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0:00
Hello, my name is
Dr. Emily Dosmar.
I am a professor in
the Department of
Biology and Biomedical
Engineering
at Rose-Hulman
Institute of Technology
in Terre Haute, Indiana.
Today, I'm going
to speak with you
about ocular drug delivery.
0:15
Today, I'm going to
take you through
the general principles
governing ocular drug delivery.
I'll touch on what the
market looks like.
We'll go over some
fundamentals of
ocular anatomy so you're
familiar with the terms
that we'll be using.
We'll talk about some of the
classic diseases of the eye
and then we'll get into
ocular drug delivery itself,
where we'll talk about the
four primary modalities
of delivering pharmacological
agents to the eye.
We'll talk about
topical, intravitreal,
subretinal, and
subconjunctival delivery.
0:44
The global ophthalmic drug
delivery systems market is huge.
As the baby boomer
population ages
and as people tend to
live longer in general,
it's especially important
that we offer a solution to
the ocular challenges
that arise later in life.
In 2021, the market
was valued at
12.1 billion and is projected to
expand at a compound annual
growth of 8.3% from 2022-2030,
so a significant amount
of capital is wrapped
up in this market.
1:14
I'd like to spend some time
establishing some
basic understanding of
ocular anatomy that
will help you as we
discuss the different
drug delivery modalities.
The image that you
see in front of
you is a side view
of the eye with
the outward or the world-facing
part of the eye on the left.
As we move outward-in,
we're going to start with our
conversation about the sclera.
The sclera is the tough
outer layer of the eyeball.
It's part of the
white of the eye and
there's a slight bulge in
the sclera at the front of
the eye that is a clear,
thin, dome-shaped tissue
called the cornea.
The cornea is continuous
with the sclera.
The cornea is a
transparent structure
and it's part of
the eye that covers
the iris and the pupil and
allows light to enter
the inside of the eye.
Moving inward, the
conjunctiva is
a thin, mucus
membrane that lines
the inside of the eyelids
and covers the sclera.
The lens which is further
inside of the front of the eye,
is a clear elliptical structure
that sits right
behind the iris, and
it's the changes in
the curvature of
the lens that allow
changes to our vision.
We can sharpen the focus of
our vision through
changes in the lens.
You'll see the large region of
the eye labeled as
the vitreous cavity.
The vitreous cavity extends
from the back of the
lens to the back
of the eyeball and is
crucial for the eye to
maintain its shape,
and it's filled with
a very special liquid
called vitreous humor.
We're going to touch
on this later when we
talk about intravitreal
injections.
The choroid is a thin
layer of tissue that
is part of the middle layer
of the wall of the eye,
so it lies between the
sclera and the retina,
which is at the back of the eye.
The choroid is filled with
blood vessels that bring
oxygen and nutrients to
the eye and has noteworthy
blood flow that comes
into play later when we
talk about various
types of drug delivery.
The retina is a layer of
photoreceptor cells and
glial cells and several
other cell types
that sits at the
back of the eye,
and it captures incoming photons
and transmits them along
neuronal pathways as
both electrical and chemical
signals that the brain then
uses to perceive vision and
to build a visual picture.
The retina is
crucial for vision.
I also want to note that
the eye has a special
immune privilege.
It's one of the
few structures in
the body that has
immune privilege,
meaning that it limits
its immune response and
its inflammatory response
so that it could
preserve the integrity of
the structure and not cause
damage and pressure
changes that could be
devastating to the
function of the eye.
Part of this immune privilege is
also found in the
blood-retinal barrier.
The blood-retinal barrier is
a physiological barrier that
regulates the flow of nutrients,
metabolic waste products,
ions, proteins,
and water into and
out of the retina,
and it keeps things
that should not
enter the eye from
entering the eye,
but can also act as a
pretty restrictive barrier
to drugs trying
to enter the eye.
