Simultaneous OCT/ICG fluorescence imaging system for investigations of the ocular fundus

The authors report the construction of a dual channel OCT/indocyanine green (ICG) fluorescence system with the optical source common to both the OCT and fluorescence channels based on our previously described ophthalmic Optical Coherence Tomography (OCT)/confocal imaging system. The confocal channel is tuned to the fluorescence wavelength range of ICG dye. The system is compact and assembled on a chin rest and it enables the clinician to visualise the same area of the eye fundus in terms of both en face OCT slices and ICG angiograms, displayed side by side. The images are collected by fast en face scanning (C-scan) followed by slower scanning along a transverse direction and depth scanning. We demonstrate the first such dual OCT/ICG-fluorescence images from healthy eyes. The system is still capable of providing chosen OCT B-scans at selected points from the ICG confocal image, in the same way the OCT/confocal configuration was used.