Complicated cataract
Last reviewed: 23.04.2024
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Complicated cataracts are caused by unfavorable external and internal factors. Complicated cataracts are characterized by the development of turbidity under the posterior capsule of the lens and in the peripheral parts of the posterior cortex. This distinguishes complicated cataract from cortical and nuclear age-related cataracts. When examining the lens in transmitted light, turbidity moves to the opposite side of the eyeball movement. Complicated cataract with biomicroscopy cup-shaped, gray, with many vacuoles, crystals of calcium, cholesterol are visible. It resembles a pumice stone. Complicated cataract begins with coloring at the back edge of the lens, when all the colors of the spectrum are visible. Commonly complicated cataract is one-sided. This is because a complicated cataract develops in the diseased eye, where the products of intoxication are found, which, trapped with the liquid, linger in a narrow space, behind the lens. Therefore, opacities in this case begin in the posterior parts of the lens.
Complicated cataracts are divided into two subgroups:
- Cataracts caused by common diseases of the body:
- endocrine diseases, metabolic disorders, starvation, avitaminosis and poisoning by various berries;
- diabetes. Diabetic cataracts develop in 40% of diabetics, often in young people. This is a bilateral, rapidly developing cataract. Swell, cloud the most superficial layers behind and in front, a large number of vacuoles, point subcapsular deposits, water gaps between the capsule of the lens and the cortex. Following the vacuoles appear flocculent opacities resembling a "snow storm". Early refraction changes, characterized by unstable myopia (can vary throughout the day). Diabetic cataract progresses very quickly;
- tetanic cataract is observed in tetanus, convulsions, and violations of water metabolism (cholera, etc.). The course is the same as in the previous cataract;
- myotopic cataract - there are many opacities that are localized mainly in the cortex. The cleavage zone is always transparent. Between opacifications in the lens, brilliant inclusions (cholesterol crystals) can form;
- dermatogenic cataract with scleroderma, eczema, neurodermatitis. At a young age, the affected lens very quickly ripens. In the light of the slit lamp against the background of diffuse turbidity, more intense turbidity near the poles is seen;
- endocrine cataract develops with myxedema, cretinism, Down's disease. If there is a lack of intake of vitamin PP in the body, pellagra develops, which also causes a clouding of the lens (cataract);
- Cataracts caused by eye diseases.
The changes occurring in other eye tissues can be influenced by metabolic processes in the lens: pigmentary retinal dystrophy, high degree of myopia, uveitis, retinal detachment, far-reaching glaucoma, recurrent iridocyclitis and chorioretinitis of various etiology, iris and ciliary body dysfunction (Fuchs syndrome). With all these diseases there is a change in the composition of the intraocular fluid, which in turn affects the disturbance of metabolic processes in the lens and the development of opacities. A feature of all complicated cataracts is that they are usually posterocapsular, since in the area of retrolental space there is a longer contact of toxic substances with the lens, and there is no epithelium behind which plays a protective role. The initial stage of the back-capsular cataract is polychromatic iridescence under the posterior capsule. Then under the back capsule, turbidity develops, which has a rough appearance. As it spreads to the periphery, turbidity resembles a bowl, with further slow spreading, a complete cataract occurs.
An example of a combination of cataracts with the general pathology of the body can serve as a cacetal cataract that occurs in connection with the general depletion of the body during starvation, after infectious diseases (typhus, malaria, donkeys, etc.), as a result of chronic anemia.
[Secondary, pleural cataract and fibrosis of the posterior capsule of the lens
Secondary cataract occurs in the aphakic eye after extracapsular cataract extraction. This is the growth of the subcapsular epithelium of the lens, which remains in the equatorial zone of the lens bag.
In the absence of the nucleus of the lens, cells are not constrained, so they grow freely, they do not stretch. They swell in the form of small transparent balls of different sizes and lining the posterior capsule. With biomicroscopy, these cells are similar to soap bubbles or caviar grains. They are called balls Adamyuk-Elshniga by the names of scientists who first described the secondary cataract. At the initial stage of development of secondary cataract, there are no subjective symptoms. Visual acuity decreases when epithelial growths reach the central zone.
Secondary cataracts are subject to surgical treatment: they produce a dissection (dissection) of the posterior capsule of the lens, on which Adamyuk-Elshnig balls are placed. The dissection is performed by a linear incision within the pupillary zone.
The operation can also be performed using a laser beam. In this case, the secondary cataract is also destroyed within the pupil. A round hole with a diameter of 2-2.5 mm is formed. If this is not enough to ensure a high visual acuity, then the hole can be increased. In artifacial eyes, secondary cataracts develop less frequently than in aphakic ones.
Frontal cataract is formed as a result of spontaneous resorption of the lens after trauma, only the fused anterior and posterior capsules of the lens remain in the form of thick turbid film.
Cavity cataracts are dissected in the central zone by a laser beam or a special knife. In the resulting hole, if there are indications, an artificial lens of a special design can be strengthened.
Fibrosis of the posterior capsule of the lens is used to designate compaction and opacification of the posterior capsule after extracapsular extraction of cataract.
In rare cases, turbidity of the posterior capsule can be detected on the operating table after removal of the lens nucleus. Most often, turbidity develops 1-2 months after surgery because the posterior capsule has not been sufficiently purified and there are invisible thin sections of transparent crystalline masses, which subsequently grow turbid. This fibrosis of the posterior capsule is considered a complication of cataract extraction. After surgery, the posterior capsule always shrinks and thickens as a manifestation of physiological fibrosis, but it remains transparent.
The dissection of the clouded capsule is performed in those cases when visual acuity is sharply reduced. Sometimes sufficiently high vision is maintained even in the presence of significant opacities on the posterior capsule of the lens. Everything depends on the localization of these opacities. If there is at least a small gap left in the center, this may be enough to pass the light rays. In this regard, the question of dissecting the capsule the surgeon decides only after assessing the function of the eye.