147 resultados para Textual and visual


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PURPOSE: The purpose of this study was to characterize local distribution and systemic absorption of the tumor necrosis factor (TNF)-alpha inhibitory single-chain antibody fragment (scFv) ESBA105 following topical administration to the eye in vivo. METHODS: Rabbits received ESBA105 as topical eye drops in two dosing regimens. First, pharmacokinetics after the topical route of administration was compared to the intravenous (i.v.) route by means of applying the identical cumulative daily dose of ESBA105. In a second study rabbits received five eye drops daily for six consecutive days in a lower frequency topical dosing regimen. Kinetics and biodistribution of ESBA105 in ocular tissues and fluids as well as in sera were determined in all animals. RESULTS: After topical administration to the eye, ESBA105 quickly reaches therapeutic concentrations in all ocular compartments. Systemic exposure after topical administration is 25,000-fold lower than exposure after i.v. injection of the identical cumulative daily dose. ESBA105 levels in vitreous humor and neuroretina are significantly higher on topical administration than after i.v. injection. Absolute and relative intraocular biodistribution of ESBA105 is different with topical and systemic delivery routes. Compared to its terminal half-life in circulation (7 hours), the vitreal half-life of ESBA105 is significantly enhanced (16-24 hours). CONCLUSIONS: On topical administration, ESBA105 is efficiently absorbed and distributed to all compartments of the eye, whereby systemic drug exposure is very low. Based on its unique intraocular biodistribution and pharmacokinetics and the absolute intraocular levels reached, topical ESBA105 appears highly attractive for treatment of various ophthalmological disorders.

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Purpose: To phenotype a large 3 generation Swiss family with pattern dystrophy and to report a successful result of treatment with ranibizumab of a subfoveal choroidal neovascularisation (CNV) associated with pattern dystrophy in 1 patient Patients and methods: 4 affected and 3 unaffected patients (3 female 4 male, age range: 19 - 80 years) were assessed with a complete ophthalmologic examination. AF images were taken using Heidelberg Retina Angiograph and the digital color photos, fluorescein angiogragraphy (FFA) using the same TOPCON 501 camera. Electroretinogram (full-field and multifocal) was performed in 1 affected patient. One 48 years old patient developed a subfoveal CNV, which was treated with 2 injections of ranibizumab, at 3 months interval. Blood sample was taken for molecular analysis (screening of the gene RDS). Results: Two patients had a typical fundoscopic appearance of pattern dystrophy with butterfly shaped deposit at the fovea and some peripheral flecks, as shown with AF imaging.. Two others affected patients had a more unusual appearance with some macular atrophy in one or both eyes, surrounded by flecks. The visual acuity ranged from 1.0 to 0.1 according to Snellen EDTRS chart. The patient with subfoveal CNV presented a drop of vision form 1.0 to 0.6 within 10 days prior to the diagnosis and also reported some metamorphopsia. FFA and optical computerized tomography (OCT) confirmed a classic CNV. After the 1st injection her vision improved to 1.0 but persistent metamorphopsia and fluid on OCT motivated a second injection. One month after the second injection the OCT was flat and the patient had no symptoms. The results of RDS screening will be presented at the meeting. Conclusion: We present a family with pattern dystrophy, with some members having an unusual fundus appearance, which was mistaken for an early onset dry AMD. The AF imaging is a useful tool in diagnosing this condition. A CNV associated with pattern dystrophy a rare. This is the first report of a successful treatment of the CNV with anti-VEGF intravitreal injections.

