Anterior transposition of inferior oblique muscle with unequal excision for segregated vertical strabismus with asymmetric inferior oblique hyperfunction / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To explore the application of anterior transposition of inferior oblique muscle with unequal excision in treatment of segregated vertical strabismus with asymmetric inferior oblique hyperfunction.<p>METHODS: A total of 22 patients(10 males and 12 females, 28 eyes in all)who underwent anterior transposition of the unequal excisional inferior oblique muscle for dissociated vertical deviation with asymmetric inferior oblique muscle overaction were studied retrospectively. The patients were admitted from June 2015 to June 2017,with mean age at 12.32±6.81 years old(ranging from 3 to 28 years old). The binocular vision, the curative effect of DVD, the curative effect of inferior oblique muscle overaction, eye position and compensatory head posture, complications were examined postoperatively, follow-up survey was conducted at 6 to 18mo, meanly at 10.05±3.87mo.<p>RESULTS: Recovery of binocular vision: 11 cases did not have binocular vision(50%); 6 cases recovered to the first level of binocular vision(27%); 3 cases recovered to the second level of binocular vision(14%); 2 cases recovered to the third level of binocular vision(9%). The curative effect of DVD shows: 17 cases with satisfaction(77%), 5 cases with improvement(23%), and 0 case with no avail. The curative effect of inferior oblique muscle overaction shows: 13 cases with cured(59%), 9 cases with improvement(41%), and 0 case with no avail. Postoperative eye position and compensatory head posture: 1)Horizontal eye position: 1 case of under correction after exotropia correction surgery, 1 case of under correction after esotropia correction surgery, 0 case of overcorrection, 20 cases of correction; 2)Vertical eye position: 13 cases show vertical strabism deviation less than 5△, 9 cases show vertical strabism deviation between 5△ to 10△ meanly at 5.55△±2.35△, vertical eye position without overcorrection; 3)Compensatory head posture: 6 cases were disappeared, 1 case was improved. Complications: Mild anti-elevation syndromeoccurred in 1 case, narrowed palpebral fissueoccurred in 1 case, and narrowed quantity less than 1mm.<p>CONCLUSION: In general, the curative effect of anterior transposition of the unequal excisional inferior oblique muscle for dissociated vertical deviation with asymmetric inferior oblique muscle overactionis satisfactory, standard preoperative examination, individualized surgical design and surgical techniques are necessary.

The Effect of Inferior Oblique Muscle Transposition in Primary and Secondary Inferior Oblique Muscle Overaction

PURPOSE: To evaluate and compare the effect of transposition of inferior oblique muscle in patients with primary inferior oblique muscle overaction and secondary due to superior oblique muscle palsy. METHODS: The present study included 41 patients (53 eyes), who appeared to have primary or secondary inferior oblique muscle overaction due to superior oblique muscle palsy and received transposition of inferior oblique muscle with at least 3 months of follow-up. Patients were retrospectively analyzed to compare the effect of correction and its prognosis. Inferior oblique muscle overaction was graded as +1 to +4 according to the severity. Successful surgery was defined as postoperative inferior oblique muscle overaction from 0 to +1 and failure as above +2. Hypertropia in primary gaze was also recorded to evaluate the effect of correction. RESULTS: Twenty-six (35 eyes) and 15 (18 eyes) patients with primary and secondary inferior oblique muscle overaction due to superior oblique muscle palsy, respectively, received transposition of inferior oblique muscle. Patients with primary inferior oblique muscle overaction showed correction of 2.1 +/- 0.9 with preoperative inferior oblique muscle overaction of 2.0 +/- 0.7. Patients with secondary inferior oblique muscle overaction showed a correction of 2.3 +/- 0.9 with preoperative value of 2.3 +/- 0.8. Each 3.2 +/- 4.1 prism diopters (PD) and 6.5 +/- 5.3 PD of hypertropia at primary gaze showed correction of 3.0 +/- 7.4 PD and 6.3 +/- 5.1 PD, respectively, in each group. CONCLUSIONS: Primary and secondary inferior oblique muscle overaction due to superior oblique muscle palsy showed no difference in correction of overaction and hypertropia after transposition of inferior oblique muscle. Except for presence of inferior oblique muscle underaction, the correction appears effective with good prognosis.

Contralateral Inferior Oblique Muscle Overaction after Unilateral Inferior Oblique Weakening Procedures

PURPOSE: To investigate the effect of unilateral inferior oblique weakening procedures on contralateral inferior oblique muscle functions and factors that may have an effect on contralateral inferior oblique muscle overaction (IOOA). METHODS: A retrospective chart review was conducted of medical records of 40 patients who underwent unilateral inferior oblique (IO) muscle weakening procedures from 2007 to 2011 and were observed during a follow-up period of more than 6 months. These patients were composed of primary IOOA (4 patients), secondary IOOA due to superior oblique muscle (SO) palsy (21 patients), secondary IOOA due to inferior rectus muscle palsy (1 patient), and dissociated vertical deviation (DVD) accompanied with IOOA (14 patients). Factors that may have an effect on contralateral IOOA after undergoing the operation were assessed. RESULTS: There were 7 patients (17.5%) who had over +2 IOOA after operation. IOOA on contralateral eye was increased from average of +0.00 to average of +0.66 +/- 0.14 in 6 months after operation (p < 0.01). There were no statistically significant differences between preoperative factors and functional changes in contralateral IO muscle. CONCLUSIONS: There were no statistical factors that may have an effect on contralateral IOOA but the possibility of masked SO palsy before performing unilateral IO weakening procedures should be considered. In patients who have unilateral DVD associated with IOOA or small hypertropia, the contralateral IOOA can be more definite after operation; thus caution should be taken before operation.

