The diagnosis and surgical management of acquired bilateral superior oblique palsy

Boergen modification of Harada-ito surgery with and without vertical muscle surgery for acquired unilateral superior oblique muscle palsy

PURPOSE

The purpose is to report the results of the Boergen modification of the Harada-Ito procedure with and without simultaneous vertical muscle surgery in patients with acquired unilateral superior oblique muscle palsy.

PATIENTS AND METHODS

Files of patients with acquired unilateral superior oblique muscle palsy who were treated with Boergen modification of the Harada-Ito procedure were studied retrospectively. For each patient, age at the time of surgery, the presence of diplopia, compensatory head posture, and ocular deviation before and after surgery were retrieved. Results were evaluated 6 months after surgery.

RESULTS

A total of 12 patients with a mean age of 32 years at the time of surgery (range 15-45 years) were included. The underlying etiology was head trauma in eleven patients. The modified Harada-Ito procedure alone was done for three cases (Group 1), and a simultaneous combination of this procedure and vertical muscle surgery was performed in nine patients (Group 2). The average intorsional effect in the primary position was 9.2° (8° in Group 1 and 9.6° in Group 2). The average correction of hypertropia in the primary position was 8.2 prism diopters (PD) (1 PD in Group 1 and 10.6 PD in Group 2). Diplopia in the primary position and downgaze were resolved in eleven patients and ten patients, respectively. Four patients had a compensatory head tilt at their last follow-up.

CONCLUSIONS

Boergen modification of the Harada-Ito procedure, alone and combined with vertical muscle surgery, successfully corrected primary position diplopia in the majority of the patients.

Improvement in health-related quality of life with Botulinum toxin A injection in acquired superior oblique palsy

Purpose

This study aimed to investigate the outcomes of Botulinum toxin A (BTA) injection into the inferior oblique (IO) muscle for the management of unilateral acute acquired superior oblique palsy (SOP) and to evaluate changes in health-related quality of life post-injection using the Adult Strabismus-20 (AS-20) questionnaire.

Methods

A prospective cohort study was performed in patients with unilateral acute acquired SOP who received BTA injections. Four units of BTA were injected into the ipsilateral IO muscle. Ocular examinations were performed pre-and post-injection, including alignment, ocular movement, and cyclotorsion deviation. The patients' AS-20 questionnaire scores were analyzed.

Results

A total of 21 patients with acute acquired SOP were included. The initial median vertical deviation was 5 PD (range 1-16), which was improved to 0 PD (range 0-10) at both 1 and 6 months post-injection (p < 0.001 and p < 0.001, respectively). The median torsional deviation was 7° (range 2-18) at baseline and resolved to 0 degrees (range -3-5) at the 1-month and 0° (range -2-7) at the 6-month follow-up (p < 0.001 and p < 0.001, respectively). There were significant increases in the overall score (OAS), psychosocial subscale score (PSS), and functional subscale score (FSS) from baseline values at both the 1-month (p < 0.001, p < 0.001, and p = 0.001, respectively) and 6-month follow-up (all p < 0.001).

Conclusion

Injecting BTA into the ipsilateral IO muscle successfully resolved vertical and torsional deviations and significantly improved quality-of-life scores. Our findings show that BTA treatment, as an early treatment for acute acquired SOP, can help patients by significantly improving their quality of life.

Disinsertion-distal myectomy and tucking of inferior oblique combined with superior oblique full tendon advancement in superior oblique palsy

PURPOSE

To assess the preliminary outcomes of inferior oblique (IO) disinsertion-distal myectomy and tucking combined with superior oblique (SO) full tendon advancement in patients with Knapp II or III superior oblique palsy.

METHODS

This single-centered retrospective study included 16 eyes from 13 patients with Knapp Class II or III SO palsy. All patients underwent IO disinsertion-distal myectomy and tucking combined with SO full tendon advancement while under general anesthesia. Pre- and post-operative levels of vertical deviation in the primary position, abnormal head position, IO hyperfunction and SO hypofunction, torsion, as well as the presence of diplopia, were all measured, and the differences were statistically compared.

RESULTS

Pre-operatively, 12 patients had abnormal head positions, and two had diplopia. The pre-and post-operative levels of IO hyperfunction and SO hypofunction, as well as a vertical deviation in the primary position and torsion, all differed statistically significantly (p < 0.01).

