monkey sample, pi = 0.00% per nondegenerate site, 0.00% per twofold degenerate site, and 0.15% per fourfold degenerate site in the coding regions and 0.17% per site in intron 4. The blue opsin genes from the common and pygmy chimpanzees, the gorilla, the capuchin, and the howler monkey were also sequenced. Features critical to the function of the opsin are well conserved in all known mammalian sequences. However, the interhelical loops are, on average, actually more conservative than the transmembrane helical regions. In addition, these sequence data and those from some other genes indicate that the common and pygmy chimpanzees are not closely related, their divergence data being from one third to one half the date of the human-chimpanzee divergence. PMID:9549095

Shimmin, L C; Miller, J; Tran, H N; Li, W H

1998-04-01

124

Macular degeneration in an arc welder.  

PubMed

A male welder who had been working in an industrial machine plant for more than 20 years experienced acute intense pain in his left eye with continuous lacrimation while performing arc welding in 1997. Later in 1997, at the age of 39 yr, macular edema was found in his left eye. He was diagnosed with macular degeneration (MD) of the left eye in 2002, and with right eye MD in 2004. Radiation in the visible and near infrared (IR) spectra penetrates the eye and is absorbed by the retina, possibly causing thermal or photochemical damage. Such retinal damage may be permanent and, therefore, sight-threatening. The young age and history of an acute painful eye injury are not consistent with age related macular degeneration (AMD) but rather is likely maculopathy caused by welding arc exposure. PMID:17485886

Kim, Eun A; Kim, Byung-Gyu; Yi, Cheol-Ho; Kim, Il Gon; Chae, Chang-Ho; Kang, Seong-Kyu

2007-04-01

125

Macular star formation in diabetic patients with non-arteritic anterior ischemic optic neuropathy (NA-AION)  

PubMed Central

Background NA-AION is a condition that exhibits a number of unique characteristics in diabetics compared with the rest of the population. In some diabetic patients with NA-AION, lipid deposits can be observed around the macula forming an incomplete macular star. Methods We describe 12 case studies of patients with NA-AION observing the development of lipid deposits around the macula forming an incomplete macular star. Results All our patients developed some level of lipid deposits around the macula in the form of a macular hemistar in the course of their illness. Conclusion Some authors have suggested that the macular star is formed by transudation from capillaries deep in the optic disk through the intermediary tissue of Kuhnt, which is located between the retina and the anterior portion of the lamina retinalis. However, the development of the macular star is currently understood not as a simple transudation but as a multifactorial process involving the presence of vascular damage around the optic disk, which is considered one of the most important factors leading to its occurrence. Although some studies mention the presence of a macular star in patients with NA-AION, we believe that this phenomenon may be significantly more common than the current literature suggests.

Galvez-Ruiz, Alberto

2014-01-01

126

Pigment Granule Transport in Chromatophores  

NSDL National Science Digital Library

This resource describes protocols and gives instructional information for carrying out an undergraduate laboratory exercise in vertebrate physiology. Students learn and analyze the dynamics of pigment granule transport in the chromatorphores of fishes. This exercise may be used as a stand alone exercise suitable for lower division undergraduate courses, or may be expanded as a scientific-inquiry based exercise for upper-level undergraduate courses. It includes student outlines, instructor's notes, and suggested questions for laboratory reports.

Kathryn B. Toner (; )

1997-01-01

127

The Bisretinoids of Retinal Pigment Epithelium  

PubMed Central

The retina exhibits an inherent autofluorescence that is imaged ophthalmoscopically as fundus autofluorescence. In clinical settings, fundus autofluorescence examination aids in the diagnosis and follow-up of many retinal disorders. Fundus autofluorescence originates from the complex mixture of bisretinoid fluorophores that are amassed by retinal pigment epithelial (RPE) cells as lipofuscin. Unlike the lipofuscin found in other cell-types, this material does not form as a result of oxidative stress. Rather, the formation is attributable to non-enzymatic reactions of vitamin A aldehyde in photoreceptor cells; transfer to RPE occurs upon phagocytosis of photoreceptor outer segments. These fluorescent pigments accumulate even in healthy photoreceptor cells and are generated as a consequence of the light capturing function of the cells. Nevertheless, the formation of this material is accelerated in some retinal disorders including recessive Stargardt disease and ELOVL-4-related retinal degeneration. As such, these bisretinoid side-products are implicated in the disease processes that threaten vision. In this article, we review our current understanding of the composition of RPE lipofuscin, the structural characteristics of the various bisretinoids, their related spectroscopic features and the biosynthetic pathways by which they form. We will revisit factors known to influence the extent of the accumulation and therapeutic strategies being used to limit bisretinoid formation. Given their origin from vitamin A aldehyde, an isomer of the visual pigment chromophore, it is not surprising that the bisretinoids of retina are light sensitive molecules. Accordingly, we will discuss recent findings that implicate the photodegradation of bisretinoid in the etiology of age-related macular degeneration. PMID:22209824

Sparrow, Janet R.; Gregory-Roberts, Emily; Yamamoto, Kazunori; Blonska, Anna; Ghosh, Shanti Kaligotla; Ueda, Keiko; Zhou, Jilin

2012-01-01

128

Macular injury by an Nd:YAG rangefinder  

NASA Astrophysics Data System (ADS)

The authors report the clinical findings of a civilian patient who unintentionally looked into the laser beam of a British range finder, obtained on the black market. The patient was investigated by fluorescein angiography. Indocyanine green angiography (ICG) and microperimetry both in the acute stage (2 hours) and four weeks later. Hundred mg prednisone tapered over 9 days was prescribed. Additionally 50 ?g tissue plasminogen activator (TPA) and 0.5 ml pure C2F6 were injected in the vitreous. In the acute phase hemorrhage was located beneath the retina, primarily beneath the retinal pigment epithelium. Retinal defects as seen initially over the subretinal blood, were reduced after four weeks, but a retinal defect ranging from the lasered site towards the fovea remained. Visual acuity slightly increased from 20/100 to 20/63. ICG showed a large hypofluorescent spot in the macula. The technical parameters of the range finder were: Nd:YAG laser (1064 nm), pulse duration 10 ns, beam divergence 1.5 mrad, energy 10 mJ. A range finder can produce severe macular injury. The primary laser tissue interaction mechanism seems to be explosive disruption of choroidal tissue. Intravitral injection of TPA and C2F6 may be an adjunct in the therapy of acute laser lesions. A late complication can be secondary choroidal neovascularization.

Roider, Johann; Buesgen, Patrick; Hoerauf, Hans; Laqua, Horst; Birngruber, Reginald

1999-06-01

129

Structural Changes in Individual Retinal Layers in Diabetic Macular Edema  

PubMed Central

Optical coherence tomography (OCT) has enabled objective measurement of the total retinal thickness in diabetic macular edema (DME). The central retinal thickness is correlated modestly with visual impairment and changes paradoxically after treatments compared to the visual acuity. This suggests the clinical relevance of the central retinal thickness in DME and the presence of other factors that affect visual disturbance. Recent advances in spectral-domain (SD) OCT have provided better delineation of the structural changes and fine lesions in the individual retinal layers. Cystoid spaces in the inner nuclear layer and outer plexiform layer are related to quantitative and qualitative parameters in fluorescein angiography. OCT often shows vitreoretinal interface abnormalities in eyes with sponge-like retinal swelling. Serous retinal detachment is sometimes accompanied by hyperreflective foci in the subretinal fluid, which exacerbates the pathogenesis at the interface of the photoreceptors and retinal pigment epithelium. Photoreceptor damage at the fovea is thought to be represented by disruption of the external limiting membrane or the junction between the inner and outer segment lines and is correlated with visual impairment. Hyperreflective foci in the outer retinal layers on SD-OCT images, another marker of visual disturbance, are associated with foveal photoreceptor damage. PMID:24073417

Yoshimura, Nagahisa

2013-01-01

130

Effect of chromium accumulation on photosynthetic pigments, oxidative stress defense system, nitrate reduction, proline level and eugenol content of Ocimum tenuiflorum L  

Microsoft Academic Search

Ocimum tenuiflorum L. exposed to various concentrations of chromium (0.0, 10.0, 20.0, 50.0, 100.0?M) accumulated high amount of chromium in various plant parts in a concentration and duration dependent manner. Chromium induced lipid peroxidation coupled with potassium leakage. Toxic effects of chromium on O. tenuiflorum were reflected by the reductions in photosynthetic pigments, protein, cysteine, ascorbic acid and non-protein thiol

Vartika Rai; Poornima Vajpayee; Shri Nath Singh; Shanta Mehrotra

2004-01-01

131

Comparison of mercury levels in various tissues of albino and pigmented mice treated with two different brands of mercury skin-lightening creams  

Microsoft Academic Search

The use of mercury containing skin-lightening creams are becoming increasingly popular among dark-skinned women. The long term use of certain brands may cause serious health effects over the years. In the present study, we investigated the dermal absorption of mercury and its accumulation in the tissues of albino and pigmented mice treated with two brands of mercury containing skin-lightening creams

Iman Al-Saleh; Neptune Shinwari; Inaam El-Doush; Grisellhi Billedo; Mona Al-Amodi; Fathia Khogali

2004-01-01

132

Evaluation of posturing in macular hole surgery  

Microsoft Academic Search

Aim To objectively evaluate the postoperative face down posturing in macular hole surgery.Materials and Methods An electronic device called ‘Maculog’ was developed consisting of three basic components, a mercury switch triggered by the angle of tilt placed inside an earpiece, a data-recording device connected to the earpiece with cables and a windows based software program, specially written to analyse the

D Verma; M W Jalabi; W G Watts; G Naylor

2002-01-01

133

Depression in Age-Related Macular Degeneration  

ERIC Educational Resources Information Center

Age-related macular degeneration (AMD) is a major cause of disability in the elderly, substantially degrades the quality of their lives, and is a risk factor for depression. Rates of depression in AMD are substantially greater than those found in the general population of older people, and are on par with those of other chronic and disabling…

Casten, Robin; Rovner, Barry

2008-01-01

134

Steroids and the Management of Macular Edema  

Microsoft Academic Search

Macular edema (ME) is a condition which is usually secondary to an underlying disease process. It is most commonly seen following venous occlusive disease, diabetic retinopathy and posterior segment inflammatory disease. The treatment of ME varies, depending upon the underlying etiology, and has led to varying degrees of success. Traditionally, the main treatment options have included topical and systemic steroids,

Shani Golan; Anat Loewenstein

2010-01-01

135

Scotopic Microperimetry in the Early Diagnosis of Age-Related Macular Degeneration: Preliminary Study  

PubMed Central

Background. Recent clinical studies have shown that, in some degenerative retinal diseases, like age-related macular degeneration (AMD), the sensitivity of the rods decreases more rapidly than the sensitivity of the cones. The aim of this study was to evaluate if there is a correlation between the presence of hard drusen at the macular level and the rod damage responsible for the reduction in scotopic retinal sensitivity in subjects at risk for AMD. Methods. The authors selected 24 subjects (14 men and 10 women) with an average age of 67.25?±?5.7 years. Macular hard drusen were present in 50% of the subjects at the fundus oculi exam. The researchers evaluated the retinal sensitivity to light in mesopic and scotopic conditions of each subject with an MP-1 scotopic microperimeter (MP-1S). Results. In subjects with hard drusen in the fundus oculi examination, there was a statistically significant reduction in scotopic retinal sensitivity, while the mesopic retinal sensitivity was not compromised. Conclusion. This study revealed how the presence of hard drusen at the macular level is associated with a reduction in scotopic retinal sensitivity compared to a control group of healthy subjects. Retinal functionality in a scotopic setting examined with MP-1S could be useful in early diagnosis of AMD. PMID:25548774

Pescosolido, Nicola

2014-01-01

136

sA population-based study of macular choroidal neovascularization using optical coherence tomography in Eastern China  

PubMed Central

The aim of the present study was to investigate the pathomorphological and functional variations of choroidal neovascularization (CNV) in age-related macular degeneration (AMD) in a Chinese population using optical coherence tomography (OCT). This population-based study enrolled 59 patients (age, >45 years; eyes, 70) with early and intermediate-stage AMD from Youyi Road Community, Baoshan District, Shanghai, China. Comprehensive standardized ophthalmic examinations included visual acuity, anterior segment analysis using a slit lamp, dilated fundus evaluation by direct ophthalmoscopy, 90D handheld lens analysis, fundus photography, fundus fluorescein angiography (FFA) and fast optic disk scans using OCT. The macular CNV characteristic profiles in early and intermediate-stage AMD were determined by OCT. Data were obtained on the first visit and the follow-up period ranged between 6 and 24 months, where FFA and OCT outcomes of early and intermediate-stage AMD patients were analyzed. Three profiles of early and intermediate-stage AMD were created from the OCT and FFA results, each with a different prognosis. Firstly, drusens with unclear boundaries and evident pigment proliferation, as well as hypofluorescence around the drusens, was observed via FFA. A slight small arch field located in the retinal pigment epithelium (RPE)/choriocapillary layer (CCL) was shown on OCT scans, indicating exudative AMD. Secondly, RPE detachments of >1 pupillary distance, without CNV in the macular area, indicated geographic chorioretinitis atrophy. Finally, drusens with clear boundaries and few pigment proliferations and no certain surrounding fluorescence was observed via FFA, while a clear RPE/CCL band on the OCT scans indicated slow progress. The results of the present study demonstrated that combined OCT and FFA was the most efficient method for identifying CNV and diagnosing AMD. If the two techniques are not available concurrently, then OCT is a safer and more reliable technique to follow-up early and intermediate-stage AMD patients. PMID:25009585

ZHAO, JIE; HU, JUN; LU, HAO; YANG, LEI

2014-01-01

137

Novel Rodent Models for Macular Research  

PubMed Central

Background Many disabling human retinal disorders involve the central retina, particularly the macula. However, the commonly used rodent models in research, mouse and rat, do not possess a macula. The purpose of this study was to identify small laboratory rodents with a significant central region as potential new models for macular research. Methodology/Principal Findings Gerbillus perpallidus, Meriones unguiculatus and Phodopus campbelli, laboratory rodents less commonly used in retinal research, were subjected to confocal scanning laser ophthalmoscopy (cSLO), fluorescein and indocyanine green angiography, and spectral-domain optical coherence tomography (SD-OCT) using standard equipment (Heidelberg Engineering HRA1 and Spectralis™) adapted to small rodent eyes. The existence of a visual streak-like pattern was assessed on the basis of vascular topography, retinal thickness, and the topography of retinal ganglion cells and cone photoreceptors. All three species examined showed evidence of a significant horizontal streak-like specialization. cSLO angiography and retinal wholemounts revealed that superficial retinal blood vessels typically ramify and narrow into a sparse capillary net at the border of the respective area located dorsal to the optic nerve. Similar to the macular region, there was an absence of larger blood vessels in the streak region. Furthermore, the thickness of the photoreceptor layer and the population density of neurons in the ganglion cell layer were markedly increased in the visual streak region. Conclusions/Significance The retinal specializations of Gerbillus perpallidus, Meriones unguiculatus and Phodopus campbelli resemble features of the primate macula. Hence, the rodents reported here may serve to study aspects of macular development and diseases like age-related macular degeneration and diabetic macular edema, and the preclinical assessment of therapeutic strategies. PMID:20976212

Huber, Gesine; Heynen, Severin; Imsand, Coni; vom Hagen, Franziska; Muehlfriedel, Regine; Tanimoto, Naoyuki; Feng, Yuxi; Hammes, Hans-Peter; Grimm, Christian; Peichl, Leo; Seeliger, Mathias W.; Beck, Susanne C.

2010-01-01

138

Pigment-protein complexes  

SciTech Connect

The photosynthetically-active pigment protein complexes of procaryotes and eucaryotes include chlorophyll proteins, carotenochlorophyll proteins, and biliproteins. They are either integral components or attached to photosynthetic membranes. Detergents are frequently required to solubilize the pigment-protein complexes. The membrane localization and detergent solubilization strongly suggest that the pigment-protein complexes are bound to the membranes by hydrophobic interactions. Hydrophobic interactions of proteins are characterized by an increase in entropy. Their bonding energy is directly related to temperature and ionic strength. Hydrophobic-interaction chromatography, a relatively new separation procedure, can furnish an important method for the purification of pigment-protein complexes. Phycobilisome purification and properties provide an example of the need to maintain hydrophobic interactions to preserve structure and function.

Siegelman, H W

1980-01-01

139

The Role of Spectral-Domain OCT in the Diagnosis and Management of Neovascular Age-Related Macular Degeneration  

PubMed Central

Spectral-domain optical coherence tomography (SD-OCT) has emerged as the ancillary examination of choice to assist the diagnosis and management of neovascular age-related macular degeneration (AMD). SD-OCT provides more detailed images of intraretinal, subretinal, and subretinal pigment epithelium fluid when compared to time-domain technology, leading to higher and earlier detection rates of neovascular AMD activity. Improvements in image analysis and acquisition speed make it important for decision-making in the diagnosis and treatment of this disease. However, this new technology needs to be validated for its role in the improvement of visual outcomes in the context of anti-angiogenic therapy. PMID:21790112

Regatieri, Caio V.; Branchini, Lauren; Duker, Jay S.

2012-01-01

140

Retinal pigment epithelial tear after intravitreous triamcinolone acetonide injection for fibrovascular pigment epithelial detachment.  

PubMed

A 78-year-old woman was diagnosed with fibrovascular pigment epithelial detachment (PED) associated with age-related macular degeneration (AMD) affecting both eyes. Due to decreased vision in her left eye (20/2000) and disease progression, the patient received 4 mg of triamcinolone acetonide (TA) by intravitreal injection into her left eye. There were no immediate post-injection complications in the left eye. However, one week later, a retinal pigment epithelial (RPE) tear, temporal-inferior to the fovea in the left eye, was noted and confirmed by fundus photography, fluorescein angiography and optical coherence tomography. In contrast, there no similar RPE tear occurred in her right eye after treated several times by intravitreous bevacizumab injection. Not only anti-vascular endothelium growth factor agents, but also intravitreal TA when used to treat AMD with PED, would seem to induce a RPE tear in the absence of previous or concurrent adjuvant therapy. Further investigations are required to confirm the mechanism by which the RPE tear occurs. PMID:21733363

Wu, Pei-Chang; Chen, Yung-Jen; Kuo, Hsi-Kung

2011-01-01

141

Pigments Through the Ages  

NSDL National Science Digital Library

This fascinating online exhibit deals with the use of pigment and provides visitors with an "Overview", "History of Use", "Making the Pigment" and "Technical Details" for dozens of pigments that are "some of the most historically important in art". Visitors can click on "Choose a Pigment" to see a 3D image of such beauties as Cerulean Blue, Ultramarine, Naples Yellow, and Orpiment. Visitors can see a timeline of when these pigments were discovered, if they have continued being used, and in what form, artificial or natural. Carbon Black and Bone Black were the earliest pigments, and are still used today, and Titanium White is the most recent discovery, and it came into existence in 1921. The "Make Paintings" link is where visitors will probably have the most fun on the site, as they can see the progress of a painting in watercolor, pastels, oil, acrylic and the now little used method of egg tempera. Additionally, each technique is explained in detail, highlighted by photos that visitors can zoom in on for closer scrutiny.

142

Effect of change in macular birefringence imaging protocol on retinal nerve fiber layer thickness parameters using GDx VCC in eyes with macular lesions.  

PubMed

This study evaluates the effect of two macular birefringence protocols (bow-tie retardation and irregular macular scan) using GDx VCC on the retinal nerve fiber layer (RNFL) thickness parameters in normal eyes and eyes with macular lesions. In eyes with macular lesions, the standard protocol led to significant overestimation of RNFL thickness which was normalized using the irregular macular pattern protocol. In eyes with normal macula, absolute RNFL thickness values were higher in irregular macular pattern protocols with the difference being statistically significant for all parameters except for inferior average thickness. This has implications for monitoring glaucoma patients who develop macular lesions during the course of their follow-up. PMID:24469116

Dada, Tanuj; Tinwala, Sana I; Dave, Vivek; Agarwal, Anand; Sharma, Reetika; Wadhwani, Meenakshi

2014-08-01

143

Focal macular photopic negative response in patients with optic neuritis  

Microsoft Academic Search

PurposeTo investigate, by focal macular electroretinography (ERG), the change of photopic negative response (PhNR) in the recovery of visual function in patients with optic neuritis.MethodsFocal macular ERG was recorded from nine patients with acute optic neuritis (38.6±10.2 years). The photostimulator device projected 15° visual angle spotlight onto the macula. Focal macular ERG recording was performed at the onset and at

H Nakamura; K Miyamoto; S Yokota; K Ogino; N Yoshimura

2011-01-01

144

Cholesterol-mediated activation of acid sphingomyelinase disrupts autophagy in the retinal pigment epithelium  

PubMed Central

Autophagy is an essential mechanism for clearing damaged organelles and proteins within the cell. As with neurodegenerative diseases, dysfunctional autophagy could contribute to blinding diseases such as macular degeneration. However, precisely how inefficient autophagy promotes retinal damage is unclear. In this study, we investigate innate mechanisms that modulate autophagy in the retinal pigment epithelium (RPE), a key site of insult in macular degeneration. High-speed live imaging of polarized adult primary RPE cells and data from a mouse model of early-onset macular degeneration identify a mechanism by which lipofuscin bisretinoids, visual cycle metabolites that progressively accumulate in the RPE, disrupt autophagy. We demonstrate that bisretinoids trap cholesterol and bis(monoacylglycero)phosphate, an acid sphingomyelinase (ASMase) cofactor, within the RPE. ASMase activation increases cellular ceramide, which promotes tubulin acetylation on stabilized microtubules. Live-imaging data show that autophagosome traffic and autophagic flux are inhibited in RPE with acetylated microtubules. Drugs that remove excess cholesterol or inhibit ASMase reverse this cascade of events and restore autophagosome motility and autophagic flux in the RPE. Because accumulation of lipofuscin bisretinoids and abnormal cholesterol homeostasis are implicated in macular degeneration, our studies suggest that ASMase could be a potential therapeutic target to ensure the efficient autophagy that maintains RPE health. PMID:25378587

Toops, Kimberly A.; Tan, Li Xuan; Jiang, Zhichun; Radu, Roxana A.; Lakkaraju, Aparna

2015-01-01

145

Increased resolution macular thickness mapping by OCT.  

PubMed

Optical coherence tomography (OCT) poor mapping resolution has been pointed out as the biggest disadvantage of this technique when compared to others, e.g., retinal thickness analyzer. In this work we were able to solve this problem by developing an atlas of macular thickness of the human retina into which OCT scans were thereafter registered. This atlas is used to allow registering OCT scans from the Fast Macular Protocol, thus bringing OCT scans into the atlas coordinates, therefore correcting for misfixations, while simultaneously allowing to perform OCT inter-scan registration. From this initial registration, we were able to compute a thickness map into which Fast RNFL Protocol scans were merged, thus allowing for increased OCT mapping resolution. PMID:17946646

Bernardes, Rui; Santos, Torcato; Cunha-Vaz, José

2006-01-01

146

[Functional characteristics of macular telangiectasia type 2].  

PubMed

The first symptoms of macular telangiectasia type 2 usually occur between 50 and 70 years of age. Functional alterations topographically correspond to the morphological changes. Characteristic paracentral scotomata due to focal photoreceptor atrophy can be detected using microperimetry. The predominant paracentral functional loss may cause reading difficulties despite visual acuity in the range between 20/20 and 20/50. Visual acuity around 20/200 may occur once the paracentral photoreceptor atrophy extends centrally, or due to the development of a macular hole or a secondary neovascular membrane. Progression of functional loss can often only be detected by mapping scotoma size or occurrence using microperimetry, while visual acuity may remain unchanged. PMID:25204528

Heeren, T F C; Krüger, E; Holz, F G; Charbel Issa, P

2014-09-01

147

Limited inferior macular translocation for the treatment of subfoveal choroidal neovascularization secondary to age-related macular degeneration  

Microsoft Academic Search

PURPOSE: To review a series of patients with age-related macular degeneration undergoing limited macular translocation for the treatment of subfoveal choroidal neovascularization, to determine short-term visual acuity outcomes, to measure amounts of attainable retinal movement, and to identify prognostic factors.METHODS: A retrospective review was conducted on a consecutive series of patients undergoing inferior limited macular translocation with scleral imbrication for

Dante J Pieramici; Eugene De Juan Jr; Gildo Y Fujii; Sandra M Reynolds; Michele Melia; Mark S Humayun; Andrew P Schachat; Craig D Hartranft

2000-01-01

148

PERIFOVEAL VITREOUS DETACHMENT AND ITS MACULAR COMPLICATIONS  

PubMed Central

Purpose To evaluate the vitreoretinal relationship in eyes with idiopathic macular disorders putatively caused by vitreomacular traction associated with early stages of age-related posterior vitreous detachment (PVD). Methods Retrospective observational case series of 43 eyes of 40 patients diagnosed with one of several idiopathic vitreomacular conditions. Included patients had no biomicroscopic evidence for complete PVD on presentation and underwent a specific clinical assessment of the vitreoretinal relationship. Affected eyes were evaluated with slit-lamp biomicroscopy, B-scan ultrasonography, optical coherence tomography, and/or intraoperative examination of the posterior hyaloid. Results By one or more examination techniques, 41 (95.3%) of the 43 study eyes had evidence of vitreous detachment from the perifoveal macular region and the remaining two eyes had complete PVD. When measurable, the size of the vitreomacular adhesion varied by diagnosis. Of 31 eyes with perifoveal vitreous detachment seen in follow-up, only three (9.7%) showed progression to complete PVD over an average preoperative or total follow-up period of 30.0 months (range, 2 to 237 months). Surgical or spontaneous separation of the residual vitreomacular adhesion in 16 eyes was followed in 15 (93.8%) by partial or complete resolution of the symptoms and signs of macular traction. Conclusions Age-related PVD appears to be an insidious, chronic event that begins in the perifoveal macula and evolves over a prolonged period of time prior to vitreopapillary separation. Though usually asymptomatic, its early (perifoveal) stages may be complicated by one of several macular pathologies, determined in part by the size of the residual vitreomacular adhesion. PMID:17057817

Johnson, Mark W

2005-01-01

149

Macular Bioaccelerometers on Earth and in Space  

NASA Technical Reports Server (NTRS)

Space flight offers the opportunity to study linear bioaccelerometers (vestibular maculas) in the virtual absence of a primary stimulus, gravitational acceleration. Macular research in space is particularly important to NASA because the bioaccelerometers are proving to be weighted neural networks in which information is distributed for parallel processing. Neural networks are plastic and highly adaptive to new environments. Combined morphological-physiological studies of maculas fixed in space and following flight should reveal macular adaptive responses to microgravity, and their time-course. Ground-based research, already begun, using computer-assisted, 3-dimensional reconstruction of macular terminal fields will lead to development of computer models of functioning maculas. This research should continue in conjunction with physiological studies, including work with multichannel electrodes. The results of such a combined effort could usher in a new era in understanding vestibular function on Earth and in space. They can also provide a rational basis for counter-measures to space motion sickness, which may prove troublesome as space voyager encounter new gravitational fields on planets, or must re-adapt to 1 g upon return to earth.

Ross, M. D.; Cutler, L.; Meyer, G.; Vazin, P.; Lam, T.

1991-01-01

150

Rod-cone Dystrophy with Initially Preserved Visual Acuity Despite Early Macular Involvement Suggests Recessive CERKL Mutations.  

PubMed

Abstract Purpose: To highlight that recessive CERKL mutations cause an early-onset rod-cone dystrophy with initially preserved visual acuity despite early macular involvement, an unusual and distinct initial phenotypic presentation. Methods: A retrospective case series. Results: Two young Saudi Arabian adults complained of worsening night blindness over the preceding few years, one of whom had been symptomatic since early childhood. Both had retinal pigment epithelium (RPE) mottling/granularity, vascular attenuation, few bone spicules, and frank macular RPE atrophic changes despite relatively preserved visual acuity. Electroretinography was non-recordable, and ocular coherence tomography confirmed retinal thinning, particularly of the outer nuclear layer in the fovea. Each patient harbored a different homozygous CERKL mutation (p.L245P, p.C333*). The few prior reports that detail the presenting phenotype of CERKL mutations describe children or young adults with the similar unusual presenting constellation of findings: rod-cone dystrophy and frank macular atrophy but relatively preserved visual acuity. With time, central vision is affected. Conclusions: The initial presenting features of CERKL-related retinopathy are distinct and unusual. Recognition of this initial presenting phenotype can facilitate earlier molecular diagnosis and genetic counseling. PMID:24547929

Khan, Arif O; Abu-Safieh, Leen

2014-02-19

151

An Improved Method for Extraction and Separation of Photosynthetic Pigments  

ERIC Educational Resources Information Center

The method for extracting and separating hydrophobic photosynthetic pigments proposed by Katayama "et al." ("Japanese Journal of Phycology," 42, 71-77, 1994) has been improved to introduce it to student laboratories at the senior high school level. Silica gel powder was used for removing water from fresh materials prior to extracting pigments by a…

Katayama, Nobuyasu; Kanaizuka, Yasuhiro; Sudarmi, Rini; Yokohama, Yasutsugu

2003-01-01

152

Stem cell-based therapies for age-related macular degeneration: current status and prospects  

PubMed Central

Abstract: Age-related macular degeneration (AMD) is one of the major causes of irreversible blindness both in developed and developing countries. During the past decades, the managements of neovascular AMD (wet AMD) have dramatically progressed. However, still no effective treatment for non-neovascular AMD (dry AMD) which was characterized by geographic macular atrophy. Recent advances in stem cell sciences have demonstrated that retinal pigment epithelium (RPE) cells can be generated from several types of stem cells (including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, et al) by cell co-culturing or defined factors. Additionally, studies also showed that visual function could be recovered by transplantation of these cells into subretinal space in vivo. Moreover, the United States Food and Drug Administration already approved several clinical trials to evaluate the efficiencies of stem cell based cell transplantation for dry AMD patients. Till now, a few patients enrolled in these studies achieved promising outcomes. This review will summarize recent advances in stem cell based RPE differentiation, transplantation, and the preliminary results of clinical trials. The obstacles and prospects in this field will also be discussed. PMID:25550892

Mu, Yalin; Zhao, Manli; Su, Guangming

2014-01-01

153

Defective Lipid Transport and Biosynthesis in Recessive and Dominant Stargardt Macular Degeneration  

PubMed Central

Stargardt disease is a common inherited macular degeneration characterized by a significant loss in central vision in the first or second decade of life, bilateral atrophic changes in the central retina associated with degeneration of photoreceptors and underlying retinal pigment epithelial cells, and the presence of yellow flecks extending from the macula. Autosomal recessive Stargardt disease, the most common macular dystrophy, is caused by mutations in the gene encoding ABCA4, a photoreceptor ATP binding cassette (ABC) transporter. Biochemical studies together with analysis of abca4 knockout mice and Stargardt patients have implicated ABCA4 as a lipid transporter that facilitates the removal of potentially toxic retinal compounds from photoreceptors following photoexcitation. An autosomal dominant form of Stargardt disease also known as Stargardt-like dystrophy is caused by mutations in a gene encoding ELOVL4, an enzyme that catalyzes the elongation of very long chain fatty acids in photoreceptors and other tissues. This review focuses on the molecular characterization of ABCA4 and ELOVL4 and their role in photoreceptor cell biology and the pathogenesis of Stargardt disease. PMID:20633576

Molday, Robert S.; Zhang, Kang

2010-01-01

154

Estrogen signalling in the pathogenesis of age-related macular degeneration.  

PubMed

Age-related macular degeneration (AMD) is a multifactorial eye disease that is associated with aging, family history, smoking, obesity, cataract surgery, arteriosclerosis, hypertension, hypercholesterolemia and unhealthy diet. Gender has commonly been classified as a weak or inconsistent risk factor for AMD. This disease is characterized by degeneration of retinal pigment epithelial (RPE) cells, Bruch's membrane, and choriocapillaris, which secondarily lead to damage and death of photoreceptor cells and central visual loss. Pathogenesis of AMD involves constant oxidative stress, chronic inflammation, and increased accumulation of lipofuscin and drusen. Estrogen has both anti-oxidative and anti-inflammatory capacity and it regulates signaling pathways that are involved in the pathogenesis of AMD. In this review, we discuss potential cellular signaling targets of estrogen in retinal cells and AMD pathology. PMID:24911983

Kaarniranta, Kai; Machali?ska, Anna; Veréb, Zoltán; Salminen, Antero; Petrovski, Goran; Kauppinen, Anu

2015-02-01

155

Progressive macular hypomelanosis among Egyptian patients: a clinicopathological study  

PubMed Central

Background: Progressive macular hypomelanosis (PMH) is a disease of unclear etiology. Propionbacterium acnes (P. acnes) was claimed to be an etiological factor. Objectives: The purpose of this study was to document the clinicopathological features of PMH in Egyptian patients and to evaluate the therapeutic outcome. Methods: Patients with clinical features of PMH were recruited. Wood’s lamp examination, skin scrapings for fungi, and skin biopsy specimens were obtained. Biopsies were stained with hematoxylin and eosin, PAS, Fontana-Masson, and S100 protein. Patients received either narrow-band UVB (nbUVB) or nbUVB plus daily topical clindamycin 1% and benzoyl peroxide gel 5% (bcUVB). The period of active treatment was 14 weeks followed by a follow-up period of 24 weeks. Results: Twenty-nine patients were included. Microscopic evaluation of skin biopsy specimens showed no significant differences between lesional and normal skin. Fontana-Masson stained sections showed overall reduction of melanin granules in the basal layer of lesional skin only and S100 staining did not detect significant differences in the number of melanocytes in lesional and normal skin. Nearly complete repigmentation was reported in 10 patients treated with bcUVB compared to 9 patients treated with nbUVb with no significant differences between both groups after 14 weeks. Only 2 patients in each group retained the pigmentation and the remaining patients returned to the baseline color before treatment. Conclusions: This study documented the clinicopathological features of PMH among Egyptians. No permanently effective treatment is available. Further studies are needed to prove or disprove the pathogenic role of P. acnes in PMH. PMID:24396712

Selim, Mohamed Khaled; Ahmed, El-Shahat Farag; Abdelgawad, Mamdouh Morsy; El-Kamel, Mohammed Fawzy

2011-01-01

156

Biology of pigmentation  

SciTech Connect

The many factors involved in the normal pigmentation of human skin are highly complex involving anatomic, biochemical, and genetic aspects of melanocytes in the skin and the influence of UV light and various hormones on the melanocytes. It is probably more than just coincidence that the melanocytes, which are of neurogenic origin, are so responsive to several trophic hormones produced in the brain. Understanding of the various factors involved in the normal pigmentary process is crucial to explaining the many alterations and anomalies in human pigmentation.

Parker, F.

1981-01-01

157

BASIS FOR ENHANCED BARRIER FUNCTION OF PIGMENTED SKIN  

PubMed Central

Humans with darkly-pigmented skin display superior permeability barrier function in comparison to humans with lightly-pigmented skin. The reduced pH of the stratum corneum (SC) of darkly-pigmented skin could account for enhanced function, because acidifying lightly-pigmented human SC resets barrier function to darkly-pigmented levels. In SKH1 (non-pigmented) vs. SKH2/J (pigmented) hairless mice, we evaluated how a pigment-dependent reduction in pH could influence epidermal barrier function. Permeability barrier homeostasis is enhanced in SKH2/J vs. SKH1 mice, correlating with a reduced pH in the lower SC that co-localizes with the extrusion of melanin granules. Darkly-pigmented human epidermis also shows substantial melanin extrusion in the outer epidermis. Both acute barrier disruption and topical basic pH challenges accelerate re-acidification of SKH2/J (but not SKH1) SC, while inducing melanin extrusion. SKH2/J mice also display enhanced expression of the SC acidifying enzyme, secretory phospholipase A2f (sPLA2f). Enhanced barrier function of SKH2/J mice could be attributed to enhanced activity of two acidic pH-dependent, ceramide-generating enzymes, ?-glucocerebrosidase and acidic sphingomyelinase, leading to accelerated maturation of SC lamellar bilayers. Finally, organotypic cultures of darkly-pigmented-bearing human keratinocytes display enhanced barrier function in comparison to lightly-pigmented cultures. Together, these results suggest that the superior barrier function of pigmented epidermis can be largely attributed to the pH-lowering impact of melanin persistence/extrusion and enhanced sPLA2f expression. PMID:24732399

Man, Mao-Qiang; Lin, Tzu-Kai; Santiago, Juan Luis; Celli, Anna; Zhong, Lily; Huang, Zhi-Ming; Roelandt, Truus; Hupe, Melanie; Sundberg, John P.; Silva, Kathleen A.; Crumrine, Debra; Martin-Ezquerra, Gemma; Trullas, Carles; Sun, Richard; Wakefield, Joan S.; Wei, Maria L.; Feingold, Kenneth R.; Mauro, Theodora M.; Elias, Peter M.

2014-01-01

158

Genetics Home Reference: Vitelliform macular dystrophy  

MedlinePLUS

... controls the movement of charged chlorine atoms (chloride ions) into or out of cells in the retina. ... chloride ; epithelium ; gene ; incidence ; inheritance ; inheritance pattern ; inherited ; ions ; juvenile ; lipofuscin ; macula ; peripheral ; photoreceptor ; pigment ; protein ; retina ; ...

159

Macular dystrophy in Kabuki syndrome: a new clinical feature?  

PubMed

Kabuki syndrome is a rare and genetically heterogenous condition that has both systemic and ophthalmic complications. Macular dystrophy has not previously been noted in conjunction with this syndrome. The authors present a 14-year-old girl with Kabuki syndrome with macular dystrophy and confirmatory electrodiagnostics. PMID:21766738

Lindfield, Dan; Griffiths, Michael F P; Thompson, Dorothy A; Moore, Anthony T

2011-01-01

160

Cystoid macular edema associated with topical echothiophate iodide.  

PubMed

We report the case of a patient with visual loss and cystoid macular edema that was associated with the topical use of echothiophate iodide. After cessation of the drops, the cystoid macular edema nearly disappeared, and vision returned to normal. PMID:8129329

Halperin, L S; Goldman, H B

1993-12-01

161

Latent pigments activated by heat  

Microsoft Academic Search

Organic pigments are used as colourants in paints, plastics, printing inks and in the electronics industries. They can be distinguished from dyes in that they are insoluble. Whereas dyes readily dissolve to give homogeneous coloration, the application of organic pigments frequently requires a time- and energy-consuming dispersion step. Here we report a method for converting a pigment into a suitable

J. S. Zambounis; Z. Hao; A. Iqbal

1997-01-01

162

Transformations in Organic Pigments  

Microsoft Academic Search

Organic pigments are often recrystallized in various ways to effect purification and to control the particle size of the new crop of crystals. Copper phthalocyanine and indanthrene blue RS have been observed to yield crystals of varying shades, ranging from a light greenish blue to a dark reddish blue (purple). These shades have in the past been attributed only to

F. A. Hamm; Earl Van Norman

1948-01-01

163

Pigment dispersion syndrome and pigmented pattern dystrophy of retinal pigment epithelium.  

PubMed Central

The 2 rare entities, pigmentary dispersion syndrome and pigmented pattern dystrophy of the retinal pigment epithelium, were found in a young male patient. Visual function was undisturbed. Images PMID:6871146

Chew, E Y; Deutman, A F

1983-01-01

164

Small molecule mediated proliferation of primary retinal pigment epithelial cells  

PubMed Central

Retinal pigment epithelial (RPE) cells form a monolayer adjacent to the retina and play a critical role in the visual light cycle. Degeneration of RPE cells results in retinal disorders such as age-related macular degeneration. Cell transplant strategies have potential therapeutic value for such disorders; however, risks associated with and an inadequate supply of donor cells limit their therapeutic success. The identification of factors that proliferate RPE cells ex vivo could provide a renewable source of cells for transplantation. Here we report that a small molecule (WS3) can reversibly proliferate primary RPE cells isolated from fetal and adult human donors. Following withdrawal of WS3, RPE cells differentiate into a functional monolayer, as exhibited by their expression of mature RPE genes and phagocytosis of photoreceptor outer segments. Furthermore, chemically expanded RPE cells preserve vision when transplanted into dystrophic Royal College of Surgeons (RCS) rats, a well-established model of retinal degeneration. PMID:23621521

Swoboda, Jonathan G.; Elliott, Jimmy; Deshmukh, Vishal; de Lichtervelde, Lorenzo; Shen, Weijun; Tremblay, Matthew S.; Peters, Eric C.; Cho, Charles Y.; Lu, Bin; Girman, Sergej; Wang, Shaomei; Schultz, Peter G.

