Correlations of the parameters of cardiopulmonary bypass and hemodynamics during cardiac surgery and the structural and functional state of the retina

Objective. To study the structural and functional retinal changes developed in cardiac surgery patients as a consequence of cardiopulmonary bypass and to identify the factors aff ecting the nature and extent of changes observed.Material and Methods. Ten patients who underwent cardiac surgery under cardiopulmonary bypass (CPB) were studied. The ophthalmologic examination was performed before cardiac surgery and 10-14 days after the surgery.Results. On days 10 to 14, after cardiac surgery, visual acuity was restored to the maximum; the perimetry indicators, the level of intraocular pressure, and the structures of the anterior segment of the eyeballs did not change signifi cantly. The ophthalmoscopy revealed the foci of ischemic edema in the fundus along with the fi rst- and second-order arteries in 30% of cases. The thickness of ganglionic and nerve fi ber layers decreased in one patient (10%), which may be associated with the intraoperative ischemia of orbital artery branches feeding the optic nerve. These changes had direct relationships with the level of maximum mean blood pressure (MBP) during CPB and the fl uctuation of absolute MBP values during CPB: MBP ≥ 90 mmHg during CPB was associated with the occurrence of ischemic foci in the retina in 100% of cases. If the diff erence between the maximum and minimum MBP levels during CPB exceeded 20 mmHg, the changes in the retina occurred more frequently (p = 0.0350) than in the cases where MBP fl uctuations during CPB were less than 20 mmHg.Conclusions. The most signifi cant changes in the vision organs of patients undergoing cardiac surgery under CPB occur in the retina. Factors associated with the occurrence of pathological ischemic changes in the retina were fl uctuations in MBP during CPB (≥20 mmHg) and the absolute value of maximum MBP during CPB (>90 mmHg).