Postoperative Exodrift Patterns after Bilateral or Unilateral Lateral Rectus Recession in 20 Prism-diopter Intermittent Exotropia

PURPOSE: In the present study, the surgical outcome and postoperative exodrift pattern between bilateral lateral rectus recession (BLR) and unilateral lateral rectus recession (ULR) in intermittent exotropia of 20 prism diopters (PDs) were compared. METHODS: In this retrospective study, 5.0 mm BLR or 8.5 mm ULR was performed on 82 patients for the treatment of intermittent exotropia of 20 PDs with a follow-up period of 2 years. The main outcome measures were postoperative 1-week, 1-month, 6-month, 1-year and 2-year exodeviation angles with their patterns and success rates. A surgical success was considered an alignment within 10 PDs and sensory success was defined at 100 seconds of arc. RESULTS: The mean deviation angles at postoperative 1 week were 4.7 ± 5.1 PD esodeviation in the BLR group (44 patients) and 1.2 ± 4.2 PD esodeviation in the ULR group (38 patients). The BLR group was significantly more overcorrected than the ULR group (p = 0.001), but postoperative exodrift occurred in the BLR group at 1 week, 1 month, 6 months, 1 year, and 2 years. In the ULR group, the postoperative exodrift occurred at 1 week, 1 month, and 6 months which was followed by stabilized alignment. Surgical success rate at the postoperative 2-year follow-up was 75.0% in the BLR group and 81.6% in ULR group (p = 0.717). CONCLUSIONS: ULR showed less overcorrection and early exodrift up to only 6 months, resulting in stabilization of the alignment afterwards; surgical success rate at the final 2-year follow-up was similar to BLR.

The Surgical Outcomes of Unilateral Lateral Rectus Recession in Recurrent Intermittent Exotropia after Unilateral Recession-Resection

PURPOSE: To evaluate the surgical outcomes of unilateral lateral rectus (LR) recession on the contralateral eye for recurrent intermittent exotropia after unilateral recession-resection (R & R). METHODS: A retrospective analysis of 43 patients was performed. The patients were classified into 2 groups, 18 patients who underwent unilateral LR recession for intermittent exotropia of 18 to 20 prism diopters (PD) after unilateral R & R (reoperation group) and 25 patients who had primary unilateral LR recession (primary operation group). RESULTS: Significant differences in age, gender, refractive error, preoperative deviation, and near stereoacuity were not observed between the 2 groups (p > 0.05). The mean follow-up duration was 14.28 +/- 14.98 months in the reoperation group and 14.68 +/- 12.15 months in the primary operation group. Postoperative deviations were 1.11 +/- 3.89 PD at near distance and 2.00 +/- 4.70 PD at far distance in the reoperation group and 6.44 +/- 5.26 PD at near distance and 7.00 +/- 5.77 PD at far distance in the primary operation group on the final follow-up (p = 0.000, p = 0.004). The final surgical successful rates were 94.4% in the reoperation group and 64.0% in the primary group (p = 0.021). CONCLUSIONS: The long-term surgical results of unilateral LR recession on the contralateral eye was better in patients with recurrent intermittent exotropia of 18 to 20 PD after unilateral R & R than patients who had primary unilateral LR recession.

Result Comparison after Reoperation in Recurrent Exotropia According to the Type of First Operation

PURPOSE: To investigate and compare the clinical courses and surgical success rates of secondary operations in recurrent exotropia according to the type of first operation for correction of exotropia. METHODS: A retrospective chart review was performed for all patients with recurrent exotropia of the basic or pseudodivergence excess types. In group A (36 patients), bilateral lateral rectus (LR) recession was performed as the first operation and uni- or bilateral medial rectus (MR) resection was performed as the second operation. In group B (19 patients), unilateral LR recession-MR resection (R&R) was performed as the first operation and LR recession or R&R in contralateral eye as the second operation. RESULTS: There were no significant differences between the 2 groups when considering age at each operation, frequency of the amblyopia, prescription of prism, time interval for recurrence and reoperation and the final and cumulative success rates. No postoperative complications were observed in either group. The mean number of used muscles for the first and second operation was 3.9 +/- 0.4 in group A, and 3.4 +/- 0.5 in group B (p = 0.001). Mean time interval for occurrence of postoperative orthophoria was 3.7 +/- 6.2 months in group A and 6.5 +/- 16.2 in group B (p = 0.047). In group B, the incidence of esodeviation tended to increase after postoperative 1 month. CONCLUSIONS: The final success rates of reoperation between the 2 types of the first operation in recurrent exotropia were similar. Mean time between postoperative overcorrection of orthophoria was shorter in the group with bilateral LR recession followed by secondary MR resection than in the other group. Unilateral R&R followed by LR recession or R&R in contralateral eye may be more helpful to decrease the number of used muscles than in the bilateral LR recession followed by secondary MR resection.

