Dr. Joe Pizzimenti: Hello, I'm Dr. Joe Pizzimenti of Boca Raton, Florida, and like many of you, I've been using scanning lasers in the diagnosis and management of glaucoma for over 20 years. About six years ago, I made the decision to increase my practice's efficiency, its diagnostic and management capabilities and its revenues by transitioning from my GDx Nerve Fiber Analyzer to Cirrus High-Definition Spectral-Domain Optical Coherence Tomography
You see, the older generation scanning lasers limited my digital imaging capabilities to just one disease - glaucoma. My new Cirrus Spectral-Domain OCT immediately became a difference maker by adding so much more usable information, not only for glaucoma, but also other optic neuropathies plus a host of vitreoretinal diseases, corneal pathologies and anterior segment disorders
Let me take you on an historical timeline showing some of the major milestones in ophthalmic imaging. Fundus photography came about in the 1920s. About 30 years later, the first fluorescein angiography was performed. B scan ultrasonography was brought to clinic in the 1970s
Indocyanine green imaging employed an alternative dye to fluorescein and digital imaging technology in the 1980s. In the 1990s, we saw the emergence of the scanning laser opthalmascope and another technology known as scanning laser polarimetry came about. Scanning laser polarimetry is the technology that is used by the GDx Nerve Fiber Analyzer - both the VCC and the GDx Pro
OCT - and that is Optical Coherence Tomography - was first demonstrated in the lab in 1991. The Stratus OCT was the first commercially-available OCT for ophthalmic imaging, and that was brought to market in 2001
2007 saw the emergence of High-Definition Spectral-Domain Optical Coherence Tomography. And here in 2013, we can see that the Cirrus family of Spectral-Domain OCT represents the most cutting-edge, forward-thinking option for ocular disease diagnostics
In fact, Spectral-Domain OCT with the Cirrus instrument has revolutionized eye care and has revolutionized the care that I am able to provide in my practice
Scanning laser polarimetry with the original GDx technology enabled us to obtain information on retinal nerve fiber layer thickness and integrity, and these measures became useful biomarkers for glaucomatous damage to the retinal nerve fiber layer
The purpose of this technology, scanning laser polarimetry, is to measure the retinal nerve fiber layer thickness and integrity to help clinicians discriminate between healthy and glaucomatous eyes
The next generation, called the GDx VCC, incorporates a variable corneal compensation mechanism to neutralize birefringence that emerges from the cornea and the interior segment, while the GDx Pro, which you can see on the right hand side, continued to improve the reliability of retinal nerve fiber layer measurements
Let's review the individual elements of the GDx Retinal Nerve Fiber Lay OU Analysis Report with which most of you are undoubtedly familiar. As we look at the top of the report, we can see patient demographic information as well as indices that indicate the quality of the scan
Then we have our scanning laser images for the right and left optic nerves respectively. And then in the middle of those two scanning laser images, we see a table of information related to retinal nerve fiber thickness in the various regions surrounding the optic nerve head. We also have an index of inter-eye symmetry and the NFI, or nerve fiber index, a unitless measurement that predicts the likelihood of glaucomatous damage
So, below the scanning laser images, we can see the retinal nerve fiber layer thickness maps. And the brighter the colors surrounding the optic nerve, the more robust and healthy the nerve fiber layer. So, these are a pair of healthy eyes on our demonstration patient here
Below the thickness maps, we have our deviation maps that show the statistically-significant deviations from the normative database
And finally, on the bottom of our report, we have our TSNIT graph with the comparison of the retinal nerve fiber layer thickness between the right and the left eyes in the center of that graph
In addition to the standard OU analysis, the GDx VCC and GDx Pro can provide serial analysis showing, in some cases, progressive retinal nerve fiber layer loss over time. Here you can see that a number of measures were taken on the patient's eye over a period of time, and we can see some progression of glaucomatous damage indicating that we need to be more aggressive in our IOP-lowering
Although the GDx VCC and Pro instruments provided improved accuracy over the first generation technology, we were still dealing with 1990s imaging methods and clinical application that was limited to glaucoma. Cirrus High-Definition OCT, on the other hand, uses 2013 technology to help us diagnose and manage glaucoma and much, much more
The first benefit that I immediately noticed after transitioning to Cirrus OCT was better patient care. How so? Well, I was now able to detect and image various ocular conditions earlier than ever resulting in earlier treatment and improved visual outcomes for my patients
In reviewing the Cirrus OCT glaucoma analysis element, it's important to notice several similarities between the Cirrus report that you see here and the GDx report that we showed in one of the previous slides. And some of these elements in common include the retinal nerve fiber layer thickness map and retinal nerve fiber layer deviation map, as well as the TSNIT graph, which you can see on the upper right
Of course, the TSNIT graph represents the average retinal nerve fiber layer thickness along the data circle that was generated around the optic nerve from temporal aspect to the superior, nasal, inferior, and once again, temporal nerve fiber layer
A welcome addition in glaucoma diagnostics with the Cirrus instrument is the capability to perform cross-sectional imaging of the optic nerve, the optic cup and the retinal layers. And you could see this cross-section in the lower left hand aspect of this slide
And so, here's a comparison of the glaucoma analysis capabilities of the GDx versus the Cirrus OCT. And we can see that both instruments are able to generate at TSNIT map, a retinal nerve fiber layer thickness and deviation map
Some serial analysis can be performed with the GDx instrument, but true, proprietary, guided glaucoma progression analysis with advanced statistical analysis is available only on the Cirrus OCT.
