Table 2. Results of logistic regression analysis

Logistic regression analysis was used to model the risk of developing open angle glaucoma (OAG) based on apolipoprotein E (APOE) genotype and allele with an adjustment for age, gender, and intraocular pressure (IOP). A four fold reduction in open angle glaucoma risk was found with the ε2ε3 genotype compared to the ε3ε3 genotype. With the same adjustments, a three fold reduction in OAG risk was found with the ε2 allele, and a two fold increased risk of OAG was found with the ε3 allele. The ε4 allele was excluded from this model because the ε4 allele was not an independent variable.

                              Odds ratio
  Variable   p value   (95% confidence interval)
  --------   -------   -------------------------
   Age        0.6        1.01 (0.98 to 1.03)
   Gender     0.68       1.13 (0.63 to 2.03)
   IOP       <0.0001     1.98 (1.73 to 2.25)

APOE genotypes
   ε2ε3       0.012      0.26 (0.088 to 0.74)

APOE alleles
   ε2         0.018      0.29 (0.10 to 0.80)
   ε3         0.033      1.97 (1.06 to 3.67)