Objective: Dogma discourages the provision of topical anesthetics to patients with corneal injuries discharged from the emergency department because of the toxicity of concentrated solutions. We compared the analgesic efficacy of dilute topical proparacaine with placebo in emergency department patients with acute corneal injuries.
Methods: We conducted a prospective randomized controlled trial of adults with corneal injuries presenting to one of 2 tertiary care emergency departments in London, Ont. Patients were randomly assigned to groups receiving either 0.05% proparacaine or placebo drops as outpatients and were followed up to healing by a single ophthalmologist. Our primary outcome was pain reduction as measured on a 10-cm visual analog scale.
Results: Fifteen participants from the proparacaine group and 18 participants from the placebo group completed the study. The mean age of the patients was 38.7 (standard deviation 12.3) years and the majority were male (85%). Pain reduction was significantly better in the proparacaine group than in the placebo group, with a median improvement of 3.9 (interquartile range [IQR] 1.5-5.1) cm on the visual analog scale versus a median improvement of 0.6 (IQR 0.2-2.0) cm (p = 0.007). The proparacaine group was more satisfied (median level of satisfaction 8.0 [IQR 6.0-9.0] cm on a 10-cm visual analog scale v. 2.6 [IQR 1.0-8.0] cm, p = 0.027). There were no ocular complications or signs of delayed wound healing in either group.
Conclusion: Dilute topical proparacaine is an efficacious analgesic for acute corneal injuries. Although no adverse events were observed in our study population, larger studies are required to evaluate safety.