What clinical sign is commonly associated with enophthalmos?

Enophthalmos is a condition characterized by the recession or positioning of the eyeball deeper into the eye socket, which can lead to several clinical signs. One of the most commonly associated signs is the protrusion of the third eyelid. This occurs because as the globe retracts, the third eyelid, or nictitating membrane, becomes more prominent, appearing to effectively "protrude" as it covers or partially covers the exposed area.

The third eyelid serves as a protective barrier for the eye and also helps maintain moisture and health of the cornea. In cases of enophthalmos, the retraction of the eyeball alters the normal anatomy of the eye and eyelids, resulting in an increased visibility of the third eyelid. This is particularly noticeable in animals with prominent third eyelids, such as dogs.

Understanding this association can help veterinary professionals diagnose underlying conditions that may lead to enophthalmos, such as pain, dehydration, or underlying disease processes affecting the orbital space.