Effects of Topical Ketorolac and Diclofenac on Normal Corneal Sensation

BACKGROUND: A randomized, double-masked study was conducted to investigate the effects of 0.5% ketorolac tromethamine (Acular) and 0.1% diclofenac sodium (Voltaren) on normal human corneal sensation. METHODS: Thirty normal volunteers were divided into two groups, (1) two-drop group, and (2) multiple-drop group. In the two-drop group, 15 volunteers randomly received two drops of 0.5% ketorolac tromethamine on one eye and two drops of 0.1% diclofenac sodium on the fellow eye. A masked investigator measured corneal sensation with the Cochet-Bonnet esthesiometer before applying the drops, and at 15, 30, and 60 minutes after using the eye drops. In the multiple-drop group, another 15 volunteers were randomly administered one drop of 0.5% ketorolac tromethamine or 0.1% diclofenac sodium in each eye, and the procedure was repeated every 5 minutes for 20 minutes. Corneal sensation was measured before, and 0, 15, 30 and 60 minutes after applying the drops. RESULTS: In the two-drop group, neither of the eye drops had any effect on corneal sensation when only two drops were applied. In the multiple-drop group, corneal sensation was significantly reduced after multiple drops (p < 0.05) and was subsequently effective for at least 1 hour. CONCLUSION: Both 0.5% ketorolac and 0.1% diclofenac can significantly decrease corneal sensation in normal eyes when multiple drops are used.