E. Königsdörffer

Sodium fluorescein as a retinal pH indicator

Retinal neovascularization is a symptom associated with various diseases revealing ocular fundus manifestation. Often, these neovascularizations originate from retinal hypoxia. A concomitant phenomenon of hypoxia is acidosis. To recognise this would permit the identification and treatment of hypoxic fundus areas long before first vascular modifications are seen. Thus, the goal of this investigation was to elucidate whether sodium fluorescein could be used as a retinal pH indicator. Sodium fluorescein solution was diluted in PBS (ratio: 1:150,000). The pH was varied from 6.5 to 8.6 by supplementation of HCl or NaOH, respectively. The fluorescence was excited by a pulsed diode laser (wavelength: 446 nm, pulse width: 100 ps) and detected by time-correlated single photon counting (TCSPC) technique. A least-squares fit of the measured fluorescence decay versus time by an exponential function results in the fluorescence lifetime. Ten measurements were taken at each pH for statistical analysis. The dependence of the fluorescence lifetime on the temperature and the concentration of sodium fluorescein was investigated in the same way. The fluorescence lifetime was found to rise from 3.775 ns to 4.11 ns with increasing pH (6.5 to 8.6). However, the gradient decreases with increasing pH. We found highly significant differences (Students t-test, P<0.0005) of the fluorescence lifetimes for pH values with a mean difference of 0.125 at pH<7.65 whereas the differences were still significant (P<or=0.02) at pH>7.65 and mean pH differences of 0.2. The fluorescence lifetime was independent of the temperature (22 degrees C to 37 degrees C) and the concentration of sodium fluorescein (dilution 1:150,000 to 1:2000). The fluorescence lifetime of sodium fluorescein depends on the pH but not on temperature and concentration. Thus, the discrimination of areas with retinal acidosis should be possible by combination of the TCSPC technique with scanning laser ophthalmoscopy. Further investigations have to clarify whether the accuracy of the measurement at the fundus in vivo is sufficient.

Endogene Endophthalmitis bei schweren Allgemeinerkrankungen

Hintergrund: Die endogene Endophthalmitis bei schweren Allgemeinerkrankungen und reduziertem Allgemeinzustand hat trotz moderner antibakterieller, antimykotischer und operativer Therapie eine äußerst schlechte Prognose.Patienten: Die Studie zeigt den Krankheitsverlauf bei 5 Augen von 4 Patienten mit endogener Endophthalmitis. Das Alter der Patienten lag zwischen 58 und 71 Jahren. Die Zeitspanne zwischen dem Auftreten der ersten Augensymptome und der stationären Aufnahme betrug 1 Woche bis 3 Monate. An Allgemeinerkrankungen waren Endometriumkarzinom, Kolonkarzinom, Korpuskarzinom (mit Bauchfistel) und Pankreasinsuffizienz (mit Subklaviakatheter) sowie Diabetes mellitus bekannt.Ergebnisse: Entsprechend dem Keimnachweis (Candida albicans in 3 Augen, Bakterien in 2 Augen) wurde antibakteriell bzw. antimykotisch lokal, subkonjunktival und systemisch behandelt sowie eine Pars-plana-Vitrektomie und/oder Glaskörperpunktion mit Antibiotika- bzw. Antimykotikaeingabe durchgeführt. Trotzdem lagen abschließend folgende Befunde vor: 1 Auge Enucleatio bulbi, 1 Auge Evisceratio bulbi, 2 Augen Lichtschein, 1 Auge Visus 0,2.Schlußfolgerung: Die Einweisung der Patienten in Kliniken mit einer Abteilung für Glaskörperchirurgie sollte möglichst frühzeitig erfolgen. Nur so ist es möglich, schnell mit einer adäquaten Therapie zu beginnen.Background: In spite of modern antibacterial, antimycotic and operative therapies, endogenous endophthalmitis connected with other severe diseases and an impaired state of health is an eye complication with a very poor prognosis.Patients: The study presents observations about the progress of the endogenous endophthalmitis in five eyes of four patients. The age of the patients ranged from 58 to 71 years. The span between the appearance of the first eye symptoms and hospital treatment amounted to 1 week and 3 months. The general diseases have been diagnosed as endometrium cancer, colon cancer, corpus uteri cancer (with intestinal fistula) and pancreatic insufficiency (with subclavian catheter) as well as diabetes mellitus.Results: In regard to the infections we analyzed (Candida albicans in 3 eyes, bacteria in 2 eyes), very intensive medical treatment was initiated, including antibacterial or antimycotic therapy (local, subconjunctival, intraocular and systemic) as well as pars plana vitrectomy and/or vitreous puncture. Nevertheless, by the end of the clinical attendance, the following statements were established: one-eye enucleation, one-eye evisceration, two eyes perception of light, one eye visual acuity 0.2.Conclusion: The patients should be immediately admitted to a hospital with a department for vitreous surgery. Only with this option is it possible to initiate adequate therapy.

