Floaters

The small spots, flecks, specks and cobweb like images that drift through the field of vision are known as eye floaters. Even though they can be quite annoying, ordinarily they are not a cause for panic or alarm, and are actually quite common.

Spots and floaters usually appear when small particles dislodge from the back of the ciliary formation located on the front of the posterior chamber of the eye. These particles float into the vitreous which is the fluid that fills the posterior chamber of the eye.

From the time we are born, and for the entire time of our youth, there is a gel like uniformity in our vitreous. However, as we get older, the vitreous starts to liquefy and dissolve to make a watery middle. Some of the particles that have not fully dissolved will sometimes float about in the liquid centre of the vitreous. The particles can show themselves in several sizes and shapes to turn into what we call floaters.

You will notice that these kinds of floaters and spots are typically pronounced whenever you look at a clear, bright sky or a light computer screen. However, you cannot really see these small tads of debris as they float loose in the eye. Rather, the shadows from the floaters and spots are cast upon the retina as the light passes through your eye. These shadows are what you are really seeing. You will also notice that the specks never appear to stay in one spot as you try to put your focus on them. Spots and floaters move when you move your eyes. This creates an impression of drifting debris.

Is there a need for medical concern?

If you see a burst or shower of spots and floaters that are sometimes combined with flashes of lights, you should get medical help right away.

A sudden onset of these symptoms may mean that the vitreous is trying to pull away from the retina, or that the retina is being dislodged from the inner back area of the eye. This area contains nutrients, blood, and oxygen which are vital to healthy functioning. When the retina tears, the vitreous can attack its opening and actually shove the retina out. This leads to full detachment.

In the case of a retinal detachment or tear, action has to be taken quickly. A skilled eye surgeon can reattach it and may be able to restore its function before there is any permanent vision loss. The sooner surgery is done, the less likely you are to have any permanent damage.

PVDs (Posterior Vitreous Detachments) are much more common than detached retinas. They are not often an emergency, even if the floaters suddenly appear. However, some vitreous detachments can actually damage the retina by tugging. This will lead to a detachment of tear.

Photopsia, also known as light flashes, can happen when the retina gets a mechanical stimulation. This can occur when it is being torn, tugged or detached.

Causes of Eye Spots and Floaters

As stated above, PVDs (Posterior Vitreous Detachments) are a common cause of floaters. It is much less common that the symptoms can be associated with retinal detachments or tears.

What causes these detachments in the first place? When the vitreous gel fills up the inner part of the back of the eye, it attaches to the retina by pressing against it. As time passes, the vitreous turns into a centre of liquidation. This can sometimes signal that the watery areas can't support all the new weight of the heavy gel. The gel will then collapse into the liquid vitreous. When this happens, the peripheral vitreous will detach from the back inner part of the eye. This is where the retina is found.

Eye floaters that result from vitreous detachment are usually concentrated in even more liquid vitreous which is found in the centre interior of the eye. By the time half of the people hit the age of 80, they will experience this eye problem. And, if you are one of those in the 40% who have PVD's and light flashes as well, you have approximately 15% chance of experiencing a retinal tear.

During this process, light flashes mean that some traction is being put on your retina while the PVD is taking place. When the vitreous actually detaches the retina feels a release from the pressure, the flashes of light should subside gradually.

Causes of Light Flashes

Usually, light that enters your eyes will stimulate the retina. This action produces an impulse of electricity. The optic nerve then transmits this to the brain. The brain will interpret the impulse as some kind of image, or light.

If mechanically stimulated, the retina will have similar impulses of electricity to the brain. The impulse gets interrupted though as just a flicker of light. When there is tugging on the retina, a flicker or flash of light is generally seen. Depending upon the extent of the detachment or tear, these flickers of light may be temporary or remain an indefinite problem that will continue until the retina is repaired. These flickers and flashes might also happen after one experiences a blow to the head. This is usually referred to as seeing stars.

Some people experience light flashes that show themselves as jagged lines in both eyes for up to 20 minutes at a time. These kinds of flashes are generally caused by blood vessel spasms in the brain which are known as migraines.

If you experience a headache that comes with flashes, this is a migraine headache. These jagged lines can happen without a headache though. In a case like this, the flashes of light are known as ophthalmic migraine which is a migraine less the actual headache.

Another symptom can be photopsia can be a sign of digitalis toxicity. This is something that can happen to those who take medication for heart problems, especially older people.

Other Conditions that can be linked to Flashes and Floaters

Research shows that vitreous haemorrhage (bleeding) that is accompanied by a PVD (Posterior Vitreous Detachment) means that an exceptional traction has happened. This makes the possibility of a retinal detachment or tear increase. Traction that is exerted upon the retina when a PVD is occurring can also lead to puckers or macular holes developing.

Viterous floaters accompanied by vitreous detachments can also happen in circumstances including:

• CMV retinitis
• Inflammation of the interior eye
• Cataract surgery
• Diabetes
• Nearsightnedness
• YAG laser eye surgery

Inflammation that is associated with other conditions like infections can also cause the vitreous to become liquid. This can lead to PVD.

When someone is nearsighted, their eyes shape is elongated which can also increase the risk of a PVD accompanied by retinal traction. In fact, those who are nearsighted are much more likely to experience PVDs at younger ages.

During cataract surgery, PVDs are very common. They are also common during the follow up procedure as they can increase the risk of more eye trauma which can lead to detachments.

Available Treatments

Most spots and floaters are not harmful; they are more annoying than anything. Many of them will fade in time and become less of a bother. Even so, some people wish to have surgery to remove floaters. However, most doctors are not willing to do this procedure unless the person's vision is severely hampered, and this is a rarity.

Currently, the only way to clear away the webs and specks is to totally take out the gel like substance from the eye. This requires what is known as a vitrectomy procedure. It is then replaced with a liquid saline.

Remember that if a significant amount of floaters that suddenly show up could mean a detached retina. This is especially true if it is accompanied by other visual disturbances. This is a definite eye emergency that should be looked at by an eye doctor right away.