Leber Congenital Amaurosis: Unravelling the Rare Genetic Eye Disorder

Medically reviewed by Wut Win, Dispensing Optician at Feel Good Contacts.

Leber congenital amaurosis (LCA) is a group of inherited eye conditions that causes blindness or severe vision issues. This condition is rare and usually occurs from birth or early childhood. In this article you’ll learn more about the condition as well as the symptoms, causes and treatment options.

Understanding Leber congenital amaurosis (LCA)

Leber congenital amaurosis (LCA) is also associated with other eye issues, such as hyperopia (farsightedness), photophobia (light sensitivity) and involuntary eye movements.

Rods and cones are photoreceptors in the retina responsible for turning light into electrical signals that your brain can then process into images. Rods specifically allow us to see in low light settings. Cones allow us to perceive colour. LCA causes the rods and cones within the retina to stop working correctly.

Those with this condition will typically experience deteriorating vision throughout their life, resulting in blindness by their early 30s or 40s.

What causes Leber congenital amaurosis?

Leber congenital amaurosis (LCA) is inherited in an autosomal recessive way, this means that a copy of the mutated gene from each parent must be present for the condition to occur in the child. There are 19 different gene mutations that can be inherited from parents contributing to the development of LCA.

Symptoms and diagnosis

Genetic testing will help to produce a diagnosis of Leber congenital amaurosis. As this condition occurs primarily in infants and newborns, it can be challenging to know if the child is experiencing vision issues. Signs to look for include:

• Excessive rubbing of the eyes
• Deep set eyes
• Shaking eyes (nystagmus)

Other symptoms of LCA include:

• Keratoconus
• Slow pupil responses/no responses at all
• Photophobia
• Hyperopia
• Nyctalopia (night blindness)
• Strabismus (crossed eyes)

Treatment options for LCA

There is no cure for Leber congenital amaurosis, eye care professionals will help the child to preserve and optimise the vision they have. This can be done using low vision aids such as magnifying glasses, adjustable lamps/torches, telescopes, and large-print books. Technology can also be an excellent resource for those with low vision, audiobooks, for example, allow those with LCA to enjoy literature without struggling to read the small print often found in books. Increasing the screen size of digital devices such as computers and mobile phones can also help.

There are also specific schools and teachers that specialise in management of low vision and blindness in children. These resources can help children with vision issues to become more independent and confident, as well as teaching them the most efficient ways to navigate the world as partially sighted person.

Research and future outlook

Gene therapy could be a promising new treatment option for those with LCA. This involves inserting new DNA into the cells of the eyes. This process introduces a healthy version of the malfunctioning gene which should then, in theory, improve vision. This type of treatment has already been successful in animal studies with mostly positive results in humans. Although perfect sight is not restored, those who underwent treatment showed vastly improved vision, allowing them to see better in low light conditions and perceive colour more accurately.