Cases Of Superior Oblique Palsy Research Articles

Vertical Comitance of Hypertropia in Congenital and Acquired Superior Oblique Palsy.

Ivanir and Trobe have claimed that hypertropia (HT) that is greater in upgaze than downgaze, or equal to it, is characteristic of decompensated congenital superior oblique (SO) palsy and never present in ischemic, traumatic, or tumorous SO palsy. The reliability of this claim was tested in patients with SO palsy confirmed by MRI demonstration of subnormal ipsilesional SO size. Quasi-coronal, surface coil MRI was performed in target-controlled central gaze to identify patients with a unilateral reduction in SO cross section indicative of palsy. Nine patients gave an unequivocal history or had markedly increased vertical fusional amplitudes indicative of congenital onset (mean age 38 ± 16 years, SD). Seven patients had unequivocal acquired onset (age 47 ± 14 years and symptom duration 5.4 ± 4.8 years), including 2 with demonstrated trochlear Schwannoma and 5 with onset after severe head trauma. Fifteen patients had gradually progressive onset unequivocally not congenital yet not associated with any identifiable precipitating event (age 52 ± 20 years and symptom duration 13 ± 14 years). Maximum SO cross section averaged 8.6 ± 3.9 mm2 in congenital palsy, not significantly different from 11.3 ± 3.5 mm2 in acquired palsy (P = 0.08) either unequivocally or progressively acquired, but significantly less than about 19 mm2 contralesionally in SO palsy (P < 10-4). Although mean central gaze HT was greater at 20.6 ± 8.0Δ in 9 cases of congenital than that in 22 acquired cases at 11.4 ± 6.8Δ (P = 0.002), HT was 8.4 ± 16.3Δ less in upgaze than downgaze in congenital SO palsy and 3.7 ± 11.2Δ less in acquired SO palsy. In congenital palsy, 33% of patients had HT greater in upgaze than downgaze while in 67% HT was greater in downgaze (by up to 42Δ). In acquired SO palsy, HT was greater in upgaze than downgaze or equal to it in 8 cases (36%, P = 0.87, X2). In acquired SO palsy, HT was greater in upgaze than downgaze in 37% and greater in downgaze than upgaze in 59% of cases. The HT was equal in upgaze and centralgaze in no congenital and 3 acquired cases of SO palsy. Trends were similar in unequivocal acquired and progressive acquired (noncongenital) SO palsy (P > 0.4). Hypertropia is not characteristically greater in upgaze than downgaze in congenital SO palsy proven by SO atrophy on MRI. In fact, average HT is greater in downgaze than upgaze in both acquired and congenital palsy, sometimes strikingly so in the latter. The finding of HT greater in upgaze than downgaze, or equal to it, does not reliably indicate that SO palsy is congenital, nor does maximum SO cross section.

Stepped Strabismus Surgery.

PurposeTo present stepped strabismus surgery as a novel technique in cases of small to moderate angle strabismus.MethodsRetrospective chart review of cases of stepped strabismus surgery from 2010 untill 2018. In stepped surgery, the first muscle is operated on under rapid induction-recovery IV propofol infusion. Patient is assessed in the OR. If deemed necessary, other muscles are operated on under general anesthesia. No adjustable sutures are used.ResultsThe technique was used in 22 cases of superior oblique palsy (SOP) (primary position hypertropia in the range of 12–25 prism diopters) and 29 horizontal strabismus cases (angles in the range 12–20 prism diopters). The first step was an inferior oblique myectomy in the SOP cases and a single rectus recession in the horizontal cases. After intraoperative assessment, 31% (16/51) needed additional muscle surgery. After 6 months of follow up, the overall reoperation rate was 9%. The technique was well tolerated by all patients.ConclusionStepped strabismus surgery is a useful technique for small to moderate angle strabismus cases with the potential for reducing the number of extraocular muscles operated on without compromising the surgical outcome.

