Corneal diameter in Greenland Eskimos. Anthropometric and genetic studies with special reference to primary angle-closure glaucoma.

In a population survey the corneal diameter (DC) was measured in 1,211 adult Greenland Eskimos from six districts. Using a Wessely keratometer, trnasversal and vertical readings were performed, and the CD value taken as the average. The unimodal distributions obtained were found to differ from normality. The results suggested a small decrease of CD with age whereas the sex difference (0.2 mm) was highly significant. Geographical variation was found, a West Greenland group (Umanaq) being below the others, while the purest Eskimos (from Angmagssalik) showed higher mean values. A Danish control sample had significantly larger corneae, about 0.5 mm above the Eskimos, and agreed with other reports on Europeans. The CD values and the anterior chamber depth (ACD) were positively correlated. The Eskimo primary angle-closure glaucoma patients showed a slight deviation towards the lower CD classes. The familial CD distributions suggested a mainly genetic determination of corneal size.