The use of botulinum toxin A in the treatment of functional epiphora

The purpose of this study was to investigate the hitherto undescribed effects of botulinum toxin A injected into the lacrimal gland in patients with functional epiphora.

A prospective non-comparative interventional case series study was designed to include patients with functional epiphora who presented to the Oculoplastic unit at the Wolverhampton and Midland Counties Eye Infirmary. Botulinum toxin A (2.5-5 units) was injected into the palpebral lobe of the lacrimal gland on the worst affected side via a transconjunctival approach under topical anaesthesia. Patients underwent a Schirmer test and provided a subjective evaluation of their epiphora symptoms, indoors and outdoors, at baseline and at 1, 4 and 13 weeks after injection. The mean score for symptoms indoors and outdoors was calculated.

Fourteen patients agreed to take part in the study. Subjective epiphora scores improved in 8 out of the 11 patients (72.7%) who completed 13 weeks of follow-up. Schirmer test results showed objective reduction in tearing from baseline but did not strongly correlate with the subjective epiphora scores. Transient mild ptosis and diplopia were experienced by two patients.

The results from this small pilot study are encouraging, although larger, controlled trials are needed to assess the optimal dose of BTX-A, its long-term efficacy and safety, and the role of multiple injections.