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Treatment of Superior Oblique Palsy with Superior Oblique Tendon Tuck and Inferior Oblique Muscle Myectomy
Treatment of Superior Oblique Palsy with Superior Oblique Tendon Tucl< and Inferior Oblique Muscle Myectomy RICHARD A. SAUNDERS, MD
Abstract: Twelve patients underwent quantitated superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy in the primary treatment of unilateral superior oblique muscle palsy. Preoperatively, each patient exhibited a vertical deviation of 30-55 prism diopters in at least one position of gaze. Following a single operation, satisfactory ocular alignment was obtained in all but one case, with fusion demonstrable in clinically significant gaze positions. Eight of 12 patients had no measurable vertical deviation in primary position, and two others had residual hyperphorias of only two prism diopters. No tucks were removed for postoperative Brown's syndrome. Superior oblique tendon tuck combined with ipsilateral inferior oblique muscle myectomy appears to be a safe and effective treatment for large angle superior oblique muscle palsy. [Key words: cranial nerve palsy, superior oblique muscle palsy, superior oblique tendon tuck.] Ophthalmology 93: 1023-1 027, 1986
Patients presenting with cyclovertical muscle palsies are frequently symptomatic from diplopia, anomalous head posture, and loss of binocular vision in functionally important gaze positions. Treatment is generally directed toward achieving fusion in the practical field of gaze, elimination of abnormal head posture, and reduction in symptoms. In attempting to achieve these objectives, weakening the overacting direct antagonist (inferior oblique muscle), appears to be the preferred initial procedure of most authors. I - 7 This surgical approach is generally recommended, regardless of the magnitude of the hyperdeviation being treated. However, it has been our experience that patients with large angle, vertical deviations, either in primary position or other diagnostic gaze positions, usually do not achieve lasting cure with single muscle operations. We have therefore routinely combined
From the Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina. Presented at an Annual Meeting of the American Academy of Ophthalmology. Reprint requests to Richard A. Saunders, MD, 171 Ashley Avenue. Charleston, SC 29425.
quantitated superior oblique tendon tuck with ipsilateral inferior oblique muscle myectomy in these cases. This article reports 12 patients with large angle superior oblique muscle palsy treated by this method over the past six years.
MATERIALS AND METHOD Clinical data were collected on 12 patients ranging in age from 5 to 53 years, who underwent superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy in the management of unilateral superior oblique muscle palsy. Six of these cases were believed to be congenital in origin, with the others being either post-traumatic or of undetermined cause. One patient had injury to the trochlear nerve during resection of a cerebello-pontine angle tumor. Patients selected for this study had pre-operative vertical deviations of at least 30 prism diopters in one or more diagnostic gaze positions (mean, 37.9). Hyperdeviation in primary position ranged from 10 to 55 prism diopters (mean, 24.7). All patients had clinical overaction of the ipsilateral inferior oblique muscle and fell into classes III or IV superior oblique muscle palsy, as described by 1023
OPHTHALMOLOGY •
AUGUST 1986 •
Fig 1. Intraoperative forced duction technique used to quantitate each superior oblique tendon tuck. The tuck is adjusted so that resistance to elevation in adduction is first detected as the inferior limbus crosses an imaginary line between the medial and lateral canthus. (Reprinted with permission, University of Wisconsin Press, Madison, Wisconsin. ll )
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Fig 2. Correction of hyperdeviation in 12 patients following superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy. Distance measurement. Circles denote greatest preoperative deviation in a diagnostic position of gaze; broad arrowheads, preoperative deviation in primary position; narrow arrowheads, postoperative deviation in primary position.
Knapp8,9 and Knapp and Moore. 10 There was a minimum waiting period of six months between the onset of symptoms and surgical treatment. Patients who had undergone previous strabismus surgery, or in whom the diagnosis was equivocal, were excluded from the study. Small angle horizontal deviations, when present, were not incorporated into the surgical plan. No patient received concomitant surgery on any rectus muscle. A description of our surgical methods has been previously reported. II The ipsilateral inferior oblique muscle was weakened by myectomy, using the technique described by Jampolsky.12 A quantitated superior oblique tendon tuck ranging from 6 to 16 mm was then performed using 5-0 braided dacron suture. The tightness of the 1024
VOLUME 93 •
NUMBER 8
tuck was adjusted intraoperatively (Fig 1). No intraoperative complications were encountered. Before surgery, each patient underwent complete ophthalmological examination. In addition, detailed evaluation of ocular motility was performed. This included prism/cover measurements in primary position and the eight diagnostic gaze positions 30° from primary position, Bielschowsky head tilt test, measurement of subjective cyclotorsion using an amblyoscope or double Maddox rod, and assessment of binocular status with the Worth 4 dot (at 6 meters and 113 meter), and the Randot Stereotest circles. Postoperative examination was performed by the surgeon at one week, one month, and at four-month intervals. In addition, a complete orthoptic evaluation was independently performed on every patient. In cases where there was a disparity between the postoperative findings of the surgeon and the independent examiner, the data of the independent examiner were used for the purposes of this study. Long-term follow-up data were obtained whenever possible. Post-surgical follow-up of the 12 patients ranged from 10 months to 45 months (mean, 24 months; median, 18 months). Follow-up motility evaluation included assessment of post-operative Brown's syndrome. Duction limitation was assessed on a -1 to -4 scale. With the operated eye fixating, the patient was asked to look into the field of action of the ipsilateral inferior oblique muscle. Failure to complete a full duction was presumed to be a restriction caused by the superior oblique tendon tuck. The duction limitation was described as -4 when the adducted eye could not be elevated to the horizontal meridian; - 3 if it could be elevated to, but not above, the horizontal meridian; -2 if it could be elevated 2 mm above the horizontal meridian; and -1 if the inferior limbus reached the horizontal meridian, but this represented a duction limitation when compared with the normal eye.