2013-01-01

165

Alpha-Lipoic Acid for the Prevention of Diabetic Macular Edema  

Microsoft Academic Search

Introduction: To evaluate the effect of ?-lipoic acid (ALA) on the occurrence of diabetic macular edema. Methods: Randomized, double-blind, placebo-controlled, multicenter, multinational study. Patients were randomized to the treatment group with 600 mg ALA per day or the placebo group. Every 6 months stereo fundus photographs, HbA1c levels, and an ophthalmological examination were documented. The primary endpoint was the occurrence

Christos Haritoglou; Joachim Gerss; Hans P. Hammes; Anselm Kampik; Michael W. Ulbig

2011-01-01

166

Alteration of the visual evoked potential by macular holes: Comparison with optic neuritis  

Microsoft Academic Search

Nine patients with maculopathy (macular holes, macular cysts, and lamellar holes) and ten patients with optic neuritis were examined in order to determine changes in the visual evoked potential (VEP) in response to pattern-reversal stimulation. Eyes with lamellar holes had normal P100 latency, but eyes with macular cysts and macular holes had prolonged P100 latency. Eyes with optic neuritis exhibited

L. N. Johnson; R. D. Yee; R. S. Hepler; D. A. Martin

1987-01-01

167

Vitrectomy Combined with Intravitreal Triamcinolone Acetonide Injection and Macular Laser Photocoagulation for Nontractional Diabetic Macular Edema  

PubMed Central

Purpose To evaluate the efficacy of vitrectomy combined with intravitreal injection of triamcinolone acetonide (IVTA) and macular laser photocoagulation for the treatment of nontractional diabetic macular edema (DME) refractory to anti-vascular endothelial growth factor (VEGF) therapy. Methods Twenty-eight eyes from 28 subjects who were diagnosed with nontractional DME refractory to three or more sequential anti-VEGF injections underwent sequential vitrectomy, IVTA, and macular laser photocoagulation. Changes in best-corrected visual acuity (BCVA) and central subfield thickness (CST) during the six months following vitrectomy were evaluated. Additionally, the CST and BCVA outcomes were compared with those of 26 eyes treated with the same triple therapy for nontractional DME refractory to conventional treatment, such as IVTA or macular laser photocoagulation, or both. Results The mean logarithm of the minimum angle of resolution BCVAs before and one, three, and six months after vitrectomy were 0.44 ± 0.15, 0.36 ± 0.18, 0.31 ± 0.14, and 0.34 ± 0.22, respectively. The mean CSTs were 433.3 ± 77.9, 329.9 ± 59.4, 307.2 ± 60.2, and 310.1 ± 80.1 microns, respectively. The values of both BCVA and CST at one, three, and six months were significantly improved from baseline (p < 0.05). The extent of CST reduction during the first month after triple therapy was greater in eyes refractory to conventional treatment than in eyes refractory to anti-VEGF (p = 0.012). Conclusions Vitrectomy combined with IVTA and macular laser photocoagulation had a beneficial effect on both anatomical and functional outcomes in eyes with nontractional DME refractory to anti-VEGF therapy. PMID:23730111

Kim, Jae Hui; Ha, Hyo Shin; Kim, Jae Ryung

2013-01-01

168

Outcomes of chronic macular hole surgical repair  

PubMed Central

Purpose: To report visual and anatomic outcomes of chronic macular hole surgery, with analysis of pre-operative OCT-based hole size and post-operative closure type. Settings and Design: An IRB-approved, retrospective case series of 26 eyes of 24 patients who underwent surgery for stage 3 or 4 idiopathic chronic macular holes at a tertiary care referral center. Statistical Analysis: Student's t-test. Results: Nineteen of 26 eyes (73%) had visual improvement after surgery on most recent exam. Twenty-one of 26 eyes (81%) achieved anatomic closure; 16 of 26 eyes (62%) achieved type 1, and five of 26 eyes (19%) achieved type 2 closure. Post-operative LogMAR VA for type 1 closure holes (0.49) was significantly greater than for type 2 closure and open holes (1.26, P < 0.003 and 1.10, P < 0.005, respectively), despite similar pre-operative VA (P = 0.51 and 0.68, respectively). Mean pre-operative hole diameter for eyes with type 1 closure, type 2 closure, and holes that remained open were 554, 929, and 1205 microns, respectively. Mean pre-operative hole diameter was significantly larger in eyes that remained open as compared to eyes with type 1 closure (P = 0.015). Conclusion: Vitrectomy to repair chronic macular holes can improve vision and achieve long-term closure. Holes of greater than 3.4 years duration were associated with a greater incidence of remaining open and type 2 closure. Larger holes (mean diameter of 1205 microns) were more likely to remain open after repair. PMID:25116773

Shukla, Shripaad Y; Afshar, Armin R; Kiernan, Daniel F; Hariprasad, Seenu M

2014-01-01

169

[Pharmacological treatment for diabetic macular edema].  

PubMed

Diabetic macular edema(DME) is a major cause of vision loss and has a remarkable impact on the quality of life of diabetic patients. New pharmacological approaches based on the use of intravitreal drugs, such as corticosteroids and anti-vascular endothelial growth factor, have recently been developed for the treatment of DME. Even though laser therapy has been the standard treatment for DME, the results of several clinical trials have shown the superiority of some of these new agents to laser therapy. The purpose of this review is to briefly summarize the currently available new pharmacological treatments for DME in Japan. PMID:25812378

Fukumoto, Masanori; Ikeda, Tsunehiko

2015-03-01

170

Intravitreal bevacizumab therapy for idiopathic macular telangiectasia  

Microsoft Academic Search

Purpose  To investigate the efficacy of intravitreal bevacizumab for the treatment of idiopathic macular telangiectasia (IMT).\\u000a \\u000a \\u000a \\u000a Methods  Ten eyes of eight consecutive patients with IMT were studied. Four eyes had type 1, and six had type 2 IMT according to Yannuzzi’s\\u000a classification. All patients were treated with intravitreal bevacizumab (1.25 mg) injections at baseline. Monthly fundus and\\u000a optical coherence tomography (OCT) examinations

Yoko Matsumoto; Mitsuko Yuzawa

2010-01-01

171

Spectral-Domain Optical Coherence Tomography Use in Macular Diseases: A Review  

Microsoft Academic Search

The introduction of spectral-domain optical coherence tomography (SD-OCT) has improved the clinical value for assessment of the eyes with macular disease. This article reviews the advances of SD-OCT for the diagnostic of various macular diseases. These include vitreomacular traction syndrome, cystoid macular edema\\/diabetic macular edema, epiretinal membranes, full-thickness macular holes, lamellar holes, pseudoholes, microholes, and schisis from myopia. Besides offering

Sebastian Wolf; Ute Wolf-Schnurrbusch

2010-01-01

172

Impaired cholesterol efflux in senescent macrophages promotes age-related macular degeneration  

PubMed Central

Summary Pathologic angiogenesis mediated by abnormally polarized macrophages plays a central role in common age-associated diseases such as atherosclerosis, cancer and macular degeneration. Here we demonstrate that abnormal polarization in older macrophages is caused by programmatic changes that lead to reduced expression of ATP binding cassette transporter ABCA1. Downregulation of ABCA1 by microRNA-33 impairs the ability of macrophages to effectively efflux intracellular cholesterol, which in turn leads to higher levels of free cholesterol within senescent macrophages. Elevated intracellular lipid polarizes older macrophages to an abnormal, alternatively activated phenotype that promotes pathologic vascular proliferation. Mice deficient for Abca1, but not Abcg1, demonstrate an accelerated aging phenotype, whereas restoration of cholesterol efflux using LXR agonists or miR-33 inhibitors reverses it. Monocytes from older humans with age-related macular degeneration showed similar changes. These findings provide an avenue for therapeutic modulation of macrophage function in common age-related diseases. PMID:23562078

Sene, Abdoulaye; Khan, Aslam A.; Cox, Douglas; Nakamura, Rei E.I.; Santeford, Andrea; Kim, Bryan M.; Sidhu, Rohini; Onken, Michael D.; Harbour, J. William; Haqbi-Levi, Shira; Chowers, Itay; Edwards, Peter A.; Baldan, Angel; Parks, John S.; Ory, Daniel S; Apte, Rajendra S.

2013-01-01

173

[Synthesis of melanin pigments by Antarctic black yeast].  

PubMed

Five strains of the black yeast similar to Exophiala nigra (Nadsoniela nigra), which we have isolated from the Antarctic biotopes, are studied. At cultivation in a periodic operation the maximum level of absolutely dry biomass in five tested strains constituted 3.2-7.8 g/l of medium, melanin pigment yield being 6-9% of absolutely dry mass of cells. Two highly productive strains have been selected. Pigments of the studied black yeast are water-insoluble, however dissolve in alkali and concentrated acids. The maximum absorption of the yeast pigments was in the range of 220 nm. The above-stated properties of pigments of the investigated yeast correspond to the description of melanin fractions of Nadsoniela nigra and some microscopic mushrooms. The water-soluble melanin-pigments have been obtained after the dialysis of alkaline solution of the pigment. UV-spectra and visible absorption spectra of water solution of melanin-pigments are almost identical to those of initial alkaline solutions. It is shown that the studied yeast are resistant to high concentrations of toxic metals (Hg2+, Cu2+, Co2+, Cr(VI) and Ni2+), and introduction of Co2+ into the cultivation medium leads to the increase of pigments synthesis. PMID:23120979

Tashirev, A B; Romanovskaia, V A; Rokitko, P V; Matveeva, N A; Shilin, S O; Tashireva, A A

2012-01-01

174

Macular abnormalities in Italian patients with retinitis pigmentosa  

PubMed Central

Aim To investigate the prevalence of macular abnormalities in a large Caucasian cohort of patients affected by retinitis pigmentosa (RP). Methods A retrospective study was performed by reviewing the medical records and optical coherence tomography (OCT) scans in a cohort of 581 RP patients in order to assess the presence of macular abnormalities —that is, cystoid macular oedema (CMO), epiretinal membrane (ERM), vitreo-macular traction syndrome, and macular hole. Results Macular abnormalities were observed in 524 (45.1%) out of the 1161 examined eyes. The most frequent abnormality was CMO, observed in 237 eyes (20.4%) from 133 patients (22.9%), followed by ERM, assessed in 181 eyes (15.6%) from 115 patients (19.8%). Moreover, vitreo-retinal abnormalities were significantly (p<0.05) associated with older age, cataract surgery, or cataract. CMO appeared to be significantly (p<0.05) associated with female gender, autosomic dominant inheritance pattern, and cataract. Conclusions Macular abnormalities are more frequent in RP compared to the general population. For that reason, screening RP patients with OCT is highly recommended to follow-up the patients, evaluate the natural history of disease, and identify those patients who could benefit from current or innovative therapeutic strategies. PMID:24532797

Testa, Francesco; Rossi, Settimio; Colucci, Raffaella; Gallo, Beatrice; Di Iorio, Valentina; della Corte, Michele; Azzolini, Claudio; Melillo, Paolo; Simonelli, Francesca

2014-01-01

175

Idiopathic macular telangiectasia type 2: ?the progressive vasculopathy.  

PubMed

Purpose. To describe the complete sequence of the progressive vasculopathy in macular telangiectasia type 2.?Methods. This is a report of a case demonstrating the complete vasogenic sequence in macular telangiectasia type 2 over the course of 15 years, and representative images from a collective of 150 patients with macular telangiectasia type 2 employing fundus photography, fluorescein angiography, and optical coherence tomography.?Results. Macular telangiectasia may progress along a predictable vasogenic sequence which consists of nonproliferative stages, characterized by temporal loss of macular luteopigment and inner retinal volume loss in the absence of vascular changes, followed by a progressive proliferative vasculopathy, first involving the deep capillary plexus with eventual extension of the vascular changes circumferentially in the inner retinal capillary plexus. Late proliferative stages may become indistinguishable from advanced neovascular age-related macular degeneration.?Conclusions. While it is rare to observe the complete vasogenic sequence of macular telangiectasia type 2, a classification into nonproliferative and proliferative stages can be established, and may prove helpful as the mechanisms driving the pathogenic process through those stages are identified. PMID:23138663

Engelbert, Michael; Yannuzzi, Lawrence A

2012-11-01

176

Photooxidative damage in retinal pigment epithelial cells via GRP78 and the protective role of grape skin polyphenols.  

PubMed

Blue light induced oxidative damage and ER stress are related to the pathogenesis of age-related macular degeneration (AMD). However, the mechanism of blue light-induced damage remained obscure. The objective of this work is to assess the photooxidative damage to retinal pigment epithelial cells (RPE) and oxidation-induced changes in expression of ER stress associated apoptotic proteins, and investigate the mechanism underlying the protective effects of grape skin extracts. To mimic lipofuscin-mediated photooxidation in vivo, ARPE-19 cells that accumulated A2E, one of lipofuscin fluorophores, were used as a model system to investigate the mechanism of photooxidative damage and the protective effects of grape skin polyphenols. Exposure of A2E containing ARPE-19 cells to blue light resulted in significant apoptosis and increases in levels of GRP78, CHOP, p-JNK, Bax, cleaved caspase-9, and cleaved caspase-3, indicating that photooxidative damage to RPE cells is mediated by the ER-stress-induced intrinsic apoptotic pathway. Cells in which GRP78 had been knocked down with shRNA were more vulnerable to photooxidative damage. Pre-treatment of blue-light-exposed A2E containing ARPE-19 cells, with grape skin extracts, inhibited apoptosis, in a dose dependent manner. Knockdown GRP78 blocked the protective effect of grape skin extracts. PMID:25447759

Zhao, Zhao; Sun, Tao; Jiang, Yun; Wu, Lijiang; Cai, Xiangzhong; Sun, Xiaodong; Sun, Xiangjun

2014-12-01

177

Development of a surface to increase retinal pigment epithelial cell (ARPE-19) proliferation under reduced serum conditions.  

PubMed

Age related macular degeneration of the eye is brought about by damage to the retinal pigment epithelium (RPE) and is a major cause of adult blindness. One potential treatment method is transplantation of RPE cells grown in vitro. Maintaining RPE cell viability and physiological function in vitro is a challenge, and this must also be achieved using materials that can be subsequently used to deliver an intact cell sheet into the eye. In this paper, plasma polymerisation has been used to develop a chemically modified surface for maintaining RPE cells in vitro. Multiwell plates modified with a plasma copolymer of allylamine and octadiene maintained RPE cell growth at a level similar to that of TCPS. However, the addition of bound glycosaminoglycans (GAGs) to the plasma polymerised surface significantly enhanced RPE proliferation. Simply adding GAG to the culture media had no positive effect. It is shown that a combination of plasma polymer and GAG is a promising method for developing suitable surfaces for cell growth and delivery, that can be applied to any substrate material. PMID:24493476

Zuber, Agnieszka A; Robinson, David E; Short, Robert D; Steele, David A; Whittle, Jason D

2014-05-01

178

The time course of photoadaptation and pigmentation studied using a novel method to distinguish pigmentation from erythema.  

PubMed

The dynamics of human pigmentation in response to ultraviolet radiation (UVR) remain poorly characterized. In part, this is attributable to methodological issues relating to the overlap in spectra of hemoglobin and melanin. We describe a new method, based on the recording of reflectance properties following iontophoresis of a potent vasoconstrictor, noradrenaline. This removes the influence of blood, allowing measurement of pigmentation, represented as L* on the L*a*b* scale. Blood flow was separately assessed using laser Doppler flowmetry. We show that there is a clear dose response with the dose of UVR administered, that pigmentation peaks at 1 wk and declines over the following 10 wk, but does not return to baseline within this period. We show clear differences in the degree, but not the temporal pattern of pigmentation between different pigmentary groups. We also report that the relation between facultative pigment and constitutive pigment is incomplete, with a wide scatter of responses for the development of pigmentation irrespective of constitutive levels. For comparison we also document overall photoadaptation and relate changes in pigmentation to the overall changes in photoadaptation. PMID:15482486

Oh, Carol; Hennessy, Alison; Ha, Tom; Bisset, Yvonne; Diffey, Brian; Rees, Jonathan L

2004-11-01

179

A novel clinical sign in macular telangiectasia type 2.  

PubMed

The objective of the study is to report, and propose a hypothesis for, a novel clinical sign in patients with macular telangiectasia type 2. Nine consecutive patients with macular telangiectasia and visible parafoveal graying were examined. The parafoveal graying decreased in intensity with continuous light exposure from an indirect ophthalmoscope. After dark adaptation for 15 minutes, the intensity of parafoveal graying increased again. This phenomenon appears to be a novel and global sign in patients with macular telangiectasia type 2. It could be a possible photochemical reaction occurring due to the release of chromophores from the abnormal Müller cells. PMID:25559527

Jindal, Animesh; Choudhury, Himadri; Pathengay, Avinash; Flynn, Harry W

2015-01-01

180

Involvement of endoplasmic reticulum stress in all-trans-retinal-induced retinal pigment epithelium degeneration.  

PubMed

Excess accumulation of endogenous all-trans-retinal (atRAL) contributes to degeneration of the retinal pigment epithelium (RPE) and photoreceptor cells, and plays a role in the etiologies of age-related macular degeneration (AMD) and Stargardt's disease. In this study, we reveal that human RPE cells tolerate exposure of up to 5?µM atRAL without deleterious effects, but higher concentrations are detrimental and induce cell apoptosis. atRAL treatment significantly increased production of intracellular reactive oxygen species (ROS) and up-regulated mRNA expression of Nrf2, HO-1, and ?-GCSh within RPE cells, thereby causing oxidative stress. ROS localized to mitochondria and endoplasmic reticulum (ER). ER-resident molecular chaperone BiP, a marker of ER stress, was up-regulated at the translational level, and meanwhile, the PERK-eIF2?-ATF4 signaling pathway was activated. Expression levels of ATF4, CHOP, and GADD34 in RPE cells increased in a concentration-dependent manner after incubation with atRAL. Salubrinal, a selective inhibitor of ER stress, alleviated atRAL-induced cell death. The antioxidant N-acetylcysteine (NAC) effectively blocked RPE cell loss and ER stress activation, suggesting that atRAL-induced ROS generation is responsible for RPE degeneration and is an early trigger of ER stress. Furthermore, the mitochondrial transmembrane potential was lost after atRAL exposure, and was followed by caspase-3 activation and poly (ADP-ribose) polymerase cleavage. The results demonstrate that atRAL-driven ROS overproduction-induced ER stress is involved in cellular mitochondrial dysfunction and apoptosis of RPE cells. PMID:25331497

Li, Jie; Cai, Xianhui; Xia, Qingqing; Yao, Ke; Chen, Jingmeng; Zhang, Yanli; Naranmandura, Hua; Liu, Xin; Wu, Yalin

2015-01-01

181

Role of Unfolded Protein Response Dysregulation in Oxidative Injury of Retinal Pigment Epithelial Cells  

PubMed Central

Abstract Aims: Age-related macular degeneration (AMD), a major cause of legal blindness in the elderly, is associated with genetic and environmental risk factors, such as cigarette smoking. Recent evidence shows that cigarette smoke (CS) that contains high levels of potent oxidants preferably targets retinal pigment epithelium (RPE) leading to oxidative damage and apoptosis; however, the mechanisms are poorly understood. The present study aimed to investigate the role of endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) in CS-related RPE apoptosis. Results: ER stress and proapoptotic gene C/EBP homologous protein (CHOP) were induced in the RPE/choroid complex from mice exposed to CS for 2 weeks and in human RPE cells treated with hydroquinone, a potent oxidant found at high concentrations in CS. Suppressing ER stress or inhibiting CHOP activation by pharmacological chaperones or genetic approaches attenuated hydroquinone-induced RPE cell apoptosis. In contrast to enhanced CHOP activation, protein level of active X-box binding protein 1 (XBP1), a major regulator of the adaptive UPR, was reduced in hydroquinone-treated cells. Conditional knockout of XBP1 gene in the RPE resulted in caspase-12 activation, increased CHOP expression, and decreased antiapoptotic gene Bcl-2. Furthermore, XBP1-deficient RPE cells are more sensitive to oxidative damage induced by hydroquinone or NaIO3, a CS-unrelated chemical oxidant. Conversely, overexpressing XBP1 protected RPE cells and attenuated oxidative stress-induced RPE apoptosis. Innovation and Conclusion: These findings provide strong evidence suggesting an important role of ER stress and the UPR in CS-related oxidative injury of RPE cells. Thus, the modulation of the UPR signaling may provide a promising target for the treatment of AMD. Antioxid. Redox Signal. 20, 2091–2106. PMID:24053669

Chen, Chen; Cano, Marisol; Wang, Joshua J.; Li, Jingming; Huang, Chuangxin; Yu, Qiang; Herbert, Terence P.; Handa, James T.

2014-01-01

182

Effect of Hemodialysis on Retinal Thickness in Patients with Diabetic Retinopathy, with and without Macular Edema, Using Optical Coherence Tomography  

PubMed Central

Background. Effects of hemodialysis (HD) treatment on retinal thickness and macular edema are unclear. Objective. To evaluate changes in retinal thickness using optical coherence tomography (OCT) in end stage renal disease (ESRD) patients with diabetic retinopathy (DR), with and without diabetic macular edema (DME), undergoing HD. Methods. Nonrandomized prospective study. Forty eyes of DR patients with ESRD treated with HD were divided into two groups: patients with macular edema and patients without macular edema. Both eyes were analyzed. Patients underwent an ophthalmic examination including OCT measurements of retinal thickness, blood albumin and hemoglobin A1C levels, blood pressure, and body weight, 30 minutes before and after HD. Results. We found no significant effects of HD on retinal thickness among patients both with and without DME. The former showed a trend towards reduction in retinal thickness in foveal area following HD, while the latter showed an increase. There was no correlation between retinal thickness and mean blood pressure, weight, kinetic model value—Kt/V, glycemic hemoglobin, or albumin levels before and after HD. Conclusions. HD has no significant effect on retinal thickness among patients with or without DME. Further studies on larger cohorts and repeated OCT examinations are needed to confirm the preliminary findings in this study. PMID:25298889

Azem, Nur; Spierer, Oriel; Shaked, Meital; Neudorfer, Meira

2014-01-01

183

Role of inflammation in previously untreated macular edema with branch retinal vein occlusion  

PubMed Central

Background The association of inflammatory factors and the aqueous flare value with macular edema in branch retinal vein occlusion (BRVO) patients remains unclear. The relationship between the aqueous flare value and the vitreous fluid levels of vascular endothelial growth factor (VEGF), interleukin (IL)-6, monocyte chemotactic protein (MCP)-1, soluble intercellular adhesion molecule 1 (sICAM-1), and soluble VEGF receptor-2 (sVEGFR-2) was evaluated to investigate the role of inflammation in BRVO associated with macular edema. Aqueous flare values and the vitreous levels of VEGF, IL-6, MCP-1, sICAM-1, and sVEGFR-2 were compared between previously untreated patients with BRVO and patients with macular hole (MH). Methods Vitreous samples were obtained from 45 patients during vitreoretinal surgery (28 patients with BRVO and 17 with MH), and the levels of VEGF, IL-6, MCP-1, sICAM-1, and sVEGFR-2 were measured by enzyme-linked immunosorbent assay. Retinal ischemia was evaluated by measuring the area of capillary non-perfusion using fluorescein angiography and the Scion Image program. Aqueous flare values were measured with a laser flare meter and macular edema was examined by optical coherence tomography. Results The median aqueous flare value was significantly higher in the BRVO group (12.1 photon counts/ms) than in the MH group (4.5 photon counts/ms, P?levels of VEGF, IL-6, MCP-1, and sICAM-1 in the BRVO group (??=?0.54, P?=?0.005; ??=?0.56, P?=?0.004; ??=?0.52, P?=?0.006; and ??=?0.47, P?=?0.015, respectively). The aqueous flare value was also significantly correlated with the foveal thickness in the BRVO group (??=?0.40, P?=?0.037). Conclusions Inflammation may induce an increase of vascular permeability and disrupt the blood-aqueous barrier via release of inflammatory factors (VEGF, IL-6, MCP-1, and sICAM-1) in BRVO patients with macular edema. PMID:24884703

2014-01-01

184

The response of human retinal pigmented epithelial cells in vitro to changes in nitric oxide concentration stimulated by low levels of red light  

NASA Astrophysics Data System (ADS)

The goal of this project is to explore the role of nitric oxide (NO) in regulating the response of hTERT-RPE to low-level exposures to red light. Exposure to low-level red light has been shown to positively affect wound healing, reduce pain, and encourage cell proliferation. The current explanation for this effect is described as an interaction between the photons and cytochrome c oxidase (Cco), which plays a role in regulation of intracellular NO levels in addition to being the mitochondrial protein complex where reduction of oxygen occurs in the process of oxidative phosphorylation. Exposure to 2.88 J/cm2 of 671-nm and 637-nm light shows a two-fold increase in NO immediately after exposure, and a 56% increase in ATP measured at ~5 h post exposure. Levels of NF-?B mRNA and protein were measured at six and 24 h, respectively, and found to increase six fold, correlating with increases in NO levels. Light-stimulated increased levels of NO also correlated with an 11-fold increase in Bcl-2 and a 70% decrease in Bax mRNA levels, relative to controls. NF-?B promotes cell growth and Bcl-2 is an apoptosis suppressor protein. Bax is a positive apoptotic effector protein. These results support the hypothesis that light-induced changes in the intracellular levels of NO play a role in the beneficial effects of low-level light photobiomodulation

Lavey, Brent J.; Estlack, Larry E.; Schuster, Kurt J.; Rockwell, Benjamin A.; Wigle, Jeffrey C.

2013-03-01

185

Asymmetry in Hemifield Macular Thickness as an Early Indicator of Glaucomatous Change  

PubMed Central

Purpose. To investigate whether asymmetry in hemifield macular thickness can serve as an early indicator of glaucomatous structural damage using spectral domain optical coherence tomography. Methods. Five zones in the macular thickness map were defined. Each zone included reciprocal areas in the superior and inferior hemifield. Differences in average retinal thickness (DRT) between corresponding regional pairs were measured in each of the five zones in 50 healthy eyes. An abnormality was defined as the DRT value lying outside the 95% confidence intervals. An eye was considered to yield an “abnormal macular hemifield test” (MHT) if abnormality was evident in any zone. The sensitivity and specificity for glaucoma detection of MHT and average circumpapillary retinal nerve fiber layer (cRNFL) classification were determined. Results. A total of 114 healthy, 103 glaucoma-suspect, and 74 glaucomatous eyes were included. Overall, 5.8%, 36.9%, 88.4%, and 77.4% of the eyes of the healthy, glaucoma-suspect (GS), early glaucoma (EG), and advanced glaucoma (AG) groups yielded abnormal MHT results, respectively. In EG eyes, the sensitivity of an abnormal MHT result was significantly greater than that of abnormal average cRNFL classification (P = 0.008). In the GS and AG groups, the sensitivity did not significantly differ between an abnormal MHT result and an average cRNFL classification (P = 0.880, 0.180). Compared with sectoral cRNFL thickness measurements, MHT showed a similar level of diagnostic performance. Specificity was not different between an abnormal MHT result and an average cRNFL classification (P = 0.687). Conclusions. Evaluation of asymmetry in hemifield macular thickness may serve as an assessment tool in the early diagnosis of glaucoma. PMID:22247461

Um, Tae Woong; Wollstein, Gadi; Yun, Sung-Cheol; Na, Jung Hwa; Schuman, Joel S.

2012-01-01

186

Macular Oedema Related to Idiopathic Macular Telangiectasia Type 1 Treated with Dexamethasone Intravitreal Implant (Ozurdex)  

PubMed Central

A 65-year-old female presented with visual disturbance in her right eye lasting for over 2 months. Following investigations, she was diagnosed with MacTel type 1 in the right eye. Visual symptoms were refractory to initial treatment with intravitreal bevacizumab and thereafter intravtireal triamicinolone. The patient was then treated with Ozurdex, following which central macular thickness (CMT) decreased (from 397??m to 286??m) and visual acuity deteriorated (from logMAR 0.48 to 0.59). At 14 weeks posttreatment with Ozurdex, a recurrence of cystoid macular oedema (CMO) was observed. Following a second Ozurdex, visual acuity improved (from logMAR 0.7 to 0.64) and CMT decreased (from 349??m to 279??m). An additional recurrence of CMO was observed at eighteen weeks following the second Ozurdex. Following a third Ozurdex injection visual acuity deteriorated (from logMAR 0.74 to 0.78) and CMT decreased (from 332??m to 279??m). Conclusion. Treatment of macular oedema secondary to MacTel with Ozurdex demonstrated promising anatomical outcomes. However, visual outcomes continued to gradually deteriorate. PMID:25045562

Kamal, Ahmed

2014-01-01

187

Macular oedema related to idiopathic macular telangiectasia type 1 treated with dexamethasone intravitreal implant (ozurdex).  

PubMed

A 65-year-old female presented with visual disturbance in her right eye lasting for over 2 months. Following investigations, she was diagnosed with MacTel type 1 in the right eye. Visual symptoms were refractory to initial treatment with intravitreal bevacizumab and thereafter intravtireal triamicinolone. The patient was then treated with Ozurdex, following which central macular thickness (CMT) decreased (from 397??m to 286??m) and visual acuity deteriorated (from logMAR 0.48 to 0.59). At 14 weeks posttreatment with Ozurdex, a recurrence of cystoid macular oedema (CMO) was observed. Following a second Ozurdex, visual acuity improved (from logMAR 0.7 to 0.64) and CMT decreased (from 349??m to 279??m). An additional recurrence of CMO was observed at eighteen weeks following the second Ozurdex. Following a third Ozurdex injection visual acuity deteriorated (from logMAR 0.74 to 0.78) and CMT decreased (from 332??m to 279??m). Conclusion. Treatment of macular oedema secondary to MacTel with Ozurdex demonstrated promising anatomical outcomes. However, visual outcomes continued to gradually deteriorate. PMID:25045562

Loutfi, Mohamed; Papathomas, Thomas; Kamal, Ahmed

2014-01-01

188

Raman Spectroscopy of Microbial Pigments  

PubMed Central

Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions. PMID:24682303

Edwards, Howell G. M.; Oren, Aharon

2014-01-01

189

The peripheral clock regulates human pigmentation.  

PubMed

Although the regulation of pigmentation is well characterized, it remains unclear whether cell-autonomous controls regulate the cyclic on-off switching of pigmentation in the hair follicle (HF). As human HFs and epidermal melanocytes express clock genes and proteins, and given that core clock genes (PER1, BMAL1) modulate human HF cycling, we investigated whether peripheral clock activity influences human HF pigmentation. We found that silencing BMAL1 or PER1 in human HFs increased HF melanin content. Furthermore, tyrosinase expression and activity, as well as TYRP1 and TYRP2 mRNA levels, gp100 protein expression, melanocyte dendricity, and the number gp100+ HF melanocytes, were all significantly increased in BMAL1 and/or PER1-silenced HFs. BMAL1 or PER1 silencing also increased epidermal melanin content, gp100 protein expression, and tyrosinase activity in human skin. These effects reflect direct modulation of melanocytes, as BMAL1 and/or PER1 silencing in isolated melanocytes increased tyrosinase activity and TYRP1/2 expression. Mechanistically, BMAL1 knockdown reduces PER1 transcription, and PER1 silencing induces phosphorylation of the master regulator of melanogenesis, microphthalmia-associated transcription factor, thus stimulating human melanogenesis and melanocyte activity in situ and in vitro. Therefore, the molecular clock operates as a cell-autonomous modulator of human pigmentation and may be targeted for future therapeutic strategies. PMID:25310406

Hardman, Jonathan A; Tobin, Desmond J; Haslam, Iain S; Farjo, Nilofer; Farjo, Bessam; Al-Nuaimi, Yusur; Grimaldi, Benedetto; Paus, Ralf

2015-04-01

190

Evaluation of circulating miRNAs in wet age-related macular degeneration  

PubMed Central

Purpose In the present study, we aimed to investigate the changes in plasma miRNA in patients with wet age-related macular degeneration. Methods The expression profiles of 384 miRNAs in plasma from 33 patients (22 male, 11 female) who were diagnosed with wet age-related macular degeneration with fundus examination, fundus fluorescein angiography, and optical coherence tomography and 31 controls (17 male, 14 female) were evaluated using high-throughput quantitative real-time PCR. Results Our results demonstrated that the expression level of five miRNAs (miR-17-5p, miR-20a-5p, miR-24-3p, miR-106a-5p, and miR-223-3p) was significantly upregulated in patients with age-related macular degeneration when compared to the control group (p<0.05). The expression level of 11 miRNAs (miR-21-5p, miR-25-3p, miR-140-3p, miR-146b-5p, miR-192-5p, miR-335-5p, miR-342-3p, miR-374a-5p, miR-410, miR-574-3p, and miR-660-5p) was significantly downregulated in patients (p<0.05). In addition, ten miRNAs (miR-26b-5p, miR-27b-3p, miR-29a-3p, miR-139-3p, miR-212–3p, miR-324-3p, miR-324-5p, miR-532-3p, miR-744-5p, and miR-Let-7c) were expressed only in the patient group. Conclusions Our results suggest that plasma miRNA levels may change in wet age-related macular degeneration. These molecules may have an important therapeutic target in patients who are unresponsive to antivascular endothelial growth factor therapy. However, further studies must be conducted for possible effects of miRNAs in vascular disorders of eye such as age-related macular degeneration. PMID:25221421

Y?ld?r?m, Özlem; Dinç, Erdem; Ayaz, Lokman; Fidanc?, ?enay Balc?; Tamer, Lülüfer

2014-01-01

191

Porous Poly(?-Caprolactone) Scaffolds for Retinal Pigment Epithelium Transplantation  

PubMed Central

Purpose. Retinal pigment epithelium (RPE) transplantation is a promising strategy for the treatment of dry age-related macular degeneration (AMD). However, previous attempts at subretinal RPE cell transplantation have experienced limited success due to poor adhesion, organization, and function on aged or diseased Bruch's membrane. Instead, cell-based strategies may benefit from a synthetic scaffold that mimics the functions of healthy Bruch's membrane to promote the formation of a functional RPE monolayer while maintaining metabolite exchange between the vasculature and outer retina. Methods. This study evaluated the behavior of human RPE on nanopatterned porous poly(?-caprolactone) (PCL) film as a potential scaffold for therapeutic transplantation. Fetal human RPE (fhRPE) was cultured on porous PCL, nonporous PCL, or Costar porous polyester transwells for up to 8 weeks and assessed using light microscopy, fluorescent microscopy, transepithelial resistance, quantitative PCR, ELISAs, and phagocytosis assays. Results. fhRPE on porous PCL displayed improved markers of maturity and function compared with both porous polyester transwells and nonporous PCL, including pigmentation, increased cell density, superior barrier function, up-regulation of RPE-specific genes, and polarized growth factor secretion. Conclusions. This study indicates that porous PCL is an attractive scaffold for RPE transplantation. In addition to being biocompatible with the subretinal space, porous PCL also allows for trans-scaffold metabolite transport and significantly improves RPE cell behavior compared to nonporous PCL or porous polyester transwells. PMID:24550370

McHugh, Kevin J.; Tao, Sarah L.; Saint-Geniez, Magali

2014-01-01

192

A2E Induces IL-1ß Production in Retinal Pigment Epithelial Cells via the NLRP3 Inflammasome  

PubMed Central

Aims With ageing extracellular material is deposited in Bruch’s membrane, as drusen. Lipofuscin is deposited in retinal pigment epithelial cells. Both of these changes are associated with age related macular degeneration, a disease now believed to involve chronic inflammation at the retinal-choroidal interface. We hypothesise that these molecules may act as danger signals, causing the production of inflammatory chemokines and cytokines by the retinal pigment epithelium, via activation of pattern recognition receptors. Methods ARPE-19 cells were stimulated in vitro with the following reported components of drusen: amyloid-ß (1-42), Carboxyethylpyrrole (CEP) modified proteins (CEP-HSA), N?-(Carboxymethyl)lysine (CML) modified proteins and aggregated vitronectin. The cells were also stimulated with the major fluorophore of lipofuscin: N-retinylidene-N-retinylethanolamine (A2E). Inflammatory chemokine and cytokine production was assessed using Multiplex assays and ELISA. The mechanistic evaluation of the NLRP3 inflammasome pathway was assessed in a stepwise fashion. Results Of all the molecules tested only A2E induced inflammatory chemokine and cytokine production. 25 µM A2E induced the production of significantly increased levels of the chemokines IL-8, MCP-1, MCG and MIP-1?, the cytokines IL-1ß, IL-2, IL-6, and TNF-?, and the protein VEGF-A. The release of IL-1ß was studied further, and was determined to be due to NLRP3 inflammasome activation. The pathway of activation involved endocytosis of A2E, and the three inflammasome components NLRP3, ASC and activated caspase-1. Immunohistochemical staining of ABCA4 knockout mice, which show progressive accumulation of A2E levels with age, showed increased amounts of IL-1ß proximal to the retinal pigment epithelium. Conclusions A2E has the ability to stimulate inflammatory chemokine and cytokine production by RPE cells. The pattern recognition receptor NLRP3 is involved in this process. This provides further evidence for the link between A2E, inflammation, and the pathogenesis of AMD. It also supports the recent discovery of NLRP3 inflammasome activation in AMD. PMID:23840644

Anderson, Owen A.; Finkelstein, Arthur; Shima, David T.

2013-01-01

193

Macular Hypoplasia in Congenital Disorder of Glycosylation Type Ia  

PubMed Central

Congenital disorders of glycosylation are a rare group of metabolic disorders that can result in multiorgan disease. This article describes a novel finding of macular hypoplasia in congenital disorders of glycosylation type Ia. PMID:22649348

Wang, Bob Z.; Siriwardana, Pradeep; Taranath, Deepa

2012-01-01

194

Differences in Ozone Sensitivity at Different NPK Levels of Three Tropical Varieties of Mustard ( Brassica campestris L.): Photosynthetic Pigments, Metabolites, and Antioxidants  

Microsoft Academic Search

The effects of ambient O3 at two different levels of nitrogen, phosphorus, and potassium, (recommended and 1.5 times the recommended NPK) on three\\u000a tropical varieties of mustard (Brassica campestris L. var. Kranti, Aashirwad and Vardan) were explored to unravel the mechanism of protection under higher NPK level at a rural\\u000a experimental site using open top chambers. Ambient O3 concentrations ranged

Poonam Singh; Madhoolika Agrawal; Shashi Bhushan Agrawal

2011-01-01

195

Patterns of diabetic macular edema with optical coherence tomography  

Microsoft Academic Search

PURPOSE: We report cross-sectional images of diabetic macular edema and correlation between tomographic features and visual acuity with best correction by means of optical coherence tomography.METHOD: In a prospective study, optical coherence tomography was performed in 59 eyes of 42 patients with diabetic macular edema and in 10 eyes of 10 normal control subjects.RESULTS: Optical coherence tomography showed three patterns

Tomohiro Otani; Shoji Kishi; Yasuhiro Maruyama

1999-01-01

196

Treatment of cystic macular lesions in hereditary retinal dystrophies.  

PubMed

Cystic macular lesions frequently contribute to impaired visual acuity in hereditary retinal dystrophies. Their pathogenesis varies and is not entirely understood. Carbonic anhydrase inhibitors have proven to be potentially efficacious, although not in all cases. We discuss the various factors and mechanisms implicated in the etiology of cystic macular lesions (anatomical abnormalities, impairment of the blood-retinal barrier, tangential vitreous traction, and mutations in retinoschin, etc.) and the various treatments that have been proposed. PMID:24160730

Salvatore, Serena; Fishman, Gerald A; Genead, Mohamed A

2013-01-01

197

Optical coherence tomography imaging of macular oedema  

PubMed Central

Macular oedema (ME) occurs in a wide variety of pathological conditions and accounts for different degrees of vision loss. Early detection of ME is therefore critical for diagnosis and therapeutic management. Optical coherence tomography (OCT) is a non-contact, diagnostic method that uses infrared light, which allows the analysis of the retinal structure by means of high-resolution tomographic cross sections. The identification, localisation, quantification and long-term follow-up of fluid collections are the most important capabilities of OCT. Since the introduction of OCT in clinical practice, it has become an invaluable diagnostic tool and different patterns of ME have been reported. The purpose of this manuscript is to review OCT profiles of ME according to the aetiology and describe what has been reported regarding intraretinal features in vivo. PMID:24934220

Trichonas, George; Kaiser, Peter K

2014-01-01

198

Topical application of PPADS inhibits complement activation and choroidal neovascularization in a model of age-related macular degeneration.  

