Purpose
To evaluate imaging including Ultra-wide field Fluorescein angiography and Indocyanine Green angiography using a modified Heidelberg Spectralis with noncontact ultra-widefield lens system.
Methods
35 eyes underwent fluorescein angiography using the Heidelberg Spectralis noncontact ultra-wide field lens 105 degree diagonal system. Central images were initially obtained centered on the fovea. Views of the far periphery were obtained of the areas of interest , by directing the camera (non-contact) in the appropriate direction. Imaging modalities included infrared, intravenous fluorescein or oral fluorescein and indocyanine green angiography as well as autofluoresence, red free and infrared images. The digital images were then evaluated and compared to the images taken by the same machine using the 30 degrees and the 55 degree wide angle lens system.
Results
: 35 eyes were evaluated. Using directional Ultra-wide field view and auto-montaging software, we could image the retina for a diameter of 28mm allowing a field of view to include the equator and some structures anterior to it. The native resolution of 1536x1536 was sufficient to see important retinal details including vascular abnormalities and far peripheral non-perfusion and neovascularization. An advantage of using the Specralis over a dedicated wide angle device is that higher resolution image of an area of interest can be obtained by switching to the standard Spectralis lens (5 microns/pixel) versus the low nominal resolution of the usable wide-angle lens of the Spectralis (10 microns/pixel with 55° degree lens) or Optos (14 microns/pixel on standard view and 11 microns/pixel on high-resolution view) system lenses. The lens could be used for oral or intravenous fluorescein angiography and other imaging modalities.
Conclusions
Images taken from Ultra-wide field noncontact lens system of Heidelberg Spectralis permits a 105 degrees field of view covering which can be easily montaged to cover equator to equator of the retina. . The device allows for AF, IR, IVFA, Oral FA and ICG ultra-wide field views enabling visualization and localization of important choroidal and retinal structures from equator to equator.
Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)