Orbital measurements in the presence of epicanthi in healthy North American Caucasians.

Anthropometric examination of 1,312 healthy North American Caucasians (654 boys, 658 girls) aged 6-18 years revealed epicanthus in 387 subjects (29.5%, 198 boys and 189 girls). Significantly more epicanthi were minor (232, 59.9%) than major, i.e., moderate or marked (155, 40.1%; SED = 3.5, diff. = 19.8). Only one quarter of major epicanthi were marked, i.e., covered the inner canthus (39, 3% of entire sample population). The prevalence of major epicanthi decreased significantly with age in both sexes. Surface measurements did not confirm the visual illusion that the interocular distance is wide in subjects with epicanthus. The nasal root was on average shallower and the eye fissure shorter and more tilted in subjects with major epicanthus than in those without. Though minor epicanthus in Caucasians is a statistical variation of normal eye lid structure, major epicanthus persisting in adulthood may indicate developmental disturbance. Anthropometry provides accurate measurements of orbital dimensions necessary to identify such developmental disturbances.