Comparison between the Correlations of Retinal Nerve Fiber Layer Thickness Measured by Spectral Domain Optical Coherence Tomography and Visual Field Defects in Standard Automated White-on-White Perimetry versus Pulsar Perimetry

Purpose. To compare the structure-function relationships between retinal nerve fiber layer thickness (RNFLT) and visual field defects measured either by standard automated perimetry (SAP) or by Pulsar perimetry (PP). Materials and Methods. 263 eyes of 143 patients were prospectively included. Depending on the RNFLT, patients were assigned to the glaucoma group (group A: RNFL score 3–6) or the control group (group B: RNFL score 0–2). Structure-function relationships between RNFLT and mean sensitivity (MS) measured by SAP and PP were analyzed. Results. Throughout the entire group, the MS assessed by PP and SAP correlated significantly with RNFLT in all sectors. In the glaucoma group, there was no significant difference between the correlations RNFL-SAP and RNFL-PP, whereas a significant difference was found in the control group. Conclusions. In the control group, the correlation between structure and function based on the PP data was significantly stronger than that based on SAP

Ein mikrochirurgisches Wetlab für Studierende steigert das Interesse an der Augenheilkunde

HINTERGRUND Praktischen Inhalten wird in den Curricula der Humanmedizin zunehmend Platz eingeräumt. Bei verbreitetem Bewerbermangel trägt dies zu einem vermehrten Interesse seitens der Studierenden an den jeweiligen Fachbereichen bei. Einen praktischen Reiz der Augenheilkunde stellt die mikrochirurgische Arbeitsweise dar. Eine Einführung kann beispielsweise mit einem mikrochirurgischen Nahtkurs geleistet werden. ZIE DER ARBEIT Erfassung des Zugewinns des Interesses an der Augenheilkunde mittels Evaluation eines Nahtkurs-Wetlabs inklusive Nähen unter dem Mikroskop. MATERIAL UND METHODEN Die Daten wurden im Blockpraktikum Augenheilkunde des 6. Semesters an der Universitätsmedizin Mainz im April 2019 erhoben. In einem Fragebogen wurden verschiedene Aussagen auf Ordinalskalen gemeinsam mit dem Zentrum für Qualitätssicherung und -entwicklung der Johannes-Gutenberg-Universität Mainz bewertet und ausgewertet. ERGEBNISSE Es wurden 64 Evaluationsbögen von 8 Gruppen unterschiedlicher Dozenten zu je 8 Teilnehmern ausgewertet. Das Wetlab wurde im Mittel mit einer Schulnote von 1,24 ± 0,5 (MW±SD) bewertet. Es bestand Zustimmung (1 = stimme völlig zu, 7 = stimme gar nicht zu) zum Wunsch nach weiteren Wetlabs unter dem Mikroskop (1,86 ± 1,28) sowie nach dem Erlernen von mehr augenchirurgischen Techniken (2,02 ± 1,13). Das Interesse an der Augenheilkunde (1 = sehr groß, 7 = sehr gering) nahm von 3,66 ± 1,55 zu Beginn des Kurses auf 2,52 ± 1,00 zu. DISKUSSION Das Interesse an der Augenheilkunde lässt sich mittels eines mikrochirurgischen Wetlabs steigern. Bei Studierenden kann so das Interesse an der Augenheilkunde geweckt werden, was sich vorteilhaft auf Bewerbersituation und Forschungsarbeiten auswirken kann. So können sich bereits im Studium Erfahrungen und praktische Techniken der Augenheilkunde angeeignet werden

Elevated intraocular pressure induces neuron-specific β-III-tubulin expression in non-neuronal vascular cells

