Influence of Strabismus Surgery on Fundus Hemodynamics Based on Swept-Source Optical Coherence Tomography Angiography Blood Flow Parameters.

PURPOSE: To investigate the impact of strabismus surgery on fundus hemodynamics using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS: A total of 124 patients with strabismus undergoing horizontal rectus muscle surgery were included in this non-randomized contemporaneous controlled trial. Patients were divided into unilateral recession (UR) and recession-resection (RR) groups based on the number of rectus muscles operated on. The UR group was further subdivided into lateral rectus (LR) and medial rectus (MR) subgroups. SS-OCTA imaging was performed preoperatively, and at 1 day, 1 week, and 1 month postoperatively, using a 12 × 12 mm macular scan to quantify hemodynamic parameters: vessel density (VD) of superficial capillary plexus (SCP) and deep capillary plexus (DCP), choroidal thickness (CT), choriocapillaris perfusion (CCP), choroidal vascular index (CVI), and choroidal vascular volume (CVV).

RESULTS: Horizontal rectus muscle surgery induced transient fundus hemodynamic changes, with significant differences observed near the fovea and peripheral retina, but not in the operated muscle quadrant. SCP and DCP increased in the peripheral retina postoperatively, while remaining stable near the fovea. CCP increased, with earlier changes near the fovea. CVV and CT increased at 1 week postoperatively, whereas CVI decreased, all returning to baseline by 1 month. The choroid exhibited more pronounced hemodynamic changes than the retina. RR surgery caused greater changes than UR, with LR surgery having a greater impact than MR surgery.

CONCLUSIONS: This study highlights transient ocular hemodynamic changes following horizontal rectus muscle surgery, varying by retinal region and number of muscles operated, providing new insights into fundus hemodynamics using SS-OCTA.