transient visual obscuration
Brief episodes of visual loss lasting seconds, typically associated with increased intracranial pressure and papilledema.
Full Definition
Transient visual obscurations (TVOs) are brief episodes of monocular or binocular vision loss lasting seconds to minutes, often triggered by postural changes such as standing or coughing. They represent a hallmark symptom of increased intracranial pressure and are frequently associated with papilledema. TVOs may be described as graying out, fogging, or complete blackout of vision and typically resolve spontaneously. The mechanism involves transient ischemia of the optic nerve head due to elevated intracranial pressure. Recognition of TVOs is crucial as they often precede permanent visual loss in patients with idiopathic intracranial hypertension or other causes of elevated intracranial pressure.
Usage
Usage note: May be abbreviated as TVO in clinical notes but spell out in formal reports.
In Context
- "The patient reported transient visual obscurations upon standing, suggesting elevated intracranial pressure." — Clinical history
- "Transient visual obscurations preceded the development of permanent visual field defects." — Disease progression