45 research outputs found

    Central serous chorioretinopathy

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    The pathogenesis of central serous chorioretinopathy (CSC) is still not fully understood. The involvement of corticosteroids is undisputed, although their exact role has not been clarified; other parts of the underlying mechanism of CSC have been mainly elucidated by imaging techniques such as fluorescein and indocyanine green angiography. Even though most cases of CSC are self-limiting, severe as well as recurrent courses exist, and for these patients only a limited number of treatment options are available: laser photocoagulation, with a risk of scotoma and choroidal neovascularization, and photodynamic therapy. In this review article, we give an overview of its epidemiology, the current understanding of its pathogenesis as well as systemic and ocular risk factors. We illuminate modern diagnostic tools as well as current treatment options in the context of CSC, particularly in the light of a better understanding of corticosteroids and their receptors involved in its pathogenesis

    Temsirolimus Inhibits Proliferation and Migration in Retinal Pigment Epithelial and Endothelial Cells via mTOR Inhibition and Decreases VEGF and PDGF Expression

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    Due to their high prevalence, retinal vascular diseases including age related macular degeneration (AMD),retinal vein occlusions (RVO),diabetic retinopathy (DR) and diabetic macular edema have been major therapeutic targets over the last years. The pathogenesis of these diseases is complex and yet not fully understood. However, increased proliferation, migration and angiogenesis are characteristic cellular features in almost every retinal vascular disease. The introduction of vascular endothelial growth factor (VEGF) binding intravitreal treatment strategies has led to great advances in the therapy of these diseases. While the predominant part of affected patients benefits from the specific binding of VEGF by administering an anti-VEGF antibody into the vitreous cavity, a small number of non-responders exist and alternative or additional therapeutic strategies should therefore be evaluated. The mammalian target of rapamycin (mTOR) is a central signaling pathway that eventually triggers up-regulation of cellular proliferation, migration and survival and has been identified to play a key role in angiogenesis. In the present study we were able to show that both retinal pigment epithelial (RPE) cells as wells as human umbilical vein endothelial cells (HUVEC) are inhibited in proliferating and migrating after treatment with temsirolimus in non-toxic concentrations. Previous studies suggest that the production of VEGF, platelet derived growth factor (PDGF) and other important cytokines is not only triggered by hypoxia but also by mTOR itself. Our results indicate that temsirolimus decreases VEGF and PDGF expression on RNA and protein levels significantly. We therefore believe that the mTOR inhibitor temsirolimus might be a promising drug in the future and it seems worthwhile to evaluate complementary therapeutic effects with anti-VEGF drugs for patients not profiting from mono anti-VEGF therapy alone

    Anti-angiogenic properties of rapamycin on human retinal pericytes in an in vitro model of neovascular AMD via inhibition of the mTOR pathway

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    Purpose Choroidal neovascularizations (CNV) are partially stabilized through a coverage of pericytes leading to a partial anti-VEGF resistence. Drugs licensed for neovascular AMD (nAMD) do not take this mechanical and growth factor-driven CNV stability into account. The purpose of this work was to see if inhibiting the mammalian target of rapamycin (mTOR) may successfully block angiogenic cellular pathways in primary human retinal pericytes in an in vitro model of nAMD. Methods The mTOR inhibitor rapamycin was used to treat human retinal pericytes (HRP) at doses ranging from 0.005 to 15 g/ml. A modified metabolism-based XTT-Assay was used to assess toxicity and anti-proliferative effects. A scratch wound experiment showed the effects on migration. On Cultrex basement membrane gels, the influence of rapamycin on the development of endothelial cell capillary-like structures by human umbilical vein vascular endothelial cells (HUVEC) in the absence and presence of pericytes was investigated. Results Rapamycin showed no signs of toxicity within its range of solubility. The drug showed dose dependent anti-proliferative activity and inhibited migration into the scratch wound. Endothelial cell tube formation in a HUVEC monoculture was effectively inhibited at 45%. A co-culture of HUVEC with pericytes on Cultrex induced endothelial tube stabilization but was disrupted by the addition of rapamycin leading to degradation of 94% of the tubes. Conclusions Rapamycin allows for an efficient modulation of aspects of angiogenesis in pericytes via mTOR-modulation in vitro. Further studies are needed to elucidate whether rapamycin may have an impact on CNV in nAMD in vivo

