Autonomic Nervous System Activity and Normal Tension Glaucoma (ANS)
|ClinicalTrials.gov Identifier: NCT01192061|
Recruitment Status : Completed
First Posted : August 31, 2010
Last Update Posted : January 25, 2011
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.
|Condition or disease|
|Normal Tension Glaucoma|
|Study Type :||Observational|
|Actual Enrollment :||97 participants|
|Observational Model:||Case Control|
|Official Title:||Autonomic Nervous System Activity, Peripheral Microcirculation and Retrobulbar Hemodynamics in Normal Tension Glaucoma Patients.|
|Study Start Date :||February 2010|
|Primary Completion Date :||January 2011|
|Study Completion Date :||January 2011|
|Normal tension glaucoma group|
- Time and spectral-domain measures of heart rate variability [ Time Frame: 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
- retrobulbar hemodynamic parameters of ophthalmic (OA), central retinal (CRA) and short ciliary posterior arteries (SCPA) [ Time Frame: baseline ]peak systolic velocity (PSV) of OA, CRA and SPCA, end diastolic velocity (EDV) of OA, CRA and SPCA, resistance index (RI) of OA, CRA and SPCA
- measures of blood pressure (BP) diurnal variability [ Time Frame: baseline ]standard devation of of the average systolic BP (SD SBP24), diastolic BP (SD DBP24) and mean BP (SD MBP24) during the whole day, standard devation of of the average systolic BP (SD SBPd), diastolic BP (SD DBPd) and mean BP (SD MBPd) during the day and standard devation of of the average systolic BP (SD SBPn), diastolic BP (SD DBPn) and mean BP (SD MBPn) at night.
- parameters of postocclusive hyperemia response [ Time Frame: baseline ]biological zero (BZ) (mean flow signal during occlusion), maximum hyperemia response (MAX) (maximum flow signal of post-occlusive hyperemia response), time of recovery (TR) (time from the end of occlusion until the moment when flow signal returns to the rest values), time to peak-flow (TM) (time from the moment of the end of occlusion until the moment of maximum hyperemic response), and half time of hyperemia (TH) (time from the moment of the end of occlusion until the moment when flow signal reaching the maximum value will fall by half)
- optical coherence tomography parameters of optic nerve head [ Time Frame: baseline ]disc area (DA), cup area (CA), rim area (RA), cup/disc area ratio (CDR), cup/disc horizontal ratio (CDHR), cup/disc vertical ratio (CDVR)
- optical coherence tomography parameters of the retinal nerve fibre layer (RNFL) [ Time Frame: baseline ]mean RNFL thickness (RNFL M), mean inferior RNFL thickness (RNFL I), mean superior RNFL thickness (RNFL S), mean temporal RNFL thickness (RNFL T), mean nasal RNFL thickness (RNFL N).
- optical coherence tomography parameters of macula [ Time Frame: baseline ]minimum macula thickness (TF MIN), mean macula thickness (TF M), mean inferior interior macula thickness (IIM), mean superior interior macula thickness (SIM), mean nasal interior macula thickness (NIM), mean temperal interior macula thickness (TIM), mean inferior outer macula thickness (IOM), mean superior outer macula thickness (SOM), mean nasal outer macula thickness (NOM), mean temporal outer macula thickness (TOM), volume foveola (VF) and volume macula (VM).
- Parameters of visual field examination [ Time Frame: baseline ]mean defect (MD), pattern standard deviation (PSD)
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01192061
|Military Medical Institute|
|Warsaw, Poland, 04-141|
|Principal Investigator:||Joanna Wierzbowska, MD, PhD||Military Medical Institute, Department of Ophthalmology, 128 Szaserow Str. 04-141 Warsaw, Poland|