Cup-to-disk ratio information - not available on the GDx but is available on the Cirrus OCT
In terms of retinal nerve fiber layer thickness, the numbers are interpolated or estimated on the GDx instrument, and they vary relative to the birefringence from the nerve fiber layer, whereas in Cirrus OCT, the retinal nerve fiber layer thickness can be directly measured in microns
Whereas the Cirrus OCT provides valuable information about the retinal ganglion cells, the GDx analysis is limited primarily to just the retinal nerve fiber layer
The Cirrus OCT provides a scanning laser image of the optic nerve, with the optic cup and the optic disk borders identified for you
The statistical analysis table on the lower left hand part of the slide is easy to interpret, as the areas of concern are color-coded. Note that this table provides more than just retinal nerve fiber layer thickness and symmetry information. It also quantifies the neuro retinal rim area - a crucial measurement in considering whether or not a patient has glaucoma and whether or not that glaucoma is progressing
So, it quantifies the neuro retinal rim area. The Cirrus also measures the relative size of the optic nerve head, calculates cup-to-disk ratios and optic cup volume - all very useful information in the diagnosis and management of optic neuropathy
Here are two patient cases that illustrate both some similarities and differences between the GDx and the Cirrus OCT technologies
Let's review the Cirrus retinal nerve fiber layer and optic nerve cube printout on a middle-aged, Black female that has been living with bilateral, open-angle glaucoma. At the top of the analysis report, we can see that there are both patient demographic sections as well as reliability indices such as signal strength
Then we have our retinal nerve fiber layer thickness map, which is analogous to the thickness map that we also receive from the GDx instrument. Now we can see that, with respect to our patient, there some mild to moderate nerve fiber damage - both superiorly and inferiorly - on the right eye and more severe damage as a result of more advanced glaucoma in the left eye
In between the two thickness maps is our data table showing parameters such as average retinal nerve fiber thickness, retinal nerve fiber layer symmetry and using color codes to highlight those areas that may indicate glaucomatous damage and glaucomatous progression
We also have information on the neuro retinal rim, the area of the optic nerve, average cup-to-disk ratio, vertical cup-to-disk ratio and optic cup volume
Below that, we have our retinal nerve fiber layer deviation map that has been overlaid on the OCT fundus image for the right and left eyes respectively. And we can see in these deviation maps that left eye clearly demonstrates greater deviation from the normative database
In between the two deviation maps, we have a graphical representation of neuro retinal rim thickness around that data circle. And we can see that there is in fact a significant difference as we look at the OD and OS comparison with the left eye demonstrating more diffuse and localized nerve fiber layer loss and neuro retinal rim thinning
Below the deviation maps, we have our TSNIT retinal nerve fiber thickness that has been calculated along that circle, and it's displayed in graphical format and compared to the age-matched normative database. Now retinal nerve fiber thickness and comparison to normative data is shown both in quadrants and in clock-hour displays in the lower central aspect of this printout
Now, we also receive cross-sectional imaging of the optic cup, the optic nerve and the retinal nerve fiber layers. So, we can assess both the width of the optic cup, the depth of the optic cup and the thickness of the retinal nerve fiber layer
So, here's the same patient's GDx analysis with similar scanning laser images on top. We have our thickness and deviation maps and our TSNIT graph - all very similar to the information generated by the Cirrus instrument
However, there is no information here on this printout about the condition of the neuro retinal rim, the optic cup or the cup-to-disk ratios. This type of analysis is not available on the older generation GDx instrument, but only available on the Cirrus HD OCT
Both serial and guided progression glaucoma analyses are available on the Cirrus OCT using a robust normative database for comparison. We can see that two baseline exams are required for this advanced progression analysis. The third exam is then compared to the two baseline exam
Below the thickness maps, we can see a sub-pixel map that demonstrates change from baseline. And those yellow pixels indicate change from both baseline exams
The third and fourth exams are then compared to both of the baselines, and any change identified in three out of the four comparisons is indicated by the red pixels that you see here
The Cirrus progression analysis on our patient's right eye shows that, despite our best efforts, there is retinal nerve fiber thickness map and TSNIT profile progression, progression of glaucomatous damage. And so, this patient soon received selective laser trebuculoplasty in an effort to achieve optimal lowering of their intraocular pressure