PURPOSE Pathological alterations within optic nerve axons and progressive loss of the parental retinal ganglion cell (RGC) bodies are characteristics of glaucomatous neuropathy. Abnormally elevated intraocular pressure (IOP) is thought to be the major risk factor for most forms of glaucomatous changes, while lowering of the IOP is the mainstream of treatment. However, the pathophysiological mechanisms involved in neurodegenerative changes are poorly understood. It remains still a matter of debate whether elevated IOP harms the neurons directly or indirectly through alterations in the retinal vascularization. METHODS We analysed morphological and molecular changes within the retina exposed to elevated IOP in an animal model of glaucoma in vivo, in retinal explants and in cultured dissociated retinal cells each incubated under elevated air pressure in vitro, imitating elevated IOP. RESULTS Although ß-III-tubulin expressing RGCs decreased within the course of the disease, total amount of ß-III-tubulin protein within the retina increased, leading to the assumption that other cells than RGCs abnormally express ß-III-tubulin due to elevated IOP. Surprisingly, we found that β-III-tubulin, a marker developmentally regulated and specifically expressed in neurons under normal conditions, was strongly up-regulated in desmin-, PDGFR-β- and α-SMA-positive pericytes as well as in endothelin-1-positive endothelial cells both in vivo under elevated IOP and in vitro under elevated culture atmosphere pressure that simulated IOP elevation. Beta-III-tubulin-driven signalling pathways (ERK 1/2, pERK1/2 and cdc42/Rac) were also regulated. CONCLUSION The unprecedented regulation of neuron-specific β-III-tubulin in pericytes and endothelial cells is likely associated with a role of the retinal vasculature in the IOP-induced development and manifestation of glaucomatous degenerative optic nerve response

Hydrogen sulfide protects retinal ganglion cells against glaucomatous injury in vitro and in vivo

Purpose: Hydrogen sulfide (H2S) is recognized as a novel third signaling molecule and gaseous neurotransmitter. Recently, cell protective properties within the central nervous and cardiovascular system have been proposed. Our purpose was to analyze the expression and neuroprotective effects of H2S in experimental models of glaucoma. Methods: Elevated IOP was induced in Sprague-Dawley rats by means of episcleral vein cauterization. After 7 weeks, animals were killed and the retina was analyzed with label-free mass spectrometry. In vitro, retinal explants were exposed to elevated hydrostatic pressure or oxidative stress (H2O2), with and without addition of a slow-releasing H2S donor Morpholin-4-ium-methoxyphenyl-morpholino-phosphinodithioate (GYY4137). In vivo, GYY4137 was injected intravitreally in animals with acute ischemic injury or optic nerve crush. Brn3a+ retinal ganglion cells (RGCs) were counted in retinal flat mounts and compared. Optical coherence tomography (OCT) was performed to examine the vessels. Comparisons were made by t-test and ANOVA (P < 0.05). Results: IOP elevation caused significant RGC loss (P < 0.001); 3-mercaptosulfurtransferase, an H2S producing enzyme, showed a 3-fold upregulation within the retina after IOP elevation. GYY4137 protected RGCs against elevated pressure and oxidative stress in vitro depending on the concentration used (P < 0.005). In vivo, intravitreal administration of GYY4137 preserved RGCs from acute ischemic injury and optic nerve crush (P < 0.0001). Retinal vessel diameters enlarged after intravitreal GYY4137 injection (P < 0.0001). Conclusions: H2S is specifically regulated in experimental glaucoma. By scavenging reactive oxygen species and dilating retinal vessels, H2S may protect RGCs from pressure and oxidative stress–induced RGC loss in vitro and in vivo. Therefore, H2S might be a novel neuroprotectant in glaucoma

Revision of encapsulated blebs after trabeculectomy : long-term comparison of standard bleb needling and modified needling procedure combined with transconjunctival scleral flap sutures

Purpose To compare two surgical approaches for treating encapsulated blebs after trabeculectomy with mitomycin C, in terms of the development of intraocular pressure and progression of glaucoma in a long-term follow up: 1. bleb needling alone vs. 2. a combined approach of needling with additional transconjunctival scleral flap sutures, to prevent early ocular hypotony. Methods Forty-six patients with failing blebs after trabeculectomy with mitomycin C were enrolled in this study. Patients received either needling revision alone (group 1; n = 23) or a combined needling with additional transconjuctival flap sutures, if intraoperatively the intraocular pressure was estimated to be low (group 2; n = 23). Intraocular pressure (IOP), visual acuity, visual fields, and optic nerve head configuration by means of Heidelberg Retina Tomograph (HRT®) were analysed over time. Results from both groups were compared using Mann-Whitney U-test for single timepoints. Results IOP did not differ significantly between the two groups during follow-up at three months (P = 0.13), six months (P = 0.12), one year (P = 0.92) and two years (P = 0.57) after surgery. Furthermore, there was no significant difference in the course of glaucoma concerning the optic nerve anatomy between the two groups (Rim Area Change in the Moorfields Regression Analysis of HRT®) till two years after surgery (P = 0.289). No functional impairment in visual acuity and visual fields was found in the groups of the study. Conclusions Single needling procedure is a standard successful method for restoring the function of encapsulated blebs. Postoperative hypotony represents a possible hazard, which can be minimized by additional transconjunctival flap sutures. Long-term results suggest that this modification is equally effective in lowering the IOP and preventing the progression of glaucoma as the standard needling procedure. To our knowledge this is the first study to investigate the long-term effect of tranconjunctival sutures for the prevention of hypotony

