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Acute testicular torsion in children is an emergency and has to be diagnosed urgently. Doppler sonography is increasingly used in imaging the acute scrotum. Nevertheless, in uncertain cases, surgical exploration is required. In this study, we attempted to define the role of Doppler sonography in the diagnostic workup of the acutely painful scrotum. All patients admitted between 1999 and 2005 with acute scrotal pain were included. After clinical assessment, patients were imaged by Doppler sonography with a ''high-end'' instrument. In cases of absent arterial perfusion of the testis in Doppler sonography, surgical exploration was carried out. Patients with unaffected perfusion were followed clinically by ultrasound for up to 2 years. Sixty-one infants and children aged 1 day to 17 years (median: 7.9 years) were included. In 14 cases, sonography demonstrated absent central perfusion, with abnormal parenchymal echogenicity in six. Absence of venous blood flow together with reduction of central arterial perfusion was found in one infant. In these 15 patients, surgical exploration confirmed testicular torsion. Among the other 46 patients, we found four cases with increased testicular perfusion and 27 with increased perfusion of the epididymis. In one infant, a testicular tumour was found sonographically, and orchiectomy confirmed diagnosis of a teratoma. Follow-up examinations of the conservatively treated patients showed good clinical outcome with physiologic central perfusion as well as normal echogenic pattern of both testes. No case of testicular torsion was missed. By means of Doppler sonography, an unequivocal statement regarding testicular perfusion was possible in all cases. The initial Doppler diagnosis was confirmed by operative evaluation and follow-up ultrasound. Testicular torsion can therefore be excluded by correctly performed ultrasound with modern equipment. [ABSTRACT FROM AUTHOR]

Thermal and spatial-spectral imaging methods are used to investigate the soldering quality in high-power laser-bar devices. The temperature distribution and the wavelength profile across a driven laser bar correlate with the local thermal resistance between laser and cooler and, thus, with the uniformity of the solder layers. Measurements with a properly soldered and a deficiently soldered laser bar are made for the illustration and comparison of the methods. [ABSTRACT FROM PUBLISHER]

Anhand von 132 vitrektomierten Augen, zeitgleich operiert mit Phakoemulsifikation via sklerocornealem Zugang und 40 Augen via CMP (Cool Micro Phaco) werden die Vor- und Nachteile dieser beiden OP-Methoden bei vier verschiedenen Indikationen, die zur kombinierten OP führten, aufgelistet. 132 Augen von 125 Patienten, die im Zeitraum 2000-2003 wegen Ablatio, Makulaforamen, diabetischer Retinopathie und diabetischer Makulopathie operiert wurden, sind in diese retrospektive Studie aufgenommen worden. Bei allen Patienten wurde primär die Phakoemulsifikation mit Linsenimplantation vor der Vitrektomie durchgeführt. In insgesamt 12 Augen wurde davor noch eine Cerclage mit einem 4,1 mm Silikonband angelegt. Bei allen Augen wurde eine faltbare oder rollbare Acryllinse in den Kapselsack implantiert, alle Operationen, außer zwei, erfolgten in Lokalanästhesie (Retrobulbärblock). Die größte Gruppe stellten die Diabetiker mit und ohne Makulopathie [61], gefolgt von den Makulopathien [34] und den Ablationes [30] dar. In der Gruppe von 40 Augen mit rein cornealem Zugang (Schnitt von 2,75 respektive 3 mm) zeigen sich bei den Ablationes in einem prozentuell höherem, aber statistisch nicht signifikantem Prozentsatz Vorderkammerabflachungen mit Irisprolaps bei Intentation im Gegensatz zu den Augen mit sklerocornealem Zugang (4,1 mm) mit großer Diagonale des Tunnels. Die Ergebnisse der kombinierten Operationen mit zwei verschiedenen Zugängen zur Katarakt ohne Verwendung einer Naht zeigen keine schweren Nachteile einer Methode, beweisen aber, dass die Mikroinzisionsphako genau so sicher wie die sclerocorneale Öffnung ist. The aim of the study was to compare the microphaco incision cataract surgery in combination with a vitrectomy with a sclerocorneal incision cataract extraction in combination with vitrectomy in regard to its feasability and safety. A total of 132 eyes of 125 patients who underwent surgery due to retinal detachment, diabetic retinopathy and diabetic macular edema at the Ophthalmology department of the Medical University in Innsbruck, Austria were included in this retrospective interventional case series. Patients who were operated between 2000 and 2003 were randomly assigned either to the group who underwent combined surgery using corneocsleral incision or to the group using microphaco incision. For both, the cool microphaco procedure and sclerocorneal phako combined with the vitrectomy a high speed cutter, provided by OS3 System (Örtli) was used. Intraoperative complications were flattening of the anterior chamber, irisprolaps and miosis. Postoperative complications compromized iriscapture, hemorrhages in the anterior and posterior chamber and air and silicone bubbles in the anterior chamber inspite of narrowing of the pupil after acetylcholin installation. The mean time between primary oil filling and oil removal was 7.7 months. Mean ocular tension was found to be 15.3 mm Hg. No correlation could be found between surgery indication and postoperative tension. No severe sight threatening complications were observed in either group. Furthermore statistical analyses revealed no significant difference comparing both groups in respect to the incidence of complications. Especially no higher incidence of anterior chamber flattening occurred in the microincision group. The visual results in both treatment groups were equivalent. Both surgical techniques provide an enhanced and excellent perioperative visualisation and safe access to the anterior retina. Visual rehabilition in most of the patients was obtained soon after surgery allowing the patients to return to work very rapidly.The results demonstrate the advantages of the combined surgical procedure in general and enforce the equivality of the double procedure using microphaco incisions in respect to efficacy, feasability and most important to safety. [ABSTRACT FROM AUTHOR]