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Purpose: Retinal stem cells (RSCs) can be isolated from radial glia population of the newborn mouse retina (Angénieux et al., 2006). These RSCs have great capacity to renew and generate neurons including cells differentiated towards the photoreceptor lineage (Mehri-Soussi et al., 2006). However, our published results showed poor integration and survival rate after cell grafting into the retina. The uncontrollable environment of retina seems to be the problem. To bypass this, we are trying to generate hemi-retinal tissue in vitro that can be used for transplantation. Methods: Expanded RSCs were seeded in a mixture of poly-ethylene-glycol (PEG)-polymer-based hydrogels crosslinked by peptides that also serve as substrates for matrix metalloproteinases. Different doses of crosslinker peptides were tested. Several growth factors were studied to stimulate cell proliferation and differentiation. Results: Cells were trapped in hydrogels and cultured in the presence of FGF2 and EGF. Spherical cell clusters indicating proliferation appeared within several days, but there was no cell migration within the gel. We then added cell adhesion molecules integrin ligand RGDSP, or laminin, or a combination of both, into the gel. Cells grown with laminin showed the best proliferation. Cells grown with RGDSP proliferated a few times and then started to spread out. Cells grown with the combination of RGDSP and laminin showed better proliferation than with RGDSP alone and larger spread-outs than with laminin alone. After stimulations with first FGF2 and EGF, and then only FGF2, some cells showed neuronal morphology after 2 weeks. The neuronal population was assessed by the presence of neuronal marker b-tubulin-III. Glial cells were also present. Further characterizations are undergoing. Conclusions: RSC can grow and migrate in 3D hydrogel with the addition of FGF2, EGF, RGDSP and laminin. Further developments are necessary to form a homogenous tissue containing retinal cells.

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BACKGROUND: Previous reports have emphasized the self-limited nature of idiopathic neuroretinitis. There is less information about a subgroup of patients who suffer recurrent episodes with worse visual outcome. We sought to better characterize the clinical features of recurrent idiopathic neuroretinitis including the effects of immunosuppressive treatment. METHODS: Retrospective chart review of neuroretinitis patients from a single institution from 1983 to 2008. Inclusion criteria included two or more episodes of acute visual loss with disc oedema and macular exudates in a star pattern. Cases due to a specific infectious or inflammatory aetiology were excluded. RESULTS: Forty-one patients were included with an average follow up of 67 months. Median age at the time of the first episode was 28 years (range 10-54 years). Attacks were bilateral sequential in 34 patients (83%). We documented a total of 147 episodes in 75 eyes with an average of 3.6 attacks per patient. The average interval between attacks was 3 years. Visual field loss had a nerve fibre bundle pattern in most cases. Only 36% of eyes retained 6/12 or better visual acuity and greater than two-thirds of their visual field. Long-term immunosuppressive treatment in 13 patients decreased the attack rate by 72%. CONCLUSIONS: Recurrent idiopathic neuroretinitis typically affects young adults, with no gender preference. Recovery is limited and visual loss is cumulative with repeated attacks, often resulting in severe permanent visual loss. Immunosuppressive treatment appears to lessen the attack frequency.

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Purpose: Mutations in the ligand-binding domain (LBD) of NR2E3 cause recessively inherited enhanced short wavelength sensitive (S-) cone syndrome (ESCS), Goldmann-Favre syndrome (GFS) and clumped pigmentary retinal degeneration (CPRD). In addition to ligand binding, the LBD contains also essential amino acid sequences for the oligomerization of nuclear receptors. The aim of our studies is to characterize the impact of mutations in the LBD on receptor oligomerization and transcriptional activity of NR2E3. Methods: The different NR2E3 mutants were generated by QuickChange mutagenesis and analyzed in 293T-based transactivation studies and BRET2 (bioluminescence resonance electron transfer) assays. In silico homology modeling of mutant proteins was also performed using available crystallographic data of related nuclear receptors. Results: The mutants p.W234S, p.A256V, p.A256E, p.L263P, p.R309G, p.R311Q, p.R334G, p.L336P, p.L353V, p.R385P and p.M407K, all located in the LBD, showed impaired receptor dimerization at various degrees. Impaired repressor dimerization as assessed by BRET2 assays did not always correlate with impaired repressor function of NR2E3 as assessed by cell-based reporter assays. There were minor differences of transcriptional activity of mutant proteins on mouse S-opsin (opn1sw), mouse cone arrestin (arr3) and human cone arrestin, suggesting that the effect of LBD mutations was independent of the promoter context. Conclusions: Mutational analysis and homology modeling allowed the characterization of potential oligomerization interfaces of the NR2E3 LBD. Additionally, mutations in NR2E3 LBD may cause recessive retinal degenerations by different molecular mechanisms.

