Age cataracts (senile) develop in 60-90% of people over 60 years of age. The pathogenesis of cataract development at this age is associated with a decrease in the amount of soluble proteins and an increase in the number of insoluble proteins, a decrease in the number of amino acids and active enzymes and the amount of ATP. Cysteine is converted into cystine. All this leads to a clouding of the lens. Among senile cataracts, pre-cataracts are distinguished - coronary cataract occurs in 25% of people who have reached puberty. The turbidity of the semilunar form spreads more peripherally than the age-related nucleus, represents a strip with rounded edges that extends around the periphery of the lens in the form of a crown, sometimes has a blue \
Age-related cataracts are sometimes found not only in the elderly, but also in people of active adulthood. Most often it is bilateral, but turbidity does not always develop simultaneously in both eyes.
Age cataracts are different in localization. The most common is cortical (90%), less often - nuclear and subcapsular.
In the development of senile cataract, four stages are distinguished: beginning cataract, immature (or swelling), mature and overripe.
I stage of cataract - initial. The first signs of turbidity appear in the crust of the lens at the equator. The central part remains transparent for a long time. According to the structure of the lens, turbidity has the form of radial strokes or sector-like bands, the broad base of which is directed towards the equator. When examined in transmitted light, they appear as black backs on the red background of the pupil. The first signs at this stage are "flies" before the eyes, spots, the desire to rub their eyes.
Characteristic is the hydration of the crystal, it is saturated with water, as it gets thicker, water gaps appear in the form of radio black bands. Fibers of the lens are stratified along the periphery - spice-like opacities. In the transmitted light, with such a pattern, the spokes are visible.
Vision at a beginning cataract decreases in the case when opacities reach the pupil area. May appear myopia. Patients who have had myopia associated with hydration of the lens, stop using positive glasses and note an improvement in vision with less positive correction during reading. At this time, it is necessary to appoint installations of vitamin drops. During this period biomicroscopy is used to recognize the pre-catarrhal state of the lens. With biomicroscopy, there are:
- symptoms of dissociation of the cortex. At the same time, the bark is cut as it were, dark layers appear in it - water that is between the lens fibers of the cortex;
- a symptom of gaping cortical seams, or a symptom of the formation of water cracks. The fluid is between the zones of separation, and the seam of the cortex is gaping;
- Under the anterior and posterior capsules, vacuoles are detected, ie, the lens becomes vacuolized. When the water appears in the lens, it begins to grow dull. Vision can not suffer. Beginning cataract can remain a water position for a long time, but sooner or later it progresses and goes to the second stage of immature (or swelling) cataract.
II stage of cataract - immature cataract. The turbidity increases, merge with each other, gradually closing the pupil. The opacities of gray-white light, the seams of the nucleus mutate. Due to the swelling of turbid fibers, the volume of the lens increases. In this case, the anterior chamber becomes smaller, the intraocular pressure may increase as compared to the second eye. However, at this stage, not all cortical layers become turbid, the anterior layers remain transparent. The degree of cataract maturity in this stage is determined by the shade from the iris, which is formed in lateral illumination, when the shadow falls from the pupil edge of the iris (from the source of the light). The thicker the layer of transparent front layers of the lens, the wider the shadow from the iris, the less mature cataract. The degree of maturity of cataracts also determines the state of vision. With unripe cataracts, visual acuity gradually decreases. The more mature cataracts, the lower the objective vision. It can fall to such an extent that a person does not see the subject even at close range. Swelling of the lens leads to phakomorphic glaucoma.
III stage of cataract - mature cataract. The lens loses water, becomes dirty gray, all cortical layers, down to the anterior capsule of the lens, grow turbid. The turbidity of the lens becomes uniform, the shadows from the iris are not visible in the lateral illumination, the anterior chamber is deepened, the lens decreases in size by the time of ripening, since it loses water. When studying in transmitted light with an enlarged pupil, its glow is absent. The objective vision is completely lost, only the light perception remains. Against the background of homogeneous turbidity, subcapsular plaques can form under the capsule. Maturation of senile cataract is slow: from one year to three years. Especially slow are those forms in which turbidity starts from the core or from layers adjacent to it.
IV stage of cataract - an overripe cataract. Cataract transfusion can follow two paths. In some cases, the lens gives a lot of water, decreases in volume, shrivels. Muddy cortical masses become dense; Cholesterol and lime are deposited in the capsule of the lens, forming shiny or white plaques on it.
In other, more rare cases, turbid cortical substance and lens masses become liquid, with a milky tone. The disintegration of protein molecules leads to an increase in the osmotic pressure, moisture passes under the lens capsule, it increases in volume, the surface capsule finishes. This phase is called milk cataract. In the stage of ripening, thus, the lens dehydration occurs. The first sign of ripening is the appearance of the folding of the capsule of the lens, a gradual decrease in the volume volume. The bark is liquefied by overripe, and the core in it descends. Recurrence of a cloudy lens with the descent of the nucleus is called a blink of a cataract. Through the upper zone of such a lens, one can see the reflex, and with a positive correction from above can be the vision of the patient.
In such cases, if the patient does not operate, the capsule in the negative begins to pass through the hrustatik protein. In this case, the phacogenic iridocyclitis or phacotoxic glaucoma may develop, due to the fact that the lens of the lens clogs the angle of the anterior chamber of the eye.
Nuclear cataract - it must be differentiated from the lens of the lens. In cataracts, turbidity is distributed to the embryonic core and seams. With age nuclear cataract, central vision is disturbed early: distance vision suffers, "false myopia" develops nearby, which can be up to 12.0 diopters.
First, turbidity of the embryonic nucleus is formed, then it spreads to all layers. The cloudy central layers are clearly delineated from the peripheral transparent zone. There is no decay of the lens material. This is a dense cataract. Sometimes the nucleus can acquire a brown or black color. This cataract is also called brown. Nuclear cataract remains immature for a long time. If it ripens, then talk about cataract mixed - nuclear-cortical.
Subcapsular cataract is an age-old, very insidious disease, as the youngest peripheral part of the lens becomes turbid, first of all the anterior capsule, under it develop vacuoles and opacities - delicate, of different sizes. As the turbidity increases, they spread to the equator and resemble a cup-shaped cataract. On the cortex of the lens, turbidity does not spread. Cataract should be differentiated with complicated cataract.
The origin of senile cataract is now associated with impaired oxidative processes in the lens, caused by a deficiency in the body of ascorbic acid. Great importance in the development of senile cataract is also attached to deficiencies in the body of vitamin B 2 (riboflavin). In this regard, with the beginning of senile cataract, in order to prevent the progression of cataracts, ascorbic acid and riboflavin are prescribed in the form of eye drops or riboflavin with potassium iodide (also in the form of eye drops).
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