Murat V. Kalayoglu, M.D.
Contributing EditorScreening examinations for diabetic retinopathy and other retinal diseases require regular visits to the eye specialist. Many individuals in the United States do not have easy access to an ophthalmologist. In other parts of the world, the relative scarcity of ophthalmologists greatly hinders eye care, which is sought only when a dramatic loss of vision occurs. If patients are able to have a fundus exam through their primary care physician’s office, then diseases such as diabetic retinopathy, age-related macular degeneration, glaucoma and even retinal tears could be diagnosed and treated in a timely manner.
While it is impossible to have an eye M.D. in every primary care office, patients soon may have access to excellent alternatives. Indeed, a diagnostic digital retinal imaging device is now available that can take dilated fundus photographs and send the images over the internet to a centralized reading center. The images are examined and interpreted by a team of retina specialists, and the results are sent back to the primary care physician’s office within 48 hours. Patients found to have retinal disease are referred to an ophthalmologist.
Several digital retinal imaging cameras are available. These devices could also be used to transmit images over the internet. Such retinal imagers - incorporating high-resolution digital imaging with sophisticated software - are already proving to be attractive ancillary equipment for ophthalmologists. For example, the Topcon Telemedicine System combines the TRC-NW6 Non-Mydriatic Retinal Camera with proprietary software for easy transmission of images through the internet. Canon’s CR-DGi non-mydriatic camera also advertises telemedicine through digital imaging. Visual Pathways’s ARIS camera allows undilated fundus photography at high resolution (1000 x 1000 10-bit pixels per 30 degrees) and stores images digitally, again allowing the possibility of telemedicine.
The main advantage of these devices is that dilation is usually not required to acquire high-quality digitial images. However, the field of view captured by these imagers also is limited. This caveat prevents non-mydriatic imaging of the retinal periphery, and consequently captured images may miss peripheral diseases such as lattice degeneration and retinal tears.
A recently developed retinal imager can capture high-quality images of much of the retina through an undilated pupil, and consequently may be particularly well suited for ophthalmic telemedicine. The OptoMap Retinal Exam, developed by Optos (Marlborough, MA), is a ultra-widefield imager incorporating a “panoramic” scanning laser ophthalmoscope. The imager can obtain high resolution retinal snapshots, and allows visualization of 200 degrees of retina through an undilated pupil. Captured images are then viewed and manipulated through the company’s U-Revu software, and can be beamed anywhere through the internet at the click of a button. The image is acquired within a fraction of a second and allows peripheral views of the retina; such widefield photography is a particularly attractive feature of the camera, since the photos may catch peripheral tears in addition to diseases affecting the disc and macula.
New innovations in digitial retinal imaging likely will build on panoramic scanning laser ophthalmoscopy to allow even greater widefield views through the undilated pupil. It may soon be possible for a patient to enter a mall kiosk, have a full, undilated, widefield fundus photograph taken and beamed to a centralized reading center, and receive an interpretation by e-mail within 24 h. Individuals with suspected retinal disorders can be referred to an Ophthalmologist. Additional developments such as 3-dimensional viewing and software image enhancement will facilitate interpretation and increase the value in retinal imaging. And while digital retinal imaging is unlikely to replace the dilated examination anytime soon, digital imager – guided ophthalmic telemedicine promises to play a prominent role in patient care for years to come.