Prostaglandin E2 levels of aqueous and vitreous humor in ketorolac 0.4% and nepafenac 0.1% administered healthy rabbits

Purpose: To compare the lowering effects of ketorolac 0.4% and nepafenac 0.1% on aqueous and vitreous humor prostaglandin E-2 (PGE(2)) levels in rabbits.Methods: Ketorolac and nepafenac ophthalmic solutions were administered to the right eyes of 24 healthy rabbits after randomized division into two groups. The left eyes of these rabbits were considered as controls for the two groups. On the 4th day of the experiment, the samples were taken from the aqueous and vitreous humors of the rabbits bilaterally, and PGE(2) levels were measured by an enzyme immune assay kit.Results: Ketorolac and nepafenac achieved a statistically significant decrease (p<0.001, for each) in PGE(2) levels in the aqueous (11.75 6.15 and 14.75 +/- 7.60 pg/mL, respectively) and the vitreous humor (6.58 +/- 4.62 and 9.83 +/- 4.55 pg/mL, respectively).Conclusions: Both ketorolac and nepafenac inhibited PGE(2) levels in both the aqueous and vitreous humors of rabbits. Although PGE(2)-lowering effects were similar in the aqueous humor, nepafenac seemed to be more potent than ketorolac in the vitreous humor.