An adjustable superior oblique tendon spacer with the use of nonabsorbable suture

Surgical management of Helveston syndrome (Triad exotropia)

Purpose

To evaluate and compare different surgical approaches for the treatment of Helveston syndrome and provide further information for preoperative planning.

Methods

From February 2008 to December 2018, data of 52 patients with Helveston syndrome were retrospectively reviewed. Different surgical approaches were selected based on the extent of A-pattern exotropia, dissociated vertical deviation (DVD), and both superior oblique muscle overaction (SOOA) with fundus photograph intorsion. Eye position, A-pattern, DVD, superior oblique muscle function, and binocular vision function were evaluated pre- and postoperatively. The average follow-up duration was 20.5 months.

Results

Nine cases underwent simultaneous horizontal deviation correction with bilateral superior rectus recession, 24 underwent simultaneous horizontal deviation correction with bilateral superior oblique muscle lengthening, and 19 underwent two stages of horizontal deviation correction with superior oblique muscle lengthening, and later bilateral superior rectus recession. A-pattern, DVD, SOOA, and fundus intorsion were all collapsed in all patients postoperatively. Forty-five patients had an orthophoric eye position with considerably aligned ocular movements postoperatively. The total success rate was 86.5%. Postoperatively, eight of the 10 patients with diplopia experienced a recovery of binocular single vision and three had a recovery of rudimentary stereopsis (Titmus 3000–400 s of arc). The compensatory head posture of patients improved significantly postoperatively.

Conclusions

The surgical planning of Helveston syndrome should be designed based on the degree of the A-pattern, SOOA, DVD, and the intorsion in fundus photographs, and the appropriate approach should be selected to improve patient satisfaction.

Superior oblique split tendon elongation for Brown's syndrome: Long-term outcomes

PURPOSE

To report the outcomes of superior oblique split tendon elongation in Brown's syndrome.

METHODS

Charts of 17 consecutive Brown's syndrome patients who underwent superior oblique split tendon elongation were reviewed and clinical data regarding preoperative, intraoperative, and postoperative data were collected.

RESULTS

About 17 eyes of 17 children with congenital Brown's syndrome underwent superior oblique split tendon elongation between January 2012 and March 2020 by a single surgeon. Mean age at surgery was 5.47 ± 2.82 (range 1.50-13.2). Eight (47.1%) were female. Preoperative deficit of elevation in adduction was -4 in all children. At the end of surgery, all eyes were freely elevated on adduction, on forced duction test. Mean follow-up time of 26.24 ± 11.22 (range 11-53) months. In 15 of 17 children (88.2%), motility improved, orthotropia in primary position was achieved, and head posture eliminated (p < 0.001). Superior oblique palsy occurred in two children, who after reoperation, achieved an acceptable outcome. No intraoperative complications were recorded.

CONCLUSION

The superior oblique split tendon elongation procedure is a useful surgical technique with stable and satisfying outcomes for the treatment of severe congenital Brown's syndrome.

Graded superior oblique tendon suture lengthening: A novel procedure

PURPOSE

Literature regarding different superior oblique (SO) weakening procedures showed variable results. Here, we aim to evaluate the effect of a novel superior oblique tendon suture lengthening (SOSL) procedure on weakening of SO in patients with A-pattern exotropia associated with dissociated vertical deviation and SO overaction (triad exotropia).

METHODS

The medical records of triad exotropia patients who underwent SOSL or SO tenotomy were reviewed. Surgical results of SOSL procedure mainly regarding the correction of A pattern, SO overaction, and fundus intorsion were analyzed and compared with those of SO tenotomy procedure.

RESULTS

SOSL demonstrated comparable efficacy in correction of A pattern (20.2^△ ± 10.7^△ vs 29.2^△ ± 16.1^△, p = 0.172), normalization of SO overaction (1.9 ± 0.9 vs 2.4 ± 1.5, p = 0.349), and conversion of fundus intorsion (11.1° ± 7.0° vs 11.3° ± 4.4°, p = 0.691) as SO tenotomy. Moreover, the success rate of A pattern collapse was significantly higher in the SOSL group than in the SO tenotomy group (86% vs 40%, p = 0.028). None of the patients in the SOSL group, but two in the SO tenotomy group, presented SO palsy postoperatively. In the SOSL group, the corrected magnitude of SO overaction strongly correlated with the dosage of suture lengthening (p < 0.001).