Here's a 75-year-old White male that has plateau iris syndrome in his right eye with moderate glaucomatous damage, as shown here on his GDx report. It's especially apparent as we look at the retinal nerve fiber thickness maps where we have bright, robust nerve fiber layer in the left eye and in comparison the right eye has areas of deficit completely surrounding that optic nerve - so 360. And this is reflected in the table of summary parameters as well as the TSNIT map and deviation maps
In comparison to the GDx, the Cirrus OCT on our same patient provides much more information, including neuro retinal rim thickness asymmetry which we can clearly see in the center of our printout
Also available are the retinal nerve fiber layer quadrant and clock-hour analyses
Finally, we can see on these extracted cross-sections in both the vertical and horizontal cuts, we can see a widening and a deepening of the optic cup of the right eye as a result of the plateau iris syndrome - so, quite a bit more information, quite a bit more valuable data in terms of following our glaucoma patients with the Cirrus OCT
So in addition, the Cirrus OCT provides ganglion cell analysis. And as we know, glaucoma by definition is a progressive ganglion cell loss
Now here, our ganglion cell analysis on our patient with the plateau iris syndrome clearly shows that the ganglion cell thickness has deficits in the right eye in comparison to the left eye, which has relatively normal ganglion cell thickness. So, this is another very useful parameter, not only for glaucoma, but for following other optic neuropathies - for instance, patients living with multiple sclerosis who may have a mild to moderate degree of optic nerve atrophy
Here are some other advantages of Spectral-Domain OCT technology. First of all, OCT data is a cross-sectional, volumetric cube of information. It is not estimated, nor is it interpolated
Spectral-Domain OCT measures thickness in microns on the retinal nerve fiber layer and ganglion cell layer analyses. Finally, OCT provides information about multiple structures, including the nerve fiber layer, the optic nerve head, the neuro retinal rim, as well as the vitreoretinal interface, the macula, cornea, iridocorneal angle and other structures - other ocular tissues, as well
OCT also provides more value and more information for your time and your practice. So, here's just a short list of retinal pathologies that you will be able to diagnose, image and, in many cases, follow yourself without having to obtain a retina consult. This is beyond the capability of the GDx instrument but well within the capabilities of spectral domain OCT
So, if you're seeing many patients with glaucoma, chances are you're also seeing some patients with retinal disease. Common conditions such as drusen, both dry and wet macular degeneration, diabetic retinopathy with or without macular edema, central serous corneal retinopathy, retinal vascular occlusions, hereditary conditions such as condistrophy, Stargardt's disease, retinitis pigmentosa, vitreomacular adhesion and vitreomacular traction that can lead to things like cystoid macular edema, macular holds and epiretinal membranes, the detection of retinal pigment epithelial detachments becomes much easier with cross-sectional, volumetric, 3D imaging available with OCT
When one considers that so much more can be uncovered with Cirrus OCT than with the GDx, the value for your time and practice grows exponentially. Here we can see that the test time for both of these scanning lasers is less than five minutes. But, for that five minutes of test time, the data that you are acquiring with Cirrus OCT is approximately four times that that you've acquired with the GDx, and that enables a wide variety of clinical applications
Things open up beyond glaucoma - as we said, cystoid macular edema, common retinal diseases. You will also be able to do excellent pre- and postoperative management of patients that have undergone an epiretinal membrane peel as well as intravitreal injections for conditions like wet macular degeneration and diabetic macular edema
Cirrus Spectral Domain OCT has several ways to analyze the data cube from macular disease alone. So, let's review just a few of these. There's the macular thickness analysis report, advanced visualization analysis and high-definition five-line raster scan with analysis
So, here is a macular thickness analysis, and this report clearly shows that our patient has central serous chorioretinopathy. And the OCT can actually help us diagnose based on the appearance of the OCT
So, we can see here that on the lower left hand side, the cross-sections clearly show an area of sub retinal fluid right in the center of the fovea. And this is pathognomonic for central serous chorioretinopathy
On the upper left hand part of the analysis, we have a thickness map superimposed over our scanning laser image. And those bright areas on the thickness map once again indicate that there is fluid - in this case, in the subsensory retinal space
To the right of that image, we have the internal limiting membrane-to-RPE thickness grid where the average thickness in nine zones centered around the center of the fovea is calculated. And we can follow this patient over time, hopefully watching them return back to normal thickness values
On the right hand side, we can see the segmentation analysis that shows both the thickness and single layer analysis where we can isolate the internal limiting membrane, and on the bottom in brown, the retinal pigmented epithelium
This is the same patient, and I just wanted to show you that above we have the image that is generated by the scanning laser ophthalmoscope and Spectral-Domain OCT, and we have the individual cross-sections, both in black and white and also in color