CONCLUSIONS

Inferior oblique disinsertion distal myectomy and tucking combined with SO full tendon advancement surgery appears to be an effective procedure in patients with congenital and acquired Knapp Class II or III SO palsy.

Types of Surgery Performed and Reoperation Rate for Congenital Superior Oblique Palsy: a Claims Database Study

PURPOSE

To investigate types of surgeries performed to treat a presumed congenital superior oblique palsy (SOP) and the reoperation rate.

METHODS

This was a population-based retrospective cohort study using claims data from the United States. Patients who underwent strabismus surgery for a presumed congenital SOP with ≥ 3 months of continuous enrolment after the initial surgery were included. We investigated age, surgical methods and the time interval between the initial surgery and reoperation. The hazard ratios for reoperation were estimated according to the surgical methods using Cox regression analysis.

RESULTS

A total of 3,998 patients underwent surgery for presumed congenital SOP; 2,981 (74.6%) on only one vertical muscle (excluding superior oblique). Reoperation was performed on 427 patients (10.7%). Compared to patients who underwent unilateral surgery on one vertical muscle (excluding superior oblique muscle), patients who underwent surgery that included the superior oblique muscle (unilateral 2.08; 95% CI, 1.61-2.67, p < 0.001; bilateral 2.44; 95% CI, 1.40-4.28, p = 0.002) and two or more vertical muscles (excluding the superior oblique muscle) (unilateral 2.99; 95% CI, 2.00-4.49, p < 0.001; bilateral 1.68; 95% CI, 1.23-2.28, p = 0.001) had increased hazard ratios for reoperation. The median period between the initial surgery and reoperation was 168.0 [Q1-Q3 84.0-407.8] days and negatively correlated with patient age at initial surgery (r = -0.199, p < 0.001).

CONCLUSION

The reoperation rate for presumed congenital SOP was 10.7%. Patients who underwent surgery on two or more vertical muscles or the superior oblique muscle had an increased risk of reoperation.

Surgical outcome of graded Harada-Ito procedure in the treatment of torsional diplopia ‒ a retrospective case study with long-term results

To review and evaluate the surgical outcomes of the Fells-modified Harada-Ito procedure using a dosage scale approach with long-term follow up in patients with torsional diplopia. The records of patients who underwent the modified Harada-Ito procedure by the same surgeon during 2012-2019 were retrospectively reviewed regarding pre- and post-operative data and individual dose-scale used for the surgery. The modified Harada-Ito procedure involved advancing the anterior half of the superior oblique tendon toward the inferior edge of the lateral rectus muscle by a distance determined using a five-graded scale. A total of 27 patients (mean age 57.6 years, range, 22-81 years; 10 female) were included. Evaluating surgical outcome showed a significant difference in pre- to post-operative cyclodeviation (p = <0.001). Pre-operative mean extorsion was -10.4° and mean torsional correction achieved was 7.7°. The dose-effect relationship showed a wide spread effect, yet yielded a high success rate. All but two patients were symptom free from their torsional diplopia at the last post-operative evaluation, on average 24 months after surgery. Post-operative results and the dose-effect of the modified Harada-Ito corresponded with the aimed-for correction of torsional diplopia.. Fusion evaluation and individually based pre-operative assessments proved essential in determining individual doses for successful surgical outcomes.

Clinical Features and Surgical Results in Harada-Ito Surgery Patients

Symptomatic excyclotorsion is an important clinical problem, especially in acquired superior oblique muscle palsy. Excyclotorsion can disrupt the fusion and cause torsional diplopia. Harada-Ito surgery (HI) is a widely used method for treating excyclotorsions. This method relieves the torsional diplopia by increasing the effect of the incyclotorsion. In this study, we aimed to report the clinical features of patients with torsional diplopia due to acquired trochlear nerve palsy and the results of HI surgery in these patients.

