Purpose: To evaluate the safety and analgesic efficacy of ketorolac tromethamine 0.4% ophthalmic solution in postoperative photorefractive keratectomy (PRK) patients.Setting: Fifteen clinical sites in the eastern and southern United States.Methods: This pooled analysis of 2 multicenter, randomized, double-masked, vehicle-controlled, parallel-group studies comprised 313 patients having unilateral PRK. After surgery, patients were treated with 1 drop of ketorolac tromethamine 0.4% ophthalmic solution (Acular(R) LS) (n = 156) or vehicle (n = 157) 4 times daily for up to 4 days. Pain intensity, pain relief, use of escape medication, and severity of ocular symptoms were assessed. Adverse events, epithelial healing, and visual acuity were recorded.Results: There was significantly less pain intensity experienced by patients in the ketorolac group (P<.001). During the first 12 hours post PRK, 50% fewer patients in the ketorolac group than in the vehicle group had severe to intolerable pain (41.6% [64/154] and 84.5% [131/155], respectively). The median time to no pain was 30 hours in the ketorolac group and 54 hours in the vehicle group (P<.001, survival analysis). Ketorolac patients reported significantly greater pain relief than vehicle patients throughout the study (P<.001). Ketorolac patients used significantly less escape medication than vehicle patients for 48 hours post PRK (P=<.008). Treatment-related adverse events occurred in 2.6% (4/156) of ketorolac patients and 6.4% (10/157) of vehicle patients.Conclusion: Ketorolac 0.4% ophthalmic solution is safe and effective in reducing ocular pain when used 4 times daily for up to 4 days post PRK.