Impact of myopic progression and axial growth on recurrence of intermittent exotropia two years after surgery: A retrospective study

PURPOSE: To evaluate the impact of myopia progression and axial length (AL) elongation on recurrence of childhood intermittent exotropia (IXT) two years after surgery. METHODS: We reviewed the medical records of 238 patients aged 4 to 10 years who underwent surgery for basic-type IXT and had more than 2 years of postoperative follow-up. Patients were assigned to two groups: the maintained group (188 patients with 10 prism diopters (PD) or less of IXT) and the recurred group (50 patients with 20 PD or more of IXT). We compared the annual rates of myopia progression and AL elongation between the two groups, as well as those according to ocular dominance within each group. We also analyzed factors, including follow-up duration and sensory status, that might contribute to IXT recurrence. RESULTS: The annual rates of myopia progression and AL elongation were significantly higher in the maintained group than in the recurred group (-0.63 ± 0.45 vs. -0.46 ± 0.34 diopters (D)/year, P = 0.02; 0.32 ± 0.17 vs. 0.30 ± 0.12 mm/year, P = 0.02, respectively). There were no significant differences in myopic axial growth rates according to ocular dominance. IXT recurrence was strongly associated with longer follow-up and poorer IXT control rather than with myopic eye growth ( P < 0.01 for each). CONCLUSIONS: Greater myopic progression and axial growth were observed in the maintained group compared with the recurred group, suggesting that they may not be major factors contributing to postoperative recurrence of childhood IXT.