The cataract is a blurring of the lens. This blurring results in the image that the patient sees progressively losing more and more in sharpness and intensity of colors. Blurring is usually the result of aging of the lens.
The Greek word cataract is officially used in the international literature. It used to be believed that the pupil’s gray color comes from cloudy fluid inside the eye.
Cataract occurs in about 99% of the population at the age of over 65 years. More than 3 million cataract surgeries are performed annually in the US.
How is cataract caused?
Our lens displays two important features:
- is transparent
- is soft and flexible so that it can change its shape by a circular muscle (accommodation effect). This is possible until the age of about 45 years and so objects can be perceived and clearly seen both near and far.
These two characteristics are affected by proteins and lens fluid. Over the years their composition changes, fluid builds up in the lens, which disrupts the balance between liquid and non-liquid components of the lens and causes it to blur. That is how the cataract starts.
There are several stages of lens blurring, which progress and move on to the next:
- the beginning cataract with mild blurring
- the advanced cataract
- the pre-mature cataract : lens blurring is very advanced
- the mature cataract: the lens is completely blurry
- the over-mature cataract: its dark brown core is seated at the bottom of the fluidized lens. This stage now occurs very rarely in developed countries.
The main causes of cataracts are:
- old age (senile cataract)
- trauma (traumatic cataract)
- diabetes mellitus (diabetic cataract)
- intraocular inflammation (complicated cataract)
- congenital lens blurring (congenital cataract)
- other causes are disorders of lens metabolism, poor nutrition, and ultraviolet radiation.
- The vision decreases.
- Colors and contrast are less intense.
- The eye is sensitive to bright light.
- The affected perceives the environment pale.
- In some cases, there is diplopia
At an advanced stage vision decreases so much that even blindness can occur. The pupil’s getting a gray color. When shooting with flash no longer appear “red eyes”.
With the examination by the doctor in the slit lamp, a diagnostic microscope. With the thin beam of light and the corresponding magnification it can diagnose which layer of the lens has blurred.
Intraocular, artificial lens that replaces cataracts in the during the surgery
Senile cataract is the most common ocular disease which can be treated surgically. Cataract surgery is also the most common in medicine in general.
The decision on the operation is made every time personally and depends on the patient’s requirements:
- is the patient due to blurring strongly affected or has no serious problem?
- Are there other eye diseases (diseases of the retina, optic nerve, strabismus, etc.)?
- if the lens is too blurry the surgery may also be without any benefit in terms of vision necessary. Even a rapidly occurring “edema” of the lens after e.g., an injury can cause a sudden opening of the lens capsule. This leads to an inflammatory reaction of the eye with high pressure. Over time, the thickness of the lens increases, which flattens the anterior chamber, resulting in an increase in pressure even in very high levels. In an hypermature cataract, lens albumins can penetrate the capsule and cause inflammation with accompanying high intraocular pressure.
- Most operations are performed under local anesthesia.
- After opening the cornea (2.2 mm incision which does not require suturing at the end of the operation) the nucleus and cortex of the lens are emulsified and removed.
- Then a folded intraocular lens (made of acrylic material) is inserted and replaces the removed blurry lens. This artificial lens should replace the lens that has been removed in terms of eye refraction. The calculation of the refractive power of the lens is made by the measurement of the curvature of the cornea as well as the length of the eyeball by ultrasound or laser device.
- These two measurements allow precisely the choice of the intraocular lens. This can correct myopia, hyperopia and astigmatism.
Cataract is a progressive disease that causes a gradual decrease in vision. Through the operation a complete restoration can be achieved. Modern lenses have proven to be particularly safe and effective for many years. Inflammations are extremely rare. At 10-15% occurs 6 months up to 5 years after surgery the so-called secondary cataract which is a blurring of the posterior capsular bag, usually causes a slight decrease in vision and is treated without surgery, within a few minutes using an YAG -LASER device.