Cranial nerve palsies in childhood

We review ocular motor cranial nerve palsies in childhood and highlight many of the features that differentiate these from their occurrence in adulthood. The clinical characteristics of cranial nerve palsies in childhood are affected by the child's impressive ability to repair and regenerate after injury. Thus, aberrant regeneration is very common after congenital III palsy; Duane syndrome, the result of early repair after congenital VI palsy, is invariably associated with retraction of the globe in adduction related to the innervation of the lateral rectus by the III nerve causing co-contraction in adduction. Clinical features that may be of concern in adulthood may not be relevant in childhood; whereas the presence of mydriasis in III palsy suggests a compressive aetiology in adults, this is not the case in children. However, the frequency of associated CNS abnormalities in III palsy and the risk of tumour in VI palsy can be indications for early neuroimaging depending on presenting features elicited through a careful history and clinical examination. The latter should include the neighbouring cranial nerves. We discuss the impact of our evolving knowledge of congenital cranial dysinnervation syndromes on this field.

The sensitivity of the bielschowsky head-tilt test in diagnosing acquired bilateral superior oblique paresis

PURPOSE

To determine the sensitivity of the Bielschowsky head-tilt test and other commonly used criteria in identifying patients with true bilateral superior oblique paresis.

DESIGN

A retrospective chart review was performed to identify patients seen between 1978 and 2009 who were diagnosed with acquired bilateral superior oblique paresis.

METHODS

All patients had a confirmed history of head trauma or brain surgery with altered consciousness followed by symptomatic diplopia. Bilateral superior oblique paresis was defined and diagnosed by the above history, including the presence of greater extorsion in downgaze than upgaze on Lancaster red-green testing, a V-pattern strabismus, and bilateral fundus extorsion. We analyzed findings of the Bielschowsky head-tilt test, the Parks 3-step test, and reversal of the hypertropia from straight-ahead gaze to the other 8 diagnostic positions of gaze to determine these tests' sensitivity in identifying true bilateral superior oblique paresis.

RESULTS

Twenty-five patients were identified with the diagnosis of true bilateral superior oblique paresis. The Bielschowsky head-tilt test had a 40% sensitivity, the Parks 3-step test had a sensitivity of 24%, and reversal of the hypertropia had a sensitivity of 60% in making the diagnosis of true bilateral superior oblique paresis.

CONCLUSIONS

What previously has been described as masked bilateral superior oblique paresis simply may be a reflection of inherent poor sensitivity of the Bielschowsky head-tilt test, the Parks 3-step test, and reversal of the hypertropia in diagnosing bilateral superior oblique paresis. Hence, none of these tests should be relied on exclusively to make this diagnosis.

Outcomes of Harada-Ito surgery for acquired torsional diplopia

PURPOSE

To evaluate the outcomes of Harada-Ito surgery in correcting various types of torsional diplopia.

METHODS

The medical records of patients who underwent Harada-Ito surgery at two academic institutions were retrospectively reviewed. Data collected included etiology of torsional diplopia, strabismus and torsion measurements, reoperation rate, patient symptoms, and use of prism. Postoperative success was defined as a lack of diplopia in the primary position at distance and downgaze at near with or without prism. Failure was defined as persistent torsional diplopia; partial success was defined as surgical success but with restrictive strabismus in the secondary gaze positions.

RESULTS

A total of 26 patients (mean age, 46 years; range, 13-89 years) were included. Of these, 17 had superior oblique palsy. The mean follow-up duration was 2 years (range, 2-60 months). The surgical outcome was success in 73% of patients, partial success in 7%, and failure in 19%. All patients with ≤10° of torsion preoperatively obtained surgical success. Patients in the failure group had higher amounts of preoperative torsion compared to the success group (P = 0.009). The reoperation rate was 23%, including four patients with additional surgery for downgaze esotropia or torsion. One-third of the patients wore a prism immediately after surgery.

CONCLUSIONS

Harada-Ito surgery successfully treated torsional diplopia. Patients with ≤10° of preoperative torsion had a better outcome. Downgaze diplopia was a common reason for additional surgery.

Simulated torsional disparity disrupts horizontal fusion and stereopsis

PURPOSE

To investigate how increasing torsional disparity affects clinical measures of the quality of binocular single vision.

METHODS

Synoptophore targets were adjusted to present varying degrees of torsional disparity (relative to the fusion-free rest position of the eyes) such as might be observed in a patient with excyclotropia. This disparity was increased in 2 degrees increments up to 10 degrees in 21 normal subjects. The fusional divergence and convergence amplitudes and random-dot stereoacuity were measured at each level of torsional disparity.

