Extraocular muscle damage associated with endoscopic sinus surgery: an ophthalmology perspective

BACKGROUND

Orbital complications associated with endoscopic sinus surgery are well documented. Damage to the medial rectus muscle results in complicated strabismus and disturbing diplopia. The aim of this study was to characterize the types of extraocular muscle injury and the number of muscles involved that may complicate endoscopic sinus surgery and correlate its occurrence to factors in the surgical procedure itself.

METHODS

A retrospective chart review was performed of 14 patients with strabismus after endoscopic sinus surgery. Operative notes of the surgical procedure, pathology reports of the intraoperative specimens, postoperative pattern of strabismus, the extraocular muscle involved, and the type of muscle injury characterized by orbital imaging were reviewed in each patient.

RESULTS

In our series, not only the medial rectus muscle but also the inferior rectus and the superior oblique muscles were damaged with multiple muscles being involved in one patient. Extraocular muscle injury varied from hematoma, entrapment of muscle in the fractured orbital wall, damage to the oculomotor nerve entry zone, muscle transection, and partial or complete muscle destruction with entrapment in scar tissue. Use of the microdebrider causes extensive irreparable muscle damage.

CONCLUSION

Extraocular muscle damage complicating endoscopic sinus surgery can produce therapeutically challenging complicated strabismus.

Isolated superior oblique tucking: an effective procedure for superior oblique palsy with profound superior oblique underaction

PURPOSE

To compare efficacy and complications of isolated unilateral superior oblique tucking in patients with unilateral superior oblique palsy (SOP).

METHOD

A retrospective analysis of 24 cases of unilateral SOP, 13 Acquired (group 1), and 11 Congenital (group 2), who underwent isolated unilateral superior oblique tuck over a 13-year period was performed.

RESULTS

The mean preoperative vertical deviation in primary gaze was 10 +/- 3 PD for group 1 and 12 +/- 5 PD for group 2 and mean vertical deviation in lateral gaze of affected superior oblique was 19 +/- 5 PD for group 1 and 21 +/- 9 PD for group 2. The mean postoperative vertical deviation in primary gaze for group 1 after a mean follow-up period of 15 +/- 21 months was 1 +/- 3 PD; for group 2 after a mean follow-up period of 17 +/- 13 months was 2 +/- 3 PD, and in lateral gaze of affected superior oblique was 3 +/- 5 PD for group 1 and 5 +/- 6 PD for group 2. The mean correction of vertical deviation in primary gaze at last follow-up was 8 +/- 2 PD for group 1 and 9 +/- 5PD for group 2 ( P > 0.05) and in the lateral gaze field of affected superior oblique muscle was 16 +/- 4 PD for group 1 and 15 +/- 5 PD for group 2 ( P > 0.05). The mean preoperative torsion was 9 +/- 4 degrees for group 1 and 9 +/- 2 degrees for group 2; mean postoperative torsion was 1.2 +/- 2.2 degrees for group 1 and 1 +/- 1 degrees for group 2. The mean torsion corrected for group 1 was 8 +/- 3 degrees and for group 2 was 8 +/- 2 degrees ( P > 0.05). Only one patient in group 1 and three patients in group 2 required reoperation to correct residual deviation. A mild postoperative limitation to elevation in adduction was seen in all cases but was asymptomatic and lessened over time.

CONCLUSION

Isolated unilateral superior oblique tucking corrected a large amount of the vertical deviation and torsion with minimal complications in selective patients of both congenital and acquired superior oblique palsy. Superior oblique tucking is a safe and effective procedure and can be considered in patients with SOP meeting selective criteria.

Combined adjustable rectus muscle resection--recession for incomitant strabismus

INTRODUCTION

We sought to report the results of combined adjustable suture resection and recession of a rectus extraocular muscle in a subset of patients who are asymptomatic in the primary position but diplopic in secondary functional gaze positions.

METHODS

We undertook a retrospective chart review of 12 patients who underwent a surgical procedure consisting of combined resection and recession of the same rectus extraocular muscle on adjustable suture, the amount of recession being double the amount of resection.