Injection locking of two DFB semiconductors opens new possibilities to generate effective signals for optical sensing, in order to reach better performances. Pure wave forms can be generated with qualities exceeding those obtained using external modulators. This is illustrated through the application to the distributed Brillouin sensing that shows significant progress with respect to established techniques. [ABSTRACT FROM AUTHOR]

A novel method for determining gain in long-cavity Fabry-Pe´rot diode lasers is presented. Gain is extracted from a return-loss measurement via a simple model. The experimental setup is based on the injection of a low-coherence probe signal into the laser cavity and synchronous detection of the reflected light. Using a fiber-optics setup, gain can be determined in commercial fiber-coupled laser modules. The novel technique is particularly suitable for diode lasers with very long cavities. To illustrate the method, the gain spectra of a 980-nm pump diode laser with 1800-μm cavity length are determined. Gain saturation due to probe signal injection is addressed. [ABSTRACT FROM PUBLISHER]

AIMS: To define the effect of the neuropeptides substance P, calcitonin gene related peptide, vasoactive intestinal polypeptide, neuropeptide Y, and secretoneurin on the proliferation of human retinal pigment epithelial (RPE) cells. METHODS: ARPE-19 cells were used. The cells were cultured in Dulbecco's modified Eagle's medium. 1000 and 2000 cells were incubated with the peptides for 3 and 5 days, and the effect of the peptides was evaluated by an ATP lite assay dose dependently. Furthermore, specific antagonists at 10(-6) M were used to find out whether the effect would be reversed. RESULTS: In brief, each of the peptides tested had an inhibiting effect. This inhibiting effect was weak but highly significant, averaging 10% to 15%, and was most pronouncedly seen at concentrations between 10(-10) M and 10(-14) M. Each antagonist reversed the inhibiting effect fully. CONCLUSIONS: These results clearly indicate that RPE cells are under neural control and the low effective concentration of the peptides may be the one physiologically acting on these cells. The results are of important relevance both physiologically and pathophysiologically: physiologically, the inhibitory effect may mean that these peptides cause the cells to remain in a differentiated condition. Pathophysiologically, the findings are relevant in proliferative vitreoretinopathy where RPE cells proliferate in excess. The authors hypothesise that the inhibiting effect diminishes when these cells are swept out and actively migrate from their physiological location and thus, dedifferentiate and begin to proliferate. This hypothesis improves the knowledge of the initial processes in the pathogenesis of the disease as there seems to be a discrepancy between facilitatory and inhibitory influences favouring the former in proliferative vitreoretinopathy. Furthermore, these neuropeptides constitute the first endogenous inhibitors of RPE cell proliferation. [ABSTRACT FROM AUTHOR]

