What is a key symptom of proptosis related to DM sinus infection?

Proptosis, or exophthalmos, is a significant clinical manifestation in patients with a diabetic sinus infection, primarily due to the underlying inflammation and infection that can affect the extraocular muscles and orbital structures. Bulging of the eye occurs as a result of orbital swelling and mass effect from sinus disease, which is common in diabetic patients who are particularly susceptible to infections, including those of the sinuses.

In the context of diabetes, infections can lead to conditions such as orbital cellulitis, which may cause proptosis due to both the collection of pus and the inflammation of surrounding tissues, pushing the eye forward. This symptom is more pronounced in the setting of orbital involvement where the packaging of the eye in the orbit results in an observable displacement.

The other symptoms listed, such as increased intraocular pressure, painful eye movement, and redness around the eye, may also be present in certain cases of eye or orbital disease but are not as directly indicative of proptosis as the observable or palpable bulging of the eye itself. Thus, the key symptom associated with the proptosis seen in diabetic sinus infection is the prominent bulging of the eye, representing a specific and significant clinical finding.