There have been several reports that classical unilateral lateral rectus recession of 7-8mm obtained the high rate of undercorrection in the surgical treatment of intermittent exotropia of 15-20PD, at 4 years of age or older. We evaluated surgical correction amount, success rate between unilateral lateral rectus recession of 7-8mm and 11-12mm, and amount of abduction limiations of 11-12mm recession. Mean surgical correction amount were 9.1+/-4.5PD in 7-8mm recession group, and 14.4+/-3.0PD in 11-12mm recession group.The difference of surgical correction amount between the two groups was statistically significant(p<0.05). The percentage of undercorrection over 8PD were 66.7% in 7-8mm group, none in 11-12mm recession group. Abduction limitation was minimal in 12mm recession group. In conclusion, 11-12mm unilateral lateral rectus recession had more decreased rate of undercorrection than 7-8mm unilateral lateral rectus recession group in the treatment of intermittent exotropia of 15-20PD, at 4 years of age or older.
Exotropia*

No abstract available.
Exotropia*

We reviewed the relationship between primary inferior oblique overaction and the anatomical position of the inferior oblique muscle insertion. We measured the distance from the limbus to the lower portion of the lateral rectus muscle insertion and from the lower portion of the lateral rectus muscle insertion to the anterior portion of the inferior oblique muscle insertion. Of 79 eyes examined, there were exotropia and primary inferior oblique overaction in 23 eyes and exotropia only in 56 eyes. There was no statistically significant difference of the insertion site between the two groups (IOOA group and non-raOA group). It is ours impression that the anatomical position of the inferior oblique muscle insertion is not closely related to primary inferior oblique overaction, and a histopathologic change of the inferior oblique muscle is an important factor in primary inferior oblique overaction.
Exotropia

No abstract available.
Exotropia*

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 (P<0.05) in that 3.10 PD between primary and downward position (p>0.05). 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.
Exotropia ; Humans

PURPOSE: To investigate whether combining inferior oblique weakening procedures with bilateral lateral rectus recession as a surgical approach to intermittent exotropia enhances postoperative horizontal angle of deviation over bilateral lateral rectus recession alone. METHODS: Patients were allocated to one of two surgical groups: a bilateral lateral rectus recession group (Group 1) or a bilateral lateral rectus recession with bilateral inferior oblique weakening group (Group 2). Group differences in the angle of distance deviation were evaluated preoperatively and at 3- and 12-months postoperatively. RESULTS: There were no significant differences in preoperative factors or angles of deviation between Group 1 (n = 98) and Group 2 (n = 77); no significant intergroup difference in the angle of deviation was observed at any postoperative time point (p > 0.05). CONCLUSIONS: Combined inferior oblique weakening procedures did not significantly influence the horizontal angle of deviation after surgery for intermittent exotropia. Accordingly, there is no need to revise the surgical amount of lateral rectus recession.
Exotropia* ; Humans

PURPOSE: To compare distance stereoacuity in patients with intermittent exotropia before and after surgery using the Frisby Davis distance stereotest (FD2), and to determine the preoperative factors that affect the postoperative distance stereoacuity. METHODS: A total of 56 patients with intermittent exotropia were examined for the present study. To determine preoperative factors that affect postoperative distance stereoacuity, age, gender, distance control, and presence of fusion were measured. The deviation angle was measured at near and at distance by using a prism cover test. Distance stereoacuity was measured with the FD2 test. RESULTS: According to the results of the FD2 test, the mean preoperative distance stereoacuity of patients was 64.7 +/- 76.1 sec of arc, and improved to 53.6 +/- 85.9 sec of arc postoperatively. The distance stereoacuity improved notably from 63.0 to 40.0 sec of arc after the successful surgery. No significant correlation was present between type of surgery, distance control, presence of fusion, and postoperative improvement of distance steroacuity. CONCLUSIONS: Decreased stereoacuity in intermittent exotropic patients improved postoperatively, and the FD2 test was valuable in evaluating the stereoacuity in intermittent exotropic patients pre- and postoperatively.
Exotropia ; Humans

