Icare-CenterVue’s DRSplus is a confocal fundus imaging system that uses white LED illumination — which includes the entire visible spectrum — to produce TrueColor and detail-rich images, setting a new standard for retinal imaging. The technology was originally offered on CenterVue’s Eidon, a confocal optical system. “When we first introduced TrueColor confocal technology, we realized that it was so superior to standard fundus cameras that we decided to expand its use to all of our imaging products,” says Luca Zalunardo, vice president of marketing, Icare USA, which merged with CenterVue in April of 2020.
K. Bailey Freund, MD, clinical professor of ophthalmology at New York University Grossman School of Medicine, who was the first US physician to use the device, says, “The DRSplus uses white diode illumination to produce true color images, which are much closer to what we see clinically with standard fundus cameras. Confocal optics eliminate much of the scattered light, resulting in images with excellent contrast, rich detail, and high resolution, even when media opacities would significantly degrade the image quality obtained with a standard flash fundus camera. I consistently obtain good quality images in patients with pupils as small as 2 mm.”
HOW IT WORKS
DRSplus uses a confocal scanner and a white light flash to take retinal images. “In many ways, it works like a document scanner; it uses a line of light to scan through the retina and a confocal linear aperture to limit the scattering of light in order to acquire the best image quality,” Zalunardo says.
The default retinal image is 45 degrees, and the device can acquire montage images up to 80 degrees. Other options include stereo disc images and external photos. The device aligns, focuses, and captures images automatically. “Impressively, it can image both eyes in less than 30 seconds,” says Dr. Freund.
Because it has a full-color sensor, Atul Jain, MD, partner, Retina Consultants San Diego, who helped develop the product and uses it for patient exams, says that images are true to life in their appearance without artifact or pseudocolor — like images taken with scanning laser imaging systems or those with only a black and white capture sensor.
FEATURES AND BENEFITS
When designing the DRSplus, Zalunardo says the goal was to solve the main issues common to all fundus cameras: ease of use, resolution, inability to penetrate media opacities and small pupils, dirty lenses, patient ergonomics, and affordable price.
“It seemed like we asked our research and development team to do the impossible,” Zalunardo says. “But they achieved all of these goals with the DRSplus.” The device, which self-aligns the patient’s eye and penetrates pupils as small as 2.5 mm as well as opacities such as cataracts, uses a different technology than that of standard fundus cameras.
Dr. Freund says, “The detailed images are quite helpful in identifying areas that warrant a more careful look with ophthalmoscopy or OCT. Previously, images of this quality would require a highly skilled ophthalmic photographer and a well-dilated eye with clear ocular media. With minimal training, all of my office staff members can acquire high-quality fundus images in nondilated patients,” he says. “These images are particularly useful in educating patients by clearly demonstrating what their evaluation shows. The 10-megapixel resolution allows for sufficient magnification without loss of quality for low-vision patients.”
Dr. Freund uses the DRSplus when retinal findings of interest are located within the central 45 degrees of the fundus. These patients have common diagnoses such as age-related macular degeneration, diabetic macular edema, retinal vein occlusion, vitreoretinal interface disorders, macular dystrophies, and inflammatory maculopathies, he says.
Dr. Jain uses the system for almost all of his patients, particularly those with posterior, midperipheral, and optic nerve pathologies. “It’s so much more helpful to use a large high-resolution color photograph of a patient as a teaching aid than an abstract OCT image that patients can recognize but can’t relate to or fully understand,” he says.
It’s also great for predocumentation and postdocumentation and educating patients for all types of conditions from age-related macular degeneration, diabetic retinopathy, glaucoma, retinal detachments, epiretinal membranes, and even floaters. The DRSplus can also perform external photography for conditions such as iris nevus or corneal pathologies that need to be documented, Dr. Jain continues.
Soon, the DRSplus will offer another one of the Eidon’s features — a cup-to-disc ratio calculation. “This is a great feature because nonmydriatic photos allow for cup-to-disc ratio measurements that are accurate and reproducible, so you can document changes over time rather than relying on drawings, which are subjective and open to interpretation and errors,” Dr. Jain says. He notes that he can obtain nonmydriatic images of both the right and left eye within 12 seconds of pushing the button to take the image.
Dr. Freund says DRSplus is ideally suited for telescreening programs for retinal diseases such as diabetic retinopathy. “Remote screening in areas with limited access to eye care services can help detect sight-threating retinal diseases that needs to be treated,” he says.
EASE OF USE
DRSplus is fully automatic; users preset the type of scan desired (ie, single or multiple fields of the retina, stereo images, or external eye images) on the touchscreen and then press “start.” As soon as images are taken, they are visible in remote stations. “The device’s automation guarantees consistency in results across technicians and patients, so clinicians don’t have to worry about workflow disruptions,” says Zalunardo.
Patients appreciate how their fundus images can reveal findings that relate to their visual symptoms. Sometimes images show unexpected findings warranting closer inspection with ophthalmoscopy, OCT, or angiography, Dr. Freund says.
Patients also find the device easier on their neck and back compared to the chin rests used in most other imaging systems, Dr. Freund says. They also find the illumination to be less intense than that used in standard fundus photography, because the flash is softer.
Dr. Freund adds that the DRSplus has been particularly useful during the COVID-19 pandemic, allowing patients to maintain social distancing. “The device has allowed me to work more efficiently with improved patient flow and has reduced the need for face-to-face slit lamp examinations, which likely increases the risk of virus transmission,” he says. RP