Long-term surgical outcomes of infantile-onset esotropia in preterm patients compared with full-term patients

Background/aims: To compare surgical outcomes between preterm and full-term patients with infantile-onset esotropia. Methods: This study included 56 preterm and 162 full-term patients with infantile-onset esotropia who underwent strabismus surgery. The extent of surgery was reduced by 0.5 mm per muscle in preterm patients who were born at <30 weeks of gestation. Surgical outcomes over time, including surgical success, overcorrection rate, undercorrection rate and surgical dose-response were compared between preterm and full-term patients. Results: The Cox proportional hazards regression model and competing risk analysis showed no statistically significant differences in the rate of surgical success or undercorrection over time between preterm and full-term patients. However, the final overcorrection rate was greater in preterm children than in full-term children (p=0.019). The average surgical dose-response was 3.99 prism dioptres (PD)/mm in full-term children and 4.40 PD/mm in preterm children. Conclusions: The results of this study showed a favourable outcome using a mildly reduced amount of surgery in preterm patients with infantile-onset esotropia. Surgical dose -response was significantly greater in preterm patients than in full-term patients.