Corneal abrasions are the most commonly encountered emergent ophthalmologic issue in the emergency department (ED) and are generally associated with significant discomfort.¹ Yet, in the ED we often perform a single intervention that appears to instantly cure these patients: instillation of a topical anesthetic (e.g., proparacaine, tetracaine). As a result, emergency physicians have increasingly demonstrated interest in providing patients with take-home relief via topical anesthetics; however, the use of topical anesthetics in patients with corneal abrasions has long stirred up intense debate between emergency phsicians and ophthalmologists.² Ophthalmologists, who are on the receiving end of ophthalmic complications, have opposed topical anesthetics in these patients due to concern regarding potential vision-threatening complications such as toxic keratopathy.³ The concern regarding adverse effects historically stemmed from case reports and series skewed by publication bias and often addressing situations that included welders and those with topical anesthetic abuse.

Now, ACEP has published a consensus guideline that has fueled this controversy. The consensus guideline serves up an interesting read—“spilling the tea” on what went down in this document that began as a joint guideline between ACEP and the American Academy of Ophthalmology (AAO).

First, the guideline gives the following Level B recommendation: “In adult ED patients with simple corneal abrasions as defined in these guidelines, it appears safe to prescribe or otherwise provide a commercial topical anesthetic (i.e., proparacaine, tetracaine, oxybuprocaine) for use up to every 30 minutes as needed during the first 24 hours after presentation as long as no more than 1.5 to 2 mL total (an expected 24-hour supply) is dispensed and any remainder is discarded after 24 hours.” This recommendation is a win for emergency physicians who favor doling out topical anesthetics in select patients.

This recommendation was informed by evidence derived from case reports and series, ophthalmology literature after photorefractive keratectomy, four ED-based randomized trials (totaling 307 patients) and two ED-based nonrandomized studies (totaling nearly 2,000 patients). Although the ACEP guideline does not analyze the pooled data, a Cochrane review examining the randomized trials found the relative risk (RR) of incomplete resolution of epithelial defects by 24-72 hours and complications at longest time point not statistically significant in post-trauma corneal abrasions treated with topical anesthetic versus placebo (RR 1.37, 95 percent CI 0.78- 2.42 and RR 1.13, 95 percent CI 0.23-5.46, respectively).⁴

The ACEP guideline gives a smattering of supporting recommendations, including that tetracaine, proparacaine, and oxybuprocaine appear similarly safe, that clinicians should consider patient-specific medical and social factors, and that topical anesthesia appears a more effective analgesic than acetaminophen with or without an opioid. Use in pediatric patients should be avoided due to a lack of studies in these patients.⁵

No, not all patients with corneal abrasions can or should get take-home topical anesthetics; however, a subset of carefully selected adult patients with a simple corneal abrasion can take home a <24-hour supply. When considering dispensing topical anesthetics, the ACEP clinical policy provides additional recommended information to add to patient discharge instructions.⁵ Importantly, these instructions highlight the importance of the <24 hour timeframe and potential adverse consequences. These instructions can be adapted for local use and, in my own practice, serve as a stimulus for shared decision making with the patient.

Many ophthalmologists are unhappy with the ACEP recommendations and anecdotally report an increasing number of patients presenting to clinic with entire bottles of topical anesthetic from the ED.^3,6 The guideline contains a description of the drama that unfolded when the joint ACEP-AAO workgroup submitted their recommendations: The AAO supported the literature review but disagreed with the recommendations and eventually withdrew support.⁵ Although not supported by published evidence to date, the concerns from our ophthalmologic colleagues should not be ignored. In fact, with regard to rare outcome data, the studies are rather small. Additionally, our Achilles’ heel in emergency medicine is the lack of follow-up on downstream outcomes, which can lead to overconfidence in our practice patterns and gestalt. We are unlikely to become aware of our misdiagnoses, such as mistaking microbial keratitis or a corneal ulcer for a corneal abrasion. Emergency physicians are unlikely to see adverse sequelae unless we actively seek follow-up. It is critical to take certain steps when contemplating topical anesthetic for home use.

• Be certain of the diagnosis of a simple corneal abrasion. This means a thorough exam, using the slit lamp, to exclude foreign body/rust ring, ulcer, laceration, infection, or keratitis. Also, be sure to address pertinent features in the history to ensure fewer than two days since onset, no chemical or thermal cause, no history of herpetic eye disease, and similar issues.
• Counsel patients on potential risks.
• Dispense <1.5 to 2 mL (40 drops) of anesthetic and throw away the rest.
• Provide written and verbal instructions to the patient on appropriate use, including duration of use, follow-up, and risks.
• Consider discussing with local ophthalmologists.

Dr. Westafer is assistant professor in the department of emergency medicine at the UMass Chan Medical School–Baystate and co-host of FOAMcast.

References

1. Channa R, Zafar SN, Canner JK, et al. Epidemiology of eye-related emergency department visits. JAMA Ophthalmol. 2016;134(3):312-319.
2. Klauer KM. Science has repeatedly debunked this stubborn ophthalmology myth. ACEP Now. Published September 19, 2018. Accessed September 15, 2024.
3. Weiser P. American Academy of Ophthalmology. Topical anesthetics: The latest on use for corneal abrasions. Published February 1, 2024. Accessed September 15, 2024.
4. Sulewski M, Leslie L, Liu S-H, et al. Topical ophthalmic anesthetics for corneal abrasions. Cochrane Database Syst Rev. 2023;8(8):CD015091.
5. Green SM, Tomaszewski C, Valente JH, et al. Use of topical anesthetics in the management of patients with simple corneal abrasions: consensus guidelines from the American College of Emergency Physicians. Ann Emerg Med. 2024;83(5):477-489.
6. Chuck RS, Jeng BH, Lum F. Consensus guidelines versus evidence-based medicine in the treatment of corneal abrasions. Ophthalmology. 2024;131(5):524–525.