Sinus Infections
Sinusitis, also known as a sinus infection or inflammation of the sinuses, is yet another condition that causes the depression of the under-eye skin from the orbital rim. It is caused by a blockage of fluid in the hollow spaces within the bones between the eyes, behind the cheekbones, and in the forehead resulting in inflammation.
Inflamed sinuses cause swelling due to abnormalities to the blood flow in the blood vessels and capillaries behind the eyes and nasal cavities. When the blood vessels swell, the veins behind the eyes dilate and darken, causing dark circles to appear. Recurring swelling and shrinking of the eye area due to sinusitis usually cause pressure and pain, eventually leading to the darkening and hollowing of the eye area.
Sinus infection is also a common cause of unilateral enophthalmos. According to a study, enophthalmos results from the acquired atelectasis of the maxillary sinus. Nevertheless, it was reported that with early diagnosis and prompt treatment, the collapse of the maxillary sinus with inferior bowing of the orbital floor resulting from sinus infection could be easily resolved.
