Inferior Oblique Transposition Research Articles

Surgical outcomes and observation in exotropia cerebral palsy children with cortical visual impairment

PurposeCortical visual impairment (CVI) is the common cause of pediatric visual impairment in cerebral palsy (CP) while exotropia is the most common strabismus associated with CP. We aim to observe the strabismic surgery outcomes in pediatric patients with CP and CVI.MethodOur medical records were collected from pediatric patients treated in our hospital from May 1, 2017 to Jan 1, 2022. With normal intelligence assessment and diagnosis of exotropia in children with CP and CVI, microsurgeries were performed under intravenous combined inhalation anesthesia. The strabismus was examined by the prism test under best vision correction and the contrast sensitivity testing (CST) was measured at five levels of spatial frequencies.ResultA total of 38 exotropia patients with CP and CVI were identified and included for analysis during the study period with age ranged from 5 to 12 years (mean 8.45 years) and mean follow up duration was 8.7 months (6–42 months). After bilateral lateral rectus recession (with/without medial rectus resection or inferior oblique transposition), the exotropia amount of participants were obviously revealed from − 30 ~ − 140 (median, IQR: − 50, 40) prism diopters (PD) preoperatively to 0 ~ − 15 (0, 5) PD postoperatively. Statistically significantly improvements were observed at all levels of spatial frequency on CST postoperatively, especially at high spatial frequency areas (p < 0.05).ConclusionOur results demonstrated that the effect of strabismus surgery on exotropia in children with CP and CVI were stable and monocular contrast sensitivity post- operation increased significantly at all spatial frequencies levels.

Asymmetric Bilateral Inferior Oblique Transposition of a Bilateral Inferior Oblique Overaction Associated with Dissociated Vertical Deviation

Purpose: Inferior oblique overaction with a dissociated vertical deviation occurs secondary to infantile exotropia or esotropia. In terms of correction, asymmetric bilateral inferior oblique transposition has been the treatment of choice, but the surgical amount depended largely on the surgeon’s experience. We report successful bilateral inferior oblique transposition using our own standard methods.Methods: We performed a retrospective medical chart review of patients with bilateral inferior oblique overaction and dissociated vertical deviation who underwent bilateral inferior oblique transposition at the Korea University Medical Center from January 2013 to December 2020. We performed either symmetric or asymmetric transposition; the reattachment sites of the bilateral inferior obliques were determined according to preoperative differences of the inter-eye deviations of dissociated vertical deviation. When the differences were &lt; 5 prism diopters, correction was considered successful. To avoid the development of anti- elevation syndrome, the inferior oblique muscles were re-attached near the equator.Results: Twenty-three patients were analyzed, all of whom underwent bilateral inferior oblique transposition; 12 required additional horizontal muscle surgery. The deviation difference (both eyes) and inferior oblique overaction grade were significantly lower postoperatively. We did not encounter any case of anti-elevation syndrome.Conclusions: The surgical extent of asymmetric bilateral inferior oblique transposition should reflect the difference in dissociated vertical deviation the two eyes.

Instantaneous Reconstruction of Inferior Rectus: Asset for Vision

Orbital lesions are frequent findings after blunt periocular trauma causing diplopia, muscle avulsion etc. Four patients presented with diplopia after a penetrating injury to the right eye. Examination revealed right hypertopia and limitation of infraduction of right eye with rupture of Inferior Rectus. Immediate repair of inferior rectus muscle with anterior transposition of inferior oblique is a safe and effective procedure to restore motility

The Efficacy of Anterior-Nasal Surgery in Managing Inferior Oblique Overaction either with DVD or with V Pattern

