Common Causes of Whiteout
If you have recurring whiteouts, counting their duration in real time can help you get the correct diagnosis. Note any specific details that whiteouts seem to have in common. Do they happen right after you get up from a chair, for example? Most often, whiteouts occur when a person is on the verge of fainting from a sudden drop in blood pressure. About 1 in 3 people will faint at some point in their life.
“Fainting can be mild when related to sudden stress,” says Sarah Thornton, a neuro-ophthalmologist at Wills Eye Hospital in Philadelphia. “Getting up too quickly, straining too hard, becoming dehydrated, or taking certain medications can also lead to hypotension — low blood pressure — and potentially whiteout.”
A less common risk: “Whiteouts can occur with changes in G-force,” says Geist, for example, in a car accident or on a roller coaster. A white veil caused by stress or physical exertion will disappear in just a few minutes.
A link to more serious conditions?
Although fainting is usually mild, always tell your doctor if you have fainted – sometimes whiteouts and fainting spells are linked to something serious.
“Underlying heart disease, such as aortic stenosis, could cause symptoms of fainting, including whiteout,” says Dean M. Cestari, neuro-ophthalmologist at Mass General Brigham Mass Eye and Ear in Boston and associate professor of ophthalmology at Harvard Medical School. Other such conditions can include arrhythmias, heart failure, and atrial fibrillation.
Whiteouts can also have neurological implications. “Transient visual obscurations, also known as TVOs, last for a few seconds,” Cestari explains. “They can appear as flashes of white light and lead to loss of vision. OVTs are caused by swelling of the optic nerve and can occur when you change positions, such as standing up quickly.
OVTs are a symptom of papilledema, a rare swelling of the swollen optic disc caused by increased intracranial pressure (ICP). ICP can be caused by brain tumors or hemorrhages.
Retinal detachment is another possibility. “If you have recent-onset vision loss in which you see flashes of light, which you might think are whiteout, plus floaters, see an eye doctor to rule out this condition,” says Cestari. “Or if they come on suddenly, go to the emergency room.”
But whiteouts aren’t usually associated with strokes or transient ischemic attacks (TIAs), says Eric R. Eggenberger, an ophthalmologist and neurologist at the Mayo Clinic in Jacksonville, Florida.
“Typically, stroke-like events cause a sudden, painless onset and complete loss of vision or vision loss, often involving the upper or lower half of the visual field in one eye only,” says Eggenberger. “In contrast, whiteouts typically involve both eyes and begin in a 360-degree peripheral pattern with a slower progressive constriction toward the center of your vision.”
Take notes on timing and duration of whiteouts
To help your doctor determine the exact cause of a whiteout, try to determine if only one eye is affected. It may not be immediately apparent.
“Closing one eye is actually what you should do if you have sudden vision loss – close the eye that you think is affected. You can cover your eye, but it’s best to close it, so you don’t push your fingers and obscure anything,” Cestari explains. “So see what you see with the other eye. If everything looks normal, you have lost sight in the eye you closed and you can tell your doctor that you have lost sight in that single eye. If everything looks weird, you’ve also lost vision in your right eye. Knowing this information can help your doctor determine a cause.
Again, note how long the whiteout lasted as accurately as possible.
It is always worth seeing an optometrist or ophthalmologist or your GP after experiencing whiteout. “Discuss the episode, as well as any other symptoms you may have been experiencing, to help determine the underlying cause and identify appropriate treatment, if needed,” Geist adds.