RESULTS Following a single operation, 8 of 12 (67%) patients had no measurable hyperdeviation in primary position on their last follow-up examination. An additional two patients (17%) had only 2 prism diopters of residual hyperphoria. Subjective cyclotorsion was completely eliminated in eight patients and reduced to negligible levels in the remaining four patients. Individual patient data for vertical deviation and cyclotorsion is provided in Figures 2 and 3. Normal responses on the Worth 4 dot were obtained in 6 of 12 patients (50%) preoperatively and in 11 of 12 patients (92%) postoperatively. Stereo acuity of at least 100 seconds of arc was demonstrated in 8 of 12 patients (67%) preoperatively and in all 12 patients (100%) postoperatively. In addition, seven patients showed improved stereo acuity following surgery. Eleven of 12 patients (92%) had their symptoms eliminated or reduced to a negligible level. All 12 patients achieved fusion in the practical field of gaze at near and including primary position. This was defined as 30° either
SAUNDERS •
SUPERIOR OBLIQUE PALSY
Table 1. Functional Results Following Single Operation for Superior Oblique Muscle Palsy
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Fig 3. Correction of excyclotorsion in 12 patients following superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy. Circles denote preoperative cyclotorsion; arrowheads, postoperative cyclotorsion. Arrowhead appearing alone denotes the absence of preoperative data.
Post-operative Result
Number of Patients
Elimination of significant symptoms Fusion in practical field of gaze Residual torticollis Significant Brown's syndrome
11/12 12/12 3/12 1/12
Table 2. Postoperative Brown's Syndrome Duction Limitation
Number of Eyes
o
2 6 1 2 1
-1
-1-2
side of primary position, 20° upgaze, and 30° downgaze. Torticollis was improved in all patients and totally eliminated in nine (75%) (Table 1). A moderate Brown's syndrome was usually present in the immediate postoperative period and tended to be more pronounced than the intraoperative forced duction limitation. However, ductions improved with time, and 8 of 12 patients (67%) had limitations graded at -1 or less on their last post-operative visit (Table 2). No tucks were removed for this compli~ cation. 13 Mean postoperative hyperdeviation was 1.6 prism diopters in primary position. The effect of surgery ranged from 10 to 53 prism diopters (mean, 24.5). An attempt was made to correlate the preoperative vertical deviation in primary position with the amount of tuck eventually performed at the time of surgery. No statistically significant correlation was found using the Spearman rank correlation analysis. However, a significant correlation (P < 0.05) was present when the vertical'deviation in the field of greatest hypertropia (X) was compared with the amount of tuck (Y) performed at the time of surgery (Table 3). This relationship produces a linear regression line Y = 0.23X + 0.84 with a standard deviation of 2.51 mm.
-2
-2-3 -3 -4
o o
Table 3. Relationship of Preoperative Deviation to Amount of Tendon Tuck Performed Tendon Tuck (mm)
Preoperative Deviation (primary position)*
Preoperative Deviation (maximum)*
6 6 8 8 8 8 10 10 10 12 14 16
20 25 25 30 10 18 25 25 28 25 10 55
30 30 30 35 50 30 40 40 40 30 45 55
* Prism diopters.
