RÉSUMÉ
Objective@#To compare the postoperative alignment of patients surgically corrected for esotropia or exotropia 6 weeks and 6 months after surgery.@*Method@#This retrospective study reviewed clinical records of patients who underwent horizontal muscle surgery at the University of the Philippines-Philippine General Hospital from 2010 to 2014. The changes in alignment from 1 week to 6 weeks and from 1 week to 6 months after surgery were compared for overcorrection, undercorrection, and adequate correction groups. ANOVA and Pearson correlation were used.@*Results@#Twenty two esotropia and 10 exotropia patients were included. Overcorrected esotropia patients had an esotropic change in alignment (15.50+13.44 PD after 6 weeks, p=0.026; 25+18.38 PD after 6 months, p=0.008). Under corrected esotropia patients had an exotropic change in alignment (-1.25+5.91 PD after 6 weeks, p=0.026;-4.38+14.16 PD after 6 months, p=0.008). Undercorrected exotropia patients had an esotropic change in alignment (6.67+6.35 PD after 6 weeks, p=0.028; 6+9.85 PD after 6 months, p=0.024). The presence of vertical deviations in esotropia caused an exotropic change in alignment after 6 months (p=0.03).@*Conclusion@#Although an exotropic drift is more commonly reported, fusional vergences may account for postoperative alignment changes towards orthotropia.