Zeiss Guided Progression Analysis Essay

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Deutsche Version untenstehend.

First Zeiss Cirrus 5000 HD OCT in Switzerland by

Dr. med. Peter Maloca,Blueye Vision Tech & GETOCT.COM.

Provided by Blueye Vision Tech GmbH

->visit Blueye Vision Tech

GETOCT.COM was given the opportunity as a first party in Switzerland to test the brand new Cirrus 5000 from Zeiss Switzerland.

 

What is the worth of healthy eyes?  GETOCT.COM. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

Already the Cirrus 4000 showed its intuitive, compact dimensions, a nice designed user interface and a great robustness. Thus, the Cirrus 4000 had 7 years worked daily without any fail! This is a very nice performance for a computer, for a highly complex optical coherence (OCT) scanner it is almost a miracle. The new Cirrus 5000 system features a modernized system based on a fast Windows 7 computer with much more faster processing and OCT camera system, a larger viewing monitor and a wireless mouse and keyboard. You will experience an increased speed, more comfort and and a better reliability.

->View first Swiss Impression of the brandnew ZeissCirrus5000 Optical Coherence OCT. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

->Download Swiss Impressions Zeiss Cirrus5000HDOCT:Impressions Cirrus5000 GETOCT

Hard Core test NEW FastTrac™ retinal tracking system – full video without a cut.

This video shows the latest OCT technology in full length- without a cut.

-> View Tracker Test by GETOCT. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

This demo film is shown in “real life”, without a cut or ​​any corrections. A young gentleman was measured to test the functionality of the newly introduced Fast Tracker. In the middle of the measurement, the person moves away from the scanner, sits down again, and very surprisingly, the scanner automatically finds the last position and finishes the scanning procedure as if nothing has happened. Surprise, suprise!

Download Video -> Hard Core Test Eyetracker Cirrus5000HD GETOCT

General featuresOCT Tools offered by Zeiss Cirrus 5000HDOCT.

Macula OCT Tools:

  • Precision FoveaFinder™
  • NEW FastTrac™ retinal tracking system
  • NEW Macular Thickness OU Analysis
  • Advanced RPE analysis
  • Macular Thickness and Change Analysis
  • Macular Thickness Normative Data

Glaucoma OCT Tools:

  • Retinal Nerv Fiber Analysis (RNFL)
  • Retinal Nerv Fiber Analysis (RNFL) Normative Data
  • Ganglion Cell Analysis
  • Guided Progression Analysis (GPA™)

Cornea Tools:

  • Axial Corneal Tghickness Analysis
  • Corneal 3D Imaging

 

First encounter- Cirrus 5000 HD OCT – a solid big brother.

Zeiss offered a wide range of tools to for the diagnosis of glaucoma, maculopathies and anterior segment conditions without an additional lens to be installed. At the first touch with the Cirrus 5000  you find your way very quickly. The setup has been consistently adapted from Cirrus 4000 and expanded:

The mouse and keyboard are now wireless and elegant to use. The mouse fits well in the hand, for larger hands it might be a little too small. The keyboard shows a need of getting used, because the keys are close together and the keyboard is arched. The arrow keys are placed into only one piece. The screen is much larger which facilitates the survey.

Professional OCT simplicity. “Reduce to the max “, was chosen as maxime and successfully implemented. A visual tour of the software is intuitive and pleasant as the controls are reduced to the most necessary and were placed very clear. The technical adaptation to the examiner of such a highly complex OCT technology is exemplary. In an OCT aquisition test – carried out by a 65 year old woman who had no knowledge of computers or even strange things like OCT – the data collection lasted under professional guidance only 2 minutes and 42 seconds.

Patient data. The input of the patient data go as previously very fast and easy.

Acquisition of the OCT data. The positioning of the head, focusing on the desired location to go quickly as before – perfect for OCt beginners. The generous protocols consist of anterior segment analysis (corneal thickness and mapping), macular thickness and cross scan regular or high definition (HD-OCT), Enhanced Depth Imaging (EDI) , ganglion-cell analysis, retinal nerve fiber layer analysis (RNFL), optic nerve head analysis (OHD).

New Tools Zeiss Cirrus 500 HD OCT.

Modernized system. Nice handling with wireless mouse and keyboard. Much larger display for relaxing computer work und data representation. Exacter, faster and reproducible data aquisition, and above all very fast data processing.

Fast Tracis an active eye-tracker allows repeatable measurements of identical sites. The tracker is optional, which means that it can be turned off in patients with a perfect fixation. If fixation is impaired, for example in cases of maculopathies, the tracker supports the OCT measurement. The method compensates blinking and eye movements, which otherwise often lead to artifacts and a poor image quality and leads to a wastage of precious time. The patient can now even stand-up and leave the room during the measurement, later sit down and The Cirrus 5000 HD OCT continues with the measurement at the predetermined location accurately. In a test this feature worked perfectly: a surprisingly positive result. This may be important in patients who need a break because theybecome tired very quickly or unexpectedly need to use the lavatory.

Synopsis of the macular dataset both eyes. It is encouraging that now the data of macular measurements in a synopsis can be represented. This makes comparison and pathological changes easier to explain to the patient.