CASE REPORT Case 8. A 5-year-old girl was referred for treatment of a suspected left superior oblique muscle palsy. History revealed a right face turn and left hypertropia in right gaze dating from early childhood. Her ophthalmologic examination was normal except for motility. An intermittent left hypertropia of25 prism diopters was present in primary position at distance and near. There was 3+ overaction of the left inferior oblique muscle and -2 underaction of the left superior oblique muscle. A maximum vertical deviation of 40 prism diopters was measured in 30° right gaze and in up-right gaze. Bielschowsky head tilt test was positive to the left. The' patient was unable to cooperate with double Maddox rod testing; however, no objective cyclotorsion was noted in either eye on fundus examination. She was diagnosed as having a congenital left superior oblique muscle palsy and was hospitalized for strabismus surgery. Using our quantitated technique,1l a to-mm left superior
oblique tendon tuck and left inferior oblique muscle myectomy were performed. One month postoperatively, a small right hypertropia was present in primary position and right gaze. This was associated with a left head tilt and a moderate Brown's syndrome in the operated eye. Two years after surgery, the patient was orthophoric in primary position at both distance and near and could fuse in aU diagnostic gaze positions. Her face turn was gone. No torsion could be demonstrated with the double Maddox rod. A mild Brown's syndrome was present in the left eye and associated with a small right hypertropia and diplopia in extreme upgaze (Fig 4). She was otherwise asymptomatic.
DISCUSSION There is general agreement that the preferred operation for treatment of most patients with unilateral superior 1025
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•
AUGUST 1986 •
VOLUME 93
•
NUMBER 8
Fig 4. Left, five-year-old girl with congenital left superior oblique muscle palsy one month after a lO-mm left superior oblique tendon tuck and left inferior oblique muscle myectomy. A moderate Brown's syndrome is present in the operated eye. Right, same patient two years postoperatively. There is no measurable hyperdeviation in primary position at distance or near. The Brown's syndrome has improved.
oblique palsy is weakening of the overacting direct antagonist, inferior oblique muscle. This can be successfully accomplished by measured recession, disinsertion, myectomy, or even denervation and extirpation. 6,7,14,15 Response to surgery appears to be related to the magnitude of the preoperative vertical deviation, and most patients therefore achieve satisfactory postoperative alignment. While some authors recommend two-muscle procedures as the initial operation in patients with larger angle vertical deviations,8-12,16,17 this appears to be a minority view. However, there is evidence that these patients are not predictably cured with single-muscle operations. Middleman and Folk reported on the surgical management of 86 patients with superior oblique muscle palsy seen over a seven-year period. 17 Seventeen patients (20%) required surgery on two muscles to achieve satisfactory postoperative alignment. Middleman and Folk recommended combining inferior oblique muscle myectomy with contralateral inferior rectus muscle recession in patients when more than 25 prism diopters of hyperdeviation is present in primary position. Toosi and von Noorden calculated the quantitative effect of isolated inferior oblique muscle myectomy in patients with unilateral superior oblique muscle palsy.6 While their overall results were favorable, this series has a preponderance of smaller angle deviations. Mean preoperative deviation in primary position was 15.1 prism diopters, with only 4 patients of33 (12%) measuring more than 25 prism diopters of hypertropia in the field of action of the paretic superior oblique or antagonist inferior oblique muscles. In these cases, the average reduction in hypertropia was substantially less than the amount of deviation measured preoperatively, suggesting that some patients were surgically undercorrected, at least in oblique gaze positions. The authors do not state whether secondary surgical procedures were eventually required. Reynolds et al retrospectively reviewed 20 cases of infants with congenital superior oblique muscle palsy operated before two years of age. 18 In the presence of a man1026
ifest hyperdeviation in primary position, none of the six patients treated by inferior oblique weakening alone was cured by this procedure. In contrast, six of seven patients (86%) without a manifest deviation in primary position responded satisfactorily to isolated inferior oblique muscle weakening. All three patients treated with combined superior oblique tendon tuck and ipsilateral inferior oblique muscle weakening achieved satisfactory post-operative alignment. While statistical analysis does not show twomuscle procedures to be superior because of the small number of patients involved, it does suggest that inferior oblique muscle weakening alone will result in failure if a primary position hypertropia is found on preoperative examination. It would thus appear, at least in these younger patients, that more aggressive surgical management is warranted. All patients in our series demonstrated at least 30 prism diopters of hypertropia in one or more fields of gaze preoperatively. It has been our experience that isolated inferior oblique muscle weakening in these larger angle cases usually leads to long-term undercorrection. While single muscle surgery may yield improved control of the deviation in patients with well-developed fusional vergences, reoperation can still be required for persisting symptoms. Some authors favor concomitant recession of the ipsilateral inferior oblique and contralateral inferior rectus muscles. 