RESULTS

The amount of incomitance reduced from a preoperative mean of 11.6 prism diopters (PD) to a postoperative mean of 2.9 PD. All 4 rectus muscles underwent operation No significant change in the primary position alignment occurred. Diplopia was eliminated in 11 of the 12 patients postoperatively.

CONCLUSION

The combined adjustable suture resection and recession operation is an effective and easy procedure for treatment of this subset of patients with incomitant strabismus.

Superior oblique muscle involvement in thyroid ophthalmopathy

BACKGROUND

Rectus muscle involvement in thyroid ophthalmopathy is well documented. The inferior rectus is the most frequently involved, followed by the medial, superior, and infrequently the lateral rectus. This study reports involvement of the superior oblique muscle as a contributory cause of restrictive strabismus in patients with thyroid ophthalmopathy.

METHODS

This is a retrospective review of four patients with known thyroid ophthalmopathy who presented with incomitant vertical strabismus, A-pattern, overdepression in adduction, underelevation in adduction, and incyclotorsion. All patients underwent preoperative orbital imaging. Two of the four patients had previous orbital decompressions. All patients underwent surgery on the SO muscle.

RESULTS

Preoperative scans showed enlargement of one or both SO muscles in all patients and intraoperative forced duction testing revealed restriction to elevation in adduction in all cases. Preoperative A-pattern ranged from to 6 to 22 prism diopters. All subjects had preoperative incyclotorsion, ranging from 2 and 14 degrees. Improvement of the versions, hypertropia, and cyclotorsion followed surgical weakening procedures on the SO muscle.

CONCLUSION

Thyroid ophthalmopathy may involve the SO muscle. Clinical manifestations include preoperative A-pattern strabismus, incyclotorsion, and restrictive limitation to elevation in adduction. Orbital imaging documents SO muscle enlargement. Awareness of SO involvement in thyroid ophthalmopathy assists the surgeon to develop a more precise surgical strategy to correct the hypotropia.

Lateral rectus resections in divergence palsy: results of long-term follow-up

INTRODUCTION

Lateral rectus resections have been previously advocated as surgical options to treat patients with divergence palsy who do not respond well to prisms. This study was undertaken to review the results and long-term follow-up of patients with divergence palsy who underwent lateral rectus resections at our institution.

METHODS

Retrospective review of 29 patients (age 35-83 years) with divergence palsy. Five subjects underwent unilateral lateral rectus resection between 4.5 and 5.5 mm on adjustable suture and 24 subjects underwent bilateral lateral rectus resection between 3 and 7 mm on adjustable sutures.

RESULTS

Preoperatively, all patients had diplopia at distance and an esodeviation, which was greater at distance (mean 14.7 +/- 5.1Delta) than at near (mean 4.7 +/- 3.5Delta). Twenty-five subjects had previously been treated with prisms. Postoperative follow-up period ranged from 6 to 96 months (mean 38.7 +/- 27.3 months). The angle of deviation at distance was significantly reduced to -0.1 +/- 3.2Delta postoperatively ( P < 0.0001). The angle of deviation at near reduced significantly to -2.2 +/- 3.3Delta postoperatively ( P < 0.0001). No patient was overcorrected for near. Two patients experienced recurrent postoperative diplopia at distance subsequently at 1 and 4 years, which was corrected with prism glasses and lateral rectus re-resection.

CONCLUSION

Lateral rectus resection in patients with divergence palsy is an effective and stable procedure in patients with divergence palsy over long-term follow-up periods, with minimal risk of overcorrections at near.

Rectus muscle orbital wall fixation: a reversible profound weakening procedure

INTRODUCTION

Surgical treatment of third nerve palsy, sensory exotropia and strabismus secondary to anomalous innervation of the rectus muscles, frequently require large rectus muscle recessions in an attempt to maintain alignment in the primary position and reduce the effects of misinnervation. The aim of this study was to describe and evaluate the results of inactivation of a rectus muscle by its attachment to the adjacent orbital wall.

