Congenital Superior Oblique Palsy Research Articles

Use of a Microelectromechanical Systems Sensor for Objective Measurements of Abnormal Head Posture in Congenital Superior Oblique Palsy Patients.

The purpose of this study was to design an objective method for measurement of head positions as achieved with use of a microelectromechanical systems (MEMS) sensor. In addition, to use this system to observe the abnormal head position (AHP) in patients with congenital superior oblique palsy (SOP) before and after their surgery. An MEMS sensor was designed for recording of the pitch, roll, and yaw values of the head position in real time. The MEMS sensor was then fixed on the synoptophore from -30 degrees to +30 degrees positions horizontally and vertically to test the accuracy of these measurements. Then, we tested 13 participants with AHP using the MEMS method and the photographic method and compared their correlations. Finally, the pitch, roll, and yaw values of head positions were measured using this MEMS sensor in 31 patients with congenital SOP as performed before and after their surgery. The MEMS sensor (LPMS-B2; Alubi, Guangzhou, China; 400 hertz [Hz]), as based on the theory of a gyroscope, was designed and connected to a smartphone via Bluetooth. It was able to conveniently record the patient's pitch, roll, and yaw head positions in real time, recordings which were consistent with the scales of the synoptophore (P > 0.05) and good correlations with the photographic method (P < 0.001). The main preoperative AHP in patients with SOP was roll (22/31, 71%). Pre- and postoperative vertical deviations were 16.4 ± 7.3 prism diopters (PD) and 4.1 ± 4.2 PD, respectively (P = 0.001). The AHP in patients with SOP was positively correlated with the angle of extorsion in the dominant eye (P = 0.01), rather than that of the vertical deviation. The MEMS sensor described in this report is a simple, practical, and accurate objective device for use in head position measurements. In patients with SOP, the AHP is related to the angle of extorsion in the dominant eye. The MEMS sensor was designed as a micro-wireless dynamic high-precision device for AHP measurement, which has the potential for use in a clinic.

Surgical outcomes in patients with congenital superior oblique palsy: A comparison between clinical and radiological diagnosis

PurposeThe diagnosis of superior oblique (SO) palsy can be achieved by examining the radiological and clinical characteristics. Despite their usefulness, the radiological and clinical methods are not always aligned to each other. The objective of this research is to analyze the surgical results of eyes with SO palsy, based on whether the diagnosis was made radiologically or clinically. DesignA prospective study, conducted at a single tertiary hospital. MethodsFollowing the diagnosis of SO palsy, either through clinical assessment or radiological imaging, the patients were categorized into three distinct groups according to their clinical measurements and MRI findings. Group 1 exhibited consistent clinical measurements and MRI findings indicating SO palsy, whereas Group 2 displayed clinical measurements without MRI confirmation. In contrast, Group 3 presented inconclusive measurements, but MRI scans revealed signs of atrophy. Patients underwent inferior oblique (IO) myectomy with and without contralateral inferior rectus recession and ocular deviation before and after myectomy were collected. ResultsThe study included 49 patients with congenital unilateral SO palsy (average age: 30 years). Out of 35 patients who tested positive across all three stages of the test, 15 did not show notable muscle atrophy in their MRI findings. In contrast, among those who displayed muscle atrophy in their MRI scans, 58.8 % had positive outcomes in all steps of the three-step assessment. Group 1 and 3 displayed a reduced muscle volume measuring 110.988 ± 42.49 mm³ and 91.5 ± 56.8 mm³, respectively, on the affected side. Group 2 showcased a muscle volume of 184.1 ± 44.64 mm³ on the affected side. In all three groups with SO palsy eyes who underwent IO myectomy, there was a reduction in hypertropia in the primary position, with no statistically significant differences observed among the groups (P = 0.1). All five patients with SO palsy who underwent IO myectomy with contralateral inferior rectus recession were classified in group 3, and they exhibited a significant reduction in hypertropia postoperatively. ConclusionComparable results can be attained through IO surgery in patients with SO palsy, regardless of whether they are diagnosed through clinical or radiological means.

