Occupational Diseases / / May 24, 2016
Professional cataracts in the conditions of production may be influenced by both physical and chemical factors, physical factors of the occurrence of cataracts may be caused by the systematic influence of radiant energy.Depending on the part of the spectrum, wavelength and frequency of oscillations of the lens damage in the initial period are different clinical forms.
heat (fire) cataract
etiological factors are infrared rays with a wavelength of 7.50 to 2400 nM.Rays freely pass through the cornea and the iris, without damaging them, and to a large extent adsorbed by the lens, causing it to overheat (glassmakers, smelters, blacksmiths and others.).
first signs of heat cataracts appear at the posterior pole of the lens in the form of small subcapsular sharply defined "dust."As the disease progresses it gradually increases the amount of, and formed a tight circle, or blurred in the form of a saucer at the posterior pole.Later blurred moving on in front of the lens axis.In light of the slit la
Wearing glasses with blue-light filter glass SS-14 or with glass, reflecting up to 38% of infrared rays.Cooling water and air curtains between the heat source and the workplace.
Electromagnetic waves of radio frequencies in the range of 1 mm -10 cm can cause the development of cataracts.While the biological effect of the radio frequency electromagnetic field to a large extent due to the formation of heat in the tissue, cataracts does not occur on the thermal type.
In light of the slit lamp at the equator of the lens mainly in the lower quadrants are seen multiple small opacities of different shapes with indistinct borders.Some elements opacities are located on poles in the field of capsule, usually the front.Sometimes they are located in the cortex, the area of the adult nucleus, partially entering the outer sections of the embryonic nucleus.With progression, they increase in number and all capture area of the lens.
arises from exposure to ionizing radiation (X-rays, gamma rays, neutrons) in workers X-ray rooms, with gammadefektoskopii metals during maintenance of nuclear reactors, working with radioactive isotopes, and so on. D.
especially dangerous againstcataractogenic action repeated exposure to low doses of neutrons.Cataracts usually develop gradually, the duration of the latent period is dependent on the dose received and on average from 2 to 5 years.
Clinic The clinic has many similarities with the clinic of heat cataracts.Blurred first appears at the posterior pole of the lens under the capsule in the form of fine granules or vacuoles.Grit gradually becomes disk (or "donut"), sharply delimited from the transparent part of the lens.In this step, cataracts visual acuity is not affected.Later clouding takes the form of a bowl or saucer.In light of the slit lamp blurred by its structure resembles a tuff with a metallic tint.In the later period there vacuoles and poyasoobraznye haze under the anterior capsule.Gradually, the entire lens becomes opaque to light perception vision falls.In most cases, radiation cataracts progress slowly.Sometimes the initial haze kept for years without causing significant reduction of vision.Symptoms of radiation sickness are optional.
Chemical factors cataract
to chemical factors that may cause cataracts include nitro-derivatives of toluene (TNT - TNT).The emergence of toxic (TNT) cataract is often the first and only symptom, indicating that the penetration into the body of TNT.The first signs of cataracts can be observed after 2 years from the start of exposure to a toxic substance.
cataract development goes through a series of stages: initial symptoms are reduced to the appearance of point opacities of different sizes in the equatorial zone of the lens, are visible only in the light of the slit lamp with dilated pupils.As the cataract progresses they become more and they give the impression of a sparse crown on the Equator, In addition, the cloud begin to appear in the pupillary area subcapsular, which form a ring or disc, equal to the diameter of the pupil, -koltsevidnaya (discoid) stage.Then, along with this discoid turbidity, haze occur wedge-shaped, the apex of which faces towards the center of the lens - step wedge.Visual acuity deteriorates.Later Discard cloudy areas become even denser, increasing their vertices are joined at the center of the lens.Ophthalmoscopy difficult, vision is greatly reduced, sometimes up to hundredths (immature cataract).Finally, the entire lens becomes cloudy (mature cataract).
Pathology body of intoxication TNT is not associated with a hit product in the conjunctiva, and is the result of intoxication.
All kinds of professional cataracts develop slowly and do not violate long disability of patients.However, progressive cataract is always a contraindication to continuing to work with a professional to call it factor.In the case of radiation, TNT and microwave - cataract disability examination questions are solved taking into account the patient's general condition (signs of radiation sickness or exposure to toxic TNT microwave fields).