Outcomes of inferior oblique myectomy versus recession combined with lateral rectus recession in V-pattern exotropias.

PURPOSE: To compare outcomes of bilateral lateral rectus recession (BLRc) paired with either bilateral inferior oblique myectomy (BIOm) or bilateral inferior oblique recession (BIOc) to correct V-pattern exotropia.

METHODS

The medical records of children (≤18 years) who underwent BLRc with BIOm or BIOc (10 mm) for V-pattern intermittent exotropia between December 2020 and May 2022 and who had at least 6 months' postoperative follow-up were reviewed. Outcomes included horizontal alignment, bilateral inferior oblique action, stereopsis, postoperative exotropia control score, and additional strabismus surgeries. Analysis was stratified by preoperative V pattern into subgroups of 10Δ-14Δ and ≥15Δ.

RESULTS

Fifty patients underwent BLRc with BIOm (n = 26) or BIOc (n = 24), with no difference in age, sex, or follow-up length. Preoperatively, there were no differences in stereopsis, horizontal or vertical deviations in primary position, strabismus control, or inferior oblique overaction (IOOA). The BIOc group had greater preoperative V pattern than the BIOm group (18.1 ± 6.8 D vs 14.3 ± 7.0 D, resp. [P = 0.03]). There was no difference in BLRc surgical dose. At final follow-up (mean, 448 ± 189 days), both groups showed a postoperative decrease in horizontal deviation, amount of V pattern, and IOOA. For patients with ≥15Δ V pattern, BIOm decreased V pattern amount at distance (P = 0.02) and IOOA (P = 0.0035) more than BIOc, and BIOm patients had better control of residual strabismus at distance (P = 0.03) compared with the BIOc group overall, as well as for both V pattern subgroups. Two patients with BIOm and one with BIOc underwent additional strabismus surgery.

CONCLUSIONS

BIOm or BIOc in combination with BLRc decreased the angle of exotropia and improved control. However, BIOm, especially with large V patterns, had a greater effect on decreasing the V pattern and IOOA and showed better control of residual strabismus.