Clinical effect of superior oblique re-tucking for recurrent or residual compensatory head position

Objective: To evaluate the effects of re-tucking the superior oblique muscle on recurrent or residual compensatory head position. Methods: A retrospective case series study was conducted. 12 recurrent or residual compensatory head position patients (12 eyes) with congenital superior oblique palsy who underwent superior oblique re-tucking in Tianjin Eye Hospital from March 2015 to February 2021 were included. All patients had a history of superior oblique tucking procedure and showed signs of superior oblique muscle palsy without inferior oblique muscle overaction. During surgery, the Guyton forced duction test is used to evaluate the relaxation of the superior oblique muscle tendon, which affects the re-tucking length of the muscle.Their head position, vertical deviation, eye movement, fovea-disa angle, and Bielschowsky head tilt test were assessed pre-and post-surgery. Statistical analysis was performed using ttest and paired samples Wilcoxon signed rank test. Results: Out of the 12 patients, 8 were male and 4 were female, aged between 2 and 9 years. The initial surgery was done at age 6, with a superior oblique recession length of (7.17±1.03) mm. Recurrent head tilt occurred in 11 patients after (3.82±0.98) months postoperatively, and 1 patient had residual head tilt, with a followup period of six months or more. Ocular motility examination revealed underaction of the superior oblique muscle, positive Bielschowsky's head tilt test, and Guyton forced duction tese indicating relaxation of the paralyzed superior oblique muscle tendon. Scar adhesion was observed at the stop of the superior oblique muscle, as well as the previous sutures. The scar and the sutures around the stop of the superior oblique muscle were released, the mean re-tucking amount was(7.83±1.59)mm. Follow-up at 12 to 18 months postoperatively showed disappearance of compensatory head position, significant improvement in superior oblique muscle lag, normal ocular motility, and no occurrence of Brown syndrome. The results of Bielschowsky head tilt were negative in 9 cases and still positive in 3 cases after superior oblique re-tucking. The primary vertical deviation was 2.5 (2.0, 5.3) prism diopter pre-operatively and 1 (0, 1) prism diopter post-operatively, respectively. The difference was statistically significant (U=6.00, P<0.001). The total amount of FDA in both eyes was (-22.04±5.47)° and (-15.27±6.08)° pre-and post-operatively, respectively. The difference was statistically significant (t=2.87, P=0.009). All 12 patients have normal eye movement after superior oblique re-tucking procedure. All patients had no compensatory head position at last follow-up. Conclusions: Superior oblique re-tucking is suitable for patients with relaxation of the superior oblique muscle tendon and extrocular rotation as the main sign. It can effectively and safely correct the recurrent or residual compensatory head position after re-tucking the superior oblique muscle.

Effect of vertical central plication on vertical deviations

PurposeTo evaluate the surgical effect of the Wright central plication on vertical rectus muscles to correct vertical strabismus. MethodsIn this multicenter, retrospective, observational outcomes study, data were collected from two surgeons in different practice settings (2017-22). All patients who underwent vertical rectus central plication were included; those undergoing any concurrent strabismus surgery for vertical strabismus were excluded. Primary outcome was amount of strabismus correction in prism diopters per vertical rectus central plication. Secondary outcome was to determine factors associated with better or worse surgical outcomes and patient and patient responses. Data were analyzed using descriptive and bivariate statistics. ResultsA total of 36 patients were included. Mean age was 60 years. Mean follow-up was 8.4 months. Of the 36 patients, 11 (31%) had idiopathic strabismus, and 7 (19%) had congenital superior oblique palsy. The remainder had a history that included prior ocular surgery, trauma, and Brown syndrome; 16 (44 %) had prior strabismus surgery. Of 31patients with preoperative diplopia, 23 (74%) had postoperative resolution of diplopia, and 10 of 16 patients with preoperative prisms (63%) no longer required prisms postoperatively. Mean vertical deviation change was 4.7Δ. Subgroup analysis removing patients with congenital superior oblique palsy showed a larger response of 5.5Δ. 78% of patients had a final deviation <5Δ. No complications or induced postoperative diplopia was reported. ConclusionsIn our study cohort, vertical rectus central plication corrected approximately 5Δ (range, 4.5Δ-5.5Δ) of vertical strabismus due to a variety of causes.

