Topical ophthalmic anesthetics for corneal abrasions: findings from a Cochrane systematic review and meta-analysis

Despite potential benefit, outpatient use of topical ophthalmic anesthetics can result in poor healing, infection, scar, and blindness. An unbiased analysis of randomized controlled trials (RCTs) is needed to examine their effectiveness and safety compared with placebo or other treatments for corneal abrasions.

Cochrane Central Register of Controlled Trials, MEDLINE, Embase.com, Latin American and Caribbean Health Sciences, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform were searched on February 10, 2023, without restriction on language or publication date. The published review protocol served as registration.

Systematic review and meta-analysis of nine RCTs describing 314 participants with post-traumatic abrasions and 242 participants with post-surgical abrasions, with a median study length of 7 days (interquartile range, 7-14), show no evidence of a difference in pain control between anesthetics and placebo at 24 h in post-trauma cases. Self-reported pain at 24 h is reduced with anesthetics plus topical nonsteroid anti-inflammatory drug in post-surgical participants (mean difference [MD], -5.72 on a 10-point scale; 95% CI, -7.35 to -4.09; 1 RCT; 30 participants) and at 48 h with anesthetics alone in post-trauma participants (MD, -5.68; 95% CI, -6.38 to -4.98; 1 RCT; 111 participants). Anesthetics are associated with 37% increased risk of non-healing defects (risk ratio, 1.37; 95% CI, 0.78 to 2.42; 3 RCTs; 221 post-trauma participants). All evidence is of very low certainty. Over 50% of trials have an overall high risk of bias.

Available evidence is insufficient to support outpatient use of topical anesthetics for corneal abrasions with respect to pain, re-epithelialization, and complication risk.