The middle-Norway eye-screening study. III. The prevalence of capsular glaucoma is influenced by blood-group antigens.

The association between blood groups (ABO, Rh, Kell, Duffy) and pseudo-exfoliation syndrome, simple, and capsular glaucoma have been evaluated. The findings were: 1). No statistically significant abnormalities regarding blood group distribution in persons with pseudo-exfoliation syndrome. 2). In contrast to simple glaucoma, capsular glaucoma showed an abnormal distribution in the ABO- and the Kell-system. There was less glaucoma prevalence in the capsular A1-group compared to the O-group (p = 0.013), and less in the K1 negative group compared to the K1 positive one (p = 0.005). This trend was even escalated when combining the two systems: Among the K1 negative persons the glaucoma prevalence was lower in the A1-group compared to the O-group (p = 0.003). In the K1 negative group only 9 of 61 A1-persons developed glaucoma, in contrast to the K1 positive group where 4 of 4 A1-persons had glaucoma. This difference gave p < or = 0.00038, whereas the corresponding difference for the O-groups showed p = 0.65. It is concluded that once a person with blood group A1 has developed pseudo-exfoliation syndrome, the risk that capsular glaucoma will occur is about 7 times higher when that person is K1 positive compared to K1 negative. Perhaps this observation may be used as a prognostic factor for non-glaucomatous PE positive persons.