Ethnic variation in deep lateral orbital anatomy and its implications on decompression surgery

AIM: To describe differences in the deep lateral orbital wall (specifically, trigone) between Chinese, Malay, Indian and Caucasian subjects Methods: Single-centre retrospective Computed Tomogram (CT)-based study; 20 subjects of each ethnicity were used from existing databases, matched for gender, average age and laterality. Subjects below 16 years of age were excluded. DICOM image viewing software CARESTREAM Vue PACS (Carestream Health Inc., USA) and OsiriX version 7.5 (Pixmeo., Switzerland) were used to measure deep lateral wall length, thickness and volume, as well as orbital depth and statistical analyses performed using Statistical Package for Social Sciences version 21 (IBM, USA).

RESULTS: In each group, there were 12 males (60%) and average age was not significantly different (p = 0.682-0.987). Using Chinese subjects as a reference, in Chinese, Malay, Indian and Caucasian subjects, mean trigone thickness was 13.68, 14.02, 11.60 (p