To present a case of brain abscess formation accompanied by improvement of orbital cellulitis.

A 54-year-old male came to our clinic complaining of swelling and pain of the left periorbital area and decreased visual acuity (VA) of the left eye. Initial best-corrected visual acuity (BCVA) was 0.3 and intraocular pressure was 27 mmHg in the left eye. Eye movement in all directions was restricted and 4 mm of proptosis was observed in the left eye. An orbital CT scan demonstrated pansinusitis and orbital cellulitis of the left eye. The patient underwent endoscopic sinus surgery and was treated with systemic antibiotics. However, periorbital swelling was aggravated and another orbital CT scan was performed and analyzed. The CT scan showed localized periorbital abscess of the left eye, and the authors performed an incision and drainage (I&D) of abscess procedure. After the operation, BCVA of the left eye was recovered to 0.8 and eye movement improved and periorbital swelling decreased. However, 15 days after the I&D, the patient complained of a severe headache. Brain magnetic resonance imaging (MRI) was performed and showed an abscess of the left frontal lobe of the brain. The authors consulted with a neurosurgeon, and the patient received intravenous antibiotics and mannitol. The headache steadily decreased, and three months after the first visit, a follow-up brain MRI was performed. The MRI showed almost complete disappearance of the abscess and six months after the first visit, BCVA was recovered to 1.0 and eye movement was full in all directions.

Although orbital cellulitis is improved by treatment of antibiotics and surgery, if the patient complains of neurologic symptoms such as headache, other complications such as brain abscess formation should be considered.