After receiving approval from the US Food and Drug Administration earlier this year, Topcon Medical Systems’ DRI OCT Triton became the first commercially available instrument to offer multimodal swept-source OCT in the in the United States.
The instrument incorporates a built-in retinal camera, uses eye tracking when capturing selected scans, and combines Topcon’s years of expertise in OCT imaging, color, red-free, fluorescein angiography, and fundus autoflouresence imaging. “With the diagnostic power of swept-source OCT, it provides the world’s fastest scan per second at a speed of 100,000 A-scans per second,” says Carl Glittenberg, MD, FEBO, global medical director for Topcon. It also features exceptionally easy image capture and a 1-micron, 1,050-nm light source.
Netan Choudhry, MD, FRCS(C), medical director at Vitreous Retina Macula Specialists of Toronto in Canada, was prompted to try the instrument because of its swept-source technology. “The longer wavelength allows for deeper penetration through the eye, allowing for better visualization of the retina and choroid,” he says. “I can now image through gas, oil, blood, and cataracts.”
The DRI OCT Triton aids in the diagnosis, documentation, and management of ocular health and diseases in adults. The noncontact, high-resolution tomographic and biomicroscopic imaging device incorporates a digital camera for photographing, displaying, and storing data of the retina and surrounding parts of the eye to be examined under mydriatic and nonmydriatic conditions, Dr. Glittenberg says.
The device is also indicated for in vivo viewing, axial cross-sectional, and 3-dimensional imaging and measurement of posterior ocular structures, including the retina, retinal nerve fiber layer, macula, and optic disc as well as imaging anterior ocular structures. It includes a reference database for posterior ocular measurements, which allow for the quantitative comparison of the retinal nerve fiber layer, optic nerve head, and the macula in the retina to a database of known normal subjects.
Dr. Glittenberg explains that the device’s faster scanning speed enables users to capture a clear B-scan by acquiring more A-scans within a given image acquisition time. Images are clearly described from vitreous, retina, and choroid in a single capture, without degrading OCT image quality in deeper depth. The deepest layers of the eyes can be imaged, even through opacities such as cataracts, hemorrhages, and blood vessels.
Multimodal imaging allows physicians to image a patient with several different types of imaging technology. “When analyzed together, different imaging modalities can increase a physician’s ability to detect disease and learn more about a patient’s condition,” Dr. Glittenberg says.
DRI OCT Triton can acquire the OCT and fundus image in a single capture. By using pinpoint registration, a physician can identify the B-scan location on the fundus image. Clear comparison between the B-scan and fundus image can support clinical efficiency during diagnosis.
With en face visualization software, the Triton can create a live en face fundus image, an ideal tool for precisely locating the scan position. “This makes it easy to see the disc, retinal vessels, and scanning position, even in patients with small pupils,” Dr. Glittenberg says. A physician can view the retina topographically, layer by layer. “The usefulness of this imaging technique in the diagnosis of a wide range of posterior-segment conditions is being discussed among researchers.”
Having one instrument provide these capabilities reduces the need to invest in several pieces of capital equipment, the number of instruments at a practice, and the need to move patients from instrument to instrument, which improves patient throughput, Dr. Glittenberg adds.
According to Dr. Choudhry, the device offers an intuitive touch screen, allowing technician staff to rapidly acquire images. Operators can repeat images as needed within a short time period. Also, OCT scan location can be easily set by selecting the scan area on the fundus image, making fundus abnormalities viewable without any additional operator steps.
BENEFITS TO PATIENTS
Conventional OCT uses visible 840-nm wavelength light, which may distract patients, causing them to involuntarily trace visible scan lines. The DRI OCT Triton’s invisible 1050-nm wavelength light helps patients to concentrate on the fixation target during the measurement, making patients more comfortable and reducing involuntary eye movement.
Dr. Choudhry says rapid acquisition and increased patient comfort have significantly improved patient wait times and flow through his practice. “In cases where we used ultrasound to examine the retina due to media opacities, the Triton provides OCT detail in virtually all those cases, obviating the need for a B-scan exam for that patient. “In particular, OCT shines in patients with small pupils, dense cataracts, and vitreous hemorrhage (or opacities) — virtually any impedance to the optical pathway,” he concludes. RP