Occurrence and subsequent development of vertical deviations in patients treated surgically for infantile esotropia

Purpose: The purpose of this study was to evaluate the onset of dissociated vertical deviation (DVD) and inferior oblique overaction (IOOA), their subsequent development, and their correlation with pre and postoperative parameters. Methods: Medical records of patients with infantile esotropia who underwent surgery between 2005 and 2017 were retrospectively reviewed. DVD and IOOA were measured before and after surgery. Patients were divided into two groups based on horizontal and vertical deviation at the time of presentation: those with infantile esotropia only (group A) and patients with infantile esotropia who developed vertical deviation (group B). Results: Out of a total of 102 patients, DVD occurrence was seen in 53 patients (51.9%) and IOOA was seen in 50 patients (48.04%). DVD was seen in 22 patients at the time of initial examination and in 31 patients postoperatively. IOOA at presentation was seen in 45 patients (44.1%) and 5 patients (8.8%) postoperatively. No statistical difference was found in the age of surgery, angle of deviation, mean follow?up, and mean refractive error within both groups. The postoperative motor outcome was statistically comparable between the two groups (P = 0.29). Sensory outcomes of fusion (P = 0.048) and stereopsis (P?value = 0.00063) were better in group A. Conclusion: No correlation was found between the age of occurrence and development of vertical deviation with refractive error, angle of deviation, age, or type of surgery. We found that motor outcomes are not affected but sensory outcomes are affected in patients with vertical deviations. This indicates that DVD and IOOA are developed due to inherent disruption of fusion and stereopsis

Inferior oblique belly transposition in the treatment of mild inferior oblique overaction with small angle vertical strabismus / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To observe the effect of inferior oblique belly transposition(IOBT)in unilateral mild inferior oblique overaction with small angle vertical stabismus.<p>METHODS: The data of patients who underwent IOBT in our hospital from September 2019 to August 2021 were analyzed retrospectively. Inclusion criteria targeted patients with mild inferior oblique overaction(2+ and below)and small angle incomitant vertical strabismus(4-9PD). The horizontal deviation and vertical deviation in both primary and lateral gazes were measured, and the degree of inferior oblique overaction and fovea-disc angle(FDA)were also evaluated preoperatively and postoperatively.<p>RESULTS: A total of 16 cases(16 eyes)were included, aged 4-39 years. One case was 5a postoperative congenital esotropia with secondary unilateral inferior oblique overaction by mild superior oblique palsy, whereas 15 patients had monocular primary inferior oblique overaction with horizontal strabismus. The follow-up was 3-6mo. The mean improvement of inferior oblique overaction was 2.00(1.25, 2.00)grade from +2.00(2.00, 2.00)preoperatively to 0.00(0.00, 0.00)postoperatively, the difference was statistically significant(<i>Z</i>=-3.70, <i>P</i><0.001). The horizontal strabismus decreased from 69.13±25.86PD preoperatively to 2.75±2.59PD postoperatively(<i>t</i>= 9.929, <i>P</i><0.001). The vertical strabismus in the primary position decreased from preoperative 7.44±1.32PD to 1.00±1.21PD postoperatively(<i>t</i>=22.335, <i>P</i><0.001), mean corrected hypertropia 6.44±1.15PD, and vertical strabismus in lateral gazes decreased from preoperative 12.44±2.73PD to 3.00±2.13PD postoperatively, mean corrected hypertropia 9.44±2.73PD, these differences were statistically significant(<i>t</i>=13.819, <i>P</i><0.001). The FDA decreased from -8.85°±6.53° preoperatively to -6.49°±7.01° postoperatively, the difference was statistically significant(<i>t</i>=-2.384, <i>P</i><0.001), with a mean reduction of 2.36°. No postoperative complications such as postoperative overcorrection or inferior oblique underaction were observed.<p>CONCLUSION:IOBT is safe and effective in correcting unilateral mild inferior oblique overaction with small angle vertical strabismus.

