Association between Nocturnal Blood Pressure Reduction and Progression of Visual Field Defect in Patients with Primary Open-Angle Glaucoma or Normal-Tension Glaucoma

Abstract

Purpose

To assess prospectively the relationship between nocturnal blood pressure reduction (dip) and progression of the visual field defect in patients with normal-tension glaucoma (NTG) or primary open-angle glaucoma (POAG).

Patients and Methods

The subjects studied were 38 patients with glaucoma (23 patients with NTG, 15 patients with POAG), in whom 48-h ambulatory blood pressure monitoring was conducted, who were followed for at least 4 years, and in whom reliable visual field tests were performed at least 5 times. The progression was determined by the mean deviation (MD) slope analysis system installed in the Humphrey field analyzer Statpac program. Glaucoma patients with a dip of <10% were assigned to the nondipper group, those with a dip of 10%–20% to the tipper group, and those with a dip of >20% to the extreme dipper group. The dipper group was defined as physiologic dippers, while the nondipper and the extreme dipper groups were defined as nonphysiologic dippers, to study the relationship between the disturbance of the dip and progression of the visual field defect.

Results

Thirteen patients showed significant progression, while 25 patients did not. There were no significant differences in the mean intraocular pressure and follow-up period between the patients with progression and those without progression. Half (7/14) of the nondippers, 20% (4/20) of the dippers, and 50% (2/4) of the extreme dippers showed progression, indicating a tendency of progression in the nondipper and the extreme dipper groups. The nonphysiologic dippers had a higher incidence of progression compared with the physiologic dippers (P = 0.05). Among the glaucoma patients in the nondipper and dipper categories only, those with progression had significantly smaller dips (P = 0.02).

Conclusion

These results suggest that disturbance in the physiologic dip may be involved in the progression of glaucoma.