Ok, now that we've been all
oriented to the structures of the eyes
and we kind of have a good sense of
where things are, what they're made up of,
let's start getting into some
of the ophthalmologic pathology.
And we're going to start with the
outside and work our way all the way in,
diseases of the eyelids as first.
Let's start with the upper lid and lower lid,
the upper and lower palpebrae, so the lids.
And we're going to talk about diseases that are
blepharitis, chalazion, and hordeolum okay, or stye.
Inflammation of the lid margins is blepharitis.
And it can involve a number of
structures, so basically it's inflammation.
kind of at the edges of the
eye, including some of the glands
and some of the muscles and skin that are there.
So inflammation of the blephs, if you will.
So signs and symptoms of
blepharitis, you're looking at it right here.
This does not look like a happy guy at all.
And that lid is swollen.
I'm sure it's very tender.
You don't want to rub it at all, and it's red.
So you're looking at the
hallmarks of inflammation:
erythema, edema, and there's also pain here.
There will be an itchy gritting or burning
sensation so the eye is not innervated, but the lid is.
And it will as a result of all the
inflammation that's going on there,
It will feel tender or burning,
he'll have a variety of sensations.
It will be very, very uncomfortable.
The eyes are excess, there's excess
watering, and this is because of the activity.
The inflammation is driving
various glands to secrete more fluids.
Some of this, especially if it's
extending out into the lacrimal glands,
we will have inflammation that
may secondarily involve that.
So we will get increased watery
eyes from the increased drainage.
The inflammation causes vasodilation,
increased vascular permeability of the conjunctiva
and in the lid margins.
And that conjunctiva, becomes red and
injected, so instead of having nice white sclera,
we are beginning to see the vessels that are
normally relatively inapparent in the conjunctiva.
And with the materials that are being
released by the glands and then when they
condense, aggregate, crosslink, etcetera,
we will get skin crusting and scaling.
So there are going to be
inflammatory cells that have crawled out.
They will form kind of a crust or
a scale on the eyelid margin eyelashes.
And again, that will be contribute to
some of that gritty sensation that's there.
So a number of things and a little
bit of inflammation goes a long way
when it involves the eye.
Because of all this excess fluid,
the vision will tend to be blurred
and because of inflammation, light shining into
the eye, when you want to actually have undergo
miosis and mydriasis, you'd want to
kind of expand the eye or contract the eye,
actually hurts because we're pulling on smooth
muscle and there are nerves that are there.
Okay, so the anatomical structures
that are involved in blepharitis.
We've looked at these previously and we're
going to talk specifically about some of them.
But basically it's the muscles, the levator
palpebrae superioris that keeps the lid up.
The orbicularis oculi muscle, that's the one
that allows you to close your eyes, your eyelids.
And then there's going to be the underlying structures.
The tarsus, remember, this is the
connective tissue that gives integrity,
kind of a framework, scaffolding upon which
we're going to have the levator in the orbicularis sit.
The tarsus also has within it glands that
are going to be part of the lubrication of the eye.
Meibomian glands and then glands
that are associated with the eyelashes.
We've talked about these previously, but the
gland of Moll and the gland of Zeiss, great names.
I don't know who Moll and Zeiss were, but
they got their name, these particular glands,
and they're basically just sebaceous
glands or modified sebaceous glands
that sit attached to the hair
follicles that form the eyelashes.
Anterior blepharitis is that mainly centered
around the skin and the skin structures,
the eyelashes, a little bit of hair follicles that
sit over the front of the lid or at the end of the lid.
And then you can have a posterior blepharitis.
Obviously, if there's anterior,
there's got to be the posterior.
Posterior blepharitis, it's going to
involve the structures of the tarsus,
in particular the Meibomian glands.
Okay, so these are the structures that are
there and they are inflamed, hence blepharitis.
Let's look at these things
in a little bit more details.
So what causes blepharitis,
many, many different causes.
And some of these may be systemic, as we'll see.
Some of these may be very focal and just
hit the eye because of things we do to your eye.
Okay, so seborrheic dermatitis is a
chronic inflammation of sebaceous glands
It can be very focal, but seborrheic
dermatitis can happen everywhere
and if you've if you've had flaky, itchy,
oily scalp that's seborrheic dermatitis.
Anywhere that there's hair, that can happen
because there are sebaceous
glands associated with that hair.
You're going to have chronic inflammation
due to increased immune response.
It's basically an exaggerated
inflammation out of control, that's rosacea.
Again, it can be systemic.
It can be focal, can be in any particular area,
but if it involves the eyelid, you'll get blepharitis.
You can have atopic, otherwise
known as contact dermatitis.
And that is things that you might rub on
your eye, makeup and other things like that,
even just what is in the detergent that you
clean your eyes with or on a towel or whatever.
You can get a delayed-type hypersensitivity to that.
And that inflammation of
the lid will cause blepharitis
You can have psoriasis, which
is an autoimmune disorder.
Many of the immunologic mechanisms are
going to be akin to delayed-type hypersensitivity
but this one is driven by specific adaptive immune
elements that are recognizing elements of the skin.
And again, it tends to be systemic,
tends to be everywhere on the skin,
but can particularly affect the eyes, eyelids.
Bacterial infections are probably
going to be a major driver for blepharitis
There's a lot of bacteria on our
skin, the eyelids are no exception.
And Staphylococcus is going to be the most
common bacterial infection, Staph aureus in particular.
Then you can have a variety of viral infections -
molluscum, varicella zoster, herpes simplex, etc.
You can have parasitic infections.
So this sounds incredibly distasteful, but you can
have little parasites that live within the hair follicles
that eat dead skin - Demodex.
And they can elicit inflammatory
responses and give you a blepharitis.
So cosmetics and pollen.
So other irritants and allergens
specifically can do that just because
there is a particular element that may be inflammatory
and then some medications and retinoids in particular.
If we give Accutane, for example,
for people who have chronic acne,
what that elevated retinoid level does
is change the nature of the epithelium
in the glands from something that's more cuboidal
or columnar into something that's more squamous.
And so we don't get the normal production
or movement of the various components.
And the retinoids may actually cause
a significant amount of inflammation.
Okay, those are causes.
How do we diagnose it?
Well, you saw it.
You diagnosed it on that very first slide.
That kind of swollen eyelid looks painful.
There's you know, there's blurring.
Its clinical symptoms, okay.
And the treatment?
It's mainly keeping the eyelid clean,
getting rid of the bacteria, not rubbing
things that are particularly
inflammatory on top of that.
If there is infection, then we
may need to provide antibiotics.
It can be topical, it can be systemic.
And then warm compresses help
because when we put on a warm compress,
we're causing increased vascular flow.
We're actually causing vasodilation,
which will help to clear some irritants,
but will also help to bring in inflammatory
elements if we need to treat an infection.
So warm compresses are
frequently very good, just kind of
over the counter sorts of things
that you can do to treat this.
Okay, so that's blepharitis and
it's mostly the upper lid, it's mostly
the kind of inflammation of those structures.