12 ,17 While this allows the convenient use of an adjustable suture in adult patients, rectus muscle recession does not effectively correct cyclotorsion, frequently results in lower eyelid deformity, and may yield inappropriate results in patients with lateral gaze incomitance. In addition, some patients prefer to have their surgery limited to the abnormal eye. Following superior oblique te~don tuck and ipsilateral inferior oblique muscle myectomy, all patients initially had evidence of iatrogenic Brown's syndrome in the operated eye. This finding was frequently accompanied by a small overcorrection in primary position and subjective cyclotorsion. However, the Brown's syndrome failed to
SAUNDERS •
SUPERIOR OBLIQUE PALSY
improve, causing persisting clinical symptoms, in only one patient. The remaining patients reported diplopia (if any) only in extreme gaze positions. No tuck take-downs were performed or recommended. Our one patient on whom surgery failed was initially asymptomatic but had his right hypertropia return three y~ars post-operatively. The cause of this late recurrence is uncertain. Our mean correction of hyperdeviation in primary position was 24.5 prism diopters. This is signific~ntly greater than the effect achieved by inft1nor obliqu~ muscle myectomy alone (P < 0.01).6 One patient had more than 50 prism diopters of hypertropia corrected in primary position. Since we had only one patient with a permanent overcorrection (an occult bilateral superior oblique muscle palsy), it appears that our more aggressive surgical approach is justified, regardless of the magnitude of the preoperative hyperdeviation in primary position. StatistiCal analysis of our data also suggests that the greatest hypertropia in a diagnostic position of gaze is a better predictor of. surgical requirement than the deviation measured in . . I pnmary posItion. While our results in this selected group of patients are obviously favorable, not all patients surgically treated for superior oblique muscle palsy had similar outcomes. In this report, we h'lve intentionally excluded patients treated by other surgical modalities, either by choice or out of necessity, or in whom there was a significant horizpntal deviation requiring correction. As a group, they fared worse, with a tendency toward overcorrection of their horizontal strabismus. Use of adjustable sutures has eliminated some, but not all, of our problems in this regard. In summary, we report on the surgical results of 12 patients treated with quantitated superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy for large angle superior oblique muscle palsy. While this was not a controlled series, our results appear to be superior to those in which inferior oblique weakening is performed alone. However, comparison with studies providing limited clinical information is difficult and conclusions as to relative efficacy should be tentative. While our technique is not difficult to perform, patient selection is important, and other surgeons may achieve different results.
REFERENCES 1. Parks MM, Hamtil LW. Surgical management of isolated cyclovertical muscle palsy. J Pediatr Ophthalmol Strabismus 1971; 8: 145-52. 2. Awaya S, Nozaki H, Miyake Y, et al. Inferior oblique myectomy in superior oblique paresis. Jpn J Clin Ophthalmol1973; 27:619-28. 3. Parks MM. Ocular Motility and Strabismus. Hagerstown: Harper & Row, 1975; 161. 4. Folk ER. Indications for weakening the inferior oblique muscle. Am Orthopt J 1975; 25:131-4. 5. Younge BR, Sutula F. Analysis of trochlear nerve palsies; diagnosis, etiology, and treatment. Mayo Clin Proc 1977; 52:11-8. 6. Toosi SH, von Noorden GK. Effect of isolated inferior oblique muscle myectomy in the management of superior oblique muscle palsy. Am J Ophthalmol 1979; 88:602-8. 7. Katz NNK. Denervation and extirpation of the inferior oblique muscle as the primary surgical procedure in the treatment of superior oblique palsy. In: Reinecke RD, ed. Strabismus II; Proceedings of the Fourth Meeting of the Intemational Strabismological Association October 2529, 1982 ASilomar, Califomia. Orlando FL: Grune & Stratton, 1984; 821-7. 8. Knapp P. Diagnosis and surgical treatment of hypertropia. Am Orthopt J 1971; 21:29-37. 9. Knapp P. Classification and treatment of superior oblique palsy. Am Orthopt J 1974; 24:18-22. 10. Knapp P, Moore S. Diagnosis and surgical options in superior oblique surgery. Int Ophthalmol Clin 1976; 16(3):137-49. 11. Saunders RA, Tomlinson E. Quantitated superior oblique tendon tuck in the treatment of superior oblique muscle palsy. Am Orthopt J 1985; 35:81-9. 12. Jampolsky A. Vertical strabismus surgery. In: Symposium on Strabismus; Transactions of the New Orleans Academy of Ophthalmology. St Louis: CV Mosby, 1971; 382-4. 13. Helveston EM. Superior oblique strengthening procedures. Am Orthopt J 1'984; 34:100-3. 14. Dyer JA, Duke DG. Inferior oblique weakening procedures. Int Ophthalmol Clin 1976; 16(3):103-12. 15. Helveston EM, Haldi BA. Surgical weakening of the inferior oblique. Int Ophthalmol Clin 1976; 16(3):113-26. 16. Khawam E, Scott AB, Jampolsky A. Acquired superior oblique palsy; diagnosis and management. Arch OphthalmoI1~67; 77:761-8. 17. Mittelman 0, Folk ER. The evaluation and treatment of superior oblique muscle palsy. Trans Am Acad Ophthalmol Otolaryngol 1976; 81:893-8. 18. Reynolds JD, Biglan AW, Hiles DA. Congenital superior oblique palsy in infants. Arch Ophthalmol1984; 102:1503-5.