New Zeiss Forum Software Suite(network based and very fast data transfer and data analysis).  For the digital data transfer,  Zeiss provides an interesting way offering a central software solution (Zeiss Forum) so that the patient data have to be typed in only once at the reception and investigative requests to the inthe network existing Zeiss machines are sent instantly. Save time. Save paper. Save money. Go digital. It works and nearly all kind of data output from different manufacturers, even videos can be imported. The so-called “Turnschuh-Laufwerk” or  “sneaker-drive” is now a thing of the past.

Not enough about OCT? What is still missing?

Data analysis. Various analytical protocols process the acquired OCT data. If several identical scansets were performed in one patient, it happens quickly, that a wrong data set is clicked to be analyzed. The analytical protocol “crunshes” then all the data to a visual representation, but “the dog cannot be stopped”. A small “Cancel button” would save time.

Patient data. Best enter first the day and month of birth, then choose the dropdown menu to complete the year of birth very quickly. The represntation of the months is now relatively dynamically as the past or future months appears a little smoother. This is a matter of taste. However,  displaying like “one click, one month” would be prefered and zack you are done.

Analysis screendesign. Fortunately, the number of analysis options has increased, which leads to safer diagnosis and treatments of eye diseases. Because of the abundance, not all protocols appear at the same time, therefore time-consuming scrolling is needed. To change this, it should not be a computer science major effort. Only enlarge the “analysis protcolls window” down and efficiency is improved by a simple step.

Black-On-White versus White-On-Black mode. What’s missing is a small switch button to quickly change the color coding of the OCT images, ideally black-on-white, since the layers are better visible, printer ink can be saved to reduce costs and to protect the environment . This desire was expressed many years ago.

Security. Currently there is a good security setup of the device with password protection and separate selection of the OCT operator. This is especially useful in large and busy eye centers. In smaller offices  ethe first steps are rather cumbersome and make no real sense, because often only one or two investigators are involved.

Corneal thickness measurement (Corneal Thickness). Zeiss treats the cornea to neglected. It would be beautiful to have a survey of the entire corneal cube in micrometers (OCT pachymetry), not only a  few and small sized sections. It would also be helpful if the compartments (epithelium, stroma) are measured in Thickness and volume, especially for refractive surgery or keratoconus. Moreover: measurements should not only be possible vertically along the laser optical axis, but also obliquely, for example, in corneal scars or corneal wounds. A longer corneal scan length would be very desirable, why not at last 14 millimeters?

Chamber angle (Anterior Segment). In certain situation the numeric definition of the anterior chamber angle is helpful.

Children and Teen: normative database for macula and glaucoma. Why is the “OCT-life” beginning at 18 years? In practice, there are many children and young people by the way. Therefore, a normative database for the under-18s is important. Ths is missing nearly by all OCT manufacturers.

Noise-fan. The new Cirrus 5000 system is very quiet, almost “OCT-whispering” only. Cirrus 4000 produces much more noise, so the existing aerators can be replace, especially OCT operators who sit all day near the OCT scanner would be veryy happy. By the way: it is possible to replace the fans of the Cirrus 4000, to reduce the noise impact. Ask the Zeiss representant!
What are you missing? Please write your comment below! Please enter your comments in the comment section below, thank you!

Brand new OCT Cirrus 5000 GETOCT.COM. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

Erstes Zeiss Cirrus 5000 HD OCT in der Schweiz,

von Dr. med. Peter Maloca, Luzern, Blueye Vision TechGETOCT.

GETOCT.COM hatte als erste in der Schweiz die Chance  erhalten, das brandneue Cirrus 5000 OCT (Optical Coherence Tomography oder Optische Kohärenztomography, kurz OCT) zu testen. Bereits das Cirrus 4000 zeigte seine intuitive Bedienbarkeit, kompakte Masse, ein schönes und praktisches Design und eine grosse Robustheit. So hat das Cirrus 4000 HD OCT seit 7 Jahren täglich funktioniert – ohne einen Ausfall. Das ist eine ausserordentliche Leistung für einen Computer, für einen hochkomplexen OCT-Scanner ist es fast ein Wunder.

Das neue modernisierte Cirrus 5000 HD OCT-System verfügt über eine zeitgemässe Hard- und Software, basierend auf einem schnellen Computer mit Windows 7 mit 64 bit, einem deutlich beschleunigten OCT-Kamera-System, einem angenehm größeren 19 Zoll Monitor und einer drahtlosen Maus und Tastatur. Dies führt zu einer schnelleren Verarbeitung mit kürzeren Zeiten für den Patienten und den Augenarzt. Die OCT-Scangeschwindigkeit liegt zwischen 27,000 bis 68,000 pro Sekunde.

Cirrus 5000 OCT – der grosse Bruder
Nicht zuletzt fand sich eine ausserordenltiche breite Palette an Tools zur Diagnose von Glaukom, Maculopathien und Vordersegment, ohne dass eine Zusatzlinse installiert werden muss.

Erste Berührung.

Schon bei der ersten Berührung findet man sich sehr schnell zurecht. Das Setup wurde konsequent vom bewährten und weit verbreiteten Cirrus 4000 HD OCT adaptiert und erweitert:

Die Maus und das Keyboard sind jetzt kabellos und elegant zu bedienen. Die Maus sitzt gut in der Hand, kann für grössere Hände aber etwas zu klein daherkommen. Die Tastatur ist gewöhnungsbedürftig, da die Tasten eng beieinander sind und die Tastatur gewölbt ist. Die Tastatur ist auf Englisch, sodass das x und y gesucht werden müssen. Daran gewöhnt man sich aber sehr rasch. Die Pfeiltaste besteht nun aus einem Guss und wirkt zu sperrig. Ein grosser, aufgeräumter Bildschirm erleichtert die Arbeit sehr.