Objective: This study aims at determining the efficacy of anterior and nasal transposition of Inferior Oblique to manage dissociated vertical deviation and vertically incomitant horizontal strabismus (V pattern). Method: This study was both prospective and uncontrolled; it included 60 patients who suffered from inferior oblique overaction. The participants were divided into two groups: Group A had 30 patients with vertically incomitant horizontal strabismus while group B had 30 patients with dissociated vertical deviation. Preoperative examination included: Assessment of vision, ductions and versions in the six cardinal directions of gaze and severity of IOOA graded from 0 to +4. The percentage of dissociated vertical deviation was measured using the prism under cover test in primary position. Follow-up visits occurred in the following intervals: After one week, one month, four months, and six months respectively. In each follow-up visit, the measurements of ductions, versions, and alignment in primary position were recorded. Results: Group A showed no pattern in 93.3% of cases postoperatively while 6.7% of cases developed insignificant V pattern (0.8 ± 2.9 ΔD), with statistically significant difference between the pre-and post-operative values (pvalue< 0.001). Meanwhile, group B showed a complete resolution of DVD in 100% of cases with preoperative (DVD<15 ΔD) and in 20% of cases with preoperative DVD ≥ 15 ΔD; the remaining cases had residual DVD (3.6 ± 4.1 ΔD). Conclusion: Anterior-nasal transposition of the Inferior Oblique muscle is an effective procedure for cases with severe or recurrent inferior oblique overaction when other standard procedures of Inferior Oblique muscle fail. For DVD ≥ 15 ΔD, we recommend a combined anterior-nasal transposition of inferior oblique with superior rectus recession.

Modified anterior transposition of the inferior oblique muscle

To introduce a modified method of anterior transposition of inferior oblique (ATIO) and compare with traditional method in terms of efficacy and complications. The medical records of patients who had undergone unilateral ATIO and were followed for at least 6months were reviewed retrospectively. The patients were divided into two groups according to the surgical method: modified ATIO (modified group, n=16) and traditional ATIO (traditional group, n=15). In modified ATIO, the anterior nasal fibers of the inferior oblique muscle were anchored to the sclera and the posterior temporal fibers were folded and buried under the fixed anterior nasal fiber of inferior oblique muscle. In the traditional method, both the anterior and posterior fibers were fixed with individual suturing. Postoperative change in vertical deviation and grade of inferior oblique overaction (IOOA) were analyzed. Complications, including antielevation syndrome, fat adherence syndrome, and lower lid deformity were assessed. Both modified and traditional methods effectively weakened the action of the inferior oblique muscle. The efficacy of the two methods did not differ in terms of change in vertical deviation (P=0.225) and grade of IOOA (P=0.169). Antielevation syndrome occurred more frequently in the traditional group than in the modified group (8/15 vs 2/16, resp. [P=0.019]). Incidences of fat adherence syndrome (0/15 vs 0/16 [P=1.0]) and lid deformity (3/15 vs 1/15 [P=0.678]) were not different. Modified ATIO was comparable to traditional ATIO in correcting vertical deviation and IOOA and had a lower risk of antielevation syndrome compared with traditional ATIO.

Simultaneous Superior Rectus Recession and Anterior Transposition of Inferior Oblique Muscle as a Surgical Option for Traumatically Lost Inferior Rectus Muscle

ABSTRACTPurpose: To evaluate the role of simultaneous superior rectus (SR) recession and anterior transposition of inferior oblique (ATIO) muscle in patients with traumatically lost inferior rectus (IR) muscle.Methods: Six patients with history of ocular trauma, followed by sudden onset vertical diplopia along with marked hypertropia (HT) and limitation of depression in abduction in the affected eye suggestive of IR disinsertion, were included in this prospective study. The patients were treated by simultaneous SR recession and ATIO muscle in the affected eye by limbal conjunctival approach under local anesthesia.Results: Preoperatively, primary position HT of 40–50 (mean 44.16 ± 4.91) prism diopters (PD) was present in all cases which increased to 65–70 (mean 65.83 ± 5.84) PD in down and in the ipsilateral gaze along with marked limitation of depression in abduction and A pattern. On exploration, the IR could not be traced in four cases. Fibrotic muscle sheath with retracted IR was found 10–12 mm away from the limbus in rest of the two patients. ATIO (6.5 mm from the limbus) with simultaneous recession of ipsilateral SR was done under local anesthesia.At 12 weeks postoperatively, three patients were orthophoric in primary position and vertical alignment with in 4–7 PD in primary position was achieved in rest of the three patients.Conclusion: Simultaneous SR recession with ATIO seems to be a good alternative to achieve satisfactory vertical alignment for patients with traumatically lost inferior rectus muscle.