Result Comparison after Reoperation in Recurrent Exotropia According to the Type of First Operation

PURPOSE: To investigate and compare the clinical courses and surgical success rates of secondary operations in recurrent exotropia according to the type of first operation for correction of exotropia. METHODS: A retrospective chart review was performed for all patients with recurrent exotropia of the basic or pseudodivergence excess types. In group A (36 patients), bilateral lateral rectus (LR) recession was performed as the first operation and uni- or bilateral medial rectus (MR) resection was performed as the second operation. In group B (19 patients), unilateral LR recession-MR resection (R&R) was performed as the first operation and LR recession or R&R in contralateral eye as the second operation. RESULTS: There were no significant differences between the 2 groups when considering age at each operation, frequency of the amblyopia, prescription of prism, time interval for recurrence and reoperation and the final and cumulative success rates. No postoperative complications were observed in either group. The mean number of used muscles for the first and second operation was 3.9 +/- 0.4 in group A, and 3.4 +/- 0.5 in group B (p = 0.001). Mean time interval for occurrence of postoperative orthophoria was 3.7 +/- 6.2 months in group A and 6.5 +/- 16.2 in group B (p = 0.047). In group B, the incidence of esodeviation tended to increase after postoperative 1 month. CONCLUSIONS: The final success rates of reoperation between the 2 types of the first operation in recurrent exotropia were similar. Mean time between postoperative overcorrection of orthophoria was shorter in the group with bilateral LR recession followed by secondary MR resection than in the other group. Unilateral R&R followed by LR recession or R&R in contralateral eye may be more helpful to decrease the number of used muscles than in the bilateral LR recession followed by secondary MR resection.

Change of Strabismus Angle and Deviation After Unilateral or Bilateral Lateral Rectus Recession in Exotropia

PURPOSE: To compare the changes in strabismus angle and deviation between two groups: a bilateral lateral rectus recession (Group 1) and a unilateral lateral rectus recession in exotropia (Group 2). METHODS: A retrospective survey was conducted on 198 patients who had received exotropia surgery in our ophthalmology clinic from September 2003 to April 2007. A total of 116 patients were in Group 1, and 82 patients were in Group 2. RESULTS: The average deviations of the first postoperative month and the first postoperative year were -1.96 D +/- 4.75, 2.5 D +/- 7.82 for Group 1 and 0.77 D +/- 2.87, 5.94 D +/- 3.38 for Group 2. Revealing statistical significance between the 2 Groups: Group 1 had 30 failure cases (25.9%) and their 1 postoperative year average deviation was 5.42 D +/- 13.97, while Group 2 showed 24 failure cases (29.3%) and their 1-postoperative-year average deviation was 13.0-79 +/- 3.04. Group 1 had less strabismus angle and a greater standard deviation than Group 2, as Group 1 had more overcorrection. Among the 30 failure cases of Group 1, 9 were overcorrected and 21 were undercorrected, but all 24 failure cases in Group 2 were undercorrected. CONCLUSIONS: The strabismus angle after lateral rectus recession showed a wider variation and a larger difference in bilateral lateral rectus recession than in the unilateral lateral rectus recession.

