Peripheral vasospasm and nocturnal blood pressure dipping--two distinct risk factors for glaucomatous damage?
OBJECTIVE
To evaluate the relationship between peripheral vasospasm and circadian blood pressure rhythm in patients with primary open angle glaucoma (POAG).


METHODS
Nail-fold capillaroscopy, combined with a cold provocation test, and 24-hour blood pressure monitoring was carried out in 130 patients with POAG (M:F 58:72; mean age 60 +/- 14 years), 99 with high-tension glaucoma (HTG) and 31 with normal-tension glaucoma (NTG). Peripheral blood flow parameters were compared for patients with a nocturnal fall in mean systemic blood pressure (MBP) of less than 10% (non-dippers), patients with a nighttime MBP fall of 10-20% (dippers), and patients with a nighttime MBP fall of more than 20% (over-dippers).


RESULTS
Patients with POAG showed a significantly lower blood flow velocity both at baseline (p < 0.01) and after cold provocation (p < 0.02) and a significantly higher percentage of cold-induced blood-flow standstill (p < 0.0001) in the nail-fold capillaroscopy than normal controls. The numbers of non-dippers (50), dippers (66) and over-dippers (14) did not differ between the HTG and NTG group. There were no significant differences between non-dippers, dippers, and over-dippers in peripheral blood flow parameters.


CONCLUSIONS
Our findings indicate that vasospasm and low blood pressure may be distinct risk factors for glaucomatous damage. It also appears that screening for vascular dysregulation and systemic hypotension should not be restricted to NTG patients alone.
University Eye Clinic, Basel, Switzerland.
M
M
Pache
B
B
Dubler
J
J
Flammer
D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm / Q000502:physiology; D003941:Diagnostic Techniques, Ophthalmological; D005123:Eye / Q000473:pathology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D020678:Microscopic Angioscopy; D008875:Middle Aged; D009262:Nails / Q000098:blood supply*; D009798:Ocular Hypertension / Q000175:diagnosis / Q000503:physiopathology; D012307:Risk Factors; D014661:Vasoconstriction