Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT03170778 |
| Other study ID # |
36401 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
February 13, 2016 |
| Est. completion date |
May 1, 2022 |
Study information
| Verified date |
May 2022 |
| Source |
Stanford University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
The purposes of this study are to identify indicators of vision problems and ocular
abnormalities in patients with a Fontan circulation through a standardized questionnaire and
to correlate the intraocular pressure measured with the Icare tonometer with central venous
pressure measured with the VENUS 2000 CVP non-invasive system to determine whether
intraocular pressure can be used as a surrogate measure of increased central venous pressure
in patients with a Fontan circulation.
Description:
Numerous authors have described optic disc edema, globe flattening, choroidal folds which
were thought to be part of the well-defined but still idiopathic syndrome of idiopathic
intracranial hypertension.
The pathogenesis of idiopathic intracranial hypertension is not well understood. Recent
reports, however suggest that elevated cerebral venous pressure underlines the process. The
close relationship that exist between spinal fluid pressure and cerebral venous pressure has
been definitely established. It was found that patients with increased venous pressure due to
heart failure had an increase in spinal fluid pressure as well.
Furthermore, numerous authors have described venous stasis retinopathy, bilateral choroidal
detachments, intraretinal hemorrhages, vessel tortuosity, microaneurysms, capillary leakage,
central retinal vein occlusion, open angle glaucoma, choroidal effusion, etc. in patients
with pulmonary arterial hypertension. Elevated venous pressure found in pulmonary arterial
hypertension is responsible for the delayed choroidal perfusion and the reduced venous blood
outflow. This explains the clinical findings of venous stasis retinopathy, choroidal
detachments, etc. which are related to elevated episcleral, retinal and choroidal venous
pressure secondary to elevated systemic venous pressure (increased pulmonary vascular
resistance in patients with pulmonary arterial hypertension leads to right heart failure and
subsequent elevation in systemic venous pressure).
Systemic venous pressures in Fontan patients are comparable with those in patients with
significant right heart failure in a 2- ventricular circulation. With Fontan anatomy the
elevated central venous pressure is transmitted to the dural venous sinuses of the brain
through jugular veins and the paraspinal venous plexus and after the Fontan procedure brain
venous pressure are chronically elevated.
The investigators believe that the long-term effects of the Fontan operation can result in a
spectrum of ocular changes similar to those occurring in patients with idiopathic
intracranial and pulmonary arterial hypertensions due to chronically elevated cerebral venous
pressure.
It has been reported that intraocular pressure is directly related to the episcleral and
jugular venous pressure in patients without underlying ophthalmic diseases. Several previous
studies have shown a linear correlation between central venous pressure and intraocular
pressure. Therefore, the investigators believe that the monitoring of intraocular pressure
may be simple and effective method for estimating central venous pressure in patients with
Fontan circulation.
