Efeito da rotação da cabeça na pressão intraocular em decúbito ventral: estudo randomizado

Abstract

Background and objectives: The increased intraocular pressure (IOP) -which decreases perfusion pressure on the optic nerve -increases by prone positioning (1). The aim of our study was to compare the effect of head rotation 45 o laterally in prone position on the increase in IOP of upper placed and lower placed eyes in patients undergoing percutaneous nephrolithotomy (PCNL). Methods: Forty-fi ve patients were randomly divided into 2 Groups. IOP of the patients were recorded bilaterally in supine position before the operation had started. Patients were turned to prone position. The head was placed on a prone headrest without external direct compression to both eyes. Patients in Group I were kept in strictly neutral prone position where as patients in Group II were placed prone with their heads rotated 45º laterally to the right side. At the end of the operation, patients were turned to supine position and their IOP was measured immediately. Results: There was no difference related to demographics, duration of surgery, blood loss and fl uid input data. IOP values after surgery in prone position increased signifi cantly compared to preoperative values in both groups (p < 0.05). After surgery in prone position IOP values of the upper positioned eyes in Group II were signifi cantly lower than Group I and lower positioned eyes in Group II (p < 0.05). Conclusion: prone positioning increases IOP. In patients with prone position with a head rotation of 45o laterally, IOP in the upper positioned eye was signifi cantly lower.

The Effect of Intranasal Pressure on Intraocular Pressure

“…In a previous study, the effect of the reverse trendelenburg position on IOP was studied in spine surgery patients; the position led to less venous congestion and no patient experienced increased IOP. 13,14 This result indicates that prone position leads to increase in venous pressure. However, there are no data addressing the question of how the orbital venous pressure affects IOP in humans.…”