Clinical presentations, complications, and outcomes of benoxinate topical ophthalmic anesthetic abuse: a retrospective cohort study

Abstract Background Topical anesthetic abuse is a concerning ophthalmic morbidity that may lead to irreversible visual loss. The primary goal of this study was to compare the clinical presentations, complications, healing duration and visual acuity changes between topical ophthalmic anesthetic users and non-users after superficial corneal trauma. The secondary goal was to correlate different variables related to the use of topical ophthalmic anesthetics with the final clinical outcomes. Methods This retrospective cohort study reviewed files of patients with a positive history of superficial corneal trauma at Alexandria Ophthalmology Hospital Cornea Clinic, Alexandria, Egypt, between January 2021 and January 2026. Patients were divided according to the use of benoxinate eye drops into two groups (benoxinate users and benoxinate non-users). Data extracted included the patient’s job, the cause of the initial injury, the use of topical ophthalmic anesthetic (duration, frequency, and continuation after presentation), clinical picture, complications, healing duration, and visual outcomes. Results A total of 181 eyes in 147 patients was included, 84 eyes in benoxinate users and 97 eyes in benoxinate non-users. Welders (76.2%), and males (89.3%) predominated in the benoxinate group ( p < 0.001). The mean duration of benoxinate use was 11.67 (2–50) days. Clinical manifestations, particularly corneal melting (15 eyes, 17.9%), eyelid contact dermatitis (9 eyes, 10.7%), ring infiltration (26 eyes, 31.0%), complications as corneal vascularization (7 eyes, 8.3%), and perforation (17 eyes, 20.2%) were significantly higher in benoxinate users. Mean difference in visual acuity before and after treatment was significantly lower in benoxinate users (0.18 ± 0.25) than in benoxinate non-users (0.34 ± 0.23), ( p < 0.001). Mean healing duration was markedly longer in benoxinate users (41.05 (4– 100)) days compared with the benoxinate non-users (7.93 (3–21)) days ( p < 0.001). Adherent leukoma was observed only in patients who continue using benoxinate after starting treatment (15 eyes, 48.4%). Conclusions Abusing topical ophthalmic anesthetics is associated with severe, permanent, and sight-threatening outcomes. Frequent and prolonged use of topical ophthalmic anesthetics aggravates ocular complications, and delays healing.