FOCUS Fall 2020

Vision Trends:
GENE THERAPY
Scientific breakthroughs in gene therapy have given hope to patients with congenital eye
diseases. Opticians, as part of the first line responders of the eye care health system, should be
aware of how correcting defective genes can make a difference in their patients’ vision.
How does it work?
Our genes are a unit of heredity that we obtain
from our parents and they are held to determine
some of our specific traits and the likelihood of
inherit certain disease and conditions. Each human
body contains about 30,000 genes that send
information to the cell for making proteins which are
the building blocks of everything in our body. If one
of our genes mutates, it can interrupt accurate
protein production resulting in over or under
production. If cells have the wrong amount or don’t
a have a specific protein, they won’t work right and
eventually will cause a condition or a disease.
Eye care and gene therapy
This kind of therapy is especially effective for eyecare
patients. Eyes are easy to inject and monitor,
as they allow for accurate location and distribution
of the injection site and they don’t have the normal
inflammatory immune response to foreign antigens.
Another advantage that is conducive to gene
therapy is that the eyes have a limited number of
photoreceptor cells that can renew themselves; but
they can’t grow or regenerate. If targeted cells are
injected into an organ in the human body that can
regenerate death cells, we would need to inject the
new cells with corrective genes every time to
preserve the therapeutic effect.
Approximately 250 genetic mutations
have been found to cause Inherited
Retinal Dystrophies (IRD) which is a
large group of different genetic retinal
disorders.
Although there are important differences between
these diseases, they all involve the progressive loss
of vision and are caused by gene mutations. Gene
mutations in which retinal cells that help sense and
send light signals die.
Some of the most common types of gene
therapy are:
Gene replacement
A new gene is introduced into a cell to
replace a mutated gene.
Gene editing
Molecular scissors are used to “edit” a
broken gene by cutting out the mutation.
F O C U S
P| 12