A Valid Indication and the Effect of Bilateral Inferior Oblique Transposition on Recurrent or Consecutive Horizontal Deviation in Infantile Strabismus.

PurposeTo evaluate the effects of bilateral inferior oblique transposition (BIOT) on horizontal deviation from primary position among patients with bilateral dissociated vertical deviation (DVD) associated with inferior oblique overaction (IOOA) in infantile strabismus.MethodsRetrospective chart review was conducted among 19 patients with infantile strabismus. All patients had DVD and IOOA with consecutive or recurrent horizontal deviation and underwent modified BIOT surgery. Patients were divided into three subgroups: patients who underwent BIOT (BIOT group, n = 9) alone, BIOT with medial rectus recession or lateral rectus resection simultaneously (ET BIOT group, n = 6), or BIOT with lateral rectus recession or medial rectus resection simultaneously (XT BIOT group, n = 4). Postoperative angle of horizontal deviation (prism diopter, PD) and corrected magnitude of horizontal deviation (PD) at final visit after surgery were analyzed in each group.ResultsThe mean age was 55.11 ± 21.05 months (range, 32 to 115). The mean follow-up period was 8.68 ± 2.87 months (range, 6 to 18). Preoperative horizontal deviation was 4.23 ± 5.99 PD (range, 0 to 16) in BIOT, −17.33 ± 6.76 PD (range, −30 to −10) in ET BIOT, and 17.50 ± 2.52 PD (range, 14 to 20) in XT BIOT. Esodeviation is represented by negative values. DVD and IOOA were reduced less than +1 in all patients. The corrected amount of horizontal deviation was 3.56 ± 5.18 PD (range, 0 to 16) in BIOT surgery alone and larger in XT BIOT (18.50 ± 3.41 PD) than in ET BIOT (12.33 ± 5.57 PD, p = 0.004).ConclusionsMinimal exodeviation was corrected by BIOT alone. In addition, secondary eso- or exodeviation at great magnitudes should be corrected with proper horizontal muscle surgery along with BIOT.

Comparison of outcome of inferior oblique weakening procedures, myectomy and anterior transposition, from western India

Context: Inferior oblique (IO) weakening is one of the commonest surgical procedures on the oblique muscles. Purpose: To compare the results of two IO weakening procedures, myectomy, and anterior transposition, done for IO over-action and dissociated vertical deviation (DVD). Setting and design: Tertiary eye-care center. Retrospective review Materials and Methods: Patients operated for IO over-action and DVD were studied. All patients had undergone a comprehensive ocular examination with full orthoptic evaluation and cycloplegic refraction. In the anterior transposition of IO, the IO muscle was recessed from its insertion and placed lateral to the insertion of the inferior rectus. In myectomy, the IO tendon was cut at two sites 5 mm apart and the cut ends cauterized and left free. The outcome measure was pre and post-operative IO action measurement. Statistical analysis: T-test. Results: Eighty six children (128 eyes) underwent IO weakening procedures, 81 (62.4%) were myectomy and 47 (36.2%) were anterior transpositions. The average age was 8.9 years (standard deviation, SD 3.51), 53 (61.6%) were girls. Twenty-three had DVD and 42 patients had bilateral IO surgeries. Thirty-eight (44.2%) had esotropia and 47 (54.6%) had exotropia co-existent; one had only primary IO over-action. The pre-and post-operative IO over-action was 1.61 and 0.59 for myectomy and 1.61 and 0.29 for anterior transposition, respectively. On comparing the pre- vs post-IO action, P < 0.001 for both techniques, but post-operative anterior transposition versus myectomy had P = 0.156 by the t-test. Conclusion: Both techniques were effective and the difference between the two techniques was not statistically significant.

