Superior Oblique Posterior Tenectomy Research Articles

Factors influencing the result of superior oblique weakening procedures in patients with superior oblique overaction in horizontal strabismus

BackgroundFew studies have evaluated the surgical outcome of superior oblique weakening procedures in patients with superior oblique overaction associated with exotropia or esotropia. This study aimed to evaluate the outcome of superior oblique muscle weakening and the influencing factors in patients with superior oblique overaction.MethodsThe medical charts of 37 patients (55 eyes) with superior oblique overaction associated with esotropia or exotropia who were treated with a superior oblique weakening procedure at the Seoul National University Hospital from January 2010 to June 2017 were retrospectively reviewed. Superior oblique overaction was graded using, a 6-point scale ranging from + 0.5 to + 3, and pre- and postoperative grades were recorded for all patients.ResultsThe mean age of the patients was 91.81 ± 59.37 months. Superior oblique muscle suture spacer and superior oblique posterior tenectomy were performed for 17 (23 eyes) and 20 (32 eyes) patients, respectively. Surgical success was achieved in 15 (65.2%) eyes in the suture spacer group and 23 (71.9%) eyes in the posterior tenectomy group. Surgical success was achieved for 69.1% (38/55 eyes) of patients. Dissociated vertical deviation exhibited a significant negative association with the surgical success rate (p < 0.001).ConclusionsThere was no significant difference in surgical success rate between the superior oblique posterior tenectomy and superior oblique suture spacer groups in superior oblique overaction associated with horizontal strabismus. Associated dissociated vertical deviation can affect the surgical success of the superior oblique weakening procedure.

The efficacy of superior oblique posterior tenectomy in the treatment of A-pattern exotropia without ocular intorsion: A retrospective study

BackgroundSuperior oblique weakening is a common method to treat A-pattern strabismus. This study aims to evaluate the surgical results of the bilateral superior oblique posterior tenectomy procedure to treat A-pattern strabismus patients who had bilateral superior oblique overaction without objective ocular intorsion.MethodsThe records of 18 consecutive patients who underwent surgery of superior oblique posterior tenectomy close to its insertion with superior oblique overaction (SOOA)-associated A-pattern strabismus between September 1, 2015 and August 31, 2018 were retrospectively reviewed. Ocular alignment, objective torsion, A-pattern and ocular motility were assessed. Ocular alignment was measured in the primary position, 25° upgaze, and 25° downgaze using the prism bar cover test, and torsion was measured using fundus photographs.ResultsA total of 18 patients (mean age: 15 years; 6 female, 12 male) underwent bilateral superior oblique posterior tenectomy and simultaneous horizontal rectus muscle surgery were included. The mean preoperative A-pattern deviation was 15 PD and the mean postoperative A-pattern deviation was 2.25 PD with a mean reduction of 12.75 PD. The mean preoperative superior oblique overaction was 2.28 and the mean postoperative superior oblique overaction was 0.43 with a mean reduction of 1.85. There was no significant correlation between the ocular torsional, vertical alignment change and the superior oblique posterior tenectomy procedure.ConclusionsSuperior oblique posterior tenectomy surgery selectively improved the A-pattern and superior oblique overaction but not affect the primary position vertical deviation, as well as the ocular torsion. It is an effective procedure to treat the mild to moderate superior oblique overaction associated A pattern strabismus without ocular intorsion.

The Role of Superior Oblique Posterior Tenectomy Along With Inferior Rectus Recessions for the Treatment of Chin-up Head Positioning in Patients With Nystagmus.