PubMed

Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly. AMD patients have elevated levels of membrane attack complex (MAC) in their choroidal blood vessels and retinal pigment epithelium (RPE). MAC forms pores in cell membranes. Low levels of MAC result in an elevation of cytokine release such as vascular endothelial growth factor (VEGF) that promotes the formation of choroidal neovascularization (CNV). High levels of MAC result in cell lysis and RPE degeneration is a hallmark of advanced AMD. The current standard of care for CNV associated with wet AMD is intravitreal injection of anti-VEGF molecules every 4 to 12 weeks. Such injections have significant side effects. Recently, it has been found that membrane pore-forming proteins such as ?-haemolysin can mediate their toxic effects through auto- and paracrine signaling and that complement-induced lysis is amplified through ATP release followed by P2X receptor activation. We hypothesized that attenuation of P2X receptor activation may lead to a reduction in MAC deposition and consequent formation of CNV. Hence, in this study we investigated topical application of the purinergic P2X antagonist Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) as a potential treatment for AMD. We found that 4.17 µM PPADS inhibited formation of HUVEC master junctions and master segments by 74.7%. In a human complement mediated cell lysis assay, 104 µM PPADS enabled almost complete protection of Hepa1c1c7 cells from 1% normal human serum mediated cell lysis. Daily topical application of 4.17 mM PPADS for 3 days attenuated the progression of laser induced CNV in mice by 41.8% and attenuated the deposition of MAC at the site of the laser injury by 19.7%. Our data have implications for the future treatment of AMD and potentially other ocular disorders involving CNV such as angioid streaks, choroidal rupture and high myopia. PMID:24130789

Birke, Kerstin; Lipo, Erion; Birke, Marco T; Kumar-Singh, Rajendra

2013-01-01

199

Topical Application of PPADS Inhibits Complement Activation and Choroidal Neovascularization in a Model of Age-Related Macular Degeneration  

PubMed Central

Age-related macular degeneration (AMD) is the most common cause of blindness among the elderly. AMD patients have elevated levels of membrane attack complex (MAC) in their choroidal blood vessels and retinal pigment epithelium (RPE). MAC forms pores in cell membranes. Low levels of MAC result in an elevation of cytokine release such as vascular endothelial growth factor (VEGF) that promotes the formation of choroidal neovascularization (CNV). High levels of MAC result in cell lysis and RPE degeneration is a hallmark of advanced AMD. The current standard of care for CNV associated with wet AMD is intravitreal injection of anti-VEGF molecules every 4 to 12 weeks. Such injections have significant side effects. Recently, it has been found that membrane pore-forming proteins such as ?-haemolysin can mediate their toxic effects through auto- and paracrine signaling and that complement-induced lysis is amplified through ATP release followed by P2X receptor activation. We hypothesized that attenuation of P2X receptor activation may lead to a reduction in MAC deposition and consequent formation of CNV. Hence, in this study we investigated topical application of the purinergic P2X antagonist Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) as a potential treatment for AMD. We found that 4.17 µM PPADS inhibited formation of HUVEC master junctions and master segments by 74.7%. In a human complement mediated cell lysis assay, 104 µM PPADS enabled almost complete protection of Hepa1c1c7 cells from 1% normal human serum mediated cell lysis. Daily topical application of 4.17 mM PPADS for 3 days attenuated the progression of laser induced CNV in mice by 41.8% and attenuated the deposition of MAC at the site of the laser injury by 19.7%. Our data have implications for the future treatment of AMD and potentially other ocular disorders involving CNV such as angioid streaks, choroidal rupture and high myopia. PMID:24130789

Birke, Kerstin; Lipo, Erion; Birke, Marco T.; Kumar-Singh, Rajendra

2013-01-01

200

Perceptual learning in patients with macular degeneration  

PubMed Central

Patients with age-related macular degeneration (AMD) or hereditary macular dystrophies (JMD) rely on an efficient use of their peripheral visual field. We trained eight AMD and five JMD patients to perform a texture-discrimination task (TDT) at their preferred retinal locus (PRL) used for fixation. Six training sessions of approximately one hour duration were conducted over a period of approximately 3 weeks. Before, during and after training twelve patients and twelve age-matched controls (the data from two controls had to be discarded later) took part in three functional magnetic resonance imaging (fMRI) sessions to assess training-related changes in the BOLD response in early visual cortex. Patients benefited from the training measurements as indexed by significant decrease (p = 0.001) in the stimulus onset asynchrony (SOA) between the presentation of the texture target on background and the visual mask, and in a significant location specific effect of the PRL with respect to hit rate (p = 0.014). The following trends were observed: (i) improvement in Vernier acuity for an eccentric line-bisection task; (ii) positive correlation between the development of BOLD signals in early visual cortex and initial fixation stability (r = 0.531); (iii) positive correlation between the increase in task performance and initial fixation stability (r = 0.730). The first two trends were non-significant, whereas the third trend was significant at p = 0.014, Bonferroni corrected. Consequently, our exploratory study suggests that training on the TDT can enhance eccentric vision in patients with central vision loss. This enhancement is accompanied by a modest alteration in the BOLD response in early visual cortex. PMID:25368597

Plank, Tina; Rosengarth, Katharina; Schmalhofer, Carolin; Goldhacker, Markus; Brandl-Rühle, Sabine; Greenlee, Mark W.

2014-01-01

201

Optical coherence tomography classification of diabetic cystoid macular edema  

PubMed Central

Purpose To propose a new classification of diabetic cystoid macular edema (CME) based on optical coherence tomography (OCT) findings and cover all new important findings. Patients and methods A retrospective study was carried out in the El-Minia Investigation Eye Center between January 2012 and November 2012. It included 104 eyes of 86 patients, aged between 50 and 71 years, all with type II diabetes mellitus of duration from 5 to 20 years. All patients were diagnosed to have CME, as assessed by OCT, with measurement of the vertical size of the largest macular cyst and maximum macular thickness, and the relation between them. Results Patients were divided into four groups. Eyes with cysts less than 30% of macular thickness were considered to have CME I (n = 4, 3.84%), while those between 30% and 60% were considered to have CME II (n = 62, 59.62%). Eyes with cysts between 60% and 90% of macular thickness were considered to have CME III (n = 36, 34.62%). CME IV was diagnosed when the size of the cyst became more than 90% of the macular thickness, and this was encountered in two eyes (1.92%). Conclusions OCT is a useful technique for quantitative measurement and helps in better anatomical characterization of CME, and this classification of diabetic CME may be of value in classification of CME due to causes other than diabetes. PMID:24039393

Helmy, Yasser M; Allah, Heba R Atta

2013-01-01

202

Novel compstatin family peptides inhibit complement activation by drusen-like deposits in human retinal pigmented epithelial cell cultures.  

PubMed

We have used a novel human retinal pigmented epithelial (RPE) cell-based model that mimics drusen biogenesis and the pathobiology of age-related macular degeneration to evaluate the efficacy of newly designed peptide inhibitors of the complement system. The peptides belong to the compstatin family and, compared to existing compstatin analogs, have been optimized to promote binding to their target, complement protein C3, and to enhance solubility by improving their polarity/hydrophobicity ratios. Based on analysis of molecular dynamics simulation data of peptide-C3 complexes, novel binding features were designed by introducing intermolecular salt bridge-forming arginines at the N-terminus and at position -1 of N-terminal dipeptide extensions. Our study demonstrates that the RPE cell assay has discriminatory capability for measuring the efficacy and potency of inhibitory peptides in a macular disease environment. PMID:23954241

Gorham, Ronald D; Forest, David L; Tamamis, Phanourios; López de Victoria, Aliana; Kraszni, Márta; Kieslich, Chris A; Banna, Christopher D; Bellows-Peterson, Meghan L; Larive, Cynthia K; Floudas, Christodoulos A; Archontis, Georgios; Johnson, Lincoln V; Morikis, Dimitrios

2013-11-01

203

Light Scattering in Pigmented Coatings  

Microsoft Academic Search

Small silica particles uniformly coated by a shell of titania, were produced by wet chemical methods. The pigments were dispersed in polymeric binders and were applied as paints to glass substrates. Total reflectance and transmittance were determined by integrating sphere measurements. Luminous and solar reflectance of paints containing the novel pigments were comparable with paints containing commercial titania. The spectral

W. E Vargas; P Greenwood; J. E Otterstedt; G. A Niklasson

2000-01-01

204

Comparative chromatography of chloroplast pigment  

NASA Technical Reports Server (NTRS)

Methods for isolation of low concentration pigments of the cocklebur species are described. The methods entail two step chromatography so that the different sorption properties of the various pigments in varying column parameters can be utilized. Columnar and thin layer methods are compared. Many conditions influence separability of the chloroplasts.

Grandolfo, M.; Sherma, J.; Strain, H. H.

1969-01-01

205

Melanocyte biology and skin pigmentation  

Microsoft Academic Search

Melanocytes are phenotypically prominent but histologically inconspicuous skin cells. They are responsible for the pigmentation of skin and hair, and thereby contribute to the appearance of skin and provide protection from damage by ultraviolet radiation. Pigmentation mutants in various species are highly informative about basic genetic and developmental pathways, and provide important clues to the processes of photoprotection, cancer predisposition

Jennifer Y. Lin; David E. Fisher

2007-01-01

206

Macular optical coherence tomography findings and GPR143 mutations in patients with ocular albinism.  

PubMed

The aim of this study was to describe macular findings using spectral-domain optical coherence tomography (SD-OCT) in patients with ocular albinism (OA) and their carrier mothers, and to identify the frequency of GPR143 gene mutations in these patients. The study included five patients with a clinical diagnosis of OA. SD-OCT of the macular area was performed in both patients and their mothers. The anatomical characteristics of the macula and retinal pigment epithelium (RPE), patterns of autofluorescence and infrared imaging were analyzed. Polymerase chain reaction amplification of the complete coding sequence of GPR 143 was performed and subsequently analyzed by direct sequencing in patients and their possible carrier mothers. SD-OCT images revealed the presence of inner retinal layers in the fovea, an abnormal disposition of the Henle layer and a lack of thickening in the perifoveal area. We found increased thickness in the RPE to the outer segment and in the outer segment to the outer nuclear layer that is associated with increased visual acuity. Autofluorescence images revealed an absence of normal hipoautofluorescence in the fovea. No changes were observed in the images of their carrier mothers. Mutation screening and sequence analysis of the GPR 143 gene revealed a novel pathological mutation in two patients. Abnormalities in the macula were observed in all patients. SD-OCT is a useful tool for the assessment of patients with OA. No changes were observed in the SD-OCT of carrier mothers. Only two patients had the GPR143 gene mutation. PMID:24526317

Sepúlveda-Vázquez, H E; Villanueva-Mendoza, C; Zenteno, J C; Villegas-Ruiz, V; Pelcastre-Luna, E; García-Aguirre, G

2014-10-01

207

Automated diagnosis of Age-related Macular Degeneration using greyscale features from digital fundus images.  

PubMed

Age-related Macular Degeneration (AMD) is one of the major causes of vision loss and blindness in ageing population. Currently, there is no cure for AMD, however early detection and subsequent treatment may prevent the severe vision loss or slow the progression of the disease. AMD can be classified into two types: dry and wet AMDs. The people with macular degeneration are mostly affected by dry AMD. Early symptoms of AMD are formation of drusen and yellow pigmentation. These lesions are identified by manual inspection of fundus images by the ophthalmologists. It is a time consuming, tiresome process, and hence an automated diagnosis of AMD screening tool can aid clinicians in their diagnosis significantly. This study proposes an automated dry AMD detection system using various entropies (Shannon, Kapur, Renyi and Yager), Higher Order Spectra (HOS) bispectra features, Fractional Dimension (FD), and Gabor wavelet features extracted from greyscale fundus images. The features are ranked using t-test, Kullback-Lieber Divergence (KLD), Chernoff Bound and Bhattacharyya Distance (CBBD), Receiver Operating Characteristics (ROC) curve-based and Wilcoxon ranking methods in order to select optimum features and classified into normal and AMD classes using Naive Bayes (NB), k-Nearest Neighbour (k-NN), Probabilistic Neural Network (PNN), Decision Tree (DT) and Support Vector Machine (SVM) classifiers. The performance of the proposed system is evaluated using private (Kasturba Medical Hospital, Manipal, India), Automated Retinal Image Analysis (ARIA) and STructured Analysis of the Retina (STARE) datasets. The proposed system yielded the highest average classification accuracies of 90.19%, 95.07% and 95% with 42, 54 and 38 optimal ranked features using SVM classifier for private, ARIA and STARE datasets respectively. This automated AMD detection system can be used for mass fundus image screening and aid clinicians by making better use of their expertise on selected images that require further examination. PMID:25127409

Mookiah, Muthu Rama Krishnan; Acharya, U Rajendra; Koh, Joel E W; Chandran, Vinod; Chua, Chua Kuang; Tan, Jen Hong; Lim, Choo Min; Ng, E Y K; Noronha, Kevin; Tong, Louis; Laude, Augustinus

2014-10-01

208

Potential Sources and Roles of Adaptive Immunity in Age-Related Macular Degeneration: Shall We Rename AMD into Autoimmune Macular Disease?  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly throughout the industrialized world. Its most prominent pathologic features are lesions involving the retinal pigment epithelium (RPE) the Bruch's membrane, the degeneration of photoreceptors, and, in the most aggressive cases, choroidal neovascularization. Genetic associations between the risk of developing AMD and polymorphism within components of the complement system, as well as chemokine receptors expressed on microglial cells and macrophages, have linked retinal degeneration and choroidal neovascularization to innate immunity (inflammation). In addition to inflammation, players of the adaptive immunity including cytokines, chemokines, antibodies, and T cells have been detected in animal models of AMD and in patients suffering from this pathology. These observations suggest that adaptive immunity might play a role in different processes associated with AMD such as RPE atrophy, neovascularization, and retinal degeneration. To this date however, the exact roles (if any) of autoantibodies and T cells in AMD remain unknown. In this review we discuss the potential effects of adaptive immune responses in AMD pathogenesis. PMID:24876950

2014-01-01

209

Low wintertime vitamin D levels in a sample of healthy young adults of diverse ancestry living in the Toronto area: associations with vitamin D intake and skin pigmentation  

Microsoft Academic Search

BACKGROUND: Vitamin D plays a critical role in bone metabolism and many cellular and immunological processes. Recent research indicates that concentrations of serum 25-hydroxyvitamin D [25(OH)D], the main indicator of vitamin D status, should be in excess of 75 nmol\\/L. Low levels of 25(OH)D have been associated with several chronic and infectious diseases. Previous studies have reported that many otherwise

Agnes Gozdzik; Jodi Lynn Barta; Hongyu Wu; Dennis Wagner; David E Cole; Reinhold Vieth; Susan Whiting; Esteban J Parra

2008-01-01

210

Altered gene expression in dry age-related macular degeneration suggests early loss of choroidal endothelial cells  

PubMed Central

Purpose Age-related macular degeneration (AMD) is a major cause of blindness in developed countries. The molecular pathogenesis of early events in AMD is poorly understood. We investigated differential gene expression in samples of human retinal pigment epithelium (RPE) and choroid from early AMD and control maculas with exon-based arrays. Methods Gene expression levels in nine human donor eyes with early AMD and nine control human donor eyes were assessed using Affymetrix Human Exon ST 1.0 arrays. Two controls did not pass quality control and were removed. Differentially expressed genes were annotated using the Database for Annotation, Visualization and Integrated Discovery (DAVID), and gene set enrichment analysis (GSEA) was performed on RPE-specific and endothelium-associated gene sets. The complement factor H (CFH) genotype was also assessed, and differential expression was analyzed regarding high AMD risk (YH/HH) and low AMD risk (YY) genotypes. Results Seventy-five genes were identified as differentially expressed (raw p value <0.01; ?50% fold change, mean log2 expression level in AMD or control ? median of all average gene expression values); however, no genes were significant (adj. p value <0.01) after correction for multiple hypothesis testing. Of 52 genes with decreased expression in AMD (fold change <0.5; raw p value <0.01), 18 genes were identified by DAVID analysis as associated with vision or neurologic processes. The GSEA of the RPE-associated and endothelium-associated genes revealed a significant decrease in genes typically expressed by endothelial cells in the early AMD group compared to controls, consistent with previous histologic and proteomic studies. Analysis of the CFH genotype indicated decreased expression of ADAMTS9 in eyes with high-risk genotypes (fold change = –2.61; raw p value=0.0008). Conclusions GSEA results suggest that RPE transcripts are preserved or elevated in early AMD, concomitant with loss of endothelial cell marker expression. These results are consistent with the notion that choroidal endothelial cell dropout or dedifferentiation occurs early in the pathogenesis of AMD. PMID:24265543

Whitmore, S. Scott; Braun, Terry A.; Skeie, Jessica M.; Haas, Christine M.; Sohn, Elliott H.; Stone, Edwin M.; Scheetz, Todd E.

2013-01-01

211

Iris phenotypes and pigment dispersion caused by genes influencing pigmentation  

PubMed Central

Summary Spontaneous mutations altering mouse coat colors have been a classic resource for discovery of numerous molecular pathways. Although often overlooked, the mouse iris is also densely pigmented and easily observed, thus representing a similarly powerful opportunity for studying pigment cell biology. Here, we present an analysis of iris phenotypes among sixteen mouse strains with mutations influencing melanosomes. Many of these strains exhibit biologically and medically relevant phenotypes, including pigment dispersion, a common feature of several human ocular diseases. Pigment dispersion was identified in several strains with mutant alleles known to influence melanosomes, including beige, light, and vitiligo. Pigment dispersion was also detected in the recently arising spontaneous coat color variant, nm2798. We have identified the nm2798 mutation as a missense mutation in the Dct gene, an identical re-occurrence of the slaty light mutation. These results suggest that dysregulated events of melanosomes can be potent contributors to the pigment dispersion phenotype. Combined, these findings illustrate the utility of studying iris phenotypes as a means of discovering new pathways, and re-linking old ones, to processes of pigmented cells in health and disease. PMID:18715234

Hawes, Norman L.; Trantow, Colleen M.; Chang, Bo; John, Simon W.M.

2010-01-01

212

Natural pigments and sacred art  

NASA Astrophysics Data System (ADS)

Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The iconographer uses earthly creations to create divine images: "Thine own of Thine own we offer unto Thee." (Byzantine Liturgy). Thus, by combining geology with art and religion, I can render homage to God through His creation by using minerals of the Planet Earth, as natural pigments in painting His image.

Kelekian, Lena, ,, Lady

2010-05-01

213

Mapping of Photosynthetic Pigments in Spanish Reservoirs  

NASA Astrophysics Data System (ADS)

We present the preliminary results of the first stage of the project AO-594, which comprises the development and calibration of algorithms for photosynthetic pigment mapping in Spanish reservoirs. In the years 2001-2002, an extensive field campaign was made in 36 reservoirs and lakes in order to obtain a database of Rrs spectra (400-1000 nm), photosynthetic pigments concentration and phytoplankton composition. The sampled water bodies cover a wide range of environmental conditions, trophic levels and phytoplankton communities. As a first approach in algorithm development, we have explored the relationships between ratios of MERIS bands and pigment concentrations through simple linear regression analysis. The bands have been selected based on the spectral properties of each pigment and a peak analysis of the Rrs spectra. For chlorophyll a, we have found a very good linear relationship (R2 =0.919) using the ratio between bands 9 and 7. Similar results are found using band 8 instead of 7. In any case, the model derived for the whole range of concentrations (0-500 mg m3 ) fails for low values (<15 mg m-3 ). Possible solutions include the use of - non-linear models or the use of two different models depending on the ratio values. For cyanobacteria detection, the ratio between bands 9 and 6 (the later centred at 620 nm) shows a good correlation (R2 =0.723) with phycocyanin concentration measured fluorometrically, and better (R2 =0.945) with zeaxanthin measured using HPLC. The correlation of other indicator pigments with MERIS band ratios is less strong, but is still possible to develop algorithms accurate enough for bloom monitoring. We also discuss the problems found with the L2 MERIS reflectance imagery that we have tried to use for model calibration. We present the results of the study carried on six reservoirs in northeastern Spain. In a date coincident with a MERIS image (June 19th, 2003) we have collected pigment concentration and reflectance data measured from a boat and 10 m resolution imagery for the 15 MERIS bands acquired with an airborne CASI-2 sensor. This three-level data has allowed us to calculate a new set of reflectance MERIS bands from the L1B imagery and compare them with the L2 imagery. The comparison could be useful for modifying the current atmospheric correction algorithms applied for L2 data generation, which we have observed that frequently fail in inland waters.

Peńa-Martinez, R.; Domínguez-Gómez, J.-A.; de Hoyos, C.; Ruiz-Verdú, A.

2004-05-01

214

Three Studies Point to Same Risk Gene for Age-Related Macular Degeneration  

MedlinePLUS

... Training and Jobs Three studies point to same risk gene for age-related macular degeneration Listen NIH- ... the same gene as a rare, but powerful risk factor for age-related macular degeneration (AMD), a ...

215

Segmentation and quantification of retinal lesions in age-related macular degeneration using polarization-sensitive optical coherence tomography  

NASA Astrophysics Data System (ADS)

We present polarization-sensitive optical coherence tomography (PS-OCT) for quantitative assessment of retinal pathologies in age-related macular degeneration (AMD). On the basis of the polarization scrambling characteristics of the retinal pigment epithelium, novel segmentation algorithms were developed that allow one to segment pathologic features such as drusen and atrophic zones in dry AMD as well as to determine their dimensions. Results from measurements in the eyes of AMD patients prove the ability of PS-OCT for quantitative imaging based on the retinal features polarizing properties. Repeatability measurements were performed in retinas diagnosed with drusen and geographic atrophy in order to evaluate the performance of the described methods. PS-OCT appears as a promising imaging modality for three-dimensional retinal imaging and ranging with additional contrast based on the structures' tissue-inherent polarization properties.

Baumann, Bernhard; Götzinger, Erich; Pircher, Michael; Sattmann, Harald; Schütze, Christopher; Schlanitz, Ferdinand; Ahlers, Christian; Schmidt-Erfurth, Ursula; Hitzenberger, Christoph K.

2010-11-01

216

Detection of pigment network in dermatoscopy images using texture analysis  

PubMed Central

Dermatoscopy, also known as dermoscopy or epiluminescence microscopy (ELM), is a non-invasive, in vivo technique, which permits visualization of features of pigmented melanocytic neoplasms that are not discernable by examination with the naked eye. ELM offers a completely new range of visual features. One such prominent feature is the pigment network. Two texture-based algorithms are developed for the detection of pigment network. These methods are applicable to various texture patterns in dermatoscopy images, including patterns that lack fine lines such as cobblestone, follicular, or thickened network patterns. Two texture algorithms, Laws energy masks and the neighborhood gray-level dependence matrix (NGLDM) large number emphasis, were optimized on a set of 155 dermatoscopy images and compared. Results suggest superiority of Laws energy masks for pigment network detection in dermatoscopy images. For both methods, a texel width of 10 pixels or approximately 0.22 mm is found for dermatoscopy images. PMID:15249068

Anantha, Murali; Moss, Randy H.; Stoecker, William V.

2011-01-01

217

Interocular Symmetry in Macular Choroidal Thickness in Children  

PubMed Central

Objective. To report interocular differences in choroidal thickness in children using spectral domain optical coherence tomography (SD-OCT) and correlate findings with biometric data. Methods. This observational cross-sectional study included 91 (182 eyes) healthy children aged 6 to 17 years with no ocular abnormality except refractive error. After a comprehensive eye exam and axial length measurement, high definition macular scans were performed using SD-OCT. Two observers manually measured the choroidal thickness at the foveal center and at 1500?µm nasally, temporally, inferiorly, and superiorly. Interocular differences were computed; correlations with age, gender, refractive error, and axial length were performed. Results. Mean age was 10.40 ± 3.17 years; mean axial length and refractive error values were similar between fellow eyes. There was excellent correlation between the two observers' measurements. No significant interocular differences were observed at any location. There was only a trend for right eyes to have higher values in all thicknesses, except the superior thickness. Most of the choroidal thickness measurements correlated positively with spherical equivalent but not with axial length, age, or gender. Conclusion. Choroidal thickness measurements in children as performed using SD-OCT revealed a high level of interobserver agreement and consistent interocular symmetry. Values correlated positively with spherical equivalent refraction. PMID:25525509

Al-Haddad, Christiane; El Chaar, Lama; Noureddin, Baha'

2014-01-01

218

Selective Cone Photoreceptor Injury in Acute Macular Neuroretinopathy  

PubMed Central

Purpose To evaluate retinal structural and functional abnormalities in a patient with Acute Macular Neuroretinopathy (AMN). Methods An adaptive optics scanning light ophthalmoscope (AOSLO) was used to image the photoreceptor mosaic and assess rod and cone structure. Spectral domain optical coherence tomography (SD-OCT) was used to examine retinal lamination. Microperimetry was used to assess function across the macula. Results Microperimetry showed reduced function of localized areas within retinal lesions corresponding to subjective scotomas. SD-OCT imaging revealed attenuation of two outer retinal bands typically thought to reflect photoreceptor structure. AOSLO images of the photoreceptor mosaic revealed a heterogeneous presentation within these lesions. There were areas containing non-waveguiding cones and other areas of decreased cone density where the remaining rods had expanded to fill in the vacant space. Within these lesions, cone densities were shown to be significantly lower than eccentricity matched areas of normal retina, as well as accepted histological measurements. A 6-month follow up revealed no change in rod or cone structure. Conclusions Imaging of AMN using an AOSLO shows a preferential disruption of cone photoreceptor structure within the region of decreased retinal sensitivity (as measured by microperimetry). AO-based imaging tools provide a noninvasive way to assess photoreceptor structure at a level of detail that is not resolved by use of conventional SD-OCT or other clinical measures. PMID:23615345

Hansen, Sean O.; Cooper, Robert F.; Dubra, Alfredo; Carroll, Joseph; Weinberg, David V.

2014-01-01

219

Cadmium exposure and age-related macular degeneration.  

PubMed

Cadmium (Cd) has been proposed as a risk factor for age-related macular degeneration (AMD), but the association between Cd exposure and AMD risk in large population studies is unknown. This study evaluated the association of Cd exposure with AMD in a large representative sample of Korean men and women. This was a cross-sectional study of 3865 Korean adults ?40 years of age who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) during 2008-2011. Cd concentrations in whole blood were measured by graphite-furnace atomic absorption spectrometry. The presence of AMD was determined in digital non-mydriatic fundus photographs. Cd levels were higher in participants with AMD compared with those without AMD (1.3 vs 1.1??g/l, respectively, P<0.001). In fully adjusted models, the odds ratio for AMD comparing the highest with the lowest Cd quartiles was 1.92 (95% CI=1.08-3.39; P for trend 0.029). In restricted cubic spline models, the association between Cd and AMD was approximately linear, with no evidence of threshold effects. Blood Cd concentrations were independently associated with the prevalence of AMD. If the association is proven causal, population-based preventive strategies to decrease Cd exposure could reduce the population burden of AMD.Journal of Exposure Science and Environmental Epidemiology advance online publication, 12 November 2014; doi:10.1038/jes.2014.75. PMID:25388812

Kim, Myung Hun; Zhao, Di; Cho, Juhee; Guallar, Eliseo

2014-11-12

220

Intraocular injection of crystalline cortisone as adjunctive treatment of diabetic macular edema  

Microsoft Academic Search

PURPOSE: To report the clinical outcome of a diabetic patient with macular edema treated with an intravitreal injection of crystalline cortisone.METHODS: Interventional case report. A 73-year-old patient with diabetes mellitus presented with clinically significant diffuse macular edema caused by nonproliferative diabetic retinopathy. Despite grid laser coagulation in the macular region, cystoid macular edema progressed, and within 6 months before the

Jost B Jonas; Antje Söfker

2001-01-01

221

Statins for age-related macular degeneration  

PubMed Central

Background Age-related macular degeneration (AMD) is a progressive late onset disorder of the macula affecting central vision. Age-related macular degeneration is the leading cause of blindness in people over 65 years in industrialized countries (Congdon 2003). Recent epidemiologic, genetic and pathological evidence has shown AMD shares a number of risk factors with atherosclerosis, leading to the hypothesis that statins may exert protective effects in AMD. Objectives To examine the effectiveness of statins compared with other treatments, no treatment, or placebo in delaying the onset and/or progression of AMD. Search strategy We searched CENTRAL in The Cochrane Library, MEDLINE, EMBASE and LILACS on 30 April 2009 and the WHO International Clinical Trials Registry Platform on 11 May 2009. We searched reference lists and the Science Citation Index. There were no language or date restrictions in the search for trials. Selection criteria We included randomized controlled trials (RCTs) that compared statins with other treatments, no treatment, or placebo in participants who were either susceptible to or diagnosed as having early stages of AMD. Data collection and analysis Two authors independently evaluated the search results against the selection criteria. Two Italian speaking colleagues extracted data. One author entered data. We did not perform a meta-analysis because only one completed RCT was identified. Main results Two studies met the selection criteria. One trial reported insufficient details to assess the risk of bias; the other trial is ongoing. Of the completed trial, the analyses of 30 participants did not show a statistically significant difference between the simvastatin and the placebo arm in visual acuity at three months of treatment (decimal visual acuity 0.21± 0.56 in simvastatin and 0.19± 0.40 in placebo arm) or 45 days after the completion of treatment (decimal visual acuity 0.20± 0.50 in simvastatin and 0.19± 0.48 in placebo arm). The lens and retina status were unchanged during and after the treatment period for both groups. Of the ongoing trial, the preliminary analyses of 42 participants who completed 12 months follow-up did not show a statistically significant difference between the simvastatin and the placebo arm in visual acuity, drusen score or visual function (effect estimates and confidence intervals were not available). We contacted the investigators and will update the review as data become available. Authors' conclusions Evidence from currently available RCTs was insufficient to conclude that statins have any role in preventing or delaying the onset or progression of AMD. PMID:19588411

Gehlbach, Peter; Li, Tianjing; Hatef, Elham

2014-01-01

222

Effects of ambient and elevated CO2 on growth, chlorophyll fluorescence, photosynthetic pigments, antioxidants, and secondary metabolites of Catharanthus roseus (L.) G Don. grown under three different soil N levels.  

PubMed

Catharanthus roseus L. plants were grown under ambient (375?±?30 ppm) and elevated (560?±?25 ppm) concentrations of atmospheric CO2 at different rates of N supply (without supplemental N, 0 kg N ha(-1); recommended N, 50 kg N ha(-1); and double recommended N, 100 kg N ha(-1)) in open top chambers under field condition. Elevated CO2 significantly increased photosynthetic pigments, photosynthetic efficiency, and organic carbon content in leaves at recommended (RN) and double recommended N (DRN), while significantly decreased total nitrogen content in without supplemental N (WSN). Activities of superoxide dismutase, catalase, and ascorbate peroxidase were declined, while glutathione reductase, peroxidase, and phenylalanine-ammonia lyase were stimulated under elevated CO2. However, the responses of the above enzymes were modified with different rates of N supply. Elevated CO2 significantly reduced superoxide production rate, hydrogen peroxide, and malondialdehyde contents in RN and DRN. Compared with ambient, total alkaloids content increased maximally at recommended level of N, while total phenolics in WSN under elevated CO2. Elevated CO2 stimulated growth of plants by increasing plant height and numbers of branches and leaves, and the magnitude of increment were maximum in DRN. The study suggests that elevated CO2 has positively affected plants by increasing growth and alkaloids production and reducing the level of oxidative stress. However, the positive effects of elevated CO2 were comparatively lesser in plants grown under limited N availability than in moderate and higher N availability. Furthermore, the excess N supply in DRN has stimulated the growth but not the alkaloids production under elevated CO2. PMID:25304238

Singh, Aradhana; Agrawal, Madhoolika

2015-03-01

223

The pigment glands of cottonseed  

Microsoft Academic Search

Summary  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a The efficacy of a given solvent for the extraction of the gland pigments of cottonseed has been shown to be determined not\\u000a only by its solvent power for the pigments but also by its ability to attack the pigment glands and the extent to which these\\u000a glands are exposed to its action, which in turn depends upon the

Charlotte H. Boatner; Catherine M. Hall

1946-01-01

224

Vitrectomy for diffuse diabetic macular edema associated with a taut premacular posterior hyaloid  

Microsoft Academic Search

PURPOSE: To evaluate the role of vitrectomy in eyes with diffuse diabetic macular edema associated with a taut posterior hyaloid.METHODS: Records of 55 eyes of 50 patients with diabetic retinopathy and diffuse clinically significant diabetic macular edema who underwent vitrectomy with stripping of the premacular posterior hyaloid were reviewed. In all 55 eyes, diffuse diabetic macular edema was present on

Scott D Pendergast; Tarek S Hassan; George A Williams; Morton S Cox; Raymond R Margherio; Philip J Ferrone; Bruce R Garretson; Michael T Trese

2000-01-01

225

Indocyanine green staining and removal of internal limiting membrane in macular hole surgery: histology and outcome  

Microsoft Academic Search

PURPOSE: To report the surgical technique, outcome, and histologic findings involving indocyanine green staining and removal of internal limiting membrane in primary macular hole surgery.METHODS: Prospectively, consecutive patients with idiopathic macular hole or myopic macular hole with retinal detachment were recruited. After pars plana vitrectomy and epiretinal membrane removal, the internal limiting membrane was stained and removed. The specimens were

Alvin K. H Kwok; Winnie W. Y Li; C. P Pang; Timothy Y. Y Lai; Gary H. F Yam; Nongnart R Chan; Dennis S. C Lam

2001-01-01

226

Ultrastructure and Three-Dimensional Reconstruction of Several Macular and Papular Telangiectases  

Microsoft Academic Search

Eight types of telangiectases were studied by light and electron microscopy and by 3-dimensional reconstruction from photomicrographs. Five were macular: mat telangiectasia of scleroderma, generalized essential telangiectasia, nevus flammeus, and 2 macular types not previously described. Three were papular: cherry angioma, angiokeratoma (Fabry), and angiokeratoma (Fordyce). The macular telangiectases were produced by dilatation of postcapillary venules of the upper horizontal

Irwin M. Braverman; Agnes Keh-Yen

1983-01-01

227

Human skin pigmentation as an adaptation to UV radiation  

PubMed Central

Human skin pigmentation is the product of two clines produced by natural selection to adjust levels of constitutive pigmentation to levels of UV radiation (UVR). One cline was generated by high UVR near the equator and led to the evolution of dark, photoprotective, eumelanin-rich pigmentation. The other was produced by the requirement for UVB photons to sustain cutaneous photosynthesis of vitamin D3 in low-UVB environments, and resulted in the evolution of depigmented skin. As hominins dispersed outside of the tropics, they experienced different intensities and seasonal mixtures of UVA and UVB. Extreme UVA throughout the year and two equinoctial peaks of UVB prevail within the tropics. Under these conditions, the primary selective pressure was to protect folate by maintaining dark pigmentation. Photolysis of folate and its main serum form of 5-methylhydrofolate is caused by UVR and by reactive oxygen species generated by UVA. Competition for folate between the needs for cell division, DNA repair, and melanogenesis is severe under stressful, high-UVR conditions and is exacerbated by dietary insufficiency. Outside of tropical latitudes, UVB levels are generally low and peak only once during the year. The populations exhibiting maximally depigmented skin are those inhabiting environments with the lowest annual and summer peak levels of UVB. Development of facultative pigmentation (tanning) was important to populations settling between roughly 23° and 46° , where levels of UVB varied strongly according to season. Depigmented and tannable skin evolved numerous times in hominin evolution via independent genetic pathways under positive selection. PMID:20445093

Jablonski, Nina G.; Chaplin, George

2010-01-01

228

Efficacy of autologous platelets in macular hole surgery.  

PubMed

The introduction of optical coherence tomography has allowed accurate measurement of the size of macular holes. A retrospective consecutive review was performed of 21 patients undergoing macular hole repair with vitrectomy, gas tamponade, and autologous platelet injection and we assessed the effect of macular hole parameters on anatomic and functional outcomes. We looked at the demographic features, final visual outcome, and anatomical closure. Twenty-one patients were included in the study. They underwent routine vitrectomy with gas tamponade (C3F8) and injection of autologous platelets. All patients were advised to maintain a facedown posture for 2 weeks. Anatomical closure was confirmed in all cases and 20 out of 21 of patients had improved postoperative visual acuity by two or more lines. In our series, the macular hole dimensions did not have much effect on the final results. The use of autologous platelets and strict facedown posture seems to be the deciding factor in good anatomical and visual outcome irrespective of macular hole dimensions. PMID:23626459

Konstantinidis, Aristeidis; Hero, Mark; Nanos, Panagiotis; Panos, Georgios D

2013-01-01

229

Intravitreal triamcinolone for intraocular inflammation and associated macular edema  

PubMed Central

Triamcinolone acetonide (TA) is a corticosteroid that has many uses in the treatment of ocular diseases because of its potent anti-inflammatory and anti-permeability actions. Intraocular inflammation broadly referred to as uveitis can result from several causes, including the immune system and after ophthalmic surgery. One of the most common reasons for vision loss with uveitis is macular edema. TA has been used for many years as an intravitreal injection for the treatment of ocular diseases. Several case control studies have been reported showing the efficacy of TA in the treatment of intraocular inflammation and associated macular edema caused by Behcet’s disease, Vogt-Koyanagi-Harada syndrome, sympathetic ophthalmia and white dot syndromes. It has also been shown efficacious in cases of pars planitis and idiopathic posterior uveitis. Some authors have reported its use in postoperative cystoid macular edema. Many of the studies on the use of TA in controlling intraocular inflammation and concomitant macular edema showed its effect to be transient in many patients requiring reinjection. Complications can arise from intravitreal injection of TA including elevated intraocular pressure and cataract. Rarely, it can be associated with infectious and non-infectious endophthalmitis. TA may be useful as an adjuvant in the treatment of uveitis and its associated macular edema, especially in patients resistant or intolerant to standard treatment. PMID:19668543

Couch, Steven M; Bakri, Sophie J

2009-01-01

230

Characteristics of Fixational Eye Movements in People With Macular Disease  

PubMed Central

Purpose. Fixation stability is known to be poor for people with macular disease and has been suggested as a contributing factor for the poor visual performance of these individuals. In this study, we examined the characteristics of the different components of fixational eye movements and determined the component that plays a major role in limiting fixation stability in people with macular disease. Methods. Sixteen observers with macular disease and 14 older adults with normal vision (control observers) monocularly fixated a small cross presented using a Rodenstock scanning laser ophthalmoscope, for trials of 30 seconds. The retinal image and the position of the cross on the retina were recorded digitally. Eye movements were extracted from the recorded videos at a sampling rate of 540 Hz using a cross-correlation technique. A velocity criterion of 8°/s was used to differentiate between slow drifts and microsaccades. Results. Observers with macular disease demonstrated higher fixation instability, larger amplitudes of slow drifts and microsaccades, and lower drift velocities, when compared with older adults with normal vision. The velocity and the rate of microsaccades were comparable between the two groups of observers. Multiple linear regression analysis showed that the amplitude of microsaccades, and to a smaller extent, the amplitude of slow drifts, play a major role in limiting fixation stability. Conclusions. Fixation stability in people with macular disease is primarily limited by the amplitude of microsaccades, implying that rehabilitative strategies targeted at reducing the amplitude of microsaccades should improve fixation stability, and may lead to improved visual functions. PMID:25074769

Kumar, Girish; Chung, Susana T. L.

2014-01-01

231

Inhibitors of intracellular signaling pathways that lead to stimulated epidermal pigmentation: perspective of anti-pigmenting agents.  

PubMed

Few anti-pigmenting agents have been designed and developed according to their known hyperpigmentation mechanisms and corresponding intracellular signaling cascades. Most anti-pigmenting agents developed so far are mechanistically involved in the interruption of constitutional melanogenic mechanisms by which skin color is maintained at a normal and unstimulated level. Thus, owing to the difficulty of confining topical application to a specific hyperpigmented skin area, potent anti-pigmenting agents capable of attenuating the natural unstimulated pigmentation process have the risk of leading to hypopigmentation. Since intracellular signaling pathways within melanocytes do not function substantially in maintaining normal skin color and are activated only by environmental stimuli such as UV radiation, specifically down-regulating the activation of melanogenesis to the constitutive level would be an appropriate strategy to develop new potent anti-pigmenting agents with a low risk of hypopigmentation. In this article, we review the hyperpigmentation mechanisms and intracellular signaling pathways that lead to the stimulation of melanogenesis. We also discuss a screening and evaluation system to select candidates for new anti-melanogenic substances by focusing on inhibitors of endothelin-1 or stem cell factor-triggered intracellular signaling cascades. From this viewpoint, we show that extracts of the herbs Withania somnifera and Melia toosendan and the natural chemicals Withaferin A and Astaxanthin are new candidates for potent anti-pigmenting substances that avoid the risk of hypopigmentation. PMID:24823877

Imokawa, Genji; Ishida, Koichi

2014-01-01

232

Inhibitors of Intracellular Signaling Pathways that Lead to Stimulated Epidermal Pigmentation: Perspective of Anti-Pigmenting Agents  

PubMed Central

Few anti-pigmenting agents have been designed and developed according to their known hyperpigmentation mechanisms and corresponding intracellular signaling cascades. Most anti-pigmenting agents developed so far are mechanistically involved in the interruption of constitutional melanogenic mechanisms by which skin color is maintained at a normal and unstimulated level. Thus, owing to the difficulty of confining topical application to a specific hyperpigmented skin area, potent anti-pigmenting agents capable of attenuating the natural unstimulated pigmentation process have the risk of leading to hypopigmentation. Since intracellular signaling pathways within melanocytes do not function substantially in maintaining normal skin color and are activated only by environmental stimuli such as UV radiation, specifically down-regulating the activation of melanogenesis to the constitutive level would be an appropriate strategy to develop new potent anti-pigmenting agents with a low risk of hypopigmentation. In this article, we review the hyperpigmentation mechanisms and intracellular signaling pathways that lead to the stimulation of melanogenesis. We also discuss a screening and evaluation system to select candidates for new anti-melanogenic substances by focusing on inhibitors of endothelin-1 or stem cell factor-triggered intracellular signaling cascades. From this viewpoint, we show that extracts of the herbs Withania somnifera and Melia toosendan and the natural chemicals Withaferin A and Astaxanthin are new candidates for potent anti-pigmenting substances that avoid the risk of hypopigmentation. PMID:24823877

Imokawa, Genji; Ishida, Koichi

2014-01-01

233

Computational assessment of effective dose and patient specific doses for kilovoltage stereotactic radiosurgery of wet age-related macular degeneration  

NASA Astrophysics Data System (ADS)

Age-related macular degeneration (AMD) is a leading cause of vision loss and a major health problem for people over the age of 50 in industrialized nations. The current standard of care, ranibizumab, is used to help slow and in some cases stabilize the process of AMD, but requires frequent invasive injections into the eye. Interest continues for stereotactic radiosurgery (SRS), an option that provides a non-invasive treatment for the wet form of AMD, through the development of the IRay(TM) (Oraya Therapeutics, Inc., Newark, CA). The goal of this modality is to destroy choroidal neovascularization beneath the pigment epithelium via delivery of three 100 kVp photon beams entering through the sclera and overlapping on the macula delivering up to 24 Gy of therapeutic dose over a span of approximately 5 minutes. The divergent x-ray beams targeting the fovea are robotically positioned and the eye is gently immobilized by a suction-enabled contact lens. Device development requires assessment of patient effective dose, reference patient mean absorbed doses to radiosensitive tissues, and patient specific doses to the lens and optic nerve. A series of head phantoms, including both reference and patient specific, was derived from CT data and employed in conjunction with the MCNPX 2.5.0 radiation transport code to simulate treatment and evaluate absorbed doses to potential tissues-at-risk. The reference phantoms were used to evaluate effective dose and mean absorbed doses to several radiosensitive tissues. The optic nerve was modeled with changeable positions based on individual patient variability seen in a review of head CT scans gathered. Patient specific phantoms were used to determine the effect of varying anatomy and gaze. The results showed that absorbed doses to the non-targeted tissues were below the threshold levels for serious complications; specifically the development of radiogenic cataracts and radiation induced optic neuropathy (RON). The effective dose determined (0.29 mSv) is comparable to diagnostic procedures involving the head, such as an x-ray or CT scan. Thus, the computational assessment performed indicates that a previously established therapeutic dose can be delivered effectively to the macula with IRay(TM) without the potential for secondary complications.

