Night blindness ( " night blindness " ) - Causes, Symptoms and Treatment .MF .
night blindness ( "night blindness") - a disease manifested by deterioration of vision in twilight and at night.
normal vision at dusk
Vision with night blindness
Causes night blindness
pathogenesis of night blindness is associated with impaired synthesis and decay of rhodopsin in the retinal cones.It may be congenital, essential and symptomatic.In the first case, the disease is inherited.Essential day-blindness develops due to vitamin A deficiency (retinol), vitamin deficiencies from the beginning to the onset of symptoms may take up to 2 years as stocks have enough in the body for a year.Occurs when diseases of the gastrointestinal tract, where absorption is broken, or a diet with insufficient intake of vitamin A, PP, B1.Optimal human need for this vitamin is 5,000 IU.
Symptomatic day-blindness occurs when lesions of the retina or optic nerve (macular degeneration, glaucoma, chorioretinitis extensive, complicated myopia).
Symptoms of night blindness
Patients complain of a deteri
For diagnosis using the following methods:
- visometry (often the norm in essential)
- perimetry (possibly narrowing of the visual fields, particularly in color)
- ophthalmoscopy - with congenital night blindness on the retina small rounded degenerative lesions
- adaptometry (the study of dark adaptation) - the patient looks at the brightly lit adaptometry screen for 2 minutes.Then place an object (usually geometric shapes) and intersect the time after which it will become visible.Normally, no more than 45 seconds.There are other versions of this method
- electroretinography - functional condition of the retina - first disappearing wave A, then electroretinogram becomes negative
- different methods of research to identify the causes of symptomatic night blindness (refractometer tonography, ophthalmoscopy, examination with Goldman lens, optical coherence tomography and others.)
- consultation of the gastroenterologist to determine the causes of vitamin A deficiency
Treatment of Congenital night blindness
"night blindness" can not be treated.
In the case of symptomatic treatment of night blindness is the elimination of the underlying disease.
In other cases, after the elimination of the factors which have led to essential "night blindness," and the appointment of diet and vitamin A, night vision is completely restored.Foods rich in retinol: cod liver oil, beef, pork, butter, cheese, egg yolk.Carotene (provitamin A) contain carrots, cabbage, sorrel, corn, apricots, parsley.For the treatment of adults taking vitamin A to 100,000 IU every day, children up to 5000 IU daily for several months.Be sure to appoint B vitamins
Ophthalmologist Letyuk TZ