1027
Abstract: Twelve patients underwent quantitated superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy in the primary treatment of unilateral superior oblique muscle palsy. Preoperatively, each patient exhibited a vertical deviation of 30-55 prism diopters in at least one position of gaze. Following a single operation, satisfactory ocular alignment was obtained in all but one case, with fusion demonstrable in clinically significant gaze positions. Eight of 12 patients had no measurable vertical deviation in primary position, and two others had residual hyperphorias of only two prism diopters. No tucks were removed for postoperative Brown's syndrome. Superior oblique tendon tuck combined with ipsilateral inferior oblique muscle myectomy appears to be a safe and effective treatment for large angle superior oblique muscle palsy. [Key words: cranial nerve palsy, superior oblique muscle palsy, superior oblique tendon tuck.] Ophthalmology 93: 1023-1 027, 1986
Patients presenting with cyclovertical muscle palsies are frequently symptomatic from diplopia, anomalous head posture, and loss of binocular vision in functionally important gaze positions. Treatment is generally directed toward achieving fusion in the practical field of gaze, elimination of abnormal head posture, and reduction in symptoms. In attempting to achieve these objectives, weakening the overacting direct antagonist (inferior oblique muscle), appears to be the preferred initial procedure of most authors. I - 7 This surgical approach is generally recommended, regardless of the magnitude of the hyperdeviation being treated. However, it has been our experience that patients with large angle, vertical deviations, either in primary position or other diagnostic gaze positions, usually do not achieve lasting cure with single muscle operations. We have therefore routinely combined
From the Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina. Presented at an Annual Meeting of the American Academy of Ophthalmology. Reprint requests to Richard A. Saunders, MD, 171 Ashley Avenue. Charleston, SC 29425.
quantitated superior oblique tendon tuck with ipsilateral inferior oblique muscle myectomy in these cases. This article reports 12 patients with large angle superior oblique muscle palsy treated by this method over the past six years.
MATERIALS AND METHOD Clinical data were collected on 12 patients ranging in age from 5 to 53 years, who underwent superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy in the management of unilateral superior oblique muscle palsy. Six of these cases were believed to be congenital in origin, with the others being either post-traumatic or of undetermined cause. One patient had injury to the trochlear nerve during resection of a cerebello-pontine angle tumor. Patients selected for this study had pre-operative vertical deviations of at least 30 prism diopters in one or more diagnostic gaze positions (mean, 37.9). Hyperdeviation in primary position ranged from 10 to 55 prism diopters (mean, 24.7). All patients had clinical overaction of the ipsilateral inferior oblique muscle and fell into classes III or IV superior oblique muscle palsy, as described by 1023
OPHTHALMOLOGY •
AUGUST 1986 •
Fig 1. Intraoperative forced duction technique used to quantitate each superior oblique tendon tuck. The tuck is adjusted so that resistance to elevation in adduction is first detected as the inferior limbus crosses an imaginary line between the medial and lateral canthus. (Reprinted with permission, University of Wisconsin Press, Madison, Wisconsin. ll )
,--
55
-
50
. ~
Ci
45
40
o '0
35
.~
30
2
5 >= «
'>
~ II:
25
20
15
-
10
UJ
5
I
o
,..
a.
-5 -10
-
\
Fig 2. Correction of hyperdeviation in 12 patients following superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy. Distance measurement. Circles denote greatest preoperative deviation in a diagnostic position of gaze; broad arrowheads, preoperative deviation in primary position; narrow arrowheads, postoperative deviation in primary position.
Knapp8,9 and Knapp and Moore. 10 There was a minimum waiting period of six months between the onset of symptoms and surgical treatment. Patients who had undergone previous strabismus surgery, or in whom the diagnosis was equivocal, were excluded from the study. Small angle horizontal deviations, when present, were not incorporated into the surgical plan. No patient received concomitant surgery on any rectus muscle. A description of our surgical methods has been previously reported. II The ipsilateral inferior oblique muscle was weakened by myectomy, using the technique described by Jampolsky.12 A quantitated superior oblique tendon tuck ranging from 6 to 16 mm was then performed using 5-0 braided dacron suture. The tightness of the 1024
VOLUME 93 •
NUMBER 8
tuck was adjusted intraoperatively (Fig 1). No intraoperative complications were encountered. Before surgery, each patient underwent complete ophthalmological examination. In addition, detailed evaluation of ocular motility was performed. This included prism/cover measurements in primary position and the eight diagnostic gaze positions 30° from primary position, Bielschowsky head tilt test, measurement of subjective cyclotorsion using an amblyoscope or double Maddox rod, and assessment of binocular status with the Worth 4 dot (at 6 meters and 113 meter), and the Randot Stereotest circles. Postoperative examination was performed by the surgeon at one week, one month, and at four-month intervals. In addition, a complete orthoptic evaluation was independently performed on every patient. In cases where there was a disparity between the postoperative findings of the surgeon and the independent examiner, the data of the independent examiner were used for the purposes of this study. Long-term follow-up data were obtained whenever possible. Post-surgical follow-up of the 12 patients ranged from 10 months to 45 months (mean, 24 months; median, 18 months). Follow-up motility evaluation included assessment of post-operative Brown's syndrome. Duction limitation was assessed on a -1 to -4 scale. With the operated eye fixating, the patient was asked to look into the field of action of the ipsilateral inferior oblique muscle. Failure to complete a full duction was presumed to be a restriction caused by the superior oblique tendon tuck. The duction limitation was described as -4 when the adducted eye could not be elevated to the horizontal meridian; - 3 if it could be elevated to, but not above, the horizontal meridian; -2 if it could be elevated 2 mm above the horizontal meridian; and -1 if the inferior limbus reached the horizontal meridian, but this represented a duction limitation when compared with the normal eye.
