Curative effect of slanted bilateral lateral rectus recession for convergence insufficiency-type intermittent exotropia / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To observe curative effect and safety of slanted bilateral lateral rectus recession for convergence insufficiency-type intermittent exotropia.<p>METHODS:This study included 29 patients who underwent slanted bilateral lateral rectus recession for convergence insufficiency-type intermittent exotropia in our hospital between October 2017 and November 2019 with a follow-up of 6mo, the deviation, the surgical success rate, the binocular vision function and the complications were observed.<p>RESULTS:In our study, the mean near deviations, the mean distance deviations and the near-distance deviation differences reduced from -41.72±3.35PD, -23.28±9.75PD and 16.90±2.47PD before surgery to -5.97±4.85PD, -2.66±4.78PD, 3.28±1.10PD 6mo after surgery, the surgical success rate was 76%. The Grades I and Ⅱ binocular vision function improved 6mo after surgery(<i>P</i><0.05), the distance stereopsis and the near stereopsis were not statistically significant(<i>P</i>>0.05). None of the patients developed A-V pattern, limitation of eye movement, restrictive strabismus, vertical strabismus, and rotated diplopia, some patients had transient horizontal diplopia, which disappeared within 2-3wk after surgery.<p>CONCLUSION:Slanted bilateral lateral rectus recession may successfully reduce the near exodeviations, the distance exodeviations and the near-distance deviations difference without obvious complications, proved to be a safe and effective procedure for the treatment of convergence insufficiency-type intermittent exotropia.

Changes in Types of Recurrent Intermittent Exotropia after Surgical Correction of Basic Type Intermittent Exotropia

PURPOSE: To report the surgical outcomes and changes in types of recurrent exotropia after surgical correction of basic type intermittent exotropia. METHODS: We retrospectively analyzed the medical records of 91 patients who underwent reoperations for recurrent exotropia after primary surgical correction, and who visited our hospital for a period of at least one year after the reoperation. When distant deviation was >30 prism diopters (PD), we defined convergence insufficiency type (CI type) if the difference of the deviation angle was >10 PD and basic type exotropia if the difference was 33% of the distant deviation angle. RESULTS: The types of recurrent exotropia were similar to those of the preoperative condition in 68 patients (74.7%), and newly emergent CI type was observed in 23 patients (25.3%). With regard to the incidence of CI type, bilateral lateral rectus recession was more common than unilateral lateral rectus recession after primary surgery and medial rectus resection and unilateral lateral rectus recession, but the difference was not significant (p = 0.615). Recurrent CI type exotropia was observed 6 months after primary surgery (p 0.05). There was no significant difference in the success of reoperations between the two groups (p > 0.05). CONCLUSIONS: The types of recurrent exotropia after surgical correction of primary basic type intermittent exotropia differed from those of preoperative exotropia, which was not related to various factors before surgery. Recurrent exotropia was successfully treated by appropriately selected reoperations, regardless of the type of exotropia.

Comparison between Modified Bilateral Lateral Rectus Recession and Augmented Unilateral Recession-resection for Convergence Insufficiency Exotropia

PURPOSE: To compare the surgical outcomes between modified bilateral lateral rectus muscle (BLR) recession and augmented unilateral recession-resection (R&R) for the convergence insufficiency intermittent exotropia (IXT). METHODS: 37 patients with convergence insufficiency IXT were divided into two groups: 13 patients (underwent BLR recession) and 24 patients (underwent unilateral R&R). Success was defined as within 10 prism diopters (PD) at distance and near, and within 10 PD of the difference between them at postoperative 12 months. RESULTS: After the patch test, the preoperative distance deviation angle in the BLR group was 29.9 ± 8.4 PD, and the near deviation angle was 42.3 ± 9.7 PD; the difference between them was 12.5 ± 3.2 PD. In the R&R group, the preoperative distance deviation angle was 26.7 ± 5.8 PD, and the near deviation angle was 41.5 ± 7.4 PD; the difference between them was 14.8 ± 4.3 PD (p = 0.235, p = 0.987, and p = 0.123). At the 12-month follow-up in the BLR group, the distance angle was 3.8 ± 5.1 PD, and the near deviation angle was 4.9 ± 6.1 PD; the difference between them was 2.9 ± 5.9 PD. In the R&R group, the postoperative distance deviation angle was 4.7 ± 6.1 PD, and the near deviation angle was 7.9 ± 6.6 PD; the difference between them was 3.65 ± 5.1 PD (p = 0.708, p = 0.162, and p = 0.632, respectively). The surgical success rate did not differ significantly between groups at 12 months postoperatively (76.9%: BLR group and 70.8%: R&R group; p = 0.690). CONCLUSIONS: Modified BLR recession showed a similar surgical success rate to augmented unilateral R&R, and was effective in reducing both distance and near exodeviation, and in decreasing the difference between distance and near deviation in convergence insufficiency IXT.

