Surgical Outcome of Single Inferior Oblique Myectomy in Small and Large Hypertropia of Unilateral Superior Oblique Palsy

Clinical outcomes of inferior oblique myectomy in age categorized patients with unilateral superior oblique palsy

Background

Unilateral superior oblique palsy (SOP) is the most common isolated cranial nerve palsy. This report looks at the results and safety of inferior oblique (IO) myectomy for SOP.

Methods

A retrospective chart review of patients with fusional ability who underwent IO myectomy for unilateral SOP over a 15-year period, at one of our university-associated health care centers. Primary outcomes were: distance hypertropia and excyclotropia in primary position, inferior oblique overaction (IOOA) and the correlation between the age at surgery and the residual distance hypertropia.

Results

A total of 73 patients with unilateral SOP who underwent IO myectomy were included in the analysis. Mean pre-operative values were: distance hypertropia: 15.41 ± 6.8 Prism Diopters (range 4-30 PD), IOOA: +2.2 ± 0.7 (range 0-3.5) and excyclotropia: +5.34 ± 3.6° (range 0-12°). Mean post-operative values were: distance hypertropia: 3.7 ± 3.4PD [0-14PD], IOOA: -0.1 ± 0.8 [(-2)-2] and excyclotropia: +1.1 ± 2.3°[(-5)-10]. The younger age group (0-20 years old) had a trend toward smaller preoperative distance hypertropia (P = 0.051), and a significantly smaller distance hypertropia post-operatively (p = 0.007). There was no case of ocular complication.

Conclusions

On average, IO myectomy results in a 11.7PD reduction of the distance hypertropia, and 4° reduction of excyclotropia, with an effective reduction of IOOA. While these results are comparable to other surgical methods reported in the literature, they underline an efficacy without the risks of complications such as anti-elevation syndrome and possible scleral perforation. The younger age group had a trend toward smaller preoperative deviation, and better outcomes compared to the older age group.

One- vs Two- vertical muscle surgery in the management of unilateral superior oblique muscle palsy with hypertropia over 20 PD

Purpose: To compare the surgical outcomes of One- versus Two-vertical muscle surgery in patients with unilateral superior oblique muscle palsy (SOP) with primary position hypertropia (HT) over 20 PD. Patients in Group 1 underwent inferior oblique anterior transposition plus resection (IOATR), while patients in Group 2 underwent inferior oblique anterior transposition (IOAT) along with contralateral inferior rectus (IR) recession. Methods: Medical data of all SOP patients treated by either procedure from 2000 to 2023 in our strabismus center were recruited. We compared surgical outcomes between Group 1 and Group 2 by analyzing HT correction, rate of under-correction, and over-correction. Results: The study included 33 patients in Group 1 and 23 in Group 2. Both groups were similar in age, sex, etiology, affected side, diplopia, and head tilt. Group 2 achieved higher HT correction in all measured gazes. Group 1 had a higher risk of under-correction (18.18% in Group 1 vs 8.69% in Group 2) while Group 2 had a higher rate of over-correction (21.73% vs 0% in Group 1). Conclusion: In patients with severe unilateral SOP, Two-vertical muscle surgery achieved higher amounts of HT correction in all gazes despite a significantly higher risk of over-correction.

Surgical treatment of unilateral acquired superior oblique muscle palsy in adults by inferior oblique belly transposition: a retrospective analysis

PURPOSE

Evaluate and analyze the efficacy of inferior oblique belly transposition (IOBT) in treating adult patients with diplopia and small-angle hypertropia caused by mild to moderate inferior oblique overaction (IOOA) secondary to acquired superior oblique palsy (SOP).

METHODS

Nine adult patients with diplopia and small-angle hypertropia associated with mild to moderate IOOA secondary to unilateral acquired SOP were included in the current retrospective study. All patients received the IOBT procedure between February 2019 and May 2023 at The Second People's Hospital of Jinan and were followed up for more than 6 months after the surgery. During the procedure, the belly of the inferior oblique muscle was fixed to the sclera at 5 mm posterior to the temporal insertion of the inferior rectus muscle. The following indicators were reviewed pre- and post-surgery: the vertical deviation (VD) in the primary position and in the Bielschowsky test, the fovea disc angle (FDA) of the affected eye, changes in IOOA, and diplopia.

