Improving Diabetes Care
Discover how widefield angiography can help in diagnosis, treatment and follow-up.
BY THOMAS W. STONE, MD
I have been using optomap FA Dynamic Ultra-widefield Angiography for just under a year now, and I believe this technology will have a dramatic impact on our field, possibly as great as the impact optical coherence tomography (OCT) has had during the past 5 to 10 years.1 Here, I will discuss how the widefield instrument has helped my partners and me improve the management of our diabetes patients.
This device has the potential to have great impact through a shift in the paradigm we use to treat our patients with retinal vascular disease. As we all have seen throughout our careers, paradigm shifts occur from time to time in medicine. For example, a shift occurred in neuroimaging, where the use of MRIs reduced exam time required to determine the location of pathology. A similar shift has occurred in our own field, as the need for a detailed macular exam with a contact lens has become less critical, because OCT scans can provide more detailed and reproducible data more accurately. OCT technology has allowed the clinician to make more informed decisions with more data, and has helped the diagnosis and treatment of macular disease to evolve. The optomap FA with widefield imaging provides similar advances for examining peripheral vascular pathology, and thus has the potential to change how we treat patients.
In our practice, we have two fundus cameras, two OCT units and an ophthalmic imaging system network. Our typical 30° fundus images give us a view from the disc to just past the macula. Anything that requires a wider field necessitates the use of multiple images taken in succession and then combined together with montage software.
In contrast, the Optos P200MA system provides a view that is dramatically larger, because we routinely obtain high-quality images that reach past the equator in all directions. The device also allows for excellent visualization in patients with media opacities due to the nature of its scanning laser optics.
Another way we are able to obtain more information from these images, beyond that provided from the increased retinal area image, is by separating the images from the red and green lasers. The device acquires its color images through these two lasers, and normally combines them into one composite overlay image. However, you can select just one of these individual laser separations to appear on screen, so you can select either outer or inner retinal layers. And you can obtain better definition by teasing out mild distortions introduced after the image has been combined.
We were initially concerned about how this system would integrate with our existing imaging software, but we found that it comes with an unlimited number of viewing software licenses. We put these in each of our exam lanes, where we can show patients their pathology, manipulate the images to get the clearest view and document the pathology. The Optos viewing software comes with a robust drawing element, which allows me to circle and annotate areas where I plan to use laser treatment. When I review the photos with patients during subsequent visits, my annotations are easily accessed.
We have been encouraged by the clinical utility of the widefield imaging technology over the past year. Just like every practice, we try to stay current with the latest diagnostic and therapeutic devices, and there are always plenty from which to choose. We frequently try new technology, but we only keep the devices that seem to provide real advantages and advances for our patients. After using it for several months, we realized that this technology provides diagnostic and therapeutic opportunities that have not been available through the use of fundus cameras and traditional imaging, so we decided the Optos P200MA platform was a good acquisition for our practice. It is a bonus that patients really like the system, mainly because it is a noncontact system. Patients simply sit still as we acquire rapid sequences of images.
Most patients don't know the first thing about the retina, so it is up to you to educate your surgery patients as much as possible. We found the Optomap to be very helpful in this regard, and it has been documented that patient education improves compliance in diabetes care.2 For example, I have a patient with retinoschisis who did not understand why she needed to come back once a year — until I showed her the image in Figure 1. I have found that giving patients visual proof helps justify treatment and follow-up recommendations.
Figure 1. Vivid images, such as this one from a patient with retinoschisis, help show patients the extent of their condition.
RESULTS IN PRACTICE
My partner and I have analyzed 187 cases involving fluorescein angiography and the Optomap. We have used the device more frequently on patients with diabetes than age-related macular degeneration (AMD), because for the first time, we have been eager to assess the peripheral perfusion of our diabetes patients. We also have used the device to evaluate other retinal vascular diseases, such as vein occlusions and cystoid macular edema.
EXCELLENT PERIPHERAL DOCUMENTATION
The first thing most people notice with Optos images is that you can see and document a great deal of peripheral pathology with relative ease. This has allowed us to expedite our clinical exam by replacing our detailed retinal drawings of peripheral lesions. At times, the technology can help you find new pathology you might not have identified otherwise, especially in patients who have a difficult time with the clinical exam but tolerate photos relatively well.
DETERMINING EXTENT OF PATHOLOGY
Where the Optos really shines, though, is in its ability to obtain high-quality angiograms of patients with retinal vascular disease. We have been able to see much more peripheral disease in these patients. For example, I had a patient with a branch vein occlusion that continued to leak and produce macular edema after macular laser treatment. The ultra-widefield view helped us see that a very large untreated area was still affected within the peripheral macula. Additional laser to this area helped in this case.
We were initially concerned about the quality of macular images with this technology, but we have found it to be excellent. We routinely treat central macular disease, as well as peripheral disease, with guidance from the high-resolution macular images obtained with the Optos P200MA system.
We also have discovered that some patients with diabetic macular edema had more peripheral retinal ischemia than we realized. Evidence suggests these patients may have a reduction in central diabetic macular edema if the peripheral ischemia is ablated. We now take this into consideration as part of our treatment algorithm in patients who have extensive peripheral pathology, shown on widefield imaging. On occasion, we have found patients who have occult peripheral neovascularization by using this advanced imaging technology (Figure 2).
Figure 2. This patient was referred for diabetic macular edema in the right eye. On exam, we saw mild neovascularization of the disc. With an Optos angiogram, multiple areas of peripheral neovascularization were identified as well as later leaking disc neovascularization. The patient underwent uncomplicated photocoagulation, which resulted in regression of the edema and neovascularization. High-resolution macular Optos images were used to guide treatment of the macular disease.
The detailed peripheral angiograms also are very helpful in patients with proliferative diabetic retinopathy (PDR). We have had multiple cases in which we thought only one eye was involved on exam — until the ultra-widefield angiogram detected significant proliferation in both eyes (Figure 3). In many of these patients, it came as a bit of a surprise when widefield imaging revealed how advanced their diabetes was. This information led us to see patients at shorter time intervals, and often perform laser treatment before the disease became overtly symptomatic.
Figure 3. This is the right eye of a patient who presented with vitreous hemorrhage in his left eye. A few small hemorrhages were apparent on exam of the right eye, but this did not cause significant concern until we saw remarkably widespread peripheral nonperfusion on widefield angiography. PRP laser subsequently was performed in both eyes.
We also have used widefield imaging in PDR patients who continue to bleed after they have had fairly complete panretinal photocoagulation. By identifying the site of persistent leakage and proliferation, we can perform a targeted retinal photocoagulation and hopefully stop the disease in a more selective manner.
In some patients with uveitis or Coats disease, it can be difficult to know when and how to administer treatment to keep their disease from becoming active. The ultra-widefield technology has helped us decide when these patients may need a continuation of systemic medication for uveitis, or when they need targeted retinal photocoagulation to an area of leakage in Coats disease. It also provides prognostic information in these cases.
The Optomap will continue to help us in practice, because it provides a detailed peripheral view, helps us monitor and document pathology more effectively and provides better patient education. The peripheral and macular views more effectively meet the needs of our photographers and patients. The device also integrates well with existing systems. We expect this new technology to improve outcomes in patients. RP
Dr. Stone is in group practice at Retina Associates of Kentucky in Lexington, Kentucky