Notfälle in der Augenheilkunde : Vermittlung anhand interaktiver Key-feature-Fälle für Medizinstudierende

Hintergrund Wichtiges Ziel eines Curriculums für Medizinstudierende ist, die Fähigkeit zum selbstständigen Erkennen und Einordnen von Notfällen zu vermitteln. Die Augenheilkunde steht hierbei aufgrund fachspezifischer „red flags“, also Warnsymptomen und -zeichen, vor der Herausforderung, dass solche selten von anderen Organsystemen hierauf übertragen werden können. Um Medizinstudierende dabei zu fördern, die „red flags“ der Augenheilkunde in ihrer späteren Tätigkeit zu erkennen, entwickelten wir für unser eLearning-Angebot leitsymptomorientierte interaktive Fallvignetten. Material und Methoden Es wurden 7 interaktive Fallvignetten zu potenziell bedrohlichen ophthalmologischen Symptomen und Zeichen wie „schmerzloser Visusverlust“ oder „rotes Auge“ entwickelt. Hierbei werden Studierende mit Bild und Text durch einen Fall geführt und zu entscheidenden Aspekten („key features“) mit verschiedenen Frageformaten geprüft. Die interaktiven Fälle wurden mithilfe von eLearning-Authoring-Software umgesetzt und als Lernmodule in der Learning-Management-Präsenz der Augenklinik integriert. Die Patientenfälle waren Teil unseres Praktikums der Augenheilkunde. Die Fälle wurden im Anschluss von den Studierenden evaluiert. Ergebnisse Die Fälle wurden im Mittel mit einer Note von 1,51 ± 0,68 (Mittelwert ± Standardabweichung) bewertet (n = 163). Auf einer Likert-Skala wurden sie mit 1,60 ± 0,81 als hilfreich für das eigene Lernen empfunden (1 = sehr hilfreich, 7 = gar nicht hilfreich; n = 164). Die Informationsmenge und Auswahl der Szenarien wurden ebenfalls positiv evaluiert. Diskussion Um Studierenden im engen zeitlichen Rahmen eines Kurses mehr Sicherheit im Erkennen und der primären Versorgung von augenärztlichen Notfällen verschaffen zu können, können praxisorientierte Key-feature-Fälle Bestandteil eines eLearning-Angebotes sein

Umsetzung eines digitalen Semesters Augenheilkunde während der COVID-19-Pandemie

Hintergrund Die erste Welle der COVID-19-Pandemie stellte Lehrende und Studierende vor große Herausforderungen, da die studentische Lehre trotz Einschränkung des Präsenzunterrichts stattzufinden hatte. Für Präsenzunterricht und Veranstaltungen mit Patientenkontakt mussten kurzfristig zwischen Mitte März und Beginn des Semesters im April Alternativen gestaltet werden. Ziel der Arbeit Beschreibung von Konzept und Umsetzung der studentischen Lehre an der Augenklinik der Universitätsmedizin Mainz in kompletter digitaler Form im Sommersemester 2020. Konzeptvorstellung Vorlesung, Untersuchungskurs und Praktikum der Augenheilkunde finden an der Universitätsmedizin Mainz im 5. und 6. Semester im Studiengang Humanmedizin statt. Grundlage der Neukonzeption war der bisherige Kursaufbau. Das umgesetzte Konzept umfasste Vorlesungen als Videopodcasts, Untersuchungsvideos, Online-Untersuchungskonferenzen, leitsymptomorientierte interaktive Patientenfälle, Operationsvideos, Anamnesevideos von Patienten und die Gestaltung eines „Live-Patientenzimmers“, in dem Patientenfälle inklusive Live-Übertragung des Spaltlampenbefundes und der Fundoskopie präsentiert wurden. Die Evaluation durch Studierende zeigte eine sehr gute Annahme des Konzeptes. Diskussion Es gelang innerhalb eines Zeitrahmens von 4 Wochen eine vollständige Überarbeitung und Digitalisierung des Kurses Augenheilkunde. Der größte Anteil der Neugestaltung beinhaltete die mediale Produktion von Untersuchungsvideos, interaktiven Patientenfällen und Videopodcasts der Vorlesungen. Diese digitalen Lehrkonzepte können auch in den nächsten Semestern nach Wiederaufnahme des Präsenzunterrichts genutzt werden und die Präsenzlehre in der Augenheilkunde unterstützen.Background The first wave of the COVID-19 pandemic posed great challenges for teachers and students, as teaching had to take place despite the restriction of classroom teaching. For attendance lessons and events with patient contact alternatives had to be arranged at short notice between mid-March and the beginning of the semester in mid-April. Objective Description of the concept and implementation in the student teaching at the Department of Ophthalmology of the University Medical Center Mainz in complete digital form in spring 2020. Presentation of concept Lectures, examination course and practical training in ophthalmology take place in the 5th and 6th semester of the study of human medicine. The basis of the new concept were the former course curricula. Implemented concepts included a complete revision and implementation of lectures as video podcasts, examination videos, online examination conferences, interactive patient cases, narrated videos of surgery, anamnesis videos of patients and the design of the virtual patient room, a live online practice with presentation and examination of patients including transmission of the slit-lamp image to reproduce anterior and posterior segment examination. An evaluation showed a very positive reception of the new concept by students. Discussion Within a tight timeframe of 4 weeks a complete revision of the ophthalmology course was achieved. The implementation was time-consuming, with the largest share in the media production of examination videos, interactive patient cases and video podcasts of the lectures. We consider a reduction of classroom teaching for parts of the learning objectives that can be represented by such videos to be possibly useful. An independent digital appropriation of such content may enable a more productive learning environment in face-to-face teaching