Comparison of the Stability of Postoperative Alignment in Sensory Exotropia: Adjustable Versus Non-Adjustable Surgery

PURPOSE: To compare the success rates and stabilities of postoperative alignment between adjustable and the non-adjustable surgeries in the treatment of sensory exotropia. METHODS: A retrospective analysis was performed on all patients with sensory exotropia who had undergone unilateral lateral rectus recession and medial rectus resection (R&R) between January 1998 and August 2005. Thirty-four patients underwent conventional R&R, and 20 patients underwent R&R with adjustable suture of the lateral rectus. The surgical results between the two groups were analyzed with regard to the preoperative and post-operative deviation angles and the postoperative drift. The postoperative deviation angle was measured on postoperative day 1 as well as at two weeks, three months, six months and the final visit after surgery. RESULTS: There were no statistically significant differences in the mean preoperative and postoperative deviation angles between the two groups. In 30 (88%) patients in the non-adjustable group and 15 (75%) patients in the adjustable group, postoperative deviation was less than 15 prism diopters (PD) at the three month follow-up. There was no significant difference in the mean postoperative drift between the two groups. CONCLUSIONS: Strabismus surgery with adjustable sutures did not show a significantly better result than surgery without adjustable sutures in the treatment of sensory exotropia. Considering the amount of postoperative exodrift in both groups, we postulate that the immediate ocular alignment after surgery for sensory exotropia should be orthophoric or 5-6 PD of esodeviation.

Result Analysis According to Surgical Amout after Unilateral Lateral Rectus Recession in Patients with Exodeviation under 25PD

PURPOSE: Study by result analysis the proper recession amount according to the deviation angle after unilateral lateral rectus recession in exodeviation. METHODS: A retrospective analysis data from 139 patients who underwent unilateral lateral rectus recession with 15~24PD exodeviation and monitored for 12 months or longer was performed. The analyzed patients were divided into 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm groups according to the surgical amount of recession and 15~18PD, 19~20PD, 21~24PD groups according to the deviation angle. The strabismus surgery and results analyses were based on distance deviation. Alignment within 4PD of esodeviation and 10PD of exodeviation was considered a surgical success. RESULTS: The success rates were 53.8% for the 15~18PD group and 40% for the 19~20PD group in the 7.5 mm recession group, 77.7% for the 15~18PD group and 66.7% for the 19~20PD group and 63.6% for the 21~24PD group in the 8 mm recession group, 100% for the 15~18PD group and 81.2% for the 19~20PD group and 72.7% for the 21~24PD group in the 8.5 mm recession group, 83.3% for the 15~18PD group and 85.7% for the 19~20PD group and 83.3% for the 21~24PD group in the 9 mm recession group, 100% for the 19~20PD group and 76.9% for the 21~24PD group in the 9.5 mm recession group at 1 year postoperative. The rates of -1 abduction limitation were respectively 3.1%, 12% and 21.4% in the 8.5 mm, 9 mm and 9.5 mm recession groups and the rate of -2 abduction limitation was 14.3% in the 9.5 mm recession group at 1 year postoperative. CONCLUSIONS: Considering the success state and abduction limitaions, the proper surgical amount of recession is 8.5 mm in the 15~18PD group and 9 mm in the 19~20PD and 21~24PD groups.

Comparison of Surgical Results Between Unilateral Recession-Resection and Bilateral Resections in Recurrent Exotropia

PURPOSE: The purpose of this study was to compare the surgical results between unilateral lateral rectus recession-medial rectus resection (R and R) and bilateral medial rectus resections in recurrent exotropia. METHODS: In this retrospective study, 22 patients with recurrent exotropia of the basic or pseudodivergence excess types were enrolled. In group A (14 patients), unilateral R and R was performed during the first operation, and R and R was performed in contralateral eyes during the second operation. In group B (8 patients), bilateral lateral rectus recessions were performed during the first operation and bilateral medial rectus resections during the second operation. RESULTS: The mean time interval between the first and second operations was 28.9 months (range, 5 to 64 months) in Group A and 59.9 months (range, 35 to 75 months) in Group B, which was a significant difference between the two groups (p=0.006). The success rates at last follow-up after the second operation were 85.7% in Group A and 87.5% in Group B, which was not statistically different between the two groups (p<1.000). CONCLUSIONS: There was no difference in success rate after the second operation between the two groups. Therefore, the operation method for recurrent exotropia can be chosen according to the operator's preference.

