Assessment of Optic Sheat Diameter (ONSD) and Eyeball Transverse Diameter (ETD) Ratio Measurement From Ocular Ultrasound

The aim of this study is to evaluate the effects of different carbon dioxide gas insufflation pressures on the ultrasound-guided optic nerve sheath diameter in patients undergoing laparoscopic cholecystectomy and to determine the possible relationship between these changes and intracranial pressure. The study aims to gain a better understanding of the neurophysiological effects of gas pressures used during laparoscopic surgery and to obtain scientific data aimed at improving patient safety.

Inclusion Criteria: * Patients aged between 18 and 80 years. * Patients scheduled for laparoscopic cholecystectomy. * ASA (American Society of Anesthesiologists) physical status I or II. Exclusion Criteria: * History of intracranial space-occupying lesion or high intracranial pressure (ICP). * History of abdominal trauma. * History of orbital/ocular trauma.