Vitreous floaters are specks, clouds, circles, cobwebs, dots, or lines in a person’s field of vision. These small, dark, shadowy shapes move as one moves their eyes. They look like they are running away when an individual tries looking directly at them.
Floaters affect many people. However, they are mostly ignored. Floaters are not easily noticeable until they increase in number. But they can become obvious when looking at something as brilliant as the blue sky.
As people age, the vitreous (a substance that looks like a gel and which fills about 80% of the eye) thickens or shrinks. The shrinking leads to posterior vitreous detachment (PVD). PVD occurs when the gel that fills the eye separates from the retina. This detachment happens at once instead of gradually, giving rise to floaters. PVD is not sight-threatening and does not need treatment.
However, a doctor should be consulted urgently when a retinal detachment occurs. A retinal detachment happens when an area of the retina is lifted from its normal back position. There will be a sudden increase in floaters together with flashes in the field of vision. Peripheral vision loss (darkness on the sides of a person’s vision) will also increase.
If left untreated, retinal detachment can result in visual impairment or blindness within two to three days.
Causes and Risk Factors
Floaters are caused by the shrinking of the vitreous. When the vitreous shrinks, strings that cast tiny shadows on the retina emerge.
Vitreous floaters are part of the aging process. Age causes the vitreous to become more liquid thus forming clumps. The clumps cast shadows on the retina, giving rise to floaters. They can be bothersome at first, but with time they come to rest below the line of sight. However, they never leave entirely.
When inflammation occurs in the uvea (located on the back of the eye), it causes posterior uveitis. Posterior uveitis then leads to the release of inflammatory debris (floaters).
Hemorrhaging and eye injuries may cause floaters. Blood cells are seen as floaters thus bleeding in the eye causes vitreous floaters. The bleeding may be caused by illnesses such as hypertension and diabetes. Injuries to the eye also cause bleeding.
Retinal tears can be responsible for vitreous floaters as well. The force of a sagging vitreous can tug on the retina causing it to tear. The tear may lead to retinal detachment.
People at risk include those with diabetes, hyperopia, and those who have had a cataract operation. Individuals with eye trauma are at risk. Aging can also be a risk factor.
Signs & Symptoms
The symptoms of floaters include:
- Floaters that appear as cobwebs or specks floating in a person’s field of vision
- Spots that move when a person tries to look at them
- Noticeable spots when a person looks at a plain or white background
- Peripheral vision loss
The eye care professional conducts a comprehensive eye examination. The examination is done especially on the back of the eye to establish the cause of the floaters.
Treatment is directed towards removing the floaters from the vitreous even though most floaters do not require treatment.
Surgery is required if the floaters suddenly increase such that they significantly affect vision. Vitrectomy will be conducted to remove floaters from the vitreous. In vitrectomy, vitreous gel and floaters are removed from the eye and replaced with a salt solution.
However, most eye doctors are hesitant to recommend vitrectomy due to the risk of complications. These include bleeding, retinal detachment, retinal tears, and cataracts. Unless the floaters seriously interfere with vision, they do not recommend surgery.
They are largely ignored as they do not cause any significant threat to vision.