Which mechanism is NOT one of the common mechanisms of enophthalmos?

Which mechanism is NOT one of the common mechanisms of enophthalmos?

• A. Active globe retraction
• B. Passive globe retraction
• C. Abnormal muscle contraction
• D. Orbital volume imbalances

Answer: (C)

Enophthalmos, which refers to the posterior displacement of the eye within the orbit, can occur due to various mechanisms that affect the positioning of the eye. One of the mechanisms is active globe retraction, where the ocular muscles actively pull the globe back into the orbit. Another mechanism is passive globe retraction, which may occur due to changes in the surrounding tissues or structures that lead to a loss of volume or support. Orbital volume imbalances, often due to conditions such as atrophy of intraorbital fat, can also contribute to the appearance of enophthalmos by effectively increasing the space available within the orbit, allowing the globe to move backwards. However, the mechanism of abnormal muscle contraction does not typically lead to enophthalmos. Instead, it usually results in the eye being positioned abnormally due to overactivity or spasm of the muscles that control eye movement. Since muscle contractions would typically have the opposite effect—potentially causing exophthalmos (protrusion of the eye)—this distinguishes it from the true mechanisms that lead to enophthalmos. Thus, understanding the typical causes of enophthalmos and the physiological behaviors of the ocular muscles provides clarity on why abnormal muscle contraction is not a mechanism associated with

Enophthalmos, which refers to the posterior displacement of the eye within the orbit, can occur due to various mechanisms that affect the positioning of the eye. One of the mechanisms is active globe retraction, where the ocular muscles actively pull the globe back into the orbit. Another mechanism is passive globe retraction, which may occur due to changes in the surrounding tissues or structures that lead to a loss of volume or support. Orbital volume imbalances, often due to conditions such as atrophy of intraorbital fat, can also contribute to the appearance of enophthalmos by effectively increasing the space available within the orbit, allowing the globe to move backwards.

However, the mechanism of abnormal muscle contraction does not typically lead to enophthalmos. Instead, it usually results in the eye being positioned abnormally due to overactivity or spasm of the muscles that control eye movement. Since muscle contractions would typically have the opposite effect—potentially causing exophthalmos (protrusion of the eye)—this distinguishes it from the true mechanisms that lead to enophthalmos.

Thus, understanding the typical causes of enophthalmos and the physiological behaviors of the ocular muscles provides clarity on why abnormal muscle contraction is not a mechanism associated with