By Anthony Ekong, MD, Retina & Uveitis Subspecialist at Illinois Retina & Eye Associates
Have you ever experienced a dark spot in front of your eye that seems to float or move around? If you have, you may be experiencing floaters in your eye.
Floaters may appear as small specks, cobwebs, or hair-like structures that move in your field of vision. They are caused by tiny clumps of cells or opacities floating inside the vitreous, a gel-like substance that fills the inside of the eye. What you are seeing are the shadows they cast on the retina as light passes through the eye. Floaters are usually more pronounced when looking at a light colored background such as a blank wall or sky.
Light flashes usually indicate that the retina is mechanically stimulated or the vitreous is pulling on it. Flashes also may occur after being hit in the eye or after a strong blow to the head.
Oftentimes, people with migraine may also experience flashes of light caused by inappropriate stimulation of the vision-related part of the brain. These types of flashes usually appear as jagged lines in both eyes, sometimes lasting 10-20 minutes. If a headache follows the flashes, it is called a migraine headache. When the jagged lines occur without a headache, the light flashes are called an ophthalmic migraine.
Causes of Floaters:
The vitreous is held together by structural proteins called collagen and hyaluronic acid. These help maintain its gel-like consistency and firm attachment to the retina throughout our youth.
With age, the vitreous loses its collagen and the stabilizing influence of the collagen fibers. Usually the fibers break, forming clumps or strands inside the eye. These strands can cast tiny shadows on the retina and present as floaters. Subsequently, the vitreous shrinks and separates from the optic disc margin. This separation is called posterior vitreous detachment or PVD and is part of the normal aging process. It usually affects people over age 50, but may occur earlier in people who are nearsighted. PVD usually develops in the fellow eye from 6 months to 2 years after developing in the first. The prevalence of PVD is about 70 percent in people over 70 years old.
The main symptoms of PVD are new floaters often accompanied by flashing light (lightning streaks) in the peripheral, or side vision. Inflammation inside the eye and vitreous hemorrhage (bleeding inside the eye) can also cause floaters.
Complications of PVD include retinal tears or detachments, vitreous hemorrhage, macular holes, and epiretinal membrane.
Are floaters/flashes serious?
Many patients are alarmed when floaters first appear and for good reason. Most serious retinal conditions are painless. In some cases, when the vitreous detaches, it tears a hole in the retina. Rarely, fluid from the vitreous can enter the hole and detach the retina. More than 10 percent of patients with a sudden onset of floaters and flashes may have retinal tears or detachments.
The majority of floaters are harmless and merely annoying. However, the eyes should be examined promptly to determine its cause and to rule out retinal tears or detachments. With time, many floaters will move away from central vision and become less bothersome.
Floaters and flashes of light are common age-related eye changes. In rare cases, floaters can be surgically removed if vision and activities of daily living are significantly affected.
Dr. Ekong is a fellowship trained retina and uveitis specialist, one of the only dual trained subspecialists outside Chicago in Illinois. To schedule an appointment, please call the Illinois Retina & Eye Associates at 309-589-1880 in Peoria, 877-223-7403 in Galesburg and 815-223-7400 in Peru.
Photo credit: Oxford/iStock