THE LITERATURE on mongolism is replete with marked differences in incidence of some of the more common eye findings associated with this condition. Few authors define or even partially describe the sign they are reporting, and fewer still explain the means by which the sign was measured. There is no doubt that different authors have used different criteria in reaching their conclusions, and therefore comparison between the results of one report and another is difficult. Furthermore, lack of definition produces confusion, and some signs may receive an emphasis conducive to misdiagnosis.
In this study, four of the common eye findings in mongolism, easily determined without special instruments or training, are defined, the pertinent literature reviewed, and the incidence in institutionalized and noninstitutionalized patients with mongolism compared with normal controls. The signs are slanting eyes, epicanthic folds, Brushfield spots, and hypoplasia of the iris. As the frequency of Brushfield spots is