Professionelle OCT-Schlichtheit. “Reduce to the max”, wurde als Maxime gewählt und erfolgreich verwirklicht. Die visuelle Führung durch die Software ist intuitiv und angenehm, da die Bedienelemente auf das Allernötigste reuziert und sehr übersichtlich platziert wurden. Die technische Adaptation an den Untersucher einer so hochkomplexen OCT-Technologie ist vorbildhaft. Bei einem OCT-Aufnahmetest – ausgeführt durch eine 65 jährige Frau, die keine Ahnung von Computern oder geschweige OCT hatte – dauerte die Daten Erfassung unter professioneller Anleitung nur 2 Minuten und 42 Sekunden.

Patientendaten: die Eingabe der Patientendaten und des Geburtsdatums gehen wie bis anhin sehr flüssig und zeitsparend. Am besten erfolgt zuerst die Eingabe das Tages und der Monats der Geburt, danach soll das DropDownmenu angeklickt werden, um das Geburtsjahr rasch zu vervollständigen. Am Bildschirm huscht nun relativ dynamisch bei der Wahl des Monats die Anzeige vorbei und erscheint etwas flüssiger. Bevorzugt wird aber die Darstellung “ein Klick, ein Monat”, zack und fertig.

Neuestes  Zeiss Forum Datensuite (blitzschneller Datentrasfer und Datenanalyse im Netzerk): für den Datentransfer bietet Zeiss eine interessante Möglichkeit durch eine zentrale Software-Lösung (Zeiss Forum), sodass die Patientendaten am Empfang nur einmal eingetippt werden müssen und dann Untersuchungs-Aufträge über das Netzwerk an vorhandene Zeiss- Maschinen blitzschnell geschickt werden. Spare Zeit, Papier und Geld. Das sogenannte “Turnschuh-Laufwerk” gehört ab jetzt der Vergangenheit an. Erfreulicherweise und für den klinischen Alltag sehr wichtig können in die Forum Suite Daten von fast allen anderen Firmen über einen separaten Kanal importiert werden, sogar Videos.

Aquisition der OCT-Daten. Die Positionierung des Kopfes, die Fokussierung auf die gewünschte Lokalisation des vorderen oder hinteren AUgensegments gehen sehr rasch wie bisher. Gerade OCT-Beginner werden Freude daran haben und sich rasch eingewöhnen. Die grosszügigen Protokolle bestehen aus Vordersegment-Analyse (Cornea-Dicke und Mapping), Makula-Dicke und Querschnitt, Enhanced Depth Imaging (EDI) , Ganglien-Zell-Analyse, retinale Nerven-Faser-Schicht Analyse (RNFL), Opticus.

Neue Funktionen Zeiss Cirrus 5000 HD OCT.

Modernisiertes System. Haptisch ist die Benutzung der kabellosen Maus und der Tastatur sehr angenehm. Ein deutlich größerer Monitor sorgt für entspannte Arbeit am Computer und Darstellung der OCT-Daten, was auch bei der Erklärung der Pathologien für den Patienten hilfreich ist. Das führt zu einer genaueren, merklich schnelleren und reproduzierbareren Datenaufnahme und vor allem sehr schnellen Datenverarbeitung.

Fast Trac ist ein aktiver Augen-Tracker erlaubt die wiederholbare Messung identischer Lokalisationen. Der Tracker ist optional, das heisst, dass man bei Patienten mit perfekter Fixation, der Tracker ausgeschaltet werden kann. Ist die Fixation beeinträchtigt, zum Beispiel bei Makulopathien, unterstützt der Tracker die Messung. Die Methode kompensiert Blinzeln und Augenbewegungen, was sonst häufig zu Artefakten und schlechten Bildern führt und Zeit kostet. Der Patient kann nun sogar während der Messung vom Scanner weggehen, sich hinsetzen und Cirrus fährt mit der Messung an der genau vorgegebenen Stelle weiter. Beim Selbstversuch zeiget sich ein erstaunlich positives Resultat. Das kann wichtig sein bei Patienten, die rasch ermüden, eine Pause benötigen oder unerwartet auf das WC müssen.

Makula-Synopsis. Erfreulich ist, dass nun die Daten einer Makula-Messung in einer Synopsis beider Augen darstellbar sind. Das erleichtert den Vergleich und krankhafte Veränderungen sind dem Patienten einfacher erklärbar.

Nicht genug von OCT? Was fehlt noch?

Datenanalyse.  Diverse Analyseprotokolle verarbeiten die erhaltenen OCT-Daten. Wurden bei einem Patienten mehrere gleiche Scans durchgeführt, passiert es rasch, dass ein falsches Datenset angeklickt wird. Das Analyseprotokoll “zermalmt” dann sämtliche Daten zu einer bildlcihen Darstellung und ist nicht zu stoppen. Ein kleiner “Abbrechen-Knopf” spart Zeit.