Modified Inferior Oblique Transposition Considering the Equator for Primary Inferior Oblique Overaction (IOOA) Associated with Dissociated Vertical Deviation (DVD)

Purpose: Inferior oblique anterior transposition (IOAT) should be done only in patients with inferior oblique overaction (IOOA) and dissociated vertical deviation (DVD) without fusional potential because the procedure can cause anti-elevation syndrome. This study reports the results of modified inferior oblique transposition onto the equator in 7 patients diagnosed with infantile exotropia or esotropia associated with IOOA and DVD.Methods: We performed modified inferior oblique (IO) transposition onto or considering the equator on 7 patients who had infantile exotropia or esotropia associated with IOOA and DVD. Five patients had infantile exotropia, and the other two patients had infantile esotropia. Six patients had undergone bilateral rectus -- Bilateral Lateral Rectus (BLR) or Bilateral Medial Rectus (BMR) -- recession previously and one patient underwent BLR recession and IO transposition simultaneously. They had more than +1.5 IOOA with DVD in both eyes. IO was transposed vertically onto the equator in this study. The mean distance between the lateral border of the inferior rectus insertion and the equator was 5.6 mm (range: 4.5 to 6.5 mm). Three months after the operation, degree of IOOA and DVD in each eye was evaluated.Results: IOOA and DVD were markedly reduced in all patients (+0.5 ∼+1 for IOOA postoperatively). Mild contralateral IOOA was noted but the motility disturbance was successfully corrected in all cases postoperatively.Conclusion: Bilateral IO transposition onto the equator could minimize antielevation and corrected IOOA and DVD successfully in patients with infantile exotropia or esotropia.

Inferior oblique transposition for large hypertropia after vertical rectus transposition

Consecutive vertical deviations occur in 13% to 30% of cases after full tendon vertical rectus transposition (VRT) surgery in adult patients with abducens nerve palsy. We report a 7-year-old boy with congenital abducens nerve palsy who developed a large hypertropia following VRT with posterior fixation sutures. During subsequent surgery, extensive scarring of the vertical rectus muscles was observed, and an inferior oblique nasal anterior transposition was performed. The patient was orthotropic in primary position through 18 months of follow-up. The causes and management options for vertical deviation following VRT are discussed.

Inferior Oblique Transposition Onto the Equator: The Role of the Equator in Development of Contralateral Inferior Oblique Overaction

To investigate the role of the location of the equator and orientation of newly attached inferior oblique (IO) muscle in the development of contralateral inferior oblique overaction (IOOA). Fourteen patients (14 eyes) with 5 to 12 prism diopters (PD) of hyperdeviation in primary position with unilateral, congenital, superior oblique palsy were included. Seven patients underwent modified IO transposition onto the equator (equator group) and seven patients underwent modified IO 14-mm recession (14-mm group). IOOA in the contralateral eye and the angle of strabismus were assessed at 3 months postoperatively. Mean angles of hyperdeviation in primary gaze and sursoadduction were 0.7 and 2.1 PD in the equator group and 0.6 and 2.4 PD in the 14-mm group, respectively. Six patients (86%) developed anti-elevation syndrome and four patients (57%) showed definite 2+ or higher IOOA in the contralateral eye in the equator group. Three patients (43%) in the 14-mm group also developed contralateral IOOA, although it was 1+ or less. The postoperative difference in contra-lateral IOOA between groups was statistically significant (P = .04). This finding suggests that vertical orientation of the IO muscle is another important contributor in the development of contralateral IOOA in addition to the location of the newly attached IO muscle.