    The national comprehensive cancer network distress thermometer as a screening tool for the evaluation of quality of life in uveal melanoma patients

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    Purpose To assess quality of life (QoL) status via the National Comprehensive Cancer Network (NCCN ) distress thermometer as a psychooncological screening tool in uveal melanoma patients. Methods One hundred and six consecutive patients suffering from uveal melanoma completed the distress thermometer between 04/2018 and 12/2018. Practical, emotional, family concerned, spiritual, physical and overall distress levels, distribution of distress and subgroup analyses defining groups of potential high distress levels in need of intervention were assessed. Descriptive statistics, cross‐tabulations, chi‐square and Fisher's exact test as well as correlation coefficients (Spearman's rho) and receiver operating characteristic (ROC ) were used for analysis. Results Patients with higher T‐category had significantly more emotional problems and spiritual concerns (p = 0.046 and p = 0.023, respectively). Female patients accounted for higher rates of physical issues (p = 0.034). Lower best corrected visual acuity (BCVA ) was correlated with higher distress levels (p = 0.037). Patients resulting in loss of BCVA of ≥3 lines reported higher distress levels (p = 0.029). A distress threshold of 5 on the basis of ROC analysis showed a corresponding sensitivity of 100% and specificity of 76%. Conclusion The NCCN distress thermometer could be integrated well into our clinical routine and proved to be a rapid, yet sensible screening tool for emotional and physical distress in patients with uveal melanoma. Special attention should be paid to patients with higher T‐category and patients resulting in lower levels of BCVA . As in patients with different tumour entities, the established distress threshold of ≥5 proposing intervention proved to be adequate for uveal melanoma patients

    Comparative Evaluation of Combined Navigated Laser Photocoagulation and Intravitreal Ranibizumab in the Treatment of Diabetic Macular Edema

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    Objective: To evaluate if a standardized combination therapy regimen, utilizing 3 monthly ranibizumab injections followed by navigated laser photocoagulation, reduces the number of total ranibizumab injections required for treatment of diabetic macular edema (DME). Research Design and Methods: A 12-month, prospective comparison of 66 patients with center-involving DME: 34 patients with combination therapy were compared to 32 patients treated with ranibizumab monotherapy. All patients initially received 3 monthly ranibizumab injections (loading phase) and additional injections pro re nata (PRN). Combination therapy patients additionally received navigated laser photocoagulation after the loading phase. Main outcome measures were mean number of injections after the loading phase and change in BCVA from baseline to month 12. Results: Navigated laser combination therapy and ranibizumab monotherapy similarly improved mean BCVA letter score (+8.41 vs. +6.31 letters, p=0.258). In the combination group significantly less injections were required after the 3 injection loading phase (0.88 +/- 1.23 vs. 3.88 +/- 2.32, p<=0.001). By month 12, 84% of patients in the monotherapy group had required additional ranibizumab injections as compared to 35% in the combination group (p<=0.001). Conclusions: Navigated laser combination therapy demonstrated significant visual gains in most patients. Retreatment rate and number of injections were significantly lower compared to ranibizumab monotherapy and compared to the results of conventional laser combination therapy previously reported in pivotal anti-VEGF studies

    Comparison of variables measured with a Scheimpflug device for evaluation of progression and detection of keratoconus