Sudden-onset trochlear nerve palsy: clinical characteristics and treatment implications

To identify clinical characteristics, etiologies, and treatment implications of sudden-onset, acquired cases of superior oblique palsy. The medical records of patients diagnosed with trochlear nerve palsy between January 2010 and January 2018 were reviewed retrospectively to identify cases of acquired trochlear nerve palsy with a specific date of onset of acute symptoms or specific causative incident. Patients with congenital palsies or an uncertain date of onset, history of other strabismus, concomitant oculomotor or abducens nerve palsies, or history of strabismus surgery were excluded. Of 214 patients with superior oblique palsy, 23 had sudden-onset, acquired palsies. There were 14 cases of unilateral palsy and 9 cases of bilateral palsy. Patients with unilateral palsy presented with vertical diplopia, while those with bilateral palsy complained of either torsional (4/9 patients) or vertical (5/9 patients) diplopia. The most common etiologies were severe trauma associated with traumatic brain injury, followed by central nervous system neoplasm and stroke. Fifteen patients underwent surgical intervention, 3 of whom required more than one surgery. Patients with acute superior oblique palsy invariably complain of vertical and/or torsional diplopia. Neuroimaging should be considered in cases of acquired superior oblique palsy without a known traumatic cause. Bilateral cases of acquired superior oblique palsy are more challenging to manage surgically because of symptomatic torsional diplopia.

Stepped strabismus surgery

Purpose To present stepped strabismus surgery as a novel technique in cases of small to moderate angle strabismus. Methods Retrospective chart review of cases of stepped strabismus surgery from 2010 untill 2018. In stepped surgery, the first muscle is operated on under rapid induction-recovery IV propofol infusion. Patient is assessed in the OR. If deemed necessary, other muscles are operated on under general anesthesia. No adjustable sutures are used. Results The technique was used in 22 cases of superior oblique palsy (SOP) (primary position hypertropia in the range of 12-25 prism diopters) and 29 horizontal strabismus cases (angles in the range 12-20 prism diopters). The first step was an inferior oblique myectomy in the SOP cases and a single rectus recession in the horizontal cases. After intraoperative assessment, 31% (16/51) needed additional muscle surgery. After 6 months of follow up, the overall reoperation rate was 9%. The technique was well tolerated by all patients. Conclusion Stepped strabismus surgery is a useful technique for small to moderate angle strabismus cases with the potential for reducing the number of extraocular muscles operated on without compromising the surgical outcome.

Superior Oblique Tuck: Its Success as a Single Muscle Treatment for Selected Cases of Superior Oblique Palsy

Purpose: To investigate the results of superior oblique tuck (SOT) for selected cases of superior oblique palsy (SOP) over a 17-year period. The results were correlated by correction of deviation; re-operation rates; rates of iatrogenic Brown’s syndrome; and finally, correlation between tuck size and deviation change. Any differences between the results for congenital and acquired SOP are reported.Methods: A retrospective, cohort study of adults with SOP—with diplopia greatest in the area of action of the paretic superior oblique—who underwent SOT between 1992 and 2009. Pre-, intra- and postoperative measurements were collected. Vertical and torsional measurements in both primary position and area of maximal deviation were analyzed. Intraoperative tuck size was measured and correlated to effect.Results: We report 75 cases of isolated SOT with a mean follow-up of 8.6 months. Significant improvement in deviation in all positions measured was shown (P<0.0001 for all). Twenty-two (29.3%) cases underwent further procedures due to residual diplopia. There were no intraoperative complications. Brown’s syndrome was demonstrated using a Lees screen in 10 cases but none of these were symptomatic. No patients required tuck revision. There was no correlation between tuck size and changes in either vertical or torsional deviations. 42 (56%) had acquired SOP with no significant differences in pre- or postoperative measurements to congenital cases.Conclusions: This is the largest series of SOTs reported with 71% of cases having successful outcome with the one surgical procedure. There are significant improvements in the postoperative measurements for both vertical deviation and torsion. 29.3% of cases required a further procedure consisting mainly of contralateral inferior rectus weakening although ipsilateral inferior oblique weakening was also performed. Because of the lack of correlation between tuck size and correction obtained, we would suggest that SOT should be considered as “one tightness fits all” rather than “one size fits all.”

Treatment of Knapp Class V superior oblique palsy with contralateral inferior rectus muscle recession

Objective: To describe the clinical features of patients with Knapp Class V superior oblique palsy (hypertropia greatest across the lower fields of gaze) and to present the results of a contralateral, adjustable, inferior rectus muscle recession procedure performed on these patients. Design: Clinical, cohort study. Participants: We retrospectively reviewed a series of 4 cases of superior oblique palsy (Knapp Class V). The patients, seen between the years 1991 and 2000, were selected from the private practice of 1 of the authors (Michael Flanders). Methods: Clinical and surgical data were extracted from the patients' records. All patients had had complete ophthalmologic and orthoptic assessments. Those included in this series had difficulty reading and compensated by lowering their chins. They had a hypertropia, which increased in downgaze, decreased in upgaze, and increased on ipsilateral head tilt. Both the ipsilateral superior oblique and inferior rectus muscles were underactive. All 4 patients underwent contralateral, adjustable, inferior rectus muscle recession. Results: The mean vertical deviation of the paretic eye preoperatively was 8.25 prism D (PD) in primary position and 20 PD in downgaze. Postoperatively it was 2 PD in primary position and 5 PD in downgaze. All patients had improved head posture and a more comfortable reading position after surgery. Mean follow-up was 6.4 years (range 1–9 years). Conclusions: Contralateral inferior rectus muscle recession is an effective treatment for visual symptoms associated with Knapp Class V superior oblique palsy.

