Okuläre Pulsamplitude als biometrischer Messwert in der Glaukomdiagnostik

Zusammenfassung: Hintergrund: Die dynamische Konturtonometrie (DCT) ermöglicht direkte transkorneale Messungen des Augeninnendrucks und der okulären Pulsamplitude (OPA). Ziel dieser Studie war es, herauszufinden, ob die OPA als biometrischer Messwert Aussagen über verschiedene Glaukomformen erlaubt. Patienten und Methoden: Es wurden 441 Augen von 222Patienten in die Studie aufgenommen. Zur Druckmessung dienten die DCT und ein Applanationstonometer nach Goldmann. Ergebnisse: Die mittlere OPA betrug 3,1±1,4mmHg. Augen mit okulärer Hypertension (3,6±1,3mmHg) zeigten signifikant höhere Werte als gesunde Augen (3,1±1,4mmHg) und solche mit Niederdruckglaukom (2,9±1,4mmHg). Nach erfolgreicher Trabekulektomie wurden signifikant tiefere Werte (2,4±1,3mmHg) als bei Gesunden gemessen. Schlussfolgerung: Die OPA scheint diverse Formen des Glaukoms zu charakterisieren, könnte aber auch direkt von der Höhe des Augendrucks abhängen. Es muss weiter abgeklärt werden, ob sie einen prädiktiven Faktor in der Diagnose und der Verlaufsbeurteilung des Glaukoms darstell

Combining Ligand Deuteration with Ligand Bulkiness in Non-Heme Iron Oxidation Catalysis: Enhancing Catalyst Lifetime and Site-Selectivity

Bulky tri-isopropyl silyl (TIPS) substituents and deuterium atoms in the ligand design have been shown to enhance the site-selective oxidation of aliphatic C−H bonds and the epoxidation of C=C bonds in non-heme iron oxidation catalysis. In this work, a series of non-heme iron complexes were developed by combining TIPS groups and deuterium atoms in the ligand. These bulky deuterated complexes show a significant increase in catalytic performance compared to their counterparts containing only TIPS groups or deuterium atoms. A broad range of substrates was oxidized with excellent yields, particularly, using [Fe(OTf)2((S,S)-TIPSBPBP-D4)] (1-TIPS-D4) (0.1 mol % to 1 mol %) via a fast or slow oxidant addition protocol, resulting in an overall improvement in catalytic performance. Notably, in the oxidation of the complex substrate trans-androsterone acetate, the use of a slow addition protocol and a lower catalyst loading of 1-TIPS-D4 resulted in significant increases in reaction efficiency. In addition, kinetic and catalytic studies showed that deuteration does not affect the catalytic activity and the secondary C−H site-selectivity but increases the catalysts’ lifetime resulting in higher conversion/yield. Accordingly, the yield of selectively oxidized secondary C−H products also increases with the overall yield by using the bulky deuterated iron complexes as catalysts. These catalytic improvements of the bulky deuterated complexes exemplify the enhanced design of ligands for homogeneous oxidation catalysis

Progressive improvement of impaired visual acuity during the first year after transsphenoidal surgery for non-functioning pituitary macroadenoma

Improvement of visual field defects continues even years after the initial surgical treatment. Because this process of continuing improvement has not been documented for visual acuity, we audited our data to explore the pattern of recovery of visual acuity until 1 year after transsphenoidal surgery for non-functioning pituitary macroadenoma. Retrospective follow-up study. Forty-three patients (mean age 56 +/- 14 years), treated by transsphenoidal surgery for non-functioning pituitary macroadenoma, were included in this analysis. Visual acuity improved significantly within 3 months after transsphenoidal surgery. The mean visual acuity increased from 0.65 +/- 0.37 to 0.75 +/- 0.36 (P <0.01) (right eye), and from 0.60 +/- 0.32 to 0.82 +/- 0.30 (P <0.01) (left eye). Visual acuity was improved 1 year after transsphenoidal surgery compared to the 3 months postoperative values. The mean visual acuity increased from 0.75 +/- 0.36 to 0.82 +/- 0.34 (P <0.05) (right eye), and from 0.82 +/- 0.30 to 0.88 +/- 0.27 (P <0.05) (left eye). Visual acuity improves progressively after surgical treatment for non-functioning pituitary macroadenomas, at least within the first year after transsphenoidal surger

Kontinuierliche Augeninnendruckmessung : Erste Ergebnisse einer drucksensitiven Kontaktlinse

