LCA most commonly stands for Leber congenital amaurosis, a rare inherited eye disease that causes severe vision loss in infants. The acronym also appears in cardiology, where it refers to the left coronary artery, the major blood vessel supplying the left side of the heart. Since Leber congenital amaurosis is the meaning most people are trying to understand, that’s what this article covers in depth, with a brief section on the cardiac meaning at the end.
What Leber Congenital Amaurosis Is
Leber congenital amaurosis is a group of inherited retinal diseases that damage the light-sensing cells at the back of the eye. It affects roughly 1 in 30,000 to 1 in 81,000 births and accounts for about 5% of all inherited retinal disorders. About one in three babies with LCA is born blind. Others begin showing symptoms around six months of age, when parents notice that the baby doesn’t track objects or respond normally to light.
Common early signs include frequent eye rubbing or poking (beyond what tired babies normally do), eyes that shake rhythmically (nystagmus), crossed or misaligned eyes, strong sensitivity to light, and pupils that respond slowly or not at all to changes in brightness.
What Causes It
LCA is genetic. A child inherits a faulty copy of the same gene from each parent, so neither parent typically has vision problems themselves. At least 25 different genes can cause LCA, but four account for the majority of diagnosed cases: CEP290 (about 15% of cases), GUCY2D (12%), CRB1 (10%), and RPE65 (8%). Together, known gene mutations explain 70 to 80% of all LCA diagnoses. The remaining cases involve rarer genes, some of which are still being identified.
Each gene plays a different role in how retinal cells develop, maintain themselves, or process light signals. That’s why LCA isn’t a single disease but a spectrum. The specific gene involved influences how quickly vision declines, whether any useful sight remains, and which treatments may eventually apply.
How LCA Is Diagnosed
Doctors typically suspect LCA when an infant shows severely reduced vision along with nystagmus and abnormal pupil responses. The key diagnostic test is an electroretinogram (ERG), which measures the electrical activity of the retina in response to light. In babies with LCA, the ERG signal is either severely weakened or completely absent. However, performing this test on infants is challenging because the retina is still maturing during the first year of life, which can make results hard to interpret.
Genetic testing has become essential for confirming the diagnosis. In some cases, infants initially diagnosed with LCA based on their symptoms and ERG results turn out to have a different condition entirely once their DNA is analyzed. Broad genetic panels that screen dozens of retinal disease genes at once can pinpoint the exact mutation, which matters not just for an accurate diagnosis but for determining whether a child qualifies for gene therapy.
How Vision Changes Over Time
Most children with LCA experience severe vision loss within the first decade of life. In one long-term study of patients with CEP290 mutations, 64% could only count fingers or worse in their better-seeing eye at their first clinical visit. The somewhat reassuring finding from that research: vision did not significantly worsen over years of follow-up. For many patients, the level of sight they have in early childhood, however limited, tends to remain relatively stable rather than continuing a steep decline.
That said, the experience varies by gene. Some forms of LCA leave children with enough residual vision to read large print or navigate familiar environments, while others result in near-total blindness from infancy.
Gene Therapy for RPE65 Mutations
The first and so far only approved gene therapy for LCA targets mutations in the RPE65 gene. The treatment, called Luxturna, delivers a working copy of the RPE65 gene directly to retinal cells using a harmless viral carrier. Once those cells can produce the RPE65 protein again, the visual cycle restarts and light sensitivity improves.
Not everyone with LCA qualifies. The treatment is specifically for people with confirmed mutations in both copies of the RPE65 gene, and only if enough healthy retinal cells remain. Doctors evaluate this by measuring retinal thickness and checking for signs of irreversible degeneration. A clinical and genetic diagnosis alone isn’t enough to determine eligibility.
Cost is a significant barrier. Luxturna is priced at $425,000 per eye, or $850,000 for both eyes. Insurance and government programs are expected to cover most of that expense, and the manufacturer has negotiated agreements with some insurers to limit out-of-pocket costs. The company has also offered rebate programs tied to clinical outcomes, meaning insurers can recoup some cost if the treatment doesn’t work as expected.
CRISPR Gene Editing for CEP290 Mutations
Because RPE65 mutations cause only about 8% of LCA cases, researchers have been working on treatments for more common forms of the disease. The most advanced effort targets CEP290 mutations, which cause LCA type 10 and currently have no approved treatment.
A clinical trial called BRILLIANCE used CRISPR gene editing to directly correct the CEP290 mutation inside the eye. Results published in the New England Journal of Medicine showed that 11 of 14 participants experienced measurable improvements in vision and quality of life. About 79% showed some degree of visual improvement, and the treatment was considered safe, with no serious toxicities reported. The trial included 12 adults and two children, all treated in one eye only.
Living With LCA
For the majority of people with LCA who don’t qualify for gene therapy, management focuses on maximizing the vision they have and building independence. Low-vision aids, including electronic magnifiers, computer-based tools, and optical devices, can help children and adults make use of whatever residual sight remains. Orientation and mobility training teaches safe navigation of unfamiliar environments, and adaptive skills programs help with education and daily tasks.
Children with LCA typically qualify for early intervention services and specialized educational support. As they grow, vocational resources including job placement assistance and income support programs are available through community organizations. These services won’t restore vision, but they can make a meaningful difference in quality of life.
LCA as a Cardiac Term
In cardiology, LCA refers to the left coronary artery, the blood vessel that branches off the aorta just above the heart’s aortic valve. It quickly splits into two major branches: the left anterior descending artery, which feeds the front of the heart and most of the wall between the two ventricles, and the left circumflex artery, which supplies the side of the left atrium and ventricle. When doctors discuss blocked or narrowed coronary arteries, the LCA and its branches are often involved because they supply such a large portion of the heart muscle.
A rare congenital defect called ALCAPA occurs when the left coronary artery originates from the pulmonary artery instead of the aorta. In infants, this can cause episodes of severe paleness, sweating, and irritability that are sometimes mistaken for colic. It’s a serious condition that requires surgical correction, but it is far less common than the typical use of “LCA” in eye disease contexts.