METHODS

Seven subjects diagnosed with third-nerve palsy (three cases), Duane syndrome (two cases), sensory exotropia (one case), and congenital aberrant innervation of vertical rectus muscles (one case) underwent rectus muscle inactivation by orbital wall fixation. The rectus muscle was disinserted from the globe and reattached to the adjacent orbital periosteum using non-absorbable sutures. This surgery was performed on the lateral rectus muscle in six subjects, and surgery was performed on both ipsilateral vertical rectus muscles in one.

RESULTS

Postoperatively four of six patients were aligned within 12 prism diopters of orthotropia in primary position. All patients had improvement of the anomalous head posture. In Duane syndrome, lateral rectus inactivation markedly reduced co-contraction and globe retraction. No overcorrections resulted.

CONCLUSION

A rectus muscle may be functionally inactivated when its insertion is attached to the orbital periosteum. Advantages of this procedure over extirpation and free tenotomy include permanent disinsertion of the muscle from globe and reversibility.

Strabismic complications following endoscopic sinus surgery: diagnosis and surgical management

INTRODUCTION

Endoscopic surgical techniques improve the surgeon's view of sinus structures but are subject to extraocular muscle complications that cause permanent diplopia.

METHODS

A series of 15 patients with strabismus following endoscopic sinus surgery was reviewed retrospectively to characterize the type of muscle injury and report the results of surgical correction.

RESULTS

A variety of insults to the medial rectus (MR) muscle occurred, ranging from contusion, hematoma, oculomotor nerve damage with paralysis, muscle transection, and muscle destruction. Inferior rectus and superior oblique muscle trauma was observed. High-resolution computed tomography and magnetic resonance imaging scans proved essential in determining the extent and nature of muscle injury. Surgical approaches included anterior orbitotomy with muscle recovery and transposition procedures.

CONCLUSIONS

Several extraocular muscles may be traumatized. Timing and type of surgical treatment depend on severity, type of injury, and number of muscles involved. If the remaining posterior segment of the MR muscle is longer than 20 mm and is contractile, muscle recovery via anterior orbital approach is suggested. If injury is more severe, muscle transposition procedures may be helpful. In cases where there is coexistent medial and inferior rectus injury, transposition procedures may not be possible. Inactivation of the antagonist and use of an orbital periosteal flap as a globe tether to center it may be options.

Surgical management of severe cocontraction, globe retraction, and pseudo-ptosis in Duane syndrome

BACKGROUND

Correction of severe cocontraction and pseudo-ptosis present unique surgical challenges in patients with Duane syndrome.

METHODS

We report four Duane syndrome patients with esotropia in primary position, poor abduction, and severe cocontraction causing limitation to adduction, globe retraction, and pseudo-ptosis. All were treated with partial tendon transposition of the vertical rectus muscles augmented with Foster fixation sutures and surgical weakening of the ipsilateral lateral rectus muscle. One patient had a large recession of the lateral rectus muscle, and in three patients, the lateral rectus muscle was inactivated by removing from the globe and attaching its insertion to the lateral orbital wall.

RESULTS

Postoperatively, all patients were aligned within eight prisms diopters of orthotropia, had no face turn, and improved adduction and abduction. The two patients who had restriction to abduction on intraoperative forced ductions also had residual esotropia in primary position and underwent recession of the ipsilateral medial rectus muscle as a second procedure. Postoperative binocular single visual field was enlarged by 56 to 500% in the three patients who were tested preoperatively and postoperatively. Globe retraction and cocontraction were markedly relieved. Palpebral fissure widened 1.0 and 6.0 mm in two patients who had preoperative and postoperative measurements.

CONCLUSION

In Duane syndrome patients, severe cocontraction, globe retraction, and limitation to adduction may improve if the lateral rectus muscle is maximally recessed or its insertion is inactivated from the globe. Partial transposition of the vertical rectus muscles augmented with Foster sutures improved the angle of esotropia in primary position and abduction. Medial rectus muscle recession is indicated when the passive forced duction test reveals moderate-to-severe restriction to abduction.

