Study Objective: To determine whether the use of diclofenac ophthalmic solution is a safe and effective analgesic in the treatment of traumatic corneal abrasions in the emergency department., Methods: We conducted a prospective, randomized, double-blinded, placebo-controlled clinical trial. Consenting consecutive patients with corneal abrasions who presented to a community-based ED from August through February 1998 were randomly assigned to receive either diclofenac or control vehicle drops. Pain relief was measured using a visual Numeric Pain Intensity Scale (NPIS) before and after treatment. Exclusion criteria were as follows: age younger than 18 years, pregnancy, history of glaucoma, ocular infection, recent eye surgery, other signs of ocular trauma, narcotics within 6 hours, minimal pain (NPIS score <3), and any allergy to diclofenac or nonsteroidal anti-inflammatory drugs. Patients were discharged with study drug or control vehicle solution, a topical antibiotic, oxycodone-acetaminophen as a rescue analgesic, and a pain diary. The outcome measurements were improvement in NPIS score 2 hours after treatment, use of oxycodone-acetaminophen, and occurrence of any adverse effects., Results: Forty-nine patients were enrolled in the study; 25 received diclofenac and 24 received control vehicle drops. Both groups were similar in gender, age, pretreatment pain duration, NPIS score, and analgesic use. There was significantly greater improvement in the 2-hour NPIS score in the diclofenac group (3.1; 95% confidence interval [CI] 2.3 to 4) compared with the control group (1.0; 95% CI 0.1 to 2.0). The difference between the 2 groups was 2.1+/-1.3 (95% CI 0.8 to 3.4). There was a trend toward fewer patients taking rescue oxycodone-acetaminophen in the diclofenac group (20%; 95% CI 4% to 36%) versus the control group (42%; 95% CI 22% to 62%). Other than transient mild stinging, there were no complications associated with diclofenac use., Conclusion: Diclofenac ophthalmic solution appears to be a safe and effective analgesic in the treatment of traumatic corneal abrasions in the ED.