Postoperative outcomes for unilateral congenital trochlear nerve palsy: A retrospective cohort study

Congenital trochlear nerve palsy is the most common cause of vertical strabismus. The goal of this study was to investigate surgical outcomes after superior oblique tendon plication with or without inferior oblique recession in children and adults with unilateral congenital trochlear nerve palsy. Data and outcomes were collected in patients with a diagnosis of unilateral congenital superior oblique palsy during a retrospective single-center study conducted at the University Hospital of Tours. A reproducible, standard ophthalmological and oculomotor examination was performed pre- and postoperatively at 1 year, including presence or absence of diplopia, vertical and horizontal deviations, and compensatory head posture. Surgical success, defined as an endpoint including absence of diplopia in primary position, absence of head tilt, and vertical deviation at distance fixation<5 prism diopters (PD), was analyzed. A total of fifty-seven patients (median [IQR] age of 11 years [5-42]) were analyzed. Patients experienced a significant reduction in vertical distance and near deviations (p<0.001), compensatory head tilt (p<0.001), and diplopia after surgery (p<0.001). Surgical success was higher in adults (17/24, 70.8%) than in children (15/33, 45.5%), although this did not reach statistical significance (p=0.0657). This study suggests that plication of the superior oblique muscle tendon, with or without recession of the inferior oblique muscle, can be effective in treating unilateral congenital trochlear nerve palsy. Further studies are necessary to compare surgical procedures and investigate their efficacy in adults compared to children in the short and long term.

Characteristics of Guyton's exaggerated forced duction test (FDT) and torsional FDT in congenital superior oblique palsy

Objective: To investigate the characteristics of Guyton's exaggerated forced duction test (FDT) and torsional FDT in patients with congenital superior oblique palsy (CSOP) and their correlation with clinical features. Methods: This cross-sectional study included single-eye CSOP patients and intermittent exotropia (IXT) patients scheduled for strabismus correction surgery at Tianjin Eye Hospital from September 2021 to March 2022. Prior to surgery, measurements of fovea-disc angle (FDA) and maximum cross-sectional area of the superior oblique muscle (max-CSA) were obtained in both eyes of the patients. The Guyton's exaggerated FDT and torsional FDT were performed intraoperatively to assess the degree of superior oblique muscle relaxation. The characteristics of the two FDT tests and their correlation with vertical strabismus angle, FDA, and max-CSA were analyzed. Statistical analyses were conducted using t-test, ANOVA, Tukey's test, Mann-Whitney U test, and chi-square test. Results: A total of 42 patients (84 eyes) were included in the study, including 19 IXT patients (38 eyes) and 23 CSOP patients (46 eyes, 23 eyes with palsy and 23 eyes without palsy). There were no statistically significant differences in gender composition or age between the IXT and CSOP patients (all P>0.05). The degrees of superior oblique muscle relaxation measured by the Guyton's exaggerated FDT were (-2.52±1.20), (-0.35±0.71), and (-0.03±0.16) for the palsy eye, non-palsy eye, and IXT eyes, respectively, showing significant differences (F=88.10, P<0.001). The torsional FDT measurements yielded external rotation angles of 48.70°±9.67°, 37.39°±5.40°, and 38.95°±2.88° for the palsy eye, non-palsy eye, and IXT eyes, respectively, showing significant differences (F=16.67, P<0.001). There was no statistically significant difference in internal rotation angles (F=2.36, P=0.100). The FDA values were-12.11°±7.42° for IXT patients and-19.02°±4.95° for CSOP patients, while the max-CSA values for the palsy eye and non-palsy eye of CSOP patients were (7.59±4.69) mm² and (11.63±3.64) mm², respectively, all showing significant differences (all P<0.001). The degree of superior oblique muscle tendon relaxation assessed by the Guyton's exaggerated FDT was negatively correlated with the external rotation angle measured by the torsional FDT (r=-0.64, P=0.001). They were positively correlated with max-CSA (r=0.45, P=0.030) and negatively correlated with max-CSA (r=-0.52, P=0.011). However, there was no correlation with vertical and rotational strabismus angle (r=-0.12, P=0.579; r=0.33, P=0.126) and FDA (r=-0.02, P=0.921; r=-0.23, P=0.309). Conclusions: Guyton's exaggerated FDT and torsional FDT can both assess the degree of superior oblique muscle relaxation in patients with CSOP. Furthermore, these two tests are correlated with changes in superior oblique muscle morphology. However, FDT cannot reflect the degree of vertical and rotational strabismus in patients.

