Have you ever noticed tiny black specks or strings that seem to “float” through your field of vision? How about flashes of white light on one side or the other? The former are called “floaters” and, while annoying, are rarely cause for concern. Flashes, though, may signal an eye emergency, and warrant an immediate trip to the eye doctor.
Here’s what you need to know.
Floaters are in the Vitreous
The large chamber at the back of the eye is filled with a jelly-like substance called the vitreous. The vitreous rests against the light-sensitive membrane at the back of the eye called the retina. When we’re younger, the vitreous is clear, allowing light to pass through to the retina, which then transmits that light into nerve signals that the brain processes as images.
As we get older, the vitreous gel liquifies, and begins to accumulate debris. Floaters are the shadows that this debris casts on the retina. If you think you might have floaters, look up at the sky on a clear day; they are much more noticeable then.
Fortunately, most floaters are harmless and do not require medical attention. They may even fade with time.
On the other hand, a significant increase in floaters, especially when accompanied by flashes of white light, may signal something more serious.
Flashes May be Dangerous
Shortly after my 52nd birthday, I was cutting up a tree that had fallen in our backyard during a winter storm. While I was swinging the ax, I saw what appeared to be a large cobweb in my right eye. That evening, I began to see arc-shaped flashes of white light on the right side of my peripheral vision. The large floater and the flashes were classic symptoms of an eye condition called posterior vitreous detachment.
Posterior vitreous detachment occurs when the vitreous gel begins to pull away from the retina. As the gel pulls away, the retina responds by causing us to see flashes of light, usually on the sides of our vision. These light flashes are called “photopsia” and are easiest to see during the dark, particularly while driving at night.
Sometimes, a large round floater that looks like a smoke ring will suddenly appear. This “smoke ring” represents the circular area where the vitreous gel was once attached to the optic nerve in the back of the eye.
It’s important to note that while I experienced my symptoms while performing vigorous activity, this condition can happen at any time. Two years later, the same thing happened to my left eye—while I was sitting and reading the newspaper!
Posterior Vitreous Detachment
Indeed, most of us will experience posterior vitreous detachment at some time. This is because as we age, the vitreous gel naturally liquefies and begins to pull away from the retina. Studies suggest that up to 65 percent of adults age 65 and older have posterior vitreous detachment. It may occur even earlier in those who are nearsighted, or who have had eye trauma, inflammation or surgery.
At this time, there is no specific treatment for posterior vitreous detachment. However, your eye doctor will want to examine your eyes regularly, to ensure that the detachment is not causing serious damage.
Complications of PVD
One such complication is vitreous hemorrhage, which occurs when the vitreous fills with blood. Typical symptoms of a vitreous hemorrhage are new floaters that look like black dots, threads or smoke. A posterior vitreous detachment accompanied by vitreous hemorrhage increases the likelihood of a retinal tear to 70 percent.
When the retina tears, the liquefied vitreous is able to pass through the opening caused by the tear. This, in turn, can cause the retina to begin to pull away from the back of the eye. When the retina pulls away from the eye completely, this is called a retinal detachment. Forty percent of all retina tears lead to retinal detachments. While retinal detachment is painless, it is a medical emergency and requires immediate surgery to reattach the retina. Otherwise, you may face a permanent loss of vision.
Fortunately, retinal tears are treatable with laser therapy or cryotherapy. These treatments help create a watertight seal around the tear to prevent leakage, and ultimately will protect your vision.
If you are experiencing new floaters or flashes, it’s important to have your eyes checked immediately. If the doctor does not find a retinal tear but you’re still experiencing symptoms, he may ask you to return every few weeks to ensure that a retinal tear has not occurred.
To make an appointment, please call the office of Joseph “Jack” Timmes, M.D., at 703-560-7797.