Analyse-Bildschirm. Erfreulicherweise wuchs die Zahl der Analysemöglichkeiten an, was zu einer sicheren Diagnose und Therapie bei Augenkrankheiten führt. Aufgrund der Fülle werden aktuell nicht sämtliche Protokolle angezeigt, sodass geblättert werden muss. Hier sollte nur das “Protokoll-Fenster” etwas nach unten verbreitertert werden und schon ist die Effizienz gesteigert. Das sollte kein grosser Informatik-Aufwand sein.

Schwarz-Auf-Weiss versus Weiss-Auf-Schwarz Darstellung. Was noch fehlt ist ein kleiner Schaltknopf, um schnell die Farbkodierung der OCT-Bilder zu wechseln, idealerweise Schwarz-Auf-Weiss, da somit die Schichten besser erkennbar sind, Drucker-Tinte gespart werden kann, sich die Kosten reduzieren und die Umwelt geschützt wird. Dieser kleine Wunsch wurde schon vor Jahren geäussert.

Sicherheit.  Aktuell besteht eine gute Zugangssicherheit des Gerätes mit Passwortschutz und separater Auswahl des OCT-Operateurs. Das ist vor allem sinnvoll in grösseren und stark frequentierten Augenzentren. In kleineren Augenarztpraxen sind die ersten Schritte eher umständlich und machen keinen richtigen Sinn, da oft nur ein oder höchstens zwei Untersucher die Messungen durchführen und der ZUgang zum OCT-Scanner mir seinen Patientendaten eingeschränkt ist. Darum sollte hier die Option angeboten werden, dass nach dem Druck des Startknopfes direkt die Analyse/Aquisitionsmaske gezeigt wird oder das bisherige Regime gewählt werden kann.

Hornhaut-Dickenmessung (Corneal Thickness).  Zeiss behandelt die Hornhaut etwas stiefmütterlich, dabei ist die Hornhaut die zentrale Struktur für gutes Sehen und auch für gute OCT-Bilder. Hier besteht Entwicklungspotential. Schön wäre eine Vermessung des ganzen Hornhautkubus in Mikrometern, nicht nur weniger Querschnitte. Zudem wäre es hilfreich, wenn die cornealen Kompartimente (Epithel, Stroma) ausgemessen werden in Dicke und Volumen, gerade für die refraktive Chirurgie mit Laser, wo aktuell meist nur Durchschnittswerte verwendet werden,  oder bei Keratokonus mit seiner unregelmässig dicken Epithelschicht. Zudem sollte eine Messung einer Läsion in Mikrometern nicht nur vertikal entlang der optischen Laserachse möglich sein, sondern auch schräg, zum Beispiel bei Hornhautnarben, Hornhautwunden. Wünschenswert wäre auch ein längere bzw. selbst einstellbarere Scanlänge und -richtung. Erweiterungen folgen wahrscheinlich mit den nächsten Versionen.
Kammerwinkel  (Anterior Segment).  In gewissen Situation ist eine Winkeldarstellung der Vorderkammer in Grad hilfreich.

Kinder und Jugendliche normative Datenbank für Makula und Glaukom. Warum beginnt das “OCT-Leben” erst ab 18 Jahren? In der Praxis gibt es übrigens viele Kinder und Jugendliche. Darum ist eine normative Datenbank für die unter 18jährigen wichtig. Das fehlt bei fast allen OCT-Herstellern.

Lärmentwicklung-Lüfter. Das neue Cirrus 5000 System ist sehr leise, es verbreitet fast nur ein “OCT-Geflüster”. Der Computer des Cirrus 4000 produziert im direkten Vergleich etwas mehr Lärm. Übrigens: beim Cirrus 4000 können die Ventilatoren durch geräuscharme Modelle ersetzt werden! Darüber freuen sich vor allem die OCT-Operateure, die den ganzen Tag an der Kiste sitzen müssen.

Teilen Sie uns mit, was Ihnen fehlt (Comments unten).

 

OCT Optical Coherence Tomography (OCT)

High Definition Gallery Zeiss Cirrus 5000 HD OCT

The potential of the new Zeiss Cirrus 5000 (optical coherence tomography, OCT) are represtend by following images.
Folgende Bilder zeigen das Potential von Zeiss Cirrus 5000 HD OCT (Optische Kohärenztomographie, OCT):

OCT Angle Closure Glaucoma GETOCT.

OCT Angle Closure Glaucoma. Nicer details, better insight into deeper layers. Note the very narrow anterior chamber angle, iris in too close in contact with the corneal endothelium. Trabecular meshwork is pictured.  Copyright © 2013 GETOCT™ Ltd. All rights reserved.

Anterior Segment HD OCT, 3D Corneal OCT GETOCT.

Anterior segment HD OCT GETOCT. The very nice thing with the Cirrus is that you must not buy for the anterior segment an additional anterior segment lens. The lens is embedded in the device and thus by a mishap does not get destroyed or contaminated. It is still worth with time to clean the main front lens again with adequate aids. Aggressive cleaning agents are prohibited, handkerchiefs, cloths, lint-free cotton swab and especially to hard pressure, too. The video image shows a rectangle measuring cube (1) which provides a nice corneal cross-section (2). Along the vertical scan beam the thickness measurement is possible (3, thin cornea with 509 microns.  In certain diseases, for example, scars, even an oblique length measurement would be desirable (4). The red inset (4) shows a nice 3D representation of the cornea, which can be cut and rotated to look at a particular lesion. A corneal thickness- mapping – similar to the macular thickness map or like a corneal topography – is, however, still not offered. Probably because the measured data points allow only a minor interpolation and offer only a very relative thickness of the cornea. Attention: be careful with corneal thickness measurements obtained with other scanners. These images show only an interpolation from a few hundred data points, not the reality. Even with good positioning of the eye, artifacts occur (5, red arrow). This should be switched off, through a optional software adjustment, as the localization is not plausible for a general pathology. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 

Bilateral Macular Thickness OCT analysis GETOCT.

