Subperiosteal orbital abscess: volumetric criteria for surgical drainage.

OBJECTIVE: To investigate predictive factors of surgical management of subperiosteal orbital abscess in children.

METHODS: A retrospective monocentric study was conducted between 2000 and 2011 with children hospitalized for acute pediatric orbital cellulitis (APOC). Clinical, biological and radiological data as well as medical and surgical management were collected and analyzed. All patients received intravenous antibiotics and underwent a CT-scan. Orbit and subperiosteal intraorbital abscess dimensions were measured on axial and coronal planes and the abscess volume was calculated using a spheroid model.

RESULTS: Eighty-three children with APOC (mean age: 4.5 years) were included, 53 were boys (63.9%). Thirty-two children (38.6%) presented with a subperiosteal orbital abscess. Mean abscess volume was 570mm(3) and mean exophthalmos was 4.7mm. Twenty patients were treated surgically, 11 of which by an endoscopic approach. A positive correlation was observed between the volume of the abscess or exophthalmos and surgical drainage: 57.9% of patients underwent surgery when exophthalmos was >4mm, 29.4% between 2 and 4mm, and none when <2mm. All patients with an abscess volume >500mm(3) or >5% of orbital volume were operated on whereas only 30% or 39% of patients, respectively, in case of smaller volumes (P<0.05).

CONCLUSION: Surgery for subperiosteal orbital abscess is usually performed in case of visual complications or unfavorable medical outcome. The importance of the exophthalmos and the volume of the abscess measured on the CT-scan are predictive factors of surgery in children with subperiosteal orbital abscess without visual complications.