Leber’s congenital amaurosis (LCA) is an inherited dystrophy of retina. It mainly causes an infant to be born with loss of vision. It is inherited in an autosomal recessive manner, in which it is caused to the child when both parents carry a defective gene. Leber’s congenital amaurosis and early-onset retinitis pigmentosa are the most common disease which affects at the ratio of 3 in 100,000 infants.
Infants with LCA mostly blind at birth or gradually lose vision within their few years of life.
Newborn children with Leber’s congenital amaurosis suffer from impairment of vision. Infants when born or later develop wandering involuntary eye movements often called as nystagmus. These type of children tend to push their eyes or push them with their punch or sometimes with fingers. This condition is characteristic and is called as Franceschetti's oculo-digital sign (Eye poking, pressing, and rubbing). This may direct to malformed and weak corneas and cataracts.
The appearance of the fundus is enormously variable. Although the retina may originally appear normal, a retinopathy suggestive of retinitis pigmentosa is normally observed soon later in childhood. The electroretinogram (ERG) done for diagnosis is typically not useful for detection of Leber’s congenital amaurosis.
The appearance of the retinas may change with age but once childhood is past, vision usually remains stable. The individual with Leber’s congenital amaurosis may only have vision at the level of seeing light and dark or detecting hand motions.
Other symptoms may include crossed eyes (strabismus), unusual sensitivity to light (photophobia); abnormal protrusion of the anterior, hearing loss, mental retardation, delays in the attainment of skills that need coordination of mental and psychomotor retardation.
High hyperopia is also sometimes observed in Leber’s congenital amaurosis which is considered as a result of impaired ability of the eye to accommodate to visual stimuli as a result of onset of visual impairment in early childhood.
There is no particular treatment for Leber’s congenital amaurosis. Individuals with this disorder can take assistance by the use of low-vision aids condition, they have adequate vision.
Treatment given can be supportive. Kids and their parents should be guided to programs for the visually impaired child nearby their locality.
Individuals with Leber’s congenital amaurosis get advantage if the refractive error is corrected, and given maximum access to educational and professional opportunities.
Secondary complications of Leber’s congenital amaurosis can be avoided by preventing children from constantly poking and pressing their eyes.
Examination and trials of vision must be conducted for the individuals suffering from the secondary complications and also those with residual vision, glaucoma and cataract.
Leber’s congenital amaurosis is usually a group of diseases inherited genetically as recessive traits and in very rare conditions as dominant trait. But it can be associated with several other diseases like neurological dysfunction, kidney disorders and imbalance of chromosomes.
Research indicates the participation of twelve genes in Leber’s congenital amaurosis. But in some genes combinations of mutations is detected. These genes GUCY2D, RPE65, AIPL1, RPGRIP1, CRB1, CRX, and RDH12 genes were detected with molecular biology techniques.
Leber’s congenital amaurosis is differentiated with the gene mutation associated with it. Such as ten types mentioned here-