Flashes & Floaters
Anatomy of the Eye
The back compartment of the eye, between the back of the lens and the back wall of the eye, is filled with a clear gel called vitreous. Light passes through the window of the eye, the cornea, through the pupil and through the lens and then it travels through the vitreous onto the lining of the back of the eye called the retina. The vitreous gel starts off crystal clear and then gradually becomes less clear as we age.
Symptoms of Floaters
As the vitreous ages, parts of the gel condense. This will be signified as shadowy dots, lines or cobwebs that float by, especially when seen against a bright background such as the sky or a white wall. We call these “floaters.” They seem to float by because the gel is like a clear syrup inside the eye and if part of the gel is not clear and you move your head or turn your eye the gel moves and so does the part that isn’t transparent; it appears to dart by or float across your field of view. It is very common for people to experience floaters by the time they reach their 30’s.
Changes in Floaters
When someone reaches their 60’s or 70’s (or earlier if they are very nearsighted) they commonly experience a sudden change in their floaters because the vitreous begins to liquefy and shrink. The back part of the gel will suddenly begin to separate from the back wall of the eye and move forward. The condensed areas become visible since they have moved into the middle of the eye. The entire back face of the gel is somewhat less transparent than the body of the gel and if light enters the eye from a certain direction it may reflect off this back surface of the gel and appear shadowy or similar to a hazy or wavy curtain, temporarily in the line of sight.
Causes of Flashes
In some people as part of the gel moves forward, some of it remains stubbornly adhered to the back wall of the eye. In these instances it is usually stuck to the peripheral portion of the retina. As the eye or head is turned and the gel moves the part that is stuck will tug on the retina and a flash of light will be seen for a second (usually off to the side). This is because the retina is made up of visual nerves, so tugging on them stimulates them and a flash of light is seen.
The flashes are seen right in the beginning when the gel first begins to move forward and the new floaters are seen. At first these flashes may be seen numerous times a day and usually they gradually decrease in frequency over the first several weeks and months and then eventually stop. Even though the new and prominent floaters may be annoying, typically if you ask a patient six months to a year later they will say that the floaters don’t seem to bother them anymore.
Retinal Tears / Retinal Detachment
In some patients the retinal tugging that is causing the flashes of light could lead to a tear in the retina (this is rare). The retina is like a sheet of cellophane attached to the entire back wall of the eye. The tears usually occur in the periphery where the gel may be tugging on it. If a tear occurs, then fluid inside the eye can travel through the tear and track between the retina and the back wall of the eye thereby separating the retina off the back wall of the eye. This is called a retinal detachment. Wherever the retina is detached there is no vision. Since this usually occurs first in the periphery, it may be experienced as a total loss of vision in the peripheral field of view as if a curtain is being pulled across the vision from the side, and it may advance across the center of vision.
Diagnosis of Flashes and Floaters
If you have new floaters or are experiencing flashes of light in Richmond, you should be examined by an ophthalmologist. The ophthalmologist will dilate your pupil to get a good look at the periphery of the retina to check for any tears. If there is no tear, you will be asked to return again in several weeks for a reexamination. As long as the flash of light continues, the gel is still tugging on the retina raising the odds that a tear could occur.
Treatment for Retinal Tears
If a tear is noted, then a simple in-office laser procedure can be performed. This painless procedure is similar to welding the tear so that fluid cannot track through it, leading to a detachment. If any black curtain-like vision loss is noted or if new and more prominent floaters are noted, then you should call your ophthalmologist right away.
Treatment for Retinal Detachment
If a retinal detachment is noticed, then surgery will be performed to reattach the retina. The sooner a retinal detachment is repaired the better the chances for excellent visual recovery. Please do not ignore changes in the vision, especially if you have any vision loss.
Vitreous shrinking and separating is a common problem and one that most people will experience as they age. Most only experience new floaters, and the symptoms gradually go away. Some will experience flashes, and these too usually decrease in frequency and eventually disappear. Understanding the symptoms and notifying your ophthalmologist within 24 hours is important so the proper steps can be taken to minimize the rare but potentially serious problems.