Einfluss von Palmitinsäure auf die mitochondriale Funktion und Morphologie von INS1 Beta-Zellen

Eine Veränderung der Proteinexpression der mitochondrialen Teilungs- und Fusionsgene führt zu einer Störung der mitochondrialen Dynamik. Eine Erhöhung an freien Fettsäuren wird als Trigger für eine gestörte Insulinsekretion diskutiert. Diese Arbeit zeigt, dass der Verlust der GSIS in den GUR INS1-Zellen mit einer reduzierten Proteinexpression korreliert. Eine verstärkte mitochondriale Alterung und der damit einhergehende mitochondriale Funktionsverlust sind eine Erklärung für eine verminderte ATP/ADP-Ratio in den GUR INS1-Zellen im Vergleich zu den GR INS1-Zellen

Recurrent corneal erosions related to an ocular injury 15 years before presentation

Purpose: To report the case of a patient who presented with recurrent corneal erosions caused by an undetected plastic foreign body in the upper eyelid, which had remained asymptomatic for nearly 15 years following an ocular injury. Observations: A 39-year-old patient presented with recurrent corneal erosions and frontal headaches of unknown aetiology over the preceding eight months. The patient had previously been seen by twelve different ophthalmologists and had been treated over a 6-month period with a bandage contact lens, and therapeutic corneal scraping had been performed twice. However, the corneal erosion had repeatedly reappeared after removal of the bandage contact lens. On clinical examination prior to a planned phototherapeutic keratectomy, we extracted a 1.5 cm plastic foreign body, localised in the subtarsal area of the upper conjunctival fornix. Upon specific questioning, the patient denied any recent trauma, but reported a work-related accident with an accompanying eye injury 15 years before presentation. Conclusions and importance: Posttraumatic foreign bodies in the eye may remain asymptomatic for prolonged periods before giving rise to clinical signs such as recurrent corneal erosions. Hence, a thorough clinical examination with meticulous eyelid eversion should always be performed in such patients

Therapierefraktäre Epiphora nach Dakryozystorhinostomie – Stellenwert von Bildgebung und Histopathologie

Eine 73-jährige Patientin stellte sich wegen erneuter Epiphora sowie Rötung und Schwellung des rechten Lakrimalbereichs vor (Abb. 1a). Die Schwellung war indolent, und es entleerte sich kein Pus. Fünf Monate zuvor war bereits eine endonasale Dakryozystorhinostomie extern durchgeführt worden. Der Visus lag bestkorrigiert beidseits bei 1,0; und der restliche morphologische Befund des vorderen und hinteren Augenabschnitts sowie der Augeninnendruck waren unauffällig. Bemerkenswert in der Vorgeschichte war ein Plattenepithelkarzinom der Zervix (pT1b1 pN0 [0/25]), das 2005 chirurgisch und mit adjuvanter Strahlentherapie behandelt wurde

Temporary iris-lens diaphragm to assist descemet membrane endothelial keratoplasty in aphakic patients

Purpose: Presenting a simple technique using an inversely implanted contact lens to create a temporary diaphragm to assist DMEK surgery in aphakic, partially aniridic and vitrectomized eyes. Observations: The postoperative course was without pressure abnormalities and the anterior chamber remained deep. The cornea completely cleared within 3 weeks and remained clear after removal of the contact lens showing a corneal thickness of 544 μm and an intact endothelial cell pattern on endothelial cell microscopy after 3 months. Conclusion and Importance: The inversely implanted contact lens provides an easily accessible temporary diaphragm, making DMEK surgery a safer procedure even in complex eyes without an adequate posterior barrier

Age-related loss of human vitreal viscoelasticity

Purpose: To determine the viscoelasticity of human vitreous bodies and its changes with age in order to benefit the understanding and therapy of vitreoretinal diseases. Methods: In a postmortem study, 190 human vitreous bodies were extracted from 33- to 92-year-old donors, analyzed with regard to their viscoelastic properties via dynamic mechanical analyses, and compared with bovine and porcine vitreous. Postmortem intervals and donor-related parameters were examined as potential parameters influencing vitreous viscoelasticity. Dynamic moduli of different hyaluronic acid (HA) solutions as well as human vitreous treated with HA injections were determined by frequency sweep tests. Results: With age the viscoelasticity of human vitreous bodies decreased significantly and independently of postmortem intervals, diabetes, and the donor's sex. The storage modulus G′ and loss modulus G″ correlated strongly with the donor's age with r = −0.789 and r = −0.764, respectively. Bovine and porcine vitreous bodies exhibited dynamic moduli comparable only to the viscoelastic properties of aged human vitreous and are thus limited models for the simulation of the human vitreous. The viscoelasticity of aged human vitreous bodies was found to be increased after intravitreal injections of highly concentrated HA. Conclusions: The present postmortem study is the first to show a significant age-related reduction in the viscoelasticity of entire human vitreous bodies. Highly concentrated HA injections may serve as a possible therapeutic approach for restoring the viscoelasticity of aged vitreous bodies. Translational Relevance: These findings improve the understanding and therapy of the vitreous liquefaction with age and the associated vitreoretinal diseases