Adjustable Superior Oblique Tendon Spacer with Application of Nonabsorbable Suture for Treatment of Isolated Inferior Oblique Paresis

Abstract

To evaluate and report the outcomes of a superior oblique tendon spacer procedure using nonabsorbable adjustable sutures in patients with inferior oblique (10) paresis. This interventional case series included 6 eyes of 6 patients with 10 paresis. All met Bielschowsky/Parks Three-step Test criteria to identify an isolated 10 paresis. In all patients, the superior oblique tendon was exposed; 2 nonabsorbable polyester sutures were placed 3 mm apart, and the tendon was cut. With the use of a slipknot, the cut ends of the tendon were separated 5 to 7 mm. Tendon separation was adjusted intraoperatively according to the fundus torsion and exaggerated traction test. The mean duration of follow-up was 8.1 months (range, 5-12 [corrected] months). Four patients had congenital 10 paresis and 2 had iatrogenic 10 paresis following denervation/myectomy of 10. Mean primary position hypotropia improved from 15.2 prism diopters (PD) before surgery to 2.7 PD in congenital 10 paresis and from 11.5 PD to 2.5 PD in iatrogenic 10 paresis. In congenital 10 paresis, mean preoperative superior oblique overaction and 10 underaction was +2 and -2, which decreased to 0 and -1.25 respectively; fundus incyclotorsion resolved in all patients. Superior oblique overaction and 10 underaction improved in iatrogenic 10 paresis as well. In no patient did an overcorrection develop. The adjustable superior oblique tendon suture spacer procedure is an effective and safe option for correcting 10 paresis without developing iatrogenic superior oblique paresis.