Miller Fisher syndrome (MFS) is a variant of Guillain-Barré syndrome and is characterised by a clinical triad of ophthalmoplegia, ataxia and areflexia. This report presents an atypical case of MFS characterized by ocular and gastrointestinal involvement, and anti-ganglioside antibody-positivity. A 17-year old boy was referred to our ophthalmology emergency room with signs and symptoms of diplopia and upper lid ptosis of the right eye. He underwent a complete ophthalmologic examination with special reference to strabologic status, as well as a neuropediatric examination with serum antiganglioside antibody panel. Strabologic examination showed horisontal diplopia (near and far), ptosis of the upper eyelid on the right and bilateral ophthalmoplegia (limited elevation). Orthoptic examination revealed esotropia of 8 prism dioptres (PD) at near and 18 PD at far distance. A pediatric neurologist found normal limb power, deep tendon reflexes and flexor plantar responses, but attenuated right patellar reflex. Serum anti-GQ1b IgG (+++), anti-GQ1b IgM (++) and anti-GD1a IgM(++) were positive. Positivity of anti-GQ1b IgG antibody confirmed the existence of incomplete MFS. We treated the patient with systemic intravenous immunoglobulins for five days, and after five months of follow-up, all symptoms resolved. MFS can present itself as a wide range of clinical features and its timely recognition is important. Despite the alarming nature of the disease, patients with MFS tend to have a good recovery of presented symptoms, and without any significant residual deficit.

In this chapter, we intend to present the disease entity, which will include definition, types of exodeviation, symptoms, etiology, risk factors and nonsurgical treatment, as well as surgical management. The types of exodeviations that will be included are pseudoexotropia, exophoria, intermittent exotropia, sensory exotropia, and consecutive exotropia. We will also write about diagnosis of the disease itself, which includes the basics of a strabological examination. There will be special attention paid to the intermittent exotropia considering that intermittent exotropia is the most common type of exodeviations, with a special focus on its treatment. Postoperative treatment options will also be topic to discuss.