Variation and heritability of ocular dimensions. A population study among adult Greenland Eskimos.

Adult Greenland Eskimos from Umanaq town (age 15+) and villages (age 40+) were examined. Optical pachymetry, ultrasonic oculometry, corneal diameter and curvature measurements, and subjective refraction were performed in 5-600 persons. Frequent occurrence of primary angle-closure glaucoma motivated the survey. Age-, sex- and family-variations were studied by linear regression analyses. Conspicuous age effect was found with respect to increase of lens thickness and forward displacement of the lens with age. Almost no age influence was found with respect to increase of lens thickness and forward displacement of the lens with age. Almost no age influence was found with respect to corneoscleral size, i. e. axial length, corneal size and corneal radius of curvature. Conspicuous heritability (h2=0.6-0.8) was found in corneoscleral size parameters as well as lens position, while refractive error showed a much smaller genetic influence.