Overview and comparison of screen test methods used in quantifying ocular motility disorders

In much the same way as a formal visual field test using a perimeter can document and quantify a visual field defect, so can plotting the limited range of motion of extraocular muscles on a screen at a fixed distance provide a graphic pattern for interpretation and a quantified baseline for subsequent comparison. Classic patterns may be recognized in both examples, such as a homonymous hemianopia in a visual field defect or an incomitant esotropia from abducens palsy in a motility defect. Both techniques permit the examiner to interpret the results in a graphic rather than strictly numerical fashion and aid in differential diagnosis. More accurate sequential follow-up is provided to document progression, recovery, or stability of the condition and assist in its medical or surgical management.