Botulinum Toxin for the Treatment of Nystagmus Associated with Exotropia

Purpose: Nystagmus can severely impact the visual function, lifestyle and quality of life of patients. Patient with Nystagmus may assume an abnormal compensatory head position and it can result in posture disorders. Botulinum toxin is an important treatment for much pathology of the eye, in particular for blepharospasm, strabismus and nystagmus. The mechanism of action is to prevent lease of acetylcholine in the neuromuscular junction getting the neuromuscular blockade and transient flaccid paralysis. The objective of this work is to evaluate the efficacy of botulinum toxin injection in patients with Nystagmus. Methods: n. 6 patients, (3 females and 3 males) aged 17 - 35 years, exhibiting exotropia (XT) associated with Nystagmus received an injection of Botulinum Toxin A Dysport (Ipsen) in the Lateral Muscles of each eye with a 27-gauge retrobulbar needle. Patients underwent an orthoptic and ophthalmic eye exam before and after surgery. Results: A significant reduction of the nystagmus in primary position was reported in all patients; the abnormal position of the head was noticeably reduced. Side-effects were limited and well tolerated by the patients. Conclusion: Botulinum toxin injection is a valuable treatment of Nystagmus associated with exotropia.