This is a 64-year-old radiologist with a family history of advanced age-related macular degeneration. Now, we can see here on the macular thickness analysis that, as we look at the cross-sections, there are some areas that appear as bumpy nodules at the level of the pigment epithelium. Now, these represent several large, soft drusen that put this patient at risk for advanced disease just like his mother had
On the right hand side, we can see that the segmentation analysis resembles a small mountain range, especially in the internal limiting membrane-to-RPE segment and the retinal pigment epithelial segment on the bottom
Here's the high-definition 5-line raster scan in both black and white and in color for the same patient with a large drusen. Now in the cross-section that we see on the bottom in black and white on the right and in color on the left, we can see large bumps representing large, soft drusen
Macular holes can be detected quite a bit more easily with OCT technology. In the image above, we see three intraretinal cysts. So, any time we see dark areas within the OCT cross section, that means that there is intraretinal fluid
On the lower left hand side, we see a partial thickness or lamellar macular hole. Note that there is still some viable sensory retinal tissue within the center of that partial thickness hole
On the other hand, the black and white image on the lower right shows that this patient has a small-diameter, but full-thickness macular hole, and note that there is some cyst-like area of change on either side of the hole
Conditions such as diabetic retinopathy can be imaged, not only with high-definition fundus photography, but now we can get the volumetric imaging with Spectral-Domain OCT. And this has enabled us to detect areas of intraretinal thickening and intraretinal fluid on a patient with diabetic macular edema
OCT has revolutionized the detection and management of patients with disorders of the vitreoretinal interface. We spoke about macular holes a few slides earlier. This is an example of advanced visualization on the OCT of an epiretinal membrane. This patient also has a pseudo hole, as we can see, in the cross-section in the middle of the right hand side of the report
Also note the surface wrinkling that is apparent on the en face images that were generated using advanced visualization strategies on Cirrus OCT
We can manually guide our 5-line high-definition raster scan to include the macula, the optic nerve head, or both. In this case, on the right hand side, we can see both the optic cup and portions of the macula and fovea in cross-section
On the lower left hand side, the HD raster scan is able to help us generate a 3D rendering of the retinal thickness. In this case it appears that the patient has, once again, a large area of drusen resulting in elevation of the retinal pigment epithelium
Plateau iris and angle closure glaucoma is pathology that is beyond the capabilities of GDx technology. The Cirrus highlights these areas of narrow angles and plateau iris, and this will help us provide better care for our patients with glaucoma
Another application for Cirrus OCT includes the measurement of central corneal thickness in a completely non-invasive manner. And so, we have anterior-segment imaging with an anterior segment cube. Here we see the cornea, and the red area indicates central corneal thickness and a central measurement in the management of patients living with glaucoma
Zeroing in on that cornea cross-section, the light blue arrow is pointing to the tear film. Then the white arrow is pointing to the corneal epithelium. The red arrow is headed towards Bowman's layer. In between, we have the large area of stroma, and then green arrow zeroing in on decimet's membrane and the corneal endothelium
So, this allows the Cirrus instrument to assist us in the diagnosis and management of ocular surface disorders and various corneal distrophies and degenerations
In this age of electronic health records, one of the key concepts is connectivity. And with Cirrus Review software, you will be able to review scans from your exam lane or back in your office
The Forum System of archive and viewer eye care data management streamlines patient workflow by providing access to all patient examinations both locally and remotely. Integration of data and combined reports are now at your fingertips with the Forum System
Here we can see the Humphrey Field Analyzer Report combined with the Cirrus OCT in a patient that is being followed for glaucoma. And so, we have an excellent combination of information on the patient structure and function, an ideal way to follow any ocular disease
Here is how transitioning to Cirrus OCT can enhance your practice's growth and financial well-being while at the same time raising the level of patient care. First, upgrading to Cirrus OCT gives us the ability to add anterior segment imaging and, even more importantly, vitreoretinal OCT imaging to our practice. This will enable us to achieve reimbursement for a wider range of conditions
Reliability, confidence in the test results and the excellent reputation associated with the Cirrus and the Carl Zeiss Meditec brand is another advantage in upgrading your technology
It has been a real pleasure discussing these concepts with you. Thanks so very much for spending your precious with me. I would be happy to answer any questions.