Dissociated vertical deviation: Simplified

Dissociated vertical deviation (DVD) is not a well-understood ocular motility disorder. It is defined as an intermittent anomaly of a non-fixing eye consisting of upward excursion, ex-cyclotorsion, and lateral deviation. It can present as latent or manifest deviation. It is usually bilateral, asymmetrical, and often associated with latent nystagmus and infantile esotropia. In unilateral cases, it can be associated with amblyopia. Binocular vision is usually absent in these patients. There are huge variations in the measurements of DVD, as it becomes visible only with one eye covered, hence making quantification of its magnitude difficult. Therefore, choosing an adequate management option is difficult. Management options include both conservative as well as surgical treatment. Conservative management is done with spectacles correction to encourage fusion. Surgical management is indicated in large, frequent DVD or with anomalous head posture. Surgical options commonly adopted are superior rectus recession with or without posterior fixation sutures. Different surgical approaches to DVD are currently being used but no recommended guidelines are available, hence is based on the amount of deviation and experience of a surgeon.