The role of C.T. scans in managing the orbital complications of ethmoiditis.

Thirty-three cases of ethmoidities with orbital complications were reviewed to determine the accuracy of clinical diagnosis and the benefit of CT scans in planning treatment. Patients were classified according to the Schramm et al. 1982 criteria of orbital involvement with ethmoiditis: periorbital cellulitis with chemosis (PCC)-9, and orbital cellulitis (OC)-11, subperiosteal abscess (SPA)-9, and orbital abscess (OA)-4. These patients received CT scans acutely for diagnostic purposes and demonstrated an 84% accuracy with the final clinical groupings. Of 33 patients, 9 had a shift in clinical classification based on the CT scan result interpreted by the Radiology Department or surgical findings. There were no false positives in the periorbital or orbital cellulitis patients, and no false negatives in the subperiosteal and orbital abscess patients. Thus classification changes caused no change from medical to surgical treatment in any of the cases. The conclusion is that a knowledgeable clinical exam established the correct grouping in 70% of the patients versus 82% with the CT scan. An urgent CT scan is advised for patients in clinical groups SPA, OA, or cavernous sinus thrombosis (CST) to determine the imminent need for surgery, as the cases may be underestimated. Patients with PC or PCC can be managed medically with elective CT scans not routinely indicated.