103 research outputs found

    Sourcing photoreceptor-like cells for treating vision loss

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    Preoperative electrophysiological characterization of patients with primary macula-involving rhegmatogenous retinal detachment

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    Purpose: To determine 1) which components of retinal function are impaired after rhegmatogenous retinal detachment, 2) which outer retinal pathways (rod- or cone-driven) are more severely affected, and 3) whether there is concomitant inner retinal dysfunction. Methods: We conducted a prospective observational study in a large academic institution. We performed preoperative electroretinography on eight patients to assess outer and inner retinal function. In all cases, a comparison between the eye with the detached retina and the control fellow eye was made. Results: Eyes with a detached retina had significantly lower a-wave and b-wave amplitudes with respect to both rod- and cone-dominated testing parameters (P < 0.05) and reduced 30 Hz flicker responses compared to fellow eyes (P < 0.05); the effect size was similar for all significantly reduced parameters (r~0.6). There were no significant differences between eyes with detached retinas and control fellow eyes with respect to b/a-wave ratios, a-wave latencies, or b-wave latencies. Conclusion: Patients with rhegmatogenous retinal detachment have preoperative outer retinal dysfunction equally affecting both rod- and cone-driven pathways, and they have minimal inner retinal dysfunction

    Combined epiretinal and internal limiting membrane peeling facilitated by high dilution indocyanine green negative staining

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    We describe the utilization of indocyanine green (ICG) dye to facilitate combined/en bloc removal of epiretinal membranes (ERM) along with internal limiting membranes (ILM). The method utilizes a highly diluted preparation of ICG in dextrose water solvent (D5W). Elimination of fluid air exchange step facilitating staining in the fluid phase and low intensity lighting help minimize potential ICG toxicity. The technique demonstrates how ICG facilitates negative staining of ERMs and how ILM peeling concomitantly can allow complete and efficient ERM removal minimizing surgical time and the necessity for dual or sequential staining

    Combined SIRT3 and SIRT5 deletion is associated with inner retinal dysfunction in a mouse model of type 1 diabetes

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    Abstract Diabetic retinopathy (DR) is a major cause of blindness in working adults in the industrialized world. In addition to vision loss caused by macular edema and pathological angiogenesis, DR patients often exhibit neuronal dysfunction on electrophysiological testing, suggesting that there may be an independent neuronal phase of disease that precedes vascular disease. Given the tremendous metabolic requirements of the retina and photoreceptors in particular, we hypothesized that derangements in metabolic regulation may accelerate retinal dysfunction in diabetes. As such, we induced hyperglycemia with streptozotocin in mice with monoallelic Nampt deletion from rod photoreceptors, mice lacking SIRT3, and mice lacking SIRT5 and tested multiple components of retinal function with electroretinography. None of these mice exhibited accelerated retinal dysfunction after induction of hyperglycemia, consistent with normal-appearing retinal morphology in hyperglycemic Sirt3 −/− or Sirt5 −/− mice. However, mice lacking both SIRT3 and SIRT5 (Sirt3 −/− Sirt5 −/− mice) exhibited significant evidence of inner retinal dysfunction after induction of hyperglycemia compared to hyperglycemic littermate controls, although this dysfunction was not accompanied by gross morphological changes in the retina. These results suggest that SIRT3 and SIRT5 may be involved in regulating neuronal dysfunction in DR and provide a foundation for future studies investigating sirtuin-based therapies

    Longitudinal Growth Differentiation Factor 15 (GDF15) and Long-term Intraocular Pressure Fluctuation in Glaucoma: A Pilot Study

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    Purpose: Growth Differentiation Factor 15 (GDF15) was previously identified as a molecular marker of retinal ganglion cell stress in rodent models of glaucoma and was elevated in the aqueous humor (AH) of patients with primary open-angle glaucoma as a possible risk factor for glaucoma progression. The purpose of this study was to determine whether changes in the AH GDF15 levels were associated with intraocular pressure (IOP) changes in eyes undergoing glaucoma surgery. Methods: Here, we performed a prospective, longitudinal pilot study in nine patients to determine whether changes in AH GDF15 levels from surgery to post-surgery follow-up were associated with IOP fluctuation. An initial AH sample was taken from the peripheral corneal paracentesis during planned glaucoma surgery, and a second sample was taken during an outpatient follow-up visit, approximately six months later. Results: There was a statistically significant correlation between GDF15 fold change and IOP standard deviation (r = 0.87, P = 0.003), IOP range (r = 0.87, P = 0.003), and maximum IOP (r = 0.86, P = 0.003). There was no correlation between the GDF15 fold change and baseline IOP (r = 0.50, P = 0.17), final IOP (r = 0.038, P = 0.92), or mean IOP (r = 0.40, P = 0.28). Conclusion: Our findings in this pilot study suggest that longitudinal changes in AH GDF15 may be associated with IOP fluctuation during the postoperative period. Further studies are necessary to corroborate these findings in a larger patient population and to explore the possibility that AH GDF15 may be used not only to improve treatment algorithms but also as a surrogate endpoint in clinical trials

    Full thickness macular hole case after intravitreal aflibercept treatment

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    BACKGROUND: The pathogenesis of macular hole formation is widely accepted as a tractional force at the vitreo-retinal interface in fovea. We report a case of macular hole after intravitreous aflibercept injection for age-related macular degeneration (AMD) associated with contraction of the retinal pigment epithelium (RPE) at the edge of a fibrovascular pigment epithelial detachment (PED). CASE PRESENTATION: A 94-year old man with neovascular AMD affecting his left eye accompanied by a fibrovascular PED was examined for severe vision loss. Although RPE tear in his left eye was identified before the first aflibercept intravitreous injection performed in order to treat neovascular AMD, he received three aflibercept injections as induction treatment. After induction treatment, a full thickness macular hole was identified associated with the contracted rolled RPE edge beneath the retina. CONCLUSION: Macular hole is commonly formed associated with tangential vitreous traction. Current report suggests that rapid contraction of the RPE underneath the retina can be one of the causes of a macular hole, and one of the side effects of anti-VEGF therapy for neovascular AMD

    Senescence regulates macrophage activation and angiogenic fate at sites of tissue injury in mice

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    Abnormal angiogenesis plays a key role in diseases of aging such as heart disease, certain cancers, and eye diseases including age-related macular degeneration. Macrophages have been shown previously to be both anti- and proangiogenic, and their role in regulating angiogenesis at sites of tissue injury is critical and complex. In this study, we analyzed cytokine gene expression patterns of mouse macrophages by real-time quantitative PCR and tested the functional effects of senescence on gene expression and macrophage polarization. Following laser injury to the retina, IL-10 was upregulated and Fas ligand (FasL), IL-12, and TNF-α were downregulated in ocular macrophages of old mice (>18 months of age). Downregulation of FasL on macrophages led to a loss of the antiangiogenic phenotype, as evidenced by the inability of these macrophages to inhibit vascular endothelial cells. Our results demonstrate that senescence, FasL, and IL-10 are key determinants of macrophage function that alter the growth of abnormal postdevelopmental blood vessels in disease processes including blinding eye disease
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