Point-of-care ultrasonography for detecting raised intracranial pressure through optic nerve sheath diameter in non-traumatic headache patients

Figure 1 Anatomical relationship of the optic nerve sheath to the intracranial subarachnoid space, illustrating sheath expansion in raised intracranial pressure. ICP: Intracranial pressure; CSF: Cerebrospinal fluid.

Figure 2 Ultrasonographic technique for measuring optic nerve sheath diameter using point-of-care ultrasound. A: Proper ultrasound probe placement over the closed eyelid for optic nerve sheath diameter measurement; B: Sonographic image of the optic nerve sheath diameter with calipers placed 3 mm posterior to the retina. ONSD: Optic nerve sheath diameter.

Figure 3  Diagnostic accuracy of point-of-care ultrasound–measured optic nerve sheath diameter for detecting raised intracranial pressure, showing sensitivity, specificity, and cut-off values from key studies.