The Effect of Unilateral Lateral Rectus Recession for the Treatment of Moderate-Angle Exotropia

PURPOSE: To evaluate the surgical results and the amount of correction per millimeter after unilateral lateral rectus recession for moderate-angle exotropia in a pediatric population. METHODS: This study included 30 subjects who underwent 9-mm unilateral lateral rectus recession for basic type intermittent exotropia with deviation of 23 to 28 prism diopters (PD) and were followed-up for 6 months or more after surgery. RESULTS: Seventeen subjects were male and 13 were female. The mean age of subjects was 9.7 years. Defining satisfactory postoperative ocular alignment as 8PD or less, 25 of 30 subjects (83.3%) were satisfactorily aligned at 2 months postoperatively. The success rates at 4, and 6 months postoperatively were 76.7% respectively. No overcorrected subjects were found after 2 months postoperatively. A postoperative limitation of abduction was not found in all subjects after 2 months postoperatively. The average amount of correction per millimeter of recession at 2, 4, and 6 months was 2.83+/-0.26PD, 2.75+/-0.37PD, and 2.72+/-0.44PD respectively (range, 1.56 to 3.18PD). There was no statistically significant difference in the amount of correction per millimeter throughout the follow-up period (ANOVA, p=0.05). CONCLUSIONS: Unilateral lateral rectus recession appears to be an effective surgical procedure for the treatment of moderate-angle exotropia. However to reduce the rate of undercorrection, which is one of disadvantages of this procedure, proper patient selection is required.

Comparison of Surgical Results between Bilateral and Unilateral Lateral Rectus Recession in 20~25 Prism Diopters Intermittent Exotropia

PURPOSE: To compare the postoperative results of unilateral lateral rectus recession with bilateral lateral rectus recession between 20 prism diopters (PD) and 25 PD intermittent exotropia for basic type. METHODS: We analyzed retrospectively the data of 27 patients underwent unilateral lateral rectus recession and 38 patients underwent bilateral lateral rectus recession with 20 PD and 25 PD intermittent exotropia for basic type from June 1996 to May 2000 at the Department of Ophthalmology of Chonnam National University Hospital. RESULTS: There were 10 cases (37.0%) in unilateral group and 8 cases (21.1%) in bilateral group showing undercorrection in the amount of deviation more than 10 PD and 2 cases (5.3%) in bilateral group showing overcorrection in the amount of deviation more than 10 PD, and there was no overcorrection in unilateral group. There was a tendency of recurrence of exotropia during the first postoperative month, but the alignment after 1 month postoperative was not much different from the alignment at the last follow-up. The mean amount of correction after surgery was 13.78+/-7.65 PD (Mean+/-SD) in unilateral group and 20.32+/-8.37 PD (Mean+/-SD) in bilateral group (P=0.002). Success rate was 73.6% in bilateral group, better than 63.0% in unilateral group although there was no statistically significant difference (p>0.05). CONCLUSIONS: The undercorrection rate of bilateral lateral rectus recession is less than that of unilateral lateral rectus recession and more satisfactory surgical outcome was obtained in bilateral lateral rectus recession; therefore bilateral lateral rectus recession can lead to good result in 20~25 PD intermittent exotropia for basic type.

Surgical Results in Basic Exotropia of Moderate Degree

The purpose of this study is to assess the postoperative stability for exotropia by comparing the deviation at postoperative 2 years to those at 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year after surgery in children with basic exotropia of between 25 and 30 prism diopters. They were classified into two groups:one group[n=20]with unilateral lateral rectus recession and medial rectus resection, and another group[n=15] with bilateral lateral rectus recession. There was no difference in age at the time of surgery or preoperative angle of deviation between the two groups. Exodrift occurred according to an increase in follow-up and maximal correlation between postoperative 6 months and 2 years in both groups[r=0.85, r=0.81, respectively, p>0.05]was noted. Success rates at postoperative 2 years were 65%and 60%, respectively[p>0.05]. In conclusion, long-term surgical results for exotropia of moderate degree and basic type could be predicted from angle of deviation at postoperative 6 months, regardless of the type of surgery.