Systemic hypertension and glaucoma: mechanisms in common and co-occurrence

Aims: To determine whether systemic hypertension and glaucoma might coexist more often than expected, with possible implications for treatment. Methods: Case-control study using general practitioner database of patients with glaucoma matched with controls for age and sex. Results: Hypertension was significantly more common in the 27 080 patients with glaucoma ( odds ratio 1.29, 95% confidence intervals 1.23 to 1.36, p< 0.001) than in controls. Treatment by oral beta blockade appeared to protect from risk ( odds ratio 0.77, 95% CI 0.73 to 0.83, p< 0.0001), but oral calcium channel antagonists or angiotensin converting enzyme ( ACE) inhibitors did not ( odds ratios 1.34, 1.24 to 1.44 and 1.16 1.09 - 1.24, respectively, p< 0.0001 in each case). Oral corticosteroid treatment was associated with enhanced risk ( odds ratio 1.78, 1.61 to 1.96). Conclusion: Common pathogenetic mechanisms in ciliary and renal tubular epithelia may explain coincidence of glaucoma and systemic hypertension. The choice of cardiovascular treatment, could substantially influence glaucoma incidence, with b blockade protecting and ACE inhibitors or calcium channel blockers not affecting underlying risk.