Macular thickness OU analysis GETOCT. Macular Thickness analysis allows now a very nice representation of the data aquired with Macular Cube Scan imaging. The SLO image looks much sharper due to the faster camera system. The plot of retinal thickness with false color is softer and looks more detailed. Although many data are shown, the arrangement is simple and does not overload the print out. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 

OCT Enhanced Depth Imaging (EDI) GETOCT.

OCT Enhanced Depth Imaging (EDI). With the  EDI mode the deeper choroidal structures are much better seen. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 

OCT Advanced RPE Change GETOCT in Dry Age Related Maculopathy (dry AMD OCT) GETOCT.

OCT Advanced RPE Change. A progression of retinal pigment layer lesion (RPE) is demonstrated with the red dots on the right, showing a worsening of the maculopathy and a poor prognosis in dry age reated maculopathy (AMD). Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 

OCT Macular Change Analysis Coss Section OCT GETOCT.

OCT Macular Change Analysis Coss Section OCT. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 

Normal OCT Optic Nerve Head (ONH) RNFL AnalysisGETOCT.

OCT ONH (Optic Nerve Head) RNFL Analysis in a healthy subject. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 

Guided Progression (GPA) Retinal Nerve Fiber (RNFL) Analysis in Progressing Glaucoma GETOCT.

Guided Progression Analysis (GPA) GETOCT. With the Guided Progression Analysis the retinal nerve fiber layer (RNFL) is tracked over time. A significant change of the RNFL area around the optic disc will be discovered and beautifully illustrated. The image shows three consequent RNFL data sets (top left). After two years a wedge-shaped RNFL defect temoral-inferiorly emerges (brown area, red arrow), so the therapy must be re-evaluated in order to prevent further damage. Red inset: detailed view of the nerve fiber lesion in the RNFL mapping/SLO image and a corresponding circular RNFL cross section around the nerve head. Very nice and of clinical importance: this analysis is unique (double RNFL information): RNFL maping around the optic disc plus standard circular RNFL analysis, including the change over time. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 OCT Ganglion Cell Analysis (GCL) in Advanced Glaucoma GETOCT.

OCT Ganglion Cell Analysis (GCL) in advanced glaucoma on the right eye. The normal thickness of the ganglion cell layer is reduced (“eaten doughnut sign or Homer Simpson sign”) , normal dounut like configuration of the retinal ganlion cell layer in the left eye. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

Memory Aid  – Glaucoma “Homer Simpson Sign” – “Donut Glaucoma” by GETOCT.COM:

Glaucoma Homer Simpson Sign GETOCT. Glaucoma “Homer Simpson Sign” by GETOCT (“donut glaucoma”), normal ganglion cell layer (GCL), left image below,  devastated ganglion cell layer (right image).  The ganglion cells are essential in signal transmition, for example, to assess glaucoma. Normally, their frequency is centrally greatest where they are located in a shape of a ring. In progressing glaucoma these cells die, so that this ring is slowly disappearing. A memory aid for ganglion cell layer (GCL): In keeping with the famous “Januar Loch” in Switzerland (a uncomfortable situation without money and at the limit tipically ocuring in the first month of a new year), a masterful baker in Lucerne is offering a “January hole pastries”. In Anglo-Saxon area it is referred to a “donut”. The cartoon character “Homer Simpson” eats mainly donuts, there “”Homer Simpson donut sign” in cases with reduced ganglion cell desity.     Die Gangienzellen sind essentiell zum Beispiel zur Beurteilung eines Glaukoms. Normalerweise ist ihre Häufigkeit zentral am grössten, wo sie ringförmig angeordnet sind. Bei einem Glaukom zeigt sich ein Verlust dieser wichtigen Zellen, sodass der Ring langsam verschwindet. Gedächtnisstütze: in Anlehnung an das “berüchtigte Januarloch” gibt es einen Meisterbäcker in Luzern, der ein “Januarloch-Gebäck” anbietet (siehe Foto). Im angelsächsischen Gebiet wird von einem Donut gesprochen. Die Comic Figur Homer Simpson ernährt sich vor allem von Donuts, daher als Gedächtnisstütze “Homer Simpson donut sign”.

OCT Extraordinary Diabetic Retinal Edema GETOCT.

OCT Extraordinary Diabetic Edema. Eleveted retina with intraretinal cystoid spaces and subretinal fluid as a sign of a uncontrolled diabetes mellitus. The eye is only affected as an organ of a systemic disease. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

OCT Extraordinary Diabetic Edema Cross Section GETOCT.

OCT Extraordinary Diabetic Edema. Intraretinal cystoid spaces and subretinal fluid as a complication of an uncontrolled diabetes mellitus.  Copyright © 2013 GETOCT™ Ltd. All rights reserved.

OCT Retinal Plaquenil Toxicity (Retinal Atrophy) GETOCT.

Plaquenil Toxicity, bilateral synopsis view. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

Plaquenil Toxicity OCT (Retinal Atrophy) GETOCT.

