LALES data support role of blood pressure on glaucoma risk

Analyses from the Los Angeles Latino Eye Study (LALES) show low perfusion pressure (systolic, diastolic, and mean), low diastolic blood pressure, and high systolic blood pressure all were independently associated with an increased risk of primary open-angle glaucoma (POAG), said Farnaz Memarzadeh, MD.

"These are all modifiable risk factors and so it is conceivable that we may be able to reduce the risk of POAG by maintaining blood pressure at a physiologic level on a long-term basis," said Dr. Memarzadeh, Doheny Eye Institute, University of Southern California, Los Angeles.

LALES is a cross-sectional population based study of adult Latinos in Los Angeles County. Among the 6,130 participants, 287 (4.7%) had POAG.

Logistic regression analyses were performed to evaluate the risk of POAG in relation to blood pressure (BP) and perfusion pressure (PP) variables. The analyses showed persons with systolic BP >160 mm Hg and those with DBP of 60 mm Hg and below had an approximate two-fold increased risk of POAG compared with their counterparts in the respective reference groups (SBP 111 to 120 mm Hg; DBP 71 to 80 mm Hg).

Dr. Memarzadeh said that the results showing low PPs and low diastolic BP were risk factors for POAG are consistent with the findings of several cross-sectional studies and recent longitudinal data on risks of POAG development and progression. The effect of elevated systolic BP and PPs on risk of glaucoma is more controversial because of conflicting information in the literature, however.

"While these features were risk factors for POAG in LALES and in various cross-sectional studies, recent longitudinal data from the Barbados Eye Study found hypertension was not a risk factor for increasing glaucoma incidence," Dr. Memarzadeh said. "Similarly, hypertension was not a risk factor for glaucoma progression in the Early Manifest Glaucoma Trial."