The Surgical Outcome and Stereopsis between Pseudodivergence Excess Type and Convergence Insufficiency Type

PURPOSE: To compare the surgical outcomes and stereopsis between pseudodivergence excess type and convergence insufficiency type in intermittent exotropia. METHODS: In a retrospective comparative analysis of 42 eyes, 18 eyes that were of the convergence insufficiency type (group 1) and 24 eyes that were or the pseudodivergence excess type (group 2) were analyzed. Recession-resection was performed in the same eye. Success was defined to be within ±8 PD after 12 months postoperatively; more than ±8 PD was defined as recurrence. Stereopsis was measured by the Titmus test. RESULTS: After the patch test, the mean preoperative near angle in group 1 was 35.56 ± 6.62 PD and the far angle was 23.06 ± 6.22 PD. In group 2, the mean preoperative near angle was 26.92 ± 6.30 PD and the far angle was 28.29 ± 7.41 PD. The group 1 postoperative (12 months) mean near angle was 6.89 ± 8.46 PD and the far angle was 6.11 ± 7.90 PD. In group 2, the mean postoperative near angle was 1.75 ± 2.85 PD and the far angle was 3.42 ± 3.98 PD. The success rate of group 1 was 50% and the success rate of group 2 was 83.3%. The success rate of both group were statistically significant differences (p = 0.021). The postoperative (12 months) mean of near stereopsis for group 1 was 588 ± 1,124 seconds, and group 2 was 101.25 ± 102 seconds. There were no statistically differences in postoperative (12 months) stereopsis. CONCLUSIONS: The success rate of the pseudodivergence excess type was significantly higher than in the convergence insufficiency type.

The Ratio of Accommodative-Convergence to Accommodation in Patients with Intermittent Exotropia

PURPOSE: To measure the ratio of accommodative-convergence to accommodation (AC/A ratio) in patients with pseudodivergence excess type and convergence insufficiency type of intermittent exotropia [X(T)], and to compare with a normal group. METHODS: A total of 55 subjects were divided into 3 groups: pseudodivergence excess type, convergence insufficiency type, and normal group. Age, gender, and refractive error of patients were examined. The deviation angle was measured at near and distance by using a prism cover test, followed by an interpupillary distance measurement. The AC/A ratio was calculated using a heterophoria and a gradient method. RESULTS: There was no statistically significant difference in age, gender, and the refractive errors among the 3 groups. The mean value of AC/A ratio using the heterophoria method was 9.50 in pseudodivergence excess type patients, 2.59 in convergence insufficiency type patients, and 5.47 in the normal group. Using the gradient method, the mean value of AC/A ratio was 1.47, 0.03, and 2.08 in each group, respectively. There was no statistically significant difference in mean values between patients with pseudodivergence excess type and the normal group, except when obtained using the gradient method (p = 0.43). CONCLUSIONS: A distinct difference in AC/A ratio existed when computed by the heterophoria method between patients with pseudodivergence excess type or convergence insufficiency type and the normal group. In the gradient method, however, the ratios of convergence insufficiency type patients were lower compared to the normal group, indicating the gradient method is more accurate than the heterophoria method.

The Ratio of Accommodative-Convergence to Accommodation in Patients with Intermittent Exotropia

PURPOSE: To measure the ratio of accommodative-convergence to accommodation (AC/A ratio) in patients with pseudodivergence excess type and convergence insufficiency type of intermittent exotropia [X(T)], and to compare with a normal group. METHODS: A total of 55 subjects were divided into 3 groups: pseudodivergence excess type, convergence insufficiency type, and normal group. Age, gender, and refractive error of patients were examined. The deviation angle was measured at near and distance by using a prism cover test, followed by an interpupillary distance measurement. The AC/A ratio was calculated using a heterophoria and a gradient method. RESULTS: There was no statistically significant difference in age, gender, and the refractive errors among the 3 groups. The mean value of AC/A ratio using the heterophoria method was 9.50 in pseudodivergence excess type patients, 2.59 in convergence insufficiency type patients, and 5.47 in the normal group. Using the gradient method, the mean value of AC/A ratio was 1.47, 0.03, and 2.08 in each group, respectively. There was no statistically significant difference in mean values between patients with pseudodivergence excess type and the normal group, except when obtained using the gradient method (p = 0.43). CONCLUSIONS: A distinct difference in AC/A ratio existed when computed by the heterophoria method between patients with pseudodivergence excess type or convergence insufficiency type and the normal group. In the gradient method, however, the ratios of convergence insufficiency type patients were lower compared to the normal group, indicating the gradient method is more accurate than the heterophoria method.