COMBINED LATERAL RECTUS RESECTION AND MEDIAL RECTUS RECESSION FOR UNILATERAL TYPE 1 DUANE RETRACTION SYNDROME: A PROSPECTIVE INTERVENTIONAL STUDY

Abstract

Purpose: The aim of current study was to estimate the effectiveness and complication rates of a small amount of resection of lateral rectus (LRR) blended with recession of medial rectus (MRR) performed in severe esotropia in patients with unilateral Type 1 Duane Retraction Syndrome (DRS).

Methods: Nine-teen consecutive patients (age 15.37 ± 11.03 years) with unilateral Type 1 DRS, more than or equal to 25 PD esotropia and severe (−3) restrictions of abduction were selected for the study and those with significant retraction of globe or leash phenomenon preoperatively were omitted. All were operated under combined surgery comprised of 4–6 mm MR recession, and 2–4.5 mm LR resection. Primary outcomes were extent of esotropia correction and margin of abduction improvement at 12 weeks after surgery, with abnormal posture of the head (AHP) and grade of globe retraction being the secondary ones.

Results: Pre-surgery esotropia (33.42 ± 6.25 PD) fell to 0.11 ± 0.46 prism dioptre at  week 12 post-op (p < 0.001). The mean decrease in abduction restriction (ranging from -2 moderate abduction limitation to 0 no restriction) from -2.16 to −0.39 (p<0.001). There were no reported cases with progression and the median grade of globe-retraction  changed from 1 (mild) to 0 (none) (Z = −3.035, p = 0.002). 66.7% of the patients with abnormal head posture improved (p < 0.05). Repeated-measures ANOVA verified that there were no differences in the gains in alignment between postoperative visits (F = 424.19, p < 0.001).

Conclusion: MR resection of moderate amplitude and limited LR resection (<4.5 mm) was very effective in this very select group of unilateral Type 1 DRS patients with only slight amount of retraction preoperatively. The technique provided accurate primary-position alignment and good horizontal force balance with limited globe retraction and marked improvements in abduction, which may be superior long term compared with only recession of MR.