Evaluation of the effect of horizontal and oblique muscle surgery on choroidal thickness

Objectives: To evaluate the changes in subfoveal choroidal thickness after horizontal and oblique muscle surgeries in patients with strabismus. Materials and methods: Fifty-eight patients diagnosed with strabismus and had strabismus surgery between July 2018 to January 2019 were included in this retrospective study. Group 1 consists of patients underwent inferior oblique muscle recession surgery (n=18) and Group 2 consists of patients underwent horizontal rectus muscle surgery (n=40). The subfoveal choroidal thickness was measured using enhanced depth imaging optic coherence tomography preoperatively and first day and first month after surgery. Results: In Group 1, a significant increase was observed in choroidal thickness on postoperative first day compared to baseline values (p<0.05). When preoperative and postoperative first month measurements were compared, an insignificant increase was observed in Group 1 (p>0.05). In group 2, there was an increase in choroidal thickness on first day and the first month postoperatively, but no significant difference was found compared to preoperative choroidal thickness values. Conclusion: Our study showed that subfoveal choroidal thickness increases in the early period after horizontal and oblique muscle surgeries. We speculate that these changes may be due to the inflammation caused by surgical trauma and the altered choroidal microcirculation.