Background: As a multifactorial disease, glaucoma may be associated with pressure-dependent and pressure-independent factors. Ocular hypertension (OHT) may develop into primary open angle glaucoma (POAG) for many patients. Groups with OHT and POAG were compared for pressure-dependent and independent risk factors. A high prevalence of any factor(s) could indicate a contribution to progression from OHT to POAG. Methods: A sample of patients with POAG (n = 438) and with OHT (n = 301) were selected from those attending a tertiary referral private glaucoma practice, and data were collected regarding age and intraocular pressure at the time of diagnosis, sex, family history of glaucoma, systemic hypertension, diabetes, Raynaud's phenomenon, migraine and myopia. Results: After multivariate analysis, older age at time of diagnosis (Χ25 = 73.89, P < 0.001), myopia (odds ratio [OR] = 1.5, 95% confidence interval [CI] 1.0-2.2; P < 0.05), a family history of glaucoma (OR = 1.6, 95% CI 1.1-2.3; P < 0.001) and a high intraocular pressure (Χ24 = 16.96; P = 0.002) were found to be more prevalent among those with POAG. No other significant differences could be found between the two groups. Conclusion: Patients who have OHT may be at higher risk of developing POAG if they also have myopia, a family history of glaucoma or are of older age.