Individuals with a high pulse pressure (the difference between the systolic [top number] and diastolic [bottom number] blood pressure), appear to have an increased risk for high-tension open-angle glaucoma, according to a report in the June issue of Archives of Ophthalmology.
Researchers have previously examined the role of vascular factors in the development of open-angle glaucoma, an eye disease often associated with increased intra-ocular pressure and that involves loss of certain retinal cells and atrophy of the optic nerve, according to background information in the article. "Still, the relations between risk factors such as systemic hypertension [high blood pressure], systolic or diastolic blood pressures or perfusion pressures and open-angle glaucoma remain controversial," the authors write.
Caroline A. A. Hulsman, M.D., Ph.D., and colleagues at the Academic Medical Center, Amsterdam, and Erasmus Medical Center, Rotterdam, the Netherlands, analyzed data from 5,317 individuals, 215 of whom had definite or probable open-angle glaucoma and 5,102 of whom did not have the condition. At the beginning of the study, between 1990 and 1993, participants received eye examinations and their blood pressure was measured. During the third phase of the study, between 1997 and 1999, arterial stiffness (a change in artery structure associated with an increased risk of cardiovascular disease) was also measured. Based on their intraocular pressure (pressure within the eye), individuals with glaucoma were classified into high-tension open-angle glaucoma (pressure greater than 21 millimeters of mercury) and normal-tension open-angle glaucoma (pressure of 21 millimeters of mercury or less).
"We found that high-tension open-angle glaucoma was associated with high pulse pressure, possibly with increased carotid arterial stiffness and, only in persons treated for systemic hypertension, with low diastolic perfusion pressure," the authors write. "In these persons, normal-tension open-angle glaucoma was associated with high diastolic blood pressure, whereas the association between normal-tension open-angle glaucoma and low diastolic perfusion pressure was inverted."
"Although our findings of high-tension open-angle glaucoma and normal-tension open-angle glaucoma need to be confirmed in other population-based studies and the numbers of cases are low, we conclude that the mechanisms involved in the etiology of high-tension open-angle glaucoma may be different from those in normal-tension open-angle glaucoma," they write.