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PURPOSE: We characterized the pupil responses that reflect rod, cone, and melanopsin function in a genetically homogeneous cohort of patients with autosomal dominant retinitis pigmentosa (adRP). METHODS: Nine patients with Gly56Arg mutation of the NR2E3 gene and 12 control subjects were studied. Pupil and subjective visual responses to red and blue light flashes over a 7 log-unit range of intensities were recorded under dark and light adaptation. The pupil responses were plotted against stimulus intensity to obtain red-light and blue-light response curves. RESULTS: In the dark-adapted blue-light stimulus condition, patients showed significantly higher threshold intensities for visual perception and for a pupil response compared to controls (P = 0.02 and P = 0.006, respectively). The rod-dependent, blue-light pupil responses decreased with disease progression. In contrast, the cone-dependent pupil responses (light-adapted red-light stimulus condition) did not differ between patients and controls. The difference in the retinal sensitivity to blue and red stimuli was the most sensitive parameter to detect photoreceptor dysfunction. Unexpectedly, the melanopsin-mediated pupil response was decreased in patients (P = 0.02). CONCLUSIONS: Pupil responses of patients with NR2E3-associated adRP demonstrated reduced retinal sensitivity to dim blue light under dark adaptation, presumably reflecting decreased rod function. Rod-dependent pupil responses were quantifiable in all patients, including those with non-recordable scotopic electroretinogram, and correlated with the extent of clinical disease. Thus, the chromatic pupil light reflex can be used to monitor photoreceptor degeneration over a larger range of disease progression compared to standard electrophysiology.

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Five patients with a chief visual complaint of photophobia were subsequently found to have compressive lesions of the optic chiasm. Visual acuity and visual field deficits were often subtle. Magnetic resonance imaging scanning revealed large suprasellar masses, including three pituitary adenomas, a craniopharyngioma, and a clivus chordoma. Photophobia resolved in all patients following treatment of the tumors. A compressive lesion of the optic chiasm should be considered in patients who experience persistent photophobia unexplained by ocular abnormalities.

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BACKGROUND: Perioperative visual loss (PVL) refers to the loss of vision following surgery performed at distance from the visual pathways. An ischemic optic neuropathy (ION) is the most frequent clinical presentation of PVL, and can be bilateral. PATIENTS AND METHODS: A retrospective chart review of 11 consecutive patients with PVL examined between 2002 and 2007 was undertaken. RESULTS: An ION was found in all 11 cases: 8 were anterior (AION) and 3 were posterior (PION). Visual loss was bilateral in 9 patients. Mean visual acuity (VA) was 0.2 on the Snellen chart (0.74 LogMAR). Most frequently an arcuate/altitudinal visual field defect was present. PVL followed orthopedic (6), spinal (1), cardiac (2) and vascular (2) procedures. The average delay between surgery and visual loss was 32 hours (range: 0-96 hours). Average lowest perioperative hemoglobin level was 75 g/L. Average follow-up time was 14.7 months. VA improved by at least 2 Snellen lines in 5/20 eyes (25 %). CONCLUSIONS: PVL is a rare but dreadful complication of surgery, and is usually associated with severe anemia. Like other causes of ION, there is no specific therapy. Prompt correction of the anemia might decrease the rate of this complication