Effect of inferior oblique myectomy on ocular torsion according to the absence of the trochlear nerve in unilateral congenital superior oblique palsy.

To evaluate the effect of inferior oblique (IO) myectomy on ocular torsion according to the absence of the trochlear nerve in unilateral congenital superior oblique palsy (UCSOP). We retrospectively reviewed the clinical data of patients who had been diagnosed with UCSOP and underwent ipsilateral IO myectomy (n = 43). Patients were classified into the present and absent groups according to the absence of the trochlear nerve and superior oblique hypoplasia on magnetic resonance imaging (MRI). For quantitative analysis of ocular torsion, disc-fovea angles (DFA) were collected in both eyes using fundus photographs taken within three months before surgery and one month after surgery. DFA of the paretic eye did not differ according to the absence of the trochlear nerve (9.4±5.6° in the present group vs. 11.0±5.4° in the absent group, p = 0.508). However, the present group had a larger DFA in the non-paretic eye than the absent group (14.1±6.7° in the present group vs. 8.0±5.0° in the absent group, p = 0.003). The change of ocular torsion after IO myectomy in the paretic eye was -5.3±3.7° in the present group and -4.8±3.5° in the absent group, respectively (p = 0.801). In the non-paretic eye, the change in DFA was -1.5±3.0° in the present group, which was larger than that in the absent group (0.7±2.6°, p = 0.047). In the multivariate analysis, the change in DFA was correlated with only the preoperative DFA (standardized β = -0.617, p<0.001 in the paretic eye, and standardized β = -0.517, p<0.001 in the non-paretic eye). In the paretic eye, there was no significant difference in the change of ocular torsion between both groups, whereas in the non-paretic eye, the present group had a larger change in DFA after IO myectomy than the absent group. However, in the multivariable analysis, the change in ocular torsion was significantly correlated with preoperative excyclotorsion but not with the presence of the trochlear nerve itself.

This issue of ACTA

This issue of ACTA

Differences in gene expression between the primary and secondary inferior oblique overaction.

BackgroundThis study sought to define different adaptive changes in the molecular levels of the overacting inferior oblique muscle in primary and secondary inferior oblique overaction.MethodsThe inferior oblique muscles of patients with congenital superior oblique palsy (SOP) and those of patients with congenital esotropia were collected during surgery. RNA-seq technology was performed to detect the differentially expressed genes (DEGs) between the two groups. A comprehensive analysis of the gene expression profiles was then conducted, including the identification of DEGs, a Gene Ontology (GO) analysis, and a gene set enrichment analysis (GSEA). Finally, a protein-protein interaction (PPI) network was constructed with Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape software.ResultsWe identified 221 DEGs, of which 104 were significantly upregulated and 117 were downregulated in the SOP group. Additionally, several isoforms of the myosin heavy chain (MyHC) gene were found to be significantly and differentially expressed in the SOP group, including 3 upregulated fast-twitch MyHC isoforms (i.e., MYH1, MYH4, and MYH13) and 1 downregulated slow-twitch MyHC isoform (i.e., MYH3). The GO analysis indicated that the upregulated DEGs were mainly enriched in the muscle system process and muscle contraction. The GSEA analysis revealed that the upregulated pathways of ribosome, proteasome, oxidative phosphorylation, fatty acid metabolism, viral myocarditis, and cardiac muscle contraction were enriched.ConclusionsOur findings provide insights into the different molecular changes of inferior oblique muscle overaction secondary to SOP and suggest the potential pathological mechanisms of inferior oblique overaction (IOOA) in SOP. The results suggest that upregulated fast-twitch MyHC isoforms and downregulated slow-twitch MyHC isoform in SOP may contribute to the increased force of its inferior oblique muscle.

