Abstract:
Changes in the barrier mechanisms in the eye should determine the rational route for the
administration and dosage of each drug in the treatment of traumatic injuries and other pathologies.
The aim of this study was to examine the efficacy of intra-arterial delivery of 14C-riboflavin (as an
“indicator”) and compare it with intravenous and intramuscular administration in an animal model of
chemical eye burn. 14C-riboflavin (14C-I) was administered by intra-arterial (carotid artery), intravenous
(femoral vein) and intramuscular (femoral muscle) routes. The total radioactivity was determined over
2 h in the plasma and structures of the rabbit’s eyes using a scintillation counter. The results of the
study show that intravascular administration of 14C-I gives significantly higher concentrations of total
radioactivity in the blood and is accompanied by a significant increase in the permeability of the bloodbarrier and barrier in eyes suffering from burns. The highest concentration in the plasma and aqueous
humour of the anterior chamber of the eye was observed during the first hour with the intra-arterial
route of administration of 14C-I in either burnt and unburnt eyes. The distribution of total radioactivity
in the structures of the eye over the 2 h of the experiment showed a higher level of the drug under
intra-arterial administered in the uveal regions, namely: the iris, ciliary body, choroid, retina and also
the sclera and cornea. This experimental model shows that intra-arterial administration can increase
the bioavailability of a drug to the structures of the eye within a short period of time.
