Cell-sized hyperfluorescent near-infrared signals appearing in regions with no prior autofluorescence or RPE signal change during the study.

Retinal ICG fluorescence 790 nm excitation channel images are shown alongside matched 488 nm excitation autofluorescence images. Subject 3 had detectable ICG cell staining in peripheral blood. By size and location these could represent weakly ICG labelled cells infiltrating the retina, rather than arising from RPE staining alone. LE = left eye, RE = right eye. Scale bars = 200 μm.