A superior and inferior orbital rim-based exophthalmometer (orbitometer).

In exophthalmometry when the lateral orbital rim is used as the instrument's fixation base, any alteration in the rim will render serial measurements inaccurate. The exophthalmometer we describe (technically, an "orbitometer") uses the superior and inferior orbital rim areas as a base of reference, making it particularly useful in lateral orbitotomy procedures. This instrument can be aligned at the midpupil horizontally and vertically with a vertical fixation bar. In addition, a vertical bar gradient scale allows measurement of hypoophthalmos and hyperophthalmos.