RESULTS

After IOBT, the VD in the primary position decreased from 7.22△ ± 1.72△ (range 4△-10△) to 1.22△ ± 1.30△ (range 0△-3△). The VD in the Bielschowsky test decreased from 13.00△ ± 1.80△ to 3.22△ ± 1.09△. The FDA decreased from 10.02° ± 3.34° to 6.26° ± 1.91°. The grade of IOOA was reduced from 2.00 (1.00, 2.00) to 0.00 (0.00, 1.00). All changes were statistically significant (P < 0.001 or P = 0.006). Diplopia was resolved completely for all patients.

CONCLUSIONS

IOBT can effectively treat adults with diplopia and small-angle hypertropia caused by mild to moderate IOOA secondary to acquired SOP.

Clinical characteristics and surgical outcomes in patients with superior oblique muscle palsy: a retrospective study on 1057 patients

BACKGROUND

To evaluate the clinical findings of patients with SOP who underwent surgery.

METHODS

This historical cohort study was performed on 1057 SOP patients managed with surgery in Farabi Hospital, Iran, from 2011 to 2022.

RESULTS

There were 990 (93.7%) patients with unilateral SOP with the mean age of 21.8 ± 14.8 years. Of these, 715 patients (72.2%) were diagnosed with congenital SOP, and 275 patients (27.8%) had acquired SOP (P < 0.001). In contrast, 67 (6.3%) patients were diagnosed with bilateral SOP, with the mean age of 19.4 ± 15.6 years. Among these, 18 cases exhibited the masked type. The mean angle of vertical deviation in primary position at far in unilateral and bilateral cases was 15.6 ± 8.3 and 13.3 ± 9.1 △, respectively (P < 0.001). In unilateral cases, abnormal head posture (AHP) was detected in 847 (85.5%) patients and 12 (1.2%) had paradoxical AHP. Amblyopia was found in 89 (9.9%) unilateral and 7 (10.3%) bilateral cases. Solitary inferior oblique myectomy, was the most common surgery in both unilateral (n = 756, 77.1%) and bilateral (n = 35, 52.2%) patients. The second surgery was performed for 84 (8.6%) unilateral and 33 (49.3%) bilateral cases (P < 0.001). The prevalence of amblyopia and the mean angle of horizontal deviation were significantly higher in patients who needed more than one surgery (all P < 0.05).

CONCLUSION

Congenital SOP was more than twice as frequent as acquired SOP and about 90% of unilateral and 50% of bilateral cases were managed with one surgery. Amblyopia and significant horizontal deviation were the most important factors for reoperation.

TRIAL REGISTRATION

The Institutional Review Board approval was obtained from the Tehran University of Medical Sciences (IR.TUMS.FNM.REC.1400.012) and this study adhered to the tenets of the Declaration of Helsinki and HIPAA.

Phased strabismus surgery under topical anesthesia

PURPOSE

To evaluate the feasibility and outcomes of phased strabismus surgery under topical anesthesia, with intraoperative comparison of ocular alignment in supine and seated positions.

METHODS

This retrospective clinical investigation analyzed the data of patients who underwent phased strabismus surgery with fixed sutures under topical anesthesia. The technique consisted of 2 phases, spaced out with an intraoperative alternate prism cover test (performed in supine and seated positions): (1) surgery on one or two muscles, as defined by a preoperative surgical plan; (2) if judged necessary, a further one-muscle surgery. Surgical success was defined as a residual angle of horizontal and vertical deviation ≤±8Δ and ≤5Δ, respectively, and the presence of single binocular vision in primary position in patients with preoperative diplopia. Follow-up visits were scheduled 1 day, 1 month, and 6 months after surgery.

RESULTS

The review identified 38 patients (age range: 10-80 years). Surgery was well tolerated by all patients. Twelve (32%) required a second phase. No statistically significant differences were found for intraoperative angles of deviation in supine and seated positions. Surgical success was reached, respectively, in 88% and 87% of cases with horizontal and vertical deviation 6 months after surgery. No patients were reoperated during the follow-up period.

CONCLUSIONS

Phased strabismus surgery is a feasible technique for various types of strabismus in adults and children. Secondly, intraoperative evaluation of ocular alignment can be performed either with the patient seated or supine, with the same accuracy in terms of surgical success.

