Over the past few decades many technologies have revolutionized the practice of medicine. Perhaps one of the most revolutionary technologies has been Optical Coherence Tomography (OCT). Since the first high profile description of OCT technology in 1991 in the journal Science, this technology has dramatically transformed the way physicians diagnose and treat their patients in several fields in medicine. For Ophthalmology, OCT imaging has become a noninvasive diagnostic tool that allows physicians to visualize and measure anatomical structures without any invasive procedures. It is safe to say the management of diabetic retinopathy, age-related macular degeneration and many others is not practical without OCT. Not only has OCT revolutionized the current practice of Ophthalmology but ongoing developments in OCT technology are among the most promising for providing tomorrow’s advances. Our research group at the USC Roski Eye Institute is involved in the development of the next generation of OCT imaging methods that promise to improve the lives and vision of millions of patients.
OCT emits low-coherence electromagnetic beams and images of the retinal surface by taking advantage of the interference patterns generated by these beams as they interact with the tissue and are reflected back to the detector. The current resolution of most OCT devices is on the order of 10-20 microns which rival measurements obtained from invasive procedures utilizing biopsies and histology. For example, our research group at the USC Roski Eye Institute has recently demonstrated that OCT based angiography (visualization of retinal capillaries) can help measure the earliest changes in the retinal capillaries of subjects with diabetic retinopathy. We have also shown that OCT based imaging methods can quantify retinal vascular changes in other retinal diseases such as uveitis and retinal vascular occlusion that were previously not possible. By allowing these kinds of measurements, physicians and scientists can detect disease activity earlier and more reliably administer treatments. We can also more accurately determine what treatments are effective without the need for invasive procedures.
Future advances in OCT imaging promise to add even more detail and range to these capabilities both in the clinic and in the operating room. Intraoperative use of OCT technology may be one of the new frontiers in OCT imaging. Outside Ophthalmology OCT imaging also has promising applications in the diagnosis and treatment of neurodegenerative disorders like Parkinson’s and Alzheimer’s Disease. With OCT, physicians can potentially use non-invasive assessment of the retina to determine when or if changes in the retinal composition parallel to changes in neural pathology. These may serve as early-detection methods, and they can provide baseline measures of neural integrity, through which clinicians can track disease progression. Much research still needs to be done, but the investment of research dollars in OCT and ancillary imaging methods over the past few decades has directly enabled scientists to develop novel treatments for blinding diseases and also directly enabled physicians to use these treatments to effectively prevent severe vision loss in millions of patients around the world. It is likely that with continued investment in this field and other novel technologies we can impact the general health of many millions more patients.
Dr. Amir Kashani is an Assistant Professor of Clinical Ophthalmology at the USC Roski Eye Institute. He is residency and fellowship trained and a member of the Society of Heed Scholars.