Plasma fluorescein and fluorescein glucuronide in patients with selected eye diseases

Systemically administered fluorescein (F) is rapidly transformed to the fluorescent metabolite fluorescein glucuronide (FG). Little is known about how diseases can influence the synthesis or disposition of FG. We studied F and FG in the plasma ultrafiltrate of 75 people who were normal or had diabetes, retinitis pigmentosa, or idiopathic rhegmatogenous retinal detachment. F and FG were determined by high-performance liquid chromatography. The concentration of FG was comparable to F 1 h after an intravenous injection of F, both in normal subjects and in patients with retinitis pigmentosa, which suggests that FG may not be an important contributor to the vitreous fluorescence at that time. At later times FG substantially exceeded F. The concentration of FG was significantly higher in diabetics than in the other groups 14 h after an oral dose of F. Accordingly, the possible effect of disease on plasma dye concentrations should be considered in studies measuring F by fluorescence hours after systemic F administration, since this could influence the intraocular fluorescence irrespective of any alteration in ocular function.