Overlay of the land
When you capture a retinal scan, you get a snapshot of a specific area of a patient’s retina at a specific point in time under specific conditions, which will highlight (and obscure) specific factors. For example, when a 39-year-old male patient presented to Dr. Majcher’s practice with serous chorioretinopathy, which had reactivated following a steroid injection for shoulder arthritis, she was able to use optical coherence tomography (OCT) to identify the presence of subretinal fluid.
However, instead of serving as isolated endpoints, using ZEISS FORUM Retina Workspace, Dr. Majcher used this imaging as building blocks to lead to greater insights—first by taking in multiple views of the retinal landscape at once. “After capturing a 21-line raster OCT scan of this patient’s retinas at his two-month follow-up, I was then able to overlay it on top of the color fundus photography,” she explains. “By doing this, I was able to see that he had a multilobe serous pigment epithelial detachment as well as some retinal pigment epithelial (RPE) atrophy and choroidal hypertransmission. It's really useful to be able to correlate our OCT with our color fundus photography and some RPE abnormalities that we observe during our clinical examinations.”
Taking a closer look at the area of RPE remodeling, using the ZEISS FORUM Retina Workspace’s Macular Thickness tool, which enables you to synchronize and compare several macular OCT cube scans, Dr. Majcher was first able to verify that the subretinal fluid had resolved. However, she also identified a shallow, irregular RPE elevation, sometimes referred to as a double-layer sign. Because the RPE separation from Bruch’s membrane is a sign of the potential presence of either sub-RPE or type I choroidal neovascular membranes, Dr. Majcher performed OCT angiography (OCTA) imaging. “Not only am I able to access my OCTA data within ZEISS FORUM, but I can view all the different presets and foss displays alongside the B-scan overlay to compare the angiography and structural presentations,” she highlights. “I was able to confirm that what I’d seen using OCT alone was a well-formed neovascular net. And because I could verify that there weren’t any associated fluid, blood, or hemorrhages, I was able to make a clinical decision—to closely monitor this patient without any present need for treatment.”
A tale told through time
But sometimes the full story of a patient’s retinas isn’t told in a single sitting. Dr. Majcher saw another patient with a well-formed neovascular net—however, this time, when she evaluated OCTA with the B-scan overlay, she saw that this patient’s epithelial detachment was highly vascularized and red. Knowing that a non-exudative choroidal neovascular membrane has a greater risk of conversion to exudative disease, Dr. Majcher made the decision to monitor this patient closely and asked him to return for a three-month evaluation—however, Dr. Majcher and her team weren’t actually able to see him until six months later. When they did, despite the patient not having any metamorphopsia or complaints, when Dr. Majcher looked at his ZEISS CLARUS photography in FORUM, she observed that there was now exudation present alongside some associated subretinal hemorrhage.
“Seeing this, I wanted to compare the imagery from this six-month follow-up appointment to that captured during the baseline examination; I’m able to do so by synchronizing multiple 21-line raster OCT scans from different appointments,” explains Dr. Majcher. “By doing this, we can directly evaluate what’s going on in the exact same location—in this case I could confirm with certainty that there was an area that had no subretinal fluid present before but did at the six-month appointment, suggestive of conversion to exudative AMD.” Alongside this, Dr. Majcher used the dedicated Macular Thickness Analysis section to compare, synchronize, and evaluate multiple macular cube OCT scans and the corresponding quantitative trend data. This prompted her to refer the patient to a retinal specialist for anti-VEGF therapy.
“I love how customizable ZEISS FORUM Retina Workplace is,” Dr. Majcher highlights. “For example, when tracking the quantitative data, we can do so focusing on the exact macular region of our choice. I was able to use this capability both to observe the progression of the pathology in this patient—from a typical, flat RPE contour to a shallow, irregular pigment detachment which ultimately formed exudation features—and also to monitor the patient’s improvement with anti-VEGF therapies over time.”
Documenting degeneration
There are also tools for monitoring the progression of age-related macular degeneration in patients over time—as Dr. Majcher highlights, the majority of these can be accessed in the ‘Advanced RPE Analysis’ tab. “The sub-RPE slab of this section in particular provides a great way of monitoring patients’ geographic atrophy (GA),” she says. “Using the functionalities of this tool, we’re able to, rather than a conventional cross-sectional B-scan, generate enface OCT scans in which areas of choroidal hypertransmission are highlighted. It enables us to create a 2D map of areas of choroidal hypertransmission—and thus GA.”
The sub-RPE slab also offers trendline analysis, which not only delineates the areas of GA but also tracks them quantitatively as they change over time. You also have the option of using near-infrared reflective (NIR) imagery, another modality that Dr. Majcher says is great for monitoring GA progression over time—and once a patient approaches advanced-stage macular degeneration, tools like RPE elevation maps can be used to track factors suggestive of high risk of progression. But again, these tools don’t have to be used in isolation. “When monitoring our patients’ GA, we can superimpose our OCT raster scans and color fundus photography on top of what we're viewing in Workplace enabling us to ensure that the delineation of GA areas has been accurate and enabling us to correlate our OCT and clinical pathologic findings,” says Dr. Majcher.
Because, as her case studies highlight, making full use of your imagery allows you to have all the information needed to detect problems as early as possible on hand. This means you can make fully informed decisions, refer patients promptly for therapy, and preserve as much of their vision as possible.