Partial rectus muscle-augmented transpositions in abduction deficiency

PURPOSE

Lateral posterior fixation sutures increase the effect of full rectus extraocular muscle transpositions. Partial rectus muscle transposition may be indicated to minimize the risk of anterior ischemia when multiple rectus muscles require surgery to achieve ocular alignment.

PURPOSE

To report a modification of full vertical rectus muscle transposition with lateral posterior fixation sutures for use in patients at risk for anterior segment ischemia.

METHODS

Ten cases of unilateral split rectus muscle transposition augmented with lateral posterior fixation sutures were analyzed. Five patients had Duane's syndrome with esotropia in primary position, and five patients had sixth-nerve palsy.

RESULTS

Seven patients had a history of ipsilateral rectus muscle surgery, and three patients underwent simultaneous surgery on ipsilateral horizontal rectus muscles. In Duane's syndrome patients, the preoperative angle of deviation at distance was 15.8 +/- 5.8 prism diopters (PD) (range, 10 to 25) compared with 3.2 +/- 4.4 PD (range, 0 to 8) postoperatively (P =.005). In patients with sixth-nerve palsy, the preoperative angle of deviation at distance was 45.2 +/- 23.9 PD (range, 16 to 80) compared with -5 +/- 14.1 PD (range, -30 to 5) postoperatively (P =.004). Postoperative binocular single visual fields enlarged in seven of seven patients.

CONCLUSION

Partial rectus muscle-augmented transposition allows surgery on multiple ipsilateral rectus muscles in (1) Duane's syndrome patients with esotropia, marked cocontraction, and/or limitation to both horizontal rotations and in (2) sixth-nerve palsy patients with ipsilateral medial rectus tightness. Augmented partial rectus muscle transpositions improve ocular alignment and may enlarge binocular single fields in patients with persistent deviations despite previous muscle surgery.

Preoperative prism adaptation for acquired esotropia: long-term results

PURPOSE

The efficacy of preoperative prism adaptation in subjects with acquired esotropia has been established at 6 and 12 months postoperatively. We evaluated the outcomes of subjects with acquired esotropia who had preoperative prism adaptation and were followed longer than 12 months.

METHODS

A retrospective analysis was undertaken of 2 groups of subjects with acquired esotropia who underwent bilateral medial rectus recessions based on the distance angle of deviation and were followed more than 12 months postoperatively. Group A subjects had preoperative prism adaptation to determine the target angle for corrective surgery. In Group B subjects, surgery was based on the maximum angle of strabismus at distance, determined by alternate prism cover test without preoperative prism adaptation.

RESULTS

We compared 17 subjects in Group A and 19 subjects in Group B. The postoperative follow-up period was 3 +/- 1.7 years in Group A and 4.8 +/- 1.8 years in Group B. The age at the last visit was 9.1 +/- 2 years in Group A and 10 +/- 2 years in Group B. Postoperative residual esotropia was 2.6 +/- 2.5 PD at distance in Group A patients and 6.6 +/- 5.9 PD in group B patients (P =.002). Residual esotropia at near was 3 +/- 3.8 PD in Group A and 11.5 +/- 8.12 PD in Group B (P <.01). More Group B subjects required bifocal spectacles to achieve optimal alignment at near (P =.001).

CONCLUSION

Acquired esotropia subjects operated on for their distance prism-adapted angle maintained better motor alignment over a long-term follow-up period when compared with nonprism-adapted subjects operated on for their distance angle.

Timing of postoperative adjustment in adjustable suture strabismus surgery

PURPOSE

The use of adjustable sutures in strabismus surgery has increased the rate of surgical success. Little data are available on the optimum timing for postoperative adjustment after strabismus surgery. We wanted to compare 2 common practices of adjustable suture technique after strabismus surgery.

METHODS

Two comparable groups of 40 patients each, who had strabismus surgery with adjustable suture technique, were prospectively studied. Group A had early adjustment the same day of the surgery about 6 hours after the operation, and group B had late adjustment the next day about 24 hours after the operation. Subjective scoring tables were used to evaluate the pain felt by the patient before, during, and after the adjustment and any difficulties of the adjustment process. Requirements of postoperative pain medications and final alignment 6 weeks after surgery were also compared.

