Botulinum Toxin Dosage for Strabismus

Condition	Units
Horizontal Strabismus*- under 25 PD	2.5
Horizontal Strabismus- over 25 PD	2.5-5.0
6th Nerve Palsy- Injection into Medial Rectus
Early- 1-3 months	1-2
Later with transposition or Medial contracture	2.5
Vertical Muscles
Inferior Rectus for comitant deviation	2.5
Inferior Rectus for thyroid	5
Inferior Oblique	2.5
Superior Rectus (rare)	2
Other indications
Children with Infantile esotropia or exotropia (bilateral injections)	2.5
Weak Muscles: Myasthenia, external ophthalmoplegia, aberrant regeneration, cerebral palsy	1-2
Retrobulbar injection for nystagmus	25

smaller doses for medial rectus, larger for lateral rectus and smaller doses for small women
From: McNeer, Magoon and Scott. Chemodenervation Therapy: Technique and Indications in Clinical Strabismus Management p.428