Calcein: a new dye for evaluation of the blood-retinal barrier by fluorophotometry

A vitreous fluorophotometry study was performed on rabbits to compare the characteristics of carboxyfluorescein and calcein with those of sodium fluorescein. Our results demonstrated that carboxyfluorescein and calcein attained midvitreous concentrations similar in magnitude to fluorescein approximately one hour after injection of the dye. As long as three to four hours after injection of the dye, the mean fluorescence levels of calcein in the chorioretina were much higher than those of sodium fluorescein and carboxyfluorescein. These results point out that calcein has potential experimental and clinical use as a probe of the blood-ocular barrier as well as in experimental and clinical angiography of the fundus.