Adjustable superior oblique tendon spacer with application of nonabsorbable suture for treatment of isolated inferior oblique paresis

Purpose To evaluate and report the outcomes of a superior oblique tendon spacer procedure using nonabsorbable adjustable sutures in patients with inferior oblique (IO) paresis. Methods This interventional case series included 6 eyes of 6 patients with IO paresis. All met Bielschowsky/Parks Three-step Test criteria to identify an isolated IO 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. Results The mean duration of follow-up was 8.1 months (range, 5-12 months). Four patients had congenital IO paresis and 2 had iatrogenic IO paresis following denervation/myectomy of IO. Mean primary position hypotropia improved from 15.2 prism diopters (PD) before surgery to 2.7 PD in congenital IO paresis and from 11.5 PD to 2.5 PD in iatrogenic IO paresis. In congenital IO paresis, mean preoperative superior oblique overaction and IO underaction was +2 and −2, which decreased to 0 and −1.25 respectively; fundus incyclotorsion resolved in all patients. Superior oblique overaction and IO underaction improved in iatrogenic IO paresis as well. In no patient did an overcorrection develop. Conclusions The adjustable superior oblique tendon suture spacer procedure is an effective and safe option for correcting IO paresis without developing iatrogenic superior oblique paresis.