Surgical approach in Terson syndrome : vitreous and retinal findings

Purpose To report some interesting findings in patients with bilateral Terson syndrome. Methods We describe six eyes from three patients with Terson syndrome. Pars plana vitrectomy was performed in one eye twelve weeks, and in four eyes six months after the acute event. In one eye blood was suddenly spontaneously absorbed after four months. Results The four eyes operated six months after injury showed severe complications and final visual acuity was between light perception and 0.6. The eye with surgical attendance twelve weeks after the acute injury had an uneventful course, and final visual acuity was 0.7. Conclusions Because of severe ocular complications and with a view to early rehabilitation, vitrectomy has been recommended for eyes with bilateral Terson syndrome, without spontaneous blood resorption. Surgery should be performed in at least one eye not later than four to eight weeks after the acute injury.

Measurement of flow-physiologic parameters of retinal blood circulation in type 1 and 2 diabetics before and after photocoagulation.

In seven diabetics of type 1 and seven of type 2, the flow physiologic magnitudes were measured in a retinal quadrant before and after photocoagulation. The segmental blood flow, the arterial flow velocity, and the diameters of artery and vein are smaller after photocoagulation than before. Investigations into the time course of the flow-physiologic parameters following photocoagulation show that the flow-physiologic values are stationary about 2 weeks after photocoagulation.

Messungen zur Ermittlung des Blutvolumendurchflusses in großen retinalen Gefäßen des Menschen

A combined measuring unit for the Retinophot is described which can be used to determine the blood flow through the great retinal vessels. This method is possible by combination of the two-point photometry with length measurements by means of rocking-plate micrometry. The first measuring results are presented.A combined measuring unit for the Retinophot is described which can be used to determine the blood flow through the great retinal vessels. This method is possible by combination of the two-point photometry with length measurements by means of rocking-plate micrometry. The first measuring results are presented. Es wird eine kombinierte Meßeinheit für das Retinophot beschrieben, mit der sowohl Längenmessungen, als auch Indikatorlaufzeitmessungen an großen retinalen Gefäßen des Menschen durchgeführt werden können. Somit ist es möglich, den Blutvolumendurchfluß in großen retinalen Gefäßstücken zu ermitteln. Die Indikatorlaufzeitmessung wurde auf der Basis der Zwei-Punkte-Photometrie realisiert. Das Prinzip der Längenmessung beruht auf der Planplattenmikrometrie. Erste Meßergebnisse werden vorgestellt.

Measurements of retinal microcirculation in retinal vessel occlusion before and after treatment

Blood flow, arterial velocity, and vascular diameter were measured in patients with retinal vessel occlusion before and after treatment, especially after light coagulation. The mean values in the patient group showed significantly reduced blood flow and velocity compared to the normal group. The mean group difference before and after therapy revealed that while there is an increase in blood flow after treatment, the normal value is not reached. Individual patient values indicated both increased and decreased blood flow and velocity after treatment as compared with the values before therapy. There are various stages in microcirculatory disease and the microcirculation also behaves differently after treatment, which could be observed by measurement in vivo of the physiological flow parameters.

Spektrale Differenzierung in Eigenfluoreszenzbildern des Augenhintergrunds von Patienten mit altersabhängiger Makuladegeneration

ZusammenfassungHintergrundEine veränderte Eigenfluoreszenz des Augenhintergrunds wird gegenwärtig insbesondere im Zusammenhang mit der altersabhängigen Makuladegeneration diskutiert. Zu ihrer richtigen Bewertung sind jedoch weitere Kenntnisse über das chemische Substrat der Fluoreszenz erforderlich.MethodeDie Autofluoreszenz des Augenhintergrunds wurde mit einer Funduskamera beobachtet. Die Anregung erfolgte im blauen Spektralbereich. Zur Aufzeichnung der Fluoreszenz wurde eine 3-Chip-CCD-Farbkamera benutzt. Zum Vergleich wurden die Fluoreszenzspektren von Lipofuszin, A2-E, FAD, NADH2 und AGE mit dem Jenaer Ophthalmospektrometer aufgenommen.ErgebnisseIm Gegensatz zu einem gesunden Fundus zeigen die Autofluoreszenzaufnahmen an Patienten mit AMD deutlich lokalisierbare Areale spektral unterschiedlicher Fluoreszenzemission. Die jeweils gefundenen Emissionsspektren zeigen starke Überlappungen.SchlussfolgerungenDie vorgestellte Technik ermöglicht es, spektrale Unterscheidungen in Bildern der Autofluoreszenz des Augenhintergrunds vorzunehmen. Neben der des Lipofuszins wurde bei Patienten mit nichtexsudativer AMD eine kurzwelligere Fluoreszenz beobachtet.AbstractIntroductionAlterations in the intrinsic ocular fundus fluorescence are under discussion particularly in connection with age-related macular degeneration. However, further knowledge of the chemical substrate of fluorescence is necessary.MethodOcular fundus autofluorescence was observed using a fundus camera. The fluorescence emission was recorded using a 3-chip CCD camera. For comparison, the fluorescence spectra of lipofuscin, A2-E, FAD, NADH2 and AGE’s were recorded by the Jena ophthalmo-spectrometer.ResultsIn contrast to the homogeneous intrinsic fluorescence of a normal fundus, the fluorescence images of patients suffering from AMD showed remarkable local differences. The detected fluorescence spectra showed remarkable overlaps.DiscussionWe introduced a new technique enabling the detection of spectral differences in images of ocular fundus autofluorescence. Besides the fluorescence of lipofuscin, we found a green one in patients suffering from nonexudative AMD.

