What is a cataracts ( eye disease )?
Cataract is a clouding of the eye lens which reduces see. In extreme cases, the lens of the eye is completely opaque, causing blindness of the eye occurs.
Worldwide, approximately 17.5 million people blind from cataracts. That's almost half of the total number of blind people. Between age 50 and 65 years, approximately half of all people already signs of cataracts, but most find there no hindrance of yet. Around 75 years, 70% have cataracts. From that age the face trouble taken by the disease significantly. People with diabetes are often already at a younger age affected by cataracts. When the glasses after the age of 60 gradually starts to change, for example, one can read without glasses, this is often by cataracts. Blurred vision especially in bright backlight and double vision in one eye are also common symptoms in cataract.
What causes cataracts
In the eye, immediately behind the pupil, is normally clear and transparent lens. This is composed of proteins, and water. When the cataract lens is slowly turbid, so that the light is no longer to fall through it. For this are many causes, but the cause of the clouding of the lens is not known in most cases. According to some sources of ultraviolet light from the sun play a role, but this was never proven.
In cataract due to diabetes mellitus results in an increased blood sugar levels in the eye in increased conversion of glucose to sorbitol. This is done via an enzyme. Since the lens membranes lack virtually impermeable to sorbitol, and also the enzyme to break down sorbitol, sorbitol accumulates in high concentrations in the lens. That remains the case even if the glucose levels return to normal. These high sorbitolconcentraties create an osmotic gradient which causes water is drawn into the cells in order to maintain the osmotic balance, with the same purpose, the cell is discharging, then small molecules such as amino acids, inositol, glutathione, niacin, vitamin C, magnesium, and potassium. Since these nutrients, protect the lens from damage, its loss will result in an increased susceptibility to damage. The result is that damage to the proteins in the lens, clump together and become discolored, causing cataract is formed.
The proteins in the lens are arranged such that the lens is transparent. But in cataract these proteins are broken down into pieces. The pieces clump together in the lens. Thereby discolor the lens to yellow, green and on to orange and brown. Sometimes appear whitish clouds or flakes into the lens. These are called opacities. Initially, they hinder the incident light barely. As they get bigger and fatter, but that they scatter light more and more. Less light reaches the retina and moreover the incident light rays are bent. As the lens has become completely opaque, there is a total of cataract. The lens is partially opaque, it is called incomplete cataracts.
Although cataracts can be caused by many conditions, it is usually an age phenomenon. In this case, it often affects both eyes. Eye trauma, diabetes and some medicines, when taken very long, can contribute to the development of cataracts. It is not known why the lens changes with age. Besides "senile cataract" there are various other forms, such as after an injury to the eye lens or hereditary causes.
Congenital cataract
In rare cases, congenital cataracts, called congenital cataracts. This can have several causes. Congenital cataracts may occur because the mother had rubella during pregnancy. Other problems during pregnancy can cause cataracts.
Sometimes congenital cataract an isolated disorder. It may also be a component of syndromes, such as, for example, at 1q21.1-deletion syndrome. Congenital cataracts may be hereditary. There may also cataracts occur in childhood, by an illness or after an accident. The severity of the haze of the lens of the eye can vary considerably. The cataract can occur in either one as both eyes. The clouding of the lens is always offered a bad image in the brains. The visual cortex is therefore not encouraged to learn to observe. Untreated, the outlook for congenital cataracts therefore bad.
The treatment of the affected eye will often consist of operating as early as possible of the cataract. An implant lens with a baby is not possible because the eye in the first years of life is growing very fast. The glasses own lens should replace is so thick that it has strong side effects. Therefore chosen correction with a contact lens. After surgery and correction with a contact lens can learn to observe the eye. The treatment process is long and intense, but the prospects are reasonable. Of course it all depends on whether there are other abnormalities of the eye or eyes. Vibrant eyes (nystagmus) make the outlook worse example. At one time the contact lens can be replaced by an implant lens.
Types of cataract
Depending on the location of the lens where the blurry image was created, we distinguish three types of cataracts.
Nuclear cataract
This form of cataract, also called cataracts nuclearis, is most common. He emerges in the center of the lens and is usually detected quickly. The most common symptoms are light scattering, seeing double images and foggy and waning picture.
Cortical cataracts
The first symptoms of cortical cataracts marsh straw Ebeling his jet-shaped opacities in the outer cortical portion of the lens. The opacities are expanding from the outside of the lens to the center, such as the spokes of a wheel. When these opacities reach the central part of the lens, they are disruptive and vision loss occurs on. Include people with diabetes, this form anymore.
Posterior subcapsular cataract
In this form there is first formed a small, mat spot in the back of the center of the lens. This spot is increasing. Early symptoms are blurred vision when outside and load when reading. This type of cataract is fairly typical for people undergoing treatment with corticosteroids. It also speaks well of cortisone cataract.
Eye cataracts treatment
Nowadays, this condition is almost always treatable: the lens becomes opaque become removed, and an artificial lens is placed in the place. This intervention by an ophthalmologist usually takes place under local anesthesia and has a low risk of complications. However, one can then no longer so accommodating for near vision, for example reading glasses needed. But this was in most patients, if only because of their age, for whom already the case. Overall it is just a (half) -dagopname hospital required for the operation and the patient can go home the same day. Implantation of the lens is now actually always done, because otherwise thick glasses or contact lenses should wear to see.
Cataracts Surgery
Many people are afraid of the surgery because they think they will have to keep their eyes open, but even though the surgery almost never happens under total anesthesia, keeping open is never a problem. A few days after the operation, one does not have more of the eyes. Yet it may be that after a few days of sight is not yet optimal. This may also be due to other eye problems.