Hanlon, Justin Mitchell

234

Yolk Pigments of the Mexican Leaf Frog  

Microsoft Academic Search

Eggs of the Mexican leaf frog contain blue and yellow pigments identified as biliverdin and lutein, respectively. Both pigments are bound to proteins that occur in crystalline form in the yolk platelet. The major blue pigment is biliverdin IX alpha . The eggs vary in color from brilliant blue to pale yellow-green depending on the amount of each pigment. These

Guido V. Marinetti; Joseph T. Bagnara

1983-01-01

235

21 CFR 178.3725 - Pigment dispersants.  

Code of Federal Regulations, 2012 CFR

...exceed 0.45 percent by weight of the pigment. The pigmented articles may contact...this chapter. Phosphorylated tall oil fatty acids (CAS Reg. No. 68604-99-9...exceed 1.0 percent by weight of the pigment. The pigmented polymeric films...

2012-04-01

236

21 CFR 178.3725 - Pigment dispersants.  

Code of Federal Regulations, 2011 CFR

...exceed 0.45 percent by weight of the pigment. The pigmented articles may contact...this chapter. Phosphorylated tall oil fatty acids (CAS Reg. No. 68604-99-9...exceed 1.0 percent by weight of the pigment. The pigmented polymeric films...

2011-04-01

237

21 CFR 178.3725 - Pigment dispersants.  

Code of Federal Regulations, 2014 CFR

...exceed 0.45 percent by weight of the pigment. The pigmented articles may contact...this chapter. Phosphorylated tall oil fatty acids (CAS Reg. No. 68604-99-9...exceed 1.0 percent by weight of the pigment. The pigmented polymeric films...

2014-04-01

238

21 CFR 178.3725 - Pigment dispersants.  

Code of Federal Regulations, 2013 CFR

...exceed 0.45 percent by weight of the pigment. The pigmented articles may contact...this chapter. Phosphorylated tall oil fatty acids (CAS Reg. No. 68604-99-9...exceed 1.0 percent by weight of the pigment. The pigmented polymeric films...

2013-04-01

239

Macular hole secondary to toxoplasmic retinochoroiditis.  

PubMed

Ocular toxoplasmosis causes abnormalities in the vitreous that are responsible for several types of well-known complications including retinal detachment and epiretinal membranes. We report on a patient who developed toxoplasmic panuveitis with a full-thickness macular hole (MH) and was successfully treated with vitreoretinal surgery. A 35-year-old Hispanic female presented with a 2-week history of loss of visual acuity and metamorphopsia in her right eye. Funduscopy revealed a typical toxoplasmosis lesion and a MH, which was confirmed by optical coherence tomography. After 8 weeks of medical treatment with sulfamethoxazole (800 mg)/trimethoprim (160 mg) and steroids, the intraocular inflammation was considered inactive. Pars plana vitrectomy with inner limiting membrane peeling and injection of 24 % sulphur hexafluoride gas were performed to treat the MH, without success. Repeat pars plana vitrectomy was then performed with injection of 14 % perfluoropropane (C3F8). Closure of the MH was achieved after this second procedure. Vitreoretinal surgery may be safe and effective for treating MHs secondary to toxoplasmosis lesions, a very uncommon complication of this disease. PMID:23479051

Arana, Begońa; Fonollosa, Alex; Artaraz, Joseba; Martinez-Berriotxoa, Agustin; Martinez-Alday, Nerea

2014-02-01

240

Economic Considerations of Macular Edema Therapies  

PubMed Central

Purpose To relate costs and treatment benefits for macular edema due to diabetes (DME) and branch and central retinal vein occlusion (BRVO, CRVO). Design A model of resource utilization, outcomes, and cost effectiveness and utility. Participants none Methods Results from published clinical trials (index studies) of laser, intravitreal corticosteroids, intravitreal anti-vascular endothelial growth factor (VEGF) agents, and vitrectomy trials were used to ascertain visual benefit and clinical protocols. Calculations followed from the costs of one year of treatment for each treatment modality and the visual benefits as ascertained. Main Outcome measures Visual acuity (VA) saved, cost of therapy, cost per line saved, cost per line-year saved, and costs per quality adjusted life years (QALYs). Results The lines saved for DME (0.26 to 2.02), BRVO (0.74 to 4.92), and CRVO (1.2 to 3.75) yielded calculations of costs/line of saved VA for DME ($1329 to 11609), BRVO ($494 to 13039), and CRVO ($704 to 7611), costs/line-year for DME ($60 to 561), BRVO ($25 to 754), and CRVO ($45 to 473), and costs/QALY of $824 to $25566. Conclusion Relative costs and benefits should be considered in perspective when applying and developing treatment strategies. PMID:21507488

Smiddy, William E.

2012-01-01

241

Animal models of age related macular degeneration  

PubMed Central

Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations. PMID:22705444

Pennesi, Mark E.; Neuringer, Martha; Courtney, Robert J.

2013-01-01

242

Prodigiosin from Vibrio sp. DSM 14379; A New UV-Protective Pigment  

Microsoft Academic Search

Pigments such as melanin, scytonemin and carotenoids protect microbial cells against the harmful effects of ultraviolet (UV)\\u000a radiation. The role in UV protection has never been assigned to the prodigiosin pigment. In this work, we demonstrate that\\u000a prodigiosin provides a significant level of protection against UV stress in Vibrio sp. DSM 14379. In the absence of pigment production, Vibrio sp.

Maja Bori?; Tjaša Danev?i?; David Stopar

243

Difficulty in performing everyday activities in patients with juvenile macular dystrophies: comparison with patients with retinitis pigmentosa  

Microsoft Academic Search

AIMSTo ascertain the level of perceived difficulty experienced by patients with central vision loss due to juvenile macular dystrophies in the performance of everyday activities. A second objective was to compare their perceived difficulty with that of patients with retinitis pigmentosa (RP) with primarily peripheral vision loss.METHODS72 patients with Stargardt disease, cone dystrophy, or cone-rod dystrophy who had visual acuities

Janet P Szlyk; Gerald A Fishman; Sandeep Grover; Beatrise I Revelins; Deborah J Derlacki

1998-01-01

244

Pigment dispersion in organic solvents  

Microsoft Academic Search

The interactions between pigments, solvents, and additives play a decisive part in the formulation of paints and coatings.\\u000a These interactions were examined by means of calorimetric measurements of the enthalpies of displacement and by determining\\u000a the adsorbed additive amounts of pigments from non-polar solvents. The combination of the two method proved particularly favorable\\u000a for examining the type of interaction between

M. Liphard; W. von Rybinski

245

Carotenoid pigments of peanut oil  

Microsoft Academic Search

A method for analysis of carotenoid pigments in peanut oil is described. The major carotenoid pigments found in peanut oil\\u000a were beta-carotene and lutein. A sample of oil from immature peanuts contained 60 g of beta-carotene and 138 g of lutein\\u000a per liter of oil. The total carotenoid concentration in oil from mature peanuts appears to be less than 1

Harold E. Pattee; Albert E. Purcell

1967-01-01

246

Aqueous Cytokines as Predictors of Macular Edema in Patients with Diabetes following Uncomplicated Phacoemulsification Cataract Surgery  

PubMed Central

This study aims to ascertain whether cytokines in the aqueous humor can predict macular edema (ME) in diabetic patients following uncomplicated phacoemulsification cataract surgery. Undiluted aqueous humor samples were obtained from 136 consecutive type 2 diabetic patients who underwent cataract surgery. The concentrations of 27 cytokines were measured in aqueous humor using the multiplex bead immunoassay. At the final follow-up examination, 116 patients completed 4 weeks of follow-up, and the incidence of macular edema was 29.31% (34 patients) 4 weeks after cataract surgery. Compared to the ME (?) patients, the concentrations of interleukin-1? (IL-1?) (P < 0.001), IL-6 (P < 0.001), IL-8 (P < 0.001), interferon-induced protein-10 (IP-10) (P = 0.003), monocyte chemotactic protein-1 (MCP-1) (P < 0.001), and vascular endothelial growth factor (VEGF) (P < 0.001) in the ME (+) patients were significantly higher. In addition, the aqueous levels of IL-1? (r = 0.288), IL-6 (r = 0.345), IL-8 (r = 0.256), IP-10 (r = 0.377), MCP-1 (r = 0.423), and VEGF (r = 0.279) were positively correlated with the postoperative foveal center point thickness (FCPT). However, the aqueous levels of IL-10 (P = 0.003) and IL-12 (P = 0.017) were significantly lower in patients with ME. These results suggest IL-1?, IL-6, IL-8, IL-10, IL-12, IP-10, MCP-1, and VEGF may be potential predictors of postoperative macular thickness in patients with diabetes following uncomplicated phacoemulsification cataract surgery.

Dong, Ning; Xu, Bing; Wang, Bingsong; Chu, Liqun; Tang, Xin

2015-01-01

247

Comparison of Natural Course, Intravitreal Triamcinolone and Macular laser photocoagulation for Treatment of Mild Diabetic Macular Edema  

PubMed Central

Purpose: To assess the natural course of the mild diabetic macular edema(DME) and to compare the visual outcomes with the patients with receiving either macular laser photocoagulation or intravitreal injection of triamcinolone acetonide(IVTA). Methods: 28 eyes with central macular thickness (CMT) of between 250 to 300µm were followed without treatment and 48 eyes with CMT between 300 to 500µm had been divided into 3 subgroups according to treatment. We evaluated the best corrected visual acuity (BCVA) and CMT of natural course group and compared the BCVA and CMT of the patients who had been treated with IVTA or macular laser treatment. Results: The eyes with DME between 250 to 300µm showed no significant change in BCVA and CMT at 6 month. Among the eyes with DME between 300 to 500µm, all 3 subgroups showed no statistically significant change of BCVA at any follow up period and no significant difference was revealed among the subgroups. All subgroups showed significant reduction of CMT after 1 month and maintained until final follow-up and there was no significant difference among subgroups. Conclusions: Mild DME between 250 to 500µm did not show significant worsening of BCVA or macular edema without any specific treatment. PMID:23372430

Kwon, Soon Il; Baek, Sung Uk; Park, In Won

2013-01-01

248

Yolk pigments of the Mexican leaf frog.  

PubMed

Eggs of the Mexican leaf frog contain blue and yellow pigments identified as biliverdin and lutein, respectively. Both pigments are bound to proteins that occur in crystalline form in the yolk platelet. The major blue pigment is biliverdin IX alpha. The eggs vary in color from brilliant blue to pale yellow-green depending on the amount of each pigment. These pigments may provide protective coloration to the eggs. PMID:6681678

Marinetti, G V; Bagnara, J T

1983-02-25

249

Juvenile-Onset Macular Degeneration and Allied Disorders  

PubMed Central

While age-related macular degeneration (AMD) is a leading cause of central vision loss among the elderly, many inherited diseases that present earlier in life share features of AMD. These diseases of juvenile-onset macular degeneration include Stargardt disease, Best disease, retinitis pigmentosa, X-linked retinoschisis, and other allied disorders. In particular, they can be accompanied by the appearance of drusen, geographic atrophy, macular hyperpigmentation, choroidal neovascularization, and disciform scarring just as in AMD, and often may be confused for the adult form of the disease. Diagnosis based on funduscopic findings alone can be challenging. However, the use of diagnostic studies such as electroretinography, electrooculography, optical coherence tomography, and fundus autofluorescence in conjunction with genetic testing can lead to an accurate diagnosis. PMID:24732760

North, Victoria; Gelman, Rony; Tsang, Stephen H.

2015-01-01

250

A Novel Source of Methylglyoxal and Glyoxal in Retina: Implications for Age-Related Macular Degeneration  

PubMed Central

Aging of retinal pigment epithelial (RPE) cells of the eye is marked by accumulations of bisretinoid fluorophores; two of the compounds within this lipofuscin mixture are A2E and all-trans-retinal dimer. These pigments are implicated in pathological mechanisms involved in some vision-threatening disorders including age-related macular degeneration (AMD). Studies have shown that bisretinoids are photosensitive compounds that undergo photooxidation and photodegradation when irradiated with short wavelength visible light. Utilizing ultra performance liquid chromatography (UPLC) with electrospray ionization mass spectrometry (ESI-MS) we demonstrate that photodegradation of A2E and all-trans-retinal dimer generates the dicarbonyls glyoxal (GO) and methylglyoxal (MG), that are known to modify proteins by advanced glycation endproduct (AGE) formation. By extracellular trapping with aminoguanidine, we established that these oxo-aldehydes are released from irradiated A2E-containing RPE cells. Enzyme-linked immunosorbant assays (ELISA) revealed that the substrate underlying A2E-containing RPE was AGE-modified after irradiation. This AGE deposition was suppressed by prior treatment of the cells with aminoguanidine. AGE-modification causes structural and functional impairment of proteins. In chronic diseases such as diabetes and atherosclerosis, MG and GO modify proteins by non-enzymatic glycation and oxidation reactions. AGE-modified proteins are also components of drusen, the sub-RPE deposits that confer increased risk of AMD onset. These results indicate that photodegraded RPE bisretinoid is likely to be a previously unknown source of MG and GO in the eye. PMID:22829938

Yoon, Kee Dong; Yamamoto, Kazunori; Ueda, Keiko; Zhou, Jilin; Sparrow, Janet R.

2012-01-01

251

Spontaneous resolution of macular edema after silicone oil removal  

PubMed Central

AIM To investigate the macular changes in eyes filled with silicone oil (SO) and course of these changes after SO removal. METHODS A retrospective optical coherence tomography scan review was conducted for twenty-four patients who underwent uncomplicated pars plana vitrectomy with SO tamponade for complex retinal detachments were detected with optical coherence tomography before, and one week, one month and three months after SO removal. RESULTS Mean duration of SO tamponade was 3.6±1.0mo (range: 3-7mo). Cystoid macular edema (CME) was detected in 3 eyes before SO removal. Submacular fluid was represented in 1 eye before silicone SO removal. Resolution of CME and submacular fluid was achieved 1mo after SO removal in all eyes. Mean best corrected visual acuity (BCVA) was 1.15±0.65 (range, hand movement to 0.2) before SO removal in the eyes without macular changes. After SO removal, the mean BCVA values at 1wk and 1 and 3mo, and 0.82±0.23, 0.76±0.21, and 0.70±0.19, all of which were significantly better than baseline (P=0.030, 0.017, 0.006 respectively). In the eyes with macular CME and subretinal fluid the mean BCVA was significantly improved at 3mo after SO removal compared with baseline (P=0.037). CONCLUSION Decreased visual acuity in eyes filled with SO could be caused by macular complications due to SO. CME and subretinal fluid may resolve without any additional macular surgery after SO removal. PMID:25540755

Karahan, Eyyup; Tuncer, Ibrahim; Zengin, Mehmet Ozgur; Kucukerdonmez, Cem; Kaynak, Suleyman

2014-01-01

252

Use of antivascular endothelial growth factor for diabetic macular edema  

PubMed Central

Background Diabetic macular edema (DME) is one of the manifestations of diabetic retinopathy leading to loss of central vision and visual acuity. It manifests itself with swelling around the central part of the retina, the area responsible for sharp vision. Current treatment includes laser therapy and intravitreal steroids with preventative measures including diabetes control. No one treatment has guaranteed control of diabetic macular edema which leads to deteriorating visual acuity, function and quality of life in patients. Vascular endothelial growth factor (VEGF) has been shown to be a critical stimulus in the pathogenesis of macular edema secondary to diabetes.1 Antiangiogenic therapy encompassed treatment with anti-VEGF which inhibits VEGF-driven neovascularization hence macular edema leading to decreased visual acuity. Objective For this review, we evaluated the effectiveness of intravitreal anti-VEGF in treating DME. Data sources We identified five trials (n = 525) using electronic databases (Cochrane Central Register of Controlled Trials [Central], Medline®, and Excerpta Medica Database [EMBASE®]) in October 2008, supplemented by hand searching of reference lists, review articles, and conference abstracts. Methods We included all randomized clinical trials (RCTs) evaluating any form of intravitreal anti-VEGF for treating DME. The main outcome factor was change in best-corrected visual acuity and central macular thickness. One author assessed eligibility, methodological quality, and extracted data. Meta analysis was performed when appropriate. Results We included three trials of adequate methodological quality in our meta-analysis. Patients treated with anti-VEGF showed improvement in visual acuity of ?0.17 (95% confidence interval [CI]: ?0.23, ?0.10) and central macular thickness ?84.69 (95% CI: ?117.09, ?52.30). Patients treated with combined anti-VEGF and intravitreal triamcinolone showed improvement of visual acuity of ?0.19 (95% CI: ?0.27, ?0.11) and central macular thickness mean change being –111.20 (95% CI: ?148.13, ?74.28). Conclusions Anti-VEGF has been associated with an improvement in visual acuity and central macular thickness in the analysis, however trial analysis was of a short duration and further research is needed to determine long-term benefits. PMID:20535227

Karim, Rushmia; Tang, Benjamin

2010-01-01

253

Topical Nonsteroidal Anti-Inflammatory Drugs for Macular Edema  

PubMed Central

Nonsteroidal anti-inflammatory drugs (NSAIDs) are nowadays widely used in ophthalmology to reduce eye inflammation, pain, and cystoid macular edema associated with cataract surgery. Recently, new topical NSAIDs have been approved for topical ophthalmic use, allowing for greater drug penetration into the vitreous. Hence, new therapeutic effects can be achieved, such as reduction of exudation secondary to age-related macular degeneration or diabetic maculopathy. We provide an updated review on the clinical use of NSAIDs for retinal diseases, with a focus on the potential future applications. PMID:24227908

Parmeggiani, Francesco; Romano, Mario R.; dell'Omo, Roberto

2013-01-01

254

Epiretinal membrane formation associated with idiopathic macular telangiectasia: case report.  

PubMed

A 46-year-old woman complained of blurred and distorted vision in both eyes. Ophthalmic examination showed that visual acuity was 20/200 for the right eye and counting fingers left eye. Fundoscopy revealed perimacular hemorrhages, aneurismal dilatation of the vessels in the posterior pole, and a white and elevated lesion adjacent to vascular changes. We report a case of idiopathic macular telangiectasia and epiretinal membrane that occurs concomitantly. To our knowledge, this is the first report that describes an association between idiopathic macular telangiectasia and epiretinal membrane formation. PMID:25410182

Gomes, Flávia Cid; Felix, Joăo Paulo Fernandes; Nascimento, Maurício Abujamra; Lira, Rodrigo Pessoa Cavalcanti

2014-08-01

255

Macular hole formation associated with idiopathic parafoveal telangiectasia  

Microsoft Academic Search

Background  To report the occurrence of a full thickness macular hole in association with idiopathic parafoveal telangiectasia.\\u000a \\u000a \\u000a \\u000a Methods  Observational case report.\\u000a \\u000a \\u000a \\u000a Results  A 60-year-old female with a history of bilateral idiopathic parafoveal telangiectasia presented with acute complaints of decreased\\u000a vision and metamorphopsia in her right eye. The patient's retinal examination was significant for idiopathic parafoveal telangiectasia\\u000a bilaterally, and a new, full-thickness macular hole

Jeffrey L. Olson; Naresh Mandava

2006-01-01

256

Statins for age-related macular degeneration  

PubMed Central

Background Age-related macular degeneration (AMD) is a progressive late onset disorder of the macula affecting central vision. Age-related macular degeneration is the leading cause of blindness in people over 65 years in industrialized countries (Congdon 2003). Recent epidemiologic, genetic and pathological evidence has shown AMD shares a number of risk factors with atherosclerosis, leading to the hypothesis that statins may exert protective effects in AMD. Objectives To examine the effectiveness of statins compared with other treatments, no treatment, or placebo in delaying the onset and/or progression of AMD. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 9), MEDLINE (January 1950 to September 2011), EMBASE (January 1980 to September 2011), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to September 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 16 September 2011. Selection criteria We included randomized controlled trials (RCTs) that compared statins with other treatments, no treatment, or placebo in participants who were either susceptible to or diagnosed as having early stages of AMD. Data collection and analysis Two authors independently evaluated the search results against the selection criteria. Two Italian speaking colleagues extracted data. One author entered data. We did not perform a meta-analysis because only one completed RCT was identified. Main results Two studies met the selection criteria. One trial reported insufficient details to assess the risk of bias; the other trial is ongoing. Of the completed trial, the analyses of 30 participants did not show a statistically significant difference between the simvastatin and the placebo arm in visual acuity at three months of treatment (decimal visual acuity 0.21± 0.56 in simvastatin and 0.19± 0.40 in placebo arm) or 45 days after the completion of treatment (decimal visual acuity 0.20± 0.50 in simvastatin and 0.19± 0.48 in placebo arm). The lens and retina status were unchanged during and after the treatment period for both groups. Of the ongoing trial, the preliminary analyses of 42 participants who completed 12 months follow-up did not show a statistically significant difference between the simvastatin and the placebo arm in visual acuity, drusen score or visual function (effect estimates and confidence intervals were not available). We contacted the investigators and will update the review as data become available. Authors' conclusions Evidence from currently available RCTs was insufficient to conclude that statins have any role in preventing or delaying the onset or progression of AMD. PMID:22419318

Gehlbach, Peter; Li, Tianjing; Hatef, Elham

2013-01-01

257

Comparison of Modified-ETDRS and Mild Macular Grid Laser Photocoagulation Strategies for Diabetic Macular Edema  

PubMed Central

Purpose To compare two laser photocoagulation techniques for treatment of diabetic macular edema (DME): modified-ETDRS direct/grid photocoagulation (mETDRS) and a, potentially milder, but potentially more extensive, mild macular grid (MMG) laser technique in which small mild burns are placed throughout the macula, whether or not edema is present, and microaneurysms are not treated directly. Methods 263 subjects (mean age 59 years) with previously untreated DME were randomly assigned to receive laser photocoagulation by mETDRS (N=162 eyes) or MMG (N=161 eyes) technique. Visual acuity, fundus photographs and OCT measurements were obtained at baseline and after 3.5, 8, and 12 months. Treatment was repeated if DME persisted. Main Outcome Measure Change in OCT measures at 12-months follow up. Results From baseline to 12 months, among eyes with baseline central subfield thickness ? 250 microns, central subfield thickening decreased by an average of 88 microns in the mETDRS group and decreased by 49 microns in the MMG group (adjusted mean difference: 33 microns, 95% confidence interval 5 to 61 microns, P=0.02). Weighted inner zone thickening by OCT decreased by 42 and 28 microns, respectively (adjusted mean difference: 14 microns, 95% confidence interval 1 to 27 microns, P=0.04), maximum retinal thickening (maximum of the central and four inner subfields) decreased by 66 and 39 microns, respectively (adjusted mean difference: 27 microns, 95% confidence interval 6 to 47 microns, P=0.01), and retinal volume decreased by 0.8 and 0.4 mm3, respectively (adjusted mean difference: 0.3 mm3, 95% confidence interval 0.02 to 0.53 mm3, P=0.03). At 12 months, the mean change in visual acuity was 0 letters in the mETDRS group and 2 letters worse in the MMG group (adjusted mean difference: 2 letters, 95% confidence interval ?0.5 to 5 letters, P=0.10). Conclusions At 12 months after treatment, the MMG technique is less effective at reducing OCT measured retinal thickening than the more extensively evaluated current mETDRS laser photocoagulation approach. However, the visual acuity outcome with both approaches is not substantially different. Given these findings a larger long-term trial of the MMG technique is not justified. Application to Clinical Practice Modified ETDRS focal photocoagulation should continue as a standard approach for treating diabetic macular edema. PMID:17420366

2008-01-01

258

Treatment of cystoid macular edema with the new-generation NSAID nepafenac 0.1%  

PubMed Central

Purpose: To describe the use of nepafenac 0.1% for cystoid macular edema (CME). Methods: This was a multicenter retrospective review of 22 CME cases (20 patients) treated with nepafenac 0.1% (six with concomitant prednisolone acetate 1%) from December 2005 to April 2008: three acute pseudophakic CME cases, 13 chronic/recalcitrant pseudophakic CME cases, and six cases of uveitic CME. Pre- and post-treatment retinal thickness and visual acuity were reported. Results: Following treatment for six weeks to six months, six eyes with uveitic CME showed a mean retinal thickness improvement of 227 ± 168.1 ?m; mean best-corrected visual acuity (BCVA) improvement was 0.36 ± 0.20 logMAR. All three cases of acute pseudophakic CME improved after four to 10 weeks of nepafenac, with a mean improvement in retinal thickness of 134 ± 111.0 ?m. BCVA improved in two patients (0.16 and 0.22 logMAR) but not in the third due to underlying retinal pigment epithelium changes. Thirteen eyes with chronic/recalcitrant pseudophakic CME demonstrated a mean improvement in retinal thickness of 178 ± 128.7 ?m after nepafenac and mean BCVA improvement of 0.33 ± 0.19 logMAR. Conclusion: The positive outcomes of these 22 eyes strongly suggest that nepafenac 0.1% is a promising drug for the treatment of CME. Additional study under randomized controlled conditions is warranted. PMID:19668559

Hariprasad, Seenu M; Akduman, Levent; Clever, Joseph A; Ober, Michael; Recchia, Franco M; Mieler, William F

2009-01-01

259

Microdevice-based cell therapy for age-related macular degeneration.  

PubMed

This chapter reports the application of a micromachined parylene-C device as an artificial Bruch's membrane for the stem cell-based therapy of age-related macular degeneration. The feasibility of parylene-C as a substitute substrate material is demonstrated by evaluating the permeability of membranes of submicron thicknesses. It has been found that parylene-C membranes thinner than 0.3 µm possess similar molecular weight exclusion limit and nutrient diffusion flux to that of the healthy human Bruch's membrane. This conclusion is further validated by the in vitro perfusion cell viability test. Since the submicron parylene-C itself is difficult to handle, we design a mesh-supported submicron parylene membrane (MSPM) to provide sufficient mechanical support. This MSPM can support the growth of retinal pigment epithelial (RPE) cells in a monolayer with well-polarized morphology. Human embryonic stem cell-derived H9-RPE cells are cultured in vitro on the MSPM for one month before the implantation of the MSPM into the rat's retina. To facilitate the surgical implantation, a parylene-C/SU-8 hybrid microfluidic device is designed as an inserter. Histological studies with hematoxylin-eosin staining and immunofluorescence staining show that the implanted RPE cells adhere well to the artificial Bruch's membrane and are able to maintain high viability and normal morphology in vivo. PMID:24732769

Lu, Bo; Tai, Yu-Chong; Humayun, Mark S

2014-01-01

260

Fundus Autofluorescence and RPE Lipofuscin in Age-Related Macular Degeneration  

PubMed Central

Genes that increase susceptibility to age-related macular degeneration (AMD) have been identified; however, since many individuals carrying these risk alleles do not develop disease, other contributors are involved. One additional factor, long implicated in the pathogenesis of AMD, is the lipofuscin of retinal pigment epithelium (RPE). The fluorophores that constitute RPE lipofuscin also serve as a source of autofluorescence (AF) that can be imaged by confocal laser ophthalmoscopy. The AF originating from lipofuscin is excited by the delivery of short wavelength (SW) light. A second autofluorescence is emitted from the melanin of RPE (and choroid) upon near-infrared (NIR-AF) excitation. SW-AF imaging is currently used in the clinical management of retinal disorders and the advantages of NIR-AF are increasingly recognized. Here we visit the damaging properties of RPE lipofuscin that could be significant when expressed on a background of genetic susceptibility. To advance interpretations of disease-related patterns of fundus AF in AMD, we also consider the photochemical and spectrophotometric features of the lipofuscin compounds responsible for generating the fluorescence emission.

Sparrow, Janet R.; Duncker, Tobias

2014-01-01

261

Recent developments in the management of dry age-related macular degeneration  

PubMed Central

Dry age-related macular degeneration (AMD), also called geographic atrophy, is characterized by the atrophy of outer retinal layers and retinal pigment epithelium (RPE) cells. Dry AMD accounts for 80% of all intermediate and advanced forms of the disease. Although vision loss is mainly due to the neovascular form (75%), dry AMD remains a challenge for ophthalmologists because of the lack of effective therapies. Actual management consists of lifestyle modification, vitamin supplements, and supportive measures in the advanced stages. The Age-Related Eye Disease Study demonstrated a statistically significant protective effect of dietary supplementation of antioxidants (vitamin C, vitamin E, beta-carotene, zinc, and copper) on dry AMD progression rate. It was also stated that the consumption of omega-3 polyunsaturated fatty acids, such as docosahexaenoic acid and eicosapentaenoic acid, has protective effects. Other antioxidants, vitamins, and minerals (such as crocetin, curcumin, and vitamins B9, B12, and B6) are under evaluation, but the results are still uncertain. New strategies aim to 1) reduce or block drusen formation, 2) reduce or eliminate inflammation, 3) lower the accumulation of toxic by-products from the visual cycle, 4) reduce or eliminate retinal oxidative stress, 5) improve choroidal perfusion, 6) replace/repair or regenerate lost RPE cells and photoreceptors with stem cell therapy, and 7) develop a target gene therapy. PMID:25878491

Buschini, Elisa; Fea, Antonio M; Lavia, Carlo A; Nassisi, Marco; Pignata, Giulia; Zola, Marta; Grignolo, Federico M

2015-01-01

262

NLRP3 Inflammasome: Activation and Regulation in Age-Related Macular Degeneration  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of legal blindness in the elderly in industrialized countries. AMD is a multifactorial disease influenced by both genetic and environmental risk factors. Progression of AMD is characterized by an increase in the number and size of drusen, extracellular deposits, which accumulate between the retinal pigment epithelium (RPE) and Bruch's membrane (BM) in outer retina. The major pathways associated with its pathogenesis include oxidative stress and inflammation in the early stages of AMD. Little is known about the interactions among these mechanisms that drive the transition from early to late stages of AMD, such as geographic atrophy (GA) or choroidal neovascularization (CNV). As part of the innate immune system, inflammasome activation has been identified in RPE cells and proposed to be a causal factor for RPE dysfunction and degeneration. Here, we will first review the classic model of inflammasome activation, then discuss the potentials of AMD-related factors to activate the inflammasome in both nonocular immune cells and RPE cells, and finally introduce several novel mechanisms for regulating the inflammasome activity. PMID:25698849

Gao, Jiangyuan; Liu, Ruozhou Tom; Cui, Jing Z.; Matsubara, Joanne A.

2015-01-01

263

Stem cell therapies for age-related macular degeneration: the past, present, and future.  

PubMed

In the developed world, age-related macular degeneration (AMD) is one of the major causes of irreversible blindness in the elderly. Although management of neovascular AMD (wet AMD) has dramatically progressed, there is still no effective treatment for nonneovascular AMD (dry AMD), which is characterized by retinal pigment epithelial (RPE) cell death (or dysfunction) and microenvironmental disruption in the retina. Therefore, RPE replacement and microenvironmental regulation represent viable treatments for dry AMD. Recent advances in cell biology have demonstrated that RPE cells can be easily generated from several cell types (pluripotent stem cells, multipotent stem cells, or even somatic cells) by spontaneous differentiation, coculturing, defined factors or cell reprogramming, respectively. Additionally, in vivo studies also showed that the restoration of visual function could be obtained by transplanting functional RPE cells into the subretinal space of recipient. More importantly, clinical trials approved by the US government have shown promising prospects in RPE transplantation. However, key issues such as implantation techniques, immune rejection, and xeno-free techniques are still needed to be further investigated. This review will summarize recent advances in cell transplantation for dry AMD. The obstacles and prospects in this field will also be discussed. PMID:25609937

Dang, Yalong; Zhang, Chun; Zhu, Yu

2015-01-01

264

Genetic Basis of Inherited Macular Dystrophies and Implications for Stem Cell Therapy  

PubMed Central

Untreatable hereditary macular dystrophy (HMD) presents a major burden to society in terms of the resulting patient disability and the cost to the healthcare provision system. HMD results in central vision loss in humans sufficiently severe for blind registration, and key issues in the development of therapeutic strategies to target these conditions are greater understanding of the causes of photoreceptor loss and the development of restorative procedures. More effective and precise analytical techniques coupled to the development of transgenic models of disease have led to a prolific growth in the identification and our understanding of the genetic mutations that underly HMD. Recent successes in driving differentiation of pluripotent cells towards specific somatic lineages have led to the development of more efficient protocols that can yield enriched populations of a desired phenotype. Retinal pigmented epithelial cells and photoreceptors derived from these are some of the most promising cells that may soon be used in the treatment of specific HMD, especially since rapid developments in the field of induced pluripotency have now set the stage for the production of patient-derived stem cells that overcome the ethical and methodological issues surrounding the use of embryonic derivatives. In this review we highlight a selection of HMD which appear suitable candidates for combinatorial restorative therapy, focusing specifically on where those photoreceptor loss occurs. This technology, along with increased genetic screening, opens up an entirely new pathway to restore vision in patients affected by HMD. PMID:19551904

Mellough, Carla B; Steel, David HW; Lako, Majlinda

2009-01-01

265

Oxidative Stress, Hypoxia, and Autophagy in the Neovascular Processes of Age-Related Macular Degeneration  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of severe and irreversible loss of vision in the elderly in developed countries. AMD is a complex chronic neurodegenerative disease associated with many environmental, lifestyle, and genetic factors. Oxidative stress and the production of reactive oxygen species (ROS) seem to play a pivotal role in AMD pathogenesis. It is known that the macula receives the highest blood flow of any tissue in the body when related to size, and anything that can reduce the rich blood supply can cause hypoxia, malfunction, or disease. Oxidative stress can affect both the lipid rich retinal outer segment structure and the light processing in the macula. The response to oxidative stress involves several cellular defense reactions, for example, increases in antioxidant production and proteolysis of damaged proteins. The imbalance between production of damaged cellular components and degradation leads to the accumulation of detrimental products, for example, intracellular lipofuscin and extracellular drusen. Autophagy is a central lysosomal clearance system that may play an important role in AMD development. There are many anatomical changes in retinal pigment epithelium (RPE), Bruch's membrane, and choriocapillaris in response to chronic oxidative stress, hypoxia, and disturbed autophagy and these are estimated to be crucial components in the pathology of neovascular processes in AMD. PMID:24707498

Veréb, Zoltán; Facskó, Andrea; Kaarniranta, Kai

2014-01-01

266

Stem cell therapies for age-related macular degeneration: the past, present, and future  

PubMed Central

In the developed world, age-related macular degeneration (AMD) is one of the major causes of irreversible blindness in the elderly. Although management of neovascular AMD (wet AMD) has dramatically progressed, there is still no effective treatment for nonneovascular AMD (dry AMD), which is characterized by retinal pigment epithelial (RPE) cell death (or dysfunction) and microenvironmental disruption in the retina. Therefore, RPE replacement and microenvironmental regulation represent viable treatments for dry AMD. Recent advances in cell biology have demonstrated that RPE cells can be easily generated from several cell types (pluripotent stem cells, multipotent stem cells, or even somatic cells) by spontaneous differentiation, coculturing, defined factors or cell reprogramming, respectively. Additionally, in vivo studies also showed that the restoration of visual function could be obtained by transplanting functional RPE cells into the subretinal space of recipient. More importantly, clinical trials approved by the US government have shown promising prospects in RPE transplantation. However, key issues such as implantation techniques, immune rejection, and xeno-free techniques are still needed to be further investigated. This review will summarize recent advances in cell transplantation for dry AMD. The obstacles and prospects in this field will also be discussed. PMID:25609937

Dang, Yalong; Zhang, Chun; Zhu, Yu

2015-01-01

267

Treatment of macular degeneration, according to Bangerter.  

PubMed

Age-related macular degeneration (AMD) is a common cause of visual loss among elderly patients. Although some risk factors have been determined, the ultimate cause of the disease is not known. For a long time, therapeutic nihilism has been the rule among ophthalmologists confronted with such patients. Bangerter has not shared this attitude, especially since the time that he incidentally discovered, more than 40 years ago, the beneficial effects of radiotherapy, in discouraging the growth of new vessels at the posterior pole of the eye. A variety of approaches are combined and used by Bangerter in the treatment of the different types of AMD, including retrobulbar injections of either vasodilating medications (in the dry - or atrophic - type) or corticosteroids (in the wet - or exudative - type), general medical measures aimed at improving metabolic and vascular functions such as supplementation with trace elements, antioxidants, and vitamins; ozone therapy; advice to increase physical fitness, improve nutrition, and abstain from smoking; and protection from excessive light exposure. Being convinced of the usefulness of his type of combination treatment, he has always rejected undertaking controlled clinical trials, of only single aspects of the therapy, as unethical and invalid. For this reason, scientific journals have not proven cooperative in several attempts at publishing his results, as collected in retrospective surveys. Recently, however, some of the several approaches combined by Bangerter in treating AMD have been pronounced effective by other investigators. We present here an overview of his treatment approaches, as few people are aware of them, to clear up misconceptions and to set records straight. PMID:9348273

Teichmann, K D

1997-10-30

268

Spontaneous closure of stage IV idiopathic full-thickness macular hole and late reopening as a lamellar macular hole: a case report  

PubMed Central

Introduction Spontaneous closure of traumatic macular holes is described as a common event in the peer-reviewed literature. However, the spontaneous closure of stage III and IV full-thickness idiopathic macular holes has been reported in less than 15 cases in the literature, this being an extremely rare event, with their reopening being even more infrequent. We report a case of a spontaneous closure of stage IV idiopathic full-thickness macular hole and late reopening as a lamellar macular hole. Case presentation A 67-year-old Spanish man was referred to our hospital with a complaint of decreased vision in his right eye and metamorphopsia for approximately 11?months. He did not report any trauma. Diagnosis was based on fundoscopic and optical coherence tomography. They revealed a stage IV full-thickness idiopathic macular hole and a small epiretinal membrane. Three months later the hole spontaneously closed, and two years later we appreciated its reopening as a lamellar macular hole. Conclusions The contraction of the epiretinal membrane could have contributed to cystic spaces and their fusion, subsequently, to the formation of a lamellar macular hole. To the best of our knowledge this is the first report in the literature of a spontaneously closed full-thickness idiopathic macular hole with reopening as a partial thickness macular defect. PMID:22742449

2012-01-01

269

The visual pigment cyanide effect.  

PubMed

The visual pigment of the Tokay gecko (Gekko gekko) with its in situ absorption maximum at 521 nm has its spectral position at 500 to 505 nm when chloride-deficient digitonin is used for the extraction. In this case the addition of chloride or bromide to the extract restores the maximum to 521 nm. This property, characteristic of gecko pigments in general, does not occur with any of the rhodopsins that have been tested. Simple salts of cyanide, a pseudohalogenoid with an ionic radius close to those of chloride and bromide and/or its hydrolysis product attacks both this gecko pigment and rhodopsins in the dark. This is seen as a slow thermal loss of photopigment if (sodium) cyanide is present at concentrations above 40 mM for the gecko pigment and 150 mM for the rhodopsins of the midshipman (Porichthys notatus) and of the frog (Rana pipiens). In all cases the loss of the photopigment is accompanied by the appearance of a spectral product with maximum absorption at about 340 nm. Cyanide addition has no effect on the photosensitivity of the native pigments and neither does it alter, as do chloride, bromide and other anions, the spectral absorbance curve. The spectral product at 340 nm also appears when the visual pigments are photolyzed in the presence of cyanide salts below the threshold concentrations given above. Incubation of digitonin-solubilized all-trans-retinal with (sodium) cyanide leads to a reaction product with absorption spectrum similar to that obtained with visual pigments under comparable conditions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2626492

Crescitelli, F; Karvaly, B

1989-12-01

270

Vestibular dysfunction, altered macular structure and trait localization in A/J inbred mice.  

PubMed

A/J mice develop progressive hearing loss that begins before 1 month of age and is attributed to cochlear hair cell degeneration. Screening tests indicated that this strain also develops early onset vestibular dysfunction and has otoconial deficits. The purpose of this study was to characterize the vestibular dysfunction and macular structural pathology over the lifespan of A/J mice. Vestibular function was measured using linear vestibular evoked potentials (VsEPs). Macular structural pathology was evaluated using light microscopy, scanning electron microscopy, transmission electron microscopy, confocal microscopy and Western blotting. Individually, vestibular functional deficits in mice ranged from mild to profound. On average, A/J mice had significantly reduced vestibular sensitivity (elevated VsEP response thresholds and smaller amplitudes), whereas VsEP onset latency was prolonged compared to age-matched controls (C57BL/6). A limited age-related vestibular functional loss was also present. Structural analysis identified marked age-independent otoconial abnormalities in concert with some stereociliary bundle defects. Macular epithelia were incompletely covered by otoconial membranes with significantly reduced opacity and often contained abnormally large or giant otoconia as well as normal-appearing otoconia. Elevated expression of key otoconins (i.e., otoconin 90, otolin and keratin sulfate proteoglycan) ruled out the possibility of reduced levels contributing to otoconial dysgenesis. The phenotype of A/J was partially replicated in a consomic mouse strain (C57BL/6J-Chr 17(A/J)/NaJ), thus indicating that Chr 17(A/J) contained a trait locus for a new gene variant responsible to some extent for the A/J vestibular phenotype. Quantitative trait locus analysis identified additional epistatic influences associated with chromosomes 1, 4, 9 and X. Results indicate that the A/J phenotype represents a complex trait, and the A/J mouse strain presents a new model for the study of mechanisms underlying otoconial formation and maintenance. PMID:25645995

Vijayakumar, Sarath; Lever, Teresa E; Pierce, Jessica; Zhao, Xing; Bergstrom, David; Lundberg, Yunxia Wang; Jones, Timothy A; Jones, Sherri M

2015-04-01

271

NUTRITIONAL SUPPLEMENTATION, CATARACTS AND AGE-RELATED MACULAR DEGENERATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Age-related cataract and age-related macular degeneration (AMD) are the major causes of visual impairment and blindness in the aging population. Specific nutrients in the diet that are thought to be important in the prevention of these diseases are vitamins C and E, the carotenoids, lutein and zeaxa...

