Vitreous
Synonyms in a broader sense
Medical: Corpus vitreum
English: vitreous
definition
The vitreous humor is part of the eye. It fills a large part of the posterior chamber and is primarily used to maintain the shape of the eyeball (Bulbus oculi) responsible. Changes to the vitreous humor can lead to vision problems in the broader sense.
Vitreous anatomy
The Vitreous lies as a spherical, transparent structure inside the eye. Towards the front it is limited by the lens, backwards through the Retina (retina).
He is about 98% from water, the remaining 2% do Collagen fibers and Hyaluronic acid molecules out. Hyaluronic acid belongs to the Glycosaminoglycans (Abbr .: GAG, polysaccharides) which together form part of the extracellular matrix of the body. So they fill the space between the cells.
Many of the glycosaminoglycans - so too Hyaluronic acid - have the ability to bind a lot of water due to their structure, they have a high water-binding capacity. Their surroundings are often of a jelly-like consistency.
So does the vitreous humor of the eye.
- Cornea - Cornea
- Dermis - Sclera
- Iris - iris
- Radiant Bodies - Corpus ciliary
- Choroid - Choroid
- Retina - retina
- Anterior chamber of the eye -
Camera anterior - Chamber angle -
Angulus irodocomealis - Posterior chamber of the eye -
Camera posterior - Eye lens - Lens
- Vitreous - Corpus vitreum
- Yellow spot - Macula lutea
- Blind spot -
Discus nervi optici - Optic nerve (2nd cranial nerve) -
Optic nerve - Main line of sight - Axis opticus
- Axis of the eyeball - Axis bulbi
- Lateral rectus eye muscle -
Lateral rectus muscle - Inner rectus eye muscle -
Medial rectus muscle
You can find an overview of all Dr-Gumpert images at: medical illustrations
Function of the vitreous
Everyone Beam of light traverses the entire vitreous humor after being at Cornea (Cornea) and lens - depending on the angle of incidence - was broken and bundled.
He then falls on the one behind the Vitreous lying retina in which the Photoreceptors lie. These convert light stimuli into electrical signals, which are the beginning of a complex signal cascade that extends into Central nervous system is enough to take care of the creation of the image that we see at the end.
The vitreous itself is primarily responsible for maintaining the rounded shape of the eyeball due to its spherical shape with which it fills a large part of the posterior chamber. In addition, its transparency is a prerequisite for the incident light rays falling on the retina unhindered.
Changes and diseases
Serious diseases of the Vitreous are rather rare. However, there are some processes in which it can lead to impaired vision.
However, this rarely changes Visual acuity (Visual acuity) per se, but rather disturbing point or blotch vision in the field of vision of the affected person Eye. In the case of a vitreous detachment, the rear part of the vitreous becomes partially detached from the Retina. Depending on the severity, this can lead to "spots or streaks" of the affected person. If there is a vitreous detachment, there is a risk of simultaneous Retinal detachmentwhich represents an ophthalmological emergency.
A clouding of the vitreous usually leads to the small dots called "Mouches volantes" (French - flying mosquitoes) which move as if floating through the field of vision. To a certain extent, this phenomenon is physiological (i.e. normal) and can occur even at a young age.
It affects visual acuity in these cases (Visual acuity) Not. A significant increase in floaters, on the other hand, can be an indication of a pathology, such as a vitreous detachment or a vitreous hemorrhage and should then be clarified by a doctor.
Vitreous shrinkage
Vitreous body shrinkage is a slowly progressing reduction in size of the vitreous body. The cause are degenerative processes that can vary in severity in each person. The vitreous loses its shape with age. Due to the clumping of stabilizing fibers, the vitreous humor can no longer store enough water to completely fill the inside of the eye.
If the vitreous shrinks more, the vitreous detachment can occur. As the retina is no longer adequately stabilized, it can peel off as a result. Even if the vitreous humor is glued to the retina, it can damage it by shrinking it. However, this is the exception.
Vitreous body shrinkage is often not noticed. Most of the time, so-called "floaters" (French: flying mosquitoes) occur, which can be perceived as annoying. They are usually harmless. However, if they appear suddenly or in larger quantities, they can indicate damage to the eye. Flashes of light caused by irritation of the retina should be examined by an ophthalmologist. The same applies to the so-called "soot rain". These are many small dark spots that are suddenly noticed. They can be signs of retinal damage.
Read more on this topic at: Vitreous detachment
Vitreous detachment
With age, the vitreous shrinks and changes its consistency. While it still has the consistency of thick pudding in children, it becomes more and more liquid with age. The reason for this is a separation of stabilizing fibers and water, which makes up about 98% of the vitreous.
The vitreous body develops an irregular shape that no longer lies smoothly against the retina and shrinks slightly. Free water collects in the resulting crevices. A gap forms between the vitreous humor and the retina. At the front of the eye, the vitreous is more firmly fixed, which means that there is usually no detachment here.
Vitreous detachment is widespread and in most cases harmless. It occurs in around 65% of all people over the age of 60. Those affected often complain about "floaters". These are serpentine or point-like shapes that are mainly seen when looking at bright surfaces. In addition, flashes of light can be perceived as a result of irritation to the retina.
Even if the vitreous detachment is usually harmless, it can lead to more threatening diseases such as retinal detachment.
- Vitreous detachment
Vitreous opacity
The vitreous humor degenerates with age. The support fibers, which are normally evenly distributed, separate from the water content and clump together. This creates denser structures, that can catch light. Since the vitreous body lies directly in front of the retina, these light-tight shapes are perceived by the person concerned in the field of vision. The perceived shapes are referred to as "Mouches volantes" (French: flying mosquitoes). These are mostly serpentine lines or points.
The Visual acuity is of it not affected. Floaters are mainly perceived against a light background. Even people with a non-clouded vitreous body sometimes see these shapes. A sudden increase in number and density these phenomena should, however, from one Ophthalmologist clarified be as they too Harbingers of Serious Illnesses could be.
Will the Floaters Perceived as very annoying or there is a risk of complications, an operation can be useful. With the so-called Vitrectomy become Surgically removed parts of the vitreous and replaced with saline. A modern method is laser vitreolysis. Both techniques have advantages and disadvantages and must be discussed in detail with the attending physician.
Vitreous hemorrhage
The actual vitreous body has no blood vessels. The vitreous hemorrhage is therefore one Bleeding into the vitreous humor. The blood comes from the vessels of the eye around it.
If blood spreads in the body, it follows the path of least resistance. While the outside of the eye is enclosed by the sinewy leather skin, the glass body is soft and malleable. Inflowing blood can therefore Spread almost unhindered.
Because the vitreous barely of Nerve endings is streaked, is the vitreous hemorrhage often not painful. The affected patients mostly complain reddish discoloration and Clouding of their field of vision. In the case of severe vitreous bleeding, the Eyesight thereby strong limited be.
The possible causes vitreous hemorrhage diverse. Often it is a External force acting on the eye, for example a punch. She can also do the Consequence of inflammatory diseases when eye vessels are damaged. High blood pressure also damages the blood vessels in the eye. At the rare one Eales syndrome vitreous hemorrhage occurs, among other things. No exact causes are known for this disease.
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