Purpose: To evaluate the effect of nocturnal dip and blood pressure (BP) variability on paracentral scotoma in early open-angle glaucoma.
Methods: The present study included 72 early normal-tension glaucoma (NTG) patients and 34 early primary open-angle glaucoma (POAG) patients. Nocturnal dip and weighted standard deviation (wSD) were determined by 24-hour ambulatory BP monitoring (24-hr ABPM). The mean deviation (MD) and pattern deviation (PD) were measured with visual field. Correlations between nocturnal dip and/or BP variability and paracentral scotoma were assessed using Student's t-test, Pearson's correlation test, and linear logistic regression analysis.
Results: The systolic and diastolic nocturnal dip and paracentral scotoma occurrence demonstrated a statistically significant correlation in the early NTG group (systolic nocturnal dip: p=0.047, diastolic nocturnal dip: p=0.011). In the early NTG group, the subgroup with paracentral scotoma had a greater nocturnal dip than those patients without paracentral scotoma (systolic nocturnal dip: p=0.000; diastolic nocturnal dip: p=0.000). In the early NTG group, the subgroup with paracentral scotoma had higher wSD of SBP than the patients without paracentral scotoma (p=0.003). In the logistic regression analysis of the factors that can affect paracentral scotoma SBP dip and SBP, wSD appeared to significantly affect the occurrence of paracentral scotoma in the early NTG group.
Conclusions: Early NTG patients with paracentral scotoma have nocturnal dip and large BP variability. Therefore, in early glaucoma patients, particularly in early NTG with paracentral scotoma, nocturnal dip and BP variability should be assessed with 24-hr ABPM.
Keywords: 24-hr ambulatory blood pressure; blood pressure variability; early open-angle glaucoma; nocturnal dip; normal tension glaucoma; paracentral scotoma.