RESULTS

Despite adequate statistical power, no significant differences were found between the groups regarding pain before, during, and after adjustment, difficulties performing the adjustment, and final alignment after 6 weeks (P > .05). Both adjustment schedules were equally associated with mild to moderate pain before, during, and after the adjustment. In the first 24 hours after surgery, no overall difference in the use of pain medications was found. Nausea and vomiting in the first 24 postoperative hours were more common in the early adjustment group (P = .02).

CONCLUSION

The surgeon can feel free to choose the timing for postoperative adjustment. However, when performing an early adjustment, the surgeon should be especially prepared to control nausea and vomiting.

Vertical rectus muscle augmented transposition in Duane syndrome

INTRODUCTION

Reduction or elimination of face turn and esotropia in the primary position while maintaining the largest possible diplopia-free field are the major surgical goals in Duane syndrome with esotropia. Unsatisfactory postoperative results may occur because of limitation in adduction, poor abduction, or induced vertical deviations. Recent reports have shown enhanced results from rectus muscle transposition techniques when a lateral posterior augmentation fixation is placed.

METHODS

Preoperative and postoperative data of 2 groups of subjects who had Duane syndrome with esotropia in primary position and markedly reduced abduction were comparatively analyzed. Group A consisted of subjects who had transposition of both vertical rectus muscles to the lateral rectus muscle with a posterior lateral augmentation suture placed in each transposed muscle. Group B subjects had transposition of both vertical rectus muscles to the lateral rectus muscle without the posterior lateral augmentation suture.

RESULTS

A total of 32 subjects in group A and 22 subjects in group B were analyzed. In group A, anomalous head position improved 19.1 degrees +/- 10.3 degrees compared with group B subjects who improved 10.6 degrees +/- 5.8 degrees (P <.05). In group A, esotropia in primary position improved 16.4 +/- 9.2 PD compared with group B subjects who improved 8.5 +/- 6.9 PD (P <.05).

CONCLUSIONS

Subjects with Duane syndrome and esotropia in primary position who had undergone augmented transposition of the vertical rectus muscles obtained improved head position and better alignment in primary position and had a reduction in the incidence of reoperation for undercorrection when compared with similar patients who had undergone vertical rectus muscle transposition without posterior lateral augmentation sutures.

Facial asymmetry in superior oblique muscle palsy and pulley heterotopy

INTRODUCTION

Some observers have considered facial asymmetry as characteristic of congenital superior oblique muscle (SO) palsy. However, recent orbital imaging studies have determined that incomitant vertical strabismus resembling SO palsy can be caused by heterotopic rectus muscle pulleys. This finding suggests that facial asymmetry may predict the presence of abnormal orbital anatomy rather than be secondary to ocular torticollis.

METHODS

Subjects who underwent orbital computed tomography or magnetic resonance imaging were divided into 5 groups based on clinical evaluation and previously established imaging criteria: (1) congenital SO palsy; (2) acquired SO palsy; (3) strabismus with pulley heterotopy; (4) strabismus without SO palsy or pulley heterotopy; and (5) orthotropic subjects. Frontal photographs were digitized and the following 3 facial morphometric features recorded: (1) angle of inclination of each orbit; (2) relative facial size; and (3) facial angle.

RESULTS

The 79 subjects who underwent imaging were divided into the 5 groups as follows: 6 with congenital SO palsy; 7 with acquired SO palsy; 20 with pulley heterotopy; 26 with strabismus without SO palsy or pulley heterotopy; and 20 control subjects. All subjects with either congenital or acquired SO palsy had torticollis. Multivariate analysis demonstrated no significant differences in any of the 3 facial morphometric features among any of the groups.

CONCLUSION

Facial asymmetry as assessed by these 3 morphometric features is not useful in distinguishing between congenital SO palsy or pulley heterotopy and other acquired forms of strabismus. This finding casts doubt on the relationship between ocular torticollis and facial asymmetry.