Examinations of a series of 1241 subjects showed episcleral pigment spots bearing relation to scleral canal emissaries to be most frequent among Eskimos (prevalence 85%), somewhat less frequent among Mongols (68%), and the rarest among white Northern Europeans (16%). The prevalence is the highest among women and rises very little with increasing age. The pigmentation is most often bilateral in Eskimos (66%), more rarely so in Caucasians (18%). It is most often localized superiorly (54%). Then follows in decreasing order to frequency:inferiorly (26%), nasally (13%), and - significantly more rarely - temporally (7%). The pigmentation is most often related to an artery (90%), most often one running a radial course (39%) or in the incyclo-direction (32%). Its average length in caucasians is 1.1 mm. Pigmentations are significantly related to the colour of the iris (visible in 8% of blue irides, against in 40% of brown).
PMID: 4003053 [PubMed - indexed for MEDLINE]
