Abstract
Abstract: :
Purpose: Published data on normal exophthalmometry measurements in Asians is limited. This study compares normal range of globe protrusion between healthy Asians and Caucasian adults. Methods: Globe protrusion was assessed using the Hertel exophthalmometer on 39 Asian (23 women, 16 men) and 69 Caucasian (48 women, 21 men) volunteers. Inclusion criteria included age between 18 and 65 with no history of thyroid abnormalities, orbital trauma, high myopia (greater then –7 D) or other abnormality which might affect globe position. Three sets of measurements of the right and left eyes were averaged for each subject and compared using the two–sample t–test. Results: Asian subjects had significantly lower values of globe protrusion than Caucasian subjects. Mean (+ SD) exophthalmometry measurements were lower in Asian women compared to Caucasian women (14.5 + 2.0 mm vs 16.4 + 2.5 mm, p<0.01) and in Asian men compared to Caucasian men (15.5 + 2.2 mm vs 18.2 + 2.1 mm, p<0.01). Ages of subjects were slightly younger in Asian adults (38 + 12 years, range 20 to 61 years) than in Caucasian adults (43 + 11 years, range 23 to 64 years) (p=0.063). Conclusions: In healthy adults under 65, the upper normal limits were 18.6 mm for Asian women, 19.9 mm for Asian men, 21.3 mm for Caucasian women, 22.5 mm for Caucasian men. Differences in globe protrusion may due to variation of orbit and skull structure from anthropological or racial differences.
Keywords: comparative anatomy • orbit • anatomy