Purpose: To detect the levels of the sensory peptide calcitonin gene-related peptide in aqueous humor of patients with proliferative vitreoretinopathy and to compare them with those of uninflamed eyes (cataract and uncomplicated rhegmatogenous retinal detachment). Materials and methods: Using a highly specific and sensitive radioimmunoassay the concentration of calcitonin gene-related peptide was detected in fresh samples of aqueous humor obtained via paracentesis. Furthermore, calcitonin gene-related peptide-like immunoreactivities were characterized by high-pressure liquid chromatography. Results: The mean level of calcitonin gene-related peptide was 6.11 fmol/ml in cataract controls and 14.77 fmol/ml in uncomplicated rhegmatogenous retinal detachment. In the cataract group, 9 of 18 cases were below the detection limit and in the retinal detachment group, 5 of 16. In proliferative vitreoretinopathy, the peptide averaged 76.92 fmol/ml and none of the samples was below the detection limit. High-pressure liquid chromatography revealed one major peak corresponding to synthetic calcitonin gene-related peptide. Conclusion: In recent studies, we found elevated levels of the sensory peptide substance P in aqueous humor of patients with proliferative vitreoretinopathy. This fact and the present result, the elevation of calcitonin gene-related peptide in aqueous humor of eyes with proliferative vitreoretinopathy, clearly point to an involvement of sensory peptides in the pathobiology of the disease. The source of the elevation is not clear, but we hypothesize that it originates from a neurogenic mechanism, i.e. an acceleration of the peptides by their enhanced release from the iris/ciliary body complex subsequent to sensitization of sensory neurons, thus representing a very interesting epiphenomenon of proliferative vitreoretinopathy. Our results constitute novel aspects in the pathophysiological concept of proliferative vitreoretinopathy and extend the knowledge about the pathobiology of the disease process. [ABSTRACT FROM AUTHOR]

A theoretical and experimental study of a graded-index separate confinement heterostructure (GRIN-SCH) distributed feedback (DFB) multiquantum-well (MQW) diode laser emitting at 1.55 μm subject to external light injection from several lasers is presented. Lang's model for the classical single master-slave configuration is extended to include light injection from several master lasers. Free carrier transport effects are taken into account. An experimental validation of the model for two master lasers is made by means of a quantitative comparison between measured and calculated optical spectra. A fiber optics experimental setup makes it possible to measure precisely the power which is injected into the slave laser from each master laser. Measurements and model are in good quantitative agreement [ABSTRACT FROM PUBLISHER]

Bei der 8. Innsbrucker Fortbildung für Augenärzte (IFA) 1996 wurde ein interaktives Kommunikationssystem eingesetzt, um die Meinung der Zuhörerschaft in den aktuellen Vortrag einbinden zu können und bei abschließenden Fallbeispielen die jeweiligen Therapieschemata der teilnehmenden Kollegen zu erfragen. Dazu wurden im Auditorium ferngesteuerte Befragungselemente (ähnlich einer TV-Fernbedienung) verteilt, wobei der Zuhörende zu speziellen Fragestellungen während des aktuellen Vortrages die jeweils für ihn zutreffende Antwort in den ferngesteuerten Sender eingeben konnte. Insgesamt ergab sich bei der Auswertung der Ergebnisse, daß im Bereich der Dokumentation diabetischer Augenveränderungen und bei der forensischen Absicherung vor Laserkoagulationen und invasiven diagnostischen Maßnahmen dringlicher Handlungsbedarf gegeben ist. Bei der Führung des Diabetikers aus ophthalmologischer Sicht und der Behandlung, insbesonders bei Photokoagulationen, werden nach statistischer Auswertung unserer Ergebnisse ebenfalls noch zu wenig die Ergebnisse großer multizentrischer Studien beachtet und in praxi übernommen. Insgesamt zeigt sich aufgrund unserer Ergebnisse, daß weitere Fortbildungsveranstaltungen in der Thematik Diabetes mellitus auch in Zukunft ihre Rechtfertigung haben. At the 8th Innsbruck Postgraduate Symposium for Ophthalmologists 1996 an interactive communication system was used to evaluate the opinions of and therapy shemes proposed by symposium participants. Remote-control boxes were distributed in the auditorium so that audience members could directly participate in case reports being presented. Evaluation of the results made it clear that more work is urgently needed for documentation of diabetic eye lesions as well as for forensic procedures before commencing photocoagulation treatment or invasive diagnostics (e. g. fluorescein angiography). Statistical analysis of our findings also showed that in many cases diabetic patients are not treated (e. g. photocoagulation treatment) in conformity with the results of well known multicenter studies. We conclude that symposia on diabetes mellitus for ophthalmologists will continue to be important in future. [ABSTRACT FROM AUTHOR]