CONCLUSION

SOSL procedure could effectively eliminate the clinical manifestations associated with SO overaction. The graded dosage of SOSL leads to more controllable and predictable results compared to SO tenotomy, which makes SOSL a good alternative choice for SO weakening.

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

Background

Few 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.

Methods

The 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.

Results

The 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).

Conclusions

There 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.

Clinical evidence supporting the use of donor sclera as spacer material in complicated cases of strabismus surgery - retrospective evaluation of surgical results in 117 patients with thyroid-associated ophthalmopathy or congenital strabismus

PURPOSE

To examine the outcome of the use of donor sclera as spacer material in complicated cases of strabismus surgery.

METHODS

A retrospective cohort study on patients with complicated thyroid-associated ophthalmopathy (TAO) (n = 42) or congenital strabismus (n = 75). Patients underwent strabismus surgery during 1994-2014. The surgical results were evaluated in terms of the reduction in the angle of deviation, the need for re-operation, complications and patient satisfaction.

RESULTS

The majority of the TAO patients underwent surgery for vertical strabismus (n = 25). The vertical angle of deviation in the primary position was significantly reduced from a median of 23 prism dioptres (PD) to 2 PD (n = 35, p < 0.001). The horizontal angle of deviation in primary position for TAO patients with esotropia was significantly reduced, from a median of 35 PD to 2 PD (n = 17, p < 0.001). The majority of the congenital cases had horizontal strabismus (esotropia = 29, exotropia = 27). The angle of deviation in esotropia was reduced from a median of 29 PD to 8 PD (n = 36, p < 0.001) and in exotropia from 30 PD to 10 PD (n = 34, p < 0.001). Most of the patients were satisfied with the outcome of surgery, and only 12% required re-operation within 2 years.

CONCLUSION

This is the first clinical study on the use of donor sclera as spacer material in complicated cases of strabismus surgery. The surgical results were good in terms of the reduction in the angle of deviation, the need for re-operation, complications and patient satisfaction, supporting the use of donor sclera for strabismus surgery.

Effect of bilateral superior oblique split lengthening on torsion

INTRODUCTION

Superior oblique split lengthening (SOSL) is done for weakening of superior oblique. It corrects the superior oblique overaction (SOOA) and A pattern. Its effect on the torsion of the eye is not known. We present our data on the effect of this particular procedure on torsion.

MATERIALS AND METHODS

We did a study of 16 patients (32 eyes) who underwent bilateral SOSL and compared the disc foveal angle (DFA) preoperatively and postoperatively. The split lengthening was done from 4 mm to 7 mm depending upon the overaction of superior oblique.

RESULTS

The mean age was 15.3 ± 8.4 years. Mean preoperative DFA in the right eye (RE) was -3.9° and in the left eye (LE) was -2.9°. Mean postoperative DFA in RE was 0.2° and in LE was 0.9°. The mean change in the DFA for RE was 4.1° ± 1.3° and for LE was 3.8° ± 1.2°. All the patients were aligned horizontally within 6 prism diopter and no pattern and no diplopia postoperatively. The A pattern was corrected in all the patient postsurgery. For each mm of surgery, an improvement of 0.8° was seen in the DFA.

CONCLUSION

We report the effect of SOSL on torsion. The SOSL reduces intorsion postsurgery and is, therefore, a valuable procedure in SOOA where both pattern and in torsion needs to be corrected.

Effects of Bilateral Superior Oblique "Hang-Back" Recession in Treatment of A-pattern Strabismus with Superior Oblique Overaction

PURPOSE

To investigate the efficacy and safety of bilateral hang-back recession of superior oblique (SO) muscles in the treatment of A-pattern strabismus with superior oblique overaction (SOOA).

