Proparacaine vs Placebo for Corneal Injuries (Dogma)

Introduction: Traumatic injuries to the outer covering of the eye (the cornea) are a common emergency department complaint. They cause significant patient distress including pain, loss of sleep and missed work days. There is currently no accepted, uniform approach to pain management in this patient population. Emergency medicine and ophthalmology texts state that prolonged use of medications that anesthetize the cornea is not recommended. Several recent publications in the ophthalmology literature show that the outpatient use of dilute local anesthesia in patients after eye surgery is a safe and effective method of pain control. In this study, we used Proparacaine (a local anesthetic), in a similar manner, for the outpatient emergency department management of traumatic corneal injuries.

Methods: We performed a clinical trial on a sample of adult patients presenting with traumatic corneal injuries to two university affiliated emergency departments in London, Canada.

Patients providing signed informed consent to participate in the study received a vial of clear liquid that contained either Proparacaine or plain water (placebo), a pain log, topical antibiotics and oral Acetaminophen (Tylenol) with Codeine for breakthrough pain.

Patients were instructed to use the "study drug" on an "as-needed" basis for the next seven days. Patients completed a pain scale describing their discomfort immediately prior to, and five minutes after self-administration of the study drug. All patients were followed closely in an ophthalmology outpatient clinic on Days 1, 3 and 5 after presentation to the emergency department. At the last ophthalmology clinic visit, the patients' pain logs were collected.

The protocol was approved by the Research Ethics Board for Health Sciences Research Involving Human Subjects at the University of Western Ontario.