Bruce J. Martin

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Acute loss of sleep produces few apparent physiological effects at rest. Nevertheless, many anecdotes suggest that adequate sleep is essential for optimum endurance athletic performance. To investigate this question, heavy exercise performance after 36 h without sleep was compared with that after normal sleep in eight subjects. During prolonged treadmill(More)
AIMS To determine if normal tension glaucoma (NTG) patients differ from age matched controls in blood flow to the peripapillary retina, as measured with confocal scanning laser Doppler flowmetry (cSLDF; "Heidelberg retinal flowmetry"). METHODS 12 NTG patients and 12 age matched controls were compared using (a) 10 x 10 pixel boxes (the instrument default(More)
The pathogenesis of normal-tension glaucoma remains unknown. Because ocular vasospasm has been proposed as a possible mechanism, we investigated ocular vessel flow velocity in normal-tension glaucoma patients at rest and under treatment with a cerebral vasodilator. Ten normal-tension glaucoma patients and nine age- and gender-matched controls had flow(More)
AIMS/BACKGROUND Mechanical and vascular factors may both contribute to glaucoma. This study investigated the relation of mechanical to vascular factors by examining how acute IOP elevation altered flow velocities in the central retinal and ophthalmic arteries. METHODS IOP was elevated from a baseline near 14 to approximately 45 mm Hg using suction(More)
PURPOSE To review the role of ocular perfusion in the pathophysiology of age-related macular degeneration (AMD), the leading cause of irreversible blindness in the industrialized world. METHODS Medline search of the literature published in English or with English abstracts from 1966 to 2000 was performed using various combinations of relevant key words.(More)
PURPOSE The purpose of this study was to evaluate the test-retest reproducibility of measures of blood flow velocities using color Doppler imaging (CDI) in orbital arteries. PATIENTS AND METHODS Measures of peak systolic velocity, end-diastolic velocity, and resistive index were performed in a group of 15 normal tension glaucoma patients and in 15 healthy(More)
PURPOSE beta-Adrenergic blocking drugs lower intraocular pressure. The question of whether these drugs also alter, either directly or indirectly, orbital hemodynamics is potentially of great importance for patients with normal-tension glaucoma who may have some degree of reversible vasospasm. METHODS We compared the effect of selective (betaxolol) and(More)
Glaucoma remains a major eye illness with unknown etiology. Although elevated intraocular pressure is clearly a major risk factor, vascular deficits may contribute to initiation and progression of glaucoma. When intraocular pressure is acutely elevated in healthy individuals, the resistance index (derived from the peak systolic and end-diastolic velocities(More)
PURPOSE The objective of this study was to establish the ability of laser Doppler flowmetry to detect relative changes in human optic nerve head hemodynamics caused by physiologic blood gas perturbations. METHODS Laser Doppler flowmetry permits the noninvasive assessment of relative blood velocity, volume, and flow (flux) in a sample volume of the nerve(More)
PURPOSE To understand those factors that determine the decrease in intraocular pressure (IOP) that occurs during acute dynamic exercise. METHODS Three aspects of the exercise-IOP relationship were studied. These included graded exercise, with and without CO2 addition for isocapnia; comparison of the IOP response of trained and sedentary subjects to a(More)