Changes in Ocular Excyclotorsion According to Graded Inferior Oblique Recession

PURPOSE: To investigate changes in ocular excyclotorsion in patients with inferior oblique overaction (IOOA) according to amount of correction by graded inferior oblique recession and to compare the amount of excyclotorsion between primary IOOA and secondary IOOA. METHODS: This study included 54 eyes of 54 patients who were diagnosed with unilateral IOOA and underwent graded inferior oblique recession. Fundus photographs were taken pre- and postoperatively. The sum of angles of torsion of both eyes was used to analyze changes in excyclotorsion. The angle of excyclotorsion was analyzed using the ImageJ program. RESULTS: Eighteen eyes were grade 2, 24 eyes were grade 3 and 12 eyes were grade 4. Preoperative angle of excyclotorsion was 16.23 ± 5.96° for the patients with grade 2 eyes, 18.83 ± 5.76° for the patients with grade 3 eyes and 29.00 ± 10.23° for the patients with grade 4 eyes. Therefore, as the degree of IOOA increased, the amount of excyclotorsion became larger. There was no statistical significance between grade 2 and grade 3 (p = 0.467), however, there was a statistically significant difference between grade 3 and grade 4 (p < 0.001). Postoperative angle of excyclotorsion was significantly decreased in each group (grade 2: p = 0.020, grade 3: p < 0.001, grade 4: p = 0.041). The amount of surgical recession of inferior oblique muscle showed a positive correlation with a decrease in the angle of excyclotorsion, but was not statistically significant. The amount of excyclotorsion and the decrease of excyclotorsion after surgery were larger in secondary IOOA than in primary IOOA, but were not statistically significant (p = 0.260). CONCLUSIONS: As the preoperative degree of IOOA increased, the amount of correction of excyclotorsion became larger but there is no statistical significance. Correction of IOOA and excylclotorsion is expected after graded inferior oblique recession.

The Clinical Characteristics of V-Pattern Exotropia Without Inferior Oblique Muscle Overaction

PURPOSE: To compare the surgical outcome between V-pattern intermittent exotropia without inferior oblique overaction and comitant intermittent exotropia. METHODS: The authors of the present study investigated 15 patients (V-pattern group) who had standard horizontal surgery with half-tendon width vertical transposition and 36 patients (Comitant group) with unilateral rectus muscle recession/resection. Preoperative visual acuity, presence of amblyopia, abnormal head posture, stereoacuity, amount of exotropia, and duration of postoperative diplopia were recorded. Surgical success was defined as final alignment of orthophoria or less than 10 PD orthophoria. RESULTS: The frequency of good stereoacuity with 80 sec of stereoacuity or more was higher in the V-pattern group (73.3%) than in the Comitant group (33.3%) (Fisher's exact test, p = 0.01). One case of V-pattern showed consecutive esotropia for 1 year postoperatively. Exotropia recurred in 2 patients in the V-pattern group (13.3%), and in 4 patients in the Comitant group (11.1%) 1 year postoperatively. Surgical success rates were statistically significant higher in the V-pattern group (86.7%) as compared to the Comitant group (58.3%) on final follow-up (Fisher's exact test, p = 0.04). CONCLUSIONS: V-pattern exotropia patients without inferior oblique overaction who had standard horizontal surgery with half-tendon width vertical transposition showed a lower recurrence rate of exotropia than patients with comitant intermittent exotropia.

The Outcome of Graded Inferior Oblique Recession in the Congenital Unilateral Superior Oblique Palsy

PURPOSE: To examine changes in vertical deviation and improvement in head tilt after graded inferior oblique (IO) recession surgery in patients with congenital unilateral superior oblique palsy (SOP). Frequency of inferior oblique overaction (IOOA) or bilateral SOP in the contralateral eye after surgery was also investigated. METHODS: We retrospectively reviewed medical records of 65 patients who had undergone graded IO recession surgery in unilateral congenital SOP with at least 1 year of postoperative follow-up. Postoperative vertical deviation was classified as excellent (under 3 prism diopters, PD), good (4-7 PD) or poor (over 8 PD). The occurrence of IOOA was considered if more than 2 IOOAs were observed in the contralateral eye after surgery. RESULTS: Forty-five of the 65 patients (69%) obtained excellent results and 67.3% had improvement in head tilt after surgery. IOOA in the contralateral eye was not observed in any patients before surgery. Postoperative IOOA in the contralateral eye occurred in 9 patients (13.8%) and a diagnosis of masked bilateral SOP was made in 1 patient (1.5%). CONCLUSIONS: The graded IO recession procedures are considered to be an effective surgical method for the treatment of unilateral congenital SOP. However, IOOA or masked bilateral SOP occurring in the contralateral eye was observed in 15.3% of the patients undergoing surgery.

