Association of ABO blood groups with glaucoma in the Pakistani population

Objective: To study the association of blood groups with different types of glaucoma including primary open-angle glaucoma (POAG), primary closed-angle glaucoma (PCAG), and pseudoexfoliative glaucoma (PEXG) in the Pakistani population. Study Design: The present study was a prospective case control study. Participants: ABO and Rh blood groups were analyzed in 2046 controls and 477 glaucoma patients (220 POAG, 146 PCAG, and I I I PEXG). Methods: Hemagglutination patterns were used to determine the prevalence of the ABO and Rh blood groups in all the subjects. Logistic regression analysis was carried out to evaluate any association of the different blood groups with glaucoma. Results: In the present study, the percentage of blood groups A, B,AB, and 0 in patients was found to be 19%, 41%, 10%, and 30%, and in the control group, the values were 26%, 31%, 12%, and 31%, respectively. A significant positive association was found between the B blood group and glaucoma (p value < 0.05, odds ratio [OR] 1.5, and chi(2) 15.8). Logistic regression analysis revealed that the blood group B was associated with all types of glaucoma with OR of 1.35 (95% CI 1.01-1.80; p = 0.04) for POAG, 1.71 (95% Cl 1.21-2.40; p = 0.002) for PCAG, and 1.61 (95% Cl 1.09-2.36; p = 0.016) for PEXG. POAG was also found to be associated with the Rh-allele (p < 0.05) with an OR of 4.05 (95% Cl 2.98-5.51), as compared with controls. Conclusions: In the Pakistani patient cohort, blood group B is associated with all types of glaucoma and the Rh-allele is associated only with POAG.