Evaluation techniques for paretic vertical strabismus

Vertical strabismus can be associated with paretic or restrictive causes. Paretic causes may be due to a weak muscle or paresis, or to a total lack of muscle function caused by a third, fourth or sixth cranial nerve palsy. When examining a patient with vertical strabismus, it is paramount that we differentiate between a restricted cause and paretic cause. This paper discusses the nonsurgical techniques used in evaluating paretic vertical strabismus. There are no easy methods, and evaluation techniques can vary depending on the cooperation of the patient. It is essential to look at versions and ductions, pattern strabismus, measure in all positions of gaze and evaluate torsion. We know that measuring strabismus, especially in children can be challenging. Afew different tests and techniques are discussed. A review of the literature regarding the different evaluation techniques for vertical strabismus were collated and analyzed.