Botox could be used in the management of both Epiphora & Dry Eye !!!
Botulinum neurotoxin (BoNT) is the first biological toxin used in the treatment of ophthalmic diseases. When used appropriately, it weakens the force of muscular contraction and/or inhibits glandular secretion.
Botulinum toxin-A has shown satisfactory results in lacrimal gland tearing disorders.
■The lacrimal gland is innervated by the cholinergic fibers of seventh cranial nerve. Injection of botulinum toxin-A (BTA) in the lacrimal gland decreases tear production by blocking presynaptic release of acetylcholine into neuromuscular end plates of cholinergic nerve fibers.
The indications include gustatory hyper lacrimation, refractory proximal bicanalicular obstruction, irreversible loss of lacrimal drainage system post trauma or post dacryocystectomy, multiple failed dacryocystorhinostomy, post punctal cautery, and functional epiphora.
Injection of 2.5–5 units of botulinum toxin type A into the palpebral lobe of the lacrimal gland results in a clinically significant reduction in tear production and improvement in symptoms in the majority of patients.
BTA injection in the lacrimal gland is devoid of the risks and complications of an invasive surgery and general anesthesia. Injection can be performed in an outpatient clinic. This technique is easy, minimally invasive, and less time consuming, compared with surgery. However, its effect is transient .
BTA injection in the lacrimal gland has led to high success rates in improving lacrimal outflow obstruction in elderly patients, in poor surgical candidates or in those unwilling to have surgery.
■BTA can be used for managing dry eye as well. Injections used for dry eye treatment cause reduction in lacrimal drainage function by paralyzing the orbicularis oculi muscle, decreasing blinking and the lacrimal pump. It is injected into the medial lower eyelid near the punctum.
proper patient selection, dosing and site of application as important factors for successful therapy with the lowest risk of complication.