Diagnostic imaging has played an increasing role in eye care in recent years. The progress across this landscape in the past decade has been monumental. Data from modern imaging devices has truly changed the way ophthalmologists think about a patient picture, and the data is often necessary for determining clinical management. One of the newest technologies available to vitreoretinal specialists is ultra-widefield imaging. This technology is incorporated into an entire line of scanning laser ophthalmoscope devices from Optos, including the latest, the Optos 200Tx. The 200Tx is the first instrument that provides visualization of ultra-widefield autofluorescence changes in the retinal pigment epithelium. It also provides multiple wavelength imaging, including options for color, red-free and fluorescein angiography.
Ultra-widefield fundus fluorescein angiography (UWFFA) has opened up areas of study previously untapped in the vitreoretinal subspecialty. Until recently, the retinal periphery was not examined, mainly because no easy way to image it existed. Under optimal conditions, traditional angiographic methods employing film or digital fundus cameras can capture 50º views. With seven standard fields, a 75º view of the fundus can be obtained. With luck and a compliant patient, certain contact lens systems allow imaging out to the 120º range. However, none of these modalities can compare to the ultra-widefield view of up to 200º provided by the Optos devices.
Perhaps even more valuable than the wide field of view, the fluorescein images obtained by the Optos devices are captured simultaneously. Seven standard fields and contact lens systems capture images in a successive fashion and then assemble a montage. Because the transit of fluorescein dye occurs quickly, in about 10 to 30 seconds, traditional technologies omit what could be revealing stages of dye transit through the fundus. In contrast, the Optos devices permit simultaneous detection of several foci of neovascular dye leakage. This is important because each focus may have different levels of dye leakage when viewed at the same time point.
Enhanced view of the periphery has led to several exciting new clinical findings, most of which have occurred in the past 2 years. The technology has unveiled new insights regarding the role of peripheral pathology in retinal vascular, degenerative and inflammatory diseases. Potential new disease markers have emerged, as have the first efforts to quantify peripheral pathology. There is also hope that UWFFA with targeted retinal photocoagulation (TRP) will help to prolong the effects of anti-VEGF or steroid intravitreal therapy in certain macular diseases where peripheral ischemia exists.
In the discussions that follow, a group of vitreoretinal surgeons who are involved in research with UWFFA and have vast experience with it share their insights regarding implementation of this relatively new technology in clinical practice as well as current and future directions for research.
|Seenu M. Hariprasad, MD|
Associate Professor of Ophthalmology & Visual Science Chief of the Vitreoretinal Service and Director of Clinical Research at The University of Chicago Medical Center