Abstract
Purpose :
The inferior oblique’s (IO) tertiary action is abduction; therefore, surgical weakening of the IO could theoretically result in greater rates of overcorrection when combined with lateral rectus recession to treat exotropia. Prior studies are limited; however, those that have been performed identified minimal to no difference in success rates and horizontal deviation following surgery. Our study compared success rates, overcorrection rates, and postoperative horizontal alignment between patients with exotropia who underwent bilateral lateral rectus recession (BLRc) alone vs BLRc combined with IO weakening.
Methods :
A retrospective analysis of 192 patients was performed; 170 underwent BLRc and 22 underwent BLRc combined with an IO weakening procedure. Patients with prior eye muscle surgery, ocular disease other than strabismus, or other neurologic or congenital conditions were excluded. Pearson’s chi-square tests compared surgical success and overcorrection rates. Mann-Whitney U tests compared postoperative horizontal deviation at distance and near. Negative values represented exodeviation.
Results :
There was no significant difference in postoperative outcomes after 1 week. Outcomes for BLRc only versus BLRc combined with IO weakening were as follows: success rates 29.6% and 33.3% (p=0.727, 1 week), 76.2% and 83.3% (p=0.500, 6-10 weeks); overcorrection rates 56.5% and 50.0% (p=0.586, 1 week), 7.6% and 0% (p=0.268, 6-10 weeks); mean postoperative deviation at distance 10.8±15.1 and 7.3±15.4 (p=0.230, 1 week), -2.2±13.4 and -5.3±12.4 (p=0.304, 6-10 weeks); and mean postoperative deviation at near 11.6±13.4 and 4.4±13.5 (p=0.032*, 1 week), -0.3±14.1 and -3.4±11.1 (p=0.247, 6-10 weeks).
Conclusions :
The addition of an IO weakening surgery did not result in a significant difference in the surgical success rate, overcorrection rate, or postoperative horizontal deviation by 6-10 weeks for patients treated with BLRc for exotropia. Both groups experienced improvements in all three outcome measures between the 1-week and 6–10-week postoperative visit.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.