Impact of intermittent exotropia and surgical realignment on myopia progression in myopic children

To determine whether untreated intermittent exotropia (IXT) accelerates pediatric myopia and whether strabismus surgery modifies this risk.

This retrospective study enrolled 259 children aged 6-14 years with spherical equivalent refraction (SER) ≤ -0.75 D; 90 orthotropic controls, 86 untreated IXT, and 83 post-surgery IXT (PS-IXT) with successful alignment. Exclusion criteria included prior ocular surgery, trauma, or myopia-control interventions. After standardized cycloplegia, certified optometrists measured SER and axial length (AL) at baseline, 6 and 12 months.

Baseline SER, AL, age and gender distribution did not differ among the three cohorts (all P > 0.05). At the 12-month endpoint, the IXT group exhibited a significantly greater myopic shift (-0.91 ± 0.36 D vs -0.50(-0.75,-0.37) D; P < 0.001) and axial elongation (0.41 ± 0.17 mm vs 0.30(0.20,0.36) mm; P < 0.001) relative to orthotropic controls. Similarly, when compared with the surgically aligned (PS-IXT) group, the IXT cohort displayed excess myopic progression (-0.91 ± 0.36 D vs -0.38(-0.63,-0.13) D; P < 0.001) and axial elongation (0.41 ± 0.17 mm vs 0.25(0.13,0.37) mm; P < 0.001). In contrast, the PS-IXT and control groups were comparable for both refractive change (-0.50(-0.75,-0.37) D vs -0.38(-0.63,-0.13) D; P = 0.204) and axial elongation (0.30(0.20,0.36) mm vs 0.25(0.13,0.37) mm; P = 0.998).

Untreated IXT constitutes an independent, modifiable driver of accelerated myopia in children; timely surgical realignment normalizes the subsequent refractive and axial trajectory and should be incorporated into comprehensive myopia-prevention strategies.