This research protocol focuses on the pre- and post-operative evaluation of ICP using non-invasive methods, particularly in the context of surgery for brain tumor removal. By utilizing ocular ultrasound to measure ONSD and ONSD/ETD ratios, this study hypothesizes that the utility of these parameters in monitoring ICP pre- and post-operative periods could be effective.

This research protocol focuses on the pre- and post-operative evaluation of ICP using non-invasive methods, particularly in the context of brain tumor resection surgery. By utilizing ocular ultrasound to measure ONSD and ONSD/ETD ratios, this study hypothesizes that the utility of these parameters in monitoring ICP pre- and post-operative periods could be effective.

This study aims to evaluate the effectiveness of the ONSD and the ONSD/ETD ratio using ultrasound as a non-invasive method for measuring intracranial pressure pre- and post-operatively in brain tumor patients.

Inclusion Criteria:

• • Adult patients (>21 years) undergoing brain tumor resection surgery.

  • Preoperative imaging-confirmed diagnosis of the tumor.
  • American Society of Anesthesiologists (ASA) physical status II to IV
  • Consent to participate in the study.

Exclusion Criteria:

• • Preexisting ocular conditions affecting the optic nerve or globe integrity, such as glaucoma, thyroid-associated ophthalmopathy, or other optic nerve diseases.

  • Combined ocular and optic nerve injuries at admission.
  • History of cranial trauma, prior neurosurgery, or lumbar puncture performed within 2 weeks before the measurement of optic nerve sheath diameter (ONSD).
  • History of subarachnoid hemorrhage (SAH).
  • Serious complications that could affect life expectancy, such as hematological disorders or malignancies.
  • Refusal to participate or withdrawal of consent at any stage.

This is a prospective observational study that will be conducted on 60 adult patients aged more than 21 years with ASA physical status II or IV. These patients will be admitted for brain tumor resection surgery at Tanta University Hospitals undergoing brain tumor resection surgery.