Clinical features of excyclotorsion in the non-paretic eye of patients with congenital unilateral superior oblique palsy

BackgroundTo investigate preoperative clinical features and postoperative results according to the correspondence between excyclotorsion and the paretic eye in patients with congenital unilateral superior oblique palsy (USOP).MethodsA retrospective review of medical charts was performed. The patients were divided into the accordance (ocular excyclotorsion in the paretic eye) and disaccordance (ocular excyclotorsion in the non-paretic eye) groups. The degree of excyclotorsion (scale, 0–4) was measured. Age, sex, hypertropia at the primary position, fixation preference, inferior oblique overaction, and degree of excyclotorsion were measured.ResultsNinety-eight patients were included in this study. There were 70 (71.4%) and 28 patients (28.6%) in the accordance and disaccordance groups. Sixteen patients (22.9%) in the accordance group and 12 patients (42.9%) in the disaccordance group were aged under 2 years (p = 0.04). A fixation preference of the paretic eye was observed in 2 (2.9%) and 8 (28.6%) patients in the accordance and disaccordance groups (p < 0.01). The postoperative degree of excyclotorsion in the accordance group (0.14 ± 0.39) was lower than that in the disaccordance group (0.28 ± 0.71) (p = 0.01). The residual postoperative excyclotorsion (> 1) were observed in the disaccordance group (14 patients, 50%) and accordance group (16 patients, 22.9%) (p = 0.01).ConclusionPreoperative disaccordance between excyclotorsion and the paretic eye was observed in patients who were under 2 years of age and preferred fixation of the paretic eye. The postoperative degree of excyclotorsion was lower in the accordance group.

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

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

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.

Facial Asymmetry in Unilateral Congenital Superior Oblique Muscle Palsy.

This study was conducted to evaluate facial asymmetry in unilateral congenital superior oblique muscle palsy (SOP). The results showed that all facial asymmetry parameters had a higher frequency in SOP patients compared with orthotropic individuals. This study aimed to evaluate the characteristics of facial asymmetry in unilateral congenital SOP and compare with orthotropic individuals. This cross-sectional comparative case series was conducted in 58 patients with ocular torticollis caused by SOP (mean ± standard deviation age, 18 ± 12 years) and 58 orthotropic individuals (mean ± standard deviation age, 19 ± 13 years). The exact form of torticollis was determined by direct observation from yaw, roll, and pitch axes. Four photographs were taken from patients: (1) with torticollis to calculate the amount of head tilt; (2) with the head in the straight position to calculate the facial angle and relative facial size (RFS); and (3 and 4) with the head positioned downward (to compare the cheek size) and upward (to assess columella deviation and nostril asymmetry). Twenty-nine patients (50%) had a head tilt, 23 (39.66%) had combined head tilt and a face turn, and 6 (10.44%) had a pure face turn. The mean ± standard deviation of head tilt, facial angle, and RFS was 10.11 ± 6.31°, 1.11 ± 1.67°, and 1.003 ± 0.126 in SOP patients, respectively, and the mean RFS and facial angle were significantly higher in SOP patients compared with orthotropic individuals (both P < .001). Facial hemihypoplasia, unilateral cheek compression, nostril asymmetry, and columella deviation were observed in 43 (74.1%), 31 (53.4%), 39 (67.2%), and 38 patients (65.5%), respectively, which were all significantly more common compared orthotropic individuals (P < .001). Facial asymmetry was seen in 52 patients (91.2%) and 17 orthotropic subjects (29.3%), respectively (P < .001). All quantitative and qualitative facial asymmetry parameters had a higher frequency in SOP patients compared with orthotropic subjects.