PURPOSE: To investigate the dose-effect relationship of unilateral medial rectus resection for recurrent exotropia after bilateral lateral rectus recession. METHODS: This study comprised 39 patients who underwent unilateral medial rectus resection for recurrent exotropia under 25 PD and bilateral rectus recession for prior surgery of exotropia. The medial rectus was resected from 5.0 to 7.0 mm according to angle deviation at a distance. The postoperative deviated angle was checked at one week, 3 months and 6 months postoperatively to investigate the amount of corrected deviation per resected muscle. RESULTS: The average preoperative deviation was 21.33 +/- 2.96 PD. We resected mean 6.26 +/- 0.57 mm of the medial rectus muscle. The postoperative deviated angle was 0.82 +/- 3.47, 1.87 +/- 3.10 and 5.40 +/- 4.79 PD at 1 week, 3 months and 6 months after surgery, respectively. The corrected deviated angle per millimeter (mm) was 3.29 +/- 0.68, 3.17 +/- 0.58 and 2.75 +/- 0.89 PD at 1 week, 3 months and 6 months after surgery. There were no significant differences among the changes of postoperative deviation per millimeter according to the amount of medial rectus (MR) resection (p-value = 0.423, 0.382) The success rate was 89.75%, 92.31% and 87.18% at 1 week, 3 months and 6 months after surgery, respectively. The expected corrected angle according to the amount of resection remained constant and was 3.04-3.22 PD/mm at 3 months after surgery and 2.79-2.82 PD/mm at 6 months after surgery. CONCLUSIONS: The dose-effect per millimeter was decreased as time passed. There was no statistical difference among the corrected deviation angles per millimeter according to the amount of MR resection. We expect that the calculated dose-effect relationship may be a useful guideline for unilateral medial rectus resection for recurrent exotropia.
Exotropia* ; Humans

PURPOSE: This study was to evaluate the influence of monocular occlusion on the preoperative ocular alignment and the surgical outcome of basic intermittent exotropia. METHODS: We examined 42 patients with basic intermittent exotropia who were operated and followed for at least 6 months postoperatively from January 2001 to August 2002. In all patients, angle of misalignment measured while the patients fixate on an accommodative target at 6m and 33cm, and after 2 hours of monocular occlusion. The subjects were divided into two groups: Gruop 1-far angle of misalignment did not increase after 2 hours of monocular occlusion, Group 2-far angle of misalignment increased in 3PD or more after 2 hours of monocular occlusion. Group 2 underwent surgery for the increased deviation of far angle. RESULTS: Among 42 patients with basic intermittent exotropia, Group 1 included 27 (64.3%) patients and Group 2 15 (35.7%) patients. In Group 2, the mean ( +/- SD) increase in the angle of exotropia after 2 hours of monocular occlusion was 5.33 ( +/- 2.74)PD. The success rate of surgery was 77.8% (21/27 patients) in Group 1, 93.3% (14/15 patients) in Group 2 at 6 months after surgery and 70.4% (19/27 patients), 93.3% (14/15 patients) at the final visit. There was no statistically significant difference (p> 0.05). CONCLUSIONS: This study showed the significant influence of monocular occlusion on the ocular misalignment before surgery and surgical outcome in basic intermittent exotropia. Angle of misalignment measured after 2 hours or more of monocular occlusion seemed to be meaningful.
Exotropia* ; Humans

It is the purpose of this study to compare the postoperative results of surgery for 39 patients with exotropia under 25 prism diopters (PD). Two surgical methods were done; 8 to 9mm unilateral recission of the lateral rectus muscle in 17 patients (unilateral gruop) and 4 to 6mm bilateal recession in 20 patients (bilateral group). The preoperative deviations on the average were 20.8PD in unilateral and 22.6PD in bilateral grou, and postoperatie corrections on the average were 16.5PD in unilateral and 22.8PD in bilateral group. The 41.2% in unilateral droup and 59.1% in bilateral group were under +/-5PD in postoperative deviation. There were 12 cases (70.6%) in unilateral and 20 cases (90.9%) in bilateral group showing the amount of deviation less than 10PD of under or overcorrection. InBilateral group, higher success rate was observed, but there was no statistical difference (p=0.053) between the two groups. The limitation of abduction was observed in the 4 cases of unilateral group but there was no significant cosmetic problem. From our surgical results, the outcome of the bilateral recission for the lateral rectus muscle is better than that ofthe unilateral recession for the correction of exotropia under 25PD although there was no statistical difference.
Exotropia* ; Humans