EFFECTS OF THE CYCLOOXYGENASE INHIBITOR IBUPROFEN ON RETINAL AND CHOROIDAL BLOOD-FLOW DURING HYPEROXIA IN NEWBORN PIGLETS

Purpose: The effect of the cyclooxygenase inhibitor ibuprofen (IB) on choroidal (ChBF) and retinal (RBF) blood flow during hyperoxia was exa mined in 21 spontaneously breathing newborn piglets. Methods: ChBF and RBF were measured using radiolabelled microspheres before and 30 min after either saline or IB (30 mg/kg, IV) infusion in room air and subs equently, after 90 min of hyperoxia (O-2) Results: The basal RBF and C hBF did not change after IB infusion. However, during hyperoxia a sign ificant decrease in RBF was observed in the IB group(54 +/- 5 to 37 +/ - 3 ml/min/100 g, p < 0.02) and in the control group (54 +/- 3 to 37 /- 5 ml/min/100 g, p < 0.02). Also, ChBF decreased in the IB group (2, 635 +/- 446 to 1,670 +/- 199 ml/min/100 g, p < 0.02) and in the contro l group, (2,997 +/- 346 to 2,014 +/- 246 ml/min/100 g, p < 0.02) durin g hyperoxia. Conclusions: Despite cyclooxygenase inhibition with IB, R BF and ChBF decreased to the same extent as in the control group follo wing exposure to O-2. These data suggest that hyperoxia decrease RBF a nd ChBF through mechanisms and/or mediators other than the cyclooxygen ase by-products of arachidonic acid metabolism.