The Correlation between Hypertropia and Head Tilt in Congenital Unilateral Superior Oblique Muscle Palsy.

Purpose:To evaluate the correlation between the angle of deviation in different gazes and the amount of head tilt in patients with congenital unilateral superior oblique muscle palsy (SOP).Methods:This case series study was performed on 20 consecutive SOP patients with head tilt. Based on the Bielschowsky three-step test, the angle of deviation was measured in different gazes. Furthermore, the hypertropia difference between the two lateral gazes (gaze difference) and the two head tilt sides (bilateral head tilt difference) was calculated. For measuring head tilt, close-up pictures from 40 cm with a habitual abnormal head position were captured and analyzed by the Corel Draw X7 software.Results:The mean age of patients was 13 ± 9 years (range, 2.5–31 years). The mean angle of hypertropia in ipsilateral and contralateral head tilt was 24.5 Δ ± 7.1 Δ and 6.5 Δ ± 4.2 Δ, respectively (P < 0.001), and in ipsilateral and contralateral lateral gaze positions, it was 8.2 Δ ± 5.5 Δ and 22.5 Δ ± 6.1 Δ, respectively (P < 0.001). The mean of bilateral head tilt hypertropia difference was 18 Δ ± 5.3 Δ and gaze hypertropia difference was 14.3 Δ ± 6.16 Δ. There was a positive correlation between bilateral head tilt hypertropia difference and the amount of head tilt (R = 0.609, R2 = 0.371, P = 0.004, the amount of head tilt = 0.39 × [Bilateral head tilt hypertropia difference] +1.77). The amount of head tilt also had a positive correlation with the gaze hypertropia difference (R = 0.492, R2 = 0.242, P = 0.028, the amount of head tilt = 0.27 × [gaze hypertropia difference] +4.81).Conclusion:In SOP patients, the amount of head tilt had a positive correlation with bilateral head tilt hypertropia difference and also gaze hypertropia difference.

A single inferior rectus muscle surgery for treatment of congenital superior oblique palsy with small deviation in primary position.

To evaluate outcomes of one muscle surgery for treatment of congenital superior oblique palsy (SOP) with Knapp Class V. Medical records were retrospectively reviewed for the patients with the congenital SOP type V who underwent surgical treatment through one muscle surgery between July 2015 and September 2020. The surgical procedure was resection-recession on the contralateral inferior rectus muscle of the hypertrophic or paretic eye. Vertical alignment at nine cardinal gaze positions, and resolution of the abnormal head posture were evaluated pre- and postoperatively. The follow-up was scheduled regularly at postoperative day 1, 1 week, 1 month, and followed by 2-month intervals until 18 months. Twelve patients were included in this study, with a mean age of 6.4 years (range from 3 to 10 years). The mean follow-up period was 10.5 months after surgery (range from 6 to 18 months). The average vertical deviation at primary position was 6.33△ ± 2.93△ preoperatively and 0.75△ ± 1.14△ postoperatively (p < 0.05). The average vertical deviation at downgaze was 23.33△ ± 4.75△ preoperatively and 1.92△ ± 1.62△ postoperatively (p < 0.05). All patients had an abnormal head position preoperatively. Postoperative results indicated that the patients' abnormal head position had been improved significantly. The surgical procedure of resection-recession on a single inferior rectus muscle is a successful intervention for the correction of superior oblique palsy (SOP) with Knapp Class V.

Inferior oblique recession associated to partial temporal inferior rectus recession in unilateral congenital superior oblique palsy.