METHODS

Thirty-one (31) patients (62 eyes) with A-pattern horizontal deviation and SOOA underwent hang-back recession of SO and retrospective analysis of the surgical amount of hang-back recession of SO, preoperative and postoperative A-pattern, ocular motility, and corrected objective torsion. Patients were evaluated before and 6 to 9 months after surgery.

RESULTS

The average A-pattern horizontal deviation was 27.58 ± 11.47 prism diopters (PD) before surgery and 3.48 ± 3.70 PD after surgery (n=31, P<0.05). The mean corrected A-pattern was horizontal deviation 24.10 ± 10.32 PD. The average scale of SOOA on a scale of +1 to +4 was +3.05 ± 0.80 before surgery and +0.42 ± 0.50 after surgery in 62 eyes (P<0.05). The mean corrected objective torsion was 4.91° ± 4.53°. The surgical amount of SO hang-back recession ranged from 4 to 10 mm (mean: 7.62 ± 1.18 mm), which was related to the preoperative A-pattern and corrected A-pattern. There were no surgical complications.

CONCLUSIONS

SO hang-back recession is a safe and efficient option for A-pattern caused by SOOA.

Biomechanics of superior oblique Z-tenotomy

BACKGROUND

A recent report suggests that 70%-80% Z-tenotomy of the superior oblique tendon is necessary to effectively treat A-pattern strabismus associated with over depression in adduction. To clarify the clinical effect, we compared the biomechanics of Z-tenotomy on the superior oblique tendon, superior rectus tendon, and isotropic latex material.

METHODS

Fresh bovine superior oblique tendons were trimmed to 20 mm × 10 mm dimensions similar to human superior oblique tendon and clamped in a microtensile load cell under physiological conditions of temperature and humidity. Minimal preload was applied to avoid slackness. Tendons were elongated until failure following Z-tenotomies, made from opposite tendon margins, spaced 8 mm apart and each encompassing 0%, 20%, 40%, 50%, 60%, or 80% tendon width. Digitally sampled failure force was monitored using a precision strain gauge. Control experiments were performed in similar-sized specimens of bovine superior rectus tendon and isotropic latex.

RESULTS

Progressively increasing Z-tenotomy of latex caused a linearly graded reduction in force. In contrast, Z-tenotomy of up to 50% in superior oblique and superior rectus tendons caused nonlinear reduction in force transmission that reached a negligible value at 50% tenotomy and greater.

CONCLUSIONS

Z-tenotomy up to 50% progressively reduces extraocular tendon force transmission, but Z-tenotomy of ≥50% is biomechanically equivalent in vitro to complete tenotomy.

The efficacy of superior oblique Z-tenotomy in the treatment of overdepression in adduction (superior oblique overaction)

INTRODUCTION

To evaluate the efficacy of superior oblique Z-tenotomy in the treatment of overdepression in adduction (superior oblique overaction) with respect to collapse of A-pattern strabismus and normalization of versions.

METHODS

The medical records of patients who underwent bilateral superior oblique Z-tenotomy for mild to moderate overdepression in adduction and A-pattern strabismus between June 2004 and August 2010 were retrospectively reviewed. Surgical indications included mild to moderate overdepression in adduction (+2 to 3) and an A pattern of 10(Δ) to 40(Δ) between upgaze and downgaze. A monopolar electrode microdissection needle was used to make two tenotomies, 60% to 80% in width and 8 mm apart, perpendicular to the axes of the tendon in opposite directions. Surgical success included a postoperative A pattern of ≤10(Δ) and overdepression in adduction of ≤1.

RESULTS

A total of 20 patients (mean age, 9.8 years; age range, 3-34) underwent bilateral superior oblique Z-tenotomy during the study period: 2 patients (10%) with esotropia and 18 with exotropia (90%). Average decrease in pattern was 16(Δ) (range, 0(Δ)-32.5(Δ)). Success rate for pattern collapse was 78%, with resolution of overdepression in adduction of 90%.

