The pigment dispersion syndrome was noted in 10% of white and black subjects with and without glaucoma. This suggested pigment dispersion was not a high risk factor in the development of glaucoma. The HLA-B7 antigen was less prevalent and HLA-B13 and Bw17 antigens were significantly more prevalent in individuals with the pigment dispersion syndrome than in subjects without the syndrome. Either HLA-B13 or Bw17 antigen was found in 23 (77%) of 30 patients with the pigment dispersion syndrome and in only 13 (6%) of the 203 subjects without pigment dispersion. Pigmentary glaucoma was characterized by a significantly higher prevalence of combinations of HLA-B12 and B13 or HLA-B12 and Bw17 antigens as compared to the pigment dispersion syndrome without glaucoma, primary open-angle glaucoma, or the general population. This suggested that pigmentary glaucoma differed genetically from primary open-angle glaucoma and was a separate entity.