Keratoconus. Patofiziologija and the parent
Despite the considerable examination, the etiology keratoconus remains some kind of secret. According to national Fund Keratoconus of the United States, it is probable, that keratoconus can grow out of many various factors: genetic, ecological or cellular, any of which can generate a trigger mechanism to start illness. After begun, illness usually develops progressive dissolution of stratum Luchnika, a membrane laying between a corneal epithelium and a stroma. As these two contact, cellular and structural changes in a cornea adversely damage its integrity and lead vypiraniju and to a cicatrization which are characteristic for disturbance. Within any individual keratoconic corneas, there can be found by fields of the degenerate thinning coexisting with fields, transferring healing of fine wounds.
The visual contortion tested by the patient, arrives from two radiants, one being the nonregular strain of a surface of a cornea; another being cicatrizing which meets on its subjected to action highpoints. These factors operate to generate fields on a cornea which kartirujut the image to various situations on a retina and give rise to a symptom monocular polyopia. The effect can worsen in low easy Conditions, as the pupil adapting for darkness extends to subject to action more than the nonregular surface of a cornea. A cicatrization, apparently, aspect of corneal degradation; however, recent, major, multilateral examination guesses, that clearing by contact lenses can enlarge probability of this detection by the factor more than two.
Many examinations have specified, that keratoconic corneas show symptoms of the enlarged activity proteases, a class of enzymes which fracture some of traversal communications of collagen in a corneal stroma, with the simultaneous lowered expression proteaznyh inhibitors. Other examinations have guessed, that the reduced activity a fermental dehydrogenase of aldehyde can be responsible for build-up of the free radicals and oxidizing views in a cornea. It seems probable, that irrespectively process pathogenetical the damage caused by activity within a cornea, comes to an end on reduction in its thickness and biomechanical strength.
Genetic predisposition to keratoconus was observed, with the illness running in certain families, and incidences have informed concordances in identical didymous things. Frequency of occurrence in the close terms of a family clearly is not spotted, though it, as is known, is much higher than it in the blanket population, and examinations have gained the estimates which are settling down between 6 % and 19 %. The responsible gene has not been obviously identified: two isolated involvings of examinations, substantially homogenetic communities on the contrary kartirovalo prospective gene situations to chromosomes 16q and 20q. However, the majority of genetic examinations agrees about dominating autosomal model inheritence. Keratoconus also it is more often diagnosed in people with Downwards syndrome though the parents for this communication have not been spotted yet. Keratoconus allergies, and an eczema, and it rather obshche for some or all these illnesses have been bound to allergic illnesses which include an asthma, to damage one person. Many examinations guess, that vigorous eye rubbing can promote a progression keratoconus, and that patients need to discourage from practice.
(Keratoconus. Patofiziologija and the parent)
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