272

Nutritional modulation of age-related macular degeneration  

Technology Transfer Automated Retrieval System (TEKTRAN)

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30-50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated wi...

273

Serous macular detachment associated with optic nerve pits  

Microsoft Academic Search

Between September 1972 and March 1989, we examined 25 eyes of 24 patients exhibiting optic nerve-head pits associated with serous macular detachment. We followed 21 patients for a period of 1–15 years (mean, 62 months). Various treatment modalities were applied, depending on the time of initial examination. Five eyes underwent no treatment and three eyes underwent two distinct treatment modalities.

Mireille Bonnet

1991-01-01

274

Clinical characterization and genetic mapping of North Carolina Macular Dystrophy  

PubMed Central

North Carolina macular dystrophy (NCMD) is an autosomal dominant macular disease, was mapped to 6q14-q16.2, the disease-causing gene has yet not been identified. It shares phenotypic similarity with age-related macular degeneration including drusen and choroidal neovascularization. We collected six families with NCMD including 75 members, and conducted clinical characterization and genetic mapping for these families. Forty five patients were diagnosed as NCMD; all six NCMD families were mapped to MCDR1 locus using genetic linkage analysis. MCDR1 interval was refined to 3 cM (1.8mb) between D6S1716 to D6S1671 via fine mapping using microsatellite markers in these six families, all eleven annotated genes within the interval were analyzed by mutation screening in coding regions, no mutation was found, suggesting a potential novel gene or a new pathological mechanism causing NCMD. The refinement of MCDR1 locus will aid the disease-causing gene identification. Functional studies of NCMD genes should provide important insights into pathogenetic mechanisms of NCMD and age-related macular degeneration. PMID:17976682

Yang, Zhenglin; Tong, Zongzhong; Chorich, Louis J.; Pearson, Erik; Moore, Anthony; Hunt, David M.; Zhang, Kang

2008-01-01

275

Cystoid macular oedema following cataract extraction in patients with diabetes  

Microsoft Academic Search

The course of cystoid macular oedema (CMO) following extracapsular cataract extraction with posterior chamber intraocular lens implantation was prospectively studied in 44 eyes of 44 consecutive diabetic patients without preoperative CMO. In 50% of eyes CMO was observed 6 weeks after surgery and in 25% was still present at 1 year. The preoperative presence of diabetic retinopathy significantly affected the

A. Pollack; H. Leiba; A. Bukelman; M. Oliver

1992-01-01

276

Staining of Internal Limiting Membrane in Macular Hole Surgery  

Microsoft Academic Search

emoval of internal limiting membranes (ILMs) is a potentially useful surgical approach to close an idiopathic macular hole. However, the removal of ILMs is diffi- cult to perform because of poor visibility of the ILMs. We have developed a technique for staining the ILM with a solution of indocyanine green to facilitate the removal of ILMs in eyes with an

Kazuaki Kadonosono; Norihiko Itoh; Eiichi Uchio; Satoshi Nakamura; Shigeaki Ohno; Arch Ophthalmol

2000-01-01

277

1Continue on pg 2 What Is Macular Degeneration?  

E-print Network

't By Jonna Jefferis Prevent Blindness America has designated February National Age-Related Macular already occurred. There is no FDA-approved treatment for dry AMD. Taking steps to prevent AMD from Degeneration Awareness Month to increase public education about this potentially devastating disease. Age

278

Preventing Depression in Age-Related Macular Degeneration  

Microsoft Academic Search

Context: Age-related macular degeneration is a preva- lent disease of aging that may cause irreversible vision loss, disability, and depression. The latter is rarely rec- ognized or treated in ophthalmologic settings. Objective: To determine whether problem-solving treat- ment can prevent depressive disorders in patients with recent vision loss. Design: Randomized, controlled trial. Setting: Outpatient ophthalmology offices in Philadel- phia, Pennsylvania.

Barry W. Rovner; Robin J. Casten; Mark T. Hegel; Benjamin E. Leiby; William S. Tasman

2007-01-01

279

Expression of pigment epithelium?derived factor and thrombospondin?1 regulate proliferation and migration of retinal pigment epithelial cells  

PubMed Central

Abstract Age?related macular degeneration (AMD) is the leading cause of vision loss among elderly. Although the pathogenesis of AMD is associated with retinal pigmented epithelium (RPE) dysfunction and abnormal neovascularization the detailed mechanisms remain unresolved. RPE is a specialized monolayer of epithelial cells with important functions in ocular homeostasis. Pathological RPE damage contributes to major ocular conditions including retinal degeneration and irreversible loss of vision in AMD. RPE cells also assist in the maintenance of the ocular angiogenic balance by production of positive and negative regulatory factors including vascular endothelial growth factor (VEGF), thrombospondin?1 (TSP1), and pigment epithelium?derived factor (PEDF). The altered production of PEDF and TSP1, as endogenous inhibitors of angiogenesis and inflammation, by RPE cells have been linked to pathogenesis of AMD and choroidal and retinal neovascularization. However, lack of simple methods for isolation and culture of mouse RPE cells has resulted in limited knowledge regarding the cell autonomous role of TSP1 and PEDF in RPE cell function. Here, we describe a method for routine isolation and propagation of RPE cells from wild?type, TSP1, and PEDF?deficient mice, and have investigated their impact on RPE cell function. We showed that expression of TSP1 and PEDF significantly impacted RPE cell proliferation, migration, adhesion, oxidative state, and phagocytic activity with minimal effect on their basal rate of apoptosis. Together, our results indicated that the expression of PEDF and TSP1 by RPE cells play crucial roles not only in regulation of ocular vascular homeostasis but also have significant impact on their cellular function. PMID:25602019

Farnoodian, Mitra; Kinter, James B.; Yadranji Aghdam, Saeed; Zaitoun, Ismail; Sorenson, Christine M.; Sheibani, Nader

2015-01-01

280

Acute retinal pigment epitheliitis: spectral domain optical coherence tomography, fluorescein angiography, and autofluorescence findings.  

PubMed

A 17-year-old presented with central and paracentral scotomas in his right eye for one week. There was no remarkable medical or ocular history. Blood analyses were within normal range. At presentation both eyes' best-corrected visual acuities were 20/20. Slit-lamp examination result was normal. Fundus examination revealed yellow-white hypopigmented areas in the macula. Fluorescein angiography (FA) showed hypofluorescence surrounded by ring of hyperfluorescence. Fundus autofluorescence (FAF) was slightly increased. Spectral domain optical coherence tomography (SD-OCT) showed disruption of IS/OS junction with expansion of abnormal hyperreflectivity from retinal pigment epithelium to the outer nuclear layer (ONL). One month later fundus examination showed disappearance of the lesions. FA revealed transmission hyperfluorescence. FAF showed increased autofluorescence and pigment clumping. Hyperreflective band in SD-OCT disappeared. Loss of photoreceptor segment layers was observed in some of the macular lesions. The diagnosis of acute retinal pigment epitheliitis can be challenging after disappearance of fundus findings. FA, FAF, and SD-OCT are important tests for diagnosis after resolution of the disease. PMID:25767511

Aydo?an, Tu?ba; Güney, Esra; Akçay, Betül ?lkay Sezgin; Bozkurt, Tahir Kansu; Ünlü, Cihan; Ergin, Ahmet

2015-01-01

281

Acute Retinal Pigment Epitheliitis: Spectral Domain Optical Coherence Tomography, Fluorescein Angiography, and Autofluorescence Findings  

PubMed Central

A 17-year-old presented with central and paracentral scotomas in his right eye for one week. There was no remarkable medical or ocular history. Blood analyses were within normal range. At presentation both eyes' best-corrected visual acuities were 20/20. Slit-lamp examination result was normal. Fundus examination revealed yellow-white hypopigmented areas in the macula. Fluorescein angiography (FA) showed hypofluorescence surrounded by ring of hyperfluorescence. Fundus autofluorescence (FAF) was slightly increased. Spectral domain optical coherence tomography (SD-OCT) showed disruption of IS/OS junction with expansion of abnormal hyperreflectivity from retinal pigment epithelium to the outer nuclear layer (ONL). One month later fundus examination showed disappearance of the lesions. FA revealed transmission hyperfluorescence. FAF showed increased autofluorescence and pigment clumping. Hyperreflective band in SD-OCT disappeared. Loss of photoreceptor segment layers was observed in some of the macular lesions. The diagnosis of acute retinal pigment epitheliitis can be challenging after disappearance of fundus findings. FA, FAF, and SD-OCT are important tests for diagnosis after resolution of the disease. PMID:25767511

Aydo?an, Tu?ba; Güney, Esra; Akçay, Betül ?lkay Sezgin; Bozkurt, Tahir Kansu; Ünlü, Cihan; Ergin, Ahmet

2015-01-01

282

Retinal pigment epithelium development, plasticity, and tissue homeostasis.  

PubMed

The retinal pigment epithelium (RPE) is a simple epithelium interposed between the neural retina and the choroid. Although only 1 cell-layer in thickness, the RPE is a virtual workhorse, acting in several capacities that are essential for visual function and preserving the structural and physiological integrities of neighboring tissues. Defects in RPE function, whether through chronic dysfunction or age-related decline, are associated with retinal degenerative diseases including age-related macular degeneration. As such, investigations are focused on developing techniques to replace RPE through stem cell-based methods, motivated primarily because of the seemingly limited regeneration or self-repair properties of mature RPE. Despite this, RPE cells have an unusual capacity to transdifferentiate into various cell types, with the particular fate choices being highly context-dependent. In this review, we describe recent findings elucidating the mechanisms and steps of RPE development and propose a developmental framework for understanding the apparent contradiction in the capacity for low self-repair versus high transdifferentiation. PMID:24060344

Fuhrmann, Sabine; Zou, ChangJiang; Levine, Edward M

2014-06-01

283

Stem cells as source for retinal pigment epithelium transplantation.  

PubMed

Inherited maculopathies, age related macular degeneration and some forms of retinitis pigmentosa are associated with impaired function or loss of the retinal pigment epithelium (RPE). Among potential treatments, transplantation approaches are particularly promising. The arrangement of RPE cells in a well-defined tissue layer makes the RPE amenable to cell or tissue sheet transplantation. Different cell sources have been suggested for RPE transplantation but the development of a clinical protocol faces several obstacles. The source should provide a sufficient number of cells to at least recover the macula area. Secondly, cells should be plastic enough to be able to integrate in the host tissue. Tissue sheets should be considered as well, but the substrate on which RPE cells are cultured needs to be carefully evaluated. Immunogenicity can also be an obstacle for effective transplantation as well as tumorigenicity of not fully differentiated cells. Finally, ethical concerns may represent drawbacks when embryo-derived cells are proposed for RPE transplantation. Here we discuss different cell sources that became available in recent years and their different properties. We also present data on a new source of human RPE. We provide a protocol for RPE differentiation of retinal stem cells derived from adult ciliary bodies of post-mortem donors. We show molecular characterization of the in vitro differentiated RPE tissue and demonstrate its functionality based on a phagocytosis assay. This new source may provide tissue for allogenic transplantation based on best matches through histocompatibility testing. PMID:24933042

Bertolotti, Evelina; Neri, Alberto; Camparini, Monica; Macaluso, Claudio; Marigo, Valeria

2014-09-01

284

Oxidized LDL Induces Apoptosis of Human Retinal Pigment Epithelium Through Activation of ERK-Bax/Bcl-2 Signaling Pathways.  

PubMed

Abstract Purpose: Retinal pigment epithelium (RPE) cell dysfunction and death play a vital role in the pathogenesis of age-related macular degeneration (AMD). We previously reported that oxidized low-density lipoprotein (OX-LDL) induces retinal degeneration in vivo. In this study, we investigated the role of the ERK-Bax/Bcl-2 signaling pathways in OX-LDL-induced apoptosis in human RPE. Methods: ARPE-19 cells were incubated with 10-100?mg/mL n-LDL or OX-LDL for 24?h. Cell viability was assessed using the Cell Titer 96 Aqueous One Solution cell proliferation assay. RPE apoptosis was measured with a flow cytometer. Reverse transcription polymerase chain reaction was used to detect Bcl-2 and Bax mRNA levels in RPE cells. Bcl-2 and Bax protein expression was measured by western blotting. Activation of extracellular signal-regulated kinase (ERK) protein was evaluated by western blot analysis. One-way analysis of variance was used to compare differences. Results: OX-LDL treatment decreased ARPE-19 cell viability in a dose-dependent manner, whereas n-LDL had no effect. Compared with the control group, OX-LDL significantly increased the apoptosis of RPE, 10?mg/mL, 50?mg/mL, 100?mg/mL apoptosis rate was 6.43?±?0.19%, 5.12?±?0.27%, 5.53?±?0.35%, respectively. OX-LDL also increased Bcl-2 expression and decreased Bax expression significantly. The Bcl-2 to Bax ratio was elevated after OX-LDL treatment. Inhibition of ERK downregulated Bax and was associated with RPE apoptosis. Conclusions: Our data suggest that apoptosis induced by OX-LDL in RPE partly depends on Erk-Bax/Bcl-2 signaling pathway activation. These results may provide further information regarding the effects of OX-LDL in human RPE and their potential role in AMD pathogenesis. PMID:24956392

Yating, Qiu; Yuan, Yao; Wei, Zhang; Qing, Gu; Xingwei, Wu; Qiu, Qinhua; Lili, Yin

2014-06-23

285

Quantitative analysis of macular contraction in idiopathic epiretinal membrane  

PubMed Central

Background We aimed to quantify the displacement of macular capillaries using infrared fundus photographs and image processing software (ImageJ) in patients with idiopathic epiretinal membrane (ERM) who have undergone vitrectomy and to analyze the correlation between vessel displacement and retinal thickness. Methods This prospective study included 16 patients who underwent vitrectomy for idiopathic ERM. Ophthalmic examination and optical coherence tomography (OCT) were performed before and 3 months after surgery. The length of radial vessel segment included in each area (VLA) and the length from the foveola to the vessel branching point (FBL) depending on the superior, inferior, nasal, and temporal areas of the macula were measured using infrared fundus images and image processing software (ImageJ). Preoperative and postoperative parameters were compared and correlations between VLA, FBL, macular thickness, and visual acuity were assessed. Results The VLA of superior, inferior, and temporal areas showed a significant postoperative reduction. VLA differences showed a positive correlation with differences in macular thickness, which corresponded to the superior, inferior, and temporal areas; however, no correlation was observed in the nasal area. The FBL of the superior and inferior areas was significantly increased postoperatively. A positive correlation was observed between FBL differences and macular thickness differences in the superior area. Postoperative change in VLA and FBL did not show a significant correlation with postoperative best corrected visual acuity (BCVA) and BCVA differences. Conclusions Infrared fundus photographs and image processing software can be useful for quantifying progressive changes in retinal surface distortion after surgical removal of ERM. Macular edema and vascular distortion showed significant improvement after surgery. Furthermore, a correlation was observed between topographic and tomographic changes. PMID:24735324

2014-01-01

286

Carotenoid pigments of genus Rhodococcus.  

PubMed

A study of carotenoid pigments of the genus Rhodococcus was carried out. According to carotenes contained, Rhodococcus species were divided into three groups: the first group of Rhodococcus luteus, R. coprophilus, R. lentifragmentus, and R. maris, which formed beta-carotene; the second group of R. equi, R. rubropertinctus, R. aichiensis, R. sputi, R. chubuensis, R. obuensis, R. bronchialis, R. roseus, R. rhodochrous, R. rhodnii, and R. terrae, which formed gamma-carotene-like substance; and the third group of R. aurantiacus, which formed neither carotene. Other carotenoid pigments were different according to the species. PMID:2770561

Ichiyama, S; Shimokata, K; Tsukamura, M

1989-01-01

287

DNA Forensics and Color Pigments  

NSDL National Science Digital Library

Students perform DNA forensics using food coloring to enhance their understanding of DNA fingerprinting, restriction enzymes, genotyping and DNA gel electrophoresis. They place small drops of different food coloring ("water-based paint") on strips of filter paper and then place one paper strip end in water. As water travels along the paper strips, students observe the pigments that compose the paint decompose into their color components. This is an example of the chromatography concept applied to DNA forensics, with the pigments in the paint that define the color being analogous to DNA fragments of different lengths.

National Science Foundation GK-12 and Research Experience for Teachers (RET) Programs,

288

Macular ganglion cell-inner plexiform layer thinning in patients with visual field defect that respects the vertical meridian.  

PubMed

The aim of this work is to compare the thinning patterns of the ganglion cell inner-plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) as measured using Cirrus high-definition optical coherence tomography (HD-OCT) in patients with visual field (VF) defects that respect the vertical meridian. Twenty eyes of 11 patients with VF defects that respect the vertical meridian were enrolled retrospectively. The thicknesses of the macular GCIPL and pRNFL were measured using Cirrus HD-OCT. The 5 and 1% thinning area index (TAI) was calculated as the proportion of abnormally thin sectors at the 5 and 1% probability level within the area corresponding to the affected VF. The 5 and 1% TAI were compared between the GCIPL and pRNFL measurements. The color-coded GCIPL deviation map showed a characteristic vertical thinning pattern of the GCIPL, which is also seen in the VF of patients with brain lesions. The 5 and 1% TAI were significantly higher in the GCIPL measurements than in the pRNFL measurements (all p?Macular GCIPL analysis clearly visualized a characteristic topographic pattern of retinal ganglion cell (RGC) loss in patients with VF defects that respect the vertical meridian, unlike pRNFL measurements. Macular GCIPL measurements provide more valuable information than pRNFL measurements for detecting the loss of RGCs in patients with retrograde degeneration of the optic nerve fibers. PMID:25104464

Shin, Hye-Young; Park, Hae-Young Lopilly; Choi, Jin-A; Park, Chan Kee

2014-09-01

289

The genetic basis of divergent pigment patterns in juvenile threespine sticklebacks.  

PubMed

Animal pigment patterns are important for a range of functions, including camouflage and communication. Repeating pigment patterns, such as stripes, bars and spots have been of particular interest to developmental and theoretical biologists, but the genetic basis of natural variation in such patterns is largely unexplored. In this study, we identify a difference in a periodic pigment pattern among juvenile threespine sticklebacks (Gasterosteus aculeatus) from different environments. Freshwater sticklebacks exhibit prominent vertical bars that visually break up the body shape, but sticklebacks from marine populations do not. We hypothesize that these distinct pigment patterns are tuned to provide crypsis in different habitats. This phenotypic difference is widespread and appears in most of the freshwater populations that we sampled. We used quantitative trait locus (QTL) mapping in freshwater-marine F2 hybrids to elucidate the genetic architecture underlying divergence in this pigmentation pattern. We identified two QTL that were significantly associated with variation in barring. Interestingly, these QTL were associated with two distinct aspects of the pigment pattern: melanophore number and overall pigment level. We compared the QTL locations with positions of known pigment candidate genes in the stickleback genome. We also identified two major QTL for juvenile body size, providing new insights into the genetic basis of juvenile growth rates in natural populations. In summary, although there is a growing literature describing simple genetic bases for adaptive coloration differences, this study emphasizes that pigment patterns can also possess a more complex genetic architecture. PMID:21304547

Greenwood, A K; Jones, F C; Chan, Y F; Brady, S D; Absher, D M; Grimwood, J; Schmutz, J; Myers, R M; Kingsley, D M; Peichel, C L

2011-08-01

290

The genetic basis of divergent pigment patterns in juvenile threespine sticklebacks  

PubMed Central

Animal pigment patterns are important for a range of functions, including camouflage and communication. Repeating pigment patterns, such as stripes, bars and spots have been of particular interest to developmental and theoretical biologists, but the genetic basis of natural variation in such patterns is largely unexplored. In this study, we identify a difference in a periodic pigment pattern among juvenile threespine sticklebacks (Gasterosteus aculeatus) from different environments. Freshwater sticklebacks exhibit prominent vertical bars that visually break up the body shape, but sticklebacks from marine populations do not. We hypothesize that these distinct pigment patterns are tuned to provide crypsis in different habitats. This phenotypic difference is widespread and appears in most of the freshwater populations that we sampled. We used quantitative trait locus (QTL) mapping in freshwater–marine F2 hybrids to elucidate the genetic architecture underlying divergence in this pigmentation pattern. We identified two QTL that were significantly associated with variation in barring. Interestingly, these QTL were associated with two distinct aspects of the pigment pattern: melanophore number and overall pigment level. We compared the QTL locations with positions of known pigment candidate genes in the stickleback genome. We also identified two major QTL for juvenile body size, providing new insights into the genetic basis of juvenile growth rates in natural populations. In summary, although there is a growing literature describing simple genetic bases for adaptive coloration differences, this study emphasizes that pigment patterns can also possess a more complex genetic architecture. PMID:21304547

Greenwood, A K; Jones, F C; Chan, Y F; Brady, S D; Absher, D M; Grimwood, J; Schmutz, J; Myers, R M; Kingsley, D M; Peichel, C L

2011-01-01

291

The role of pigmentation in face perception  

E-print Network

Faces each have distinct pigmentation as well as shape, which suggests that both cues may play a role in the perception of faces. However, there is a common implicit assumption that pigmentation cues are relatively ...

Russell, Richard (Richard P.)

2005-01-01

292

Induced pigmentation in zooplankton: a trade-off between threats from predation and ultraviolet radiation.  

PubMed

Ultraviolet (UV) radiation is harmful to all life, and the ongoing depletion of the ozone layer is likely to affect interactions among both terrestrial and aquatic organisms. Some organisms have evolved adaptations to reduce radiation damage, such as the various types of protective pigmentation of freshwater zooplankton. However, strong pigmentation also increases vulnerability to visually hunting predators. Hence, where both UV radiation and predation are intense, zooplankton may be sandwiched between conflicting selective pressures: to be pigmented and to be transparent at the same time. Here, I show that the level of pigmentation in copepods is up to ten times higher in lakes without predatory fishes than where fishes are present. Moreover, animals from the same population exposed to either UV light or predator scent showed a 10% difference in pigmentation after only four days, suggesting that pigmentation is an inducible trait. Hence, individual copepods are not passive victims of selective predation or radiation damage, but adjust the level of pigmentation according to the prevailing threat. The ability to adjust pigmentation level rapidly may be especially useful in situations where risk assessment is difficult due to strong seasonal and spatial variation in risk variables, such as in Arctic regions. With progressive thinning of the ozone layer, the ability of some but not other organisms to adjust protection against UV radiation may lead to counter-intuitive, large-scale alterations in freshwater food webs. PMID:11413651

Hansson, L A

2000-11-22

293

Induced pigmentation in zooplankton: a trade-off between threats from predation and ultraviolet radiation.  

PubMed Central

Ultraviolet (UV) radiation is harmful to all life, and the ongoing depletion of the ozone layer is likely to affect interactions among both terrestrial and aquatic organisms. Some organisms have evolved adaptations to reduce radiation damage, such as the various types of protective pigmentation of freshwater zooplankton. However, strong pigmentation also increases vulnerability to visually hunting predators. Hence, where both UV radiation and predation are intense, zooplankton may be sandwiched between conflicting selective pressures: to be pigmented and to be transparent at the same time. Here, I show that the level of pigmentation in copepods is up to ten times higher in lakes without predatory fishes than where fishes are present. Moreover, animals from the same population exposed to either UV light or predator scent showed a 10% difference in pigmentation after only four days, suggesting that pigmentation is an inducible trait. Hence, individual copepods are not passive victims of selective predation or radiation damage, but adjust the level of pigmentation according to the prevailing threat. The ability to adjust pigmentation level rapidly may be especially useful in situations where risk assessment is difficult due to strong seasonal and spatial variation in risk variables, such as in Arctic regions. With progressive thinning of the ozone layer, the ability of some but not other organisms to adjust protection against UV radiation may lead to counter-intuitive, large-scale alterations in freshwater food webs. PMID:11413651

Hansson, L A

2000-01-01

294

Dietary antioxidants prevent age-related retinal pigment epithelium actin damage and blindness in mice lacking ?v?5 integrin.  

PubMed

In the aging human eye, oxidative damage and accumulation of pro-oxidant lysosomal lipofuscin cause functional decline of the retinal pigment epithelium (RPE), which contributes to age-related macular degeneration. In mice with an RPE-specific phagocytosis defect due to lack of ?v?5 integrin receptors, RPE accumulation of lipofuscin suggests that the age-related blindness we previously described in this model may also result from oxidative stress. Cellular and molecular targets of oxidative stress in the eye remain poorly understood. Here we identify actin among 4-hydroxynonenal (HNE) adducts formed specifically in ?5(-/-) RPE but not in neural retina with age. HNE modification directly correlated with loss of resistance of actin to detergent extraction, suggesting cytoskeletal damage in aging RPE. Dietary enrichment with natural antioxidants, grapes or marigold extract containing macular pigments lutein/zeaxanthin, was sufficient to prevent HNE-adduct formation, actin solubility, lipofuscin accumulation, and age-related cone and rod photoreceptor dysfunction in ?5(-/-) mice. Acute generation of HNE adducts directly destabilized actin but not tubulin cytoskeletal elements of RPE cells. These findings identify destabilization of the actin cytoskeleton as a consequence of a physiological, sublethal oxidative burden of RPE cells in vivo that is associated with age-related blindness and that can be prevented by consuming an antioxidant-rich diet. PMID:22178979

Yu, Chia-Chia; Nandrot, Emeline F; Dun, Ying; Finnemann, Silvia C

2012-02-01

295

Diabetic macular edema: new concepts in patho-physiology and treatment.  

PubMed

Diabetic macular edema (DME), a serious eye complication caused primarily by hyperglycemia, is one of the major causes of blindness. DME, which is characterized by cystic retinal thickening or lipid deposition, is prone to relapse after successful treatment. DME is a complex pathological process caused by multiple factors, including breakdown of the inner and outer blood-retinal barriers, oxidative stress, and elevated levels of vascular endothelial growth factor which have been demonstrated in both preclinical and clinical studies. Starling's law theory explains many of the features of DME. Early detection and treatment of DME can prevent vision loss. Current effective interventions for DME include treatment of systemic risk factors, such as elevated blood glucose, blood pressure and dyslipidemia. Ophthalmic treatments include laser photocoagulation, surgery and intraocular pharmacotherapy. New drugs, which are given by intraocular injection, have emerged in recent years to become first line treatment for DME that affects the central macula with loss of vision. Laser photocoagulation is still the gold standard of treatment for DME which does not involve the central macular. This review outlines these new treatments with particular emphasis on the optimal timing of how they are given. PMID:24955234

Zhang, Xinyuan; Zeng, Huan; Bao, Shian; Wang, Ningli; Gillies, Mark C

2014-01-01

296

Severe macular edema induced by pioglitazone in a patient with diabetic retinopathy: a case study.  

PubMed

We report a case of severe diabetic macular edema (DME) that developed after pioglitazone was used by a patient with proliferative diabetic retinopathy. A 30-year-old woman with poorly controlled type 2 diabetes mellitus visited our clinic in 2004. She had moderate pre-proliferative diabetic retinopathy OU. Because of the rapid progression of the diabetic retinopathy, she received pan-retinal photocoagulation in both eyes. Two weeks before using pioglitazone, her visual acuity was 0.9 OD and 0.7 OS. On October 2007, pioglitazone was prescribed by her internist because of poorly controlled blood glucose level. Two weeks later, her body weight increased, and her face became edematous. Her visual acuity decreased to 0.5 OU, and ophthlamoscopy showed severe DME in both eyes. Two weeks after stopping pioglitazone, her visual acuity improved to 0.8 OD and 0.5 OS, but the DME was still severe in the optical coherence tomographic images. Then, one half the usual dose (25 mg) of spironolactone, a diuretic, was given and her macular edema was resolved. Her final visual acuity improved to 0.9 OD and 0.7 OS. We recommend that when a patient taking pioglitazone complains of decreased vision, the physician should promptly consult an ophthalmologist. PMID:19183764

Oshitari, Toshiyuki; Asaumi, Noriko; Watanabe, Masaru; Kumagai, Ken; Mitamura, Yoshinori

2008-01-01

297

Severe macular edema induced by pioglitazone in a patient with diabetic retinopathy: a case study  

PubMed Central

We report a case of severe diabetic macular edema (DME) that developed after pioglitazone was used by a patient with proliferative diabetic retinopathy. A 30-year-old woman with poorly controlled type 2 diabetes mellitus visited our clinic in 2004. She had moderate pre-proliferative diabetic retinopathy OU. Because of the rapid progression of the diabetic retinopathy, she received pan-retinal photocoagulation in both eyes. Two weeks before using pioglitazone, her visual acuity was 0.9 OD and 0.7 OS. On October 2007, pioglitazone was prescribed by her internist because of poorly controlled blood glucose level. Two weeks later, her body weight increased, and her face became edematous. Her visual acuity decreased to 0.5 OU, and ophthlamoscopy showed severe DME in both eyes. Two weeks after stopping pioglitazone, her visual acuity improved to 0.8 OD and 0.5 OS, but the DME was still severe in the optical coherence tomographic images. Then, one half the usual dose (25 mg) of spironolactone, a diuretic, was given and her macular edema was resolved. Her final visual acuity improved to 0.9 OD and 0.7 OS. We recommend that when a patient taking pioglitazone complains of decreased vision, the physician should promptly consult an ophthalmologist. PMID:19183764

Oshitari, Toshiyuki; Asaumi, Noriko; Watanabe, Masaru; Kumagai, Ken; Mitamura, Yoshinori

2008-01-01

298

Bestrophin-1 influences transepithelial electrical properties and Ca2+ signaling in human retinal pigment epithelium  

PubMed Central

Purpose Mutations in BEST1, encoding Bestrophin-1 (Best1), cause Best vitelliform macular dystrophy (BVMD) and other inherited retinal degenerative diseases. Best1 is an integral membrane protein localized to the basolateral plasma membrane of the retinal pigment epithelium (RPE). Data from numerous in vitro and in vivo models have demonstrated that Best1 regulates intracellular Ca2+ levels. Although it is known from in vitro and crystal structure data that Best1 is also a calcium-activated anion channel, evidence for Best1 functioning as a channel in human RPE is lacking. To assess Best1-associated channel activity in the RPE, we examined the transepithelial electrical properties of fetal human RPE (fhRPE) cells, which express endogenous Best1. Methods Using adenovirus-mediated gene transfer, we overexpressed Best1 and the BVMD mutant Best1W93C in fhRPE cells and assessed resting transepithelial potential (TEP), transepithelial resistance, short circuit current (Isc), and intracellular Ca2+ levels. Cl- currents were directly measured in transfected HEK293 cells using whole-cell patch clamp. Results Best1W93C showed ablated Cl- currents and, when co-expressed, suppressed the channel activity of Best1 in HEK293 cells. In fhRPE, overexpression of Best1 increased TEP and Isc, while Best1W93C diminished TEP and Isc. Substitution of Cl- in the bath media resulted in a significant reduction of Isc in monolayers overexpressing Best1, but no significant Isc change in monolayers expressing Best1W93C. We removed Ca2+ as a limit on transepithelial electrical properties by treating cells with ionomycin, and found that changes in Isc and TEP for monolayers expressing Best1 were absent in monolayers expressing Best1W93C. Similarly, inhibition of calcium-activated anion channels with niflumic acid reduced both Isc and TEP of control and Best1 monolayers, but did not notably affect Best1W93C monolayers. Stimulation with extracellular ATP induced an increase in TEP in control monolayers that was greater than that observed in those expressing Best1W93C. Examination of [Ca2+]i following ATP stimulation demonstrated that the expression of Best1W93C impaired intracellular Ca2+ signaling. Conclusions These data indicate that Best1 activity strongly influences electrophysiology and Ca2+ signaling in RPE cells, and that a common BVMD mutation disrupts both of these parameters. Our findings support the hypothesis that Best1 functions as an anion channel in human RPE. PMID:25878489

Kinnick, Tyson R.; Stanton, J. Brett; Johnson, Adiv A.; Lynch, Ronald M.; Marmorstein, Lihua Y.

2015-01-01

299

A Spectrophotometric Analysis of Pigments in Apples  

Microsoft Academic Search

Methods of pigment extraction using traditional polar organic solvents (acetone or methanol) were compared to those employing a chloroform–methanol mixture. We found that, for spectrophotometric pigment analysis in the apple peel, the cuticular lipids must be preliminarily extracted from the samples with chloroform and MgO must be added during homogenization to prevent pigment degradation. The traditional extraction did not result

A. E. Solovchenko; O. B. Chivkunova; M. N. Merzlyak; I. V. Reshetnikova

2001-01-01

300

Molecular Evolution of Human Visual Pigment Genes  

Microsoft Academic Search

By comparing the published DNA sequences for (a) the genes encoding the human visual color pigments (red, green, and blue) with (b) the genes encoding human, bovine, and Drosophila rhodopsins, a phylogenetic tree for the mammalian pigment genes has been constructed. This evolutionary tree shows that the common ancestor of the visual color pigment genes diverged first from that of

Shozo Yokoyama; Ruth Yokoyama

1989-01-01

301

Swapping one red pigment for another.  

PubMed

Betalains are bright red and yellow pigments, which are produced in only one order of plants, the Caryophyllales, and replace the more familiar anthocyanin pigments. The evolutionary origin of betalain production is a mystery, but a new study has identified the first regulator of betalain production and discovered a previously unknown link between the two pigment pathways. PMID:25547597

Davies, Kevin M

2015-01-01

302

Clinicopathologic correlate of a fresh eyelid pigment implantation  

SciTech Connect

An eyelid with freshly applied black eyeliner pigment was examined histologically. X-ray microanalysis of the pigment suspension from the manufacturer's vial indicated that its composition was 98% iron and 2% titanium. Transmission electron microscopic examination disclosed that particles were in the extracellular matrix; intracellular particles were not seen. By light microscopy, implant material was detected in various levels of the dermis and was found in dermal lymphatics as well as within and surrounding a hair follicle. This study suggests that systemic exposure to the implant material is possible and offers explanations for permanent eyelash loss, which the authors have seen following this procedure.

Tse, D.T.; Folberg, R.; Moore, K.

1985-10-01

303

Primary “Brown Pigment” Bile Duct Stones  

PubMed Central

Bile duct stones from 42 patients were morphologically and chemically analysed. The calculi from 27 patients had important primary bile duct stone (PBDS) features, consisting of a general ovoid shape and fragile structure, with alternating light and dark brown pigmented layers on cross-section. Chemically these stones contained low levels of cholesterol, with high levels of bilirubin and calcium. Subsequent infrared spectroscopy analysis showed that calcium bilirubinate and calcium palmitate were the only calcium salts present. Calcium palmitate was prominent in the light brown layers. A morphological and chemical comparison with gallbladder stones showed that bile duct “stasis stones” were similar in morphological and chemical composition to the brown pigment gallbladder calculi. However, they were distinct from most gallbladder stones, indicating that primary bile duct calculi have an aetiology that is different to 90% of gallbladder calculi. Primary bile duct calculi were observed to occur with or without the presence of a gallbladder, and more interestingly, in the bile duct of two patients with cholesterol gallbladder stones. Bile duct bile of patients with primary choledocholithiasis were always moderately to profusely infected and with abundant calcium bilirubinate precipitation. Moreover, this study has shown that PBDS chemical analyses profiles were consistent and correlated well with their defined morphology. Consequently, PBDS may be accurately identified at the time of operation by morphology. An important aetiological factor would appear to be infection, which would seem to promote bile duct bile stasis and eventual stone growth. PMID:1931789

Sali, Avni; Little, Peter; Nayman, Jack; Elzarka, Ayman

1991-01-01

304

Rapid and Efficient Directed Differentiation of Human Pluripotent Stem Cells Into Retinal Pigmented Epithelium  

PubMed Central

Controlling the differentiation of human pluripotent stem cells is the goal of many laboratories, both to study normal human development and to generate cells for transplantation. One important cell type under investigation is the retinal pigmented epithelium (RPE). Age-related macular degeneration (AMD), the leading cause of blindness in the Western world, is caused by dysfunction and death of the RPE. Currently, RPE derived from human embryonic stem cells are in clinical trials for the treatment of AMD. Although protocols to generate RPE from human pluripotent stem cells have become more efficient since the first report in 2004, they are still time-consuming and relatively inefficient. We have found that the addition of defined factors at specific times leads to conversion of approximately 80% of the cells to an RPE phenotype in only 14 days. This protocol should be useful for rapidly generating RPE for transplantation as well as for studying RPE development in vitro. PMID:23599499

Buchholz, David E.; Pennington, Britney O.; Croze, Roxanne H.; Hinman, Cassidy R.

2013-01-01

305

In vivo Optical Coherence Tomography of Light-Driven Melanosome Translocation in Retinal Pigment Epithelium  

PubMed Central

Optical coherence tomography (OCT) may revolutionize fundamental investigation and clinical management of age-related macular degeneration and other eye diseases. However, quantitative OCT interpretation is hampered due to uncertain sub-cellular correlates of reflectivity in the retinal pigment epithelium (RPE) and photoreceptor. The purpose of this study was twofold: 1) to test OCT correlates in the RPE, and 2) to demonstrate the feasibility of longitudinal OCT monitoring of sub-cellular RPE dynamics. A high resolution OCT was constructed to achieve dynamic imaging of frog eyes, in which light-driven translocation of RPE melanosomes occurred within the RPE cell body and apical processes. Comparative histological examination of dark- and light-adapted eyes indicated that the RPE melanin granule, i.e., melanosome, was a primary OCT correlate. In vivo OCT imaging of RPE melanosomes opens the opportunity for quantitative assessment of RPE abnormalities associated with disease, and enables longitudinal investigation of RPE kinetics correlated with visual function. PMID:24025778

Zhang, Qiu-Xiang; Lu, Rong-Wen; Messinger, Jeffrey D.; Curcio, Christine A.; Guarcello, Vincenzo; Yao, Xin-Cheng

2013-01-01

306

MECHANISMS FOR COUNTERING OXIDATIVE STRESS AND DAMAGE IN RETINAL PIGMENT EPITHELIUM  

PubMed Central

Clinical and experimental evidence supports that chronic oxidative stress is a primary contributing factor to numerous retinal degenerative diseases, such as age-related macular degeneration (AMD). Eyes obtained postmortem from AMD patients have extensive free radical damage to the proteins, lipids, DNA, and mitochondria of their retinal pigment epithelial (RPE) cells. In addition, several mouse models of chronic oxidative stress develop many of the pathological hallmarks of AMD. However, the extent to which oxidative stress is an etiologic component versus its involvement in disease progression remains a major unanswered question. Further, whether the primary target of oxidative stress and damage is photoreceptors or RPE cells, or both, is still unclear. In this review, we discuss the major functions of RPE cells with an emphasis on the oxidative challenges these cells encounter and the endogenous antioxidant mechanisms employed to neutralize the deleterious effects that such stresses can elicit if left unchecked. PMID:22878106

Plafker, Scott M.; O’Mealey, Gary B.; Szweda, Luke I.

2013-01-01

307

The genomic response of the retinal pigment epithelium to light damage and retinal detachment  

PubMed Central

The retinal pigment epithelium (RPE) plays an essential role in maintaining the health of the retina. The RPE is also the site of pathologic processes in a wide variety of retinal disorders including monogenic retinal dystrophies, age-related macular degeneration, and retinal detachment. Despite intense interest in the RPE, little is known about its molecular response to ocular damage or disease. We have conducted a comprehensive analysis of changes in transcript abundance (the “genomic response”) in the murine RPE following light damage. Several dozen transcripts, many related to cell-cell signaling, show significant increases in abundance in response to bright light; transcripts encoding visual cycle proteins show a decrease in abundance. Similar changes are induced by retinal detachment. Environmental and genetic perturbations that modulate the RPE response to bright light suggest that this response is controlled by the retina. In contrast to the response to bright light, the RPE response to retinal detachment over-rides these modulatory affects. PMID:18815272

Rattner, Amir; Toulabi, Leila; Williams, John; Yu, Huimin; Nathans, Jeremy

2008-01-01

308

BACILLUS PYOCYANEUS AND ITS PIGMENTS  

PubMed Central

The principal conclusions that seem to me justified are as follows: 1. The fluorescent pigment formed by some varieties of B. pyocyaneus is produced under conditions identical with those governing the production of the pigment by other "fluorescent bacteria." 2. The production of pyocyanin is not dependent upon the presence of either phosphate or sulfate in the culture medium. It is formed in non-proteid as well as in proteid media, but is not a necessary accompaniment of the metabolic activities of the organism (e. g. tartrate solution). 3. The power of producing pyocyanin under conditions of artificial cultivation is lost sooner than the fluorescigenic power. 4. There are greater natural and acquired differences in pyocyanigenic power than in fluorescigenic. 5. The fluorescent pigment may be oxidized slowly by the action of light and air as well as by reagents into a yellow pigment, and pyocyanin may be similarly oxidized into a black pigment. 6. A convenient separation of B. pyocyaneus into four varieties would be the following: var. ?, pyocyanigenic and fluorescigenic (most common); var. ?, pyocyanigenic only (rare); var. ?, fluorescigenic only (not uncommon, closely related to "B. fluorescens liquefaciens"); var. ?, non-chromogenic. 7. Except for the occasional loss of one or another function the different varieties are not so plastic as sometimes assumed, and cannot be readily converted into one another by subjection to varying conditions of life. 8. The signification and correlation of the almost countless physiological variations among the members of this group in respect to growth in gelatin, behavior to temperature, indol production, etc., remain to be determined. It is not yet clear that the variations in chromogenic power can be in any way correlated with the presence or absence of other physiological functions. PMID:19866929

Jordan, Edwin O.