CONCLUSIONS

Z-tenotomy of the superior oblique tendon collapsed A-pattern strabismus and normalized versions.

Comparison of superior oblique suture spacers and superior oblique silicone band expanders

PURPOSE

To compare suture spacers with silicone band expanders in superior oblique-weakening surgery.

METHODS

We retrospectively reviewed the charts of consecutive patients who had superior oblique weakening with either suture spacers or silicone expanders and had been followed for a minimum follow-up of 6 months. The ductions, versions, and the degree of fundus torsion were analyzed in all patients before and after surgery. In addition, surgery time and postoperative complications were analyzed.

RESULTS

The record review identified 25 patients, of whom 13 had been treated with superior oblique muscle suture spacers and 12 with superior oblique muscle silicone expanders. Both groups showed improved ductions and versions. In patients with Brown syndrome, complete normalization of superior oblique muscle overaction occurred in 67% of patients who had suture spacers and 67% of patients who had silicone expanders. In patients with A-pattern strabismus, normal function of the superior oblique muscle occurred in 75% of patients with suture spacers and 67% of patients with silicone expanders. Surgery time was significantly less in patients who had suture spacers. Severe orbital inflammation occurred in 1 patient around the silicone band and was managed by removal of the implant.

CONCLUSIONS

Both suture spacers and silicone expanders improved the comitance of versions and normalized superior oblique muscle function. Longer surgery time and more severe inflammatory reaction are possible drawbacks of silicone expanders.

Adjustable suture strabismus surgery

Surgical management of strabismus remains a challenge because surgical success rates, short-term and long-term, are not ideal. Adjustable suture strabismus surgery has been available for decades as a tool to potentially enhance the surgical outcomes. Intellectually, it seems logical that having a second chance to improve the outcome of a strabismus procedure should increase the overall success rate and reduce the reoperation rate. Yet, adjustable suture surgery has not gained universal acceptance, partly because Level 1 evidence of its advantages is lacking, and partly because the learning curve for accurate decision making during suture adjustment may span a decade or more. In this review we describe the indications, techniques, and published results of adjustable suture surgery. We will discuss the option of 'no adjustment' in cases with satisfactory alignment with emphasis on recent advances allowing for delayed adjustment. The use of adjustable sutures in special circumstances will also be reviewed. Consistently improved outcomes in the adjustable arm of nearly all retrospective studies support the advantage of the adjustable option, and strabismus surgeons are advised to become facile in the application of this approach.

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 (10) paresis.

METHODS

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.

RESULTS

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.

CONCLUSIONS

The adjustable superior oblique tendon suture spacer procedure is an effective and safe option for correcting 10 paresis without developing iatrogenic superior oblique paresis.

Superior oblique tendon expansion with Achilles tendon allograft for treating Brown syndrome

PURPOSE

To report the results of treatment of Brown syndrome using Achilles tendon allograft as a superior oblique tendon expander.

METHODS

Achilles tendon allografts were prepared from the tissue bank. Five eyes of 3 patients with congenital Brown syndrome (mean age, 6 years) were enrolled in the study. Surgery was performed with a superotemporal conjunctival fornix approach. The superior oblique tendon was exposed and severed; then a 2- to 3-mm-wide strip of Achilles tendon (with a thickness of 1-2 mm) was trimmed and sutured between the cut ends using double-armed 5-0 Mersilene sutures. The length of the expander ranged from 7 mm to 8 mm, depending on the severity of the disease.

RESULTS

The preoperative hypotropia in primary position ranged from 15(Δ) to 30(Δ), with abnormal head position in 1 patient. Nine months after the operation, 2 eyes with moderate Brown syndrome showed an improvement in the hypotropia to <3(Δ), and 2 eyes with severe disease had residual hypotropia of 5(Δ). Another eye with severe Brown syndrome had a residual hypotropia of 20(Δ). The elevation in adduction improved by 1 grade in 1 eye and resolved in the other 4 eyes. The amount of correction in the deviation improved with time. None of the patients developed secondary superior oblique palsy, rejection, infection, extrusion, prolonged ocular inflammation, or foreign body sensation.