To evaluate the clinical outcomes of bilateral superior oblique posterior 7/8th tenectomy with inferior rectus recession on improving chin-up head positioning in patients with horizontal nystagmus. Medical records were reviewed from 2007 to 2017 for patients with nystagmus and chin-up positioning of 15° or more who underwent combined bilateral superior oblique posterior 7/8th tenectomy with an inferior rectus recession of at least 5 mm. Thirteen patients (9 males and 4 females) were included, with an average age of 7.3 years (range: 1.8 to 15 years). Chin-up positioning ranged from 15° to 45° degrees (average: 30°). Three patients had prior horizontal muscle surgeries, 1 for esotropia and 2 for horizontal null zones causing anomalous face turns. Ten patients underwent other concomitant eye muscle surgery: 3 had esotropia, 1 had exotropia, and 2 had biplanar nystagmus null point requiring a horizontal Anderson procedure. Four patients underwent simultaneous bilateral medial rectus tenotomy and reattachment. All patients had improved chin-up positioning. Eight patients had complete resolution, whereas 5 had minimal residual chin-up positioning. Three patients developed an eccentric horizontal gaze null point with compensatory anomalous face turn with onset 2 weeks, 2 years, and 3 years postoperatively. Average follow-up was 42.7 months. No postoperative pattern deviations, cyclodeviations, or inferior oblique overaction were seen. No surgical complications were noted. Bilateral superior oblique posterior 7/8th tenectomy in conjunction with bilateral inferior rectus recession is a safe and effective procedure for improving chin-up head positioning in patients with horizontal nystagmus with a down gaze null point. [J Pediatr Ophthalmol Strabismus. 2018;55(4):234-239.].

The role of superior oblique posterior tenectomy for treatment of small vertical deviations in Brown syndrome

The role of superior oblique posterior tenectomy for treatment of small vertical deviations in Brown syndrome

Bilateral posterior tenectomy of the superior oblique muscle for the treatment of A-pattern strabismus

To evaluate the efficacy of bilateral posterior superior oblique tenectomy for the treatment of A-pattern strabismus due to superior oblique overaction regardless of the magnitude of the pattern. The medical records of patients with A-pattern esotropia or exotropia in the presence of superior oblique overaction who underwent combined horizontal muscle surgery along with bilateral superior oblique posterior 7/8 tenectomy from 2003 to 2013 were retrospectively reviewed. Patients with at least 3 months' follow-up were included. A total of 73 patients were included. Of these, 46 had esotropia; 27, exotropia. The preoperative A-pattern deviation for the study population was 19.6(Δ) ± 11.4(Δ) (range, 10-60), with a final postoperative patten collapse of 18.2 ± 3.6. Superior oblique overaction was 2.3 ± 0.7 preoperatively and 0.3 ± 0.7 postoperatively. Overall, 87.7% of patients had a successful collapse of their pattern to <10(Δ) following the initial bilateral superior oblique posterior tenectomy, with an additional 4.1% following a second procedure. Of patients with a pattern deviation of <25(Δ), 87.9% had successful collapse of the pattern following 1 surgery, and 86.7% of patients who had a pattern of ≥25(Δ) had successful collapse. Postoperatively, 7 patients demonstrated mild inferior oblique overaction. No surgical complications were noted. A uniform dose of bilateral posterior 7/8 tenectomy surgery successfully collapses A-pattern deviations of all magnitudes.

Effect of 10-mm Superior Oblique Posterior Tenectomy Combined with Frenulum Dissection in A-Pattern with Superior Oblique Overaction

To evaluate the effect of 10-mm tenectomy of the posterior fibers of the superior oblique (SO) tendon combined with dissection of the frenulum for correction of A-pattern deviation and vertical deviation with SO overaction. Retrospective, interventional case series. Seventy-five patients with A-pattern strabismus associated with SO overaction who underwent surgery between March 1, 2004 and August 31, 2007. Retrospective analysis of A-pattern strabismus patients with SO overaction who underwent unilateral or bilateral 10-mm SO posterior tenectomy combined with frenulum dissection and who underwent at least 12 months of follow-up. The mean preoperative amount of A-pattern for all patients was 21.20 +/- 7.25 prism diopters (PD), with a mean postoperative collapse of 17.63 +/- 5.33 PD (range, 10 to 30 PD), which was statistically significant (P = .001). After surgery, the mean A-pattern correction was 22.12 +/- 6.30 PD in the group that underwent bilateral posterior tenectomy and 13.33 +/- 5.20 PD in the group that underwent unilateral posterior tenectomy. The mean degree of preoperative vertical deviation in the group that underwent unilateral posterior tenectomy was 11.50 +/- 3.96 PD, and the mean correction was 9.21 +/- 4.22 PD (P = .01). There were no surgical complications, except in 5 patients, who manifested mild inferior oblique overaction. We believe that 10-mm SO posterior tenectomy combined with frenulum dissection effectively collapses A-pattern deviation of less than 25 PD with mild to moderate SO overaction and reduces associated vertical deviation of 10 PD.

