Refractive errors and axial length among Alaskan Eskimos.

An epidemiological study of the prevalence of refractive errors was made of the Eskimo population of the Norton Sound and Bering Straits region of Alaska. It was possible to determine the subjective refraction in 83.7% of 1673 persons examined: 44.9% were emmetropic, 44.7% myopic and 10.4% hyperopic. Myopia was found more often in women (48.3%) than in men (41.3%), while emmetropia was found more often in men (49.3%) than in women (40.3%). Nine,four percent of the men were hyperopic and 11.4% of the women. The prevalence of myopia increased with age, with a maximum of 67.2% in the age group between 30 and 40 years. Subsequently, the number of myopes decreased rapidly. Little hyperopia was seen before the age of 50 years, it then increased rapidly, up to 71.5% for persons above the age of 80 years. Emmetropia, on the other hand, decreased with age. Ultrasound examination showed that an increasing axial length was associated with more myopia.