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PURPOSE: To determine whether bovine corneal endothelial (BCE) cells and keratocytes express the inducible form of nitric oxide synthase (NOS) after exposure to cytokines and lipopolysaccharide (LPS), and to study the regulation of NOS by growth factors. METHODS: Cultures of bovine corneal endothelial cells and keratocytes were exposed to increasing concentrations of LPS, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha). At selected intervals after exposure, nitrite levels in the supernatants were evaluated by the Griess reaction. Total RNA was extracted from the cell cultures, and messenger RNA levels for inducible NOS (NOS-2) were measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Exposure of BCE cells and keratocytes to LPS and IFN-gamma resulted in an increase of nitrite levels that was potentiate by the addition of TNF-alpha. Analysis by RT-PCR demonstrated that nitrite release was correlated to the expression of NOS-2 messenger RNA in BCE cells and keratocytes. Stereoselective inhibitors of NOS and cycloheximide inhibited LPS-IFN-gamma-induced nitrite release in both cells, whereas transforming growth factor-beta (TGF-beta) slightly potentiated it. Fibroblast growth factor-2 (FGF-2) inhibited LPS-IFN-gamma-induced nitrite release and NOS-2 messenger RNA accumulation in keratocytes but not in BCE cells. CONCLUSIONS: The results demonstrate that in vitro activation of keratocytes and BCE cells by LPS and cytokines induces NOS-2 expression and release of large amounts of NO. The high amounts of NO could be involved in inflammatory corneal diseases in vivo.

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Purpose:In the retina, the balance between pro- and anti-angiogenic factors is critical for angiogenesis control but is also involved in cell survival and maintenance. For instance, the anti-angiogenic factor PEDF is neuroprotective for photoreceptors (PRs) in models of retinal degeneration. We previously reported upregulation of VEGF (24h to 48h post lesion) in the light-damage (LD) model. Furthermore, systemic delivery of PEDF, as well as lentiviral gene transfer of an anti-VEGF antibody rescue PRs from cell death. Studies in vitro show that VEGF induces retinal endothelial cells apoptosis via the alteration of the Akt1/p38 MAPK signalling pathway under hypoxic conditions. Thus, in this study, we investigate the effect of high levels of VEGF on retinal pigmented epithelium (RPE) permeability and molecular targets expression after light-induced PR degeneration. Methods:To characterize the action of VEGF in the retina during the course of LD, we exposed adult Balb/c mice to 5'000 lux for 1h, and we collected neural retinas and eye-cups (containing RPE) at different time points after the LD. We analysed protein expression by Elisa and Western blotting. In order to study RPE cell permeability after the LD we stained β-catenin on flat mounted RPE. Results:In the neural retina, preliminary results indicate that high levels of VEGF induce a significant upregulation of VEGF receptor 2, whereas VEGF receptor 1 expression is decreased. Concomitantly with VEGF upregulation, LD increases the Src phosphorylation between 24h to 48h. Furthermore, we observe that β-catenin translocates to the cytoplasm of RPE cells between 24h to 36h after the lesion, indicating an increase on the RPE permeability, which could contribute indirectly to the deleterious effect of VEGF observed during light-induced PR apoptosis. Conclusions:This study further involves VEGF in LD and highlights the prime importance of angiogenic factor balance for PR survival. Our results suggest that PR apoptosis is augmented by RPE cell permeability, which may induce high level of VEGF and could be deleterious. The specific action of RPE permeability on PR survival and the role of Src in the retina are under investigation.

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Purpose: To describe the clinical, histologic and genetic findings of corneal opacities in the trisomy 8 mosaic syndrome. Methods: 3 children aged 8 years (Patients A), 6 years (Patients B) and 1 month (Patients C) respectively, were referred with corneal opacities for ophthalmologic evaluation. The 2 older patients had been previously diagnosed with trisomy 8 mosaicism, while the third was diagnosed after the ocular examination. Automated lamellar keratoplasty (ALTK) was performed on the most amblyopic eye. Histopathologic analysis with immunohistochemical markers and cytogenetic studies by FISH using haploid probes for chromosome 8 and chromosome 16 (control) were performed on the excised corneal lesion. Results: All patients presented vascularized corneal opacities involving the superficial stroma, and amblyopia with a bilateral involvement in two of them (Patients A and B). Post-operative follow-up (range 6-20 months) was satisfactory, with the graft remaining clear and improved visual acuity, allowing iso-acuity and stereoscopy in the one month old child (Patients C). The clinically observed corneal opacities corresponded histopathologically to the replacement of the normal anterior corneal stroma by a choristomatous loose richly vascularized connective tissue containing mucopolysacharides. Bowman's membrane was absent. There were no adnexal structures. The overlaying epithelium expressed keratin 3 in all three cases. Keratin 19 was found in the suprabasal epithelial cells in one case but was absent in the other cases. There were no expression of keratin 7 and 1 as well as MUC5AC in the epithelial cells. FISH analysis from 100 interphase cells of the affected tissue and normal conjontival probe revealed normal diploid cells. Conclusions: In this series, the corneal opacities associated with trisomy 8 mosaic syndrome share a common clinical, histopathological and genetic features. ALTK should be considered at diagnosis to prevent amblyopia in these children.