Plaquenil Toxicity OCT, Scanning-Laser-Image SLO superposed with retinal thickness mapping. Note the massive atrophy of retinal tissue (blue area). Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 

OCT 3D OCT and SLO Retinal Imaging GETOCT.

3D OCT and SLO Retinal Imaging. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

 

3D and Cross Sectional OCT Resolution Cirrus 5000 GETOCT.

3D resolution Cirrus 5000 GETOCT. Actually no OCT scanner offers a real good 3D representation of OCT data providing real clinical significance . In this case the image in 3D seems very nice, but in 3D the real insertion of a tractional maculopathy may not be pictured (1,2). The basic data for the 3D imaging is based on cross sectional images with a lower resolution (2, macula cross scan with vitreous insertion leading to a full thickness hole. This is clinically not to detect). Using higher computer power, so called high density cross scan images are shown (4). These scans are improved in quality by superposition and summation of many single cross scan. Copyright © 2013 GETOCT™ Ltd. All rights reserved.

OCT Comparision CIRRUS 4000 HD versus 5000 HD OCT (Optical Coherence Tomography).

Comparision CIRRUS 4000 HD versus 5000 HD OCT (Optical Coherence Tomography). They seem the same but the details make the difference. Scanner control with Cirrus 5000 HD is wireless (on the right), the display is enhanced (Cirrus 4000 with 15″ and 1024×768 versus Cirrus 5000 with 19″ and 1280×1024 pixel).  Copyright © 2013 GETOCT™ Ltd. All rights reserved.

And now a congratulation makes sense. Dr. med. Peter Maloca for his detailed work about the OCT maschines and you as my interested blog reader, who persevered to the end of this post.

CONGRATULATIONS! You have OCT power!

I hope, I could offer you some inspiration!
And please, enter a few comments below and sign up for our GETOCT community here.

yours Peter Maloca, MD

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Fast Trac

-> Play Video First Swiss Impressions Zeiss Cirrus 5000 HD OCT:

Podcast: Play in new window | Download (10.5MB)

Technology is changing rapidly, and one of the benefits of that change has been a steady improvement in surgeons’ ability to image and analyze structural change in the eye.1 This is significant, because imaging technology can detect and quantify structural information that would otherwise require very specific training and experience for a surgeon to uncover—if the information could be detected at all. Comparing serial simultaneous stereoscopic optic disc photographs remains the gold standard for detecting glaucoma progression via structural change. However, this isn’t widely done in clinical practice. It’s time-consuming, and the stereoscopic cameras needed to obtain this type of photograph are not widely available. Furthermore, not many of today’s surgeons have the training to expertly examine the photographs.

Fortunately, computer-guided digital technologies such as optical coherence tomography and confocal scanning laser ophthalmoscopy have steadily become more sophisticated, making it possible to monitor, quantify and analyze the eye in ways that would have been impossible a few years ago. 

Evolving Clinical Analysis

Robert N. Weinreb, MD, distinguished professor and chair of ophthalmology at the University of California San Diego and director of both the Shiley Eye Center and the Hamilton Glaucoma Center at UCSD, believes that imaging technology has reached the point at which it deserves to be an integral part of glaucoma management. 

“Traditionally, the clinical approach to managing glaucoma has been to examine for progression or to stage the disease, and then base our treatment on a prediction of the patient’s probable loss of function,” he says. “Until recently, we’ve detected progression largely using event-based analysis. Such an approach looks for a progression milestone—i.e., the event. For example, we might use the technology to determine whether an observed loss of neuroretinal rim is outside of two standard deviations found in a normative database. Or, we might seek to ascertain whether the mean deviation in a visual field has worsened by a certain amount.

  
A normative database can help identify the status of a patient’s glaucoma. Left: a patient recently diagnosed. The black line, showing the classic double-hump pattern, is almost entirely within the normal (green) range. Quadrant analysis is largely within normal limits as well. Right: advanced glaucoma. Note the placement of the tracing line and quadrant colors indicating that the thickness falls outside of the normal range. (Image courtesy Peter A. Netland, MD, PhD.) 
“Another promising approach that’s recently become practical with structural imaging is to measure the rate of change in a given measurement,” he continues. “That allows us to estimate the likelihood and expected severity of an individual’s functional loss. This type of analysis, which bears some resemblance to monitoring visual fields, is referred to as trend-based analysis.”

Dr. Weinreb cites a recent study that used OCT to evaluate retinal nerve fiber layer thickness in 116 eyes over a period of five years, using Zeiss’s guided progression analysis system.2 “The data showed that this was an effective way to identify individuals exhibiting progressive loss, as well as to determine their rate of loss,” he says. “Notably, the group of subjects identified by this method only slightly overlapped those showing progression by visual field analysis.”

Benefits of Imaging

Dr. Weinreb notes that imaging technology offers a number of significant advantages as a tool for managing glaucoma:

• Today’s imaging technology allows expert examination by non-experts. “For example, several studies have demonstrated that digital analysis of serial confocal scanning laser ophthalmoscopy images compares favorably with expert comparison of serial optic disc stereophotographs,” he says. “In one study this technology performed at least as well for detecting optic nerve changes caused by experimentally induced IOP increases in monkey eyes as glaucoma specialists evaluating photographs.3 Two other studies also found reasonable agreement between CSLO images analyzed with proprietary software and analysis of optic disc photographs.”4,5

• Image acquisition is relatively easy. “Ease of image acquisition is valuable because ease of use allows more frequent scanning, which is important for determining the rate at which the disease is progressing,” he points out. “The more frequently you conduct exams, the better your estimates of the rate of change.”