Clinical Manifestations of Inferior Oblique Overaction in Patients with Horizontal Strabismus

PURPOSE: To investigate the clinical manifestations of and the surgical success rates in patients with horizontal strabismus and inferior oblique overaction (IOOA). METHODS: The patients included in the present study had received myectomy for correction of IOOA and had at least 3 months of follow-up. The patients were divided into 2 groups; patients who received myectomy and surgery for horizontal strabismus simultaneously (combined group, 74 eyes of 49 patients) and patients who received myectomy only (myectomy group, 29 eyes of 24 patients). Chief complaints, head tilt, bilaterality of IOOA, ocular torsion, and the surgical success rates were analyzed. RESULTS: In the combined group, 51% of the chief complaints were horizontal deviation, and in the myectomy group 42% were upward deviation and 29% were head tilt. Objective head tilt was 29% in the combined group and 54% in the myectomy group and the difference was significant. There was no significant difference statistically in the success rate of myectomy. CONCLUSIONS: The frequency of symptoms associated with IOOA in the combined group was lower than in the myectomy group. Therefore, preoperative examination regarding IOOA should be carefully performed in patients who are planning a horizontal strabismus surgery because there was no difference in surgical success rate between the 2 groups, the association with horizontal strabismus may have no effect on the surgical results of IOOA.

Clinical Evaluation of Excyclotorsion in Patients with Primary Inferior Oblique Overaction

PURPOSE: To evaluate the amount of excyclotorsion according to degree of inferior oblique overaction (IOOA) in patients with primary IOOA. METHODS: Fifty-nine primary IOOA patients who underwent inferior oblique muscle surgery were evaluated. Visual acuity, ocular movement test, prism cover test, Bielschowsky head tilt test, fundus photograph and photographic examination for excyclotorsion were performed. The correlation analysis was performed for the excyclotorsion according to the amount of IOOA (Control group; IOOA < 1, Group 1; 1 < or = IOOA < 2, Group 2; 2 < or = IOOA < 3, Group 3; 3 < or = IOOA < 4, Group 4; IOOA = 4). RESULTS: Excyclotorsion was 7.37 +/- 2.36degrees in the Control group, 9.29 +/- 3.79degrees in Group 1, 10.04 +/- 4.39degrees in Group 2, 17.98 +/- 4.62degrees in Group 3, and 24.70 +/- 4.61degrees in Group 4. The amount of IOOA and excyclotorsion showed a positive correlation (Pearson's correlation coefficient r = 0.675). Asymmetric IOOA was observed in 35 patients (59.3%) and symmetric IOOA was observed in 24 patients (40.7%). Asymmetric IOOA combined with hypertropia was presented in 9 patients (37.5%) and symmetric IOOA combined with hypertropia was presented in 3 patients (8.6%). Therefore, patients with asymmetric IOOA have a higher incidence of vertical diplopia. The amounts of IOOA and excyclotorsion were greater in primary IOOA with esotropia than in subjects with exotropia (p = 0.001). CONCLUSIONS: The excyclotorsion was proportional to the amount of IOOA in Group 3 and Group 4. The aspect of excyclotorsion was widely distributed in Group 1 and Group 2 compared to that in the Control group.

Clinical Manifestations and Surgical Outcomes of Intermittent Exotropia with or without Dissociated Vertical Deviation

PURPOSE: Clinical manifestations and surgical outcomes of intermittent exotropia with or without dissociated vertical deviation (DVD) were evaluated. METHODS: Patients who were diagnosed with intermittent exotropia following surgical correction were divided into 2 groups: 66 patients with DVD (DVD group) and 81 patients without DVD (XT group). The postoperative deviation between exodeviation of 10 prism diopters (PD) and esotropia of 5 PD was considered surgically successful. RESULTS: The onset of strabismus occurred at an earlier age in the DVD group. There were more cases of nystagmus, inferior oblique muscle overaction, superior oblique muscle overaction, and AV pattern in the DVD group than in the XT group, but there were no differences between the 2 groups in terms of head tilt, amblyopia, and age at first operation. While exodeviation in the DVD group was smaller than in the XT group, stereopsis in the DVD group was statistically worse than in the XT group in the Titmus test. At postoperative 1 month, the XT group had better surgical outcome, but at postoperative 6 and 12 months, there were no differences in the surgical outcomes of intermittent exotropia between the 2 groups. Regarding DVD surgery, a postoperative DVD angle less than 10 PD accounted for 90.0% of the cases. CONCLUSIONS: Intermittent exotropia combined with DVD had worse stereoacuity and lesser exodeviation. There was no statistically significant difference in the surgical outcomes of intermittent exotropia with or without DVD.

