Purpose
Brown Syndrome, or superior oblique (SO) tendon sheath syndrome, is characterized by overaction of the SO tendon, seen clinically as a restriction of elevation above midline in adduction. Surgical management is necessary in patients who demonstrate a significant vertical deviation in primary gaze or an anomalous head positioning (AHP) in order to maintain binocular fusion. Classical treatment includes complete SO tenectomy, recession, and spacer tenotomy. These procedures are limited by inconsistent results including scarring, under-elevation in adduction and persistent diplopia. The use of SO posterior 7/8ths tenectomy has shown to be effective in minimizing complications such as loss of torsional function and SO palsy. The purpose of this study is to evaluate the effect of SO posterior 7/8ths tenectomy on AHP in patients with Brown Syndrome.
Methods
Retrospective chart review was conducted from 2003 to 2014 for patients with Brown Syndrome and an anomalous head positioning who underwent ipsilateral SO posterior 7/8ths tenectomy. Brown Syndrome was confirmed intra-operatively through forced duction testing.
Results
A total of 8 patients (3 male) met inclusion criteria. The mean age at surgery was 43 +/- 21 months (median 37, range 17 to 79 months). Of the 8 patients, 6 had simultaneous horizontal muscle surgery. All had SO overaction with the inability to elevate past midline in adduction.<br /> Mean pre-operative vertical deviation in primary gaze was 6.4 prism diopters (PD) +/- 4.4, range 2 to 16 PD.<br /> At the most recent postoperative visit, 6 patients (75%) had complete resolution of their AHP (5 following initial surgery and 1 following reoperation). Two patients had mild persistent AHP, but were improved from preoperative evaluation. No patient had restored elevation past midline in adduction.<br /> Mean post-operative vertical deviation in primary gaze was 1.0 PD +/- 2.8. (p <0.01)<br /> Average post-operative follow-up was 32 months. No surgical complications were noted.
Conclusions
Our study demonstrates that SO posterior 7/8ths tenectomy is an effective procedure for improving both AHP and vertical deviation in primary gaze in Brown syndrome. All patients improved from their initial AHP. This approach should be considered to potentiate binocular fusion in these patients.