Nonproliferative diabetic retinopathy-reflection spectra of the macula before and after laser photocoagulation.

This study examines the influence of diabetic and laser photocoagulation on the reflection spectra of the macula. In the investigation 43 patients with type II diabetes mellitus and 33 normals were included. It was shown that the optical density in diabetics is increased compared to normals. After laser photocoagulation the reflection spectra have changed, suggesting a decrease in optical density. It is proposed that the therapeutic effect of photocoagulation in diabetic retinopathy is related to an alteration in blood flow in the choroid.

Multisubstance analysis of reflection spectra before and after laser photocoagulation for proliferative diabetic retinopathy

Purpose The aim of the study was to provide new data that add to the understanding of diabetic retinopathy and its treatment by photocoagulation. Patients and Methods. Using a spectrometric method, the reflection spectra of the macula in six type II diabetics with proliferative diabetic retinopathy were measured before and after laser photocoagulation and compared with normals. The investigations were done one day before laser photocoagulation and again the day after. Further measurements were made 14 days, 6 weeks and 4 months after coagulation. The reflection spectra were assessed by multisubstance analysis. Results and Conclusions. The contents of xanthophyll, melanin and choroidal oxyhemoglobin and the intensity of scattered light were significantly altered after laser coagulation. For example, in patients with proliferative diabetic retinopathy the content of oxyhemoglobin in the choroid was lower than normal, but it rose after laser treatment. This suggests an improved oxygen supply of the choroid after laser coagulation, implying reduced retinal hypoxia.

Messung strömungsphysiologischer Größen der Netzhautzirkulation bei Diabetikern Typ 1 und 2

Segmental blood flow, velocity, and vessel diameter were measured in 21 eyes of diabetic individuals with diabetes type 1 and 2. The results for arterial blood flow, velocity, arterial and venous vessel diameter in diabetes show significant differences from the results measured in normal individuals. These flow magnitudes, excluding arterial diameter, significantly depend on the duration time of diabetes. The retinal blood flow magnitudes alter before the marks of diabetic retinopathy are visible. There are differences between the results in diabetes type 1 and type 2 regarding dependence on the duration time of diabetes.ZusammenfassungAn 21 Augen von Diabetikern Typ 1 und 15 Augen von Diabetikern Typ 2 wurden Blutvolumendurchfluß, Blutgeschwindigkeit und Gefäßdurchmesser in einem retinalen Quadranten gemessen. Der arterielle und venöse Durchmesser der Hauptgefäße dieses Quadranten sowie der Blutvolumendurchfluß und die arterielle Blutgeschwindigkeit der Probanden beider Diabetestypen zeigen signifikante Unterschiede zu den Normalwerten und bis auf die Arteriendurchmesser bei Typ 2 signifikante Abhängigkeit von der Diabetesdauer. Bei Diabetikern Typ 1 ist bereits im Stadium 0 der diabetischen Retinopathie eine Veränderung der gemessenen Größen nachweisbar. Diabetiker Typ 1 und Typ 2 unterscheiden sich in dieser experimentellen Studie im Verlauf der Abhä ngigkeit der gemessenen Größen von der Diabetesdauer.Segmental blood flow, velocity, and vessel diameter were measured in 21 eyes of diabetic individuals with diabetes type 1 and 2. The results for arterial blood flow, velocity, arterial and venous vessel diameter in diabetes show significant differences from the results measured in normal individuals. These flow magnitudes, excluding arterial diameter, significantly depend on the duration time of diabetes. The retinal blood flow magnitudes alter before the marks of diabetic retinopathy are visible. There are differences between the results in diabetes type 1 and type 2 regarding dependence on the duration time of diabetes.