The Case of Inferior Oblique Muscle Overaction after Orbital Trauma

PURPOSE: To report a case of inferior oblique muscle overaction after orbital trauma. CASE SUMMARY: A 19-year-old male presented with a blowout fracture of the right inferior orbital wall. The patient had no history of facial asymmetry, head tilt, strabismus or diplopia. The day after the reduction operation, the patient complained of diplopia on the down-gaze. The patient had orhthophoria in the primary position. However, the right eye showed a limitation on infraduction. Six weeks later, the limitation of infraduction resolved, however the diplopia worsened. The right eye showed excessive elevation in adduction and hypertropia in the primary position. The hypertropia increased on left gaze, and decreased on right gaze. Bielschowsky's head test revealed a negative result. The fundus photographs showed a mild excyclotorsion of the right eye. Five months later, the symptoms and signs were stable and surgery was performed. Under general anesthesia, the exaggerated forced duction test and traction with strabismus hook on the right inferior oblique muscle revealed tightness. The inferior oblique muscle was found to be recessed. After the operation, the diplopia, hypertropia and the excessive elevation on adduction of the right eye resolved. CONCLUSIONS: A contracture and resultant overaction of inferior oblique muscle could develop after trauma on the inferior orbital wall. Trauma on the inferior orbital wall should be considered as one of the primary causes of acquired inferior oblique overaction.

Analysis of Effect of Inferior Oblique Myectomy in Patients With Inferior Oblique Overaction

PURPOSE: To investigate the effect of inferior oblique (IO) myectomy by analyzing the correlation of the amount of inferior oblique overaction (IOOA), hypertropia and excyclotorsion before, between, and after IO myectomy in patients with various degrees of IOOA. METHODS: A total of 86 eyes from 59 patients with IOOA who underwent IO myectomy were enrolled in the present study. The correlation analysis was performed for the amount of IOOA, hypertropia and excyclotorsion before and after surgery, according to the preoperative amount of IOOA, hypertropia, and excyclotorsion. RESULTS: The IOOA decreased from +2.5 +/- 0.6 before surgery to -0.01 +/- 0.25 (p < 0.05) after surgery. The vertical deviation was 5.7 +/- 6.3 prism diopter (PD) and 2.3 +/- 5.2 PD (p < 0.05) postoperatively. The amount of cyclodeviation was 15.3 +/- 7.6degrees before surgery and 6.6 +/- 5.7degrees (p < 0.05) after surgery. The amount of surgical correction for IOOA and the hypertropia was significantly correlated with preoperative deviation (p < 0.05, p < 0.05). The amount of excyclotorsion before and after surgery was also positively correlated but was not statistically significant (p = 0.05). CONCLUSIONS: IO myectomy can correct any degree of IOOA, hypertropia, and related excyclotorsion.

The Effect of Minimal Amount Inferior Oblique Recession in Superior Oblique Palsy

PURPOSE: To investigate the effect of vertical deviation change, head tilt and diplopia relief, we performed a minimal amount of inferior oblique recession regardless of the vertical deviation angle and the degree of inferior oblique overaction (IOOA) in superior oblique palsy patients. METHODS: We retrospectively analyzed 20 cases of unilateral congenital or acquired superior oblique palsy, which were treated with inferior oblique muscle recession from May 2005, to August 2007. We compared vertical deviation change, head tilt and diplopia relief following surgery. Improvement of head tilt was determined by patient satisfaction measurements. The inferior oblique muscle was attached 4 mm posterior and 2 mm temporal to the lateral border of the inferior rectus muscle insertion in all patients. RESULTS: The average angle of vertical deviation prior to surgery was 12.4 prism diopters (PD), and the total average correction in the angle of vertical deviation after surgery was 9.6PD. After surgery, head tilt improved in 13 of 16 eyes(81%), and of the four remaining eyes, vertical diplopia was absent. CONCLUSIONS: Although vertical deviation remained after surgery, if patients have enough vertical fusional amplitude, they should be able to overcome the diplopia and the head tilt. Judging from the indication of inferior oblique recession in diplopia and cosmetic problem in superior oblique palsy, a minimal amount of inferior oblique recession is thought to be an effective treatment of unilateral superioroblique palsy with no significant IOOA.

