Floaters: diagnosis and management

What are floaters?

Floaters are small, dark shapes that pass through your vision. You may see spots, squiggles, cobwebs, or cloudy veils that intermittently blur your vision. While floaters may appear to be in front of you, they are actually floating inside your eye. The gel that fills the eye is called vitreous, and floaters are components of the vitreous that swirl around when the eye moves, casting shadows that some people can see. This effect is most visible when looking at a bright, uniform background, such as a computer screen, white wall, or blue sky.

What causes floaters?

As we age, our vitreous starts to shrink and liquify, a process called vitreous syneresis. The aging changes in the vitreous can cause clumps or strands to form in the vitreous, which leads to symptoms of floaters. Eventually, age-related changes in the vitreous cause it to shrink enough that it separates from the back of the eye, a process called posterior vitreous detachment. New or more prominent floaters can appear at the time of posterior vitreous detachment.

When is it serious?

If you experience a sudden onset of new floaters, floaters accompanied by flashes of light, or a shadow blocking part of your vision, you should be assessed urgently by an eye specialist. These symptoms could suggest a tear in the retina or a detached retina, which are vision-threatening complications of the vitreous separation described above.

Treatment for floaters

Most floaters do not require treatment, and they often become less noticeable with time. If they are severe enough to affect your vision or impair your quality of life, treatment can be considered. Treatment may include vitrectomy surgery to remove the floaters, or laser to break them into smaller pieces. If you have a medical condition that causes floaters (diabetes, autoimmune disease), then further treatment may be necessary to address the underlying cause.

Vitrectomy surgery for floaters

Vitrectomy surgery removes the vitreous through needle-sized incisions. A fine instrument called a vitrector is inserted to gradually remove the vitreous from the eye. The vitreous is replaced with a clear saline solution, to help your eye maintain its shape. After surgery, the vitreous cavity remains optically clear, without floaters, as the eye gradually replaces the saline with a solution called aqueous humour from the front of the eye. Determining if you are a candidate for this type of surgery requires consultation with a retina specialist.

Laser vitreolysis

Vitreolysis uses a small shock wave of energy from a laser to break up the floaters, which may make them less noticeable. Unlike vitrectomy, the laser does not actually remove the floaters, so the relief it provides is more variable. Not all floaters are suitable for laser treatment, as the laser can’t be used in close proximity to vital structures in your eye.