Choroidal volume changes following blow-out fracture repair

Purpose To investigate the serial choroidal volume change following orbital blow-out fracture (BOF) repair. Methods The choroidal volume was measured by optical coherence tomography in patients who underwent BOF repair, preoperatively and postoperatively at 1, 4, 12 and 24 weeks. The orbital volume ratio (OVR) was obtained by dividing the orbital volume of the traumatized orbit by that of the contralateral side using three-dimensional computed tomography imaging. The choroidal volume change was compared between both eyes using a linear mixed model. Results We analyzed the choroidal volume of 11 patients. Choroidal volume showed a trend of slight increase during the immediate postoperative period, and then, choroidal volume decreased abruptly between postoperative 1 to 4 weeks (beta-coefficient - 0.22, P < 0.001). Choroidal volume also showed gradual decrease between postoperative 4 to 24 weeks (beta-coefficient - 0.02, P < 0.001). During the study period, there were no significant differences in choroidal volume change between BOF and contralateral unaffected eyes (beta-coefficient - 0.20, P = 0.711). The hyperopic refractive errors (beta-coefficient 0.27, P = 0.028) and the larger preoperative OVR (beta-coefficient 10.37, P = 0.013) were associated with larger choroidal volume. Conclusions Choroidal volume showed a similar decreasing change following BOF repair between the BOF and the contralateral unaffected eyes. Moreover, choroidal volume of both eyes was associated with the degree of orbital volume expansion due to BOF, suggesting that choroidal volume change after BOF repair was affected not only by trauma-associated local hemodynamic changes but also by systemic influences such as inflammatory response.