Aim: To investigate the relation between change in systemic blood pressures and change in intraocular pressure. Methods: This was a population based study of people 43-86 years old living in Beaver Dam, Wisconsin. Measurements at baseline and 5 year follow up of systemic blood pressures, intraocular pressures, and history of use of blood pressure medications. Results: Intraocular pressures were significantly correlated with systolic and diastolic blood pressures at both baseline and follow up. There were significant direct correlations between changes in systemic blood pressures and changes in intraocular pressure. There was a 0.21 (95% CI: 0.16 to 0.27) mm Hg increase in IOP for a 10 mm Hg increase in systolic and 0.43 (0.35 to 0.52) mm Hg increase in IOP for a 10 mm Hg increase in diastolic blood pressure. Further adjustment for diabetes and medication use did not alter these associations. Decreased systolic or diastolic blood pressures of more than 10 mm Hg over 5 years were significantly associated with decreased IOP. Conclusions: Reduced systemic blood pressure is associated with reduced intraocular pressure. This finding should be evaluated in other studies, especially with respect to the possibility of resultant decreased risk of open angle glaucoma. I ntraocular pressure (IOP) has been found to be associated with systemic blood pressure levels in population based studies.1-10 The relation appears to be reasonably consistent across the range of values of IOP and both systolic and diastolic blood pressures. It has been postulated that treatment of hypertension may place the eye at relatively increased risk of visual field deficits because of an imbalance in the relation of blood pressure to IOP.11 This thought has been given credence, in part, because of the clinical dictum that sudden lowering of blood pressure is associated with loss of visual field in some people.12 Blood pressure increases with age in most populations, and medical intervention has been successful in lowering blood pressure and the subsequent risk of the systemic sequelae of high blood pressure. There are limited data as to whether the moderate changes in blood pressure that often accompany treatment for hypertension are associated with synchronous changes in IOP. We evaluated these questions in data from the Beaver Dam Eye Study.
METHODSA population based study of people 43-86 years of age (n = 4926) was conducted in Beaver Dam, Wisconsin in 1988-90. Details of the census used to identify and locate study subjects have been published previously.13 A follow up examination was performed 5 years after baseline (n = 3684). Institutional review board approval at the University of Wisconsin Medical School was granted for each phase of the study. Informed consent was obtained from study participants. The tenets of the Declaration of Helsinki were adhered to. During the study evaluations, blood pressures were obtained according to a modification of the Hypertension Detection and Follow-up Program protocol 14 which entails three measurements, ...