Have you observed floating squiggly lines, thread-like strands, or spots in your field of vision? What are they? Where do they come from? Are they serious?
Eye floaters are distracting, and at best are annoying. Most of us learn to ignore them. Let’s start with a little physiology: At the front of our eye, the cornea and lens focus rays of light onto the retina, in the back. As the light makes its way to the retina, it passes through the vitreous humor, a jellylike material that fills the back two-thirds of the eye. At birth and during childhood, the vitreous gel is clear and transparent.
As we age, this gel undergoes some liquefaction, resulting in small pockets of liquid lying within the firmer gel. In addition, collagen fibers in the gel become thickened and denser. Each of these strands casts a small shadow onto the surface of the retina, and these shadows look like floaters in the eye. As we look from side to side or up and down, these fibers, deposits, or boundaries between liquid pockets also shift in position, making the shadows move and appear to float or undulate.
Those at increased risk for floaters are older, nearsighted, diabetic, and/or have had cataract surgery. Serious causes of floaters include infections, inflammation, hemorrhage, retinal tears, and eye injury.
Occasionally, a section of the vitreous pulls fine fibers away from the retina all at once, rather than gradually, causing many new floaters to appear suddenly. This is called a vitreous detachment, which in most cases is not sight threatening, and requires no treatment.
Occasionally, eye floaters are due to white blood cells in the vitreous, a result of inflammation or infection. Anti-inflammatory drugs or antibiotics will reduce the number of white blood cells, and as a result, the number of floaters will decrease.
A detached retina is a serious emergency that causes a sudden increase in floaters. It occurs if part of the retina is lifted or pulled from its normal position at the back wall of the eye. A retinal detachment may also be accompanied by light flashes or peripheral vision loss. If left untreated, it can lead to permanent damage and even blindness, within just two or three days.
Generally, the treatment for floaters is watchful waiting. On rare occasion, floaters can be so dense and numerous that they significantly affect vision. A surgical procedure (vitrectomy) can remove floaters from the vitreous. The vitreous gel, which is mostly water, is removed along with floating debris. The vitreous is replaced with a salt solution. This operation carries significant risks, due to the possibility of retinal detachment, retinal tears, and cataract. Most eye surgeons will not perform this surgery.
Although certain herbs, vitamins, and iodine-containing products claim to decrease eye floaters, no oral or eye drop medications have been proven effective in clinical trials. Preventing trauma to the eyes and controlling diabetes are the best ways to help prevent floaters.
When should you see a doctor? A few floaters are not likely a serious problem. See an ophthalmologist if the number of floaters increases dramatically, is sudden in onset, if you experience flashes of light or any visual loss, develop floaters after eye surgery or trauma, or have pain.
The prognosis is good - well over 90% of people with floaters are not bothered by their presence, and no action is needed.
Dr. Alan Frischer is former chief of staff and former chief of medicine at Downey Regional Medical Center. Write to him in care of this newspaper at 8301 E. Florence Ave., Suite 100, Downey, CA 90240.