We are delighted to have Dr. Leila Rafla-Demetrious, an ophthalmologist at New York Presbyterian Hospital and a new member of the WVFC Medical Advisory Board, explain the cause, evaluation, and treatment of flashes and floaters. These common eye symptoms sometimes mean that a serious problem must be treated quickly. This is another great article that I urge you to print, keep in the Medicine file, and also email to friends and family. —Dr. Patricia Yarberry Allen
When I hear that a patient is coming in with new-onset flashing lights and floaters, I take notice. While these symptoms often accompany a benign condition, they can sometimes herald a more serious one, and they call for a thorough and immediate evaluation.
Flashes and floaters are generally unilateral [confined to one eye], and can be a sign of a relatively benign vitreous detachment, a retinal tear or hole, or an impending or full-blown retinal detachment.
The retina is the tissue that lines the back of the eye; it functions like the film of a camera for the eye, feeding images back to the brain. In front of this tissue sits the vitreous, a clear jelly that fills the sphere of the eye. It is attached in areas to the back of the eye, and sometimes contains small clumps, which you may already see as floating specks or clouds. These types of “floaters” are common, and while sometimes distracting, are usually nothing to worry about.
However, flashing lights, which generally occur at the side of the vision, as well as the appearance of new floaters, may signify something more ominous, and can mean that the vitreous jelly is pulling on its retinal attachments. If the jelly tugs and pulls away cleanly, you are left with a vitreous detachment, in which one or more new, generally well-formed, specks or webs are created. If, however, the vitreous pulls too vigorously on a weak spot in the retina, a retinal tear or hole may also form. This can then lead to a retinal detachment, in which the retina pulls away from the wall of the eye, causing a curtain-like effect in the visual field. Untreated, a retinal detachment can lead to permanent visual loss.
What are the risk factors that contribute to a retinal tear or detachment? Significant nearsightedness; head or eye trauma; prior eye surgery; prior inflammatory disease of the eye; history of retinal detachment in the other eye; and history of previously diagnosed areas of peripheral retinal weakness. People with a family history of retinal detachment are also at risk, even if they are not very nearsighted or have no other personal risk factors.
If you see sudden new flashing lights, and/or new floaters, or a veil in your visual field, you should see an ophthalmologist as soon as possible. This specialist will take a history and then do a full examination, including a dilated retinal exam, to take a good look at the peripheral retina of both eyes, since the risk factors often hold true for both eyes. If no retinal hole or tear is found, the ophthalmologist will often advise that you return within a few weeks, especially if you are still experiencing flashing lights, to recheck the retina for the development of new breaks.
Vitreous floaters alone do not require treatment, and will generally break up on their own over time. If a tear or hole is found, however, various treatment options are available, depending on the size and location of the break(s) and the ophthalmic surgeon’s preference. The goal of all procedures at this point is to wall off the break to prevent a full detachment, and possibly the use of an in-office laser treatment to seal off a small tear or hole will be necessary. A larger tear that is associated with a detachment will likely need surgical intervention, the goal of which is to re-flatten the retina back to its original position, and to treat the area so that is doesn’t re-detach. This may include an intraocular injection of gas, a buckling procedure, or treatment with cryotherapy (treatment with freezing) or Endolaser.
People often confuse the phenomena of bilateral flashing lights and visual distortions with retinal detachment symptoms. I hear these complaints very often, and though they can be disconcerting to a patient, they are not related to the retina, nor do they signify impending detachments. Generally, these episodes are discrete and short-lived (15-30 minutes), tend to be more central in one’s vision, and can be seen from either eye at the same time. You may also experience wavy lines, visual field cuts, and even tunnel vision during this time, and may be left with a headache at the end of the episode. These episodes represent ocular migraines, which originate in the brain, and are common among, but not limited to, people with a personal or family history of migraine. These are generally not cause for an emergent doctor visit, though those with a new onset of frequent ocular migraines should discuss this with their medical doctor or neurologist.