Effect of acetazolamide on outward permeability of blood-retina barrier using differential vitreous flyorophotometry

Abstract

Purpose. To measure fluorescein (F) and fluorescein monoglucuronide (FG) concentrations in the vitreous and evaluate the effect of acetazolamide (AZM) on the outward permeability of the blood-retina barrier (BRB) using differential vitreous fluorophotometry (DVF). Methods. DVF was performed 180 minutes after intravenous injection of AZM (5 mg/kg) and 50 mg of sodium fluorescein in six rabbits (AZM group). DVF also was performed in six rabbits injected intravenously with only 50 mg of sodium fluorescein (control group). The F/FG ratio was calculated based on the concentrations of F and FG obtained by DVF. DVF also was performed 180 minutes after 50 mg of intravenous injection of sodium fluorescein in five rabbits given probenecid (150 mg/kg) intraperitoneally (probenecid group). Results. The average F/FG ratio was 0.36 ± 0.17 (range, 0.22–0.66) in the AZM group, which was significantly smaller than the control value of 0.74 ± 0.22 (range, 0.50–1.60). The average F/FG ratio at 180 minutes after injection was 1.51 ± 0.46 (range, 0.94–2.00) in the probenecid group, which was significant higher (p < 0.05) than that of the AZM or control group. Conclusions. This study showed that the F/FG ratio might be a good indicator of the estimated outward permeability of the BRB using DVF and that AZM may accelerate the outward active transport function of the BRB.