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    Keratoconus is a progressive ectatic corneal disorder, which can result in severe visual impairment. The new ABCD keratoconus classification system allows differentiated description of the disease. Aim of the study was to evaluate the components of this novel staging system (ARC, PRC, thinnest pachymetry) as well as topometric indices, deviation of normality indices, and other parameters in terms of repeatability and reliability. 317 eyes with keratoconus were examined twice with a Scheimpflug device (Pentacam, Oculus). Bland Altman analysis and intraclass correlations were carried out to evaluate the parameters repeatability and reliability. Apart from IHA (ICC=0.730), all parameters showed excellent reliability (ICC>0.900). ARC, PRC, thinnest pachymetry, Kmax, CKI, KI, Rmin, and Progression Avg were the best repeatable parameters with relative repeatability values<2.5%. Other parameters performing well in terms of repeatability were IHD, ISV, IVA, and final D (RR<13%). Regression analysis revealed consistently high repeatability along all stages of keratoconus for PRC, thinnest pachymetry, and CKI. All parameters of the ABCD staging system showed excellent reliability and repeatability, PRC and thinnest pachymetry even at all stages of keratoconus and can consequently be reliably used in the determination of keratoconus progression

    Fenofibrate Inhibits Cytochrome P450 Epoxygenase 2C Activity to Suppress Pathological Ocular Angiogenesis

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    Neovascular eye diseases including retinopathy of prematurity, diabetic retinopathy and age-related-macular-degeneration are major causes of blindness. Fenofibrate treatment in type 2 diabetes patients reduces progression of diabetic retinopathy independent of its peroxisome proliferator-activated receptor (PPAR)α agonist lipid lowering effect. The mechanism is unknown. Fenofibrate binds to and inhibits cytochrome P450 epoxygenase (CYP)2C with higher affinity than to PPARα. CYP2C metabolizes ω-3 long-chain polyunsaturated fatty acids (LCPUFAs). While ω-3 LCPUFA products from other metabolizing pathways decrease retinal and choroidal neovascularization, CYP2C products of both ω-3 and ω-6 LCPUFAs promote angiogenesis. We hypothesized that fenofibrate inhibits retinopathy by reducing CYP2C ω-3 LCPUFA (and ω-6 LCPUFA) pro-angiogenic metabolites. Fenofibrate reduced retinal and choroidal neovascularization in PPARα-/-mice and augmented ω-3 LCPUFA protection via CYP2C inhibition. Fenofibrate suppressed retinal and choroidal neovascularization in mice overexpressing human CYP2C8 in endothelial cells and reduced plasma levels of the pro-angiogenic ω-3 LCPUFA CYP2C8 product, 19,20-epoxydocosapentaenoic acid. 19,20-epoxydocosapentaenoic acid reversed fenofibrate-induced suppression of angiogenesis ex vivo and suppression of endothelial cell functions in vitro. In summary fenofibrate suppressed retinal and choroidal neovascularization via CYP2C inhibition as well as by acting as an agonist of PPARα. Fenofibrate augmented the overall protective effects of ω-3 LCPUFAs on neovascular eye diseases

    Photoreceptor glucose metabolism determines normal retinal vascular growth

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    Abstract The neural cells and factors determining normal vascular growth are not well defined even though vision‐threatening neovessel growth, a major cause of blindness in retinopathy of prematurity (ROP) (and diabetic retinopathy), is driven by delayed normal vascular growth. We here examined whether hyperglycemia and low adiponectin (APN) levels delayed normal retinal vascularization, driven primarily by dysregulated photoreceptor metabolism. In premature infants, low APN levels correlated with hyperglycemia and delayed retinal vascular formation. Experimentally in a neonatal mouse model of postnatal hyperglycemia modeling early ROP, hyperglycemia caused photoreceptor dysfunction and delayed neurovascular maturation associated with changes in the APN pathway; recombinant mouse APN or APN receptor agonist AdipoRon treatment normalized vascular growth. APN deficiency decreased retinal mitochondrial metabolic enzyme levels particularly in photoreceptors, suppressed retinal vascular development, and decreased photoreceptor platelet‐derived growth factor (Pdgfb). APN pathway activation reversed these effects. Blockade of mitochondrial respiration abolished AdipoRon‐induced Pdgfb increase in photoreceptors. Photoreceptor knockdown of Pdgfb delayed retinal vascular formation. Stimulation of the APN pathway might prevent hyperglycemia‐associated retinal abnormalities and suppress phase I ROP in premature infants
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