CONCLUSIONS

Superior oblique tendon elongation with Achilles tendon allograft had acceptable short-term results in 4 of 5 eyes treated for Brown syndrome.

Postoperative Adjustable Surgery of the Superior Oblique Tendon

PURPOSE

To describe a surgical procedure for loosening or tightening the superior oblique (SO) tendon that enables bedside adjustment following the surgery, with surgical outcome reported.

METHODS

A permanent suture separates the two cut ends of the SO tendon, with a sliding noose for adjustment. The noose is accessed by having the patient look up or straight ahead, not down, during adjustment at the bedside. Records of 17 patients who underwent this surgery between June 2000 and January 2003 were reviewed and analyzed for outcome.

RESULTS

Seventeen patients, 18 eyes, mean age 43.7 years (range 5.9 to 71 years) had SO surgery with postoperatively adjustable sutures. Twelve eyes of 11 patients had a loosening procedure, and six eyes had a tightening procedure. Seven of the patients had had precious eye muscle surgery, four having had previous surgery on the same SO tendon. All but one patient returned for the follow-up examination, ranging from 1.5 to 7 months postoperatively. Torsional imbalances in 12 patients improved in all but two. In four patients with a preoperative A pattern, the A pattern improved from 16 PD to 0 PD on average. In eight patients with vertical misalignment in straight ahead gaze who had no other cyclovertical muscle surgery simultaneously, the mean reduction was 7 PD. All patients except one had improvement in preoperative symptoms.

CONCLUSION

Both loosening and tightening procedures can be performed successfully using a postoperative adjustment technique for the SO tendon.

Horizontal mattress technique for superior oblique suture spacer

Superior oblique tendon overaction and Brown syndrome have been managed surgically by means of tenotomy/tenectomy, use of a silicon expander, and elongation with autologous fascia lata. These solutions are problematic with respect to corrective precision, injury and complications, or surgical difficulty. We present a simple "mattress" suture spacer technique that allows a precise and secure intraoperative adjustment.

Z-tenotomy of the superior oblique tendon and horizontal rectus muscle surgery for A-pattern horizontal strabismus

PURPOSE

Few studies have investigated combined surgeries for horizontal deviation and A pattern caused by superior oblique overaction (SOOA). This study presents our experience with combined surgery and examines the effect of the type of strabismus and prior surgery on outcome.

METHODS

The medical records of patients who underwent combined surgery for horizontal deviation occurring with A-pattern misalignment from 2000 through 2004 were reviewed. The procedure consisted of horizontal extraocular muscle recession or resection with superior oblique Z-tenotomy. The criteria for surgical success were horizontal deviation at primary gaze of </=10(Delta), A pattern of </=8(Delta), and SOOA of </=1.0.

RESULTS

The study group included 28 patients with a mean age of 13.4 years. Thirteen (46.4%) had A-pattern esotropia; 15 (53.6%) had A-pattern exotropia. Fifteen (50%) had undergone previous surgery. The success rate for the whole group was 60.7%. There was no statistically significant difference in success rate between patients with esotropia (53.8%) or exotropia (66.7%) (p = 0.48) or between patients in whom the combined procedure was the primary (71.4%) or secondary (50.0%) treatment (p = 0.246). Measurements of horizontal strabismus remained stable throughout follow-up in the esotropia group but were unpredictable in the exotropia group.

CONCLUSIONS

The success rate of combined horizontal deviation/A-pattern surgery is unaffected by type of horizontal deviation or prior surgery.

Super oblique tendon elongation with fascia lata

PURPOSE

Superior oblique lengthening with a silicone retinal band is used to treat superior oblique overaction (SOOA); however, secondary infection, implant extrusion, orbital cellulitis, and adhesion may occur. We present a method of superior oblique tendon elongation in which autogenous fascia lata is used to decrease the likelihood of these complications.

