Duane—minus (Duane sine retraction and Duane sine limitation): possible incomplete forms of Duane retraction syndrome

Purpose To report ocular motility patterns that mimic, but do not fulfil the full clinical picture of Duane retraction syndrome (DRS) and to describe their clinical features and surgical management. Methods This is a retrospective case series study conducted on patients with DRS, mimicking non-comitant exotropia or esotropia and a face turn. Patients were included only if they lacked either globe retraction on adduction (sine retraction) or limitation of adduction or abduction on ductions (sine limitation not >0.5). Any overshoots or pattern strabismus was recorded. The ocular motility and alignment, details of surgery and their surgical outcomes were analysed. Results Twenty-one patients were identified; 13 in the sine retraction and 8 in the sine limitation group. All patients presented with a compensatory face turn. Overshoots were present in 10 (77%) and 7 patients (88%) in the sine retraction and sine limitation groups, respectively. Forced duction test showed tightness of the ipsilateral medial and the ipsilateral lateral rectus muscle in esotropic ( n = 3) and exotropic patients ( n = 18), respectively. Orthotropia was achieved in 82% of patients following ipsilateral medial or lateral rectus muscle recession. Conclusions There is a subset of patients who present with motility pattern similar to DRS but lack its complete diagnostic criteria. The presence of a face turn, overshoots on adduction or an ipsilateral tightness of the affected muscle should make one consider DRS sine retraction/sine limitation. The patients in our study responded well to lines of management similar to those of DRS.