Im Zeitraum April 1992 bis Januar 1996 wurden 25 Augen wegen subretinalen bzw. submakulären Blutungen mit und ohne choroidalen Neovaskularisationen (CNV) vitrektomiert und die Veränderungen über eine Retinotomie entfernt. In 5 von 25 Fällen handelte es sich um eine traumatische Blutung, die aufgrund der Methodik mit einbezogen wurde. Das durchschnittliche Alter der 20 Patienten mit CNV war 63,5 Jahre, das der traumatischen Fälle 48,2 Jahre. In allen Fällen wurde nach vollständiger Vitrektomie eine Retinotomie durchgeführt, um die subretinalen Verän-derungen zu entfernen. Diese Öffnung lag ausschließlich über 600μ von der Macula entfernt und wurde in 15 von 25 Fällen mittels Laser umstellt. Abschließend wurde ein Wasser/Luftaustausch vorgenommen. Ein deutlicher Visusanstieg (ETDRS -chart) war nach einem Beobachtungszeitraum von durchschnittlich 12 Monaten in nur 7 Fällen zu beobachten. Eine Stabilisierung mit Reduktion des Zentralskotoms in 12 Augen und eine Visus-Reduktion in 6 Augen. Als Komplikation trat in einem Fall eine PVR-Ablatio auf und in 2 weiteren Fällen mußte eine Kataraktextraktion angeschlossen werden. Unsere Ergebnisse lassen den Schluß zu, daß bei submakulären Blutungen — unabhängig vom Alter — eine Verbesserung der Sehleistung (Visus und Gesichtsfeld) erreichbar ist, hingegen eine CNV bei AMD ohne Blutung nur bedingt eine Indikation zur Extraktion ist. Between April 92 and January 97 25 eyes with subretinal hemorrhage and choroidal neovascularisation were vitrectomised. All subretinal membranes were removed. 5 eyes out of 25 had traumatic subretinal bleeding. 20 patients suffering from CNV had a mean-age 63.5. After removal of vitreous a retinotomy was performed. Throughout this hole hemorrhage and CNV was extracted. 15 from 25 retinotomies were treated with laser coagulation. All eyes were filled with air at the end of the procedure. An increase of visual acuity (VA) after a mean-observation period (of 12 months) was seen in 7 eyes. 12 eyes were stable by simultaneous reduction of the central skotoma. 6 eyes showed decreased vision after surgery. As worst complication one case of retinal detachment was treated successfully. The results suggest that removal of subretinal neovascularisation is successfull only in eyes with spontaneous hemorrhage. [ABSTRACT FROM AUTHOR]

Secretoneurin is a newly discovered peptide found in high concentrations in brain. We have studied the release of secretoneurin and noradrenaline from superfused hypothalamic slices from rat brain. Both electrical stimulation and potassium induced depolarisation released secretoneurin and noradrenaline from these slices in a calcium-dependent manner. Electrical stimulation caused a preferential release of noradrenaline when compared to the secretion elicited by high potassium. The time course of secretoneurin release was more protracted than that of noradrenaline. The calcium channel blocker ω-conotoxin inhibited only the electrically induced release of noradrenaline, whereas nifedipine inhibited only that of secretoneurin. These results establish that secretoneurin is secreted from neurons. Inhibition of this release by nifedipine is consistent with the concept that secretion from large dense core vesicles occurs at sites different from that of small vesicles and depends on calcium influx via L-type calcium channels. [ABSTRACT FROM AUTHOR]

A new generation of wavelength stabilised, uncooled 980 nm pump modules in MiniDIL housings is presented, enabling 400 mW ex-fibre power over a temperature range of 10°C to 70°C. At 100°C 200 mW power is still obtained with a robust fibre coupling scheme. [ABSTRACT FROM AUTHOR]