RESULTS

Horizontal fusional vergence was not significantly altered from the baseline measures at 2 degrees and 4 degrees of torsional disparity. However, both the divergence and the convergence amplitudes declined and were significantly different than the baseline measures at 6 degrees . A similar decline in the random-dot stereoacuity measurements was evident. Fine levels of stereopsis were decidedly affected at greater than 4 degrees of torsional disparity, while more gross levels were similarly affected beyond 6 degrees .

CONCLUSIONS

Although human binocular vision can demonstrate the sensory capacity for cyclofusion beyond 10 degrees , torsional disparity of 6 degrees or more significantly degrades horizontal fusional vergence and stereopsis. Torsion in excess of this degree might therefore be a barrier to asymptomatic and comfortable binocular single vision and may require appropriate attention in the planning of more successful surgery for superior oblique palsy and cyclovertical incomitant strabismus.

A concept for the surgical treatment of trochlear palsy

The outstanding clinical symptom of acquired uni- and bilateral trochlear palsy is excyclotropia which increases in down-gaze. Any surgical treatment must aim at reducing this deviation. To achieve this, we have routinely used a modification of the Harada-Ito operation over the last 20 years. The anterior part of the tendon is pulled anteriorly and laterally by a loop of unresorbable suture. This not only increases incyclotorsion but also depression in adduction and reduces the V-pattern. In cases with more than 5 degrees vertical deviation, we performed an additional tuck of the posterior part of the tendon. Our results are compared with those of either superior oblique tuck or combined operations on the oblique muscles published by other authors. They have also used the Harms' tangent screen for quantification of the effect of the operations. In down-gaze, similar results have been obtained but less postoperative Brown's syndrome was found with our modified Harada-Ito procedure. Thus, our modification of the Harada-Ito procedure is an effective and safe approach to the surgical treatment of trochlear palsy with less postoperative limitation of elevation and less torsional overcorrection in up-gaze.

The long-term torsion effect of the adjustable Harada-Ito procedure

PURPOSE

The Harada-Ito procedure is a widely used technique in the treatment of excyclotorsion. While previous studies have demonstrated its initial success, long-term data have not been readily available. The purpose of this study is to describe the long-term torsion effect of the adjustable Harada-Ito procedure.

METHODS

All Harada-Ito procedures performed by 1 surgeon from 1982 to 1998 with at least 1 year of follow-up were reviewed. Torsion was evaluated using the double Maddox rods preoperatively, 1 day postoperatively, 2 months, 6 months, 1 year, 18 months, then annually thereafter. The effectiveness of the procedure was evaluated by comparing preoperative values to those at follow-up exams. The stability of the procedure was also evaluated by comparing torsion at 1 day and 2 months postoperatively to the torsion at subsequent exams. All comparisons were performed using the Student's t test.

RESULTS

Eighty Harada-Ito procedures were performed by 1 surgeon during this period. Nineteen patients had at least 1 year of follow-up (range, 1-7 years; mean, 2.0 years). Mean excyclotorsion values were 10.7 degrees preoperatively, 1.0 degrees at 1 day, 1.0 degrees at 2 months, 3.4 degrees at 6 months, 4.8 degrees at 1 year, and 5.3 degrees at 18 months. There was a significant improvement of excyclotorsion compared to preoperative torsion up to 12 months after surgery (P <or=.05). However, there was regression of the torsion effect from 2 months to 12 months after surgery (P =.02). After 12 months, there did not appear to be any further regression at 18 and 24 months postop (P =.79 and.84, respectively), although the number of patients with follow-up beyond 1 year was small (n = 3).

CONCLUSIONS

The Harada-Ito procedure is an effective procedure to treat excyclotorsion. However, regression toward excyclotorsion occurs between 2 months to 12 months postoperatively. These results suggest that an initial overcorrection may aid in long-term success of this procedure.

Unilateral modified Harada-lto procedure for excyclotorsion secondary to unilateral superior oblique palsy

BACKGROUND

The Fells modification of the Harada-lto procedure is usually performed bilaterally for the correction of excyclotorsion secondary to acquired bilateral superior oblique paresis. Excyclotorsion is not usually a major complaint in true unilateral superior oblique paresis. Occasional cases, however, may find this symptom bothersome and it may interfere with fusion. The purpose of the present study is to determine the effect of the unilateral modified Harada-lto procedure on the correction of symptomatic excyclotorsion in unilateral superior oblique paresis.