Efficacy and Risk Factors of Pyrrotinib in Second- and Third-Line Treatments for HER2-Positive Advanced Breast Cancer

A study to examine the efficacy and risk factors associated with pyrrotinib in the second- and third-line treatment of advanced breast cancer with Human epidermal growth factor receptor 2- (HER2-) positive cells was conducted. Progression-free survival (PFS) was assessed as the primary endpoint, and the objective response rate (ORR), overall survival (OS), and safety were secondary endpoints. Across all the patients, the ORR was 48.57%, and the disease control rate (DCR) was 94.29%. In the follow-up period, the median PFS was 15 months, and second-line treatment had significantly longer PFS than third-line treatment (P = 0.027). The OS among all the patients was up to 28 months, but the median OS has not yet been reached. Diarrhea (69.57%) was the most important AE, mainly in grades 1 and 2. According to the COX regression analysis, brain metastasis was a risk factor for PFS, while second-line treatment and capecitabine chemotherapy were relevant to a longer PFS correlation among patients. In the second- and third-line treatment, pyrrotinib is still highly effective and safe. Pyrrotinib is a potential ideal salvage treatment plan for patients who failed in first-line treatments.

Effectiveness of Inferior Oblique Myectomy in Unilateral Superior Oblique Palsy Depending on Magnitude of Hyperdeviation

Purpose: To evaluate surgical outcome and effectiveness of inferior oblique (IO) myectomy on unilateral superior oblique palsy (SOP) as a primary treatment.Methods: This study is a retrospective review of the medical records of 99 patients who had undergone IO myectomy due to SOP as a first-line treatment. Sixty-five patients with hyperdeviation of 15 prism diopters (PD) or less were categorized into group 1, 22 patients with hyperdeviation between 16 PD to 20 PD into group 2, and 12 patients with hyperdeviation higher than 20 PD into group 3. Preoperative hyperdeviation, postoperative hyperdeviation, and improvement of head tilting were then compared between the 3 groups. Surgery was determined to be successful when the post-op residual hyperdeviation is less than 5 PD, or when the improvement of hyperdeviation and head tilting was noted, for the patients who had preoperative deviation less than 5 PD, and without hypercorrection.Results: All groups showed significant improvement of hyperdeviation, and the amount of correction was larger in group with larger preoperative hyperdeviation. 80.3%, 95.0%, and 90.9% of patients showed improvement of head tiling and success rate was 87.7%, 77.3%, and 50.0% in group 1, 2, and 3 respectively. Group 1 and 2, group 2 and 3 had no significant difference in success rate but only group 1 and 3 had significant difference.Conclusions: Considering success rate with improvement of head position, self-titrating and possibility of overcorrection, IO myectomy could be an effective option as a first-line surgical treatment for unilateral SOP with hyperdeviation of 20 PD or less. However, due to a 50% success rate in patients with hyperdeviation larger than 20 PD, a secondary operation must be considered following IO myectomy, or a two-muscle procedure must be considered as a primary treatment.

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.

Facial Asymmetry in Unilateral Congenital Superior Oblique Muscle Palsy

SIGNIFICANCE

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.

PURPOSE

This study aimed to evaluate the characteristics of facial asymmetry in unilateral congenital SOP and compare with orthotropic individuals.

METHODS

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).

RESULTS

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).

CONCLUSIONS

All quantitative and qualitative facial asymmetry parameters had a higher frequency in SOP patients compared with orthotropic subjects.

Effect of inferior oblique muscle belly transposition on versions and vertical alignment in primary position

PURPOSE

To evaluate the effect of inferior oblique muscle belly transposition (IOBT) on vertical deviation (VD) in primary position and inferior oblique overaction (IOOA).

METHODS

Twenty-eight patients who underwent unilateral IOBT for mild hypertropia (≤ 10^△) due to unilateral IOOA were included. Surgical results regarding the correction of hypertropia, IOOA, and fovea disc angle (FDA) were analyzed and compared between groups A (VD ≤ 5^△) and B (5^△ < VD ≤ 10^△).

RESULTS

IOBT showed an overall reduction of 5.86^△ (± 2.24^△) of primary position VD, a mean correction of 1.00 (± 0.27) of IOOA, and an average change of 1.83° (± 3.02°) of FDA. The surgical success rate of IOBT for VD correction and IOOA elimination in all patients was 68% and 71%, respectively. The correction of VD was correlated with preoperative VD significantly (r = 0.86, p < 0.001). Consistently, IOBT demonstrated comparable efficacy in reduction of VD between group A and group B (p = 0.507). Furthermore, the two groups were comparable in the success rates for correcting VD and IOOA (both p > 0.05). None of the patients developed consecutive hypotropia, postoperative contralateral IOOA, or anti-elevation syndrome postoperatively.

