The authors have demonstrated a significant decrease of the plasmatic ionized calcium level in 84 patients during retinal fluorangiography likely due to a chemical bond between calcium and fluorescein. The side effects noticed during the procedure were similar to that quoted in the literature; their frequency, however, was not correlated with the decrease of the plasmatic ionized calcium level, even though the magnitude of the decrease was twice as great in the patients who experienced some trouble as in those who did not. This lack of correlation may be related to the too small patients sample. A greater frequency of side effects has been noticed in patients treated by calcium inhibitors.