What are floaters?

What is the vitreous?

The vitreous lies behind the lens in the eye. It is a transparent gel, being mostly water (99%); there are also strands of collagen, which hold the vitreous body. Other molecules such as Hyaluronin are Fibrillin form a matrix that holds the vitreous together.

What is it used for?

The vitreous was used to support the blood supply for the infantile lens. During adult life the vitreous has little or no use, however it can cause significant disease within the eye, such as scars on, or holes in the macula.

How do floaters form?

As light interacts with the vitreous the proteins break down and pools of fluid (lacuna) form in the vitreous cavity. These then destabilize the whole of the vitreous gel causing this to fall forward and induce a posterior vitreous detachment.

What is a posterior vitreous detachment?

Vitreous detachment is a separation of the vitreous from the retina and optic disc, this occurs in about 10% of 50 year olds, and 60% of 70 year olds. Some patients see flashes as the gel separates from the retina. Others see showers of floaters. About 15% of patients with new floaters develop a retinal tear. So all patients with new floaters need retinal examinations.

How are floaters formed?

Floaters are the shadows formed by vitreous / posterior hyloid debris. They can also be caused by drops of blood, inflammation cells and occasional vitreous degeneration – asteroid hylosis.

As light shines through the vitreous shadows formed by the gel fall on the retina as floaters. Some patients see moving floaters and also larger areas of foggy vision.

What are the symptoms of floaters?

For some patients floaters do affect their everyday lives causing destruction when driving and reading. Some note floaters when using the computer causing problems when they typing or using spread sheets.

What treatments are there?

The main treatment for floaters is a vitrectomy operation. This is increasingly safe and comfortable surgery. New instruments create tiny (0.9mm) openings in the white (sclera). A light source is introduced and the gel is removed with a small cutting instrument. At the end of the surgery a small bubble of air is inserted into the eye. This keeps the eye stable after the operation. For many patients they can tolerate the floaters and no treatment is necessary. Some surgeons have used lasers to move the floaters, others think that this is dangerous and potentially can damage the retina.

What will replace the gel when it is removed?

The eye produces its own fluid at a constant rate; this fills the vitreous cavity with clear fluid allowing the passage of light without shadows. The eye uses this fluid to generate pressurize the eye. Some pressure is important to maintain focused vision.

What about the after care?

Following the vitrectomy anti-biotic and anti-inflammatory drops are used regularly for about one month.

Are there any risks with surgery?

Any surgery carries risk, for Vitreoretinal surgery there is around a 1% risk of retinal detachment, and a 1:1000 for infection and serious haemorrhage. Some patients can have problems with pressure requiring drops. If complications occur they can be rectified with a further operation. The main risk however is the formation of cataract – this occurs in about 70% of patients within the first year. If an early cataract is present therefore, it can be removed during the vitrectomy operation itself.