METHOD

A retrospective case-note review of patients with unilateral superior oblique paresis undergoing unilateral modified Harada-lto procedures during the five-year period 1988-1993 was performed.

RESULTS

Six patients fulfilled the inclusion criteria. Superior oblique paresis was congenital in one case, secondary to trauma in two cases and idiopathic acquired in three cases. There were four males and two females aged from 25 to 63 years and all but one had previous surgery. The mean pre-operative excyclotorsion was approximately 10 degrees (range 8-14 degrees). Mean post-operative excyclotorsion was 3 degrees (range 2 degrees incyclotorsion -10 degrees excyclotorsion).

CONCLUSION

The unilateral modified Harada-lto procedure is an effective surgical treatment of excyclotorsion resulting from superior oblique paresis and may improve sensory and motor fusion.

Intraoperative adjustable suture surgery for bilateral superior oblique palsy

BACKGROUND

The modified Harada-Ito procedure has been reported to be an effective treatment for correction of cyclotorsion in bilateral superior oblique palsy. However, there are no reports regarding its use in intraoperative adjustable suture surgery.

METHODS

The authors performed a retrospective study of 12 patients with traumatic bilateral superior oblique palsy who were classified as having either symmetric or asymmetric palsy according to the symmetry of the alternate hyperdeviation on side gazes. Cyclotorsion and vertical and horizontal deviation in the nine diagnostic positions were measured preoperatively and postoperatively.

RESULTS

Of the 12 patients, 6 were determined to have symmetric palsy and 6 asymmetric palsy. Intraoperative adjustable suture surgery with the modified Harada-Ito procedure was performed bilaterally in the six patients with symmetric palsy and unilaterally in those with asymmetric palsy. The median measured value of extorsion in the primary position was reduced from 14.5 degrees to 2.5 degrees in patients with symmetric palsy and from 9.5 degrees to 2.0 degrees in those with asymmetric palsy. In downgaze, some degree of residual extorsion remained, and there was no significant change in esodeviation after surgery. In five patients with symmetric palsy and in all of those with asymmetric palsy, normal single binocular vision in the primary position but did not that in downgaze was restored after surgery.

CONCLUSION

Intraoperative adjustable suture surgery is an effective treatment in correcting torsion, but may not be as effective for esodeviation in downgaze.

Superior oblique tuck surgery in the management of superior oblique palsies

Three hundred and twenty-four patients with superior oblique muscle palsies required surgery over a 15-year period. Forty-four patients underwent superior oblique tuck surgery. Fifteen patients had unilateral and six bilateral tucks alone. Seventeen had unilateral tucks and three bilateral tucks in conjunction with other extraocular muscle surgery. Three had unilateral tucks with a contralateral Harada-Ito procedure. The best results were obtained with isolated superior oblique tucks and tucks in conjunction with a contralateral inferior rectus muscle recession or an ipsilateral inferior oblique muscle weakening procedure. The mean vertical correction following isolated, unilateral surgery was 3.6 prism diopters (range, 0 to 11 delta) in primary gaze and 15.3 delta (range, 0 to 40 delta) in the field of maximum deviation. The mean eso correction in downgaze with bilateral superior oblique tucks was 15.2 delta (range, 10 to 21 delta). There was no statistically significant correlation between the size of the tuck and the amount of deviation corrected. Some degree of postoperative Brown syndrome was seen in all patients, but became less marked with time and in no patient was it severe enough to require reversal of the tuck. In only four patients was there a significant lessening of the effect of the procedure with time. The results show that the superior oblique tuck procedure is an effective operation. In patients with unilateral muscle palsies, 64.3% with an abnormal head posture, 37.5% with diplopia, and 100% with both an abnormal head posture and diplopia achieved an excellent result. In patients with bilateral muscle palsies, 50% with an abnormal head posture and 66% with both an abnormal head posture and diplopia achieved an excellent result.

Bilateral fourth nerve palsy due to cerebellar haemangioblastoma

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