To evaluate the association of open-angle glaucoma (OAG) with ABO, Rh and Duffy blood groups in the population-based Barbados Eye Study.
Setting and Participants:
A subset of black Barbados Eye Study participants, which included 199 OAG cases and 1063 controls.
ABO, Rh and Duffy blood groups were determined as part of a comprehensive study visit, which included assessment for OAG through perimetry, fundus photography, and ophthalmologic examination.
Comparison of blood groups between OAG cases and non-OAG controls, expressed as odds ratios and 95% confidence intervals.
Associations were found with the Duffy Fya+ group, which is more frequent in white than black populations. In Mantel-Haenszel analyses, OAG was positively associated with Duffy Fya+ in men (odds ratio, 2.67; confidence interval, 1.52 to 4.69) and in persons with intraocular pressure more than 21 mm Hg (odds ratio, 3.32; confidence interval, 1.49 to 7.38). Logistic regression analyses confirmed these findings (interaction of Duffy Fya+ and male gender, P=.01; interaction of Duffy Fya+ and intraocular pressure, P=.04). No associations between OAG and the ABO or Rh blood groups were seen.
The associations with Duffy Fya+, which had not been reported previously in a black population, support the involvement of genetic factors in OAG. However, the lack of association between OAG and blood group markers of African ancestry is inconsistent with a genetic explanation for the differences in OAG prevalence between blacks and whites. Our findings suggest gene-environment interactions in OAG, to be explored by further studies of OAG and Fy markers by racial group and gender.