1899-01-01

309

The Alzheimer's A beta -peptide is deposited at sites of complement activation in pathologic deposits associated with aging and age-related macular degeneration.  

PubMed

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in older individuals worldwide. The disease is characterized by abnormal extracellular deposits, known as drusen, that accumulate along the basal surface of the retinal pigmented epithelium. Although drusen deposition is common in older individuals, large numbers of drusen and/or extensive areas of confluent drusen represent a significant risk factor for AMD. Widespread drusen deposition is associated with retinal pigmented epithelial cell dysfunction and degeneration of the photoreceptor cells of the neural retina. Recent studies have shown that drusen contain a variety of immunomodulatory molecules, suggesting that the process of drusen formation involves local inflammatory events, including activation of the complement cascade. Similar observations in Alzheimer's disease (AD) have lead to the hypothesis that chronic localized inflammation is an important element of AD pathogenesis, with significant neurodegenerative consequences. Accordingly, the amyloid beta (A beta) peptide, a major constituent of neuritic plaques in AD, has been implicated as a primary activator of complement in AD. Here we show that A beta is associated with a substructural vesicular component within drusen. A beta colocalizes with activated complement components in these "amyloid vesicles," thereby identifying them as potential primary sites of complement activation. Thus, A beta deposition could be an important component of the local inflammatory events that contribute to atrophy of the retinal pigmented epithelium, drusen biogenesis, and the pathogenesis of AMD. PMID:12189211

Johnson, Lincoln V; Leitner, William P; Rivest, Alexander J; Staples, Michelle K; Radeke, Monte J; Anderson, Don H

2002-09-01

310

The Alzheimer's A?-peptide is deposited at sites of complement activation in pathologic deposits associated with aging and age-related macular degeneration  

PubMed Central

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in older individuals worldwide. The disease is characterized by abnormal extracellular deposits, known as drusen, that accumulate along the basal surface of the retinal pigmented epithelium. Although drusen deposition is common in older individuals, large numbers of drusen and/or extensive areas of confluent drusen represent a significant risk factor for AMD. Widespread drusen deposition is associated with retinal pigmented epithelial cell dysfunction and degeneration of the photoreceptor cells of the neural retina. Recent studies have shown that drusen contain a variety of immunomodulatory molecules, suggesting that the process of drusen formation involves local inflammatory events, including activation of the complement cascade. Similar observations in Alzheimer's disease (AD) have lead to the hypothesis that chronic localized inflammation is an important element of AD pathogenesis, with significant neurodegenerative consequences. Accordingly, the amyloid beta (A?) peptide, a major constituent of neuritic plaques in AD, has been implicated as a primary activator of complement in AD. Here we show that A? is associated with a substructural vesicular component within drusen. A? colocalizes with activated complement components in these “amyloid vesicles,” thereby identifying them as potential primary sites of complement activation. Thus, A? deposition could be an important component of the local inflammatory events that contribute to atrophy of the retinal pigmented epithelium, drusen biogenesis, and the pathogenesis of AMD. PMID:12189211

Johnson, Lincoln V.; Leitner, William P.; Rivest, Alexander J.; Staples, Michelle K.; Radeke, Monte J.; Anderson, Don H.

2002-01-01

311

Cost-effectiveness of smoking cessation to prevent age-related macular degeneration  

Microsoft Academic Search

BACKGROUND: Tobacco smoking is a risk factor for age-related macular degeneration, but studies of ex-smokers suggest quitting can reduce the risk. METHODS: We fitted a function predicting the decline in risk of macular degeneration after quitting to data from 7 studies involving 1,488 patients. We assessed the cost-effectiveness of smoking cessation in terms of its impact on macular degeneration-related outcomes

Susan F Hurley; Jane P Matthews; Robyn H Guymer

2008-01-01

312

Hydroxytyrosol protects retinal pigment epithelial cells from acrolein-induced oxidative stress and mitochondrial dysfunction.  

PubMed

Hydroxytyrosol (HTS) is a natural polyphenol abundant in olive oil. Increasing evidence indicates HTS has beneficial effect on human health for preventing various diseases. In the present study, we investigated the protective effects of HTS on acrolein-induced toxicity in human retinal pigment epithelial cell line, ARPE-19, a cellular model of smoking- and age-related macular degeneration. Acrolein, a major component of the gas phase cigarette smoke and also a product of lipid peroxidation in vivo, at 75 ?mol/L for 24 h caused significant loss of cell viability, oxidative damage (increase in oxidant generation and oxidative damage to proteins and DNA, decrease in antioxidants and antioxidant enzymes, and also inactivation of the Keap1/Nrf2 pathway), and mitochondrial dysfunction (decrease in membrane potential, activities of mitochondrial complexes, viable mitochondria, oxygen consumption, and factors for mitochondrial biogenesis, and increase in calcium). Pre-treatment with HTS dose dependently and also time dependently protected the ARPE-19 cells from acrolein-induced oxidative damage and mitochondrial dysfunction. A short-term pre-treatment with HTS (48 h) required > 75 ?mol/L for showing protection while a long-term pre-treatment (7 days) showed protective effect from 5 ?mol/L on. The protective effect of HTS in this model was as potent as that of established mitochondria-targeting antioxidant nutrients. These results suggest that HTS is also a mitochondrial-targeting antioxidant nutrient and that dietary administration of HTS may be an effective measure in reducing and or preventing cigarette smoke-induced or age-related retinal pigment epithelial degeneration, such as age-associated macular degeneration. PMID:20938484

Liu, Zhongbo; Sun, Lijuan; Zhu, Lu; Jia, Xu; Li, Xuesen; Jia, Haiqun; Wang, Ying; Weber, Peter; Long, Jiangang; Liu, Jiankang

2007-12-01

313

Congenital X-linked ataxia, progressive myoclonic encephalopathy, macular degeneration and recurrent infections.  

PubMed

We report on 2 boys (maternal cousins), with severe congenital ataxia with generalized hypotonia, psychomotor retardation and recurrent bronchopulmonary infections. Later, they developed myoclonic encephalopathy and macular degeneration. Serial brain imaging investigations showed a cyst of the septum pellucidum, persistence of the cavum vergae, corpus callosum and cerebellar vermis hypoplasia without cortical atrophy. In the maternal pedigree, 5 males had recurrent bronchopneumonia associated with severe congenital hypotonia and died during the first years of life. Neurophysiological studies, including nerve conduction velocities, brainstem auditory evoked responses, somatosensory evoked potentials were normal. Electroretinogram showed normal wave morphology. Visual evoked potentials were mildly impaired. Extensive screening for metabolic disease gave normal results. Immunologic investigations showed normal T and B cell number, T cell function and immunoglobulin levels in both patients with a reduced level of IgG2 subclass in one. PMID:1605224

Bertini, E; Cusmai, R; de Saint Basile, G; Le Deist, F; Di Capua, M; Gaggero, D R; Dionisi-Vici, C; Santillo, C; Caniglia, M

314

Photodynamic Therapy and Intravitreal Bevacizumab with Versus without Triamcinolone for Neovascular Age-related Macular Degeneration; a Randomized Clinical Trial  

PubMed Central

Purpose: To compare the outcomes of photodynamic therapy (PDT) combined with intravitreal bevacizumab (IVB) with versus without intravitreal triamcinolone (IVT) in neovascular age-related macular degeneration (AMD). Methods: Eighty-four eyes with active CNV secondary to AMD with no prior treatment were enrolled and followed for 1-year. Eligible eyes were randomly assigned to either PDT/IVB or PDT/IVB/IVT. The main outcome measure was change in best-corrected visual acuity (BCVA). Results: Mean patient age was 71 ± 9 years. BCVA changes from baseline were statistically significant in both study arms at all follow-up intervals, however no significant difference was observed between the two groups regarding BCVA changes at week 12 (95% CI:-0.11–0.12 LogMAR) and other time points (all P > 0.6). Mixed model analysis revealed a significant effect from age (P < 0.001), pigment epithelial detachment (P = 0.009) and baseline BCVA (P < 0.001) on visual improvement. Significant central macular thickness (CMT) reduction occurred at all-time points as compared to baseline in both groups which was comparable between the study arms. There was no significant difference between the study arms in terms of retreatment rate (P = 0.1) and survival to the first repeat IVB injection (P = 0.065). Conclusion: Additional low-dose IVT to a PDT/IVB regimen for neovascular AMD provided no beneficial effects in terms BCVA or CMT, yet demonstrated a trend toward extending the injection-free period. PMID:25709773

Piri, Niloofar; Ahmadieh, Hamid; Taei, Ramin; Soheilian, Masoud; Karkhaneh, Reza; Lashay, Alireza; Golbafian, Faegheh; Yaseri, Mehdi; Riazi-Esfahani, Mohammad

2014-01-01

315

An Experimental Model for Exudative Age-related Macular Degeneration with Choroidal Neovascularization Using the Common Marmoset.  

PubMed

This study aimed to establish an experimental exudative age-related macular degeneration (AMD) model in the common marmoset (Callithrix jacchus), which is a small New World monkey. Choroidal neovascularization (CNV) was induced by laser irradiation on the left eye of each animal under anesthesia. Eight laser spots were applied around the macular area using the image-guided laser system (532 nm) attached with Micron III at 650 mW-2,000 mW power. Laser pulse duration and spot size were fixed at 100 ms and 50 µm, respectively. At 14 days after laser irradiation, fluorescein angiograms were observed. At 21 days after laser irradiation, the fluorescein angiograms were transcardially perfused to the bilateral common carotid arteries with 4% paraformaldehyde for the transverse section or with fluorescein-conjugated dextran (MW = 2,000 kDa) for the retinal pigment epithelia (RPE)-choroidal flatmount. At 14 days after laser irradiation, late hyperfluorescence and leakage within or beyond the lesion borders were observed in a laser power-dependent manner. In the RPE-choroidal flatmount, the mean size of the CNV lesions at 1,500 mW was 1.34 ± 0.49 × 10(5) µm(2) (Mean ± S.D., n = 29), and the coefficient of variation for each CNV area was 36.5% (n = 29). In conclusion, we succeeded in producing an experimental exudative type of AMD model in the common marmoset. This model may be useful in elucidating the pathophysiological mechanism and screening of new candidates for exudative AMD. PMID:25760220

Shimazawa, Masamitsu; Masuda, Tomomi; Nakamura, Shinsuke; Miwa, Miki; Nakamura, Katsuki; Hara, Hideaki

2015-01-01

316

Evaluation of serum lipid concentrations and genetic variants at high-density lipoprotein metabolism loci and TIMP3 in age-related macular degeneration  

Microsoft Academic Search

PURPOSE: To analyze the association between polymorphisms in the TIMP3 gene and genes of the high-density lipoprotein (HDL) metabolism and age-related macular degeneration (AMD), and evaluate serum lipid and lipoprotein levels in AMD patients compared with control individuals. METHODS: Single nucleotide polymorphisms in or near the TIMP3, ABCA1, FADS1-3, CETP, LIPC, and LPL genes were genotyped. Serum levels of apolipoprotein

S. Fauser; D. Smailhodzic; A. Caramoy; J. P. van de Ven; B. Kirchhof; C. B. Hoyng; B. J. Klevering; S. Liakopoulos; A. I. den Hollander

2011-01-01

317

Therapy of Nonexudative Age-Related Macular Degeneration  

Microsoft Academic Search

\\u000a Age related macular degeneration (AMD) is the leading cause of blindness among adults over the age of 65 in the Western world.\\u000a The prevalence of AMD is expected to increase dramatically, from 1.75 million in 2000 to 2.95 million in 2020, due to the\\u000a rapidly aging population. Given the large and now increasing burden of disease, the identification of modifiable

Annal D. Meleth; Veena R. Raiji; Nupura Krishnadev; Emily Y. Chew

318

Multifocal electroretinography in patients with Stargardt’s macular dystrophy  

Microsoft Academic Search

AIMSTo describe the topography of multifocal electroretinograms (ERGs) and to explore its diagnostic value in patients with Stargardt’s macular dystrophy (SMD).METHODS51 patients with SMD were examined by means of the m-sequence technique to characterise the topography of electroretinographic responses in the central visual field. The results were compared with data from 30 normal volunteers.RESULTSIn 49 of 51 patients with SMD,

U Kretschmann; M W Seeliger; K Ruether; T Usui; E Apfelstedt-Sylla; E Zrenner

1998-01-01

319

Predicting cataract surgery results using a macular function test  

Microsoft Academic Search

Purpose: To assess the predictive value of a macular function test in the preoperative evaluation of cataract patients.Setting: Clinique Générale St-Jean, Brussels, Belgium.Methods: This prospective study comprised 396 uneventful consecutive cataract procedures performed by 1 surgeon from September 2000 to February 2001. The best corrected visual acuity (BCVA) and the density and location of the lens opacities were recorded preoperatively.

Jérôme C. Vryghem; Hugo Van Cleynenbreugel; Joachim Van Calster; Kathleen Leroux

2004-01-01

320

Smoking and age-related macular degeneration: review and update.  

PubMed

Age-related macular degeneration (AMD) is one of the main socioeconomical health issues worldwide. AMD has a multifactorial etiology with a variety of risk factors. Smoking is the most important modifiable risk factor for AMD development and progression. The present review summarizes the epidemiological studies evaluating the association between smoking and AMD, the mechanisms through which smoking induces damage to the chorioretinal tissues, and the relevance of advising patients to quit smoking for their visual health. PMID:24368940

Velilla, Sara; García-Medina, José Javier; García-Layana, Alfredo; Dolz-Marco, Rosa; Pons-Vázquez, Sheila; Pinazo-Durán, M Dolores; Gómez-Ulla, Francisco; Arévalo, J Fernando; Díaz-Llopis, Manuel; Gallego-Pinazo, Roberto

2013-01-01

321

Smoking and Age-Related Macular Degeneration: Review and Update  

PubMed Central

Age-related macular degeneration (AMD) is one of the main socioeconomical health issues worldwide. AMD has a multifactorial etiology with a variety of risk factors. Smoking is the most important modifiable risk factor for AMD development and progression. The present review summarizes the epidemiological studies evaluating the association between smoking and AMD, the mechanisms through which smoking induces damage to the chorioretinal tissues, and the relevance of advising patients to quit smoking for their visual health. PMID:24368940

Velilla, Sara; García-Medina, José Javier; García-Layana, Alfredo; Pons-Vázquez, Sheila; Pinazo-Durán, M. Dolores; Gómez-Ulla, Francisco; Arévalo, J. Fernando; Díaz-Llopis, Manuel; Gallego-Pinazo, Roberto

2013-01-01

322

Mutations in IMPG1 Cause Vitelliform Macular Dystrophies  

PubMed Central

Vitelliform macular dystrophies (VMD) are inherited retinal dystrophies characterized by yellow, round deposits visible upon fundus examination and encountered in individuals with juvenile Best macular dystrophy (BMD) or adult-onset vitelliform macular dystrophy (AVMD). Although many BMD and some AVMD cases harbor mutations in BEST1 or PRPH2, the underlying genetic cause remains unknown for many affected individuals. In a large family with autosomal-dominant VMD, gene mapping and whole-exome sequencing led to the identification of a c.713T>G (p.Leu238Arg) IMPG1 mutation, which was subsequently found in two other families with autosomal-dominant VMD and the same phenotype. IMPG1 encodes the SPACR protein, a component of the rod and cone photoreceptor extracellular matrix domains. Structural modeling indicates that the p.Leu238Arg substitution destabilizes the conserved SEA1 domain of SPACR. Screening of 144 probands who had various forms of macular dystrophy revealed three other IMPG1 mutations. Two individuals from one family affected by autosomal-recessive VMD were homozygous for the splice-site mutation c.807+1G>T, and two from another family were compound heterozygous for the mutations c.461T>C (p.Leu154Pro) and c.1519C>T (p.Arg507?). Most cases had a normal or moderately decreased electrooculogram Arden ratio. We conclude that IMPG1 mutations cause both autosomal-dominant and -recessive forms of VMD, thus indicating that impairment of the interphotoreceptor matrix might be a general cause of VMD. PMID:23993198

Manes, Gaël; Meunier, Isabelle; Avila-Fernández, Almudena; Banfi, Sandro; Le Meur, Guylčne; Zanlonghi, Xavier; Corton, Marta; Simonelli, Francesca; Brabet, Philippe; Labesse, Gilles; Audo, Isabelle; Mohand-Said, Saddek; Zeitz, Christina; Sahel, José-Alain; Weber, Michel; Dollfus, Hélčne; Dhaenens, Claire-Marie; Allorge, Delphine; De Baere, Elfride; Koenekoop, Robert K.; Kohl, Susanne; Cremers, Frans P.M.; Hollyfield, Joe G.; Sénéchal, Audrey; Hebrard, Maxime; Bocquet, Béatrice; Ayuso García, Carmen; Hamel, Christian P.

2013-01-01

323

Mutations in IMPG1 cause vitelliform macular dystrophies.  

PubMed

Vitelliform macular dystrophies (VMD) are inherited retinal dystrophies characterized by yellow, round deposits visible upon fundus examination and encountered in individuals with juvenile Best macular dystrophy (BMD) or adult-onset vitelliform macular dystrophy (AVMD). Although many BMD and some AVMD cases harbor mutations in BEST1 or PRPH2, the underlying genetic cause remains unknown for many affected individuals. In a large family with autosomal-dominant VMD, gene mapping and whole-exome sequencing led to the identification of a c.713T>G (p.Leu238Arg) IMPG1 mutation, which was subsequently found in two other families with autosomal-dominant VMD and the same phenotype. IMPG1 encodes the SPACR protein, a component of the rod and cone photoreceptor extracellular matrix domains. Structural modeling indicates that the p.Leu238Arg substitution destabilizes the conserved SEA1 domain of SPACR. Screening of 144 probands who had various forms of macular dystrophy revealed three other IMPG1 mutations. Two individuals from one family affected by autosomal-recessive VMD were homozygous for the splice-site mutation c.807+1G>T, and two from another family were compound heterozygous for the mutations c.461T>C (p.Leu154Pro) and c.1519C>T (p.Arg507(?)). Most cases had a normal or moderately decreased electrooculogram Arden ratio. We conclude that IMPG1 mutations cause both autosomal-dominant and -recessive forms of VMD, thus indicating that impairment of the interphotoreceptor matrix might be a general cause of VMD. PMID:23993198

Manes, Gaël; Meunier, Isabelle; Avila-Fernández, Almudena; Banfi, Sandro; Le Meur, Guylčne; Zanlonghi, Xavier; Corton, Marta; Simonelli, Francesca; Brabet, Philippe; Labesse, Gilles; Audo, Isabelle; Mohand-Said, Saddek; Zeitz, Christina; Sahel, José-Alain; Weber, Michel; Dollfus, Hélčne; Dhaenens, Claire-Marie; Allorge, Delphine; De Baere, Elfride; Koenekoop, Robert K; Kohl, Susanne; Cremers, Frans P M; Hollyfield, Joe G; Sénéchal, Audrey; Hebrard, Maxime; Bocquet, Béatrice; Ayuso García, Carmen; Hamel, Christian P

2013-09-01

324

Proteomic analysis of vitreous from diabetic macular edema  

Microsoft Academic Search

To identify and analyze diabetic macular edema (DME)-related proteins in the vitreous, en masse, using two-dimensional gel (2D gel) electrophoresis and mass-spectrometry (MS). Vitreous samples were corrected from 20 eyes with pre-proliferative diabetic retinopathy associated with DME (DME group) and without DME (non-DME group). They were subjected to 2D gel electrophoresis, and the spot intensities were compared between the groups.

Masayuki Ouchi; Karen West; John W. Crabb; Shigeru Kinoshita; Motohiro Kamei

2005-01-01

325

Intravitreal bevacizumab for type 1 idiopathic macular telangiectasia  

Microsoft Academic Search

PurposeTo evaluate the effect of intravitreal bevacizumab injection for treating type 1 idiopathic macular telangiectasia (IMT).MethodsRetrospective case series of five eyes of five male patients with type 1 IMT that were treated with 2–3 injections of intravitreal bevacizumab. Best-corrected visual acuity, foveal thickness obtained by optical coherence tomography, and fluorescein angiography (FA) were monitored over a period of up to

K Takayama; S Ooto; H Tamura; K Yamashiro; A Otani; A Tsujikawa; N Yoshimura

2010-01-01

326

Metamorphopsia in patients with macular telangiectasia type 2  

Microsoft Academic Search

Purpose To assess metamorphopsia in patients with macular telangiectasia (MacTel) type 2. Methods In a prospective observational cohort study, 40 eyes of 20 patients with MacTel type 2 were investigated by funduscopy, fluorescein\\u000a angiography, optical coherence tomography and microperimetry. Metamorphopsia was assessed using Amsler grids following a standard\\u000a protocol and standardized questionnaire. Results Metamorphopsia was present in 30 (83%) out

Peter Charbel Issa; Frank G. Holz; Hendrik P. N. Scholl

2009-01-01

327

Multifocal electroretinography in patients with Stargardt's macular dystrophy  

PubMed Central

AIMS—To describe the topography of multifocal electroretinograms (ERGs) and to explore its diagnostic value in patients with Stargardt's macular dystrophy (SMD).?METHODS—51 patients with SMD were examined by means of the m-sequence technique to characterise the topography of electroretinographic responses in the central visual field. The results were compared with data from 30 normal volunteers.?RESULTS—In 49 of 51 patients with SMD, macular electroretinographic activity was markedly diminished or non-detectable. Towards more peripheral areas, ERG responses of the SMD patients approached those of normals. Implicit times were not markedly delayed at any eccentricity.?CONCLUSION—In contrast with Ganzfeld electroretinography, multifocal electroretinography is useful to detect foveal dysfunction in SMD. Areas of dysfunction were found to be usually larger than expected from psychophysical measurements and morphological alteration. In early stages of the disease it was possible to detect foveal dysfunction, even in patients lacking morphological fundus changes and with good visual acuity.?? Keywords: Stargardt's macular dystrophy; fundus flavimaculatus; electroretinography PMID:9602623

Kretschmann, U; Seeliger, M; Ruether, K; Usui, T; Apfelstedt-Sylla, E; Zrenner, E

1998-01-01

328

ZIP2 and ZIP4 Mediate Age-Related Zinc Fluxes Across the Retinal Pigment Epithelium  

Microsoft Academic Search

Decreases in systemic and cellular levels of zinc (Zn2+) during normal aging correlate with several age-related pathologies including age-related macular degeneration. Zn2+ homeostasis in tissues is not only dependent on dietary intake but also on optimal expression and function of its influx\\u000a (ZIP) and efflux (ZnT) transporters. We recently showed that many of the Zn2+ transporters are expressed by the

Kar Wah Leung; Anzor Gvritishvili; Yanling Liu; Joyce Tombran-Tink

329

Holographic films from carotenoid pigments  

NASA Astrophysics Data System (ADS)

Carotenoids pigments presents in pineapple can be more than just natural dyes, which is one of the applications that now at day gives the chemical industry. In this research shown that can be used in implementing of holographic recording Films. Therefore we describe the technique how to obtain this kind of pigments trough spay drying of natural pineapple juice, which are then dissolved with water in a proportion of 0.1g to 1mL. The obtained sample is poured into glass substrates using the gravity method, after a drying of 24 hours in laboratory normal conditions the films are ready. The films are characterized by recording transmission holographic gratings (LSR 445 NL 445 nm) and measuring the diffraction efficiency holographic parameter. This recording material has good diffraction efficiency and environmental stability.

Toxqui-López, S.; Lecona-Sánchez, J. F.; Santacruz-Vázquez, C.; Olivares-Pérez, A.; Fuentes-Tapia, I.

2014-02-01

330

Pigmented paravenous retinochoroidal atrophy (Review)  

PubMed Central

Pigmented paravenous retinochoroidal atrophy (PPRCA) is an uncommon disease characterized by perivenous aggregations of pigment clumps associated with peripapillary and radial zones of retinochoroidal atrophy that are distributed along the retinal veins. Patients are usually asymptomatic and the disease process is non-progressive or slow and subtly progressive. It is commonly bilateral and symmetric. The cause of the condition may be unknown or idiopathic, although a dysgenetic, degenerative, hereditary etiology or even an inflammatory cause has been hypothesized. A non-inflammatory cause is referred to as primary, while inflammation-associated PPRCA is referred to as secondary or pseudo PPRCA. The present study reviewed and summarized the features of PPRCA. PMID:24926324

HUANG, HOU-BIN; ZHANG, YI-XIN

2014-01-01

331

Development of gene therapy for treatment of age-related macular degeneration.  

PubMed

Intraocular neovascular diseases are the leading cause of blindness in the Western world in individuals over the age of 50. Age-related macular degeneration (AMD) is one of these diseases. Exudative AMD, the late-stage form, is characterized by abnormal neovessel development, sprouting from the choroid into the avascular subretinal space, where it can suddenly cause irreversible damage to the vulnerable photoreceptor (PR) cells essential for our high-resolution, central vision. The molecular basis of AMD is not well understood, but several growth factors have been implicated including vascular endothelial growth factor (VEGF), and the advent of anti-VEGF therapy has markedly changed the outcome of treatment. However, common to all current therapies for exudative AMD are the complications of repeated monthly intravitreal injections, which must be continued throughout one's lifetime to maintain visual benefits. Additionally, some patients do not benefit from established treatments. Strategies providing long-term suppression of inappropriate ocular angiogenesis are therefore needed, and gene therapy offers a potential powerful technique. This study aimed to develop a strategy based on RNA interference (RNAi) for the sustained attenuation of VEGF. We designed a panel of anti-VEGF short hairpin RNAs (shRNA), and based on the most potent shRNAs, microRNA (miRNA)-mimicked hairpins were developed. We demonstrated an additive VEGF silencing effect when we combined the miRNAs in a tricistronic miRNA cluster. To meet the requirements for development of medical treatments for AMD with long-term effects, the shRNA/miRNA is expressed from vectors based on adeno-associated virus (AAV) or lentivirus (LV). Both vector systems have been found superior in terms of transduction efficiency and persistence in gene expression in retinal cells. The capacity of AAV-encoded RNAi effector molecules to silence endogenous VEGF gene expression was evaluated in mouse models, including the model of laser-induced choroidal neovascularization (CNV), and we found that subretinal administration of self-complementary (sc)-AAV2/8 encoding anti-VEGF shRNAs can impair vessel formation. In parallel, a significant reduction of endogenous VEGF was demonstrated following injection of scAAV2/8 vectors expressing multiple anti-VEGF miRNAs into murine hind limb muscles. Furthermore, in an ongoing project we have designed versatile, multigenic LV vectors with combined expression of multiple miRNAs and proteins, including pigment epithelium-derived factor (PEDF), a multifunctional, secreted protein that has anti-angiogenic and neurotrophic functions. Co-expression of miRNAs and proteins from a single viral vector increases safety by minimizing the viral load necessary to obtain a therapeutic effect and thereby reduces the risk of insertional mutagenesis as well as the immune response against viral proteins. Our results show co-expression of functional anti-VEGF-miRNAs and PEDF in cell studies, and in vivo studies reveal an efficient retinal pigment epithelium (RPE)-specific gene expression following the incorporation of the vitelliform macular dystrophy 2 (VMD2) promoter, demonstrating the potential applicability of our multigenic LV vectors in ocular anti-VEGF gene therapy, including combination therapy for treatment of exudative AMD. In conclusion, these highly promising data clearly demonstrate that viral-encoded RNAi effector molecules can be used for the inhibition of neovascularization and will, in combination with the growing interest of applying DNA- or RNA-based technologies in the clinic, undoubtedly contribute to the development of efficacious long-term gene therapy treatment of intraocular neovascular diseases. PMID:24953666

Askou, Anne Louise

2014-07-01

332

Fully automated detection of diabetic macular edema and dry age-related macular degeneration from optical coherence tomography images  

PubMed Central

We present a novel fully automated algorithm for the detection of retinal diseases via optical coherence tomography (OCT) imaging. Our algorithm utilizes multiscale histograms of oriented gradient descriptors as feature vectors of a support vector machine based classifier. The spectral domain OCT data sets used for cross-validation consisted of volumetric scans acquired from 45 subjects: 15 normal subjects, 15 patients with dry age-related macular degeneration (AMD), and 15 patients with diabetic macular edema (DME). Our classifier correctly identified 100% of cases with AMD, 100% cases with DME, and 86.67% cases of normal subjects. This algorithm is a potentially impactful tool for the remote diagnosis of ophthalmic diseases. PMID:25360373

Srinivasan, Pratul P.; Kim, Leo A.; Mettu, Priyatham S.; Cousins, Scott W.; Comer, Grant M.; Izatt, Joseph A.; Farsiu, Sina

2014-01-01

333

Decision support system for age-related macular degeneration using discrete wavelet transform.  

PubMed

Age-related macular degeneration (AMD) affects the central vision and subsequently may lead to visual loss in people over 60 years of age. There is no permanent cure for AMD, but early detection and successive treatment may improve the visual acuity. AMD is mainly classified into dry and wet type; however, dry AMD is more common in aging population. AMD is characterized by drusen, yellow pigmentation, and neovascularization. These lesions are examined through visual inspection of retinal fundus images by ophthalmologists. It is laborious, time-consuming, and resource-intensive. Hence, in this study, we have proposed an automated AMD detection system using discrete wavelet transform (DWT) and feature ranking strategies. The first four-order statistical moments (mean, variance, skewness, and kurtosis), energy, entropy, and Gini index-based features are extracted from DWT coefficients. We have used five (t test, Kullback-Lieber Divergence (KLD), Chernoff Bound and Bhattacharyya Distance, receiver operating characteristics curve-based, and Wilcoxon) feature ranking strategies to identify optimal feature set. A set of supervised classifiers namely support vector machine (SVM), decision tree, [Formula: see text]-nearest neighbor ([Formula: see text]-NN), Naive Bayes, and probabilistic neural network were used to evaluate the highest performance measure using minimum number of features in classifying normal and dry AMD classes. The proposed framework obtained an average accuracy of 93.70%, sensitivity of 91.11%, and specificity of 96.30% using KLD ranking and SVM classifier. We have also formulated an AMD Risk Index using selected features to classify the normal and dry AMD classes using one number. The proposed system can be used to assist the clinicians and also for mass AMD screening programs. PMID:25112273

Mookiah, Muthu Rama Krishnan; Acharya, U Rajendra; Koh, Joel E W; Chua, Chua Kuang; Tan, Jen Hong; Chandran, Vinod; Lim, Choo Min; Noronha, Kevin; Laude, Augustinus; Tong, Louis

2014-09-01

334

Quantification of External Limiting Membrane Disruption Caused by Diabetic Macular Edema from SD-OCT  

PubMed Central

Purpose. Disruption of external limiting membrane (ELM) integrity on spectral-domain optical coherence tomography (SD-OCT) is associated with lower visual acuity outcomes in patients suffering from diabetic macular edema (DME). However, no automated methods to detect ELM and/or determine its integrity from SD-OCT exist. Methods. Sixteen subjects diagnosed with clinically significant DME (CSME) were included and underwent macula-centered SD-OCT (512 × 19 × 496 voxels). Sixteen subjects without retinal thickening and normal acuity were also scanned (200 × 200 × 1024 voxels). Automated quantification of ELM disruption was achieved as follows. First, 11 surfaces were automatically segmented using our standard 3-D graph-search approach, and the subvolume between surface 6 and 11 containing the ELM region was flattened based on the segmented retinal pigment epithelium (RPE) layer. A second, edge-based graph-search surface-detection method segmented the ELM region in close proximity “above” the RPE, and each ELM A-scan was classified as disrupted or nondisrupted based on six texture features in the vicinity of the ELM surface. The vessel silhouettes were considered in the disruption classification process to avoid false detections of ELM disruption. Results. In subjects with CSME, large areas of disrupted ELM were present. In normal subjects, ELM was largely intact. The mean and 95% confidence interval (CI) of the detected disruption area volume for normal and CSME subjects were meannormal = 0.00087 mm3 and CInormal = (0.00074, 0.00100), and meanCSME = 0.00461 mm3 and CICSME = (0.00347, 0.00576) mm3, respectively. Conclusions. In this preliminary study, we were able to show that automated quantification of ELM disruption is feasible and can differentiate continuous ELM in normal subjects from disrupted ELM in subjects with CSME. We have started determining the relationships of quantitative ELM disruption markers to visual outcome in patients undergoing treatment for CSME. PMID:23111607

Chen, Xinjian; Zhang, Li; Sohn, Elliott H.; Lee, Kyungmoo; Niemeijer, Meindert; Chen, John; Sonka, Milan; Abrŕmoff, Michael D.

2012-01-01

335

Insights into the mechanisms of macular degeneration associated with the R172W mutation in RDS.  

PubMed

Mutations in the photoreceptor tetraspanin gene peripherin-2/retinal degeneration slow (PRPH2/RDS) cause both rod- and cone-dominant diseases. While rod-dominant diseases, such as autosomal dominant retinitis pigmentosa, are thought to arise due to haploinsufficiency caused by loss-of-function mutations, the mechanisms underlying PRPH2-associated cone-dominant diseases are unclear. Here we took advantage of a transgenic mouse line expressing an RDS mutant (R172W) known to cause macular degeneration (MD) in humans. To facilitate the study of cones in the heavily rod-dominant mouse retina, R172W mice were bred onto an Nrl(-/-) background (in which developing rods adopt a cone-like fate). In this model the R172W protein and the key RDS-binding partner, rod outer segment (OS) membrane protein 1 (ROM-1), were properly expressed and trafficked to cone OSs. However, the expression of R172W led to dominant defects in cone structure and function with equal effects on S- and M-cones. Furthermore, the expression of R172W in cones induced subtle alterations in RDS/ROM-1 complex assembly, specifically resulting in the formation of abnormal, large molecular weight ROM-1 complexes. Fundus imaging demonstrated that R172W mice developed severe clinical signs of disease nearly identical to those seen in human MD patients, including retinal degeneration, retinal pigment epithlium (RPE) defects and loss of the choriocapillaris. Collectively, these data identify a primary disease-causing molecular defect in cone cells and suggest that RDS-associated disease in patients may be a result of this defect coupled with secondary sequellae involving RPE and choriocapillaris cell loss. PMID:24463884

Conley, Shannon M; Stuck, Michael W; Burnett, Justin L; Chakraborty, Dibyendu; Azadi, Seifollah; Fliesler, Steven J; Naash, Muna I

2014-06-15

336

Strategy for the Management of Macular Edema in Retinal Vein Occlusion: The European VitreoRetinal Society Macular Edema Study  

PubMed Central

Objective. To compare the efficacy of different therapies in the treatment of macular edema associated with retinal vein occlusion (RVO). Design. This is a nonrandomized, multicenter collaborative study. Participants. 86 retina specialists from 29 countries provided clinical information, including choice of treatment and outcome, on 2,603 patients with macular edema including 738 cases of RVO. Methods. Reported data included the type and number of treatments performed, visual acuities, and other clinical and diagnostic findings. Main Outcome Measures. The mean increase in visual acuity and mean number of treatments performed. Results. 358 cases of central retinal vein occlusion (CRVO) and 380 cases of branch retinal vein occlusion (BRVO) were included in this investigation. Taking all RVO cases together, pars plana vitrectomy with internal limiting membrane (ILM) peeling alone resulted in an improvement in vision greater than other therapies. Those treated with intravitreal antivascular endothelial growth factor (anti-VEGF) injection alone showed the second greatest improvement in vision. Dexamethasone intravitreal implant alone and intravitreal triamcinolone alone both resulted in modest visual gains. Conclusions. In the treatment of macular edema in RVO, vitrectomy with ILM peeling may achieve visual improvement and may be a good option for certain cases. Anti-VEGF injection is the most effective of the nonsurgical treatments. PMID:25705695

Adelman, Ron A.; Parnes, Aaron J.; Bopp, Silvia; Saad Othman, Ihab; Ducournau, Didier

2015-01-01

337

Strategy for the Management of Macular Edema in Retinal Vein Occlusion: The European VitreoRetinal Society Macular Edema Study.  

PubMed

Objective. To compare the efficacy of different therapies in the treatment of macular edema associated with retinal vein occlusion (RVO). Design. This is a nonrandomized, multicenter collaborative study. Participants. 86 retina specialists from 29 countries provided clinical information, including choice of treatment and outcome, on 2,603 patients with macular edema including 738 cases of RVO. Methods. Reported data included the type and number of treatments performed, visual acuities, and other clinical and diagnostic findings. Main Outcome Measures. The mean increase in visual acuity and mean number of treatments performed. Results. 358 cases of central retinal vein occlusion (CRVO) and 380 cases of branch retinal vein occlusion (BRVO) were included in this investigation. Taking all RVO cases together, pars plana vitrectomy with internal limiting membrane (ILM) peeling alone resulted in an improvement in vision greater than other therapies. Those treated with intravitreal antivascular endothelial growth factor (anti-VEGF) injection alone showed the second greatest improvement in vision. Dexamethasone intravitreal implant alone and intravitreal triamcinolone alone both resulted in modest visual gains. Conclusions. In the treatment of macular edema in RVO, vitrectomy with ILM peeling may achieve visual improvement and may be a good option for certain cases. Anti-VEGF injection is the most effective of the nonsurgical treatments. PMID:25705695

Adelman, Ron A; Parnes, Aaron J; Bopp, Silvia; Saad Othman, Ihab; Ducournau, Didier

2015-01-01

338

Risk Factors for Four-Year Incidence and Progression of Age-Related Macular Degeneration: The Los Angeles Latino Eye Study  

PubMed Central

PURPOSE To identify risk factors for 4-year incidence and progression of age-related macular degeneration (AMD) in adult Latinos. DESIGN Population-based prospective cohort study. METHODS Participants, aged 40 or older, from The Los Angeles Latino Eye Study (LALES) underwent standardized comprehensive ophthalmologic examinations at baseline and at 4 years of follow-up. Age-related macular degeneration was detected by grading 30-degree stereoscopic fundus photographs using the modified Wisconsin Age-Related Maculopathy Grading System. Multivariate stepwise logistic regression was used to examine the independent association of incidence and progression of AMD and baseline sociodemographic, behavioral, clinical, and ocular characteristics. RESULTS Multivariate analyses revealed that older age (OR per decade of age: 1.52; 95% CI: 1.29, 1.85) and higher pulse pressure (OR per 10 mm Hg: 2.54; 95% CI: 1.36, 4.76) were independently associated with the incidence of any AMD. The same factors were associated with early AMD, soft indistinct drusen, and retinal pigmentary abnormalities. Additionally, presence of clinically diagnosed diabetes mellitus was independently associated with increased retinal pigment (OR: 1.66; 95% CI: 1.01, 2.85), and male gender was associated with retinal pigment epithelial depigmentation (OR 2.50; 95% CI: 1.48, 4.23). Older age (OR per decade of age: 2.20; 95% CI: 1.82, 2.67) and current smoking (OR: 2.85; 95% CI: 1.66, 4.90) were independently associated with progression of AMD. CONCLUSIONS Several modifiable risk factors were associated with 4-year incidence and progression of AMD in Latinos. The results suggest that interventions aimed at reducing pulse pressure and promoting smoking cessation may reduce incidence and progression of AMD, respectively. PMID:21679916

CHOUDHURY, FARZANA; VARMA, ROHIT; MCKEAN-COWDIN, ROBERTA; KLEIN, RONALD; AZEN, STANLEY P.

2011-01-01

339

Disease susceptibility of the human macula: differential gene transcription in the retinal pigmented epithelium/choroid.  

PubMed

The discoveries of gene variants associated with macular diseases have provided valuable insight into their molecular mechanisms, but they have not clarified why the macula is particularly vulnerable to degenerative disease. Its predisposition may be attributable to specialized structural features and/or functional properties of the underlying macular RPE/choroid. To examine the molecular basis for the macula's disease susceptibility, we compared the gene expression profile of the human RPE/choroid in the macula with the profile in the extramacular region using DNA microarrays. Seventy-five candidate genes with differences in macular:extramacular expression levels were identified by microarray analysis, of which 29 were selected for further analysis. Quantitative PCR confirmed that 21 showed statistically significant differences in expression. Five genes were expressed at higher levels in the macula. Two showed significant changes in the macular:extramacular expression ratio; another two exhibited changes in absolute expression level, as a function of age or AMD. Several of the differentially expressed genes have potential relevance to AMD pathobiology. One is an RPE cell growth factor (TFPI2), five are extracellular matrix components (DCN, MYOC, OGN, SMOC2, TFPI2), and six are related to inflammation (CCL19, CCL26, CXCL14, SLIT2) and/or angiogenesis (CXCL14, SLIT2, TFPI2, WFDC1). The identification of regional differences in gene expression in the RPE/choroid is a first step in clarifying the macula's propensity for degeneration. These findings lay the groundwork for further studies into the roles of the corresponding gene products in the normal, aged, and diseased macula. PMID:17662275

Radeke, Monte J; Peterson, Katie E; Johnson, Lincoln V; Anderson, Don H

2007-09-01

340

Polarized human embryonic stem cell-derived retinal pigment epithelial cell monolayers have higher resistance to oxidative stress-induced cell death than nonpolarized cultures.  

