Bilateral medial rectus resection for primary large-angle exotropia

Dose-Response of Primary Bilateral Medial Rectus Resection in Infantile Exotropia

PURPOSE

To evaluate the dose-response relationship for primary bilateral medial rectus resection in children with exotropia, based on outcomes with this procedure.

METHODS

Dose-response at both distance and near were calculated as prism diopters correction per millimeter (PD/mm) of rectus resection. All surgeries were performed under general anesthesia through a fornix incision, using doubled-armed 6-0 polyglactin sutures. The resection amount ranged from 5 to 8 mm in each eye, according to the surgical dosage based on the largest angle of preoperative deviation.

RESULTS

The mean surgical dose-response for all procedures was 2.83 ± 1.03 PD/mm of resection at distance and near. The overall success rate was 53% at the final examination after a mean follow-up of 21.9 months. Patients with moderate angles (25 to 45 PD) had a higher success rate than those with 50 PD or greater deviation.

CONCLUSIONS

Primary bilateral medial rectus resection should be considered as a surgical alternative in childhood exotropia, particularly for moderate and constant deviations. [J Pediatr Ophthalmol Strabismus. 2022;59(1):24-27.].

Outcomes and Dose-Response Ratio of Surgery on Three Muscles in Large-Angle Exotropia

Purpose:

To evaluate the efficacy of three-muscle surgery for the treatment of large-angle exotropia with particular attention to the success rate and mean dose-response ratio.

Methods:

In a retrospective study, medical records were reviewed for 48 patients with exodeviation between 50 and 80 prism diopter (PD) who underwent bilateral lateral rectus recession as well as one medial rectus resection. Sex, age at surgery, presence of amblyopia, amount of preoperative and postoperative deviation, total amount of recessed and resected muscles, dose-response ratio, and associated vertical deviations were analyzed.

Results:

The mean age of patients at surgery was 25.4 ± 14.3 years old (range, 1–55). The mean preoperative deviation was measured 62.8 ± 7.5 PD (range, 50–80 PD). The mean amount of total recession and resection was 23 ± 1.3 mm. After a mean follow-up of 15 ± 25 months (range, 3–144), 85.4% of patients were within 10 PD of orthophoria. The mean postoperative deviation decreased to 3.8 ± 7.5 PD (range, 0–30 PD). A mean dose-response ratio of 2.5 ± 0.3 PD/mm (range, 0.9–3.1 PD/mm) was found. Of all patients, 14.6% demonstrated undercorrection.

Conclusion:

Simultaneous surgery on three muscles is an effective method in resolving large-angle exotropia and results in excellent outcomes with low risk of undercorrection.

Supramaximal Recession and Resection Surgery in Large-Angle Strabismus: Outcomes of Large Interventional Case Series Exotropia and Esotropia

Purpose:

To assess the postoperative surgical outcomes and the changes in deviation in patients treated by supramaximal recession and resection (R&R) of rectus muscles to correct the large-angle exotropia and esotropia.

Methods:

This study was a prospective interventional case series, and patients with esotropia of ≥65 prism diopter (PD) or exotropia of ≥60 PD who had undergone supermaximal R&R in non-fixating eye with lower vision in unilateral strabismus or bilateral medial rectus (BMR) recession up to 8.5 mm for esotropia and bilateral lateral rectus (BLR) recession up to 12.5 mm for exotropia in bilateral strabismus were enrolled. Successful results were achieved if postoperation deviation was <10 PD for esotropia and <15 PD for exotropia during their final examinations.

Results:

A total of 131 cases (48 patients with esotropia and 83 patients with exotropia) were included. The mean ages of the patients with esotropia and exotropia were 16.83 ± 15.06 and 23.19 ± 11.29 years, respectively. The mean preoperative esodeviations for bilateral and unilateral surgeries were 69.5 ± 6.5 and 80.7 ± 10.3, respectively, and these values for bilateral and unilateral exodeviations surgeries were 67.3 ± 7.6 and 74.2 ± 12.1, respectively. The overall successful outcomes were achieved in 50% of the esotropic patients and 79.5% of the exotropic patients. At final follow-up examination, no patient had diplopia on lateral gazes.

Conclusion:

Based on our surgical results, it is possible to consider monocular recession-resection surgery in non-fixating eye (with poor vision) or BLR and BMR recession in both eyes as a viable option for surgical treatment of large angles deviations.

Bilateral Lateral Rectus Recession for the Treatment of Recurrent Exotropia after Bilateral Medial Rectus Resection

PURPOSE

To evaluate the efficacy of bilateral lateral rectus muscle recession (BLR) to treat recurrent exotropia after bilateral medial rectus muscle resection (BMR).

METHODS

Twenty-four patients who underwent BLR for recurrent exotropia and were followed up for more than 6 months were included in this retrospective study. All of them had prior BMR. The angle of deviation, success rates, near stereopsis, and surgical effect of BLR were evaluated. Surgical success was defined as postoperative deviations ≤10 prism diopters (PD).

RESULTS

The overall mean follow-up time after reoperation for patients was 24.13 ± 15.01 months (range 6-60 months). The mean angle of deviation at distance was significantly reduced from -37.75 ± 14.93 PD to +1.50 ± 6.43 PD (p < 0.001). Twenty-two (91.6%) of 24 patients had successful outcomes, 1 (4.2%) had overcorrection, and 1 (4.2%) had undercorrection at the last follow-up. Improved stereopsis after reoperation was observed in 78.3% (18/23) of the patients. The mean surgical effect was 2.78 ± 0.71 PD/mm.

CONCLUSION

Based on our results, BLR could be an effective and safe method for treating recurrent exotropia after a moderate to large amount of BMR.

Outcomes of bilateral lateral rectus recession in treatment of recurrent exotropia after bilateral medial rectus resection

PURPOSE

To report the results of bilateral lateral rectus muscle recession for recurrent exotropia in cases where the primary surgery was a bilateral medial rectus resection.

METHODS

Retrospective chart review of 15 subjects who completed 6 months of follow-up. Data collected included patients' demographics and pre- and post-operative measurements of ocular alignment and motility. Surgical nomogram used was the same nomogram we use for primary cases of exotropia.

RESULTS

At 6-month follow-up, 73.3% of cases had a successful surgical outcome (defined as 8 PD of esotropia to 10 PD of exotropia). In addition, recession of lateral rectus muscles against the previously resected medial recti did not result in a significant increase in the limitation of abduction.

CONCLUSION

Bilateral lateral rectus recession using standard surgical tables is a safe and effective method for treating recurrent exotropia following bilateral medial rectus resection. Even large primary resections up to 12 mm do not seem to affect the results of bilateral lateral rectus recession.