The Effect of Reoperation in Inferior Oblique Overaction

PURPOSE: To evaluate the efficacy of re-recession or extirpation of inferior oblique (IO) muscle in recurrent or undercorrected IO overaction (IOOA). METHODS: We reviewed the records of 26 patients (33 eyes) with the recurrent or undercorrected IOOA after the graded recession of IO muscle, who underwent re-recession or extirpation of IO muscle, and was followed up for at least 6 months. We performed extirpation of IO muscle overacting larger than +2 after 14 mm recession of IO muscle or larger than +3 after 10 mm recession of IO muscle. In case of +2 IOOA after 10 or 8 mm recession of IO muscle, we carried out 14 mm re-recession of IO muscle. IOOA under +1 was defined as a successful case after re-operation. RESULTS: Thirty one of 33 eyes (93.9%) were corrected successfully after re-operation; 24 eyes with extirpation of IO muscle (96.0%) and 7 eyes with 14 mm re-reccession of IO muscle (87.5%) were successful. CONCLUSIONS: One of the advantages of graded recession of IO muscle is that additional re recession or extirpation of IO muscle can be preformed if needed. Extirpation or 14 mm re-recession of IO muscle was effective re operation procedure to correct a recurred or undercorrected IOOA.

The Relationship of Hypertropia, Inferior Oblique Overaction and Extorsion in Congenital Superior Oblique Palsy

PURPOSE: To evaluate the correlation among hypertropia, inferior oblique overaction (IOOA), and extorsion. METHODS: Thirty-one patients with congenital unilateral superior oblique palsy were evaluated. Visual acuity tests, refraction tests, ocular movement tests, prism cover tests, and fundus photography were performed. The correlations of vertical deviation, IOOA, and extorsion were analyzed. The operation method involved weakening the inferior oblique muscle, and then a comparison was made between measurements 1 month preoperative and 1 month postoperative for vertical deviation, inferior oblique overaction, and extorsion. RESULTS: On average, preoperative hypertropia was 8.84+/-6.88 prism diopters (PD), IOOA was 2.20+/-0.69, and extorsion was 18.06+/-5.83 degrees. The Pearson's correlation of IOOA and extorsion, hypertropia and IOOA, and extorsion and hypertropia were r=0.620, r=0.327, and r=0.126, respectively. Postoperative hypertropia, IOOA, and extorsion were reduced to 1.42+/-3.11PD, 0.42+/-1.11, and 8.63+/-5.09, respectively. CONCLUSIONS: Both extorsion and hypertropia showed significant positive correlations with IOOA, whereas hypertropia and extorsion revealed somewhat weaker positive correlations in congenital monocular superior oblique palsy. In addition, the amount of hypertropia was reduced, and extorsion and IOOA improved after recession of the inferior oblique muscle.

The Effect of Myectomy on the Grading of Overaction of the Inferior Oblique Muscle

PURPOSE: This study assesses the surgical results of inferior oblique myectomy on the degree of overaction in patients with overaction greater than +2 of the inferior oblique muscle. METHODS: Seventy eyes of 54 patients underwent an inferior oblique myectomy and at least 6 months of follow-up. Patients with contracture of the superior rectus muscle or dissociated vertical deviation were excluded. The chief complaints, preoperative and postoperative degrees of overaction of the inferior oblique muscle, the angle of hypertropia, and head tilt were analyzed. RESULTS: Deviation of the eyeball (38.9%) and head tilt (25.9%) were the most common complaints. Overall, the success rate was 91.4%, and the likelihood of success decreased with increasing severity of overaction of the inferior oblique muscle. The angle of hypertropia reduced from 11.9 (Prism diopters, PD) preoperatively to 2.2PD postoperatively (p=0.000). Preoperative head tilting was seen in 20 patients (37%) and all saw postoperative improvement. CONCLUSIONS: Inferior oblique myectomy is effective in treating the overaction of the inferior oblique muscle without contracture of the superior rectus muscle or dissociated vertical deviation, especially in patients with greater than +2 overaction of the inferior oblique muscle.