PubMed

Oxidative stress-mediated injury to the retinal pigment epithelium (RPE) is a major factor involved in the pathogenesis of age-related macular degeneration (AMD), the leading cause of blindness in the elderly. Human embryonic stem cell (hESC)-derived RPE cells are currently being evaluated for their potential for cell therapy in AMD patients through subretinal injection of cells in suspension and subretinal placement as a polarized monolayer. To gain an understanding of how transplanted RPE cells will respond to the highly oxidatively stressed environment of an AMD patient eye, we compared the survival of polarized and nonpolarized RPE cultures following oxidative stress treatment. Polarized, nonpolarized/confluent, nonpolarized/subconfluent hESC-RPE cells were treated with H2O2. Terminal deoxynucleotidyl transferase dUTP nick end labeling stains revealed the highest amount of cell death in subconfluent hESC-RPE cells and little cell death in polarized hESC-RPE cells with H2O2 treatment. There were higher levels of proapoptotic factors (phosphorylated p38, phosphorylated c-Jun NH2-terminal kinase, Bax, and cleaved caspase 3 fragments) in treated nonpolarized RPE-particularly subconfluent cells-relative to polarized cells. On the other hand, polarized RPE cells had constitutively higher levels of cell survival and antiapoptotic signaling factors such as p-Akt and Bcl-2, as well as antioxidants superoxide dismutase 1 and catalase relative to nonpolarized cells, that possibly contributed to polarized cells' higher tolerance to oxidative stress compared with nonpolarized RPE cells. Subconfluent cells were particularly sensitive to oxidative stress-induced apoptosis. These results suggest that implantation of polarized hESC-RPE monolayers for treating AMD patients with geographic atrophy should have better survival than injections of hESC-RPE cells in suspension. PMID:25411476

Hsiung, Jamie; Zhu, Danhong; Hinton, David R

2015-01-01

341

Cataract Surgery and the Development or Progression of Age-related Macular Degeneration: A Systematic Review  

Microsoft Academic Search

Age-related macular degeneration and cataract are the most frequent eye disorders of elderly people worldwide. The aim of this systematic review was to evaluate the effect of cataract surgery on the development and progression of age-related macular degeneration. Data were collected by means of a systematic literature search in 28 databases and an additional update in Pubmed. Search results were

Angelina Bockelbrink; Stephanie Roll; Klaus Ruether; Andrej Rasch; Wolfgang Greiner; Stefan N. Willich

2008-01-01

342

Hemorrhagic Macular Infarction after Intravitreal Bevacizumab for Chronic Multifocal Central Serous Chorioretinopathy  

PubMed Central

We hereby report a case of hemorrhagic macular infarction after intravitreal bevacizumab for chronic multifocal central serous chorioretinopathy (CSC). Issues regarding safety and adverse effects of bevacizumab are discussed. To the best of our knowledge, this is the first reported case of hemorrhagic macular infarction after intravitreal bevacizumab for chronic multifocal CSC. PMID:25126075

Kelkar, Aditya; Gandhi, Poonam; Amoaku, Winfried; Kelkar, Jai; Kelkar, Shreekant; Raut, Priyanka; Shah, Rachana

2014-01-01

343

Cystoid macular edema associated with juvenile idiopathic arthritis resolved by a dexamethasone intravitreal implant.  

PubMed

Uveitis, glaucoma, and cystoid macular edema frequently develop in patients with juvenile idiopathic arthritis. The authors describe a case of cystoid macular edema associated with juvenile idiopathic arthritis that had not responded to intravitreal triamcinolone acetonide and bevacizumab but improved significantly following intravitreal injection with a dexamethasone 0.7 mg implant. PMID:24811080

Totan, Yüksel; Güler, Emre; Guragaç, Fatma B; Dervisogullari, Mehmet S; Tenlik, Aylin; Hepsen, Ibrahim F

2014-01-01

344

Optical Coherence Tomographic and Visual Results at Six Months after Transitioning to Aflibercept for Patients on Prior Ranibizumab or Bevacizumab Treatment for Exudative Age-Related Macular Degeneration (An American Ophthalmological Society Thesis)  

PubMed Central

Purpose: To study optical coherence tomographic (OCT) results and vision at 6 months after transition (post-Tx) from intravitreal bevacizumab and/or ranibizumab to aflibercept for treatment of neovascular age-related macular degeneration (nAMD). The null hypothesis was the lack of improvements in OCT metrics and vision outcome in study eyes at 6 months after transitioning from bevacizumab or ranibizumab to aflibercept. Methods: This retrospective study assessed 6 monthly OCT (Cirrus) data after transitioning to aflibercept for eyes on prior Legacy-ranibizumab, Legacy-bevacizumab, or mixed treatment for nAMD. Outcome measures were subretinal fluid (SRF), cystoid macular edema (CME), pigment epithelial detachment (PED) heights and volumes, central 1- and 3-mm subfield, Macular Volume, and best spectacle and pinhole visual acuity (VA). A single masked investigator performed all OCT measurements. Results: One hundred eighty-nine eyes in 172 patients in Legacy-bevacizumab (95 eyes), Legacy-ranibizumab (84 eyes), or Mixed Group(10 eyes) were switched to aflibercept and followed for 6 months. Significant post-Tx reductions were noted in SRF/CME heights and volumes (all P<.001). Similar findings were noted for PED heights (122.8 ?m vs 79.4 ?m) and PED volumes (all P<.001). Post-Tx VA was better (20/43 vs 20/51, P<.001). There were no differences between Legacy-bevacizumab and Legacy-ranibizumab groups in OCT and VA changes. Post-Tx VA, SRF/CME, and PED heights and volumes were improved for Nonresponders (suboptimal response to bevacizumab/ranibizumab) (P=.001 to <.001), but not Responders (good responses to same). The only adverse event was a retinal pigment epithelial tear in one eye. Conclusions: Significant improvements in vision and OCT metrics developed in Nonresponders but not in Responders. Post-Tx VA and OCT measures were similar for eyes on prior bevacizumab or ranibizumab. Post-Tx adverse events were uncommon. PMID:25646034

Chan, Clement K.; Jain, Atul; Sadda, Srinivas; Varshney, Neeta

2014-01-01

345

Nonphotosynthetic pigmented bacteria in a potable water treatment and distribution system.  

PubMed Central

The occurrence of pigmented bacteria in potable water, from raw source water through treatment to distribution water, including dead-end locations, was compared at sample sites in a large municipal water system. Media used to enumerate heterotrophic bacteria and differentiate pigmented colonies were standard method plate count (SPC), m-SPC, and R2A agars, incubated up to 7 days at 35 degrees C. The predominant pigmented bacteria at most sample locations were yellow and orange, with a small incidence of pink organisms at the flowing distribution site. Seasonal variations were seen, with the yellow and orange organisms shifting in dominance. SPC agar was the least productive medium for both heterotroph counts and pigmented bacteria differentiation. At the flowing distribution site, percentages of pigmented bacteria on SPC medium ranged from 2.3 to 9.67 times less than on m-SPC and from 2.3 to 9.86 times less than on R2A. At the same site, seasonal trends in the percentage of pigmented bacteria were the same for m-SPC and R2A media, and the highest and lowest percentages occurred in the fall and winter, respectively. At site 6, there appeared to be an inverse relationship between the yellow and orange pigmented groups, but upon analysis, this did not hold and all correlations between yellow and orange pigmented bacteria were positive. The study results indicate that pigmented bacteria could readily be detected by using plate counting media developed for heterotroph enumeration in potable waters with incubation periods of 7 days. Pigmented bacteria can be used as an additional marker for monitoring changes in water quality. High numbers of heterotrophs, including pigmented forms, were found at dead-end locations, usually in the absence of a free chlorine residual and when the water temperature was greater than 16 degrees C. The association of some pigmented bacteria with nosocomial and other infections raises concern that the organisms may have originated from the potable water supply. High levels of pigmented bacteria could pose an increased health risk to immunologically compromised individuals. Therefore, the bacterial quality of the distribution water should be controlled to prevent the development of high concentrations of heterotrophic plate count bacteria, including the pigmented forms. PMID:2729990

Reasoner, D J; Blannon, J C; Geldreich, E E; Barnick, J

1989-01-01

346

Photopolymerization of pigmented thiol–ene systems  

Microsoft Academic Search

Photopolymerization kinetics and optical properties of pigmented thiol–ene coatings were investigated using photo-DSC, real-time FTIR, colorimetry, and AFM. Pigment has no deleterious effect on the unique ability of thiol–ene systems to photopolymerize in air. When trimethylolpropane tris-(3-mercaptopropionate) is incrementally added to tripropylene glycol diacrylate with and without calcium lithol rubine, a red organic pigment, the photopolymerization rate in nitrogen steadily

T. M. Roper; T. Kwee; T. Y. Lee; C. A. Guymon; C. E. Hoyle

2004-01-01

347

Comparison of methods to assess pigment dispersion  

Microsoft Academic Search

Two inks made with different red pigments were evaluated by common methods to assess the degree of pigment dispersion. One\\u000a pigment is more difficult to disperse than the other in the vehicle used. The five methods that could detect changes in dispersion\\u000a with each pass over a three-roll mill were a light scattering particle size distribution analyzer, a NPIRI fineness

T. Van Sang; Bhaskar V. Velamakanni; Ronald R. Adkins

2001-01-01

348

Continental variation in wing pigmentation in Calopteryx damselflies is related to the presence of heterospecifics.  

PubMed

Wing pigmentation in Calopteryx damselflies, caused by the deposition of melanin, is energetically expensive to produce and enhances predation risk. However, patterns of melanisation are used in species identification, greater pigmentation is an accurate signal of male immune function in at least some species, and there may be a role for pigment in thermoregulation. This study tested two potential hypotheses to explain the presence of, and variation in, this pigmentation based on these three potential benefits using 907 male specimens of Calopteryx maculata collected from 49 sites (34 discrete populations) across the geographical range of the species in North America: (i) pigmentation varies with the presence of the closely related species, Calopteryx aequabilis, and (ii) pigment increases at higher latitudes as would be expected if it enhances thermoregulatory capacity. No gradual latitudinal pattern was observed, as might be expected if pigmentation was involved in thermoregulation. However, strong variation was observed between populations that were sympatric or allopatric with C. aequabilis. This variation was characterised by dark wings through allopatry in the south of the range and then a step change to much lighter wings at the southern border of sympatry. Pigmentation then increased further north into the sympatric zone, finally returning to allopatry levels at the northern range margin. These patterns are qualitatively similar to variation in pigmentation in C. aequabilis, meaning that the data are consistent with what would be expected from convergent character displacement. Overall, the results corroborate recent research that has suggested sexual selection as a primary driver behind the evolution of wing pigmentation in this group. PMID:24949250

Hassall, Christopher

2014-01-01

349

Continental variation in wing pigmentation in Calopteryx damselflies is related to the presence of heterospecifics  

PubMed Central

Wing pigmentation in Calopteryx damselflies, caused by the deposition of melanin, is energetically expensive to produce and enhances predation risk. However, patterns of melanisation are used in species identification, greater pigmentation is an accurate signal of male immune function in at least some species, and there may be a role for pigment in thermoregulation. This study tested two potential hypotheses to explain the presence of, and variation in, this pigmentation based on these three potential benefits using 907 male specimens of Calopteryx maculata collected from 49 sites (34 discrete populations) across the geographical range of the species in North America: (i) pigmentation varies with the presence of the closely related species, Calopteryx aequabilis, and (ii) pigment increases at higher latitudes as would be expected if it enhances thermoregulatory capacity. No gradual latitudinal pattern was observed, as might be expected if pigmentation was involved in thermoregulation. However, strong variation was observed between populations that were sympatric or allopatric with C. aequabilis. This variation was characterised by dark wings through allopatry in the south of the range and then a step change to much lighter wings at the southern border of sympatry. Pigmentation then increased further north into the sympatric zone, finally returning to allopatry levels at the northern range margin. These patterns are qualitatively similar to variation in pigmentation in C. aequabilis, meaning that the data are consistent with what would be expected from convergent character displacement. Overall, the results corroborate recent research that has suggested sexual selection as a primary driver behind the evolution of wing pigmentation in this group. PMID:24949250

2014-01-01

350

Nitisinone improves eye and skin pigmentation defects in a mouse model of oculocutaneous albinism  

PubMed Central

Mutation of the tyrosinase gene (TYR) causes oculocutaneous albinism, type 1 (OCA1), a condition characterized by reduced skin and eye melanin pigmentation and by vision loss. The retinal pigment epithelium influences postnatal visual development. Therefore, increasing ocular pigmentation in patients with OCA1 might enhance visual function. There are 2 forms of OCA1, OCA-1A and OCA-1B. Individuals with the former lack functional tyrosinase and therefore lack melanin, while individuals with the latter produce some melanin. We hypothesized that increasing plasma tyrosine concentrations using nitisinone, an FDA-approved inhibitor of tyrosine degradation, could stabilize tyrosinase and improve pigmentation in individuals with OCA1. Here, we tested this hypothesis in mice homozygous for either the Tyrc-2J null allele or the Tyrc-h allele, which model OCA-1A and OCA-1B, respectively. Only nitisinone-treated Tyrc-h/c-h mice manifested increased pigmentation in their fur and irides and had more pigmented melanosomes. High levels of tyrosine improved the stability and enzymatic function of the Tyrc-h protein and also increased overall melanin levels in melanocytes from a human with OCA-1B. These results suggest that the use of nitisinone in OCA-1B patients could improve their pigmentation and potentially ameliorate vision loss. PMID:21968110

Onojafe, Ighovie F.; Adams, David R.; Simeonov, Dimitre R.; Zhang, Jun; Chan, Chi-Chao; Bernardini, Isa M.; Sergeev, Yuri V.; Dolinska, Monika B.; Alur, Ramakrishna P.; Brilliant, Murray H.; Gahl, William A.; Brooks, Brian P.

2011-01-01

351

Nitisinone improves eye and skin pigmentation defects in a mouse model of oculocutaneous albinism.  

PubMed

Mutation of the tyrosinase gene (TYR) causes oculocutaneous albinism, type 1 (OCA1), a condition characterized by reduced skin and eye melanin pigmentation and by vision loss. The retinal pigment epithelium influences postnatal visual development. Therefore, increasing ocular pigmentation in patients with OCA1 might enhance visual function. There are 2 forms of OCA1, OCA-1A and OCA-1B. Individuals with the former lack functional tyrosinase and therefore lack melanin, while individuals with the latter produce some melanin. We hypothesized that increasing plasma tyrosine concentrations using nitisinone, an FDA-approved inhibitor of tyrosine degradation, could stabilize tyrosinase and improve pigmentation in individuals with OCA1. Here, we tested this hypothesis in mice homozygous for either the Tyrc-2J null allele or the Tyrc-h allele, which model OCA-1A and OCA-1B, respectively. Only nitisinone-treated Tyrc-h/c-h mice manifested increased pigmentation in their fur and irides and had more pigmented melanosomes. High levels of tyrosine improved the stability and enzymatic function of the Tyrc-h protein and also increased overall melanin levels in melanocytes from a human with OCA-1B. These results suggest that the use of nitisinone in OCA-1B patients could improve their pigmentation and potentially ameliorate vision loss. PMID:21968110

Onojafe, Ighovie F; Adams, David R; Simeonov, Dimitre R; Zhang, Jun; Chan, Chi-Chao; Bernardini, Isa M; Sergeev, Yuri V; Dolinska, Monika B; Alur, Ramakrishna P; Brilliant, Murray H; Gahl, William A; Brooks, Brian P

2011-10-01

352

New yellow pigments: ZnO?Bi 2O 3  

Microsoft Academic Search

A zinc oxide pigment with an admixture of bismuth oxide has been prepared as a new yellow pigment for colouring plastics and paints. The effect of the Bi2O3 content in the starting mixture on the colour hue of the pigment and the temperature conditions for the pigment synthesis have been evaluated. The optimum conditions for the synthesis of the pigments

Petra Šulcová; Miroslav Trojan

1998-01-01

353

Complement component C5a Promotes Expression of IL22 and IL17 from Human T cells and its Implication in Age-related Macular Degeneration  

Microsoft Academic Search

Background  Age related macular degeneration (AMD) is the leading cause of irreversible blindness in elderly populations worldwide. Inflammation,\\u000a among many factors, has been suggested to play an important role in AMD pathogenesis. Recent studies have demonstrated a strong\\u000a genetic association between AMD and complement factor H (CFH), the down-regulatory factor of complement activation. Elevated\\u000a levels of complement activating molecules including complement

Baoying Liu; Lai Wei; Catherine Meyerle; Jingsheng Tuo; H Nida Sen; Zhiyu Li; Sagarika Chakrabarty; Elvira Agron; Chi-Chao Chan; Michael L Klein; Emily Chew; Frederick Ferris; Robert B Nussenblatt

2011-01-01

354

Annular and central heavy pigment deposition on the posterior lens capsule in the Pigment dispersion syndrome  

Microsoft Academic Search

Purpose To report annular and central heavy pigment deposition on the posterior lens capsule in a case of pigment dispersion syndrome.\\u000a Methods Case report. Results A 36-year-old female with bilateral pigment dispersion syndrome presented with progressive decrease in visual acuity in the\\u000a right eye over the past 1–2 years. Clinical examination revealed the typical findings of pigment dispersion syndrome including\\u000a bilateral

Burak Turgut; Peykan Türkçüo?lu; Nurettin Deniz; Onur Çatak

2008-01-01

355

Complement Factor H, Vitronectin, and Opticin Are Tyrosine-Sulfated Proteins of the Retinal Pigment Epithelium  

PubMed Central

Lack of tyrosine sulfation of ocular proteins results in disorganized photoreceptor structure and drastically reduced visual function, demonstrating the importance of this post-translational modification to vision. To understand the role that tyrosine sulfation plays in the function of ocular proteins, we identified some tyrosine-sulfated proteins in the retinal pigment epithelium using two independent methods, immuno-affinity column purification with an anti-sulfotyrosine specific antibody and computer-based sequence analysis of retinal pigment epithelium secretome by means of the prediction program Sulfinator. Radioactive labeling followed by thin layer electrophoresis revealed that three proteins, vitronectin, opticin, and complement factor H (CFH), were post-translationally modified by tyrosine sulfation. The identification of vitronectin and CFH as tyrosine-sulfated proteins is significant, since both are deposited in drusen in the eyes of patients with age-related macular degeneration (AMD). Furthermore, mutations in CFH have been determined to be a major risk factor in the development of AMD. Future studies that seek to understand the role of CFH in the development of AMD should take into account the role that tyrosine sulfation plays in the interaction of this protein with its partners, and examine whether modulating sulfation provides a potential therapeutic target. PMID:25136834

Kanan, Yogita; Siefert, Joseph C.; Kinter, Michael; Al-Ubaidi, Muayyad R.

2014-01-01

356

The new paradigm: retinal pigment epithelium cells generated from embryonic or induced pluripotent stem cells  

PubMed Central

Summary Compared with neural crest-derived melanocytes, retinal pigment epithelium (RPE) cells in the back of the eye are pigment cells of a different kind. They are a part of the brain, form an epithelial monolayer, respond to distinct extracellular signals, and provide functions that far exceed those of a light-absorbing screen. For instance, they control nutrient and metabolite flow to and from the retina, replenish 11-cis-retinal by re-isomerizing all-trans-retinal generated during photoconversion, phagocytose daily a portion of the photoreceptors’ outer segments, and secrete cytokines that locally control the innate and adaptive immune systems. Not surprisingly, RPE cell damage is a major cause of human blindness worldwide, with age-related macular degeneration a prevalent example. RPE replacement therapies using RPE cells generated from embryonic or induced pluripotent stem cells provide a novel approach to a rational treatment of such forms of blindness. In fact, RPE-like cells can be obtained relatively easily when stem cells are subjected to a two-step induction protocol, a first step that leads to a neuroectodermal fate and a second to RPE differentiation. Here, we discuss the characteristics of such cells, propose criteria they should fulfill in order to be considered authentic RPE cells, and point out the challenges one faces when using such cells in attempts to restore vision. PMID:20846177

Bharti, Kapil; Miller, Sheldon S.; Arnheiter, Heinz

2010-01-01

357

Treatment of retinal pigment epithelial detachment with antiangiogenic therapy  

PubMed Central

Purpose Evaluate the efficacy of pegaptanib, a selective anti-vascular endothelial growth factor (VEGF) agent, and bevacizumab, a nonselective anti-VEGF agent, for retinal pigment epithelial detachment (PED) associated with occult choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). Methods Prospective, comparative, nonrandomized pilot study included patients with PED comprising >50% of total lesion in subfoveal location with visual acuity (VA) 20/40–20/400 and lesions either previously untreated or treated only with photodynamic therapy/verteporfin. Seven patients received pegaptanib 0.3 mg intravitreally (IVT); eight received IVT bevacizumab 1.25 mg. Follow-up occurred every 4–6 weeks for 6 months. Reinjection of initial medication occurred if there was intra- or subretinal fluid observed by optical coherence tomography (OCT) or increased PED. Endpoints were mean changes from baseline to month 6 in VA (ETDRS) and foveal thickness. Results At baseline, mean VA was lower, and mean foveal thickness was greater in pegaptanib versus bevacizumab-treated patients (36.1 vs 49.5 letters; 470.4 vs 321.1 ?m). Mean improvements to month 6 in VA and foveal thickness were greater for pegaptanib (VA: +9.1 vs +7.2 letters; foveal thickness: ?88.2 vs ?52.9 ?m). On average, pegaptanib-treated patients had slower but more sustained improvement in VA and foveal thickness; bevacizumab-treated patients showed rapid improvement with a slow return towards baseline. Both agents were well tolerated. Conclusion Intravitreal injections of pegaptanib or bevacizumab are both efficacious and safe treatments for PED associated with occult CNV secondary to AMD. PMID:20463807

Arias, Luis

2010-01-01

358

[Nd-YAG laser iridotomy in pigment dispersion syndrome and pigment dispersion glaucoma].  

PubMed

Pigment dispersion syndrome is characterized by iris transillumination defects, Krukenberg spindels, and dense trabecular pigmentation. Additional features are bilaterality, myopia, concavity of the peripheral iris, a higher incidence in men than in woman,and young age of onset. A mechanism of reverse pupillary block causes iridozonular friction. Laser iridotomy is recommended as treatment to prevent further pigment dispersion and pigmentary glaucoma. PMID:12748808

Schwenn, O; Shah, B; Vogel, A; Yun, S H

2003-05-01

359

Microperoxisomes in retinal pigment epithelium.  

PubMed

Microperoxisomes were found to be abundant in the retinal pigment epithelium of the human, rhesus monkey, mice, rats, domestic fowl, and frog by ultrastructural histochemistry. They were rare in other cells of the retina and choroid. These organelles had a granular matrix, ranged in diameter from 0.15 mum to 0.30 mum, and were bound by a single tripartite membrane which often maintained slender connections with the smooth endoplasmic reticulum and other microperoxisomes. They exhibited a positive reaction (electron opaque product) following incubation in diaminobenzidine and H2O2 for the demonstration of the peroxidatic activity of catalase (Novikoff et al., J. Histochem. Cytochem. 20: 1006, 1972). The reaction was inhibited by: (1) aminotriazole; (2) dichlorophenol-indophenol; (3) preheating at 95 degrees C.; or (4) elimination of H2O2. Microperoxisomes, like the well-known peroxisomes (microbodies) of liver cells have been inplicated in various aspects of lipid metabolism and the detoxification of H2O2. We demonstrated for the first time that microperoxisomes respond to drug-induced changes in lipid metabolism, as previously shown for peroxisomes. Nafenopin is a recently utilized drug which greatly decreases serum lipids, increases hepatic catalase activity, and induces an increased size and number of hepatic peroxisomes. Black, beige, albino, and obese mutant mice of the C57BL/6J strain treated with nafenopin for several weeks showed a two- to threefold increase in the number of microperoxisomes in the retinal pigment epithelium. Microperoxisomes of the retinal pigment epithelium may be involved in the transport, storage, and rapid turnover of lipids associated with the maintenance of photoreceptor outer segment disc membranes. PMID:810456

Robison, W G; Kuwabara, T

1975-11-01

360

Prognostic phenotypic and genotypic factors associated with photodynamic therapy response in patients with age-related macular degeneration  

PubMed Central

Background This study aimed to demonstrate the phenotypic and genotypic factors associated with photodynamic therapy (PDT) for age-related macular degeneration (AMD). Methods The study included 149 patients with exudative AMD treated by PDT. Eight phenotypic factors and ten genotypic factors for three single nucleotide polymorphisms (SNPs; rs800292, rs1061170, rs1410996) in the complement factor H (CFH) gene, rs 11200638-SNP in the high temperature requirement A-1 (HTRA1) gene, two SNPs (rs699947, rs2010963) in the vascular endothelial growth factor (VEGF) gene, and four SNPs (rs12948385, rs12150053, rs9913583, rs1136287) in the pigment epithelium-derived factor (PEDF) gene were evaluated. Results A significant association with best-corrected visual acuity change was demonstrated in the greatest linear dimension, presence or absence of pigment epithelial detachment, and HTRA1-rs11200638 genotype statistically (P=3.67×10?4, 1.95×10?2, 1.24×10?3, respectively). Best-corrected visual acuity in patients with AA genotype of HTRA1-rs11200638 significantly decreased compared with that in patients with GG genotype (P=1.33×10?3). Logistic regression analyses demonstrated HTRA1-rs11200638 genotype was most strongly associated with best-corrected visual acuity outcome from baseline at 12 months after photodynamic therapy (P=4.60×10?3; odds ratio 2.363; 95% confidence interval 1.303–4.285). Conclusion The HTRA1-rs11200638 variant showed the most significant association. Therefore, this variant may be used as a prognostic factor to estimate the PDT response with significant predictive power. PMID:25525324

Tsuchihashi, Takashi; Mori, Keisuke; Horie-Inoue, Kuniko; Okazaki, Yasushi; Awata, Takuya; Inoue, Satoshi; Yoneya, Shin

2014-01-01

361

Melanin pigmented solar absorbing surfaces  

SciTech Connect

Selectivity enhancement is shown to result for melanin, a black biopolymer pigment, for sufficiently low sample density. The effect is proposed to follow from a consideration of the evanescent waves associated with the total internal reflection phenomenon. A relationship is discussed among powder density, pH and the paramagnetic properties of melanin; this relationship is shown to be consistent with, and offer support to an amino-acid side group proposed earlier as part of the melanin structure. A brief discussion is also presented on the optical properties of melanin and the relative importance of quinhydrone, a change transfer complex believed to exist in the polymeric structure of melanin.

Gallas, J.M.; Eisner, M.

1980-01-01

362

Pathology Case Study: Pigmented Lesion  

NSDL National Science Digital Library

This is a case study presented by the University of Pittsburgh Department of Pathology in which a 69-year-old man has a pigmented lesion on his right ear. Visitors are given the patient history and microscopic description, including images, and are given the opportunity to diagnose the patient. This is an excellent resource for students in the health sciences to familiarize themselves with using patient history and laboratory results to diagnose disease. It is also a helpful site for educators to use to introduce or test student learning in dermatologic pathology.

Ejadi, Samuel

363

Pigmented Lesion of Buccal Mucosa  

PubMed Central

Pigmented lesions are commonly found in the mouth. Such lesions represent a variety of clinical entities, ranging from physiologic changes to manifestation of systemic illness and malignant neoplasm. Diagnosis of such lesions requires a proper case history, extraoral and intraoral examination, and, in some cases, biopsy, aspiration cytology, and laboratory investigations. Here we present a case of purple lesion on the buccal mucosa of a 34-year-old male patient which was provisionally diagnosed as mucocele but on the basis of histopathological picture it was finally diagnosed as angiofibroma, and we also discuss the clinical and histopathological differential diagnosis. PMID:25161669

Bajpai, Manas; Kumar, Malay; Kumar, Manish; Agarwal, Deshant

2014-01-01

364

Subconjunctival sirolimus in the treatment of diabetic macular edema  

PubMed Central

Background Diabetic macular edema (DME) is a leading cause of blindness in the developed world. Sirolimus has been shown to inhibit the production, signaling, and activity of many growth factors relevant to the development of diabetic retinopathy. This phase I/II study assesses the safety of multiple subconjunctival sirolimus injections for the treatment of DME, with some limited efficacy data. Methods In this phase I/II prospective, open-label pilot study, five adult participants with diabetic macular edema involving the center of the fovea and best-corrected ETDRS visual acuity score of ?74 letters (20/32 or worse) received 20 ?l (440 ?g) of subconjunctival sirolimus at baseline, month 2 and every 2 months thereafter, unless there was resolution of either retinal thickening on OCT or leakage on fluorescein angiography. Main outcome measures included best-corrected visual acuity and central retinal thickness on OCT at 6 months and 1 year, as well as safety outcomes. Results Repeated subconjunctival sirolimus injections were well-tolerated, with no significant drug-related adverse events. There was no consistent treatment effect related to sirolimus; one participant experienced a 2-line improvement in visual acuity and 2 log unit decrease in retinal thickness at 6 months and 1 year, two remained essentially stable, one had stable visual acuity but improvement of central retinal thickness of 1 and 3 log units at 6 months and 1 year respectively, and one had a 2-line worsening of visual acuity and a 1 log unit increase in retinal thickness at 6 months and 1 year. Results in the fellow eyes with diabetic macular edema, not treated with sirolimus, were similar. Conclusions Subconjunctival sirolimus appears safe to use in patients with DME. Assessment of possible treatment benefit will require a randomized trial. PMID:21567211

Krishnadev, Nupura; Forooghian, Farzin; Cukras, Catherine; Wong, Wai; Saligan, Leorey; Chew, Emily Y.; Nussenblatt, Robert; Ferris, Frederick

2011-01-01

365

Evidence for Enhanced Tissue Factor Expression in Age-related Macular Degeneration  

PubMed Central

Tissue factor (TF) is the primary initiator of blood coagulation. In addition to hemostasis, TF can initiate intracellular signaling and promote inflammation and angiogenesis, the key processes underlying the pathogenesis of age-related macular degeneration (AMD). AMD, the leading cause of irreversible blindness among the elderly, involves many genetic and environmental risk factors, including oxidative stress and inflammation. In this study, TF expression was examined in human AMD tissue and in the eyes of a model of AMD, the Ccl2?/?/Cx3cr1?/? (DKO) mouse, as well as in the ARPE-19 cell line after lipopolysaccharide (LPS) and H2O2 stimulation. Total RNA was extracted from tissue samples and further analyzed by real-time RT-PCR. Immunohistochemistry was performed to evaluate TF protein expression. In the human retina, a 32-fold increase of TF mRNA expression was detected in AMD macular lesions compared to normal maculae. TF protein expression was also enhanced in human AMD maculae. Similarly, TF transcript and protein expression were moderately increased in retinal lesions, neuroretinal tissue, and cultured RPE cells of DKO mice compared to age-matched wild-type mice. TF expression level correlated with age in both wild-type and DKO mice. In order to better understand how AMD might lead to enhanced TF expression, 1, 5, and 10 ?g/mL LPS as well as 100 and 200 ?M H2O2 were used to stimulate ARPE-19 cells for 24 and 2 hours, respectively. LPS treatment consistently increased TF transcript and protein expression. H2O2 alone or in combination with LPS also moderately enhanced TF expression. These results indicate that upregulated TF expression may be associated with AMD, and inflammatory and oxidative stress may contribute to TF expression in AMD eyes. PMID:21042291

Cho, Youngeun; Cao, Xiaoguang; Shen, DeFen; Tuo, Jingsheng; Parver, Leonard M.; Rickles, Frederick R.; Chan, Chi-Chao

2010-01-01

366

Multimodality imaging in clinical diagnosis and treatment of macular disease  

NASA Astrophysics Data System (ADS)

Accurate diagnosis and treatment of disease is a function of how well the pathology can be imaged. Coregistering images from different modalities can offer significant advantages. Multi-modal imaging is finding its place in Ophthalmology and we illustrate and analyze its use in macular disease. New technologies have provided the ability to simultaneously capture FA and OCT images, allowing dynamic analysis at the exact point of interest. We establish that the combined imaging protocol is easier and faster for both patient and technician, and ultimately and most importantly more capable of guiding the physician to a diagnosis and treatment.

Taibl, Jessica N.; Sayegh, Samir I.

2013-03-01

367

Inflammation and Macular Oedema after Pars Plana Vitrectomy  

PubMed Central

Cystoid macular oedema (CMO) is a major cause of reduced vision following intraocular surgery. Although the aetiology of CMO is not completely clarified, intraocular inflammation is known to play a major role in its development. The macula may develop cytotoxic oedema when the primary lesion and fluid accumulation occur in the parenchymatous cells (intracellular oedema) or vasogenic oedema when the primary defect occurs in the blood-retinal barrier and leads to extracellular fluid accumulation (extracellular oedema). We report on the mechanisms of CMO formation after pars plana vitrectomy and associated surgical procedures and discuss possible therapeutic approaches. PMID:24288446

Romano, Vito; Angi, Martina; del Grosso, Renata; Romano, Davide; Vinciguerra, Paolo; Romano, Mario R.

2013-01-01

368

Future Therapies of Wet Age-Related Macular Degeneration  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly population, and the prevalence of the disease increases exponentially with every decade after the age of 50 years. While VEGF inhibitors are promising drugs for treating patients with ocular neovascularization, there are limitations to their potential for improving vision in AMD patients. Thus, future therapies are required to have the potential to improve visual outcomes. This paper will summarize the future strategies and therapeutic targets that are aimed at enhancing the efficacy and duration of effect of antiangiogenic strategies. PMID:25802751

Jin, Daisuke; Sawada, Yu; Abe, Sanae; Yoshitomi, Takeshi

2015-01-01

369

Present and Possible Therapies for Age-Related Macular Degeneration  

PubMed Central

Age-related macular degeneration (AMD) is the most common cause of blindness in the elderly population worldwide and is defined as a chronic, progressive disorder characterized by changes occurring within the macula reflective of the ageing process. At present, the prevalence of AMD is currently rising and is estimated to increase by a third by 2020. Although our understanding of the several components underpinning the pathogenesis of this condition has increased significantly, the treatment options for this condition remain substantially limited. In this review, we outline the existing arsenal of therapies available for AMD and discuss the additional role of further novel therapies currently under investigation for this debilitating disease. PMID:25097787

Kamal, Ahmed

2014-01-01

370

Bevacizumab in the treatment of idiopathic macular telangiectasia  

Microsoft Academic Search

Background  To describe functional and morphological long-term follow-up results in patients with idiopathic macular telangiectasia (IMT)\\u000a treated with intravitreal bevacizumab.\\u000a \\u000a \\u000a \\u000a Methods  Retrospective case series of three consecutive male patients with IMT who were treated with intravitreal bevacizumab injections.\\u000a Best corrected visual acuity (BCVA) as well as fluorescein angiography (FA) and optical coherence tomography (OCT) were monitored\\u000a over the period of up to

Maria-Andreea Gamulescu; Andreas Walter; Helmut Sachs; Horst Helbig

2008-01-01

371

Macular Pigment Measurement by Heterochromatic Flicker Photometry in Older Subjects: The Carotenoids and Age-Related Eye Disease Study  

Microsoft Academic Search

METHODS. MPOD in eyes of 54 women, age 50 and 79 years (mean, 66), was studied. The spatial profile of MPOD was measured in the right eye, and two spatial points were also measured in the left eye. Forty-eight of these inexperienced subjects completed the protocol on two separate visits. For a subset of the group, the MPOD at two

D. Max Snodderly; Julie A. Mares; Billy R. Wooten; Lisa Oxton; Michael Gruber

2004-01-01

372

Drosophila pigmentation evolution: Divergent genotypes underlying convergent phenotypes  

E-print Network

Drosophila pigmentation evolution: Divergent genotypes underlying convergent phenotypes Patricia J. Myriad pigment patterns in the genus Drosophila offer numerous opportunities to address this question of pigmentation in selected species. Here, we ex- amine Drosophila americana and Drosophila novamexicana, inter

Gruber, Jonathan

373

Rescue of compromised lysosomes enhances degradation of photoreceptor outer segments and reduces lipofuscin-like autofluorescence in retinal pigmented epithelial cells.  

PubMed

Healthful cell maintenance requires the efficient degradative processing and removal of waste material. Retinal pigmented epithelial (RPE) cells have the onerous task of degrading both internal cellular debris generated through autophagy as well as phagocytosed photoreceptor outer segments. We propose that the inadequate processing material with the resulting accumulation of cellular waste contributes to the downstream pathologies characterized as age-related macular degeneration (AMD). The lysosomal enzymes responsible for clearance function optimally over a narrow range of acidic pH values; elevation of lysosomal pH by compounds like chloroquine or A2E can impair degradative enzyme activity and lead to a lipofuscin-like autofluorescence. Restoring acidity to the lysosomes of RPE cells can enhance activity of multiple degradative enzymes and is therefore a logical target in early AMD. We have identified several approaches to reacidify lysosomes of compromised RPE cells; stimulation of beta-adrenergic, A2A adenosine and D5 dopamine receptors each lowers lysosomal pH and improves degradation of outer segments. Activation of the CFTR chloride channel also reacidifies lysosomes and increases degradation. These approaches also restore the lysosomal pH of RPE cells from aged ABCA4(-/-) mice with chronically high levels of A2E, suggesting that functional signaling pathways to reacidify lysosomes are retained in aged cells like those in patients with AMD. Acidic nanoparticles transported to RPE lysosomes also lower pH and improve degradation of outer segments. In summary, the ability of diverse approaches to lower lysosomal pH and enhance outer segment degradation support the proposal that lysosomal acidification can prevent the accumulation of lipofuscin-like material in RPE cells. PMID:24664687

Guha, Sonia; Liu, Ji; Baltazar, Gabe; Laties, Alan M; Mitchell, Claire H

2014-01-01

374

Efficient Delivery and Functional Expression of Transfected Modified mRNA in Human Embryonic Stem Cell-derived Retinal Pigmented Epithelial Cells.  

PubMed

Gene- and cell-based therapies are promising strategies for the treatment of degenerative retinal diseases such as age-related macular degeneration, Stargardt disease, and retinitis pigmentosa. Cellular engineering before transplantation may allow the delivery of cellular factors that can promote functional improvements, such as increased engraftment or survival of transplanted cells. A current challenge in traditional DNA-based vector transfection is to find a delivery system that is both safe and efficient, but using mRNA as an alternative to DNA can circumvent these major roadblocks. In this study, we show that both unmodified and modified mRNA can be delivered to retinal pigmented epithelial (RPE) cells with a high efficiency compared with conventional plasmid delivery systems. On the other hand, administration of unmodified mRNA induced a strong innate immune response that was almost absent when using modified mRNA. Importantly, transfection of mRNA encoding a key regulator of RPE gene expression, microphthalmia-associated transcription factor (MITF), confirmed the functionality of the delivered mRNA. Immunostaining showed that transfection with either type of mRNA led to the expression of roughly equal levels of MITF, primarily localized in the nucleus. Despite these findings, quantitative RT-PCR analyses showed that the activation of the expression of MITF target genes was higher following transfection with modified mRNA compared with unmodified mRNA. Our findings, therefore, show that modified mRNA transfection can be applied to human embryonic stem cell-derived RPE cells and that the method is safe, efficient, and functional. PMID:25555917

Hansson, Magnus L; Albert, Silvia; González Somermeyer, Louisa; Peco, Rubén; Mejía-Ramírez, Eva; Montserrat, Núria; Izpisua Belmonte, Juan Carlos

2015-02-27

375

Blue light-induced inflammatory marker expression in the retinal pigment epithelium-choroid of mice and the protective effect of a yellow intraocular lens material in vivo.  

PubMed

Oxidative stress in the retinal pigment epithelium (RPE) is a well-accepted pathogenic change in vision-threatening diseases such as age-related macular degeneration. One source of oxidative stress is excessive light exposure, which causes excessive activation of the visual cycle. Because short wavelength light (blue light) has more energy, it is reported to be more harmful to photoreceptor cells than the other wavelengths of light. However, the biological effect of blue light in the RPE of living animals and the protective effect of a yellow intraocular lens (IOL) material that blocks blue light is still obscure. Therefore, we compared the pathogenic effect in the RPE-choroid complexes of mice exposed to light in a box made of a clear or a yellow IOL material. We measured the level of reactive oxygen species (ROS) using 2', 7'-dichlorodihydrofluorescein diacetate, the mRNA levels of inflammatory cytokines and a macrophage marker by real-time polymerase chain reaction, and the protein level of monocyte chemotactic protein-1 (MCP-1) by ELISA. The ROS level after light exposure was suppressed in the RPE-choroids of light-exposed mice in the yellow IOL material box. In parallel, all the inflammatory cytokines that we measured and a macrophage marker were also suppressed in the RPE-choroids of light-exposed mice in the yellow IOL material box. Therefore, a yellow IOL material suppressed, and thus blue light exacerbated, the increase in the ROS level and inflammatory cytokine expression as well as macrophage recruitment in the RPE-choroid in vivo after light exposure. PMID:25576667

Narimatsu, Toshio; Negishi, Kazuno; Miyake, Seiji; Hirasawa, Manabu; Osada, Hideto; Kurihara, Toshihide; Tsubota, Kazuo; Ozawa, Yoko

2015-03-01

376

Localization of Complement 1 Inhibitor (C1INH/SERPING1) in Human Eyes with Age-Related Macular Degeneration  

PubMed Central

Age-related macular degeneration (AMD) is a common degenerative disease resulting in injury to the retina, retinal pigment epithelium and choriocapillaris. Recent data from histopathology, animal models and genetic studies have implicated altered regulation of the complement system as a major factor in the incidence and progression of this disease. A variant in the gene SERPING1, which encodes C1INH, an inhibitor of the classical and lectin pathways of complement activation, was recently shown to be associated with AMD. In this study we sought to determine the localization of C1INH in human donor eyes. Immunofluorescence studies using a monoclonal antibody directed against C1INH revealed localization to photoreceptor cells, inner nuclear layer neurons, choriocapillaris, and choroidal extracellular matrix. Drusen did not exhibit labeling. Genotype at rs2511989 did not appear to affect C1INH abundance or localization, nor was it associated with significant molecular weight differences when evaluated by Western blot. In a small number of eyes (n=7 AMD and n=7 control) AMD affection status was correlated with increased abundance of choroidal C1INH. These results indicate that C1INH protein is present in the retina and choroid, where it may regulate complement activation. PMID:19607829

Mullins, Robert F.; Faidley, Elizabeth A.; Daggett, Heather T.; Jomary, Catherine; Lotery, Andrew J.; Stone, Edwin M.