RESULTS Following a single operation, 8 of 12 (67%) patients had no measurable hyperdeviation in primary position on their last follow-up examination. An additional two patients (17%) had only 2 prism diopters of residual hyperphoria. Subjective cyclotorsion was completely eliminated in eight patients and reduced to negligible levels in the remaining four patients. Individual patient data for vertical deviation and cyclotorsion is provided in Figures 2 and 3. Normal responses on the Worth 4 dot were obtained in 6 of 12 patients (50%) preoperatively and in 11 of 12 patients (92%) postoperatively. Stereo acuity of at least 100 seconds of arc was demonstrated in 8 of 12 patients (67%) preoperatively and in all 12 patients (100%) postoperatively. In addition, seven patients showed improved stereo acuity following surgery. Eleven of 12 patients (92%) had their symptoms eliminated or reduced to a negligible level. All 12 patients achieved fusion in the practical field of gaze at near and including primary position. This was defined as 30° either
SAUNDERS •
SUPERIOR OBLIQUE PALSY
Table 1. Functional Results Following Single Operation for Superior Oblique Muscle Palsy
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Fig 3. Correction of excyclotorsion in 12 patients following superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy. Circles denote preoperative cyclotorsion; arrowheads, postoperative cyclotorsion. Arrowhead appearing alone denotes the absence of preoperative data.
Post-operative Result
Number of Patients
Elimination of significant symptoms Fusion in practical field of gaze Residual torticollis Significant Brown's syndrome
11/12 12/12 3/12 1/12
Table 2. Postoperative Brown's Syndrome Duction Limitation
Number of Eyes
o
2 6 1 2 1
-1
-1-2
side of primary position, 20° upgaze, and 30° downgaze. Torticollis was improved in all patients and totally eliminated in nine (75%) (Table 1). A moderate Brown's syndrome was usually present in the immediate postoperative period and tended to be more pronounced than the intraoperative forced duction limitation. However, ductions improved with time, and 8 of 12 patients (67%) had limitations graded at -1 or less on their last post-operative visit (Table 2). No tucks were removed for this compli~ cation. 13 Mean postoperative hyperdeviation was 1.6 prism diopters in primary position. The effect of surgery ranged from 10 to 53 prism diopters (mean, 24.5). An attempt was made to correlate the preoperative vertical deviation in primary position with the amount of tuck eventually performed at the time of surgery. No statistically significant correlation was found using the Spearman rank correlation analysis. However, a significant correlation (P < 0.05) was present when the vertical'deviation in the field of greatest hypertropia (X) was compared with the amount of tuck (Y) performed at the time of surgery (Table 3). This relationship produces a linear regression line Y = 0.23X + 0.84 with a standard deviation of 2.51 mm.
-2
-2-3 -3 -4
o o
Table 3. Relationship of Preoperative Deviation to Amount of Tendon Tuck Performed Tendon Tuck (mm)
Preoperative Deviation (primary position)*
Preoperative Deviation (maximum)*
6 6 8 8 8 8 10 10 10 12 14 16
20 25 25 30 10 18 25 25 28 25 10 55
30 30 30 35 50 30 40 40 40 30 45 55
* Prism diopters.
