Non-medial Subperiosteal Abscess in a 63-Year-Old Female: A Case Report and Literature Review.

We present a rare case of non-medial subperiosteal abscess secondary to orbital cellulitis in a 63-year-old female. The patient reported a five-day history of progressive swelling, pain, and diminished vision in the left eye. Computed tomography (CT) of the orbit revealed an extraconal soft tissue density, suggestive of an orbital collection, which when correlated clinically and radiologically, was diagnosed as orbital cellulitis secondary to sinusitis, leading to a subperiosteal abscess. Despite undergoing multiple external drainage procedures, the patient, unfortunately, experienced complete vision loss in the affected eye. While non-medial abscesses due to orbital cellulitis are infrequent, they are often associated with more severe outcomes, including vision loss and intracranial complications, compared to those in medial locations. This case underscores the importance of combined surgical approaches, including both sinus and external drainage, to prevent severe vision loss and potentially life-threatening intracranial sequelae.