Exaggerated traction test for the oblique muscles.

Retroplacement and torsional manipulation of the globe during forced duction testing provide an exaggerated traction test of the oblique muscles, allowing graded evaluation of superior oblique and inferior oblique tightness. On a scale from 0 to 4 +, normal superior oblique tightness averages 1.5+, and normal inferior oblique tightness averages about 1+. The degree of superior oblique or inferior oblique tightness correlates well with clinical overaction of these muscles, allowing better distinction between oblique overaction and dissociated vertical deviation. Also, the effect of partial superior oblique tenotomy can be monitored, and a complete tenotomy can be confirmed with certainty.