A prototype of a pressure-sensitive contact lens (CL-DCT) based on dynamic contour tonometry (DCT) has been developed for continuous intraocular pressure (IOP) monitoring. The purpose of the present study was to assess the clinical applicability of this CL-DCT. MATERIAL AND METHODS: In 24 healthy subjects continuous IOP recording with the CL-DCT for 100 s was accomplished including IOP monitoring during 2 consecutive Valsalva manoeuvres. The measurement procedure was repeated after 5 min on the same eye and compared with the initial measurement. RESULTS: Continuous pressure curves were recorded in 20 subjects. The CL-DCT revealed an individual increase in IOP from 0.74 to 8.26 mmHg during the Valsalva manoeuvres. Comparison of the 2 consecutive IOP measurements yielded a mean deviation of +/-0.4 mmHg. CONCLUSIONS: CL-DCT allows non-invasive and continuous measurements of IOP. The measured values are comparable to the expected ones. Further studies are necessary to compare the measurement accuracy of CL-DCT with that of slit lamp adapted DCT (SL-DCT)

Rekonstruktive Irischirurgie bei 11 Patienten mit einem künstlichen Irisdiaphragma

Hintergrund. Irisdefekte sind nicht nur kosmetisch störend, sondern behindern die Patienten im Alltag durch starke Blendung, Verlust von Kontrastsensitivität und Visusverminderung. Die Irisprothese nach Koch ist das weltweit einzige faltbare Irisdiaphragma zur Vorderabschnittrekonstruktion bei Patienten mit partieller oder vollständiger Aniridie. Anamnese und Befund. Verlaufspräsentation von 6 Patienten mit einer traumatischen und 3 Patienten mit einer iatrogen-partiellen Aniridie nach komplizierter Kataraktoperation. Bei 2 Patientinnen (3 Augen) mit Aniridiesyndrom wurde die Katarakt operiert und eine Artificial Iris implantiert. Therapie und Verlauf. Bei allen 11 Patienten zeigte sich ein regelrechter postoperativer Verlauf und ein gutes bis sehr gutes kosmetisches Resultat. Die zumeist zuvor stark traumatisierten Augen wiesen teilweise hohe postopertive Intraokulardruckwerte auf, die aber alle medikamentös behandelt werden konnten. Schlussfolgerungen. Bei sorgfältiger Indikationsstellung und Anwendung ist die flexible Irisprothese eine wertvolle Erweiterung des Spektrums rekonstruktiver Möglichkeiten im vorderen Augensegment. Background. Iris defects are mostly acquired after injury, or may be iatrogenic after surgical excision of iris tumours or the result of collateral trauma after anterior segment surgery. They cause severe visual disability, e.g. glare, loss of contrast sensitivity, and loss of best corrected visual acuity. The foldable Koch iris prosthesis has a customised iris design and may be used to reconstruct the anterior segment in patients with partial or complete aniridia. History and Signs. We present the surgical management and clinical course of 6 patients with traumatic iris defects, together with 3 patients with partial aniridia after cataract surgery. Cataract surgery and implantation of an artificial iris were performed in 2 female patients (3 eyes) with congenital aniridia syndrome. Therapy and Outcome. No patient exhibited complications in the postoperative course, with the exception of various intraocular pressure peaks due to secondary glaucoma, that were all corrected by medication to lower topical pressure. Conclusions. In patients with major iris defects, the artificial iris allows functionally and aesthetically satisfactory reconstruction of the anterior segment

