Exophthalmos (Proptosis) Differential Diagnoses

Updated: Sep 25, 2018
  • Author: Michael Mercandetti, MD, MBA, FACS; Chief Editor: Hampton Roy, Sr, MD  more...
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DDx

Diagnostic Considerations

Pseudoproptosis can manifest itself in many ways. If the contralateral orbit is enophthalmic, then the ipsilateral side will be viewed erroneously as being proptotic. If there is contralateral blepharoptosis, there can be the appearance of ipsilateral proptosis. Axial myopia or buphthalmos can mimic proptosis as can asymmetrical bones of the orbital rims or midface. Pseudoproptosis also can be simulated by upper eyelid or lower eyelid retraction. The resultant scleral show creates the impression of the globe protruding forward. In patients with contralateral enophthalmos, the normal orbit, which is situated more anteriorly, may simulate proptosis when there is none.

Additionally, technical error in measuring the amount of protrusion may occur. This can be due to the design of the exophthalmometer or in its use. [30] However, in a study by Mourits et al, there was a high level of interobserver reliability with the use of the Hertel exophthalmometer. [24] Lam et al also reported good Hertel measurements intraobserver and reliable measurements interobserver. [34]

Differential Diagnoses