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Purpose:To report the functional, anatomic outcome and safety profile of 23-gauge pars plana vitrectomy (PPV) combined with peeling and intravitreal injection of triamcinolone acetonide (TA) in eyes with idiopathic epiretinal membranes (ERM). Methods:Retrospective, nonrandomized study of consecutive patients who underwent 23-gauge transconjunctival sutureless PPV with subsequent membrane peeling and intravitreal TA injection for an idiopathic ERM. All patients were operated between February 2007 and February 2008 at the Jules Gonin University Eye Hospital. The minimum follow-up was 6-months. Results:Thirty-nine eyes of 39 patients were included. The mean follow-up was 7 months (SD: 2.2, range: 6-15 months). Twenty-two (56%) eyes were pseudophakic and 17 (44%) were phakic at the time of surgery. Mean preoperative intraocular pressure (IOP) was 14 mmHg (SD: 3.5). At the final follow-up mean IOP was 14.5 (SD: 2.7) that did not differ significantly from the IOP at baseline (P: 0.14- 2-tailed t test). Five patients (13%) needed temporary topical anti-glaucoma treatment.Mean preoperative BCVA was 0.28 decimal equivalent (logMAR 0.54, SD: 0.2, range: 1.0 - 0.2). and improved significantly (P <0.0001, 2-tailed t test) to a mean of 0.6 decimal equivalent (logMAR 0.22, SD: 0.16, range: 0.6 - 0) at the final follow-up. The visual acuity improved by a mean of 3.2 lines (SD 2.1, range 0- 8). Twenty-nine patients (74%) demonstrated a gain of 3 or more lines.Mean central macular thickness (CMT) was 456 µm (SD: 77) at the baseline that reduced significantly (P <0.0001, 2-tailed t test) at the final follow-up to 327µm (SD: 79). Average CMT reduction was 131µm (SD: 77, range: 36- 380 µm). A subgroup analysis of 15 selected cases that had CMT measurement 1 week after surgery demonstrated that 84% of the total final reduction in CMT occurred during the first week. Conclusions:23-gauge sutureless transconjunctival vitrectomy with the concomitant administration of intravitreal TA is a safe and effective technique for the treatment of idiopathic ERM and may speed up anatomical recovery.

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Purpose:To functionally and morphologically characterize the retina and optic nerve after transplantation of Brain-derived neurotrophic factor (BDNF) and Glial-derived neurotrophic factor (GDNF) secreting mesenchymal stem cells (MSCs) into glaucomatous rat eyes. Methods:Chronic ocular hypertension (COH) was induced in Brown Norway rats. Lentiviral constructs were used to transduce rat MSCs to produce BDNF, GDNF, or green fluorescent protein (GFP). The fellow eyes served as internal controls. Two days following COH induction, eyes received intravitreal injections of transduced MSCs. Electroretinography was performed to assess retinal function. Tonometry was performed throughout the experiment to monitor IOP. 42 days after MSC transplantation, rats were euthanized and the eyes and optic nerves were prepared for analysis. Results:Increased expression and secretion of BDNF and GDNF from lentiviral-transduced MSCs was verified using ELISA, and a bioactivity assay. Ratio metric analysis (COH eye/ Internal control eye response) of the Max combined response A-Wave showed animals with BDNF-MSCs (23.35 ± 5.15%, p=0.021) and GDNF-MSCs (28.73 ± 3.61%, p=0.025) preserved significantly more visual function than GFP-MSC treated eyes MSCs (18.05 ± 5.51%). Animals receiving BDNF-MSCs also had significantly better B-wave (33.80 ± 7.19%) and flicker ERG responses (28.52 ± 10.43%) than GFP-MSC treated animals (14.06 ± 12.67%; 3.52 ± 0.07%, respectively). Animals receiving GDNF-MSC transplants tended to have better function than animals with GFP-MSC transplants, but were not statistically significant (p=0.057 and p=0.0639). Conclusions:Mesenchymal stem cells are an excellent source of cells for autologous transplantation for the treatment of neurodegenerative diseases. We have demonstrated that lentiviral- transduced MSCs can survive following transplantation and preserve visual function in glaucomatous eyes. These results suggest that MSCs may be an ideal cellular vehicle for delivery of specific neurotrophic factors to the retina.

