Leber Congenital Amaurosis

Leber congenital amaurosis (LCA) is an inherited retinal disease that causes sight loss in very young children or at birth. Leber congenital amaurosis causes the photoreceptors (light capturing cells) in the retina (light sensitive layer at the back of the eyes) to stop working. This causes children with Leber congenital amaurosis to progressively lose their vision. Leber congenital amaurosis is relatively rare, approximately 1 in 80,000 children are affected and there are up to 20 different forms of Leber congenital amaurosis. Leber congenital amaurosis symptoms can vary with each type.

Symptoms start from early childhood or birth and progress; they could remain stable through early adulthood

• Nystagmus (involuntary shaking of the eyes)

• Reduced or loss of vision

• Tunnel vision (loss of peripheral vision)

• Lack of visual response in babies

• Night blindness

• Poor pupil reactions

• Deep set or sunken eye

• Children may press their eyes with their fingers or fists, this known as oculodigital syndrome or reflex

• Sensitivity to bright lights

• Hypermetropia (long sighted)

• Cataracts

• Keratoconus

• Can be associated with other systemic or developmental conditions.

The retinas of infants with Leber congenital amaurosis may appear normal, however a test called an electroretinography (ERG) will detect little or no visual function. This is one of the tests that can be used to diagnose Leber congenital amaurosis.

As the child gets older, blood vessels on the retina appear narrow, pigmentary changes are seen on the retina (salt and pepper changes), atrophy of the choroid, retina and optic nerves are seen too.

Leber congenital amaurosis is inherited. So far 20 different types of defective genes have been identified as cause of Leber congenital amaurosis. Some of these genes are RPE65 (LCA 2); AIPL1 (LCA 4); CEP290 (LCA 10) and RDH12 (LCA 13). Defects in the gene cause the loss of normal vision.

There is currently no treatment for Leber congenital amaurosis. However there are clinical trials being conducted into the replacement of the mutated gene RPE65, to re-establish normal vision. The research is looking into using a virus to replace the defective gene with a normal healthy gene. The trials showed improvement in vision with patients suffering from Leber congenital amaurosis, however they are still on going and more trials for other forms of Leber congenital amaurosis are being planned. Another research treatment is an oral tablet that can reawaken the retinal cells, to improve vision. Whilst the treatments are still undergoing research it does give hope for the future.

• Patients may be referred to a low vision clinic. A low vision clinic will give patient’s practical advice and magnifying aids to help see better

• Some hospital eye services have an ECLO (Eye Clinic Liaison Officer) who can provide further support

• Check with your ophthalmologist if you can be registered as sight impaired or severely sight impaired. Registration can help with financial concessions and expert practical help

• Children will need to be reviewed by different governing bodies, which will produce a statement on how to best help the child learning & development. Please click the link for further information.

https://www.rnib.org.uk/information-everyday-living-education-and-learning-young-childrens-education/special-educational

• Contacting the RNIB for further support, visual aids and practical advice.

RNIB, 0303 123 9999, helpline@rnib.org.uk, or visit the RNIB at 105 Judd St, London WC1H 9NE