Understanding Flashes and Floaters
Floaters are a very common complaint among several of our patients. They are secondary to a condition known as a posterior vitreal detachment (PVD). As we age, the vitreous humor of the eye tends to contract or shrink, and eventually separates from the retina. A PVD is extremely common by the fourth and fifth decade of life, and is known to occur at an earlier age in highly myopic (nearsighted) individuals. In general, posterior vitreous separation is innocuous, though floaters, which are harmless, are nevertheless annoying.
What is the Vitreous?
The vitreous is a clear jelly-like substance within the eye, which takes up the space behind the lens and in front of the retina, the light sensitive layer at the back of the eye. It is 99% water. The other 1% consist of substances which are important in maintaining the shape of the vitreous. The vitreous is attached to the retina, more strongly in some places than others.
Why do we get Floaters?
When the vitreous detaches from the retina, one of the three things occur.
* The vitreous may pull away from the retina, leaving both the reina and vitreous intact.
* Small pieces of the vitreous may partially pull away, break off, and float into the newly created space.
* The vitreous, which has a loose attachment to the retina and ONH, pulls away, taking part of the whole retina with it. This often results in a partial or full retinal detachment.
Due to the serious consequences and potential permanent visual loss, ALL patient complaints of flashes, floaters or veils, often called a curtain in their vision, need to be evaluated on an emergency basis. We typically recommend a dilated eye examination to rule out a retinal hole, tear, or detachment.
What do we notice?
Many people are not aware that they have developed PVD, but some notice symptoms such as floaters, flashing lights or a veil. Floaters can take many forms from little dots, circles, lines, to clouds or cobwebs. The floaters are created by a shadow of the floating vitreal debris that is projected onto the retina. Sometimes, people experience a large floater, which can be distracting and make things difficult to read. The flashing lights that often occur are also caused by the PFV. As the outer part of the vitreous detaches from the retina, it can pull on this light sensitive membrane, especially where the vitreous is attached quite strongly to the retina. The pull of the vitreous in these areas stimulates the retina. This stimulation causes the sensation of flashing lights since the brain interprets all stimulation signals from the retina as light. The veil may be caused from either a very large floater or a retinal detachment.
If no other abnormalities are present, the risk of visual loss is extremely low. Patients are usually cautioned, however, that they should return if they experience flashes of light, many new floaters, or a curtain-like loss of vision. These latter symptoms may be present with a retinal hole, tear, or detachment. Otherwise, the patient may be routinely evaluated at a later date, or not at all, depending on the circumstances.
How do we treat This?
Unfortunately, at the moment nothing can be done medically for this condition. The floaters, which are often large and distracting at first, tend to "settle" to the bottom of the eye, thus relieving the annoyance. However, this often takes weeks or months. The brain tends to adapt to the floaters and eventually is able to ignore them, so they only become a problem in very bright light. In the interim, you can try a few of the following options to "work around" the floater.
* Enlarging things can help with floaters, so you are able to see things around the blank spots caused by them.
* You can often move your eye in the direction of the floaters to cause the jelly-like vitreous to move to out of the central vision.
Contact us today to schedule an appointment at the Gaddie Eye Centers.