Fluorescein. Physiochemical factors affecting its fluorescence.

Fluorescein's property of fluorescence is reviewed. Of the many factors which affect its fluorescence, concentration is probably the most important and it best explains why leaking aqueous turns fluorescein bright green during Seidel's test. The intensity and pattern of fluorescein staining of corneal lesions is probably due to the concentration and distribution of fluorescein in the cornea. The concentration of fluorescein achieved in the retinal blood vessels during fluorescein angiography affects its fluorescence.