Superior Rectus Transposition in the Management of Duane Retraction Syndrome: Current Insights

Abstract

Various surgical approaches have been described for the management of Duane retraction syndrome (DRS), a type of congenital cranial dysinnervation disorder (CCDD), the goals of which include correcting the primary position deviation and abnormal head posture (AHP), minimizing globe retraction and overshoots and improving the ocular rotations. Vertical rectus transposition (VRT) is one such technique, found more effective in improving abduction and thereby expanding the field of binocular vision, as compared to horizontal muscle surgery. VRT, however, is associated with the risk of inducing vertical deviations and also poses a risk for development of anterior segment ischemia. To overcome these concerns, transposition of only the superior rectus to the lateral rectus was proposed and evaluated to reveal improvement in alignment, AHP and motility comparable to VRT but with lesser surgical time and fewer post-operative complications. With promising results in the management of DRS, superior rectus transposition (SRT) has been extensively studied and has evolved over the last decade with several modifications to further increase the efficiency and reduce the risk of post-operative complications. This article focusses on the pre-operative considerations while planning SRT in DRS, various approaches and surgical techniques described, and the outcomes and complications of SRT in DRS. The role of SRT in the management of other CCDDs may be explored with further studies.

Superior Rectus Transposition Surgery: Safety, Efficacy, and Place in Therapy

“…6 Negalur et al mentioned some absolute and relative contraindications for SRT, such as exotropia in adduction or severe globe retraction. 4 In our opinion, there is no absolute contraindication for SRT use in esotropic DRS, esotropic Mobius syndrome, and sixth nerve palsy. As will be mentioned in the next parts of the article, the change in globe retraction is minimal after SRT.…”

“…SRT can be used for surgical treatment of unilateral or bilateral esotropic DRS, esotropic Mobius syndrome, and sixth nerve palsy. 4 Among sixth nerve palsy cases, the best candidates for SRT are cases with no LR force and abduction limitation of −4 or higher. 5 There are rare reports of nasal SRT in the treatment of XT.…”

“…Fornix or limbal incision was used to expose the SR muscle. 4 The attachments between SR muscle and levator palpebrae and superior oblique muscle were dissected. 5 The SR muscle was then sutured with 6/0 polyglactin 910 sutures.…”

“…5 The sole relative contraindication in our practice is presence of preoperative intorsion in fundus or double Maddox rod testing. 4 Since SRT can induce incyclotorsion, the cases with preoperative intorsion are at risk of postoperative torsional diplopia. [9][10][11] Therefore, although we prefer use of SRT in some circumstances, no other contraindications to its use exists in our practice.…”

“…5 An augmentation suture with 6/0 polyester was used in most studies. 4 The augmentation suture was passed through the sclera, 6-12 mm posterior to the insertion of LR, incorporating one-third or one-fourth of the SR width. 5 In some studies, SR and LR were tied together, with no scleral pass.…”