A Single Eye Injection Treats Genetic Blindness
Genetic health conditions are usually the
most difficult or impossible to treat. This is exactly why a recent
research article about a novel treatment capable of reversing a genetic
eye disease called Leber Congenital Amaurosis (LCA) is such a major
medical advance. LCA appears at birth or in the first few months of life
and causes severe vision loss and blindness.
A novel treatment developed by the
University of Pennsylvania and Children’s Hospital of Philadelphia is
capable of reversing blindness caused by LCA with a single eye
injection. Learn more about this exceptional treatment and how it could
open the door to genetic treatments for an array of other inherited
health conditions below.
What is Leber congenital amaurosis (LCA)?
LCA is a genetic eye disease that affects
about 1 in 40,000 newborns. The condition is associated with multiple
genetic mutations that target the retina and cause severe vision loss or
blindness and nystagmus, a condition when the eyes make repetitive,
uncontrolled movements.
Depending on the severity of the condition, the pupils of patients with
LCA may also be less responsive to the light or nonresponsive
altogether. The condition accounts for 20% of blindness in school-age
children and nearly all patients suffering from this condition become
completely blind by age 30-40. LCA is considered an incurable disease.
A new genetic treatment is capable of
reversing
LCA
Researchers at the University of Pennsylvania and Children’s Hospital of
Philadelphia developed a genetic treatment for LCA in the early 2000s.
The novel treatment is a gene replacement therapy in the form of an eye
injection that targets the mutated RNA and promotes healthy protein
expression in the retina. It’s called Antisense oligonucleotide therapy
(AOT), and it essentially restores vision either partially or
completely.
In a 2017 study, the researchers
administered the AOT treatment to 10 patients every 3 months, which
ended up improving their eyesight in the daytime by promoting the
creation of the right proteins in their retinas. What this older study
didn’t tell you but a recently published follow-up case study did, is
that one of the patients, the 11th one, ended up refusing to continue
participating in the study after receiving only one injection.
The patient had zero night vision and low vision overall. Just a month
after the first shot, the patient started to show outstanding
improvements in vision. The patient’s vision continued to improve
rapidly in the next 15 months and approximated that of the patients who
got multiple injections. The delayed response was something the
researchers have predicted, but the massive improvement of patient 11
has exceeded all expectations.
Hopefully, the treatment will soon be approved completely and become
available for all patients suffering from vision loss or blindness due
to LCA. Notably, similar genetic treatments have already been approved
by the FDA to treat neurological medical conditions, and ongoing trials
are being conducted to explore AOT therapies to treat Alzheimer’s
disease, Parkinson’s disease, and Huntington's disease. Certainly, we
will follow the future of these promising genetic therapies with great
interest.