Leber congenital amaurosis

Autres termes

• Leber's congenital tapetoretinal amaurosis

Définition

Leber's congenital amaurosis, or Leber's congenital tapetoretinal amaurosis, refers to a group of severe congenital retinal dystrophies. Hereditary in origin, it causes progressive deterioration of the retina, leading to total and irreversible loss of vision. The onset of blindness varies according to the form of the disease.

In some cases, blindness occurs from birth or during the first year of life, while in others, residual visual acuity persists for several decades.

Leber's congenital amaurosis accounts for 5% of retinal dystrophies, and is responsible for 20% of blindness in school-age children.

Causes

Leber's congenital amaurosis is genetic in origin. Several mutations affecting different genes coding for specific retinal proteins may be the cause. Depending on the gene affected, the disease can be more or less severe and early-onset.

Symptoms

Depending on the form of Leber congenital amaurosis present, several symptoms may appear. These include

• Nystagmus (incessant, jerky eye movements)
• Poor visual acuity
• Reduced visual field
• Slow pupillary responses
• Wandering eye movements
• Hypersensitivity to glare (photophobia)
• Strabismus

Diagnosis

Diagnosis of Leber's congenital amaurosis involves several stages:

• Clinical observations (slow or absent pupil response to light, opacification of the lens, presence of nystagmus, etc.).
• Fundus examination (retinal vessel damage, possible signs of retinal degeneration, abnormal retinal pigmentation, optic nerve atrophy, etc.).
• Electroretinography (dysfunction of the retina, particularly its response to light stimuli)
  Genetic analysis (presence of genetic mutations characteristic of the pathology)

Treatments

To this day, Leber's congenital amaurosis remains an incurable pathology. Treatment is based mainly on measures tailored to the needs of the visually impaired, in order to promote the autonomy of those concerned. Regular medical monitoring is essential, particularly to detect the onset of amblyopia, glaucoma or cataracts.

Research into new treatments is ongoing. These include gene therapy and optogenetics.

Frequency

The incidence of Leber's congenital amaurosis is estimated at between one in 33,000 and one in 50,000 live births.

References

Orphanet: Amaurose congénitale de Leber

Amaurose congénitale de Leber (ACL) - Symptômes, Causes et traitements (vulgaris-medical.com)

Amaurose congénitale de Leber • Retina Suisse

Source : CUSM