Efficacy and Safety of Botulinum Toxin Injections for Epiphora Management: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis evaluate the efficacy and safety of lacrimal gland botulinum toxin (BTX) injection for managing epiphora.

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a comprehensive search of MEDLINE, Cochrane CENTRAL, and EMBASE databases was conducted to include studies published from 2000 to March 2024 that evaluated patients treated with lacrimal gland BTX injections for epiphora. Data extraction covered study design, patient demographics, types of BTX used, injection techniques, dosage, follow-up duration, and outcomes, including (Schirmer test and Munk scores) and adverse events. Methodological quality was assessed for each study type.

From 517 studies identified in the literature search, 19 studies met the inclusion criteria involving 415 glands injected with BTX. Schirmer test scores decreased at 3 months (mean difference = 8.80; 95% confidence interval: 5.28-12.32; p < 0.01) and at 6 months (mean difference = 5.33; 95% confidence interval: 2.77-7.90; p < 0.01). The overall incidence of adverse events was 22% (95% confidence interval: 12-32%), and ptosis (63%) and diplopia (21%) were the most common. Reinjection was more common in the functional epiphora group, with a pooled rate of 81%, compared with 43% in the nonfunctional group ( p = 0.12).

Injecting as little as 2.5 units of BTX into the lacrimal gland is effective in reducing tear production in epiphora, with sustained clinical benefits and a transient adverse event profile. These findings support its use as a nonsurgical alternative, particularly for patients ineligible for or averse to invasive procedures. Further studies are needed to refine dosing and long-term efficacy.