2009-01-01

377

Pathway activation profiling reveals new insights into Age-related Macular Degeneration and provides avenues for therapeutic interventions  

PubMed Central

Age-related macular degeneration (AMD) is a major cause of blindness in older people and is caused by loss of the central region of the retinal pigment epithelium (RPE). Conventional methods of gene expression analysis have yielded important insights into AMD pathogenesis, but the precise molecular pathway alterations are still poorly understood. Therefore we developed a new software program, “AMD Medicine”, and discovered differential pathway activation profiles in samples of human RPE/choroid from AMD patients and controls. We identified 29 pathways in RPE-choroid AMD phenotypes: 27 pathways were activated in AMD compared to controls, and 2 pathways were activated in controls compared to AMD. In AMD, we identified a graded activation of pathways related to wound response, complement cascade, and cell survival. Also, there was downregulation of two pathways responsible for apoptosis. Furthermore, significant activation of pro-mitotic pathways is consistent with dedifferentiation and cell proliferation events, which occur early in the pathogenesis of AMD. Significantly, we discovered new global pathway activation signatures of AMD involved in the cell-based inflammatory response: IL-2, STAT3, and ERK. The ultimate aim of our research is to achieve a better understanding of signaling pathways involved in AMD pathology, which will eventually lead to better treatments. PMID:25543336

Makarev, Evgeny; Cantor, Charles; Zhavoronkov, Alex; Buzdin, Anton; Aliper, Alexander; Csoka, Antonei Benjamin

2014-01-01

378

Progress and perspectives on the role of RPE cell inflammatory responses in the development of age-related macular degeneration  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries. The etiology of AMD remains poorly understood and no treatment is currently available for the atrophic form of AMD. Atrophic AMD has been proposed to involve abnormalities of the retinal pigment epithelium (RPE), which lies beneath the photoreceptor cells and normally provides critical metabolic support to these light-sensing cells. Cumulative oxidative stress and local inflammation are thought to represent pathological processes involved in the etiology of atrophic AMD. Studies of tissue culture and animal models reveal that oxidative stress-induced injury to the RPE results in a chronic inflammatory response, drusen formation, and RPE atrophy. RPE degeneration in turn causes a progressive degeneration of photoreceptors, leading to the irreversible loss of vision. This review describes some of the potential major molecular and cellular events contributing to RPE death and inflammatory responses. In addition, potential target areas for therapeutic intervention will be discussed and new experimental therapeutic strategies for atrophic AMD will be presented. PMID:22096347

Qin, Suofu; Rodrigues, Gerard A

2008-01-01

379

IL-18 attenuates experimental choroidal neovascularization as a potential therapy for wet age-related macular degeneration.  

PubMed

Age-related macular degeneration (AMD) is the most common form of central retinal blindness globally. Distinct processes of the innate immune system, specifically activation of the NLRP3 inflammasome, have been shown to play a central role in the development of both "dry" and neovascular ("wet") forms of the disease. We show that the inflammatory cytokine interleukin-18 (IL-18) can regulate choroidal neovascularization formation in mice. We observed that exogenous administration of mature recombinant IL-18 has no effect on retinal pigment epithelial (RPE) cell viability, but that overexpression of pro-IL-18 or pro-IL-1? alone can cause RPE cell swelling and subsequent atrophy, a process that can be inhibited by the promotion of autophagy. A direct comparison of local and systemic administration of mature recombinant IL-18 with current anti-VEGF (vascular endothelial growth factor)-based therapeutic strategies shows that IL-18 treatment works effectively alone and more effectively in combination with anti-VEGF therapy and represents a novel therapeutic strategy for the treatment of wet AMD. PMID:24695684

Doyle, Sarah L; Ozaki, Ema; Brennan, Kiva; Humphries, Marian M; Mulfaul, Kelly; Keaney, James; Kenna, Paul F; Maminishkis, Arvydas; Kiang, Anna-Sophia; Saunders, Sean P; Hams, Emily; Lavelle, Ed C; Gardiner, Clair; Fallon, Padraic G; Adamson, Peter; Humphries, Peter; Campbell, Matthew

2014-04-01

380

Current Treatment Limitations in Age-Related Macular Degeneration and Future Approaches Based on Cell Therapy and Tissue Engineering  

PubMed Central

Age-related macular degeneration (AMD) is the leading cause of blindness in the Western world. With an ageing population, it is anticipated that the number of AMD cases will increase dramatically, making a solution to this debilitating disease an urgent requirement for the socioeconomic future of the European Union and worldwide. The present paper reviews the limitations of the current therapies as well as the socioeconomic impact of the AMD. There is currently no cure available for AMD, and even palliative treatments are rare. Treatment options show several side effects, are of high cost, and only treat the consequence, not the cause of the pathology. For that reason, many options involving cell therapy mainly based on retinal and iris pigment epithelium cells as well as stem cells are being tested. Moreover, tissue engineering strategies to design and manufacture scaffolds to mimic Bruch's membrane are very diverse and under investigation. Both alternative therapies are aimed to prevent and/or cure AMD and are reviewed herein. PMID:24672707

Fernández-Robredo, P.; Sancho, A.; Johnen, S.; Recalde, S.; Gama, N.; Thumann, G.; Groll, J.; García-Layana, A.

2014-01-01

381

Pathway activation profiling reveals new insights into age-related macular degeneration and provides avenues for therapeutic interventions.  

PubMed

Age-related macular degeneration (AMD) is a major cause of blindness in older people and is caused by loss of the central region of the retinal pigment epithelium (RPE). Conventional methods of gene expression analysis have yielded important insights into AMD pathogenesis, but the precise molecular pathway alterations are still poorly understood. Therefore we developed a new software program, "AMD Medicine", and discovered differential pathway activation profiles in samples of human RPE/choroid from AMD patients and controls. We identified 29 pathways in RPE-choroid AMD phenotypes: 27 pathways were activated in AMD compared to controls, and 2 pathways were activated in controls compared to AMD. In AMD, we identified a graded activation of pathways related to wound response, complement cascade, and cell survival. Also, there was downregulation of two pathways responsible for apoptosis. Furthermore, significant activation of pro-mitotic pathways is consistent with dedifferentiation and cell proliferation events, which occur early in the pathogenesis of AMD. Significantly, we discovered new global pathway activation signatures of AMD involved in the cell-based inflammatory response: IL-2, STAT3, and ERK. The ultimate aim of our research is to achieve a better understanding of signaling pathways involved in AMD pathology, which will eventually lead to better treatments. PMID:25543336

Makarev, Evgeny; Cantor, Charles; Zhavoronkov, Alex; Buzdin, Anton; Aliper, Alexander; Csoka, Anotonei Benjamin

2014-12-01

382

The biogeochemistry of tetrapyrrole pigments, emphasizing chlorophyll  

SciTech Connect

Electronic absorption spectra recorded on native geopigments and on in vitro derivatives, obtained with combinations of copper insertion and borohydride reduction reactions, allowed a sensitive chromophore identification' scheme to be developed. Quantitation of the Ni and VO geoporphyrins, as well as the benzo-forms of each, was tested and precisions at the level of 100 [+-] 5% found. An overall methodology for obtaining repeatable low-voltage mass spectra on geoporphyrin arrays is presented. Repeatabilities for the various mass spectral-derived indices were; %DPEP ([+-]2%), X ([+-]2%), A.I.([+-]5%) and % BENZ ([+-]10%). Quantitation of the metallobenzoporphyrins was much better ([+-]2%) with UV/VIS techniques. Tetrapyrrole geochemistry was investigated at all stages of organic evolution. Thus, viable and senescent/dead uni-algal cultures, sediment trap material, surface (<1m) sediments, deep ocean long cores (DSDP), oil shales and petroleum crudes were investigated. Results indicate that the chlorophylls can serve as sources for a variety of geoporphyrins. Early in diagenesis two competing reactions dictate further fossilization.' First is the loss of the carbomethoxy group. This produces pyropheophorbides which can either lead to the true DPEP series, via a sequence of defunctionaliation reactions or, via intramolecular cyclization (dehydration), to certain 13[sup 2], 17[sup 3]-cyclopheophorbide enols. The latter, following defunctionalization, give rise to DiDPEP and/or DPEP-type pigments with a 7-membered exocyclic ring. Second, chlorophyll nuclei which have undergone oxidative scission of the isocyclic ring can, through purpurins and chlorins, theoretically yield C28-C30 ETIO-series porphyrins. Bacteriochlorophyll-a was found to be a dominant pigment in several anoxic sediments and is suggested as an important and highly specific precursor for certain geoporphyrins (i.e 3-methyl-desethyl-DPEP).

Louda, J.W.

1993-01-01

383

Protection against minocycline pigment formation by ascorbic acid (vitamin C).  

PubMed

Minocycline, a member of the tetracycline family of antibiotics, is widely used in the treatment of acne. Its use has been associated with intrinsic staining of adult human teeth, bones, and soft tissues. It causes blackening of the thyroid glands in both animals and humans. It has been determined that the pigment is the product of an oxidation reaction. Laboratory studies have shown that the pigment formation can be induced by exposure to ultraviolet light in the presence of air, and that an antioxidant, such as ascorbic acid (vitamin C), can block its formation. The present study was undertaken to determine whether the antioxidant vitamin C could prevent the pigmentation of tissues of laboratory rats given minocycline. Based on other studies, one group of rats was given minocycline by stomach tube at a dose of 75 mg/kg/day, 5 days per week, for 6 weeks. A second experimental group was given the same regimen of minocycline plus a supplement of ascorbic acid at a level of 0.1% of the diet. A control group received no treatment at all; all rats were maintained on laboratory rats chow and water ad libitum. The rats were euthanized by carbon dioxide inhalation. Nasomaxillary bones, including central incisors, and thyroid glands were removed and fixed with 10% buffered formalin. Bones and teeth showed no gross signs of staining and, therefore, were not processed further. Thyroid glands were visibly darker in the minocycline group; specimens from all three groups were processed histologically. Microscopic examination revealed extensive deposits of black pigment throughout the follicles of the minocycline group, whereas the group receiving both minocycline and vitamin C showed no sign of pigmentation and were indistinguishable from controls. It is suggested that patients on long-term minocycline medication be monitored for thyroid function. PMID:9893512

Bowles, W H

1998-01-01

384

Pigments, Parasites and Personalitiy: Towards a Unifying Role for Steroid Hormones?  

PubMed Central

A surging interest in the evolution of consistent trait correlations has inspired research on pigment patterns as a correlate of behavioural syndromes, or “animal personalities”. Associations between pigmentation, physiology and health status are less investigated as potentially conserved trait clusters. In the current study, lice counts performed on farmed Atlantic salmon Salmo salar naturally infected with ectoparasitic sea lice Lepeophtheirus salmonis showed that individual fish with high incidence of black melanin-based skin spots harboured fewer female sea lice carrying egg sacs, compared to less pigmented fish. There was no significant association between pigmentation and lice at other developmental stages, suggesting that host factors associated with melanin-based pigmentation may modify ectoparasite development to a larger degree than settlement. In a subsequent laboratory experiment a strong negative correlation between skin spots and post-stress cortisol levels was revealed, with less pigmented individuals showing a more pronounced cortisol response to acute stress. The observation that lice prevalence was strongly increased on a fraction of sexually mature male salmon which occurred among the farmed fish further supports a role for steroid hormones as mediators of reduced parasite resistance. The data presented here propose steroid hormones as a proximate cause for the association between melanin-based pigmentation and parasites. Possible fundamental and applied implications are discussed. PMID:22493685

Kittilsen, Silje; Johansen, Ida Beitnes; Braastad, Bjarne Olai; Řverli, Řyvind

2012-01-01

385

Specific features of the corrosion inhibition of an aluminum alloy by a nonchromate pigment mixture  

Microsoft Academic Search

The combination of zinc phosphate\\/molybdate and calcium-containing ion-exchange pigment enables one to inhibit efficiently\\u000a the local corrosion of an aluminum-copper alloy in a slightly acid medium. Here, the charge-transfer resistance of the metal\\u000a under the action of extract of this mixture of nonchromate pigments is at the same level as in a medium with the extract of\\u000a strontium chromate. Using

I. M. Zin’; S. B. Lyon; L. M. Bilyi; M. B. Tymus’

2008-01-01

386

Characterization of chlorophyll pigments present in canola seed, meal and oil  

Microsoft Academic Search

Chlorophyll pigments present in canola seed, meal and crude and degummed oils were analyzed by high-performance liquid chromatography\\u000a (HPLC) with a fluorescence detector. Chlorophylls a and b, low levels of pheophytin a, and occasionally traces of pheophorbide\\u000a and its methyl ester were present in canola seed. Meals and oils contained magnesium-deficient chlorophyll pigments such as\\u000a pheophorbide a, methylpheophorbide a, pheophytins

Y. Endo; C. T. Thorsteinson; J. K. Daun

1992-01-01

387

ORGANIC DYES AND PIGMENTS DATA BASE  

EPA Science Inventory

The objective of this research program was to compile a data base covering all the commercially significant dyes and pigments produced or imported in the United States. The Organic Dyes and Pigments Data Base (ODPDB) contains the following data elements: chemical-related data (co...

388

Pigment Dispersion Methods for Electron Microscopy  

Microsoft Academic Search

A method of preparing a pigment dispersion for electron microscopy is described, wherein the pigment, such as zinc oxide, is first wet with water and is then dispersed in a solution of cellulose acetate. Another method is described in which mechanical or chemical damage of the particles is avoided by the use of an electrostatic dispersion apparatus.

H. C. O'Brien

1945-01-01

389

An unusual complication of blunt ocular trauma: A horseshoe-shaped macular tear with spontaneous closure  

PubMed Central

A case of horseshoe-shaped macular tear after blunt trauma with the course of the tear and the relevant findings obtained by spectral-domain optical coherence tomography (SD-OCT) is described. A 21-year-old man who had suffered blunt trauma 5 days previously visited our clinic complaining of vision loss in his left eye. Ophthalmic examination and SD-OCT images revealed a horseshoe-shaped macular tear. A month later at the second visit, the macular tear was found to have spontaneously closed. There have been many cases reported previously of the spontaneous closure of traumatic macular holes. A horseshoe-shaped macular tear is an atypical clinical presentation. However, the mechanism of spontaneous closure is hypothetically as same as that for a macular hole. High-resolution images and three-dimensional maps taken with SD-OCT can provide more details on macular diseases and are more useful than time-domain OCT images. PMID:24817754

Karaca, Umut; Durukan, Hakan A; Mumcuoglu, Tarkan; Erdurman, Cuneyt; Hurmeric, Volkan

2014-01-01

390

Present and future treatment possibilities in macular degeneration  

NASA Astrophysics Data System (ADS)

Purpose: To discuss present and future treatment possibilities in different types of choroidal neovascularisation. Methods: Presented are angiographic- and OCT-findings in patients with macular degeneration of different origin. Choroidal neovascularisations, which are not likely to respond positively to established procedures like thermal laser coagulation or photodynamic therapy will be discussed. Results and conclusions: Present study-guidelines and new methods of pharmacological intervention are analysed in different patterns of macular degeneration. Conventional laser coagulation in the treatment of classic, extrafoveal CNV and photodynamic therapy of predominantly classic subfoveal CNV still represent a gold standard. There are new recommendations, loosening the tight criteria of the TAP and VIP-guidelines, which cover, for instance, wider visual acuity ranges and the treatment of juxtafoveally located choroidal neovascularisations. Positive findings in literature confirm the role of PDT in pathologic myopia and other non-AMD CNV. Studies about surgical procedures, like macula- or RPE-translocation after surgical removal or thermal laser destruction of the CNV are in progress and are expected to show promising results. Phase II/III studies will soon point out the effect of anti-VEGF agents. The application of intravitreal (triamcinolone) or peribulbar (anecortave acetat) steroids could be useful. The combination with surgical or laser techniques could bring further benefit to the patient.

Fisher, E.; Wegner, A.; Pfeiler, T.; Mertz, M.

2005-11-01

391

Predicting visual outcomes for macular disease using optical coherence tomography.  

PubMed

In recent years, the management of macular disease has undergone radical changes, in part because of new therapeutic approaches, but also due to the introduction of a new imaging modality - optical coherence tomography (OCT). The application of OCT imaging has clarified many aspects of chorioretinal disease pathophysiology and elucidated many hitherto unrecognized disease characteristics. From an early stage in its development, OCT has also been revolutionary in attempting to extract clinically useful measurements from image data in an automated fashion. As a result, OCT-derived measurements of retinal thickness have been rapidly embraced in clinical and research settings. However, as knowledge of OCT image analysis has developed, it has become increasingly clear that even accurate measurements of retinal thickness may fail to predict visual outcomes for many diseases. As a result, the focus of much current clinical imaging research is on the identification of other OCT-derived anatomic biomarkers predictive of visual outcomes - such biomarkers could serve as surrogate endpoints in clinical trials and provide prognostic information in clinical practice. In this review, we begin by highlighting the importance of accurate visual function assessment and describing the fundamentals of OCT image evaluation, before describing the current state-of-the-art with regard to predicting visual outcomes, for a variety of macular diseases, using OCT. PMID:23960916

Keane, Pearse A; Sadda, Srinivas R

2011-04-01

392

Predicting visual outcomes for macular disease using optical coherence tomography  

PubMed Central

In recent years, the management of macular disease has undergone radical changes, in part because of new therapeutic approaches, but also due to the introduction of a new imaging modality – optical coherence tomography (OCT). The application of OCT imaging has clarified many aspects of chorioretinal disease pathophysiology and elucidated many hitherto unrecognized disease characteristics. From an early stage in its development, OCT has also been revolutionary in attempting to extract clinically useful measurements from image data in an automated fashion. As a result, OCT-derived measurements of retinal thickness have been rapidly embraced in clinical and research settings. However, as knowledge of OCT image analysis has developed, it has become increasingly clear that even accurate measurements of retinal thickness may fail to predict visual outcomes for many diseases. As a result, the focus of much current clinical imaging research is on the identification of other OCT-derived anatomic biomarkers predictive of visual outcomes – such biomarkers could serve as surrogate endpoints in clinical trials and provide prognostic information in clinical practice. In this review, we begin by highlighting the importance of accurate visual function assessment and describing the fundamentals of OCT image evaluation, before describing the current state-of-the-art with regard to predicting visual outcomes, for a variety of macular diseases, using OCT. PMID:23960916

Keane, Pearse A.; Sadda, Srinivas R.

2011-01-01

393

Intravitreal Diclofenac for Refractory Uveitic Cystoid Macular Edema  

PubMed Central

Purpose To evaluate the effect of a single dose of intravitreal diclofenac on best- corrected visual acuity (BCVA) and central macular thickness (CMT) in patients with refractory uveitic cystoid macular edema (CME). Methods In this prospective non-comparative case series, 8 eyes of 8 patients with refractory CME secondary to chronic intermediate uveitis received a single intravitreal injection of diclofenac (500 µg/0.1ml) in addition to other systemic (oral prednisolone and methotraxate) and topical (betamethasone) remission maintaining drugs. Outcome measures were changes in BCVA and CMT after treatment. Results Mean BCVA remained relatively unchanged at 12, 24 and 36 weeks (0.69, 0.70 and 0.64 LogMAR, respectively) as compared to baseline (0.71 LogMAR). Mean CMT, however, decreased from 488 µm at baseline to 416 and 456 µm at 24 and 36 weeks, respectively. None of the changes were statistically significant. Conclusion In eyes with refractory uveitic CME, intravitreal injection of diclofenac insignificantly reduced CMT but this was not associated with visual improvement. PMID:23825712

Ramezani, Alireza; Fard Esmaeilpour, Nassim; Eskandari, Armen; Rabbanikhah, Zahra; Soheilian, Roham; Soheilian, Masoud

2013-01-01

394

Analysis of macular OCT images using deformable registration  

PubMed Central

Optical coherence tomography (OCT) of the macula has become increasingly important in the investigation of retinal pathology. However, deformable image registration, which is used for aligning subjects for pairwise comparisons, population averaging, and atlas label transfer, has not been well–developed and demonstrated on OCT images. In this paper, we present a deformable image registration approach designed specifically for macular OCT images. The approach begins with an initial translation to align the fovea of each subject, followed by a linear rescaling to align the top and bottom retinal boundaries. Finally, the layers within the retina are aligned by a deformable registration using one-dimensional radial basis functions. The algorithm was validated using manual delineations of retinal layers in OCT images from a cohort consisting of healthy controls and patients diagnosed with multiple sclerosis (MS). We show that the algorithm overcomes the shortcomings of existing generic registration methods, which cannot be readily applied to OCT images. A successful deformable image registration algorithm for macular OCT opens up a variety of population based analysis techniques that are regularly used in other imaging modalities, such as spatial normalization, statistical atlas creation, and voxel based morphometry. Examples of these applications are provided to demonstrate the potential benefits such techniques can have on our understanding of retinal disease. In particular, included is a pilot study of localized volumetric changes between healthy controls and MS patients using the proposed registration algorithm. PMID:25071959

Chen, Min; Lang, Andrew; Ying, Howard S.; Calabresi, Peter A.; Prince, Jerry L.; Carass, Aaron

2014-01-01

395

Diabetic papillopathy with macular edema treated with intravitreal ranibizumab  

PubMed Central

We report a case of diabetic papillopathy that demonstrated a resolution of optic disk swelling and rapid visual recovery when intravitreal ranibizumab was administered. A 51-year-old male presented with acute painless visual loss in his right eye. His vision was 20/320 in the right eye and 20/50 in the left eye. Fundus examination of the right eye showed nonproliferative diabetic retinopathy with macular edema and a swollen optic disk. Fluorescein angiography showed dye leakage from the right optic disk. Optical coherent tomography revealed a significant increase in retinal nerve fiber-layer thickness. Magnetic resonance imaging of the brain was normal. The patient received a single intravitreal ranibizumab (0.5 mg) injection. Two weeks following injection, there was marked regression of the disk swelling and improvement of macular edema, with vision improving to 20/100. Three months following injection, there was complete resolution of the optic disk swelling. No further treatment was required. PMID:24348012

Kim, Moosang; Lee, Jang-Hun; Lee, Seung-Jun

2013-01-01

396

Occurrence and formation kinetics of pyranomalvidin-procyanidin dimer pigment in Merlot red wine: impact of acidity and oxygen concentrations.  

PubMed

Once released from red grape skins, anthocyanins undergo various chemical reactions leading to the formation of more stable pigments such as pyranoanthocyanin, as well as other derivatives. Among these pigments, pyranoanthocyanins linked directly to flavanol dimers have been detected and identified in aged Port wine but not in dry red wine. These pigments are very important with regard to the wine color evolution since they are involved in wine color evolution and stabilization. During this investigation, the occurrence in dry red wine of two pyranomalvidin-procyanidin dimer has been established by low and high resolution HPLC-UV-MS analysis. Moreover, the impact of acidity and oxygen levels on their formation in red wine has been estimated. After four months of evolution, the results showed that, for the same pH, the quantity of this pigment was correlated with oxygen concentrations. Moreover, for the same quantity of oxygen, the concentration of this pigment was related to the acidity level. PMID:24476064

Pechamat, Laurent; Zeng, Liming; Jourdes, Michael; Ghidossi, Rémy; Teissedre, Pierre-Louis

2014-02-19

397

Morphision: A method for subjective evaluation of metamorphopsia in patients with unilateral macular pathology (i.e., full thickness macular hole and epiretinal membrane)  

PubMed Central

Background: Lack of clinical tests to quantify spatial components of distortion in patients with full thickness macular holes (FTMH) and epiretinal membranes (ERM). Aim: To develop a test for subjective evaluation of visual distortion in the central visual field around fixation in patients with unilateral FTMH or ERM. Settings and Design: Prospective case-control study carried out at tertiary referral center. Materials and Methods: Twenty-five patients with unilateral macular disease (13 macular epiretinal membranes, 12 full-thickness macular holes), and nine controls (without ocular pathology) underwent ophthalmological examination with logMAR ETDRS visual acuity, near vision and contrast sensitivity assessed. Macular optical coherence tomography and metamorphopsia assessment using Morphision test was also carried out. This test consists of a set of modified Amsler charts for detection, identification, and subjective quantification of visual distortion in the central visual field around fixation. Morphision test content and construct validity, and reliability (test-retest method) were evaluated. Sixteen patients completed an unstructured survey on test performance and preference. Results: Every patient with unilateral FTMH or ERM identified a particular chart using Morphision test (content validity). None of the normal subjects without symptoms of metamorphopsia identified any distortion (construct validity). Test-retest showed a 100% consistency for frequency and 67% for amplitude. The mean amplitude difference between measurements was 0.02 degrees (SD = 0.038). The coefficient of repeatability was 0.075. There was a correlation between Morphision amplitude score and visual acuity and contrast sensitivity, individually. Conclusions: Morphision test allowed detection and subjective quantification of metamorphopsia in the clinical setting in our patients with unilateral macular epiretinal membranes and full thickness macular holes. PMID:24008785

Ugarte, Marta; Shunmugam, Manoharan; Laidlaw, D Alistair H; Williamson, Tom H

2013-01-01

398

Structure of plant bile pigments  

SciTech Connect

Selective peptide cleavage has provided a general procedure for the study of the structure, including stereochemistry, of plant bile pigments. The information derived from the synthesis and spectral analysis of a series of 2,3-dihydrodioxobilins allows the determination of the trans relative stereochemistry for ring A of the ..beta../sub 1/-phycocyanobilin from C-phycocyanin as well as for ring A of phytochrome. A complete structure proof of the five phycoerythrobilins attached to the ..cap alpha.. and ..beta.. subunits of B-phycoerythrin is described. One of these tetrapyrroles is doubly-peptide linked to a single peptide chain through two thioethers at the C-3' and C-18' positions. The four remaining phycoerythrobilins are singly-linked to the protein through thioethers at the C-3' position and all possess the probable stereochemistry C-2(R), C-3(R), C-3'(R), and C-16(R).

Schoenleber, R.W.

1983-12-01

399

Fucoidan Reduces Secretion and Expression of Vascular Endothelial Growth Factor in the Retinal Pigment Epithelium and Reduces Angiogenesis In Vitro  

PubMed Central

Fucoidan is a polysaccharide isolated from brown algae which is of current interest for anti-tumor therapy. In this study, we investigated the effect of fucoidan on the retinal pigment epithelium (RPE), looking at physiology, vascular endothelial growth factor (VEGF) secretion, and angiogenesis, thus investigating a potential use of fucoidan for the treatment of exudative age-related macular degeneration. For this study, human RPE cell line ARPE-19 and primary porcine RPE cells were used, as well as RPE/choroid perfusion organ cultures. The effect of fucoidan on RPE cells was investigated with methyl thiazolyl tetrazolium – assay, trypan blue exclusion assay, phagocytosis assay and a wound healing assay. VEGF expression was evaluated in immunocytochemistry and Western blot, VEGF secretion was evaluated in ELISA. The effect of fucoidan on angiogenesis was tested in a Matrigel assay using calcein-AM vital staining, evaluated by confocal laser scanning microcopy and quantitative image analysis. Fucoidan displays no toxicity and does not diminish proliferation or phagocytosis, but reduces wound healing in RPE cells. Fucoidan decreases VEGF secretion in RPE/choroid explants and RPE cells. Furthermore, it diminishes VEGF expression in RPE cells even when co-applied with bevacizumab. Furthermore, fucoidan reduces RPE-supernatant- and VEGF-induced angiogenesis of peripheral endothelial cells. In conclusion, fucoidan is a non-toxic agent that reduces VEGF expression and angiogenesis in vitro and may be of interest for further studies as a potential therapy against exudative age-related macular degeneration. PMID:24558482

Dithmer, Michaela; Fuchs, Sabine; Shi, Yang; Schmidt, Harald; Richert, Elisabeth; Roider, Johann; Klettner, Alexa

2014-01-01

400

Fucoidan reduces secretion and expression of vascular endothelial growth factor in the retinal pigment epithelium and reduces angiogenesis in vitro.  

PubMed

Fucoidan is a polysaccharide isolated from brown algae which is of current interest for anti-tumor therapy. In this study, we investigated the effect of fucoidan on the retinal pigment epithelium (RPE), looking at physiology, vascular endothelial growth factor (VEGF) secretion, and angiogenesis, thus investigating a potential use of fucoidan for the treatment of exudative age-related macular degeneration. For this study, human RPE cell line ARPE-19 and primary porcine RPE cells were used, as well as RPE/choroid perfusion organ cultures. The effect of fucoidan on RPE cells was investigated with methyl thiazolyl tetrazolium--assay, trypan blue exclusion assay, phagocytosis assay and a wound healing assay. VEGF expression was evaluated in immunocytochemistry and Western blot, VEGF secretion was evaluated in ELISA. The effect of fucoidan on angiogenesis was tested in a Matrigel assay using calcein-AM vital staining, evaluated by confocal laser scanning microcopy and quantitative image analysis. Fucoidan displays no toxicity and does not diminish proliferation or phagocytosis, but reduces wound healing in RPE cells. Fucoidan decreases VEGF secretion in RPE/choroid explants and RPE cells. Furthermore, it diminishes VEGF expression in RPE cells even when co-applied with bevacizumab. Furthermore, fucoidan reduces RPE-supernatant- and VEGF-induced angiogenesis of peripheral endothelial cells. In conclusion, fucoidan is a non-toxic agent that reduces VEGF expression and angiogenesis in vitro and may be of interest for further studies as a potential therapy against exudative age-related macular degeneration. PMID:24558482

Dithmer, Michaela; Fuchs, Sabine; Shi, Yang; Schmidt, Harald; Richert, Elisabeth; Roider, Johann; Klettner, Alexa

2014-01-01

401

Noninvasive two-photon microscopy imaging of mouse retina and retinal pigment epithelium through the pupil of the eye.  

PubMed

Two-photon excitation microscopy can image retinal molecular processes in vivo. Intrinsically fluorescent retinyl esters in subcellular structures called retinosomes are an integral part of the visual chromophore regeneration pathway. Fluorescent condensation products of all-trans-retinal accumulate in the eye with age and are also associated with age-related macular degeneration (AMD). Here, we report repetitive, dynamic imaging of these compounds in live mice through the pupil of the eye. By leveraging advanced adaptive optics, we developed a data acquisition algorithm that permitted the identification of retinosomes and condensation products in the retinal pigment epithelium by their characteristic localization, spectral properties and absence in genetically modified or drug-treated mice. This imaging approach has the potential to detect early molecular changes in retinoid metabolism that trigger light- and AMD-induced retinal defects and to assess the effectiveness of treatments for these conditions. PMID:24952647

Palczewska, Grazyna; Dong, Zhiqian; Golczak, Marcin; Hunter, Jennifer J; Williams, David R; Alexander, Nathan S; Palczewski, Krzysztof

2014-07-01

402

Microcystic macular oedema in multiple sclerosis is associated with disease severity  

PubMed Central

Macular oedema typically results from blood–retinal barrier disruption. It has recently been reported that patients with multiple sclerosis treated with FTY-720 (fingolimod) may exhibit macular oedema. Multiple sclerosis is not otherwise thought to be associated with macular oedema except in the context of comorbid clinical uveitis. Despite a lack of myelin, the retina is a site of inflammation and microglial activation in multiple sclerosis and demonstrates significant neuronal and axonal loss. We unexpectedly observed microcystic macular oedema using spectral domain optical coherence tomography in patients with multiple sclerosis who did not have another reason for macular oedema. We therefore evaluated spectral domain optical coherence tomography images in consecutive patients with multiple sclerosis for microcystic macular oedema and examined correlations between macular oedema and visual and ambulatory disability in a cross-sectional analysis. Participants were excluded if there was a comorbidity that could account for the presence of macular oedema, such as uveitis, diabetes or other retinal disease. A microcystic pattern of macular oedema was observed on optical coherence tomography in 15 of 318 (4.7%) patients with multiple sclerosis. No macular oedema was identified in 52 healthy controls assessed over the same period. The microcystic oedema predominantly involved the inner nuclear layer of the retina and tended to occur in small, discrete patches. Patients with multiple sclerosis with microcystic macular oedema had significantly worse disability [median Expanded Disability Score Scale 4 (interquartile range 3–6)] than patients without macular oedema [median Expanded Disability Score Scale 2 (interquartile range 1.5–3.5)], P?=?0.0002. Patients with multiple sclerosis with microcystic macular oedema also had higher Multiple Sclerosis Severity Scores, a measure of disease progression, than those without oedema [median of 6.47 (interquartile range 4.96–7.98) versus 3.65 (interquartile range 1.92–5.87), P?=?0.0009]. Microcystic macular oedema occurred more commonly in eyes with prior optic neuritis than eyes without prior optic neuritis (50 versus 27%) and was associated with lower visual acuity (median logMAR acuity of 0.17 versus ?0.1) and a thinner retinal nerve fibre layer. The presence of microcystic macular oedema in multiple sclerosis suggests that there may be breakdown of the blood–retinal barrier and tight junction integrity in a part of the nervous system that lacks myelin. Microcystic macular oedema may also contribute to visual dysfunction beyond that explained by nerve fibre layer loss. Microcystic changes need to be assessed, and potentially adjusted for, in clinical trials that evaluate macular volume as a marker of retinal ganglion cell survival. These findings also have implications for clinical monitoring in patients with multiple sclerosis on sphingosine 1-phosphate receptor modulating agents. PMID:22539259

Gelfand, Jeffrey M.; Nolan, Rachel; Schwartz, Daniel M.; Graves, Jennifer

2012-01-01

403

Lutein and zeaxanthin supplementation reduces photo-oxidative damage and modulates the expression of inflammation related genes in retinal pigment epithelial cells  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oxidative damage and inflammation are related to the pathogenesis of age-related macular degeneration (AMD). Epidemiologic studies suggest that insufficient dietary lutein and zeaxanthin intake or lower serum zeaxanthin levels are associated with increased risk for AMD. The objective of this work w...

404

Carotenoid pigments of facultatively anaerobic spirochetes.  

PubMed

Carotenoid pigments were purified from a previously undescribed, red, halophilic spirochete (spirochete RS1), and from Spirochaeta aurantia strain J1. Both spirochetes are facultative anaerobes and produce pigments when growing aerobically. The major pigments of the two spirochetes were identified by means of chromatographic analysis, absorption spectroscopy, hydride reduction, acetylation and silylation experiments, and mass spectrometry. It was concluded that the major pigment from spirochete RS1 was 4-keto-1',2'-dihydro-1'-hydroxytorulene. This conclusion was further supported by infrared spectroscopy and additional analytical data. The evidence showed that the major pigment from S. aurantia was 1',2'-dihydro-1'-hydroxytorulene. Chromatographic and spectrophotometric evidence indicated that this pigment was also present, as a minor carotenoid component, in spirochete RS1. These pigments have been previously detected almost exclusively in gliding bacteria, such as species of Flexibacter, Stigmatella, and Myxococcus. The occurrence of 4-keto-1',2'-dihydro-1'-hydroxytorulene and 1',2'-dihydro-1'-hydroxytorulene in both spirochetes and gliding bacteria may have significance with respect to the evolutionary development of these organisms. PMID:1158846

Greenberg, E P; Canale-Parola, E

1975-09-01

405

Study of Biological Pigments by Single Specimen Derivative Spectrophotometry  

PubMed Central

The single specimen derivative (SSD) method provides an absolute absorption spectrum of a substance in the absence of a suitable reference. Both a reference and a measuring monochromatic beam pass through a single sample, and the specimen itself acts as its own reference. The two monochromatic beams maintain a fixed wavelength difference upon scanning, and the difference in absorbance of the two beams is determined. Thus, the resulting spectrum represents the first derivative of the conventional type absorption spectrum. Tissues and cell fractions have been examined at room and liquid N2 temperature and chromophoric molecules such as the mitochondrial cytochromes and blood pigments have been detectable in low concentrations. In the case of isolated cellular components, the observed effects of substrates and inhibitors confirm similar studies by conventional spectrophotometry. The extension of the SSD concept to the microscopic level has permitted the study of the tissue compartmentalization and function of cytochromes and other pigments within layered tissue. PMID:4392452

Goldstein, Jack M.

1970-01-01

406

Visual function and serous retinal detachment in patients with branch retinal vein occlusion and macular edema: a case series  

PubMed Central

Background The influence of serous retinal detachment (SRD) on retinal sensitivity in patients with branch retinal vein occlusion (BRVO) and macular edema remains unclear. This is despite the frequent co-existence of SRD and cystoid macular edema (CME) in BRVO patients on optical coherence tomography (OCT) and the fact that CME is the most common form of macular edema secondary to BRVO. We investigated visual function (visual acuity and macular sensitivity), macular thickness, and macular volume in patients with BRVO and macular edema. Methods Fifty-three consecutive BRVO patients (26 women and 27 men) were divided into two groups based on optical coherence tomography findings. Macular function was documented by microperimetry, while macular thickness and volume were measured by OCT. Results There were 15 patients with SRD and 38 patients with CME. Fourteen of the 15 patients with SRD also had CME. Visual acuity was significantly worse in the SRD group than in the CME group (P = 0.049). Also, macular thickness and macular volume within the central 4°, 10°, and 20° fields were significantly greater in the SRD group (P = 0.008, and P = 0.007, P < 0.001 and P < 0.001, and P < 0.001 and P < 0.001, respectively). However, macular sensitivity within the central 4°, 10°, and 20° fields was not significantly worse in the SRD group than in the CME group. Conclusions SRD itself may decrease visual acuity together with CME, because nearly all SRD patients also had CME. SRD does not seem to influence macular function on microperimetry. PMID:21943190

2011-01-01

407

Key Regulatory Role of Dermal Fibroblasts in Pigmentation as Demonstrated Using a Reconstructed Skin Model: Impact of Photo-Aging  

PubMed Central

To study cutaneous pigmentation in a physiological context, we have previously developed a functional pigmented reconstructed skin model composed of a melanocyte-containing epidermis grown on a dermal equivalent comprising living fibroblasts. The present studies, using the same model, aimed to demonstrate that dermal fibroblasts influence skin pigmentation up to the macroscopic level. The proof of principle was performed with pigmented skins differing only in the fibroblast component. First, the in vitro system was reconstructed with or without fibroblasts in order to test the global influence of the presence of this cell type. We then assessed the impact of the origin of the fibroblast strain on the degree of pigmentation using fetal versus adult fibroblasts. In both experiments, impressive variation in skin pigmentation at the macroscopic level was observed and confirmed by quantitative parameters related to skin color, melanin content and melanocyte numbers. These data confirmed the responsiveness of the model and demonstrated that dermal fibroblasts do indeed impact the degree of skin pigmentation. We then hypothesized that a physiological state associated with pigmentary alterations such as photo-aging could be linked to dermal fibroblasts modifications that accumulate over time. Pigmentation of skin reconstructed using young unexposed fibroblasts (n?=?3) was compared to that of tissues containing natural photo-aged fibroblasts (n?=?3) which express a senescent phenotype. A stimulation of pigmentation in the presence of the natural photo-aged fibroblasts was revealed by a significant increase in the skin color (decrease in Luminance) and an increase in both epidermal melanin content and melanogenic gene expression, thus confirming our hypothesis. Altogether, these data demonstrate that the level of pigmentation of the skin model is influenced by dermal fibroblasts and that natural photo-aged fibroblasts can contribute to the hyperpigmentation that is associated with photo-aging. PMID:25490395

Duval, Christine; Cohen, Catherine; Chagnoleau, Corinne; Flouret, Virginie; Bourreau, Emilie; Bernerd, Françoise

2014-01-01

408

The Short-term Efficacy of Subthreshold Micropulse Yellow (577-nm) Laser Photocoagulation for Diabetic Macular Edema  

PubMed Central

Purpose This pilot study aimed to evaluate the efficacy and safety of subthreshold micropulse yellow (577-nm) laser photocoagulation (SMYLP) in the treatment of diabetic macular edema (DME). Methods We reviewed 14 eyes of 12 patients with DME who underwent SMYLP with a 15% duty cycle at an energy level immediately below that of the test burn. The laser exposure time was 20 ms and the spot diameter was 100 µm. Laser pulses were administered in a confluent, repetitive manner with a 3 × 3 pattern mode. Results The mean follow-up time was 7.9 ± 1.6 months. The baseline-corrected visual acuity was 0.51 ± 0.42 logarithm of the minimum angle of resolution (logMAR), which was improved to 0.40 ± 0.35 logMAR (p = 0.025) at the final follow-up. The central macular thickness at baseline was 385.0 ± 111.0 µm; this value changed to 327.0 ± 87.7 µm (p = 0.055) at the final follow-up. Conclusions SMYLP showed short-term efficacy in the treatment of DME and did not result in retinal damage. However, prospective, comparative studies are needed to better evaluate the efficacy and safety of this treatment. PMID:25276079