Blood Pressure, Perfusion Pressure, and Open-Angle Glaucoma: The Los Angeles Latino Eye Study

The pathogenesis of open-angle glaucoma (OAG) remains unknown. Although elevated intraocular pressure (IOP) is thought to play a major role in the development and progression of the disease, it is generally well understood that other factors, particularly those affecting the blood supply to the optic nerve head may play a significant role. Numerous studies have been conducted to investigate the relationship between OAG and vascular factors such as systemic hypertension, hypotension, atherosclerosis, and vasospasm.1–9 Study results, however, are conflicting, and the impact of high or low blood pressure on the development of OAG is still not fully understood. According to the vascular theory of OAG pathogenesis, low blood pressure (BP), particularly in the face of elevated IOP, can reduce perfusion pressure (PP) at the optic nerve head, causing ischemic damage to the retinal ganglion cells.10,11 In cases of chronically elevated BP, on the other hand, increased peripheral resistance and small-vessel disease can also reduce perfusion of the optic nerve head. In addition, IOP and BP are positively correlated4,12,13 resulting in further difficulty in interpreting the existing data and understanding the relationship between OAG and BP. The objective of this study was to evaluate the cross-sectional relationship between BP, PP, and OAG in the Los Angeles Latino Eye Study (LALES). LALES is a population-based study of Latinos in Los Angeles County that was initiated to better understand health care and eye disease in this minority population.14