Written by Sam Parnell
Short-term use of topical tetracaine for uncomplicated corneal abrasions was associated with significant pain reduction and decreased need for opioid medications, with no difference in wound healing or serious complications. However, larger studies are needed to definitively demonstrate safety and rule out rare adverse events.
Why does this matter?
Corneal abrasions are the most common ocular injuries encountered in the acute care setting. Most corneal abrasions heal spontaneously within 24 to 72 hours, but they are particularly painful, and adequate analgesia can be a real problem. Discharging patients with topical anesthetic agents such as tetracaine or proparacaine can provide excellent analgesia but has historically been avoided due to concerns for poor wound healing and subsequent corneal ulceration, scarring, or blindness.
However, evidence for the harmful effects of topical anesthetics is limited and comes from case reports, case series, and animal studies, many of which included high concentrations and long-term use of topical agents. So, is this dogma justified, or can topical anesthetics be a useful tool to treat the severe pain associated with corneal abrasions?
You’ll melt your eye out…or will you?
This was a prospective, randomized, double-blind, placebo-controlled trial of 111 patients comparing patient home use of topical tetracaine 0.5% (1 drop every 30 minutes as needed for a maximum of 24 hours) vs placebo (artificial tears) for uncomplicated corneal abrasions.
Topical tetracaine use was associated with lower median pain score (1/10 vs 8/10) and decreased use of hydrocodone tablets for breakthrough pain (median 1 vs 7) compared to placebo for the first 24 to 48 hours. No serious adverse events were reported, and there was no significant difference in the rate of complications or residual corneal abrasions noted at the 24- to 48-hour follow up visits. Of note, there were numerous exclusion criteria, and only patients with uncomplicated corneal abrasions were included. In addition, this was a small, single center study, and it was not powered to establish safety or rule out rare adverse events.
Based on this data, short-term use of topical tetracaine for up to 24 hours appears to be both efficacious and relatively safe. However, the overall safety profile and rate of rare adverse events is still unknown. Therefore, before you send patients home with topical tetracaine for corneal abrasions, counsel them on the correct use of topical anesthetic agents and on the potential risks of abuse/misuse. Patients discharged with topical anesthetics should also be given strict return precautions along with instructions for close ophthalmology follow-up.
These resources take an in depth look and literature review of topical anesthetics for corneal abrasion.
Short-Term Topical Tetracaine Is Highly Efficacious for the Treatment of Pain Caused by Corneal Abrasions: A Double-Blind, Randomized Clinical Trial. Ann Emerg Med. 2020 Oct 27;S0196-0644(20)30739-3. doi: 10.1016/j.annemergmed.2020.08.036. Online ahead of print.
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