Bilateral Duane’s syndrome OMC unit

Case presentation

Duane’s retraction syndrome Core problem – LR has double innervation 3rd nerve & 6th nerve  MR & LR co-fire on aDduction - determines retraction Clinical presentation depends on: how aberrant is LR innervation [% of 3rd vs. % of 6th] How tight the MR / LR become

Usual pattern: “Type 1” restricted ABduction some ET some retraction ET retraction on ADduction Limitation of ABduction Face turn ABduction restricted  LR innervation tight MR ‘chronic ET ADduction restricted tight LR

Clinical presentation depends on balance of abnormal innervation to LR LR innervation 3 N 6N 30% 70% ET – less Some retraction on ADduction LR innervation 3N 6N 70% 30% ET more More retraction on ADduction ABduction restricted LR innervation tight MR ‘chronic ET’ ADduction restricted tight LR

TREATMENT Traditional: ipsi MR recession. No long term follow up Strabismus specialists rarely do this  iatrogenic “Type 3” Usual surgery: contralateral MR Rc, or transposition of SR & IR Up & downshoot ipsi LR Rc & split Severe retraction LR fixation to periosteum & SR - IR transposition