Abstract
Purpose: :
An understanding of normal ranges of exophthalmometry has clinical importance for the assessment of globe position. As limited published data exists on exophthalmometry among various ethnic groups, this study compares normal ranges among Asians, African-Americans, Latinos, and Caucasians within a single university service.
Methods: :
A retrospective chart review identified 84 patients evaluated between 9/1/08 and 11/30/08, including 12 Asians, 13 African-Americans, 14 Latinos, and 45 Caucasians. Inclusion criteria were age >17 and adequate documentation of exophthalmometry measurements (Hertel exophthalmometer). Exclusion criteria included any condition affecting globe position, such as a retroorbital mass or thyroid-related orbitopathy. Only right eyes were included.
Results: :
Mean ± SD exophthalmometry measurements for various ethnic groups were 14.9 ± 2.0 (Asian), 17.2 ± 2.5 (Caucasian), 17.8 ± 2.9 (Latino), and 20.6 ± 2.5 (African-American). Based on two-sample t-test calculations, Asians had a statistically significant lower exophthalmometry average than all other ethnic groups (p<0.01) while African-Americans had a statistically significant higher exophthalmometry average than all other ethnic groups (p<0.02). The only comparison that was not statistically significant was between Latinos and Caucasians (p=0.51).
Conclusions: :
Normal ranges of globe protrusion differ among the four ethnic groups analyzed in this study, with Asians and African-Americans having the lowest and highest values, respectively. These differences may be due to anthropological variations in orbit and skull structure.
Keywords: orbit • clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology • face perception