Fluorophotometry and the Blood-Ocular Barrier in Experimental Systemic Hypertension

Abstract
• Fluorophotometry was used to evaluate alterations in the blood-ocular barrier to fluorescein in rats with experimental hypertension. One hour after intravenous injection of fluorescein, 16.6 mg/kg, concentrations in the anterior chamber were increased from mean normotensive values of 135 μg/mL to 299 μg/mL (P =.005) in animals with severe hypertension. Fluorescein concentrations in the vitreous also were increased from 50 μg/mL in normotensive rats to 109 μg/mL (P =.005) in hypertensive animals. With increasing duration of systemic pressures above 160 mm Hg, anterior chamber fluorescein concentrations rose from baseline of 135 μg/mL to 210 μg/mL after one to four weeks of hypertension, and to 394 μg /mL after five to eight weeks (P =.005). Similarly, vitreous concentrations increased from baseline of 50 μg/mL to 76 μg/mL and 136 μg/mL (P =.005) after the shorter and longer periods of hypertension. Control of hypertension with return of systolic pressure to below 120 mm Hg caused a reversal of the abnormal fluorescein permeability.