Optic nerve sheath diameter
Measurement of the optic nerve sheath diameter by ultrasound is a promising non-invasive technique that may help detect intra-cranial pressure. Many studies demonstrate that this measurement appears to demonstrate a high degree of diagnostic accuracy including sensitivity and specificity in the detection of elevated intra-cranial pressure (1-7). There are caveats, however, and we encourage you to peruse the material and watch the tutorial to get a more complete sense of this important tool.
This page and video tutorial will explore this measurement, how it is performed, and the current controversies.