Hemeralopia( "night blindness") - Causes, symptoms and treatment. MF.

Hemeralopia( "night blindness") - a disease manifested by deterioration of vision in the twilight and at night.

Normal vision at dusk

Vision with hemorrhagia

Causes of night blindness

The pathogenesis of hemorrhagia is associated with impaired synthesis and decomposition of rhodopsin in the retinal cones. Can be congenital, essential and symptomatic. In the first case, the disease is inherited. Essential hememelopia develops due to a deficiency of vitamin A( retinol), from the onset of hypovitaminosis to the onset of symptoms, it can take up to 2 years, since there are enough reserves in the body for a year. Occurs in diseases of the gastrointestinal tract, when absorption is impaired, or with diets with insufficient intake of vitamin A, PP, B1.The optimal human need for these vitamins is 5000 IU.

Symptomatic hemorrhagia occurs with lesions of the retina or optic nerve( retinal dystrophy, glaucoma, extensive chorioretinitis, complicated myopia).

Symptoms of night blindness

Patients complain of a worsening of twilight vision up to blindness in low light conditions.

Survey

For the diagnosis use the following methods:

- visometry( often normal with essential)
- perimetry( possible narrowing of the visual fields, especially on the colors)
- ophthalmoscopy - with congenital hemeralopia on the retina small round degenerative foci
- adaptometrystudy of dark adaptation) - the patient looks at the brightly illuminated screen of the adaptometer for 2 minutes. Then put some object( more often a geometric form) and mark the time through which it becomes visible. Normally not more than 45 seconds. There are other modifications of this method
- electroretinography - the functional state of the retina - wave A first disappears, then the electroretinogram becomes negative
- various research methods to identify the causes of symptomatic hemalopia( refractometry, tonography, ophthalmoscopy, examination with the Goldman lens, optical coherence tomography,)
- consultation of a gastroenterologist for determining the causes of vitamin A deficiency

Treating hemorrhagia

Congenital "night blindness" leeniyu not be.

In the case of symptomatic hemostalopia, treatment consists in eliminating the underlying disease.

In other cases, after eliminating the factors that led to the essential "chicken blindness", and the appointment of diet and vitamin A, twilight vision is restored completely. Foods rich in retinol: liver of cod, beef, pork, butter, cheese, egg yolk. Carotene( provitamin A) contain carrots, cabbage, sorrel, corn, apricots, herbs. For the treatment of adults, vitamin A is taken up to 100,000 IU every day, children up to 5000 IU daily up to several months. Be sure to prescribe vitamins of group B.

Doctor ophthalmologist Letyuk T.Z.