Calcium Uptake and Release through Sarcoplasmic Reticulum in the Inferior Oblique Muscles of Patients with Inferior Oblique Overaction

We characterized and compared the characteristics of Ca2+ movements through the sarcoplasmic reticulum of inferior oblique muscles in the various conditions including primary inferior oblique overaction (IOOA), secondary IOOA, and controls, so as to further understand the pathogenesis of primary IOOA. Of 15 specimens obtained through inferior oblique myectomy, six were from primary IOOA, 6 from secondary IOOA, and the remaining 3 were controls from enucleated eyes. Ryanodine binding assays were performed, and Ca2+ uptake rates, calsequestrins and SERCA levels were determined. Ryanodine bindings and sarcoplasmic reticulum Ca2+ uptake rates were significantly decreased in primary IOOA (p < 0.05). Western blot analysis conducted to quantify calsequestrins and SERCA, found no significant difference between primary IOOA, secondary IOOA, and the controls. Increased intracellular Ca2+ concentration due to reduced sarcoplasmic reticulum Ca2+ uptake may play a role in primary IOOA.

Long-term Outcome of Graded Inferior Oblique Recession

PURPOSE: To evaluate the efficacy and prognosis of graded inferior oblique recession in inferior oblique overaction. METHODS: We reviewed the records of 92 patients (184 eyes) who had been diagnosed with inferior oblique overaction and who had undergone an inferior oblique recession in both eyes. All were followed up for a minimum of 1 year postoperatively, and preoperative exclusion criteria included superior oblique palsy, history of vertical rectus muscle surgery, and previously performed inferior oblique muscle surgery. Inferior oblique overaction was graded from +1 (mild overaction) to +4 (severe overaction) and each group had 6 mm, 8 mm, 10 mm, and 14 mm inferior oblique recessions performed, respectively. Cases of postoperative inferior oblique overaction under +1 were considered successful. (In the group initially graded as +1, a postoperative grade of 0 was considered a success.) On the other hand, a grade over +1 was considered a failure. RESULTS: The average postoperative follow-up time was 43.7 months (12~159 months). On final examination, 6-mm inferior oblique recession (5 eyes) resulted in 100% success, 8-mm inferior oblique recession (76 eyes) resulted in a 94.7% success rate, 10-mm inferior oblique recession (97 eyes) resulted in an 87.5% success rate, and 14-mm inferior oblique recession (6 eyes) resulted in a 50% success rate. The overall success rate was 89.7% (165 eyes of the 184 eyes). CONCLUSIONS: Graded inferior oblique recession in patients diagnosed with inferior oblique overaction was an effective procedure with stable, long-term outcomes.

The Effect of Graded Recession and Anteriorization on Unilateral Superior Oblique Palsy

PURPOSE: We wanted to examine the effect of graded recession and anteriorization of the inferior oblique muscle on patients suffering from unilateral superior oblique palsy. METHODS: Inferior oblique muscle graded recession and anteriorization were performed on twenty-two patients (22 eyes) with unilateral superior oblique palsy. The recession and anteriorization were matched to the degree of inferior oblique overaction and hypertropia. The inferior oblique muscle was attached 4 mm posterior to the temporal border of the inferior rectus muscle in six eyes, 3 mm posterior in five eyes, 2 mm posterior in five eyes, 1 mm posterior in five eyes, and parallel to the temporal border in one eye. RESULTS: The average angle of vertical deviation prior to surgery was 11.3+/-3.9 prism diopters (PD). The total average correction in the angle of vertical deviation after surgery was 10.8+/-3.8 PD. In the parallel group, the average reduction was 14 PD. After surgery, normal inferior oblique muscle action was seen in eighteen of twenty-two eyes (81.8%). CONCLUSIONS: Graded recession and anteriorization of the inferior oblique muscle is thought to be an effective surgical method to treat unilateral superior oblique palsy of less than 15 PD.

