109 research outputs found

    A portable widefield fundus camera with high dynamic range imaging capability

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    Fundus photography is indispensable for clinical detection and management of eye diseases. Limited image contrast and field of view (FOV) are common limitations of conventional fundus cameras, making it difficult to detect subtle abnormalities at the early stages of eye diseases. Further improvements of image contrast and FOV coverage are important to improve early disease detection and reliable treatment assessment. We report here a portable fundus camera, with a wide FOV and high dynamic range (HDR) imaging capabilities. Miniaturized indirect ophthalmoscopy illumination was employed to achieve the portable design for nonmydriatic, widefield fundus photography. Orthogonal polarization control was used to eliminate illumination reflectance artifact. With independent power controls, three fundus images were sequentially acquired and fused to achieve HDR function for local image contrast enhancement. A 101{\deg} eye-angle (67{\deg} visual-angle) snapshot FOV was achieved for nonmydriatic fundus photography. The effective FOV can be readily expanded up to 190{\deg} eye-angle (134{\deg} visual-angle) with the aid of a fixation target, without the need of pharmacologic pupillary dilation. The effectiveness of HDR imaging was validated with both normal healthy and pathologic eyes, compared to a conventional fundus camera.Comment: 12 pages, 8 figure

    The endonasal approach for treatment of cerebral aneurysms: A critical review of the literature

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    The last two decades of neurosurgery have seen flourishing use of the endonasal approach for the treatment of skull base tumors. Safe and effective resections of neoplasms requiring intracranial arterial dissection have been performed using this technique. Recently, there have been a growing number of case reports describing the use of the endonasal approach to surgically clip cerebral aneurysms. We review the use of these approaches in intracranial aneurysm clipping and analyze its advantages, limitations, and consider future directions. Three major electronic databases were queried using relevant search terms. Pertinent case studies of unruptured and ruptured aneurysms were considered. Data from included studies were analyzed. 8 case studies describing 9 aneurysms (4 ruptured and 5 unruptured) treated by the endonasal approach met inclusion criteria. All studies note the ability to gain proximal and distal control and successful aneurysm obliteration was obtained for 8 of 9 aneurysms. 1 intraoperative rupture occurred and was controlled, and delayed complications of cerebrospinal fluid leak, vasospasm, and hydrocephalus occurred in 1, 1, and 2 patients, respectively. Described limitations of this technique include aneurysm orientation and location, the need for lower profile technology, and challenges with handling intraoperative rupture. The endonasal approach for clipping of intracranial aneurysms can be an effective approach in only very select cases as demonstrated clinically and through cadaveric exploration. Further investigation with lower profile clip technology and additional studies need to be performed. Options of alternative therapy, limitations of this approach, and team experience must first be considered

    Safety and efficacy of intra-arterial fibrinolytics as adjunct to mechanical thrombectomy : a systematic review and meta-analysis of observational data

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    Background Achieving the best possible reperfusion is a key determinant of clinical outcome after mechanical thrombectomy (MT). However, data on the safety and efficacy of intra-arterial (IA) fibrinolytics as an adjunct to MT with the intention to improve reperfusion are sparse. Methods We performed a PROSPERO-registered (CRD42020149124) systematic review and meta-analysis accessing MEDLINE, PubMed, and Embase from January 1, 2000 to January 1, 2020. A random-effect estimate (Mantel-Haenszel) was computed and summary OR with 95% CI were used as a measure of added IA fibrinolytics versus control on the risk of symptomatic intracranial hemorrhage (sICH) and secondary endpoints (modified Rankin ScalePeer reviewe

    Safety and efficacy of intra-arterial fibrinolytics as adjunct to mechanical thrombectomy: A systematic review and meta-analysis of observational data

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    Background: Achieving the best possible reperfusion is a key determinant of clinical outcome after mechanical thrombectomy (MT). However, data on the safety and efficacy of intra-arterial (IA) fibrinolytics as an adjunct to MT with the intention to improve reperfusion are sparse. Methods: We performed a PROSPERO-registered (CRD42020149124) systematic review and meta-analysis accessing MEDLINE, PubMed, and Embase from January 1, 2000 to January 1, 2020. A random-effect estimate (Mantel-Haenszel) was computed and summary OR with 95% CI were used as a measure of added IA fibrinolytics versus control on the risk of symptomatic intracranial hemorrhage (sICH) and secondary endpoints (modified Rankin Scale ≤2, mortality at 90 days). Results: The search identified six observational cohort studies and three observational datasets of MT randomized-controlled trial data reporting on IA fibrinolytics with MT as compared with MT alone, including 2797 patients (405 with additional IA fibrinolytics (100 urokinase (uPA), 305 tissue plasminogen activator (tPA)) and 2392 patients without IA fibrinolytics). Of 405 MT patients treated with additional IA fibrinolytics, 209 (51.6%) received prior intravenous tPA. We did not observe an increased risk of sICH after administration of IA fibrinolytics as adjunct to MT (OR 1.06, 95% CI 0.64 to 1.76), nor excess mortality (0.81, 95% CI 0.60 to 1.08). Although the mode of reporting was heterogeneous, some studies observed improved reperfusion after IA fibrinolytics. Conclusion: The quality of evidence regarding peri-interventional administration of IA fibrinolytics in MT is low and limited to observational data. In highly selected patients, no increase in sICH was observed, but there is large uncertainty

    Aspirin

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    Crosscurrents: art images/commercial images.|Arthur S. Penn photography symposia.

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    Recorded in Ithaca, NY by Cornell University., Sponsored by: Herbert F. Johnson Museum of Art., Speaker(s): Curator, writer and book editor., Lecture, April 29, 1989.43 minutesHeiferman describes the uses of photography by the media and shows how the study of photography can be, in actuality, a historical review.1_o5miq2g01_l13jhrs

    Image World : Art and Media Culture

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    Defining media images as a pervasive social reality, the authors outline the history of media images and their social impact. The artists' use of these images both as subject and strategy in their photography, video and filmwork is discussed. Includes a chronology of technological developments and political and social events in art and the media. Circa 190 bibl. ref

    Intraarterial Thrombolysis as Rescue Therapy for Large Vessel Occlusions

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    Update in Molecular Testing for Intraocular Lymphoma

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    The diagnosis of primary vitreoretinal lymphoma and central nervous system lymphoma is challenging. In cases with intraocular involvement, vitreous biopsy plays a pivotal role. Several diagnostic tests are employed to confirm a diagnosis and include cytologic evaluation, immunohistochemistry, flow cytometry, and cytokine analysis. The limitations of these conventional diagnostic tests stem from the often paucicellular nature of vitreous biopsy specimens and the fragility of malignant cells ex vivo. Several emerging molecular techniques show promise in improving the diagnostic yield of intraocular biopsy, possibly enabling more accurate and timely diagnoses. This article will review existing diagnostic modalities for intraocular lymphoma, with an emphasis on currently available molecular tests
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