Patients with orbital disease should be specifically evaluated for globe displacement in all three dimensions. The ophthalmologist is familiar with anterior posterior displacement of the globe, but vertical displacement as well as horizontal displacement should be evaluated. The displacement of the globe leads very directly to the location of the orbital mass, Orbital masses will push the globe directly opposite the location of the origin of the mass; i.e., muscle cone masses push the globe forward, superior nasal orbital masses push the globe inferotemporally. Recognition of the locale of the mass can often help to include or exclude certain types of tumor from the differential diagnosis.
A sensitive way to determine anterior displacement of the globe is to visualize the patient in a marked, chin-up position. A good observer can estimate as little as 1 mm of asymmetry in the forward protrusion of the corneal apex in this position. This proptosis can be quantitated with the exophthalmometer, the most common being the Hertel instrument. However, these instruments are notoriously inaccurate when used to document change in proptosis, Horizontal displacement is determined by measuring from the midline of the nasal dorsum to the midline of the pupillary axis or the medial limbus. Vertical dystopia (vertical displacement of the globe) is harder to quantitate but can be recognized by holding a ruler horizontally across the face and resting the ruler at the lower edge of one pupil or the lower limbus and comparing it with the position of the other pupil or limbus. This will often help to point out small amounts of vertical displacement that might otherwise be missed.
Cranial nerve function is evaluated first, assessing motor nerves by evaluating the ductions and versions of both globes, as well as the excursion of the eyelids. The evaluation of eyelid function is well described in the chapter on ptosis in this textbook. Finally, fifth cranial nerve function is assessed by determining sensory aspects of the cornea.
Examination of the orbit should involve auscultation with the bell of the stethoscope. Vascular lesions, both chronic and acute, can be diagnosed. The bell is placed over the forehead, cheek, and finally the globe, with the eyes closed, comparing the left with the right side. Palpation for abnormal lymph nodes is particularly important in the preauricular and submandibular areas.
Once again, the vast majority of patients will present to the ophthalmologist with a relatively limited number of complaints: (a) the acute onset of redness, pain, and pain of the eyelids and/or the eye, often accompanied by diplopia, (b) change in appearance, most often related to vertical or anterior displacement of the globe, (c) diplopia, and (d) irritation, excessive tearing, or photophobia as a result of the orbital disease.