Autonomic Nervous System Activity, Peripheral Microcirculation and Retrobulbar Hemodynamics in Normal Tension Glaucoma Patients.
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 97
- 试验地点
- 1
- 主要终点
- Time and spectral-domain measures of heart rate variability
研究概览
简要总结
Evidence has accumulated that systemic and ocular mechanisms, responsible for regulating blood flow in the area of the optic disc, such as reduced ocular perfusion pressure, abnormal autoregulation and vascular dysregulation may be involved in the pathogenesis of normal tension glaucoma (NTG). Defective cardiovascular neuroregulation has been advocated as a possible one of the main systemic contributing factors in the etiology of NTG. Based on the results of previous studies, the hypothesis has been posed that patients with NTG have an impaired diurnal heart rate variability (HRV) or high activity of the sympathetic component of autonomic nervous system (ANS) and endothelial dysfunction. Impaired balance of ANS, resulting in increased demand for oxygen in the tissues and subsequent low threshold of hypoxia in all organs (including the eye) can be an important link in the pathogenetic pathway of NTG, making the optic nerve more sensitive to small and short-term changes in perfusion pressure and prone to damage even under a statistically "normal" intraocular pressure (IOP).
The aim of this study is to evaluate the activity and characteristics of the following systems: the central ANS (through a 24-hour analysis of heart rate variability and blood pressure), peripheral vascular system (through the analysis of the post-occlusive hyperemia reaction within the distal part of left upper limb) and the local retrobulbar circulation as measured by color Doppler imaging (CDI) in patients with NTG and healthy volunteers. The correlations between all above systems, as well as between them and the structural and functional parameters of the optic nerve, and the retina in both groups will be also analyzed.
详细描述
Fifty patients with NTG and 50 age and gender-matched control subjects will be recruited. All patients will be underwent eye examination (medical history, best corrected visual acuity, slit-lamp and stereo optic disc evaluation, Goldmann applanation tonometry, central corneal thickness measurement , Humphrey central 24-2 threshold perimetry test and optical coherence tomography of the optic nerve head, retinal nerve fibre layer and macula. CDI examination of the retrobulbar vessels will be performed. 24-hour ambulatory electrocardiogram and blood pressure monitoring will be performed simultaneously. Time- and frequency-domain measures of HRV will be calculated. BP will be measured in 20 minutes intervals during the day and 30 minutes intervals at night. The occlusive provocative test and finger hyperemia will be assessed by two-channels laser-Doppler flowmeter.
研究设计
- 研究类型
- Observational
- 观察模型
- Case Control
- 时间视角
- Prospective
入排标准
- 年龄范围
- 30 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •both gender
- •early to moderate NTG
- •without significant cardiac or pulmonary conditions. Glaucoma is diagnosed on the basis of a glaucomatous appearance of the optic disc (cup-to-disc ratio greater than 0.6 or an interocular cup-to-disc ratio asymmetry greater than or equal to 0.2, and at least one of the following abnormalities: thinning of the rim, notching, nerve fiber layer defects, or peripapillary atrophy), correlating with visual field defects in two consecutive central 24-2 program of Humphrey threshold perimetry, according to the European Glaucoma Society (EGS) diagnostic criteria (abnormal glaucoma hemifield test or cluster of three non-edge contiguous points at the <5% level on the pattern deviation plot with at least one point at the <1% level, with < 25% fixation losses and false positives and false negatives responses). Early and moderately glaucomatous loss is defined according to the Hodapp et al. classification, based on the Mean Defect (MD) index of visual fields less than - 6 dB (decibels) and - 12 dB but more than -6 dB, respectively, and on the basis of a vertical cup/disc ratio less than 0.
- •Control group
- •both gender
- •age and gender-matched
- •without glaucoma
- •without significant cardiac or pulmonary conditions.
排除标准
- •ocular hypertension
- •primary open angle glaucoma (high pressure glaucoma, IOP>21mmHg)
- •secondary open angle glaucoma
- •angle closure glaucoma
- •history of eye surgery
- •history of eye trauma
- •myopia above -6.0 diopters (D)
- •corneal dystrophies
- •uncontrolled arterial hypertension
- •atrial fibrillation
- •atrial flutter
- •pacemaker
- •history of cardiac arrest
- •vasovagal syndrome
- •diabetes mellitus
- •primary damage to the autonomic nervous system
- •Shy-Drager syndrome
- •encephalomyelitis, multiple sclerosis
- •brain and spinal cord tumors
- •renal failure
- •carotid sinus hypersensitivity syndrome carotid sinus
- •carotid artery stenosis
- •pregnancy
- •breast-feeding
结局指标
主要结局
Time and spectral-domain measures of heart rate variability
时间窗: baseline
standard deviation of normal to normal RR intervals (SDNN), standard deviation of normal to normal RR intervals index (SD SD), root mean square of succesive differences (RMS-SD), percentage of normal to normal RR interval, greater than 50 ms (pNN50), low-frequency component (LF), high frequency component (HF), LF/HF) ratio
次要结局
- retrobulbar hemodynamic parameters of ophthalmic (OA), central retinal (CRA) and short ciliary posterior arteries (SCPA)(baseline)
- measures of blood pressure (BP) diurnal variability(baseline)
- parameters of postocclusive hyperemia response(baseline)
- optical coherence tomography parameters of optic nerve head(baseline)
- optical coherence tomography parameters of the retinal nerve fibre layer (RNFL)(baseline)
- optical coherence tomography parameters of macula(baseline)
- Parameters of visual field examination(baseline)