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PURPOSE: When treating peripheral ectatic disease-like pellucid marginal degeneration (PMD), corneal cross-linking with UV-A and riboflavin (CXL) must be applied eccentrically to the periphery of the lower cornea, partly irradiating the corneal limbus. Here, we investigated the effect of standard and double-standard fluence corneal cross-linking with riboflavin and UV-A (CXL) on cornea and corneal limbus in the rabbit eye in vivo. METHODS: Epithelium-off CXL was performed in male New Zealand White rabbits with two irradiation diameters (7 mm central cornea, 13 mm cornea and limbus), using standard fluence (5.4 J/cm(2)) and double-standard fluence (10.8 J/cm(2)) settings. Controls were subjected to epithelial removal and riboflavin instillation, but were not irradiated with UV-A. Following CXL, animals were examined daily until complete closure of the epithelium, and at 7, 14, 21, and 28 days. Animals were killed and a corneoscleral button was excised and processed for light microscopy and immunohistochemistry. RESULTS: For both irradiation diameters and fluences tested, no signs of endothelial damage or limbal vessel thrombosis were observed, and time to re-epithelialization was similar to untreated controls. Histological and immunohistochemical analysis revealed no differences in the p63 putative stem cell marker expression pattern. CONCLUSIONS: Even when using fluence twice as high as the one used in current clinical CXL settings, circumferential UV-A irradiation of the corneal limbus does not alter the regenerative capacity of the limbal epithelial cells, and the expression pattern of the putative stem cell marker p63 remains unchanged. This suggests that eccentric CXL may be performed safely in PMD.

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Detailed sampling of the Upper Triassic atoll-type carbonates of the Sambosan Accretionary Complex throughout Southwest Japan yielded highly abundant and diversified porcelaneous, microgranular, agglutinated and hyaline foraminifers of Carnian-Rhaetian age, as well as some microproblematica and ostracods. The foraminiferal assemblages were collected from shallow-water carbonates originated upon volcanic seamounts surrounded by deep-water radiolarian chert in a mid-open oceanic realm of the Panthalassan Ocean during Triassic time. Because most studies of the Upper Triassic microfauna come from the former Tethys, counterparts of the Panthalassan Ocean are pivotal to decipher the micropalaeontological biodiversity of the western circum Pacific, as well as to evaluate the distribution patterns of organisms and their evolution trends throughout the Tethys and Panthalassa. This study reports on 42 genera and 60 species whose associations can be used as sedimentary facies indicators of carbonate buildup environments. Japanese specimens show a strong Tethyan affinity, and especially with the Peri- and Southern Tethyan forms. A palaeobiogeographic distribution analysis using a large foraminiferal database is led, in order to evaluate the extraordinary spreading of these Upper Triassic foraminifers between the Neo-Tethys and the Panthalassa. Data are finally integrated in a new plate tectonic model, where six faunistic provinces are defined, each containing a characteristic foraminiferal assemblage. This map provides for the first time a useful and visual synthesis of the Upper Triassic foraminifer palaeobiogeographic distribution.