Energy Metabolism in the Inner Retina in Health and Glaucoma

Glaucoma, the leading cause of irreversible blindness, is a heterogeneous group of diseases characterized by progressive loss of retinal ganglion cells (RGCs) and their axons and leads to visual loss and blindness. Risk factors for the onset and progression of glaucoma include systemic and ocular factors such as older age, lower ocular perfusion pressure, and intraocular pressure (IOP). Early signs of RGC damage comprise impairment of axonal transport, downregulation of specific genes and metabolic changes. The brain is often cited to be the highest energy-demanding tissue of the human body. The retina is estimated to have equally high demands. RGCs are particularly active in metabolism and vulnerable to energy insufficiency. Understanding the energy metabolism of the inner retina, especially of the RGCs, is pivotal for understanding glaucoma's pathophysiology. Here we review the key contributors to the high energy demands in the retina and the distinguishing features of energy metabolism of the inner retina. The major features of glaucoma include progressive cell death of retinal ganglions and optic nerve damage. Therefore, this review focuses on the energetic budget of the retinal ganglion cells, optic nerve and the relevant cells that surround them

Crystallins are regulated biomarkers for monitoring topical therapy of glaucomatous optic neuropathy.

Optic nerve atrophy caused by abnormal intraocular pressure (IOP) remains the most common cause of irreversible loss of vision worldwide. The aim of this study was to determine whether topically applied IOP-lowering eye drugs affect retinal ganglion cells (RGCs) and retinal metabolism in a rat model of optic neuropathy. IOP was elevated through cauterization of episcleral veins, and then lowered either by the daily topical application of timolol, timolol/travoprost, timolol/dorzolamide, or timolol/brimonidine, or surgically with sectorial iridectomy. RGCs were retrogradely labeled 4 days prior to enucleation, and counted. Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), matrix-assisted laser desorption ionization mass spectrometry, Western blotting, and immunohistochemistry allowed the identification of IOP-dependent proteomic changes. Genomic changes were scrutinized using microarrays and qRT-PCR. The significant increase in IOP induced by episcleral vein cauterization that persisted until 8 weeks of follow-up in control animals (p<0.05) was effectively lowered by the eye drops (p<0.05). As anticipated, the number of RGCs decreased significantly following 8 weeks of elevated IOP (p<0.05), while treatment with combination compounds markedly improved RGC survival (p<0.05). 2D-PAGE and Western blot analyses revealed an IOP-dependent expression of crystallin cry-βb2. Microarray and qRT-PCR analyses verified the results at the mRNA level. IHC demonstrated that crystallins were expressed mainly in the ganglion cell layer. The data suggest that IOP and either topically applied antiglaucomatous drugs influence crystallin expression within the retina. Neuronal crystallins are thus suitable biomarkers for monitoring the progression of neuropathy and evaluating any neuroprotective effects