Role of ocular pulse amplitude in glaucoma

The ocular pulse amplitude is defined as the difference between diastolic and systolic intraocular pressure. The ocular pulse is generated by the pulsatile ocular blood flow in the choroid. It is dependent on the dynamics of the cardiovascular system, the rigidity of the ocular vessels on one side and the biomechanical properties of the eye on the other side. In addition the influence of outflow facility of the aqueous humor, the level of the intraocular pressure itself and last but not least the rigidity of the sclera on the ocular pulse amplitude is until now not clear. Dynamic contour tonometry (Pascal®) does not only measure intraocular pressure almost independent of corneal thickness and curvature but also allows easy and fast measurement of ocular pulse amplitude on the slit lamp. The ocular pulse amplitude in healthy subjects is between 1.2 and 4 mmHg. If the ocular pulse amplitude is larger than 1.2 mmHg spontaneous pulsations of the central retinal vein are visible on fundoscopy. In patients with ocular hypertension the ocular pulse amplitude is larger than in normal subjects but this is mainly due to higher IOP levels. In patients with manifest open-angle glaucoma the ocular pulse amplitude stays initially within the normal range. In more advanced stages of the disease and especially in patients with ocular perfusion pressure dependent optic neuropathy the ocular pulse amplitude is gradually reduced. Due to the various factors influencing ocular pulse amplitude a direct correlation between reduced ocular pulse amplitude and reduced ocular perfusion pressure has not been established as yet. New approaches investigating the variations of the ocular pressure Fourier spectral analysis are promising, especially when simultaneous analysis of the arterial blood pressure is performed. These techniques may allow a fast and easy discrimination between healthy and glaucomatous patients in the near future. If ocular pulse amplitude exhibits a massive inter-ocular asymmetry in the presence of symmetrical ocular findings of extraocular vascular pathologies (i.e. carotid stenosis) are the most likely cause and therefore should be excluded. Der Unterschied zwischen diastolischem und systolischem Augeninnendruck wird als okuläre Pulsamplitude (OPA) bezeichnet. Die okuläre Pulsamplitude entsteht durch den pulsatilen Blutfluss in der Choroidea und wird durch die Dynamik des kardiovaskulären Systems, die Rigidität der Gefäße sowie durch biometrische Faktoren des Auges beeinflusst. Die Abflussfazilität des Kammerwassers, die Höhe des Augendrucks selbst oder eine individuell unterschiedliche Elastizität der Bulbuswand wirken in bisher noch nicht restlos geklärtem Ausmaß auf die okuläre Pulsamplitude ein. Mit der dynamischen Konturtonometrie (Pascal®) lässt sich neben einer von Hornhautdicke und -radius weitgehend unabhängigen Druckmessung die okuläre Pulsamplitude einfach und schnell bestimmen. Die konturtonometrisch ermittelte OPA beträgt bei Augengesunden 1,2–4 mmHg. Bei OPA-Werten über 1,2 mmHg kann bei Augengesunden ein spontaner Puls der Zentralvene beobachtet werden. Während die OPA bei Patienten mit okulärer Hypertension druckabhängig i. d. R. höher ist als bei Augengesunden, ist sie bei Patienten mit klinisch manifestem Glaukom initial noch im Normbereich, bei fortschreitendem Gesichtsfeld- und Papillenschaden oder beim Glaukom mit vorrangiger Mangelperfusion am Sehnervenkopf zunehmend herabgesetzt. Ein Rückschluss von der Höhe der OPA auf die okuläre Durchblutung konnte wegen der zahlreichen Einflussfaktoren bis jetzt nicht im Einzelnen bewiesen werden. Neuere Untersuchungen mit einer Fourier-Spektralanalyse des okulären Pulses, und wenn möglich auch synchron des arteriellen Pulses, könnten in Zukunft einen vielversprechenden Ansatz zur Diskrimination zwischen Augengesunden und Glaukompatienten darstellen. Bei einer deutlich asymmetrischen OPA und gleichzeitig vorliegenden symmetrischen okulären Befunden sollte eine extraokuläre (vaskuläre) Ursache gesucht werden

A New Glaucoma Severity Score Combining Structural and Functional Defects

Background In order to assess glaucoma severity and to compare the success of surgical and medical therapy and study outcomes, an objective and independent staging tool is necessary. A combination of information from both structural and functional testing is probably the best approach to stage glaucomatous damage. There has been no universally accepted standard for glaucoma staging. The aim of this study was to develop a Glaucoma Severity Score (GSS) for objective assessment of a patient's glaucoma severity, combining both functional and structural information. Materials and methods The Glaucoma Severity Score includes the following 3 criteria: superior and inferior Retinal Nerve Fibre Layer (RNFL) thickness, perimetric mean defect (MD), and agreement of anatomical and perimetric defects, as assessed by two glaucoma specialists. The specialists defined a staging tool for each of the 3 criteria in a consensus process, assigning specific characteristics to a scale value between 0 and 2 or 0 and 3, respectively. The GSS ranges between 0 and 10 points. In a prospective observational study, the data of 112 glaucoma patients were assessed independently by the two specialists according to this staging tool. Results The GSS was applied to 112 eyes and patients (59.8 % female) with a mean age of 66.3 ± 13.1 years. Mean GSS was 4.73 points. Cohen's kappa coefficient was determined to measure inter-rater agreement between glaucoma specialists for the third criterion. With κ = 0.83, the agreement was very good. Thus, all 3 criteria of the GSS may be regarded as objective. Conclusions The Glaucoma Severity Score is an objective tool, combining both structural and functional characteristics, and permitting comparison of different patients, populations and studies. The Glaucoma Severity Score has proven effective in the objective assessment of 112 glaucoma patients and is relatively user-friendly in clinical practice. A comparative study of the GSS with the results of the FORUM® Glaucoma Workplace (Carl Zeiss Meditec AG, Jena, Germany) will be the next step. If outcomes match, the Glaucoma Severity Score can be accepted as a promising tool to stage glaucoma and monitor changes objectively in patients when comparing glaucoma progression in study analyses