Anterior Transposition of Inferior Oblique Muscle for Treatment of Unilateral Superior Oblique Muscle Palsy with Inferior Oblique Muscle Overaction

Although many weakening procedures for the inferior oblique muscle have been advocated, there is some controversy as to the most beneficial procedure for weakening overacting inferior oblique muscles. This study was undertaken to determine if unilateral anterior transposition of the inferior oblique muscle alone could be a safe and effective procedure for treating unilateral superior oblique palsy from the perspective of hypertropia, inferior oblique overaction, and abnormal head posture. The records of 33 patients, who underwent anterior transposition of the inferior oblique muscle for unilateral superior oblique palsy at our institution between Jan 1995 and Dec 2002, were retrospectively reviewed. The average preoperative inferior oblique overaction was 2.3 +/-0.64, and the hypertropia in the primary position was 12.3 +/-7.69 prism diopter (PD). Twenty-six patients showed head tilt to the opposite direction preoperatively. After the anterior transposition of the inferior oblique, inferior oblique overaction was diminished in 32 patients (97%). Twenty-six out of 33 patients (79%) had no hypertropia in the primary position at last postoperative assessment. Of the 26 patients with head tilt before surgery, 21 patients (81%) achieved full correction after surgery. Satisfactory results were obtained in most of the patients in our study with the exception of three patients who required additional surgery. No patient demonstrated postoperative hypotropia in the primary position. None of the patients noticed elevation deficiency or lower lid elevation. The anterior transposition of the inferior oblique was found to be safe and effective for treating superior oblique palsy with secondary overaction of the inferior oblique muscle.

The Clinical Characteristics of Dissociated Vertical Deviation Combined with Exotropia

PURPOSE: The clinical characteristics and post-operative prognosis of dissociated vertical deviation (DVD) combined with exotropia was evaluated. METHOD & MATERIALS: The clinical appearance such as the frequency of DVD, vision, amount of deviation, stereoacuity, sensory abnormality, the presence of latent nystagmus, head tilting and operation results were evaluated in patients who were diagnosed with comitant exotropia followed by surgical correction with 3 month follow-up. RESULTS: Eight (16.0%) patients had exotropia combined with DVD, the combined DVD showed an angle of vertical deviation 15.88+/-7.26 delta, for the right eye and 13.50+/-6.55 deltafor the left eye in the primary position. All but 1 patient showed subnormal stereoacuity in the Titmus stereopsis test and most showed suppression in near and far in the Worth 4 dot test. Four (50%) patients were associated with latent nystagmus and one (12.5%) patient showed head tilting. Three months after the operation, all patients showed a residual DVD under 8 delta. CONCLUSION: DVD is frequently combined with exotropia and is associated with decreased stereoacuity, latent nystagmus, head tilting, inferior oblique overaction (IOOA), and superior oblique overaction (SOOA). DVD showed no relation to the amount of deviation of exotropia but was usually associated with a small angle of exotropia ( or =50 delta). The correction of DVD with exotropia showed satisfactory results.

The Change of Deviation Angle according to Gaze Position in Exotropes with Inferior Oblique Overaction

PURPOSE: To determine the correlation between the grade of inferior oblique overaction and the change of deviation angle according to gaze position. METHODS: We classified 90 patients into 4 groups according to the grade of inferior oblique overaction. Deviation angle was respectively measured in upward, primary and downward position at far and the difference between them was analyzed. And we assessed the frequency of V and Y pattern and the concordance of deviating eye between at primary position and at upgaze. RESULTS: Mean bilateral sum of the IOOA was +3.58 and average of deviation angle was 33.64 PD in upward position, 27.82 PD in primary position and 24.72 PD in downward position. Difference of deviation angle between upward and primary position was 5.82 PD (P0.05). The frequency of V pattern exotropia was 17.6% in group A, 17.1% in group B, 50% in group C and 85.7% in group D while the frequency of Y pattern among V pattern was 100%, 66.7%, 75% and 25% respectively. The chief deviating eye or IOOA predominant eye at primary position diverged during upgaze only in 67% of patients. CONCLUSIONS: The larger the inferior oblique overaction, the more V pattern exotropia was observed and deviation angle was increased at higher IOOA groups. Overall exotropia patients with IOOA shows rather Y shape than V shape. And chief deviating eye was not always deviating eye at upgaze.