Modern Diagnostic Methods for Orbital Lesions

Abstract

We have a number of valuable modern diagnostic methods available which make the detection and classification of an orbital lesion relatively easy and highly reliable. The diagnostic work-up of a patient with unilateral exophthalmus has to proceed logically and step-by step:

• 1. History: The main questions are whether the patient has any other signs or symptoms of Graves disease and what is the duration of the exophthalmus. The answers may give us a clue as to the underlying cause. The rapidly increasing proptosis due to an orbital rhabdomyosarcoma is a good example. A history of chronic periorbital sinus troubles would point toward a mucocele or a pyocele. The history of a systemic affection (leukemia, vasculitis, etc.) may indicate an orbital involvement by this disease.

• 2. Physical examination: The direction and extent of the exophthalmus may give us a clue as to the site of the lesion. Interference with ocular motility, pressure on the globe, damage to the optic nerve and other factors have to be evaluated. Ausculation and palpation still remain an important aspect in the diagnostic work-up. The palpation should be done vigorously using the little finger. When a tumor can be palpated, its consistency and surface can be evaluated.

• 3. Evaluation for Graves disease: We always have to keep in mind that the most frequent cause for a unilateral exophthalmus is the orbitotopathy of Graves disease. The systemic manifestations may be minimal and even the most sophisticated laboratory tests may be inconclusive. The clinical picture (retraction of the lids, periorbital edema, etc.) is often indicative for this condition.

• 4. Radiologic examinations: Plain skull x-rays are indicated in every patient with an orbital lesion. The yield of positive findings is admittedly small, but important clues may be obtained.