To evaluate the effectiveness of inferior oblique recession with contralateral partial temporal inferior rectus recession in patients with decompensated congenital unilateral superior oblique palsy (SOP) in correcting moderate vertical deviations in primary position. The medical records of patients with SOP who underwent inferior oblique recession with contralateral partial temporal inferior rectus recession were reviewed retrospectively. Vertical deviation in primary position, subjective torsion, diplopia, residual deviation, and the deviation decrease were evaluated. Four patients (three males and one female, age range 29-56 years) with congenital unilateral SOP and mean vertical deviation of 21.0 ± 5.3PD (range 14-25D) in primary position were included. Mean correction of hypertropia in primary position with this technique was 15.5 ± 5.3PD (range 10-20PD). The mean hypertropia on gaze to the contralateral side changed from 30.0 ± 10.8D before surgery to 9.3 ± 7.9D after surgery. Torsion had a mean change of 4.8° of incyclodeviation. Preoperatively, all patients had head tilt and diplopia, which was resolved in all but one patient, who will need surgery. Patients were followed an average of 18 months. No adverse events were reported in any subjects. When performing recession of inferior oblique muscles in SOP associated to a full recession of the contralateral inferior rectus, there is a risk of overcorrection in those with moderate angles. Performing a partial recession in the contralateral inferior rectus eye corrected up to 20PD in primary position in our series, reducing this risk.

Characteristics of Facial Asymmetry in Congenital Superior Oblique Palsy according to Trochlear Nerve Absence.

Methods A total of 287 consecutive patients diagnosed with congenital SOP and 82 control subjects were included. Congenital SOP patients were grouped according to the presence (present group) or absence (absent group) of the trochlear nerve using thin-section high-resolution MRI of cranial nerves. We developed a computer-aided detection (CAD) system that could automatically analyze objective indices of facial asymmetry using frontal face photographs. Results Of the 287 patients with congenital SOP, 60% of patients had ipsilateral trochlear nerve absence and superior oblique muscle (SO) hypoplasia (absent group), while the remaining 40% had a normal SO and trochlear nerve (present group). All but one objective indices related to facial asymmetry were significantly different between congenital SOP patients and controls (all P < 0.05). Among these features, the angle of nose deviation was significantly larger in the absent group compared to the present group (P < 0.001). Conclusion Objective analysis of facial asymmetry using our novel CAD system was useful for identifying distinct features of congenital SOP. Deviation of the nose was more prominent in congenital SOP patients with trochlear nerve absence.

Abnormal Head Posture in Unilateral Superior Oblique Palsy

ABSTRACT Purpose: To evaluate the manifestations and severity of abnormal head posture (AHP) in unilateral congenital and acquired superior oblique palsy (SOP) patients and to assess the effect of AHP on facial appearance. Patients and methods: This case series study was performed on 60 consecutive SOP patients, which consisted of 47 patients with congenital SOP and 13 patients with the acquired source. The exact type of AHP in congenital and acquired cases was determined based on direct observation. In addition, a close-up picture from 40 cm with habitual AHP was captured from all patients. For evaluation of the severity of AHP and measurement of head tilt, these pictures were analyzed by the Corel Draw X7 software (Corel Corp, Canada). Besides, qualitative and quantitative facial asymmetry parameters were evaluated by the assessment of pictures of patients, which were taken in different gazes. Results: Five different manifestations of AHP were observed to the contralateral side of the palsy; 1 – pure head tilt, 2 – simultaneous head tilt and turn, 3 – pure head turn, 4 – head tilt and chin down, and 5 – head tilt and turn with chin down. The frequency of these five manifestations of AHP in the congenital group were 23 (48.9%), 10 (21.3%), 4 (8.5%), 5 (10.6%), and 5 (10.6%) patients, respectively (P <.001) and in acquired patients, were 1 (7.7%), 8 (61.5%), 2 (15.4%), 2 (15.4%), and 0 (0%), respectively (P =.024). In all SOP patients, the most common manifestations of AHP were pure head tilt (40%), simultaneous head tilt and turn (30%), and head tilt with chin down (11.7%), respectively. The mean degrees of head tilt in congenital and acquired patients were 15.10° ± 9.34° and 9.61° ± 5.84°, respectively (P =.022). Conclusion: The most common type of AHP in congenital SOP patients was contralateral head tilt, but in acquired cases was simultaneous head tilt and turn. The mean amount of head tilt in the acquired group was significantly higher than congenital patients; in contrast, the frequency of facial asymmetry was higher in the congenital group compared with the acquired patients.

