exophthalmometry
Exophthalmometry is the clinical measurement of forward ocular projection, or exophthalmos, using an exophthalmometer. It provides a quantitative estimate of how far the eyeball sits anterior to the orbital margin. This measurement is commonly used to detect and monitor proptosis associated with conditions such as thyroid eye disease, orbital tumors, inflammatory orbitopathy, and trauma, and to track changes over time or in response to treatment.
The most widely used instrument is the Hertel exophthalmometer, though other designs exist. These devices measure
Normal values vary by population and age, but adult ranges are typically around 12 to 20 millimeters,
Limitations include inter-examiner variability, differences in instrument base, and individual orbital anatomy; measurements can be influenced