Unrelated individuals were selected as cases or controls for this study. All subjects consented to sharing their samples. Both cases and controls were examined by a trained ophthalmologist. All cases and controls were at least 35 years old and all were Caucasian. Cases had either reproducible visual field loss in at least one eye in a nerve fiber layer distribution on two independent reliable visual fields, or a vertical cup to disc ratio (CDR) of at least 0.8 in the one eye. For automated visual fields, a reliable visual field was defined by fixation loss ≤ 33%, false positive rate ≤ 20% and false negative rate ≤ 20%. Intraocular pressure was noted for all cases, but was not part of the case definition. Exclusion criteria for cases included: myopia of −8D or greater, clinical findings suggestive of secondary glaucomas (pigment dispersion, exfoliation and anterior segment dysgenesis) and narrow filtration angles. Controls did not have a family history of glaucoma, had intraocular pressures less than 21 mmHg, had vertical cup to disc ratios of less than 0.7 and CDR asymmetry of less than 0.2. Controls also did not have any evidence of secondary glaucomas or narrow filtration angles.