• Digital data is more easily analyzed. “The quantified nature of digital data is ideal for statistical analysis and comparison,” notes Dr. Weinreb. “This is a key factor in our developing ability to calculate the rate of glaucoma progression, making it possible to predict which individuals are at the greatest risk of functional impairment and/or blindness.”2,6

• Imaging provides an objective measure of progression. “When we examine a patient clinically, we may think the eye looks worse,” he says. “Perhaps the rim is narrower, or the RNFL appears to be thinner. But with today’s imaging technology we have objective, quantitative measures that studies are showing correlate well to disease progression.”

Dr. Weinreb cites one recently published study that used Zeiss’s Stratus OCT to obtain RNFL measurements in 253 eyes of 253 patients annually, while also obtaining visual fields and optic disc stereophotographs. Progression was detected with the visual fields using Zeiss’s GPA soft-ware and by masked assessment of the stereophotographs by expert graders. The data showed that mean rates of change in average RNFL thickness were significantly higher in eyes that progressed, with a sensitivity of 77 percent and specificity of 80 percent.7 “Notably, RNFL parameters were significantly better at discriminating progressed eyes than measurements of the optic nerve head or macular thickness,” he adds.

• Reproducibility is better than that obtained with clinical assessment of photographs, and better than the test-retest variability of most clinicians. Dr. Weinreb notes that this is true at least in part because digital data capture and analysis is non-subjective. 

• Digital data is easily exported into electronic medical records. “This advantage is likely to become even more significant as medicine continues to move toward the paperless office,” he points out.

• Imaging allows measurement of anatomical features that can’t otherwise be measured. These include the lamina cribrosa and choroidal thickness, as shown in a recent study.8 “Some of these regions are showing promise as bellwethers that may reveal glaucomatous damage early in the disease,” he notes.

“For example, measuring the ganglion cell complex in the macula has turned out to be a very sensitive and specific test for glaucomatous damage,” he says. (Retinal ganglion cells extend through three layers: the retinal nerve fiber layer; the ganglion cell layer; and the inner plexiform layer, which consists of the retinal ganglion cell dendrites.) “The reason for measuring the ganglion cell complex at the macula is that the retinal ganglion cells have the greatest density in this area, where they can be six cells deep. In fact, 50 percent of retinal ganglion cells are located in the central 4.5 mm around the macula. So even though the macula is a very small part of the retina, you can detect signs of change there with high sensitivity.” 

• Imaging allows earlier and more informed clinical decisions than simple clinical examination. “Thanks to steady improvements in instruments’ speed of image capture and resolution, as well as improved software for data analysis, our ability to detect a problem early in the disease continues to improve, surpassing what we can discover with a traditional examination,” says Dr. Weinreb. “In some situations, detection of disease and/or progression via imaging may also be possible earlier than would be possible using visual fields.”

Combining Data

New methods for combining structural and functional data are showing promise. In a recent study, a Bayesian hierarchical model used to integrate the two types of data identified significantly more progressed eyes than the ordinary least-squares regression method; it also identified many more than were identified via expert analysis of optic disc stereophotographs.9(Image courtesy Felipe A. Medeiros, MD, PhD.)
Given that both structural and functional testing are valuable and appear to be largely complementary rather than redundant, a sensible next step in the evolution of glaucoma management is improving ophthalmologists’ ability to monitor and combine both kinds of information. Dr. Weinreb points out that the first step along this road has already been taken by some companies; Zeiss’s Cirrus HD-OCT, for example, now offers an automatically generated report that summarizes key data from the Humphrey Field Analyzer and Cirrus OCT. The report provides an overview of both structure and function status, so the clinician doesn’t have to spend time looking for multiple reports. Optovue’s RTVue OCT will soon be adding a similar feature presenting its data along with visual field data from Haag-Streit’s Octopus or Oculus’s Centerfield II perimeter. (Optovue is also developing software that will produce a map overlaying the two types of data.)

Taking this evolution even further, Dr. Weinreb notes that a recent paper by Felipe Medeiros, MD, PhD, at the UCSD, reported his use of a Bayesian hierarchical model to integrate rates of change from the visual field index (SAP) with average retinal nerve fiber layer thickness measurements made using scanning laser polarimetry with enhanced corneal compensation.9 “The study included data from annual exams of 434 eyes included in the Diagnostic Innovations in Glaucoma Study,” he says. “Dr. Medeiros compared this approach to analysis using the conventional method—ordinary least-squares regression. Although the approaches had equally good specificity when identifying healthy eyes—100 percent—the Bayesian method identified significantly more progressed eyes than the conventional method—22.7 percent vs. 12.8 per-cent (p<0.001). Furthermore, the Bayesian method identified a much greater proportion of the eyes that were categorized as progressing by expert analysis of optic disc stereophotographs than the OLS regression method did: 74 percent vs. 37 percent (p=0.001).”

Clearly, says Dr. Weinreb, combining structural and functional data holds promise as a resource for monitoring glaucoma progression.

