Alterations in retinal microcirculation following cardiac surgery: a prospective observational study using optical...

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with microcirculatory changes. Little is known about the effect of CPB on the structural and vascular parameters of the retina. We aimed to investigate changes in these parameters in patients after CPB surgery.

In this prospective observational clinical trial, 44 patients who underwent elective CPB surgery were enrolled. All subjects underwent a complete ophthalmological examination, optical coherence tomography (OCT), and OCT angiography (OCTA) preoperatively and 1 week after surgery. Changes in macular retinal thickness (RT), ganglion cell complex (GCC), vascular density (VD) of the superficial (SCP) and deep (DCP) capillary plexuses, and peripapillary retinal nerve fiber layer (RNFL) were assessed in relation to CPB duration and aortic cross-clamp (ACC) time.

A statistically significant decrease in RT (p = 0.008) and VD of the SCP (p = 0.023) was observed in the central macula postoperatively. There was a statistically significant increase in peripapillary RNFL thickness in all quadrants and in macular GCC thickness in all regions except the superior region of the ganglion cell and inner plexiform layer (GCL +). A positive correlation was found between ACC time and RT, as well as the VD of SCP changes and the VD of DCP in the central macula.

CPB surgery induces significant retinal changes, including reduced RT and VD of the SCP in the central macula, along with increased thickness of the peripapillary RNFL and most regions of the macular GCC. Since retinal alterations are associated with ACC time, it is crucial to minimize ACC time to reduce the risk of ophthalmological complications.