CONCLUSIONS

IOBT achieved satisfactory outcomes in patients with mild primary position VD (≤ 10^△) that is associated with unilateral IOOA, without any risk of overcorrection of VD and contralateral IOOA for a follow-up period of up to 12 months. This procedure is considered effective and safe alternative for weakening the IO in patients with appropriate surgical indications.

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.

Abnormal Head Posture in Unilateral Superior Oblique Palsy

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.

Efficacy of isolated inferior oblique anteriorization on large-angle hypertropia associated with unilateral superior oblique palsy

PURPOSE

To evaluate the results of inferior oblique anteriorization for the treatment of large-angle hypertropia secondary to superior oblique palsy and to determine predictors of success and the occurrence of antielevation syndrome.

METHODS

In this prospective study, 25 patients with unilateral congenital and acquired superior oblique palsy who had a primary position hypertropia of at least 25^Δ underwent inferior oblique anteriorization in the paretic eye. Postoperative changes in vertical deviation of primary position and contralateral gaze, abnormal head posture, extorsion, associated horizontal deviation, inferior oblique overaction, superior oblique underaction, and elevation in abduction were examined. Surgical success was defined as residual hypertropia in primary position of ≤4^Δ at final examination.

RESULTS

The mean age of patients at surgery was 19.8 ± 11.9 years (range, 4-49). The mean preoperative deviation in the primary position was 27.6^Δ ± 3.2^Δ; in contralateral gaze, 35.0^Δ ± 3.8^Δ; these measurements decreased postoperatively to 4.7^Δ ± 5.6^Δ and 7.0^Δ ± 5.5^Δ, respectively, after a median follow-up of 8 months. The success rate was 72%, with no difference between patients with a preoperative deviation of 25^Δ-29^Δ and those with deviation of 30^Δ-35^Δ. In a multivariate logistic regression, preoperative extorsion was negatively related to success (OR = 8.01; P = 0.03). At the final follow-up, 4 patients (16%) showed antielevation syndrome and were clinically asymptomatic.

CONCLUSIONS

In unilateral superior oblique palsy, one-muscle surgery, including inferior oblique anteriorization, can be conducted to resolve large-angle hypertropia of >25^Δ. Excyotorsion is a risk factor that increases the likelihood of failure.

Outcome of inferior oblique disinsertion versus myectomy in the surgical treatment of unilateral congenital superior oblique palsy

PURPOSE

To compare the outcome of inferior oblique disinsertion and myectomy in patients with unilateral congenital superior oblique palsy.

METHODS

In this prospective study, consecutive patients with superior oblique palsy underwent either myectomy or disinsertion of the inferior oblique muscle. Success was defined as postoperative hypertropia of ≤5^Δ in primary position and no hypotropia. In cases with preoperative hypertropia of ≤5^Δ, success was defined as improved hypertropia and resolution of abnormal head position (AHP).

RESULTS

A total of 62 patients were included: 34 underwent myectomy; 28, disinsertion. Preoperative primary position hypertropia was 15.8^Δ ± 7.4^Δ in the myectomy group and 14.5^Δ ± 7.3^Δ in the disinsertion (P = 0.756). AHP was present in 85.3% and 85.7% of patients, respectively (P = 1). Mean follow-up was in the myectomy group 7.5 ± 6.7 months and 6.9 ± 3.0 months in the disinsertion group (P = 0.637). Correction of hypertropia in primary position was more pronounced in the myectomy group (14.3^Δ ± 7.4^Δ vs 10.0^Δ ± 5.4^Δ; P = 0.013). Success was achieved in 91.2% of myectomy and 60.7% of disinsertion patients (P = 0.006). Persistence of AHP did not differ between groups (8.8% in the myectomy group vs 7.1% in the disinsertion group [P = 1]). Comparison of patients with preoperative hypertropia of ≤15^Δ revealed nonsignificant differences between groups in rate of success (100% vs 81.3% [P = 0.226]) and correction of primary position hypertropia (8.8^Δ ± 3.2^Δ vs 7.6^Δ ± 4.0^Δ [P = 0.336]).

CONCLUSIONS

In our study cohort, inferior oblique myectomy had a greater effect in reduction of primary position hypertropia; however, disinsertion proved as effective as myectomy if preoperative vertical deviation was ≤15^Δ. Both procedures effectively corrected AHP and demonstrated self-adjustment.