CASE REPORT Case 8. A 5-year-old girl was referred for treatment of a suspected left superior oblique muscle palsy. History revealed a right face turn and left hypertropia in right gaze dating from early childhood. Her ophthalmologic examination was normal except for motility. An intermittent left hypertropia of25 prism diopters was present in primary position at distance and near. There was 3+ overaction of the left inferior oblique muscle and -2 underaction of the left superior oblique muscle. A maximum vertical deviation of 40 prism diopters was measured in 30° right gaze and in up-right gaze. Bielschowsky head tilt test was positive to the left. The' patient was unable to cooperate with double Maddox rod testing; however, no objective cyclotorsion was noted in either eye on fundus examination. She was diagnosed as having a congenital left superior oblique muscle palsy and was hospitalized for strabismus surgery. Using our quantitated technique,1l a to-mm left superior
oblique tendon tuck and left inferior oblique muscle myectomy were performed. One month postoperatively, a small right hypertropia was present in primary position and right gaze. This was associated with a left head tilt and a moderate Brown's syndrome in the operated eye. Two years after surgery, the patient was orthophoric in primary position at both distance and near and could fuse in aU diagnostic gaze positions. Her face turn was gone. No torsion could be demonstrated with the double Maddox rod. A mild Brown's syndrome was present in the left eye and associated with a small right hypertropia and diplopia in extreme upgaze (Fig 4). She was otherwise asymptomatic.
DISCUSSION There is general agreement that the preferred operation for treatment of most patients with unilateral superior 1025
OPHTHALMOLOGY
•
AUGUST 1986 •
VOLUME 93
•
NUMBER 8
Fig 4. Left, five-year-old girl with congenital left superior oblique muscle palsy one month after a lO-mm left superior oblique tendon tuck and left inferior oblique muscle myectomy. A moderate Brown's syndrome is present in the operated eye. Right, same patient two years postoperatively. There is no measurable hyperdeviation in primary position at distance or near. The Brown's syndrome has improved.
oblique palsy is weakening of the overacting direct antagonist, inferior oblique muscle. This can be successfully accomplished by measured recession, disinsertion, myectomy, or even denervation and extirpation. 6,7,14,15 Response to surgery appears to be related to the magnitude of the preoperative vertical deviation, and most patients therefore achieve satisfactory postoperative alignment. While some authors recommend two-muscle procedures as the initial operation in patients with larger angle vertical deviations,8-12,16,17 this appears to be a minority view. However, there is evidence that these patients are not predictably cured with single-muscle operations. Middleman and Folk reported on the surgical management of 86 patients with superior oblique muscle palsy seen over a seven-year period. 17 Seventeen patients (20%) required surgery on two muscles to achieve satisfactory postoperative alignment. Middleman and Folk recommended combining inferior oblique muscle myectomy with contralateral inferior rectus muscle recession in patients when more than 25 prism diopters of hyperdeviation is present in primary position. Toosi and von Noorden calculated the quantitative effect of isolated inferior oblique muscle myectomy in patients with unilateral superior oblique muscle palsy.6 While their overall results were favorable, this series has a preponderance of smaller angle deviations. Mean preoperative deviation in primary position was 15.1 prism diopters, with only 4 patients of33 (12%) measuring more than 25 prism diopters of hypertropia in the field of action of the paretic superior oblique or antagonist inferior oblique muscles. In these cases, the average reduction in hypertropia was substantially less than the amount of deviation measured preoperatively, suggesting that some patients were surgically undercorrected, at least in oblique gaze positions. The authors do not state whether secondary surgical procedures were eventually required. Reynolds et al retrospectively reviewed 20 cases of infants with congenital superior oblique muscle palsy operated before two years of age. 18 In the presence of a man1026
ifest hyperdeviation in primary position, none of the six patients treated by inferior oblique weakening alone was cured by this procedure. In contrast, six of seven patients (86%) without a manifest deviation in primary position responded satisfactorily to isolated inferior oblique muscle weakening. All three patients treated with combined superior oblique tendon tuck and ipsilateral inferior oblique muscle weakening achieved satisfactory post-operative alignment. While statistical analysis does not show twomuscle procedures to be superior because of the small number of patients involved, it does suggest that inferior oblique muscle weakening alone will result in failure if a primary position hypertropia is found on preoperative examination. It would thus appear, at least in these younger patients, that more aggressive surgical management is warranted. All patients in our series demonstrated at least 30 prism diopters of hypertropia in one or more fields of gaze preoperatively. It has been our experience that isolated inferior oblique muscle weakening in these larger angle cases usually leads to long-term undercorrection. While single muscle surgery may yield improved control of the deviation in patients with well-developed fusional vergences, reoperation can still be required for persisting symptoms. Some authors favor concomitant recession of the ipsilateral inferior oblique and contralateral inferior rectus muscles. 12 ,17 While this allows the convenient use of an adjustable suture in adult patients, rectus muscle recession does not effectively correct cyclotorsion, frequently results in lower eyelid deformity, and may yield inappropriate results in patients with lateral gaze incomitance. In addition, some patients prefer to have their surgery limited to the abnormal eye. Following superior oblique te~don tuck and ipsilateral inferior oblique muscle myectomy, all patients initially had evidence of iatrogenic Brown's syndrome in the operated eye. This finding was frequently accompanied by a small overcorrection in primary position and subjective cyclotorsion. However, the Brown's syndrome failed to