Contralateral Inferior Oblique Overaction after Inferior Oblique Recession in Unilateral Moderate Primary Inferior Oblique Overaction

PURPOSE: To investigate the incidence rate of inferior oblique muscle overaction (IOOA) in the contralateral eye and the effect of inferior oblique (IO) muscle recession of the contralateral eye in the patients who received IO muscle recession for unilateral moderate (+2 or +3) primary IOOA. METHODS: Medical records of 88 patients with unilateral primary IOOA who underwent unilateral IO muscle recession were retrospectively reviewed and observed during a follow-up period of more than 1 year. Graded recession of the IO muscle was performed according to the degree of IOOA. If postoperative IOOA was below +1, the surgery was considered successful. If IOOA in the contralateral eye was more than +2 after surgery, the IOOA was considered to have occurred. RESULTS: In cases where IOOA was +2 and +3 before the surgery, the success rate was 98.2% and 100%, respectively, showing an overall success rate of 98.8%. The incidence of contralateral IOOA after recession of the unilateral IO muscle was 24.1% in the +2 group and 16.6% in the +3 group with an overall incidence rate of 21.6% and when the IO muscle recession of the contralateral eye was performed, the success rate was 100%. CONCLUSIONS: The incidence of contralateral IOOA was 21.6% after the unilateral IO muscle recession in moderate unilateral primary IOOA. A satisfactory outcome was obtained through an additional IO muscle recession in the contralateral eye.

Secondary Superior Oblique Overaction after Inferior Oblique Muscle Myectomy in a Patient Misdiagnosed with Inferior Oblique Muscle Overaction

PURPOSE: To report a case of superior oblique muscle tenotomy in a patient with suspected bilateral inferior oblique muscle overaction. The patient showed secondary superior oblique muscle overaction and inferior oblique muscle underaction after inferior oblique muscle myectomy. CASE SUMMARY: The patient showed V-pattern exotropia with suspected bilateral inferior oblique muscle overaction. After bilateral lateral rectus muscle recession with bilateral inferior oblique muscle myectomy, the patient showed secondary esotropia and inferior oblique underaction. After the surgery, progressive secondary superior oblique muscle overaction continued and finally, a superior oblique muscle tenotomy was performed. After the superior oblique muscle tenotomy, the superior oblique muscle overaction was corrected but the inferior oblique muscle underaction continued. CONCLUSIONS: After an inferior oblique muscle myectomy, secondary superior oblique muscle overaction can develop. Thus, caution should be taken in diagnosing inferior oblique muscle overaction in patients who show minimally inferior oblique muscle overaction as well as the surgical methods chosen.

The Surgical Effects of Inferior Oblique Anteriorization

PURPOSE: To find out the effect and proper indications, we studied the effect and complications of anteriorization of the inferior oblique muscle in each type of strabismus. METHODS: We retrospectively studied 33 cases (50 eyes) of primary inferior oblique overaction (IOOA), 17 cases (17 eyes) of superior oblique muscle palsy, and 20 cases (27 eyes) of dissociated vertical deviation (DVD), who received inferior oblique anterior transposition at Chonnam National University Ophthalmology Department from January 1996 to December 2001. RESULTS: In the cases of primary IOOA, the success rate for IOOA of +3~4 was 88%. In the cases of superior oblique palsy, the mean correction of vertical deviation was 14.4 delta. In superior oblique palsy of preoperative vertical deviation less than 15 delta, the success rate was 83%. In DVD, the mean correction of vertical deviation was 9.6 delta and the success rate of preoperative deviation less than 10 delta was 80%. In 11 eyes of 11cases out of 70 cases, complications, including like elevation limitation, IOOA of opposite eye, and hypotropia at primary position, occurred. CONCLUSIONS: In cases of IOOA of +3~4, with superior oblique palsy of preoperative vertical deviation about 15 delta, and DVD of preoperative deviation less than 10 delta, good results were obtained by inferior oblique anteriorization.

The Effect of Modified Anterior Transposition of the Inferior Oblique Muscle for Hypertropia in Superior Oblique Muscle Palsy with Inferior Oblique Muscle Overaction

PURPOSE: The authers studied the effect of modified anterior transposition of the inferior oblique muscle for hypertropia in superior oblique muscle palsy combined inferior oblique muscle overaction. METHODS: We retrospectively analysed 19 cases of superor oblique palsy, which were treated by modified inferior oblique muscle anterior transposition from January 1999 to march 2001. Mean follow-up was 14.6 months. The medial portion of inferior oblique muscle was transpositioned to 1mm posterior position of the temporal insertion of inferior rectus muscle and lateral portion of inferior oblique muscle was moved 5mm on imaginary line, which is the line of between temporal insertion of inferior rectus and inferior insertion of lareral rectus muscle, to the direction of inferior insertion of lateral rectus muscle from temporal insertion of inferior rectus muscle, then backward 6mm from that point perpendicularly. RESULTS: The success rates in modified anterior transposition were 94% in under 20delta of hypertropia and 89.5% in over +3 of IOOA. CONCLUSIONS: Modified anterior transposition is an effective procedure of +3 to +4 inferior oblique muscle overaction and hypertropia in superior oblique muscle palsy as a primary surgery.