A review on use of botulinum toxin for intractable lacrimal drainage disorders.

[PURPOSE] To review the published literature on botulinum toxin (BTX) for epiphora secondary to refractory lacrimal drainage disorders.

[METHODS] The authors performed a Pub Med search of all articles published in English on BTX injection into lacrimal gland for epiphora secondary to lacrimal drainage disorders. Relevant cross-references were obtained from the resultant studies. Data reviewed included demographics, indications, dose of BTX, number of injections, transconjunctival or transcutaneous route, outcomes and complications. Animal experiments of BTX into lacrimal gland were included and analyzed separately.

[RESULTS] Botulinum toxin injection into lacrimal gland, in animal studies, has shown to reduce the tear volume significantly lasting for approximately a month without any histological changes. The major indications have been refractory canalicular obstructions and functional epiphora. The commonly used dose was 2.5 U. Outcomes in the few studies published are encouraging with transient ptosis being the most common complication.

[CONCLUSIONS] Botulinum toxin into the lacrimal gland is a minimally invasive alternative in cases of refractory epiphora secondary to lacrimal drainage disorders. In these subsets of patients, the reported concentrations, dosage and outcome measures are variable and need larger studies for standardization.