Four out of five people know this: annoying little dots, streaks and “clouds” in their field of vision. If you notice them too – should you be worried? Should you take it to an ophthalmologist’s office? Or can they simply be overlooked?
Sitting in the sun, maybe reading a book, relaxing: That sounds wonderful if it weren’t for that little black spot that keeps flitting through your field of vision. Or the large streak that is visible with every eye movement and is simply annoying when reading.
More than 80 percent of all people are familiar with this phenomenon: vitreous opacities, which can be particularly noticeable against a light background such as white walls or paper. They are also called “Mouches volantes” (French for flying mosquitoes or flies). And they can definitely be annoying. But how do these annoying clouds actually arise? And are they dangerous?
Vitreous body changes over the course of life
To do this, you have to take a closer look at the vitreous humor of the eye, i.e. the mass that makes up the majority of the inside of our eyeball. “It is a gel-like substance that fills the space between the lens and the retina,” says Prof. Hans Hoerauf, director of the Göttingen University Eye Clinic. The vitreous body consists of around 98 percent water, the rest is collagen fibers and hyalocytes, a certain type of cell.
However, the composition of the vitreous body changes over the course of life. The collagen fibers can compact and clump together while the gel-like part becomes more fluid. “It can then happen that these tiny structures within the vitreous body cast shadows on the retina, which we perceive as opacities,” explains Hoerauf.
You can’t really do anything about it: “As you get older, usually from the age of 40 onwards, the vitreous body shrinks and changes its structure,” says ophthalmologist Hoerauf. And he has bad news for nearsighted people: they have a higher chance of developing vitreous opacities because their vitreous body tends to change earlier and more severely.
Not every cloudiness is a problem
These opacities do not necessarily have to be a problem: “If they are very close to the retina, i.e. attached to the inner wallpaper of the eye, then the shadows they cast are very intense. If they are further away, they become more blurry,” says Matthias Pollhammer. He is a specialist in ophthalmology and head of the ophthalmic surgery department of the professional association of ophthalmologists.
However, there is often a certain habituation effect, according to the ophthalmologist. Our brain learns to ignore these clouds. For some people, however, this effect does not occur.
“There is certainly a psychological component,” says Hans Hoerauf. “Some people get used to the vitreous opacity, others become almost depressed about it.” This can be a challenge for people in certain professions. “If you constantly have to look into the microscope or, as a technical draftsman, you always have white paper in front of you, then cloudiness can be very annoying.”
Prevention not possible
Anyone hoping to be able to prevent vitreous opacity with home remedies or a good lifestyle will unfortunately have to be disappointed: “There are no connections with any dietary habits, UV radiation or other changeable factors,” says Matthias Pollhammer.
The hope that the cloudiness could simply disappear again as if by magic is also in vain. “Mouches volantes” can change, but they cannot dissolve.
When to go to the doctor’s office with it
After all: As a rule, one can assume that the vitreous opacities are harmless and do not require any action. However, if they occur particularly suddenly or frequently or are accompanied by flashes of light, we recommend going to an ophthalmologist. “Then you should definitely clarify or rule out other causes,” says Pollhammer. “Inflammatory processes, for example, can release cells and other particles into the vitreous body, causing clouding.”
Other serious illnesses must also be ruled out, such as retinal detachments or diabetic retinopathy, an eye disease caused by diabetes. Last but not least, regular eye examinations are recommended from the age of 40 onwards in order to detect the classic diseases of aging early.
Treatment options for severe cloudiness
For most people, vitreous opacities are a tolerable problem. “However, if the opacities are severe or significantly impair the quality of life, then surgical intervention may be indicated,” says Hoerauf.
In a so-called vitrectomy, the vitreous body is surgically removed and replaced with fluid. This reliably eliminates vitreous opacities, but does involve risks. Infections can occur or “a rare but very serious complication, namely a retinal detachment,” says Hoerauf. Then you have to have another operation very quickly. Depending on the extent of the detachment, reading ability may be lost.
Another problem with vitrectomy: “A cataract, i.e. a clouding of the lens, always occurs, although at a longer interval, but certainly after a vitreous body operation,” says Hoerauf. From a certain age, retinal surgeons would therefore combine vitrectomy with cataract surgery. The lens is replaced by an artificial lens.
Another, newer option is vitreolysis using laser: This involves shredding the collagen fibers in the vitreous body. “However, it is only suitable for certain forms of clouding if they are not too close to the retina,” says ophthalmologist Hoerauf. Although you can’t achieve complete freedom from symptoms, it can significantly reduce the annoying streaks and spots.
The conclusion is basically simple: If other causes have been clarified, you can take the “mouches volantes” in stride. In the comforting knowledge that almost everyone else in the world has just as annoying dots swimming through their optics.