Surgical management of dissociated vertical deviation associated with A-pattern strabismus

Dissociated vertical deviation (DVD), pattern strabismus, and oblique muscle dysfunction frequently coexist, and the recognition of bilaterality, symmetry, and lateral incomitance is important in selecting appropriate surgical management. In this study, we compare 3 different surgical approaches in patients with DVD associated with A-pattern strabismus. This was a retrospective review of 40 consecutive patients with DVD and A-pattern strabismus who underwent strabismus surgery. Bilateral superior rectus muscle recession was performed in 9 patients, bilateral superior rectus recession and superior oblique posterior tenectomy were performed in 14 patients, and bilateral superior oblique temporal tenotomy and inferior oblique recession were performed in 17 patients. Bilateral superior rectus muscle recession corrected 7(Delta) +/- 2(Delta) of A pattern, 10(Delta) +/- 3(Delta) of vertical deviation and 4(Delta) +/- 2(Delta) of DVD asymmetry. Bilateral superior rectus muscle recession combined with superior oblique posterior tenectomy corrected 17(Delta) +/- 3(Delta) of A pattern, 10(Delta) +/- 2(Delta) of vertical deviation, and 4(Delta) +/- 2(Delta) of asymmetry. Bilateral superior oblique muscle temporal tenotomy combined with inferior oblique recession corrected 30(Delta) +/- 4(Delta) of A pattern, 9(Delta) +/- 3(Delta) of vertical deviation, and 2(Delta) +/- 2(Delta) of asymmetry. In patients with DVD and A patterns, the size of the A pattern and the symmetry of the DVD are of major importance for surgeons determining appropriate procedures. Bilateral superior rectus muscle recession corrects small amounts of A pattern. Larger amounts of A pattern require additional superior oblique weakening or weakening of all four oblique muscles. superior rectus muscle recession is warranted if the asymmetry is larger than 5(Delta).

Superior Oblique Posterior Tenectomy in Patients With Brown Syndrome with Small Deviations in the Primary Position

Procedures used to weaken the superior oblique muscle (SO) tendon in the treatment of patients with Brown syndrome, may result in severe complications, including complete SO palsy, overcorrections, foreign body extrusion, and scarring with limitation to ocular rotations. SO posterior tenectomy moderately weakens abduction and depression while preserving most of the torsional action of the SO muscle. We sought to evaluate motor and sensorial results after SO posterior tenectomy in patients with Brown syndrome who had a small vertical deviation (less than 7 prism diopters [PD]) in primary position but severe limitation to elevation in adduction. We retrospectively analyzed 12 consecutive patients with unilateral Brown syndrome who underwent a 15 mm tenectomy of the posterior four-fifths fibers of the ipsilateral SO tendon. Intraoperative forced duction showed restriction to elevation in adduction in all subjects. No patient had concomitant surgery on any other extraocular muscle. The mean patient age at diagnosis was 6.9 +/- 1.7 years. Preoperative vertical deviation measured 4 +/- 1 PD in the primary position and 12 +/- 2 PD in elevation in adduction. Postoperative follow-up was 24.7 +/- 9.2 months. Postoperatively, all patients had less than 2 PD of orthotropia in the primary position, and the deviation in elevation in adduction was significantly improved at 3 +/- 2 PD (P < 0.05). Elevation in adduction improved from -4.0 preoperatively to -1.9 +/- 1 postoperatively (P = 0.0000003) and no patient experienced underaction of the SO. Postoperatively, all patients had stereopsis in primary position. The use of SO posterior tenectomy improves alignment and ocular rotations in patients with Brown syndrome, resulting in fusion, small vertical deviation in primary position, and minimal-to-no anomalous head posture, in whom the most important finding is a disfiguring downshoot on attempted adduction. Other advantages include minimal-to-no postoperative SO muscle underaction and no risk of foreign body extrusion, fibrosis, and scarring.