Ist der einseitige Strabismus sursoadductorius eine paretische Störung? - Kernspintomographische Untersuchungen

Recent reports postulate that the concomitant vertical deviation found in congenital superior oblique palsy is due to mechanical abnormalities rather than a congenitally paretic muscle, and is overcome in most patients by fusion. On the basis of the clinical characteristics alone a primary paresis is indeed unlikely. Although intraoperatively a different elasticity of the superior oblique tendon exists in congenital versus acquired cases of superior oblique palsy, preoperatively performed MR imaging shows that the clinical findings in congenital superior oblique muscle malfunction could nevertheless be of paretic origin. Seventeen consecutive patients (males: n = 13; females: n = 4) were examined. The vertical deviation in adduction was concomitant in vertical versions, the excyclotropia was small and concomitant in all directions of gaze and was less than 10 degrees even after diagnostic occlusion. All patients showed a positive Bielschowsky head tilt phenomenon and large fusional ability. We performed preoperative MR imaging of both orbits in high resolution 3 mm sections in coronal and axial orientations with and without contrast enhancement. In sixteen patients we found a significant reduction in muscle volume or even total aplasia of the superior oblique muscle of the affected side in comparison to the sound muscle on the other side. In contrast, two patients had a full blown clinical picture of a congenital superior oblique palsy but showed symmetrical muscle volumes on both sides in all coronal sections. Hypoplasia or aplasia of the superior oblique muscle on magnetic resonance imaging provides evidence for a primary paretic cause for the vertical squint found with congenital superior oblique dysfunction. It is not clear, however, whether this is caused by a primary hypoplasia or is of neurogenic origin. Our data together with the consistent difference in tendon morphology of the congenital and acquired forms of superior oblique palsy seem to exclude a purely neurogenic cause for the affection.

Skew Transposition of Vertical Rectus Muscles for Excyclovertical Deviation

Purpose: The authors established a surgical treatment for excyclovertical strabismus in which either the inferior rectus muscle or the superior rectus muscle was transposed diagonally. The effects and the safety of the procedure, called skew transposition, were studied. Methods: Eighteen operations using local anesthesia with eye drops were performed on 17 cases, including 10 with superior oblique palsy. Diplopia was checked during the operation with the cooperation of each patient. Both the clinical findings and eye deviation were examined during observation periods. Results: After the first operation, the diplopia in the primary position had disappeared in 10 cases and had improved in the other 7. The average effect of all operations on excyclodeviation was a correction of 6.2 degrees in the primary position. In the 7 cases of superior oblique palsy that received nasal recession of the inferior rectus muscle, the average correction of excyclodeviation was 6.4°, and vertical deviation improved 1.8° per 1 mm of recession. In no case did the diplopia worsen, nor were there any complications. Conclusions: This safe procedure facilitates the simultaneous improvement of both excyclo- and vertical deviations. It may become the treatment of choice for excyclovertical strabismus.

A model of the mechanics of binocular alignment

A computer model (SQUINT) of the static mechanics of human eyes is developed and applied to the diagnosis and treatment of defects of binocular alignment (strabismus). Brief discussions of ocular anatomy, binocular vision, strabismus and its surgical correction, and early strabismus modeling are provided for nonspecialists in these areas. Models of muscle force, muscle path, globe translation, and binocularity are developed. To illustrate the use of the model in clinical cases, it is applied to the diagnosis and surgical treatment of a case of superior oblique palsy. The model's implementation under the UNIX operating system is described.

Superior Oblique Palsy: Diagnosis and Classification

A review of 130 cases of superior oblique palsy suggests that simple office procedures are sufficient to establish the diagnosis. Prism and cover test measurements with alternate eyes fixing in the nine diagnostic positions of gaze proved to be the greatest help in classifying these cases with regard to surgical planning.