Die Kryokoagulation von Netzhautforamina kann zur Ausstreuung von retinalem Pigmentepithel führen, was die proliferative Vitreoretinopathie (PVR) stimulieren kann. In einer konsekutiven Reihe von 15 Augen von insgesamt 15 Patienten mit Netzhautablösungen < als 3 Quadranten ohne PVR wurde eine transsklerale Diodenlaserkoagulation (TD) durchgeführt. In keinem Fall wurde eine Exodrainage angeschlossen, eine Silikonplombe diente als Tamponade des Foramens (in 3 Augen 2 Foramen), eine primäre Netzhautanlegung wurde in allen Fällen erreicht, eine proliferative Vitreoretinopathie wurde in keinem Fall beobachtet, als einzige Komplikation trat eine Verbrennung am Muskelrand des Musculus rectus temporalis auf. Durch eine Laserbehandlung entsteht eine sofortige Verbindung zwischen retinalem Pigmentepithel und Netzhaut, eine Ausschwemmung von Zellen wird verhindert, womit theoretisch das PVR-Risiko vermindert wird. Obwohl der Zeitaufwand für eine transsklerale Diodenlaserkoagulation größer als für eine Kryobehandlung ist, lassen unsere vorläufigen Ergebnisse diesen Aufwand als gerechtfertigt erscheinen. 15 patients (15 eyes) were treated with transscleral diode lasercoagulation for uncomplicated retinal detachment without signs of proliferative Vitreoretionpathy (PVR). Exodrainage was not necessary in any case. A silicone buckle was used to tamponade the retinal break. Permanent sealing of the break was achieved in all eyes. Follow up was overall one year. No serious adverse effect, exept one small burn in a muscle (M.r.inf.) was observed. Lasercoagulation can avoid dispersion of retinal pigment epithelial cells (one possible reason for PVR), which occurs normally in cryocoagulation of retinal breaks. Beside the fact that TD is more timeconsuming than cryocoagulation, it may eventually avoid PVR. [ABSTRACT FROM AUTHOR]

Die pathophysiologischen Mechanismen, die zur zellulären Proliferation bei der proliferativen Vitreoretinopathie führen, sind weitgehend unbekannt. Eine mögliche Beteiligung von Neuropeptiden wird diskutiert, zumal die Konzentration an Substanz P in intraokulärer Flüssigkeit der betroffenen Patienten deutlich erhöht ist. In dieser Studie wurde ein weiteres Neuropeptid im Kammerwasser untersucht, nämlich vasoaktives intestinales Polypeptid. Die Bestimmung mittels Radioimmunoassay ergab eine signifikant erhöhte Konzentration dieses Peptids im Kammerwasser von Patienten mit proliferativer Vitreoretinopathie verglichen mit Kataraktpatienten, die als Kontrollen dienten. Zumal vasoaktives intestinales Polypeptid die Proliferation von retinalen Pigmentepithelzellen des Huhns in der Zellkultur induziert, könnte dieses Peptid in die Mechanismen involviert sein, die zur zellulären Proliferation bei der proliferativen Vitreoretinopathie führen. The pathophysiological events leading to cellular proliferation in proliferative vitreoretinopathy are largely unknown. An involvement of neuropeptides in that disease has recently been discussed, as substance P was found to be highly enriched in the intraocular fluid of patients with proliferative vitreoretinopathy. In the present study, aqueous humor was analyzed for another neuropeptide, vasoactive intestinal polypeptide. Radioimmunoassay revealed significantly increased levels of that polypeptide in the aqueous humor of patients with proliferative vitreoretinopathy as compared with cataract patients who served as controls. As vasoactive intestinal polypeptide contributes to the environment of the retinal pigment epithelial cell layer and induces proliferation of these cells in vitro, this peptide may be involved in the pathogenetic mechanisms leading to cellular proliferation in proliferative vitreoretinopathy. [ABSTRACT FROM AUTHOR]

Multiple Netzhautveränderungen im Bereich des hinteren Pols können mit Hilfe moderner diagnostischer Verfahren wie der Optical Cohaerenz Tomographie (OCT) und dem Retinal Thickness Analyzer (RTA) relativ einfach dokumentiert werden. Es wird über eine 22jährige myope Patientin berichtet, die nach einer operativ versorgten peripheren Ablatio retinae eine zentrale Restablatio entwickelt. Die Netzhautabhebung wird vor und nach der Vitrektomie mittels RTA und OCT dokumentiert. Neue Untersuchungstechniken zur Netzhautdickenmessung ermöglichen zusätzlich zur oberflächlichen Netzhautbetrachtung pseudohistologische strukturelle Netzhautspaltuntersuchungen. Aus diesem Grund sind prae- und postoperative Vergleiche, insbesondere bei Netzhautforamina, epiretinalen Gliosen, zentralen Netzhautablösungen und subretinalen Membranen äußerst interessant und rechtfertigen ihren Einsatz. Various ophthalmological pathologies such as sub/intraretinal exudates or sub/epiretinal membranes easily can be demonstrated by retinal thickness measurement or optical coherence tomography. A young woman with high myopia causing a central retinal detachment is presented who was documented pre- and postoperatively by RTA and OCT. The efficiency of retinal surgery especially in retinal holes, epiretinal or subretinal membranes can be determined by pseudohistological measurements of the retina using RTA or OCT. [ABSTRACT FROM AUTHOR]