Role of nocturnal arterial hypotension in optic nerve head ischemic disorders.
OBJECTIVE
To investigate the role of nocturnal arterial hypotension, intraocular pressure (IOP) and heart rate in optic nerve head (ONH) ischemic disorders, and the effects of systemic factors and topical beta-blocker eye-drops on nocturnal arterial hypotension and heart rate.


METHODS
We investigated prospectively, by 24-hour ambulatory blood pressure (BP) monitoring and diurnal curve of the IOP, 275 white patients with anterior ischemic optic neuropathy (AION - 114), normal tension glaucoma (NTG - 131) and primary open angle glaucoma (POAG - 30).


RESULTS
Hourly average BP data analyses showed a significantly greater drop in mean diastolic BP (p < 0.009) at night in NTG than AION. Cases with visual field deterioration had significantly (p = 0.05) lower minimum nighttime diastolic BP. Arterial hypertensives on oral hypotensive therapy showed a significantly lower mean nighttime systolic BP (p = 0.006) and larger mean percentage drop in systolic (p < 0.0001), diastolic (p = 0.0009) and mean (p < 0.0001) BPs. Normotensives and hypertensives without therapy had no such difference. IOP showed no significant correlation with visual field deterioration in any of these conditions. Patients using beta-blocker eyedrops, compared with those not using them, had greater percentage drop in diastolic BP (p = 0.028), lower minimum nighttime diastolic BP (p = 0.072) and lower minimum nighttime heart rate (p = 0.002).


CONCLUSIONS
Findings of our study suggest that nocturnal hypotension, by reducing the ONH blood flow below a crucial level during sleep in a vulnerable ONH, may play a role in the pathogenesis of AION and glaucomatous optic neuropathy (GON) and progression of visual loss in them. Thus, nocturnal hypotension may be the final insult in a multifactorial situation.
Hayreh
S S
SS
Department of Ophthalmology and Visual Sciences, College of Medicine, University of Iowa, Iowa City 52242-1091, USA.
Podhajsky
P
P
Zimmerman
M B
MB
D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007022:Hypotension / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D007429:Intraocular Pressure / Q000187:drug effects / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions; D009898:Optic Disk / Q000098:blood supply*; D018917:Optic Neuropathy, Ischemic / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D011446:Prospective Studies; D014794:Visual Fields
D000319:Adrenergic beta-Antagonists; D009883:Ophthalmic Solutions