Range of forced cyclorotation in superior oblique palsy and V-pattern strabismus.

To quantify a passive range of cyclorotation using a smartphone application and evaluate its associations with fundus torsion and rectus muscle cyclorotation in superior oblique palsy (SOP) and V-pattern strabismus. Fifty-two patients showing overelevation in adduction (30 with congenital SOP and 22 with V-pattern strabismus) underwent forced cyclorotation on the photographs. A photograph of the globe was taken in maximally excyclorotated and incyclorotated positions after marking at the 6 and 12 o'clock limbus under general anaesthesia, and the rotational alignment of these markings was read using the toriCAM application. The degrees of forced cyclorotation were compared between the two groups. Disc-fovea angle on fundus photographs and rectus muscle cyclorotation in the coronal view on orbital computed tomography were correlated with the range of forced excyclorotation. The range of forced excyclorotation was greater in V-pattern strabismus than that in SOP (58.5° vs. 46.8°, p < 0.001), whereas the ranges of incyclorotation were similar between the two groups (39.0° vs. 39.0°, p = 0.543). Regression analysis revealed a significant increase in the range of excyclorotation with the degree of rectus muscle excyclorotation, after accounting for age and angle of hypertropia (r2 = 0.475, p = 0.001). The range of excyclorotation did not correlate with the amount of fundus extorsion and grade of overelevation in adduction. The range of excyclorotation was correlated with the rectus muscle excyclorotation in these populations, suggesting that the results from this forced cyclorotation test may reflect orbital alignment and oblique muscle status.

Effect of unilateral inferior oblique weakening on fundus torsion in bilateral eyes of children with congenital superior oblique palsy.

To study the change of torsion in both eyes after unilateral inferior oblique (IO) weakening on children with congenital superior oblique palsy (SOP). This retrospective study enrolled all patients diagnosed with unilateral congenital superior oblique palsy (UCSOP) accompanied by inferior oblique overaction (IOOA). A total of 120 eyes of 60 patients were divided into group 1 (more extorted paretic eye) and group 2 (more extorted nonparetic eye). The degree of fundus torsion was evaluated before and 1mo after the IO weakening procedure. The torsion of the fundus was recorded by measuring the disk-foveal angle (DFA) using fundus photography. Group 1 included 26 cases and group 2 included 34 cases, thus the rate of extorsion was insignificantly higher in the nonparetic eye (P=0.10). The preoperative DFA in the paretic and nonparetic eyes was 13.21±5.95, 7.97±4.25 in group 1, and 4.65±3.79, 13.16±5.35 in group 2 (both P<0.001). The postoperative DFA in the paretic and nonparetic eyes was 8.57±4.87, 7.32±4.27 in group 1 (P=0.24), and 3.85±6.00 and 9.94±5.45 in group 2 (P<0.001). The amount of postoperative reduction of the DFA in the paretic and nonparetic eyes was 4.64±3.90, 0.65±0.76 in group 1 (P=0.002), and 0.80±0.81, 3.21±5.50 in group 2 (P=0.01). The difference in the amount of reduction of DFA in the more extorted eye in group 1 (paretic eye) vs group 2 (nonparetic eye) was insignificant (P=0.30). Excyclotorsion in the nonparetic eye has a similar probability in the paretic eye in UCSOP children, and weakening of the ipsilateral IO has a more obvious effect on the decrement of extorsion in the more extorted eye regardless of which eye is paretic.