Amaurosis

Amaurosis (Greek ἀμαυρός ( amauros ) " dark, blind" ), also referred to as full dummy or rare Black Star, is the medical term for the complete absence of light perception of one or both eyes at the loss of any visual stimulus processing. With regard to a visual acuity exam, this corresponds to the value " 0 - no light perception." As objective evidence of amaurosis occurs a perfect rigidity of the pupil a ( Amaurotic pupillary rigidity ), in which no direct light reaction is triggered more.

Causes

As a cause of amaurosis can diverse congenital or acquired factors come into consideration, which are capable of eliciting a complete interruption of light stimulus transmission to the brain. These include, for example, retinal detachment, degenerative diseases of the network or choroid, or optic nerve transection compression, poisoning, tumors or vascular events. Hysterical amaurosis are rare and usually occur on both sides. A genetic cause can be a mutation of the gene NMNAT1, which had not been previously associated with human diseases.

Amaurosis and blindness

From the amaurosis of the concept of blindness is to be distinguished. According to general legislation and according to the definition of the World Health Organization ( WHO) takes the property "blind" on people with one, albeit very small, residual vision to, which is not the case with the amaurosis. In this respect, a amaurotic eye is always blind, but a blind eye does not necessarily have amaurotic. In the context of social and legal aspects of care also referred blindness usually the state of a "person", not the one eye as "organ". Thus, a person is not considered blind in the legal sense with a unilateral amaurosis and intact vision in the other eye.

Amaurosis fugax

Amaurosis fugax (Latin fugax = "transient" ) is an acute, reversible and usually unilaterally extending arterial vascular occlusion of the supplying the retina central retinal artery, which has a short-term, full darkening of the affected eye into. He is often considered as the first signs of cerebral circulatory disorder and can also occur in conjunction with a carotid artery stenosis.

Leber's Congenital Amaurosis

Leber's Congenital Amaurosis (also: Congenital Tapeto - retinal amaurosis, LCA) is a congenital and usually autosomal recessive disorder of the pigment epithelium of the retina with degenerative manifestations of the choroid. It was first described by the German ophthalmologist and scientist Theodor Carl Gustav of liver 1869. Patients come already significantly visually impaired or blind to the world, and the probability of disease subsequent siblings is about 25 %. More than 10 % of all congenital cases of blindness can be attributed to the Leber's amaurosis.

Sleep disorders in totally blind

In totally blind it often comes to circadian sleep-wake rhythm disorders of the type of free-running rhythm and other sleep-wake rhythm disorders, because the synchronizing the popularly known "inner clock " called circadian rhythm required timer light -dark cycle fails.