W. Herrmann
University of Regensburg
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Featured researches published by W. Herrmann.
Experimental Eye Research | 2008
Karin Kobuch; W. Herrmann; Carsten Framme; Helmut G. Sachs; Veit-Peter Gabel; Jost Hillenkamp
The purpose of this study was to characterise an ex-vivo adult porcine retina-retinal pigment epithelium (RPE) perfusion organ culture model. Fresh porcine full-thickness retina-RPE-choroid tissue samples were clamped into tissue carriers and mounted in two-compartment containers. The retinal and choroidal sides were continuously perfused with culture medium. pO(2), [Na(+)], [K(+)], [Cl(-)], [glucose], [lactate], and pH were measured in the medium. Tissue samples were examined after 24h, 4, 7, and 10 days in culture. The morphology of the retina and the RPE was examined by light and electron microscopy (LM, EM). The retinal cellular integrity was further examined by immunohistochemistry (Ki 67, GFAP, rhodopsin, synaptophysin, syntaxin, NF 200, TUNEL-test). Fresh porcine full-thickness retina-RPE-choroid tissue samples and tissue samples in static organ culture served as controls. LM, EM, and immunohistochemistry showed intact retinal and RPE cytoarchitecture kept in perfusion culture. Photoreceptor outer segments showed first signs of degeneration after 24h, significant signs of apoptosis and necrosis appeared in the retina after 4 days in perfusion culture. Control tissue samples kept in static culture showed disintegration of the retinal cytoarchitecture after 4 days in culture. The data show that adult porcine retina-RPE tissue can be maintained morphologically intact in perfusion organ culture for at least 10 days. Although first signs of degeneration set in after 24h the structural preservation of the tissue in perfusion organ culture is superior to that in static culture. The perfusion culture model of the retina refines organotypic in vitro test systems and may help to reduce the number of necessary animal experiments in retina and RPE research. It offers new perspectives for the safety testing of substances designed for intraocular application.
American Journal of Ophthalmology | 2011
Ahmed Nashed; Parykshit Saikia; W. Herrmann; Veit-Peter Gabel; Horst Helbig; Jost Hillenkamp
PURPOSE To determine the functional and anatomic outcome of early surgical repair with vitrectomy and silicone oil in open-globe injuries with retinal detachment (RD). DESIGN Retrospective consecutive interventional case series. METHODS All patients with open-globe injuries with RD treated between 1997 and 2007 underwent primary repair including vitrectomy with silicone oil within 8 hours after presentation. For data analysis, patients were divided into 3 groups according to the BETT classification: Group 1, intraocular foreign body; Group 2, penetrating injury; Group 3, globe rupture. Outcome measures were final reading visual acuity (0.4 logMAR or better), final ambulatory visual acuity (1.6 logMAR or better), endophthalmitis, and postoperative proliferative vitreoretinopathy (PVR). RESULTS Eighty-eight patients were included (Group 1, n = 13; Group 2, n = 36; Group 3, n = 39). Mean follow-up was 22 months (standard deviation [SD] = 23, range 6-107 months). Eight percent of patients retained reading vision without significant difference between the 3 groups. Fewer patients in Group 3 than in Group 1 or 2 retained ambulatory visual acuity (Group 1, 62%; Group 2, 64%; Group 3, 33%, P = .024). Endophthalmitis occurred in 3.4% of eyes (1 eye in each group). PVR grade B-C, type 1-3 developed in 44% of patients without significant difference between the 3 groups. Re-RD occurred in 38% of eyes. CONCLUSIONS Few patients achieved reading vision while 50% of patients retained ambulatory visual acuity. Final visual outcome is related to the severity of the injury. The frequency of postoperative endophthalmitis is low. Postoperative development of advanced PVR is avoided in most patients.
Graefes Archive for Clinical and Experimental Ophthalmology | 2005
W. Herrmann; Chris P. Lohmann; Martina Demmler-Hackenberg; Veit-Peter Gabel
BackgroundYoung patients with vitreous, retinal and subvitreal haemorrhages without neovascularisation or prior trauma are a diagnostic challenge for the physician. In this case report, a patient is presented who developed unilateral, spontaneous, subvitreal, retinal and subretinal haemorrhages and was diagnosed with von Willebrand’s disease.Case reportA 33-year-old Caucasian woman presented at our clinic with unilateral subvitreal, retinal and subretinal haemorrhages. The haemorrhages occurred spontaneously without prior trauma, and the patient had no history of prior bleeding complications. Analysis of the coagulation-fibrinolysis system and von Willebrand multimer analysis led to the diagnosis von Willebrand’s disease type I.ConclusionsSpontaneous subvitreal, retinal and subretinal haemorrhages may be associated with coagulation disorders. Especially in young patients, von Willebrand’s disease should be considered as a possible cause.
Cornea | 2004
W. Herrmann; Christoph Winkler von Mohrenfels; Chris P. Lohmann
Purpose: Tangier disease is an autosomal recessive disorder in which cholesterol-rich lipids are deposited at various tissues of the body including the cornea. In this case report, the corneal changes in a patient with Tangier disease are described. Methods: A 72-year-old patient who was diagnosed with Tangier disease 25 years before received a complete eye examination including confocal microscopy and Cochet-Bonnet esthesiometry. Results: Slit-lamp biomicroscopy and confocal microscopy showed bilateral corneal opacifications caused by lipid accumulation. Confocal microscopy showed that pathologic changes in the cornea in Tangier disease are limited to the stroma. Neither a reduced corneal sensation nor lid abnormalities as previously described in Tangier disease were found. Conclusion: Confocal microscopy helps to identify corneal changes in the stroma caused by Tangier disease easily missed in a slit-lamp examination. The ocular manifestations of Tangier disease do not necessarily include a reduced corneal sensitivity and lid abnormalities.
Graefes Archive for Clinical and Experimental Ophthalmology | 2007
Jost Hillenkamp; Parykshit Saikia; W. Herrmann; Carsten Framme; Veit-Peter Gabel; Helmut G. Sachs
Journal of the American Chemical Society | 1981
David C. Calabro; Dennis L. Lichtenberger; W. Herrmann
Graefes Archive for Clinical and Experimental Ophthalmology | 2005
W. Herrmann; Chirag Pradip Shah; Christoph Winkler von Mohrenfels; Bernhard Gabler; Karsten Hufendiek; Chris P. Lohmann
Graefes Archive for Clinical and Experimental Ophthalmology | 2005
W. Herrmann; Chirag Shah; Bernhard Gabler; Christoph Winkler von Mohrenfels; K. Hufendiek; Chris P. Lohmann
Graefes Archive for Clinical and Experimental Ophthalmology | 2007
W. Herrmann; Manuela Muecke; Michael Koller; V.–P. Gabel; Chris P. Lohmann
Investigative Ophthalmology & Visual Science | 2004
Bernhard Gabler; B. Fuchs; W. Herrmann; C. Winkler von Mohrenfels; C. Kölwel; E. Wiegrebe; A. Göpferich; Chris P. Lohmann