In this Cirrus HD-OCT sequence, RNFL damage was evident before detectable visual field loss; an inferotemporal RNFL defect was observed in the thickness map in the presence of a normal visual field on 7/18/2008. Inferotemporal RNFL progression was detected on 3/10/2009 (yellow pixels in the RNFL thickness change map) and confirmed in subsequent visits (red pixels), while possible visual field progression wasn’t noted until 11/2/2010 (EMGT criteria). (Image courtesy Christopher K. S. Leung, ChB, MD.) 

Imaging Caveats

Of course, today’s imaging technology is still far from perfect, and human error is still a factor during clinical use, so when using this technology it’s important to be conscious of its limitations and the ways in which it can produce misleading data. Dr. Weinreb notes several important considerations:

• Imaging isn’t 100-percent accurate. “For that reason, clinicians must take all available information into consideration, including functional measurements, and use their best clinical judgment to evaluate the information as a whole,” he says.

• Assessment of scan quality is important. Dr. Weinreb notes that the best technology can still be undercut by artifacts, eye movement, corneal conditions and the like. 

• Atypical patients may produce misleading data. “There are many atypical patients—particularly high myopes or patients with tilted discs—for whom you can’t readily interpret the information these technologies are able to produce,” he observes.

• Normative databases may not be representative of all patient populations. “A normative database from a European ancestry population is not necessarily relevant to a Japanese population,” he points out. “Furthermore, normative databases are statistical in nature. That means there’s always a low probability that a patient who is outside normal parameters according to the database really is normal, but happens to fall at the low end of the statistical distribution.”

It’s a Good Time to Start

Despite these limitations, Dr. Weinreb believes that the evidence has demonstrated that imaging technologies are ready for use in glaucoma clinical practice. “With all the new software that’s available, including the ganglion cell complex analyses for diagnosis, trend analysis for progression and the ability to combine structural and functional testing, there’s an opportunity to use imaging much more effectively in clinical practice than has been possible previously,” he says. “That belief is also shared by the World Glaucoma Association, and the Preferred Practice Patterns of the American Academy of Ophthalmology, both of which recommend imaging as part of routine clinical care.”

Dr. Weinreb notes that in the glaucoma community, the evolution of imaging technology has added fuel to the ongoing debate regarding whether structural or functional testing is more important for diagnosis and/or monitoring the progression of the disease. “If imaging technology is ready for clinical use in glaucoma management—and the clinical evidence suggests that it is—which approach should clinicians rely upon?” he asks. “My answer is that we need to take advantage of both structural and functional testing, rather than relying primarily on one or the other. The data they provide are complementary. 

“Of course, because they monitor different aspects of the disease, one approach or the other may be more efficacious in a given situation, depending on factors such as how many tests you’re doing and the stage of the patient’s disease,” he continues. “For example, structural testing is probably more sensitive early in the disease process; in late-stage disease, visual fields are probably better. The structure is so damaged at that point that it’s hard to detect any increase in the damage.

“If your practice still relies primarily on basic examination and visual fields, this is a good time to consider investing in some of this technology, given all the outstanding instruments and software packages that are available,” he concludes. “Just remember not to rely exclusively on imaging for your final decisions about diagnosis or treatment. There’s no substitute for good clinical judgment.” 

1. Mansouri K, Leite MT, Medeiros FA, Leung CK, Weinreb RN. Assessment of rates of structural change in glaucoma using imaging technologies. Eye 2011;25:3:269-77.

2. Leung CK, Cheung CY, Weinreb RN, et al. Evaluation of retinal nerve fiber layer progression in glaucoma: A study on optical coherence tomography guided progression analysis. Invest Ophthalmol Vis Sci 2010;51:1:217-22.

3. Burgoyne CF, Mercante DE, Thompson HW. Change detection in regional and volumetric disc parameters using longitudinal confocal scanning laser tomography. Ophthalmology 2002;109:455-466.

4. Ervin JC, Lemij HG, et al. Clinician change detection viewing longitudinal stereophotographs compared to confocal scanning laser tomography in the LSU Experimental Glaucoma (LEG) Study. Ophthalmology 2002;109:467-481.

5. Chauhan BC, McCormick TA, et al. Optic disc and visual field changes in a prospective longitudinal study of patients with glaucoma: Comparison of scanning laser tomography with conventional perimetry and optic disc photography. Arch Ophthalmol 2001;119:1492-1499.

6. Kourkoutas D, Buys YM, Flanagan JG, Hatch WV, Balian C, Trope GE. Comparison of glaucoma progression evaluated with Heidelberg retina tomograph II versus optic nerve head stereophotographs. Can J Ophthalmol 2007;42:1:82-88.

7. Medeiros FA, Zangwill LM, Alencar LM, Bowd C, Sample PA, Susanna R Jr, Weinreb RN. Detection of glaucoma progression with stratus OCT retinal nerve fiber layer, optic nerve head, and macular thickness measurements. Invest Ophthalmol Vis Sci. 2009;50:12:5741-8.

8. Lee EJ, Kim TW, Weinreb RN, Park KH, Kim SH, Kim DM. Visualization of the lamina cribrosa using enhanced depth imaging spectral-domain optical coherence tomography. Am J Ophthalmol 2011;152:1:87-95.

9. Medeiros FA, Leite MT, Zangwill LM, Weinreb RN. Combining structural and functional measurements to improve detection of glaucoma progression using Bayesian hierarchical models. Invest Ophthalmol Vis Sci 2011;52:8:5794-803.

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