An adult patient with double vision

A 27-year old Nepali man presented with a four-day history of fever, vomiting and horizontal diplopia. There was no history of trauma. The patient has esotropia of the left eye or what is commonly known as a squint or strabismus. The squint is an inward squint (synonyms include convergent squint or esodeviation of the eye). Esotropia is a condition where either one or both eyes are turned inward. Congenital esotropia, often seen in infants below six years old, may give rise to amblyopia. Accommodative esotropia is common among patients with moderate amounts of hypermetropia or hyperopia. Esotropias can be concomitant, where the degree of deviation is independent of the direction of the gaze, or incomitant, where the degree of deviation is influenced by the direction of the gaze. This patient had incomitant esotropia as the squint was revealed when he was asked to look to the left. A comprehensive step-bystep approach to a patient presenting with a squint has been described extensively in literature