Simultaneous optical coherence tomography—Indocyanine Green dye fluorescence imaging system for investigations of the eye’s fundus

We have developed a dual-channel optical coherence tomography–Indocyanine Green dye (OCT–ICG) f luorescence system based on a previously reported ophthalmic OCT confocal imaging system. The confocal channel is tuned to the f luorescence wavelength range of the ICG, and light from the same optical source is used to generate the OCT image and to excite the ICG f luorescence. The system enables the clinician to visualize simultaneously en face OCT slices and corresponding ICG angiograms of the ocular fundus, displayed side by side. C-scan (constant depth) and B-scan (cross section) images are collected by a fast en face scan (T scan). The pixel-to-pixel correspondence between the OCT and angiography images allows the user to capture OCT B scans precisely at selected points on the ICG confocal images.