SAUNDERS •
SUPERIOR OBLIQUE PALSY
improve, causing persisting clinical symptoms, in only one patient. The remaining patients reported diplopia (if any) only in extreme gaze positions. No tuck take-downs were performed or recommended. Our one patient on whom surgery failed was initially asymptomatic but had his right hypertropia return three y~ars post-operatively. The cause of this late recurrence is uncertain. Our mean correction of hyperdeviation in primary position was 24.5 prism diopters. This is signific~ntly greater than the effect achieved by inft1nor obliqu~ muscle myectomy alone (P < 0.01).6 One patient had more than 50 prism diopters of hypertropia corrected in primary position. Since we had only one patient with a permanent overcorrection (an occult bilateral superior oblique muscle palsy), it appears that our more aggressive surgical approach is justified, regardless of the magnitude of the preoperative hyperdeviation in primary position. StatistiCal analysis of our data also suggests that the greatest hypertropia in a diagnostic position of gaze is a better predictor of. surgical requirement than the deviation measured in . . I pnmary posItion. While our results in this selected group of patients are obviously favorable, not all patients surgically treated for superior oblique muscle palsy had similar outcomes. In this report, we h'lve intentionally excluded patients treated by other surgical modalities, either by choice or out of necessity, or in whom there was a significant horizpntal deviation requiring correction. As a group, they fared worse, with a tendency toward overcorrection of their horizontal strabismus. Use of adjustable sutures has eliminated some, but not all, of our problems in this regard. In summary, we report on the surgical results of 12 patients treated with quantitated superior oblique tendon tuck and ipsilateral inferior oblique muscle myectomy for large angle superior oblique muscle palsy. While this was not a controlled series, our results appear to be superior to those in which inferior oblique weakening is performed alone. However, comparison with studies providing limited clinical information is difficult and conclusions as to relative efficacy should be tentative. While our technique is not difficult to perform, patient selection is important, and other surgeons may achieve different results.
REFERENCES 1. Parks MM, Hamtil LW. Surgical management of isolated cyclovertical muscle palsy. J Pediatr Ophthalmol Strabismus 1971; 8: 145-52. 2. Awaya S, Nozaki H, Miyake Y, et al. Inferior oblique myectomy in superior oblique paresis. Jpn J Clin Ophthalmol1973; 27:619-28. 3. Parks MM. Ocular Motility and Strabismus. Hagerstown: Harper & Row, 1975; 161. 4. Folk ER. Indications for weakening the inferior oblique muscle. Am Orthopt J 1975; 25:131-4. 5. Younge BR, Sutula F. Analysis of trochlear nerve palsies; diagnosis, etiology, and treatment. Mayo Clin Proc 1977; 52:11-8. 6. Toosi SH, von Noorden GK. Effect of isolated inferior oblique muscle myectomy in the management of superior oblique muscle palsy. Am J Ophthalmol 1979; 88:602-8. 7. Katz NNK. Denervation and extirpation of the inferior oblique muscle as the primary surgical procedure in the treatment of superior oblique palsy. In: Reinecke RD, ed. Strabismus II; Proceedings of the Fourth Meeting of the Intemational Strabismological Association October 2529, 1982 ASilomar, Califomia. Orlando FL: Grune & Stratton, 1984; 821-7. 8. Knapp P. Diagnosis and surgical treatment of hypertropia. Am Orthopt J 1971; 21:29-37. 9. Knapp P. Classification and treatment of superior oblique palsy. Am Orthopt J 1974; 24:18-22. 10. Knapp P, Moore S. Diagnosis and surgical options in superior oblique surgery. Int Ophthalmol Clin 1976; 16(3):137-49. 11. Saunders RA, Tomlinson E. Quantitated superior oblique tendon tuck in the treatment of superior oblique muscle palsy. Am Orthopt J 1985; 35:81-9. 12. Jampolsky A. Vertical strabismus surgery. In: Symposium on Strabismus; Transactions of the New Orleans Academy of Ophthalmology. St Louis: CV Mosby, 1971; 382-4. 13. Helveston EM. Superior oblique strengthening procedures. Am Orthopt J 1'984; 34:100-3. 14. Dyer JA, Duke DG. Inferior oblique weakening procedures. Int Ophthalmol Clin 1976; 16(3):103-12. 15. Helveston EM, Haldi BA. Surgical weakening of the inferior oblique. Int Ophthalmol Clin 1976; 16(3):113-26. 16. Khawam E, Scott AB, Jampolsky A. Acquired superior oblique palsy; diagnosis and management. Arch OphthalmoI1~67; 77:761-8. 17. Mittelman 0, Folk ER. The evaluation and treatment of superior oblique muscle palsy. Trans Am Acad Ophthalmol Otolaryngol 1976; 81:893-8. 18. Reynolds JD, Biglan AW, Hiles DA. Congenital superior oblique palsy in infants. Arch Ophthalmol1984; 102:1503-5.
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