METHODS

Six patients (5 female, 1 male) aged 7-22 years (mean, 17 years) with 40-85(Delta) exotropia and SOOA (range, +2 to +4; mean, +3.5) underwent bilateral superior oblique lengthening with insertion of fascia lata. In the last 2 cases, the values of elongation were augmented by 2 mm. Fascia lata was harvested through a linear incision on the lateral aspect of the patient's thigh.

RESULTS

Postoperatively, correction of A-pattern exotropia to within 10(Delta) was achieved in 66% of the cases as well as correction of SOOA to within +1 in 58% of the cases, with a follow-up of 9 months. All patients with +2 to +3 SOOA (3 cases) were fully corrected, whereas those with +4 SOOA (9 eyes) had residual overaction of +1 to +3. In the 4 eyes with augmented elongation, residual SOOA was between 0 and +2. No patient developed superior oblique palsy.

CONCLUSIONS

Autogenous fascia lata may be used as an alternative to a silicone band for superior oblique lengthening. Our results were comparable with published results for the silicone band, with a lower rate of overcorrection. The improved biocompatibility makes it likely that autogenous fascia lata will have a lower complication rate than with a silicone band.

Superior oblique tendon spacer with application of nonabsorbable adjustable suture for treatment of Brown syndrome

PURPOSE

To evaluate the outcomes of a superior oblique tendon spacer procedure using nonabsorbable adjustable sutures in patients with Brown syndrome.

METHODS

This noncomparative interventional case series includes 25 eyes of 25 patients with Brown syndrome. In all patients the superior oblique tendon was exposed; two nonabsorbable polyester sutures were placed 4 mm apart, and the tendon was cut. With the use of a slipknot, the cut ends of the tendon were separated 5 to 8 mm. Tendon separation was adjusted intraoperatively according to the exaggerated traction test and indirect ophthalmoscopy.

RESULTS

Overall 25 eyes of 25 patients with mean age of 8.00 +/- 4.62 years were operated and followed for a mean period of 13.2 +/- 7.6 months (range, 3 to 30 months). Mean elevation in adduction improved from -3.96 before surgery to -0.67 (p < 0.001); mean hypotropia improved from 11.08(Delta) to 0.32(Delta) (p < 0.001). Two patients developed overcorrection, but recurrence was not observed in any case. The patients continued to improve over the follow-up period.

CONCLUSIONS

The adjustable superior oblique tendon suture spacer procedure has favorable results and seems to be technically easier than a silicone expander procedure for Brown syndrome.

Surgical and functional results of augmented superior oblique muscle z-tenotomy in patients with superior oblique overaction and Brown's syndrome

BACKGROUND AND OBJECTIVE

To compare the effectiveness of augmented superior oblique Z-tenotomy (SOZT) with fixed standard SOZT in canceling preoperative superior oblique overaction associated with A pattern anisotropia or V pattern in Brown's syndrome.

PATIENTS AND METHODS

Sixteen consecutive patients with superior oblique overaction or Brown's syndrome were treated by removal of a triangular piece of the superior oblique tendon near its insertion (augmented SOZT). Outcome was compared with 20 consecutive historical controls after standard SOZT.

RESULTS

The decrease in superior oblique overaction in the right and left eyes and fundus intorsion and the collapse of A pattern anisotropia were more significant for patients with superior oblique overaction (P = .003, P = .007, P = .05, P = .0015, respectively) and patients with Brown's syndrome (P = .025, P = .03, and P = .05, respectively). No study patient with superior oblique overaction and A pattern anisotropia required reoperation compared with 5 of 14 controls (37.5%); rates for patients with Brown's syndrome were 0 for the study group and 3 of 6 (50%) for the control group.

CONCLUSIONS

Augmented SOZT is superior to standard SOZT for correcting superior oblique overaction, intorsion, A or V pattern, and stereopsis. It is not associated with complications or reoperation. The size of the Z-tenotomy can be modified according to the intraoperative assessment to achieve symmetric results.

Superior oblique posterior tenectomy in patients with Brown syndrome with small deviations in the primary position

INTRODUCTION

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.

PURPOSE

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.

METHODOLOGY

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.

RESULTS

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.

CONCLUSION

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.